The existence theorems of positive solutions for threepoint boundary value problems at rersonance for a kind of nonlinear second-order differential equation are obtained.
利用A-proper半线性算子不动点指标理论，我们研究了多点共振边值问题正解的存在性，得到了一类二阶非线性微分方程三点共振边值问题正解存在性定理。
Second, based on the spherical vector wave function in uniaxial anisotropic medium, and the first, second, third and fourth spherical Bessel functions satisfy the same differential equation and recursive formula. The scattering fields in terms of spherical vector wave function from a uniaxial anisotropic spherical shell and an anisotropic uniaxial-coated conducting sphere by a plane wave are derived. The electromagnetic fields in uniaxial anisotropic medium and free space can be expressed in terms of spherical vector wave functions in uniaxial anisotropic media and isotropic medium.
二、在建立均匀各向异性单轴介质球矢量波函数理论的基础上，利用二阶线性偏微分方程的性质和第一、第二、第三和第四类球Bessel函数满足相同的微分方程和递推关系，我们分别研究了单轴介质球壳和单轴介质涂覆导体球对平面波的电磁散射特性，首先给出了各个区域的电磁场用球矢量波函数来表示的解析表达式，进而利用电磁场在边界上满足电磁场切向连续的边界条件和球谐函数的正交性，得出了各向异性单轴介质球结构中电磁场用球矢量波函数表示的系数所满足的矩阵方程。
Congenital microcolon is second symptom with intestinal obstruction. X-ray plays an important role in diagnosis and differential diagnosis of the primary disease with congenital microcolon.
细小结肠症是肠梗阻后的继发征象，X线检查对其原发疾病诊断和鉴别诊断有重要价值。
Measuring precision of pulse wave velocity relies on the extraction of reference point of pulse wave velocity to a great extent, we use the first time the peak point of second-differential as the reference point of pulse wave velocity to have improved measuring precision.
脉搏波波速的测量精度在很大程度上取决于波速参考点的提取，首次采用二次差分峰值点作为波速参考点，提高了测量精度。
Real estate and second-hand housing prices were declining trend Link differences Road from the south and along the central axis of the housing and second-hand housing prices in contrast can be seen within the second ring, both the gap in per square meter more than 1, 000 yuan, Temple of Heaven region reached 1, 900 yuan high; while in the South Second Ring with tricyclic and second-hand housing between the housing price differential maintained at between 600-700 million; the South Fourth Ring surrounding the price gap between the rich that only 400 yuan about.
房地产和二手房价格下降的趋势链接分歧道从南方和沿中轴线为中心的住房和二手房的价格对比可以看出二环内，双方的差距更达到每平方米超过1000元，天坛地区达成一九〇〇元高，而在南二环与三环和二手房之间的住房价格差保持在600-700亿美元之间；南四环周边的价格差距，贫富之间的差距只有400元左右。
In Chapter 2, a steady permeability identification problem in elliptic equa-tions for two-dimensional orthotropic medium is considered. We construct afunctional, obtain its first and second Gateaux differential, and prove that thefunctional is strictly convex on a convex admissible function set. We seek to iden-tify the permeability by minimization of the above functional.
第二章研究了二维稳态正交异性介质的渗透率反演问题，我们构造了一个泛函，求得该泛函的一、二阶Gateaux微分，证明了它在一个凸的容许集上的严格凸性，并使用极小化泛函即变分方法来求解此问题。
Studies on quantitative determination of active principles in Chinese herbal medicine by second derivative differential pulse polarography.
二阶导数差示脉冲极谱法的建立及在药物分析中的应用。药学学报，1992，27(2)：157。[4] 梁云爱，李见春，门孝英。环磷酰胺及其制剂的二阶导数差示脉冲极谱法定量研究。
Compared with second-harmonic restraining method, this algorithm can avoid the problem of delaying action of differential relays.
该识别法与二次谐波制动原理相比，不会出现某些内部故障情况下由于二次谐波大可能造成差动保护延时动作的问题。
To the pump motor differential protection circuit in the differential current transformer load only the second cable of different length, a difference of about 50 m, and rated current, the differential relay of the power consumption is not more than 3 va, the second load not heavy.
在给水泵电机差动保护回路中的电流互感器负荷差别只是二次电缆长度的不同，大约相差50 m，并且在额定电流下，差动继电器的功率消耗不大于3 va，二次负载并不重。
The adaptive second harmonic restrained method was suggested if the winding differential protection scheme was used while the CT was mounted on the inner side of △ winding.
GE公司的工程师首先提出了利用涌流中二次谐波幅值与相位的特征自适应二次谐波制动方案，并在其开发的T60差动保护装置中得到了实现。
In the second part, we discuss the existence of solutions of differential equations, the uniqueness of solutions and multiple solutions.
第二部分讨论了微分方程解的存在性问题，同时涉及到解的唯一性及多解性问题。
A new adaptive second mutation differential evolution algorithm based on the variance of the population's fitness is presented.
提出一种基于群体适应度方差自适应二次变异的差分进化算法。
The main protections apply the ratio differential relay of the second-harmonic restraint principle with the judgment method of magnetizing inrush and CT disconnects judgment method.
在本设计中，主保护采用了附有励磁涌流和CT断线判断功能的二次谐波制动的比例差动保护方案。
This article use the improved integral inequalities with the deviate variable and some skills of inequalities as well as related knowledge about second-order differential equation, to obtain the following results: the classification of limit point case or limit circle case and boundedness for second order differential or difference equation with deviative variable, discussed the classification for certain n-order differential equations, Criteria for the classification of second order differential equation with deviative variable.
本文利用推广的具有偏差变元的积分不等式，结合不等式的一些技巧以及常微分方程的相关知识对一类二阶具有偏差变元的微分方程及一类二阶差分方程极限圆型的分类问题作了相关的研究工作，并且讨论了一类n阶具有偏差变元的常微分方程解的平方可积性与有界性和一类二阶非线性具有偏差变元的微分方程解的有界性。
The inflexion is the second differential of the speed curve and the physical meaning is the same to the jerk, so the jerk is introduced into the control model of anti-skid system.
拐点是制动曲线的三阶导数，它的物理意义和冲动不谋而合，这也是本文在防滑器控制模型中引入冲动物理量的原因之一。
We prove that the BDF methods of first and second order and the trapezoidal rule are τ(0)-stable when they are applied to the delay differential equations of the form y'(t =ay +by (t-1), t≥0, y =g, -1≤t≤0, with a, b∈R.
证明了关于延迟微分方程y'=ay+by(t-1)，t≥0，y=g，-1≤t≤0，其中a，b∈R，一阶及二阶BDF方法和梯形方法是τ（0）-稳定的。
In the second part of Chapter 5, the supremum of real parts of characteristic roots for a nonsingular neutral degenerate retarded functional differential equation is studied.
第五章的第一部分讨论了非奇异中立型时滞方程的指数稳定性，所得的指数稳定的判定定理不同于文中的定理2。
With differential geometry knowledge, the local characters of the blade surface are analyzed. Based on researching the cylindrical cutters osculating location, the methods to calculate the osculating location of the conic cutter and the torus cutter are discussed. A method of tool path planning based on the second order osculating method is preferred.
利用微分几何学知识，分析了螺旋桨桨叶曲面的局部特征，在研究圆柱刀二阶密切法规划刀位的基础上，探讨了圆锥刀和圆环刀的二阶密切刀位计算方法，采用二阶密切法规划刀位可以显著地提高加工精度。
According to structure and heating mechanism of permanent magnet synchronous motor, a simplified thermal model of second order differential equation and its scheme and strategy of thermal protection based on motor servo system hade been presented.
0引言目前，电机的热保护大多是根据绕组电流与时间的反时限特性曲线设计的。
The Periscope Drawtube will be bent because of the water resistance in sailing and this bend will cause the error of star measurement. Due to its especial structure, contactless measurement is the only way to measure its bend degree. First this paper introduces the method by linear array CCD based on structure and light path; Second it expatiates linear array CCD work principle and driving scheduling with example of TCD1501C and the driving circuit by CPLD. The output signal of linear array CCD includes common disturbance so the differential amplifier is needed. In order to make the signal adapt to computer processing, a threshold circuit with Schmitt characteristic and the data process following threshold are given. At last, some key problems in application are given.
潜艇潜望镜的镜筒在航行时受到水的阻力会产生弯曲变形，这种变形会造成潜艇对星体测量的误差；由于镜筒结构的特殊性，对其弯曲程度的测量只能采用非接触方法；首先从结构和光路方面介绍采用线阵CCD作为检测元件实现对镜筒弯曲程度的测量；其次以东芝公司的线阵CCD（TCD1501C）为例阐述了其工作原理及驱动时序的控制要点，并介绍了基于可编程逻辑器件的线阵CCD的驱动电路；线阵CCD输出的信号中含有共模干扰，必须采用差分放大器将其抑制；为将信号转化为适合计算机处理的数字信号，文中给出了有一定实用价值具有施密特特性的二值化处理电路及二值化后的数据处理过程；最后阐述了在实际使用中的一些关键问题。