均匀地

Scattering characteristics are studied of inhomogeneous cylinders immersed in an absorbing medium illuminated normally by plane waves. Scattering and extinction cross sections are derived, and the efficient algorithm is presented. Scattering matrix is simulated and discussed.

系统地解决了吸收介质中非均匀柱粒子对垂直入射平面波的散射问题，包括散射场、散射截面、消光截面的解析解，提出了快速、有效的计算方法；数值模拟了均匀、非均匀圆柱的散射矩阵，并与已有文献发表结果对比。

If the profile curve has been denoted by a nonuniform rational quadratic B-spline curve, it is very convenient to represent the surface of revolution as a nonuniform rational biquadratic B-spline surface.

只要轮廓曲线用非均匀有理二次B样条曲线来表示，就可相当方便地把旋转曲面表示成非均匀有理双二次B样条曲面。

A new particle swarm optimization, PSO with bounded mutation operator, was developed. In contrast to the original PSO, in this algorithm, PSO with bounded mutation operator would make the particles redistributed cquably close to boundary when place of particle exceeds feasible region during iteration.

提出了一种新的粒子群优化算法——带边界变异的PSO，其原理是：在迭代的过程中，当粒子的位置超出可行域时，带边界变异的PSO让粒子的位置重新均匀分布在边界附近；当粒子的速度超出可行域时，则使其均匀分布到整个可行区间，而不是像原始PS0那样在这2种情况下都只是简单地取边界值。

There are also closed centers embedded on the belt, appearing zonal non-uniformity. The classic method of zonal deviation can just depict the zonal non-uniformity of subtropical high partly, while meridional deviation from the zonal mean along the equator can describe both the belt and the centers on it, i.

用传统的纬向偏差仅仅能部分地描述副高的纬向不均匀；而用新引进的相对于赤道的纬向平均的经向偏差可以同时描述副高带及其上单体的经向和纬向不均匀。

This testing machine is good at studying the deformation and failure of inhomogeneous and discontinuous media from the angle of loading equability .

该试验装置可以更好地从均匀加载的角度研究非均匀，非连续介质的变形及破坏规律。

The deformation mechanism is mainly the single-slip and cross-ship, the fracture mechanism is mainly the congregation of transgranular micro-hole, and large uniform deformation occurred before tough fracture, and therefore, the ability of plastic deformation and the mechanical properties of the material were remarkably improved. These fully indicate that the new melt-treatment developed in this work is an effective and advanced technique, and further testify that the improvement of metallurgical quality of the material is the key to enhance its mechanical properties, especially its plastic deformation performance. The results of tensile and compression tests at elevated temperature also indicate that the suitable hot-working temperature range is 400～450℃. 4. A steady-state plastic flow exists during the plastic deformation of the aluminum sheet used for pressure can at elevated temperature. A hyperbolic sine relationship can be satisfied between the steady-state flow stress and strain rate by introducing an Arrhenius term which involves some thermal activation parameters, i.

压力罐用铝材中的主要冶金缺陷为Al〓O〓夹杂物、气孔及富Fe杂质相；高效熔体处理显著改善了材料的冶金缺陷的存在形态，使含杂量明显减少、夹杂物尺寸变细小且分布均匀，富Fe杂质相变为细小、分布均匀的团球状或短棒状的复杂化合物，同时也明显细化了结晶组织；此外，由于高效熔体处理有效地减少了材料中裂纹萌生源数量，因而改变了材料的塑性变形微观过程及断裂方式，主要以单滑移和交滑移进行塑性变形，断裂方式为穿晶微孔聚集型，韧性断裂前产生了大量的均匀变形，不易出现变形失稳，从而显著提高了罐用铝材的塑变能力和力学性能。

Through the experiments on hydration of AH in the following sulphate（Li_2SO_4、MgSO_4 、 Al_2(SO_4)_3 、MnSO_4 、CuSO_4 、CoSO4 、CdSO_4 、ZnSO_4 、NiSO_4 、FeSO_4）, dissoluble sulfate hydrate origining from hydration process of AH affects it's hydrous rate, hydrous rate of AH does not connect with Z/R of cation in stimulation, theory that Z/R affect hydrous rate of AH does not exist. Third, hydration of AH in dissoluble sulfate complies with dissolve-nucleate -grow theory, concentration of Ca~2+ from dissolving of CaSO_4 is higher than one of CaSO_4·2H_2O, calcium sulphate dihydrite gets a motivity of crystallization. dissoluble sulfate takes the following function: double-salt or dissoluble sulfate hydrate from hydration of AH in it becomes heterogeneous particle and a kind of nucleation catalyzer, and reduces surface barrier when DH becomes crystal because the crystal of DH precedently appears in uneven place. Results indicate hydration of AH does not conform with double-salt theory, but it conform with this mechanism: dissolve-nucleate-grow, formation of DH is an uneven nucleation and crystalizaion process.

通过对CaSO_4在Na_2SO_4 、K_2SO_4 、Rb_2SO_4 、Cs_2SO_4 、(NH_4)_2SO_4溶液中水化过程，以及CaSO_4·2H_2O、CaSO_4与以上硫酸盐反应速度、产物的研究，说明复盐理论不正确；CaSO_4在（Li_2SO_4、MgSO_4 、 Al_2(SO_4)_3 、MnSO_4 、CuSO_4 、CoSO_4 、CdSO_4 、ZnSO_4 、NiSO_4 、FeSO_4）溶液中水化，水化过程中硫酸盐水合物的析晶影响着无水硫酸钙水化，与激发剂阳离子Z/R值大小无关，阳离子的Z/R参数影响水化率的规律并不存在； 3、无水硫酸钙在可溶性硫酸盐中的水化按照溶解-成核-生长理论进行，CaSO_4达到溶解平衡时Ca~2+的浓度大于CaSO_4·2H_2O溶解平衡的Ca~2+的浓度，CaSO_4·2H_2O获得结晶的驱动力，可溶性硫酸盐起到形成晶核的作用：水化过程与CaSO_4生成复盐或析出水合物所形成的细小物相，作为异质微粒使母相中存在不均匀性，这些不均匀性有效地降低成核时的表面能位垒，使CaSO_4·2H_2O晶核优先地在这些具不均匀性的地方形成，因此这些物质起成核催化剂作用。

The project involved:(1) Development of time and space resolved soft x-ray diagnostic instruments: a pinhole transmission grating streak spectrograph and a stigmatic grazing incidence grating flat-field streak spectrogrph, which are the most powerful in x-ray laser and laser plasma researches of our laboratory.

它们已成为我们实验室X射线激光和激光等离子体软X射线发射实验研究中最有力的诊断手段。（2）系统地研究了X射线激光增益介质—线状激光等离子体的均匀性。结果表明线聚焦激光照明的均匀性是实现均匀线性状激光等离子体的必要条件。

The simulation results of the cylinder-block model were given in the article, consistent with that of Middlemen"s. It was shown that the block part could improve the uniformity of the flow distribution. The analysis of the flow field of some materials with different power-law factor in the die designed by Mckelvey was close to that of Mckelvey"s. It was shown that the flow distribution was uniform in the die that can producesheets with 1200mm in width. During the analysis the flow channel was divided into several parts to get the details about the fluid flow in each area. A conclusion was drawn after analyzing the influence of the die pressure on the flow distribution, that the higher pressure is good for the output and bad for the uniformity of the distribution. Simulation of the die applying the cylindrical main runner showed the fact that when the cylinder replaced the cone the change of uniformity was trivial. The uniformity of the non-block flow channel was so poor that the block in the proper position of the die channel was necessary. The project of the die for the wider sheet was put forth, and the analysis of the fluid flow in the die was shown.

本文模拟了圆柱管缝隙流模型的三维流动场，得到了与Middlemen结论一致的流动均匀性，并通过模拟直观地展示了采用阻尼块可以改善挤出均匀性的现象；分析了多种幂率指数的流体在Mckelvey等人设计的流道模型中的流动分布，得到了与Mckelvey的分析结果接近的压力降和流量偏差；本文建立了1200mm幅宽机头流道的三维有限元模型，并逐个分析各个区域和多个截面的流动分布状况，由此揭示了1200mm幅宽L-型机头流道内的流北京化工大学硕士学位论文动分布基本均匀，并在分析了机头压力对于挤出流动分布的影响后得出结论：较高的机头压力可以获得较大的产量，但是不利于物料均匀分布；模拟了采用圆柱管主流道时机头流道内的流动分布，得出结论：主流道由圆锥管改为圆柱管时对流动均匀性影响不大，通过设置适当的阻尼仍然可以达到挤出平衡；模拟了两端进料式圆柱管无阻尼流道的流动均匀性后得到结论：两端进料式无阻尼结构的流动均匀性较差，宽机头中仍然有必要设置阻尼块；确定宽幅机头流道的基本方案，并设计了一种宽幅防水卷材挤出机头流道的结构，通过流动模拟表明该种结构的流动均匀性较好；考察了宽幅机头对于不同厚度片材的挤出适应性，得到结论：当生产不同厚度的片材时，阻尼块高度需要调整。

Based on the efficient approach developed above, cases of foundationinhomogeneity with stiffness varying according to an exponential function along the radialdirection, and cases of foundation inhomogeneity with stiffness discontinuity and with weakinterlayer strata on the earthquake response of concrete arch dams as well as gravity damswere analyzed. It is found that taking into account the effect of foundation inhomegeneity forthe earthquake safety assessment of concrete arch and gravity dams has great significance.

在以上理论的基础上，本文充分利用比例边界有限元法能够模拟非均匀无限域的优点，合理地提出了重力坝、拱坝的非均匀无限地基模型，分别研究了地基材料弹性模量沿深度按指数变化的无限不均匀地基和地基中存在断层或软弱夹层时对重力坝和拱坝的地震响应影响。

By the time of its fall, most of the prisoners were writers who had written against the corruptions of the government.

到它被攻陷的时候，里面多数的犯人是写了反对政府贪污文章的作家。

The most obvious variation to ovum morphological character was that the color was changed from light green to sepiaceous in embryonic development, and all the ovums were almost hatched after 96h.

在胚胎发育过程中卵的形态特征最明显的变化是颜色从淡绿到深褐色，卵在发育96h后卵基本全部孵化。