检索结果-南通市图书馆

Exploring Sulfur Chemistry in TMC-1 with NSRT

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2024年第2期41卷 129-132页

作者： Wasim Iqbal Xiaohu Li Juan Tuo Ryszard Szczerba Yanan Feng Zhenzhen Miao Jiangchao Yang Jixing Ge Gleb Fedoseev donghui quan Qiang Chang Chuan-Lu Yang Tao Yang Gao-Lei Hou Yong Zhang Xuan Fang Xia Zhang Fangfang Li Rong Ma Xiaomin Song Zhiping Kou Yuxuan Sun Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Xinjiang Key Laboratory of Radio Astrophysics Urumqi 830011China Key Laboratory of Radio Astronomy Chinese Academy of SciencesNanjing 210008China University of Chinese Academy of Sciences Beijing 100049China Nicolaus Copernicus Astronomical Center Rabia´nska 887-100 Toru´nPoland Research Laboratory for Astrochemistry Ural Federal UniversityKuibysheva St.48620026 EkaterinburgRussia Astronomical Computing Research Center Zhejiang LaboratoryHangzhou 311100China School of Physics and Optoelectronic Engineering Shandong University of TechnologyZibo 255000China School of Physics and Optoelectronic Engineering Ludong UniversityYantai 264025China State Key Laboratory of Precision Spectroscopy East China Normal UniversityShanghai 200062China MOE Key Laboratory for Non-Equilibrium Synthesis and Modulation of Condensed Matter School of PhysicsXi’an Jiaotong UniversityXi’an 710049China School of Physics and Astronomy Sun Yat-sen UniversityGuangzhou 510275China Laboratory for Space Research Faculty of ScienceThe University of Hong KongHong KongChina National Astronomical Observatories Chinese Academy of SciencesBeijing 100012China

There have been several studies on sulfur depletion in dense cores like TMC-1(Taurus Molecular Cloud 1),employing updated reaction networks for sulfur species to explain the missing sulfur in the gas within dense *** of these studies used a C/O ratio of 0.7 or *** present NSRT(NanShan 26m Radio Telescope)observations of TMC-1 alongside results from time-dependent chemical simulations using an updated chemical *** findings highlight the impact of the C/O ratio on the gas-phase evolution of C2S and *** simulation results show that the C/O ratio is an important parameter,playing a fundamental role in determining the gas-phase abundances of sulfur species in dense cores.

关键词： sulfur Sulfur depletion

Gas-Grain Modeling of Interstellar O2

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Physics 2020年第1期33卷 107-113页

作者： Xia Zhang donghui quan Jarken Esimbek Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China Department of Chemistry Eastern Kentucky UniversityRichmondKY 40475USA Key Laboratory of Radio Astronomy Chinese Academy of SciencesUrumqi 830011China

Molecular oxygen(O2)is essential to human beings on the *** elemental oxygen is rather abundant,O2 is rare in the interstellar *** was only detected in two galactic and one extra-galactic *** inconsistency between observations and theoretical studies is a big challenge for astrochemical *** we report a two-phase modeling research of molecular oxygen,using the Nautilus gas-grain *** apply the isothermal cold dense models in the interstellar medium with two typical sets of initial elemental abundances,as well as the warm-up models with various physical *** cold dense conditions,we nd that the timescales for gas-phase CO,O2 and H2O to reach peak values are dependent on the hydrogen density and are shortened when hydrogen density *** warm-up models,O2 abundances are in good agreement with observations at temperatures rising after 10^5 *** both isothermal and warm-up models,the steady-state O2 fractional abundance is independent of the hydrogen density,as long as the temperature is high enough(>30 K),at which O2 is prevented from signi cant depleting onto grain *** addition,low density is preferable for the formation of O2,whether molecular oxygen is under cold conditions or in warm regions.

关键词： Astrochemistry Models Interstellar medium Molecules Abundances

Femtosecond time-resolved difference absorption spectroscopy of all-trans-β-Apo-8′-carotenal

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2004年第2期47卷 208-222页

作者： ZHANG Lei quan donghui WANG Li YANG Guozhen WENG Yuxiang Institute of Physics Chinese Academy of Sciences Beijing 100080 China Institute of Physics Chinese Academy of Sciences Beijing 100080 China Institute of Physics Chinese Academy of Sciences Beijing 100080 China Institute of Physics Chinese Academy of Sciences Beijing 100080 China Institute of Physics Chinese Academy of Sciences Beijing 100080 China

The femtosecond time-resolved difference absorption spectra of all-trans-b- Apo-8′-carotenal have been recorded and analyzed by the singular-value decomposition (SVD) method followed by global fitting using a sequential model for the excited-state energy relaxation. With this model, we have obtained the excited-state absorption spectra and the lifetimes of the corresponding excited states both in nonpolar solvent n-hexane and polar solvent methanol. Three excited states, namely S3(170fs), S2(2.32ps) and S1(26ps) in n-hexane, and two excited states S2 (190fs) and S1(9.4ps) in methanol have been observed. The excited-state absorption spectra of all-trans-b-Apo-8′-carotenal in methanol display a red shift and broadeness, while the lifetime of S1 state becomes shorter. It is proposed that these effects are related to the presence of a carbonyl functional group that leads to the solvent effect on the excited-state energy level. At the same time, it is shown that the SVD method is a useful tool in resolving the time-resolved absorption spectra.

关键词： singular value decomposition, femtosecond time-resolved spectroscopy, ail-trans-β- Apo-8′-carotenal.

E ect of Optical Depth on Study of Chemical Properties of Massive Star Forming Clumps

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Physics 2020年第1期33卷 114-118页

作者： Jian-jun Zhou Run-xia Li donghui quan Jarken Esimbek Yu-xin He Da-lei Li Xin-di Tang Gang Wu Wei-guang Ji Zheng-xue Chang Xia Zhang Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of the Chinese Academy of Sciences Beijing 100080China Key Laboratory of Radio Astronomy Chinese Academy of SciencesUrumqi 830011China Department of Chemistry Eastern Kentucky UniversityRichmond KY 40475USA

Here we present the study on chemical properties of massive star forming clumps using N2H^+(1-0),H^13CO+(1-0),HCN(1-0)and HN^13C(1-0)data from the literature[***.563,A97(2014)].We found that abundances of H^13CO+ and HN^13C are a ected by H2 column *** the median values of these two abundances increase by nearly 10 times from stages A to B,H^13CO+and HN^13C are suitable for tracing the evolution of massive star forming *** order of rapidity in growth of abundances of all the four studied molecules from stages A to B,is H^13CO^+,HCN,HN^13C,and N2H^+,from the highest to the *** results suggest that the observing optically thin molecular lines with high angular resolution are necessary to study the chemical evolution of massive star forming clumps.

关键词： Stars formation Clumps Molecules Radio lines

Investigation on AIDS-related Knowledge, Attitude, Belief and Practice among Crew Travelling between the Mainland, HongKong and Macao

在线全文

学校读者我要写书评

暂无评论

旅行医学科学 1996年第4期2卷 156-160页

作者： Lou donghui Gu Tai quan Tu Zhijian Nanhai Frontier Health and Quarantine Bureau of, P. R. China

A modified version of the WHO/AIDS KABP Questionaire’was administered to 444 cargo ship’s crew and 55 passenger ship’s crew. The result showed that most of them had basic AIDS-related knowledge, but the knowledge about preventive measures was insufficant and misconceptions about the transmission of AIDS was widespread, nearly half of them thought that AIDS could be infected by mosquito bites or kiss, and 9% of them thought that AIDS could be infected by dancing or shaking hands with AIDS patients. 15.6% of the cargo vessel’s crew and 11.1% of the passanger ship’s crew didn’t believe those infected with HIV might appear healthy. There were 62.2% of the cargo vessel’s crew and 75.5% of the passanger ship’s crew who had sexual experience had used condoms, but 40% of them didn’t believe the protective effect of condoms. A negative association was found between knowledge level about AIDS and some AIDS-related high risk behaviours. 14.8% of the crew admitted that they had multiple sexual partners, 4.4% of the crew ours out of mainland, 2.2% of cargo vessel’s crew had history of drug injection. The group who had multiple sexual partners expressed less fear of being infected with HIV(P<0.01), they also had stronger tendency to have sexual behaviours with the casual partners without condoms (P<0.01).

关键词： AIDS KABP Crew

Electronic structure and effective mass of pristine and Cl-doped CsPbBr_(3)

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第5期33卷 167-171页

作者：魏志远魏愉昊徐申东彭舒婷 Makoto Hashimoto 路东辉潘旭匡泯泉肖正国何俊峰 Department of Physics and CAS Key Laboratory of Strongly-coupled quantum Matter Physics University of Science and Technology of ChinaHefei 230026China Chongqing Key Laboratory of Micro & Nano Structure Optoelectronics and School of Physical Science and TechnologySouthwest UniversityChongqing 400715China Key Laboratory of Photovoltaic and Energy Conservation Materials Institute of Applied TechnologyHefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China Stanford Synchrotron Radiation Lightsource and Stanford Institute for Materials and Energy Sciences SLAC National Accelerator LaboratoryMenlo ParkCalifornia 94025USA

Organic–inorganic lead halide perovskites(LHPs) have attracted great interest owing to their outstanding optoelectronic ***,the underlying electronic structure would determinate the physical properties of *** as for now,limited studies have been done to reveal the underlying electronic structure of this material system,comparing to the huge amount of investigations on the material *** effective mass of the valance band is one of the most important physical parameters which plays a dominant role in charge transport and photovoltaic *** pristine CsPbBr_(3),the Fr?hlich polarons associated with the Pb–Br stretching modes are proposed to be responsible for the effective mass *** this regard,it would be very interesting to explore the electronic structure in doped ***,we report high-resolution angle-resolved photoemission spectroscopy(ARPES) studies on both pristine and Cl-doped CsPbBr_(3).The experimental band dispersions are extracted from ARPES spectra along both ■ and ■ high symmetry *** calculations are performed and directly compared with the ARPES *** results have revealed the band structure of Cl-doped CsPbBr_(3) for the first time,which have also unveiled the effective mass renormalization in the Cl-doped CsPbBr_(3) *** dependent measurements indicate that the chlorine doping could moderately tune the renormalization *** results will help understand the physical properties of LHPs as a function of doping.

关键词： lead halide perovskites electronic structure effective mass

在线全文

学校读者我要写书评

暂无评论

一种基于硅传感器的空间中子探测器设计

北京大学学报（自然科学版） 2024年第4期60卷 657-664页

作者：杨哲沈国红张斌全张珅毅常远荆涛权子达侯东辉孙莹中国科学院国家空间科学中心北京100190 中国科学院大学北京100049 天基空间环境探测北京市重点实验室北京100190 中国科学院空间环境态势感知技术重点实验室北京100190 上海卫星工程研究所上海200240

针对空间站轨道复杂的中子辐射环境,设计一种中子探测器,采用硅层叠结构,利用核反冲法及核反应法进行中子的间接探测,获取空间站轨道中子辐射的能谱信息。该中子探测器的探测范围指标为0.025 eV~10MeV,搭载于天宫空间站梦天实验舱的空... 详细信息

针对空间站轨道复杂的中子辐射环境,设计一种中子探测器,采用硅层叠结构,利用核反冲法及核反应法进行中子的间接探测,获取空间站轨道中子辐射的能谱信息。该中子探测器的探测范围指标为0.025 eV~10MeV,搭载于天宫空间站梦天实验舱的空间辐射生物学暴露实验装置上,用于监测空间站低地球轨道的中子辐射环境,获取在轨探测数据,可为研究空间中子对生物体造成辐射效应的作用机理提供重要依据,也可为研究次级粒子对航天器电子元件造成的单粒子效应提供必要的空间环境参数。

关键词：空间中子探测器空间中子辐射环境硅传感器中子能谱测量天宫空间站梦天实验舱

同方期刊数据库博看期刊

基于EBSD技术构建弹性各向异性粗晶材料超声仿真模型的研究

在线全文

学校读者我要写书评

暂无评论

机械工程学报 2016年第18期52卷 24-30页

作者：陈尧罗忠兵张东辉周全刘丽丽杨会敏林莉大连理工大学无损检测研究所大连116085 中国核工业二三建设有限公司北京101601 核工业工程研究设计有限公司北京101601

针对弹性各向异性粗晶材料晶粒结构和取向定量描述困难,导致超声检测仿真结果与试验符合程度较差的问题,提出基于电子背散射衍射(Electron back-scatter diffraction,EBSD)技术确定晶粒形态及晶体取向的建模思路。利用EBSD技术实测得到... 详细信息

针对弹性各向异性粗晶材料晶粒结构和取向定量描述困难,导致超声检测仿真结果与试验符合程度较差的问题,提出基于电子背散射衍射(Electron back-scatter diffraction,EBSD)技术确定晶粒形态及晶体取向的建模思路。利用EBSD技术实测得到了尺寸为96 mm×12 mm的离心铸造奥氏体不锈钢(Centrifugally cast austenitic stainless steel,CCASS)轴-径向截面的晶体取向图谱,选择15°取向相(差)角定义EBSD图谱的晶粒结构,并对晶体取向进行归一化处理。在此基础上借助Bond变换法赋以晶粒在对应晶体取向下的刚度矩阵,对模型中晶粒的弹性特征进行量化表征,建立CCASS超声检测模型。采用时域有限差分法进行数值计算,结果表明:利用该方法能够较好地重现CCASS超声检测特有的结构噪声和主频降低等现象,为揭示超声波在弹性各向异性粗晶结构中的散射机理提供了解决思路。

关键词：电子背散射衍射超声检测仿真弹性各向异性粗晶

盆底疝合并阴道膨出、直肠脱垂及直肠壁间粪石一例

在线全文

学校读者我要写书评

暂无评论

中华结直肠疾病电子杂志 2024年第2期13卷 162-165页

作者：奚世文李蓉孙东辉王权吉林大学第一医院普通外科中心胃结直肠外科长春130021 吉林大学第一医院普通外科中心乳腺外科长春130021

目前,盆底疝的发病率在全球呈逐年上升趋势,其中,老年女性发病率相对较高,在不同程度影响患者的生活质量,为其日常生活带来诸多困扰。有时,此类患者还可能合并其他症状,如直肠脱垂、阴道膨出等,临床医生应正确并充分地认识盆底疝的存在... 详细信息

目前,盆底疝的发病率在全球呈逐年上升趋势,其中,老年女性发病率相对较高,在不同程度影响患者的生活质量,为其日常生活带来诸多困扰。有时,此类患者还可能合并其他症状,如直肠脱垂、阴道膨出等,临床医生应正确并充分地认识盆底疝的存在,制定合理的手术方案,才能有效的治疗此类疾病。

关键词：盆底疝直肠脱垂阴道膨出粪石