系数

Using the theory of radiative capture reaction and combining our department experiment, we investigate two nuclear reactions,〓 and 〓, and calculate the cross sections and astrophysical reaction rate of them.

我们对ANC系数的近似模型无关性给出了一个数学形式理论证明，并结合具体的核反应，利用数值计算验证了ANC系数的近似模型无关性；在E1跃迁情况下，我们给出了一个用ANC系数计算辐射俘获反应截面的计算公式。

The effect of coating ingradient on arc stability and slag detachability for basic electrode is discussed; and the status of current research on effect of coating ingradient on welding technology for basic electrode abroad is reveiwed.

利用光谱分析和扫描电镜对高硬度钢质堆焊层金属进行分析，采用修正后的焊条药皮重量系数计算公式计算出Nb、Ti、V的过渡系数，讨论了上述元素在碱性焊条中过渡系数的影响因素，初步得出Nb、Ti、V的过渡规律。

Slag detachability of new slag system basic electrode ;2. Weld fume quantity and emission rate of new slag system basic electrode ;3. It was discussed about the influence of the mentioned elements on the transition coefficient of basic electrode .

利用光谱分析和扫描电镜对高硬度钢质堆焊层金属进行分析，采用修正后的焊条药皮重量系数计算公式计算出Nb、Ti、V的过渡系数，讨论了上述元素在碱性焊条中过渡系数的影响因素，初步得出Nb、Ti、V的过渡规律。

The internal relation between a large number of existing aerodynamic sketches and performance parameters of centrifugal fan is analyzed and investigated by means of statistical method,the correspondence relation between speed coefficient and diametral quotient,impeller outlet breadth and diametral quotient is found.

应用统计的方法对大量已有离心通风机的空气动力学略图和性能参数之间的内在关系进行分析研究，发现了速度系数σ与直径系数δ之间以及叶片出口宽度b2与直径系数δ之间存在着对应关系，利用这些关系提出了确定风机叶轮主要参数的新方法。

This function is infinite-order differentiable with respect to wavelet coefficient, and can adaptively shrink wavelet coefficient in the neighborhood of the threshold.

其为收缩因子函数与小波系数的乘积，对小波系数无穷可导、可在阈值邻域内对小波系数自适应收缩。

The nonlinear sliding mode controller is taken as an example, the implementation form of δ operator discretization control, the error analysis and the algorithms stability are studied both theoty and engineering application.

数值仿真表明，当高速开关阀的节流孔流量系数、摩擦片的磨损量、摩擦系数、传动系的弹性系数等因素在允许范围内变化时，滑模控制器的跟踪误差远低于一般的PID控制器。

According to the feature of the SARS Chest Radiographic Images, the wavelet analysis method is put forward to dispose the SARS images and the wavelet coefficients are picked up. After the wavelet threshold noise reducing and the wavelet threshold enhancing disposure to the each of the wavelet coefficients, the clear images are reconstructed at last.

摘 要：通过对非典型肺炎的胸部 X 线图像的特征分析，提出采用小波分析方法，对图像做小波变换，提取各层小波分解系数，利用阈值法对各系数作去噪预处理，然后再利用阈值法对各系数做衰减或增强处理，最后重构出清晰图像。

In heat transfer experiment under ambient temperature and pressure, the profile of heat transfer coefficient, and its relation with injection flow rate and downcomer flow rate are investigated.

通过常温常压下传热实验，获得了反应堆压力容器内对流换热系数的分布，对流换热系数与安注流速和下降环腔流速的关系，含气率对对流换热系数的影响。

In this paper, a speckle reduction method for SAR images based on Dual Tree Complex Wavelet Transform is proposed. It first presumes the probability distribution function for complex wavelet coefficients of the original nature image, and then applies MAP theory to estimate coefficients from the noisy wavelet coefficients. Filtered image can be derived after inversed DTCWT.

该方法首先对无噪声污染图像的复数小波系数的统计概率分布进行建模；然后利用此先验概率模型，采用最大后验概率方法从含噪小波系数中估计出无噪声污染的小波系数：最后经重构得到滤波后的图像。

The results show that the microstructure of ventra1 scale for python was composed of micro-convex and plank structure that was periodically arranged, it was mensurable and could be described by 9 characteristic parameters. Its surface was different in their forward and backward lean angle. The frictional coefficient of the ventra1 scale had closely relationship with moving direction, it decreased with the increasing load. The value of the frictional coefficient was about 0.07. The frictional coefficient while python moved backward and laterally were equal, and that was 33% more than that moved ahead. The frictional force of the ventra1 scale surface was caused by mechanical tooth function of micro-convex, acting intermolecular force and material's elastic hysteresis. The difference of forward and behind bevel for micro-convex was the anisotropy reason of frictional force.

结果表明：腹鳞表面的微观结构由指状微突体和板结构部分周期排列而成，其结构可用9个特征参数定量描述；腹鳞表面摩擦力由分子作用力、表面微突体的犁沟力、楔形作用力以及材料弹性滞后共同引起；腹鳞表面的摩擦系数在0.07左右并与运动方向有关，摩擦系数随载荷增加而减小；后向运动及左、右侧向运动时摩擦系数基本相等，比前向运动时高33%左右；腹鳞表面微突体不同方向上倾斜角度的差异是引起摩擦各向异性的主要原因。

Shop assistant: Please check at the door.

店员：请您到门口柜台交费。

In the end, transportation of PAHs in the environmental matrix was preliminarily investigated and discussed according to PAHs data of soils and sediments from a certain region in Shanghai. The result indicated that there are two or more pathways on PAHs transportation in the environmental matrix.

最后，对上海特定地区内PAHs在环境介质中的迁移径途进行了分析讨论，结果表明上海市土壤和沉积物等环境介质中PAHs的迁移存在多种途径。