Probabilistic Analysis of the Reliability and Fatigue Life of Machine Parts by Fatigue Failure

Journal of Machinery Manufacture and Reliability - The problem of calculating the reliability and fatigue life of machine parts by the fatigue failure under random changes in the actual and limit...     

Preparation of Silver Nanowires via a Rapid,Scalable and Green Pathway

Rapid synthesis of silver nanowires(Ag NWs) with high quality and a broad processing window is challenging because of the low selectivity of the formation of multiply twinned particles at the nucleation stage for subsequent Ag NWs growth.Herein we report a systematic study of the water-involved heterogeneous nucleation of Ag NWs with high rate(less than 20 min) in a simple and scalable preparation method.Using glycerol as a reducing agent and a solvent with a high boiling point,the reaction is rapidly heated to 210 ℃ in air to synthesize Ag NWs with a very high yield in gram level.It is noted that the addition of a small dose of water plays a key role for obtaining highly pure Ag NWs in high yield,and the optimal water/glycerol ratio is0.25%.After investigating a series of forming factors including reaction temperature and dose of catalysts,the formation kinetics and mechanism of the Ag NWs are proposed.Compared to other preparation methods,our strategy is simple and reproducible.These Ag NWs show a strong Raman enhancement effect for organic molecules on their surface.     

Simulation of characteristics of double-junction solar cells based on ZnSiP2 heterostructures on silicon substrate

Design and operation modes of double-junction monolithic lattice-matched solar cells based on the ZnSiP₂/Si system of materials have been calculated. The effect of the photoactive region thickness and minority carrier lifetime in ZnSiP₂ layers on the efficiency of conversion of the incident solar light energy into electrical power was determined. It is shown that solar cells based on ZnSiP₂/Si heterostructures can provide efficiencies of 28.8% at AM1.5D, 100 mW/cm², and 33.3% at AM1.5D, 200 W/cm².     

On Application of Carbon-Containing Electrode Materials in Technology of Electrospark Alloying: Part 1. Peculiarities of Coating Formation Using Electrospark Treatment of Titanium Alloy OT4-1

Electrospark treatment of OT4-1 titanium alloy was performed sequentially with a STIM-20N hard-alloy electrode (TiC–20% Ni) and carbon-containing material (graphite and carbon-based composite materials). Kinetics of the mass transfer of the hard-alloy electrode was studied. The cathode mass loss during the first minute of the treatment was established. The kinetics results were processed using the methods of mathematical statistics. The erosion resistance of the applied carbon-containing materials was determined. Phase composition and relief of the coatings formed were analyzed. It was found that the application of the carbon-containing material increases the content of refractory phases in the coatings. Increase in the time of the treatment using the carbon-containing materials decreases the roughness of the coatings.     

渤海湾盆地石油地质储量和产量增长趋势的预测

渤海湾盆地的石油地质储量发现过程具有明显的渐进性、阶段性和长期性，石油产量的增长也具有一定的起伏性，用一个周期的单旋回哈伯特模型难以预测其发展趋势。通过分析渤海湾盆地的勘探开发历程，结合新一轮常规油气资源评价的结果，分别采用4个和3个哈伯特旋回拟合石油地质储量发现和产量增长曲线。预测结果显示，2005-2015年渤海湾盆地处于石油地质储量发现高峰期，2015年左右其石油产量达到高峰，之后处于下降趋势。实践证明，利用多旋回哈伯特模型对具有“多峰”特征的石油地质储量和产量的未来趋势进行预测是一种有效的方法。     

反转构造的反转程度及其与油气聚集的关系

结合典型反转构造地震剖面，分析了断层型和褶皱型两类反转构造的反转程度，上下皆正断层型和向形褶皱型反转构造的反转程度轻微；上逆下正断层型和透镜形褶皱型反转构造的反转程度中等；上下皆逆断层型和背形褶皱型反转构造的反转程度强烈。分析了反转构造的反转程度与油气聚集的关系，处于轻微反转程度的上下皆正断层型反转和向形褶皱型反转，以及处于强烈反转程度的上下皆逆断层型反转和背形褶皱型反转不利于油气聚集；处于中等反转程度的上逆下正断层型反转和透镜形褶皱型反转类型有利于油气聚集成藏。     

低勘探程度区域油气资源评价方法

目前中国油气资源勘探和开发面临后备可采储量不足，低勘探程度区域受到重视。为了提高低勘探程度区域的资源评价精度，在前人评价的基础上，通过研究并利用勘探程度较高区域的资源评价结果，求准低勘探程度区域的油气聚集量，进而模拟求出其烃排聚系数、储量密度系数、单储系数和单生系数等关键参数，提出了利用练台地质推断法对低勘探程度区域进行评价，并对该方法评价的风险进行了分析。综合地质推断法的成果更能准确反映一个盆地、坳（凹）陷或区带的油气潜力及其分布特征。     

控制爆破在复杂基坑开挖中的应用

在紧邻厂房中控室的基坑开挖中，根据复杂环境条件与施工要求，采用浅孔微差爆破并通过选取合理开沟掏槽位置来控制最小抵抗线方向以及控制一次最大起爆药量等措施，达到了控制飞石、降低爆破地震的效果，保证了爆破质量与爆破安全，提高了施工效率。     

利用整合区域特性约束提高孔隙率模拟精度

本文将空间结构变化的要求与动态资料确定的储量共同作为约束,建立了包含两个约束条件的目标函数, 应用模拟退火算法对孔隙率的空间分布进行预测。在实现过程中,通过初始控制参数的给定及目标函数修改提高了运算效率。由于目标函数有效地整合了静、动态信息,从而降低了模拟结果的不确定性．提高了模拟的精度。合成数据及实际数据的模拟试验表明,整合区域特性约束不仅提高了孔隙率模拟精度,而且算法收敛快、稳定性高。     

应用数字PWM器件SA4828的大功率直流电源

本文介绍一种智能型、高精度PWR控制器SA4828，其控制实行全数字化产生三相脉宽调制波形．本文采用此器件设计大功率直流电源应用于22KW直流电机测试，对感性负载表现出具有纹波小，响应迅速、硬件电路简洁、控制简单易于编写的优点。