查询词典 derivative

The Frechet derivative of the cost function is determined via the solution of an adjoint partial differential equation, and the boundary shape is then modified in a direction of descent. This process is repeated until an optimum solution is approached. The advantage is that the cost function variation is independent of the flow field variation, with the result that the gradient of cost function with respect to arbitrary number of design variables can be determined without the need for additional flow-field evaluations. So each design cycle requires the numerical solution of both the flow and the adjoint equations leading to a computational cost roughly equal to the cost of two flow solutions.

虽然他们的研究成果大多数都可以在公开性文献上看到，但是其中一些具体的细节问题的处理方法却没有透露，比如：伴随方程如何离散求解才能减小最终梯度计算中的误差，使得设计过程有效地进行；伴随方程与流动方程的边界条件是不同的，如何合理地处理伴随方程的边界条件，才能推动设计过程朝着设计目标而发展；在减阻问题中目标函数如何定义，求解梯度的具体数学公式如何推导，如何通过数值方法来实现它们等。

Thismethod adopted affine transformation model and a Lie derivative-based analytical algorithm.We introduced the process and characters in extracting information of biological visionsystem, studied the feasibility of the generalized Gabor function used as receptive fieldfunction in extracting information and analyzed affine transformation group and Liederivatives. Finally, we deduced the mathematical denotation for Lie derivatives, i.e. theinfinitesimal generator of the geometric distortion in affine transformation.

对生物视觉信息提取的过程及特点进行了介绍，其中主要研究了广义Gabor函数作为感受野函数提取初级视觉信息的可行性；对仿射变换作为外界图像信息在视觉成像系统上的投影模型的原理进行了初步讨论；对Lie变换群微分算子用于提取仿射变换不变量的分析方法作了剖析，并推导了该方法中关键部分——仿射变换Lie微分算子的具体表达式，也就是几何变形无限小微分算子的计算表达式，使下一步编程实现该方法成为可能。

The derivative nonlinear Schrodinger equation is, however, an open and important issue both in theoretical and applied aspects. The DNLS equation with nonvanishing boundary conditions is solved by introducting an affine parameter and we find that it supports a rich set of soliton solutions.

大部分完全可积的(1+1)维非线性偏微分方程，特别是有明确物理应用的方程的孤子解已经用反散射变换等方法得到，但还剩下一些难题，变形的非线性薛定谔方程在非零边值下的反散射变换就是其中一个。

They buy mortgages from banks, after, and other derivative products after binding to the form of securities sold to investors around the world.

它们从银行购买房贷，经过和其它衍生金融产品捆绑之后，以证券的形式出售给世界各地的投资者。

We applied ATR Fourier Transform Infrared spectra and second derivative spectra to analyze the alcoholicity and content of sugar of red wines produced by different manufacturers for the first time.

首次采用衰减全反射傅里叶变换红外光谱法并结合二级导数谱对市售的若干种不同厂家葡萄酒的酒精含量和糖含量进行了快速无损分析。

The research results showed that the alcoholicity of derivative sugar from hemicellulose would be 40g/L (over 90％ of the theoretical output)after 48 hours′ fermentation with addition of some nutritional component.

试验研究表明，半纤维素衍生糖补充一定的营养成分，经过48h发酵，乙醇浓度可达40g/L，是理论产率的90％以上。

Put the discrete algebraic equations of initial derivative conditions and algebraic equation system of governing differential equation together to form a new algebraic system.

采用重心Lagrange插值近似未知函数，推导了未知函数各阶导数微分矩阵的显式表达式，建立了求解二阶常微分方程初值问题的重心Lagrange插值配点法。

It can turn the alkane into the alcohol and the alkene into the derivative of ethylene oxide in air at room temperature by its catalysis.

该项研究不仅有助于人们了解细胞色素P-450的催化机理，而且在有机合成和医学上将具有广泛的应用前景。

Novel chitosan derivative with long alky groups as the hydrophobic moieties and carboxymethyl groups as the hydrophilic moieties was synthesized. The chemical structure of N-octyl-O, N-carboxymethyl chitosan was characterized via FTIR, 1H NMR and elemental analysis. The physical properties were analyzed with wide angle X-ray diffraction and differential scanning calorimetry.

以天然可生物降解的壳聚糖为原料，通过在壳聚糖6位羟基上引入羧甲基，在2位氨基上引入疏水烷基链，制得N-辛基－O，N-羧甲基壳聚糖两亲性衍生物，分别用FTIR、1H NMR和元素分析等技术对其结构进行表征，用广角X射线衍射和差示扫描量热法对具物理性质进行分析，并考察其在各种溶剂中的溶解性能及其对难溶性药物的增溶能力。

Alkylamine reaction with dialkyl cyanodithioiminocarbonate was catalyzed by quaternary ammonium salts at room temperature to yield 3-alkylamine-5-amino-1,2,4-triazole in good quality and high yields. After imidization and reaction with an α,β-unsaturated acid derivative, the reaction intermediate was hydrolyzed in the presence of a Lewis acid to obtain the target product.

烷基胺与氰基亚胺硫代二甲酯在季氨盐催化作用下得到质量好、收率高的3-烷氨基-5-氨基-1，2，4-三氮唑，进一步经过亚胺中间体并与α，β-不饱和酸酯作用后，中间产物在Lewis酸催化作用下水解得到三唑嘧啶酮。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐