检索结果-南通市图书馆

人口与发展 2012年第4期18卷 14-20页

作者：李新运史纪慧山东财经大学管理科学与工程学院山东济南250014

区域人口与经济发展之间具有密切的互动关系。采用格兰杰检验法判定二者之间的因果关系,采用多元回归分析法提取二者之间的数量关系。根据1978～2010年统计数据和历次人口普查数据,对青岛市人口与经济发展之间的定量关系进行了实证研究。

关键词：人口经济发展互动关系格兰杰检验回归分析

Distribution and mapping of temperate savanna in the sandy lands of eastern China

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2025年第1期68卷 128-141页

作者： Xiaoya li Feng WANG Tao DUAN Kaijie YANG Bin YANG Chunmei WANG xin TIAN Qi LU Institute of Ecological Conservation and Restoration Institute of Desertification Studies Chinese Academy of Forestry Institute of Desertification Institute of Desertification Studies Chinese Academy of Forestry Institute of Great Green Wall Satellite Application Centre for Ecology and Environment MEE Institute of Microelectronics Chinese Academy of Sciences Aerospace Information Research Institute Chinese Academy of Sciences Institute of Forest Resource Information Techniques Chinese Academy of Forestry

Savannas are distributed globally across various *** perform a significant socioeconomic role in regulating net primary productivity and the terrestrial carbon *** to the high spatial heterogeneity induced by the mixed distribution of trees and grasses,current global land-cover classification maps often classify savannas as forests or grasslands Temperate savannas in China cover a vast area,yet their spatial patterns and extent remain poorly *** study developed a novel remote sensing temperate savannas mapping method by integrating very high-resolution （VHR） unmanned aerial vehicle （UAV） and GF-6 satellite imagery based on the vegetation structure characteristics of temperate savannas using the FAO definition of *** and validation datasets were collected from VHR UAV imagery covering the main temperate savannah types with a ground area of 1818 *** fractional woody vegetation cover （FWVC） and fractional herbaceous vegetation cover （FHVC） in temperate savannas were estimated by integrating Classification and Regression Tree and Random Forest *** current distribution of temperate savannas in the Horqin and Otindag Sandy Lands of Eastern China was mapped to a unit area of 0.5 *** root-mean-square error （RMSE） values for the FWVC and FHVC models were 10.69% and 11.67%,and the R2values were 0.66 and 0.63,*** assessment indicated that the new temperate savanna map had high identification accuracy,with a Kappa coefficient of 0.70,overall accuracy of 0.88,and average accuracy of *** savannas in the sandy lands of eastern China were primarily distributed in the northern Horqin Sandy Land the central and eastern regions of the Otindag Sandy Land,and the transition zone from the southern slopes of the Greater Khingan Mountains to the plains,covering a total area of 3.27×10～6 *** main savannah types were elm,oak/maple,and shrub *** savannas were widely distributed in the Otindag Sandy

关键词： Temperate savanna UAV imagery GF-6 Fractional woody vegetation cover Fractional herbaceous vegetation cover Machine learning

同方期刊数据库

在线全文

学校读者我要写书评

暂无评论

基于MFA的辽宁省环境经济系统分析

运筹与管理 2016年第5期25卷 222-230页

作者：刘心李云龙杨晨东北财经大学数学学院辽宁大连116025 东北财经大学经济学院辽宁大连116025 华为技术有限公司广东深圳518129

采用物质流（MFA）分析方法、依照质量守恒定律，探寻1990—2011年辽宁省物质流输入输出结构和趋势。发现辽宁省区域开采（DME）和直接物质投入（DMI）在1990～2000年间增速并不明显，2000年以后增幅明显提高。区域物质投入（TMI）和物... 详细信息

采用物质流（MFA）分析方法、依照质量守恒定律，探寻1990—2011年辽宁省物质流输入输出结构和趋势。发现辽宁省区域开采（DME）和直接物质投入（DMI）在1990～2000年间增速并不明显，2000年以后增幅明显提高。区域物质投入（TMI）和物质总需求（TMR）曲线呈现“N”型增长。考察物质消耗强度（MCI）和环境效率（EEE），分析显示辽宁省经济产出需要的相对物质质量投入整体上呈减少趋势，环境修复成绩显著，说明政府环境维护工作已起效，但整体来说粗放型经济发展模式仍然存在。

关键词：物质流环境效率消耗强度经济系统

在线全文

学校读者我要写书评

暂无评论

济南市土地利用遥感动态监测研究

水土保持研究 2007年第2期14卷 179-181,183页

作者：曲凯李新运山东师范大学人口.资源与环境学院山东经济学院信息管理学院济南250014

采用遥感与GIS相结合的技术对济南市土地资源进行遥感调查,按照全国二级分类系统建立判别标志,绘制了2000年和2004年济南市土地利用现状图和变化图。并简要分析了这4年间济南市土地利用的变化情况。

关键词：遥感 GIS 土地利用济南市

Vector meson's spin alignments in high energy reactions

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 5-20页

作者： Jin-Hui Chen Zuo-Tang liang Yu-Gang Ma xin-li Sheng Qun Wang Key Laboratory of Nuclear Physics and Ion-beam Application (MoE) Institute of Modern PhysicsFudan University Institute of Frontier and Interdisciplinary Science Key Laboratory of Particle Physics and Particle Irradiation (MOE)Shandong University INFN-Firenze Department of Modern Physics University of Science and Technology of China School of Mechanics and Physics Anhui University of Science and Technology

The global spin alignment of vector mesons has been observed by the STAR collaboration at the Relativistic Heavy Ion Collider （RHIC） at Brookhaven National Laboratory （BNL）.It provides a unique opportunity to probe the correlation between the polarized quark and antiquark in the strongly coupled quark-gluon plasma （sQGP） produced in relativistic heavy ion collisions,opening a new window to explore the properties of s *** addition,spin alignments of vector mesons have also been observed in other high-energy particle collisions such as e+e-annihilations at high energies where hadron production is dominated by quark fragmentation *** results obtained are quite different from those obtained in heavy ion collisions where quark coalescence/combination mechanism dominates suggesting strong dependence on hadronization *** comprehensive studies in different hadronization processes are *** this article,we present a brief review of theoretical and experimental advances in the study of vector meson’s spin alignments in a variety of high-energy particle collisions,with emphasis on hadronization mechanisms.

关键词： vector meson spin alignment global polarization relativistic heavy ion collisions fragmentation

开发区与行政区融合发展的制度逻辑与实践过程——以武汉经济技术开发区(汉南区)为例

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

北京行政学院学报 2018年第1期 21-27页

作者：李云新文娇慧中南财经政法大学公共管理学院湖北武汉430073

开发区与行政区融合发展是开发区进行"二次创业"的重要选择。运用制度分析框架解释这一现象,并试图呈现武汉经济技术开发区(汉南区)融合发展的实践过程。开发区与行政区融合发展过程中地方政府的行为体现了宏观制度环境和中观制度安排... 详细信息

开发区与行政区融合发展是开发区进行"二次创业"的重要选择。运用制度分析框架解释这一现象,并试图呈现武汉经济技术开发区(汉南区)融合发展的实践过程。开发区与行政区融合发展过程中地方政府的行为体现了宏观制度环境和中观制度安排的相互嵌套和相互作用。制度环境重大变迁对开发区与行政区融合发展提出了客观要求,纵向属地发包和横向竞争给地方政府提供了强大激励,行政区划的刚性约束使融合发展成为降低交易成本的理性选择。武汉开发区与汉南区融合发展的实践体现了行政关系、空间关系和产业关系的多维尺度重构。两区融合发展取得了显著成效,但仍面临着融合发展法律依据模糊、两区治理理念差异显著等诸多困境,需要通过多种措施实现综合发展绩效最大化。

关键词：开发区行政托管区域治理改革创新

荔枝采后炭疽病的发生情况及对贮藏效果的影响

在线全文

学校读者我要写书评

暂无评论

植物保护学报 2006年第4期33卷 351-356页

作者：刘爱媛陈维信李欣允华南农业大学园艺学院广东省果蔬保鲜重点实验室广州510642

为了明确广东、海南荔枝采后主要病害及其发生和危害情况，从两省荔枝主产区取果，在常温贮藏条件下观察荔枝采后病害的发生情况，测定荔枝果皮上炭疽病菌潜伏侵染率及其对荔枝采后生理变化和贮藏效果的影响。结果表明：荔枝采收后在28... 详细信息

为了明确广东、海南荔枝采后主要病害及其发生和危害情况，从两省荔枝主产区取果，在常温贮藏条件下观察荔枝采后病害的发生情况，测定荔枝果皮上炭疽病菌潜伏侵染率及其对荔枝采后生理变化和贮藏效果的影响。结果表明：荔枝采收后在28℃下贮藏，炭疽病、霜疫病和酸腐病的发病率分别为95．3％、6．5％和8．2％。炭疽病在采后3—4天开始表现症状，7天后发病率为60．8％～100％，9天后发病率为83．1％～100％，该病害是引起荔枝采后腐烂的主要病害，其病原菌主要来自采前潜伏侵染。从幼果果皮上可分离出潜伏侵染的炭疽病菌，随着果实的生长，果皮上的潜伏侵染率不断上升，到采收时炭疽病菌潜伏侵染率达到90％左右。炭疽病菌潜伏侵染率较高的荔枝果实。其采后呼吸速率、乙烯释放量、果皮丙二醛含量均显著升高，褐变腐烂较快，贮藏效果较差，即使在采后用杀菌剂处理，防治效果也不明显。采收时荔枝果皮上炭疽病菌潜伏侵染率越低，贮藏效果越好。在荔枝果实生长期间喷雾2—3次杀菌剂可显著地降低炭疽病菌潜伏侵染率，减轻荔枝采收后炭疽病的发生严重程度，提高荔枝贮藏效果。

关键词：炭疽病荔枝贮藏

宁南山区典型草本植物茎叶分解对土壤酶活性及微生物多样性的影响

在线全文

学校读者我要写书评

暂无评论

应用生态学报 2016年第10期27卷 3182-3188页

作者：李鑫李娅芸安韶山曾全超西北农林科技大学黄土高原土壤侵蚀与旱地农业国家重点实验室陕西杨凌712100 西北农林科技大学资源环境学院陕西杨凌712100

采用凋落物分解袋法,以宁南山区典型草本植物长芒草、铁杆蒿、百里香为研究对象,分析了3种植物茎叶分解过程中土壤酶活性变化特征和分解后期微生物多样性特征,以及土壤酶活性与初始土壤化学性质的关系.结果表明:植物茎叶分解480 d后,各... 详细信息

采用凋落物分解袋法,以宁南山区典型草本植物长芒草、铁杆蒿、百里香为研究对象,分析了3种植物茎叶分解过程中土壤酶活性变化特征和分解后期微生物多样性特征,以及土壤酶活性与初始土壤化学性质的关系.结果表明:植物茎叶分解480 d后,各处理土壤酶活性均有不同程度的增加,且长芒草处理土壤蔗糖酶活性和碱性磷酸酶活性最高,分别为32.40和1.99 mg·g^(-1)·24 h^(-1),百里香处理土壤脲酶活性最高(2.66 mg·g^(-1)·24 h^(-1)),铁杆蒿处理土壤纤维素酶活性最高(1.42 mg·g^(-1)·72 h^(-1)).分解末期土壤纤维素酶活性与土壤初始微生物生物量碳呈显著正相关;分解末期土壤纤维素酶活性与土壤初始硝态氮含量呈显著负相关.添加植物茎叶处理土壤细菌和真菌的Ace指数、Chao指数和Shannon指数均显著大于对照,Simpson指数显著小于对照.植物茎叶的分解显著提高了土壤细菌和真菌的丰度及多样性,进而提高了植物茎叶的分解速率,促进了生态系统营养物质的循环与转化.

关键词：草本植物土壤酶活性微生物多样性

Maintaining moderate levels of hypochlorous acid promotes neural stem cell proliferation and differentiation in the recovery phase of stroke

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第3期20卷 845-857页

作者： lin-Yan Huang Yi-De Zhang Jie Chen Hai-Di Fan Wan Wang Bin Wang Ju-yun Ma Peng-Peng li Hai-Wei Pu xin-Yian Guo Jian-Gang Shen Su-Hua Qi School of Medical Technology Xuzhou Key Laboratory of Laboratory DiagnosticsXuzhou Medical UniversityXuzhouJiangsu ProvinceChina School of Pharmacy Xuzhou Medical UniversityXuzhouJiangsu ProvinceChina Department of Laboratory Medicine Branch Hospital of Huai’an First People’s HospitalHuai’anJiangsu ProvinceChina Department of Laboratory Medicine the Affiliated Hospital of Xuzhou Medical UniversityXuzhouJiangsu ProvinceChina School of Chinese Medicine The University of Hong KongHong Kong Special Administrative RegionChina

It has been shown clinically that continuous removal of ischemia/reperfusion-induced reactive oxygen species is not conducive to the recovery of late ***,previous studies have shown that excessive increases in hypochlorous acid after stroke can cause severe damage to brain *** previous studies have found that a small amount of hypochlorous acid still exists in the later stage of stroke,but its specific role and mechanism are currently *** simulate stroke in vivo,a middle cerebral artery occlusion rat model was established,with an oxygen-glucose deprivation/reoxygenation model established in vitro to mimic *** found that in the early stage(within 24 hours)of ischemic stroke,neutrophils produced a large amount of hypochlorous acid,while in the recovery phase(10 days after stroke),microglia were activated and produced a small amount of hypochlorous ***,in acute stroke in rats,hypochlorous acid production was prevented using a hypochlorous acid scavenger,taurine,or myeloperoxidase inhibitor,4-aminobenzoic acid *** results showed that high levels of hypochlorous acid(200μM)induced neuronal apoptosis after oxygen/glucose deprivation/***,in the recovery phase of the middle cerebral artery occlusion model,a moderate level of hypochlorous acid promoted the proliferation and differentiation of neural stem cells into neurons and *** suggests that hypochlorous acid plays different roles at different phases of cerebral ischemia/reperfusion *** levels of hypochlorous acid(5 and 100μM)promoted nuclear translocation ofβ-*** transfection of single-site mutation plasmids,we found that hypochlorous acid induced chlorination of theβ-catenin tyrosine 30 residue,which promoted nuclear ***,our study indicates that maintaining low levels of hypochlorous acid plays a key role in the recovery of neurological function.

关键词： cell differentiation cerebral ischemia/reperfusion injury chlorination hypochlorous acid microglia neural stem cell neurogenesis nuclear translocation stroke β-catenin

Exploring Nanoscale Perovskite Materials for Next‑Generation Photodetectors:A Comprehensive Review and Future Directions

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2025年第2期17卷 46-108页

作者： xin li Sikandar Aftab Maria Mukhtar Fahmid Kabir Muhammad Farooq Khan Hosameldin Helmy Hegazy Erdi Akman State Key Laboratory of Pulsed Power Laser Technology National University of Defense TechnologyHefei 230037AnhuiPeople’s Republic of China Anhui Laboratory of Advanced Laser Technology Hefei 230037AnhuiPeople’s Republic of China Nanhu Laser Laboratory Changsha 410015HunanPeople’s Republic of China Department of Semiconductor Systems Engineering and Clean Energy Sejong UniversitySeoul 05006Republic of Korea Department of Artificial Intelligence and Robotics Sejong UniversitySeoul 05006Republic of Korea School of Engineering Science Simon Fraser UniversityBurnabyBC V5A 1S6Canada Department of Electrical Engineering Sejong UniversitySeoul 05006South Korea Department of Physics Faculty of ScienceKing Khalid UniversityP.O.Box 9004AbhaSaudi Arabia Central Labs King Khalid UniversityAlQura’aP.O.Box 96061413 AbhaSaudi Arabia Scientific and Technological Research and Application Center Karamanoglu Mehmetbey University70100 KaramanTurkey

The rapid advancement of nanotechnology has sparked much interest in applying nanoscale perovskite materials for photodetection *** materials are promising candidates for next-generation photodetectors(PDs)due to their unique optoelectronic properties and flexible synthesis *** review explores the approaches used in the development and use of optoelectronic devices made of different nanoscale perovskite architectures,including quantum dots,nanosheets,nanorods,nanowires,and *** a thorough analysis of recent literature,the review also addresses common issues like the mechanisms underlying the degradation of perovskite PDs and offers perspectives on potential solutions to improve stability and scalability that impede widespread *** addition,it highlights that photodetection encompasses the detection of light fields in dimensions other than light intensity and suggests potential avenues for future research to overcome these obstacles and fully realize the potential of nanoscale perovskite materials in state-of-the-art photodetection *** review provides a comprehensive overview of nanoscale perovskite PDs and guides future research efforts towards improved performance and wider applicability,making it a valuable resource for researchers.

关键词： Nanoscale perovskites Photodetectors Nanosheets Nanorods Nanowires Quantum dots Nanocrystals