再好的种子，一旦种植在贫瘠的土壤里，活下来就实属不易，还要开花结果？获得好收成？这就更加的不易。 最好的办法是改良土壤，实在改不了的土壤，就种植些适应能力强的作物，比如干旱缺水的地方，土质偏碱，就种些豆子之类的，还有芝麻也不需要很多水，水多了反倒不利于其生长；而有些植物就需要勤浇灌，比如各种蔬菜，特别是大叶蔬菜，没有水是很难长好的。所以尽管土壤有不同，种子也有不同，只要精心栽培，总不至于无收成！这就是在栽培农作物活动中的“因地制宜”。 很多人喜欢把教师称作“园丁”，园丁就是负责栽培植物的，尽管园丁的栽培更多的是用于装饰和美化环境，这和农作物栽培的农人其实属于一类性质。如果我们接受教师类似于园丁的话，那么教师所开展的教育活动就合农作物栽培有一比。那么在人的教育上也要“因人施教”。因人施教应该有个前提，那就是教师与学生的比例不能过低。现在大学都在扩大招生，呼拉一下子招了很多人，不光是物质资源不够，就是教师资源也差的很多。 教室、图书馆、运动场、食堂...这些资源并不能无限制地扩大，同样，一个国家，一个单位所能承受的教师人力资源也并不可以向有多少就有多少。因此，这样的教育就出现了师资和资源都不足的问题。 这样就很难保证精耕细作！要是在农作物栽培，那也属于广种薄收的经营，一样的道理，现在的大学教育很难保证真正优秀人才的培养。 但是，人就没有那么多的多样性，人的适应逆境的能力也有限，所以培植人才的土壤不行，什么也培育不出来，即使是很优秀的人才，也会因为不适合水土而一事无成。 所以人才的流动可以表现出“孔雀东南飞”这样的大规模迁徙的特点，留不住人才和培养不出人才的时候都要去看看环境是否出了什么问题。 热力学定律与记忆 热力学第一定律即能量守恒定律 物体内能的增加等于物体吸收的热量和对物体所作的功的总和. 系统在绝热状态时，功只取决于系统初始状态和结束状态的能量，和过程无关。 孤立系统的能量永远守恒。 系统经过绝热循环，其所做的功为零，因此第一类永动机是不可能的（即不消耗能量做功的机械）。 两个系统相互作用时，功具有唯一的数值，可以为正、负或零。 热力学第二定律 没有外界输入能源、能量， 粒子 最终都会慢慢的停顿下来，继而不再产生热能。 热力学第零定律 If system A and system B are in thermal equilibrium with system C , then system A is in thermal equilibrium with system B 热力学第零定律是关于热量平衡的定律 viewed as a binary relation, 遵守欧几里的关系（Euclidean relation）。 If we assume that the binary relationship is also reflexive, then it follows that thermal equilibrium is an equivalence relation. Equivalence relations are also transitive and symmetric. The symmetric relationship allows one to speak of two systems being "in thermal equilibrium with each other", 相互热平衡 如果两个系统均和第三个系统处于热平衡状态，那么这两个系统之间也相互处于热平衡状态 However, this statement requires the implicit assumption of both symmetry and reflexivity, rather than reflexivity alone. The law is also a statement about measurability. To this effect the law allows the establishment of an empirical parameter, the temperature, as a property of a system such that systems in equilibrium with each other have the same temperature. The notion of transitivity permits a system, for example a gas thermometer, to be used as a device to measure the temperature of another system. Although the concept of thermodynamic equilibrium is fundamental to thermodynamics, the need to state it explicitly as a law was not widely perceived until 富勒和普朗克在 1930代提出的。零定律的提出远远晚于第一定律、第二定律和第三定律。 The importance of the law as a foundation to the earlier laws is that it allows the definition of temperature in a non-circular way without reference to entropy, its conjugate variable. 热力学第一定律 The first law of thermodynamics may be expressed by several forms of the fundamental thermodynamic relation: Increase in internal energy of a system = heat supplied to the system + work done on the system For a thermodynamic cycle the net heat supplied to the system equals the net work done by the system. The net change in internal energy is the energy that flows in as heat minus the energy that flows out as the work that the system performs on its environment. Work and heat are not defined as separately conserved quantities; they refer only to processes of exchange of energy. These statements entail that the internal energy obeys the principle of conservation of energy. The principle of conservation of energy may be stated in several ways: Energy can be neither created nor destroyed. It can only change forms. In any process in an isolated system, the total energy remains the same. 热力学第二定律 The second law of thermodynamics asserts the existence of a quantity called the entropy of a system and further states that When two isolated systems in separate but nearby regions of space, each in thermodynamic equilibrium in itself (but not necessarily in equilibrium with each other at first) are at some time allowed to interact, breaking the isolation that separates the two systems, allowing them to exchange matter or energy, they will eventually reach a mutual thermodynamic equilibrium. The sum of the entropies of the initial, isolated systems is less than or equal to the entropy of the final combination of exchanging systems. In the process of reaching a new thermodynamic equilibrium, total entropy has increased, or at least has not decreased. It follows that the entropy of an isolated macroscopic system never decreases. The second law states that spontaneous natural processes increase entropy overall, or in another formulation that heat can spontaneously be conducted or radiated only from a higher-temperature region to a lower-temperature region, but not the other way around. The second law refers to a wide variety of processes, reversible and irreversible. Its main import is to tell about irreversibility. The prime example of irreversibility is in the transfer of heat by conduction or radiation. It was known long before the discovery of the notion of entropy that when two bodies of different temperatures are connected with each other by purely thermal connection, conductive or radiative, then heat always flows from the hotter body to the colder one. This fact is part of the basic idea of heat, and is related also to the so-called zeroth law, though the textbooks' statements of the zeroth law are usually reticent about that, because they have been influenced by Carathéodory's basing his axiomatics on the law of conservation of energy and trying to make heat seem a theoretically derivative concept instead of an axiomatically accepted one. Šilahv (1997) notes that Carathéodory's approach does not work for the description of irreversible processes that involve both heat conduction and conversion of kinetic energy into internal energy by viscosity (which is another prime example of irreversibility), because "the mechanical power and the rate of heating are not expressible as differential forms in the 'external parameters'". The second law tells also about kinds of irreversibility other than heat transfer, and the notion of entropy is needed to provide that wider scope of the law. According to the second law of thermodynamics, in a reversible heat transfer, an element of heat transferred, δQ , is the product of the temperature ( T ), both of the system and of the source or destination of the heat, with the increment ( dS ) of the system's conjugate variable, its entropy ( S ) The second law defines entropy, which may be viewed not only as a macroscopic variable of classical thermodynamics, but may also be viewed as a measure of deficiency of physical information about the microscopic details of the motion and configuration of the system, given only predictable experimental reproducibility of bulk or macroscopic behavior as specified by macroscopic variables that allow the distinction to be made between heat and work. More exactly, the law asserts that for two given macroscopically specified states of a system, there is a quantity called the difference of entropy between them. The entropy difference tells how much additional microscopic physical information is needed to specify one of the macroscopically specified states, given the macroscopic specification of the other, which is often a conveniently chosen reference state. It is often convenient to presuppose the reference state and not to explicitly state it. A final condition of a natural process always contains microscopically specifiable effects which are not fully and exactly predictable from the macroscopic specification of the initial condition of the process. This is why entropy increases in natural processes. The entropy increase tells how much extra microscopic information is needed to tell the final macroscopically specified state from the initial macroscopically specified state. 热力学第三定律 The third law of thermodynamics is usually stated as follows: The entropy of a perfect crystal at absolute zero is exactly equal to zero. This is explained in statistical mechanics by the fact that a perfect crystal has only one possible microstate (microscopic state) at extremely low temperatures: The locations and energies of every atom in a crystal are known and fixed. (In quantum mechanics, the location of each atom is not exactly fixed, but the wavefunction of each atom is fixed in the unique ground state for its position in the crystal.) Entropy is related to the number of possible microstates, and with only one microstate, the entropy is exactly zero. The third law is also stated in a form that includes non-crystal systems, such as glasses: As temperature approaches absolute zero, the entropy of a system approaches a minimum. The minimum, not necessarily zero, is called the residual entropy of the system.
标签: 运动场
