管下的

It is shown that the mechanical properties including Young's modulus, tensile strength, critical strain and stress under buckling can be enhanced with the decreasing of intershell spacing. The shear strength can be enhanced by 2-3 orders of magnitude when the intershell spacing is reduced to 20%, which is also dependent on commensuration. Zigzag-type carbon nanotubes have higher shear strength. The axial stress in tubes when the load transferring from outmost tube to inner tube is observed as well.

研究了单壁纳米管束横截面的六方化失稳现象，给出各种管径的面内压力－应变关系曲线；每条曲线都给出一个明显的拐点而且有很强的非线性；线弹性模量与参考构形有关，也受管直径的影响；分析了管束横截面的晶格不稳定性特征，表明晶格的缺陷能够明显的减小临界值；模拟了在不同应变下纳米管束对静水压的反应，发现不同压力下的截面形态不同，在很高压力下相邻管之间会形成化学键。

The characteristics of pressure fluctuation in a standpipe at negative pressure gradient were investigated based on measurement in the gas-solid two-phase circulating fluidized bed.

通过对气固循环流化床负压差下料立管的压力测量，分析了立管下料过程的压脉动特性。

Worn surface morphology was examined with scanning electron microscopy, and wear volume was measured with a Talysurf 5P-120 topographer. Results show that CNTs, in mass concentration of 0.01%~0.1%, can greatly improve the antiwear ability of lubricating oil. With addition of CNTs, the maximum reduction of wear rate is about 57%, and scratches on the worn surfaces become slighter and more uniform. The maximum decrease of friction coefficient is about 15% with 0.025% CNTs additive at the load of 300 N. The antiwear mechanism has been discussed.

结果表明：碳纳米管作为润滑油添加剂表现出优良的抗磨性能，在质量分数仅为0.0125%～0.1000%时，润滑油的抗磨性能显著提高；在质量分数约为0.0500%时其抗磨效果最佳，磨损率降低幅值达57%；在较高载荷下，添加0.0250%的碳纳米管能够使其摩擦系数减小约15%，但随着碳纳米管质量分数的增加，摩擦系数迅速提高；含碳纳米管润滑油的磨斑表面平整，划痕较细且分布均匀。

METHODS: The endodontic instrument was assumed as a metal conical bar. The normal stress of bending loads and the shear stress of torsional loads were calculated with the knowledge of mechanics. The relations between stress and such parameters as angle and radius of canal curvature, radius of instrument, polar moment of inertia, and metal elastic modulus were analyzed. The criteria for yielding and fracture of the instrument were discussed.

将根管器械刃部假设截面为圆的金属细锥杆，利用材料力学及断裂力学的原理与方法，分别计算根管器械在弯、扭载荷下的应力分布，分析应力与根管弯曲角度、根管弯曲半径、器械直径、器械横截面极惯性距、金属弹性模量等参数的确切关系；探讨器械屈服、断裂失效的准则。

METHODS: The endodontic instrument was assumed as a metal conical bar, the normal stress of bending loads and the shear stress of torsional loads were calculated with the knowledge of mechanics , the relations between stress and such parameters as angle and radius of canal curvature, radius of instrument, polar moment of inertia, metal elastic modulus were analyzed, the criteria for yielding and fracture of the instrument were discussed .

将根管器械刃部假设为截面为圆的金属细锥杆，利用材料力学及断裂力学的原理与方法，分别计算根管器械在弯、扭载荷下的应力分布，分析应力与根管弯曲角度、根管弯曲半径、器械直径、器械横截面极惯性距、金属弹性模量等参数的确切关系；探讨器械屈服、断裂失效的准则。

The method of CFD numerical simulation is employed to replace experimental investigation. Hence, STAR-CD of the commercial software is used to simulate the outer flow field and heat transfer performance of integrated heat sink with heat pipes cooled by airflow. It is found that simulated results agree with experimental results well, which indicates that simulation method is reasonable and reliable. Further, simulated computations for different fin thickness, fin pitches and air velocities are performed to analyze their effects on heat transfer performance of heat sink. Finally, a new optimized structure of integrated heat sink with heat pipes is provided to meet future demands for cooling CPU and its heat transfer is also evaluated. For multi-heat source and higher dissipation power of electronic devices, the integrated heat sink with heat pipes attatched fins stagged in different positions of channels is presented and its flow and temperature fields are also simulated to enhance heat transfer. As a conclusion, all mentioned above are useful for the design of heat sink with excellent efficiency of heat dissipation and further research.

应用商业软件Star-CD对CPU集成热管散热器的外部流场和传热特性进行了数值模拟，将数值模拟结果和试验结果对比，验证了所提出的数值计算方法是可靠和可行的；利用此数值模拟方法对CPU集成热管散热器在不同散热翅片间距、厚度和气流速度下散热器的流动与传热性能进行了数值计算，分析了这些参数的变化对散热器传热性能的影响；针对未来CPU冷却的要求，确定了与最优气体流速匹配的最佳翅片间距、厚度的CPU集成热管散热器的新结构；利用试验评测了根据数值模拟提供的新结构开发出的新CPU集成热管散热器的传热性能；最后在场协同强化传热的理论的基础上，对CPU集成热管散热器的散热翅片错位排列来强化散热器的散热，满足未来大功率、多热源的电子元件的散热，为今后进一步优化散热器提供了依据。

For the problem of the ratio of inner to outer diameter of long tube, according to the "residual core" in the target plays an important role in DOP of long tube penetrator, the analytical model of long tube pentration in semi-infinite homogeneous steel target is established and calculated to devide three kinds of different scopes, the rule of varied by the ratio of inner to outer diameter is analyzed. The patterns of penetration of the yawed tubular against a normal homogeneous semi-infinite target is established, the size and direction of "residual core" is analyzed, under the different impact yawed, the regularity of variations in the yawed of the tube and depth of the penetrateion is described during the penetrateion against the plate.

二是对于长管体的不同内外径比，依据长管体时形成的中间&靶芯&是其侵彻机理不同于长杆体的重要因素，分三种情况建立了长管体对半无限均质靶板的简化理论模型，并进行了分析，得出了穿深随内外径比变化的规律；描述了带攻角长管体垂直侵彻半无限厚靶的物理图像，分析了&靶芯&力的大小和方向，建立了侵彻简化模型，给出了在不同的初始攻角条件下，管体在侵彻过程中攻角和穿深的变化规律。

Down pull effects during settlement result in the loads acting on top of projecting conduit are larger than the self weight of the soil above the conduit. On the other hand, for ditch conduits, the pressures on them are smaller than the self weight of the soil above them.

埋管受力与结构及其两侧土体的刚度有很大关系，上埋式管道，其两侧覆土变形相对大于管顶覆土，沉降中产生向下的拖曳效应，致使管顶受到相对其上土体自重更大的荷载，而沟埋式管道则与此相反，管顶受荷小于其上土体自重。

The down tube takes full advantage of the bottom bracket shell's 90mm width, the top and down tubes are pushed right up to the edges of the integrated head tube, and the top tube is fairly broad throughout its length.

在下管充分利用的中轴 shell 的90毫米宽，顶部和下管权推到综合管头部的边缘，而上管是其整个长度相当广泛。

On the basis of the existing sieving method of sieving thyratrons, serving the typical fuze detonating circuit as the circuit of sieving thyratrons, and applying the operation conditions of the typical fuze detonating circuit in the sieving circuit, we can measure more accurately the turn on voltage, trigger voltage, turn on time, and leak of electricity of the thyratrons.

在现有闸流管检测方法的基础上，将实际的引信起爆电路作为闸流管的检测电路，将起爆电路的工作条件施加于检验电路，可以更准确地给出闸流管的导通电压、触发电压，同时测量出闸流管的导通时间以及闸流管在关断状态下的漏电流。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了