古老变粒岩区岩体风化规律的研究

古老变粒岩地区 ,岩体风化剧烈、风化深度大且各处风化深度差异极大 ,地表多呈散砂粒状 ,该文对其在水利水电工程地质勘察中遇到问题进行了深入研究 ,初步掌握了古老变粒岩区岩体风化规律     

某型自动榴弹发射器身管铬层厚度研究

为解决某型35 mm自动榴弹发射器身管铬层设计存在合格率低和生产成本高的问题,对其身管铬层厚度进行研究。找出身管铬层厚度设计的缺陷,对其进行深入分析,提出将身管铬层厚度进行调整的方法,并以大量试验进行验证。结果表明:该方法既能缩短生产时间,降低镀铬溶液、水、电、气等物质消耗和生产成本,还能提高生产效率以及产品的合格率。     

Toughening of polylactide with epoxy-functionalized methyl methacrylate–butyl acrylate copolymer

Glycidyl methacrylate-functionalized methyl methacrylate–butyl acrylate (GACR) core–shell structure copolymers were synthesized to toughen polylactide (PLA). With an increase in GACR content, the PLA/GACR blends showed decreased tensile strength and modulus; however, the elongation at break and the impact strength were significantly increased compared with that of PLA. The brittle fracture of neat PLA was gradually transformed into ductile fracture by the addiction of GACR. From dynamic mechanical analysis, the rigidity of the PLA/GACR blends was decreased with the increase of GACR content. The addition of GACR decreased the degree of crystallinity of PLA. The GACR was found to aggregate to form clusters with size increasing with increasing GACR content by transmission electron microscope analysis. The clusters dispersed in PLA matrix uniformly. It was found that PLA demonstrated large area, plastic deformation (shear yielding) and cavities in the blend upon being subjected the tensile and impact tests, which was an important energy-dissipation process and led to a toughened and transparent blend.     

化学工程与石油化工节能

文章重点讨论了如何应用动量传递原理、热量传递原理、质量传递原理和化学反应工程等化学工程的基本理论指导石油化工节能工作。     

胶原三维多孔基质常用交联方法

胶原三维多孔基质在组织工程中有广泛应用,但是其降解速率快、机械性能较差,通过交联可以改善其性能。常用的有物理和化学交联方法,物理交联包括热交联、紫外交联、γ射线交联等,化学交联包括使用醛类、碳二亚胺等化学交联剂及京尼平、原花青素等天然交联剂,多种交联方式联用可有效提高交联效果。     

基于等代层模型的盾构法地层移动优化反分析

该文提出了盾构施工引起的地层移动的反分析优化方法,采用共轭梯度法优化程序并且基于等代层模型来评价地层移动,分析了回填注浆对地层移动的影响。通过南京地铁某盾构隧道监测数据的反分析结果,发现在粘土层中盾构施工对地表的影响角度大约为45°,回填注浆可以减少60%~80%的自然空隙。建立了新的经验公式来预测南京地区盾构施工引起的地层移动,实例表明该公式具有良好的效果。     

船用微引燃双燃料发动机多缸平衡控制的试验

针对船用微引燃双燃料发动机多缸不平衡问题,开展了多缸平衡控制的仿真与试验,建立发动机仿真模型,用试验测量的进气歧管压力验证了模型精度,基于仿真模型定量分析了发动机各缸燃气量和过量空气系数的差异.采用燃气喷射量补偿的方法对各缸进行缸平衡控制的研究,分别以各缸爆发压力、平均指示有效压力(IMEP)和排气温度为控制变量修正各...     

大跨度悬挑脚手架在某办公大楼项目中的应用

着重对高空大跨度悬挑脚手架的设计与施工进行介绍,采用型钢外伸,钢丝绳作拉索,多层逐步外挑以及设置相应的拉索保险。通过分析计算,并考虑各节点的设置构造,从而设计出完整的悬挑脚手架方案,在工程中得到很好的应用。     

熔速对氩气保护GH4169G合金电渣锭组织及夹杂物的影响

研究了熔速对氩气保护GH4169G电渣锭宏微观组织及非金属夹杂物的影响。结果表明:适当增加熔速有利于缩短铸锭的局部凝固时间,减小二次枝晶间距,从而细化枝晶组织,但对Nb、Ti等易偏析元素沿径向的宏观分布影响不大。熔速对GH4169G铸锭中的夹杂物类型影响较小,主要为氧化物、氟化物和氮化物三类。夹杂物在铸锭表面最多,向内部迅速减少并趋于稳态。铸锭内部夹杂物多以氧化物为核心,氮化物为次外层,碳化物为最外层的双层或三层结构。采用MeltFlow-ESR模拟方法,分析了熔速对重熔过程中夹杂物运动轨迹的影响,发现提高熔速有利于夹杂物向铸锭表面运动,降低铸锭表面夹杂物富集区的厚度和铸锭内部夹杂物的数量。此外,提高熔速有利于缩短夹杂物析出长大的时间,降低夹杂物尺寸。     

The Dead-Pressing Phenomenon in an ANFO Explosive

The dead-pressing phenomenon or pressure desensitization in ANFO as well as in other civil explosives is well-known. However, to our knowledge, the detailed study of this phenomenon in ANFO has not been carried out or reported. Therefore, such a study was planned in a SveDeFo research program. Blasting experiments in iron pipes were performed. Mainly, the density of dead-pressing and the transmission distance of detonation in the dead-pressed ANFO were studied. The results show that the dead-pressing density of the tested ANFO, Prillit A (a trademark of Nitro Nobel AB in Sweden), in diameters 45 mm, 60 mm and 75 mm of steel pipes is respectively 1.35, 1.39 and 1.43 [g/cm³]. The dependence of the detonation transmission distance on the density of the ANFO has also been outlined.