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Mathematical Modeling of Pneumatic Artificial Muscle Actuation via Hydrogen Driving Metal Hydride-LaNi5

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Journal of Bionic Engineering 2012年第1期9卷 110-118页

作者： Thananchai Leephakpreeda School of Manufacturing Systems and Mechanical Engineering Sirindhorn International Institute of Technology Thammasat University P.O. Box 22 Thammasat-Rangsit Post Office Pathumthani 12121 Thailand

Quantitative understanding of mechanical actuation of intricate Pneumatic Artificial Muscle （PAM） actuators is technically required in control system design for effective real-time implementation. This paper presents mathematical modeling of the PAM driven by hydrogen-gas pressure due to absorption and desorption of metal hydride. Empirical models of both mechanical actuation of industrial PAM and chemical reaction of the metal hydride-LaNi5 are derived systematically where their interac- tions comply with the continuity principle and energy balance in describing actual dynamic behaviors of the PAM actuator （PAM and hydriding/dehydriding-reaction bed）. Simulation studies of mechanical actuation under various loads are conducted so as to present dynamic responses of the PAM actuators. From the promising results, it is intriguing that the heat input for the PAM actuator can be supplied to, or pumped from the reaction bed, in such a way that absorption and desorption of hydrogen gas take place, respectively, in controlling the pressure of hydrogen gas within the PAM actuator. Accordingly, this manipulation results in desired mechanical actuation of the PAM actuator in practical uses.

关键词： mathematical model pneumatic artificial muscle metal hydride storage

Removing paint from a metal substrate using a flattened top laser

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Chinese Physics B 2012年第10期21卷 295-301页

作者：施曙东李伟杜鹏王萌宋峰刘淑静陈念江赵鸿杨文是 School of Physics Nankai University Electricity Department Patent Office Department of Physics College of Basic Medical SciencesTianjin Medical University Science and technology on Solid-State Laser Laboratory

In this paper,we investigate laser cleaning using a flattened top laser to remove paint coating from a metal *** the irradiation of a flattened top laser,the coating paint of the metal substrate can be removed efficiently by laser induced ablation,stress,and displacement *** temperature distribution,stress,and displacement are calculated in the coating layer and substrate using finite element *** effects of a Gaussian laser and a flattened top laser and the results of different diameters of laser spot are *** investigation shows that the flattened top laser can reduce the substrate damage and enhance the cleaning *** method meets the need of large area industrial cleaning applications by optimizing the flattened top laser parameters.

关键词： laser cleaning laser ablation finite element method flattened top laser beam

Selenium Doping in Bi-based Superconductors

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Journal of Materials Science & technology 2000年第3期16卷 351-353页

作者： Affia Aslam and S.A.Siddiqi (Centre for Solid State Physics, University of the Punjab, Lahore-54590, Pakistan) J.A.A.Khan and R.Shaheen (Pakistan Institute of Nuclear Science & technology, Post office Nilore, Islamabad, Pakistan) Centre for Solid State Physics University of the Punjab Lahore-54590 Pakistan Pakistan Institute of Nuclear Science and technology Islamabad Post Office Nilore Pakistan

Six different compositions in Bi2Sr2Ca2Cu3Oy:Sex with x=0.0, 0.05, 0.1, 0.2, 0.3, 0.4 have been prepared by the solid state reaction method to explore doping of selenium in the system. Sintering at 847±4℃ and subsequent annealing at 827℃ has been carried out for different time periods. The samples have been characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and measurement of resistance below room temperature has been carried out by four-probe method. Superconducting transition temperature (Tc) value shows dependence on Se concentration: the highest Tc(0)=:94 K is observed for x=0.3. A detailed Auger electron spectroscopic (AES) analysis has been carried out to investigate the presence of Se in the grains of the superconductors. It has also been found that Se increases the Tc(0) value and promotes the formation of high temperature superconducting phase (2223), which coexists with low temperature phase (2212) in the sintered samples.

关键词： Selenium Doping in Bi-based Superconductors high XRD Bi

The Propagation Background in Social Networks:Simulating and Modeling

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International Journal of Automation and computing 2020年第3期17卷 353-363页

作者： Kai Li Tong Xu Shuai Feng Li-Sheng Qiao Hua-Wei Shen Tian-Yang Lv Xue-Qi Cheng En-Hong Chen School of Computer Science and technology University of Science and Technoloty of ChinaHefei 230027China IT Center of Chinese National Audit office Beijing 100073China Institute of Computing technology Chinese Academy of SciencesBeijing 100190China

Recent years have witnessed the booming of online social network and social media platforms,which leads to a state of information *** extensive efforts have been made by publishers to struggle for the limited attention of audiences,still,only a few of information items will be received and ***,for simulating the information propagation process,competition among propagating items should be considered,which has been largely ignored by prior works on propagation *** possible reason may be that,it is almost impossible to identify the influence of propagation background from real diffusion *** that end,in this paper,we design a comprehensive framework to simulate the propagation process with the characteristics of user behaviors and network ***,we propose a propagation background simulating(PBS)algorithm to simulate the propagation background by using users′behavior dynamics and *** this line,an ICPB(independent cascade with propagation background)model is adapted to relieve the impact of propagation background by using users′*** experiments on kinds of synthetic and real networks have demonstrated the effectiveness of our methods.

关键词： Social network information overload propagation background simulating modeling

Water quality and growth of phytoplankton for the Yellow River estuary reservoirs—current status of water environment

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Journal of Harbin Institute of technology(New Series) 2010年第6期17卷 776-781页

作者：王云波高桥幸彦杜茂安张杰松本恭明 Shenyang Urban Construction Project office Original Engineering Consultants Co. LTD School of Municipal and Environmental Engineering Harbin Institute of Technology

In this paper,the characteristics of the water quality in Yellow River estuary reservoirs were surveyed and the progress of the eutrophication was investigated by observing the behavior of nitrogen and *** results showed that the concentration of dissolved inorganic nitrogen and total nitrogen was very high in all the reservoirs,and the level of nitrogen was eutrophic *** to Vollenweider's type model for phosphorus load,the total phosphorus was close to permissible load in Guangnan and Xinan *** sometimes,the total phosphorus exceeded an excessive load in Gengjing *** Yellow River estuary reservoirs,Cyanobacteria,and Diatom phytoplankton were observed mainly,and the cyanobacteria was a the dominant species in summer.

关键词： dominant species eutrophication Vollenweider’s type model cyanobacteria

Water quality and growth of phytoplankton for the Yellow River estuary reservoirs—The nutrients release from reservoir sediments

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Journal of Harbin Institute of technology(New Series) 2011年第1期18卷 61-66页

作者：高桥幸彦杜茂安李观元王云波张杰松本恭明 Original Engineering Consultants Co. LTD School of Municipal and Environmental Engineering Harbin Institute of Technology Shenyang Urban Construction Project office

Effects of nutrients released from sediments on eutrophication in lakes and reservoirs were not well known in China. In the test, the release conditions of nitrogen and phosphorus from the sediments were observed by batch experiment. The test results revealed that the content released is correlated to the initial content of organic matter in sediments. In the Gengjing area, when the water quality of waterway, grit chamber and reservoir were compared, the water quality of the waterway was the highest, and lowered in the order of the grit chamber and the reservoir. The grit chamber could get not only fine sand removal but also the organic substance, nitrogen, phosphorus and phytoplankton, therefore it is important to operate and maintain the grit chamber to preserve the water quality of the reservoir. Due to little organic substance in sediments, ammonium nitrogen and phosphorus weren't released during the incubation. But from the absorptiometric turbidity unit (ATU) test results, although the release of ammonium concentration was very low, ammonium oxidizing and nitrite oxidizing bacteria existed in sediments.

关键词： nutrients batch experiment waterway grit chamber reservoir ammonium nitrogen and phosphorus

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Facile and scalable preparation of ultra-large boron nitride nanosheets and their use for highly thermally conductive polymer composites

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Frontiers of Materials Science 2022年第1期16卷 119-131页

作者： Wenyu WU Bin GUO Xiaojing LIU Huaxin MA Zhao ZHANG Zhi ZHANG Minghao CUI Yu GU Ruijun ZHANG State Key Laboratory of Metastable Materials Science and technology Yanshan UniversityQinhuangdao 066004China Academic Affairs office Tangshan Normal UniversityTangshan 063000China

Due to their excellent physical and chemical properties,boron nitride nanosheets(BNNSs)have shown great application potential in many ***,the difficulty in scalable preparation of large-size BNNSs is still the current factor that limits ***,a simple yet efficient microwave-assisted chemical exfoliation strategy is proposed to realize scalable preparation of BNNSs by using perchloric acid as the edge modifier and intercalation agent of *** as-obtained BNNSs behave a thin-layered structure(average thickness of 3.9 nm)with a high yield of~16%.Noteworthy,the size of BNNSs is maintained to the greatest extent so as to realize the preparation of BNNSs with ultra-large size(up to 7.1μm),which is the largest so far obtained for the top-down exfoliated *** from the large size,it can significantly improve the thermal diffusion coefficient and the thermal conductivity of polyvinyl alcohol by 51 and 62 times respectively,both showing a higher value than the one previously *** demonstrates that the prepared BNNSs have great promise in enhancing the thermal conductivity of polymer materials.

关键词： boron nitride nanosheet thermal conductivity chemical exfoliation large size

An investigation on the dosimetric impact of hip prosthesis in radiotherapy

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Nuclear Science and Techniques 2016年第1期27卷 29-36页

作者： Wen-Cheng Shao Yan-Ling Bai Wen-Bo Zhao Pu-Nan Sun Feng-Li Liu Department of Radiation Physics Harbin Medical University Cancer Hospital Beijing Xiao Qing Environmental Engineering Co. LtdHarbin office School of physical science and technology Heilongjiang University

The objectives of this study are to evaluate the dosimetric impact of hip prosthesis using ELEKTA linac X-rays and compare the dose perturbations of metallic and nonmetallic hip prostheses. The local dose distributions of typical hip prostheses were calculated for 4, 8, and 15 MV beams by Geant4. Three prosthesis materials were selected in calculation to reveal the relation between material type and local dose perturbations of prostheses. Furthermore,the effect of nominal energy on prosthesis perturbation was also discussed and analyzed. Taking the calculated dose to the hip joint as reference, considerable differences were observed between prostheses and hip joints. In the prosthesis shadow region, the relative dose decreasing was up to 36, 21, and 16 % for the Co–Cr–Mo alloy, titanium alloy, and ceramic prostheses, respectively. In backscattering region, the relative dose increasing was about1–7 %. Overall, the results show that the dose perturbation effect of prostheses was mainly determined by material type, nominal energy, and density. Among these typical hip prostheses, ceramic prosthesis introduces the lowest dose perturbations.

关键词：髋关节剂量学假体放射治疗扰动效应 Geant4 X射线剂量直线加速器

Application of Rare Earths in Oil Country Tubular Goods

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Journal of Rare Earths 1996年第3期14卷 189-194页

作者：林勤姚庭杰刘爱生陈宁叶文余宗森卢先利 University of Science and technology Beijing Beijing 100088 China Iron and Steel Research Institute Boo Shan Iron and Steel Corporation China Rare Earth office Ministry of Metallurgical Industry China

The effect of rare earths(RE) on purifying molten steels, modifying inclusion and micro-alloying are studied in J55 steel. The results show that RE improves the transverse impact energy and increases the resistance of perforation cracking. The extent on modifying MnS and Al2O3 inclusions is dependent on the activity ratios of RE to Mn and RE to Al. The(a(RE). a(s))/(a(o) . a(Al)) value determines the relative amount of REAlO(3) and RE(2)O(2)S and the properties of steel. RE segregation on grain boundary reduces the segregation of phosphorus and sulfur there.

关键词： RE purifying molten steel modifying inclusion micro-alloying J55 steel