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Numerical investigation of the wind environment around tall buildings in a central business district

Frontiers of Earth Science 2019年第4期13卷 848-858页

作者： Pingzhi FANG Deqian ZHENG Ming GU haifeng cheng Bihong ZHU Shanghai Typhoon Institute of China Meteorological Administration Shanghai 200030China School of Civil Engineering and Architecture Henan University of TechnologyZhengzhou 450001China State Key Laboratory for Disaster Reduction in Civil Engineering Tongji UniversityShanghai 200092China Shanghai Investigation Design&Research Institute Co.Ltd.Shanghai 200335China

The wind environment around tall buildings in a central business district(CBD)was numerically *** district covers an area of-^4.0 km2 and features a high density of tall *** this study,only buildings taller than 20 m were considered,resulting in 173 tall buildings in the *** numerical investigation was realized using the commercial computational fluid dynamics code FLUENT with the realizable A-6:turbulence *** efforts were made to maintain inflow boundary conditions throughout the computational *** reliability of the numerical method was validated using results from an experimental investigation conducted in the core area of the CBD(〜1.5 km2).Experimental and numerical investigations of wind speed ratios at the center of the three tallest buildings in the CBD agree within an uncertainty factor of *** the experimental and numerical results show that wind speed ratios in the wind field with exposure category D are higher than those from the wind field with exposure category *** on the above validation work,the wind environment around tall buildings in the whole CBD was then investigated by numerical *** flow phenomena and patterns,such as stagnation points,shielding effects,separation flow,and channeling flow,were identified around the tall *** pedestrianlevel wind environment around tall buildings in the CBD was further evaluated using nearby meteorological wind *** evaluation results show that some pedestrian activities,such as sitting at the center of the three tallest buildings,are unadvisable when the wind blows from the south-east.

关键词： wind environment pedestrian-level wind computational fluid dynamics wind speed ratio central business district

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Oxidation Behavior of C/C-SiC Gradient Matrix Composites

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Journal of Materials Science & Technology 2001年第5期17卷 543-546页

作者： Jingyi DENG, Wenchuan LIU, haifeng DU, Huiming cheng and Yiyi LI Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China Chinese Acad Sci Inst Met Res Shenyang 110016 Peoples R China

Oxidation behavior of C/C-SiC gradient matrix composites and C/C composites were compared in stationary air. The results show that oxidation threshold of C-SiC materials increases with the amount of SiC particles in the codeposition matrix. Oxidation rate of C/C-SiC gradient matrix composites is significantly lower than that of C/C material. The micro-oxidation process was observed by SEM.

关键词： Oxidation Behavior of C/C-SiC Gradient Matrix Composites SiC SIC

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Mg AmorphousZr_(0.9)Ti_(0.1)(Ni_(0.57)Mn_(0.28)V_(0.1)Co_(0.05))_(2.1)Composite for Hydrogen Storage

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Journal of Materials Science & Technology 2003年第2期19卷 141-144页

作者： Haiyan LENG, Demin CHEN, Manqi LU, haifeng ZHANG, Huiming cheng and Ke YANGInstitute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China Inst. of Metal Res. Chinese Acad. of Sci. Shenyang 110016 China

The reactive mechanical alloying (RMA) method was used to produce Mg-40 wt pet amorphous Zr0.9Ti0.1(Nio.57-Mn0.28\/***.o5)2.i composite in this study, and the absorption/desorption property of the composite was improved remarkably. The composite possessed excellent kinetic properties even at moderate temperature (393 K) without activation. Owing to the formation of the embrittle MgH2, the reactive mechanical milling process reduced the particle size of Mg and made the composite phase being highly efficiently distributed, which determined the excellent hydriding properties of the composite.

关键词： Mg Hydrogen storage material RMA Amorphous

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Effect of Yajieshaba,a preparation of Dai indigenous medicine,on enhanced liver detoxification

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Journal of Traditional Chinese Medicine 2015年第2期35卷 197-205页

作者： Duan Xiaohua Zheng Jin Wang Hui cheng haifeng Zhang Chao Yu Zepu the Key Modern Research Laboratory for Ethno-pharmacognosy of Yunnan Higher School Yunnan University of Traditional Chinese Medicine

OBJECTIVE:To explore the mechanistic effects of Yajieshaba(YJSB) on enhanced liver ***:The effects of YJSB on alanine aminotransferase(ALT) and aspartate aminotransferase(AST) were assayed in five acute chemical liver injury models[carbon tetrachloride(CCU),D-galactosamine(D-Glan),4-acetamidophenol(AAP),thioacetamide(TAA) and 1-naphthyl isothiocyanate(ANIT)].Sleep latency and sleep time of pentobarbital sodium were tested in control mice and CCL model miceafter oral YJSB *** effects of YJSB on drug metabolism enzymes of liver microsomes were tested in control rats and CCI_4model *** levels of cytochrome P450(CYP450) and Cyt b5 in liver microsomes were assayed using the method by Omura and Sato,and activities of erythromycin N-demethylase(ERD)and aminopyrine N-demethyl(ADM) were evaluated by Nash *** substrate-based high performance liquid chromatography(HPLC)methods were established for CYP3A4 and ***:The level of serum ALT was reduced by YJSB at 3.51 g/kg in the five models as follows:CCl_4 > D-Glan,AAP,ANIT > *** treatment did not reduce the level of serum *** at 3.51 g/kg prolonged the sleep latency in control mice and shortened the sleep time of control mice and CCl_4 model *** control rats,YJSB at 2.43 g/kg increased the levels of CYP450 and Cyt b5 and induced the activities of ERD and ADM;for liver injuries induced by CCI_4 in rats,YJSB at 2.43 g/kg increasedthe levels of CYP450 and Cyt *** results suggest that YJSB at 2.43 g/kg induces CYP3A4 and ***:These results suggest that YJSB enhanced liver detoxification and the mechanisms may be partially related to CYP3A4 and CYP1A2 induction.

关键词： Cytochrome P-450 enzyme system Chromatography high pressure liquid Liver detoxification Yajieshaba

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Metamaterial-inspired infrared electrochromic devices with wideband microwave absorption for multispectral camouflage

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Photonics Research 2024年第11期12卷 2435-2446页

作者： ZHEN MENG DONGQING LIU JIAFU WANG YONGQIANG PANG TIANWEN LIU YAN JIA BOHENG GUI haifeng cheng Science and Technology on Advanced Ceramic Fibers and Composites Laboratory College of Aerospace Science and EngineeringNational University of Defense Technology Shaanxi Key Laboratory of Artificially-Structured Functional Materials and Devices Air Force Engineering University Electronic Materials Research Laboratory Key Laboratory of the Ministry of EducationXi'an Jiaotong University

Infrared (IR) electrochromic devices,capable of dynamically controlling thermal radiation,hold promising applications in adaptive ***,the strong microwave reflective properties inherent in the device’s electrodes present a significant challenge,rendering them susceptible to radar detection and weakening their camouflage *** by the remarkable electromagnetic control capabilities of metamaterials,the integration of frequency selective surfaces into IR electrochromic devices is proposed to address this multispectral compatibility *** designed integrated metadevices simultaneously exhibit large and reversible IR emissivity tunability (Δε≥0.55 at 3–5μm,Δε≥0.5 at 7.5–13μm) and wideband microwave absorption (reflection loss≤-10 dB at 8.5–18 GHz).Furthermore,the monolithic integrated design of the shared barium fluoride substrate offers a simple device architecture,while careful design considerations mitigate coupling between IR electrochromism and microwave wideband *** work introduces opportunities for the development of multispectral adaptive camouflage systems,offering potential advancements in concealment technology.?2024 Chinese Laser Press

关键词： Fluoride Localized surface plasmon resonance Optical constants Polymers Scanning electron microscopy Thin films

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Effect of Surface Modification on Microwave Absorbing Properties of Magnetic Metal Fibers

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Journal of Wuhan University of Technology(Materials Science) 2007年第2期22卷 218-220页

作者：谢炜 Key Lab of Novel Ceramic Fibers & Composites National University of Defense Technology

In order to avoid forming an electrical conductive network due to surface connections, the magnetic metal fibers were coated with SiO2, for surface modification by the sol-gel process. The microstructure, composition and electromagnetic characteristics of SiO2-coated and uncoated metal fibers were studied using SEM, EDAX, and a voter network analyzer. The reflectivity was simulated using the RAMCAD software. The electromagnetic parameters and absorption properties of SiO2-coated metal fibers were improved greatly due to optimal impendence matching and the electric conductivity decreased, compared to those of uncoated materials.

关键词： magnetic metal fiber SiO: film electromagnetic parameters microwave absorption surface modification

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Effect of Grinding Techniques on Absorbing Characteristics of Short Iron Fibers

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Journal of Wuhan University of Technology(Materials Science) 2007年第3期22卷 400-403页

作者：程海峰 Key Lab of Advancd Ceramic Fibers & Composites National University of Defense Technology

Microwave-absorbing properties of iron fibers can be adjusted by their aspect ratio. This paper presents several modification techniques for grinding long iron fibers to a suitable aspect ratio. The grinding instruments include pulsator, jet mill and muller. The aspect ratio distribution, microstructure, electromagnetic parameter and reflectivity of the samples were analyzed and discussed in detail. The results show that the fractions of 5〈aspect ratio〈40 for the three methods are 69.03%, 81.11% and 80.2% , respectively, that is, suitable short iron fibers can be obtained by the jet mill and muller. Furthermore, the short iron fibers milled by jet mill and muller have better absorbing propterties than those obtained by the pulsator under the same condition. Therefore, their microwave absorption properties can be improved by regulating the electromagnetic parameters with grinding.

关键词： short iron fiber electromagnetic parameter microwave-absorbing property

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溅射工作气压对Fe/Si_3N_4多层膜微波磁性的影响

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真空科学与技术学报 2010年第1期30卷 22-27页

作者：杨长胜程海峰海军装备研究院航空装备论证研究所上海200436 国防科技大学新型陶瓷纤维及复合材料国防科技重点实验室长沙410073

在不同的溅射气压下,采用连续磁控溅射制备了Fe/Si3N4多层膜,探讨了溅射气压对多层膜微波磁性的影响。研究发现,溅射气压影响着多层膜的沉积速率和微结构,在溅射铁子层时,Ar气流量控制在300sccm^400sccm下,在溅射氮化硅子层时,氩气与氮... 详细信息

在不同的溅射气压下,采用连续磁控溅射制备了Fe/Si3N4多层膜,探讨了溅射气压对多层膜微波磁性的影响。研究发现,溅射气压影响着多层膜的沉积速率和微结构,在溅射铁子层时,Ar气流量控制在300sccm^400sccm下,在溅射氮化硅子层时,氩气与氮气的流量控制在2∶1,总流量控制在320sccm时制备得到的多层膜具有最好的磁性能。

关键词：溅射气压多层膜磁控溅射磁导率

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Dielectric-ion-conductive ZnNb2O6 layer enabling rapid desolvation and diffusion for dendrite-free Zn metal batteries

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Journal of Energy Chemistry 2025年第1期100卷 693-701页

作者： haifeng Yang Jian Wang Panpan Zhang Xiaomin cheng Qinghua Guan Jing Dong Bixian Chen Lujie Jia Jing Zhang Yongzheng Zhang Yunjian Liu Hongzhen Lin School of Materials Science and Engineering Jiangsu University i-Lab & CAS Key Laboratory of Nanophotonic Materials and Devices Suzhou Institute of Nano-Tech and Nano-Bionics Chinese Academy of Sciences Helmholtz Institute Ulm (HIU) Karlsruhe Institute of Technology (KIT) School of Materials Science and Engineering Xi'an University of Technology State Key Laboratory of Chemical Engineering East China University of Science and Technology

Rechargeable aqueous zinc-metal batteries （AZMBs） are promising candidates for large-scale energy storage systems due to their low cost and high ***,their performance and sustainability are significantly hindered by the sluggish desolvation kinetics at the electrode/electrolyte interface and the corresponding hydrogen evolution reaction where active water molecules tightly participate in the Zn（H2O）62+solvation ***,learnt from self-generated solid electrolyte interphase （SEI） in anodes,the dielectric but ion-conductive zinc niobate nanoparticles artificial layer is constructed on metallic Zn surface （ZNB@Zn）,acting as a rapid desolvation *** zincophilic and dielectric-conductive properties of ZNB layer accelerate interfacial desolvation/diffusion and suppress surface corrosion or dendrite formation,achieving uniform Zn plating/stripping behavior,as confirmed by electronic/optical microscopies and interface spectroscopical measurements together with theoretical ***,the as-prepared ZNB@Zn electrode exhibits excellent cycling stability of over 2000 h and robust reversibility （99.54%） even under high current density and depth of discharge ***,the assembled ZNB@Zn-based full cell displays high capacity-retention rate of 80.21%after 3000 cycles at 5 A g-1and outstanding rate performance up to 10 A *** large-areal pouch cell is stabilized for hundreds of cycles,highlighting the bright prospects of the dielectric but ion-conductive layer in further application of AZMBs.

关键词： Zn metal battery Dielectric artificial layer Rapid ion diffusion Zincophilic diffusion Active water inhibition

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基于SMP准则的破裂岩统计损伤软化模型及其应用研究

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岩石力学与工程学报 2013年第S2期32卷 3160-3168页

作者：朱建明程海峰姚仰平北方工业大学建筑工程学院北京100144 北京航空航天大学交通科学与工程学院北京100191

岩石材料是一种非均质材料,而破裂岩是指岩体内部含有大量的裂隙、空洞、界面等缺陷,在荷载作用下其微元体破坏更具有随机性。在损伤理论的基础上,从微元体的强度随机分布的角度出发,在微元体强度度量方法上考虑损伤阈值的影响,假设破... 详细信息

岩石材料是一种非均质材料,而破裂岩是指岩体内部含有大量的裂隙、空洞、界面等缺陷,在荷载作用下其微元体破坏更具有随机性。在损伤理论的基础上,从微元体的强度随机分布的角度出发,在微元体强度度量方法上考虑损伤阈值的影响,假设破裂岩的微元体强度服从Weibull分布,结合考虑中主应力的SMP准则,建立破裂岩统计损伤软化本构模型,运用多种计算方法对模型参数m和F0进行确定。通过对小官庄铁矿2种破裂岩闪长玢岩以及矽卡岩的验证表明:在不同围压下,全应力–应变试验曲线与预测曲线吻合良好,能够反映损伤阈值的影响,且在较低围压下更为理想。同时,此模型能够反映随着围压的增加岩石的峰值强度增加而延性增大的性质,进一步验证模型的适用性及较强的应用价值。

关键词：岩石力学 SMP准则岩石损伤损伤阈值统计损伤本构模型围压

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