维普中文期刊产品整合服务
543篇 您的检索式:作者名="JianPing Yang"
    题名 作者 年代 出处 被引量
1A complete sequence and comparative analysis of a SARS-associated virus(Isolate BJ01)显示文摘The genome sequence of the Severe Acute Respiratory Syndrome (SARS)-associated virus provides essential information for the identification of pathogen(s), exploration of etiology and evolution, interpretation of transmission and pathogenesis, development of diagnostics, prevention by future vaccination, and treatment by developing new drugs. We report the complete genome sequence and comparative analysis of an isolate (BJ01) of the coronavirus that has been recognized as a pathogen for SARS. The genome is 29725 nt in size and has 11 ORFs (Open Reading Frames). It is composed of a stable region encoding an RNA-dependent RNA polymerase (composed of 2 ORFs) and a variable region representing 4 CDSs (coding sequences) for viral structural genes (the S, E, M, N proteins) and 5 PUPs (putative uncharacterized proteins). Its gene order is identical to that of other known coronaviruses. The sequence alignment with all known RNA viruses places this virus as a member in the family of Coronaviridae. Thirty putative substitutions have been identified by comparative analysis of the 5 SARS- associated virus genome sequences in GenBank. Fifteen of them lead to possible amino acid changes (non-synonymous mutations) in the proteins. Three amino acid changes, with predicted alteration of physical and chemical features, have been detected in the S protein that is postulated to beinvolved in the immunoreactions between the virus and its host. Two amino acid changes have been detected in the Mprotein, which could be related to viral envelope formation. Phylogenetic analysis suggests the possibility of non-human origin of the SARS-associated viruses but provides noevidence that they are man-made. Further efforts should focus on identifying the etiology of the SARS-associated virus and ruling out conclusively the existence of otherpossible SARS-related pathogen(s).QIN E'de ZHU Qingyu YU Man FAN Baochang CHANG Guohui SI Bingyin YANG Bao PENG Wenming JIANG Tao LIU Bohua DENG Yongqiang LIU Hong ZHANG Yu WANG Cui LI Yuquan GAN Yonghua LI Xiaoyu L Fushuang TAN Gang CAO Wuchun, YANG Ruifu Institute of Microbiology and Epidemiology, Chinese Academy of Military Medical Sciences, Beijing 100071, China WANG Jian, LI Wei, XU Zuyuan, LI Yan, WU Qingfa, LIN Wei, CHEN Weijun, TANG Lin, DENG Yajun, HAN Yujun, LI Changfeng, LEI Meng, LI Guoqing, LI Wenjie, L Hong, SHI Jianping, TONG Zongzhong, ZHANG Feng, LI Songgang, LIU Bin, LIU Siqi, DONG Wei, WANG Jun, Gane K-S Wong, YU Jun & YANG Huanming* Beijing Genomics Institute, Chinese Academy of Sciences, Beijing 101300 National Center for Genome Information, Beijing 101300, China 2003Chinese Science Bulletin2003,48,10:121
2Relocation of the mainshock and aftershock sequences of M_S7.0 Sichuan Lushan earthquake显示文摘The mainshock of April 20,2013 Sichuan Lushan MS7.0 earthquake was relocated using a 3-D velocity model.Double difference algorithm was applied to relocate aftershock sequences of Lushan earthquake.The locations of 2405 aftershocks were determined.The location errors in E-W,N-S and U-D direction were 0.30,0.29 and 0.59 km on average,respectively.The location of the mainshock is 102.983°E,30.291°N and the focal depth is 17.6 km.The relocation results show that the aftershocks spread approximately 35 km in length and 16 km in width.The dominant distribution of the focal depth ranges from 10 to 20 km.A few earthquakes occurred in the shallow crust.Focal depth profiles show fault planes dip to the northwest,manifested itself as a listric thrust fault.The dip angle is steep in the shallow crust and gentle in the deep crust.Although the epicenters of aftershocks distributed mainly along both sides of the Shuangshi-Dachuan fault,the seismogenic fault may be a blind thrust fault on the eastern side of the Shuangshi-Dachuan fault.Earthquake relocation results reveal that there is a southeastward tilt aftershock belt intersecting with the seismogenic fault with y-shape.We speculate it is a back thrust fault that often appears in a thrust fault system.Lushan earthquake triggered the seismic activity of the back thrust fault.FANG LiHua WU JianPing WANG WeiLai Lü ZuoYong WANG ChangZai YANG Ting CAI Yan 2013Chinese Science Bulletin2013,58,28:74
3Timing of the Wudangshan, Yaolinghe volcanic sequences and mafic sills in South Qinling: U-Pb zircon geochronology and tectonic implication显示文摘The Wudangshan, Yaolinghe volcanic-sedimentary sequences and doleritic-gabbroic sills comprise the largest exposed Precambrian basement in South Qinling. Zircons separated from 5 volcanic-pyroclas- tic samples of the Wudangshan Group, 2 volcanic samples of the Yaolinghe Group and one sample for the mafic sills were used for U-Pb dating by laser ablation-inductively coupled plasma mass spec- trometry (LA-ICPMS). The results reveal that the Wudangshan volcanic sequence was formed at (755±3) Ma (a weighted mean from the 5 samples, MSWD=0.47), whereas the Yaolinghe volcanic suite and the mafic sill were crystallized at (685±5) (2 samples, MSWD=0.36) and (679±3) Ma (MSWD=1.6), respectively, which are equal to each other within analysis errors. These ages are markedly younger than those previously documented for the rocks. The newly obtained ages for the Wudangshan and Yaolinghe Groups are identical to those of the bottom Liantuo and slightly older than those of the Nantuo Forma- tions, respectively, lower strata of the Nanhua (middle to late Neoproterozoic) stratotype section in eastern Three Gorges, Yangtze craton. A range of inherited magmatic zircons was recognized with ages of 830 to 780 Ma, which are typical of Neoprotzrozoic magmatisms recorded along the margins and interior of the Yangtze craton. Thus, there is Neoproterozoic basement comprising 830―780 Ma igne- ous suites in South Qinling; the inherited zircons were detrital sediments derived from the northern margin of the Yangtze craton. Accordingly, it is suggested that the South Qinling is a segment of the Yangtze craton before the Qinling Orogeny.LING WenLi REN BangFang DUAN RuiChun LIU XiaoMing MAO XinWu PENG LianHong LIU ZaoXue CHENG JianPing YANG HongMei 2008Chinese Science Bulletin2008,53,14:44
4Cryospheric Science: research framework and disciplinary system显示文摘Cryospheric changes and their impacts have received increasing concern, extending the research to include the interactions between earth spheres and the impacts of and social adaptation to cryospheric changes. As a result, Cryospheric Science is rapidly developing. However, the research framework of Cryospheric Science has not completely been set up, and the intension and extension of Cryospheric Science are unclear.Following a literature review, the research framework for Cryospheric Science and the discipline components are analysed in this paper. We consider that Cryospheric Science is an inevitable product of international research on the earth and environmental changes as well as on human sustainable development. It will not only strengthen the linkage between the cryosphere and other earth spheres by deepening traditional research areas, but will also bring more focus on the critical roles of the cryosphere in interactions between earth spheres, and will enhance the relationship between cryospheric change and climate, ecology, hydrology, surface environment and sustainable development. The disciplinary tree of Cryospheric Science is developed following the mainstream of change-impacts adaptation. The disciplines of Cryospheric Science were teased out against characteristics of traditional branches and the developing interdisciplinary branches of cryosphere elements, which will provide reference to Cryospheric Science as it systematically grows to maturity.Dahe Qin Yongjian Ding Cunde Xiao Shichang Kang Jianwen Ren Jianping Yang Shiqiang Zhang 2018National Science Review2018,5,2:42
5Therapeutic effects of the artemisinin analog SM934 on lupus-prone MRLIIpr mice via inhibition of TLR-triggered B-cell activation and plasma cell formation显示文摘我们以前报导了那 SM934,水溶性的 artemisinin 衍生物,是在鼠科的豺狼座模型的一个可行处理。在当前的学习,我们进一步在豺狼座容易的 MRL/lpr 老鼠上调查了 SM934 的修改剂量政体的治疗学的效果并且在 B 房间回答上探索了它的效果,在全身的豺狼座 erythematosus (SLE ) 的一个中央病原的事件。当口头上地管理了时两次每日, SM934 显著地延长了 MRL/lpr 老鼠的寿命,改善 lymphadenopathy 症状并且减少浆液的层次反原子的抗体(言论集) 并且病原的 cytokines IL-6, IL-10 和 IL-21。而且, SM934 处理由增加静止 B 房间数字在 MRL/lpr 老鼠的怒气恢复了 B 房间分隔空间,维持幼芽的中心 B 房间数字,减少激活的 B 房间数字和减少的血浆房间(PC ) 数字。前 vivo, SM934 压制了触发的像使用费的受体(TLR ) B 房间的激活和增长,以及抗体分泌物。而且,现在的学习证明 SM934 由 downregulating TLR7/9 mRNA 表示, MyD88 蛋白质表示和 NF-κ 防碍 B 房间内在的小径; B phosphorylation。在人的外部血 mononuclear 房间(PBMC ) ,与在 MRL/lpr 鼠标的结果一致, SM934 禁止了联系 TLR 的 B 房间激活和 PC 区别。在结论, SM934 的两次每日的 dosing 政体由压制 B 房间激活和血浆房间形成在豺狼座容易的 MRL/lpr 老鼠上有治疗学的效果。Yanwei Wu Shijun He Bingxin Bai Luyao Zhang Lu Xue Zemin Lin Xiaoqian Yang Fenghua Zhu Peilan He Wei Tang Jianping Zuo 2016Cellular & Molecular Immunology2016,13,3:31
6U-Pb dating of detrital zircons from the Wudangshan Group in the South Qinling and its geological significance显示文摘U-Pb dating was made by the LA-ICP-MS method for detrital zircons from the Wudangshan volcanic-sedimentary succession in the South Qinling. Samples comprise quartz sandstones of the Wudangshan Group collected from the base of the Yangping For-mation and an upper layer of the Shuangtai Formation overlain its volcanic sequence, and two river-sand collections from the drainage systems cutting across the two formations, respectively. The results show that the Yangping detrital zircons are domi-nated by 830–780 Ma grains with a minor population of ~1.0–0.84 Ga and sporadic grains of ~2.6, ~2.4 and 2.0 Ga, whereas the Shuangtai zircons yield an upper intercept age of 763±33 Ma, identical to the timing of the Wudangshan volcanism within error, with few concordant grains of 1.9 and 0.86 Ga. Age spectra for the two river-sand samples are similar to those of the Yangping and Shuangtai Formations, respectively. It thus suggests that the Wudangshan strata are less than 780 Ma, whereas their major detrital zircon populations of 1.0–0.85 Ga and 830–780 Ma are consistent with timing of the Hannan magmatic activities along the northwestern margin of the South China Block. This suggests a Hannan or adjacent area provenance for the Wudangshan strata. The Wudang area is characterized by rift-related igneous events at ~755 and ~680 Ma, respectively, pointing to a tectono-magmatic history different from the Hannan area. It is inferred that the ~755 Ma magmatism is likely to indicate a separation of the South China Block from the supercontinent Rodinia, while the ~680 Ma event suggests a further split between the South Qinling and some unknown continent.LING WenLi DUAN RuiChun LIU XiaoMing CHENG JianPing MAO XinWu PENG LianHong LIU ZaoXue YANG HongMei REN BangFang 2010Chinese Science Bulletin2010,55,22:24
7Facile Synthesis of Porous Carbon Nitride Spheres with Hierarchical Three-Dimensional Mesostructures for CO_(2) Capture显示文摘Porous carbon nitride(CN)spheres with partially crystalline frameworks have been successfully synthesized via a nanocasting approach by using spherical mesoporous cellular silica foams(MCFs)as a hard template,and ethylenediamine and carbon tetrachloride as precursors.The resulting spherical CN materials have uniform diameters of ca.4μm,hierarchical three-dimensional(3-D)mesostructures with small and large mesopores with pore diameters centered at ca.4.0 and 43 nm,respectively,a relatively high BET surface area of~550 m^(2)/g,and a pore volume of 0.90 cm^(3)/g.High-resolution transmission electron microscope(HRTEM)images,wide-angle X-ray diffraction(XRD)patterns,and Raman spectra demonstrate that the porous CN material has a partly graphitized structure.In addition,elemental analyses,X-ray photoelectron spectra(XPS),Fourier transform infrared spectra(FT-IR),and CO_(2) temperature-programmed desorption(CO_(2)-TPD)show that the material has a high nitrogen content(17.8 wt%)with nitrogen-containing groups and abundant basic sites.The hierarchical porous CN spheres have excellent CO_(2) capture properties with a capacity of 2.90 mmol/g at 25℃and 0.97 mmol/g at 75℃,superior to those of the pure carbon materials with analogous mesostructures.This can be mainly attributed to the abundant nitrogen-containing basic groups,hierarchical mesostructure,relatively high BET surface area and stable framework.Furthermore,the presence of a large number of micropores and small mesopores also enhance the CO_(2) capture performance,owing to the capillary condensation effect.Qiang Li Jianping Yang Dan Feng Zhangxiong Wu Qingling Wu Sung Soo Park Chang-Sik Ha Dongyuan Zhao 2010Nano Research2010,3,9:24
8Efficacy and safety of metformin and sitagliptin based triple antihyperglycemic therapy(STRATEGY):a multicenter,randomized,controlled,non-inferiority clinical trial显示文摘Despite the current guideline's recommendation of a timely stepwise intensification therapy,the 'clinical inertia',termed as the delayed treatment intensification,commonly exists in the real world,which may be partly due to the relatively little substantial evidence and no clear consensus regarding the efficacy and safety of triple oral agents in patients inadequately controlled with dual therapy.In this clinical trial performed in 237 centers in China,5,535 type 2 diabetic patients inadequately controlled by previous therapies were treated with a stable metformin/sitagliptin dual therapy for 20 weeks.The patients who did not reach the glycated hemoglobin A1c(HbA1c) goal were then further randomized into glimepiride,gliclazide,repaglinide,or acarbose group for an additional 24-week triple therapy.A mean HbAlc reduction of 0.85%was observed when sitagliptin was added to the patients inadequately controlled with metformin in 16 weeks.Further HbAlc reductions in the 24-week triple therapy stage were 0.65%in glimepiride group,0.70%in gliclazide group,0.61%in repaglinide group,and 0.45%in acarbose group.The non-inferiority criterion for primary hypotheses was met for gliclazide and repaglinide,but not for acarbose,compared with glimepiride,when added to metformin/sitagliptin dual therapy.The incidences of adverse events(AEs) were 29.2%in the dual therapy stage and30.3%in the triple therapy stage.Metformin/sitagliptin as baseline therapy,with the addition of a third oral antihyperglycemic agent,including glimepiride,gliclazide,repaglinide,or acarbose,was effective,safe and well-tolerated for achieving an HbAlc<7.0%goal in type 2 diabetic patients inadequately controlled with previous therapies.The timely augmentation of up to three oral antihyperglycemic agents is valid and of important clinical benefit to prevent patients from exposure to unnecessarily prolonged hyperglycemia.Wen Xu Yiming Mu Jiajun Zhao Dalong Zhu Qiuhe Ji Zhiguang Zhou Bin Yao Anhua Mao Samuel S.Engel Bin Zhao Yan Bi Longyi Zeng Xingwu Ran Juming Lu Linong Ji Wenying Yang Weiping Jia Jianping Weng 2017Science China(Life Sciences)2017,60,3:19
9A review of ecological restoration techniques in fluvial rivers显示文摘Rivers play an important role in people's living and agricultural production,however,intense human activities have broken the original ecological balance,and affected structures and functions of the river ecosystem.To restore the damaged river ecosystem back to a healthy status,effective ecological restoration measures need to be implemented.The main problems that the damaged rivers face are either the locally altered hydrological processes affected by construction of hydraulic facilities,or the deterioration of water quality resulted from pollution emissions,or both.In this study,ecological restoration techniques of the rivers affected by engineering control or pollution are reviewed respectively.In addition,three kinds of methods,i.e.physical,chemical and biological-ecological methods are introduced in details for the rivers affected by water pollution.At present,the development of river restoration techniques shows the following trends:1) the scale of ecological restoration is becoming larger;2) ecological restoration measures are required to meet multiple objectives;and 3) the management of water environment is changing from water quality management to aquatic ecosystem management.Baozhu Pan Jianping Yuan Xinhua Zhang Zhaoyin Wang Jiao Chen Jinyou Lu Wenjun Yang Zhiwei Li Na Zhao Mengzhen Xu 2016International Journal of Sediment Research2016,31,2:18
10Shear Alteration, Mass Transfer and Gold Mineralization: An Example from Jiaodong Ore Deposit Concentrating Area, Shandong, China显示文摘Taking the gold ore deposit concentrating area of Jiaodong area in Shandong, China for an example, based on geological analysis, and applying Gresens’ equation, Grant’s isocon diagram and O’hara microelement calculation method, a thorough study on shear alteration, mass transfer and gold mineralization was carried out. The authors also made mathematic simulation and geochemical analysis. The work reveals temporal spatial changing regularities of temperature field and velocity field of fluids, and also reveals fluid transport chemical reaction coupling metallogenic dynamics of the Jiaojia gold ore concentrating area. During shear alteration process of the Jiaodong gold ore concentrating area, all kinds of components transferred with different amounts, fluid rock ratio was rather high and volume strain was of dilation type. Fast flow of ore forming fluid favors the occurrence of mixed fluid. Shear fractured zones are places where there was strong transportation reaction coupling mineralization. Ore bodies were located in dilation space of shear structure where there was the greatest fluid flux. After the emplacement of the rock body, a convex heat field was formed around the rock body. It is one of the main metallogenic forces. The major reason for mineralization is the mobilization, migration and enrichment of ore forming elements induced by shear compressive extensional tectonism. Inclusion gold dominant low grade ores were formed in the early ore forming stage, while high grade ores, which contained fissure gold and polymetallic veinlets, were formed in late ore forming stage.Deng Jun Zhai Yusheng Wang Jianping Faculty of Earth Sciences and Mineral Resources, China University of Geosciences, Beijing 100083, China Yang Liqiang Institute of Geophysics, Chinese Academy of Sciences, Beijing 100101, China Fang Yun Faculty of 2000Journal of Earth Science2000,19,3:18
11Eco-environment range in the source regions of the Yangtze and Yellow rivers显示文摘Based on geographical and hydrological extents delimited, four principles are identified, as the bases for delineating the ranges of the source regions of the Yangtze and Yellow rivers in the paper. According to the comprehensive analysis of topographical characteristics, climate conditions, vegetation distribution and hydrological features, the source region ranges for eco-environmental study are defined. The eastern boundary point is Dari hydrological station in the upper reach of the Yellow River. The watershed above Dari hydrological station is the source region of the Yellow River which drains an area of 4.49×10 4 km 2 . Natural environment is characterized by the major topographical types of plateau lakes and marshland, gentle landforms, alpine cold semi-arid climate, and steppe and meadow vegetation in the source region of the Yellow River. The eastern boundary point is the convergent site of the Nieqiaqu and the Tongtian River in the upstream of the Yangtze River. The watershed above the convergent site is the source region of the Yangtze River, with a watershed area of 12.24×10 4 km 2 . Hills and alpine plain topography, gentle terrain, alpine cold arid and semi-arid climate, and alpine cold grassland and meadow are natural conditions in the source region of the Yangtze River.DING Yongjian,YANG Jianping,LIU Shiyin,CHEN Rensheng,WANG Genxu,SHEN Yongping,WANG Jian,XIE Changwei,ZHANG Shiqing(Cold and Arid Regions Environmental and Engineering Research Institute, CAS, Lanzhou 730000, China) 2003Journal of Geographical Sciences2003,13,2:18
12Safety issues and new rapid detection methods in traditional Chinese medicinal materials显示文摘The safety of traditional Chinese medicine(TCM) is a major strategic issue that involves human health. With the continuous improvement in disease prevention and treatment, the export of TCM and its related products has increased dramatically in China. However, the frequent safety issues of Chinese medicine have become the ‘bottleneck' impeding the modernization of TCM. It was proved that mycotoxins seriously affect TCM safety; the pesticide residues of TCM are a key problem in TCM international trade; adulterants have also been detected, which is related to market circulation. These three factors have greatly affected TCM safety. In this study, fast, highly effective, economically-feasible and accurate detection methods concerning TCM safety issues were reviewed, especially on the authenticity, mycotoxins and pesticide residues of medicinal materials.Lili Wang Weijun Kong Meihua Yang Jianping Han Shilin Chen 2015Acta Pharmaceutica Sinica B2015,5,1:18
13Gastrodin prevents steroid-induced osteonecrosis of the femoral head in rats by anti-apoptosis显示文摘Zheng Huifeng Yang Erping Peng Hao Li Jianping Chen Sen Zhou Jianlin Fang Hongsong Qiu Bo Wang Zhe 2014Chinese Medical Journal2014,,22:17
14Numerical and Experimental Study on Flow-induced Noise at Blade-passing Frequency in Centrifugal Pumps显示文摘With the increasing noise pollution,low noise optimization of centrifugal pimps has become a hot topic.However,experimental study on this problem is unacceptable for industrial applications due to unsustainable cost.A hybrid method that couples computational fluid dynamics(CFD)with computational aeroacoustic software is used to predict the flow-induced noise of pumps in order to minimize the noise of centrifugal pumps in actual projects.Under Langthjem’s assumption that the blade surface pressure is the main flow-induced acoustic source in centrifugal pumps,the blade surface pressure pulsation is considered in terms of the acoustical sources and simulated using CFX software.The pressure pulsation and noise distribution in the near-cutoff region are examined for the blade-passing frequency(BPF)noise,and the sound pressure level(SPL)reached peaks near the cutoff that corresponded with the pressure pulsation in this region.An experiment is performed to validate this prediction.Four hydrophones are fixed to the inlet and outlet ports of the test pump to measure the flow-induced noise from the four-port model.The simulation results for the noise are analyzed and compared with the experimental results.The variation in the calculated noise with changes in the flow agreed well with the experimental results.When the flow rate was increased,the SPL first decreased and reached the minimum near the best efficient point(BEP);it then increased when the flow rate was further increased.The numerical and experimental results confirmed that the BPF noise generated by a blade-rotating dipole roughly reflects the acoustic features of centrifugal pumps.The noise simulation method in current study has a good feasibility and suitability,which could be adopted in engineering design to predict and optimize the hydroacoustic behavior of centrifugal pumps.YANG Jun YUAN Shouqi YUAN Jianping SI Qiaorui PEI Ji 2014Chinese Journal of Mechanical Engineering2014,27,3:16
15Spectral analysis and self-adjusting mechanism for oscillation phenomenon in hydrogen-oxygen continuously rotating detonation engine显示文摘The continuously rotating detonation engine(CRDE)is a new concept of engines for aircraft and spacecraft.Quasi-stable continuously rotating detonation(CRD)can be observed in an annular combustion chamber,but the sustaining,stabilizing and adjusting mechanisms are not yet clear.To learn more deeply into the CRDE,experimental studies have been carried out to investigate hydrogen-oxygen CRDE.Pressure histories are obtained during each shot,which show that stable CRD waves are generated in the combustor,when feeding pressures are higher than 0.5 MPa for fuel and oxidizer,respectively.Each shot can keep running as long as fresh gas feeding maintains.Close-up of the pressure history shows the repeatability of pressure peaks and indicates the detonation velocity in hydrogen–oxygen CRD,which proves the success of forming a stable CRD in the annular chamber.Spectrum of the pressure history matches the close-up analysis and confirms the CRD.It also shows multi-wave phenomenon and affirms the fact that in this case a single detonation wave is rotating in the annulus.Moreover,oscillation phenomenon is found in pressure peaks and a self-adjusting mechanism is proposed to explain the phenomenon.Liu Yusi Wang Yuhui Li Yongsheng Li Yang Wang Jianping 2015Chinese Journal of Aeronautics2015,28,3:14
16Experimental Investigation on the Flow-induced Noise under Variable Conditions for Centrifugal Pumps显示文摘With extensively using of centrifugal pumps,noise generation in these pumps is increasingly receiving research attention in recent years.The noise sources in centrifugal pumps are mainly composed of mechanical noise and flow-induced noise.And the study of flow-induced noise has become a hotspot and important domain in the field.The flow-induced noise closely related to the inner pressure pulses and vibration of volute in pumps,therefore,it is necessary to research the interaction and mechanism among them.To investigate the relationships,a test system is designed which includes a test loop and a measurement system.The hydrophones and pressure sensors are installed on the outlet of the pump and vibration acceleration sensors are disposed on the pump body.Via these instruments,the signals of noise,pressure pulses and vibration are collected and analyzed.The results show that the level of flow-induced noise becomes smaller as the flow increment during low flow rate operations,and it is steadily close to the design point,then it increases with the growing of flow rate in high flow rate conditions.Furthermore,there are some similar peak points in the power spectrum charts of noise,pressure pulses and vibration.The broadband noise at low flow rate is mostly focused on the region of 0-40 times shaft frequency,which is mostly made by rotating stall and vortex;while the noise at high flow rate conditions is focused on the region of 60-100 times shaft frequency,which may be mostly made by cavitations.The proposed research is of practical and academic significance to the study of noise reduction for centrifugal pumps.YUAN Shouqi YANG Jun YUAN Jianping LUO Yin PEI Ji 2012Chinese Journal of Mechanical Engineering2012,25,3:12
17Detection of dynamic brain networks modulated by acupuncture using a graph theory model显示文摘Neuroimaging studies involving acute acupuncture manipulation have already demonstrated significant modulatory effects on wide limbic/paralimbic nuclei, subcortical gray structures and the neocortical system of the brain. Due to the sustained effect of acupuncture, however, knowledge on the organization of such large-scale cortical networks behind the active needle stimulation phase is lacking. In this study, we originally adopted a network model analysis from graph theory to evaluate the functional connectivity among multiple brain regions during the post-stimulus phase. Evidence from our findings clearly supported the existence of a large organized functional connectivity network related to acupuncture function in the resting brain. More importantly, acupuncture can change such a network into a functional state underlying both pain perception and modulation, which is exhibited by significant changes in the functional connectivity of some brain regions. This analysis may help us to better understand the long-lasting effects of acupuncture on brain function, as well as the potential benefits of clinical treatments.Lijun Bai Wei Qin Jie Tian Jianping Dai Wanhai Yang 2009Progress in Natural Science:Materials International2009,19,7:11
18Monodisperse core-shell structured magnetic mesoporous aluminosilicate nanospheres with large dendritic mesochannels显示文摘合理设计和有一个定制的活跃核心和大、树枝状的、修改 mesoporous 的多功能的混合 nanostructures 的精确合成组织了壳能支持催化作用,精力存储,和生物应用。这里,油水双相层化涂层策略被开发了准备 monodisperse 磁性的树枝状的 mesoporous 硅石核心壳结构化的 nanospheres。这些复杂 Fe 3 O 4@SiO2@dendritic-mSiO2 nanospheres 特征大树枝状的开的毛孔(2.7 和 10.3 nm ) 。显著地,硅石壳能与未改变的孔, 14 的 Si/Al 臼齿的比率,和显著地强壮的酸的地点被变换成树枝状的 mesoporous 铝矽酸盐框架,通过一条合成以后的途径。另外,结果的磁性的树枝状的 mesoporous 铝矽酸盐 nanospheres 展览在从废水的磷酸盐移动的突出的性质和有希望的申请。Jianping Yang Dengke Shen Yong Wei Wei Li Fan Zhang Biao Kong Shaohua Zhang Wei Teng Jianwei Fan Weixian Zhang Shixue Dou Dongyuan Zhao 2015Nano Research2015,8,8:11
19Molecular mechanisms of "off-on switch" of activities of human IDH1 by tumor-associated mutation R132H显示文摘人的 cytosolic NADP-IDH (IDH1 ) 最近被发现了涉及 tumorigenesis。尤其是,到目前为止识别的导出肿瘤的 IDH1 变化主要发生在 Arg132,和变化 R132H 是最流行的。这个变化损害酶的氧化 IDH 活动,但是显示把伪 - ketoglutarate (伪 K G ) 变换成 2-hydroxyglutarate 的新减小功能。这里,我们报导有或没有 isocitrate (ICT ) 的 R132H 变异的 IDH1 的结构跳了。和 mutagenesis 的结构的数据和生物化学的数据揭示一个以前未定义的起始的 ICT 有约束力的状态并且证明那项 IDH 活动要求一个 conformational 变化到一关门预先转移状态。Arg132 在催化反应起多重功能的作用;特别地, R132H 变化从起始的 ICT 有约束力的状态妨碍 conformational 变化到预先转移状态,导致 IDH 活动的缺陷。我们的结果第一次描述那有中间的符合构造,对应于一个起始的 ICT 有约束力的状态并且 R132H 变化能在这符合构造套住酶,因此使潜在地肿瘤镇压的 IDH 活动的鈥渙f f 开关鈥 ? 的分子的机制清楚些。而且,我们为获得的 伪K G 减小活动证明了 Tyr139 的必要性并且建议 Tyr139 可以由从 NADPH 在一个氢化物阴离子的转移期间在 伪K G 的 C2 原子上补偿增加的否定费用到 伪K G 起一个重要作用,它提供新卓见进 鈥渙n 开关鈥?的机制假设地由这个变化的 IDH1 的 oncogenic 减小活动。Bei Yang Chen Zhong Yingjie Peng Zheng Lai Jianping Ding 2010Cell Research2010,20,11:11
20Clearance Influence on Dynamic Response of Intermittent Roller Chain Drive显示文摘The clearances appear in chain link hinges induced by manufacturing tolerance or wear of components are the most important factor that influences the dynamic performance of the intermittent roller chain drives.Due to the existence of the clearances in chain link hinges,the serious impact vibration phenomenon which influences the stability and the position accuracy of the chain drive system would be caused in the intermittent motion.But,the problem may be that a reasonable modeling on the chain with clearances is difficult due to the large clearance's number in chain system and the fact that the clearance' size are different.Currently,the studies on the dynamics of the intermittent roller chain considering the multi-clearance' joints are rare.Most research works have only focused on the constant moving chains.Taking the intermittent roller chain system as an object,this paper designs and builds the experimental device of this kind of mechanical system.The Longitudinal vibration response of the intermittent chain under the different motion laws was tested.The experimental study shows that the clearances presented in chain link hinges can cause severe impact vibration in the intermittent motion of chain.In subsequent work,the dynamic model of the intermittent roller chain system with the multi-clearance' joints was established.By calculating the dynamic response of this kind of mechanical system under the different motion laws,the effect of the clearances on the dynamic response of the intermittent chain drive system was analyzed.The theoretical simulation shows that the serious impact vibration phenomenon of the chain system can be caused by the clearances at the start accelerating period,and the chain drive system is often accompanied by the severe shock and vibration at the moment that the chain moves from the acceleration period to deceleration period.The research conclusions made by the experimental and theoretical studies indicate that the use of motion laws with small and continuous jerk at conversion point can effectively suppress the impact vibration at this point caused by clearances' effect.Additionally,the use of nonsymmetrical motion laws with small jerk approaching the end of the indexing period can obtain a smaller residual vibration.The presented motion law can provide an important reference for the improvement of the dynamic performance of the intermittent chain drive systems.XU Lixin YANG Yuhu CHANG Zongyu SHEN Zhaoguang LIU Jianping 2010Chinese Journal of Mechanical Engineering2010,23,6:11
返回顶部 每页显示:
共28页 首页 上一页 第1页 下一页 末页 /28 跳转

网站首页 | 关于我们 | 联系我们 | 产品服务 | 客服中心 | 广告服务 | 版权声明 | 网站联盟 | 友情链接 | 售卡网点

版权所有© 渝B2-20050021-1 渝公网安备 50019002500403号 违法和不良信息举报中心

互联网出版许可证 新出网证(渝)字10号 全国400电话 - 免长途话费