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| 1 | The mechanism of breakdown in laminar-turbulent transition of a supersonic boundary layer on a flat plate-temporal mode显示文摘Temporal mode direction numerical simulation has been done for the transition of a supersonic boundary layer on a flat plate with Mach number 4.5. Analysis of the result showed that during the breakdown process in laminar-turbulent transition, the mechanism causing the mean flow profile to evolve swiftly from laminar to turbulent was that the modification of mean flow profile by the disturbances,when they became larger,led to a remarkable change of its stability characteristics. Though the most unstable T-S wave was of second mode for laminar flow, the first mode waves played the key role in the breakdown process in laminar-turbulent transition. | HUANG Zhangfeng 1, CAO Wei 1,2 & ZHOU Heng 1,2 1. Department of Mechanics, Tianjin University, Tianjin 300072, China 2. Liu-Hui Center of Applied Mathematics, Nankai University and Tianjin University, Tianjin 300072, China | 2005 | Science China(Physics,Mechanics & Astronomy)2005，48，5： | 23 |
| 2 | Fission Track Dating of Authigenic Quartz in Red Weathering Crusts of Carbonate Rocks in Guizhou Province显示文摘The Cenozoic evolution history of Guizhou Province, which is located on the southeastem flank of the Qinghai-Tibet Plateau, is unclear because of the lack of sedimentation records. The red weathering crusts widespread on the Yunnan-Guizhou Plateau may bear critical information about their evolution history. This work firstly determined the ages of four red weathering crusts in eastern, central and northern Guizhou. The material used in fission track dating is well-crystallized quartz occurring in many in-situ weathering crusts of carbonate rocks. The results showed that the fission track ages of quartz vary over a wide range from 1 to 25 Ma in the four profiles, significantly younger than the ages of the Triassic and Cambrian parent rocks. In combination with the evolution history of the regional geology during the period from 25 to 1 Ma, the ages of quartz can exclude the possibility that the origin of quartz has nothing to do with primary clastic minerals in parent rocks, authigenesis during diagenesis and hydrothermal precipitation or replacement by volcanic activities. It is deduced that the well-crystallized quartz was precipitated from Si-rich weathering fluids during the weathering process of carbonate rocks. The recorded ages of quartz from the four profiles are consistent with the episodes of the planation surfaces on the Qinghai-Tibet Plateau, the forming stages of red soil in the tropics of South China, the tectonically stable periods in Guizhou, and the ages of weathering in other parts of the world during the Cenozoic era. That is to say, the ages of authigenic quartz dated by the fission track method are well feasible and credible. | LIUXiuming WANGShijie ZHANGFeng | 2004 | Acta Geologica Sinica(English Edition)2004，78，5： | 11 |
| 3 | The investigation of coherent structures in the wall region of a supersonic turbulent boundary layer based on DNS database显示文摘Through temporal mode direct numerical simulation, flow field database of a fully developed turbulent boundary layer on a flat plate with Mach number 4.5 and Reynolds number Reθ =1094 has been obtained. Commonly used detection meth- ods in experiments are applied to detecting coherent structures in the flow field, and it is found that coherent structures do exist in the wall region of a supersonic turbulent boundary layer. The detected results show that a low-speed streak is de- tected by using the Mu-level method, the rising parts of this streak are detected by using the second quadrant method, and the crossing regions from a low-speed streak to the high-speed one are detected by using the VITA method respectively. Notwithstanding that different regions are detected by different methods, they are all accompanied by quasi-stream-wise vortex structures. | HUANG ZhangFeng ZHOU Heng LUO JiSheng | 2007 | Science China(Physics,Mechanics & Astronomy)2007，50，3： | 8 |
| 4 | SPATIAL AND TEMPORAL DYNAMICS OF SOIL ORGANIC CARBON IN RESERVED DESERTIFICATION AREA——A Case Study in Yulin City, Shaanxi Province, China显示文摘Soil organic carbon (SOC) was considered to be a key index in evaluation of soil degradation and soil C sequestration. To discuss the spatial-temporal dynamics of SOC in arable layer in reversed desertification area, a case study was conducted in Yulin City, Shaanxi Province, China. Data of SOC were based on general soil survey in 1982 and repeated soil sampling in 2003. Soil organic carbon content (SOCC) was determined by K2Cr3O7-FeSO4 titration method, and soil organic carbon density (SOCD) was calculated by arithmetic average and area weighted average method, respectively. On average, SOCC and SOCD of the arable layer in the study area from 1982 to 2003 had increased 0.51g/kg and 0.16kg/m2, respectively. Considering main soil types, the widest distributed Arid-Sandic Entisols had lowest values and increments of SOCC and SOCD during the study period; while the second widest Los-Orthic Entisols had higher values and increments of SOCC and SOCD, compared to the mean values of the whole region. The results indicated that reversed desertification process was due to the modification of land use and management practices, such as natural vegetation recovery, planting grass, turning arable land to grassland, and soil and water conservation etc., which can improve SOCC and SOCD and thus enhance soil C sequestration. | CHENGShu-lan NIUHai-shan WANGLin ZHANGFeng GAOJun-qin TIANYu-qiang | 2004 | Chinese Geographical Science2004，14，3： | 7 |
| 5 | Integration of SAR Polarimetric Features and Multi-spectral Data for Object-Based Land Cover Classification显示文摘An object-based approach is proposed for land cover classification using optimal polarimetric parameters.The ability to identify targets is effectively enhanced by the integration of SAR and optical images.The innovation of the presented method can be summarized in the following two main points:①estimating polarimetric parameters(H-A-Alpha decomposition)through the optical image as a driver;②a multi-resolution segmentation based on the optical image only is deployed to refine classification results.The proposed method is verified by using Sentinel-1/2 datasets over the Bakersfield area,California.The results are compared against those from pixel-based SVM classification using the ground truth from the National Land Cover Database(NLCD).A detailed accuracy assessment complied with seven classes shows that the proposed method outperforms the conventional approach by around 10%,with an overall accuracy of 92.6%over regions with rich texture. | Yi ZHAO Mi JIANG Zhangfeng MA | 2019 | Journal of Geodesy and Geoinformation Science2019，2，4： | 7 |
| 6 | Complete three-dimensional coseismic displacements due to the 2021 Maduo earthquake in Qinghai Province,China from Sentinel-1 and ALOS-2 SAR images显示文摘On 22 nd May 2021(local time),an earthquake of M_(s)7.4 struck Maduo county in Qinghai Province,China.This was the largest earthquake in China since the 2008 Wenchuan earthquake.In this study,ascending/descending Sentinel-1 and advanced land observation satellite-2(ALOS-2)synthetic aperture radar(SAR)images were used to derive the three-dimensional(3-D)coseismic displacements of this earthquake.We used the differential interferometric SAR(In SAR,DIn SAR),pixel offset-tracking(POT),multiple aperture In SAR(MAI),and burst overlap interferometry(BOI)methods to derive the displacement observations along the line-of-sight(LOS)and azimuth directions.To accurately mitigate the effect of ionospheric delay on the ALOS-2 DIn SAR observations,a polynomial fitting method was proposed to optimize range-spectrum-split-derived ionospheric phases.In addition,the 3-D displacement field was obtained by a strain model and variance component estimation(SM-VCE)method based on the high-quality SAR displacement observations.Results indicated that a left-lateral fault slip with the largest horizontal displacement of up to 2.4 m dominated this earthquake,and the small-magnitude vertical displacement with an alternating uplift/subsidence pattern along the fault trace was more concentrated in the near-fault regions.Comparison with the global navigation satellite system data indicated that the SM-VCE method can significantly improve the accuracy of the displacements compared to the classical weighted least squares method,and the incorporation of the BOI displacements can substantially benefit the accuracy of north-south displacement.In addition to the displacements,three coseismic strain invariants calculated based on the strain model parameters were also investigated.It was found that the eastern and western parts of the faults suffered more significant strains compared with the epicenter region. | Jihong LIU Jun HU Zhiwei LI Zhangfeng MA Lixin WU Weiping JIANG Guangcai FENG Jianjun ZHU | 2022 | Science China Earth Sciences2022，65，4： | 6 |
| 7 | New Catalysts for Coal to Ethylene Glycol显示文摘 | Zhiqiao Wang Zhongning Xu Siyan Peng Zhangfeng Zhou Pengbin Pan Lin Lin Yeyan Qin Guocong Guo Yuangen Yao | 2017 | Chinese Journal of Chemistry2017，35，6： | 6 |
| 8 | Theoretical and Experimental Study on Reaction Coupling: Dehydrogenation of Ethylbenzene in the Presence of Carbon Dioxide显示文摘到苯乙烯(圣) 的乙苯(EB ) 的除氢作用面对 CO2,在 EB,除氢作用被结合反向的水气体移动(RWGS ) ,通过理论分析和试验性的描述广泛地被调查。联合的反应证明了比在几个方面的单个除氢作用优异。热力学的分析建议 EB 的那平衡变换能被由于从除氢作用生产的氢的同时的消除联合的反应极大地改进。催化测试证明了与某些倡导者一起在活性炭或 Al2O3 上支持的那个熨斗和钒是为这个联合过程的潜在的催化剂。铁和钒的催化剂在反应机理是不同的,尽管圣产量总是在各种各样的催化剂上与 CO2 变换被联系。当一步舞小径在 V/Al2O3 上统治反应时,二拍子的圆舞小径在 Fe/Al2O3 上在联合过程起一个重要作用。科克免职和活跃部件的深减小是催化剂释放的主要原因。CO2 能通过在联合过程在高原子价保存活跃种类有效地减轻催化剂释放,尽管它不能压制焦炭免职。给词调音:联合的反应;乙苯除氢作用;苯乙烯;二氧化碳;水气体移动;反应机理; | Shuwei Chen Zhangfeng Qin Ailing Sun Jianguo Wang | 2006 | Journal of Natural Gas Chemistry2006，15，1： | 5 |
| 9 | Inflow conditions for spatial direct numerical simulation of turbulent boundary layers显示文摘The inflow conditions for spatial direct numerical simulation(SDNS) of turbulent boundary layers should reflect the characteristics of upstream turbulence,which is a puzzle. In this paper a new method is suggested,in which the flow field obtained by using temporal direct numerical simulation(TDNS) for fully developed turbulent flow(only flow field for a single moment is sufficient) can be used as the inflow of SDNS with a proper transformation. The calculation results confirm that this method is feasible and effective. It is also found that,under a proper time-space transformation,all statistics of the fully developed turbulence obtained by both temporal mode and spatial mode DNS are in excellent agreement with each other,not only qualitatively,but also quantitatively. The normal-wise distributions of mean flow profile,turbulent Mach number and the root mean square(RMS) of the fluctuations of various variables,as well as the Reynolds stresses of the fully developed turbulence obtained by using SDNS,bear similarity in nature. | HUANG ZhangFeng & ZHOU Heng Department of Mechanics,Tianjin University,Tianjin 300072,China Liu-Hui Center of Applied Mathematics,Nankai University and Tianjin University,Tianjin 300072,China | 2008 | Science China(Physics,Mechanics & Astronomy)2008，51，8： | 5 |
| 10 | Instability analysis and drag coefficient prediction on a swept RAE2822 wing with constant lift coefficient显示文摘Swept wing is widely used in civil aircraft,whose airfoil is chosen,designed and optimized to increase the cruise speed and decrease the drag coefficient.The parameters of swept wing,such as sweep angle and angle of attack,are determined according to the cruise lift coefficient requirement,and the drag coefficient is expected to be predicted accurately,which involves the instability characteristics and transition position of the flow.The pressure coefficient of the RAE2822 wing with given constant lift coefficient is obtained by solving the three-dimensional Navier-Stokes equation numerically,and then the mean flow is calculated by solving the boundary layer(BL) equation with spectral method.The cross-flow instability characteristic of boundary layer of swept wing in the windward and leeward is analyzed by linear stability theory(LST),and the transition position is predicted by eNmethod.The drag coefficient is numerically predicted by introducing a laminar/turbulent indicator.A simple approach to calculate the lift coefficient of swept wing is proposed.It is found that there is a quantitative relationship between the angle of attack and sweep angle when the lift coefficient keeps constant;when the angle of attack is small,the flow on the leeward of the wing is stable.when the angle of attack is larger than 3°,the flow becomes unstable quickly;with the increase of sweep angle or angle of attack the disturbance on the windward becomes more unstable,leading to the moving forward of the transition position to the leading edge of the wing;the drag coefficient has two significant jumping growth due to the successive occurrence of transition in the windward and the leeward;the optimal range of sweep angle for civil aircraft is suggested. | Zhenrong JING Zhangfeng HUANG | 2017 | Chinese Journal of Aeronautics2017，30，3： | 4 |
| 11 | Effect of Microinfusion of Angiotensin Ⅱ into the RVLM in Rats on the Baroreceptor Reflex Sensitivity显示文摘The present study was designed to investigate the effect of microinfusion anglotensin Ⅱ (Ang Ⅱ ),Ang Ⅱ type l(AT1)receptor antagonist lesartan into the rostral ventrolateral medulla(RVLM)on the baroreceptor reflex sensitivity(BRS)in urethane-anesthetized rats. Methods: Reflex changes in heart rate(HR)were elicited by bolus intravenous injection of phenylephrine before and during RVLM microinfusion of saline(0.5μl/h), Ang Ⅱ(1.Snmol/h), losartan (250 nmol/h), and Ang Ⅱ (1.5 nmol/h) pretreated with microinjection of losartan (50 nmol/0.51 μl)into the RVLM. The average ratio between changes in HR in beats per minute(beats, min^-1 )and changes in mean arteriaI pressutre [ MAP,mmHg(1 mmHg = 0.133 kPa) ] was used as an index of BRS. Results : Ang Ⅱ resulted in a significant decrease in the BRS for reflex bradycardia compared with control( - 2.1 ~ 0.1 vs - 3.9 + 0.4 beats.min^-1·mmHg^-1 ).Microinfusion of losartan had no significant effect on BRS for reflex bradycardia.The effect of Ang ][ was almost completely abolished by pretreatment with microinjection of losartan. Conc/us/on: These results showed that the exogenous Ang II in the RVLM produces inhibitory modulation of BRS, which is mediated by AT2 receptor.However,AT1 receptor in the RVLM is not involved in the tonic control of BRS. | ZHANGFeng GAOXing-ya ZHUGuo-qing ZHONGWan-hua | 2004 | Journal of Nanjing Medical University2004，18，3： | 4 |
| 12 | Convex quadratic programming relaxations for parallel machine scheduling with controllable processing times subject to release times显示文摘Scheduling unrelated parallel machines with controllable processing times subject to release times is investigated. Based on the convex quadratic programming relaxation and the randomized rounding strategy, a 2 approximation algorithm is obtained for a special case with the all or none property and then a 3 approximation algorithm is presented for general problem. | ZHANGFeng CHENFeng TANGGuochun | 2004 | Progress in Natural Science:Materials International2004，14，9： | 3 |
| 13 | Conservation relation of generalized growth rate in boundary layers显示文摘The elementary task is to calculate the growth rates of disturbances when the e^N method in transition prediction is performed. However, there is no unified knowledge to determine the growth rates of disturbances in three-dimensional(3 D) flows. In this paper, we study the relation among the wave parameters of the disturbance in boundary layers in which the imaginary parts of wave parameters are far smaller than the real parts.The generalized growth rate(GGR) in the direction of group velocity is introduced, and the conservation relation of GGR is strictly deduced in theory. This conservation relation manifests that the GGR only depends on the real parts of wave parameters instead of the imaginary parts. Numerical validations for GGR conservation are also provided in the cases of first/second modes and crossflow modes. The application of GGR to the eN method in 3 D flows is discussed, and the puzzle of determining growth rates in 3 D flows is clarified. A convenient method is also proposed to calculate growth rates of disturbances in 3 D flows. Good agreement between this convenient method and existing methods is found except the condition that the angle between the group velocity direction and the x-direction is close to 90?which can be easily avoided in practical application. | Runjie SONG Lei ZHAO Zhangfeng HUANG | 2018 | Applied Mathematics and Mechanics(English Edition)2018，39，12： | 3 |
| 14 | Metal-organic-framework-derived formation of Co–N-doped carbon materials for efficient oxygen reduction reaction显示文摘Non-precious metal nitrogen-doped carbonaceous materials have attracted tremendous attention in the field of electrochemical energy storage and conversion.Herein,we report the designed synthesis of a novel series of Co-N-C nanocomposites and their evaluation of electrochemical properties.Novel yolkshell structured Co nanoparticles@polymer materials are fabricated from the facile coating polymer strategy on the surface of ZIF-67.After calcination in nitrogen atmosphere,the Co–N–C nanocomposites in which cobalt metal nanoparticles are embedded in the highly porous and graphitic carbon matrix are successfully achieved.The cobalt nanoparticles containing cobalt metal crystallites with an oxidized shell and/or smaller(or amorphous)cobalt-oxide deposits appear on the surface of graphitic carbons.The prepared Co–N–C nanoparticles showed favorable electrocatalytic activity for oxygen reduction reactions,which is attributed to its high graphitic degree,large surface area and the large amount existence of Co–N active sites. | Hao Tian Chi Zhang Panpan Su Zhangfeng Shen Hao Liu Guoxiu Wang Shaomin Liu Jian Liu | 2020 | Journal of Energy Chemistry2020，29，1： | 2 |
| 15 | Multi-Scenario Millimeter Wave Wireless Channel Measurements and Sparsity Analysis显示文摘Wireless channel characteristics have significant impacts on channel modeling,estimation,and communication performance.While the channel sparsity is an important characteristic of wireless channels.Utilizing the sparse nature of wireless channels can reduce the complexity of channel modeling and estimation,and improve system design and performance analysis.Compared with the traditional sub6 GHz channel,millimeter wave(mmWave)channel has been considered to be more sparse in existing researches.However,most research only assume that the mmWave channel is sparse,without providing quantitative analysis and evaluation.Therefore,this paper evaluates the sparsity of mmWave channels based on mmWave channel measurements.A vector network analyzer(VNA)-based mmWave channel sounder is developed to measure the channel at 28 GHz,and multi-scenario channel measurements are conducted.The Gini index,Rician��factor and rootmean-square(RMS)delay spread are used to measure channel sparsity.Then,the key factors affecting mmWave channel sparsity are explored.It is found that antenna steering direction and scattering environment will affect the sparsity of mmWave channel.In addition,the impact of channel sparsity on channel eigenvalue and capacity is evaluated and analyzed. | Hang Mi Bo Ai Ruisi He Xin Zhou Zhangfeng Ma Mi Yang Zhangdui Zhong Ning Wang | 2022 | China Communications2022，19，11： | 2 |
| 16 | Pd/CeO 2 –TiO 2 catalyst for CO oxidation at low temperature: a TPR study with H 2 and CO as reducing agents显示文摘 | Huaqing Zhu Zhangfeng Qin Wenjuan Shan Wenjie Shen Jianguo Wang | 2004 | Journal of Catalysis2004，，2： | 2 |
| 17 | Electrochemical detection of methyl-paraoxon based on bifunctional cerium oxide nanozyme with catalytic activity and signal amplification effect显示文摘A new electrochemical sensor for organophosphate pesticide(methyl-paraoxon)detection based on bifunctional cerium oxide(CeO_(2))nanozyme is here reported for the first time.Methyl-paraoxon was degraded into p-nitrophenol by using CeO_(2) with phosphatase mimicking activity.The CeO_(2) nanozymemodified electrode was then synthesized to detect p-nitrophenol.Cyclic voltammetry was applied to investigate the electrochemical behavior of the modified electrode,which indicates that the signal enhancement effect may attribute to the coating of CeO_(2) nanozyme.The current research also studied and discussed the main parameters affecting the analytical signal,including accumulation potential,accumulation time,and pH.Under the optimum conditions,the present method provided a wider linear range from 0.1 to 100 mmol/L for methyl-paraoxon with a detection limit of 0.06 mmol/L.To validate the proof of concept,the electrochemical sensor was then successfully applied for the determination of methyl-paraoxon in three herb samples,i.e.,Coix lacryma-jobi,Adenophora stricta and Semen nelumbinis.Our findings may provide new insights into the application of bifunctional nanozyme in electrochemical detection of organophosphorus pesticide. | Yuzhou Sun Jinchao Wei Jian Zou Zehua Cheng Zhongming Huang Liqiang Gu Zhangfeng Zhong Shengliang Li Yitao Wang Peng Li | 2021 | Journal of Pharmaceutical Analysis2021，11，5： | 1 |
| 18 | Germacrone inhibits the proliferation of breast cancer cell lines by inducing cell cycle arrest and promoting apoptosis 显示文摘 | Zhong Zhangfeng Chen Xiuping Tan Wen | 2011 | Eur J Pharmacol2011，667，13： | 1 |
| 19 | Ethylbenzene dehydrogenation in the presence of carbon dioxide over alumina supported catalysis显示文摘 | SUN AILING QIN ZHANGFENG CHEN SHUWEi | 2004 | Catalysis Today2004，9395，： | 1 |
| 20 | Enhancement of Pd-Pt/A1203 Catalyst Performance in Naphthalene Hydroge- nation by Mixing Different Molecular Sieves in the Support 显示文摘 | Du Mingxian Qin Zhangfeng Ge Hui | 2010 | FuelProcess Technol2010，91，11： | 1 |
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