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Enhancing aerodynamic performances of a high-turning compressor cascade via boundary layer suction

Science china(Technological sciences) 2010年第10期53卷 2748-2755页

作者： GUO Shuang1, CHEN ShaoWen1, LU HuaWei2. SONG YanPing1 & CHEN Fu1 1 school of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001,{2. 2.marine Engineering College, Dalian Maritime university, Dalian 11602.,{2. 1. school of Energy Science and Engineering Harbin Institute of Technology Harbin 150001 China2. Marine Engineering College Dalian Maritime University Dalian 116026 China

Experimental investigation was carried out to study the effect of suction positions and suction flow rates on the aerodynamic performance of a compressor cascade with a large camber angle. The ink-trace flow visualization was conducted and the flow fields of the cascade were also measured. Three types of boundary layer suction configurations are compared,i.e. the suction surface suction,the endwall suction and the compound suction. Experimental results show that the large amount of suction flow rate gains more losses reduction than the small amount for a certain proper suction configuration,but the speed of loss decline slows down as the suction flow rate goes on increasing. Boundary layer suction on the suction surface obviously enhances the ability of the boundary layer around the midspan to withstand the negative pressure gradient of the flow passage. The range of the suction surface corner is also decreased. If the suction slot locates in the corner separation region where severe separation has happened,the flow separation will be terminated at the slot and redevelop downstream. And boundary layer suction on the endwall mainly influences the endwall corner region in remarkably delaying,lessening and reorganizing the corner separation. While the whole flow field is remarkably improved at both midspan and the corner region in the compound suction schemes. At higher suction flow rates,the aerodynamic performance of the compressor cascade is better than that with boundary layer suction simply on the suction surface or on the endwall. When the suction flow rate is 1.5% of the inlet mass flow,the compound suction scheme achieves a maximum loss reduction of 17% compared with the cascade without boundary layer suction.

关键词： boundary layer suction high-turning diffusion cascade suction flow rate suction position experimental investigation

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Research on Trace Elements Geochemistry of Ordovician Carbonates in Tazhong area,Tarim Basin

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地学前缘 2009年第S1期16卷 145-146页

作者： Huajun wang,Wenhui Huang,Kuangming Zhang,Min Yang school of Energy Resources,{2. university of geosciences(beijing) Key Laboratory of marine Reservoir Evolution and Hydrocarbon Accumulation Mechanism,Ministry of Education,beijing 100083,{2..

The research on the trace elements of Ordovician carbonates plays an important role in the whole research work on reservoir in Tazhong *** work applies ICP-MS,which is a new trace elements analysis technology to measure contents of different elements,systematically in the studies of the characteristics and sedimentary settings of Ordovician dolomites in Tazhong area,Tarim Basin,and argues for their enrichment mechanisms and different elements existing *** results show that there is a close relationship between geochemistry charac-

关键词： dolomite sedimentary settings geochemistry trace elements

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Audit-firm serving experience heterogeneity and audit knowledge integration:Evidence from the disclosure of key audit matters

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china Journal of Accounting Research 2024年第2期17卷 74-96页

作者： Lin wang Yuyan Jia Tusheng Xiao yingmin Yu school of Accountancy Central University of Finance and EconomicsBeijingChina china’s Management Accounting Research and Development Center Central University of Finance and EconomicsBeijingChina

Audit practice is a team effort led by signing *** examine the impact of the heterogeneity of signing auditors’audit-firm serving experiences on the disclosure of key audit matters(KAMs).Auditors with more heterogeneous serving experiences demonstrate more adequate KAM disclosure,as evidenced by more KAMs,longer texts and clearer attributions in their *** effect is influenced by the quality of audit knowledge that auditors accumulate from different serving experiences and the team-and audit-firm-level knowledge integration ***,signing auditors with more diverse service experience tend to improve audit quality,reduce the incidence of restatement or misconduct and enhance the informativeness of financial *** findings enrich the KAM disclosure research and provide insights into audit firms’human resource allocation and internal management.

关键词： Audit team Key audit matters Knowledge integration Audit serving experience

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Robust L2.L∞ control for uncertain singular systems with time-varying delay

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Progress in Natural Science:Materials International 2008年第8期18卷 1015-1021页

作者： Lin Lia,*, yingmin Jiaa, Junping Dub, Shiying Yuan c a The Seventh Research Division, beijing {2., beijing 100083, china b beijing Key Laboratory of Intelligent Telecommunications Software and Multimedia, beijing {2. of Posts and Telecommunications, beijing 100876, china c school of Electrical Engineering and Automation, Henan Polytechnic {2., Jiaozuo 454000, china The Seventh Research Division Beijing University Beijing 100083 China beijing Key Laboratory of Intelligent Telecommunications Software and Multimedia Beijing University of Posts and Telecommunications Beijing 100876 China school of Electrical Engineering and Automation Henan Polytechnic University Jiaozuo 454000 China

We study the problem of L2.L1 control for a class of uncertain singular systems with time-delay and norm-bounded parameter uncertainties in this paper. A new delay-dependent robust stability criterion is obtained in terms of linear matrix inequalities (LMIs). Based on this criterion, a state feedback controller is designed to guarantee that the closed-loop system is regular, impulse free and stable with a prescribed L2.L1 performance satisfied for all admissible parameter uncertainties. A simulation example is included to illustrate the effectiveness of the proposed method.

关键词： L2.L1 control Singular systems Delay-dependent condition LMIs

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Spatial distribution of 10m firn temperature in the Antarctic Ice Sheet

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Science china Earth sciences 2011年第5期54卷 655-666页

作者： wang YeTang1,3 & HOU ShuGui2.3 1 Shandong marine Fisheries Research Institute,Yantai 2.4006,{2. 2.MOE,Key Laboratory for Coast and Island Development,school of Geographic and Oceanographic sciences,Nanjing university,Nanjing 2.0093,{2. 3State Key Laboratory of Cryospheric Science,Cold and Arid Regions Environmental and Engineering Research Institute,Chinese Academy of sciences,Lanzhou 730000,{2. 1. Shandong marine Fisheries Research Institute Yantai 264006 China3. State Key Laboratory of Cryospheric Science Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China2. MOE Key Laboratory for Coast and Island Development School of Geographic and Oceanographic Sciences Nanjing University Nanjing 210093 China

A database of Antarctic 10 m firn temperature was constructed using available borehole temperature measurements with data quality control to extend knowledge of Antarctic climate. Slopes from a high-resolution digital elevation model and the main ice divide were used to delineate main drainage sectors across Antarctica. In each drainage sector, a quantitative relationship between temperature and latitude, longitude and altitude was established using available tim temperature data. Quantitative relationships incorporating other factors affecting Antarctic air temperature such as atmospheric circulation and small-scale to- pography were used to derive a 10-km resolution grid map of surface temperature. The resulting temperature patterns presented a reasonable depiction of both large and small-scale variations in Antarctic 10 m firn temperature. This map is useful for many spatial variation studies, Antarctic ice sheet models, and comparison with satellite-derived temperature data and outputs of atmospheric general circulation models.

关键词： Antarctica 10 m firn temperature spatial distribution

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The characteristics of sea fog with different airflow over the Huanghai Sea in boreal spring

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Acta Oceanologica Sinica 2010年第4期29卷 3-12页

作者： HUANG Jian wang Xin ZHOU Wen HUANG Huijun wang Dongxiao ZHOU Faxiu Institute of Tropical and marine Meteorology China Meteorological Administration Guangzhou 510080 China Guy Carpenter Asia-Pacific Climate Impact Centre School of Energy and Environment City University of Hong Kong Hong Kong China CAS key laboratory of tropical marine environmental dynamics South China Sea Institute of Oceanology Chinese Academy of Sciences Guangzhou 510301 China Department of meteorology Ocean University of China Qingdao 262003 China

Using the observations from ICOADS datasets and contemporaneous NCEP/NCAR reanalysis datasets during 1960-2.02.the study classifies the airflows in favor of sea fog over the Huanghai （Yellow） Sea in boreal spring （April-May） with the method of trajectory analysis,and analyzes the changes of proportions of warm and cold sea fogs along different paths of *** to the heat balance equation,we investigate the relationships between the marine meteorological conditions and the proportion of warm and cold sea fog along different airflow *** major results are summarized as follows.（1） Sea fogs over the Huanghai Sea in spring are not only warm fog but also cold *** proportion of warm fog only accounts for 44% in April,while increases as high as 57% in May.（2. Four primary airflow paths leading to spring sea fog are *** are originated from the northwest,east,southeast and southwest of the Huanghai Sea,*** occurrence ratios of the warm sea fog along the east and southeast airflow paths are high of 55% and 70%,while these along the southwest and northwest airflow paths are merely 17.9% and 50%.（3） The key physical processes governing the warm/cold sea fog are heat advection transport,longwave radiation cooling at fog top,solar shortwave warming and latent heat flux between airsea interfaces.（4） The characteristics of sea fog along the four airflow paths relate closely to the conditions of water vapor advection,and the vertical distribution of relative humidity.

关键词： spring sea fog over the Huanghai Sea airflow paths water vapor flux heat advection vertical distribution of water vapor

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Ni-based Ni-Fe-B-Si-Ta bulk metallic glasses

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Science china(Physics,Mechanics & Astronomy) 2010年第3期53卷 440-444页

作者： ZHU ChunLei1, wang Qing1, Zhao YaJun1, wang yingmin1, QIANG JianBing1 & DONG Chuang1,2. Key Lab of Materials Modification (Ministry of Education), school of Materials Science and Engineering, Dalian university of Technology, Dalian 11602., china 2.International Center for Materials Physics, Chinese Academy of sciences, Shenyang 110016, china 1. Key Lab of Materials Modification (Ministry of Education) School of Materials Science and Engineering Dalian University of Technology Dalian 116024 China2. International Center for Materials Physics Chinese Academy of Sciences Shenyang 110016 China

The glass-forming ability and properties of Ni-based Ni-Fe-B-Si-Ta bulk metallic glasses are explored in this work. The alloy compositions are determined by using a combination of the cluster line approach, the multi-alloying strategy and the substitutions of similar elements. Bulk metallic glasses with diameters of 3 mm take shape at compositions formulated under the clus- ter-plus-glue-atom model [M9B]B~[(Ni1-xFex)7.71(Si0.66Ta0.34)1.2.B]B0.94=(Ni1-xFex)70.5B17.7Si7.8Ta4, x=0.35–0.45, where the bracketed part is the cluster and the unbracketed part is the glue atoms. These alloys exhibit good magnetic properties. The maximum Is is found in the (Ni0.55Fe0.45)70.5B17.7Si7.8Ta4 alloy which reaches 0.51 T, with its Hc as low as 8.5 A/m. Interestingly, these alloys display dual glass transitions at (Ni0.65Fe0.35)70.5B17.7Si7.8Ta4, (Ni0.60Fe0.4)70.5B17.7Si7.8Ta4 and (Ni0.55Fe0.45)70.5B17.7- Si7.8Ta4 as unveiled by Temperature-Modulated Differential Scanning Calorimetry.

关键词： bulk metallic glasses cluster Ni-Fe-based alloys Modulated Differential Scanning Calorimetry

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Cell cycle and cell signal transduction in marine phytoplankton

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Progress in Natural Science:Materials International 2006年第7期16卷 671-678页

作者： liu Jingwen, JIAO Nianzhi and CAI Huinong ( Bioengineering school of Jimei {2., Xiamen 36102., china State Key Laboratory of marine Environmental sciences of Xiamen {2., Xiamen 361005, china) [a]Bioengineering school of Jimei university Xiamen China [b]State Key Laboratory of marine Environmental Science of Xiamen university Xiamen China

As unicellular phytoplankton, the growth of a marine phytoplankton population results directly from the completion of a cell cycle, therefore, cell-environment communication is an important way which involves signal transduction pathways to regulate cell cycle progression and contribute to growth, metabolism and primary production and respond to their surrounding environment in marine phytoplankton. Cyclin-CDK and CaM/Ca2. are essentially key regulators in control of cell cycle and signal transduction pathway, which has important values on both basic research and applied biotechnology. This paper reviews progress made in this research field, which involves the identification and characterization of cyclins and cell signal transduction system, cell cycle-control mechanisms in marine phytoplankton cells, cell cycle proteins as a marker of a terminal event to estimate the growth rate of phytoplankton at the species level, cell cycle-dependent toxin production of toxic algae and cell cycle progression regulated by environmental factors.

关键词： marine phytoplankton cell cycle cell signal transduction.

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Delay-dependent H2.control for discrete time-delay systems with D-stability constraints

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Progress in Natural Science:Materials International 2008年第3期18卷 297-302页

作者： Man Sun a, yingmin Jia a, Junping Du b, Shiying Yuan c a The Seventh Research Division, Beihang university, {2. 100083, china b {2. Key Laboratory of Intelligent Telecommunications Software and Multimedia, {2. university of Posts and Telecommunications, {2. 100876, china c school of Electrical Engineering and Automation, Henan Polytechnic university, Jiaozuo 454000, china The Seventh Research Division Beihang University Beijing 100083 China beijing Key Laboratory of Intelligent Telecommunications Software and Multimedia Beijing University of Posts and Telecommunications Beijing 100876 China school of Electrical Engineering and Automation Henan Polytechnic University Jiaozuo 454000 China

This paper studies the problem of H2.control for a class of discrete time-delay systems with D-stability constraints. The corresponding suffcient conditions are given in terms of linear matrix inequalities. In particular, the conditions are delay-dependent, and so they are less conservative. The obtained controller can provide an upper bound for the H2.cost function. A numerical example is given to illustrate the proposed method.

关键词： Discrete systems Time-delay Linear matrix inequality D-stability H2.control

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A Novel Location Method for Interline Power Flow Controllers Based on Entropy Theory

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Protection and Control of Modern Power Systems 2024年第3期9卷 70-81页

作者： Qiuyu Li Baohong Li Qin Jiang Tianqi liu Yin Yue yingmin Zhang Sichuan university the school of Electrical Engineering Sichuan UniversityChengdu 610065China the College of Electrical Engineering and Information Technology Sichuan University

As one of the new generation flexible AC transmission systems(FACTS)devices,the interline power flow controller(IPFC)has the significant advantage of simultaneously regulating the power flow of multiple ***,how to choose the appropriate location for the IPFC converters has not been discussed *** solve this problem,this paper proposes a novel location method for IPFC using entropy *** clarify IPFC’s impact on system power flow,its operation mechanism and control strategies of different types of serial converters are ***,to clarify the system power flow characteristic suitable for device location analysis,the entropy concept is *** this process,the power flow distribution entropy index is used as an optimization *** this index as a foundation,the power flow transfer entropy index is also generated and proposed for the IPFC location determination ***,electromechanical electromagnetic hybrid simulations based on ADPSS are implemented for *** are tested in a practical power grid with over 800 nodes.A modular multilevel converter(MMC)-based IPFC electromagnetic model is also established for precise *** results show that the proposed method can quickly and efficiently complete optimized IPFC location and support IPFC to determine an optimal adjustment in the N-1 fault cases.

关键词： Flexible alternative current transmission systems interline power flow controller modular multi-level converter optimized location method power flow transfer entropy

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