检索结果-南通市图书馆

Direct measurement of the break-out 19F(p,γ)20Ne 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 19F(p,γ)20 Ne reaction with respect to the competing 19F(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 19F(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 19F(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

Subnatural-linewidth fluorescent single photons

引用

Photonics Research 2024年第4期12卷 625-637页

作者： HE-BIN zhang GAO-XIANG li yong-CHUN liU State Key Laboratory of Low-Dimensional Quantum Physics Department of PhysicsTsinghua UniversityBeijing 100084China Department of Physics Huazhong Normal UniversityWuhan 430079China Frontier Science Center for Quantum Information Beijing 100084China

Subnatural-linewidth single photons are of vital importance in quantum optics and quantum information *** to previous research, it appears difficult to utilize resonance fluorescence to generate single photons with subnatural linewidth. Here we propose a universally applicable approach to generate fluorescent single photons with subnatural linewidth, which can be implemented based on Λ-shape and similar energy ***, the general condition to obtain fluorescent single photons with subnatural linewidth is *** single-photon linewidth can be easily manipulated over a broad range by external fields, which can be several orders of magnitude smaller than the natural linewidth. Our study can be easily implemented in various physical platforms with current experimental techniques and will significantly facilitate the research on the quantum nature of resonance fluorescence and the technologies in quantum information science.

关键词： quantum utilize optics

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

Influence of pressure disturbance wave on dynamic response characteristics of liquid film seal for multiphase pump

引用

Petroleum Science 2024年第3期21卷 2048-2065页

作者： Qing-Ping li Jin-Ya zhang Jia-Xiang zhang yong-Xue zhang CNOOC Research Institute Company limited Beijing100028China State Key Laboratory of Natural Gas Hydrate Beijing100028China College of Mechanical and Transportation Engineering China University of PetroleumBeijing2249China

Slug flow or high GVF(Gas Volume Fraction)conditions can cause pressure disturbance waves and alternating loads at the boundary of mechanical seals for multiphase pumps,endangering the safety of multiphase pump *** mechanical seal model is simplified by using periodic boundary conditions and numerical calculations are carried out based on the Zwart-Gerber-Belamri cavitation ***(User Define Function)programs such as structural dynamics equations,alternating load equations,and pressure disturbance equations are embedded in numerical calculations,and the dynamic response characteristics of mechanical seal are studied using layered dynamic mesh *** results show that when the pressure disturbance occurs at the inlet,as the amplitude and period of the disturbance increase,the film thickness gradually *** the fundamental reason for the hysteresis of the film thickness change is that the pressure in the high-pressure area cannot be restored in a timely *** maximum value of leakage and the minimum value of axial velocity are independent of the disturbance period and determined by the disturbance *** mutual interference between enhanced waves does not have a significant impact on the film thickness,while the front wave in the attenuated wave has a promoting effect on the subsequent film thickness changes,and the fluctuation of the liquid film cavitation rate and axial velocity under the attenuated wave condition deviates from the initial *** with pressure disturbance conditions,alternating load conditions have a more significant impact on film thickness and *** actual operation,it is necessary to avoid alternating load conditions in multiphase pump mechanical seals.

关键词： Multiphase pump liquid film seal Pressure disturbance wave Dynamic response characteristics

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

Simultaneous Screening and Analysis of Anti-inflammatory and Antiproliferative Compounds from Euphorbia maculata Combining Bio-affinity Ultrafiltration with Multiple Drug Targets

引用

Journal of Analysis and Testing 2022年第2期6卷 98-110页

作者： Tojofaniry Fabien Rakotondrabe Min-Xia Fan yong-li zhang Ming-Quan Guo CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture Wuhan Botanical GardenChinese Academy of SciencesWuhan 430074China University of Chinese Academy of Sciences Beijing 100049China Sino-Africa Joint Research Center Chinese Academy of SciencesWuhan 430074China Innovation Academy for Drug Discovery and Development Chinese Academy of SciencesShanghai 201203China

Euphorbia maculata has long been used for managing different impairments in Asian ***,its antioxidant,anti-inflammatory and antiproliferative potentialities,along with its potential bioactive compounds remain *** this context,a bio-a ffinity ultrafiltration strategy was developed to fish out ligand candidates against Cycloxygenase-2(COX-2),Topoisomerase I(Topo I),and TopoisomeraseⅡ(TopoⅡ).Thereafter,lead compounds activities were assessed in silico and in vitro for ascertaining the screening results and forecasting its corresponding *** a result,the *** ethyl acetate(EMEA)fraction showed interesting COX-2 inhibition activity with an IC 50 value of 0.67±0.09μg/mL,as well as good growth inhibitions for three malignant cell *** chemical fingerprinting was also conducted to enable a tentative identification of 17 compounds,among which,11 were assessed as ligand candidates to COX-2,8 compounds to Topo I,and 10 compounds to TopoⅡ.Dihydromyricetin and quercetin-3-O-arabinoside were revealed to be multipotent compounds which exerted good a ffinity to the three targeted enzymes,and also supported with their molecular docking simulations and in vitro assay *** interrelationship between ***’s associated activities(antioxidant,anti-inflammatory and antiproliferative)was revealed with the corresponding multipotent phytochemical active components from this *** also provided a useful direction for its empirical traditional use and further explorations in the near future.

关键词： Euphorbia maculata Antioxidant Anti-infl ammatory Antiproliferative UF-UPLC-QTOF-MS/MS Multipotent compounds

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

Effect of oxide inclusions on MnS precipitates and tensile mechanical property of high-strength low-alloy steel

引用

Journal of Iron and Steel Research(International) 2024年第5期31卷 1210-1220页

作者： Xiao-yong Gao Hong Wei li-feng zhang School of Mechanical Engineering Yanshan UniversityQinhuangdao066004HebeiChina School of Materials Science and Engineering Yanshan UniversityQinhuangdao066004HebeiChina School of Mechanical and Materials Engineering North China University of TechnologyBeijing100144China

The key role of oxide inclusions on the microstructure and mechanical property of a high-strength low-alloy steel was *** field emission scanning electron microscope equipped with energy-dispersive spectrometry was used to characterize MnS *** inclusions play an important role in the shape control of MnS *** oxides fovored to decrease the size and the aspect ratio of MnS *** less oxide inclusions in the steel,approximately over 16.7%MnS precipitates were with aspect ratio a>5 and pure MnS precipitates accounted for 75.9%in ***,with more oxide inclusions in the steel,only 7.4%MnS precipitates were with a>5 and pure MnS precipitates accounted for 60.1%in *** of MnS by oxide inclusions improved the strength and inhibited the *** oxide inclusions in the steel increased the yield strength and tensile strength of the steel in both longitudinal and transverse directions,and lowered the anisotropy of the mechanical property.

关键词： High-strength low-alloy steel MnS Oxide inclusion Mechanical property Anisotropy

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

Interplay between geometric and electronic structures of Pt entities over TiO_(2) for CO oxidation

引用

Science China Chemistry 2024年第2期67卷 705-714页

作者： Xixiong zhang Wen Shi Shaobo Han yong li Wenjie Shen School of Chemistry Dalian University of TechnologyDalian116024China State Key Laboratory of Catalysis Dalian Institution of Chemical PhysicsChinese Academy of SciencesDalian116023China

Monodispersed Pt colloids with a mean size of 2 nm were deposited uniformly on the {110} facets of a rod-shaped rutile TiO_(2),forming a well-defined Pt/TiO_(2) *** treatment of this precursor at elevated temperatures re-dispersed the Pt particles into clusters and ***-calcination at 673 K partially oxidized the Pt particle surface,while calcination at 773 K yielded Pt Oxclusters of 1.6 nm in 7–8 atomic *** calcination at 873 K formed a mixture of raft-like PtO_(x) clusters(1.6 nm,1–2 atomic layers) and cationic *** tested for CO oxidation at 373 K,the Pt particles showed a higher activity than the Pt Oxclusters,whereas the cationic single-atoms were much less *** H_(2)-reduction at 473 K converted the partially oxidized Pt particles into the metallic species,but they were encapsulated by TiO_(2)–xoverlayers because of the strong metal–support interactions,which decreased the activity dramatically.H_(2)-reduction of the PtO_(x) clusters at473 K enhanced the fraction of metallic Pt species without changing the size and geometry,and promoted the activity substantially.H_(2)-treatment of Pt single-atoms at 473 K increased the activity only moderately because most Pt species still kept at cationic *** results straightforwardly differentiated the catalytic behavior of Pt particles,clusters and single-atoms at the same metal loading and over the same TiO_(2) support,and further demonstrated that the electronic structures of Pt entities played a decisive role in the catalytic oxidation,in addition to the specified sizes.

关键词： Pt/TiO_(2)catalyst size effect Pt clusters active sites electronic structures CO oxidation

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

Recent Advances in In-Memory Computing:Exploring Memristor and Memtransistor Arrays with 2D Materials

引用

Nano-Micro Letters 2024年第7期16卷 1-30页

作者： Hangbo Zhou Sifan li Kah-Wee Ang yong-Wei zhang Institute of High Performance Computing(IHPC) Agency for ScienceTechnology and Research(A*STAR)1 Fusionopolis Way#16-16 ConnexisSingapore 138632Republic of Singapore Department of Electrical and Computer Engineering National University of Singapore4 Engineering Drive 3Singapore 117583Republic of Singapore Institute of Materials Research and Engineering Agency for ScienceTechnology and Research(A*STAR)2 Fusionopolis WaySingapore 138634Republic of Singapore

The conventional computing architecture faces substantial chal-lenges,including high latency and energy consumption between memory and processing *** response,in-memory computing has emerged as a promising alternative architecture,enabling computing operations within memory arrays to overcome these *** devices have gained significant attention as key components for in-memory computing due to their high-density arrays,rapid response times,and ability to emulate biological *** these devices,two-dimensional(2D)material-based memristor and memtransistor arrays have emerged as particularly promising candidates for next-generation in-memory computing,thanks to their exceptional performance driven by the unique properties of 2D materials,such as layered structures,mechanical flexibility,and the capability to form *** review delves into the state-of-the-art research on 2D material-based memristive arrays,encompassing critical aspects such as material selection,device perfor-mance metrics,array structures,and potential ***,it provides a comprehensive overview of the current challenges and limitations associated with these arrays,along with potential *** primary objective of this review is to serve as a significant milestone in realizing next-generation in-memory computing utilizing 2D materials and bridge the gap from single-device characterization to array-level and system-level implementations of neuromorphic computing,leveraging the potential of 2D material-based memristive devices.

关键词： 2D materials Memristors Memtransistors Crossbar array In-memory computing

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

Engineering single-atom Mn on nitrogen-doped carbon to regulate lithium-peroxide reaction kinetics for rechargeable lithium-oxygen batteries

引用

Journal of Energy Chemistry 2024年第7期94卷 199-207页

作者： Yaling Huang yong liu Yang liu Chenyang zhang Wenzhang li Jie li School of Chemistry and Chemical Engineering Central South UniversityChangsha 410083HunanChina School of Minerals Processing and Bioengineering Central South UniversityChangsha 4003HunanChina

Precision engineering of catalytic sites to guide more favorable pathways for li_(2)O_(2) nucleation and decom-position represents an enticing kinetic strategy for mitigating overpotential,enhancing discharge capac-ity,and improving recycling stability of li-O_(2) *** this work,we employ metal-organic frameworks(MOFs)derivation and ion substitution strategies to construct atomically dispersed Mn-N_(4) moieties on hierarchical porous nitrogen-doped carbon(Mn SAs-NC)with the aim of reducing the over-potential and improving the cycling stability of li-O_(2) *** porous structure provides more chan-nels for mass transfer and exposes more highly active sites for electrocatalytic reactions,thus promoting the formation and decomposition of li_(2)O_(2).The li-O_(2) batteries with Mn SAs-NC cathode achieve lower overpotential,higher specific capacity(14290 mA h g^(-1) at 100 mAg^(-1)),and superior cycle stability(>100 cycles at 200 mA g^(-1))compared with the Mn NPs-NC and *** functional theory(DFT)cal-culations reveal that the construction of Mn-N_(4) moiety tunes the charge distribution of the pyridinic N-rich vacancy and balances the affinity of the intermediates(liO_(2) and li_(2)O_(2)).The initial nucleation of li_(2)O_(2) on Mn SAs-NC favors the O_(2)-→liO_(2)→li_(2)O_(2) surface-adsorption pathway,which mitigates the overpoten-tials of the oxygen reduction(ORR)and oxygen evolution reaction(OER).As a result,Mn SAs-NC with Mn-N_(4) moiety effectively facilitates the li_(2)O_(2) nucleation and enables its reversible *** work establishes a methodology for constructing carbon-based electrocatalysts with high activity and selectivity for li-O_(2)batteries.

关键词： Single-atom Mn MOFs-oriented architecture Rechargeable li-O_(2)battery N-doped carbon Density functional theory calculation

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

Multi-carrier Tb/s silicon photonic coherent receiver

引用

Science China(Information Sciences) 2024年第1期67卷 284-291页

作者： Zhen WANG Xingfeng li Jingchi li Jian SHEN yong zhang Yikai SU State Key Lab of Advanced Optical Communication Systems and Networks Department of Electronic EngineeringShanghai Jiao Tong University

We propose a silicon polarization-diversity coherent receiver for wavelength-multiplexing transmission without using the large-footprint arrayed waveguide grating(AWG).We have integrated our proposed coherent receiver on the silicon-on-insulator(SOI) platform for high-capacity *** the proposed coherent receiver,high-frequency photocurrent signals from other wavelengths are suppressed by electrical low-pass ***,the signal-signal beat interference(SSBI) generated from each wavelength is eliminated by the balanced *** two features lend to the proposed coherent receiver being free of the mm-scale *** have demonstrated our proposed coherent receiver to detect a 1.12-Tb/s wavelength-division-multiplexed and polarization-division-multiplexed 16-ary quadrature amplitude modulation(PDM-16-QAM) *** compact footprint of the silicon chip promises small-form-factor receivers for future ultra-high-capacity coherent communication systems that require a high integration level and low fabrication cost.

关键词： silicon photonics optical receivers coherent communication wavelength-division-multiplexing(WDM) polarization-division-multiplexing(PDM)

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Impact wear properties of dissimilar joints between bainitic frogs and pearlite rails

引用

Journal of Iron and Steel Research(International) 2024年第1期31卷 275-287页

作者： Pin-yong Zeng Chun-guang Zuo Xiao-yu zhang Wei li Tribology Research Institute Southwest Jiaotong UniversityChengdu610031SichuanChina

The impact wear behavior and damage mechanism of dissimilar welded joints between U26Mn frog and U75 V rail before and after normalizing treatment were studied by cyclic impact *** experiment indicated that the impact wear volume of the joints increased with the increasing number of impact *** main wear mechanisms include pitting wear,mild fatigue wear,delamination wear,and fatigue wear,and plastic deformation was the primary impact wear *** them,fatigue wear had the greatest influence on wear volume,while other wear mechanisms had limited *** impact wear resistance of the base material was better than that of the heat-affected *** treatment was beneficial to improving the impact wear resistance of welded joints owing to its effect to promote pearlite recovery,grain refinement,and uniform distribution of *** martensite generated in the rail welded joints aggravated the impact wear damage to the materials,which should be avoided.

关键词： Dissimilar welded joint Impact wear Bainitic steel Damage mechanism Wear rate

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

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：