梯度法

In the algorithm, radial-basis function neural network was utilized as forward model, and genetic algorithm was used to solve the optimization problem in the inverse problem, which can avoid the local minimum solution possibly encountered in the iterative inverse algorithm based on gradient descent and consequently achieve the global optimized solution of the inverse problem.

在该算法中，径向基函数神经网络用作前向模型，遗传算法用于求解逆问题中的优化问题，其优点是能够避免基于梯度下降法的迭代逆算法中可能遇到的局部最小问题，并能得到逆问题的全局最优解。

The mixed boundary problem was reduced to a system of singular integral equations by means of Fourier transform.

利用Fourier积分变换技术将混合边值问题转化为一对奇异积分方程，通过数值求解奇异积分方程获得含裂纹功能梯度板条分别在剪切和法向载荷作用下的I型和Ⅱ型应力强度因子，并讨论了材料的非均匀性和裂纹相对尺寸对裂纹尖端应力强度因子的影响。

To establish the appropriate system for selection of Agrobacterium-mediated transformation of protocorm-like bodiesof Dendrobium nobile Lindl,materials were cultured in liquid paper medium,solid culture medium and liquid filter paper bridge,with Hyg at 7 different concentrations such as 0,20,40,50,60 and 80 mg/L.

为确立农杆菌介导法转化金钗石斛类原球茎的适宜的选择体系，利用液体纸基、固体培养基与液体滤纸桥3种培养方式，以0，20，40，50，60，80 mg/L质量浓度的潮霉素梯度试验，发现不同培养方式的选择效果有所差异。

The stability of Functionally Graded Material rectangular plate made of metal and ceramic under the action of non-conservative force is analyzed.

对由金属和陶瓷两种材料制成的功能梯度材料(Functionally Graded Material，FGM)矩形板在非保守力作用下的稳定性问题用微分求积法进行研究。

RESULTS: BMSCs was pure following density gradient centrifugation and adherence screening method. The third and fifth passage of cells had typical whirlpool-shape. Transmission electron microscope demonstrated that round or oval MSCs possessed large nuclei, big nucleus proportion, a few cellular organ.

结果：①经密度梯度离心法、贴壁筛选法并结合传代方法所得的间充质干细胞很纯，第3代和第5代细胞形态单一，细胞排列具有典型的漩涡状结构。

The earth is modeled as an oblate and rotating spheroid, and higher order terms in the multiple expansion of gravitational fields are considered. To avoid singularities in computations, the quaternion representation of the spacecraft attitude is used in the angular kinetic model equations.

其中地球被描述为绕短轴自转的椭球体，重力场梯度由四阶Jeffery常数描述，航天飞机的姿态运动用四元素法描述，以避免模型方程中的数值奇异点。

Results 4.16×10 9 oocysts were obtained in 30 mice in the 3rd group with dexamethasone of 20 μg/ml in drinking water. No significant difference in the oocyst recovery, purity and infectivity was found between methods using saturated saline floatation and sucrose density gradient centrifugation. The infectivity of the oocysts obtained from the same origin but different animals was similar.

结果 地塞米松加入量为 2 0 μg/ml的第 3组获得的卵囊量高达 4 。16× 10 9/ 30个小鼠；用饱和盐水漂浮法与用蔗糖密度梯度离心法纯化得到的卵囊具有相同的回收率和纯度；从感染小鼠与犊牛中获得的卵囊在感染性上差异不显著。

Firstly, the three-dimension boundary question and its corresponding variation question concerning the point-source electrical field on a 3-D structure are presented. Secondly, the finite element method is used to solve the variational equation. The study area is divided into many tetrahedral elements. Then, we interpolate with a tri-linear function in each element. So, the variational equation is converted into a linear equation system. Finally, taking into account saving of time, we make use of symmetric successive overrelaxation preconditioned conjugate gradient algorithm to solve large linear system, and obtain the potential value of each node, resulting in the calculation of the apparent resistivity values on the ground surface.

首先给出了三维构造中点源电场的边值问题以及相应的变分问题；然后利用有限单元法求解变分问题，采用四面体单元对研究区域进行剖分，在单元中进行三线性函数插值，将变分方程化为线性代数方程组；最后，考虑到节约计算时间，利用对称超松弛预条件共轭梯度迭代算法求解大型线性方程组，得到了各节点的电位值，进而计算出地表的视电阻率。

Ointment extracted from Plastrum Testudinis was separated by silica gel column chromatography, gradiently eluted by petroleum ether-ethyl acetate, and 16 (Ts-1～Ts-16) components were obtained, which were biologically evaluated by MTT assay and flow cytometry on the proliferation of rat marrow-derived mesenchymal stem cells. Results showed that Ts-12 induced proliferation compared with the control group ( p ＜0.05), while Ts-4 showed inhibitive effect. Other groups showed no significance ( p ＞0.05). GC-MS was used to analyze the chemical components in different groups.

中药龟板提取物浸膏经硅胶柱层析，用石油醚-乙酸乙酯作洗脱剂，梯度洗脱，得到16个组分；采用MTT法和流式细胞技术研究了它们对鼠骨髓间充质干细胞的增殖作用，实验结果显示组分Ts-12具有促进rMSCs增殖的作用( p ＜0.05)，而组分Ts-4则表现出抑制rMSCs增殖的作用( p ＜0.05)，其它样品对rMSCs的增殖作用不显著( p ＞0.05)，不具统计学意义。

For each of these machine settings the program uses a hill climbing algorithm to find the optimal plugboard settings.

对这些机器中的每一台都设置程序使用梯度算法(hill climbing algorithm，爬山法)来寻找最佳的线路连接板步线方式。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。