折点

Based on the laminate theory, a laminate weakened by damage is treated as an anisotropic thin plate. Using the complex potential method in the plane theory of elasticity of an anisotropic body, the series solution of finite anisotropic thin plate containing an elliptical inclusion is proposed with the help of Faber series. A hybrid element with an elliptical inclusion for anisotropic materials is obtained by using the hybrid variable principle, and the element efficiency is verified by numerical examples. The state of the damage is modeled by an elliptical soft inclusion, and using the point stress criterion based on characteristic curve and Yamada-Sun etc. criteria, the prediction of the strength of a composite laminate with damage is set up. The effects of various parameters on the stress distribution and the residual strength of a composite laminate weakened by damage are detailedly studied.

首先基于经典层板理论，将复合材料层板的弹性问题化归为均匀各向异性板来求解；采用各向异性体平面弹性理论中的复势方法，以Faber级数为工具，给出了有限大含椭圆核各向异性板弹性问题的级数解形式；利用杂交变分原理，成功导出含椭圆核各向异性板杂交应力有限元，并用算例验证了该单元的可行性和有效性；采用含刚度折减椭圆形弹性核的冲击损伤模型，引入基于特征曲线和Yamada-Sun破坏准则的点应力判据，建立了含损伤复合材料层板剩余强度的分析方法；通过数值计算详细讨论了各种几何参数对损伤层板应力分布、剩余强度的影响，得到了一系列对工程应用具有实用价值的结论。

Results: In three point bending, maximal plate strain in the fracture model was lowest in group A(774.50±18.00με) and highest in group D(849.67±44.03με).

结果：在三点折弯实验中，D 组中骨折端的平均应变(849.67±44.03με)最大，A 组中骨折端的平均应变(774.50±18.00με)最小。

The two-parameter unfoldings of local dynamical behavior,near the point of Hopf-Hopf bifurcation, is investigated theoretically.

理论分析了四维范式映射在Hopf-Hopf余维二分岔点附近的参数开折。

The experience of the interior is characterized by constantly shifting vanishing points, at the place of their collision in each crease of the plan, large openings cutting dormer scoops on the roof, centrifugally release the views out to the surrounding landscape.

内政部的经验，不断消失点转移在他们的每个计划折痕碰撞的地方，特点，大的通风口，削减屋顶天窗铲子，离心释放出的意见，向周围的景观。

The ancients of many strokes, the general will only talk about points, horizontal, vertical, the charge-off, press down, hook, folding, pick eight strokes, this book eight strokes to start writing, be extended to 20 types.

古人论笔画很多，一般也只是讲点，横，竖，撇，捺，钩，折，挑8个笔画，本书把8个笔画展开编写，扩展到20类，。

Local codimension two bifurcation of maps,associated with Hopf-pitchfork case,is analyzed using the center manifold theorem and normal form method of maps.

应用映射的中心流形和范式方法，研究了映射在Hopf-pitchfork余维二分岔点附近的参数开折，揭示了含间隙振动系统在余维二分岔点附近的动力学行为。

I plant has a team of experienced professional and technical personnel, manipulation of high-speed automatic packing into a sexual machine, automatic fold-machine, large-scale high-precision four-post punch, punch the ordinary type, fully automatic soft-line plastic box machine, fully automatic viscosity All machines, hydraulic and vacuum mixer machine, punching machine, pulling machine, plastic cutting machine, printer point, computer numerical control cutting machine and other advanced production equipment and testing instruments, and is equipped with emergency generators and more ensure delivery.

我工厂拥有一批经验丰富的专业技术人才，操控着高速自动吸塑成性机，全自动折边机，大型高精密四柱冲床，普通型冲床，全自动柔线胶盒机，全自动粘合机，油压机及真空密炼机，冲片机，拉片机，切胶机，点印机，电脑数控切条机等先进的生产设备和检测仪器，并配有后备发电机，更能确保交货期。

When the temperature changes, several device parameters such as the transmittance, the extinction ratio and the curve of the transmittedintensity will change accordingly for devices made of the Iceland crystal.

其次系统分折了温度对格兰·泰勒棱镜和格兰·付科棱镜的透射光强曲线的影响，利用光的干涉原理和不同振动形式的反射比公式，得到了格兰棱镜在同一入射波长、温度改变时的扰动因子极大值点的移动量以及相同的温度改变、不同人射波长时扰动困子极大值点的移动量。

The joint effect of active and reactive power on the voltage stability of a typical power system was considered by analysing the two parameter bifurcation problem related to nonlinear oscillation phenomena. Numerically, as the active power P1 increases, the Hopf points get closer and eventually coincide at P1=1.455 43 the cyclic fold curve gets closer and closer to the Hopf curve and finally intersects the Hopf curve at a singular point the period-doubling points also get closer and finally coincide at P1≈0.65. The stability behaviour is pre-determined using the normal form approach near the limit point of the Hopf curve. Hence, in the power system attention should be paid to both the consumption of active power and the decrease in the reactive power to prevent nonlinear oscillations. A controller can be designed to absorb some active power and to avoid the nonlinear oscillations that damage the system components.

针对一个典型的单机无穷大电力系统，通过分析系统的双参数分岔的非线性振荡现象，综合考虑有功和无功功率对电压稳定性的影响数值分析表明，随着有功功率的增加，电力系统的Hopf点越来越靠近，最终合为一点在P1=1.455 43处同时圈折cyclic fold 曲线也越来越靠近Hopf曲线，并在Hopf曲线的稳定与不稳定临界点处与Hopf曲线相交倍周期分岔点也随着越来越靠近，最终在P1≈0.65 合为一点应用正规形理论方法，初步确定了Hopf曲线极限点附近的稳定性态因而，电力系统应注意让负荷利用有功功率，减少无功功率的产生以防止非线性振荡另外，可以设计一个稍微吸收网络的有功功率的控制器，以避免因周期振荡而造成电力系统仪器的损坏或电压崩溃

Currently Kong Qichui, hydraulic riveting machines, metal shavings Press, metal Da Baoji, forging hydraulic hammers used for steaming Kong Qichui head of the hydraulic power, closed a single point of presses, open-presses, More reactive auto forging presses, NC Jianban, bending machines, general Jianban, bending machines, rotary forging riveting machines, bar precision cutting machine, open-book-school and other varieties of products, but also for Automobiles, bicycles, the bearings industry design, manufacturing production lines, has become the domestic Kong Qichui, hydraulic forging hammer, hydraulic riveting machine, forging equipment bearing the production, export base.

目前拥有空气锤、液压铆接机、金属屑压块机、金属打包机、液压模锻锤、用于蒸空气锤改造的液压动力头、闭式单点压力机、开式压力机、多功位自动锻造压力机、数控剪板、折弯机，普通剪板、折弯机，摆辗铆接机、棒料精密剪断机、开卷校平机等多个品种的产品，还可为汽车、自行车、轴承行业设计、制造生产流水线，已形成国内空气锤、液压模锻锤、液压铆接机、轴承锻造设备的生产、出口基地。

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。