并行式液压缸智能CAD系统的研制

根据机械产品液压缸的设计特点,作者研制集方案设计性能计算、工艺分析和结构设计专家系统于一体的并行式液压缸智能CAD(Hydraulic Cylinder Intelligent CAD,简称HICAD)系统,探索一种新的CAD结构模式。     

铅蓄电池生产企业污染防治

近年来,铅污染事件日益突出,铅蓄电池生产企业面临的环境风险越来越大,企业环境成本逐年升高,如何有效控制铅蓄电池生产过程中产生的铅烟、铅尘、废水、铅泥、铅渣等含铅废物,降低企业环境成本和环境风险,实现铅蓄电池生产企业持续健康发展,成为业内人士所共同关注的课题。笔者深入调研了天津市大部分铅蓄电池生产企业,针对存在的问题,提出了从原辅料、生产工艺、设备、过程控制、废弃物、管理、员工等多方面综合考虑,实现含铅废物从源头到生产过程再到产品全过程控制的建议。     

约束型复合阻尼隔声板的隔声性能及其应用研究

约束型复合高阻尼隔声板具有良好的隔振、隔声性能,特别适用于对隔声结构的厚度有苛刻要求的场合。对影响约束型复合高阻尼隔声板主要结构参数的研究,有利于指导其设计、制造和应用选择。根据对约束型复合高阻尼隔声板隔声计算模型的计算与实验表明,当隔声板的面积减小时,其低频隔声量会随之增加;当隔声板阻尼层的厚度等量递增时,其隔声量也近似等比例地提高;当面板材料的弹性模量较小时,隔声板的低频和高频的隔声量都会变差;当隔声板阻尼层剪切模量较高时会导致隔声量偏低。     

Photoluminescence origin of nanocrystalline SiC films

The nanocrystalline SiC films were prepared on Si then annealed at 800℃ and 1 000℃ for 30 minutes （111） substrates by rf magnetron sputtering and in a vacuum annealing system. The crystal structure and crystallization of as-annealed SiC films were determined by the Fourier transform infrared （FIR） absorption spectra and the X-ray diffraction （XRD） analysis. Measurement of photoluminescence （PL） of the nanocrystalline SiC （nc-SiC） films shows that the blue light with 473 nm and 477 nm wavelengths emitted at room temperature and that the PL peak shifts to shorter wavelength side and the PL intensity becomes stronger as the annealing temperature decreases. The time-resolved spectrum of the PL at 477 nm exhibits a bi-exponential decay process with lifetimes of 600 ps and 5 ns and a characteristic of the direct band gap. The strong blue light emission with short PL lifetimes suggests that the quantum confinement effect of the SiC nanocrystals resulted in the radiative recombination of the direct optical transitions.     

Location algorithm for seal imprints on Chinese bank-checks based on region growing

Aslegalconfirmationofbankcheck,sealimprintsare usedinOrientalcountries.Manymethodsonautomatic sealimprintverificationbyacomputerhavebeenan nounced[14],ofwhich,however,mostcannotbeapplied directly,becausetheydealwiththoseoftheimagesof onlyasealimprintother…     

准双曲面齿轮切削仿真及齿面误差分析

为了缩短准双曲面齿轮的开发周期和降低成本,采用计算机模拟HFT刀倾法对主动轮进行切削,仿真生成齿轮真实齿面,并以Solidworks为开发平台进行VBA开发获得三维齿轮的实体模型。在此基础上,比较加工齿面与设计理论齿面的差异,对不同加工速度加工的齿轮误差进行定量计算,说明加工速度对齿面粗糙度的影响。齿面误差分析结果对生产企业选用什么样的切削速度进行切削加工提供参考,并有助于TCA、LTCA等研究工作的展开。     

Nb-V复合微合金化低合金钢连续冷却转变规律

通过Nb-V复合微合金化钢奥氏体连续冷却过程的热模拟试验,结合显微组织观察和显微硬度测试,综合分析了冷却速度对实验钢相变及组织的影响.结果表明,Nb-V复合微合金化低合金钢的临界淬火速度约为23℃/s;随着冷却速度的增大,相变开始温度和结束温度均有所下降,在低冷速区间会出现魏氏组织,在高冷速区间出现马氏体和贝氏体双相组织,晶粒明显细化.     

日本是否会放弃核能——日本能源政策走向分析

能源作为日本震后经济社会发展的中长期政策大纲《日本再生基本战略》的主要支柱之一,日本能源政策的走向尤为值得关注.从短期看,日本将加大核能监管,继续扩大核电制造出口,完全弃核是不可能的;从长期看,日本会逐步降低核能在能源结构中的比例.由于核电的关停,造成日本电力供应不足,进而导致对火力发电政策的支持力度增强,未来对化石能源的依赖局面仍将持续.同时,由于核能政策的调整,一方面使得节能及提高能源使用效率成为新的支柱,另一方面可再生能源将成为重要的发展方向.近10年来,日本可再生能源占能源结构的比例一直没什么变化,约为10％,这与日本政府支持核能战略的政策导向不无关系.日本当前发展可再生能源的主要障碍是缺乏政府的长期政策扶持,其次是开发难度大、发电成本高、系统稳定性低.日本目前需要解决的课题包括全量购买制度等相关政策的导入,大幅度降低成本和解决稳定性关键技术,有效解决可再生能源利用的地域化差异等.总的来看,日本新的能源政策基本是围绕减少对核电的依赖和应对全球气候变暖来制定的.     

Microstructural characterization of Cu-poor Cu (In, Ga)Se2 surface layer

Grazing incidence X-ray diffraction (GIXRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX) are combined to investigate the microstructure and chemical composition of the surface layer in Cu(In, Ga)Se₂ (CIGS) thin films deposited using a three-stage co-evaporation process. According to the GIXRD and micro-region electron diffraction analyses, ordered defect chalcopyrite (ODC) structure does not exist in the surface layer and the surface and the bulk region of the CIGS film have the similar crystal structure. However, the results from the EDX data show that the compositional ratios of the Cu/(In + Ga) (Cu/III) have a gradient distribution across the whole surface layer. The surface layer shows a Cu-poor compositional characteristics and the Cu content increases gradually from the surface to the bulk of the material. The compositional depth profiles determined by XPS agree very well with the results of the EDX measurements. The thickness of the surface layer has been determined to be about 50-100 nm in consistence with that estimated from the compositional ratio of Cu/III. High density dislocations have been observed in the surface region of these samples by high resolution TEM analyses. Our results suggest that different compositions would induce different point defects in the surface layer.     

脱氧胆酸改性普鲁兰多糖纳米粒子制备与表征

通过酯化反应将脱氧胆酸偶联于普鲁兰多糖骨架形成具有两亲性的普鲁兰多糖衍生物(DP),采用纳米沉淀法制备纳米粒子(DPNs),考察制备条件对纳米粒子性质影响,为进一步将其作为药物载体的研究提供基础。衍生物DP结构通过FT-IR和1 H NMR表征,DPNs经透射电镜、动态光散射仪和zeta电位仪表征检测。获得不同取代度脱氧胆酸改性普鲁兰多糖衍生物,制备得到的纳米粒子呈球形,表面光滑规整,平均粒径100～300nm,zeta电位在-20mV左右。脱氧胆酸改性普鲁兰多糖衍生物通过纳米沉淀法能制备出纳米粒子,颗粒性质受制备条件影响。