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1.
Rajivgandhi Govindan Nadar Chenthis Kanisha Chelliah Vijayakumar Sekar Alharbi Naiyf S. Kadaikunnan Shine Khaled Jamal M. Alanzi Khalid F. Li Wen-Jun 《Journal of Inorganic and Organometallic Polymers and Materials》2021,31(10):3921-3933
Journal of Inorganic and Organometallic Polymers and Materials - The silver oxide nanoparticle was successfully synthesized using floral waste by simple one pot, cost effective method. The complete... 相似文献
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建立行星滚柱丝杠副的传递效率数学模型,对行星滚柱丝杠副的正传递效率进行研究,并对传动效率影响较大的接触角和螺旋升角进行定量定性的分析,得出了螺旋升角最优值为5°,接触角45°为最佳值,为行星滚柱丝杠副的结构参数优化及产品系列化设计提供参考。 相似文献
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This paper develops a mesh-free numerical method for solving PDEs, based on integrated radial basis function networks (IRBFNs) with adaptive residual subsampling training scheme. The multiquadratic function is chosen as the transfer function of the neurons. The nonlinear algebraic equation systems for weights training are solved by Levenberg–Marquardt algorithm. The performance of the proposed method is demonstrated in numerical examples by approximating several functions and solving nonlinear PDEs. The result of numerical experiments shows that the IRBFNs with the adaptive procedure requires less neurons to attain the desired accuracy than conventional radial basis function networks. 相似文献
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Theoretical analysis of the slip flow effect on gas-lubricated micro spherical spiral groove bearings for machinery gyroscope 总被引:1,自引:0,他引:1
The performance of a gas-lubricated micro spherical spiral groove bearing (MSSGB) with slip flow effect is investigated. A modified Reynolds equation incorporated with Barber’s first-order slip flow model is proposed to investigate the flow characteristics of gas in MSSGBs. Parameter transformation and oblique coordinate transformation are applied to eliminate the curve effect on the calculation domain. An improved finite difference method (FDM) based on Green’s formula is used to solve the Reynolds equation. The perturbation method is adopted to determine the dynamic coefficients. The effects of slip flow and bearing parameters, including the groove depths, rotor speeds, and eccentricity ratios, on the bearing characteristics are investigated and discussed. Prediction results show that the slip flow effect on MSSGB performance is significant. Moreover, the groove depth at micro clearance has a crucial influence on bearing performance. 相似文献
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类型系统λω×≤的PER模型 总被引:7,自引:7,他引:0
类型系统是近年来理论计算机科学的研究热点之一 .1999年周晓聪曾在文献 [1]中提出并研究了类型系统λω× ≤ 及其性质 .类型系统λω× ≤ 是λω×的扩充 ,引入了子类型关系和受限的全称类型 .与 System F的各种扩充相比 ,它区分各种上下文 ,使得规则和性质的研究更为清晰 .研究该类型系统的 PER模型作为其语义解释 ,并说明该模型的合理性 相似文献
8.
Ji-Zhou Kong Zheng Wang Chun-Yan Luan Mei-Ling Wang Fei Zhou Xue-Mei Wu Wen-Jun Zhang Kong-Jun Zhu Jin-Hao Qiu Juan-Antonio Zapien Shuit-Tong Lee 《Journal of Materials Science: Materials in Electronics》2013,24(10):3868-3874
High-quality c-axis oriented 7 mol% Al and 1.5 mol% Er co-doped ZnO films (ZEAO) were prepared on the quartz glass substrates by using sol–gel method. The influence of the annealing temperature on the crystal orientation, microstructure and optical properties of the ZEAO thin films were studied by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and UV–vis transmittance spectrophotometer, respectively. XRD results revealed that all the samples were polycrystalline with hexagonal structure and exhibited (002) preferential orientation. With increasing the annealing temperature, the grain size and orientation extent increased. The optical studies showed each ZEAO film had a relatively high transmittance above 85 %. The transmittance as high as 95 % was obtained at the annealing temperature of 800 °C, and the corresponding average grain size was about 50 nm. The cathodoluminescence (CL) spectra of these films were also used to characterize the luminescence properties. Strong UV emission centered at 380 nm was observed in the CL spectra taken for the pure ZnO. For the ZEAO sample, the blue-green emission is related to the 4f shell transition in the Er3+ ions of ZnO matrices, corresponding to a transition from the excited states (4F5/2). 相似文献
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在前言中讨论了驱油用磺酸盐的最佳结构和国内研发的石油磺酸盐、重烷基苯磺酸盐的结构、原料及使用中出现的问题.针对地质结构和物性复杂的胜利油田,研发了具有不同用途的3种多组分磺酸盐.一为稠油乳化降黏剂S-5,系单环芳烃(烷基苯)磺酸盐和多环芳烃(烷基萘)磺酸盐甲醛缩合物的混合物,对稠油的乳化能力强,耐温耐钙镁离子,注入200℃的0.5%S-5水溶液使蒸汽驱后岩心采收率提高9%和10%,使岩心采收率比蒸汽驱提高19%左右.S-5已在胜利油田几个稠油区块伴随蒸汽注入或作为注蒸汽前置液使用51井次,使注蒸汽压力降低,产油量上升.二为高温泡沫驱油剂FS-411,系C20~C30混合高碳烷基磺酸盐,小试和中试产品在250℃填砂管中的阻力因子为市售发泡剂的2倍左右,在现河C20区块4口多轮次蒸汽吞吐井同时注入蒸汽、氮气和FS-411,使注蒸汽压力上升,该轮次生产周期延长,产油量增加,含水降低.三为超低界面张力表面活性剂SL-7,以馏分油和烷基苯为原料,90℃下SL-7溶液和SL-7/HPAM溶液与胜利多种原油的界面张力均达到10-3 mN/m超低,二元复合驱的岩心采收率比聚合物驱高4.1%,将用于胜二区沙二某单元的二元复合驱.图1表11参16. 相似文献