查询词典 coefficient of diffusion

This dissertation involves the study of the growth dynamics of colloidal particles under unequilibrium and irreversibility condition. Firstly, it is of interest to investigate whether the ideal diffusion or reaction-limited aggregation universal behavior can be observed for the initially polydisperse practical system of basic yttrium carbonate as well. The fractal structure of basic yttrium carbonate aggregate cluster was observed using transmission eletron microscopy. The aggregation kinetics of basic yttrium carbonate colloids was studed using dynamic 1ight-scattering techniques. At 1.00mol/l NaCl solution the fast diffusion-limited aggregation behavior was observed with an increase in the aggregate size over time described by a power law. The aggregates are characterized by a fractal dimension D=1.82. The disordered and ramified cluster is consisted of primary colloidal particles and tenuous and more open. These are in good agreement with those observed for other colloidal system such as colloidal gold (1.86), silica (1.85) and polystyrene latex (1.82) in diffusion-limited aggregation from the static and dynamic light scattering by Lin. Therefore ideal diffusion-limited aggregation behavior can be observed in practical polydisperse system as well. Smoluchwski and fractal theories were used to obtain the aggregation rate constant for initially polydisperse system for the first time.

本论文研究胶粒的非平衡不可逆聚集动态学，分为两个部分，第一部分是通过实验研究一个新的初始多分散的碱式碳酸钇胶粒实际体系中，聚集标度性质的普适性，即使用透射电子显微技术观测聚集粒子簇的分形结构，使用动态激光光散射研究碱式碳酸钇胶粒的聚集动力学，胶粒带电而产生静电排斥作用使得碱式碳酸钇胶粒处于稳定状态，当加入电解质NaCl溶液时，碱式碳酸钇胶粒间的Debye-Hückel屏蔽距离缩短，从而降低静电排斥能垒，引起胶粒发生不可逆聚集，加入电解质NaCl的浓度为1.00mol/l时，碱式碳酸钇胶粒进行快速聚集，经历扩散控制聚集机理，形成结构疏松、更为开放的分形聚集粒子簇，其分形维数为1.82，碱式碳酸钇胶粒聚集增长动力学遵循幂函数增长规律，与Lin等使用静态激光光散射和动态激光光散射测量硅胶(1.85)、金胶(1.86)和聚苯乙烯胶乳(1.82)在扩散控制聚集状态形成聚集粒子簇的分形维数值以及粒子簇聚集增长的动力学规律相一致，表明胶粒聚集标度性质的普适性质在初始多分散的实际体系中也是存在的，首次由动态激光光散射的实验数据得到初始多分散胶粒分形粒子簇的聚集速率常数，并且其值与Smoluchowski聚集速率理论预期相符。

In this paper,two nonlinear anisotropic diffusion filtering methods are presented and they are based on the multispectral anisotropic diffusion models proposed by Pope and Acton.We build a couple of new diffusion coefficients in partial derivative equation based on Tukey's biweight estimator error norm by recurring to the relationship between robust statistics and anisotropic diffusion incorporated with the nonlinear time-dependent cooling technique for gradient threshold.

在Pope和Acton提出的两个多光谱图像各向异性扩散滤波模型的基础上，通过各向异性扩散和稳健统计学的联系，建立了基于B iwe ight Estim ator误差模型的扩散系数，同时利用非线性退化技术对梯度阈值的改进，提出了两个基于各向异性扩散方程的非线性滤波方法。

In the first part, it was investigated the interaction between Pb2+ and La4Ti9O24 ceramic bulk. The result shows that a significant Pb2+ diffusion into La4Ti9O24 ceramic bulk and a significant crystallization of the La2/3TiO3-type phase is clearly observed in the Pb2+ diffusion layer. The reacted zone consists of the La2/3TiO3-type phase exhibits the linear dependence of the square of the thickness, x, on the heat-treated time, t, in excellent agreement with the parabolic law x2 = kt, where k is the growth rate coefficient. The kinetic study thus indicates that the Pb2+/La4Ti9O24 interaction strictly obeys the theory of the reactive diffusion. Furthermore, the experimental k values were used to determine the associated activation energy, Ea, for the formation of La2/3TiO3-type phase using the Arrhenius plot and the following least-square equation, ln =-Ea/RT + A, where T is the annealing temperature, R is the universal gas constant, and A is a constant, resulting in Ea ~ 607 ?b 60 kJ/mol.

首先， 以巨观的方式观察PbO与La4Ti9O24陶瓷体介面的反应现象；利用X-ray绕射分析以及扫描式电子显微镜来观察不同的热处理温度以及不同的持温时间所制作的样品，研究结果发现， Pb2+离子会渗入到La4Ti9O24陶瓷内，同时在Pb2+离子所渗入的区域内会产生新的La2/3TiO3-type钙钛矿斜方晶相；藉由量测不同温度与时间之样品，其因Pb2+离子渗入而产生之La2/3TiO3-type相层厚度之关系，符合反应式扩散机制中 x2 = kt 之关系式(其中 x：扩散层厚度； k：反应速率常数； t：反应时间)；进一步将不同实验条件所得到之反应速率常数值代入Arrhenius方程式ln (k =-Ea/RT + A ，其中Ea：活化能； T：绝对温度； R：气体反应常数； A：常数，可以求得Pb2+离子与La4Ti9O24陶瓷发生反应式扩散所需之活化能为607 ± 60 kJ/mol。

Some parameters such as Indoor radiation heat transfer, convective heat transfer, MRT, OT, radiation heat transfer coefficient, convective heat transfer coefficient, and PMV-PPD were calculated under a steady condition. From the result, we can conclude, when operation under the combination system and worst-case test, if floor temperature is about 21℃, supply air temperature is 21℃, air velocity is 1m/s, the equlvalent coefficient of heat transfer between floor temperature and OT is 13.6w/m2k, where 5.68w/m2k is equlvalent coefficient of radiant heat transfer, 9.48w/m2k is convective heat transfer coefficient. And when air velocity is higher, supply air temperature is lower, the radiant heat transfer between floor and others is lower. In the whole experiment, the floor temperature was keeping above the indoor air dew point, and condensation was not appeared.

通过分析计算，在复合式系统运行中，最不利室外环境下，当地面温度维持在21℃左右，送风温度21℃，送风风速1m/s，此时地板对作用温度的当量综合换热系数为13.6w/m2k，其中当量辐射换热系数为5.68w/m2k，对流换热系数为9.48w/m2k，并且送风速度越高、送风温度越低，地板与其他壁面的辐射换热量有一定程度的降低，但总供冷量增加；在整个实验中地板温度始终高于地板上层空气的露点温度，并未发现有结露现象；室内空气温度梯度能满足0.1m-1.1m的温差小于3℃的要求，并且适当提高送风温度可以进一步提高人体的热舒适性。

Hence, based on acoustic potential function and boundary condition on solid interface, we get reflection coefficient and refraction coefficient of longitudinal wave and transverse wave on solid-solid interface, and provide approximate formula of the reflection coefficient and the refraction coefficient about the first critical angle of incidence. We analyze relation between the refraction coefficient and acoustic impedance.

为此，基于固体介质的声势函数和界面的边界条件，推导了固-固界面纵横波的反射系数和透射系数，以及第一临界角入射情况下反射系数和透射系数的近似公式，并且分析了透射系数与声阻抗之间的关系。

Besides, I also find that firms report negative earnings for fiscal year, which have less current and future earnings response coefficient than report positive earnings, and firms report negative cash flows from operating for fiscal year, which have less current cash flow response coefficient than report positive cash flows. Indicating that firms report negative earnings or cash flow, because losses are more transitory and which stock prices less information but which future cash flow response coefficient more than report positive cash flows. Inference of this study because cash flow have substance effect, so when firms have negative cash flows investor more care about it, which have more cash flow response coefficient, and further find while distinguishing the degree of sophisiticated investor, investor the sophisiticated degree proportion is higher. Because they know information of the earnings, firms have more degree of shareholder sophistication for fiscal year, which have more current and future earnings response coefficient than which have less.

此外，本文也发现报导损失之公司，其当期及未来盈余反应系数较报导利润之公司低，以及公司报导营业活动之现金流量为负时其当期营业活动之现金流量反应系数低於报导营业活动之现金流量为正之公司，显示公司报导损失或营业活动之现金流量为负时，因为通常都是暂时性的故其股票报酬的资讯性较低，不过其未来营业活动之现金流量反应系数高於报导营业活动之现金流量为正之公司，本研究推论因为现金流量是有实质的效果，所以当现金流量为负值时投资人应该会比较关注，所以其反应系数较高，而进一步发现当区分投资人之精明程度时，投资人精明程度比重较高，因其会辨识盈余资讯而认为公司进行损益平稳化会增加其资讯内涵，故当期及未来盈余反应系数相较於投资人精明程度较低者高。

Wavelet multi-resolution analysis is applied to decompose the signal into multiple-level and the wavelet coefficient modules of its high-frequency components are obtained. The wavelet coefficient modules of a broken signal can be extracted by software demising. The threshold of demising is decided by the difference between the wavelet coefficient modules of a broken signal and those of a noise. The wavelet coefficient modules of the broken signal were shown in different levels, then the faults can be detected and distinguished by the integrated features of the variant levels' wavelet coefficient modules.

利用小波多尺度分解技术，将信号进行多尺度的小波分解，得到不同尺度下的信号高频分量的小波系数模值，并根据奇变信号和噪声信号小波系数模值的差异，采用软阈值去噪法，对其高频分量小波系数进行去噪处理，获取不同尺度上突变信号的小波系数模值，实现对故障的检测，并可根据不同尺度上小波系数模值的对应关系，实现对多重并发故障的区分。

Furthermore, transfer coefficient between total content and variable speciation including acid-soluble/exchangeable, reducible, oxidisable fraction of heavy metals are different. Transfer coefficient of total Cr is 0.65 in tailings area, but that of variable speciation is 0.26. In contrast with Cr,transfer coefficient of total Ni is 0.26, but that of variable speciation is 0.67. The similar characteristics on Pb and Zn in cultivated soil, namely, transfer coefficient of total Zn is high, but low for variable speciation, which is reversed for Pb. Transfer coefficient of total content and variable speciation in abandoned soil are low compared with above two fields soil, especially, variable speciation of Cu and Ni are not transported almost down soil profile.

重金属总量和活性态（包括弱酸提取态、可还原态、可氧化态）迁移率也表现出很大差异，尾矿区土壤Cr总量迁移率较高为0.65，而其活性态迁移率较低为0.26，Ni与Cr迁移特征完全相反，总量迁移率为0.26，而活性态迁移率为0.67；农田土壤中Pb总量迁移率低而活性态迁移率高，Ni与Zn特征相似，总量迁移率高而活性态迁移率相对较低；大棚地土壤中重金属迁移率均较低，Cu和Ni活性态几乎未发生向下迁移。

Single factor experiments were done with the factors including the width of protrusion and the trolley's velocity, which showed that the surface frictional coefficient decreases with the width of protrusion increasing, and doesn't change with the trolley's velocity changing, which was consistent with the results of the orthogonal experiment. A theoretical model of the horizontal projection of a corrugated bionic surface's contact area was built, which showed that the contact area's horizontal projection decreases with width and interval increasing respectively and that the ratio of the contact area's horizontal projection and the vertical load decreases with the vertical load increasing. It indicated that the surface frictional coefficient decreases with the above three factors increasing respectively. Finite element modeling and analysis of interactions of a plate and soils was done using ANSYS, which showed that the plate frictional coefficient is little relative to soil elastic modulus and decreases with vertical surface pressure and that trolley's pull and vertical displacement of bionic surface's control pilot keep constant almost during the plate being pulled. Finite element modeling and analysis of interactions of a corrugated bionic surface and soils was done using ANSYS, which showed that surface frictional coefficient is little relative to soil elastic modulus and decreases with bionic surface's structural parameters and vertical pressure increasing. However, the three factors all didn't affect the surface frictional coefficient remarkably on the condition of 90% dependability. For the first time, bionic surfaces were applied to screw piles, which formed bionic screw piles, and the contrast experiments showed the bionic screw pile had certain resistance-decreasing effects.

建立了波纹型仿生曲面与土壤的接触面积的水平投影的理论模型，表明接触面积的水平投影A随着波纹型仿生曲面突起宽度、两相邻突起间距的增大而减小，接触面积的水平投影与波纹型仿生曲面表面垂直载荷之比随着波纹型仿生曲面表面垂直载荷的增大而减小，进而得出仿生曲面摩擦系数随着波纹型仿生曲面突起宽度、两相邻突起间距以及表面垂直载荷的增大而减小；利用ANSYS软件对平板与土壤的相互作用进行了有限元建模与分析，表明平板摩擦系数与土壤弹性模量关系不大，而随着表面垂直载荷的增大而减小；平板牵引过程中台车牵引力和仿生曲面控制节点垂直方向位移基本保持不变；利用ANSYS软件对波纹型仿生曲面与土壤的相互作用进行了有限元建模与分析，表明波纹型仿生曲面系数在一定范围内基本不受土壤弹性模量的影响，随着波纹型仿生曲面突起宽度、两相邻突起间距以及表面垂直载荷的增大而减小，但在可信度为90％的前提下，三个因素影响都不显著；首次将波纹型仿生曲面应用于与土壤作用方式以挤压为主的螺旋桩，形成仿生螺旋桩，并与普通螺旋桩进行了沉桩对比试验，表明波纹型仿生曲面应用于螺旋桩桩体表面具有明显的降阻作用。

A new method for determination of diffusion coefficient with diaphragm-cell has been suggested, by which the differential diffusion coefficient can be directly determined and a tentative experiment has been done.

提出了膜池测定液相扩散系数的新方法。这一新方法能够直接测定溶液的微分扩散系数，并采用标准物系对上述方法进行了初步的实验验证。

Looking to bounce back from defeat against Cesena last weekend, the Calabrian boss will be sticking to his tried and tested 4-3-3, with Lopez and Sedivic joined up front in Giampaolo's absence by either Nanni or Plasmati.

鉴于上周末对切塞纳的比赛中反败为胜，这支南方球队将会更坚持其一贯而有效的4-3-3阵型，洛佩斯和塞德维奇将取代受伤缺席的詹保罗，和纳尼或者帕斯马蒂中的一个搭档锋线。

Meanwhile, their exposure to the more freewheeling ways of the West broadened dramatically.

另外，西方较自由的生活方式对年轻人的影响增大。