查询词典 diffusion equation

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。

In order to provide a photo detector in which the generation of spontaneous noise is suppressed and external noise is effectively reduced, a p-type diffusion layer is provided on the obverse side of an n-type semiconductor substrate, a p-type low-resistance layer is provided on the obverse side of the p-type diffusion layer, a lead frame is provided on the reverse side of the n-type semiconductor substrate with an insulative resin film in between, and the p-type low-resistance layer is electrically connected to the lead frame.

为了提供能够抑制自发噪声的产生并有效地减少外部噪声的光检测器，在n型半导体衬底正面设置p型扩散层，在p型扩散层正面设置p型低电阻层，在n型半导体衬底的反面设置引线框架、中间夹有绝缘树脂薄膜，p型低电阻层电连接到引线框架。

Vascular cognitive impairment ; Diffusion tensor imaging ; Histogram analysis ; Apparent diffusion coefficient ; Anisotropy index

血管性认知功能障碍；扩散张量成像；直方图分析；表观弥散系数；各项异性指数

Vascular cognitive impairment Diffusion tensor imaging Histogram analysis Apparent diffusion coefficient Fractional anisotropy

血管性认知功能障碍；扩散张量成像；直方图分析；表观扩散系数；各项异性分数

PARTⅢMagnetic resonance imaging and diffusion tensor imaging of gray matter damage in multiple sclerosis Objective To study the Magnetic resonance imagingcharacteristics of the gray matter lesions in multiple sclerosis,and to investigate the occult damage in normal appearing gray matterby quantitative analysis using diffusion tensor imaging.

第三部分多发性硬化脑灰质损害的MRI表现及DTI定量研究目的：分析多发性硬化患者脑灰质病灶的磁共振成像特征，利用弥散张量成像定量研究MS的正常表现脑灰质是否存在隐匿性损伤。

The diffusion structure tensor in the diffusion coefficient function is a vector-valued structure tensor, which integrates the intensity and structure information of each channel, as well as the correlation among channels.

扩散滤波器中的扩散系数定义为关于彩色结构张量的函数，以使图像演化能够综合各通道信息，解决了各通道所得位移场不一致而引起的色彩混迭问题。

Thermal diffusion coefficient ; longitudinal dispersion ; transverse diffusion ; thermal pollution.

热扩散系数；纵向分散；横向扩散；热污染

The results show that in a predator-prey model, when diffusion is absent, the diffusion is the interior impetus of system for its stable equilibrium state transforming to unstable equilibrium state and is the basis for biological mode forming.

研究结果表明：在捕食－食饵模型中，扩散是使无扩散时稳定的平衡态向不稳定的平衡态转变的系统内动力，是生物模式形成的基础。

Arc-glow plasma depositing technique is a new surface coating method. With the help of vacuum arc discharge, a cold cathode arc source continually emits ion beams of coating elements with high currency density and high ionizing ratio.Upon the ion bombard and diffusion work on, the surfaces of the parts form deposited layers, diffusion layers. In this study, a commercial magnesium alloy AZ91 was coated with Ti film layer.

加弧辉光离子渗镀技术将辉光放电与弧光放电有机地结合起来，利用辉光放电空心阴极效应使工件迅速升温，同时在真空容器壁上设置一个或多个金属阴极电弧靶源，利用真空电弧放电而不断地发射出高能量、高电流密度、高离化率的欲渗金属离子流，依靠扩散和离子轰击作用快速渗入工件表面层，在工件表面可以形成渗层、镀层、渗镀结合层。

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。