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

Stellar reaction rate of 55Ni（p,γ）56Cu in Type I X-ray bursts

引用

Nuclear Science and Techniques 2019年第9期30卷 94-102页

作者： Shao-Bo Ma li-yong zhang Jun Hu Institute of Modern Physics Chinese Academy of Sciences Lanzhou 730000 China University of Chinese Academy of Sciences Beijing 100049 China College of Nuclear Science and Technology Beijing Normal University Beijing 100875 China

56Cu is close to the waiting-point nucleus 56Ni and lies on the rapid proton capture（rp） process path in Type I X-ray bursts（XRBs）. In this work, we obtained a revised thermonuclear reaction rate of 55Ni（p,γ）56Cu in the temperature region relevant to XRBs. This rate was recalculated based on the recent experimental level structure in 56Cu, the recently measured proton separation energy of Sp = 579.8（7.1） keV, together with shell-model calculation, and the mirror nuclear structure in 56Co. The associated uncertainties in the rates were estimated by a Monte Carlo method. Our revised rate is significantly different from the recent results, which were partially based on experimental results; in addition, we found that a result in a previous work was incorrect. We recommend our revised rate to be incorporated in the future astrophysical network calculations.

关键词： Nuclear astrophysics Reaction rate X-ray burst

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

Design method of multivariable PI controller for turboprop engine based on equivalent transfer function

引用

Chinese Journal of Aeronautics 2024年第9期37卷 237-260页

作者： Shancheng li yong WANG Haibo zhang Jiangsu Province Key Laboratory of Aerospace Power System College of Energy and Power EngineeringNanjing University of Aeronautics and AstronauticsNanjing 210016China

Traditional centralized Proportional Integral(PI)controller design methods based on Equivalent Transfer Functions(ETFs)have poor decoupling effect in turboprop *** this paper,a centralized PI design method based on dynamic imaginary matrix and equivalent transfer function is ***,a method for solving equivalent transfer functions based on the dynamic imaginary matrix is proposed,which adopts dynamic imaginary matrix to describe the dynamic characteristics of the system,and obtains the equivalent transfer function based on the dynamic imaginary matrix ***,for the equivalent transfer function,a central-ized PI control gain is designed using the Taylor expansion ***,this paper further proves that the centralized PI design method proposed in this paper has integral ***-ering the impact of altitude and Mach number on turboprop engines,a linear feedforward control method based on the transfer function matrix is further proposed based on the centralized PI con-troller,and the stability of the entire comprehensive control method is ***,to ensure the safe and effective operation of the turboprop engine,a temperature and torque limiting protection controller is designed for the turboprop *** results show that the centralized PI con-troller design method and linear feedforward control method proposed can effectively improve the control quality of turboprop engine control systems.

关键词： Multivariable control sys-tems Equivalent transfer function Disturbance compensation control Control parameter design Turboprop engine control

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

Design of an L1 band low noise single-chip GPS receiver in 0.18 μm CMOS technology

引用

The Journal of China Universities of Posts and Telecommunications 2010年第3期17卷 60-65页

作者： CHEN Ying-mei li Zhi-qun WANG Zhi-gong JING yong-kang zhang li Institute of Radio Frequency and Electronic Integrated Circuits Southeast University Nanjing 210096 China

This article presents an L1 band low noise integrated global positioning system （GPS） receiver chip using 0.18 μm CMOS technology. Dual-conversion with a low-IF architecture was used for this GPS receiver. The receiver is composed of low noise amplifier （LNA）, down-conversion mixers, band pass filter, received signal strength indicator, variable gain amplifier, programmable gain amplifier, ADC, PLL frequency synthesizer and other key blocks. The receiver achieves a maximum gain of 105 dB and noise figure less than 6 dB. The variable gain amplifier （VGA） and programmable gain amplifier （PGA） provide gain control dynamic range over 50 dB. The receiver consumes less than 160 mW from a 1.8 V supply while occupying a 2.9 mm2 chip area including the ESD I/O pads.

关键词： CMOS RF receiver GPS low IF satellite communications wireless communications

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

Combined surgical and interventional treatment of tandem carotid artery and middle cerebral artery embolus: A case report

引用

World Journal of Clinical Cases 2020年第3期8卷 630-637页

作者： Meng zhang Ji-Heng Hao Kai lin Qing-Ke Cui li-yong zhang Department of Neurosurgery Liaocheng Brain Hospital

BACKGROUND The 2018 American Heart Association/American Stroke Association guidelines for early management of acute ischemic stroke recommend the use of retrievable stents for mechanical thrombectomy in patients with acute internal carotid artery or middle cerebral artery M1 occlusion that can be treated within 6 h from *** cases of carotid artery with ipsilateral middle cerebral artery tandem embolization, the operation is more complicated and challenging. We here report a case of a tandem embolism, and the anatomy of the aortic arch was *** carotid artery incision and thrombectomy can not only prevent the escape of the carotid embolus but also save time during establishment of the thrombectomy *** SUMMARY The patient was a 70-year-old man. He was admitted to hospital due to sudden inability to speak and inability to move his right limb for 3 h. Imaging confirmed a diagnosis of a tandem embolism in the left carotid artery with left M1 *** artery incision thrombectomy combined with stent thrombectomy was performed. The operation was successful, and 24 h later the patient was conscious and mentally competent but had motor aphasia. His bilateral limb muscle strength level was 5, and his neurologic severity scores score was *** Carotid artery incision thrombectomy combined with stenting for carotid artery plus cerebral artery tandem embolization is clinically feasible. For patients with a complicated aortic arch and an extremely tortuous carotid artery, carotid artery incision can be chosen to establish the interventional path.

关键词： Carotid artery incision thrombectomy Mechanical thrombectomy Carotid thrombosis Middle cerebral artery occlusion Tandem occlusion Case report

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

Soil organic carbon contents, aggregate stability,and humic acid composition in different alpine grasslands in Qinghai-Tibet Plateau

引用

Journal of Mountain Science 2016年第11期13卷 2015-2027页

作者： CAO Zhi-yuan WANG yong li Jie zhang Jin-jing HE Nian-peng Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China

Alpine grassland soils on Qinghai-Tibet Plateau store approximately 33.5 Pg of organic carbon(C) at 0–0.75 m depth and play an important role in the global carbon *** investigated soil organic C(SOC),water-soluble organic C(WSOC),easily oxidizable organic C(EOC),humic C fractions,aggregate-associated C,aggregate stability,and humic acid(HA) composition along an east-west transect across Qinghai-Tibet Plateau,and explored their spatial patterns and controlling *** contents of SOC,WSOC,EOC,humic C fractions and aggregate-associated C,the proportions of macroaggregates(2-0.25) and micro-aggregates(0.25-0.053 mm),and the aggregate stability indices all increased in the order alpine desert liphatic C/aromatic C ratio of HA increased as alpine desert lity indices along this *** all these C fractions,SOC content and aggregate stability were more closely associated with humic C and silt and clay sized C in comparison with WSOC,EOC,and macro- and microaggregate *** results suggested that alpine meadow soils containing higher SOC exhibited high soil aggregation and aggregate *** annual precipitation should be the main climate factor controlling the spatial patterns of SOC,soil aggregation,and aggregate stability in this *** resistant and stable C fractions rather than labile C fractions are the major determinant of SOC stocks and aggregate stability.

关键词： Soil organic carbon Aggregate stability Humic acid Carbon-13 nuclear magnetic resonance Latitudinal transect Qinghai-Tibet Plateau

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

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 Shape and Placement of Twisted Pin Fins in a Rectangular Channel on Thermo-Hydraulic Performance

引用

Journal of Thermal Science 2024年第5期33卷 1773-1793页

作者： li yong zhang Jin zhang Yingchun zhang Jiajie MA Suxia SUNDEN Bengt XIE Gongnan College of Electrical and Power Engineering Taiyuan University of TechnologyTaiyuan 030024China Key Laboratory of Cleaner Intelligent Control on Coal&Electricity Ministry of EducationTaiyuan 030024China Shanxi Provincial Key Laboratory of High Efficiency Heat Storage and Low Carbon Heat Supply Taiyuan 030008China School of Energy and Power Engineering North University of ChinaTaiyuan 030051China Department of Energy Sciences Lund UniversityP.O.Box 118Lund SE 22100Sweden School of Marine Science and Technology Northwestern Polytechnical UniversityXi'an 710072China

To enhance the thermo-hydraulic performance of cooling channels,this investigation examines the influence of distinct cross-sectional shapes(i.e.,triangular,rectangular,and hexagonal)of twisted pin fins and their arrangements in straight and cross *** ambient air cooling test platform was established to numerically and experimentally investigate the flow and heat transfer characteristics of 360°twisted pin fins at Re=*** findings reveal that straight rows exhibit higher Nu values than cross rows for triangular and rectangular twisted pin fins,and Nu increases with *** contrast,for hexagonal twisted pin fins,only straight rows at Re=19000 exhibit superior overall thermal performance compared to cross ***,the heat transfer performance of the cooling channel with hexagonal twisted fins surpasses both triangular and rectangular configurations,especially at high Reynolds numbers(Re=22800).Although the heat transfer coefficient of the cooling channel with hexagonal twisted fins is significantly enhanced by 132.71%compared to the flat channel,it also exhibits the highest thermal resistance and relative friction among the three types of twisted fins,the maximum of which are 2.14 and ***,the hydrothermal performance factor(HTPF)of the cooling channels with different types of twisted pin fins depends on the Reynolds number and arrangement *** Re=15200,the highest HTPF achieved for the cross-row hexagonal twisted pin fins is 0.99.

关键词： twisted pin fin cross arrangement heat transfer pressure drop HTPF

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：