频率响应

To analyze the response of pavement structure under moving loading, a quarter vehicle model with single freedom degree and unevenness model are established. The dynamic loads are calculated through combining different pavement conditions and speed. When the incentive frequency which is passed to vehicles by the road is close to its own vibration frequency, vehicles will produce the greatest dynamic load.

为了分析路面结构在行车动荷载作用下的力学响应，建立了单自由度1/4车辆模型和以正弦曲线模拟路面不平整度的模型，通过将不同路面状况和行车速度的组合，分析车辆在各情形下所产生的动荷载，发现路面传给车辆的激励振动频率接近车辆自身振动频率时，车辆对路面产生的动荷载值最大。

Firstly,using the method of concentrate mass this paper establish a non-linear dynamics model of a two-stage gear train with backlashe between the gear pair,and through analysed the dynamics model,the torsional motion differential equations are got , on this basis,then calculate the torsional motion differential equations using Runge—Kutta method ,and discuss how to influence the dynamics characteristic of system when these parameters chage such as mesh frequentcies、 stiffness of the intermediate shaft、the ration of mesh frequentcies.and discuss when the chaos will happen under the change of these parameters.

首先用集中质量法建立系统的含间隙的非线性动力学模型，并根据牛顿力学定理，得到系统的运动微分方程。然后对所建立的运动微分方程运用四阶变步长Runge—Kutta方法进行了求解，并对计算结果进行分析，研究了齿轮啮合频率、中间联接轴的刚度，一、二级齿轮的啮合频率比等参数变化时，对系统非线性动力学特性的影响规律，并讨论了当参数如何变化时会导致系统的混沌响应的出现。

Generally, frequency characteristic of seismometer is obtained by measuring data, but the measuring data is disturbed by noise.

通过测试信号及其响应分析得到的一般是系统的频率特性，并且该频率特性受到噪声的污染。

If the excitation amplitude is constant and the excitation frequency is close to 3-times resonance frequency, the effect of the 3-times superharmonic resonance on the system response increases greatly.

当激励幅值不变、激励频率逐渐接近3倍超谐共振频率点时，3倍超谐振动成分对系统响应的影响逐渐增加，这表明立方非线性对系统的调节作用越来越强。

Due to the regulating by the cubnonlinearities, some parametric ranges in which 3-times superharmonic vibration or 1/3-times subharmonic vibration arises exist in the sytem. When the excitation frequency approaching 3-times or 1/3-times resonance frequency, the system response is stable and periodic .This fact shows that regulating action of the cubic nonlinearities on the vibration system is strong.

由于立方非线性对达芬系统的调节，系统存在出现3次超谐共振和1/3亚谐共振的参数域，在激振频率接近3倍或1/3倍派生系统的固有频率时，立方非线性对系统的调节作用越来越强，从而使动态响应成为稳定的周期性。

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。

In anFDD wireless system, the duplex spacing between uplink and downlink islarger than the coherence bandwidth of the mobile radio channel, thus theuplink and the downlink small-scale fading is uncorrelated. Moreover, thearray response is correlated with the frequency of the signal carrier. So it isimpossible to resue the uplink weights for downlink beamforming. As aresult, the application of smart antenna for the downlink is a difficult problem.

在频分双工系统中，由于上、下行载波的频率差大于相干频带，上、下行信道衰落是不相关的，而且阵列响应也与信号的载波频率有关，因此，上行信道不能直接用来估计下行信道，故智能天线应用于下行链路是一个难点。

Reactive oxygen species causing DNA oxidative damage comes from two kinds of ways:one is from cellular normal physiological metabolism;the other is from outer environment.Redox-sensitive green fluorescent protein was expressed in Saccharomyces cerevisiae.Recombinant cells were evaluated in monitoring the changes in the redox state of living cells when challenged with toxicologically relevant metal ions NaAsO_2 or Pb(NO_3)_2 by measuring emission intensity at 510 nm with a Hitachi F6500 fluorescence spectrophotometer,roGFP expressed in yeast responded not only to typical membrane-permeant oxidants H_2O_2 and reductants DTT,but also to toxicological metal ion-induced intracellular redox changes in a dose-dependent manner.Moreover,exposure of yeast cells to NaAsO_2 or Pb(NO_3)_2 at concentrations that induced redox changes reported by roGFP caused up to 2～3 fold increases in DNA mutation frequency.This mutagenic effect was largely caused by oxidative stress since blocking the production of hydryl radicals with thiourea significantly reduced the mutation rate as well as delayed the cell death.

本文将对氧化还原状态变化敏感的绿色荧光蛋白roGFP1-R12，在酵母细胞中实现了多拷贝强表达；荧光扫描经强氧化剂H_2O_2和还原剂DTT以及环境中重金属NaAsO_2或Pb(NO_3)_2处理后的酵母细胞悬液，测定510 nm处的荧光发射强度结果显示，表达的绿色荧光蛋白对氧化还原水平敏感，且在510 nm处的荧光强度与一定的重金属浓度呈正相关，即roGFP1-R12在510nm处的荧光发射值随重金属浓度的增高而增强，从而说明重金属对细胞的毒性在一定程度上很可能是通过破坏细胞内的氧化还原平衡发生作用；同时通过该绿色荧光蛋白对胞内氧化还原状态变化的响应情况可以来实时检测环境中的重金属；遗传学的点突变频率及致死率实验数据表明，重金属能导致菌体的点突变频率和致死率升高，且活性氧的清除剂巯基脲能明显降低这种点突变和致死率，说明由重金属引发的这种点突变和致死效应在很大程度上是依赖于重金属对细胞诱导产生的氧化胁迫。

This compensation circuit can make the stability of the LDO linear regulator undependent on the effect of load capacitor's equivalent serial resistance, and it also makes the unit gain frequency bandwidth change slightly when the load is varying, thus greatly improving the performance of transient response, Furthermore, on the basis of dynamic frequency compensation, an overcurrent protection circuit is designed.

文章针对LDO稳定性的问题，提出了一种内部动态频率补偿电路，使LDO线性稳压器的稳定性不受负载电容的等效串联电阻的影响，其单位增益带宽也不随负载电流变化而改变，大大提高了瞬态响应特性；采用Hynix 0.5μm CMOS工艺模型对电路进行仿真；此外，该电路在实现动态频率补偿的基础上又加入了系统的过流保护功能，当负载电流大于限制电流时，LDO不能正常工作；当负载电流小于限制电流时，又自动恢复到正常工作状态。

In the fourth paragraph, how the theory of the damping to forging hammer foundation advances at home and abroad, the research and application of the implement for damping to forging hammer, the structure of damping to forging hammer and the calculation methods for forging hammer foundation vibration system, which are used at home nowadays, are particularly introduced.In the fifth paragraph, aiming at direct damping under anvil block of forging hammer, the author bases a mechanics model of two-degree with damping, and optimizes the vibration parameters both in frequency field and in time field, then finds out the new simple method of optimizing the vibration parameters of the damping device under anvil block of forging hammer.

第五章针对锻锤砧下直接支承式减振基础，建立了锻锤减振系统的二自由度有阻尼振动力学模型，然后用傅立叶变换法求出振动传递率的频率关系，用直接积分法求出砧座和基础位移的时域响应，并分别对频域函数和时域函数进行参数优化，最终建立起频率函数—时域函数—优化参数间的相互关系，从而找到了锻锤砧下隔振器参数优化的简便新方法。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。