检索结果-南通市图书馆

Chinese Journal of Chemical Engineering 2021年第4期34卷 324-334页

作者： Xuke Ruan xiao-sen Li Guangzhou Institute of Energy Conversion Chinese Academy of SciencesGuangzhou 510640China CAS Key Laboratory of Gas Hydrate Guangzhou 510640China

The surface area of hydrate during dissociation in porous media is essentially important for the kinetics of hydrate *** this study,the methane hydrate surface area was investigated by the comparison results of experiments and numerical simulations during hydrate decomposition in porous *** experiments of methane hydrate depressurizationinduced dissociation were performed in a 1D high pressure cell filled with glass beads,an improved and valid 1D corescale numerical model was developed to simulate gas *** conceptual models for hydrate dissociation surface area were proposed based on the morphology of hydrate in porous media,which formed the functional form of the hydrate dissociation surface area with porosity,hydrate saturation and the average radius of sand sediment *** the establishment of numerical model for depressurizationinduced hydrate dissociation in porous media,the cumulative gas productions were modeling and compared with the experimental data at the different hydrate *** results indicated that the proposed prediction equations are valid for the hydrate dissociation surface area,and the graincoating surface area model performs well at lower hydrate saturation for hydrate dissociation simulation,whereas at higher hydrate saturation,the hydrate dissociation simulation from the porefilling surface area model is more ***,the sensitivity analysis showed that the hydrate dissociation surface area has a significant impact on the cumulative gas production.

关键词： Surface area Methane hydrate Hydrate dissociation Hydrate morphology Depressurization

Exact Calculations of Vertex ^-sγb and ,^-sZb in the Unitary Gauge

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2007年第3X期48卷 502-508页

作者： WU Lu-sen xiao Zhen-Jun Department of Physics and Institute of Theoretical Physics Nanjing Normal University Nanjing 210097 China

In this paper, we present the exact calculations for the vertex ^-sγb and ^sZb in the unitary gauge. We find that （a） the divergent- and μ-dependent terms are left in the effective vertex function Г^γμ（p, k） for b → sγ transition even after we sum up the contributions from four related Feynman diagrams; （b） for an on-shell photon, such terms do not contribute et al.; （c） for off-shell photon, these terms will be canceled when the contributions from both vertex ^sγb and ^sZb are taken into account simultaneously, and therefore the finite and gauge-independent function Zo（xt） = Co（xt）＋ Do（xt）/4, which governs the semi-leptonic decay b → sl^- l^＋, is derived in the unitary gauge.

关键词： unitary gauge Feynman diagram vertex

Endothelial progenitor cells and coronary artery disease:Current concepts and future research directions

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

World Journal of Clinical Cases 2021年第30期9卷 8953-8966页

作者： sen-Tong xiao Chun-Yan Kuang Department of Cardiovascular Diseases People’s Hospital Affiliated to Guizhou Medical UniversityGuiyang 550003Guizhou ProvinceChina Kuang Department of Cardiovascular DiseasesGuizhou Provincial People's HospitalGuiyang 550003Guizhou ProvinceChina

Vascular injury is a frequent pathology in coronary artery *** repair the vasculature,scientists have found that endothelial progenitor cells(EPCs)have excellent properties associated with *** time,research on EPCs has made encouraging progress regardless of pathology or clinical *** review focuses on the origins and cell markers of EPCs,and the connection between EPCs and coronary artery *** addition,we summarized various studies of EPC-capturing stents and EPC infusion therapy,and aim to learn from past technology to predict the future.

关键词： Endothelial progenitor cells Coronary disease Endothelial progenitor-cell capture stents Endothelial progenitor-cell infusion Clinical application

Nodal Topological Phases in s-wave Superfluid of Ultracold Fermionic Gases

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

Communications in Theoretical Physics 2018年第2期69卷 137-142页

作者： Bei-Bing Huang xiao-sen Yang Department of Physics Yancheng Institute of Technology Yancheng 224051 China Department of Physics Jiangsu University Zhenjiang 212013 China

The gapless Weyl superfluid has been widely studied in the three-dimensional ultracold fermionic superfluid. In contrast to Weyl superfluid, there exists another kind of gapless superfluid with topologically protected nodal lines, which can be regarded as the superttuid counterpart of nodal line semimetal in the condensed matter physics, just as Weyl superfluid with Weyl semimetal. In this paper we study the ground states of the cold fermionic gases in cubic optical lattices with one-dimensional spin-orbit coupling and transverse Zeeman field and map out the topological phase diagram of the system. We demonstrate that in addition to a fully gapped topologically trivial phase, some different nodal line superfluid phases appear when the Zeeman field is adjusted. The presence of topologically stable nodal lines implies the dispersionless zero-energy fiat band in a finite region of the surface Brillouin zone. Experimentally these nodal line superfluid states can be detected via the momentum-resolved radio-frequency spectroscopy. The nodal line topological superfluid provide fertile grounds for exploring exotic quantum matters in the context of ultraeold atoms.

关键词： gapless topological superfluid nodal line surface flat band

在线全文

学校读者我要写书评

暂无评论

基坑开挖对管桩竖向承载性状影响研究

湖南工业大学学报 2025年第1期39卷 19-25,78页

作者：杨庆光肖森刘峰柳雄湖南工业大学土木工程学院湖南株洲412007

针对基坑开挖引起管桩挤土效应的弱化,以及挤土效应弱化对管桩承载性质影响问题,开展了室内模型试验,并通过对模型试验进行数值建模,验证了数值模型的可靠性。在此基础上,从桩长、桩间距、桩侧摩阻力系数对开挖卸荷影响下管桩基础承载... 详细信息

针对基坑开挖引起管桩挤土效应的弱化,以及挤土效应弱化对管桩承载性质影响问题,开展了室内模型试验,并通过对模型试验进行数值建模,验证了数值模型的可靠性。在此基础上,从桩长、桩间距、桩侧摩阻力系数对开挖卸荷影响下管桩基础承载性状的影响展开研究。结果表明:开挖卸荷对管桩承载特性造成较大影响,极限承载力对应桩顶沉降量提高54.5%;数值计算发现,卸载前后极限荷载所对应最大沉降差率为9.52%,满足工程精度要求,验证了所提数值模型的可靠性;数值计算结果表明,随桩长提高,最大桩身轴力位置不断上升,而中性点位置却不断下降;桩间距越小,开挖卸荷对桩身轴力影响越大,而对负摩阻力影响越小;摩阻力系数为0.3时,摩阻力系数对桩身轴力及桩侧摩阻力发挥敏感度最高。

关键词：承载性状挤土效应侧摩阻力管桩基坑开挖

Application of fracturing technology to increase gas production in low-permeability hydrate reservoir:A numerical study

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2021年第6期34卷 267-277页

作者： Peng-Fei Shen Gang Li xiao-sen Li Bo Li Jin-Ming Zhang State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing 400044China School of Resources and Safety Engineering Chongqing UniversityChongqing 400044China Key Laboratory of Gas Hydrate Guangzhou Institute of Energy ConversionChinese Academy of SciencesGuangzhou 510640China Guangzhou Center for Gas Hydrate Research Chinese Academy of SciencesGuangzhou 510640China

Low temperature and low permeability are the challenges for the development of hydrate reservoirs in *** ice produced around the production well caused by high depressurization driving force reduces the gas production,and it is necessary to reduce the effect of ice production on gas *** this work,a new combination of fracturing technology and depressurization method was proposed to evaluate the gas production potential at the site DK-2 in Qinghai-Tibet Plateau Permafrost.A relatively higher intrinsic permeability of the fracture zone surround the horizontal production well was created by the fracturing *** simulation results showed that the fracture zone reduced the blocking of production ice to production wells and promoted the propagation of production *** the gas production increased by 2.1 times as the radius of the fracture zone increased from 0 to 4 m in 30 *** half of the hydrate reservoirs were dissociated in 30 years,and greater than 51.7%of the gas production was produced during the first 10 ***,production behaviours were sensitive to the depressurization driving force but not to the thermal *** growth of gas production was not obvious with the intrinsic permeability of the fracture zone higher than 100 m *** effect of ice production on gas production by fracturing technology and depressurization method was limited.

关键词： Gas hydrates Fracturing technology Depressurization Low-permeability Permafrost

A numerical study of hydrodynamic characteristics and hydrological processes in the coastal wetlands during extreme events

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2023年第5期35卷 963-979页

作者： Ming-liang Zhang xiao-sen Zhu Yu-jia Wang Heng-zhi Jiang Lei Cui College of Ocean Science and Environment Dalian Ocean UniversityDalian116023China Technology Innovation Center for Coastal Ecological Environment and Disaster Protection Liaoning ProvinceDalian116023China National Marine Environmental Monitoring Center Dalian116023China

Providing accurate predictions of extreme water levels through numerical simulation has become essential for disaster prevention and damage mitigation in coastal wetland *** study applies the FVCOM model to simulate storm surges caused by several typhoons in the Bohai Sea and the North Huanghai *** vegetation drag force caused by salt marsh plants is inserted into the FVCOM model for model improvement with vegetation effect by integrating RS and GIS technologies.A parametric typhoon model is coupled with background wind fields derived to acquire the spatio-temporal variations of wind and pressure fields in the computational *** simulation results reproduce the extreme storm surges induced by typhoon events very *** modeling results are compared by validating with literature results to examine the effect of vegetation on tidal waves in tidal mud ***,the coupled model is also applied to explore storm surge attenuation and land intrusion during Typhoon Winnie in the wetlands of the Liao River *** simulation results indicate that salt marsh plants can reduce the flow current with little impact on tide flooding/ebbing in vegetated ***,the results show that typhoon presence increases the inundation depth and extendes the flood time in the tidal wetlands of the study *** FVCOM model incorporating the method with vegetation drag force can provide new insights to understand the comprehensive impact of tidal wetland plants on hydrodynamic characteristics in the Bohai Sea and other waters,hence presents a more accurate quantification of the hydrological process of storm surge in the tidal wetlands.

关键词： FVCOM circulation model Parametric typhoon model coastal wetlands storm surge hydrological process

Microscopic study on the key process and influence of efficient synthesis of natural gas hydrate by in situ Raman analysis of water microstructure in different systems with temperature drop

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

Journal of Energy Chemistry 2023年第7期82卷 317-333,I0008页

作者： Wei Zhang Chun-Gang Xu xiao-sen Li Zhuo-Yi Huang Zhao-Yang Chen School of Engineering Science University of Science and Technology of ChinaHefei 230023AnhuiChina Guangzhou Institute of Energy Conversion Chinese Academy of SciencesGuangzhou 510640GuangdongChina CAS Key Laboratory of Gas Hydrate Guangzhou 510640GuangdongChina Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development Guangzhou 510640GuangdongChina School of Energy Science and Engineering University of Science and Technology of ChinaHefei 230023AnhuiChina

Gas hydrate technology has considerable potential in many ***,due to the lack of understanding of the micro mechanism of hydrate formation,it has not been commercially applied so *** hydrate formation is essentially a gas-liquid-solid phase transition of water and gas molecules at a certain temperature and *** key to the hydrate formation is the transformation of water molecule from disordered arrangement to ordered *** this process,weakly hydrogen bonded water will be correspondingly converted to strongly hydrogen bonded *** in situ Raman analysis and experiments,the position change of the corresponding peaks of the strongly hydrogen bonded water and the weakly hydrogen bonded water was compared in this work,and the key microscopic process and influence of gas hydrate formation in different systems were comprehensively studied and *** is found that,with the decrease of temperature,the OAH of the weakly hydrogen bonded water remains unchanged when the temperature drops to a certain value,which is the key to the transformation of water into cage hydrate rather than *** conversion from the weakly hydrogen bonded water to the strongly hydrogen bonded water is closely related to the gas-liquid interface force,the hydrophilicity/hydrophobicity of the promoter,the ionization degree of liquid,and the electrostatic field of the *** the four most common promoters,tetrahydrofuran(THF)has the highest efficiency in promoting methane(CH4)hydrate ***,this study provides a scientific direction and basis for the development of high efficient hydrate formation promoters,which can effectively weaken the hydrogen bond of weakly hydrogen bonded water and promote the conversion of weakly hydrogen bonded water to strongly hydrogen bonded water.

关键词： Hydrate Conversion Hydrogen bonded water Promoter Micro mechanism

Role of different types of water in bentonite clay on hydrate formation and decomposition

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2022年第10期50卷 310-316页

作者： Yu Zhang Lei Zhang Chang Chen Hao-Peng Zeng xiao-sen Li Bo Yang Key Laboratory of Gas Hydrate Guangzhou Institute of Energy ConversionChinese Academy of SciencesGuangzhouGuangdong 510640China Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development GuangzhouGuangdong 510640China University of Chinese Academy of Sciences Beijing 10083China Guangzhou Special Pressure Equipment Inspection and Research Institute Guangzhou 510663China

The equilibrium and kinetic of hydrate in sediments can be affected by the presence of external components like bentonite with a relatively large surface *** investigate the hydrate formation and decomposition behaviors in bentonite clay,the experiments of methane hydrate formation and decomposition using the multi-step decomposition method in bentonite with different water contents of 20%,40%and 60%(mass)were carried *** contents of bound,capillary and gravity water in bentonite clay and their roles during hydrate formation and decomposition were *** bentonite with water content of 20%(mass),the hydrate formation rate keeps fast during the whole formation process,and the final gas consumption under different initial formation pressures is *** bentonite with the water contents of 40%and 60%(mass),the hydrate formation rate declines significantly at the later stage of the hydrate *** final gas consumption of bentonite with the water contents of 40%and 60%(mass)is significantly higher than that with the water content of 20%(mass).During the decomposition process,the stable pressure increases with the decrease of the water *** mainly forms in free water in bentonite *** bentonite clay with the water contents of 20%and 40%(mass),the hydrate forms in capillary *** bentonite clay with the water content of 60%(mass),the hydrate forms both in capillary water and gravity *** bound water of dry bentonite clay is about 3.93%(mass)and the content of capillary water ranges from 42.37%to 48.21%(mass)of the dry bentonite clay.

关键词： Methane hydrate Bentonite Formation anddecomposition Bound water Capillary water

Optimizing Seed Water Content:Relevance to Storage Stability and Molecular Mobility

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2010年第3期52卷 324-331页

作者： Ming Zhang Jia-Jin Zhuo Xu Wang sen Wu xiao-Feng Wang Key Laboratory for Genetics and Breeding in Forest Trees and Ornamental Plants Ministry of Education Beijing Forestry University Beijing 100083 China

This research was conducted to determine the optimum moisture content （MC） that gave maximum longevity to seeds. Three species were used to represent seeds with different dry matter reserves, which gives them different sorption properties： maize （Zea mays L.）, elm （Ulmus pumila L.） and safflower （Carthamus tinctorius L.）. The seeds of elm, safflower, and maize embryos with MC ranging from 0.00- 0.15 g H2O/g dry weight （DW） were stored at 35℃ for different periods of time. The results showed that the optimum MC for seed and embryo storage varied between species （0.057 g H20/g DW for maize embryos, 0.045 g H20/g DW for elm, and 0.02 g H2O/g DW for safflower）. Drying below this optimum MC increased the aging rate and there were detrimental effects of drying. The relative humidity corresponding to optimum MC in embryos of maize, elms and safflower was about 15%, 12% and 7% respectively, according to the lipid composition of the embryos. The data provided confirmatory evidence that molecular mobility （△Azz） in elms, maize and safflower embryos was compatible with the optimum moisture content.

关键词： SEEDS MOISTURE CORN ELM SAFFLOWER MOLECULAR microbiology QUANTITATIVE research