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半导体中相干亚毫米波的产生和传播

光学学报 1996年第4期16卷 403-407页

作者：李明孙凤国 x.c.zhang 国家自然科学基金委员会信息科学部国防科学技术大学应用物理系 RensselaerPolytechnicInstitute TroyNY12180U.S.A.

研究了超短光脉冲在GaAs表面激发相干亚毫米波振幅随入射角变化的规律，前后向辐射比值随入射角度变化的规律，实验测量了在GaAs表面镀上极薄金属薄膜后所产生的相干亚毫米波振幅对薄膜厚度的依赖关系；利用光生载流子偶极辐射的理论模... 详细信息

研究了超短光脉冲在GaAs表面激发相干亚毫米波振幅随入射角变化的规律，前后向辐射比值随入射角度变化的规律，实验测量了在GaAs表面镀上极薄金属薄膜后所产生的相干亚毫米波振幅对薄膜厚度的依赖关系；利用光生载流子偶极辐射的理论模型成功地解释了实验得到的角度依赖关系和相干亚毫米波的偏振特性。

关键词：相干亚毫米波偶极辐射半导体产生传播

Long-term observation of particle matter concentration by cAWNET in china

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Long-term observation of particle matter concentration by CA...

2019新型冠状病毒肺炎(cOVID-19)中的影像学作用

创新驱动发展提高气象灾害防御能力——第30届中国气象学会年会

作者： Y.Q.Wang x.Y.zhang J.Y.Sun x.c.zhang H.Z.che Y.Li Laboratory of Atmospheric chemistry Chinese Academy of Meteorological Sciences

The mass concentrations of PM10, PM2.5 and PM1 were investigated simultaneously in 24 stations of cAWNET (china Atmosphere Watch Network) from 2006 to 2012 using GRIMM 180 instruments. The highest PM mass were observed at the stations of Zhengzhou, xiAn and Gucheng in Hua Bei Plain (HBP) of N. china, which is the most serious hazy area of china. For example, the averaged PM10, PM2.5 and PM1 concentrations at Zhengzhou are 149.9, 94.6 and 77.7 μg m 3 , respectively. The second high PM region is in E. china, and then in S. china, with the Yangtze River Delta and the Pearl River Delta areas as their major body, respectively. According to the newest air quality standard of china with annual averaged PM10 and PM2.5 mass concentrations of 70 and 35 μg m 3 , 15 stations can meet the PM10 standard and only 7 stations (most are rural and remote stations) have concentration lower than the PM2.5 standard. Due to the large contribution of coarse mineral aerosol in N. china and more secondary aerosol formation in relative warm and humid areas of S. china, the ratios of PM2.5 to PM10 exhibit obviously increasing trend from north to south, with the highest value of 80 - 90% in the Yangtze River Delta area. In the stations near the Asian dust source, the ratios are normally less then 50%. The PM1 mass contributed most of PM2.5, accounting over 80% at the most stations. Seasonally, PM concentrations are normally highest in winter and lowest in summer at most stations, with obvious increasing in spring associated with the impact of sand and dust storm (SDS). The decreasing trend followed by increasing trend was observed at xiAn from 2006 to 2012, but the trends are not reproduceted at other stations. It indicates that there is no significant improvement or deterioration trend of air quality with PM in recent years in china.

关键词： particulate matter observation spatial and temporal variation

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国际医学放射学杂志 2020年第6期 745-745页

作者：王慧慧 W.J.Yang A.Sirajuddin x.c.zhang G.S.Liu Z.Z.Teng S.H.Zhao Department of Magnetic Resonance Imaging Fuwai HospitalNational Center for Cardiovascular Diseases Chinese Academy of Medical Sciences and Peking Union Medical College

摘要中国乃至整个世界都在经历一种新型冠状病毒的爆发,它导致感染者出现呼吸系统疾病、严重肺炎,甚至死亡。2019年12月中国武汉爆发了疫情,目前仍在蔓延。这种

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Synergistically enhanced ORR and HER performance on co-N-c coupled in-situ generated Ptco intermetallic

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Journal of Energy chemistry 2025年第1期100卷 721-729页

作者： Guanyu Luo Min Song Lulu An xiao Huang Qian zhang chenhao zhang Tao Shen Shuang Wang Deli Wang Key Laboratory of Material chemistry for Energy conversion and Storage (Huazhong University of Science and Technology) Ministry of Education School of Chemistry and Chemical Engineering Huazhong University of Science and Technology

Integrating multi-scale sites in a composite catalyst is vital to realize efficient ***,a synergistic composite catalyst consisting of co atomic sites and in-situ generated Ptco intermetallic compounds （IMcs）(o-Ptco@coNc) is proposed through co pre-anchoring and subsequent impregnation-reduction *** loading of co atoms provides a chance for in-situ generating Ptco ordered intermetallic *** remaining co single atoms and Ptco IMcs construct synergistic electrocatalytic *** from the ordered structure,synergistic effect of Pt co IMcs and co single atoms,o-Ptco@coNc exhibits excellent electrocatalytic performance for oxygen reduction reaction （ORR） and hydrogen evolution reaction （HER） with mass activity of 1.21 A mgPt-1（at 0.9 V） and5.70 A mgPt-1（at an overpotential of 100 mV）,***,o-Ptco@coNc delivers negligible loss of half-wave potential and overpotential during long-term stability test in acid solutions,with 13 mV decay after 50,000 potential cycles for ORR and a 2.7 mV decay after 20,000 potential cycles for *** integration strategy of single-atomic sites coupled IMcs paves the way for enhancing the activity and durability of Pt-based electrocatalysts.

关键词： Electrolytic reduction

Limit of Spectral Resolution in Terahertz Time—Domain Spectroscopy

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chinese Physics Letters 2003年第8期20卷 1266-1268页

作者： Jingzhouxu TaoYuan SamuelMickan x.-c.zhang centerforTHzResearch RensselaerPolytechnicInstituteTroyNY12180USA

The pulsed nature of terahertz time-domain spectroscopy (THz-TDS) sets a fundamental limit on its spectral resolution. The spectral resolution of THz-TDS can be improved by increasing the duration of the temporal measurement, but is limited by the dynamic range of the system in the time domain. This paper presents calculations and experimental results relating the temporal dynamic range of a THz-TDS system to its spectral resolution. We discuss three typical terahertz sources in terms of their dynamic range and hence achievable spectral resolution.

关键词： Terahertz spectroscopy

Regulation of thermoelastic properties of concave-packaged DNA adsorption films and its relevant microcantilever detection signals

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Acta Mechanica Sinica 2021年第4期37卷 705-711,I0004页

作者： c.x.Wu N.H.zhang c.Y.zhang J.Z.Wu School of Mechanics and Engineering Science Shanghai UniversityShanghai 200444China Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Institute of Applied Mathematics and MechanicsShanghai 200072China

The packing patterns have close correlation with the thermoelastic properties of DNA adsorption films and the relevant detection signals of *** this paper,we investigate the influence of packing patterns on the thermoelastic properties of DNA adsorption films,the detection signals of microcantilevers and their temperature ***,the Parsegian's empirical potential based on a mesoscopic liquid crystal theory is employed to describe the interaction energy among coarse-grained DNA cylinders;then,the thought experiment method and the force balance method of nonlinear elastic network nodes are combined to characterize the elastic modulus,prestress and thermal expansion coefficient of DNA adsorption films;finally,based on an effective macroscopic continuum model for DNA microbeam deformation,we study the microcantilever resonance frequency shifts caused by DNA adsorptions and the temperature effect on the microcantilever static deflections,*** show that,compared with the convex-packaged,the re-entrant honeycomb packing pattern endows DNA adsorption films with a larger adjustable range of the elastic modulus and prestress,so as to make DNA-microcantilevers having an enhanced dynamic detection signal whereas a weaker response to temperature *** results are expected to provide a new option for the regulation design of DNA composite materials and microbeam sensors.

关键词： DNA-microbeam Packaging pattern Elastic property Thermal expansion coefficient Detection signal

Homotopy analysis solutions for the asymmetric laminar flow in a porous channel with expanding or contracting walls

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Acta Mechanica Sinica 2011年第2期27卷 208-214页

作者： x.-H. Si L.-c. Zheng x.-x. zhang Y. chao Applied Science School University of Science and Technology Beijing 100083 Beijing China Department of Mechanical Engineering University of Science and Technology Beijing100083 Beijing China Research Institute of chemical Defense of the EL.A 102205 Beijing China

In this paper, the asymmetric laminar flow in a porous channel with expanding or contracting walls is investigated. The governing equations are reduced to ordinary ones by using suitable similar transformations. Homotopy analysis method （HAM） is employed to obtain the expres- sions for velocity fields. Graphs are sketched for values of parameters and associated dynamic characteristics, especially the expansion ratio, are analyzed in detail.

关键词： Homotopy analysis method · Expanding or contracting wall · Asymmetric laminar flow · Porous channel · Expansion ratio

MIcROSTRUcTURE EVOLUTION AND MEcHANIcAL HARDENING OF HYPEREUTEcTOID PEARLITIc STEEL DURING cOLD ROLLING

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Acta Metallurgica Sinica(English Letters) 2007年第4期20卷 287-292页

作者： x. zhang c.x. Wang x.M. Liu Q.N. Shi Key Laboratory of Advanced Materials of Yunnan Province Kunming University of Science and Technology Kunming 650093 China Institute for Structural Materials Central Iron and Steel Research InstituteBeijing 100081 China

The microstructure evolution of different cold rolling reductions （from 0 to 81.6%） was studied by SEM （scanning electron microscopy） and TEM （transmission electron microscope）. The study showed that the orientation multiplicity of pearlitic lamellas resulted in inhomogeneous deformation of different pearlitic lamellas, and with the increase of reduction, the microstructure underwent a course of ＂homogeneity → inhomogeneity → homogeneity＂. The result of xRD （x-ray diffraction） analysis indicated that cementite did not decompose and dissolve into ferrite; the results of the mechanical property test suggested that the relationship between Rp0.2 （yield strength） and ε （true strain） was in good agreement with Hollomon relationship. With the equation Rp0.2 = 1465ε^0.18, the yield strength of the steel in different reductions could be well predicted.

关键词： cold rolling hypereutectoid pearlitic steel microstructure evolution mechanical hardening

A functional tacrolimus-releasing nerve wrap for enhancing nerve regeneration following surgical nerve repair

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Neural Regeneration Research 2025年第1期20卷 291-304页

作者： Simeon c.Daeschler Katelyn J.W.So Konstantin Feinberg Marina Manoraj Jenny cheung Jennifer zhang Kaveh Mirmoeini JPaul Santerre Tessa Gordon Gregory HBorschel SickKids Research Institute Neuroscience and Mental Health ProgramTorontoONCanada Institute of Biomaterials and Biomedical Engineering University of TorontoTorontoONCanada Indiana University School of Medicine IndianapolisINUSA Division of Plastic and Reconstructive Surgery the Hospital for Sick ChildrenTorontoONCanada Translational Biology and Engineering Program Ted Rogers Centre for Heart ResearchInstitute of Biomedical EngineeringFaculty of DentistryUniversity of TorontoTorontoONCanada

Axonal regeneration following surgical nerve repair is slow and often incomplete,resulting in poor functional recovery which sometimes contributes to lifelong ***,there are no FDA-approved therapies available to promote nerve *** accelerates axonal regeneration,but systemic side effects presently outweigh its potential benefits for peripheral nerve *** authors describe herein a biodegradable polyurethane-based drug delivery system for the sustained local release of tacrolimus at the nerve repair site,with suitable properties for scalable production and clinical application,aiming to promote nerve regeneration and functional recovery with minimal systemic drug *** is encapsulated into co-axially electrospun polycarbonate-urethane nanofibers to generate an implantable nerve wrap that releases therapeutic doses of bioactive tacrolimus over 31 *** and drug loading are adjustable for applications in small and large caliber nerves,and the wrap degrades within 120 days into biocompatible *** released from the nerve wrap promotes axon elongation in vitro and accelerates nerve regeneration and functional recovery in preclinical nerve repair models while off-target systemic drug exposure is reduced by 80%compared with systemic *** its surgical suitability and preclinical efficacy and safety,this system may provide a readily translatable approach to support axonal regeneration and recovery in patients undergoing nerve surgery.

关键词： biodegradable local drug delivery nerve injury nerve regeneration nerve wrap tacrolimus