维普中文期刊产品整合服务
566篇 您的检索式:作者名="Weihua Li"
    题名 作者 年代 出处 被引量
1An improved algorithm for fluid-structure interaction of high-speed trains under crosswind显示文摘Based on the train-track coupling dynamics and high-speed train aerodynamics,this paper deals with an improved algorithm for fluid-structure interaction of high-speed trains.In the algorithm,the data communication between fluid solver and structure solver is avoided by inserting the program of train-track coupling dynamics into fluid dynamics program,and the relaxation factor concerning the load boundary of the fluid-structure interface is introduced to improve the fluctuation and convergence of aerodynamic forces.With this method,the fluid-structure dynamics of a highspeed train are simulated under the condition that the velocity of crosswind is 13.8 m/s and the train speed is 350 km/h.When the relaxation factor equals 0.5,the fluctuation of aerodynamic forces is lower and its convergence is faster than in other cases.The side force and lateral displacement of the head train are compared between off-line simulation and co-simulation.Simulation results show that the fluid-structure interaction has a significant influence on the aerodynamics and attitude of the head train under crosswind conditions.In addition,the security indexes of the head train worsen after the fluid-structure interaction calculation.Therefore,the fluid-structure interaction calculation is necessary for high-speed trains.Tian LI Jiye ZHANG Weihua ZHANG 2011Journal of Modern Transportation2011,19,2:29
2Isolation and Identification of Cancer Stem-Like Cells from Murine Melanoma Cell Lines显示文摘In current study,cancer stem-like cells in the murine melanoma B16F10 cells were investigated.CD phenotypes of the B16F10 cells were analyzed by flow cytometry,and the specific CD phenotype cells from the B16F10 cells were isolated by MACS.Then we used colony formation assay in soft agar media,the cell growth assay in serum-free culture media as well as the tumorigenicity investigation of the specific CD phenotype cells in C57BL/6 mice, respectively,to identify cancer stem-like cells in the B16F10 cells.The results showed that the B16F10 cells could form spherical clones in serum-free culture media,and the rate of clonegenesis of CD133 + ,CD44 + and CD44 + CD133 + cells was higher than that of CD133 - ,CD44 - and CD44 + CD133 - cells in soft agar media,respectively. The tumorigenic potential of CD133 + ,CD44 + ,CD44 + CD133 + cells and CD44 + CD133 + CD24 + cells was stronger than that of CD133 - ,CD44 - ,CD44 + CD133 - cells and CD44 + CD133 + CD24 - cells in mice,respectively.In conclusion,the CD44 + CD133 + CD24 + cells have some biological properties of cancer stem-like cells or are highly similar to the characteristics of cancer stem cells(CSC).These results provide an important method for identifying cancer stem-like cells in B16F10 cells and for further cancer target therapy.Jun Dou Meng Pan Ping Wen Yating Li Quan Tang Lili Chu Fengshu Zhao Chuilian Jiang Weihua Hu Kai Hu Ning Gu 2007Cellular & Molecular Immunology2007,4,6:25
3Performance of the Seasonal Forecasting of the Asian Summer Monsoon by BCC_CSM1.1(m)显示文摘This paper provides a comprehensive assessment of Asian summer monsoon prediction skill as a function of lead time and its relationship to sea surface temperature prediction using the seasonal hindcasts of the Beijing Climate Center Climate System Model, BCC CSM1.1(m). For the South and Southeast Asian summer monsoon, reasonable skill is found in the model's forecasting of certain aspects of monsoon climatology and spatiotemporal variability. Nevertheless, deficiencies such as significant forecast errors over the tropical western North Pacific and the eastern equatorial Indian Ocean are also found. In particular, overestimation of the connections of some dynamical monsoon indices with large-scale circulation and precipitation patterns exists in most ensemble mean forecasts, even for short lead-time forecasts.Variations of SST, measured by the first mode over the tropical Pacific and Indian oceans, as well as the spatiotemporal features over the Ni no3.4 region, are overall well predicted. However, this does not necessarily translate into successful forecasts of the Asian summer monsoon by the model. Diagnostics of the relationships between monsoon and SST show that difficulties in predicting the South Asian monsoon can be mainly attributed to the limited regional response of monsoon in observations but the extensive and exaggerated response in predictions due partially to the application of ensemble average forecasting methods. In contrast, in spite of a similar deficiency, the Southeast Asian monsoon can still be forecasted reasonably, probably because of its closer relationship with large-scale circulation patterns and El Nino–Southern Oscillation.LIU Xiangwen WU Tongwen YANG Song JIE Weihua NIE Suping LI Qiaoping CHENG Yanjie LIANG Xiaoyun 2015Advances in Atmospheric Sciences2015,32,8:25
4Cardiotoxicity of 5-fluorouracil and capecitabine in Chinese patients: a prospective study显示文摘Background:5-Fluorouracil(5-FU)and capecitabine-associated cardiotoxicity ranging from asymptomatic electro-cardiography(ECG)abnormalities to severe myocardial infarction has been reported in a number of studies,but such cardiotoxicity in Chinese patients with malignant diseases has not been investigated to date.In the present study,we aimed to prospectively evaluate the incidence rates and clinical manifestations of 5-FU-and capecitabine-associated cardiotoxicity in cancer patients recruited from multiple centers in China.Methods:Among the 527 patients who completed the study,196 received 5-FU-based chemotherapy and 331 received capecitabine-based chemotherapy as either first-line or adjuvant therapy.Adverse events were reported during the treatment and up to 28 days of follow-up.Outcome measures included ECG,myocardial enzymes,cardiac troponin,brain natriuretic peptide and echocardiography.Univariate analysis and logistic regression were performed for subgroup analysis and identification of significant independent variables that are associated with cardiotoxicity of both agents.Results:In total,161 of 527 patients(30.6%)experienced cardiotoxicity.The incidence rate of cardiotoxicity was 33.8%(112/331)in the capecitabine group,which was significantly higher than the rate of 25%(49/196)in the 5-FU group(P=0.0042).110/527 patients(20.9%)suffered arrhythmia,105/527(19.9%)developed ischemic changes,while only 20/527 patients(3.8%)presented heart failure and 6/527 patients(1.1%)had myocardial infarction.Pre-existing cardiac disease,hypertension,capecitabine-based chemotherapy and duration of treatment were identified as sig-nificant risk factors associated with cardiotoxicity.The odds ratio were 15.7(prior history of cardiac disease versus no history),1.86(capecitabine versus 5-FU),1.06(5-8 versus 1-4 chemotherapy cycles)and 1.58(hypertension versus no hypertension),respectively.Conclusions:Cardiotoxicity induced by fluoropyrimidines in the Chinese population may be underestimated in clini-cal practice.Close monitoring of patients is recommended,especially for those patients at high risk for cardiotoxicity.Possible risk factors are duration of treatment,capecitabine-based chemotherapy,pre-existing cardiac diseases and hypertension.Trial registration This study was initiated on January 22,2014 and has been retrospectively registered with the registra-tion number ChiCTR1800015434 .Jianjun Peng Chao Dong Chang Wang Weihua Li Hao Yu Min Zhang Qun Zhao Bo Zhu Jun Zhang Wenliang Li Fenghua Wang Qiong Wu Wenhao Zhou Ying Yuan Meng Qiu Gong Chen 2018Cancer Communications2018,38,1:23
5Angles-only initial relative orbit determination algorithm for noncooperative spacecraft proximity operations显示文摘This research furthers the development of a closed-form solution to the angles-only initial relative orbit determination problem for non-cooperative target close-in proximity operations when the camera offset from the vehicle center-of-mass allows for range observability.In previous work,the solution to this problem had been shown to be non-global optimal in the sense of least square and had only been discussed in the context of Clohessy–Wiltshire.In this paper,the emphasis is placed on developing a more compact and improved solution to the problem by using state augmentation least square method in the context of the Clohessy–Wiltshire and Tschauner–Hempel dynamics,derivation of corresponding error covariance,and performance analysis for typical rendezvous missions.A two-body Monte Carlo simulation system is used to evaluate the performance of the solution.The sensitivity of the solution accuracy to camera offset,observation period,and the number of observations are presented and discussed.Baichun Gong Wendan Li Shuang Li Weihua Ma Lili Zheng 2018Astrodynamics2018,2,3:20
6Genome-scale detection of hypermethylated CpG islands in circulating cell-free DNA of hepatocellular carcinoma patients显示文摘Lu Wen Jingyi Li Huahu Guo Xiaomeng Liu Shengmin Zheng Dafang Zhang Weihua Zhu Jianhui Qu Limin Guo Dexiao Du Xiao Jin Yuhao Zhang Yun Gao Jie Shen Hao Ge Fuchou Tang Yanyi Huang Jirun Peng 2015Cell Research2015,25,11:19
7Growth-associated protein 43 and neural cell adhesion molecule expression following bone marrow-derived mesenchymal stem cell transplantation in a rat model of ischemic brain injury显示文摘BACKGROUND:Transplantation of bone marrow-derived mesenchymal stem cells(BMSCs) improves motor functional recovery,but the mechanisms remain unclear.OBJECTIVE:To investigate expression of growth-associated protein 43(GAP-43) and neural cell adhesion molecule following BMSC transplantation to the lateral ventricle in rats with acute focal cerebral ischemic brain damage.DESIGN,TIME AND SETTING:A randomized,controlled,animal experiment using immunohistochemistry was performed at the laboratories of Department of Neurology,Renmin Hospital of Wuhan University and Doctoral Scientific Research Work Station of C-BONS PHARMA,Hubei Province,China,from January 2007 to December 2008.MATERIALS:Monoclonal mouse anti-rat 5-bromo-2-deoxyuridine and neural cell adhesion molecule antibodies were purchased from Sigma,USA;monoclonal mouse anti-rat GAP-43 antibody was purchased from Wuhan Boster,China.METHODS:Rat models of right middle cerebral artery occlusion were established using the thread method.At 1 day after middle cerebral artery occlusion,20 μL culture solution,containing 5 × 105 BMSCs,was transplanted to the left lateral ventricle using micro-injection.MAIN OUTCOME MEASURES:Scores of neurological impairment were measured to assess neural function.Expression of GAP-43 and neural cell adhesion molecule at the lesion areas was examined by immunohistochemistry.RESULTS:GAP-43 and neural cell adhesion molecule expression was low in brain tissues of the sham-operated group,but expression increased at the ischemic boundary(P < 0.05).Transplantation of BMSCs further enhanced expression of GAP-43 and neural cell adhesion molecule(P < 0.05) and remarkably improved neurological impairment of ischemic rats(P < 0.05).CONCLUSION:BMSC transplantation promoted neurological recovery in rats by upregulating expression of GAP-43 and neural cell adhesion molecule.Yu Peng Qimei Zhang Hui You Weihua Zhuang Ying Zhang Chengyan Li 2010Neural Regeneration Research2010,5,13:18
8COVID-19 Super Spreading Event Amongst Elderly Individuals—Jilin Province,China,January 2021显示文摘Summary What is already known on this topic?Clusters of COVID-19 cases often happened in small settings(e.g.,families,offices,school,or workplaces)that facilitate person-to-person virus transmission,especially from a common exposure.What is added by this report?On January 10 and 11,2021,an individual gave three product promotional lectures in Tonghua City.Laishun Yao Mingyu Luo Tiewu Jia Xingang Zhang Zhulin Hou Feng Gao Xin Wang Xiaogang Wu Weihua Cheng Guoqian Li Jing Lu Bing Zhao Tao Li Enfu Chen Dapeng Yin Biao Huang 2021China CDC weekly2021,3,10:13
9Fault diagnosis for distillation process based on CNN–DAE显示文摘Distillation is the most widely used operation for liquid mixture separation in the chemical industry. It is of great importance to detect and diagnose faults in distillation process. Due to the strong feedback and coupling of processes in a distillation column, it is difficult to use deep auto-encoders(DAEs) alone to achieve good results in detecting and diagnosing faults, in terms of accuracy and efficiency. This paper proposes a hybrid fault-diagnosis model based on convolutional neural networks(CNNs) and DAEs, by integrating the powerful capability of CNN in feature extraction and of DAE in classification. A case study was carried out with the distillation process of depropanization. It is shown that the proposed hybrid model is of good performance compared to other models, in terms of the accuracy of fault detection in such a process. Also, with the increase of structural layers of the CNN–DAE model, the diagnostic accuracy will be improved, with an optimal accuracy of 92.2%.Chuankun Li Dongfeng Zhao Shanjun Mu Weihua Zhang Ning Shi Lening Li 2019Chinese Journal of Chemical Engineering2019,27,3:12
10Heat treatment effect on electrochemical properties of spinel Li_4Ti_5O_(12)显示文摘阳极材料 Li4Ti5O12 在 800 牰灯牥祴洠湡条浥 hLI Yue ZHAO Hailei TIAN Zhihong QIU Weihua LI Xue 2008Rare Metals2008,27,2:11
11Spatial and temporal dynamics of phytoplankton and bacterioplankton biomass in Sanya Bay, northern South China Sea显示文摘The composition of phytoplankton and the dynamics of phytoplankton and bacterioplankton biomass (PB and BB, respectively) of Sanya Bay, South China Sea, were determined. A total of 168 species (67 genera) phytoplankton were identified, including Bacillariophyta (diatom, 128 species), Pyrrophyta (35 species), Cyanophyta (3 species), and Chrysophyta (2 species). Annual average abundance of phytoplankton was 1.2 × 107 cells/m3, with the highest abundance in autumn, and the lowest in summer. Annual average diversity index (H ) and evenness (J) values were 3.96 and 0.70, respectively. Average chlorophyll-a was 2.5 mg/m3, and the average PB was 124 mg C/m3, with the highest value in autumn. Surface PB was higher than the bottom, except for summer. Annual mean bacterioplankton abundance and BB were 6.9 × 1011 cells/m3 and 13.8 mg C/m3, respectively. The highest BB was found in summer, followed by winter, spring, and autumn. Surface BB was higher than bottom all year round. The spatial distribution patterns of PB and BB were very similar with the highest biomass in the estuary, and decreased seaward, primarily due to the terrestrial input from the Sanya River and influx of oceanic water. The main factor influencing PB and BB was dissolved inorganic nitrogen (DIN). Other factors such as temperature, which is above 22°C throughout the year, had a negligible impact. The correlation between BB and PB was significant (P < 0.01). The annual average ratio of BB/PB was 0.12 (0.06-0.15). Phytoplankton primary production was one of the most important factors in controlling the distribution of bacterioplankton.ZHOU Weihua 2009Journal of Environmental Sciences2009,21,5:11
12Characteristics and sedimentary processes of lamina-controlled sand-particle imbricate structure in deposits on Lingshan Island, Qingdao, China显示文摘Imbricate structure is a common sedimentary structure and is well developed in sandy sediments.Here,we report a laminacontrolled fine-sand-particle imbricate structure in a set of very fine grained sedimentary rocks(fine sandstone,siltstone,and mudstone)at the Dockyard and Qianceng Cliff areas of Lingshan Island,Qingdao,Shandong,China.Sets of up to 300 laminae are found in stratigraphic profiles in these areas.The laminae are generally less than 1 mm thick,with most being 0.3–0.4 mm thick and the thinnest being<0.1 mm.The dip angle of the imbricate structure varies widely,between 0°and 90°,with an average dip angle of about 40°–50°,which is higher than that of imbricate riverbed gravels(about 34°).The dip angle is a function of the shape and sorting of the particles,as well as the hydrodynamic conditions under which these fine-grained sediments were deposited.Several profiles show well-developed multiscale,soft-sediment deformation structures.Flute casts,load casts,and groove casts are also common.Fragments of carbon remains occur widely and commonly constitute stringers several millimeters thick and up to 10 cm long,together with fine clasts.Vitrain lenticles are also common.Based on the imbricate structure of the Lingshan Island deposits,it is shown that in addition to paleocurrent analysis,the imbricate structure can be used to infer information about fluid properties,transport characteristics,and sedimentary processes of the depositional environment.A near-bottom underflow,either of authigenic origin or derived from cold river water in winter in a delta interdistributary bay or delta-front environment,is inferred to have provided the hydrodynamic setting in which this imbricate structure formed.The imbricate structure,together with other sedimentary structures and features,shows that the sedimentary rocks on Lingshan Island were deposited in an inland,shallow-water environment,such as a delta,and not in a deep-water or submarine continental-slope environment.SHAO ZhuFu ZHONG JianHua LI Yong MAO Cui LIU ShengXin NI LiangTian TIAN Yuan CUI XinYing LIU YunTian WANG XiaoNan LI WeiHua LIN GangShan 2014Science China Earth Sciences2014,57,5:11
13Experimental comparison between aircraft fuel tank inerting processes using NEA and MIG显示文摘Fuel tank inerting technologies are able to reduce the fire risk by injection of inert gas into the ullage or fuel, the former called ullage washing and the latter fuel scrubbing. The Green On-Board Inert Gas Generation System(GOBIGGS) is a novel technology based on flameless catalytic combustion, and owning to its simple structure and high inerting efficiency, it has received a lot of attentions. The inert gas in the GOBIGGS is mainly comprised of CO_2, N_2, and O_2(hereinafter, Mixed Inert Gas(MIG)), while that in the On-Board Inert Gas Generation System(OBIGGS), which is one of the most widely used fuel tank inerting technologies, is NitrogenEnriched Air(NEA). The solubility of CO_2 is nearly 20 times higher than that of N_2 in jet fuels,so the inerting capability and performance are definitely disparate if the inert gas is selected as NEA or MIG. An inerting test bench was constructed to compare the inerting capabilities between NEA and MIG. Experimental results reveal that, if ullage washing is adopted, the variations of oxygen concentrations on the ullage and in the fuel are nearly identical no matter the inert gas is NEA or MIG. However, the ullage and dissolved oxygen concentrations of MIG scrubbing are always higher than those of NEA scrubbing.Lei SHAO Weihua LIU Chaoyue LI Shiyu FENG Chenchen WANG Jun PAN 2018Chinese Journal of Aeronautics2018,31,7:11
14Enhanced efficiency of cadmium removal by Boehmeria nivea(L.) Gaud. in the presence of exogenous citric and oxalic acids显示文摘Boehmeria nivea(L.)Gaud.is a potential candidate for the remediation of Cd contaminated sites.The present investigation aims to explore Cd tolerance threshold and to quickly identify the role of exogenous organic acids in Cd uptake and abiotic metal stress damage.Elevated Cd levels(0–10 mg/L)resulted in an obvious rise in Cd accumulation,ranging from268.0 to 374.4 in root and 25.2 to 41.2 mg/kg dry weight in shoot,respectively.Citric acid at1.5 mmol/L significantly facilitated Cd uptake by 26.7%in root and by 1-fold in shoot,respectively.Cd translocation efficiency from root to shoot was improved by a maximum of66.4%under 3 mmol/L of oxalic acid.Citric acid exhibited more prominent mitigating effect than oxalic acid due to its stronger ligand affinity for chelating with metal and avoiding the toxicity injury of free Cd ions more efficiently.The present work provides a potential strategy for efficient Cd remediation with B.nivea.Huaying Li Yunguo Liu Guangming Zeng Lu Zhou Xin Wang Yaqin Wang Chunlin Wang Xinjiang Hu Weihua Xu 2014Journal of Environmental Sciences2014,26,12:10
15Synthesis of CNT film on the surface of micro-pyramid array and its intense pulsed emission characteristics显示文摘We developed a new scheme to suppress the electric-field-screening effect in high growth density of a carbon nanotube(CNT) film during its intense pulsed emission.We synthesize the CNT film on a tridimensional surface(t-CNT film).The tridimensional surface includes wet etched silicon pyramids,and the Ni layer is electroless plated thereon.The intense pulsed emission characteristics of the t-CNT and planar-grown CNT(p-CNT) films were measured using a diode structure in single-pulse mode.The even turn-on field decreased from 5.5 V/μm for p-CNTs to 2.8 V/m for t-CNTs,and the peak emission current increased from 232 A for p-CNTs to 324 A for t-CNTs at a peak field intensity ~12.2 V/m.The peak current of the t-CNT film increased by ~39.7% over the p-CNT film.It is clear that the micro-pyramid array can effectively suppress the field screening effect to improve the electron-emission of CNT films.ZENG FanGuang LI Xin LIU WeiHua QIAO ShuZhen MA HuaLi ZHANG Rui XIA LianSheng CHEN Yi LIU XingGuang ZHANG Huang 2012Chinese Science Bulletin2012,57,14:10
16A flexible capacitive tactile sensor array with micro structure for robotic application显示文摘A flexible capacitive tactile sensor array with micro needle structure is proposed in this paper for robotic application.Micro needle layer made of polydimethylsiloxane(PDMS)is sandwiched between the upper electrode layer made of PDMS and the bottom electrode layer fabricated on polyester(PET)film.The PDMS material renders the device adequate flexibility as it can be rolled into a cylinder.The single cell size in the fabricated 4×4 sensors array is 0.7×0.5 cm2and the initial capacitance of each cell is 0.86 p F.The fabricated cell shows a sensitivity of 3.26%/m N within the full scale range of 1 k Pa.The micro needle structure gives better repeatability and stability.The maximum error during each measurement is about 3.2%,while the minimum error is about 1.2%.HU XiaoHui ZHANG Xu LIU Ming CHEN YuanFang LI Peng PEI WeiHua ZHANG Chun CHEN HongDa 2014Science China(Information Sciences)2014,57,12:9
17Relationships between Interannual and Intraseasonal Variations of the Asian–Western Pacific Summer Monsoon Hindcasted by BCC CSM 1.1(m)显示文摘Using hindcasts of the Beijing Climate Center Climate System Model, the relationships between interannual variability(IAV) and intraseasonal variability(ISV) of the Asian–western Pacific summer monsoon are diagnosed. Predictions show reasonable skill with respect to some basic characteristics of the ISV and IAV of the western North Pacific summer monsoon(WNPSM) and the Indian summer monsoon(ISM). However, the links between the seasonally averaged ISV(SAISV) and seasonal mean of ISM are overestimated by the model. This deficiency may be partially attributable to the overestimated frequency of long breaks and underestimated frequency of long active spells of ISV in normal ISM years, although the model is capable of capturing the impact of ISV on the seasonal mean by its shift in the probability of phases.Furthermore, the interannual relationships of seasonal mean, SAISV, and seasonally averaged long-wave variability(SALWV; i.e., the part with periods longer than the intraseasonal scale) of the WNPSM and ISM with SST and low-level circulation are examined. The observed seasonal mean, SAISV, and SALWV show similar correlation patterns with SST and atmospheric circulation, but with different details. However, the model presents these correlation distributions with unrealistically small differences among different scales, and it somewhat overestimates the teleconnection between monsoon and tropical central-eastern Pacific SST for the ISM, but underestimates it for the WNPSM, the latter of which is partially related to the too-rapid decrease in the impact of El Nino–Southern Oscillation with forecast time in the model.LIU Xiangwen WU Tongwen YANG Song LI Qiaoping CHENG Yanjie LIANG Xiaoyun FANG Yongjie JIE Weihua NIE Suping 2014Advances in Atmospheric Sciences2014,31,5:9
18Chronic intermittent hypoxia accelerates liver fibrosis in rats with combined hypoxia and nonalcoholic steatohepatitis via angiogenesis rather than endoplasmic reticulum stress显示文摘In the present study,we aimed to investigate the role of endoplasmic reticulum stress(ERS)and its related inflammation and angiogenesis in liver fibrosis in a rat model of combined hypoxia and nonalcoholic steatohepatitis(NASH)and to confirm whether the intervention of hypoxia-inducible factor 1α(HIF1α)can improve fibrosis.Liver histological changes and biochemical indices,HIF1α,inflammatory factors,ERS-related parameters(GRP78,CHOP,caspase-3,and caspase-12),and angiogenesis indices(VEGFA,VEGFR2,and CD34)were evaluated.Compared with the control rats,the liver tissue of rats with hypoxia and NASH had obvious NASH characteristics and hepatic fibrosis was significantly aggravated,including bridging fibrosis in some rats.The mRNA expression levels of HIF1α,VEGFA,and VEGFR2 and total immunohistochemical staining scores of VEGFR2 and CD34 were significantly increased.In addition,HIF1α silencing significantly decreased HIF1α,biochemical indices(ALT,AST,and TG),inflammatory factors(TNFα,IL6,and IL1β),and angiogenesis indices(CD34 and VEGFR2),consequently,improved the hepatic fibrosis score in the rat model of combined hypoxia and NASH.Taken together,chronic intermittent hypoxia accelerates liver fibrosis in rats with combined hypoxia and NASH via angiogenesis rather than ERS and HIF1α intervention can improve liver fibrosis,angiogenesis,inflammatory factors,and biochemical indices.Therefore,HIF1α is a key regulatory factor of liver fibrosis in rats with combined hypoxia and NASH.Wei Wu Weiping Li Jiaojiao Wei Chunsheng Wang Yunliang Yao Weihua Zhu Weimei He Weimei Zhou Jiang Liu 2019Acta Biochimica et Biophysica Sinica2019,51,2:8
19Pantograph and catenary system with double pantographs for high-speed trains at 350 km/h or higher显示文摘The paper is aimed at developing an optimized design of the pantograph and catenary system with double pantographs at a speed of 350 km/h for the Wuhan-Guangzhou high-speed railway.First,the pantograph and catenary system for the Beijing-Tianjin high-speed railway was analyzed to verify whether its design objective could be fulfilled.It shows that the system is not able to satisfy the requirement of a sustainable running speed of 350 km/h.Then a new scheme for the pantograph and catenary system is proposed through optimization and renovation of the structure and parameters of the pantograph and catenary system,including the suspension type of the catenary,tension of the contact wire,and space between two pantographs.Finally,the dynamic performance of the new system was verified by simulation and line testing.The results show that the new scheme of the pantograph and catenary system for the WuhanGuangzhou high-speed railway is acceptable,in which the steady contact between the rear pantograph and the catenary at the space of 200 m can be maintained to ensure the current-collection quality.A current collection with double pantographs at a speed of 350 km/h or higher can be achieved.Weihua ZHANG Ning ZHOU Ruiping LI Guiming MEI Dongli SONG 2011Journal of Modern Transportation2011,19,1:8
20Improvement in the intense pulsed emission stability of grown CNT films via an electroless plated Ni layer显示文摘Carbon nanotube(CNT)films were grown on silicon wafers with and without a nickel layer(Si-CNT and Ni-CNT)via the pyrolysis of iron phthalocyanine.The nickel layer was prepared using the electroless plating method.To study the emission stability of Si-CNT and Ni-CNT cathodes during intense pulsed emission,emission characteristics were measured repeatedly with a diode structure using a Marx generator as a voltage source.For the peak values of the pulsed voltage,which were in the range between 1.62-1.66 MV(corresponding to electric field intensities between 11.57-11.85 V/μm),the first cycle emission current was 109.4 A for Si-CNT and 180.5 A for Ni-CNT.By comparing the normalized emission currents of the Si-CNT and Ni-CNT cathodes,the improvement in the emission stability can be easily quantified.The number of emission cycles necessary for the peak current to decay from 100%to 50%increased from^3 for Si-CNT to^11 for a Ni-CNT film.ZENG FanGuang LI Xin LIU WeiHua QIAO ShuZhen MA HuaLi ZHANG Rui XIA LianSheng CHEN Yi LIU XingGuang ZHANG Huang 2011Chinese Science Bulletin2011,56,22:7
返回顶部 每页显示:
共29页 首页 上一页 第1页 下一页 末页 /29 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