低碳贝氏体钢的组织类型及其对性能的影响

低碳贝氏体钢受控冷工艺的影响会得到不同类型的组织，在较慢速冷却时，在奥氏体中先形成针状铁素体，残余奥氏体会被包裹在铁素体之中，形成粒状贝氏体团。工业轧制试验表明．不同控制冷却工艺可得到两类组织，一类出现黑珠组织(富碳马氏体组织)．具有该组织的钢轧态冲击韧性低。另外一类为细化的板条贝氏体组织，具有该组织的钢轧态强度高，冲击韧性好，但伸长率不足。通过回火处理，存在黑珠组织钢的冲击韧性能得到提高，超细化板条贝氏体组织钢的伸长率也能得到改善，但后者屈服强度会比前者高100MPa左右。     

40MnV钢中微合金元素氮-碳化物的析出行为

用Thermo-cale软件对微合金钢40MnV(%：0．36-0.40C，1．36～1.40Mn，0.8～0.9V，0.011-0．016Ti，0．021-0．045Al，0．007-0．016N)中的析出相进行计算，并用电解分析，X-衍射，透射电镜研究了析出相的成分、形貌和分布。结果表明，钢中少量的N和Ti可导致在固液两相区析出尺寸为50nm的粗大TiN粒。随温度降低，析出相尺寸逐渐减小到10nm以下，形状由方形变成圆形，且析出相中V和C含量增加，N和Ti含量减少。随着钢中铝含量的增加，VN析出量减少。     

M理论的时空探讨

M理论是当今物理学最深奥的理论之一，其中涉及到一系列新时空观点，它给物理学家提出了新的挑战。本文从M理论的基本内容出发，阐述其带来的新的时空观点，以澄清物理学的困惑。     

Statistical approach and benchmarking for modeling of multi-dimensional behavior in TRISO-coated fuel particles

The fundamental design for a gas-cooled reactor relies on the behavior of the coated particle fuel. The coating layers, termed the TRISO coating, act as a mini-pressure vessel that retains fission products. Results of US irradiation experiments show that many more fuel particles have failed than can be attributed to one-dimensional pressure vessel failures alone. Post-irradiation examinations indicate that multi-dimensional effects, such as the presence of irradiation-induced shrinkage cracks in the inner pyrolytic carbon layer, contribute to these failures. To address these effects, the methods of prior one-dimensional models are expanded to capture the stress intensification associated with multi-dimensional behavior. An approximation of the stress levels enables the treatment of statistical variations in numerous design parameters and Monte Carlo sampling over a large number of particles. The approach is shown to make reasonable predictions when used to calculate failure probabilities for irradiation experiments of the New Production - Modular High Temperature Gas Cooled Reactor Program.     

具有输入饱和的组合系统的分散控制

研究了一类具有饱和输入的组合系统的分散可镇定问题. 运用M-矩阵方法, 通过线性分散状态反馈得出具有饱和输入组合系统的可镇定的充分条件. 对于具有对称结构的组合系统, 给出了更为简单的镇定条件.     

Multiresolution Visualization of Higher Order Adaptive Finite Element Simulations

h –p–adaptive projection with respect to any prescribed threshold value for the visual error. This projection can then be processed by various local rendering methods, e.g. color coding of data or isosurface extraction. Especially for color coding purposes modern texture capabilities are used to directly render higher polynomial data by superposition of polynomial basis function textures and final color look-up tables. Numerical experiments from CFD clearly demonstrate the applicability and efficiency of our approach. Received September 25, 2001; revised March 31, 2003 Published online: May 26, 2003 The authors acknowledge the valuable hints of the anonymous referees.     

细纱工序4M1E对纱线毛羽的影响与控制

在环锭纺纱系统中,细纱工序是产生纱线毛羽的主要工序.本文介绍了毛羽的概念、分类、考核指标及对织物的影响,分析了细纱工序纱线毛羽的形成原因,并通过一系列实验,论述了人、机器、原料、方法、环境等因素对纱线毛羽的影响及相应的控制措施.     

与排队系统G／G／1有关的一些结果

Ｎ．Ｕ．Ｐｒａｂｈｕ在文献［１］中利用随机游动研究Ｇ／Ｇ／１系统得到一些有趣的结果，但文献［１］Ｐ．３３定理１４的陈述不准确。本文对该定理提出修正意见，即对于Ｍ／Ｍ／１系统，Ｎ与Ｉ＝－ＳＮ仅在条件概率空间（Ω，Ｆ，Ｐ［Ｎ＜∞］）上是独立的。此外对Ｇ／Ｍ／１系统给出计算ｐ＝Ｐ［Ｎ＜∞］的公式，并且证明Ｎ与ＳＮ在（Ω，Ｆ，Ｐ［Ｎ＜∞］）上独立     

相对投射复盖

推广了投射复盖的概念，定义了相对投射复盖，讨论了它存在的条件，得出了模Ａ有Ｍ—投射复盖当且仅当存在Ｍ—投射模Ｐ及满同态ｆ：Ｐ→Ａ，使得Ｋｅｒｆ≤ｏＰ。并利用它刻划了完全环，得出了环Ｒ为完全环当且仅当任意半单模Ａ有Ｒ（Ａ）—投射复盖。