维普中文期刊产品整合服务
518篇 您的检索式:作者名="Jinjun"
    题名 作者 年代 出处 被引量
1Prediction of carbon exchanges between China terrestrial ecosystem and atmosphere in 21st century显示文摘The projected changes in carbon exchange between China terrestrial ecosystem and the atmosphere and vegetation and soil carbon storage during the 21st century were investigated using an atmos-phere-vegetation interaction model (AVIM2). The results show that in the coming 100 a, for SRES B2 scenario and constant atmospheric CO2 concentration, the net primary productivity (NPP) of terrestrial ecosystem in China will be decreased slowly, and vegetation and soil carbon storage as well as net ecosystem productivity (NEP) will also be decreased. The carbon sink for China terrestrial ecosystem in the beginning of the 20th century will become totally a carbon source by the year of 2020, while for B2 scenario and changing atmospheric CO2 concentration, NPP for China will increase continuously from 2.94 GtC·a?1 by the end of the 20th century to 3.99 GtC·a?1 by the end of the 21st century, and vegetation and soil carbon storage will increase to 110.3 GtC. NEP in China will keep rising during the first and middle periods of the 21st century, and reach the peak around 2050s, then will decrease gradually and approach to zero by the end of the 21st century.JI JinJun HUANG Mei LI KeRang 2008Science China Earth Sciences2008,51,6:48
2Review of zero-net-mass-flux jet and its application in separation flow control显示文摘Since the zero-net-mass-flux (ZNMF) jet was first used as a laboratory flow control method in 1990's, it has attracted much attention. The ZNMF jet has unique features such as compact actuator, no requirement for external air supply, complex piping, etc., and becomes a hot topic research subject in fluid mechanics. This review introduces the state of the art in the development of ZNMF jet in the quiescent fluid, the interaction of the ZNMF jet with the cross flow and its application in the separation flow control. The evolution of the vortex ring/pair and the spacial flow structure of the ZNMF in quicent fluid or cross flow are presented, as well as the key parameter effects. At last, the applications of ZNMF jet in the wake control of the circular cylinder, the separation control on the airfoil and the aerodynamic force or moment control on MAV/UAV are presented.ZHANG PanFeng WANG JinJun FENG LiHao 2008Science China(Technological Sciences)2008,51,9:30
3Research of the Unity Theory Between Three-level Space Vector and Carrier-based PWM Modulation Strategy显示文摘两电平空间矢量脉宽调制(space vector pulse widthmodulation,SVPWM)与正弦脉宽调制(sinusoidal pulse widthmodulation,SPWM)存有一定的本质关系,对于三电平,在常见的8段式SVPWM序列中可以证明,SVPWM与SPWM本质上也存在某种统一。实际的SVPWM调制中,由于要考虑中点电压平衡、减少谐波等其它性能问题,一般会利用开关冗余状态得到8段以上的开关调制序列。目前的文献中还未曾有对这些情况进行统一性地验证,因此三电平SVPWM与SPWM的统一理论存在一定的不足。研究发现,可通过严格地理论推导将传统意义上的调制波分解为2个子调制波,再进行SPWM调制,可以得到与SVPWM完全吻合的序列。该文在此方法基础上深入研究了8段以上(10、12、14段)的SVPWM调制序列与SPWM的统一。经过严格地理论推导,成功实现了含任意段数的SVPWM序列与SPWM的统一。仿真结果证明了该理论的正确性。CHEN Juan HE Yingjie WANG Xinyu LIU Jinjun 2013中国电机工程学报2013,33,9:28
4Effect of seawater on incident plane P and SV waves at ocean bottom and engineering characteristics of offshore ground motion records off the coast of southern California, USA显示文摘The effect of seawater on vertical ground motions is studied via a theoretical method and then actual offshore ground motion records are analyzed using a statistical method. A theoretical analysis of the effect of seawater on incident plane P and SV waves at ocean bottom indicate that on one hand, the affected frequency range of vertical ground motions is prominent due to P wave resonance in the water layer if the impedance ratio between the seawater and the underlying medium is large, but it is greatly suppressed if the impedance ratio is small; on the other hand, for the ocean bottom interface model selected herein, vertical ground motions consisting of mostly P waves are more easily affected by seawater than those dominated by SV waves. The statistical analysis of engineering parameters of offshore ground motion records indicate that:(1) Under the infl uence of softer surface soil at the seafl oor, both horizontal and vertical spectral accelerations of offshore motions are exaggerated at long period components, which leads to the peak spectral values moving to a longer period.(2) The spectral ratios(V/H) of offshore ground motions are much smaller than onshore ground motions near the P wave resonant frequencies in the water layer; and as the period becomes larger, the effect of seawater becomes smaller, which leads to a similar V/H at intermediate periods(near 2 s). These results are consistent with the conclusions of Boore and Smith(1999), but the V/H of offshore motion may be smaller than the onshore ground motions at longer periods(more than 5 s).Diao Hongqi Hu Jinjun Xie Lili 2014Earthquake Engineering and Engineering Vibration2014,13,2:24
5Privacy Computing: Concept, Computing Framework, and Future Development Trends显示文摘With the rapid development of information technology and the continuous evolution of personalized ser- vices, huge amounts of data are accumulated by large internet companies in the process of serving users. Moreover, dynamic data interactions increase the intentional/unintentional persistence of private infor- mation in different information systems. However, problems such as the cask principle of preserving pri- vate information among different information systems and the dif culty of tracing the source of privacy violations are becoming increasingly serious. Therefore, existing privacy-preserving schemes cannot pro- vide systematic privacy preservation. In this paper, we examine the links of the information life-cycle, such as information collection, storage, processing, distribution, and destruction. We then propose a the- ory of privacy computing and a key technology system that includes a privacy computing framework, a formal de nition of privacy computing, four principles that should be followed in privacy computing, ffect algorithm design criteria, evaluation of the privacy-preserving effect, and a privacy computing language. Finally, we employ four application scenarios to describe the universal application of privacy computing, and discuss the prospect of future research trends. This work is expected to guide theoretical research on user privacy preservation within open environments.Fenghua Li Hui Li Ben Niu Jinjun Chen 2019Engineering2019,5,6:21
6Mushroom Poisoning Outbreaks—China,2010–2020显示文摘ABSTRACT Introduction:Mushroom poisoning was the leading cause of foodborne disease outbreaks and outbreak-associated deaths in China.Mushroom poisoning outbreak surveillance can provide insight into the epidemiological characteristics of mushroom poisonings and guide policymaking and health education to reduce illnesses and deaths.Methods:Foodborne Disease Outbreak Surveillance System was upgraded in 2011 to collect foodborne disease outbreaks in China.Mushroom poisoning outbreaks during 2010–2020 were selected to analyze geographical distribution,seasonal distribution,and setting of food preparation.Results:A total of 10,036 outbreaks,which resulted in 38,676 illnesses and 788 deaths,were reported in this period.Mushroom poisonings occurred all over the country,but with highest incidence in the southwest and central China.Weiwei Li Sara M.Pires Zhitao Liu Jinjun Liang Yafang Wang Wen Chen Chengwei Liu Jikai Liu Haihong Han Ping Fu Yunchang Guo 2021China CDC weekly2021,3,24:18
7Hysteretic behavior of special shaped columns composed of steel and reinforced concrete(SRC)显示文摘This paper describes a series of experimental investigations on seventeen specimens of steel reinforced concrete special shaped(SRCSS) columns under low cyclic reversed loading using parallel crosshead equipment. Nine T-shaped SRC columns, four L-shaped SRC columns and four +-shaped SRC columns were tested to examine the effects of shape steel confi guration, loading angle, axial compressive ratio and shear-span ratio on the behavior(strength, stiffness, energy dissipation, ductility, etc.) of SRCSS column specimens. The failure modes and hysteretic performance of all the specimens were obtained in the tests. Test results demonstrate that the shear-span ratio is the main parameter affecting the failure modes of SRCSS columns. The specimens with small shear-span ratio are prone to shear failure, and the primary failure planes in SRCSS columns are parallel to the loading direction. As a result, there is a symmetry between positive and negative loading directions in the hysteretic curves of the SRCSS columns. The majority of displacement ductility coeffi cients for all the specimens are over 3.0, so that the SRCSS columns demonstrate a better deformation capacity. In addition, the equivalent viscous damping coeffi cients of all the specimens are greater than 0.2, indicating that the seismic behavior of SRCSS columns is adequate. Finally, the superposition theory was used to calculate the limits of axial compressive ratio for the specimens, and it is found that the test axial compressive ratio is close to or smaller than the calculated axial compressive ratio limit.Chen Zongping Xu Jinjun Xue Jianyang 2015Earthquake Engineering and Engineering Vibration2015,14,2:17
8Identification of Lagrangian coherent structures in the turbulent boundary layer显示文摘Using Finite-Time Lyapunov Exponents (FTLE) method, Lagrangian coherent structures (LCSs) in a fully developed flat-plate turbulent boundary layer are successfully identified from a two-dimensional (2D) velocity field obtained by time-resolved 2D PIV measurement. The typical LCSs in the turbulent boundary layer are hairpin-like structures, which are characterized as legs of quasi-streamwise vor- tices extending deep into the near wall region with an inclination angle θ to the wall, and heads of the transverse vortex tube located in the outer region. Statistical analysis on the characteristic shape of typical LCS reveals that the probability density distribution of θ accords well with t-distribution in the near wall region, but presents a bimodal distribution with two peaks in the outer region, corresponding to the hairpin head and the hairpin neck, respectively. Spatial correlation analysis of FTLE field is im- plemented to get the ensemble-averaged inclination angle θ R of typical LCS. θ R first increases and then decreases along the wall-normal direction, similar to that of the mean value of θ. Moreover, the most probable value of θ saturates at y+=100 with the maximum value of about 24°, suggesting that the most likely position where hairpins transit from the neck to the head is located around y+=100. The ensem- ble-averaged convection velocity Uc of typical LCS is finally calculated from temporal-spatial correla- tion analysis of FTLE field. It is found that the wall-normal profile of the convection velocity Uc(y) ac- cords well with the local mean velocity profile U(y) beyond the buffer layer, evidencing that the down- stream convection of hairpins determines the transportation properties of the turbulent boundary layer in the log-region and beyond.PAN Chong WANG JinJun ZHANG Cao 2009Science China(Physics,Mechanics & Astronomy)2009,52,2:14
9Chemiluminescence detection of permanganate index (COD_(Mn)) by a luminol-KMnO_4 based reaction显示文摘为与流动注射分析相结合的高锰酸盐索引(CODMn ) 的决心的一个新奇化合光(CL ) 系统在这研究被建议了。根据 luminol-KMnO4 系统的 chemiluminescent 反应, luminol-KMnO4 系统引起的轻排放被光电倍增管试管检测,并且在样品消化与 CODMn.Effects 相反地成正比以后,它的紧张由 KMnO4 的外观引起了因为决定例如 pH,集中和干扰的 CODMn 详细被调查。有 0.3 的一个线性范围的 0.3 mg/LCODMn 的察觉限制—为它的理论 CODMn 的 200 mg/L 在优化试验性的条件下面被获得。相对标准差为 5.0 mg/LCODMn 是 4.3%(n = 11 ) 。为决定 CODMn 的这个 CL 流动系统为自动分析简单、快速、合适。现在的方法获得的数据被标准 titrimetric 方法相当在对那些的好同意获得。与令人满意的结果决定真实样品被使用了。TIAN Jinjun HU Yonggang ZHANG Jie 2008Journal of Environmental Sciences2008,20,2:14
10Development of Land Surface Model BCC_AVIM2.0 and Its Preliminary Performance in LS3MIP/CMIP6显示文摘The improvements and validation of several parameterization schemes in the second version of the Beijing Climate Center Atmosphere–Vegetation Interaction Model(BCC_AVIM2.0) are introduced in this study. The main updates include a replacement of the water-only lake module by the common land model lake module(Co LM-lake) with a more realistic snow–ice–water–soil framework, a parameterization scheme for rice paddies added in the vegetation module, renewed parameterizations of snow cover fraction and snow surface albedo to accommodate the varied snow aging effect during different stages of a snow season, a revised parameterization to calculate the threshold temperature to initiate freeze(thaw) of soil water(ice) rather than being fixed at 0°C in BCC_AVIM1.0, a prognostic phenology scheme for vegetation growth instead of empirically prescribed dates for leaf onset/fall, and a renewed scheme to depict solar radiation transfer through the vegetation canopy. The above updates have been implemented in BCC_AVIM2.0 to serve as the land component of the BCC Climate System Model(BCC_CSM). Preliminary results of BCC_AVIM in the ongoing Land Surface, Snow, and Soil Moisture Model Intercomparison Project(LS3 MIP) of the Coupled Model Intercomparison Project Phase 6(CMIP6) show that the overall performance of BCC_AVIM2.0 is better than that of BCC_AVIM1.0 in the simulation of surface energy budgets at the seasonal timescale. Comparing the simulations of annual global land average before and after the updates in BCC_AVIM2.0 reveals that the bias of net surface radiation is reduced from-12.0 to-11.7 W m-2 and the root mean square error(RMSE) is reduced from 20.6 to 19.0 W m-2;the bias and RMSE of latent heat flux are reduced from 2.3 to-0.1 W m-2 and from 15.4 to14.3 W m-2, respectively;the bias of sensible heat flux is increased from 2.5 to 5.1 W m-2 but the RMSE is reduced from 18.4 to 17.0 W m-2.Weiping LI Yanwu ZHANG Xueli SHI Wenyan ZHOU Anning HUANG Mingquan MU Bo QIU Jinjun JI 2019Journal of Meteorological Research2019,33,5:14
11Application of ^(137)Cs fingerprinting technique to interpreting sediment production records from reservoir deposits in a small catchment of the Hilly Loess Plateau,China显示文摘According to variations of 137Cs and clay contents, 44 flood couplets were identified in a profile of res- ervoir deposit with a vertical length of 28.12 m in the Yuntaishan Gully. Couplet 27 at the middle of the profile had the highest average 137Cs content of 12.65 Bq·kg?1, which indicated the 1963s' deposits, then 137Cs content decreased both downward and upward in the profile. The second top and bottom couplets had average 137Cs contents of 2.15 Bq·kg?1 and 0.92 Bq·kg?1, respectively. By integrated analysis of reservoir construction and management history, variations of 137Cs contents over the profile, sediment yields of flood couplets and rainfall data during the period of 1958-1970, individual storms related to the flood couplets were identified. 44 floods with a total sediment yield of 2.36×104 m3 occurred and flood events in a year varied between 1 and 10 times during the period of 1960-1970. 7-10 flood events occurred during the wet period of 1961-1964 with very wet autumn, while only 1-2 events during the dry period of 1965-1969. Average annual specific sediment yield was 1.29×104 t·km?2·a?1 for the Yuntaishan Gully during the period of 1960-1970, which was slightly higher than 1.11 ×104 t·km?2·a?1 for the Upper Yanhe River Basin above the Ganguyi Hydrological Station and slightly lower than 1.40 ×104 t·km?2·a?1 for the nearby Zhifang Gully during the same period. Annual specific sediment yields for the Yuntaishan Gully were correlated to the wet season's rainfalls well.ZHANG XinBao WEN ZhongMing FENG MingYi YANG QinKe ZHENG JinJun 2007Science China Earth Sciences2007,50,2:13
12A single camera volumetric particle image velocimetry and its application显示文摘Volumetric particle image velocimetry(VPIV) refers to a PIV-based technique which can obtain full velocity components in a three-dimensional measurement volume.A new VPIV method with a single lens was developed.A three-vision prism was used to make viewing from different angles using one camera.The technique was tested and successfully applied to a three-dimensional three-component(3D3C) measurement of a zero-net-mass-flux jet flow.The accuracy of the measurement was investigated,specifically in steps of calibration,self-calibration and particle triangulation.Time sequence of a vortex ring development was presented.It was shown that the measurement has high accuracy with validation rate of velocity vector reaching about 95%.The flow with vortex ring passing the measurement volume was studied using both swirl strength and vorticity magnitude criteria.Through comparison,the swirl criterion was found to be superior to the criterion of vorticity in differentiating the rotation motion and the free shear.GAO Qi WANG HongPing WANG JinJun 2012Science China(Technological Sciences)2012,55,9:10
13Dynamic WTA optimization model of air defense operation of warships' formation显示文摘WTA (weapon-target allocation) of air defense operation is a very complicated problem and current models focus on static and restricted WTA problem mostly. Based on the dynamic characteristics of air defense operational command and decision of warships’ formation, a dynamic WTA model is established. Simulation results show that switch fire and repetition fire of anti-air weapon systems affect the result of the air defense operation remarkably and the dynamic model is more satisfying than static ones. Related results are gained based on the analysis of the simulation results and the results are accordant with the intuitionistic tactical judgment. The model is some reference for the research of air defense C3I system of warships’ formation.Li Jinjun Cong Rong Xiong Jiguang 2006Journal of Systems Engineering and Electronics2006,17,1:10
14Experimental cancer gene therapy by multiple anti-survivin hammerhead ribozymes显示文摘为癌症改进基因治疗的功效,我们设计了指向 survivin mRNA 的暴露的区域的四撞木鲛 ribozyme 侵入人体气管粘膜的病菌(到 R4 的 R1 ) 。除了在里面 vitro 描述,由教材扩展包括了劈开的顺序特性的一颗决心,为细胞增长并且为的试金在 vivo 肿瘤,生长被用来为 ribozyme 效率得分。survivin 表示的产生抑制经由 caspase-3-dependent 小径导致了有丝分裂的大祸和房间死亡。重要地, ribozyme 侵入人体气管粘膜的病菌的管理在一个 hepato 细胞的癌异种皮移植老鼠模型禁止了肿瘤生长。R1, R3 和 R4 ribozymes 的合作表示 synergistically 压制了 survivin 并且当这联合指向 survivin 抄本的所有主要形式,生产了大多数有势力反癌症效果。带在这份报告描述的多重撞木鲛 ribozymes 的侵入人体气管粘膜的病菌对癌症提供了柔韧的基因治疗策略。Qi Fei Hongyu Zhang Lili Fu Xinlan Dai Baomei Gao Min Ni Chao Ge Jinjun Li Xia Ding Yuwen Ke Xuebiao Yao Jingde Zhu 2008Acta Biochimica et Biophysica Sinica2008,40,6:10
15Advances in rheology and flow assurance studies of waxy crude显示文摘Flow assurance is one of the core issues in safe and economical operation of waxy crude pipelines.Its essence lies in flow and heat transfer of the crude.In the past 10 years,the authors' team has achieved a lot of innovative results in aspects of waxy crude rheology,flow assurance assessment,and pipelining technologies on the basis of decades of studies.The rheological characteristics of waxy crude are much better understood,and a method for quantitatively simulating the effect of flow shear was developed based on some theoretical breakthroughs.Studies of the mechanism of waxy crude rheology have been deepened to the quantitative level.After successful development of efficient numericalalgorithms,accurate simulations have been achieved for various complex flow and heat transfer situations in waxy crude pipelining,and a reliability-based approach to flow assurance assessment has been set up.New pipelining technologies have been developed such as batching pour-point depressant-(PPD-) treated multiple-waxy-crudes,intermittent transport of waxy crudes through long-distance pipelines,and batching hot and cold crudes.By their application,a series of problems hindering safe,efficient and flexible operation of waxy crude pipelines were tackled,demonstrating that transportation technologies for waxy crude have advanced to a new and high level.Zhang Jinjun Yu Bo Li Hongying Huang Qiyu 2013Petroleum Science2013,10,4:10
16Experimental investigations on separation control and flow structure around a circular cylinder with synthetic jet显示文摘Circular cylinder separation control and flow structure influenced by the synthetic jet have been experimentally investigated in a water channel. The synthetic jet is- sues from a slot and ejects toward upstream from the front stagnation point of the cylinder. It has been found that, similar to the traditional synthetic jet which is po- sitioned near the separation point or inside the separation region, the present synthetic jet arrangement constitutes an efficient way to control flow separation of the circular cylinder, but with a different control mechanism. The present synthetic jet leads to an upstream displacement of the front stagnation point and the forma- tion of a vortex pair near both sides of the exit orifice. When ReU based on the synthetic jet average exit orifice velocity is about lower than 43, a closed envelope forms in front of the windward side of the cylinder during the blowing cycle of syn- thetic jet, which acts as an apparent modification for the cylinder configuration. When ReU is high enough, an open envelope forms upstream of the cylinder, and the flow around the cylinder becomes much energetic. Thus, regardless of ReU, the present synthetic jet can improve separation for flow around a circular cylinder. With regard to the leeward side, as ReU increases, the flow separation region be- hind the cylinder gradually disappears. The flow over cylinder may be fully attached when the open envelope forms upstream of the cylinder and ReU is greater than 344. Then, the flow past the cylinder will converge near the back stagnation point of the cylinder, where a new vortex pair shedding periodically is generated due to the high shear layer.WANG JinJun FENG LiHao XU ChaoJun 2007Science China(Technological Sciences)2007,50,5:9
17Characteristics of Early Eocene radiolarian assemblages of the Saga area,southern Tibet and their constraint on the closure history of the Tethys显示文摘Quantitative analysis of Early Eocene radiolarian assemblages discovered in the sedimentary mélange (accretionary prism) of the Saga area,southern Tibet provides new information to constrain the timing of Tethys closure and the initial collision of India and Eurasia. The radiolarian species of Saga include Amphisphaera coronata (Ehrenberg),Buryella hannae Bak & Barwicz-Piskorz,Buryella clinata Foreman,Buryella tetradica Foreman,Calocycloma ampulla (Ehrenberg),Lamptonium fabaeforme constrictum Riedel and Sanfilippo,Lamptonium pennatum Foreman,Lithomespilus coronatus Squinabol and Lamptonium (?) colymbus Foreman. The adequate and reliable correlation of these radiolarians specimens indicates that the assemblage is of Early Eocene in age. The age and depositional envi-ronment of these radiolarians testify that deep ocean basins existed between India Plate and Asia Plate during the Early Eocene. The complete closure of Tethys must have taken place at least after the Early Eocene.LI YaLin WANG ChengShan HU XiuMian M. Bak WANG JinJun CHEN Lei 2007Chinese Science Bulletin2007,52,15:9
18Catalytic oxidation of benzene over nanostructured porous Co_3O_4-CeO_2 composite catalysts显示文摘Mesostructured Co3O4-CeO2 composite was found to be an effective catalytic material for the complete oxidation of benzene. The Co3O4-CeO2 catalysts with different Co/Ce ratios (mol/mol) were prepared via the nanocasting method and the mesostructure was replicated from two-dimensional (2D) hexagonal SBA-15 and three-dimensional (3D) cubic KIT-6 silicas, respectively. All the obtained Co3O4-CeO2 catalysts exhibited the similar symmetry with the parent silicas and well ordered mesostructures. The Co3O4- CeO2 catalysts with 2D mesostructure showed lower catalytic activities than the corresponding 3D materials. The Co3O4-CeO2 catalyst nanocasted from KIT-6 and with the Co/Ce ratio of 16/1 possessed the best catalytic benzene oxidation activity due to larger quantities of surface hydroxyl groups and surface oxygenated species. The mesostructured Co3O4-CeO2 material thus shows great potential as a promising eco-environmental catalyst for benzene effective elimination.Chunyan Ma Zhen Mu Chi He Peng Li Jinjun Li Zhengping Hao 2011Journal of Environmental Sciences2011,23,12:9
19Evaluating the accuracy performance of Lucas-Kanade algorithm in the circumstance of PIV application显示文摘Lucas-Kanade(LK) algorithm, usually used in optical flow filed, has recently received increasing attention from PIV community due to its advanced calculation efficiency by GPU acceleration. Although applications of this algorithm are continuously emerging,a systematic performance evaluation is still lacking. This forms the primary aim of the present work. Three warping schemes in the family of LK algorithm: forward/inverse/symmetric warping, are evaluated in a prototype flow of a hierarchy of multiple two-dimensional vortices. Second-order Newton descent is also considered here. The accuracy & efficiency of all these LK variants are investigated under a large domain of various influential parameters. It is found that the constant displacement constraint, which is a necessary building block for GPU acceleration, is the most critical issue in affecting LK algorithm's accuracy, which can be somehow ameliorated by using second-order Newton descent. Moreover, symmetric warping outbids the other two warping schemes in accuracy level, robustness to noise, convergence speed and tolerance to displacement gradient, and might be the first choice when applying LK algorithm to PIV measurement.PAN Chong XUE Dong XU Yang WANG JinJun WEI RunJie 2015Science China(Physics,Mechanics & Astronomy)2015,58,10:9
20Accurate measurement of wall skin friction by single-pixel ensemble correlation显示文摘The present work deals with accurately estimating wall-skin friction from near-wall mean velocity by means of PIV measurement.The estimation accuracy relies on the spatial resolution and the precision of the resolved velocity profile inside the viscous sublayer,which is a big challenge for conventional window-based correlation method(K?hler C J,et al.Exp Fluids,2012,52:1641–1656).With the help of single-pixel ensemble correlation,the ensemble-averaged velocity vector can be resolved at significant spatial resolution,thus improving the measurement accuracy.To demonstrate the feasibility of this single-pixel ensemble correlation method,we first study the velocity estimation precision in a case of steady near-wall flow.Synthetic particle images are used to investigate the effect of different image parameters.It is found that the velocity RMS-uncertainty level of the single-pixel ensemble correlation method can be equivalent to the conventional window correlation method once the effective particle number used for the ensemble correlation is large enough.Furthermore,a canonical turbulent boundary layer is synthetically simulated based on velocity statistics resolved by previous Direct Numerical Simulation(DNS)work(Schlatter P,et al.J Fluid Mech,2010,659:116–126).The relative error of wall skin friction coefficient is shown to be one-order smaller than that of the window correlation method.And the optimization strategy to further minimize the measurement uncertainty is discussed in the last part.SHEN JunQi PAN Chong WANG JinJun 2014Science China(Physics,Mechanics & Astronomy)2014,57,7:8
返回顶部 每页显示:
共26页 首页 上一页 第1页 下一页 末页 /26 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