查询词典 surface charge density

The rusults indicated that the temperature in forest was lower and the growth of ginseng was slower than out of forest, the yields were also lower; with the increase of ginseng age, the rate of net photosynthesis became higher; when the canopy density of forest reached to about 0.7～0.8, the net photosynthesis, hight, root weight, transpiration,chlorophyll conten of ginseng were higher than others, indicating that both lower and higher canopy density would reduce the rate of net photosynthesis of ginseng, and that the canpoy density of stand could be adjusted to satisfy the temperature and lighting for ginseng, and to provide the optimum ecology enviorment for the growth of ginseng.

结果表明，在生长季节内，林内温度低于林外温度，林下人参生长发育较差，产量较低；林分郁闭度为0.7~0.8时，人参的净光合速率、株高、单根重、叶绿素含量等指标较高；而郁闭度过高或过低都会影响人参生长发育；随着人参年龄的增加，净光合速率有逐渐升高的趋势。通过人为调节林分郁闭度的方式来满足人参对温度和光照因子的需求，为林下人参生长发育提供最适宜的生态环境。

At equilibrium,the rate of the metal dissolution is equal to the rate of the cathodic reaction,and the rate of the reaction is directly proportional to the current density by Faradar's law ;therefore:（6）and the Nernst equation can be rewritten(7)where B is a constant and i0 is the exchange current density,which is defined as the anodiccurrent density at the standard electrode potential.

在平衡，金属溶解的率与负极反应的率是相等的，并且反应的率与电流密度直接地是比例由Faradar的法律；因此：(6)和能斯脱等式可以被重写(7) B是常数的地方，并且i0是交换电流密度，被定义作为正极电流密度在标准电极电位。

The main research work of this dissertation is as follows: Based on the chemical reaction engineering theory and the nitrobenzene electroreduction mechanism, the plate and frame electrolyzer was designed and applied to the process of electroreduction nitrobenzene to p-aminophenol. This dissertation measured the residence time distribution data of the electrolyzer by means of the pulse response method and studied the rule of flow pattern along with the current capacity change. Under different conditions ,this dissertation studied the cyclic voltammetry properties of nitrobenzene on different electrodes by means of the dynamic cyclic voltammetry method and the electrode materials applied to the NB electroreduction have been selected primarily.Baseed on the results of cyclic voltammetry tests, this dissertation used p-electrode systems to measure the steady-state- polarization curves of nitrobenzene on different electrodes in H-type diaphragm cell, and obtained each primary factor s influence rule and the exchange current density value of each electrode.And then on the basis of the conclusions of fundamental researchs upword, the effects of influence factors on the the yield of p-aminophenol and the current efficiency,such as electrode material, current density, quantity of electricity circulated, nitrobenzene concentration . sulpuric acid concentration and so on, have been studied in detail in the systems of hign temperature , strong acidity and oxygen-poorthrough a series of electrolysis experiments in this paper.After all using Pb as anode Monel metal as cathode Dupont Nafion 417 cation-exchange membrane as membrane, this dissertation obtained the optimum technological condition: reaction temperature about 85C, current density 500A m-2, sulphuric acid concentration 20%wt.

论文的主要研究工作为：运用化学反应工程理论，结合硝基苯的电还原机理，设计出用于硝基苯直接电还原合成对氨基苯酚实验的板框式电解槽，并利用脉冲响应法测定了该板框式电解槽的停留时间分布数据，研究了流型随流量变化的规律；通过动态循环伏安法研究了硝基苯在不同电极上、不同条件下的循环伏安特性，初步评选出了用于硝基苯电还原的电极材料；结合循环伏安的测定结果，在H型隔膜电解槽中采用三电极体系测定了硝基苯在不同电极上、不同条件下的稳态极化曲线，得到了各主要因素的影响规律及硝基苯在各个电极上电还原的交换电流密度数值；在基础研究结论指导下，采用板框式电解槽，在高温、强酸、贫氧系统中，进行了一系列的电解实验，分别考察了电极材料、电流密度、通电量、硝基苯浓度、硫酸浓度等因素对收率及电流效率的影响，最终选择以蒙乃尔合金电极作为阴极、铅合金为阳极、Dupont Nofion 417阳离子交换膜为隔膜，得到由硝基苯直接电还原制对氨基苯酚的最佳电解工艺条件：反应温度85℃，电流密度500A·m~(-2)，硫酸浓度20％wt。

We investigate the distribution of charge density and spin density in an interchain coupled quasi-one-dimensional organic ferromagnet.

对具有链间耦合的准一维有机铁磁体系统的电荷密度和自旋密度的分布进行了研究。

As to our knowledge, this is the first time to investigate systematically the defects of ZnO. The density of states and the charge density shown in this paper facilitates the analysis of experimental results such as Photoemission and absorption spectra or emission spectra.

本文首次对ZnO的本征缺陷做了系统的研究，计算了每种缺陷的态密度曲线和它对电荷密度分布的影响，这些结果对能谱和光谱等实验结果的分析会有很好的借鉴意义。

Maxwell's equations group in fact was already found in the basic experimental laws of electromagnetic phenomena, as well as a single magnetic pole does not exist on the facts and the integrated displacement current assumptions, using an international system of units, these equations can be written as: DivDW =ρ or DW =ρ(1) kiDivBq = 0 or Bq = 0 (2) kiCurlEBq =- Zt or × EqkZ =- BqZt (3) ZCurlHDWDW = jE Zt, or × HW = jE Zkt (4) Z-type in the Curl, and Div were vector operator curl and divergence, Micro-k points for the Hamiltonian operator, in the rectangular coordinate system,= iZZEkx jEy kqz, iE, jE, kq along Zx, y, z-axis unit vector, a vector for any AW are × AW = CurlAW, kAW = DivAW; DW for the electric displacement, Bq for the magnetic induction intensity, Eq, and HW, respectively i field and electric field strength, jY for the conduction current density,ρ the charge density for free.

麦克斯韦方程组实际上是当时已发现的电磁现象的基本实验定律以及单个磁极不存在的事实和位移电流假设的综合，采用国际单位制，这些方程式可写成：DivDW＝ρ或DW＝ρ（1）kiDivBq＝0或Bq＝0（2）kiCurlEBq＝－Zt或×EqkZ＝－BqZt（3）ZCurlHDWDW＝jE＋Zt或×HW＝jE＋Zkt（4）Z式中Curl和Div分别为矢量算符旋度和散度，为哈密顿微k分算符，在直角坐标系中，＝iZZEkx＋jEy＋kqz，iE，jE，kq是沿Zx、y、z轴的单位矢量，对任一矢量AW有×AW＝CurlAW，kAW＝DivAW；DW为电位移，Bq为磁感应强度，Eq和HW分别为电i场和磁场强度，jY为传导电流密度，ρ为自由电荷密度。

In this paper, we have studied the dimensional effects, electronic state, the configurations of charge density and spin density for quasi-one-dimensional organic ferromagnets. First, considering interchain interaction, the itineracy of electrons, the electron-electron correlation, electron-phonon interaction and spin correlation in low dimensional system, we proposed an interchain coupling theoretical model for conjugated system and non-conjugated system of organic polymer ferromagnets, respectively. Based on the theoretical model, we studied the electronic property, spin structure, the configuration of dimerization and the stability of the ferromagnetic state with a self-consistent iterative method.

首先我们在考虑准一维有机铁磁体的链间相互作用、电子的巡游性、强的电子-电子关联、电子-声子耦合、自旋关联等因素的基础上，分别对两种类型的有机高聚物铁磁体各自提出一个包含链间耦合的理论模型，用自洽迭代的数值计算方法对其电子性质、自旋结构、二聚化特征及铁磁态的稳定性进行了研究。

We find that the behaviors of charge density wave parameter and spin density wave parameter of nonperiodic Hubbard model are similar with behaviors in periodic Hubard model, and the distribution of.

本文对一维非周期的赫伯德模型和非周期的横场中量子伊辛链的量子相变和量子纠缠以及保真度进行了系统的研究。

Due to cooperation and competition between the hopping integral and the on-site repulsion at different sites, the charge density and spin density can transfer between the radical sites and the phenylene ring sites.

由于不同格点上电子跳跃积分与Hubbard排斥能的合作与竞争，自旋密度和电荷密度可在苯环与自由基之间转移。

According to the theory of beam phase space , the projective density distributions in four dimensional and two dimensional trace space are derived for some space charge distributions often used in accelerator physics. And, the relation between beam emittance and brightness with density distributions is developed too.

针对加速器中几种常用的束流密度相空间分布形式，根据束流相空间理论，推得了它们在四维和二维径迹空间中的投影密度，并给出了束流发射度和亮度与束流密度分布的关系式，为加速器束流测量和束流诊断提供理论依据。

Now he worked in ajoint venture.

现在他在一家合资企业工作。

More troops in Afghanistan won't change any of the foregoing.

更多的在阿富汗的军队也不会改变之前的状况。