弧齿锥齿轮传动设计中数据的程序化处理

针对弧齿锥齿轮传动设计手册中复杂数表、线图数据的处理问题进行分析研究,提出了相应的程序化处理方案。将复杂数据有机融入设计计算程序,可实现对当前图形数据的直接检索和调用,解决了弧齿锥齿轮传动设计中的数据处理问题。     

渐开线螺旋花键的滚压加工

阐述了渐开线螺旋花键的滚压原理、坯料计算、工装设计及材料的选择，对滚压加工进行了很好的研究。实践表明，采用滚压技术加工的渐开线螺旋花健，不仅极大地提高了生产效率，且制件的质量也大为提高。     

Suspended electrode kinetics of mechanically activated pyrite

1　ＩＮＴＲＯＤＵＣＴＩＯＮＭｅｃｈａｎｉｃａｌａｃｔｉｖａｔｉｏｎｉｓｗｉｄｅｌｙａｐｐｌｉｅｄｉｎｅｎ ｈａｎｃｉｎｇｍｅｔａｌｌｕｒｇｉｃａｌｐｒｏｃｅｓｓ[1～ 3] ａｎｄｃｈｅｍｉｃａｌｓｙｎ ｔｈｅｓｉｓ[4 ,5] .Ｓｏｆａｒｉｔｉｓｄｉｆｆｉｃｕｌｔｔ     

钢管斜轧延伸螺旋轧制变形区工具运动速度场的研讨

建立了工具运动速度模型；开发成功了钢管斜轧延伸变形区中工具运动速度场计算机模拟软件；揭示了螺旋轧制变形区中速度分布规律。     

Worker Exposure Monitoring of Suspended Particles in a Thermal Spray Industry

The purpose of the present work was the investigation and characterization of the quality of air in a thermal spray industry, in Greece. The activities that take place in the specific facility, as well as in most other similar industries, include thermal spraying and several mechanical and metallurgical tasks that generate airborne particles, such as grit-blasting, cutting and grinding of metallic components. Since the main focus of this work was the workers exposure to airborne particles and heavy metals, portable air samplers with quartz fiber filters, were used daily for 8 h. Three samplers, carried from different employees, were used for a period of 1 month. Results showed that both particles and heavy metals concentrations were low, even in the production site, which was the most susceptible area. The only exceptions were observed in the case of cleaning and maintenance activities in the thermal spray booth and in the case of spraying outside the booth. The main reason for the low concentrations is the fact that most of the activities that could produce high-particle concentrations are conducted in closed, well-ventilated systems. Statistical elaboration of results showed that particles are correlated with Ni, Cu, Co. The same conclusion is extracted for Fe, Mn. These correlations indicate possible common sources.     

冷拔内螺旋凸筋管拔制力上界法探讨

利用上界法推导了冷拔内螺旋凸筋管拔制力计算式。实验表明,理论计算值与实测值较吻合,可为冷拔内螺旋凸筋管的拔制设备选型提供理论依据。     

Downstream Ecological Impacts of Controlled Sediment Flushing in an Alpine Valley River: A Case Study

Sediment flushing may be effective to tackle the loss of reservoir storage as a result of siltation. When operationally possible, the impact of this practice on the downstream aquatic environment can be mitigated by limiting the sediment concentration of the discharged waters (controlled sediment flushing). However, this topic is poorly documented, and concerns arise when limits are discussed. We present the results of a 3‐year field investigation concerning the controlled sediment flushing of a small reservoir on the Adda River, the main tributary of Lake Como—Italy. Two limits for suspended solid concentration (SSC) were adopted: 1.5 g L^?1, as average value throughout the whole working day, and 3.0 g L^?1, as alert threshold to adjust the ongoing activity. These constraints were essentially fulfilled in the course of the documented operations. The first year sediment flushing was more significant than the following year: 25 000 tons of fines below 2 mm in diameter were flushed in six non‐consecutive days in summer 2010, while, one year earlier, 75 000 tons were flushed in 16 non‐consecutive days. In the third year of investigation (2011), no sediment evacuation took place. The benthic macroinvertebrate and the fish communities were surveyed a short distance below the reservoir, that is, in the potentially more affected river reach. Clear pieces of evidence of environmental quality degradation were not detected; the adopted strategies can therefore be considered to be appropriate when planning sediment flushing management in comparable contexts. Copyright © 2014 John Wiley & Sons, Ltd.     

关于雾霾污染的现状及治理方案的探讨＊

雾霾是雾与霾的混合物,雾霾湿度相对较大时,雾所占的成分居多;而在相对湿度为80%～90%时,霾所占的比例较大。在雾霾天气下,人们在室外的能见度特别低,给行车出行带来很大的不便,同时,还会给人们的健康带来严重的威胁。主要对雾霾污染的现状进行了分析,并重点提出治理雾霾污染的有效方案。     

长引水系统水电站压力管道直径优化

本文基于某长引水式水电站水力过渡过程的数值模拟,针对蜗壳末端压力受涌浪压力控制的情况,进行压力管道直径的优化。结论表明,减小压力管道直径将导致蜗壳末端水锤压力增加,控制其最大值不超过涌浪压力控制值,可在一定范围内缩小压力管道直径,减少工程投资,对类似工程具有一定的参考意义。     

表面活性剂对气液两相螺旋管流流动特性的影响

为了考察阴离子型表面活性剂十二烷基硫酸钠(SDS)对气液两相螺旋管流流动特性的影响,该文用实验研究了不同浓度的SDS溶液体系气液两相螺旋管流的流型转变及压降规律。实验装置为由有机玻璃圆管制成的长2 m内径23 mm的实验段,以SDS水溶液和空气为实验介质,气液相折算流速均为0―2.5 m/s,SDS溶液质量浓度10―90 mg/kg,螺旋流由5种不同型号的金属螺旋叶轮诱导产生。利用直接观察和高速摄像相结合的方法观测流型的变化,并用液柱式压差计测量实验管段上下游间压差,实验在常温常压条件下进行。实验共得到螺旋线状流、螺旋波状分层流、螺旋轴状流、螺旋弥散流4种流型,与未添加表面活性剂体系相比较,并未得到螺旋泡状流和螺旋团状流这两种流型。同时,随着SDS溶液浓度的增大,气液两相螺旋流逐渐向螺旋弥散流流型转变,这是因为低浓度的SDS溶液随着其浓度的增大,气液界面张力逐渐减小,而气液掺混程度则会不断增大。此外,与未添加表面活性剂体系相比较,添加了SDS体系的气液两相螺旋管流压降梯度将会减小。最后,阐述了气液两相螺旋管流强化天然气水合物生成的研究及应用现状,并针对多相流研究现状,提出了气液两相流相间传热特性应成为今后研究热点等建议。