面

By using the CFD software FLUENT, the inner-flow field of centrifugal fans with ruled-surface impeller versus with enveloping surface impeller has been simulated. The static pressure distribution, the dynamic pressure distribution, the total pressure distribution, the turbulent intensity and the speed vector of the two kinds of centrifugal fans are then analyzed and compared. From the calculating results, we found that the pressure distribution, the speed vector and other parameters of the two kinds of centrifugal fans are basically same. This implies that the tool-path generating arithmetic for the machining of the impeller can meet the aerodynamic requirements of the centrifugal fan. Furthermore the method can provide proof for designing department to establish sound manufacturing tolerance for impeller.

最后采用CFD软件FLUENT，利用标准k-ε湍流模型，采用分离隐式求解器，分别对直纹面叶轮离心通风机和包络面叶轮离心通风机整体风机内部三维流场和单个通道流场进行了数值模拟计算，在计算结果的后处理中，对相同坐标值处的静压力、动压力、湍流强度和速度矢量等参数进行了分析与比较，结果表明：在相同的计算参数条件下所得到直纹面叶轮离心通风机和包络面叶轮离心通风机内部流场差别不大，从而揭示所采用的叶轮数控加工的刀位规划方法的规划误差对流体机械动力性能的影响不大，这也为设计部门制定合理的叶轮加工公差提供了依据。

Integrated with the calculation methods of soil pressure, the mechanism of soil pressure of fale is studied systematically and detailedly based on the mode of axial stress distribution of wholly grouted anchor.

在全长粘结式锚杆拉力分布模型基础之上，结合本文的土钉土压力计算方法，本文对面层土压力机理进行了系统详细的研究，提出了面层局部土压力、面层土压力及土钉最大拉力的计算公式和分布模型，理论分析和实例分析表明，本文提出的轴力分布模型和面层土压力机理是合理的，解决了面层土压力取值标准问题，为面层设计提供了定量的依掘，土钉最大拉力可直接用于土钉长度设计。

The character of heating distribution near the front and the action of diabetic heating frontogenesis on the frontal maintenance and movement are estimated by using the objective data.

利用锋面客观分析资料计算分析了南岭准静止锋锋面附近加热场的分布特征及非绝热加热锋生对锋面维持和锋面移动的作用。

Firstly, the important faces of the process of precipitation of sodium aluminate were calculated preparatory using Bravais-Friedel Donnay Harker method. Secondly, the equilibrium morphology calculations were processed on gibbsite 3×4×2 super cell and its (001),(100),(010),(011),(110),(101) and (112) slab models.

首先，用BFDH法说明了生长过程中最重要的面；其次，采用晶体平衡形态法，用Morphology程序对氢氧化铝3×4×2超晶胞及其(001)，(100)，(010)，(011)，(110)，(101)和(112)面真空slab模型进行平衡形态计算，计算结果与实验结果吻合，很好地预测了各显露面族(001)，(100)，(010)，(011)，(110)，(101)和(112)面族。

Abrasive disk for accurately grinding TI worm,as well as grinding method similar to that for globoid worm or planer enveloping hourglass worm,is used to machine hourglass worm,making the TI worm match with the worm wheel which has the same tooth surface shape as that of abrasive disk,and thus forming a new-style worm gearing .

采用精确磨削TI蜗杆的砂轮，用类似直廓环面蜗杆或平面包络环面蜗杆的磨削方法加工环面蜗杆，使该蜗杆和齿面形状与砂轮曲面相同的蜗轮相配合，形成一种新型蜗杆传动，给出了这种传动蜗杆副齿面的数学模型，并通过计算机仿真得出了这种传动蜗轮齿面上接触线的形状及分布特征，初步分析了其啮合特点。

The results show as follows: Due to unfitting between the wheel tread and profile of Frog No. 9, two-point contact occurs between the wheelset and frog and the contact patches become narrow and long; the Von Mises stress and contact force in the area of the contact patch between the tread close to the flange and the frog are so great that they go far beyond the yielding limit and enter the plastic deformation stage; this will lead to serious wearing of wheelset treads and frogs.

结果表明，由于车轮踏面与9号辙叉的型面不配合，轮对与辙叉形成两点接触，且接触斑狭长，靠近轮缘处踏面和辙叉接触斑的应力及接触力非常大，其数值远远超过材料的屈服极限，进入塑性变形阶段，这将导致车轮踏面与辙叉的磨耗严重。

Also because of the road turned to the bottom of the top players on the team at the top of the ramp, the rock loose the season still has the possibility of the Rolling Stones hit the players, Yakou the 50-100 m section of the rock surface is a monolithic block staggered zone, rock face an average of 6-7 meters high, 70-80 degrees slope is very smooth too laborious climb directly to undesirableGreat can not see well because of the snow line, and only a walk around the rock surface, in the cross section of rock surface from time to time is close to the ridge walk, the most recent is only one meter away from the cliff, and at the foot of ice or hard snow if the time is easy to slide down the ridge, more dangerous.

另外因为路线转向上方队员就在下方队员斜上方，岩石松动的季节还是有滚石击中队员的可能，垭口上50-100米路段，是整块整块的岩面交错的地带，岩面平均高6-7米，坡度70-80度，很光滑直接攀上太费力不可取，由于雪大看不出好的路线，只有绕着岩面走，在跨越岩面时有部分路段是贴着山脊走，最近的离悬崖仅一米，而且脚下如果结冰或者是硬雪时很容易滑下山脊，比较危险。

High yield,well-defined gold nanocrystals with shape of icosahedron were synthesized by the rapid reduction of gold precursors with ethylene glycolin presence of polyunder hydrothermal condition for 1 h.Au icosahedron is one of multiple twinned particleswhich has 20 faces,each were enclosed by {111} facet.

采用水热法在乙二醇体系中成功的制备出了形状规则、尺寸为200-300nm的二十面体金纳米粒子，研究结果表明，所合成的纳米颗粒是面心立方晶型，每个晶面都是{111}面。

Firstly, This paper processes geometry filtration based on character of orbit's apogee and perigee after orbit model is analyzed and based. Secondly Space Debris is separated into two kinds, coplanar and not coplanar according as location interrelation of target and debris. In Dynamic filtration's processing, considering prediction time limit and orbit perturbation, secular effects which have increaser effect is considered so that some need catching danger time point is appeased, some law about time when target and debris pass intersectant line each other is inferred, when debris and object are in different plane and some similar law also is inferred otherwise. The time list is arithmetical progression. These laws can improve calculation efficiency remarkably; Lastly orbit predict is a course approaching least distance. Danger time point in the last step become beginning time point from which debris and object's position and velocity are calculated by SXP4 Model which is an analytic model.By result, determine that relative movement trend is closer or apart, farther calculate the interval apart from time when predictive least relative distance occurs. Least relative distance and time when least distance occurs is calculated finally. It is a fast approach course adopting varied interval.

本文在分析、建立轨道摄动计算模型的基础上，首先采用基于轨道远、近地点特征对大量编目在册的空间碎片进行初步几何静态筛选，然后根据碎片与目标轨道面的相对位置特点把碎片分为异面与准共面两种情况以进行动态筛选，在筛选过程中考虑到预报时限长度和轨道摄动影响，引入了轨道摄动中具有积累效应的长期项以满足危险时间点的捕捉要求，利用了长期项摄动变化线性的特点导出了碎片与目标异面情况下各自过交线的时间序列成准等差数列的规律性和准共面情况下类似的规律性，从而显著地提高了前期轨道筛选的计算效率；最后对剩余危险碎片和目标飞行器利用SXP4轨道预报模型在前期轨道筛选的基础上以各个危险探测时间点为预报的时间起点，并根据预报计算结果，分析目标和碎片在该时间点的运动趋势是相互远离还是相互接近，推出预计最小相对距离发生时刻相对此刻的时间长度，得到其随时间变化的局部最小相对距离以及危险距离发生的时刻和相对速度，这是一个采用变时间步长、快速逼近最小相对距离的过程。

High melt surface stability could be obtained when molten metal level is located equally with upside of induction coil.

在电源频率一定的情况下，当金属液面与线圈上平面平齐时，液面波动平缓，在施加相同功率的交变电磁场条件下所得液面形状凸起越高，是电磁铸造所要求的液面状态。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。