金刚石浓度、粒度和强度对锯片切割性能的影响

文章通过一系列试验数据，总结出锯片效率和寿命与金刚石浓度粒度强度变化规律的关系，为优化锯片性能提供依据。     

Deformation analysis of micro/nano indentation and diamond grinding on optical glasses

The previous research of precision grinding optical glasses with electrolytic in process dressing (ELID) technology mainly concentrated on the action of ELID and machining parameters when grinding,whic...     

天然砂砾夯扩挤密桩在公路工程中的应用

充分利用本地资源可降低工程成本,缩短工期。结合实际工程,提出了采用当地天然砂砾为材料的夯扩挤密桩处理地基的方法,并介绍了该方法的流程及施工要点,强调了质量要求。该工程的成功应用对于指导本地区其他公路的地基处理具有重要的现实意义。     

Effect of grit-blasting on substrate roughness and coating adhesion

Statistically designed experiments were performed to compare the surface roughness produced by grit blasting A36/1020 steel using different abrasives. Grit blast media, blast pressure, and working distance were varied using a Box-type statistical design of experiment (SDE) approach. The surface textures produced by four metal grits (HG16, HG18, HG25, and HG40) and three conventional grits (copper slag, coal slag, and chilled iron) were compared. Substrate roughness was measured using surface profilometry and correlated with operating parameters. The HG16 grit produced the highest surface roughness of all the grits tested. Aluminum and zinc-aluminum coatings were deposited on the grit-blasted substrates using the twin-wire electric are (TWEA) process. Bond strength of the coatings was measured with a portable adhesion tester in accordance with ASTM standard D 4541. The coatings on substrates roughened with steel grit exhibit superior bond strength to those prepared with conventional grit. For aluminum coatings sprayed onto surfaces prepared with the HG16 grit, the bond strength was most influenced by current, spray distance, and spray gun pressure (in that order). The highest bond strength for the zinc-aluminum coatings was attained on surfaces prepared using the metal grits.     

Reducing tool wear in abrasive cutting

The abrasive Cut-Off with stationary or hand-operated machines for cutting or grinding metal is still a very common procedure in many enterprises. Because of the relatively low price of the tool ‘cut-off wheel’ little attention is paid to the life-time of the grits. Since it is possible to obtain shape-defined grits for the production of grinding wheels an experimental study was carried out producing and testing such cutting-wheels. It has been shown that it is possible to reduce the wear of the wheel by means of using shape-defined grits. The following paper describes selected experimental studies and their results.     

流量测井法测定砂砾层的渗透系数

本文在分析抽水试验法和室内渗透试验法求取砂砾层渗透系数的缺陷基础上,介绍了流量测井法测定砂砾层渗透系数的工作实例,归纳了此方法的优点。     

水泥稳定砂砾水泥剂量测定(EDTA滴定法)正确操作方法的探讨

本文对路面基层水泥稳定砂砾施工中水泥剂量测定方法(EDTA滴定法)及存在问题进行了分析,提出了统一的操作步骤,对某些试验步骤作了补充。     

城市污水处理厂关键辅助设施的节能降耗技术研究

国内新建的大部分污水厂在投产后存在水量、水质变化大的问题,往往造成电、药的浪费,能耗较高。本项目主要通过调节曝气沉砂池罗茨鼓风机的频率以及调整二氧化氯的原料配比,达到节能降耗的目的。以石井污水处理厂的关键辅助设施为研究对象,对实施项目期间的电耗、药耗以及吨水运行成本进行分析。该厂采用具有脱氮除磷功能的改良A2/O工艺。     

Performance of a plate mill and a modified Engelberg huller for small-scale dry milling and de-germing of maize

A modified Engelberg huller and a plate mill (Burr mill) were used to dry mill maize to recover superior quality grits and pure germ. With maize conditioned to a moisture content of 4% above the initial moisture content [12%, wb (wet basis)] the huller gave 68% large grits (oil and fibre ∼ 1%), 12% small grits and 14% flour fraction which contained pulverized germ (with an oil content of 16%). In the plate mill, 2% water-conditioned maize gave 38 large grits, 38% small grits and 10% whole germ (which had 18% oil, representing 64% purity). Maize which was water-conditioned to 6% added water gave 45% large grits, 30% small grits and 16% germ-bran mixture (which had 16% oil representing 57% purity). the study indicated the possibility of using the plate mill for recovering a substantial part of the germ and grits from maize, while the huller gave higher yields of large grits, but with recovery of only a small portion of germ.     

提高胎体耐磨性技术

通过对金刚石薄壁钻头大量模拟试验数据进行分析对比，并对胎体耐磨性理论的论述，阐明了加入细粒度金刚石可以有效地提高金刚石工具胎体的耐磨性，从而提高其使用寿命，而工作效率不受影响甚至有所提高。