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退耕还林对土壤抗冲能力的强化效应

湖南林业科技 2006年第2期33卷 28-32页

作者：田育新李锡泉刘正平李书明姚敏夏合新湖南省林业科学院湖南长沙410004 湖南省林业厅湖南长沙410007

抗冲性是土壤生态系统在抵抗面状侵蚀和线状侵蚀过程中所表现出的一种重要性能,主要受植物群落和土壤特征的影响。通过采用索波列夫抗冲法试验,结果表明:①退耕还林3年后,林地10、30、50 cm三个土层的平均产流历时比坡耕地延长1.2、0.87... 详细信息

抗冲性是土壤生态系统在抵抗面状侵蚀和线状侵蚀过程中所表现出的一种重要性能,主要受植物群落和土壤特征的影响。通过采用索波列夫抗冲法试验,结果表明:①退耕还林3年后,林地10、30、50 cm三个土层的平均产流历时比坡耕地延长1.2、0.87、0.52 s,地表迳流量比坡耕地减少5.216、4.286、2.613 L/m2,土壤抗冲性比坡耕地增强0.277、0.255、0.206 kg/(***);②土层越深,退耕还林对土壤产流历时的延长效应就越短,对土壤产流量的减弱效应就越小,对土壤抗冲性的强化效应就越低;③退耕还林对坡面产流历时的延长效应、对坡面产流量的减弱效应及对土壤抗冲性的强化效应随土壤母质的不同而差别很大。

关键词：土壤抗冲能力强化效应退耕还林湖南省

Study on the Ring Eulargment Reaction:Synthesis of 7,8,13,13a-tetrahydroisoindolo[1,2-b][3]benzazepine and 5,6,8,9,14,14a-hexahydroisoquino[1,2-b][3]benzazepine

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Chinese Chemical Letters 2001年第1期12卷 7-10页

作者： yu xin LIU Xiao tian LIANG Institute of Materia Medica Chinese Academy of Medical Sciences&Peking Union Medical College 1 Xian NongTan StreetBeijing 100050

A new approach to the synthesis of 7,8,13,13a-tetrahydroisoindolo[1,2-b] [3]benzazepine 5 and 5,6,8,9,14,14a-hexahydroisoquino[1,2-b][3]benzazepine 9 and related compounds is described as using ring expansion of N-he... 详细信息

关键词： Isoindolo[1,2-b]benzazepines Isoquino[1,2-b]benzazepines Ring enlargement Synthesis

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郓城井田天然焦综合勘探技术研究

山东科技大学学报（自然科学版） 2008年第2期27卷 39-43页

作者：韩景敏王怀洪田育鑫巩固王雯山东科技大学地球信息科学与工程学院山东青岛266510 山东工商学院信息与电子工程学院山东烟台264005 山东省煤田地质局山东泰安271000

郓城井田西部为天然焦和煤焦混合区。在区域及区内地质条件分析基础上,确立综合勘探方法,通过多因素、多参数综合研究,查明了岩浆侵入煤层在空间上大致形成接触变质带、天然焦带、煤焦过渡带三个变质带,探明埋深在-1 200 m水平以浅的煤... 详细信息

郓城井田西部为天然焦和煤焦混合区。在区域及区内地质条件分析基础上,确立综合勘探方法,通过多因素、多参数综合研究,查明了岩浆侵入煤层在空间上大致形成接触变质带、天然焦带、煤焦过渡带三个变质带,探明埋深在-1 200 m水平以浅的煤炭、天然焦及煤焦混合体资源储量48 348.6万t,并探索出一条有效的焦煤勘探技术路线。

关键词：郓城井田煤层天然焦岩浆岩综合勘探

未来气候情景下生态系统服务价值空间异质性分析——以柯柯牙为例

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环境生态学 2024年第8期6卷 53-63页

作者：田欣雨王让会刘春伟周丽敏南京信息工程大学应用气象学院江苏南京210044

基于CMIP6未来情景下的气候变化通过耦合FLUS模型,运用InVEST模型、CASA模型分析研究区的水源涵养、固碳释氧、土壤保持价值时空变化趋势,并利用R语言、GeoDa模型对研究区生态系统服务价值进行空间异质性分析。结果表明:在SSP245、SSP58... 详细信息

基于CMIP6未来情景下的气候变化通过耦合FLUS模型,运用InVEST模型、CASA模型分析研究区的水源涵养、固碳释氧、土壤保持价值时空变化趋势,并利用R语言、GeoDa模型对研究区生态系统服务价值进行空间异质性分析。结果表明:在SSP245、SSP585情景下单位面积水源涵养价值分别为17.34万元/km^(2)、14.28万元/km^(2);单位面积固碳释氧价值分别为107.13万元/km^(2)、101.75万元/km^(2);单位面积土壤保持价值分别为40.18万元/km^(2)、44.61万元/km^(2)。本研究结论:在未来情景下,生态系统服务价值总体呈增加趋势,SSP245情景下生态系统服务价值增加幅度更大;全局Moran s I指数整体呈波动增加趋势,其中土壤保持、水源涵养功能在空间上具有较高聚集性,固碳释氧功能聚集性相对较差,研究区北部生态系统服务价值聚集性更高;研究区内生态系统服务价值均呈协同关系,未来情景下整体协同值呈增加趋势。厘清生态子系统之间的依赖关系,形成更完善的代谢循环,对于生态系统的稳定性以及可持续发展具有重要意义。

关键词：生态系统服务价值 InVEST模型未来气候情景柯柯牙

DNA methylation and demethylation link the properties of mesenchymal stem cells: Regeneration and immunomodulation

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World Journal of Stem Cells 2020年第5期12卷 351-358页

作者： tian-Yi xin Ting-Ting yu Rui-Li Yang Department of Orthodontics Peking University School and Hospital of StomatologyNational Engineering Laboratory for Digital and Material Technology of StomatologyBeijing Key Laboratory of Digital StomatologyBeijing 100081China

Mesenchymal stem cells(MSCs)are a heterogeneous population that can be isolated from various tissues,including bone marrow,adipose tissue,umbilical cord blood,and craniofacial *** have attracted increasingly more attention over the years due to their regenerative capacity and function in *** foundation of tissue regeneration is the potential of cells to differentiate into multiple cell lineages and give rise to multiple tissue *** addition,the immunoregulatory function of MSCs has provided insights into therapeutic treatments for immune-mediated *** methylation and demethylation are important epigenetic mechanisms that have been shown to modulate embryonic stem cell maintenance,proliferation,differentiation and apoptosis by activating or suppressing a number of *** most studies,DNA hypermethylation is associated with gene suppression,while hypomethylation or demethylation is associated with gene *** dynamic balance of DNA methylation and demethylation is required for normal mammalian development and inhibits the onset of abnormal ***,the exact role of DNA methylation and demethylation in MSC-based tissue regeneration and immunomodulation requires further *** this review,we discuss how DNA methylation and demethylation function in multi-lineage cell differentiation and immunomodulation of MSCs based on previously published ***,we discuss the implications of the role of DNA methylation and demethylation in MSCs for the treatment of metabolic or immune-related diseases.

关键词： Mesenchymal stem cells DNA methylation and demethylation Multi-lineage differentiation Regeneration Immunomodulation Immune disease

Engine performance analysis and optimization of a dual-mode scramjet with varied inlet conditions

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Acta Mechanica Sinica 2016年第1期32卷 75-82页

作者： Lu tian Li-Hong Chen Qiang Chen Feng-Quan Zhong xin-yu Chang State Key Laboratory of High-Temperature Gas DynamicsInstitute of Mechanics Chinese Academy of SciencesBeijing 100190China

A dual-mode scramjet can operate in a wide range of flight conditions. Higher thrust can be generated by adopting suitable combustion modes. Based on the net thrust, an analysis and preliminary optimal design of a kerosene-fueled parameterized dual-mode scramjet at a cru- cial flight Mach number of 6 were investigated by using a modified quasi-one-dimensional method and simulated annealing strategy. Engine structure and heat release distrib- utions, affecting the engine thrust, were chosen as analytical parameters for varied inlet conditions （isolator entrance Mach number： 1.5-3.5）. Results show that different opti- mal heat release distributions and structural conditions can be obtained at five different inlet conditions. The highest net thrust of the parameterized dual-mode engine can be achieved by a subsonic combustion mode at an isolator entrance Mach number of 2.5. Additionally, the effects of heat release and scramjet structure on net thrust have been discussed. The present results and the developed analytical method can provide guidance for the design and optimization of high-performance dual-mode scramjets.

关键词： Dual-mode scramjet Engine performance Thrust Optimization Heat release distribution Simulatedannealing algorithm

浅谈“互联网+”时代的教育技术学科现状与发展

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湖北师范大学学报（自然科学版） 2020年第1期40卷 85-91页

作者：田欣雨吴海英陈云红李书明湖北师范大学计算机与信息工程学院湖北黄石435002

随着信息技术的发展进步,如何利用信息技术破解教育问题,成为各学科的研究重点。教育技术作为教育理论和现代技术相互融合而形成的交叉学科,在“互联网+”时代承担着重要的历史使命。通过研究我国教育技术学的学科理论与专业发展的现状... 详细信息

随着信息技术的发展进步,如何利用信息技术破解教育问题,成为各学科的研究重点。教育技术作为教育理论和现代技术相互融合而形成的交叉学科,在“互联网+”时代承担着重要的历史使命。通过研究我国教育技术学的学科理论与专业发展的现状,分析其中存在的问题,并提出了解决问题的方法。

关键词：教育技术学科专业

A Survey of Visual Analytic Pipelines

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Journal of Computer Science & Technology 2016年第4期31卷 787-804页

作者： Xu-Meng Wang tian-Ye Zhang yu-xin Ma Jing Xia Wei Chen State Key Laboratory of Computer Aided Design and Computer Graphics Zhejiang University Hangzhou 310058 China Innovation Joint Research Center for Cyber-Physical-Society System Zhejiang University Hangzhou 310058 China

Visual analytics has been widely studied in the past decade. One key to make visual analytics practical for both research and industrial applications is the appropriate definition and implementation of the visual analytics pipeline which provides effective abstractions for designing and implementing visual analytics systems. In this paper we review the previous work on visual analytics pipelines and individual modules from multiple perspectives： data, visualization, model and knowledge. In each module we discuss various representations and descriptions of pipelines inside the module, and compare the commonalities and the differences among them.

关键词： visual analytics pipeline visualization model knowledge

Evolution model for scientific collaboration network with local-world information

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The Journal of China Universities of Posts and Telecommunications 2014年第2期21卷 15-20,31页

作者： tian Sheng-wen LIAO Jian-xin WANG Jing-yu QI Qi State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications School of Information and Electrical Engineering Ludong University

In order to reveal the intrinsic properties of scientific collaboration networks, a new local-world evolution model on a scientific collaboration network is proposed by analysing the network growth mechanism. The act degree as the measurement of preferential attachment is taken, and the local-world information of nodes is taken into account. Analysis and simulation show that the node degree and the node strength obey the power-law distribution. Low average path length and high clustering coefficient are approved. Experiment indicates that the model can depict efficiently the topological structure and statistical characteristics of real-life scientific collaboration networks.

关键词： scientific collaboration network evolution model local-world information scale-flee act degree