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Controlling secondary flow in high-lift low-pressure turbine using boundary-layer slot suction

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Chinese Journal of Aeronautics 2024年第3期37卷 21-33页

作者： xiao qu Liunan LI Yingjie ZHANG Xingen LU Junqiang ZHU Yanfeng ZHANG School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China Key Laboratory of Light-Duty Gas-Turbine Institute of Engineering ThermophysicsChinese Academy of SciencesBeijing 100190China School of Aeronautics and Astronautics University of Chinese Academy of SciencesBeijing 100190China

The design of high-lift Low-Pressure Turbines(LPTs)causes the separation of the boundary layer on the suction side of the blade and leads to a strong secondary *** present study aims to minimize secondary losses through endwall slot suction and incoming wakes in a front-loaded high-lift LPT cascade with Zweifel of 1.58 under low Reynolds number of *** slotted schemes for the boundary layer of the endwall were designed(Plan A and Plan B),and the effects of suction mass flow on secondary flow were *** underlying physics of the endwall boundary layer of the suction and secondary flow under unsteady wakes was *** results show that slot suction at the endwall boundary layer can significantly suppress the secondary flow by removing low-momentum *** A and B significantly reduced the secondary kinetic energy by 44.2%and 36.9%,respectively,compared with the baseline cascade at the suction mass flow ratios of 1%.With an increase in the mass flow ratio of suction,the secondary flow was gradually reduced in both Plans A and *** is more beneficial to control the secondary flow to destroy the intersection of the pressure side and suction side of the horseshoe vortex before it develops into a passage *** unsteady wakes,the combined effects of incoming wakes and endwall boundary layer suction can further suppress the secondary flow at the suction mass flow ratios of 2%for Plan A,because the positive and negative vorticity inside upstream wakes accelerated the mixing of the main flow and secondary flow and thus increased the energy of secondary vortices.

关键词： Low-pressure turbine Secondary flow Flow control boundary-layer suction Incoming wake

中国农村地区间居民收入差距及构成变化:1995—2008年——基于基尼系数的分解

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经济理论与经济管理 2010年第7期30卷 74-80页

作者：屈小博都阳中国社会科学院人口与劳动经济研究所北京100732

本文采用分省的面板数据对农村地区间基尼系数分解结果表明,1995—2008年,中国农村地区间收入差距总体上仍然呈现上升趋势,基尼系数上升了0.0639,但增幅出现明显减弱趋势。基尼系数变化及农村居民工资性收入对基尼系数的贡献变化显示出... 详细信息

本文采用分省的面板数据对农村地区间基尼系数分解结果表明,1995—2008年,中国农村地区间收入差距总体上仍然呈现上升趋势,基尼系数上升了0.0639,但增幅出现明显减弱趋势。基尼系数变化及农村居民工资性收入对基尼系数的贡献变化显示出与经济发展阶段变化一致的含义;结构性效应已不再是农村地区间收入差异的唯一构成来源,收入集中效应对基尼系数起了明显的增加作用,工资性收入的集中效应超过了其他收入来源。这些构成来源的变化蕴含着中国面临调节地区间农村收入差距的政策机遇。

关键词：农村收入差距地区间基尼系数分解

PEGylated bacteria restore intestinal mucosal barrier

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Acta Pharmaceutica Sinica B 2024年第9期14卷 4186-4188页

作者： Menghang Zu Xue Xia bo xiao State Key Laboratory of Resource Insects College of SericultureTextileand Biomass SciencesSouthwest UniversityChongqing 400715China Department of Pharmacy Personalized Drug Therapy Key Laboratory of Sichuan ProvinceSichuan Provincial People’s HospitalSchool of MedicineUniversity of Electronic Science and Technology of ChinaChengdu 610054China

The mucosal barrier of the gastrointestinal tract(GIT)is crucial for the overall health of the *** disruption permits the infiltration of intestinal microorganisms into the underlying mucosa,resulting in infections and inflammatory conditions,such as inflammatory bowel disease(IBD),metabolic disorders,and autoimmune diseases1,***,strategies to protect the mucosal barrier from exogenous stimuli or to facilitate its recovery have become increasingly ***,immunomodulators,corticosteroids,and biological agents have been widely employed to treat IBD by alleviating inflammation and enhancing mucosal ***,they can also produce serious systemic toxicity3,4;therefore,there is an urgent need for exploiting innovative strategies to fortify the intestinal mucosal barrier against the invasion of exogenous damaging factors.

关键词： PEGylation Probiotic Mucus penetration Colonic mucosal barrier Colitis Diabetes

An adaptive finite-difference method for seismic traveltime modeling based on 3D eikonal equation

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Petroleum Science 2024年第1期21卷 195-205页

作者： Bao-Ping Qiao Qing-Qing Li Wei-Guang He Dan Zhao qu-bo Wu CNNC Beijing Research Institute of Uranium Geology Beijing 100029China National Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)Qingdao 266580ShangdongChina SINOPEC Geophysical Research Institute Nanjing211103JiangsuChina

3D eikonal equation is a partial differential equation for the calculation of first-arrival traveltimes and has been widely applied in many scopes such as ray tracing,source localization,reflection migration,seismic monitoring and tomographic *** recent years,many advanced methods have been developed to solve the 3D eikonal equation in heterogeneous ***,there are still challenges for the stable and accurate calculation of first-arrival traveltimes in 3D strongly inhomogeneous *** this paper,we propose an adaptive finite-difference(AFD)method to numerically solve the 3D eikonal *** novel method makes full use of the advantages of different local operators characterizing different seismic wave types to calculate factors and traveltimes,and then the most accurate factor and traveltime are adaptively selected for the convergent updating based on the Fermat *** with global fast sweeping describing seismic waves propagating along eight directions in 3D media,our novel method can achieve the robust calculation of first-arrival traveltimes with high precision at grid points either near source point or far away from source point even in a velocity model with large and sharp *** numerical examples show the good performance of the AFD method,which will be beneficial to many scientific applications.

关键词： 3D eikonal equation Accurate traveltimes Global fast sweeping 3D inhomogeneous media Adaptive finite-difference method

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我国农产品出口结构与竞争力的实证分析

国际贸易问题 2007年第3期291卷 9-15页

作者：屈小博霍学喜西北农林科技大学经济管理学院

我国农产品出口已经进入新的快速增长阶段。本文系统分析了农产品出口的商品结构、地区结构、市场结构以及出口经营主体结构的特征与变化,并用显示比较优势指数(RCA)、贸易竞争力指数(TC)以及国际市场份额等评价了我国农产品出口的国际... 详细信息

我国农产品出口已经进入新的快速增长阶段。本文系统分析了农产品出口的商品结构、地区结构、市场结构以及出口经营主体结构的特征与变化,并用显示比较优势指数(RCA)、贸易竞争力指数(TC)以及国际市场份额等评价了我国农产品出口的国际竞争力,实证分析显示农产品出口贸易结构总体反映了我国农业资源的禀赋和比较优势特征,主要集中在具有竞争优势的劳动密集型农产品,但与农产品出口大国相比,整体竞争力弱,处于低竞争劣势,部分劳动密集型农产品具有国际竞争力。

关键词：农产品出口商品结构地区结构市场结构竞争力指数

工业机器人发展与制造业转型升级——基于中国工业机器人使用的调查

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改革 2021年第8期 25-37页

作者：邓仲良屈小博中国社会科学院人口与劳动经济研究所中国社会科学院大学中国社会科学院研究生院

实现制造强国目标必须加快推进制造业智能转型。利用IFR国别数据总结了全球工业机器人应用的如下“卡尔多事实”:多数经济发达国家的人口结构变动导致了“机器换人”;工业机器人应用加快了资本深化过程;主要国家推进工业机器人应用均基... 详细信息

实现制造强国目标必须加快推进制造业智能转型。利用IFR国别数据总结了全球工业机器人应用的如下“卡尔多事实”:多数经济发达国家的人口结构变动导致了“机器换人”;工业机器人应用加快了资本深化过程;主要国家推进工业机器人应用均基于本国的产业比较优势,并将其主要应用于高技术制造业;重大技术突破主要依赖于行业内头部企业的长期技术积累。对中国代表性工业机器人及智能制造企业的调查研究表明,工业机器人头部企业的初始发展路径都具有相似产业背景;当前中国工业机器人在一般制造业应用中存在过度推广问题,在附加值较高的零部件制造业中应用程度相对不高。理论和调查研究都表明,推进工业机器人应用可通过提高生产效率和优化要素配置结构来促进制造业转型升级,但其也会对资本、劳动力等要素市场产生交互影响。因此,相关产业政策制定应遵循全球工业机器人应用的典型化特征规律,因地制宜、分门别类地引导推进工业机器人更多地应用于高技术制造业,避免盲目实施“机器换人”。

关键词：工业机器人制造业发展数字经济

Pressure-induced emission(PIE)in halide perovskites toward promising applications in scintillators and solid-state lighting

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Aggregate 2024年第1期5卷 9-15页

作者： Wenya Zhao Guanjun xiao bo Zou State Key Laboratory of Superhard Materials College of PhysicsJilin UniversityChangchunChina

High-pressure chemistry has provided a huge boost to the development of scientific ***-induced emission(PIE)in halide perovskites is gradually showing its unique charm in both pressure sensing and optoelectronic device ***,the PIE retention of halide perovskites under ambient conditions is of great commercial ***,we mainly focus on the potential applications of PIE and PIE retention in metal halide perovskites for scintillators and solid-state *** on the performance requirements of scintillator and single-component white light-emitting diodes(WLEDs),the significance of PIE and PIE retention is critically clarified,aiming to design and synthesize materials used for high-performance optoelectronic *** perspective not only demonstrates promising applications of PIE in the fields of scintillators and WLEDs,but also provides potential applications in display imaging and anti-counterfeiting of PIE ***,solving the scientific disputes that exist under ambient conditions is also simply discussed as an outlook by introducing high-pressure dimension to produce PIE.

关键词： halide perovskites high pressure light-emitting diode pressure-induced emission scintillators solidstate lighting

Cyclic Pulsating Pressure Enhanced Segregating Structuration of Ultra-High Molecular Weight Polyethylene/Graphene Composites as High-performance Light-Weight EMI Shields

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Chinese Journal of Polymer Science 2024年第7期42卷 958-967,I0008页

作者： Yun-Zhi Huang xiao-xiao Liu Lan-Wei Li Guang-Ming Huang Zhao-Xia Huang Jin-Ping qu National Engineering Research Center of Novel Equipment for Polymer Processing Key Laboratory of Polymer Processing EngineeringMinistry of EducationGuangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced ManufacturingSchool of Mechanical and Automotive EngineeringSouth China University of TechnologyGuangzhou 510641China School of Advanced Manufacturing Technology Guangdong Mechanical&Electrical PolytechnicGuangzhou 510550China

Currently,the enhancement in electromagnetic interference(EMI)performance of polymeric composite generally relies on either improving electrical conductivity(σ)for stronger electromagnetic(EM)reflections or tailoring structure for higher EM ***,we proposed a novel technique called cyclic pulsating pressure enhanced segregating structuration(CPP-SS),which can reinforce these two factors *** structural information was supplied by optical microscopy(OM)and scanning electron microscopy(SEM),both of which confirmed the formation and evolution of segregate structured ultra-high molecular weight polyethylene(UHMWPE)/graphene ***,the result showed that CPP-SS can significantly improve theσof ***,advanced specific EMI shielding efficiency of 31.1 d B/mm was achieved for UHMWPE/graphene composite at 1-mm thickness and a low graphene loading of 5 wt%.Meanwhile,it also confirmed that the intrinsic disadvantage of poor mechanical properties of conventional segregated structure composites can be *** work is believed to provide a fundamental understanding of the structural and performance evolutions of segregated structured composites prepared under CPPSS,and to bring us a simple and efficient approach for fabricating high-performance,strong and light-weight polymeric EMI shields.

关键词： Cyclic pulsating pressure Segregated structure Ultra-high molecular weight polyethylene Graphene Electromagnetic interface

Thiazoloisoindigo-based Polymer Semiconductors: Synthesis,Structure-Property Relationship, Charge Carrier Polarity, and Field-Effect Transistor Performance

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Chinese Journal of Polymer Science 2024年第1期42卷 24-31,I0006页

作者： bo-Wen Li Miao Xiong Mei-Hua Liu Zhi-Gao Li Long Sang Zi-Han Xiong Biao xiao Jian Pei xiao-bo Wan Key Laboratory of Optoelectronic Chemical Materials and Devices Ministry of EducationSchoolofOptoelectronic Materials&TechnologyJianghan UniversityWuhan430056China Bejing National Laboratoryfor Molecular Sciences the Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of EducationCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

Developing new polymeric semiconductors with excellent device performance is essential for organic electronics. Herein, we synthesized two new thiazoloisoindigo(Tz II)-based polymers, namely, P(Tz II-d Th-d Th) and P(Tz II-d Th-d Tz), by copolymerizing thiophene-flanked Tz II with bithiophene and bithiazole, respectively. Owing to the more electron-deficient nature of bithiazole than bithiophene, P(Tz II-d Th-d Tz)possesses deeper LUMO/HOMO levels of-3.45/-5.47 e V than P(Tz II-d Th-d Th)(-3.34/-5.32 e V). The organic field-effect transistor(OFET) devices based on P(Tz II-d Th-d Th) exhibited p-type behaviors with an average hole mobility value as high as 1.43 cm^(2)·V^(-1)·s^(-1), while P(Tz II-d Th-d Tz)showed typical ambipolar characteristics with average hole and electron mobilities of 0.38 and 0.56 cm^(2)·V^(-1)·s^(-1). In addition, we compared the performances of both polymers with other Tz II-based polymers reported in our previous work, and showed that the charge carrier polarity can be manipulated by adjusting the number of the thiophene units between the acceptor unit. As the increase of the number of thiophene rings,charge carrier polarity shifts from electron-dominated ambipolar transport to hole-dominated ambipolar transport and then to unipolar hole transport in OFETs, which provides an effective molecular design strategy for further optimization of polymer OFET performance.

关键词： Field-effect transistor Charge carrier polarity Thiazoloisoindigo