检索结果-南通市图书馆

Field topologies in ideal and near-ideal magnetohydrodynamics and vortex dynamics

Science China(Physics,Mechanics & Astronomy) 2015年第1期58卷 12-31页

作者： LOW B.C. high altitude Observatory National Center for Atmospheric Research

Magnetic field topology frozen in ideal magnetohydrodynamics （MHD） and its breakage in near-ideal MHD are reviewed in two parts, clarifying and expanding basic concepts. The first part gives a physically complete description of the frozen field topology derived from magnetic flux conservation as the fundamental property, treating four conceptually related topics： Eulerian and La- grangian descriptions of three dimensional （3D） MHD, Chandrasekhar-Kendall and Euler-potential field representations, magnetic helicity, and inviscid vortex dynamics as a fluid system in physical contrast to ideal MHD. A corollary of these developments clar- ifies the challenge of achieving a high degree of the frozen-in condition in numerical MHD. The second part treats field-topology breakage centered around the Parker Magnetostatic Theorem on a general incompatibility of a continuous magnetic field with the dual demand of force-free equilibrium and an arbitrarily prescribed, 3D field topology. Preserving field topology as a global con- straint readily results in formation of tangential magnetic discontinuities, or, equivalently, electric current-sheets of zero thickness. A similar incompatibility is present in the steady force-thermal balance of a heated radiating fluid subject to an anisotropic thermal flux conducted strictly along its frozen-in magnetic field in the low-fl limit. In a weakly resistive fluid the thinning of current sheets by these general incompatibilities inevitably results field notwithstanding the small resistivity. Strong Faraday in sheet dissipation, resistive heating and topological changes in the induction drives but also macroscopically limits this mode of energy dissipation, trapping or storing free energy in self-organized ideal-MHD structures. This property of MHD turbulence captured by the Taylor hypothesis is reviewed in relation to the Sun＇s corona, calling for a basic quantitative description of the breakdown of flux conservation in the low-resistivity li

关键词： magnetic topology magnetic reconnection current sheets magnetic helicity thermal conduction solar corona magnetohy-drodynamics interstellar clouds

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

Prediction and optimization of flue pressure in sintering process based on SHAP

引用

International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 346-359页

作者： Mingyu Wang Jue Tang Mansheng Chu Quan Shi Zhen Zhang School of Metallurgy Northeastern UniversityShenyang 110819China Liaoning Low-Carbon Steelmaking Technology Engineering research center Northeastern UniversityShenyang 110819China Engineering research center of Frontier Technologies for Low-Carbon Steelmaking(Ministry of Education) Shenyang 110819China

Sinter is the core raw material for blast *** pressure,which is an important state parameter,affects sinter *** this paper,flue pressure prediction and optimization were studied based on the shapley additive explanation(SHAP)to predict the flue pressure and take targeted adjustment ***,the sintering process data were collected and processed.A flue pressure prediction model was then constructed after comparing different feature selection methods and model algorithms using SHAP+extremely random-ized trees(ET).The prediction accuracy of the model within the error range of±0.25 kPa was 92.63%.SHAP analysis was employed to improve the interpretability of the prediction *** effects of various sintering operation parameters on flue pressure,the relation-ship between the numerical range of key operation parameters and flue pressure,the effect of operation parameter combinations on flue pressure,and the prediction process of the flue pressure prediction model on a single sample were analyzed.A flue pressure optimization module was also constructed and analyzed when the prediction satisfied the judgment *** operating parameter combination was then *** flue pressure was increased by 5.87%during the verification process,achieving a good optimization effect.

关键词： sintering process flue pressure shapley additive explanation prediction optimization

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

16.48% Efficient solution-processed CIGS solar cells with crystal growth and defects engineering enabled by Ag doping strategy

引用

Journal of Energy Chemistry 2025年第1期100卷 59-65页

作者： Mengyu Xu Shaocong Yan Ting Liang Jia Jia Shengjie Yuan Dongxing Kou Zhengji Zhou Wenhui Zhou Yafang Qi Yuena Meng Litao Han Sixin Wu Key Laboratory for Special Functional Materials of MOE National & Local Joint Engineering Research Centre for High-efficiency Display and Lighting Technology School of Nanoscience and Materials Engineering Henan University

Solution-processed Cu（In,Ga）Se2（CIGS） solar cells suffer from serious carrier recombination and power conversion efficiency（PCE） loss because of the poor film properties and easy formation of ***, we propose Ag&Se co-selenization strategy to enhance the crystallization and passivate harmful defects of the CIGS films. The formation of Ag-Se phase during the selenization process enables the formation of large grains and suppresses the deep level defects. It is found that Ag doping can enlarge the depletion region width, lower the Urbach energy and prolong the carrier lifetime. As a result, a champion solution-processed CIGS solar cell presents a high efficiency of 16.48% with the highly improved opencircuit voltage（VOC） of 662 m V and fill factor（FF） of 75.8%. This work provides an efficient strategy to prepare high quality solution-processed CIGS films for high-performance CIGS solar cells.

关键词： CIGS solar cells Solution-processed method Ag doping Crystal growth Defects engineering

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

Local magnetic moment oscillation around an Anderson impurity on graphene

引用

Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 192-201页

作者： Shuai Li Zhen Ma Jin-Hua Gao School of Science Hebei University of Science and Technology School of Electronics and Information Zhengzhou University of Light Industry School of Physics and Wuhan National high Magnetic Field center Huazhong University of Science and Technology

We theoretically investigate the spin resolved Friedel oscillation （FO） and quasiparticle interference （QPI） in graphene induced by an Anderson *** the impurity becomes magnetic,the resulted FO becomes spin dependent,which gives rise to a local magnetic moment oscillation with an envelop decaying as r-2in real space in the doping ***,at half filling,the electron density and local magnetic moment will not oscillate but decay as *** spin resolved FO has both sublattice and spin ***,the local magnetic moment decay at half filling only occurs at one sublattice of graphene,which is quite like the phenomenon observed in the STM experiment (***ález-Herrero et al.,Science 352,437 （2016）).We further give an analytic formula about such spin dependent FO based on the stationary phase ***,we study the interference of quasiparticles around the magnetic impurity by calculating the spin dependent Fourier-transformed local density of states （FT-LDOS）.Our work gives a comprehensive understanding about the local magnetic moment oscillation around an Anderson impurity on graphene.

关键词： Friedel oscillation local magnetic moment graphene Anderson impurity

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

Co-production of hydrogen, oxygen, and electricity via an integrated solar-driven system with decoupled water electrolyzer and Na-Zn ion battery

引用

Journal of Energy Chemistry 2025年第1期100卷 621-627页

作者： Fei Lv Longjie Liu Jiazhe Wu Pengfei Wang Lixia Pan Dengwei Jing Yubin Chen International research center for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University

Combining water electrolysis and rechargeable battery technologies into a single system holds great promise for the co-production of hydrogen （H2） and ***,the design and development of such systems is still in its ***,an integrated hydrogen-oxygen （O2）-electricity co-production system featuring a bipolar membrane-assisted decoupled electrolyzer and a Na-Zn ion battery was established with sodium nickelhexacyanoferrate （NaNiHCF） and Zn2+/Zn as dual redox *** decoupled electrolyzer enables to produce H2and O2in different time and space with almost 100%Faradaic efficiency at 100 mA ***,the charged NaNiHCF and Zn electrodes after the electrolysis processes formed a Na-Zn ion battery,which can generate electricity with an average cell voltage of 1.75 V at 10 m A *** connecting Si photovoltaics with the modular electrochemical device,a well-matched solar driven system was built to convert the intermittent solar energy into hydrogen and electric energy with a solar to hydrogen-electricity efficiency of 16.7%,demonstrating the flexible storage and conversion of renewables.

关键词： Hydrogen Electricity Decoupled water electrolyzer Na-Zn ion battery Solar energy

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

Neurological adaptations to hypoxia in Tibetan antelope (Pantholops hodgsonii) with a view of molecular biology of respiratory globin-neuroglobin

引用

中国应用生理学杂志 2012年第6期28卷 555-560页

作者： Zhen-zhong BAI Ying-zhong YANG Guo-en JIN Lan MA Ri-li Ge The research center for high altitude Medicine Medical SchoolQinghai University

Neuroglobin(Ngb) is a respiratory protein that is preferentially expressed in brain of mouse and *** this article,Tibetan antelope,living at altitude of 3 000～5 000 m for millions of years,was selected as the model of hypoxia-tolerant adaptation *** reverse transcription polymerase chain reaction(RT-PCR) and Western blot techniques,expression of Ngb gene was amplified and analyzed in antelope brain *** results showed that Ngb homology protein in Tibetan antelope was identified with more sequence similarity with cattle(96%),sheep(95%),and human(95%).We detected that there were some mutations occurred in the Open Reading Frame of Ngb in Tibetan antelope compared with *** analysis of Ngb chain showed that it was closer to cattle than the *** study suggests possible roles of central nervous system enriched Ngb in adaptation of Tibetan antelope to extremely high altitude.

关键词：中枢神经系统藏羚羊脑红蛋白呼吸系统球蛋白分子生物学逆转录聚合酶链反应缺氧

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

Energy power in mountains:difference in metabolism pattern results in different adaption traits in Tibetans

引用

中国应用生理学杂志 2012年第6期28卷 488-493页

作者： Zhen-zhong BAI Guo-en JIN Tana WU-REN Qin GA Ri-li GE The research center for high altitude Medicine Medical SchoolQinghai University

Energy metabolism plays an important role in life survival for species living in high altitude hypoxia ***-breathing organisms require oxygen to create *** are the well-adapted highlanders in Qinghai-Tibetan *** was thought that different metabolic approaches could lead to different adaptation traits to high altitude *** identified hypoxia inducible factors pathway regulators,endothelial PAS domain protein1(EPAS1)/HIF-2α and PPARA,were involved in decreasing hemoglobin concentrations in *** EPAS1 and PPARA also modulated the energy metabolism during hypoxia,we hypothesized that positive selected EPAS1 and PPARA genes were also involved in unique energy metabolisms in *** this brief review,we take a look into genetic determinations to energy metabolisms for hypoxia adaptations traits in Tibetans and mal-adaptive conditions such as high altitude diseases.

关键词：藏族人代谢模式性状缺氧诱导因子血红蛋白浓度能量代谢发电能源

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

Transonic wing stall of a blended flying wing common research model based on DDES method

引用

Chinese Journal of Aeronautics 2016年第6期29卷 1506-1516页

作者： Tao Yang Li Yonghong Zhang Zhao Zhao Zhongliang Liu Zhiyong State Key Laboratory of Aerodynamics China Aerodynamics Research and Development Center high Speed Aerodynamic Institute China Aerodynamics Research and Development Center

Numerical simulation of wing stall of a blended flying wing configuration at transonic speed was conducted using both delayed detached eddy simulation（DDES） and unsteady Reynolds-averaged Navier-Stokes（URANS） equations methods based on the shear stress transport（SST） turbulence model for a free-stream Mach number 0.9 and a Reynolds number 9.6 × 10. A joint time step/grid density study is performed based on power spectrum density（PSD） analysis of the frequency content of forces or moments, and medium mesh and the normalized time scale0.010 were suggested for this simulation. The simulation results show that the DDES methods perform more precisely than the URANS method and the aerodynamic coefficient results from DDES method compare very well with the experiment data. The angle of attack of nonlinear vortex lift and abrupt wing stall of DDES results compare well with the experimental data. The flow structure of the DDES computation shows that the wing stall is caused mainly by the leeward vortex breakdown which occurred at x/x= 0.6 at angle of attack of 14°. The DDES methods show advantage in the simulation problem with separation flow. The computed result shows that a shock/vortex interaction is responsible for the wing stall caused by the vortex breakdown. The balance of the vortex strength and axial flow, and the shock strength, is examined to provide an explanation of the sensitivity of the breakdown location. Wing body thickness has a great influence on shock and shock/vortex interactions, which can make a significant difference to the vortex breakdown behavior and stall characteristic of the blended flying wing configuration.

关键词： Delayed detached eddy simulation Flying wing Vortex lift Vortex breakdown Wing stall

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

Associations between interleukin-1 polymorphisms and gastric cancers among three ethnicities

引用

World Journal of Gastroenterology 2012年第47期18卷 7093-7099页

作者： Jiu-Da Zhao Pai-Li Geng Zhan-Quan Li Sen Cui Jun-Hui Zhao Li-Juan Wang Jin-Zhang Li Fa-Xiang Ji Guo-Yuan Li Guo-Shuang Shen Ming-Zhe Lin Cun-Fang Shen Cheng-Zhu Cao Internal Medicine-Oncology Affiliated Hospital of Qinghai University high altitude Medical research center Qinghai University

AIM:To investigate the associations between interleukin(IL)-1B and IL-1RN polymorphisms and gastric cancers among the Tibet,Hui and Han ***:Genomic DNA was extracted from peripheral blood of 210,205,and 202 healthy volunteers and from 155,158,and 197 gastric cancer patients from the Tibet,Hui,and Han populations,*** in IL-1B and IL-1RN were analyzed by denaturing high-performance liquid ***:Carriers of the IL-1B-31 CC genotype had an increased risk of intestinal type gastric cancer [odds ratio(OR) = 2.17,P = 0.037] in the Tibet *** of the IL-1B 2/L genotype had an increased risk of both intestinal and diffuse types of gastric cancer(OR = 2.08,2.31,P = 0.007,0.016,respectively) in the Hui *** the Han population,carriers of the IL-1B-31 CC,IL-1B-511CT,TT genotypes had increased risk of intestinal type gastric cancer(OR = 2.51,2.74,5.66,P = 0.005,0.002,0.000,respectively).CONCLUSION:IL-1B and IL-RN genotypes may differentially contribute to gastric cancer among the Tibet,Hui,and Han ethnicities in the Qinghai area of China.

关键词： Gastric cancer Interleukin-1B Interleukin1RN Polymorphism Risk of gastric cancer

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

A genetic adaptive pattern-low hemoglobin concentration in the himalayan highlanders

引用

中国应用生理学杂志 2013年第6期29卷 481-493页

作者： Tian-yi WU Feng-yun LIU Ouzhou-LOUBU Chao-ying CUI Xue-bin QI Bing SU National Key Laboratory of high altitude Medicine High Altitude Medical Research Institute high altitude Medical research center University of Tibet State Key Laboratory of Genetic Resources and Evolution Kunming Institute of Zoology Academy of Science

Mean hemoglobin(Hb) concentration of about 3 500 subjects derived from 17 studies of Himalayan highlanders(Tibetans, Sherpas, and Ladakhis) was compared with lowlanders(Chinese Han, Indian Tamils) lived in the Himalayas, and European climbers during Everest expeditions as well as Andean natives. The results found that Hb concentration in Himalayan highlanders was systemically lower than those reported for Andean natives and lowland immigrants. These comparative data demonstrated that a healthy native population may successfully reside at high altitude without a significant elevation in Hb, and the lower Hb levels of Himalayan highlanders than those of migrated lowlanders and Andean natives are an example of favourable adaptation over the generations. In addition, excessive polycythemia has frequently been used as a marker of chronic mountain sickness(CMS). altitude populations who have a higher Hb concentration also have a higher incidence of CMS. The low Hb in Himalayans suggested as showing adaptation over many generations in Tibetan stock. Recent work in Tibet, suggested that Tibetans there may have adapted to high altitude as a result of evolutionary pressure selecting for genes which give an advantage at altitude. All of the population genomic and statistical analysis indicated that EPAS1 and EGLN1 are mostly likely responsible for high altitude adaptation and closely related to low Hb concentration in Tibetans. These data supported the hypothesis that Himalayan highlanders have evolved a genetically different erythropoietic response to chronic hypoxia by virtue of their much longer exposure to high altitude.

关键词：血红蛋白浓度喜马拉雅山自适应模式高地高海拔地区遗传基因组中国汉族

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：