《振动与冲击》征稿简则

<正>《振动与冲击》是中国振动工程学会、上海交通大学、上海市振动工程学会联合主办的反映和交流我国力学、航空、航天、造船、车辆、机械、土木建筑、水利、电力、矿山、化工、冶金、仪器仪表、海洋工程、轻工、环境保护等领域的     

南川区矿产资源丰富铝土矿居重庆首位

重庆市南川区矿产资源丰富,已发现的矿产有煤、铁、铝土矿、水泥用灰岩、建筑石料用灰岩、玻璃用砂岩、铸型用砂岩、陶瓷用砂岩、水泥配料用砂岩、砖瓦用页岩、方解石、萤石、滑石、硫铁矿、耐火粘土、水泥配料用页岩、化肥用砂岩、镓、饰面用大理石、地热、矿泉水等20余种,已开发利用的有9种,即煤、铝土矿、石英砂岩、砖瓦用页岩、石灰岩、方解石、萤石。     

《振动与冲击》征稿简则

《振动与冲击》是中国振动工程学会、上海交通大学、上海市振动工程学会联合主办的反映和交流我国力学、航空、航天、造船、车辆、机械、土木建筑、水利、电力、矿山、化工、冶金、仪器仪表、海洋工程、轻工、环境保护等领域的振动、冲击和噪声方面的成果及经验的综合性学术刊物。     

瓶（桶）装饮用水质量合格率92%

8月初,国家质量监督检验检疫总局公布了对瓶（桶））装饮用水质量的抽查结果,本次共抽查了北京、天津、河北、内蒙古、辽宁、吉林、黑龙江、上海、江苏、浙江、安徽、福建、江西、山东、河南、湖南、湖北、广东、广西、重庆等20个省、自治区、直辖市294家企业生产300种瓶（桶）装饮用水产品。     

《振动与冲击》征稿简则

《振动与冲击》是中国振动工程学会、上海交通大学、上海市振动工程学会联合主办的反映和交流我国力学、航空、航天、造船、车辆、机械、土木建筑、水利、电力、矿山、化工、冶金、仪器仪表、海洋工程、轻工、环境保护等领域的振动、冲击和噪声方面的成果及经验的综合性学术刊物。本刊为国家科委中国科技论文统计源期刊、《中国核心期     

《振动与冲击》征稿简则

《振动与冲击》是中国振动工程学会、上海交通大学、上海市振动工程学会联合主办的反映和交流我国力学、航空、航天、造船、车辆、机械、土木建筑、水利、电力、矿山、化工、冶金、仪器仪表、海洋工程、轻工、环境保护等领域的振动、冲击和噪声方面的成果及经验的综合性学术刊物。本刊为国家科委中国科技论文统计源期刊、《中国核心期     

《振动与冲击》征稿简则

正《振动与冲击》是中国振动工程学会、上海交通大学、上海市振动工程学会联合主办的反映和交流我国力学、航空、航天、造船、车辆、机械、土木建筑、水利、电力、矿山、化工、冶金、仪器仪表、海洋工程、轻工、环境保护等领域的振动、冲击和噪声方面的成果及经验的综合性学术刊物。本刊为国家科委中国科技论文统计源期刊、《中国核心期刊要目总览》核心期刊。《中国知识资源总库中国科技期刊精品数据库》、《中国科学引文数据库》、《中国物理学文献数据库》、《中国学术期刊综合评价数据库》、《中国学术期刊文摘》源期刊,美国工程信息公司Ei-Compendex数据     

国家抽查：11批次酱油不合格

2011年5月27日酱油产品质量国家监督抽查结果显示,11种产品不符合标准的规定。这次国家质检总局共抽查了北京、天津、河北、内蒙古、辽宁、吉林、黑龙江、上海、江苏、浙江、福建、江西、山东、湖北、湖南、广东、四川、     

中国文献影像技术协会2011年第一次常务理事（扩大）会会议纪要

中国文献影像技术协会5月18日在北京召开2011年第一次常务理事（扩大）会。参加会议的有（以汉语配音排序）：陈林荣、曹宁、董建伟、霍力华、李恩学、李健、李铭、李昕岑、李茁、马淑桂、钱娟、孙静荣、屠跃明、王坤、王蕾、王青云、魏大威、杨成斌、张文增、张阳、张荫松、赵文山、赵志英、赵中新;未参加会议的常务理事有：耿志东、伍艺、徐建华、张美芳、镇锡慧。     

《振动与冲击》征稿简则

<正>《振动与冲击》是中国振动工程学会、上海交通大学、上海市振动工程学会联合主办的反映和交流我国力学、航空、航天、造船、车辆、机械、土木建筑、水利、电力、矿山、化工、冶金、仪器仪表、海洋工程、轻工、环境保护等领域的振动、冲击和噪声方面的成果及经验的综合性学术刊物。本刊为国家科委中国科技论文统计源期刊     

Air separation and liquefaction: recent developments and prospects for the beginning of the new millennium

Earlier advances in air separation and liquefaction include improvements in: overall product recovery, feed air purification, more efficient heat exchange, optimum plant control, gradual improvement in efficiency of compressors and expanders. More recent improvements include use of structured packing in distillation columns, molecular sieve adsorbents for air purification, computer simulation and control of plants, and increased machinery efficiency. Advances in fabrication and construction techniques are aimed at reducing capital costs. This paper reviews modern developments in air separation and liquefaction and attempts in this context to suggest features that might be expected to arise in the early part of the third millennium.     

驾驶员对异色物体动态距离判识对比

为研究在动态环境中,颜色因素对驾驶员空间距离判识的影响,本文选用32名驾驶员在不同深度距离和车速条件下,进行实际道路试验.驾驶员分别在昼间、黄昏和夜间对不同颜色障碍物空间距离进行判识,分析检验判识结果.结果表明:在地面动态环境中,白天不同颜色距离判识差异不显著,黄昏随着环境照度下降,判识差异显著,夜间使用灯光照明时,距...     

AutoCAD与Word和Excel图文转换的效果处理

AutoCAD计算机辅助设计软件、Word字处理软件和Excel电子表格处理软件得到了极为广泛的应用，但Word本身能绘制图形的能力很有限，用于绘制标准的工程图则更难。而使用AutoCAD绘图时，要写入大量的文本和表格也十分不便，利用Word或Excel处理软件的特点写入文字或表格，然后插入到AutoCAD绘图文件中，会取得意想不到的效果。针对在AutoCAD与Word和Excel图文转换过程中存在的问题进行了深入探讨，从而完善了工程文件中不同软件的协同设计。     

Parity-Time Symmetry in Non-Hermitian Complex Optical Media

The exploration of quantum-inspired symmetries in optical and photonic systems has witnessed immense research interest both fundamentally and technologically in a wide range of subject areas in physics and engineering. One of the principal emerging fields in this context is non-Hermitian physics based on parity-time symmetry, originally proposed in the studies pertaining to quantum mechanics and quantum field theory and recently ramified into a diverse set of areas, particularly in optics and photonics. The intriguing physical effects enabled by non-Hermitian physics and PT symmetry have enhanced significant application prospects and engineering of novel materials. In addition, there has been increasing research interest in many emerging directions beyond optics and photonics. Here, the state-of-the art developments in the field of complex non-Hermitian physics based on PT symmetry in various physical settings are brought together, and key concepts, a background, and a detailed perspective on new emerging directions are described. It can be anticipated that this trendy field of interest will be indispensable in providing new perspectives in maneuvering the flow of light in the diverse physical platforms in optics, photonics, condensed matter, optoelectronics, and beyond, and will offer distinctive application prospects in novel functional materials.     

Experimental investigation of oil retention in air conditioning systems

In air conditioning and refrigeration systems a small amount of oil is carried with the refrigerant and is retained in the system components. Oil retention characteristics in the condenser, evaporator, liquid and suction lines were measured and are presented and discussed here. Refrigerants R22, R410A, and R134a with miscible and non-miscible lubricants were considered to investigate oil retention physics in the widest possible range of transport properties. A parametric analysis in the suction line showed that oil retention depends on the oil mass fraction, vapor refrigerant mass flux, mixture viscosity ratio and orientation of the pipe. In the suction line, an increase in mixture viscosity of about 55% caused a rise in oil retention in the range of 50%, depending on the oil mass fraction. Oil retention in the upward vertical suction line is about 50% higher than in the horizontal line at similar conditions.     

超临界烯烃聚合的研究进展--(Ⅰ)聚合工艺及工业应用

超临界流体是一种特殊的热力学状态,在此状态下进行烯烃聚合具有提高催化活性、拓宽氢调范围、改善颗粒形态及促进共聚等优点,特别是作为高熔体指数双峰分布聚烯烃的制备方法,近年来备受关注。文中综述了国外乙烯、丙烯均聚及共聚的超临界工艺和工业化应用现状,并对我国正在进行的超临界烯烃聚合工艺的研究进行了展望。     

Effect of Vortex Finder Diameter on Flow Field and Collection Efficiency of Cyclone Separators

In this study, aerocyclone separators, with five different vortex finder diameters are simulated using commercially available computational fluid dynamics code Fluent 6.3.26 to analyze flow field pattern and the collection efficiency. It is found that a decrease in vortex finder diameter results in an increase in pressure drop by 47.84% and an increase in the collection efficiency by 9.54%, whereas, the increase in vortex finder diameter leads to a reduction in pressure drop by 23.87% and a decrease in the collection efficiency by 7.70% as compared to the Stairmand high efficiency cyclone. It is also observed that a decrease in vortex finder diameter leads to about 33% increase in axial velocity and about 25% increase in tangential velocity, whereas, an increase in vortex finder diameter results in about 23% decrease in axial velocity and about 12% decrease in tangential velocity as compared to the Stairmand high efficiency cyclone.     

北京城区和远郊区大气细颗粒PM_(2.5)元素特征对比分析

为了对比大气悬浮颗粒PM2.5及其所含元素在北京城区与远郊区的特征,在2007年不同季节和2008年北京奥运会期间进行了PM2.5的采样分析。结果表明:城区PM2.5和元素的浓度均高于郊区,元素浓度在城区与郊区具有不同的季节变化特征,春、冬季地壳元素浓度在城区与郊区都有所增加,在城区S元素和其它污染元素在秋、冬季最高,而郊区S元素浓度在夏季最高。污染元素的富集程度夏秋季高于春冬季,郊区高于城区,城、郊两地PM2.5中元素来源相似。雾霾天PM2.5及元素浓度在城区增加明显,奥运期间污染元素的质量分数较奥运前明显降低。     

Conservation de hachis de sardine en entreposage à l'état congeléà - 20°C: hachis obtenus à partir de sardine entière, et de sardine étêtée et éviscérée

This Paper presents a comparative study of minces prepared from headed and gutted sardines and minces prepared from whole sardines, with a view to avoiding unnecessary product handling and improving yields. Certain additives (cryoprotectants and antioxidants) were blended into some of the mince lots in an attempt to extend their storage life, and in one of the lots the mince was washed prior to mixing. The minces were prepared by extrusion and the lots were fashioned into 4 cm thick 700 g blocks, frozen in a horizontal plate freezer until a core temperature of −20°C was attained, vacuum packed and stored at −20°C for 12 months. Proximate analysis, minerals analysis (Na,K,Mg,Ca,Fe and Cu) and yield measurements were carried out prior to freezing. Protein solubility, emulsifying capacity, cooking loss, K value, pH, TBA index, viable germ counts, entero and coliform bacteria, instrumental texture analysis and sensory analysis were periodically measured. The results obtained can be summarized as follows: the method of extrusion appears to be particularly well adapted to whole fish with regard to the avoidance of handling and improving yields. In relation to mineral content the only appreciable difference is a higher sodium content in minces made from whole fish (E lots) than in minces made from gutted and headed sardines (D lots), while in the washed lots there was an appreciable decreases in the amounts of Cu, Fe, Mg and K. Protein solubility stayed at higher levels in the E lots than in the D lots, though it was high in both types of mince at the end of storage: the use of protein cryoprotectants is advisable particularly in the washed D lot (DL) and in the E lots when storage of >6 monts is required. The emulsifying capacity, which was initially higher in the E lot than in the D lot, stabilized after the second month of storage. The effect of the protein cryoprotectants was to increase slightly the emulsifying capacity, which remained higher than in the control lots throughout the storage period, even in the DL lot, which the authors feel is important with regard to the use of these minces in sausage-type products. Cooking loss was initially higher in the D lots, but after the fourth month of storage it was the same for both types. The protein cryoprotectants reduced cooking loss and were more effective in the E lots. Due to fluctuations in K values obtained, the authors do not regard them as a reliable indicator of product quality. The pH was slightly more basic in the E lots than in the D lots, and pH increased in the additive-containing lots, especially in the washed mince preparation. The TBA index only showed significant differences between the D and E lots in the final test performed. The antioxidants appeared to be more effective in the E lots than in the D lots. Washing also delayed the onset of randicity, probably through the removal of fat and catalysts with the wash water. No synergistic effect was observed between the protein cryoprotectants and the antioxidants. The total initial count of micro-organisms was substantially higher in the E lots than in the D lots because of the intestinal content, though the levels equalized during storage and at no time exceeded allowable limits. Washing did not significantly decrease germ counts. The initial excessive amounts of enterobacteria in the E lots decreased during storage, whereas the level of caliform bacteria, on the other hand, remained constant. In the E lot without additives (ESS), however, Escherichia coli was detected prior to freezing but not in any of the subsequent analyses. In general, texture as determined by instrumental methods (hardness, firmness, elasticity, and cohesiveness) gave higher values for the D lots than for the E lots. Washing increased hardness and firmness while cryoprotectants reduced them. Cooking considerably hardened the samples in the case of the D lots but did not cause variations in the E minces. Hardness and firmness remained quite stable, although there was a slight increase in the cryoprotectants-free lots and washed minces. Elasticity tended to increase in the E lots during storage, and this effect was more pronounced in the cryoprotectants-free lots; cryoprotectants had the effect of decreasing elasticity and stabilizing it in the D lots, although they were higher in the D lots than in the E lots. Elasticity and cohesiveness remained constant in the washed mince. Cohesiveness increased in all the lots during storage, and the cryoprotectants exerted no effect on this parameter. In connection with the sensory analysis, a certain sweet taste was perceived in the cryoprotectants-containing D lots, slightly reducing the quality of the product, though it was not found unpleasant and was barely detectable in the E lots. The typical sardine flavoured lots by the washed mince reduced its acceptance, though this opens up a series of technological possibilities for it. A rancid taste was detectable in the ESS lot after five months in storage, in the E lot with protein antidenaturants (ESP) after eight months, and in the E lot that contained antioxidants (ESAO) and protein antidenaturants and antioxidants (ESA), in the last test carried out.