查询词典 simultaneous differential equations

The structural form of the model consists of 66 simultaneous equations, including 28 stochastic equations and 38 definitional equations and identities.

模型的结构型由66个方程联立组成，其中随机方程28个，恒等式和定义式38个。

The sums may be from any one or combination of the following topics: pre-algebra, algebraic expressions, algebraic expansion (multiplication of binomials and trinomials), algebraic factors, simple equations,simultaneous equations and quadratic equations.

数学试题可能来自于下列主题之一或者其组合：学龄前数学，数学表达式，代数表达式，代数因数，简单等式，联立方程式和二次方程式。

In this dissertation, the best simultaneous approximation with weight to infinite sequence from simultaneous-suns in complex normed linear space is considered, and in the case when the weight satisfies a certain condition, the characterizations of approximation from a simultaneous-sun and uniqueness of approximation from a RS-set are obtained; moreover, in the case when the weight is free, the characterizations of approximation to a totally bounded sequence from a convex set are established.

本文在复赋范空间中研究了同时太阳集对无限序列的加权同时逼近问题，在权满足一定条件时，通过把所研究问题转化为连续向量值函数空间中相应集对一个上半连续函数的最佳逼近问题，得到了逼近的特征和RS集逼近的唯一性定理，有例表明它们是已有结果的本质推广；在权不受限制时，得到了凸集对全有界序列逼近的特征。

A simultaneous dual-wavelength continuous wave, quasi-cw or linearly polarized wave diode-end-pumped Nd:YAG laser operating at 1319nm and 1338nm is demonstrated. To the best of our knowledge, our experimental results achieve the highest level in the domestic domain. The simultaneous dual-wavelength laser provides an experimental basis for generating highly coherent THz wave radiation of 3.23THz by nonlinear optical difference frequency method.2. A diode-end-pumped Nd:YAG crystal, type-I critical phase matching LBO crystal intra-cavity frequency doubled, simultaneous multi-wavelength red laser at 659.5nm, 664nm and 669nm is firstly realized.

本论文主要围绕用于差频产生THz辐射源的多波长激光器及THz光子晶体的带隙特性分析而展开，论文的主要内容包括：一、从LD端面泵浦固体激光器的激光阈值公式出发，理论计算了腔镜对于两个波长的透过率关系，实现了LD端面泵浦Nd：YAG 1319nm/1338nm双波长激光连续、准连续及线偏振稳定输出。

The effects and mechanism of GABAergic neurons, NOergic neurons, opioid peptide and cyclic adenosine monophosphate in the nucleus reticularis thalami on sleep-wakefulness cycle of rats and the effects and mechanism of the 5-HTergic nerve fibers project from the nucleus raphes dorsalis to RT on sleep-wakefulness cycle of rats were investigated with the methods of brain stereotaxic, nucleus spile, microinjection and polysomngraphy.1. The effects of GABAergic neurons in RT on sleep-wakefulness cycle of rats1.1 Microinjection of 3-mercaptopropionic acid (3-MP, a kind of glutamate decarboxylase inhibitor) into RT. On the day of microinjection, sleep only decreased a litter. On the second day, sleep marked decreased and wakefulness marked increased. On the third and fourth day, sleep and wakefulness stages resumed to normal.1.2 Microinjection of gamma-amino butyric acid (GABA 1.0μg) into RT enhanced sleep and reduced wakefulness compared with control; while microinjection of L-glutamate (L-Glu, 0.2μg) decreased sleep and increased wakefulness; microinjection of bicuculline (BIC, 1.0μg), a GABAA receptor antagonist, enhanced wakefulness and reduced sleep; microinjection of baclofen (BAC, 1.0μg), GABAB receptor agonist, had the same effects as GABA.2. The effects of NOergic neurons in RT on sleep-wakefulness cycle of rats2.1 Microinjection of L-arginine (L-Arg, 0.5μg) into RT decreased sleep compared with control, but there were on statistaical difference between L-Arg group and control; while microinjection of sodium nitroprusside (SNP, 0.2μg), a NO donor into RT, sleep marked decreased and wakefulness marked increased. Microinjection of nitric oxide synthase inhibitor, N-nitro-L-arginine (L-NNA, 2.0μg) into RT enhanced sleep and reduced wakefulness.2.2 After simultaneous microinjection of L-NNA (2.0μg) and SNP (0.2μg) into RT, SNP abolished the sleep-promoting effect of L-NNA compared with L-NNA group; after simultaneous microinjection of L-NNA (2.0μg) and L-Arg(0.5μg) into RT, we found that L-NNA could not blocked the wakefulness-promoting effect of L-Arg.3. The effects of opioid peptide in RT on sleep-wakefulness cycle of rats3.1 Microinjection of morphine sulfate (MOR, 1.0μg) into RT increased wakefulness and decreased sleep compared with control; while microinjection of naloxone hydrochloride (NAL, 1.0μg), the antagonist of opiate receptors, into RT, enhanced sleep and reduced wakefulness.3.2 After simultaneous microinjection of MOR (1.0μg) and NAL (1.0μg) into RT, the wakefulness-promoting effect of MOR and the sleep-promoting effect of NAL were not observed compared with control.4. The effects of cAMP in RT on sleep-wakefulness cycle of rats Microinjection of cAMP (1.0μg) into RT increased sleep and decreased wakefulness compared with control; microinjection of methylene blue (MB,1.0μg) into RT enhanced sleep and reduced wakefulness compared with control.5. The effects of the 5-HTergic nerve fibers project from DRN to RT on sleep-wakefulness cycle of rats5.1 When L-Glu (0.2μg) was microinjected into DRN and normal sodium (NS,1.0μg) was microinjected into bilateral RT. We found that sleep was decreased and wakefulness was increased compared with control; when L-Glu (0.2μg) was microinjected into DRN and methysergide (MS,1.0μg), a non-selective 5-HT antagonist, was microinjected into bilateral RT, We found that sleep was enhanced and wakefulness was reduced compared with L-Glu group.5.2 When p-chlorophenylalanine (PCPA, 10μg) was microinjected into DRN and NS (1.0μg) was microinjected into bilateral RT, We found that sleep was increased and wakefulness was decreased compared with control; microinjection of 5-hydroxytryptaphan (5-HTP, 1.0μg), which can convert to 5-HT by the enzyme tryptophane hydroxylase and enhance 5-HT into bilateral RT, could block the effect of microinjection of PCPA into DRN on sleep-wakefulness cycle.

本研究采用脑立体定位、核团插管、微量注射、多导睡眠描记等方法，研究丘脑网状核(nucleus reticularis thalami，RT)中γ-氨基丁酸(gamma-amino butyric acid ，GABA)能神经元、一氧化氮(nitrogen monoxidum，NO)能神经元、阿片肽类神经递质、环一磷酸腺苷(cyclic adenosine monophosphate，cAMP)及中缝背核(nucleus raphes dorsalis，DRN)至RT的5-羟色胺(5-hydroxytryptamine，5-HT)能神经纤维投射对大鼠睡眠-觉醒周期的影响及其作用机制。1 RT内GABA能神经元对大鼠睡眠-觉醒周期的影响1.1大鼠RT内微量注射GABA合成关键酶抑制剂3-巯基丙酸(3-MP，5μg)，注射当天睡眠时间略有减少，第二日睡眠时间显著减少，觉醒时间明显增多，第三、四日睡眠和觉醒时间逐渐恢复至正常。1.2大鼠RT内微量注射GABA受体激动剂GABA( 1.0μg)后，与生理盐水组比较，睡眠时间增加，觉醒时间减少；而RT内微量注射L-谷氨酸(glutamic acid， L-Glu， 0.2μg)后，睡眠时间减少，觉醒时间增加；RT内微量注射GABAA受体阻断剂荷包牡丹碱(bicuculline，BIC，1.0μg)后，睡眠时间减少，觉醒时间增加；RT内微量注射GABAB受体激动剂氯苯氨丁酸(baclofen，BAC，1.0μg)后，产生了与GABA相似的促睡眠效果。2 RT内NO能神经元对大鼠睡眠-觉醒周期的影响2.1大鼠RT内微量注射NO的前体L-精氨酸(L-Arg，0.5μg)后，与生理盐水组对比，睡眠时间略有减少，但无显著性意义；而RT内微量注射NO的供体硝普钠(Sodium Nitroprusside，SNP，0.2μg)后可明显增加觉醒时间，缩短睡眠时间；微量注射一氧化氮合酶抑制剂L-硝基精氨酸(L-arginine，L-NNA，2.0μg)后，引起睡眠时间增多，觉醒时间减少。2.2大鼠RT内同时微量注射L-NNA(2.0μg)和SNP(0.2μg)后与L-NNA组比较发现SNP逆转了L-NNA的促睡眠作用；RT内同时微量注射L-NNA(2.0μg)和L-Arg(0.5μg)后，与L-NNA(2.0μg)组比较发现L-Arg可以增加觉醒而缩短睡眠，其促觉醒作用未能被NOS的抑制剂L-NNA所逆转。3 RT内阿片肽对大鼠睡眠-觉醒周期的影响3.1大鼠RT内微量注射硫酸吗啡(morphine sulfate，MOR，1.0μg)后与生理盐水组对比，睡眠时间减少而觉醒时间增加； RT内微量注射阿片肽受体拮抗剂盐酸纳洛酮(naloxone hydrochloride，NAL，1.0μg)后与生理盐水组比较，睡眠时间增加而觉醒时间减少。3.2大鼠RT内同时微量注射MOR(1.0μg)和NAL(1.0μg)后，与生理盐水组对比，原有的MOR促觉醒效果和NAL的促睡眠效果都没有表现。4 RT内环一磷酸腺苷信使对大鼠睡眠-觉醒周期的影响大鼠RT内微量注射cAMP(1.0μg)后与NS(1.0μg)组比较，睡眠时间增多而觉醒时间减少；RT内微量注射亚甲蓝(methylene blue，MB，1.0μg)后，与NS组比较，睡眠时间增多而觉醒时间减少。5中缝背核投射到丘脑网状核的5-羟色胺能神经纤维对大鼠睡眠-觉醒周期的影响5.1大鼠DRN内微量注射L-Glu(0.2μg)，同时在双侧RT内微量注射NS (1.0μg)后，与对照组(DRN和双侧RT注射NS， 0.2μg)比较，睡眠时间减少，觉醒时间增多；大鼠DRN内微量注射L-Glu(0.2μg)，同时在双侧RT内微量注射二甲基麦角新碱(methysergide， MS， 1.0μg )后，与对照组(DRN注射L-Glu 0.2μg，双侧RT注射NS 1.0μg)比较，睡眠时间增多，觉醒时间减少。5.2大鼠DRN内微量注射对氯苯丙氨酸(p-chlorophenylalanine，PCPA，10μg)，同时在双侧RT内微量注射NS (1.0μg)后，与对照组(DRN和双侧RT注射NS， 1.0μg)比较，睡眠时间增多，觉醒时间减少；大鼠DRN内微量注射PCPA(10μg)，产生睡眠增多效应后，在双侧RT内微量注射5-羟色胺酸(5-hydroxytryptaphan ， 5-HTP， 1.0μg )后，与对照组(DRN注射PCPA 10μg，双侧RT注射NS 1.0μg)比较，睡眠时间减少，觉醒时间增多。

In the secondary modeling,"Hidden Euler" approach is applied to solve the nonlinear simultaneous differential equations, and the discrete nonlinear algebraic equations are calculated by "Newton-Raphson" numerical approach.

二次建模时，采用隐式欧拉法求解常微分方程组，离散后形成的非线性代数方程组采用牛顿-辛普生方法进行计算。

Three displacement functions w,Gand ψare introduced in this paper tosimplify motion equations of elasticity problenis in spherically isotropic media to an indepen-dent partial differential equation concerning one displacement function ψand simultaneous equations concerning two other displacement functions w and G.

本文引入三个位移函数，将球面各向同性弹性力学运动方程，简化为关于ψ的二阶偏微分方程，和关于W和G的联立方程。在静力学问题中，联立方程可进一步简化，w和G可用另一位移函数F表示，而F满足一个四阶偏微分方程。

Secondly, by applying inverse Fourier integral transform to the displacement, and uniting the constitutive and geometrical equations, the analytical expression of stress in Laplace domain were derived. Thirdly, by defining dislocation density functions, the Cauchy singular integral equations were obtained according to the boundary condition and interface connection conditions, and the problem was reduced to algebraic equations by Chebyshev orthogonal polynomial. Based the these, the unknown coefficient of the algebraic equations can be solved by Schmidt method. Finally, the time response of dynamic stress intensity factor and energy release rate are obtained by inverse Laplace transform.

首先，利用积分变换方法，推导出粘弹性层的控制方程组；其次，引入位错密度函数，并结合边界条件和界面连接条件，导出反映裂纹尖端奇异性的Cauchy型奇异积分方程组，然后，应用Chebyshev正交多项式化奇异积分方程组为代数方程组，并采用Schmidt方法对其数值求解，最后，经过Laplace逆变换，求得动态应力强度因子和能量释放率的时间响应。

It is proved that the two-dimensional non-hydrostatic Boussinesq equations on the x ? z plane with the kinetic viscous term and the thermal dissipative term are unstable equations in the C 2 function class.2. If we replace the influence of the kinetic viscous term by Rayleigh friction and the thermal dissipative term by Newton cooling, the new generalized equations are stable equations in the C 1 function class. The construction of the solution space and the discriminating method for well-posedness of the problem of determining solution are given.

本文的主要结果如下：1证明了在y方向上均匀的带有运动粘性项以及热耗散项的两维非静力、Boussinesq近似的x-z面上两维旋转流体的控制方程组在C 2函数类中是一个不稳定的方程组。2如果以瑞利摩擦来代替粘性的影响，以牛顿冷却来代替热量的耗散，则所获得的一个新的方程组在C 1函数类中是一个稳定的方程组，给出了其解空间的构造和各种定解问题的适定性的判别方法。

As a result,the tooth profile equations, helix angle equations,limit curve equations and induced normal curvature equations for worm and internal gear are obtained.

介绍了一种新型的传动机构超环面行星蜗杆传动，运用啮合理论的包络法建立了这种传动中行星轮与蜗杆、行星轮与内齿轮啮合的基本方程，进而得到了蜗杆和内齿轮的齿面方程、螺旋升角方程、界限曲线方程及诱导法曲率方程等。

Aquatic or marsh-growing fern allies; known to have existed since the Cenozoic; sometimes included in Lycopodiales.

生活于水中或湿地的蕨类；从新生代生存至今；有时归于石松目之中。

The engine was uprated from a 90hp Franklin to a 125hp Lycoming.

改良过的引擎是从90hp到125hp莱康明富兰克林。