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Vertical Schottky ultraviolet photodetector based on graphene and top–down fabricated GaN nanorod arrays

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Journal of Semiconductors 2022年第6期43卷 59-65页

作者： xuemin zhang Changling Yan Jinghang Yang Chao Pang Yunzhen Yue Chunhong Zeng Baoshun zhang State Key Laboratory on High Power Semiconductor Lasers Changchun University of Science and TechnologyChangchun 130022China Nanofabrication Facility Suzhou Institute of Nano-Tech and Nano-BionicsChinese Academy of SciencesSuzhou 215123China

GaN has been widely used in the fabrication of ultraviolet photodetectors because of its outstanding properties.In this paper,we report a graphene–GaN nanorod heterostructure photodetector with fast photoresponse in the UV range.GaN nanorods were fabricated by a combination mode of dry etching and wet etching.Furthermore,a graphene–GaN nanorod heterostructure ultraviolet detector was fabricated and its photoelectric properties were measured.The device exhibits a fast photoresponse in the UV range.The rising time and falling time of the transient response were 13 and 8 ms,respectively.A high photovoltaic responsivity up to 13.9 A/W and external quantum efficiency up to 479%were realized at the UV range.The specific detectivity D*=1.44×10^(10) Jones was obtained at–1 V bias in ambient conditions.The spectral response was measured and the highest response was observed at the 360 nm band.

关键词： graphene GaN nanorods ultraviolet photodetector top–down fabrication

Deep vein thrombosis in early pregnancy:A retrospective study

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Gynecology and Obstetrics Clinical Medicine 2023年第1期3卷 44-50页

作者： Chen zhang xuemin zhang Guoli Liu Department of Obstetrics and Gynecology Peking University People’s HospitalBeijing100044China Department of Vascular Surgery Peking University People’s HospitalBeijing100044China

Objective:To investigate the clinical characteristics,management,and prognosis of deep vein thrombosis(DVT)during early pregnancy.Methods:We conducted a retrospective study among women with DVT during their first trimester of pregnancy who were admitted to the obstetrics department of Peking University People's Hospital between March 2008 and May 2021.We analyzed clinical data of eight patients,including their general condition,obstetric characteristics,diagnosis,treatment,and gestational outcomes.Results:Risk factors for DVT in the first trimester included personal history of DVT,thrombophilia and immune diseases,and DVT was more likely to affect the left leg.The main manifestation of DVT was pain or swelling of the affected limbs.D-dimer levels after anticoagulant treatment showed a downward trend compared with those before treatment(P=0.09),while D-dimer levels increased significantly after delivery compared with those before delivery(P=0.03).All the patients started on low-molecular-weight heparin(LMWH)therapy after a diagnosis of DVT.Temporary inferior vena cava(IVC)filters were implanted in 3 patients with mixed thrombosis before delivery,but were removed after the operation.Except for 1 case with thrombophilia who refused treatment,others underwent anticoagulation therapy from 6 weeks to 1 year postpartum.Seven patients achieved a successful delivery with live births.Conclusion:During early pregnancy,DVT was more common in women with maternal risk factors.More cases of venous thromboembolism(VTE)were observed in the left leg.For women with a high risk of DVT,medical intervention,early identification,accurate diagnosis and precise treatment during early pregnancy should be promoted.

关键词： Early pregnancy Deep vein thrombosis Clinical characteristics Diagnosis Treatment Prognosis

Grouting-induced ground heave and building damage in tunnel construction:A case study of Shenzhen metro

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Underground Space 2022年第6期7卷 1175-1191页

作者： Zonglei Dong xuemin zhang Chenxi Tong Xinlei Chen Han Feng Sheng zhang School of Civil Engineering Central South UniversityChangsha 410075China

This paper presents a case study of the grouting-induced ground heave and building damage in the tunnel construction of Shenzhen Metro Line 10,which passes through a crowded urban area with water-rich strata in Shenzhen,the province of Guangdong,China.It was reported that the ground surface heave of up to approximately 500 mm was observed,and the customs building above the tunnels was seriously damaged because of a 200 mm heave.Such a significant heave was closely associated with the advanced curtain grouting adopted in the tunnel construction.To this end,the heave of the ground surface and the displacement and deformation of the customs building were examined.The discrete element method(DEM)was then used to qualitatively analyze the relations between the grouting parameters and the ground disturbance.The results demonstrated that the poor dewatering work in the early stages increased the difficulty of grouting.The grouting materials with high viscosity and large grouting pressure were required for water blocking because of the large amount of confined water in the tunnel,resulting in fracture grouting.The ground was then uplifted due to the large inflow of the slurry and the excess pore water pressure.Finally,the lessons learned from this incident were discussed.The presented case study provides a reference for tunnel construction in urban areas with water-rich strata.

关键词： Grouting Ground heave Building damage Field test Numerical simulation

CUEDC2:an emerging key player in inflammation and tumorigenesis

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Protein & Cell 2011年第9期2卷 699-703页

作者： Jianghong Man xuemin zhang Institute of Basic Medical Sciences National Center of Biomedical AnalysisBeijing 100850China

CUE domain-containing 2(CUEDC2)is a protein involved in the regulation of the cell cycle,inflammation,and tumorigenesis and is highly expressed in many types of tumors.CUEDC2 is phosphorylated by Cdk1 during mitosis and promotes the release of anaphase-promoting complex or cyclosome(APC/C)from checkpoint inhibition.CUEDC2 is also known to interact with IkB kinaseα(IKKα)and IKKβand has an inhibitory role in the activation of transcription factor nuclear factor-κB.Moreover,CUEDC2 plays an important role in downregulating the expression of hormone receptors estrogen receptor-αand progesterone receptor,thereby impairing the responsiveness of breast cancer to endocrine therapies.In this review,current knowledge on the multi-functions of CUEDC2 in normal processes and tumorigenesis are discussed and summarized.

关键词： CUEDC2 inflammation cell cycle nuclear factor-κB tumorigenesis

A review of seismo-electromagnetic research in China

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Science China Earth Sciences 2022年第7期65卷 1229-1246页

作者： Guoze ZHAO xuemin zhang Juntao CAI Yan ZHAN Qinzhong MA Ji TANG Xuebin DU Bing HAN Lifeng WANG Xiaobin CHEN Qibin XIAO Xiangyu SUN Zeyi DONG Jijun WANG Jihong zhang Ye FAN Tao YE State Key Laboratory of Earthquake Dynamics Institute of GeologyChina Earthquake AdministrationBeijing 100029China Institute of Earthquake Forecasting China Earthquake AdministrationBeijing 100036China National Institute of Natural Hazards Ministry of Emergency Management of ChinaBeijing 100085China Shanghai Earthquake Agency Shanghai 200062China China Earthquake Administration Lanzhou Institute of Earthquake Lanzhou 730000China Shandong Earthquake Agency Jinan 250014China China Earthquake Network Center Beijing 100045China

The seismo-electromagnetic(EM)method is an important geophysical method that plays a major role in the observation of seismic anomalies related to earthquake precursors.It is the most promising method for a breakthrough in short-term earthquake prediction.The digital transformation and network upgrading implemented in the“Ninth five-year plan”and“Tenth five-year plan”have optimized the original observation system,improved the quality of observed data,enriched the seismicelectromagnetic information,and enhanced the analysis capability and timeliness of seismic-electromagnetic anomalies.These improvements are of major importance for the research on seismo-electromagnetics as well as for the development of new technologies.Since the beginning of the 21 st century,China has launched a satellite named CSES that was designed for the generation and study of seismo-electromagnetic data and built a high-power transmitting source and a new CSELF observation network that is used specifically for earthquake monitoring.This platform has promoted the full-time three-dimensional EM monitoring and the identification of earthquake anomalies.Based on the study of anomalies related to earthquake precursors,the physical and numerical simulations,and the study on generation mechanism of anomalies in China,we summarize the characteristics of earthquake EM anomalies and discuss the advantages and disadvantages of different EM observation methods.Finally,considering the related questions of the seismo-electromagnetic prediction and implementing the recent developments both in China and abroad,we review the current status of seismo-electromagnetic research and propose strategies for future research.

关键词： Seismo-electromagnetism Seismic anomaly Electromagnetic observation Experiment and simulation Earthquake prediction Prospect

A comparative thermodynamic analysis of Kalina and organic Rankine cycles for hot dry rock:a prospect study in the Gonghe Basin

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Frontiers in Energy 2020年第4期14卷 889-900页

作者： Xuelin zhang Tong zhang Xiaodai XUE Yang SI xuemin zhang Shengwei MEI State Key Laboratory of Control and Simulation of Power System and Generation Equipments Department of Electrical EngineeringTsinghua UniversityBeijing 100084China Jingjing Energy Storage Co. Ltd.Changzhou 213200China School of QiDi(TUS)Renewable Energy Qinghai UniversityXining 810016China

Hot dry rock is a new type of geothermal resource which has a promising application prospect in China.This paper conducted a comparative research on performance evaluation of two eligible bottoming cycles for a hot dry rock power plant in the Gonghe Basin.Based on the given heat production conditions,a Kalina cycle and three organic Rankine cycles were tested respectively with different ammonia-water mixtures of seven ammonia mass fractions and nine ecofriendly working fluids.The results show that the optimal ammonia mass fraction is 82%for the proposed bottoming Kalina cycle in view of maximum net power output.Thermodynamic analysis suggests that wet fluids should be supercritical while dry fluids should be saturated at the inlet of turbine,respectively.The maximum net power output of the organic Rankine cycle with dry fluids expanding from saturated state is higher than that of the other organic Rankine cycle combinations,and is far higher than the maximum net power output in all tested Kalina cycle cases.Under the given heat production conditions of hot dry rock resource in the Gonghe Basin,the saturated organic Rankine cycle with the dry fluid butane as working fluid generates the largest amount of net power.

关键词： hot dry rock Kalina cycle organic Rankine cycle thermodynamic analysis

Opportunities and challenges of rare and undiagnosed disease research in China

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Fundamental Research 2022年第6期2卷 827-828页

作者： Lei Wang Zhihong Liu Guang Ning xuemin zhang Xue zhang Institutes of Biomedical Science Fudan UniversityShanghai 200032China School of Medicine Zhejiang UniversityHangzhou 310058ZhejiangChina Ruijin Hospital Shanghai Jiao Tong UniversityShanghai 200025China Institute of Basic Medical Sciences National Center of Biomedical AnalysisBeijing 100850China McKusick-zhang Center for Genetic Medicine Peking Union Medical CollegeBeijing 100005China

Rare and undiagnosed diseases have been recognized as major public health concerns,despite those being affected accounting for only a small percentage of the global population.Most patients cannot get precise diagnoses or effective treatments.This situation thereby causes a heavy burden on healthcare systems,posing huge challenges not only for clinicians,but also for the family members of these patients.

关键词： diseases thereby precise

Effects of different cue positions on evoked potentials in the cerebral cortex during global and local processing of compound stimuli A study of event-related potential

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Neural Regeneration Research 2009年第11期4卷 941-946页

作者： xuemin zhang Yongna LiO Siyu Bai Yaqin Zheng School of Psychology State Key Laboratory of Cognitive Neuroscience and Learning Beijing Normal University Beijing 100875 China Department of Psychology New York State University Albany 12246 New York USA Department of Educational Psychology Xuchang University Xuchang 461000 Henan Province China

BACKGROUND： Previous studies of attentional control have focused primarily on pre-cue control of attentional cue and direction. OBJECTIVE： To measure the differences in electrical activity of brain cells while processing pre-cue and post-cue compound stimuli, and to explore brain electrical activity during global and local processing of compound stimuli according to electroencephalogram （EEG） recordings. DESIGN, TIME AND SETTING： A within-subject design study was performed at the School of Psychology, State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, China from March to May 2006. PARTICIPANTS： A total of 30 healthy, undergraduate students, aged 17-24 years, comprising 12 males and 18 females, were voluntarily enrolled from Beijing Normal University. Subjects exhibited normal or corrected-to-normal visual acuity. No significant non signal wave drift was detected during testing. METHODS： A total of 30 subjects were subjected to pre-cue and post-cue compound stimulus processing using event-related potential and EEG recordings. MAIN OUTCOME MEASURES： Evoked potential was recorded in different brain regions utilizing event-related potential to observe hemispheric symmetry, cue consistency and global-local features. RESULTS： Pre-cue compound stimuli resulted in hemispheric asymmetry for early wave （N1） and late wave （P3） in anterior brain regions. Early- and late-wave induced hemispheric asymmetry for electrode points （O1, 02, P3, P4, Pz, F3, F4, F7, F8, Fz, FP1, FP2, T7, TS, C3, C4, and Cz） during processing of pre-cue compound stimuli （P 〈 0.05）. Post-cue compound stimuli did not induce hemispheric asymmetry of brain waves induced by the above-described electrode points. No significant differences in global and local responses were determined during processing of post-cue compound stimuli. Under pre-cue conditions, significant differences were observed in N1 and P3 in the above-mentioned electrode points （P 〈 0.05）. However, under post-cue conditions, no significant differences w

关键词： compound stimuli cue event-related potential hemispheric symmetry attention

Microstructure and Mechanical Properties of a Spray-Formed Superalloy

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Acta Metallurgica Sinica(English Letters) 2014年第6期27卷 1063-1069页

作者： Fuwei Kang Fuyang Cao xuemin zhang Hongyan Yue Yicheng Feng School of Materials Science and Engineering Harbin University of Science and Technology School of Materials Science and Engineering Harbin Institute of Technology

The microstructural evolution and mechanical properties of a spray-formed superalloy were studied in this paper. Based on a better understanding of the microstructural evolution of the spray-formed superalloy during solution treatment, an optimum solution treatment process was obtained, namely, at 1,140 °C for 6 h, and air cooling（AC）. The effects of the ageing treatments on the mechanical properties of the post-solution-treated spray-formed superalloy were evaluated using ageing harden curves and tensile testing. The results indicated that the maximum hardness value was achieved at 850 °C for 8 h, AC. Due to co-precipitation of primary and secondary c0 precipitates during the heat treatment,the spray-formed superalloy obtained an excellent combination of yield strength（YS = 1,110 MPa）, ultimate tensile strength（UTS = 1,503 MPa）, ductility（elongation, EL = 21%） and excellent stress rupture properties at 650 °C（UTS = 1,209 MPa, EL = 15.8%）. The heat treatment also improved the rupture life at 650 °C/950 MPa and 750 °C/539 MPa up to 140 h without rupturing. The tensile-fractured surfaces exhibit ductile transgranular failure feature. The optimum heat treatment process was determined to be 1,140 °C/6 h＋850 °C/8 h＋AC.

关键词： Spray-formed superalloy Microstructure Ageing harden Mechanical properties