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.     

大亚湾核电站实施18个月换料的放射性后果评估

针对大亚湾核电站实施18个月换料技术改造的特点，计算了大亚湾核电站在正常运行工况下以及各种设计基准事故工况下对周围环境的放射性后果。计算结果表明，大亚湾核电站实施18个月换料技术改造后，正常运行工况安全设施的性能满足GB6249－86的要求。     

Aspects of microstructure in low carbon steels produced by the CSP process

The solidification structure, microstructure evolution during rolling and precipitates with nanometers in dimension of the low carbon steels produced by CSP process with thin slabs have been studied in recent years. Important differences in microstructure and mechanical properties between the CSP products and the conventional one were observed. These differences may arise from the much rapider solidification rate and cooling rate after casting of the thin slabs. Some aspects of the microstructure for the low carbon steels of the CSP thin slabs are summarized and compared with the conventional one.     

Plasma Induced Degradation of Benzidine in Aqueous Solution

The degradation of benzidine in aqueous solution by the low temperature plasma was examined. The results showed that the concentration of medium and the value of pH have an appreciable effect on the degradation of benzidine. What is more important is that iron ions acting as a catalyst play an important role in this reaction. For exploring the degradation mechanism of benzidine, some of the intermediate products were recorded by HPLC (high performance liquid chromatography).     

万家寨水电站经济运行的措施

针对黄河近几年来水量逐年减少和电力市场的变化 ,对提高万家寨电站的经济运行效益问题 ,进行了分析     

快淬贮氢合金的活化性能与寿命

主要讨论了快淬钛基合金具有良好活化性能及较差循环寿命的机理。研究结果表明:快淬钛基合金电极浸泡在碱液中,合金元素V、Zr、Ti、Mn、Ni以不同速度溶解,其中Ni的溶解速度最慢,使合金电极表面富Ni。富Ni电极表面具有良好的动力学性能,快淬钛基贮氢合金的放电容量急剧衰退与损失大量可吸氢的V、Zr元素密切相关。     

三相电压型低谐波PWM整流器主电路参数间的关系

三相电压型低谐波PWM整流器主电路的多个参数之间的关系较为复杂，在仿真和实验中，若给出的参数不合理，则变换器不能正常工作，从而给仿真和实验带来一定困难。文章在考虑了输入电阻的情况下，给出了功率因数角为任意值时，主电路各参数和控制参数间的稳态关系及一些参数的约束关系。上述关系对于分析和设计被研究电路具有很好的指导意义，文中的公式通过了仿真验证。     

溶胶玻璃原位合成碳纳米管的研究

目前，碳纳米管的各种制备方法如电弧法、激光消融法、催化热解法及化学气相沉积法等，都是在500～3500℃温度范围内经由气固相接触表面合成的，从而使反应的深度和广度都受到了限制．利用固相热解法尝试在溶胶玻璃中原位合成碳纳米管，该方法可以使反应在整个固相范围内同时发生，而不只是在气固相的表面合成．在制备样品的过程中采用了溶胶-凝胶法，成功地将碳源(乙酰丙酮)和催化剂(硝酸钴)均匀地分散在SiO，溶胶玻璃中，制备了纳米级的复合材料．另外，选择了乙酰丙酮作碳源，将碳纳米管的合成温度降到了400℃，实现了在低温固相条件下原位合成碳纳米管．最后通过TEM对生成的纳米碳管进行表征．     

Q345C低合金高强度结构钢板的试制

介绍采用氧气顶吹转炉→吹氩喂丝→板坯连铸→控制轧制生产Q345C低合金高强度结构钢板的生产工艺。通过对化学成分的合理设计及制订适合该厂冶炼、连铸、轧制的工艺，采取微合金化和控轧控冷相结合的有效技术措施，提高钢板的综合性能，特别是低温冲击韧性。生产的Q345C钢板，其产品质量完全符合GB／T1591—94标准要求。     

某星载大口径天线子系统的力学仿真分析

星载天线在发射及在轨阶段将面临严酷的力学环境,要求具有极高的可靠性。为了验证其刚度和强度,缩短研发周期,文中采用NX Nastran软件建立了某星载大口径天线子系统的力学仿真模型;为了验证仿真的有效性,进行了该天线子系统的模态测试,经对比发现两者数据一致性较好;基于建立的有限元模型,分析了该天线子系统在正弦振动和热循环环境工况下的结构响应和受力情况,得到了相应的加速度、位移和应力云图。结果表明,该天线子系统的结构刚强度均满足星载环境要求。该仿真分析对星载天线子系统的结构设计具有重要的指导意义。