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971.
972.
黑龙江省甜菜按糖收购计价标准的研究 总被引:1,自引:0,他引:1
13年糖分资料数理分析结果表明,相邻积温带间甜菜含糖率差异高度显著,均达到1%显著水准。将黑龙江省划分为3个甜菜按糖计价区域,其糖分标准分别为14.9%~15.5%、16.1%~16.7%和16.8%~17.4%。甜菜基本价为310元/t,超糖分标准每增加0.1°S加价2.5~28元/t,低于糖分标准每降低0.1°S减价2.5~3.0元/t。 相似文献
973.
Hui Guo Haitong Sheng Xuegang Peng Xiaoyan Yu Kimiyoshi Naito Xiongwei Qu Qingxin Zhang 《Polymer Composites》2014,35(11):2144-2149
Nanodiamond (ND) has recently attracted much attention for its outstanding mechanical and other interesting properties. Surface functionalization of ND is necessary for applications in polymers. In this study, ND particles were functionalized with amine by covalent linking of triethylene tetramine, and further grafted with epoxy which was cured with amine curing agent. The particle dispersion and mechanical properties of epoxy/ND nanocomposites were evaluated. Both fracture toughness and storage modulus of epoxy resin were significantly improved with a low loading of ND‐NH2 particles. The morphological structure of the epoxy/ND nanocomposites was examined, and toughening mechanism was explored. POLYM. COMPOS., 35:2144–2149, 2014. © 2014 Society of Plastics Engineers 相似文献
974.
N. S. Qu H. J. Ji Y. B. Zeng 《The International Journal of Advanced Manufacturing Technology》2014,72(5-8):677-683
Wire electrochemical machining (WECM) is a cutting process in which the workpiece acts as an anode and the wire as a cathode. WECM is typically used to cut plates and exhibits a great advantage over wire electro-discharge machining, namely, the absence of a heat-affected zone around the cutting area. The enhancement of WECM accuracy is a research topic of great interest. In WECM, the homogeneity of the machined slit has a decisive influence on the machining accuracy. This is the first study in which the integration of pulse electrochemical machining (ECM) and a reciprocated traveling wire electrode was used to improve the homogeneity of this slit. The experimental results show that the combination of pulse ECM and a reciprocated traveling wire electrode could enhance the accuracy of WECM and that generally a low applied voltage, pulse duty cycle, and electrolyte concentration; an appropriate traveling wire velocity; and a high pulse frequency and feeding rate enhance the accuracy and stability of WECM. Finally, a microstructure with a slit width of 177 μm, with a standard deviation of 1.5 μm, and with an aspect ratio of 113 was fabricated on a stainless steel substrate measuring 20 mm in thickness. 相似文献
975.
Fujian Sun Shengguan Qu Yuxiang Pan Xiaoqiang Li Chao Yang 《The International Journal of Advanced Manufacturing Technology》2014,73(5-8):613-622
In this paper, dry machining experiment of Ti-6Al-4 V was carried out to investigate the machining performance of a grooved tool in terms of its wear mechanisms and the effects of cutting parameters (cutting speed, feed rate, and cutting depth) on tool life and surface roughness of the machined workpiece. The results showed that chip-groove configuration substantially improved the machining performance of cutting tool. The main wear mechanisms of the grooved tool were adhesive wear, stripping wear, crater wear, and dissolution-diffusion wear. The resistance to chipping was enhanced due to the decrease of contact pressure of tool-chip interface. And the resistance to plastic deformation of tool nose was weakened at the cutting speed of more than 60 m/min. The appropriate cutting speed and feed rate were less than 70 m/min and 0.10 mm/r, respectively. With cutting speed increasing, the surface roughness of machined workpiece decreased. A high feed rate helped the formation of higher surface roughness except 0.21 mm/r. When cutting depth increased, tool nose curvature and phase transformation of workpiece material had great impact on surface roughness. 相似文献
976.
对空调机组运行过程中风机电机与冷却风扇不同步运行故障进行分析、查找原因,实施改进,消除故障,达到了同步运行的目的。 相似文献
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