Fatigue life calculation by means of the cycle counting and spectral methods under multiaxial random loading

The paper contains a new algorithm for estimation of fatigue life in HCF regime under multiaxial random loading using spectral methods. Loading of Gaussian distribution and narrow‐ and broad‐band frequency spectra were assumed. Various characteristic states of multiaxial loading were considered. The equivalent stress history was determined with use of the failure criteria of multiaxial fatigue based on the critical plane. For determination of the critical plane position, the method of variance was applied. During simulation, the authors compared the results obtained by a spectral method in the frequency domain with those from the rain‐flow algorithm in the time domain. The paper also contains the results of fatigue tests for 18G2A structural steel subjected to bending and combined bending with torsion. The tests were performed in order to verify the proposed algorithms for determination of fatigue life. It has been shown that under multiaxial random loading results of fatigue life calculated according to the considered algorithms in frequency and time domains are well correlated with the results of experiments.     

高职学生网络成瘾行为及调适

通过对高职学生中存在的网络成瘾问题的长期关注，对其危害深有感触，着重分析其内外诱因，讨论了用团体辅导的方式等进行调适的办法。     

机械设计制造及其自动化专业高素质人才培养探讨

简要介绍机械设计制造及其自动化专业人才的培养目标和业务规格，特别对如何培养专业水平高、实践能力强、综合素质全面的高层次专业人才进行详细探讨。     

Development of grain boundary allotriomorphic ferrite/granular bainite duplex steel

A new hot-rolled low alloy high strength steel with grain boundary allotriomorphic ferrite/granular bainite duplex micro-structure has been developed through novel microstructure and alloying designs without any noble metal elements such as nickel and molybdenum. Its as-rolled microstructure and mechanical properties, fatigue crack propagation behavior compared with single granular bainitic steel as well as continuous cooling transformation, were investigated in detail. The measured result of CCT (continuous cooling transformation) curve shows that such duplex microstructure can be easily obtained within a wide air-cooling rate range. More importantly, this duplex microstructure has much better combination of toughness and strength than the single granular bainite microstructure. It is found that the grain boundary allotriomorphic ferrite in this duplex microstructure can blunt the rni-crocrack tip, cause fatigue crack propagation route branching and curving, and thus it increases the resistance to fati     

Modification of High Performances of Polymer Cement Concrete

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SABUL: A Transport Protocol for Grid Computing

This paper describes SABUL, an application-level data transfer protocol for data-intensive applications over high bandwidth-delay product networks. SABUL is designed for reliability, high performance, fairness and stability. It uses UDP to transfer data and TCP to return control messages. A rate-based congestion control that tunes the inter-packet transmission time helps achieve both efficiency and fairness. In order to remove the fairness bias between flows with different network delays, SABUL adjusts its sending rate at uniform intervals, instead of at intervals determined by round trip time. This protocol has demonstrated its efficiency and fairness in both experimental and practical applications. SABUL has been implemented as an open source C++ library, which has been successfully used in several Grid computing applications.     

High Order Finite Difference Approximations of Electromagnetic Wave Propagation Close to Material Discontinuities

Electromagnetic wave propagation close to a material discontinuity is simulated by using summation by part operators of second, fourth and sixth order accuracy. The interface conditions at the discontinuity are imposed by the simultaneous approximation term procedure. Stability is shown and the order of accuracy is verified numerically.     

多通道同步高速数据采集系统研制

介绍了一个最高采样率为100MHz，采样精度为8bit，基于PCI总线和计算机并口的8通道同步高速数据采集系统的设计，整套系统具有同步误差小、触发方式多样、操作灵活等特点。     

我国城乡居民照明用电状况调查分析

本文介绍了一次全国性的居民家庭照明用电抽样调查研究案例，全面而系统地分析了我国城乡居民家庭照明用电情况和各类照明光源在居民家庭中的使用状况。     

提高200MW机组高压加热器投入率的研究

通过对武汉钢电股份有限公司2台200MW机组2年来高压加热器运行状况的统计分析，找出影响高加投入率的主要原因，提出相应的技术改造和技术措施，大大提高了高加投入率。