场

Furthermore data assimilation experiments are conducted with MM5 Adjoint-model Assimilation System made by adjoint codes. With a case of heavy rainfall taking place from 00h July 23 to 00h July 24,2002, several numerical simulation experiments of different schemes are performed. The results are as follows. MM5 Adjoint-model Assimilation System not only can improve the initial field effectively and promote the coordination with the model but also can enhance the forecast on the precipitation and other elements. The assimilation of CDW has an improvement on quality of upper wind. The effect of direct numerical simulation with utilizing the CDW to amend the initial field gains the advantage over the one not.

结果表明，MM5伴随模式同化系统能有效改善初始场与模式的协调能力，提高模式对于降水场和其它要素场的预报；使用云导风资料修正初始场后直接模拟的效果比未使用时直接模拟的效果要好，对部分区域的强降水预报精度有一定程度的改善；使用伴随模式同化系统后，加入云导风资料的同化试验对其它要素的改善与直接同化常规资料的效果相比，改善优势不明显，但从各要素的误差来看，对于风场的改善最好。

The control volume integration was applied to deduce the discrete expressions of the convection-diffusion equations. The staggered grid and SIMPLE algorithm were introduced to deal with coupling between pressure and velocity, and then the numerical computation expressions of such variables as fluid flow velocity and pressure were deduced. Using the backward difference method and incremental theory to discretize the governing equations for fields of chemical reaction, material structure and chemorheology, the numerical computation expressions of variables such as the monomer conversion, average molecular weight and fluid viscosity were constructed.

应用控制容积积分法导出了对流—扩散方程的离散表达式，引入交错网格技术与SIMPLE算法，实现了耦合的压力场与速度场的分离式求解，推导得到了流体的流动速度、压力等物理量的数值计算式；采用向后差分方法和增量方法，实现了化学反应场、材料结构场、化学流变场控制方程的离散，获得了反应转化率、聚合物平均相对分子质量、流体黏度等物理量的数值计算式。

The proposed method has the merit that the numerical characteristics of stochastic temperature field response can be obtained by analyzing the random temperature field just in one time.3. Perturbed numerical algorithm of nonprobabilistic convex set theoretical models on the temperature fieldThe uncertain parameters of physical parameters and initial boundary conditions of heat conduction are described by the convex model. The perturbation formulas of the upper and lower bounds of temperature field response with unknown-but-bounded parameters are given via the combination of matrix perturbation theory and the convex set theory model.4. Numerical analysis for transient temperature field with interval parametersConsidering the uncertainties of the transient heat transfer, the physical parameters and initial boundary conditions are regarded as interval variables.

该方法具有只进行一次随机温度场分析便可以获得其响应的数字特征的优点。3、温度场的非概率凸集合理论模型的摄动数值解法将结构导热的物理参数、温度场的初始和边界条件等不确定性参数以凸模型加以描述，基于矩阵摄动理论和处理不确定问题的凸集合理论模型的结合，导出有界不确定参数瞬态温度场响应所在集合的上、下界摄动计算公式。4、具有区间参数的瞬态温度场数值分析考虑结构瞬态热传导问题的不确定性，将结构各物理参数和温度的初、边值条件均视为区间变量。

The relationship between molecular modification of erythromycin and NMR chemical shifts was summarized. It's noticeable that downfield of shifts of H-3 (△δ 0.2) after silylation and upfield of shifts (△δ-0.4) after methylation. No changes were observed after methylation.

分析总结了红霉素分子修饰与核磁共振化学位移变化之间的关系，并且发现大环上H-3硅烷化后由高场移至低场（△δ为0.2），甲基化后又由低场移至高场（△δ为-0.4），变化均较大；而且一旦甲基化后H-3化学位移在高场几乎不再变化。

LES cooperated with the second order full extension ETG finite element method is applied to simulate three typical problems concerned with convection heat transfer with sufficient experimental data. By comparing the numerical results with the experimental results, LES is proved to be of better accuracy and stability when it is used to solve the problems concerned with convection heat transfer. The time history of the flow field and temperature field can be reflected better, and abundant information of the fields can be obtained. Furthermore the details of the change in the vortex structure can be captured.

应用大涡模拟与二阶全展开ETG有限元离散格式相结合的方法对具有实验基础的三个典型对流换热问题进行了数值模拟，并将模拟结果与相应的实验结果进行对比，证明了大涡模拟应用于对流换热问题中具有较高的稳定性和精度，能够较好地反映流场和温度场的时变过程，提供丰富的温度场和流场信息，捕捉流场中旋涡结构的变化细节，尤其适合于边界形状复杂的区段内含有大尺度各向异性涡的流动和换热问题的计算。

Studied present measuring methods" advantages and disadvantages, and presented the necessity and importance of researching propellant transient heat transfer.2.according to 130 and aeronautic 90 rocket projectiles" structure, analysed and acquired physical and mathematical models for propellant transient heat transfer, also designed propellant temperature field simulation units for test.3.acquired discrete transient heat balance equation and temperature calculation program, and gave contrasting curves between experimental temperature values and program calculating temperature values as well as maximum errors and average square root errors between them.4.by programs based on the first class boundary condition, worked out temperature distribution in propellant temperature field simulation units at different time, analysed temperature field distribution law and main elements affecting heat transfer, acquired propellant mass weighted average temperature and one at the half position of propellant maximum thickness as well as maximum errors and average square root errors between them.5.established transient heat transfer mathematical model and temperature calculation program for the third class boundary condition, drew contrasting curves between temperature experimental values and calculation values and gave maximum errors and average square root errors between them, got temperature distribution in the simulation unit at different time and main elements affecting heat conduction, figured out propellant mass weighted average temperature and one at the half position of propellant maximum thickness as well as maximum errors and average square root errors between them.

分析了现有测试方法的优缺点，提出了研究推进剂瞬态导热的必要性和重要性。 2。根据130和航90两种火箭弹的结构，分析得到了推进剂传热的物理模型和数学模型，设计了推进剂温度场模拟实验装置。 3。得到了离散形式的瞬态热平衡方程和温度场计算程序，给出了实验温度与程序计算温度值的对比曲线及其最大偏差与均方差。 4。利用程序求出了第一类边界条件下、不同时刻推进剂温度场模拟装置中的温度分布，分析了温度场的分布规律和影响传热的主要因素，求出了推进剂质量加权平均温度和最大肉厚1／2处的温度时间曲线并给出了两者之间的最大偏差与均方差。 5。建立了第三类边界条件下的瞬态导热数学模型和温度计算程序，求出了温度实测值与计算值的对比曲线并给出了两者之间的最大偏差与均方差，得到了不同时刻温度场模拟装置的温度分布与影响导热的主要因素，求出了推进剂质量加权平均温度和最大肉厚1／2处温度及两者之间的最大偏差与均方差，讨论并确定了能代表130和航90推进剂温度的特征点的位置。

The approach primarily adopts patch-based texture synthesis flow, synthesizing progressively-variant textures to reflect the diversification trend of vector fields.

在纹理合成过程中利用向量场作为指导，生成反映向量场大小和方向变化的合成结果·采用块纹理合成的流程，在对向量场合成块均匀划分的基础上，通过进一步的自适应分割，将向量场划分成为不同大小和不同形状的最终合成块，使之与向量场的变化趋势相吻合·对向量变化过于剧烈的区域，则采用点合成的方式进行纹理合成，以保证合成效果的平滑·实验表明，文中的方法可以实现快速而高质量的向量场可视化

Obviously the thermal conditions of dies and die castings and the fluid flow of liquid metal have critical influence on the quality of casting product, the production rate and the die life. Hence, computer numerical simulation has become an efficient tool to analyze as well as to control the thermal and fluid flow fields in die casting process.

压铸过程的温度场和流场是影响压铸产品质量、生产率和模具寿命的重要因素，计算机数值模拟技术为压铸温度场和流场的研究提供了有效的手段，同时也为压铸工作者控制压铸温度场和流场提供了有力的工具。

The simulation model consists of a sub-wavelength aperture and a metal-coated fiber probe scanning in constant height mode. Influences of the scanning height and the aperture size of the fiber probe on optical field detection are discussed.

选择纳米孔径的隐失场光场和镀金属膜光纤探针建立了近场光探测的理论模型，讨论了探针孔径尺寸、扫描高度等因素对光场探测的影响，以及测量光场与初始光场之间的关系等。

During the calculation of the early age temperature field, the early age physical and mechanical performance of concrete varies with its age, therefore in the second chapter we discuss the early age physical and mechanical performance of concrete and its development regulation with time, we emphasize elastic module and the development about the early age strength of concrete varying with time, at the same time consider the effect of shrink and creep upon the early age of concrete, in succession discuss how to confirm the physical parameter of thermodynamics of concrete.

之后讨论了混凝土的热物理参数的确定。为了能够正确合理的应用有限元方法求解早期混凝土温度场问题，第三章论述了求解温度场的有限元方法。第三章首先对热传导的微分方程作了阐述。之后确定温度场的边界条件。本章采用变分原理推导有限单元法计算温度场的公式。因此在第二小节叙述了变分原理，然后阐明了不稳定温度场的计算的三种方法，确定第四章分析中将采用向后差分法求解0#箱梁早期的温度场。

They weren't aggressive, but I yelled and threw a rock in their direction to get them off the trail and away from me, just in case.

他们没有侵略性，但我大喊，并在他们的方向扔石头让他们过的线索，远离我，以防万一。

In slot 2 in your bag put wrapping paper, quantity does not matter in this case.

在你的书包里槽2把包装纸、数量无关紧要。