检索结果-南通市图书馆

Journal of Integrative Plant Biology 2009年第1期51卷 107-112页

作者： yan hu wang-zhen guo tian-zhen zhang National Key Laboratory of Crop Genetics & Germplasm Enhancement Cotton Research Institute Nanjing Agricultural University Nanjing 210095 China

A bacterial artificial chromosome （BAC） library was constructed for Gossypium hirsutum acc. TM-1, a genetic and genomic standard line for Upland cotton. The library consists of 147 456 clones with an average insert size of 122.8 kb ranging from 97 to 240 kb. About 96.0% of the clones have inserts over 100 kb. Therefore, this library represents theoretically 7.4 haploid genome equivalents based on an AD genome size of 2 425 Mb. Clones were stored in 384 384- well plates and arrayed into multiplex pools for rapid and reliable library screening. BAC screening was carried out by four-round poiymerase chain reactions using 23 simple sequence repeats （SSR） markers, three sequence-related amplified polymorphism markers and one pair of primers for a gene associated with fiber development to test the quality of the library. Correspondingly, in total 92 positive BAC clones were identified with an average four positive clones per SSR marker, ranging from one to eight hits. Additionally, since these SSR markers have been localized to chromosome 12 （A12） and 26 （D12） according to the genetic map, these BAC clones are expected to serve as seeds for the physical mapping of these two homologous chromosomes, sequentially map-based cloning of quantitative trait loci or genes associated with important agronomic traits.

关键词： bacterial artificial chromosome library polymerase chain reaction screening simple sequence repeats markers TM-1 upland cotton.

Research on Pitch Control Strategies of Horizontal Axis Tidal Current Turbine

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2020年第2期34卷 223-231页

作者： wang Bing-zhen hu Teng-yan guo Yi zhang Yuan-fei National Ocean Technology Center Tianjin 300112China

Based on blade element momentum theory and generator characteristic test,a dynamic simulation model of 150 kW horizontal-axis tidal current turbine was *** matching of the dynamic characteristics between the turbine and generator under various current velocities is studied,and the influence of the pitch angle on the matching is *** the problem of maximum power output in case of low current speed and limiting power in high current speed,the relation between optimal pitch angle and output power is *** the basis of dynamic characteristic analysis,the variable pitch control strategy is *** performance of the turbine under various tidal conditions is *** research results show that the designed controller enables the turbine to operate efficiently under the condition of low current speed,and achieve the goal of limited power at high current speed.

关键词： tidal energy horizontal axis tidal current turbine(HATT) pitch control simulation

Research of Genetic Diversity in Seven Kobresia by AFLP in Tibetan Plateau

在线全文

学校读者我要写书评

暂无评论

Agricultural Sciences in China 2009年第8期8卷 994-999页

作者： zhenG Hong-mei hu tian-ming wang Quan-zhen zhang guo-yun SONG Jiang-hu College of Resources and Environment Northwest A＆F University Yangling 712100 P.R. China College of Animal Science and Technology Northwest A＆F University Yangling 712100 P.R.China Key Laboratory of Agricultural Molecular Biology of Shaanxi Province Yangling 712100 P.R.China

This work analyzed the genetic diversity of Kobresia accessions at the molecular level, and further obtained the necessary information for breeding and germplasm evaluation. Genomic DNA of Kobresia was amplified with four E＋3 and M＋3 primer combinations with AFLP （amplified fragment length polymorphism）. AFLP analysis produced 164 scorable bands, of which 154 （93.96%） were polymorphic. The mean Nei＇s gene diversity index （H） was 0.2430, and the Shannon＇s information index （I） was 0.4012, indicating the abundant genetic diversity of Kobresia. The 11 Kobresia accessions from Tibetan Plateau, China, can be classified into five groups after cluster analysis based on the UPGMA （unweigbted pair group method arithmetic average） method. In general, there was abundant genetic diversity among Kobresia accessions resources, and the genetic coefficient was unrelated to their geographic latitude. Natural habitats influenced genetic differentiation of Kobresia.

关键词： Kobresia genetic diversity AFLP

Fabrication of porous Zn_(2)TiO_(4)-ZnO microtubes and analysis of their acetone gas sensing properties

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2021年第6期40卷 1528-1535页

作者： Xiao-yan Chen Xin-zhen wang Feng-Jun Liu guo-Song zhang Xiao-Jie Song Jian tian Hong-Zhi Cui School of Materials Science and Engineering Shandong University of Science and TechnologyQingdao 266590China Shandong Province Key Laboratory of Mine Mechanical Engineering Shandong University of Science and TechnologyQingdao 266590China

Porous Zn2 Ti04-ZnO microtubes have been successfully fabricated using chemical precipitation followed by a calcination process using a carbon fiber *** porous Zn_(2)TiO_(4)-ZnO micro tubes with a diameter of~4μm consisted of Zn_(2)TiO_(4) and ZnO *** displayed worm-like pore *** fibers played an important role during the porous Zn_(2)TiO_(4)-ZnO microtube formation *** porous and hollow structure of Zn_(2)TiO_(4)-ZnO provided abundant active sensing sites and channels for gas adsorption and *** porous Zn_(2)TiO_(4)-ZnO microtubes exhibited improved gas sensing properties for acetone when compared with pure *** Zn_(2)TiO_(4)-ZnO sensor response was 33.4 for 100μg·ml^(-1) acetone at the optimum operating temperature(370℃).This was~2.7 times higher than that of pure ***,the as-prepared porous Zn_(2)TiO_(4)-ZnO microtubes displayed sufficient long-term acetone stability and *** showed the potential application for acetone *** enhanced Zn_(2)TiO_(4)-ZnO gas sensing properties are due to the unique heterogeneous and porous structure,which was analyzed using the porous and band structure.

关键词： Zn_(2)TiO_(4) Zinc oxide Porous Heterostructure Sensors

Prehistoric damaging earthquake promoted the decline of"Heluo Ancient State"in Early China

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2023年第5期66卷 1120-1132页

作者： Xiu hu Peng LU Youli LI Duowen MO Wanfa GU Qingri LIU Ailun guo Panpan CHEN hui wang yan tian Xu wang Yayi hu Jiqin zhang zhen wang Quanxing LUO Junjie XU School of Urban and Environmental Science Peking UniversityBeijing100871China Institute of Geography Henan Academy of SciencesZhengzhou450052China zhengzhou Institute of Cultural Relics and Archaeology Zhengzhou450000China The Institute of Archaeology Chinese Academy of Social SciencesBeijing100710China College of History Zhengzhou UniversityZhengzhou450000China School of Earth Sciences and Engineering Sun Yat-Sen UniversityGuangzhou510275China

The emergence of the"Ancient State"is considered an important stage in the discourse on human *** on its complex and hierarchical social structure,the Shuanghuaishu site of Henan Province is regarded as an"Ancient state",specifically the"Heluo Ancient State".The site is situated in the middle reaches of the Yellow River region and played a key role in prehistoric ***,the reasons behind its decline are ***,we conducted an integrated investigation of the archaeological excavations and archaeoseismic analyses at the Shuanghuaishu *** identified paleoseismic remains within paleo-artificial moats,which were formed owing to off-fault structures of soil liquefaction,hillslope landslides,and related ground fractures,along with shake-related wall disruption and building collapse in the residential *** dating was conducted to constrain the age for this earthquake event,which was determined to be approximately 5.0 cal kyr ***,based on the practical curve for earthquake-induced liquefaction,the preliminary estimate of the magnitude of this paleo seismic event is greater than M_(s)*** propose that the Shuanghuaishu site experienced a recession after the earthquake event,which may have influenced the continuous development of the"Heluo Ancient State"as a regional center settlement.

关键词： Shuanghuaishu site Heluo Ancient State yangshao culture Archaeoseismology Geohazards

Self-supported NiFe-LDH nanosheets on NiMo-based nanorods as high-performance bifunctional electrocatalysts for overall water splitting at industrial-level current densities

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第5期17卷 3769-3776页

作者： yan zhang Biao Feng MingLei yan zhen Shen Yiqun Chen Jingyi tian Fengfei Xu Guanghai Chen Xizhang wang Lijun yang Qiang Wu zheng hu Key Laboratory of Mesoscopic Chemistry of Ministry of Education(MOE)and Jiangsu Provincial Lab for Nanotechnology School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China College of Water Conservancy and Hydropower Engineering Sichuan Agricultural UniversityYa’an 625014China

Efficient,durable and economic electrocatalysts are crucial for commercializing water electrolysis ***,we report an advanced bifunctional electrocatalyst for alkaline water splitting by growing NiFe-layered double hydroxide(NiFe-LDH)nanosheet arrays on the conductive NiMo-based nanorods deposited on Ni foam to form a three-dimensional(3D)architecture,which exhibits exceptional performances for both hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).In overall water splitting,only the low operation voltages of 1.45/1.61 V are required to reach the current density of 10/500 mA·cm^(-2),and the continuous water splitting at an industrial-level current density of 500 mA·cm^(-2) shows a negligible degradation(1.8%)of the cell voltage over 1000 *** outstanding performance is ascribed to the synergism of the HER-active NiMo-based nanorods and the OER-active NiFe-LDH nanosheet arrays of the hybridized 3D ***,the dense NiFe-LDH nanosheet arrays enhance the local pH on cathode by retarding OH-diffusion and enlarge the electrochemically active surface area on anode,while the conductive NiMo-based nanorods on Ni foam much decrease the charge-transfer resistances of both *** study provides an efficient strategy to explore advanced bifunctional electrocatalysts for overall water splitting by rationally hybridizing HER-and OER-active components.

关键词： alkaline water splitting bifunctional electrocatalysts layered double hydroxides high durability industrial current densities

Microscopic characteristics of tight sandstone reservoirs and their effects on the imbibition efficiency of fracturing fluids:A case study of the Linxing area,Ordos Basin

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

Energy Geoscience 2024年第3期5卷 328-338页

作者： Qihui Li Dazhong Ren hu wang Haipeng Sun tian Li Hanpeng zhang zhen yan Rongjun zhang Le Qu Engineering Research Center of Development and Management for Low to Ultra-Low Permeability Oil&Gas Reservoirs in West China(Ministry of Education) College of Petroleum EngineeringXi'an Shiyou UniversityXi'anShaanxi710065China No.6 Gas Production Plant PetroChina Changqing Oilfield CompanyYan‘anShaanxi716000China No.4 Oil Production Plant PetroChina Changqing Oilfield CompanyXi'anShaanxi710021China Engineering Technology Branch CNOOC Energy Development Co.Ltd.Tianjin300452China Xi'an Key Laboratory of Tight Oil(Shale Oil)Development Xi‘an Shiyou UniversityXi'anShaanxi710065China

The Linxing area within the Ordos Basin exhibits pronounced reservoir heterogeneity and intricate micro-pore structures,rendering it susceptible to water-blocking damage during imbibition *** study delved into the traits of tight sandstone reservoirs in the 8th member of the Shihezi Formation(also referred to as the He 8 Member)in the study area,as well as their effects on fracturing fluid *** experimental techniques such as nuclear magnetic resonance(NMR),high-pressure mercury intrusion(HPMI),and gas adsorption,this study elucidated the reservoir characteristics and examined the factors affecting the imbibition through imbibition *** findings reveal that:①The reservoir,with average porosity of 8.40%and average permeability of 0.642×10^(-3)μm^(2),consists principally of quartz,feldspar,and lithic fragments,with feldspathic litharenite serving as the primary rock type and illite as the chief clay mineral;②Nano-scale micro-pores and throats dominate the reservoir,with dissolution pores and intercrystalline pores serving as predominant pore types,exhibiting relatively high pore connectivity;③Imbibition efficiency is influenced by petrophysical properties,clay mineral content,and microscopic pore *** to the heterogeneity of the tight sandstone reservoir,microscopic factors have a more significant impact on the imbibition efficiency of fracturing fluids;④A comparative analysis shows that average pore size correlates most strongly with imbibition efficiency,followed by petrophysical properties and clay mineral *** contrast,the pore type has minimal *** are vital in the imbibition process,while meso-pores and macro-pores offer primary spaces for *** study offers theoretical insights and guidance for enhancing the post-fracturing production of tight sandstone reservoirs by examining the effects of these factors on the imbibition efficiency of fracturing fluids in tight sandstones.

关键词： Tight sandstone Ordos Basin Fracturing fluid Microscopic reservoir characteristics Imbibition efficiency Influencing factor

基于数值计算方法的翼型参数化、建模与优化研究（英文）

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2016年第8期17卷 632-645页

作者： tian-tian zhang Wei huANG zhen-guo wang Li yan Science and Technology on Scramjet Laboratory National University of Defense Technology

目的:1.比较并改善翼型参数化方法,获得设计变量少、拟合精度高的参数化方法;2.在参数化的基础上利用数值模拟的方法获取翼型流场参数,优化并获得特定条件下升阻比最大的翼型。创新点:1.通过与多项式拟合方法的对比证明了类别/形状函数... 详细信息

目的:1.比较并改善翼型参数化方法,获得设计变量少、拟合精度高的参数化方法;2.在参数化的基础上利用数值模拟的方法获取翼型流场参数,优化并获得特定条件下升阻比最大的翼型。创新点:1.通过与多项式拟合方法的对比证明了类别/形状函数转换(CST)法在翼型拟合方面的优越性,并通过调整控制点分布,在不增加设计变量的基础上改善了CST方法;2.通过建立响应面模型,利用多岛遗传算法与非线性序列二次规划法相结合的方式获得了更好的翼型优化效果。方法:1.利用修饰后的CST法对翼型进行参数化拟合与设计,并通过与二项式拟合法比较来验证其优越性;2.通过数值方法对翼型周围流场进行计算并与实验结果对比,获得精确计算气动参数的仿真条件;3.通过拉丁超立方采样获得设计变量,建立设计变量与翼型升阻比之间的响应面模型,通过多岛遗传算法与非线性序列二次规划法的结合和优化,得到一定条件下升阻比最大的翼型。结论:***法是一种优秀的参数化方法,本文的优化改善了形状函数控制点选取法则,使其对翼型头部和尾部的描述更加精确;与多项式相比,CST法可以通过更少的设计变量得到更高的拟合精度。2.基于多岛遗传算法的非线性序列二次规划法在本文中用以优化翼型使其具有更高升阻比。优化前后翼型的比较显示,两种优化方法的结合可以得到比单独使用各优化方法更好的结果。

关键词：类别/形状函数转换参数化数值仿真响应面模型优化翼型设计

Experimental study of the influencing factors and mechanisms of the pressure-reduction and augmented injection effect by nanoparticles in ultra-low permeability reservoirs

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第3期21卷 1915-1927页

作者： Pan wang Yu-Hang hu Liao-Yuan zhang Yong Meng zhen-Fu Ma tian-Ru wang Zi-Lin zhang Ji-Chao Fang Xiao-Qiang Liu Qing You yan zhang Beijing Key Laboratory of Unconventional Natural Gas Geological Evaluation and Development Engineering China University of Geosciences(Beijing)Beijing100083China School of Energy Resources China University of Geosciences(Beijing)Beijing100083China Petroleum Engineering Technology Research Institute Sinopec Shengli Oilfield CompanyDongying257000ShandongChina Hekou Oil Production Plant Sinopec Shengli Oilfield CompanyDongying257200ShandongChina Petroleum Exploration and Production Research Institute SINOPECBeijing102206China CNPC Engineering Technology R&D Company Limited Beijing102206China

Nanoparticles(NPs)have gained significant attention as a functional material due to their ability to effectively enhance pressure reduction in injection processes in ultra-low permeability *** are typically studied in controlled laboratory conditions,and their behavior in real-world,complex environments such as ultra-low permeability reservoirs,is not well understood due to the limited scope of their *** study investigates the efficacy and underlying mechanisms of NPs in decreasing injection pressure under various injection conditions(25—85℃,10—25 MPa).The results reveal that under optimal injection conditions,NPs effectively reduce injection pressure by a maximum of 22.77%in core *** pressure reduction rate is found to be positively correlated with oil saturation and permeability,and negatively correlated with temperature and ***,particle image velocimetry(PIV)experiments(25℃,atmospheric pressure)indicate that the pressure reduction is achieved by NPs through the reduction of wall shear resistance and wettability *** work has important implications for the design of water injection strategies in ultra-low permeability reservoirs.

关键词： Nanoparticle Pressure reduction Augmented injection Ultra-low permeability reservoir

Fabrication and cold test of prototype of spatially periodic radio frequency quadrupole focusing linac

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2021年第1期32卷 66-74页

作者： Pei-yan Yu Bin zhang Feng-Feng wang Chen-Xing Li guo-zhen Sun Zhi-Jun wang Lu-Bei Liu Chen-zhang Yuan Yuan He hu-Shan Xu Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China

A 325 MHz aluminum prototype of a spatially periodic RF quadrupole focusing linac was developed at the Institute of Modern Physics,Chinese Academy of Sciences,as a promising candidate for the front end of a high-current *** consists of an alternating series of crossbar H-type drift tubes and RF quadrupole *** to its special geometry,cavity fabrication is a major hurdle for its engineering development and *** this paper,we report the detailed mechanical design of this structure and describe its fabrication process,including machining,assembly,and *** field distribution was measured by the bead-pull *** results show that the field errors of both the accelerating and focusing fields are within an acceptable range.A tuning scheme for this new structure is proposed and *** cold test process and results are presented in *** development of this prototype provides valuable guidance for the application of the spatially periodic RF quadrupole structure.

关键词： Spatially periodic RF quadrupole focusing linac Mechanical structure design Bead-pull measurement