检索结果-南通市图书馆

Direct measurement of the break-out ^(19)F(p,γ)^(20)Ne reaction in the China Jinping underground laboratory(CJPL)

Nuclear Science and Techniques 2024年第8期35卷 142-152页

作者： Yin‑Ji Chen Hao Zhang Li‑Yong Zhang jian‑Jun He Richard James deBoer Michael Wiescher Alexander Heger David Kahl Jun Su Daniel Odell Xin‑Yue Li jian‑guo wang Long Zhang Fu‑Qiang Cao Zhi‑Cheng Zhang Xin‑Zhi jiang Luo‑Huan wang Zi‑Ming Li Lu‑Yang Song Liang‑Ting Sun Qi Wu Jia‑Qing Li Bao‑Qun Cui Li‑Hua Chen Rui‑Gang Ma Er‑Tao Li Gang Lian Yao‑De Sheng Zhi‑Hong Li Bing guo Wei‑Ping Liu Key Laboratory of Beam Technology of the Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China Department of Physics and Astronomy The Joint Institute for Nuclear AstrophysicsUniversity of Notre DameNotre DameIN 46556USA School of Physics and Astronomy Monash UniversityClaytonVIC 3800Australia Facility for Rare Isotope Beams Michigan State UniversityEast LansingMI 48824USA Institute of Nuclear and Particle Physics and Department of Physics and Astronomy Ohio UniversityAthensOH 45701USA Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China China Institute of Atomic Energy Beijing 102413China College of Physics and Optoelectronic Engineering Shenzhen UniversityShenzhen 518060China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China College of Science Southern University of Science and TechnologyShenzhen 518055China Institute of Radiation Technology Beijing Academy of Science and TechnologyBeijing 100875China Key Laboratory of Nuclear Physics and Ion‑Beam Application(MOE) Institute of Modern PhysicsFudan UniversityShanghai 200433China School of Mathematics and Physics Handan UniversityHandan 056005China

Calcium production and the stellar evolution of first-generation stars remain fascinating mysteries in *** one possible nucleosynthesis scenario,break-out from the hot carbon–nitrogen–oxygen(HCNO)cycle was thought to be the source of the calcium observed in these oldest ***,according to the stellar modeling,a nearly tenfold increase in the thermonuclear rate ratio of the break-out ^(19)F(p,γ)^(20) Ne reaction with respect to the competing ^(19)F(p,α)^(16) O back-processing reaction is required to reproduce the observed calcium *** performed a direct measurement of this break-out reaction at the China Jinping underground *** measurement was performed down to the low-energy limit of E_(c.m.)=186 keV in the center-of-mass *** key resonance was observed at 225.2 keV for the first *** a temperature of approximately 0.1 GK,this new resonance enhanced the thermonuclear ^(19)F(p,γ)^(20) Ne rate by up to a factor of≈7.4,compared with the previously recommended NACRE *** is of particular interest to the study of the evolution of the first stars and implies a stronger breakdown in their“warm”CNO cycle through the ^(19)F(p,γ)^(20) Ne reaction than previously *** break-out resulted in the production of the calcium observed in the oldest stars,enhancing our understanding of the evolution of the first stars.

关键词： Nuclear astrophysics First stars Abundance of calcium Reaction cross section Reaction rate China Jinping underground laboratory(CJPL) JUNA

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Finite element reliability analysis of slope stability

引用

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第5期10卷 645-652页

作者： Xiao-hui TAN jian-guo wang School of Resource and Environmental Engineering Hefei University of Technology Hefei 230009 China School of Civil Engineering Hefei University of Teehnology Hefei 230009 China

The method of nonlinear finite element reliability analysis (FERA) of slope stability using the technique of slip surface stress analysis (SSA) is studied. The limit state function that can consider the direction of slip surface is given, and the formula-tions of FERA based on incremental tangent stiffness method and modified Aitken accelerating algorithm are developed. The limited step length iteration method (LSLIM) is adopted to calculate the reliability index. The nonlinear FERA code using the SSA technique is developed and the main flow chart is illustrated. Numerical examples are used to demonstrate the efficiency and robustness of this method. It is found that the accelerating convergence algorithm proposed in this study proves to be very efficient for it can reduce the iteration number greatly, and LSLIM is also efficient for it can assure the convergence of the iteration of the reliability index.

关键词： Slope stability Finite element method Reliability analysis Limited step length iteration method (LSLIM) Accelerating convergence

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Critical temperatures and pressures of reacting mixture in synthesis of dimethyl carbonate with methanol and carbon dioxide

引用

Chinese Chemical Letters 2008年第2期19卷 249-252页

作者： Xing Cui guo Zhang Feng Qin guo Fu wang jian guo wang State Key Laboratory of Coal Conversion Institute of Coal Chemistry Chinese Academy of Sciences P.O. Bx 165 Taiyuan Shanxi 030001 China Graduate School of the Chinese Academy of Sciences Beijing 100049 China

Critical temperatures and pressures of nominal reacting mixture in synthesis of dimethyl carbonate （DMC） from methanol and carbon dioxide （quaternary mixture of carbon dioxide ＋ methanol ＋ water ＋ DMC） were measured using a high-pressure view cell. The results suggested that the critical properties of the reacting mixture depended on the reaction extent as well as its initial composition （initial ratio of carbon dioxide to methanol）. Such information is essential for determining the reaction conditions when one intends to carry out the synthesis of DMC with CO2 and methanol under supercritical conditions.

关键词： Critical properties Reacting mixture Supercritical fluid Dimethyl carbonate Synthesis Methanol Carbon dioxide

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Coupling dehydrogenation of isobutane in the presence of carbon dioxide over chromium oxide supported on active carbon

引用

Chinese Chemical Letters 2008年第9期19卷 1059-1062页

作者： jian Fei Ding Zhang Feng Qin Xue Kuan Li guo Fu wang jian guo wang State Key Laboratory of Coal Conversion Institute of Coal Chemistry Chinese Academy of Sciences P.O. Box 165 Taiyuan 030001 China Graduate School of the Chinese Academy of Sciences Beijing 100049 China

The dehydrogenation of isobutane （IB） to produce isobutene coupled with reverse water gas shift in the presence of carbon dioxide was investigated over the catalyst Cr2O3 supported on active carbon （Cr2O3/AC）. The results illustrated that isobutane conversion and isobutene yield can be enhanced through the reaction coupling in the presence of carbon dioxide. Moreover, carbon dioxide can partially eliminate carbonaceous deposition on the catalyst and keep the active phase （Cr2O3）, which are then helpful to alleviate the catalyst deactivation.

关键词： Dehydrogenation Isobutane Carbon dioxide Isobutene Reaction coupling Cr2O3/AC

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Optical identification of radio-loud active galactic nuclei in the ROSAT-Green-Bank sample with SDSS spectroscopy

引用

Research in Astronomy and Astrophysics 2009年第10期9卷 1078-1102页

作者： De-Liang wang jian-guo wang Xiao-Bo Dong National Astronomical Observatories / Yunnan Observatory Chinese Academy of SciencesKunming 650011 China Graduate University of the Chinese Academy of Sciences Beijing 100039 China Center for Astrophysics University of Science and Technology of China Hefei 230026 China

Results of extended and refined optical identification of 181 radio/X-ray sources in the RASS-Green Bank （RGB） catalog are presented （Brinkmann et al. 1997） which have been spectroscopically observed in the Sloan Digital Sky Survey （SDSS） DR5. The SDSS spectra of the optical counterparts are modeled in a careful and selfconsistent way by incorporating the host galaxy＇s starlight. Optical emission line parameters are presented, which are derived accurately and reliably, along with the radio 1.4- 5 GHz spectral indices estimated using （non-simultaneous） archival data. For 72 sources, the identifications are presented for the first time. It is confirmed that the majority of strong radio/X-ray emitters are radio-loud active galactic nuclei （AGNs）, particularly blazars. Taking advantage of the high spectral quality and resolution and our refined spectral modeling, we are able to disentangle narrow line radio galaxies （NLRGs）, as vaguely termed in most previous identification work, into Seyfert II galaxies and LINERs （low-ionization nuclear emission regions）, based on the standard emission line diagnostics. The NLRGs in the RGB sample, mostly belonging to ＇weak line radio galaxies＇, are found to have optical spectra consistent predominantly with LINERs, and only a small fraction with Seyfert II galaxies. A small number of LINERs have radio power as high as 10623 - 10^26 W Hz^- 1 at 5 GHz, being among the strongest radio emitting LINERs known so far. Two sources are identified with radio-loud narrow line Seyfert 1 galaxies （NLS 1 s）, a class of rare objects. The presence is also confirmed of flat-spectrum radio quasars whose radio-optical-X-ray effective spectral indices are similar to those of High-energy peaked BL Lacs （HBLs）, as suggested by Padovani et al., although it is still a debate as to whether this is the case for their actual spectral energy distributions.

关键词： galaxies active -- galaxies quasars -- BL Lacerate objects general --X-rays general -- radio continuum general

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Characterization of hot deformation behavior of 30Si2MnCrMoVE low-alloying ultra-high-strength steel by constitutive equations and processing maps

引用

Journal of Iron and Steel Research International 2020年第7期27卷 807-819页

作者： Hai wang Dong Liu jian-guo wang Hai-ping wang Yang Hu Hao-dong Rao School of Materials Science and Engineering Northwestern Polytechnical UniversityXi’an710072ShaanxiChina State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an710072ShaanxiChina

Isothermal compression tests of as-forged 30Si2MnCrMoVE low-alloying ultra-high-strength steel were carried out on a Gleeble 3500 thermal simulator at the deformation temperatures of 950-1150℃and strain rates of 0.01-10 s^−*** on the classical stress-dislocation density relationship and the kinematics of the dynamic recrystallization,the constitutive equations of the work hardening dynamical recovery period and dynamical recrystallization period were developed by using the work hardening curve and Avrami equation,which shows good agreement with the experimental *** maps at the strain of 0.90 were constructed based on dynamic material model and were analyzed combined with microstructure observation under different *** optimum parameter based on the processing maps was obtained and verified by a supplementary *** power dissipation maps and instability maps at strains of 0.05-0.90 were also constructed,and the evolution law was analyzed in *** established constitutive equation and hot processing maps can provide some guidance for hot working process.

关键词： 30Si2MnCrMoVE ultra-high-strength steel Hot deformation Constitutive model Processing map Power dissipation efficiency

来源：

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

First identification of isatin-β-thiosemicarbazones as novel inhibitors of New Delhi metallo-β-lactamase-1： Chemical synthesis, biological evaluation and molecular simulation

引用

Chinese Chemical Letters 2018年第6期29卷 899-902页

作者： guo-Qing Song Wei-Min wang Zai-Shun Li Ying wang jian-guo wang State-Key Laboratory and Research Institute of Elemento-Organic Chemistry National Pesticide Engineering Research Center College of Chemistry Nankai University Tianjin 300071 China Tianjin International Joint Academy of Biotechnology and Medicine Tianjin 300457 China Patent Examination Cooperation jiangsu Center of the Patent Office SIPO Suzhou 215163 China

New Delhi metallo-b-lactmase-1（NDM-1） catalyzes the hydrolysis of b-lactam antibiotics and cleaves the b-lactam ring of the molecule, conferring bacterial resistance against these medicines. In an effort to discover novel agents to treat this superbug, an old drug methisazone was found to be a weak NDM-1 inhibitor, with an IC50 of 297.6 mmol/L. Based on this result, a series of isatin-β-thiosemicarbazones（IBTs）were synthesized and biologically evaluated as novel NDM-1 inhibitors. Nine of the IBT compounds showed IC50 values of 〈10 mmol/L, the best of which was 2.72 mmol/L. Comparative field analysis（Co MFA） contour maps were generated to depict the structural features and molecular docking was performed to understand the possible binding mode of these inhibitors. The present research hereby has provided valuable information for further discovery of NDM-1 inhibitors.

关键词： New Delhi metallo-β-lactmase-1 Isatin-β-thiosemicarbazones In vitro enzyme inhibition Molecular docking

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Deposition behavior of multi-particle impact in cold spraying process

引用

International Journal of Minerals,Metallurgy and Materials 2010年第5期17卷 635-640页

作者： Xiang-lin Zhou Xiang-kun Wu Hui-hua guo jian-guo wang Ji-shan Zhang State Key Laboratory for Advanced Metals and Materials University of Science mad Technology Beijing Beijing 100083 China

In the practical cold-spraying process, a number of particles impact onto a substrate and then form a coating. To study the deformation behavior and multi-particle interactions, single-particle, two-particle, and three-particle impacts were simulated using the ANSYS/LS-DYNA version 970. A copper coating was prepared and scanning electron microscopy （SEM） was employed to analyze the microstructures of the powders and the coating. Numerical results reveal that the critical deposition velocity is 600 m/s for a copper particle/copper substrate. The particles deform more fully due to multi-particle interactions, such as tamping, interlocking, and extrusion effects. The compression ratio increases from 40% to 70% as a result of the tamping effect. This is beneficial for achieving the cold-sprayed coating. The multi-particle morphology and compression ratio in the experiment are consistent with those of simulation results. Based on these results, the coating of high performance can be prepared through selecting appropriate parameters and suitable pre-treatment processes.

关键词： spraying deposition interfaces particle interactions bonding simulation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Improvement on Conventional Load Distribution Algorithm in Hot Tandem Mills

引用

Journal of Iron and Steel Research International 2007年第2期14卷 36-41页

作者： LIHai-jun XU jian-zhong wang guo-dong LIU Xiang-hua State Key Laboratory of Rolling Teehnology and Automation Northeastern University Shenyang 110004 Liaoning China

Load distribution is a key technology in strip hot rolling process, which influences the coil＇s mierostrueture and performance. Currently, Newton-Raphson algorithm is applied to load distribution of hot tandem mills in many hot rolling plants and has some serious defects such as having a strict restriction on initial iterative calculation value and requiring coefficient matrix of nonlinear equations to be nonsingular. To eliminate these defects and improve the online performance of the process control computer, Newton descendent numeric algorithm is introduced to this field to widen the initial value range and a new model named error conversion algorithm is put forth to deal with special conditions when the coefficient matrix is singular. Furthermore, considering the characteristics of load distribution, a condition of strip thickness distribution abnormality and corresponding solutions are provided which ensure that rolling parameters can be calculated normally. Simulation results show that the improved algorithm has overcome the defects of the Newton-Raphson algorithm and is suitable for online application.

关键词： load distribution hot tandem mill process control computer Newton-Raphson algorithm

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Synthesis and Crystal Structure of 5-N-i-Propyl-2-(2′-nitrobenzenesulfonyl)-glutamine

引用

Chemical Research in Chinese Universities 2006年第6期22卷 760-762页

作者： XIAO Yong-jun wang jian-guo wang Bao-lei LI Zheng-ming SONG Hai-bin Elemento-Organic Chemistry Institute State Key Laboratory of Elemento-Organic Chemistry Nankai University Tianjin 300071 P. R. China

The title compound, 5 -N-i-propyl-2-（2＇ -nitrobenzenesulfonyl）-glutamine, was synthesized and its structure was confirmed by IB, MS, ^1H NMB, and elemental analysis. The single crystal structure of the title compound was determined by X-ray diffraction. The crystal belongs to Monoclinic, space group P2（ 1 ）, with a =0. 69281 （ 11 ） nm, b = 0. 76508（12）, c = 1. 5843（3） nm, α=90°, β =90. 941 （3）°, γ =90°, V=0. 8397（2） nm^3, Z =-2, Dc = 1.477 g/cm^3,μ =0. 236 mm^-1, F（000） =392, R =0. 0297, and wR=0.0664.

关键词： 5 -N-i-Propyl-2-( 2' -nitrobenzenesulfonyl) -glutamine Synthesis Crystal structure

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：