弹回的

By analyzing the process of bending cross beam , this article elaborates different factors that affect the resilience under different conditions, from which we find out solution for resilience.

通过弯曲横梁的工艺分析，在不同的条件下，影响回弹的因素也不同，从中找出解决回弹的方法，用一套补偿回弹量的弯曲模来完成该件的制做。

Therefore it is necessary to research the mechanism of greensand used for high compacted molding methods thoroughly.This subject is one section of the National Natural Science Foundation subject ""Ivestigation on Predicting Method and Mechanism of Springback for High Compacted Sand Molds"", followed of the other completed one named ""Research on Microdeformation of Molding Sand"". A serious of experiments has been done on the reequipped three axial machine under certain technological conditions, and the mechanics, material science, rheologic science. It is systematically studied that the influences on the springback of sand mold were caused by the main influence factors: pressure, compacted rate and the content of soil. Through the analyzed experiments' data, the experienced stress-strain relationship concerning the main influence factors were obtained;under different technical parameter, the springback and spingback's potential energy are compared, the differences and indifferences between them are found out, and the springback's mechanism is discussed;according to the tests' data of YangGuoping coming from Tinghua University, experienced formula of molding sand's springback displacement is induced, the displacement and springback are compared, the margin of error's reasons are analyzed, and they are tested and verified mutually.

本课题为国家自然科学基金项目"高紧实度砂型预测方法及回弹机理的探讨"的一部分，是已结题的国家自然科学基金项目"铸造型砂微变形的研究"的后继，运用力学、材料学及流变学理论，利用改装的三轴仪，在一定的工艺条件下，作了大量系列实验，系统的研究了压实比压、紧实率和膨润土含量对砂型回弹的影响；对实验数据进行了分析和处理，得出了型砂关于压实比压、紧实率和膨润土含量的本构关系的经验公式；把各工艺参数下的型砂产生的回弹量与回弹势能进行比较，找出两者存在的异同点，并对回弹机理进行了探讨；通过清华大学杨国平的实验数据，推导出型砂回弹位移场的经验公式，并与实验测出的回弹量进行比较，分析误差造成的原因，并互相进行了验证。

My partner's play of the last trump; his clumsy play of the rebound.

我的同伴打出最后一张王牌；他笨拙地接弹回的球

An algorithm is established for compensating springback in sheet metal forming based on the theories of linearity closed loop control system, space Fourier transform, and transfer function in frequency domain as well as die experiment iteration.

以冲压件回弹引起的尺寸误差为控制目标，以线性闭环控制系统、空间Fourier变换和频域传递函数为理论基础，基于模具实验迭代，建立了模具回弹补偿修正算法。

The research results show as follows. As plastic deformation increases, the Young's modulus of material continuously changes. This variation law is able to be described using a piecewise linear function .Hardening model and whether the variation is considered or not make great effet on springback prediction. It is proved that the springback prediction result which adopts the elastic-plastic constitutive model based on INLK hardening model and the variation of Young's modulus is considered, is more close to experimental result. After the sheet metal undergoes multiple bending, the corner radius and bending height also affect springback greatly.But the effect trend is different. At the same time, the reliability of springback research using numerical simulation is proved.

研究结果表明：材料弹性模量随塑性变形的变化是不断变化的，该变化规律可用分段线性函数进行描述；强化模型及考虑弹性模量变化与否对回弹预测有很大的影响，基于INLK强化模型和考虑弹性模量变化的弹塑性本构模型对回弹的预测结果与试验最接近；多次弯曲中圆角半径与弯曲高度对板料变形后的回弹有较大影响，但影响趋势不同；证明了数值模拟方法对回弹研究的可靠性。

Amazingly enough, a beam of electrons had thus been diffracted in a manner completely analogous to a light wave bouncing off a reflection grating

一束电子波衍射的方式，同光波从一个反射光栅上弹回的方式完全类似，这真是不可思议。

This article also discusses neutrosphere and reversion of the flectional wood by using mechanics knowledge and obtains function on length of the compressing wood after reversion. The effect of softening is to direct ratio with softening time within certain scope and the plastic of wood will not increase with the augment of softening time beyond the scope.

运用力学知识对弯曲时木材的中性层、弯曲后的木材的回弹进行了分析；运用数学软件对压缩影响因素与压缩回弹后的木材的长度进行了函数拟合。

But the remnant has its own magnetic field, which repels the protons.

但是由于残骸有着自己的磁场，对弹回的质子发生排斥作用。

The relationship of spring back angle with bending clearance and die shoulder radius in the U-shaped bending of Aluminum alloy sheet was investigated.

主要研究了铝合金板材 U形弯曲回弹角与弯曲间隙、凹模入口圆弧半径之间的关系，分析了不同厚度的板材弯曲回弹角的差异。

The study shows that the effect of Young's modulus is largest, then hardening coefficient, initial yielding stress, hardening exponent and anisotropy r0 . While the effects of anisotropies r4 5 and r9 0 variation can be ignored.

研究结果表明，杨氏模量的波动对板料回弹量的影响最大，其次分别为硬化系数、初始屈服应力、硬化指数及各向异性系数r0的波动，而各向异性系数r4 5及r9 0的波动对板料回弹量的影响可忽略，且数值模拟分析材料参数对板料回弹量的影响趋势与理论分析一致。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。