查询词典 diffusion coefficient

Drugs may cross a biologic barrier by passive diffusion, facilitated passive diffusion, active transport, or pinocytosis.

药物可通过被动扩散、易化被动扩散、主动转运或胞饮作用等方式穿越生物屏障。

Drugs may cro a biologic barrier by pa ive diffusion, facilitated pa ive diffusion, active tra ort, or pinocytosis.

药物可通过被动扩散、易化被动扩散、主动转运或胞饮作用等方式穿越生物屏障。

The SCVFV(the convection-diffusion difference scheme based on control-volume face values) scheme was put forward. The theory of the SCVFV scheme was systematically elaborated. The general interpolation formula of the SCVFV scheme was given. The formulas of the SCVFV scheme based on the Cartesian coordinate were derived. The precision, the mass conservation property and the preventability of the false-diffusion of the SCVFV scheme were theoretically analyzed.

提出了基于控制容积面值的对流扩散差分格式SCVFV，系统地阐述了SCVFV格式的基本思想，给出了SCVFV插值公式的通用表达式，推导了直角坐标系下完整的SCVFV格式的表达式，从理论上分析SCVFV格式的精度、守恒性及反伪扩散性。

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。

The self-diffusion coefficients of supercritical carbon dioxide and infinite dilute diffusion coefficients of methanol and ethanol in supercritical carbon dioxide were investigated by molecular dynamics simulation.

采用分子动力学模拟的方法对超临界二氧化碳的自扩散系数及甲醇和乙醇在超临界二氧化破中的无限稀释扩散系数进行了模拟计算。

The self-diffusion coefficients and diffusion pathways of hexane, as well as the mobility of the frameworks were investigated, as a function of both temperature and loading.

本文重点研究了温度和分子数对己烷自扩散系数、扩散机理，以及骨架柔性的影响。

At the temperature range of 800～850℃, the deformation activation energy was very close to self-diffusion activation energy of grain boundary, which shows the main deformation mechanism is grain boundary sliding controlled by grain boundary diffusion.

在850℃变形激活能与晶界自扩散激活能十分相近，表明晶界扩散控制的晶界滑动是超塑性变形的主要机制。

The results show that the silicide coating is formed by reactive diffusion and the silicification process obeys parabolic relation. The coating is composed of composite structures including MoSi2 outer layer, two-phase transient zone with major NbSi2 and minor Nb5Si3, and Nb5Si3 diffusion inner layer. The coating possesses good high-temperature oxidation resistance and spalling resistance.

研究结果表明：包渗法制备硅化物涂层是通过反应扩散形成的，硅化过程服从抛物线规律；该涂层为复合结构：MoSi2相为主体层；以NbSi2相为主、并含少量Nb5Si3相的两相为过渡区；Nb5Si3相为扩散层。

It establishes the uniform, singular and two kinds of normal distributions models of diffusion layer statistical distribution, the result shows that the more singular the statistical distribution of the cathode gas diffusion layer porosity is, the better the cell performance is, and the more uniform, the worse the cell performance is.

最后，从热力学的角度分析了燃料电池过程的能量转化形式，反应的焓变主要转变成电能和热能两种能量形式；归纳了燃料电池电化学的一些基本理论模型及简单的推导过程；描述了燃料电池效率的一些不同的定义以及对采用热电联供的方式提高燃料电池能量利用效率的分析。

However, the refraction of plane wave in reaction-diffusion system obeys Snell's law only for proper diffusion coefficients and system parameters.

在二维复金兹堡-朗道方程描述的反应扩散振荡系统中，就扩散对平面波折射率的影响进行了数值研究，从Snell定律出发导出了折射率的解析表达式，数值和理论结果表明：在纯扩散情况下，平面波的折射满足Snell折射定律，扩散只影响着平面波折射率的大小；在同时存在反应扩散情况下，只有在适当的扩散系数和系统参数下，平面波的折射才满足Snell折射定律。

Sodium citrate; calcium carbonate; calcium hydroxide; potassium bicorbonate; magnesium carbonate; ferrous sulphate; Zinc sulphate; copper sulphate; manganese sulphate; potassium iodide; sodium selenite.

柠檬酸钠；碳酸钙；氢氧化钙；碳酸氢钾；碳酸镁；硫酸亚铁；硫酸锌；硫酸铜；硫酸锰；碘化钾；亚硒酸钠。

All this to say that I'm glad filmmaking hasn't become completely ironic. I can enjoy an ironic film as much as the next person, but they usually involve a message of some sort. One that's delivered in a smirkingly clever way that requires little in the way of talent.

所有这些都是说，我很高兴电影制作没有变成完全讽刺艺术，我可以和下一个人一样享受讽刺电影的乐趣，虽然他们经常会被划归到一定级别，技术方面不需要很高的才能。