回转体零件的教学型CAPP系统的开发

文章介绍了开发回转体零件的教学型CAPP系统的必要性,详细阐述了该系统的开发思路、工作流程和各模块的设计方法,并以一个示例展示CAPP系统的工作过程.在CAD/CAM教学中应用该系统可提高学习效率和效果.     

新型振动能量助力式汽车液压转向系统研究

介绍一种振动能量回收式液压减振系统.该系统能回收部分振动能量,从而降低油耗;回收的高压油液可以用于制动系统、转向助力、液压离合操纵机构等.设计了一种能回收振动能量的非充气式单筒减振器,介绍了该减振器的结构与工作原理.对新型振动能量助力式汽车液压转向系统的组成与工作原理进行了研究.该振动能量回收式液压减振系统申报了国家发明专利(CN102152778A),振动能量助力式汽车液压转向系统申报了国家实用新型专利(ZL 201120101078.4).     

热轧线钢管内除鳞系统的设计要点

介绍了钢管内除鳞系统的主要类型和特点,特别是该系统在斜轧扩径机组中的应用.重点介绍了热轧线钢管内除鳞系统的设备组成、工作流程、功能及设计要点.实际应用表明:该除鳞系统除鳞效果良好,设备运行稳定,对提高钢管内表面质量起到了重要作用.     

高速热压成型机气动系统的设计

主要介绍了高速热压成型机的气动系统的设计方案、工作原理、元件选择以及气动系统如何与电器控制系统协调工作.该系统满足对整台设备进行控制的要求.     

输油控制阀测试系统的设计与开发

介绍了某型飞机输油控制阀测试系统的组成、工作原理及设计特点,并利用PLC、变频器和触摸屏技术设计了该装置的控制系统.结果表明该测试系统设计合理,达到了预期的设计目标.     

四柱式液压机液压系统设计

介绍了四柱式液压机的功能,并对3 500kN液压机液压系统进行了设计,介绍了该液压系统的工作原理和元件选型,对系统的发热进行了计算.     

数控小型电子提花机的研制

介绍了由大连轻工业学院研制的新型驱动与新型控制方式的数控小型电子提花机的主要技术特点,详细的叙述了该设备的驱动系统和控制系统,分析了提花组件的结构及工作原理,并介绍了独特的组件电磁铁助吸技术.该电子提花机工作方式新颖,结构合理、性能可靠、操作方便.最后提出了开发网络化群控电子提花机系统是未来发展的必然趋势.     

轧辊自动超声波检测系统

介绍了轧辊自动超声波检测系统的组成、工作原理以及专有技术等.实践证明该系统不但可以对缺陷进行准确定性,还可以对缺陷进行精确定量,有效弥补了国内在该领域的技术空白.     

基于MC9S12DP256的汽车ABS数据采集系统设计

设计了基于MC9S12DP256单片机的汽车ABS数据采集系统;详细介绍了该系统的硬件电路以及系统软件设计.大量的ABS实车实验证明:该数据采集系统工作性能良好,可靠性高.采集数据的精度完全可以满足汽车ABS系统的要求.     

基于AMESim的一种取样装置的仿真

介绍了一种新型取样装置的结构和工作原理,并基于AMESim高级建模和仿真平台对其进行了建模和仿真分析.针对该取样装置在不同工作参数下的动态特性进行研究,并利用实验验证了仿真模型的正确性.实验和仿真结果表明:在合适的系统工作参数下,该系统性能稳定,在物料粒度检测系统中具有良好的应用前景.     

DISTRIBUTION OF SULFUR IN HIGH TEMPERATURE PHASES OF CAST IRON

The distribution of subversive element sulfur in high temperature phases during solidificationof cast iron was investigated by means of liquid quenching method and autoradiography.Theresults show that in grey cast iron,sulfur is concentrated in the liquid,flake graphite and in theperipherial area of D-type supercooled graphite eutectic cells,but less sulfur is in austenite.Besides,the content of sulfur in A-type graphite is higher than that in D-type graphite,andsulfur content in eutectic austenite is a little higher than that in primary austenite.While,innodular graphite cast iron less sulfur is in liquid and austenite,but more in nodular graphite.The blackness of the spots on the emulsion film corresponds to the atomic percentage ofradioactive substances located on the surface of the specimen.     

NbFe合金的生产现状和发展

评述了中国及世界主要的NbFe合金生产厂家的生产能力、现状及世界钢铁工业对NbFe合金的需求状况,展望了中国NbFe合金的未来发展趋势.巴西CBMM公司是世界上最大的NbFe合金生产企业,最近几年NbFe合金生产能力已有相当大的提高,NbFe合金产量占世界总产量的70%以上,其中出口约14 800t.中国钢铁中铌的平均含量仅为美国和欧洲的15%,因此来自中国铌的需求量至少有6倍的增长空间.宁夏东方有色集团金联公司是中国最大的NbFe合金生产厂家,其NbFe合金生产量快速增长,2005年上半年达580t,占中国NbFe合金产量的75%以上.     

Sr,B添加对Al-15.5%Si合金中共晶团尺寸的影响

考察了Sr,B及Sr＋B联合作用对Al-15．5％Si（质量分数）合金中共晶团尺寸大小的影响．实验结果表明,随合金中Sr量增加,共晶团尺寸呈减少的趋势,冷却速度对共晶团的影响也很显著;在Sr变质的合金中加入B,共晶团尺寸先显著下降,随B量增加降低幅度趋于平缓;在未变质的Al-15.5％Si合金中单独加B,共晶硅由粗大的片状变为细长的层片状,层片间距明显降低．分析认为,合金中加入Sr,导致共晶过冷度增大,因而共晶团形核驱动力增大促使共晶团细化;合金中加入B,增加了共晶团有效形核基底的数量促使共晶团显著细化．     

雌激素对卒中后抑郁大鼠血清单胺类递质的影响

目的 探讨雌激素对卒中后抑郁(PSD) 大鼠的血清单胺类递质的影响。方法 选用雌性SD大鼠, 经Open-Field 行为学评分后随机分成对照组、卒中组、PSD 组、药物治疗组和雌激素干预组,所有大鼠均行卵巢切除术。对照组为常规饲养;卒中组去卵巢后7 d 采用线栓法制备局灶性脑缺血大鼠模型;PSD 组为卒中大鼠结合孤养、束缚应激制备PSD 大鼠模型;药物治疗组对PSD 大鼠模型行帕罗西汀灌胃治疗;雌激素干预组对PSD 大鼠模型皮下包埋雌激素释放管。观察雌激素对PSD 大鼠自发性行为和外周血去甲肾上腺素(NE) 和5-羟色胺(5-HT) 的影响。结果 与对照组比较, PSD 组大鼠旷场实验水平和垂直得分明显减少, 外周血NE 和5-HT 浓度明显降低, 差异有统计学意义(P <0.05)。与PSD 组比较, 雌激素干预组大鼠旷场实验得分增加, 外周血5-HT 和NE 浓度明显升高, 差异有统计学意义(P <0.05)。与药物治疗组相较, 雌激素干预组大鼠旷场实验得分、外周血5-HT 浓度差异无统计学意义(P >0.05)。结论 雌激素能够改善PSD 大鼠的行为学、增加血清5-HT 浓度, 提示对PSD 大鼠有脑保护作用。     

Reduction in Microsegregation in Al-Cu Alloy by Alternating Magnetic Field

The microsegregation behavior of the Al-4.5 wt%Cu alloy solidified at different cooling rates under the alternating magnetic field(AMF) was investigated.The experimental results showed that the amount of non-equilibrium eutectics in the interdendritic region decreased upon applying the AMF at the same cooling rate.The change in microsegregation could be explained quantificationally by the modifications of dendritic coarsening,solid-state back diffusion and convection in the AMF.The enhanced diffusivity in the solid owing to the AMF was beneficial for the improvement in microsegregation compared to the cases without an AMF.In contrast,the enhanced dendritic coarsening and forced convection in the AMF were found to aggravate the microsegregation level.Considering the contributions of the changes in above factors,an increase in solid diffusivity was found to be primarily responsible for the reduced microsegregation in the AMF.In addition,the microsegregation in the AMF was modeled using the analytical model developed by Voller.The calculated and experimental results were in reasonable agreement.     

XRD方法在聚晶金刚石复合片界面应力表征中应用的研究

借助XRD方法对不同生产工艺、无齿、有齿型硬质合金基底制备的PDC制品进行了研究。表明：聚晶金刚石复合片在聚晶金刚石层内存在着宏观应力和微观应力；聚晶金刚石复合片表面应力大小可以反映聚晶金刚石层的应力存在状况；聚晶金刚石复合片残余应力的大小与XRD图谱的斜率成正比，因此XRD方法可以用于聚晶金刚石复合片应力的表征。     

砒石对哮喘小鼠白三烯B4 及5-脂氧合酶基因表达的影响

目的: 探讨白三烯B4 (LTB4) 水平、5-脂氧合酶(5-LO) 基因表达在小鼠哮喘发病中的作用以及砒石(arsenolite, As) 对哮喘的治疗作用与LTB4 水平及5-LO 基因表达的关系。方法: 建立小鼠卵蛋白哮喘模型, 灌胃给予砒石等药, 用ELISA 的方法检测支气管肺泡灌洗液(BALF) LTB4 含量;用RT-PCR 的方法检测肺组织中5-LO mRNA 表达的变化。结果: 哮喘小鼠BALF 中LTB4 水平、肺组织5-LO 基因表达水平较正常对照组显著升高。4 种剂量的砒石均可抑制哮喘小鼠BALF 中LTB4 的水平, 均能降低哮喘小鼠5-LO mRNA 表达的量。其中砒石5.00 mg·kg^-1 剂量的效果优于砒石0.625 mg·kg^-1剂量的效果。结论: LTB4 在气道中的高水平, 5-LO 基因表达的上调在OVA 致敏小鼠的哮喘发病中起重要作用。砒石可显著降低哮喘小鼠BALF 中LTB4 水平, 抑制哮喘小鼠肺组织中5-LO 基因的表达, 从而表现出抗哮喘的活性。     

Variations in stir zone and thermomechanically affected zone of dissimilar friction stir weld of AA5083 and AA6082 alloys

Variations in composition, microhardness (in the thermomechanically affected zone) and texture in the tool domain of the dissimilar friction stir weld of AA5083-O and AA6082-T6 alloys were investigated. The contents of the major alloying elements in the weld zones were determined using inductively coupled plasma?atomic emission spectroscopy. It was observed that a slight drop in the content of the alloying elements results from the friction stir welding process with the Mg content being the most affected amongst the major alloying elements in the two alloys. By relating the mass fractions of the major alloying elements in the parent metals of both alloys to those of the stir zone, the relative proportions of the two alloys in the stir zone were estimated with the results showing that at least 60% of the materials in the stir zone are from the retreating side of the weld. It was also revealed that the changes in the hardness profile in the thermomechanically affected zone of the retreating side are predominantly influenced by changes in grain size in that domain. Finally, the investigation further revealed that the texture component in the tool shoulder domain is different from the texture component in the tool pin domain.     

Synthesis and characterization of electrodeposited Ni-Pd alloy electrodes for methanol oxidation

A wide compositional range of Ni-Pd alloy catalysts were prepared by electrodeposition for use as anode materials for methanol oxidative fuel cells in alkaline conditions. Structural characterization of the electrocatalysts in their as-plated condition revealed that the Ni-Pd catalysts synthesized were nanocrystalline, single phase, face centered cubic materials, indicating the formation of complete solid solution in the alloy. Compositional analysis of the alloys indicated that the palladium composition of the alloy increased with decrease in current density. This change in the composition of the alloy resulted in a shift in the X-ray diffraction peaks. The percentage shift in the d-spacing calculated from X-ray diffraction is in good agreement with percentage of palladium in the alloy. The electrocatalysts prepared are active for methanol oxidation in alkaline medium.     

非对称通道内亲疏水结构影响下的纳米气泡滑移效应

目的 研究非对称性通道中亲疏水表面结构影响下纳米气泡特征与边界滑移之间的关系,以实现良好的流体减阻效果.方法 采用二元体系分子动力学方法,研究纳米气泡在通道流动中产生的滑移减阻效应.首先建立上下壁面非对称微通道模型,通过考虑微通道流动传热过程,探究纳米气泡影响下的微通道界面速度滑移现象.结果 保持亲水下壁面高度以及上下...