查询词典 diffusion constant

The hydrogen solubility in Pd follows Sieverts law, and hydrogen diffusion through the bulk of the palladium membrane is the rate determining step. Whereas other gases only permeate through the pinholes or gaps in the Pd layer;the permeation can be quantitatively described as a combination of Knudsen diffusion and viscous flow.

氢气在钯膜中溶解渗透服从Sievert定律，并且氢的渗透扩散过程是速率控制步骤；而其他气体则通过膜中的针孔或裂隙进行扩散，其传质过程为Knudsen扩散和粘性流两种传递方式的综和。

To simulate the diffusion of the vortex sheet into the flow field as time goes on, Koumoutsakos' analytical solution is employed, in which an effective vorticity flux is derived and used for solving the vorticity diffusion equation.

而涡片之环量随时间扩散进流场之现象则藉由Koumoutsakos之理论，以边界上之等效涡度通量求解扩散方程式，得解析解后，再将之离散为边界附近之新涡泡。

To simulate the diffusion of the vortex sheet into the flow field as time goes on, Koumoutsakos' analytical solution is employed, in which an effective vorticity flux is derived and used for solving the vorticity diffusion equation. The solution is then discretized into blobs (called "-blobs") in the vicinity of the boundary.

而涡片之环量随时间扩散进流场之现象则藉由Koumoutsakos之理论，以边界上之等效涡度通量求解扩散方程式，得解析解后，再将之离散为边界附近之新涡泡。

A thin film of titanium carbide is obtained by vacuum evaporating oftitanium. With diffusion treatment, the existance of titanium carbide is identified by X-raydiffraction analysis. Quantatitive analysis is made by XPS to invetigate diffusion ofcarbon atom between diamond and titanium film.

用真空蒸镀法在金刚石表面镀覆Ti层，并经扩散处理使金刚石表面形成TiC膜，实现了金刚石表面的金属化。X射线衍射分析证实了TiC的存在，利用XPS定量分析验证了在金刚石表面碳原子与钛镀层之间的反应扩散模型。

By using simplified diffusion equation,the element diffusion model was built for 12-slab stack cooling process.

根据氢和碳的元素扩散规律，可知板坯堆冷工艺可以促使氢的扩散，但对中心碳偏析影响不大。

In this paper, in terms of diffusion equation of neutral gas in thermosphere and main ion-chemistry reactions in ionospheric F region, the diffusion processes of H2, H2O and CO2 and ionospheric response to released gases are investigated.

根据中性气体在热层背景中的扩散方程，考虑电离层F区主要的离子化学反应，研究了H2，H2O和CO2气体在电离层高度上的扩散过程和电离层对所释放气体的响应，计算了气辉的体发射系数和发射强度。

PartⅢDiagnostic strategy of Breast Lesion using combination of dynamic contrast-enhanced and diffusion-weighted imagingPurpose:To evaluate the diagnostic accuracy of a combination of dynamic contrast-enhanced MR imaging and diffusion-weighted MR imaging in characterization of breast lesion and to find the strongest discriminators between malignancy and benignancy.Materials and Methods:223 patients with 236 pathology-confirmed breast lesions were examined using EPI-DWI,FSE-T2WI,SE-T1WI,DCE-MR imaging were performed using VIBRANT sequence.

第三部分磁共振动态增强扫描结合扩散加权成像诊断乳腺癌的策略研究目的：分析乳腺良、恶性病变的形态学表现、血流动力学表现，结合ADC值，采用单变量和多变量分析，挖掘有意义的恶性MR征象，制定乳腺癌的诊断策略，探讨动态增强MR(dynamic contrast-enhanced MR imaging，DCE-MRI)结合DWI对乳腺病变的诊断和鉴别诊断价值。

BY molecular dynamic simulation on the self-diffusion properties of Cu nanoclusters, we found the diffusion coefficients of copper nanoclusters Nc8949 increase with the increasing temperature and increase with reciprocals of their radii approximately at

本文通过分子动力学模拟研究了纳米铜团簇的自扩散性质，结果表明Nc8949铜团簇自扩散系数随温度的升高而增大，在温度为1000K时纳米铜团簇的扩散系数随团簇半径的倒数基本呈线性增加。

Wet stack emission will reduce the lifting height of the flue gas, and it's not beneficial to gas diffusion; the momentum of the flue gas should be guaranteed to decrease the plume downwash and to promote gas diffusion; each of the emission index of the wet flue gas can meet the requirements for the environmental protection.

数值计算与分析表明，湿烟囱排放会增强对烟囱的腐蚀性，需采用特殊的防腐处理；湿烟囱直接排放会降低烟气抬升高度，不利于扩散；为减少烟流下洗，增强扩散，应保证烟气的出口动量；湿烟气各项排放指标能满足环保要求。

The coefficients and diffusion procedure in Helmholtz equation are determined by the diffusion and dissipation property of vorticity.

理论和实验证明了曲率驱动的亥姆霍兹涡量方程模型在图像修复中的有效性。

The changes of the HAF after liver injury may be related to the volume of blood loss, the intraabdominal pressure and the pneumoperitoneum duration.

肝撞击伤伴失血后肝动脉血流量的变化与失血量、气腹压力以及气腹持续时间等有密切联系。

Reneging on our commitments to the world's poor cannot be an austerity measure, she said.

放弃我们给世界上的穷国的承诺不能成为一种紧缩措施。