扩散

Environment radon is mainly from rock and soil in geological environment, but the research is not connected with geological environment now. On the basis of physical field, the theoretical distribution model of radon in soil and exchange model of earth—air are set up by using Fick diffusion law and Dacy law, and then the research of environment radon is linked with geological environment. This paper described how the evry parameter of the theoretical model influence the radon concentration in air. The results of research indicat that molecule diffusion of radon is different from it's eddy form. Under the condition of surface radon source, the model experiment is used to study the transportation and distribution of radon in medium. The data of experiment show the relationship between radon and depth can be described by exponent. If the radioelement is well—distributtion, the concentration of radon in different depth or in different point at the same depth change with time, but the accumulated exhalation amount of radon at different point on the surface of model are close in relative long time. The author studied the exchange of radon between mediums and verified the theoretical models too.

环境氡主要来自岩石、土壤，而目前环境氡研究中与地质环境结合很少，为此作者以物理场为基础，运用气体运移的费克扩散定律和达西定律，建立起壤中氡浓度分布与大地—大气间氡交换理论模型，首次在理论上将环境氡与地质环境结合起来；论文中从理论上讨论了模型中各参数对空气中氡浓度的影响，发现空气中氡运移的分子扩散方式和湍流扩散方式存在明显差异；通过面状氡源条件下的氡运移模型实验，研究了介质中氡的运移与分布，实验数据表明氡浓度随深度的变化规律可用指数函数描述，在放射性元素分布均匀的条件下，介质中不同深度和同一深度不同点的氡浓度随时间而变，但介质表面不同点在较长时间内向空气中累计释放的氡的量是相近的；同时研究了不同介质间氡的交换，并验证了所建立的理论模型；运用理论模型预测青岛市城区壤中氡浓度、江西临川一住宅区空气中氡浓度及江西二个测区的区域空气中氡浓度分布，取得了较好的效果。

It is shown that the return time set of strong scattering is Poincaré set, the return time set of scattering is recurrent set and the return time set of weak scattering is recurrent set for group rotation.

特别地，我们得到了强扩散系统的回复时间集为Poincaré序列，扩散系统的回复时间集为回复序列以及弱扩散系统的回复时间集为相对于群旋转的回复序列。

Comparatively, Na^＋ has a wider diffusion range and higher self-diffusion coefficient than Mg^2＋.

在Na／Mg^-蒙脱石中，Na^＋和Mg^2＋的扩散方式不同，Na^＋的扩散范围相对更广，自扩散系数更大。

Based on this equation, the effect of pressure, temperature on liquid diffusion coefficients was dis〓sed, then the mutual diffusion coefficients at infinite dilution of 35 binary systems and self-diffusion coefficients of 12 pure substances under high pressure have been calculated.

根据该方程讨论了温度、压力对液体扩散系数的影响，并计算了高压下35个二元物系的无限稀释扩散系数与12个纯物质的自扩散系数。

Two types of latex particles with similar particle size, similar molecular weight and molecular weight distribution of their constituent polymers labeled by the donor phenanthrene or by the acceptor a polymerizable benzophenone were synthesized by seeded semicontinuous emulsion polymerization.

利用这些乳液粒子，研究了聚甲基丙烯酸丁酯在不同的温度下在其薄膜中的扩散，获得了不同温度时的表观扩散系数以及聚合物扩散的表观活化能。

Application and development of platelet transpiration cooling technology in LRE;2. The Computation and Analysis of Heat Transfer of Platelet Cooled Microchannel on the High Temperature and High Pressure Gas Wall;3. Physical-mathematic model is built for the process of evaporation and combustion of the two interactive arbitrary size semisphere pearly transpiration droplets in platelet hole structure under micro-gravity condition.

针对微重力条件下层板孔隙结构中两个相邻任意尺寸半球形珠状发汗的蒸发与燃烧过程，建立了相应的数学物理模型；在双球坐标系中求解分子扩散传质偏微分方程，得到发汗液珠的分子扩散组分分布的解析解和扩散速率表达式；分析得到在常温、高温条件下蒸发以及燃烧状态下发汗液珠的相互作用因子式，计算了相互作用的发汗液珠在不同条件下的发汗蒸发量以及变化趋势。

The nanocomposite RE-W thermionic emission material can accelerate the active substance diffusion in the three aspects.

发射材料从反应速率，扩散距离及晶界扩散三方面来影响活性物质的扩散速率。

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。

At the temperature as low as that at which the monomer cannot diffuse in large scale,adatom nucleation and island formation depends on the increase of adatom density.With the increase of temperature,the film growth mode depends on the competition between in-plane diffusion and inter-layer diffusion of monomers.

当薄膜生长温度低于单原子的扩散温度时，表面原子的成核和表面岛的生长主要是由沉积原子的空间随机性和表面原子密度增加而决定的，随着薄膜生长温度的提高，薄膜的生长模式则取决于单原子的层内扩散和层间扩散的竞争。

The main achievements of the project are as follows: 1 the hypothesis that a decrease in seed mass causes an increase in mean dispersal distance has been tested based on the experiments of weed dispersal by wind. The experimental results partly support the hypothesis. The results will help farmers to make an optimal strategy of weed control; 2 a statistic method for inferring probabilistic distribution function of a random variable has been developed, by which probabilistic distribution functions of weed species dispersal have been determined; 3 the reproduction structure of Bromus sterilis has been studied; 4 a more complex CA model with 25 neighborhood cells were built, which can simulate spread of a weed population. This work promotes developments in both theory and application of CA models; 5 the "mean law" in weed control has been proposed. Accordingly, the algorism of patch spring may be calibrated; 6 the "patch" and "true patch" have been mathematically defined so that herbicide can be efficiently applied; 7 simulation validates that initial configurations of weed will affect dispersal of its population and strategies of controlling it, or its distribution patterns affect its dispersal progresses.

主要完成的工作和取得的成果有：1）用实验证实了重量较轻的杂草种子并不一定飞得比较重的远，其结果有助于农民制订杂草的优化控制策略；2）发展了一种推断随机变量分布函数的统计方法并用它来获得了几个杂草种的扩散分布函数；3）对杂草Bromus sterilis的繁殖结构进行了研究；4）建立了一个具有25邻的较复杂的能模拟杂草扩散的CA模型，并在理论和应用方面促进了CA模型的发展；5）在杂草控制方面提出了&平均法则&，据此可对按块施药方法进行校正；6）精确地定义了&块&和&真块&以便在杂草控制中能更有效地使用除草剂；7）模拟证实杂草种群的初始配置影响其扩散和控制策略，或者格局影响过程。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失