查询词典 finite difference approximation

objective to study the relationships between smoking,atherosclerosis and c-reactive protein.methods to detect the serum crp and serum lipid while in quiring the smoking status for278patients with cardio-vascular disease.then analyed the crp level among different groups.results crp level had significant difference between smoking and non-smoking groups,atherosclerosis and non-atherosclerosis groups;but it seems no relationˉship with high lipid.in differentsmoking amount groups,crp level had significant difference in atherosclerosis paˉtients,but no significant difference in non-atherosclerosis patients.conclusion smoking,high lipid and crp were all very good prognostic mark in atherogenesis.crp was a significant prognostic mark in atherosclerosis influenced by smoking.

目的 初步探讨c反应蛋白crp与吸烟和动脉粥样硬化三者之间的关系。方法通过对临床278例动脉粥样硬化和非动脉粥样硬化病人血清crp和血脂的检测及吸烟情况的调查，应用spss统计软件进行差异分析，比较不同组间crp水平。结果 crp在吸烟与不吸烟组、动脉粥样硬化和非动脉粥样硬化组差异有显著性。而在血脂正常组和高血脂组差异无显著性。在不同吸烟量组间：非动脉粥样硬化组间crp水平差异无显著性，而动脉粥样硬化组差异有极显著性。结论吸烟、血脂升高、crp升高是动脉粥样硬化较好的预示指标；在吸烟人群中crp升高者更易患动脉粥样硬化。

The results were as follows. In the insert mutation genotypes, there was significant difference between body weights of 2 weeks aged BB and AB genotype (P.05), while there was no significant difference between AA and other genotypes. In the mutation genotypes, there was no significant difference in body weight. Insert mutation loci had no significant effect on fossil bone length and shank length of 0-12 weeks aged chickens, only mutation loci had a significant effect on fossil bone length and shank length of 6 weeks aged chickens.

分析多态位点与0-12周龄鸡生长发育性状的关联性，结果表明：插入突变基因型中，2周龄鸡体重BB型与AB型差异显著(P.05)，但AA型与AB型和BB型差异均不显著，而突变各基因型间没有显著差异；插入突变位点对0-12周龄鸡的龙骨长、胫骨长均没有显著影响，而突变位点仅在鸡6周龄时表现出与龙骨长、胫骨长间的差异显著性。

Through the difference 显著性comparison, from Dan jade 6 to rich friend 1, along with the agechange, a change tends to more and more optimizes; Besides grainthick, during the ear of character change difference has all achievedthe extremely remarkable level; An ear of number of lines, hundredgrains heavy, the ear long, the ear thick and so on the main ear ofcharacter change difference is remarkable, and all approaches alongwith the age assumes the obvious trend of escalation.

通过差异显著性比较，从丹玉6号到富友1号，随着年代变化，株型的变化趋向于越来越优化；除了粒厚以外，穗部性状间的变化差异都达到了极显著水平；穗行数、百粒重、穗长、穗粗等主要穗部性状变化差异显著，并都随年代的靠近呈明显上升趋势。

The numerical results also show that the Boussinesq approximation will bring large error for big wall temperature difference.

计算结果也表明，在所计算的问题中，如果采用Boussinesq假设将使计算结果误差比较大。

One bases on function value and another bases on arithmetic average difference quotient. In this paper, the author mainly studies the approximation properties of both the function value and the derivative of two kinds of splines interpolation mentioned before, and the optimal error constants are obtained finally.

文中分别就这两类插值样条的函数值及一阶导数的逼近性质展开讨论，相应得出这两种插值函数在被插函数分别为一阶连续可导和二阶连续可导情况下的最佳误差常数。

Spectral element methods for partial differencial equation is introduced in this study from viewpoint of the collocation approximation of Chebyshev polynomial. Wave Equation and its space discretization are deduced. Two time integral methods, central difference method and implicit Newmark method, are introduced, and their stability and applicability are also discussed in some details. The significance of absorbing boundary conditions in spectral element methods for Aeroacoustics is explained, and Clayton-Engquist-Majda absorbing boundary conditions is emphasized and introduced, then the discrete scheme of this boundary conditions is deduced and applied to spectral element methods for wave equation.

本文从Chebyshev多项式逼近理论出发，详细介绍了谱元方法求解偏微分方程的过程；推导了流体中的声波动方程并在空间上对其进行了谱元离散；详细讨论了两种时间积分方法──中心差分法和Newmark方法，分析了它们的稳定性条件，并从理论上对比了两种方法的优缺点和适用范围；将吸收边界条件推广应用于谱元方法求解气动声学问题中，重点介绍了Clayton-Engquist-Majda吸收边界条件的原理和公式，推导了该吸收边界条件的变分形式，并将其引入波动方程的离散形式中。

Common Reflection Surface stack is a brand-new and special ZO imaging method, the theory of CRS stack stems from paraxial ray theory, the biggest difference between CRS stack and conventional ZO imaging method is that it consider a reflector R as a circular reflector segment Cr placed in the vinicity of reflector R, Cr can be seen as the second order approximation of the reflector. The CRS traveltime surface is the multi-coverage reflection response of the reflector mirror assigned to R.

共反射面元（CommonReflection Surface=CRS）叠加技术是一种全新的、特殊的零偏移距剖面成像方法，CRS迭加理论源于傍轴射线理论，它与普通的零偏移距剖面成像方法的最大区别是它认为地下反射层是由许多个小反射弧段互相叠合组成的，认为来自某反射点附近的一个邻域内的反射信息都可以对该反射点的成像作出贡献，因此对该反射点进行零偏移距成像时就应该聚焦更多的能量参与迭加。

In Chapter 2, starting from the basic fractional ordinary differential equations,weapply a high order approximation of fractional derivative advanced by Lubich to frac-tional differential equation, construct a high numerical difference scheme to solve thefractional differential equation, present error analysis of the algorithms theoretically,and prove the consistency ,convergency and stability.

接下来的第二章中，首先从基本的分数阶常微分方程出发，对Lubich提出的一个关于分数阶导数的高阶近似，将其应用于分数阶微分方程，构造高阶数值差分格式来进行分数阶微分方程的数值求解，并在理论上给出这一算法的误差分析，证明了它的相容性，收敛性和稳定性。

It is helpful for us to construct difference approximation schemes for HJ equation with aids of schemes for conservation laws.

众所周知，即使在初值条件0是充分光滑的情况下，一般来说，虽可以得到式(1 )的连续解，但其解的导数却是间断的。

Among used machine learning methods, the gradient descent method is widely used to train various classifiers, such as Back-propagation neural network and linear text classifier. However, the gradient descent method is easily trapped into a local minimum and slowly converges. Thus, this study presents a gradient forecasting search method based on prediction methods to enhance the performance of the gradient descent method in order to develop a more efficient and precise machine learning method for Web mining.However, a prediction method with few sample data items and precise forecasting ability is a key issue to the gradient forecasting search method. Applying statistic-based prediction methods to implement GFSM is unsuitable because they require a large number of data items to model a prediction model. In the contrast with statistic-based prediction methods, GM(1,1) grey prediction model does not need a large number of data items to build a prediction model, and it has low computational load. However, the original GM(1,1) grey prediction model uses a mathematical hypothesis and approximation to transform a continuous differential equation into a discrete difference equation in order to model a forecasting model.

其中梯度法是一个最常被使用来实现机器学习的方法之一，然而梯度法具有学习速度慢以及容易陷入局部最佳解的缺点，因此，本研究提出一个梯度预测搜寻法则(gradient forecasting search method， GFSM)来改善传统梯度法的缺点，用来提升一些以梯度学习法则为基础的分类器在资讯探勘上的效率与正确性；而一个所需资料量少、计算复杂度低且精确的预测模型是梯度预测搜寻法能否有效进行最佳解搜寻之关键因素，传统统计为基础之预测方法的缺点是需要较大量的数据进行预测，因此计算复杂度高，灰色预测模型具有建模资料少且计算复杂度低等优点，然而灰色预测理论以连续之微分方程式为基础，并且透过一些数学上的假设与近似，将连续之微分方程式转换成离散之差分方程式来对离散型资料进行建模及预测，这样的作法不尽合理，且缺乏数学理论上的完备性，因为在转换过程中已经造成建模上的误差，且建模过程仅考虑相邻的两个资料点关系，无法正确反应数列未来的变化趋势。

We were cousins—his grandfather was King of Scots,and his great-grandfather was Henry VII of England.

我们是堂姐弟——他的祖父曾是苏格兰国王，他的曾祖父是英格兰的亨利二世。

I do want to help you, but I am in a quandary now!

我是想帮你，但是我现在左右为难啊！