下模

We applied the method based on certain energy estimates to prove the convergence and stability of the scheme in energy norm and maximum norm.

我们利用能量分析法证明了C-N格式在能量模和最大模意义下的收敛性和稳定性；通过矩阵分析和对广义特征值的估计得到离散L_2模意义下的收敛性和稳定性。

Furthermore, it is shown that every pure projective left R-module is closed under pure submodule if and only if every pure injective left R-module is closed under pure epimorphic image.

最后，作为应用，证明了每一纯投射左R-模在纯子模下封闭当且仅当每一纯内射左R-模在纯满像下封闭。

The modal tests of PCB and PCB assembly (free boundary condition and fixed boundary condition) were carried out. The equivalent elastic modulus and damping parameters of PCB can be gained, and the fixed boundary condition of finite element model was also determined. These will help to the following work.Second, drop impact tests of three different heights were carried out. Strains and acceleration responses of PCB were measured. Failed BGA packages of different test conditions were dyeing, and cross section analysis of failed solder joints was conducted.

针对JEDEC标准试件的局限性，提出了设计便于统计学研究焊点可靠性的试验试件的构想，利用有限元模态分析方法确定并验证了用圆形PCB组件替代JEDEC标准试件的可行性；通过一系列模态试验和有限元模态分析，确定了圆形PCB组件的相关试验参数，这不仅为跌落碰撞下PCB组件有限元模拟确定了较为合理准确的有限元模型，而且为正确地评价跌落碰撞下PCB组件的可靠性问题奠定了基础。2。

The modal tests of PCB and PCB assembly (free boundary condition and fixed boundary condition) were carried out. The equivalent elastic modulus and damping parameters of PCB can be gained, and the fixed boundary condition of finite element model was also determined. These will help to the following work. Second, drop impact tests of three different heights were carried out. Strains and acceleration responses of PCB were measured. Failed BGA packages of different test conditions were dyeing, and cross section analysis of failed solder joints was conducted. It was found in our drop tests that the root cause of lead-free solder joints under drop impact was the combined effect of mechanical shock and PCB bending vibration.

针对JEDEC标准试件的局限性，提出了设计便于统计学研究焊点可靠性的试验试件的构想，利用有限元模态分析方法确定并验证了用圆形PCB组件替代JEDEC标准试件的可行性；通过一系列模态试验和有限元模态分析，确定了圆形PCB组件的相关试验参数，这不仅为跌落碰撞下PCB组件有限元模拟确定了较为合理准确的有限元模型，而且为正确地评价跌落碰撞下PCB组件的可靠性问题奠定了基础。

The results indicate that its dynamic stress-strain curve is hyperbolic type. The dynamic strain of LCES decreases with increasing confining pressure, cement content, curing ages and cyclic loading frequency when it is subjected to the same dynamic stress. At the same dynamic strain, the dynamic secant elastic modulus E_(sec of LCES increases and the damping ratio decreases with increasing confining pressure, cement content, curing ages and cyclic loading frequency. The curves ofσ_d～ε_d,E_～ε_d and D～ε_d with different EPS content intersect respectively, the trend of LCES deformation characteristic is inversely proportional to EPS content near the intersection. The value of dynamic strain at the intersection is about 0.5%~3.0%, the magnitude of which is related to the mixing proportions and confining pressure.

试验结果表明，LCES的动应力应变骨干曲线形态符合双曲线；在相同的动应力作用下，LCES产生的动应变随着固结压力、水泥掺量、试样养护龄期和振动频率的增大而减小；在动应变相同的情况下，随着固结压力、水泥掺量、试样养护龄期和振动频率的增大，LCES的动模量增大而阻尼比减小；随着加载次数的增大，LCES的动模量在开始阶段显著降低，然后趋于稳定，但当加载次数达到几百次时，动模量又有增大的趋势；不同EPS掺入比的LCES的动应力应变骨干曲线、动模量随应变变化曲线和阻尼比随应变变化曲线都发生了相交，交点前后EPS掺入比的大小对LCES动力变形特性的影响趋势是截然相反的，交点处的动应变值一般在0.5％～3.0％范围内变化，其大小与LCES的配比以及固结压力有关。

Knowing current talented person, our person follow realizes own biggest ideal with promote principle that we combine together, make everybody very much our development be space, environment that own great ideal that leading, but the feedback is a reasonable spirit feature to talented person with our economic performance, providing to each where there is a will development with term, here the way descend our spirit feature with the exaltation that economic performance got the continuous changes and improvements.

对于现有人才，烟汽模人遵循实现自己的最大理想与发扬光大烟汽模相结合的原则，使每个人都认识到烟汽模的发展就是自己的伟大理想，而反馈给人才的是合理的精神面貌和烟汽模的经济效益，提供给每个有志者发展的空间、环境和条件，在此方针的指导下烟汽模人的精神面貌和经济效益得到了日新月异的提高。

Operating modal analysis is a new technology of modal analysis. The operating modal parameters obtained only by responses of operating machinery or ambient excitation accord with the real operating situations and the boundary conditions, and illustrate the real dynamic behavior of the operating machine.

工作模态分析方法是一种新的模态分析技术，利用工作状态或环境激励下的响应信号识别出的工作模态参数符合实际工况及边界条件，能真实的反映结构在工作状态下的动力学特性。

In the part of the vibration experiments and analysis, firstly, used the simple-beam theory to estimate the natural frequency of the beam of the 20-headed computerized embroidery machine.secondly, measured the beam of its low rank natural frequency, the beams horizontal vibrating acceleration amplitude, speed amplitude and the displacement amplitude in different rev and different turn parts. Found that it is sympathetic vibration, which bring on the thread-broken rate rise rapidly. On this base, established the finite element analysis modle of the vibrating beam, and took on hamonic analysis and modal analysis with the mold. The rusult of test and analysis offer the basis for farther improvement of the computerized embroidery machine.

振动分析部分，首先由简单梁理论出发，对横梁的固有频率进行估算；接着通过测振仪器对20头电脑刺绣机横梁进行了试验模态分析和不同工况振动测试；获得了横梁前四阶固有频率和模态振型，以及在不同工作转速、不同回转部件下横梁振动的加速度幅值、速度幅值和位移幅值；找到了横梁振动加剧的原因——共振；在此基础上建立了符合实际情况的横梁有限元模型，对模型进行了模态和谐响应计算，证实了模型的可靠性，为下一步的改进设计提供了依据。

First, this paper presents three girders model with double cable planes which main girder and side girder is connected by rigid arms, analyzes the dynamic characteristic of Yonghe cable-stayed bridge and obtains its natural vibration modes (i.e., frequency, damping values and the mode shapes ) by ANLSIS structural analysis program and uses these parameters as dynamic dactylogram of the intact case of cable-stayed bridge. Using the passage of random as the ambient vibration ,the dynamic properties of Yonghe Bridge is measured and the modal parameter of its 15 years after is identified and used as dynamic dactylogram of the damaged case. By the finite element analysis and locale vibration test, damaged and undamaged modal parameter is analyzed and curvature mode shape, which is sensitive to damage state, is introduced as possible candidate for identifying and locating damage in the cable-stayed bridge. Selecting the branch of part measured point from modal parameter, this paper deduces the damaged index which can detect the possible damaged location of the cable-stayed bridge deck and identifies the damaged region and degree for Yonghe Bridge. For the purpose of structural condition monitoring in in-situ , from another viewpoint, this paper introduces the method called the best optimization vector to detect damaged location and degree. The accuracy and reliability of the method presented in this paper are demonstrated by static analysis and test and the healthy state of Yonghe Bridge can be evaluated.

建立了双索面通过刚臂与主梁及边梁相连的三梁式力学模型，采用ANSYS结构分析程序对永和斜拉桥进行动力分析，对其振动模态参数进行识别，以此作为斜拉桥完好状态下的动力&指纹&；采用自由交通流作为环境振源，对永和斜拉桥动力特性进行测试，识别出永和斜拉桥使用15年后的模态参数，确立了破损状态下的动力&指纹&；利用有限元分析、现场振动测试，对破损前后的模态参数进行分析，提取对破损状况较敏感的模态曲率作为斜拉桥破损诊断的参数；并从模态参数中选取部分点的分量，导出可以指示斜拉桥桥面大概损伤位置的Index损伤指标，识别出斜拉桥发生破损的区段及破损程度；考虑大型斜拉桥在线监测要求识别破损的具体位置，从另一角度提出采用最优矢量法具体确定破损发生的位置及程度；为验证本文研究成果，对永和斜拉桥进行静力分析及静力测试，对其健康状况提出可靠的评价。

Was founded in 1999, its predecessor, Universal Mold Factory Cixi are experienced 8 years of arduous pioneering, in 2007, renamed as Cixi Ci Yu Motor Parts Factory, the company in the united struggle of all the employees, in the vast numbers of customers still do not transfer the trust and support, Tsz Yuk motor has been rapid and steady development, has successfully developed a red double-rotor slot mode, blanking duplex mode, the entire complex mode rotor, pole piece double dies, compound dies chip Yoke , fan-shaped tablet die complex, high-speed machine Notching Notching told alloy molds for dozens of special silicon steel motor dies, electrical silicon steel varieties covering most of the production tooling required type, in the years of production practice, accumulated a wealth of production experience, forming a complete set of processing technology.

慈钰电机公司创建于1999年，其前身是慈溪环球模具厂，经历8年的艰苦创业，于2007年更名为慈溪慈钰电机配件厂，公司在全体员工的齐心拼搏下，在广大客户始终不移的信任和支持下，慈钰电机得到了迅速而稳定的发展，先后成功开发了定转子复式冲槽模，复式落料模，定转子全复模，磁极片复式冲模，磁轭片复式冲模，扇形片复冲模，高速冲槽机专用合金告诉冲槽模等几十种电机硅钢片专用冲模，品种覆盖电机硅钢片生产需要的大部分模具种类，在多年的生产实践中，积累了丰富的生产经验，形成了一套完整的加工工艺。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。