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Vortex dynamics and entropy generation in separated transitional flow over a compressor blade at various incidence angles

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Chinese Journal of Aeronautics 2022年第3期35卷 42-52页

作者： Mingyang WANG Ziliang LI Ge HAN Chengwu YANG Shengfeng ZHAO yanfeng zhang Xin’gen LU Key Laboratory of Light-Duty Gas-Turbine Institute of Engineering ThermophysicsChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

The transition process within a Laminar Separation Bubble(LSB)that formed on a compressor blade surface was investigated using Large Eddy Simulations(LESs)at a Reynolds number of 1.5×10;and incidence angles of 0°,+3°,and+5°.The vortex dynamics in the separated shear layers were compared at various incidence angles and its effects on the loss generation were clarified through entropy *** showed that transition onset,which was accurately identified by the Linear Stability Theory(LST),was significantly promoted at the increased incidence *** such,the development of LSB was suppressed and the relative role of viscous instability played in the transition process was *** the incidence angle of 0°,two-dimensional spanwise vortices detached from the blade surface and roiled up periodically,which were further stretched and eventually evolved into large-scale hairpin *** time passed,the fully developed hairpin vortices broke down into small-scale ***,the flow near the wall reversely ejected into the outer separated shear layers and a sweeping process happened subsequently,forcing the separated shear layers to reattach and accelerating the generation of turbulent *** comparison,the strength of vortex rolling-up was weakened at higher incidence angles,and the vortex pairing and breakdown of large-scale vortices were less ***,the level of turbulent fluctuations that generated in the separated shear layers was *** entropy analysis showed that the turbulent dissipation effect related to the Reynolds shear stresses determined the largest amount of positive entropy generation,which declined to a lower level as the incidence angle increased from 0°to+5°.Correspondingly,the profile loss was reduced by 50.4%.

关键词： Aerodynamic performance Compressor airfoil Entropy Incidence angle Separation bubble Vortex dynamics

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永州市蔬菜产业发展现状、问题及对策建议

长江蔬菜 2024年第3期 1-4页

作者：张艳峰胡秀良阳海军荣答永州市农业综合服务中心湖南永州425000 永州市农业农村局永州市农业综合执法支队

通过对永州蔬菜产业发展现状进行调研分析,发现永州蔬菜产业存在基地建设标准不高、产销结构不优、专业技术人员占比低等问题。为此,提出了建优蔬菜基地,提高蔬菜生产现代化水平;健全质量监测体系,保证蔬菜绝对安全;加强品牌塑造,提升... 详细信息

通过对永州蔬菜产业发展现状进行调研分析,发现永州蔬菜产业存在基地建设标准不高、产销结构不优、专业技术人员占比低等问题。为此,提出了建优蔬菜基地,提高蔬菜生产现代化水平;健全质量监测体系,保证蔬菜绝对安全;加强品牌塑造,提升永州蔬菜价值;培育市场主体,提高蔬菜产业化程度;争取政策支持,加大蔬菜产业扶持力度等切实可行的、能推进永州蔬菜产业健康发展的对策建议。

关键词：蔬菜产业发展现状存在问题对策建议永州

Robust hydrogel adhesives for emergency rescue and gastric perforation repair

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Bioactive Materials 2023年第1期19卷 703-716页

作者： Jing Yu Yanyang Qin Yuxuan Yang Xiaodan Zhao Zixi zhang Qiang zhang Yaqiong Su yanfeng zhang Yilong Cheng School of Chemistry Xi’an Jiaotong UniversityXi’an710049China Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research College of StomatologyXi’an Jiaotong UniversityXi’an710049China Department of Dermatology The First Affiliated Hospital of Xi’an Jiaotong UniversityXi’an Jiaotong UniversityXi’an710061China

Development of biocompatible hydrogel adhesives with robust tissue adhesion to realize instant hemorrhage control and injury sealing,especially for emergency rescue and tissue repair,is still ***,we report a potent hydrogel adhesive by free radical polymerization of N-acryloyl aspartic acid(AASP)in a facile and straightforward *** delicate adjustment of steric hindrance,the synergistic effect between interface interactions and cohesion energy can be achieved in PAASP hydrogel verified by X-ray photoelectron spectroscopy(XPS)analysis and simulation calculation compared to poly(N-acryloyl glutamic acid)(PAGLU)and poly(N-acryloyl amidomalonic acid)(PAAMI)*** adhesion strength of the PAASP hydrogel could reach 120 kPa to firmly seal the broken organs to withstand the external force with persistent stability under physiological conditions,and rapid hemostasis in different hemorrhage models on mice is achieved using PAASP hydrogel as physical ***,the paper-based Fe^(3+)transfer printing method is applied to construct PAASP-based Janus hydrogel patch with both adhesive and non-adhesive surfaces,by which simultaneous wound healing and postoperative anti-adhesion can be realized in gastric perforation model on *** advanced hydrogel may show vast potential as bio-adhesives for emergency rescue and tissue/organ repair.

关键词： Adhesive hydrogel Hydrogen bond Amino acid Emergency rescue Gastric perforation repair

Varieties of Involution J-Trivial Monoids with Continuum Many Subvarieties

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Algebra Colloquium 2024年第3期31卷 467-480页

作者： Meng Gao Wenting zhang yanfeng Luo School of Mathematics and Statistics Lanzhou UniversityLanzhou 730000China

In this paper,we give a suficient condition under which an involution monoid generates a variety with continuum many *** to this result,several involution J-trivial monoids are shown to generate varieties with continuum many *** examples include Rees quotients of free involution monoids,Lee monoids with involution,and Straubing monoids with involution.

关键词： monoid involution monoid variety subvariety lattice of varieties

面向幂律图的动态图存储结构Power-PCSR

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计算机科学 2024年第8期51卷 56-62页

作者：毛志雄刘志楠高叙宁王蒙湘巩树凤张岩峰东北大学计算机科学与工程学院沈阳110167 东北大学医学与生物信息工程学院沈阳110167 中国标准化研究院北京100088

图数据在现实生活中广泛存在,且不断发生变化。传统高效的静态图存储方式——压缩行/列(Compressed Sparse Row/Column,CSR/CSR)存储方式在更新图数据时需要大量的数据迁移,不适用于动态图数据。而能够高效更新图数据的邻接表(Adjacency... 详细信息

图数据在现实生活中广泛存在,且不断发生变化。传统高效的静态图存储方式——压缩行/列(Compressed Sparse Row/Column,CSR/CSR)存储方式在更新图数据时需要大量的数据迁移,不适用于动态图数据。而能够高效更新图数据的邻接表(Adjacency List,AL)存储方式往往带有大量的指针,导致其图数据读取和分析效率低。Packed Compressed Sparse Row(PCSR)是一种基于CSR的动态图存储结构。该结构在存储边数据时并不是采用连续无空隙数组,而是采用留有空槽的压缩存储阵列(Packed Memory Arrays,PMA)结构,便于边数据的插入。因此,PCSR支持高效图更新和图分析。但是,PCSR在存储幂律图时,其性能容易受大度数顶点的影响。为此,基于PCSR提出一种支持可高效更新和分析动态幂律图的图存储结构Power-PCSR。该结构将幂律图中度数较大的顶点单独存储在一个独立的PMA中,其他所有小度数顶点与PCSR一样存储在原PMA中。小度顶点变化导致的数据迁移不会触及大度数顶点,从而大大减少了数据迁移数量;同样,大度数顶点更新导致的数据迁移只限制在每个大度数顶点的PMA内部,不会涉及小度数顶点和其他大度数顶点的数据迁移。实验显示,Power-PCSR在分析图数据时与PCSR具有相似的性能,而在更新图数据时比PCSR快2倍。

关键词：动态图存储动态图更新数据迁移 Power-PCSR 幂律图

双流体型光伏光热屋顶组件的热、电性能实验研究

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东北电力大学学报 2024年第1期44卷 94-100页

作者：张雁峰端木琳周创李祥立大连理工大学建筑工程学部辽宁大连116024

文中提出一种无盖板的双流体型光伏光热屋顶组件,通过将管板式水冷流道与折流板式空冷流道组合,降低组件水容量、提升空气出口温度,实现组件热水、热空气两种热能形式的供应。通过搭建具有稳定测试环境的性能测试试验台,研究组件工质进... 详细信息

文中提出一种无盖板的双流体型光伏光热屋顶组件,通过将管板式水冷流道与折流板式空冷流道组合,降低组件水容量、提升空气出口温度,实现组件热水、热空气两种热能形式的供应。通过搭建具有稳定测试环境的性能测试试验台,研究组件工质进出口温差、光伏电池温度等随太阳辐照度、工质流量的变化情况,对组件全天热、电性能进行分析。结果表明,该组件光伏电池冷却效果明显,水冷、空冷模式下电效率最高可达16.8%、17.6%,拥有较高的全天综合性能,全天综合利用率最高为74%。

关键词：太阳能光伏光热一体化光热性能光电性能

Effects of C impurities on the elastic properties of NiAl intermetallics

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Progress in Natural Science:Materials International 2014年第1期24卷 637-641页

作者： Xuelan Hu Ji Ma Hongwei Dou Yifan Niu yanfeng zhang Qinggong Song Sino-European Institute of Aviation Engineering Civil Aviation University of China College of Science Civil Aviation University of China

The atomic configuration and ductility of Ni Al intermetallics affected by C impurity have been studied with a first-principles pseudo-potential method. The calculation results indicate that for the substitutional cases, C prefers to replace Ni other than Al in most of the cases except for the Ni-rich case. As compared with the interstitial cases, the C atom can be more easily occupy the Ni-rich octahedron position in both of the Ni-rich and Al-rich cases. The brittleness will be decreased and the ductility will be increased after the Ni Al intermetallics doped with the impurity C atom.

关键词： Ni Al intermetallics C impurity Elastic properties First-principles

C-doped BiOCl/Bi_(2)S_(3) heterojunction for highly efficient photoelectrochemical detection and photocatalytic reduction of Cr(VI)

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Journal of Materials Science & Technology 2023年第33期164卷 188-197页

作者： Chunli Wang Nazhen Liu Xia Zhao Yong Tian Xuwei Chen yanfeng zhang Liang Fan Baorong Hou Research Center for Analytical Sciences Department of ChemistryCollege of SciencesNortheastern UniversityShenyang 110819China Key Laboratory of Marine Environmental Corrosion and Bio-fouling Institute of OceanologyChinese Academy of SciencesQingdao 266071China School of Environmental & Municipal Engineering Qingdao University of TechnologyQingdao 266033China Intelligent Policing Key Laboratory of Sichuan Province Sichuan Police CollegeLuzhou 646000China

Novel C-BiOCl/Bi_(2)S_(3) composites are prepared by hydrothermal C doping in BiOCl and in-situ growth of Bi_(2)S_(3) on *** with BiOCl,C-BiOCl has a larger exposed surface area and can effectively absorb visible *** construction of a heterojunction in C-BiOCl/Bi_(2)S_(3) further promotes the separation and transfer of photogenerated *** improved photoelectric properties,the optimized 5C-BiOCl/5Bi_(2)S_(3) is applied as a dual-functional composite for photoelectrochemical(PEC)detection and photocatalytic(PC)reduction of Cr(VI).The 5C-BiOCl/5Bi_(2)S_(3) shows a linear range of 0.02-80μM for PEC cathodic detection of Cr(VI)with a detection limit of 0.01628μ***,99.5%of Cr(VI)can be removed via absorption and PC reduction by 5C-BiOCl/5Bi_(2)S_(3),with the reduction rate constant(k)336 times higher than that of BiOCl.

关键词： C-BiOCl/Bi_(2)S_(3) Dual-functional Photoelectrochemical detection Photocatalytic reduction Cr(VI)

Transformation of monolayer MoS2 into multiphasic MoTe2： Chalcogen atom-exchange synthesis route

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Nano Research 2017年第8期10卷 2761-2771页

作者： Qiyi Fang Zhepeng zhang Qingqing Ji Siya Zhu Yue Gong Yu zhang Jianping Shi Xiebo Zhou Lin Gu Qian Wang yanfeng zhang Department of Materials Science and Engineering College of Engineering Peking University Beijing 100871 China Center for Nanochemistry (CNC) Beijing National Laboratory for Molecular Sciences College of Chemistry and Molecular Engineering Academy for Advanced lnterdisciplinary Studies Peking University Beijing 100871 China Center for Applied Physics and Technology Peking University Beijing 100871 China Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China Collaborative Innovation Center of Quantum Matter Beijing 100190 China School of Physical Sciences University of Chinese Academy of Sciences Beijing 100190 China

Molybdenum ditelluride （MoTe2）, which is an important transition-metal dichalcogenide, has attracted considerable interest owing to its unique properties, such as its small bandgap and large Seebeck coefficient. However, the batch production of monolayer MoTe2 has been rarely reported. In this study, we demonstrate the synthesis of large-domain （edge length exceeding 30 μm）, monolayer MoTe2 from chemical vapor deposition-grown monolayer MoS2 using a chalcogen atom-exchange synthesis route. An in-depth investigation of the tellurization process reveals that the substitution of S atoms by Te is prevalently initiated at the edges and grain boundaries of the monolayer MoS2, which differs from the homogeneous selenization of MoS2 flakes with the formation of alloyed Mo-S-Se hybrids. Moreover, we detect a large compressive strain （approximately -10%） in the transformed MoTe2 lattice, which possibly drives the phase transition from 2H to 1T＇ at the reaction temperature of 500 ℃. This phase change is substantiated by experimental facts and first-principles calculations. This work introduces a novel route for the templated synthesis of two-dimensional layered materials through atom substitutional chemistry and provides a new pathway for engineering the strain and thus the intriguing physics and chemistry.

关键词： transition-metal dichacogenide MoTe2 atom exchange multiphase phase transformation