求值

Given that c is the positive root of the equation , c

已知 c 是方程式=之正根，求 c 的值。

The main work can be summed up as follows: Firstly, we studied the thermal-field properties of VCSELs, and analyzed the influences of current spreading, material parameters and operating conditions on the temperature distributions. Secondly, we began with the electrode voltage and calculated the equipotential s distributions, compared the distributions of voltages and current densities in different depths of VCSELs, and then studied the influences of the oxide-confining region with different position or thickness, and the different sizes of the gain-guided aperture and emitting window on the distributions of the injected current density, carrier concentration and temperature in the active region. Thirdly, we realized the coupling of electricity, optical and thermal-fields, worked out the threshold voltage, calculated the distributions of the injected current density, carrier concentration and temperature under different offset voltages, and analyzed the impacts of temperature profile and carrier density on the refractive index, Fermi levels and optical-field. Finally, we gave the equipotential line distributions with considering N-DBR and double oxidized-confining regions, and analyzed theinfluences of N-DBR and double oxide-confining regions on the distributions of the current density, carrier concentration, temperature and optical-field.

具体工作可以概括如下：首先，研究了VCSEL的热场特性，分析了电流扩展，材料参数和工作条件对于温度分布的影响；其次，从电极电压入手，计算出激光器中的等势线分布，并对不同深度处的电压和电流分布进行比较，研究了高阻区的不同位置和不同厚度、限制层和出射窗口半径的大小对电流密度、载流子浓度和温度分布的影响；再次，实现了电、光、热耦合，求出了阈值电压，计算了不同偏置电压下的电流密度分布、载流子浓度分布和热场分布，分析了温度和载流子浓度变化对折射率、费米能级和光场的影响；最后，给出了考虑N-DBR和双氧化限制层时激光器中的等势线分布，分析了N-DBR和双氧化限制层对VCSEL电流密度、载流子浓度、温度和光场分布的影响。

To solve this problem,the equivalence relation of rough set theory is replaced by an asymmetrical similar relation,and from this relation,an asymmetrical similar matrix is defined,then a new heuristic algorithm with less space complexity that require core and knowledge reduction based on asymmetrical similar matrix is proposed,and an example is given to confirm the validity of the algorithm.

用非对称相似关系代替粗糙集理论中的等价关系，定义了非对称相似差别矩阵，提出了基于非对称相似差别矩阵的高效求核和知识约简算法。该算法无需改变初始不完备信息系统的结构，能直接处理缺省数据。实验结果表明，新算法所获得的决策规则简洁、高效，与缺省值无关。

Find the equivalent capacitance of the capacitors system.

求出电容器串联和并联时的等效电容值：。

The main contents of this course include: introduction, extraction of root from an equation, numerical solution of a system of linear equations, interpolation method, the method of fitting of a curve, numerical integration and differentiation, numerical solution of a differential equation, one-dimensional search method of extreme value problem, etc.

本课程包括以下内容：绪论、方程求根、线性方程组数值解法、插值法、曲线拟合法、数值积分与数值微分、微分方程数值解法、极值问题的一维搜索法。

Then the coefficients of entrance region effect and the relations between them, and the flowbehaviour index n can be obtained by solving the energy integral equation. Under the assumption of the velocity distribution within boundary layer: f = 1-(1-η)n+1/n for example, co...

以边界层内幂律流体层流速度分布假设f=(1一η)~(n+1/n为特例，所求出的结果与文献[4]中的理论值和实验值比较表明，本文的计算是既简便又可靠的。

Total inductance is split into two unsymmetrical parts with filter capacitor insertion.

提出了一种LCL型滤波器的新型设计方法，利用电流的纹波限制，求出了滤波器的总电感值。

This study first analyzes boundary condition of single column member and adopts relative joint bending stiffness ratio of AISC to find the effective length factor. For that a structural joint or connection is neither full rigid nor full hinge in practice, this study uses this concept to establish the semi-rigid joint model. This study then discusses the structural behaviors of tapered members results with those from and compares these previous studies.

本文先对於单一柱构件之边界条件进行分析，采用AISC规范求取有效长度系数之G值控制梁柱相对劲度，同时考虑一般实务上结构接合并非完全刚性或完全铰接，模拟介於两者间之半刚性接合，藉由模拟结果进一步探讨非均匀构架之结构行为，并与前人之研究相关成果比较。

The Mach number in the outlet of the choke is calculated,and the flowage can be decided.

计算出口处的马赫数的值，判别节流嘴内的流态，进而逆向求节流嘴上游的各参数。

The paper induces the contents and methods of investigating passengers" data, researches passenger countering on footplate based on acceleration, dealings with the data by "move" with time and eliminates the variances of adjacent data by cubic spline interpolation, then obtains the passengers" arrival rate, get off rate and throughput in the whole period by programming, which gives pursuant to dispatching.

论文研究了公交数据的调查内容和方法，并探讨了基于压力变化率的踏板式乘客计数器的设计原理；对客流数据按时间进行"平移"处理，再用三次样条插值法来消除相邻统计时段之间的差异，并编程求出整个时间段内光滑的乘客到达率、下车率以及断面通过率，作为公交调度的依据。

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。