检索结果-南通市图书馆

Historical Sediment Record of ^(137)Cs, δ-HCH, and δ^(13)C Reflects the Impact of land Use on Soil Erosion

Journal of Mountain Science 2014年第4期11卷 866-874页

作者： TANG Xiang-Yu ZHANG Xin-Bao GUAN Zhuo lONG Yi TANG Qiang lü Yu-Juan Key laboratory of Mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and Environment Chinese Academy of Sciences College of Water Resources and Architectural Engineering Northwest A&F University

This paper reports the concentrations of 137Cs, hexaehlorocyclohexane （HCH）, dichlorodiphenyltrichloroethanes （DDT） and its main degradation products, δ3C, and organic carbon in pond sediments （O-210 cm, sectioned by 2-20 cm interval） and surface soils （the 0-3 cm horizon） collected in 2OlO from Chenjia catchment, which is located in Yanting county in the hilly central Sichuan of China. α-, β-, and γ-HCH, DDT, and DDD were not detected throughout the sediment profile. Trace concentrations of δ-HCH （0.89-29.31 ng g^-1） and p,p＇- DDE （1.85-6.02 ng g^-1） were detected only in top 40 cm sediment. The 137Cs fallout peak in 1963 （corresponding to the 55-60 cm depth）, the sedimentary signature left by the last year of HCH use in 1989 （an additional indicator at 20-25 cm）, and the obvious original channel bed prior to the construction of the pond in 1956 were used as temporal markers to estimate changes in average sedimentation rate between different periods due to changes in land use. Continuous, marked decrease in average sedimentation rate （i.e., 3.79, 1.35 and 1.07 cm year-1 in 1956-1963, 1963-1989, and 1989-2010, respectively） over time was observed, probably due to the reforestation, abandoning of steep sloping farmland for afforestation and natural re-vegetation （implementation of the Grain for Green Program）, and the conversion of part of gently sloping farmlandterraces to orchard land since the 1980s, especially since the 1990s. This was corroborated by the observed decrease （more negative） in δ3C of sediment towards the surface, which indicates increased relative contribution of eroded soil particles coming from slopes with increased tree cover in sediment source area. Combined use of 137Cs, δ-HCH, and δ3C record in sediments has been demonstrated to be a powerful approach to reconstruction of response in sedimentation rate to historical land use changes.

关键词： Cesium-137 Hexaehlorocyclohexane(HCH) Sedimentation history land use

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

Quantitative impact of mating duration on reproduction and offspring sex ratio of Phytoseiulus persimilis(Acari: Phytoseiidae)

引用

Journal of Integrative Agriculture 2019年第4期18卷 884-892页

作者： lü Jia-le ZHANG Bao-he JIANG Xiao-huan WANG En-dong XU Xue-nong lab of Predatory Mites Institute of Plant Protection Chinese Academy of Agricultural Sciences

Phytoseiulus persimilis is an important biological control agent, commercially produced worldwide. To increase understandings of its reproduction, herein we provided quantitative descriptions of the inflation and deflation of its spermathecae as a function of time and copulation duration, and the quantitative impact of copulation termination on volume of spermatheca vesicle, fecundity, and offspring sex ratio. After mating started, at least one spermatheca started to inflate immediately, but no egg was produced until spermatheca volume reached 1 021 μm3. Beyond this size, cumulative fecundity was linearly correlated with vesicle volume. Producing one egg required 36 μm3 volume increase of the vesicle. Each spermatheca vesicle reached its peak size at the end of mating duration(ca. 2.38 h after mating started), and started to shrink immediately. In 24 h, ca. 71% individuals had one completely shriveled spermatheca, while in 72 h all individuals had at least one shriveled spermatheca. The estimated maximum cumulative fecundity per female after a single mating is(69.4±7.7) eggs. No significant impact of mating termination on offspring sex ratio was observed after mating duration reached 60 min, while higher proportion of male offspring was observed when mating duration is 15 or 30 min. This study is the first step to investigate possible male impact on offspring sex ratio in P. persimilis. Our results suggested the number of sperms received during mating be a restriction factor of P. persimilis offspring sex ratio regulation.

关键词： predatory mite pseudoarrhe no toky spermathecae fecun dity sex determi nation

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

Scale effect of circularly polarized luminescent signal of matter

引用

National Science Review 2023年第5期10卷 232-239页

作者： Siyu Sun Xiaolin li Chen Xu Yan li YongZhen Wu Ben l.Feringa He Tian Xiang Ma Key laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint Research Center Frontiers Science Center for Materiobiology and Dynamic ChemistrySchool of Chemistry and Molecular EngineeringEast China University of Science and Technology School of Physics East China University of Science and Technology Stratingh Institute for Chemistry and Zernike Institute for Advanced Materials Faculty of Science and EngineeringUniversity of Groningen

Circularly polarized luminescence(CPl) is an important part in the research of modern luminescent materials and photoelectric ***,chiral molecules or chiral structures are the key factors to induce CPl spontaneous *** this study,a scale-effect model based on scalar theory was proposed to better understand the CPl signal of luminescent *** chiral structures being able to induce CPl,achiral ordered structures can also have a significant influence on CPl *** achiral structures are mainly reflected in the particle scale in micro-order or macro-order,*** CPl signal measured under most conditions depends on the scale of the ordered medium,and does not reflect the inherent chirality of the excited state of the luminescent *** kind of influence is difficult to be eliminated by simple and univers al strategies in *** the same time,it is found that the measurement entropy of CPl detection may be the key factor to determine the isotropy and anisotropy of the CPl *** discovery would bring new opportunities to the research of chiral luminescent *** strategy can also greatly reduce the development difficulty of CPl materials and show high application potential in biomedical,photoelectric information and other fields.

关键词： scale effect circularly polarized luminescent chirality quantum dots perovskite

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

Electron Structure and Microwave Absorbing Ability of Flaky FeSiAl Powders

引用

Journal of Materials Science & Technology 2011年第2期27卷 170-174页

作者： T.D.Zhou D.F.liang l.J.Deng D.C.luan Xihua University Chengdu 610039China State Key laboratory of Electronic Thin Films & Integrated Devices University of Electronic Science and Technology of ChinaChengdu 610054China

Soft magnetic metallic materials have been widely used for absorbing electromagnetic *** Fe 86 t Si t Al 14（t=9,11,14 and 16） alloys powders were prepared from melt-quenched ribbons by annealing and *** a previous report we discussed the order-disordered structure of this *** this article,we studied their electron *** electron numbers of（111） and（100） plane increase with increasing Si content but Bohr magneton *** permittivity and complex permeability are both decreased with increasing Si content *** lowest value of reflectivity among the four alloys is originated from Fe 70 Si 14 Al *** peak values of reflectivity are all lower than 10 dB,and the absorbing frequency range（R 10 dB） increases from 1 to 2 GHz when t reaches 16.

关键词： Flaky powders Specific saturation magnetism Bohr magneton Absorbing ability

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

Adjusting oxygen vacancies in perovskite laCoO_(3)by electrochemical activation to enhance the hydrogen evolution reaction activity in alkaline condition

引用

Journal of Energy Chemistry 2023年第1期76卷 226-232,I0006页

作者： Chengrong Wu Yan Sun Xiaojian Wen Jia-Ye Zhang liang Qiao Jun Cheng Kelvin H.l.Zhang State Key laboratory of Physical Chemistry of Solid Surfaces College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005FujianChina School of Physics University of Electronic Science and Technology of ChinaChengdu 610054SichuanChina

Developing highly-active,earth-abundant non-precious-metal catalysts for hydrogen evolution reaction(HER)in alkaline solution would be beneficial to sustainable energy *** oxides are generally regarded as low-active HER catalysts,due to their inapposite hydrogen adsorption and water ***,we report a detailed study on perovskite laCoO_(3)epitaxial thin films as a model catalyst to significantly enhance the HER performance via an electrochemical activation *** a result,the overpotential for the activation films to achieve a current density of 0.36 m A/cm^(2)is 238 m V,reduced by more than 200 m V in comparison with that of original *** characterization revealed the activation process dramatically increases the concentration of oxygen vacancies(Vo)on the surface of laCoO_(3).We established the relationship between the electronic structure induced by Vo and the enhanced HER *** theoretical calculations revealed that the Vo optimizes the hydrogen adsorption and dissociation of water on the surface of laCoO_(3)thin films,thus improving the HER catalytic *** work may promote a deepened understanding of perovskite oxides for HER mechanism by Vo adjusting and a new avenue for designing highly active electrochemical catalysts in alkaline solution.

关键词： Hydrogen evolution reaction Perovskite oxides Activation process Oxygen vacancies

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

Vitamin C promotes the proliferation and effector functions of human γδ T cells

引用

Cellular & Molecular Immunology 2020年第5期17卷 462-473页

作者： léonce Kouakanou Yan Xu Christian Peters Junyi He Yangzhe Wu Zhinan Yin Dieter Kabelitz Institute of Immunology Christian-Albrechts-University Kiel and University Hospital Schleswig-Holstein Campus KielKielGermany The First Affiliated Hospital Biomedical Translational Research InstituteGuangdong Province Key Laboratory of Molecular Immunology and Antibody EngineeringJinan University510632 GuangzhouChina

γδT cells are of interest as effector cells for cellular immunotherapy due to their HlA-non-restricted lysis of many different tumor cell *** applications include the adoptive transfer of in vitro-expandedγδT ***,it is important to optimize the culture conditions to enable maximal proliferative and functional *** C(l-ascorbic acid)is an essential vitamin with multiple effects on immune *** is a cofactor for several enzymes,has antioxidant activity,and is an epigenetic ***,we investigated the effects of vitamin C(VC)and its more stable derivative,l-ascorbic acid 2-phosphate(pVC),on the proliferation and effector function of humanγδT cells stimulated with zoledronate(ZOl)or synthetic phosphoantigens(pAgs).VC and pVC did not increaseγδT-cell expansion within ZOl-or pAg-stimulated PBMCs,but increased the proliferation of purifiedγδT cells and 14-day-expandedγδT-cell lines in response toγδT-cell-specific *** reduced the apoptosis ofγδT cells during primary *** pVC did not prevent activation-induced death of pAg-restimulatedγδT cells,it enhanced the cell cycle progression and cellular ***,VC and pVC enhanced cytokine production during primary activation,as well as upon pAg restimulation of 14-day-expandedγδT *** and pVC also increased the oxidative respiration and glycolysis ofγδT cells,but stimulus-dependent differences were *** modulatory activity of VC and pVC might help to increase the efficacy ofγδT-cell expansion for adoptive immunotherapy.

关键词： γδT cells Vitamin C lymphocyte activation adoptive T-cell transfer

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

镧系离子间无辐射能量传递速率的教程综述

引用

发光学报 2022年第12期43卷 1871-1891页

作者： Albano N Carneiro Neto Renaldo T Moura Jr Jorge A A Coelho Mauro E Silva-Junior Janderson l Costa Oscar l Malta Ricardo l longo 阿威罗大学物理系和CICECO-阿威罗材料研究所阿威罗葡萄牙3810-193 南卫理公会大学化学系达拉斯美国75275-0314 帕拉伊巴联邦大学化学与物理系阿雷亚巴西58397-000 伯南布哥联邦大学基础化学系累西腓巴西50740-560 伯南布哥联邦大学材料科学研究生院累西腓巴西50670-901

在本教程综述中,我们重新阐述和表达了镧系离子间无辐射能量传递(ET)速率的理论形式,并且强调了考虑镧系离子本身特异性所引发的与Förster和Dexter理论不同之处。所给出的表达式遵循了Judd-Ofelt的4f-4f跃迁理论框架之下的Kushida方法,... 详细信息

在本教程综述中,我们重新阐述和表达了镧系离子间无辐射能量传递(ET)速率的理论形式,并且强调了考虑镧系离子本身特异性所引发的与Förster和Dexter理论不同之处。所给出的表达式遵循了Judd-Ofelt的4f-4f跃迁理论框架之下的Kushida方法,并计入了如下电多极机制:偶极-偶极(W_(d-d))、偶极-四极(W_(d-q))和四极-四极(W_(q-q))。更为重要的是,当前的机制也扩展包括了交换(W_(ex))和磁偶极子-磁偶极子(W_(md-md))作用,并经过改进进一步包含了屏蔽效应以及给出了F因子(费米黄金规则中的态密度)的解析表达式。与Kushida的原始方法类似,我们只考虑了强制电偶极子(FED)对Judd-Ofelt强度参数的贡献,并细节性地讨论了磁偶极-磁偶极相互作用的选择定则以及相关矩阵元的计算。此外,我们还以Tb(Ⅲ)-Eu(Ⅲ)和Yb(Ⅲ)-Er(Ⅲ)的能量传递速率计算为例,逐步展示了计算过程、主要的计算支撑信息以及所使用的计算脚本。

关键词：无辐射能量传递镧系理论计算 ln-ln能量传递速率选择定则

来源：

维普期刊数据库博看期刊

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

Supplying the trip to antibody production-nutrients,signaling,and the programming of cellular metabolism in the mature B lineage

引用

Cellular & Molecular Immunology 2022年第3期19卷 352-369页

作者： Mark R.Boothby Shawna K.Brookens Ariel l.Raybuck Sung Hoon Cho Department of Pathology Microbiology&ImmunologyMolecular Pathogenesis DivisionVanderbilt University Medical CenterNashvilleTN37232USA Department of Medicine Rheumatology&Immunology DivisionVanderbilt University Medical CenterNashvilleTN37232USA Cancer Biology Program Vanderbilt UniversityNashvilleTN37232USA Vanderbilt Institute of Infection Inflammationand ImmunologyNashvilleTN37232USA

The COVID pandemic has refreshed and expanded recognition of the vital role that sustained antibody(Ab)secretion plays in our immune defenses against microbes and of the importance of vaccines that elicit Ab protection against *** this backdrop,it is especially timely to review aspects of the molecular programming that govern how the cells that secrete Abs arise,persist,and meet the challenge of secreting vast amounts of these *** plasmablasts and plasma cells(PCs)are the primary sources of secreted Abs,the process leading to the existence of these cell types starts with naive B lymphocytes that proliferate and differentiate toward several potential *** each step,cells reside in specific microenvironments in which they not only receive signals from cytokines and other cell surface receptors but also draw on the interstitium for *** in turn influence flux through intermediary metabolism and sensor enzymes that regulate gene transcription,translation,and *** review will focus on nutrient supply and how sensor mechanisms influence distinct cellular stages that lead to PCs and their adaptations as factories dedicated to Ab *** findings of this group and others,sometimes exhibiting differences,will be summarized with regard to the journey to a distinctive metabolic program in PCs.

关键词： B lymphocyte Plasma cell Intermediary metabolism Glucose Glutamine Fatty acid Signal transduction

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

Yersinia pestis: examining wildlife plague surveillance in China and the USA

引用

Integrative Zoology 2012年第1期7卷 99-109页

作者： Sarah N.BEVINS John A.BAROCH Dale l.NOlTE Min ZHANG Hongxuan HE US Department of Agriculture Wildlife ServicesNational Wildlife Disease ProgramFort CollinsColoradoUSA Chinese Academy of Sciences Institute of ZoologyBeijingChina

Plague is a zoonotic disease caused by the bacterium Yersinia pestis lehmann and Neumann,*** it is essentially a disease of rodents,plague can also be transmitted to ***,plague has caused mas-sive morbidity and mortality events in human populations,and has recently been classified as a reemerging dis-ease in many parts of the *** public health threat has led many countries to set up wild and domestic an-imal surveillance programs in an attempt to monitor plague activity that could potentially spill over into human *** China and the USA have plague surveillance programs in place,but the disease dynamics dif-fer in each *** present data on plague seroprevalence in wildlife and review different approaches for plague surveillance in the 2 *** need to better comprehend plague dynamics,combined with the fact that there are still several thousand human plague cases per year,make well-designed wildlife surveillance pro-grams a critical part of both understanding plague risks to humans and preventing disease outbreaks in the future.

关键词： plague sentinel species surveillance Yersinia pestis

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

Structural evolution, optoelectrical and corrosion properties of electrodeposited WO_3 integration on Zn-TiO_2 electrolyte for defence super application

引用

Defence Technology（防务技术） 2018年第5期14卷 396-402页

作者： A.A.Daniyan l.E.Umoru O.S.I.Fayomi A.P.I.Popoola Department of Materials Science and Engineering Obafemi Awolowo University Department of Chemical Metallurgical and Materials Engineering Tshwane University of Technology Department of Mechanical Engineering Covenant University

Multifunctional nano composite coatings of Zn-TiO_2-WO_3 were deposited electrolytically on mild steel(MS) from Zn bath, having Zn^(2+) ions and uniform dispersion of TiO_2 and WO_3 nano particulates. The electrical, optical and corrosion resistance characteristics of the electrocodeposited coatings were assessed by Keithley 2400 Series Source meter with Multimeters, Newport Solar Simulator and a PGSTAT30 Autolab potentiostat respectively. The morphological characteristics of the composite coatings were characterized by scanning electron microscope(SEM) equipped with energy dispersive spectrometer(EDS). The result revealed that the electrocodeposits showed good stability and Zn-TiO_2-WO_3 nanocomposite deposits displayed enhanced microstructural qualities, good electrical conductivity and exhibited enriched corrosion resistance.

关键词： Nano-composite Electrocodeposition Corrosion Conductivity and resistance

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：