In the theory of blast waves

The behavior of the blast wave from an exploding spherical volume is investigated mathematically over the entire range of blast-wave propagation. The computational method uses analytical results for a similar problem for a point explosion with counter pressure and the theory of an asymptotically equivalent point explosion. The asymptotic solution of the gas-dynamic equations away from the explosion site is matched to the initial conditions of blast-wave formation due to the disintegration of the detonation shock upon its arrival at the boundary of the exploding volume. The spatial distribution of the blast-front pressure is found for combustible gaseous systems and solid explosives. The theoretical results obtained agree quantitatively with available experimental measurements. __________ Translated from Fizika Goreniya i Vzryva, Vol. 42, No. 4, pp. 93–99, July–August, 2006.     

变温条件下HDPE/CB的正电子湮灭特性

对掺杂了25份（phr）导电炭黑（CB）的样品进行了正电子湮灭寿命谱的变温测量，在玻璃化转变温度以上，随着温度的增加，自由体积的大小线性增加，在玻璃化转变温度以下，自由体积的大小基本不变，o-Ps的强度在－40℃下基本不变，从－40℃以上开始增加，但在50℃以上上升有加快的趋势，与PTC材料的PTC现象和导电性能有一定的关联。     

浅谈诺兰达工艺控制

介绍了诺兰达炉氧平衡控制方法 ,对控制中常见的问题总结了一些相应措施。     

一种提高低温流体比体积计算精度的方法

采用了一个既能提高立方型状态方程比体积计算精度，又不影响气液平衡条件的简单摩尔修正项来改进PR方程比体积的计算。本文对19种低温流体给出其修正项的值，计算饱和蒸气和液体比体积，并与未修正的PR方程的计算值比较，结果表明这种修正能显著提高低温流体（包括量子流体氢、氦和强极性的氨气）饱和液体比体积的计算精度，并对蒸气比体积的计算也略有改进。     

低剂量X射线照射诱导HeLa细胞存活的

采用集落形成法观察了低剂量X射线照射HeLa细胞的存活率，结果表明，小于0．5Gy的X射线照射细胞的存活率高于对照，得到了HeLa细胞存活的“兴奋效应”，而且在0．25Gy附近这种效应更为明显；低剂量D1（0．05，0．75Gy)的预照射降低了随后攻击量D2对细胞的损伤程度，反映出低剂量照射可诱发细胞存活的“适应性反应”。     

孤岛原油正庚烷和正戊烷沥青质乳化能力研究

从孤岛原油中分离出正戊烷和正庚烷沥青质，元素分析和红外光谱分析结果表明，相对分子质量较大的正庚烷沥青质，含杂原子和极性基团较多。将两种沥青质溶于甲苯配制的模型油，分别与蒸馏水、模拟地层水、0～900mg／LHPAM溶液、0～500mg／L黏土液按1：10体积比充分乳化，测定静置时水相（水包油乳状液）透光率，据以考察沥青质的乳化能力，结果表明：正庚烷沥青质的乳化能力强于正戊烷沥青质；矿化离子使沥青质的乳化能力减弱；随聚合物浓度增大，沥青质乳化能力增强；黏土在浓度小于200mg／L时使乳化能力减弱，浓度大于200mg／L时使乳化能力增强。模型油与HPAM溶液间的界面张力，在聚合物浓度100mg／L时有最小值，在500mg／L时有最大值，正庚烷沥青质模型油的界面张力随聚合物浓度的变化较剧烈。正庚烷模型油在聚合物溶液中的乳化油滴直径分布范围较正戊烷模型油窄，聚合物浓度较大时，油滴直径分布范围较宽。正庚烷沥青质模型油与黏土液闸的界面张力，在黏土液浓度增至300mg／L时略有升高，浓度继续增大时大幅升高，而正戊烷模型油的界面张力在黏土液浓度300mg／L时有最低值。图9表3参7。     

碘量法测铜中物质性质和分析操作

本文讨论了碘量法测定铜量中一些有关物质的特性,以及这些性质对分析条件和操作的要求。     

Surface Hardening of High-Strength Low Alloy Steels (HSLA) Dual-Phase Steels by Ball Burnishing Using Factorial Design

Burnishing is used increasingly as a finishing operation which gives additional advantages such as increased hardness, fatigue strength, and wear resistance. Experimental work based on 3⁴ factorial design was carried out to establish the effects of ball burnishing parameters on the surface hardness of high-strength low alloy steels (HSLA) dual-phase (DP) steel specimens. Statistical analysis of the results shows that the speed, feed, lubricant and ball diameter have significant effect on surface hardness.     

Polygonal extrusion

A sweeping operation called polygonal extrusion is defined to improve the modeling power of CSG-based modeling. It is assumed that a 2D cross-sectional polygon (sweeping polygon) moves in space while its containing plane is kept orthogonal to the tangent direction of the trajectory curve, a planar polygonal chain having no self-intersections. The objective of the paper is to compute the boundary of the swept volume of the sweeping polygon as a set of polygons (or triangles). The most significant challenge to accomplishing this objective is the problem of trimming the swept volume. To solve the trimming problem, 2D-curve offsetting methods are employed. Two algorithms are presented for polygonal extrusion that are based on different offsetting methods, the Voronoi diagram and PWID offset. The proposed algorithms have been implemented and tested with various examples. Published online: 28 January 2003     

纤维体积分数对K3D/MCPA复合材料力学性能的影响

本文研究了纤维体积分数对三维编织芳纶纤维增强铸性尼龙(简称K3D／MCPA)复合材料力学性能的影响。研究表明，K3D／MCPA复合材料有优异的抗冲击性能，冲击强度比三维编织芳纶纤维增强铸性尼龙(简称C3D／MCPA)和纯基体均有大幅度的提高，且随着纤维体积的提高而升高。K3D／MCPA复合材料剪切强度随纤维体积比的增大而增大，其纵向剪切强度低于纯基体和C3D／MCPA复合材料，但其横向剪切强度高于它们。K3D／MCPA复合材料弯曲强度与弯曲模量随纤维体积比的提高而提高，但与相同体积比的C3D／MCPA相比，K3D／MCPA的弯曲强度与弯曲模量均较低。