变度

The contributions of mean flow absolute vorticity advection〓term at the low level to the negative vorticity were more than that of the transient disturbances over the most part of South China and the subtropical western Pacific in the two years.

在华南大部和副热带西太平洋，这两年低层平均流绝对涡度平流〓对负涡度的贡献大于瞬变扰动。

The shape optimization is studied by adopting the domainintegrated method which is based on the calculus of variations during the shape design sensitivity analysis.

探讨了基于变分法的敏度分析在形状优化设计中的应用，提出敏度分析过程中提高速度场求解效率和有限元网格质量的新方法。

So the effect and the efficiency of the shape optimization are guaranteed. If using sensitivity analysis which is based on the calculus of variations in the shape optimization, the sensitivity analysis can be a relatively independent module. The efficiency of computing the design velocity field and the quality of mesh will be improved by using Herrmann method.

在形状优化过程中，采用基于变分法的敏度分析，可以使敏度分析成为单独模块，在进行设计速度场求解时采用Herrmann法，使速度场求解的效率和优化过程的质量得到保证。

to reduce the impact of carrier frequency offset in ofdm system,this thesis designs a new carrier frequency offset estimation scheme for ofdm system.the carrier frequency offset estimation includes acquisition and tracking.we adopt variable step size adaptive algorithm.the acquisition range of the proposed algorithm is as large as one half of the overall signal bandwidth.through this method we can not only avoid the feedback by using forward error correction,but also reduce the times of complex multiplication in order to reduce the power consumption of the system.this algorithm not only has low complexity and fast convergence nut also can improve the demodulation performance of ofdm system.computer simulation illustrates the superior performance of the proposed algorithm with regard to estimation accuracy in both awgn channel and multi—path channel.

摘 要：为了减小正交频分复用系统受频率偏差的影响，在ofdm系统中设计了一种新的载波频偏估计算法。频偏估计包括跟踪和捕获两个阶段，文中采用变步长自适应算法来进行跟踪，这个跟踪算法的捕捉范围是整个信号带宽的一半。通过此方法，不但可以利用前向纠错的方式来避免反馈，而且可以缩减复数乘法的次数以降低计算复杂度和系统功耗。该方法运算复杂度低，并具有较好的收敛性，能改善odfm的解调性能。从计算机的仿真效果可以看出无论是在awgn信道上还是在多径信道上都表现出了卓越的性能。

The atmospheric mean horizonal convergence in two examples is calculated using the two modified EVAD methods,the convergence obtained is then adjusted with the variational method,and the vertical velocity is computed in ter...

根据这2种改善的EVAD方法，分别计算出大气平均散度，再用变分法对散度值进行调整，然后利用连续方程，计算大气的垂直速度，并对各种结果进行了比较分析。

In this paper, arrangement scheme of a novel multi-star phase shifted pole changing coil was given and the methods to determine coil split ratio were analyzed. According to electromagnetic theory, 2D electromagnetic mathematical model in which stator windings were spitted coil was developed, and magnetic field distribution of the novel motor at starting was solved by finite element method, starting performance of motor was calculated. Based on energy method, rotor slot leakage reactance under different poles and different loads were calculated, and the variation of rotor slot leakage reactance with loads was gotten. Based on time-step finite element method, distribution of branch current in stator windings and operating performance were calculated and analyzed when branch was unbalance, the method to calculate circulating loss in stator windings of novel multi-star phase shifted pole changing motor was given, and the effects of the loads variation and degree of unequilibrium on circulating loss in stator windings were calculated and analyzed.

论文系统的给出了采用分裂线圈法新型多星形移相变极绕组的排列方案，进一步分析线圈分裂比的确定方法；根据电磁场理论，建立了定子为分裂线圈绕组的电机二维电磁场数学模型，并采用场路耦合法求解了新型多星形移相变极电机起动时的磁场分布，计算了电机起动性能和基于能量法计算了不同极数下起动时转子槽漏抗和不同负载时转子槽漏抗，得出转子槽漏抗随负载变化的规律；采用时步有限元法计算分析了定子绕组支路不平衡时支路电流的分布情况及运行性能，给出了新型多星形移相变极电机定子绕组环流损耗的计算方法，分析比较了负载的变化和支路不平衡度大小对定子绕组环流损耗的影响。

The results showed that after the adding starch to the sheet, the viscosity of the PVA solution increased, the dissolution time of the sheet got longer, the rate of enlargement in water was smaller, the rate of moisture became smaller, stretch intensity enhanced and the change of shape diminished; also it could be seen from the surface of sheet that the starch existed in PVA sheet as the shape of conglomerating particle.

结果表明，加入淀粉后，PVA溶液的粘度增大，膜的溶解时间变长，水上伸长率变小，含水率变小，扯断强度增强，形变缩小；通过膜表面观察，发现淀粉在膜中以聚集颗粒状态存在。

During the bleaching and dyeing process, cashmere fiber is damnified by chemical aid-agents and the workmanship used, which makes the fiber short, thick and rough, thus it affects the spinnability and weaving capability of the yarn and the handfeel of the finished products.

羊绒纤维在漂白和染色过程中，化学助剂及工艺本身对其都会造成损伤，使其长度变短，细度变粗，手感变涩，从而影响羊绒纱的可纺性、织造性能及成品手感。

So it can keep invariable bulk phase transition within a wild neutralization range;AB-I and AB-II show the similar phenomenon in bulk phase transition,but not very similar in methanol and ethanol.Perhaps this is because of competition between hydrophile and lyophobic.

AB-I样品分子链上的磺酸基团(-SO3-)完全电离，与树脂网络外部溶液浓度差始终较为恒定，所以能在较宽的中和度范围内(40%～80%)保持较为恒定的相变体积；AB-I和AB-II在电解质溶液中表现出类似的体积相变规律，而在甲醇、乙醇中表现出不尽相同的相变规律，这可能是由于AB-II中存在亲水力和疏水力相互竞争作用的结果。

At the begin of the dissertation, control strategy is analysed for improving performances of the interver in dynamic, steady-state and minishing harmonious component of the output voltage. Firstly, the theory of the voltage differential multiloop feedback strategy is analysed .

着重于对逆变电源控制策略的研究，从控制策略的角度入手改善逆变电源的输出动态性能，提高逆变电源的稳态精度，同时改善输出电压的正弦度，减少输出电压的谐波含量。

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。