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206篇 您的检索式:作者名="Heping Wang"
    题名 作者 年代 出处 被引量
1Mechanical behavior of coal under different mining rates:A case study from laboratory experiments to field testing显示文摘During the development of hot dry rock,the research on thermal fatigue damage caused by thermal shock of cold and heat cycles is the basis that ensures the long-term utilization of geothermal resources,but there are not enough relevant studies at present.Based on this,the thermal damage tests of granite at different temperatures(250,350,450°C)and quenching cycles(1,5,10,15 cycles)were carried out.Preliminary reveals the damage mechanism and heat transfer law of the quenching cycle effect on hot dry rock.The results show that with the increase of temperature and cycles,the uneven thermal expansion of minerals and the thermal shock caused by quenching promote the crack development of granite,resulting in the decrease of P-wave velocity,thermal conductivity and uniaxial compressive strength of granite.Meanwhile,the COMSOL was used to simulate the heat transfer of hot dry rock under different heat treatment conditions.It concluded that the increase in the number of quenching cycles reduced the heat transfer capacity of the granite,especially more than 10 quenching cycles,which also reflects that the thermal fatigue damage leads to a longer time for the temperature recovery of the hot dry rock mass.In addition,the three-dimensional nonlinear fitting relationship among thermal conductivity,temperature and cycle number was established for the first time,which can better reveal the change rule of thermal conductivity after quenching thermal fatigue effect of hot dry rock.The research results provide theoretical support for hot dry rock reservoir reconstruction and production efficiency evaluation.Mingzhong Gao Jing Xie Yanan Gao Wenyong Wang Cong Li Bengao Yang Junjun Liu Heping Xie 2021International Journal of Mining Science and Technology2021,31,5:39
2Preliminary results pertaining to coseismic displacement and preseismic strain accumulation of the Lushan M_S7.0 earthquake,as reflected by GPS surveying显示文摘This paper presents the coseismic displacement and preseismic deformation fields of the Lushan MS7.0 earthquake that occurred on April 20,2013.The results are based on GPS observations along the Longmenshan fault and within its vicinity.The coseismic displacement and preseismic GPS results indicate that in the strain release of this earthquake,the thrust rupture is dominant and the laevorotation movement is secondary.Furthermore,we infer that any possible the rupture does not reach the earth’s surface,and the seismogenic fault is most likely one fault to the east of the Guanxian-Anxian fault.Some detailed results are obtainable.(1)The southern segment of the Longmenshan fault is locked preceding the Lushan earthquake.After the Wenchuan earthquake,the strain accumulation rate in the southeast direction accelerates in the epicenter of the Lushan earthquake,and the angle between the principal compressional strain and the seismogenic fault indicates that a sinistral deformation background in the direction of the seismogenic fault precedes the Lushan earthquake.Therefore,it is evident that the Wenchuan MS8.0 earthquake accelerated the pregnancy of the Lushan earthquake.(2)The coseismic displacements reflected by GPS data are mainly located in a region that is 230 km(NW direction)×100 km(SW direction),and coseismic displacements larger than 10 mm lie predominantly in a100-km region(NW direction).(3)On a large scale,the coseismic displacement shows thrust characteristics,but the associated values are remarkably small in the near field(within 70 km)of the earthquake fault.Meanwhile,the thrust movement in this70-km region does not correspond with the attenuation characteristics of the strain release,indicating that the rupture of this earthquake does not reach the earth’s surface.(4)The laevorotation movements are remarkable in the 50-km region,which is located in the hanging wall that is close to the earthquake fault,and the corresponding values in this case correlate with the attenuation characteristics of the strain release.WU YanQiang JIANG ZaiSen WANG Min CHE Shi LIAO Hua LI Qiang LI Peng YANG YongLin XIANG HePing SHAO ZhiGang WANG WuXing WEI WenXin LIU XiaoXia 2013Chinese Science Bulletin2013,58,28:33
3An experimental investigation on the mechanism of fluid flow through single rough fracture of rock显示文摘The structure of fractures in nature rock appears irregular and induces complicated seepage flow behavior.The mechanism and quantitative description of fluid flow through rock fractures is a difficult subject that has been greatly concerned in the fields of geotechnical,mining,geological,and petroleum engineering.In order to probe the mechanism of fluid flow and the effects of rough structures,we conducted a few laboratory tests of fluid flow through single rough fractures,in which the Weierstrass-Mandelbrot fractal function and PMMA material were employed to produce the fracture models with various fractal roughnesses.A high-speed video camera was employed to record the fluid flow through the entire single rough fracture with a constant hydraulic pressure.The properties of fluid flow varying with the fracture roughness and the influences of the rough structure were analyzed.The components of flow resistance of a single rough fracture were discussed.A fractal model was proposed to relate the fluid resistance to the fracture roughness.A fractal equivalent permeability coefficient of a single rough fracture was formulated.This study aims to provide an experimental basis and reference for better understanding and quantitatively relating the fluid flow properties to the structures of rock fractures.JU Yang ZHANG QinGang YANG YongMing XIE HePing GAO Feng WANG HuiJie 2013Science China(Technological Sciences)2013,56,8:28
4Numerical simulation for the coupling effect of local atmospheric circulations over the area of Beijing,Tianjin and Hebei Province显示文摘Using the model system MM5.V3 and multi-layer grid nesting technique, we have done a multi-scale numerical simulation over the area of Beijing, Tianjin and Hebei Province to analyze the temperature and wind field there and study its local circulations. The results show a coupling effect of Urban Heat Island Circulation (UHIC), Mountain Valley Breeze (MVB) and Sea Land Breeze (SLB) occurs in this area when the synoptic system is weak. The SLB can penetrate deep into the mainland for about 200 km when it is blooming. MVB can extend to south and cover almost the whole plain area in Beijing. Both MVB and SLB are diurnal periodical; meanwhile the phase of MVB drops behind that of SLB for about six hours. As a local circulation, the UHIC weakens the two circulations above, and it also has a diurnal period. As a result, the coupling effect of circulations reveals not only different features in spring-summer period and autumn-winter period in a year but also the difference between early morn- ing to noonday and afternoon to night in a day. We noted the diffusion of contamination over the area around Beijing, and found the steady presence of a transport routine of contamination over North-China throughout the year caused by the Coupling Effect mentioned above. This find is important for studying the environment pollution in this area.LIU ShuHua LIU ZhenXin LI Ju WANG YinChun MA YanJun SHENG Li LIU HePing LIANG FuMing XIN GuoJun WANG JianHua 2009Science China Earth Sciences2009,52,3:20
5High-resolution records of Holocene from the Shuangchi Maar Lake in Hainan Island显示文摘The results of sedimentary characteristics, grain-size, clay mineral, C/N and pollen analysis reveal the evolution history of the Shuangchi Maar Lake of Hainan Island as well as the short-term climate variations in tropical areas. It is testified that the Maar sediment system was sensitive in recording the rapid climate changes in the Holocene. These multidisciplinary results demonstrate that the thermal maximum in the Holocene climate lasted from 7200 to 2700 aBP, with several abrupt ephemeral vibrations occurring between 7250-6120 aBP and at around 4460, 3850 and 2700 aBP. In the late Holocene, particularly at ~2700 aBP, a distinct environmental change indicating an important climate transition in the tropical eastern Asia was recorded, probably responding to the enhancement of ENSO phenomena in the Pacific Ocean. In addition, the high-resolution algae record clearly indicates periodical climate fluctuations at 500 a cyclicity during the last 2500 years.ZHENG Zhuo, WANG Jianghua, WANG Bing, LIU Chunlian, ZOU Heping, ZHANG Hua, DENG Yun & BAI Yan Department of Earth Sciences, Zhongshan University, Guangzhou 510275, China (e-mail: ee29@zsu.edu.cn) 2003Chinese Science Bulletin2003,48,5:20
6Simultaneous mineralization of CO_2 and recovery of soluble potassium using earth-abundant potassium feldspar显示文摘CO2 capture and storage(CCS) is an important strategy in combatting anthropogenic climate change.However,commercial application of the CCS technique is currently hampered by its high energy expenditure and costs.To overcome this issue,CO2 capture and utilization(CCU) is a promising CO2 disposal method.We,for the first time,developed a promising method to mineralize CO2 using earth-abundant potassium feldspar in order to effectively reduce CO2 emissions.Our experiments demonstrate that,after adding calcium chloride hexahydrate as an additive,the K-feldspar can be transformed to Ca-silicates at 800 C,which can easily mineralize CO2 to form stable calcium carbonate and recover soluble potassium.The conversion of this process reached 84.7%.With further study,the pretreatment temperature can be reduced to 250 C using hydrothermal method by adding the solution of triethanolamine(TEA).The highest conversion can be reached 40.1%.The process of simultaneous mineralization of CO2 and recovery of soluble potassium can be easily implemented in practice and may provide an economically feasible way to tackle global anthropogenic climate change.XIE HePing WANG YuFei JU Yang LIANG Bin ZHU JiaHua ZHANG Ru XIE LingZhi LIU Tao ZHOU XiangGe ZENG HongMei LI Chun LU HouFang 2013Chinese Science Bulletin2013,58,1:16
7Current technology development for CO2 utilization into solar fuels and chemicals:A review显示文摘The continuous consumption of fossil fuels causes two important impediments including emission of large concentrations of CO2 resulting in global warming and alarming utilization of energy assets.The conversion of greenhouse gas CO2 into solar fuels can be an expedient accomplishment for the solution of both problems,all together.CO2 reutilization into valuable fuels and chemicals is a great challenge of the current century.Owing to limitations in traditional approaches,there have been developed many novel technologies such as photochemical,biochemical,electrochemical,plasma-chemical and solar thermochemical.They are currently being used for CO2 capture,sequestration,and utilization to transform CO2 into valuable products such as syngas,methane,methanol,formic acid,as well as fossil fuel consumption reduction.This review summarizes different traditional and novel thermal technologies used in CO2 conversion with detailed information about their working principle,types,currently adopted methods,developments,conversion rates,products formed,catalysts and operating conditions.Moreover,a comparison of these novel technologies in terms of distinctive key features such as conversion rate,yield,use of earth metals,renewable energy,investment,and operating cost has been provided in order to have a useful review for future research direction.Azeem Mustafa Bachirou Guene Lougou Yong Shuai Zhijiang Wang Heping Tan 2020Journal of Energy Chemistry2020,29,10:16
8Respiratory Virus Multiplex RT-PCR Assay Sensitivities and Influence Factors in Hospitalized Children with Lower Respiratory Tract Infections显示文摘Multiplex RT-PCR assays have been widely used tools for detection and differentiation of a panel of respiratory viral pathogens. In this study, we evaluated the Qiagen ResPlex II V2.0 kit and explored factors influencing its sensitivity. Nasopharyngeal swab (NPS) specimens were prospectively collected from pediatric inpatients with lower respiratory tract infections at the time of admission in the Shenzhen Children's Hospital from May 2009 to April 2010. Total nucleic acids were extracted using the EZ1 system (Qiagen, Germany) and 17 respiratory viruses and genotypes including influenza A virus (FluA), FluB, parainfluenza virus 1 (PIV1), PIV2, PIV3, PIV4, respiratory syncytial virus (RSV), human metapneumovirus (hMPV), rhinoviruses (RhV), enteroviruses (EnV), human bocaviruses (hBoV), adenoviruses (AdV), four coronaviruses (229E, OC43, NL63 and HKU1), and FluA 2009 pandemic H1N1(H1N1-p) were detected and identified by the ResPlex II kit. In parallel, 16 real-time TaqMan quantitative RT-PCR assays were used to quantitatively detect each virus except for RhV. Influenza and parainfluenza viral cultures were also performed. Among the total 438 NPS specimens collected during the study period, one or more viral pathogens were detected in 274 (62.6%) and 201(45.9%) specimens by monoplex TaqMan RT-PCR and multiplex ResPlex, respectively. When results from monoplex PCR or cell culture were used as the reference standard, the multiplex PCR possessed specificities of 92.9-100.0%. The sensitivity of multiplex PCR for PIV3, hMPV, PIV1 and BoV were 73.1%, 70%, 66.7% and 55.6%, respectively, while low sensitivities (11.1%-40.0%) were observed for FluA, EnV, OC43, RSV and H1N1. Among the seven viruses/genotypes detected with higher frequencies, multiplex PCR sensitivities were correlated significantly with viral loads determined by the TaqMan RT-PCR in FluA, H1N1-p and RSV (p=0.011-0.000). The Qiagen ResPlex II multiplex RT-PCR kit possesses excellent specificity for simultaneous detection of 17 viral pathogens in NPS specimens in pediatric inpatients at the time of admission. The sensitivity of multiplex RT-PCR was influenced by viral loads, specimen process methods, primer and probe design and amplification condition.Jikui Deng Zhuoya Ma Wenbo Huang Chengrong Li Heping Wang Yuejie Zheng Rong Zhou Yi-Wei Tang 2013Virologica Sinica2013,28,2:14
9Effect of dietary interventions on the intestinal microbiota of Mongolian hosts显示文摘The gut microbiota of Mongolian hosts has distinctive characteristics due to their meat- and dairyoriented daily diets and unique genotype.The aim of the present study was to investigate the effect of switching from the typical high protein and fat Mongolian diets to carbohydrate-rich meals composed principally of wheat,rice and naked oats on the host gut microbiota within 3 weeks.Our study took the advantage of the long sequence reads produced by the Pac Bio single molecule real-time sequencing technology to enable the profiling of subjects' gut microbiota communities along the diet intervention to the species precision.We found that the bacterial richness and diversity decreased apparently along the diet intervention.During the diet intervention,the gut microbiota composition displayed no significant difference at phylum level(with major phyla of Firmicutes,Bacteroidetes,Tenericutes and Proteobacteria).The relative abundances of some genera such as Bacteroidetes,Faecalibacterium,Roseburia,Alistipes,Streptococcus,and Oscillospira were significantly altered after the diet switching started.Notably,significant changes were also observed in the proportions of the species Bacteroides dorei,Bacteroides fragilis,Bacteroides thetaiotaomicron,Ruminococcus albus,Ruminococcus faecis,Roseburia faecis and Eubacterium ventriosum.These results have demonstrated that diet and host gut microbiota is closely linked.Jing Li Haiyan Xu Zhihong Sun Qiangchuan Hou Lai-Yu Kwok Wuri Laga Yanjie Wang Huimin Ma Zhongjie Yu Bilige Menghe Heping Zhang 2016Science Bulletin2016,61,20:14
10Indirect mineral carbonation of titanium-bearing blast furnace slag coupled with recovery of TiO_2 and Al_2O_3显示文摘Large quantities of CO_2 and blast furnace slag are discharged in the iron and steel industry. Mineral carbonation of blast furnace slag can offer substantial CO_2 emission reduction and comprehensive utilization of the solid waste.This paper describes a novel route for indirect mineral carbonation of titanium-bearing blast furnace(TBBF) slag,in which the TBBF slag is roasted with recyclable(NH_4)_2SO_4(AS) at low temperatures and converted into the sulphates of various valuable metals, including calcium, magnesium, aluminium and titanium. High value added Ti-and Al-rich products can be obtained through stepwise precipitation of the leaching solution from the roasted slag. The NH_3 produced during the roasting is used to capture CO_2 from flue gases. The NH_4HCO_3 and(NH_4)_2CO_3 thus obtained are used to carbonate the CaSO_4-containing leaching residue and MgSO_4-rich leaching solution, respectively. In this study, the process parameters and efficiency for the roasting, carbonation and Ti and Al recovery were investigated in detail. The results showed that the sulfation ratios of calcium,magnesium, titanium and aluminium reached 92.6%, 87% and 84.4%, respectively, after roasting at an AS-to-TBBF slag mass ratio of 2:1 and 350 °C for 2 h. The leaching solution was subjected to hydrolysis at 102 °C for 4 h with a Ti hydrolysis ratio of 95.7% and the purity of TiO_2 in the calcined hydrolysate reached 98 wt%.99.7% of aluminium in the Ti-depleted leaching solution was precipitated by using NH_3. The carbonation products of Ca and Mg were CaCO_3 and(NH_4)_2 Mg(CO_3)_2·4H_2O, respectively. The latter can be decomposed into MgCO_3 at 100–200 °C with simultaneous recovery of the NH_3 for reuse. In this process, approximately 82.1% of Ca and 84.2%of Mg in the TBBF slag were transformed into stable carbonates and the total CO_2 sequestration capacity per ton of TBBF slag reached up to 239.7 kg. The TiO_2 obtained can be used directly as an end product, while the Al-rich precipitate and the two carbonation products can act, respectively, as raw materials for electrolytic aluminium,cement and light magnesium carbonate production for the replacement of natural resources.Lin Wang Weizao Liu Jingpeng Hu Qiang Liu Hairong Yue Bin Liang Guoquan Zhang Dongmei Luo Heping Xie Chun Li 2018Chinese Journal of Chemical Engineering2018,26,3:14
11Lattice-Boltzmann simulation of microscale CH_4 flow in porous rock subject to force-induced deformation显示文摘Accurate knowledge of the influence of rock deformation on the permeability of fluid flow is of great significance to a variety of engineering applications, such as simultaneous extraction of coal and gas, oil/gas exploitation, CO2 geological sequestration, and underground water conservation. Based on the CT representation of pore structures of sandstones, a LBM(Lattice Boltzmann Method) for simulating CH4 flow in pore spaces at microscale levels and a parallel LBM algorithm for largesize porous models are developed in this paper. The properties of CH4 flow in porous sandstones and the effects of pore structure are investigated using LBM. The simulation is validated by comparing the results with the measured data. In addition, we incorporate LBM and FEM to probe the deformation of microstructures due to applied triaxial forces and its influence on the properties of CH4 flow. It is shown that the proposed method is capable of visually and quantitatively describing the characteristics of microstructure, spatial distribution of flow velocity of CH4,permeability, and the influences of deformation of pore spaces on these quantities as well. It is shown that there is a good consistency between LBM simulation and experimental measurement in terms of the permeability of sandstone with various porosities.Yang Ju Jinbo Wang Feng Gao Heping Xie 2014Chinese Science Bulletin2014,59,26:13
12Scientific and Engineering Progress in CO_2 Minerali zation Using Industrial Waste and Natural Minerals显示文摘The issues of reducing CO_2 levels in the atmo-sphere, sustainably utilizing natural mineral resources,and dealing with indus trial waste offer challenging opportunities for sustainable development in energy and the environment. The latest advances in CO_2 mineralization technology involving natural minerals and industrial waste are summarized in this paper, with great emphasis on the advancement of fundamental science, economic evaluation, and engineering applications. We discuss several lead-ing large-scale CO_2 mineralization methodologies from a techn ical and engineering-science perspective. For each technology option, we give an overview of the technical parameters, reaction pathway, reactivity, procedural scheme, and laboratorial and pilot devices. Furthermore, we present a discussion of each technology based on experimental results and the literature. Finally, current gaps in knowledge are identified in the conclusion, and an overview of the challenges and opportunities for future research in this field is provided.Heping Xie Hairong Yue Jiahua Zhu Bin Liang Chun Li Yufei Wang Lingzhi Xie Xiangge Zhou 2015Engineering2015,1,1:12
13Estimation of Turbulent Fluxes Using the Flux-Variance Method over an Alpine Meadow Surface in the Eastern Tibetan Plateau显示文摘流动变化类似关系和数量的垂直转移在表面的不同类型上展出不同,导致在估计用流动变化方法的狂暴的流动的数量之中的相对运输效率的不同 parameterization 途径。我们调查了在雨季期间在中间的水文学条件下面在夏天在东方西藏的高原在一块开、同类、扁平的草地上使用 eddycovariance 大小的这些问题。处于不稳定的条件,温度,水蒸汽,和 CO2 跟随了流动变化类似关系,但是没出现在精确一样的方法由于不同角色(活跃或被动) 这些数量。温度,水蒸汽和 CO2 的类似常数被发现分别地是 1.12, 1.19 和 1.17。热交通比水蒸汽和 CO2 更有效。基于估计的理智的热流动,到水蒸汽和 CO2 的热的相对运输效率的五个 parameterization 方法被检验估计潜伏的热和 CO2 流动。流动变化类似关系的本地决心的策略为潜伏的热和 CO2 流动的评价被推荐。这条途径对代表平均相对运输效率更好,并且对技术上更容易适用,与另外的更复杂的相比。WANG Shaoying ZHANG Yu LU Shihua LIU Heping SHANG Lunyu 2013Advances in Atmospheric Sciences2013,30,2:11
14Imaging superoxide flash and metabolism-coupled mitochondrial permeability transition in living animals显示文摘线粒体为精力新陈代谢和反应的氧种类(ROS ) 的生产是必要的。在未经触动的房间,呼吸线粒体展览自发的 “ superoxide flashes”,对短暂 mitochondrial 渗透转变(tMPT ) 结果的 quantal 生产 ROS 事件。这里,我们在表示 superoxide 生物传感器 mt-cpYFP 的生活老鼠在 mitochondrial superoxide 闪光和 tMPT 活动的 vivo 成像执行第一,并且表明他们联合到整个身体的葡萄糖新陈代谢。柔韧的 tMPT/superoxide 闪光活动发生在骨胳的肌肉和 anesthetized 的臀部的神经转基因的老鼠。在骨胳的肌肉,成像 tMPT/superoxide 闪光揭示了线粒体的迷宫的三维的网络同时地操作。tMPT/superoxide 闪光活动响应全身的葡萄糖挑战或胰岛素刺激澎湃,以一种显然调制频率的方式并且也在 tMPT 的 gating 模式包含移动。因此,在 tMPT 依赖的 mitochondrial ROS 的 vivo 成像,信号和 metabolism-tMPT-superoxide 的发现闪光联合标记为 mitochondrial 功能并且 ROS 处于健康和疾病发信号的学习的重要工艺、概念的进展。Huaqiang Fang Min Chen Yi Ding Wei Shang Jiejia Xu Xing Zhang Wanrui Zhang Kaitao Li Yao Xiao Feng Gao Shujiang Shang Jing-Chao Li Xiao-Li Tian Shi-Qiang Wang Jingsong Zhou Noah Weisleder Jianjie Ma Kunfu Ouyang Ju Chen Xianhua Wang Ming Zheng Wang Wang Xiuqin Zhang Heping Cheng 2011Cell Research2011,21,9:11
15Numerical simulations of land surface physical processes and land-atmosphere interactions over oasis-desert/Gobi region显示文摘A land-surface physical process model was coupled with a mesoscale atmospheric model. This cou- pled model was then used to simulate the interactions between land and the atmosphere, including surface temperature, net radiation, sensible heat flux and latent heat flux over a desert/Gobi with an oasis in northwestern semiarid regions in China. Comparisons between observations and simulations were made over the oasis and the desert/Gobi, respectively. Both cold island effect and wet island ef- fect, the so-called oasis effect, were observed and simulated. Lower temperature, higher specific hu- midity and weaker turbulent transfer were present over the oasis than the desert/Gobi. A subsidence occurred over the oasis, leading to a thermally-generated mesoscale circulation.LIU ShuHua LIU HePing HU Yu ZHANG ChengYi LIANG FuMing WANG JianHua 2007Science China Earth Sciences2007,50,2:9
16Antigenic analysis of grass carp reovirus using single-chain variable fragment antibody against IgM from Ctenopharyngodon idella显示文摘Grass carp (Ctenopharyngodon idella) is an important species of freshwater aquaculture fish in China. However, grass carp reovirus (GCRV) can cause fatal hemorrhagic disease in yearling populations. Until now, a strategy to define the antigenic capacity of the virus's structural proteins for preparing an effective vaccine has not been available. In this study, some single-chain variable fragment antibodies (scFv), which could specifically recognize grass carp IgM, were selected from a constructed mouse na ve antibody phage display cDNA library. The identified scFv C1B3 clone was shown to possess relatively higher specific binding activity to grass carp IgM. Furthermore, ELISA analysis indicated that the IgM level in serum from virus-infected grass carp was more than two times higher than that of the control group at 5-7 days post infection. Moreover, Western blot analysis demonstrated that the outer capsid protein VP7 has a specific immuno-binding-reaction with the serum IgM from virus-infected grass carp. Our results suggest that VP7 can induce a stronger immune response in grass carp than the other GCRV structural proteins, which implies that VP7 protein could be used as a preferred immunogen for vaccine design.CHEN CongLin SUN XiaoYun LIAO LanJie LUO ShaoXiang LI ZhouQuan ZHANG XiaoHua WANG YaPing GUO QionLin FANG Qin DAI HePing 2013Science China(Life Sciences)2013,56,1:6
17Application of neural networks for permanent magnet synchronous motor direct torque control显示文摘Neural networks require a lot of training to understand the model of a plant or a process. Issues such as learning speed, stability, and weight convergence remain as areas of research and comparison of many training algorithms. The application of neural networks to control interior permanent magnet synchronous motor using direct torque control (DTC) is discussed. A neural network is used to emulate the state selector of the DTC. The neural networks used are the back-propagation and radial basis function. To reduce the training patterns and increase the execution speed of the training process, the inputs of switching table are converted to digital signals, i.e., one bit represent the flux error, one bit the torque error, and three bits the region of stator flux. Computer simulations of the motor and neural-network system using the two approaches are presented and compared. Discussions about the back-propagation and radial basis function as the most promising training techniques are presented, giving its advantages and disadvantages. The system using back-propagation and radial basis function networks controller has quick parallel speed and high torque response.Zhang Chunmei Liu Heping Chen Shujin Wang Fangjun 2008Journal of Systems Engineering and Electronics2008,19,3:6
18IL-17A-dependent gut microbiota is essential for regulating diet-induced disorders in mice显示文摘The gut microbiota plays a key role in obesity and related metabolic disorders, and multiple factors including diet, host genotype, and age regulate it. Many studies have examined the contribution of extrinsic factors to the regulation of the gut microbiota, but the importance of the host genetic constitution cannot be ignored. Interleukin 17A(IL-17A), a pro-inflammatory cytokine, is important in the defense against infection and diseases. Here, we investigated the association among IL-17, a high-fat diet(HFD), and the gut microbiota. Mice deficient in IL-17A were resistant to diet-induced obesity and related diseases. Compared with the Ⅱ-17^(-/-)mice, wild-type(WT) mice challenged with HFD showed obvious weight fluctuations, such as those seen in type 2 diabetes, and hematological changes similar to those associated with metabolic syndrome. However, housing WT mice and Ⅱ-17a^(-/-)mice together significantly alleviated these symptoms in the WT mice. A metagenomic analysis of the mouse feces indicated that the microbial community compositions of these two groups differed before HFD feeding. The HFD mediated shifts in the gut microbial compositions, which were associated with the mouse phenotypes.We also identified potentially beneficial and harmful species present during this period, and drew networks of the most abundant species. A functional analysis indicated pathway changes in the WT and Ⅱ-17a^(-/-)mice when fed the HFD. Collectively, these data underscore the importance of the host factor IL-17 A in shaping and regulating the gut microbiota, which conversely, influences the host health.Yujing Bi Chunxiao Li Lin Liu Jiyuan Zhou Zhengchao Li Huimin Deng Chunyan Wu Yanping Han Yajun Song Yafang Tan Xiaoyi Wang Zongmin Du Yujun Cui Yanfeng Yan Fachao Zhi Guangwei Liu Nan Qin Heping Zhang Ruifu Yang 2017Science Bulletin2017,62,15:5
19Attitude control for QTR using exponential nonsingular terminal sliding mode control显示文摘For the problem of attitude control of a quad tilt rotor aircraft with unknown external disturbances, a class of control methods based on a new exponential fast nonsingular terminal sliding surface, a new fast reaching law, and a super twisting sliding mode disturbance observer is investigated. First, the new exponential nonsingular terminal sliding surface is designed by using the advantages of nonsingular terminal sliding mode finite time convergence and strong robustness. Second, to solve the problem of a long convergence time and the serious shaking of the traditional reaching law, a new fast reaching law model with characteristics of the second-order sliding mode is put forward. Third,considering the existence of complex disturbances, the super twisting sliding mode disturbance observer is used to estimate and compensate the composite disturbances online. Finally, compared with the traditional nonsingular fast sliding mode control, simulation results show that the proposed control scheme achieves a good control performance.LIU Haibo WANG Heping SUN Junlei 2019Journal of Systems Engineering and Electronics2019,30,1:5
20An estimation method of soil wind erosion in Inner Mongolia of China based on geographic information system and remote sensing显示文摘Studies of wind erosion based on Geographic Information System(GIS) and Remote Sensing(RS) have not attracted sufficient attention because they are limited by natural and scientific factors.Few studies have been conducted to estimate the intensity of large-scale wind erosion in Inner Mongolia,China.In the present study,a new model based on five factors including the number of snow cover days,soil erodibility,aridity,vegetation index and wind field intensity was developed to quantitatively estimate the amount of wind erosion.The results showed that wind erosion widely existed in Inner Mongolia.It covers an area of approximately 90×104 km2,accounting for 80% of the study region.During 1985–2011,wind erosion has aggravated over the entire region of Inner Mongolia,which was indicated by enlarged zones of erosion at severe,intensive and mild levels.In Inner Mongolia,a distinct spatial differentiation of wind erosion intensity was noted.The distribution of change intensity exhibited a downward trend that decreased from severe increase in the southwest to mild decrease in the northeast of the region.Zones occupied by barren land or sparse vegetation showed the most severe erosion,followed by land occupied by open shrubbery.Grasslands would have the most dramatic potential for changes in the future because these areas showed the largest fluctuation range of change intensity.In addition,a significantly negative relation was noted between change intensity and land slope.The relation between soil type and change intensity differed with the content of Ca CO3 and the surface composition of sandy,loamy and clayey soils with particle sizes of 0–1 cm.The results have certain significance for understanding the mechanism and change process of wind erosion that has occurred during the study period.Therefore,the present study can provide a scientific basis for the prevention and treatment of wind erosion in Inner Mongolia.Yi ZHOU Bing GUO ShiXin WANG HePing TAO 2015Journal of Arid Land2015,7,3:5
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