轧钢加热炉改造

针对轧钢加热炉加热能力不足,炉墙冒火,自动化控制水平落后的情况,对加热炉进行了改造,延长了加热炉的长度,更换了单蓄热式空气烧嘴,并对自动控制系统进行了升级改造,从而消除了炉墙冒火的现象,提高了加热能力和自动控制水平,降低了煤气消耗,取得了良好的经济效益。     

导向筒挤压成形工艺及模具设计

探讨了导向筒挤压的可行性,对几种工艺方案进行了分析,选择了最优方案并制定了工艺流程,在此基础上设计了导向筒挤压模具。采用冷挤压工艺加工后,提高了零件精度和表面质量,改善了强度和韧性,减少了切削加工量,节约了原材料,提高了生产效率,也改善了零件的组织性能。     

带内螺纹的望远镜镜身注塑模具设计

分析了望远镜镜身的结构,提出了塑件成型及模具设计的关键点,设计了模具的整体结构。设计了可相对运动的组合式型芯,以增加内抽芯机构的运动空间,通过塑件推出时带动螺纹滑块的移动实现了内侧抽芯。设计了矩形型芯镶块、加工了避空结构,采用螺钉固定,解决了狭小空间安装小型芯的问题,避免了模具干涉。采用了锥面配合,提高了模具的定位精度,减小了配合件的摩擦。经生产验证,该模具生产的塑件质量满足图纸要求。     

高速热冲压液压机的研制

提出了研制高速热冲压液压机的必要性,确定了高速热冲压液压机的总体设计方案,详述了此类液压机的液压原理及其应用。该产品的研制成功,给国内热冲压成形工艺的研究提供了高性能的设备,同时提高了液压机的生产效率,降低了液压机的能耗,得到了国内外广大客户的认可。     

盖板钻孔攻丝夹具设计

介绍了盖板零件的结构工艺,分析了零件上的4个螺纹孔的工艺要求,针对4个螺纹孔的加工,通过采用专用的夹具,简化了生产零件的模具结构,实现了零件产品的最终要求,保证了质量,同时也提高了效率、降低了成本。     

基于流程图知识表示的工程机械液压故障诊断专家系统

根据工程机械液压系统故障诊断的特点,建立了液压故障诊断专家系统。提出了利用故障定位流程图作为专家系统诊断知识的表示方式,研究了图形化的知识库生成工具Auto Flowchart,构建了诊断知识数据库,设计了故障诊断专家系统的结构,开发了基于流程图知识表示的故障诊断专家系统。有效解决了传统专家系统知识获取困难的问题;实现了液压系统的故障定位;方便了诊断知识的维护与更新,提高了查找故障的准确率及效率。最后,以QYJ40B起重机为例进行了应用,结果表明该方法有效可行。     

基于Web的远程液压传动系统设计模式研究

为实现液压传动系统设计模式的转变以及设计资源、技术资源与产品信息的远程共享,提出了基于Web的远程液压传动系统设计模式,介绍了系统的体系结构,阐述了系统的工作流程,详细介绍了系统的各功能模块,分析了系统实现的关键技术与方法,并对该设计技术的发展趋势提出了展望。     

镁合金熔体防氧化燃烧技术的进展

综述了相关文献,介绍了镁合金氧化燃烧的机制,总结了在熔炼过程中防止镁合金氧化燃烧的各种技术,并对其利弊作了分析,指出了未来发展的方向.     

Ф5500×1800自磨机传动轴端漏油问题的处理

针对自磨机传动轴端漏油的问题,提出了引流回源的导油建议,通过引流回源,彻底解决了漏油的问题,保证了设备的正常运转,减轻了工人的劳动强度,并取得了一定的经济效益.     

低速轮胎试验机动力滑台动态特性分析

介绍了由伺服阀控制对称液压缸,并由位移传感器或速度传感器构成的轮胎试验机纵向往复运动液压位置及速度闭环控制系统,讲述了该系统的工作原理,建立了控制系统的数学模型,对速度和位置控制系统进行了校正,并采用了一种复合的控制策略实现了速度和位置的复合控制.提出了控制系统的SIMULINK仿真模型,给出了在阶跃信号作用下的滑台的速度的响应.     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

时辰药理学在高血压治疗中的应用

人体生物节律与血压水平及高血压降压治疗效果存在紧密联系。人体的昼夜生物节律通过影响抗高血压药物的药动学和药效学改变药物的治疗效果；同时，在高血压治疗过程中遵循人体血压节律，可以降低靶器官损害及心脑血管事件的风险。因此，在高血压治疗过程中，应遵循时辰药理学调整给药时间和药物剂量，以获得最佳疗效和最小毒副作用，减少不良反应及并发症的发生。     

高强钢扩孔试验方法探讨

为了探究不同试验方法对高强钢扩孔性能指标的影响，对成品热轧板复相钢 CP800进行相关扩孔试验，在不同的试验方法下采用不同加工方法的预制孔和不同的凸模模具进行配合试验，研究分析出不同试验方法下对扩孔率的影响。结果表明：在冲孔与锥模试验方法下，扩孔率比较低，扩孔数据不稳定；在冲孔与平模的配合试验下，扩孔率同样较低，且易出现底部破裂情况；在钻孔与平模的试验方法下，扩孔率相对于冲孔的组合试验来说，稳定性有明显的提高，但是也容易在底部产生破裂现象，导致试验失败；对于锥模与钻孔的配合试验，会达到最高扩孔率值，而且试验结果稳定。     

强力霉素治疗兔实验性骨关节炎的疗效及其作用机制的研究

目的: 研究强力霉素局部给药对骨关节炎软骨的影响及其作用机制。方法: 通过关节内注射木瓜蛋白酶,建立家兔膝关节炎模型。每日关节穿刺给予2、4 mg强力霉素,共4周,观察指标包括软骨大体形态,软骨Mankin's评分,软骨细胞基质金属蛋白酶-13(MMP-13)表达,关节液中NO含量和一氧化氮合酶(NOS)活性。结果: 与正常对照组相比,模型对照组软骨面粗糙,见大量裂隙,局部纤维覆盖,边缘骨赘多,Mankin's评分显著增高,MMP-13表达、NO含量和N0S活性均显著升高（P < 0.01)。给予2 mg强力霉素后,软骨面粗糙稍好转,裂隙数量减少,边缘骨赘小而少,Mankin's评分显著降低,MMP-13表达、NO含量和NOS活性均显著降低（P <0.01)。给予4 mg强力霉素后,上述改变更加显著。结论: 强力霉素关节腔内给药对家兔骨关节炎软骨退变起到明显缓解效果,且其作用有剂量相关性,作用机制与抑制NO产生、NOS活性和MMP-13表达有关。     

极地海洋环境服役材料的摩擦学研究进展

随着北极航行的发展及极地资源开发的需要，如何提高极地海洋环境服役材料的摩擦学性能愈发重要。在极地海洋环境中，碎冰、冰层和海水中的腐蚀性物质会使材料受到摩擦磨损、腐蚀及其耦合的影响;低温潮湿环境会增加材料的脆性、使材料表面覆冰、改变材料的摩擦磨损机理;强紫外线会加速涂层老化;这些因素都会降低材料的耐磨性能，最终导致材料失效。因此，极地海洋环境服役材料的摩擦学与材料的性能、服役寿命息息相关。本文介绍了极地探索所面临的摩擦磨损问题;阐述了极地温度、极地海洋大气及海水成分、海冰运动和极地微生物等极地海洋环境特点及其对材料摩擦学性能的影响;重点介绍了金属材料、无机非金属材料、高分子材料在极地海洋环境下的摩擦学进展;探讨了提升材料在极地海洋环境下的耐磨防腐技术，如改性、表面修饰等;最后，结合极地海洋环境服役材料摩擦磨损研究中所面临的问题及发展趋势，对未来极地海洋服役材料的摩擦学研究工作进行展望。     

Mathematical modeling of the gas and powder flow in HVOF systems

A mathematical model was developed to describe the gas dynamics and heat-transfer mechanism in the gas/particle flow of high- velocity oxyfuel (HVOF) systems. A numerical solution was carried out using a PC- based computer program. One- dimensional predictions of the temperature and velocity profiles of gas and particles along the axis of flow were obtained to conduct cost- effective parametric studies and quality optimization of thermal spray coatings produced by HVOF systems. The numerical computer model allows for the variation of the HVOF system parameters, such as air/fuel ratio and flow rates, cooling water inlet temperature and flow rate, barrel length, standoff distance, particle size, and gun geometry. Because of the negligible volume of the powder relative to the gas, the gaseous phase was modeled as continuous nonadiabatic, and friction flow with variable specific heats and changing cross- sectional areas of flow. The generalized continuity, momentum, and energy equations with the influence parameters were used to model the gaseous flow regime and predict its thermodynamic properties. Empirical formulas for the mean axial decay of both velocity and temperature in the supersonic jet plume region were generated from published measurements of these parameters using laser Doppler velocimeter and Ray leigh scattering techniques, respectively. The particle drag and heat- transfer coefficients were calculated by empirical formulas in terms of Reynolds, Nusselt, and Prandtl numbers to evaluate both the momentum and heat transferred between the combustion gases and the powder particles. The model predictions showed good agreement with the particle and gas temperature and velocity measurements that are available in the literature.     

Properties of Mechanically Milled Nanocrystalline and Amorphous Mg–Y–Ni Electrode Alloys for Ni–MH Batteries

Nanocrystalline and amorphous Mg2Ni-type Mg20-xYxNi10(x = 0,1,2,3 and 4) electrode alloys were fabricated using mechanical milling.The effects of the Y content and milling time on the microstructures and electrochemical performances of the alloys were investigated in detail.X-ray diffraction and transmission electron microscopy analyses revealed that the substitution of Y for Mg yields an obvious change in the phase composition and micro morphology of the alloys.When the Y content x B 1,the substitution of Y for Mg does not change the major phase Mg2 Ni,but with a further increase in the Y content,the major phase of the alloys transforms into the YMg Ni4 YMg3 phase.A nanocrystalline and amorphous structure can be obtained by mechanical milling,and the amorphisation degree of the alloy visibly increases with increased milling time.Electrochemical measurements indicate that the discharge capacity of the alloys first increases and then decreases with increasing Y content and milling time.The substitution of Y for Mg dramatically ameliorates the cycle stability of the as-milled alloys,and the mechanical milling more or less impairs the cycle stability of the alloys.Furthermore,the high rate discharge ability,electrochemical impedance spectrum,Tafel polarisation curves and potential step measurements indicate that the electrochemical kinetic properties of the as-milled alloys first increase and then decrease with increasing Y content and milling time.     

高温合金Inconel718、Inconel706和Inconel706M电渣重熔组织均匀性

对比研究了高温合金Inconel 718、Inconel 706和Inconel 706M电渣重熔铸锭的枝晶组织和析出相差异。结果表明,在3种高温合金中,718铸锭中心区域的枝晶间距与边缘区域的差值最小,并且主要偏析元素Nb和Ti在铸锭中心的偏析率与边缘的差异也最小,718铸锭的宏观组织均匀性最好;706M铸锭中心与边缘的枝晶间距差值最大,且铸锭中心的Nb元素偏析率与边缘的差异达到0.91%,铸锭宏观组织均匀性最差。718铸锭枝晶间易富集正偏析元素Nb和Mo,最高含量分别达到6.82%和3.01%;706、706M铸锭枝晶间最高Nb含量均低于4%,Ti元素含量最高均达到2%以上,同时706及706M铸锭组织中Nb的偏析率依然很大。706铸锭组织中Laves相最多,中心位置Laves相含量达到3.9%,边缘含量降低超过2%,分布不均匀;706M铸锭组织中Laves相最少,中心及边缘含量均低于2%,含量分布比较均匀。与718和706相比,706M铸锭中心区域的碳氮化物平均长度与边缘的差异最大,且组织中存在更少的针状相。     

聚苯胺在防腐方面的研究及应用现状

聚苯胺(PANI)具有良好的热稳定性和环境稳定性,经掺杂后,具有导电性及电化学性,可作为填料应用于金属防腐领域。但其分子链骨架刚性强、分子间作用力大,不易加工成型,不溶于常规的有机溶剂,当其作为填料应用到防腐涂料中存在溶解性、分散性差且与金属基底附着力不强等缺点,如能对其进行合理有效的改性,则可解决上述问题。简要探讨了溶液聚合法、反相微乳液聚合法、模板聚合法以及电化学聚合法等PANI的制备方法,并针对PANI在防腐涂料应用中存在的问题,重点阐述了PANI的质子酸掺杂改性及复合改性等不同改性方法,通过掺杂不同的质子酸对PANI进行化学改性,可降低PANI分子链之间的相互作用,从而提高其溶解性、导电性和防腐性能。将不同性能的材料与PANI进行复合改性,改善分子间作用力,能提高其加工性,从而更好的应用于金属的腐蚀防护工作。最后介绍了PANI在腐蚀防护过程中的作用、在防腐蚀涂料中的应用及相关理论的研究现状,并指出PANI防腐涂层的研究重点和发展方向。     

Laser-Pulsed Heating of Aluminum: Cavity Formation at the Surface

Laser evaporative heating of aluminum surface is modeled numerically and mushy zone formation across the solid-liquid and the liquid-vapor phases is introduced in the model study. Temperature rise in the irradiated region and the cavity formation during the laser heating pulse are predicted. Temperature-dependent properties are introduced during the simulations. Oxygen diffusion into the substrate material is considered during the laser heating process while employing temperature-dependent diffusion coefficient. An experiment resembling the simulation conditions is carried out and the morphology of the cavity produced at the surface of the laser-irradiated region is examined using scanning electron microscopy (SEM) and atomic force microscopy (AFM). It is found that the depth of liquid phase increases significantly with the progressing time and the size of the mushy zone across the solid-liquid phase is smaller than that of across the liquid and the vapor phases. The cavity depth, observed from the SEM and AFM micrographs, is shallow and similar to those predicted from the numerical simulations.