earth texture map http://planetpixelemporium.com/earth.html 3D地球 http://www.cnblogs.com/ddw1997/archive/2009/10/11/1580974.html hi I've got a quite specific problem. I want to draw a Map, consisting of 256x256 pixle Tiles (a lot of them). These cover a big area. The transformation to convert lat|lon(from the globe) to x|y (map) spawns quite big values. With these big values goes accurcy and so, if I go far away from the 0/0 Point, I get inaccuracies of multiple pixels between textures of two Tiles being next to each other (e.g. 2E8 | 0 and 2E8-1 | 0). How can I fix these messy unwanted grid appearences? The current failing implementaition is to use float to draw the primitives (this should not matter, as all Tiles are clipped to multiples of 256 in both coordinate directions). I hope this makes any sense to you. Actually, I have recently run into the exact same problem in my implementation of rendering entire planets from space to ground. In fact, what you have to do is create a new position structure that splits the accuracy between different floats. For example, struct location { vec3 metre ; vec3 megametre ; vec3 terametre ; vec3 examtre ; vec3 yottametre ; }; Then you code all of the operators and type cast functions for this structure (+, -, *, /, toVec3), you then use this location struct to encode the location of your camera and each grid tile. On rendering time, you dont translate the camera, but instead you translate the tiles by difference. For example: void render () { // ... location diff = this - position - camera . position ; vec3 diffvec = diff . toVec3 (); glPushMatrix (); glTranslatef ( diffvec . x , diffvec . y , diffvec . z ); // render the tile glPopMatrix (); } What it does is removes the difference calculation from the OpenGL pipeline which only has up to double precision and puts the work on your program which can essentially have infinite precision. Now the precision and accuracy fall the further away you are from the camera instead of the further away you are from the orgin. Happy Coding. -------------------------------------------- Jason.M.Brewster@gmail.com wrote in message news:1190266566.132704.273690@k79g2000hse.googlegroups.com... I need to map a 2d image onto a sphere in JOGL, any ideas on how to do this? It's all about putting the right texture coordinates on the vertices that make up the sphere. for 2d textures with coordinates at every vertex; The "poles" -- all the vertices there -- will have a J texture coordinate of (approximately -- you need to deal with texel centering). The vertices around the "equator" will have a J of 0.5 Get it ? The X coordinates start a approximately 0 at the "prime meridian" and go all the way aroudn the globe to approx 1 at the end (duplicating the coordinates at the "prime meridian"). I'll leave edge effects and correct centering ot texels to you. You should easily be able to use automatic texture coordinate generation, if your project permits it. jbw http://objectmix.com/graphics/136652-glusphere-texture-mapping.html
From: http://intepid.com/2005-07-17/21.50/ I’ve been playing around with the marvellous Google Earth and Google Maps , and just noticed how elegant the system for addressing image tiles is . Google Maps now offers a satellite view as well as a map view, and does so using the former Keyhole database. The view is built using tiles– 256 pixel square JPEGs fetched from the the kh.google.com server. As of this writing, the image URLs take the form: http://khm.google.com/kh?v= version t= address version is between 85 and 88, and I’ve no idea why. It doesn’t really seem to affect the projection like it once did, but it does seem to change the particular images used in some cases. It may be simply a number which must be raised occasionally to correspond with newer data– eg it once accepted 45 as a valid argument and now it doesn’t. Unfortunately leaving it out altogether results in a 404 error. address is a short string of letters encoding the location of a particular map square. The addressing mode is quite elegant, with the world recursively quartered until the desired detail level is reached. This simple heirarchical structure is known as a quadtree , and is commonly used in computer graphics. For whatever reason, Google labels the four quadrants q , r , s t . The topmost tile contains the entire world map, and is referenced with an address of t . Adding an s to this selects the lower-right quadrant of the map, and adding a further r selects the upper-right of that map, resulting in a tile containing most of Australasia. Each time an extra letter is added, we descend into a new quadrant, and this continues until the maximum detail is reached. So, for example, the hospital where I was born can be uniquely addressed using the URL: http://khm.google.com/kh?v= 88 t= tsrrtrsqsqqqrqrtsst Converting between Quadtree addresses and Longitude/Latitude This page contains Javascript to returns all tiles containing a particular location, with each yellow quadrant marking the region occupied by the subsequent map. If you’d like to copy the code you can view the page source, or simply use the excerpts shown below. The first two functions are based on equations from Wikipedia’s entry on the Mercator Projection. function MercatorToNormal ( y ) { y = -y * Math. PI / 180 ; // convert to radians y = Math. sin ( y ); y = ( 1 +y ) / ( 1 -y ); y = 0.5 * Math. log ( y ); y *= 1.0 / ( 2 * Math. PI ); // scale factor from radians to normalized y += 0.5 ; // and make y range from 0 – 1 return y ; } function NormalToMercator ( y ) { y -= 0.5 ; y *= 2 * Math. PI ; y = Math. exp ( y * 2 ); y = ( y- 1 ) / ( y+ 1 ); y = Math. asin ( y ); y = y * - 180 / Math. PI ; return y ; } function GetCoordinatesFromAddress ( str ) { // get normalized coordinate first var x = 0.0 ; var y = 0.0 ; var scale = 1.0 ; str = str. toLowerCase (); str = str. substr ( 1 ); // skip the first character while ( str. length 0 ) { scale *= 0.5 ; var c = str. charAt ( 0 ); // remove first character if ( c == ‘r’ || c == ‘s’ ) { x += scale ; } if ( c == ‘t’ || c == ‘s’ ) { y += scale ; } str = str. substr ( 1 ); } var ret = new Object (); ret. longmin = ( x – 0.5 ) * 360 ; ret. latmin = NormalToMercator ( y ); ret. longmax = ( x + scale – 0.5 ) * 360 ; ret. latmax = NormalToMercator ( y + scale ); ret. long = ( x + scale * 0.5 - 0.5 ) * 360 ; ret. lat = NormalToMercator ( y + scale * 0.5 ); return ret ; } function GetQuadtreeAddress ( long, lat ) { // now convert to normalized square coordinates // use standard equations to map into mercator projection var x = ( 180.0 + parseFloat ( long )) / 360.0 ; var y = MercatorToNormal ( parseFloat ( lat )); var quad = “t” ; // google addresses start with t var lookup = “qrts” ; // tl tr bl br for ( digits = 0 ; digits 24 ; digits++ ) { // make sure we only look at fractional part x -= Math. floor ( x ); y -= Math. floor ( y ); quad = quad + lookup. substr (( x= 0.5 ? 1 : 0 ) + ( y= 0.5 ? 2 : 0 ) , 1 ); // now descend into that square x *= 2 ; y *= 2 ; } return quad ; } ---------------------------------------- Q-tress 维基百科 中的图
Finally, I sat down and opened the book, "Silent Spring." A book I heard about when I was a little girl, from my mother who was an environmental scientist by the government's order in the late 1950s. (I became a meteorologist in China, also not by my own choice.) Even for someone who has been involved in co-teaching "Global Environmental Change" since spring 2008, the book impressed me greatly. I love the author's ability to express herself, with such a force, and am taken by her knowledge and vision of the Earth as a living being. A friend was afraid that this book would be too depressing to read. Well, yes and no. Maybe I refuse to get depressed. While I am still only half way through the book, I THINK there is hope for the Earth. Why? This is because most people would agree with me that today's America is a beautiful country (when compared to many heavily polluted developing countries). If the America could recover from the chemical assault lasted from the 1950s through the early 1970s, we surely can expect similar recovery in other countries. So, do not give up, when you see polluted food, air, water, and land in your country. It will pass, IF people stand up and speak out... Link to 《寂静的春天》 http://blog.sciencenet.cn/home.php?mod=spaceuid=306792do=blogid=456147
科学家发现碳在地球深部新的赋存状态 New host for carbon in the deep Earth 最近法国科学家在研究中发现一种新的含C高压相，这种含C高压相具有相当的稳定性，与理论计算所预测的结构非常一致，这对于认识C在地球深部的赋存状态以及地球内部的碳循环具有一定的意义。这一成果发表在2011年3月29日美国科学院院报PNAS上： http://www.pnas.org/content/108/13/5184 PDF下载： 2011-PNAS-New host for carbon in the deep Earth.pdf 以下是全文翻译：（原文中有太多的化学式，难于在编辑器中一一编辑，请见谅；所有化学式以公式请参考原文。） 全球地球化学碳循环包含地球内部和表层碳的交换。碳通过俯冲作用主要以碳酸盐形式再循环进入地幔中，通过火山作用主要以 CO2 形式释放到大气中。所以碳酸盐的稳定性以及脱碳酸盐化作用和熔融作用对于认识全球碳循环具有重要意义。由此，我们需要认识一直到核幔边界条件下这些矿物的热动力学性质和相图。但是含 C 矿物在这些条件下的性质仍然不太清楚。本文我们报道了在 1800km 以下条件下存在一种新的 Mg-Fe 含 C 化合物。它具有由共角 (CO4)4- 四面体所构成的三元环结构，与第一性原理量子计算所预测的结构 (Oganov et al.,2008) 非常接近。该碳酸盐高压相可以通过如下 Fe(II) 和 (CO3)2- 的晶内反应： 4FeO + CO2 → 2Fe2O3 + C ，来聚集大量的 Fe(III) 。这将会形成由新的高压相 + 磁铁矿 + 纳米金刚石所组成的矿物组合。 关键词： diamond, Earth mantle, phase transition, experimental petrology, redox interaction 碳酸盐是主要的含 C 矿物，能够通过大洋岩石圈深俯冲作用进入到地幔中 (1) 。俯冲下去的成分与原始的 C 一同被认为对下地幔 C 储库具有重要作用 (2,3) 。因为在深部地幔矿物中 C 的溶解度极低 (4,5) ，因此 C 有可能以单独的相存在，如碳酸盐或者金刚石。有些研究表明碳酸镁 ( 菱镁矿 ) 是方解石和白云石消失之后 C 在深部的主要赋存方式 (6-8) 。另外一些模型认为与橄榄岩达到平衡以后的碳酸盐将会在下地幔被还原成金刚石 (9) 。但是，如同在上地幔所观测到的，下地幔氧化还原状态的不均匀性很有可能也存在：例如，俯冲带是由能够在很长时间尺度都保持稳定的更加氧化的矿物所组成的 (10) 。也有观点认为氧化和还原矿物可以在地球深部共存，如富 CO2 的金伯利岩浆可以将金刚石携带至地表来 (11,12) ，并且在来自下地幔的金刚石中发现了碳酸盐包裹体 (13,14) 。有关碳酸盐稳定性的高压实验表明菱形结构的 MgCO3 菱镁矿可以稳定至 115 GPa 、 2000-3000K ，而它在高压下会形成一种新的结构 (8) 。但是，第一性原理计算预测菱镁矿在 82 GPa 会转变成由 (CO4)4- 四面体所构成的新相，在 160 GPa 会转变成类似辉石的结构。考虑到地幔中平均 Fe/Mg 摩尔比为 0.12 ，那么碳酸盐的成分可能是介于菱镁矿和 FeCO3 菱铁矿之间，这两相可以形成连续的固熔体。目前含铁碳酸盐的相变研究很少。菱铁矿可以稳定至至少 47 GPa 和 2000K(18) ，在常温下可以稳定至 90 GPa(19) 。总之，菱铁矿和菱镁矿端元的结构特征是相似的，因为 Fe(II) 和 Mg 原子之间大小不匹配可以由 Fe(II) 中的自旋态转换来补偿 (19,20) 。 结果 Result 对于 MgCO3 和 MgO+CO2 组合，高压含 C 化合物的稳定性是一致的。在两种情况下，在类似温压条件下 ( 大约 80 GPa ， 2400K) 所获取的 X 光衍射 (XRD) 图像中出现了新的峰，这些峰并不是已知的 MgO 和 CO2 氧化物或者菱镁矿结构的峰。这些峰指示在该压力范围内一种新的稳定结构。 MgO+CO2 组合在 82 GPa 、 2350 ± 150K 条件下典型的 XRD 图像如图 1A 所示。淬火到室温之后该高压相会转变回低压菱镁矿结构。对回收样品的 EELS (Electron energy loss spectroscopy) 分析结果与原位 (in situ) 观测结果是一致的。图 1B 显示自 MgO+CO2 组合回收样品在碳 K-edge 所获取的 EELS 图谱。 290.3 eV 处尖锐的峰指示 (CO3)2-(21) 。另外，根据 EELS 分析所得出的化学成分指示为 MgCO3 成分。所以，该高压相是菱镁矿的一种等化学多晶体。 图 1. (A) X-ray diffraction pattern of a sample obtained from the transformation of periclase in CO2 confining medium at 82 GPa and 2,350 ± 150 K. Crosses represent observed data after subtraction of the background and the solid line represents the profile refinement. For this refinement we used an assemblage of untransformed periclase (Upper), platinum (Middle), and the new high-pressure phase (Lower). Residual between observations and fit is shown below the spectrum. (B) C K-edge EELS spectrum done on the recovered sample. 大于 80 GPa 时，天然富菱铁矿样品在 1850-2300 K 会发生相变，生成与上述 MgCO3 样品类似的 XRD 图像，同时还有一种铁氧化物 ( 图 2A) 。这表示形成了一种 Mg-Fe 系列的含 C 高压相。与 MgCO3 端元不同地是，该高压含铁结构是可淬火的 (quenchable) 。随后对回收样品的 TEM 分析显示有三种不同相对存在：未相变的 (Fe0.75Mg0.25)CO3 菱铁矿、高压相和一种铁氧化物 ( 图 2B) 。图 2C 中显示在铁 L2,3 dege 所获取的 EELS 图像；部分图谱与残余菱铁矿晶体结构比较吻合，与在相同能量分辨率条件下所获取的含 Fe(II) 相的图谱比较相似 (22) 。菱镁矿的出现同样也由 EELS 分析所确认。该高压相 Fe L2,3 edge 处的结构显示处理含 Fe(III) 矿物的明显结构 (22,23) ，并且根据参考文献 24 所作的定量分析表明至少 3/4 的铁是以 Fe(III) 氧化态形式存在的。根据碳 K-edge 的 EELS 数据 ( 图 2D) 确认残余菱铁矿的存在，并显示未相变的碳酸盐的峰偏移到 290.7 eV 处的特征。 287.5 eV 处的小峰指示一氧化碳 (CO)(25) 可能以包裹体 / 纳米泡形式存在，形成了该高压相的独特显微结构 ( 图 2B) 。如下面所讨论的，这些包裹体是在碳酸盐高压相形成过程中生成的。 EELS 测量表明元素比值与初始碳酸盐有所不同： Fe/C ~0.61 ± 0.07 ， Fe/O ~0.22 ± 0.02 。 图 2. (A) X-ray diffraction pattern collected at 80 GPa and room temperature of siderite transformed at 1,850–2,300 K. Crosses represent observed diffraction data after subtraction of the background and solid line the profile refinement. For the refinement we used an assemblage of high-pressure polymorph of magnetite (37) (Upper), untransformed siderite (space group R-3c) (Middle), and the new high-pressure phase (Lower). Residual between observations and fit is shown below the spectrum. (B) STEM high-angle annular dark field showing the untransformed siderite (Sid), the iron oxide (Mt for magnetite), and the transformed carbonate (HP carb.) appearing as a dark gray uniform matrix in the left side of the image. (C) EELS spectra collected on the recovered sample. These spectra provide qualitative information on the Fe(III)/ Σ Fe ratio of each phase (23, 24) and noticeable features have been indicated by small bars and can be compared with reference siderite, magnetite, and Fe(III) oxide (22). Spectrum collected on the untransformed carbonate shows a high intensity peak of 707.7 eV that indicates the main iron speciation to be Fe(II). In the case of the iron oxide, the broad L3 peak at 707–709 eV with no splitting is characteristic of magnetite, whereas the L2 shows many subsplitting and an intermediate energy position between pure ferric and ferrous iron that is typical of a mixed valence of magnetite (23). The spectrum collected in the new phase shows a L3 line at higher energy loss than in carbonate groups with a fine structure indicating the main iron speciation to be Fe(III). (D) C K-edge spectra collected in the untransformed and transformed carbonate phases. In the case of siderite relic, the peak at 290.3 eV corresponds to planar (CO3)2- carbonate groups. In the spectrum collected in the transformed carbonate, the slightly broader peak at 290.7 eV is attributed to the tetrahedral (CO4)4- forming rings of (C3O9)6-. Presence of CO can also be detected in intimate association with the new phase. (Mg0.6,Fe0.4)O+CO2 在 105 GPa 、 ~2850 K 条件下的相变会形成一个由未反应的 (Mg0.6,Fe0.4)O 、菱镁矿的高压相和相同的新高压相所组成的组合。这一组合已经由 XRD 所观测到并进一步由 ATEM 所确认 ( 图 3A) 。纳米金刚石也由电子衍射和碳 K-edge EELS 图谱所鉴别出来 ( 图 3B) 图 3. (A) TEM image of the recovered sample from the ferropericlase + CO2 experiment. Magnetite (Mt), high-pressure carbon-bearing phase (HP carb.), ferropericlase (FP), and nanodiamonds (D) are present. (B) C K-edge EELS spectrum of nanodiamonds observed in the recovered sample. The spectrum presents the absorption edge at 289 eV and the dip at 303 eV is characteristic of diamond C K-edge (38, 39). 讨论 Discussion 对高温高压下 XRD 图像分析可以鉴定高压含 C 结构。 XRD 图像与在该压力范围内理论计算所得到的菱镁矿的 phase II 相 ( 空间群为 C2/m) 是一致的 (15) 。但是当使用另一个晶体对称性更低一些的 P21/c 空间群时，拟合的质量会得到明显提高。这一结构见图 4 所示，它由共角的三个 (CO4)4- 四面体组所构成，这样组成了 (C3O9)6- 环。晶格常数为： MgO+CO2 在 P=82 GPa 、 T=2350 ±150K 条件下： a=8.39 , b=6.41 , c=6.82 , β =105.49 (V=354.7 3 ) ； MgCO3 在 P=85 GPa 、 T=2400 ±150K 条件下： a=8.37 , b=6.37 , c=6.80 , β =104.57 (V=351.7 3 ) 。对于后者，假设每个晶胞化学式单位为 12 (15) ，得到的密度为 4.76 g/cm3 ，与相同 P-T 条件下的低压结构具有 +10% 的密度差异。因为有相对较小的 Fe(III) 原子的加入，这种新的含铁相的晶格体积比富镁端元的要小 10% ： (Mg0.6Fe0.4)O+CO2 在 P=105 GPa 、 T=2850 ±150K 条件下： a=7.72 , b=6.41 , c=6.57 , β =101.31 (V=319.0 3 ) ； (Mg0.25Fe0.75)CO3 在 P=80 GPa 、室温 条件下： a=7.83 , b=6.37 , c=6.73 , β =101.97 (V=328.9 3 ) 。 图 4. Structure of the new high-pressure phase in space group P21/c related to phase II of magnesite proposed by theoretical calculation (15). (CO4)4- tetrahedra appear in green and magnesium atoms are shown as violet spheres. 对于这种新的高压相由于没有现成的 EELS 图谱做参考，我们对该未知的电子态密度进行了密度泛函理论 (DFT) 计算。 Mg 态密度显示在大约 5 eV 费米能级之上有个很窄的峰，对应着碳的 K-edge 以及它的“分子”类型 (CO3)2-( 图 5) 。由这种高压含 C 新相所得到的态密度并没有任何 (CO3)2- 峰，但是在高能区 (7-11 eV) 有一个很宽的带 (band) 。晶体密度在 80 GPa 时为 4.79 g/cm3 。 (C3O9)6- 环的几何形态见图 5 右边所示。 为了解四面体 (C3O9)6- 环在减压时是如何变化的，在常温常压条件下该结构得到松弛。结果如下图所示 ( 密度为 3.60 g/cm3),C-O 键会变长。从 80 GPa 到 0 GPa C-O-C 角从大约 10-112 变到 115-118 ，这些值与已知的四面体的畸变 (distortion) 是一致得 (15) 。这些结构变化对于态密度具有重要影响。的确，正如对低密度结构的预测，整体态密度会向低能方向偏移。这些出现的窄峰对应着四面体 (C3O9)6- 环，其分子结构特征与高压实验样品的 EELS 分析结果非常相似 ( 即 290.7 eV 附近的峰 ) 图 5. DFT calculations for electronic density of state of the carbon atoms (p orbital symmetry). This unoccupied density of state roughly corresponds to the excitation probed by EELS at the C K-edge (excitonic effects are neglected in the calculation). 在含铁实验中，大量的 Fe(III) 进入到这种新结构中。实验中未见 Pt 的出现，因此 Pt 对该氧化还原反应没有影响。 Fe(III) 形成的氧化还原配对 (partner) 最终可能是 Fe(0) ，就像在高压硅酸盐如钙钛矿中观测到的一样 (9) 。但是 Fe(0) 可能只是一个过渡配对，因为在回收样品中并未观测到 Fe(0) 的存在证据。我们认为 Fe(III) 的加入更可能是由于一个氧化碳配对。我们由此认为铁的氧化是通过下面的化学反应由如 (CO3)2- 或 CO2 这样的含 C 分子结构的部分还原作用来平衡的： 20(Mg0.25Fe(II)0.75)CO3 = 20Mg0.25Fe(III)0.3(C3O9)0.2333 + 3Fe3O4 + 6CO 该反应指示含 Fe(III) 新相中的元素比值为 Fe/C ~0.43 ， Fe/O ~0.14 ，与对回收样品的 EELS 估算值非常吻合。 结论 Conclusion 我们的研究证明，在近于下地幔地温 P-T 条件下 CO2 和其他氧化物的重新作用可以形成一种新的高压含 C 相。这表明这种新相具有较高的稳定性而不会分解为简单氧化物。同样，新高压相中 Fe(III) 的出现指示部分 C 的还原，如以上化学反应。这表明在下地幔条件下 C 的氧化态和还原态可以共存。这种性质可能是由于该含 C 相具有较强的热动力学稳定性。但是若这种新相真在下地幔深部存在的话，那么碳酸盐必须能够在深俯冲中保存下来。尽管根据下地幔矿物组合推测下地幔为还原条件 (9) ，但是如果与周围地幔隔离开来碳酸盐是可以在深部保持稳定的，例如在相对低温的俯冲板片中，由局部矿物组合所控制的氧逸度会相对较高一些 (10,26) 。残留的部分碳酸盐可以被搬运到 1800 km 深度以下，并转变成这种新的含 Fe(III) 相。 参考文献： ↵ Sleep NH, Zahnle K (2001) Carbon dioxide cycling and implications for climate on ancient Earth. 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By John D. Sutter , CNN March 9, 2011 -- STORY HIGHLIGHTS Researchers are trying to create the world's most powerful magnet The magnet would be used in green technology like wind turbines and electric cars Supplies of "rare earth" elements that make up current magnets are hard to come by Arm of the Energy Department has put $6.6 million into race for new magnets (CNN) -- George Hadjipanayis' assistant came to him with perplexing news: Some incredibly strong magnetic field had caused their lab instruments to go haywire. "You're out of your mind," Hadjipanayis recalls telling him in the early 1980s. "You have something wrong; go back" and try the experiment again. Nothing was wrong, though, and Hadjipanayis soon realized that his team accidentally had created what was then, and continues to be, the world's strongest magnet -- made of a strange and little understood "rare earth" element called neodymium. That magnet would help revolutionize technology, powering wind turbine motors and giving juice to electric cars. But the luck wouldn't last. Accessible supplies of neodymium and 16 other rare earth elements -- which occupy those two orphaned rows at the bottom of the periodic table -- are running short. China, which controls supplies of 97% of these materials, doesn't like sharing them with the West. And the only U.S. mine for rare earth elements went out of production after a radioactive waste accident in the 1990s. Throw in the fact that rare earth elements are important to all kinds of technologies -- they're the reason smartphones vibrate, why TVs have vivid reds and greens, and how computer hard drives are able to etch data -- and you've got a recipe that scares many technologists and researchers. What would happen to our technological landscape without these rare earths? Hadjipanayis, chairman of physics at the University of Delaware, and researchers from two other institutions, the U.S. Department of Energy's Ames Laboratory in Iowa and GE Global Research in upstate New York, are preparing for that day. They're in a race to make an even stronger magnet than before -- an essential component in green technologies, which use magnets to transfer electrical energy into motion. And they're trying to do it by using as little neodymium as possible, since that element is getting harder to come by. For Hadjipanayis, this is a professional as well as personal struggle. He's trying to recreate the accidental success he had with magnets in the 1980s. "I have pressure," he said. "Look, this is not easy. I mean, you need also a little bit of luck. We have the concept here, but there are many, many obstacles that we need to resolve before we succeed." Rare earth mysteries Rare earth elements possess strange magnetic and conductive properties aren't found anywhere else in our cabinet of elements. Understanding precisely why this is the case would require graduate degrees in both chemistry and physics, but the for-dummies version goes something like this, according to Frank Johnson, a materials scientist at GE Global Research: "In a magnetic material, the magnetic ions are connected by springs." To keep that metaphor going, a typical rare earth element is full of super-powerful springs, but they're all jumbled up, facing various directions as if they'd been thrown onto the floor of a closet. Something magical happens when a rare earth element like neodymium is combined with specific other elements: They form crystals. And if the shape of those crystals is just right, all of the super-powerful springs align, and -- bam! -- the springs amplify each other, and you have the very powerful magnet. "They are very unique elements, and the science of them is fascinating," Johnson said. Metallic recipes Hadjipanayis didn't know that boron was the missing ingredient when he asked his lab assistant to add that gas to the metallic mixture they were working with. All he knew was that the experiments were going wrong because the metal kept crumbling and falling apart. He thought boron might do for this metallic solution what eggs and milk do for cake batter. It would smooth things over. The unexpected result: He discovered the neodymium-iron-boron magnet, which was far stronger than anything that preceded it. "For me, that was kind of a very exciting experience," Hadjipanayis said. He keeps several of these nickel-sized magnets on his desks to show visitors. Scientists measure the strength of magnets with a unit called the "maximum energy product." A typical refrigerator magnet has a rating of 3 or 4. Current neodymium magnets register 57 to 60. Several years ago, Hadjipanayis recalls going to an airport with a neodymium magnet tucked away in his coat pocket. He walked past a metal object near security, he said, and got temporarily stuck. Hadjipanayis was able to free himself from that situation. But if two neodymium magnets get stuck together, "you have to slice it into two parts." "If you're an ordinary person, you can't separate them" by pulling, he said. Now, Hadjipanayis and researchers at GE and the Ames Laboratory in Iowa are trying to create magnets that are nearly twice that strong. A world without rare earths In addition to trying to invent magnets that don't depend as heavily on rare earth elements, mining companies are trying to harvest new supplies. This carries environmental risks, however. China has become the world leader in rare earth mining and production in part because it's more willing to put up with these risks than the United States, which faced them head-on in the 1990s. A rare earth mine now owned by Molycorp Minerals was fined in 1998 for leaking hundreds of thousands of gallons of wastewater containing low levels of radioactive material. Molycorp's mine in the California desert, near the Nevada border, is set to reopen this year. A U.S. Department of Energy report from December says the country needs to ramp up its rare earth production in order to ensure that technology companies here maintain a supply of these vital elements. A spokesman for Molycorp, Jim Sims, said the reopened mine and upgraded processing center will put the U.S. back in the rare earth business -- and will do so safely. "America will have the most environmentally progressive and technologically advanced rare earth processing capability," Sims said. Starting a rare earth element mine is an expensive, long and arduous task, however. The elements aren't especially rare in nature, but they're usually found in relatively small quantities, mixed in with other materials, which makes them both difficult and somewhat uneconomical to mine and process. Consequently, the Department of Energy also says we should look for alternatives. And that's where the magnet researchers come in. A wing of the Energy Department called the Advanced Research Projects Agency-Energy, or ARPA-E, has put $6.6 million into grants for programs to develop a magnet that is stronger than any that exist on earth today -- and uses much less neodymium. That's important because a world without rare earth magnets -- or some unknown substitute -- would mean big changes in technology, said Karl Gschneidner, a senior metallurgist at the Ames Laboratory, which is in this race. For example, without rare earth magnets, laptops would be three to four times as heavy as they are now. "There's no other substitutes for them," he said. And could we create one, as magnet researchers essentially are trying to do? "The odds are less than 50-50." Remixing nature's magic Topping the natural magic of rare earth elements is no easy task. Hadjipanayis and the other researchers are using nanotechnology to essentially remix the recipe for today's strongest magnets. For now, the best they can do is break the three ingredients of a neodymium magnet into small chunks that include only a couple thousand atoms and measure 20 nanometers across. About 2,500 of these tiny "composites," as Hadjipanayis calls them, would fit in the width of a human hair. Then the lab uses bizarre techniques, from chemical treatments to shaking the elements vigorously, to try to fuse these pieces back together. Hadjipanayis said he feels like he's trying to cram 100 years' worth of work into the three years that make up his Energy Department contract. He visits the lab daily to check on the progress. He worries about the high risk involved. But he sees this grant as a way for him and other researchers to ensure the U.S. has a future in green technology. "If it happens, then you revolutionize everything," he said. 来源： http://edition.cnn.com/2011/TECH/innovation/03/09/rare.earth.magnet.race/index.html?hpt=Sbin
Encyclopedia of Earth: About the EoE The Encyclopedia of Earth (EoE) is an electronic reference about the Earth, its natural environments, and their interaction with society. The EoE is a free, expert-reviewed collection of content contributed by scholars, professionals, educators, practitioners and other experts who collaborate and review each other's work. The content is presented in a style intended to be useful to students, educators, scholars, professionals, as well as to the general public. Here is the link: http://www.eoearth.org/topics/view/63435/ p.s. What's missing from EoE? Humans, the main enemies of Earth!
Zhang ionocovalency applications (36) Zhang electronetativity of Ln shows bimodal curves of catalytic activity Zhu proposed : Zhang electronegativity of Ln shows bidodal curves for the catalytic activity of the butadiene and isoprene that consistent with the results of experiments (Fig.1) and Xa-MO calculation . Fig. 1 shows the bimodal curves and the sharp decreases at Eu 3+ and Yb 3+ . According Zhangs ionocovalent definition ： Electronegativity is in proportion to its ionic function, the effect nuclear charge n*(I z /R) ½ , and in inverse proportion to its covalent functiont, the covalent radii r, i.e., n*(I z /R) ½ /r 2 , a cation with a large covalent radius will deduct its effect of ionic function (ionic potential), i.e. its polarizing power . From Table 1 we can interestingly see that despite the increase of their ionization potential I z ( ionic wave functiont ) the suddenly increase of the covalent radii of Eu 3+ and Yb 3+ cause them immediately to decrease their ionic effects, preventing them from their getting higher electronegativities, and good catalytic conversion of the butadiene and isoprene . Table 1. Atomic parameters of Ln elements Ln Configuration Obital EN Ln 3+ EN I z Cov.Radii La 5d 1 6s 2 - 1.212 19.177 1.690 Ce 4f 1 5d 1 6s 2 1.80 1.248 20.199 1.646 Pr 4f 3 6s 2 1.84 1.263 21.019 1.648 ND 4f 4 6s 2 1.90 1.272 22.075 1.642 Pm 4f 5 6s 2 1.93 1.281 22.283 1.630 sm 4f 6 6s 2 1.96 1.275 23.423 1.660 Eu 4f 7 6s 2 1.95 1.190 24.874 1.850 Gd 4f 7 5d 1 6s 2 2.02 1.272 20.624 1.614 Tb 4f 9 6s 2 2.00 1.301 21.868 1.592 Dy 4f 10 6s 2 2.01 1.314 22.801 1.589 Ho 4f 11 6s 2 2.03 1.320 22.801 1.580 Er 4f 12 6s 2 2.04 1.328 22.697 1.567 Tm 4f 13 6s 2 2.06 1.343 23.671 1.562 Yb 4f 14 6s 2 1.85 1.269 25.029 1.699 Lu 4f 14 5d 1 6s 2 3.87 1.313 20.956 1.557 Y. Zhang,, Inorg Chem. , 1982, 21, 3886 . T.-W. Zhu, J. Neimenggu Normal University (Natural Science Ed.), 1983, 2, 22. Z. Q. Shen, Chinese Journal of Nature, 1980, 3(9), 658. Kali, Dsen et al. Theo Chim. Acta, 1980, 58, 69.
The Institute for Study of the Earth'sInterior (ISEI), Okayama University Misasa, Japan, invites an application for the following position. http://www.misasa.okayama-u.ac.jp/ http://www.misasa.okayama-u.ac.jp/eng/announcement/?eid=00451 Application Deadline$B!'(BAugust 31, 2010 Tatsuki Tsujimori -- Dr. Tatsuki Tsujimori,Associate Professor ISEI, Okayama U. Misasa, Tottori 682-0193, Japan PhD Position in Metamorphic Petrology at the Department of Earth Sciences at Carleton University Project The inverted metamorphic sequence (IMS) of the Sikkim Himalayas is characterized by a continuous increase of metamorphic grade with structural height. It contains one of the best developed Barrovian sequences of metapelitic rocks world-wide but its tectonic evolution is still unresolved. Due to its wide extent and continuous nature, the IMS serves as an excellent natural laboratory to study various rock-forming processes that occur during regional metamorphism. The successful PhD student will derive detailed information on the metamorphic history of the IMS that will help to constrain models of its tectonic evolution. Electron probe micro-analysis will be carried out and linked to results obtained through X-ray computed tomography and thermodynamic modelling. In close collaboration with an international research team, these findings will be integrated with monazite U-Th-Pb geochronology and high-precision Sm-Nd and Lu-Hf age dating. Requirements Applicants should hold a Master's degree in geosciences, chemistry or physics and should be fluent in English. The ideal candidate has a background in hard-rock geology and is interested in thermodynamic and kinetic aspects of mineral reactions. The ability to actively participate in and cooperate with an international research team will be an advantage. Funding The position will be funded for 4 years including salary, tuition, field and laboratory expenses. International students are motivated to apply for alternative funding (e.g., https://osap.gov.on.ca/OSAPPortal/en/A-ZListofAid/TCONT003465.html ) to cover tuition fees. Application Applications including a CV with publication list, a statement of research interests, and the mail and e-mail addresses of at least two referees, should be sent by e-mail to Dr. Fred Gaidies ( fgaidies@earthsci.carleton.ca ) AND mail to: Dr. Fred Gaidies Carleton University Department of Earth Sciences 1125 Colonel By Drive Ottawa, ON, K1S 5B6 Canada The closing deadline is October 15, 2010 but applications will be considered until the position is filled. --------------------------------------------------------------------------- Laboratory Manager Isotope Geochemistry Facility The Research Group of Isotope Geochemistry at the Department of Geosciences, University of Bremen requires a laboratory manager to establish, oversee and manage the new multicollector mass spectrometry and isotope chemistry clean laboratories. Applicants must hold a degree in geology, geochemistry, analytical chemistry or physics and have demonstrated expertise and operational experience in MC-ICPMS and TIMS; holding a PhD would be of advantage. The applicant should have substantial experience in using and maintaining multicollector mass spectrometers and clean laboratories. Preference will be given to Candidates with prior lab manager experience. Fluent German and English language skills (written and spoken) are required. The Laboratory Manager will be responsible for conducting and supervising maintenance and repair of instrumentation and laboratory, developing and improving analytical protocols and instrumentation, oversight of sample preparation, ensuring quality control and tracking of data and supporting internal and external research projects of students, faculty and visiting scientists. The laboratory manager will also participate in research projects pursued by the facility and will be encouraged to launch new initiatives. The incumbent can take an active role in the communication of research results to the scientific community and industry (if desired). The appointment is a permanent position, preferably starting as soon as possible. Salary level is according to German salary system TV-L and will be commensurate with experience (up to 13 TV-L). A curriculum vita, a letter of motivation describing your interest in the position, a statement describing past and current analytical accomplishments and a list of at least two references must be submitted to be considered as an applicant. The facility is under the direction of Simone Kasemann and applications and questions regarding the position should be sent electronically to simone.kasemann@uni-bremen.de . Applications quoting reference A78/10 must be received by August 13th, 2010. As the University of Bremen intends to increase the proportion of female employees in science, women are particularly encouraged to apply. In case of equal personal aptitudes and qualification priority will be given to disabled persons. Please send only copies of your documents (without hard covers and folders) as we will not be able to send back your application. ---- Simone Kasemann Professor fr Isotopengeochemie Fachbereich Geowissenschaften der Universitt Bremen Postfach 330 440 28334 Bremen Telefon: +49 421 218-65460 Email: simone.kasemann@uni-bremen.de ------------------------------------------------------------------------------ Job offer In the framework of a tectonics and sedimentology research project in the Tadjik basin of Uzbekistan and Tadjikistan, we have a post-doc position (or alternatively 2 PhD positions) available for 2 years (prolongation possible). Main duties are fieldwork on thrust and strike-slip tectonics, section balancing, and thermochronology on the burial history; publication of results is expected. The project is embedded into a multi-Institute and multi-disciplinary project on the Pamirs and Tadjik basin. Starting date: as soon as possible. Information from Lothar Ratschbacher Lothar Ratschbacher Institut fr Geowissenschaften Technische Universitt Bergakademie Freiberg Bernhard-von-Cottastr. 2 D-09596 Freiberg/Sachsen Tel.: +49-3731-393758 Fax.: +49-3731-393599 e-mail: lothar@geo.tu-freiberg.de http://tu-freiberg.de/fakult3/geoarc/ http://www.geo.tu-freiberg.de/tektono/ ---------------------------------------------------------------------------- Research Scientist position to operate and manage our new laser ablation ICP-MS/OES facility The University of New Brunswick Geology Department has an opening for a Research Scientist position to operate and manage our new laser ablation ICP-MS/OES facility. The official posting is on the UNB HR website at the following link: http://www.unb.ca/postings/eup/eup1279104716_199.html The newly renovated lab will comprise two new state-of-the-art instruments including an Agilent 7700x quadrupole ICP-MS coupled to a Resonetics M-50 Ar-F 193nm excimer laser system. The facility will also house our existing Spectro CIROS ICP-OES. The new lab will be supported by microbeam instrumentation operated by the UNB Microscopy and Microanalysis Facility and by in-house wet chemistry and sample preparation labs ( http://www.unb.ca/fredericton/science/geology/facilities.php ). The new LA-ICPMS lab will be focused on producing high quality and high impact research primarily in metamorphic and igneous petrology, ore geology, and regional tectonics. We are seeking a motivated person with a sound understanding of the theory and applications of geochemistry and mass spectrometry to problems in earth sciences. This individual must have a strong work ethic, uncompromising analytical standards and an ability to engage users and assist with the development of new techniques. Please pass this information on to any potentially interested people. Best regards, Chris McFarlane Associate Professor Department of Geology University of New Brunswick Fredericton NB E3B 5A3 office: 506-458-7211 http://www.unb.ca/fredericton/science/geology/faculty/crmm.php ------------------------------------------------------------------- JOb at Leicester This is a great opportunity to join our expanding Applied Environmental Geology Group at Leicester! Our Department of Geology is seeking to appoint a Lecturer or Senior Lecturer in Applied and Environmental Geology for a two year fixed term post to cover a period of secondment. We are particularly interested in candidates with a strong research record in, and ability to contribute to, the teaching of applied and environmental geology. You will contribute to campus based teaching and to the delivery of distance/blended learning programmes, including residential schools overseas. We particularly encourage applications from candidates able to contribute to teaching in one or more of the following fields: industrial rocks and minerals, environmental geoscience, mineral economics, the diamond industry. For further information and to apply on-line, please visit our website: www.le.ac.uk/joinus Ref: SEN00078 The closing date for this post is midnight on 25 July 2010. Dr Gawen RT Jenkin Senior Lecturer Applied Geology Chair Mineral Deposits Studies Group mdsg.org.uk Leicester Geology Department - Top Ranking for Student Satisfaction. Highest % of Student Satisfaction amongst departments teaching full-time Geology degrees for three years running (NSS www.unistats.com). Senior Lecturer Applied Geology direct dial: +44 (0116) 252 3934 Department of Geology general office: +44 (0116) 252 3933 University of Leicester fax: +44 (0116) 252 3918 LE1 7RH, UK skype: gawenjenkin ------------------------------------------------------------ Postdoc scholarship available The School of Geological Sciences at the University of Kwa-Zulu-Natal, Durban , South Africa , invites applications for a postdoctoral scholarship. The field (within geology) is not specified, but a research proposal must be part of the application, and the project is supposed to relate to one of the main research areas of the School. Thus, at least one staff member of the School will be directly involved in the application. This particular call is obviously aimed at members of the petrology and/or structural geology / tectonics community. Current projects involve the Namaqua-Natal Belt, the Bushveld Complex and high-grade Archaean terrains of the southern Kaapvaal craton margin. For more details please contact me at the address below. (Sorry, the departmental website is somewhat out of date. The position of webmaster has also not been filled yet) Anyone interested should get in touch a.s.a.p. as the deadlines set by the Faculty Office are just around the corner. Juergen Reinhardt reinhardtj@ukzn.ac.za School of Geological Sciences University of KwaZulu-Natal Durban , 4000 South Africa ----------------------------------------------------------------------- Faculty position as Lecturer or Assistant Professor in Geology The Department of Applied Geosciences at GUtech seeks applications for a faculty position as Lecturer or Assistant Professor in Geology Applicants are expected to be experienced as a field geologist, preferably having specialised in soft-rock structural geology, sedimentology, stratigraphy, ... and would be interested to carry out applied, field-oriented research projects in Oman. She or he will be responsible for ca. 10h/week teaching. Courses would center around geological field methods, geological mapping, quantitative field methods and rock microstructures and organising geological excursions. Your Profile: You should hold a PhD degree, are an excellent teacher and researcher. You have contributed to the advancement of research internationally. And you are looking forward to work at a start-up university in an exciting challenging environment. Our Offer: Our enthusiastic and open-minded Omani students will make you really like to teach and never want to leave. Successful applicants will be part of a core team playing a vital role in the further development of the University. Salary packages are competitive and commensurate with qualifications and experience. The appointment is initially for 4 years and renewable, dependent on a positive performance review. The successful candidate would preferably take up employment in September or October 2010. To apply, email your CV with a covering letter addressing all essential criteria, a statement of teaching experience, copies of relevant certificates, a selection of student evaluations of teaching (if available), and 2-3 reference letters to recruitment@gutech.edu.om no later than 16 July 2010. http://www.earthworks-jobs.com/geoscience/gutech10062.html
According to wikipedia, Physical oceanography is the study of physical conditions and physical processes within the ocean , especially the motions and physical properties of ocean waters. Physical oceanography is one of several sub-domains into which oceanography is divided; others include biological , chemical and geological oceanography. I would describe it simply that physical oceanography is like Meteorology , which is the interdisciplinary atmosphere that focuses on weather processes and forecasting (in contrast with climatology ). scientific study of the Another way to put it is, both PO (physical oceanography) and Met (meteorology) are part of Earth_science . Earth science (also known as geoscience , the geosciences or the Earth sciences ), is an all-embracing term for the sciences related to the planet Earth . It is arguably a special case in planetary science , the Earth being the only known life -bearing planet. There are both reductionist and holistic approaches to Earth sciences. The formal discipline of Earth sciences may include the study of the atmosphere, oceans and biosphere, as well as the solid earth. Typically Earth scientists will use tools from physics , chemistry , biology , chronology and mathematics to build a quantitative understanding of how the Earth system works, and how it evolved to its current state. I was trained as a meteorologist in China, not by my own three wishes but by the government's. I was then trained as a physical oceanographer in the States; this time by my own choice, because I wanted a Ph.D. degree that I could not get in China in the mid 1980s. I certainly have the advantage of being trained in both Met and PO. Some of my colleagues majored in physics and mathematics first, and they are like fish in the water, or shark in the sea
(April 22 2009 Earth Day,The picture from metronews.ca) 在加拿大感觉最深的是环境好,这是在今天报纸上的一张图片,每个人对环境都有一种爱护的好感,非常喜欢这张图片,它透明,单纯,就像每日的蓝天一样明快,Martin老师选了一个开天辟地的故事,How the World was Created http://en.wikipedia.org/wiki/Creation_myth Pan Ku's final breaths became the winds and the cloud, and his voice turned into thunder.His eyes became the sun and the moon. The giant's arms and legs became mountain ranges and his blood the rivers. The hairs on his body became plants, his tears rain and his bones sank into the ground. I wonder what his bones became? Some Chinese thought Pan Ku's life did not really end for his body parts were all around them in different forms and because his eyes were up in the heavens, he still watched over his people below. Albert Einstein famously predicted that if bees were to cease to exist, humans could last only four years after the last bee died. A shocking estimation, but these pollinators truly make our ecosystems work. Whats frightening is that the worlds pollinators, predators, prey, vegetation and oceans that we rely on for food, oxygen and water are at risk. Which is precisely why Metro is dedicating this years annual Green Metro to the topic of biodiversity a term that, quite simply put, means the vast variety of plants, animals and natural resources found on Earth. Like bees. So read on and plant a garden. Ride your bike. Remember the oceans, the bees, the worms they are your neighbours ... and our heroes.(metronews.ca) Happy Earth Day! (Maple syrup)
THIS IS THE WORLD'S FIRST GLOBAL ELECTION, BETWEEN EARTH AND GLOBAL WARMING! On March 28, you can VOTE EARTH by switching off your lights for one hour, or you can vote global warming by leaving your lights on. The results of the votes are being presented at the Global Climate Change Conference in Copenhagen 2009. We want one billion votes for earth, to tell the world leaders that we have take action against global warming. We all have a vote, and every single vote counts. Together, we can take control of the future of our planet, for future generations. Saturday, March 28, 8:30-9:30pm. Details on page: http://wwf.org
EIGEN-1S is a satellite-only gravity field model including 88 days of CHAMP data. The model is a combination of GRIM5-1S normal equation system More can be found on the section 1.3 webpages Lageos-1,-2, Starlette derived constraints on zonals additional Lageos-1,-2, Starlette and Stella laser tracking data (year 2000) CHAMP GPS satellite-to-satellite tracking data: 88days within the periods 2000, July 30 - Aug. 10, and Sept. 24 - Dec. 31 (accelerometry used for surface force reduction) Please note: although higher degree/order terms are solved in EIGEN-1S, the solution has got full power only up to about degree/order 35, which is typical for a satellite-only solution. Higher degree/order terms are solvable applying stochastic a priori information according to a degree variance model (regularization of the normal equation system). The EIGEN-1S data set contains fully normalized spherical harmonic coefficients complete to degree/order 100 with higher degree terms up to maximum degree 119 for CHAMP sensitive and resonant orders permanent tide is not included in C(2,0) C(0,0) and degree 1 terms are not solved DOT-terms (C(2,0) to C(4,0)) represent drifts per year, epoch for corresponding static terms: 1997.0 standard deviations are given along with the coefficients. The standard deviations were posteriori calibrated applying a degree dependent calibration factor (cf. header of EIGEN-1S data set) The EIGEN-1S correlation matrix of the spherical harmonic coefficients is available as a CHAMP OG Level 4 product through the CHAMP Information System and Data Centre (ISDC) the formats are described on the CHAMP web pages (op.gfz-potsdam.de/champ) under 'Online Available Documents' in the document 'CHAMP gravity field solution data formats'. from:http://www.gfz-potsdam.de/pb1/op/champ/results/index_RESULTS.html
EIGEN-CHAMP03S is a CHAMP-only gravity field model derived from CHAMP GPS satellite-to-satellite and accelerometer data out of the period October 2000 through June 2003. EIGEN-CHAMP03S is the final version of the preliminary model EIGEN-3p and results from a homogeneous reprocessing of all normal equations including the improved parametrization of the accelerometer calibration parameters. Normal equation regularisation starts at degree 60. from:http://www.gfz-potsdam.de/pb1/op/champ/results/index_RESULTS.html
标签: Earth
