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Separate characteristic of the tangential ultrasonic vibration assisted grinding(TUAG)machining is analyzed based on TUAG process, and a critical speed formula is given to correctly set the machining parameters to insure the separate characteristics of TUAG process. The critical speed is not only related to the ultrasonic vibration amplitude and frequency, but also to the grinding wheel velocity and the cutting point space, and the grinding force can be decreased during the TUAG process with separability. Grinding force experiments are conducted, and the experimental results are in good agreement with the theoretical results. 相似文献
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Anil Lachke 《Resonance》2002,7(5):50-58
In the biosphere we find cellulose and hemicellulose as the major polysaccharides. On acid or enzymatic hydrolysis,D-glucose is produced from cellulose andD-xylose is produced from xylans as the major sugar in the hydrolysate. Initially it was believed that yeasts do not fermentD-xylose to ethanol although many are capable of producing xylitol. Twenty years ago, a few yeasts that could convertD-xylose to ethanol were found. Ethanol is viewed as a potential fuel that is available from biomass and hence new methods
to generate ethanol from hitherto inaccessible sources are gaining importance. Biotechnology for efficient utilization of
lignocellulose wastes as fuels relies on the utilization of both the cellulosic as well as hemicellulosic portions of the
biomass. In this article, conversion of xylose into ethanol is discussed. 相似文献
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为了将纳米颗粒的强化传热吸收作用应用于氨水吸收制冷中,提出了在氨水溶液中添加铁酸锌纳米颗粒和复配阴/阳离子表面活性剂SDBS和CTAB的纳米流体的配制方法,并对其稳定性进行了实验研究.研究了阴阳离子活性剂质量分数、复配比例及超声分散和光照对稳定性的影响,确定了铁酸锌-氨水纳米流体分散的最佳工艺为：SDBS质量分数为1.5%,CTAB质量分数为0.015%,超声时间为30min,光照时间72h以上.最后根据双电层原理分析了活性剂质量分数对悬浮液稳定性的影响,表明存在最佳活性剂质量分数,并与实验结果相符. 相似文献
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船舶板架结构除了受到自身重力和设备重力作用外,还受到激振力的作用。应用大型有限元软件ANSYS软件对部分船体板架在受设备激振力和不受设备激振力两种情况进行计算,并就计算结果进行对比分析。结果显示,往往被我们忽视的激振力对船舶板架结构强度的影响不容忽视。 相似文献
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为了探索双壁波纹塑料管用作水井井壁管和滤水器安装井管时的轴向抗拉能力,本研究以PVC双壁波纹管加工成的双壁波纹管滤水器圆管和条板材料为研究对象、并对其管接头采用密封圈加固,螺钉加固,铁丝绑扎,管箍铁件连接四种不同加固方式,在万能拉力机上进行拉力对比试验,结果表明：开有条形孔的管材的抗拉力明显低于末开孔的,开孔率越大,抗拉力越低;3个相同试件破坏时的拉力最大为3kN,最小为2．93kN,差值为0．07kN。相差不大;开孔率相同的板状试件．波纹糟中开孔的抗拉力较棱上开孔的高28％～63％;单纯承插连接,接头抗拉力太小,不能用于井管连接;螺钉加固,铁丝绑扎加固的接头抗拉力比较强,且成本低,管箍铁件加固抗拉力大,但成本高,故建议采用承插螺钉加固与铁丝绑扎加固用于浅井和中深井。管箍铁件加固用于深井。 相似文献
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《校园英语(教研版)》2015,(12):250-252
Today,it's hard to imagine a transport world without short sea shipping.Not only does this modern version of coastal shipping experience no delays due to road congestion,low road assessment,also has the lowest transportation cost and co2 emission of all commercial transport modes.For these reasons,short sea shipping is in many cases a perfect alternative to road transport.In this research paper we designed an optimal transportation method of short sea shipping in Yemen to lower the country transportation cost of commercial goods,since Yemen is unfavorable in terms of transportation infrastructure,hard level of mountainous areas and roads are generally poor,short sea shipping is a great alternative to road transport.We collected data and computed the cost of short sea shipping in a multi stage method(warehouse and distribution centers) saving an average of 40% to 50% of transportation cost than if delivered by direct road to road.This research paper and its methodologies have favorable results in all studied aspects. 相似文献
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中小企业物流成本高居不下严重制约了中小企业的经营发展,物流成本之中权重最高的是运输成本,如何对运输成本进行有效管理,降低整体运输成本,是提高中小企业效益、减少物流费用和提高生产经营效率的关键问题。 相似文献
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Service failures of turbine blades in many instancescan be attributedto highcyclefatigue caused bylarge reso-nance stress .As dryfrictioninterface may be the most im-portant source of energy dissipation,thefriction damperis atypical devicetoreduce vibrati… 相似文献
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徐汉峰 《河北能源职业技术学院学报》2009,9(2):17-19
《管子·八观》篇提出了国侈则用费,用费则民贫;观台榭、量国费、粟行百里,稼禾盖积;用财毋已,用力毋休;民产有余,国之存也的思想,对中国会计文化建设的贡献在于审度量节、概算收支、基本建设、量力而行、观察生产、粮食安全、体察民情、安帮定国。 相似文献
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利用电磁学理论建立了带电圆环点电荷系统振动方程,讨论了系统在不同条件下的稳定性,对非线性振动系统,利用Maple计算绘图,分别作出了回复力和能量随位移的变化曲线、相图,求出了非线性振动系统的周期． 相似文献
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A novel precision vibration-assisted micro-engraving system was developed by the integration of fast tool servo and ultrasonic elliptical vibration system, in which the flexure hinge was designed to avoid backlash and PID control algorithm was established to guarantee specific precision. Apart from experimental validation of the performance of the system, various micro-V-grooves cutting experiments on aluminum alloy, ferrous material and hard cutting material were performed, in which Kistler force sensor was used to measure cutting force. Through experiments, it was clear that the vibration-assisted micro-engraving system can ensure good quality of micro-V-grooves and reduce cutting force by about 60% compared with traditional removal process without ultrasonic vibration. 相似文献
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基于麦克斯威尔方程,给出导电薄板的非线性磁弹性振动方程,以及磁场环境下的电动力学方程和电磁力表达式。在此基础上,应用伽辽金法导出相应的非线性振动微分方程组,研究横向恒定磁场中周期载荷作用下梁式薄板的稳定性问题。根据李雅普诺夫近似稳定性理论,对稳态解的稳定性进行分析,得到稳定性的判定条件。通过对算例特征值的求解对振动的稳定性进行分析。 相似文献
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宝音伊日格其 《内蒙古师范大学学报(哲学社会科学版)》2004,33(1):52-57
人的劳动具有重大作用及发展,劳动价值论包含着丰富的内容。马克思把商品的概念由物质产品扩大为劳动力、运输业和服务,并提出运输业和劳务部门的劳动也创造价值的理论,这是马克思劳动价值论的深化和发展。人的劳动和劳动价值论之间存在密切关系。 相似文献
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从超声波振动加工兼统的构成及对信号发生器的要求出发,研究超声振动加工专用超声波信号发生器的原理、设计及应用问题,解决在这种专门场合使用脉宽调制技术变压变频时可能出现的特殊问题。 相似文献
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提出FSAE赛车2种减振系统装配夹具设计中定位方案．采用计算机辅助设计软件建模方法建立了空间倾斜减振系统平面几何模型．依据工艺理论,提出并分析了2种定位方案的定位性质、定位成本和效率．研究表明：CAD建模方法提高了夹具设计的效率和质量;梯形定位块定位方法属于完全定位,其定位元件少、成本低、定位效率高;定位方案分析方法和梯形定位元件可应用于机械、汽车制造领域的夹具设计． 相似文献
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模具制造过程中引入并行工程模式,可以有效缩短模具的生产周期、降低制造成本.以往的研究大多关注并行工程的概念,而缺乏模具制造中的实际应用分析,本文以注射模具制造为研究对象,探讨了实际制造过程与这一先进理念应用的方法. 相似文献