期刊文献+
共找到2,204篇文章
< 1 2 111 >
每页显示 20 50 100
IMITATIO ALEXANDRI–THE IMAGE OF DRUSUS MINOR ON BRASS TOKENS OF THE MüNZKABINETT,STAATLICHE MUSEEN ZU BERLIN
1
作者 Alexa Kuter 《Journal of Ancient Civilizations》 2016年第1期85-122,共38页
State of research: characteristics, function, and dating of Roman brass tokens Tokens (tesserae) formed part of everyday material culture of both Greeks and Romans.1 Made of wood, bone, clay, or metal, they facilit... State of research: characteristics, function, and dating of Roman brass tokens Tokens (tesserae) formed part of everyday material culture of both Greeks and Romans.1 Made of wood, bone, clay, or metal, they facilitated, for example, entry into the theatre, identification of soldiers, participation in political meetings, or the receipt of a special amount of grain.2 展开更多
关键词 令牌 亚历山大 黄铜 模仿 形象 柏林 组成部分 物质文化
在线阅读 下载PDF
评审感言
2
作者 鲍里斯·沙德-宾索夫 尼可拉·博尔曼 +4 位作者 曹嘉明 胡越 蓝冰可 李存东 张悦 《世界建筑》 2026年第1期6-7,共2页
鲍里斯·沙德-宾索夫柏林《建筑世界》主编。我观察到一个极具说服力的趋势:建筑师正在普遍地对既有结构进行大胆的叠加。这种改造不再是修修补补,而是创造性覆盖——在旧肌理上生长出新的功能层级。这其中蕴含的未来乐观主义深深... 鲍里斯·沙德-宾索夫柏林《建筑世界》主编。我观察到一个极具说服力的趋势:建筑师正在普遍地对既有结构进行大胆的叠加。这种改造不再是修修补补,而是创造性覆盖——在旧肌理上生长出新的功能层级。这其中蕴含的未来乐观主义深深打动了我:那些曾经承载沉重记忆的旧空间,被转化为服务于年轻一代的、色彩斑斓的公共场所。通过灵活性重塑,让旧躯壳回应新问题,这种跨代际的对话能力,是当下建筑学最迷人的特质。 展开更多
关键词 创造性覆盖 未来乐观主义 建筑师 叠加
在线阅读 下载PDF
阳宗海沉积物粒度端元揭示的末次冰消期以来水文气候与人类活动演变
3
作者 李华勇 段立曾 +5 位作者 李华玉 祖奎红 孙启发 赵芳 Frank Riedel 张虎才 《地理科学》 北大核心 2026年第2期314-325,共12页
对采自云南阳宗海的沉积岩芯(YZH-1)进行AMS^(14)C测年,在建立可靠年代序列的基础上,分析钻孔粒度端元(end-member,EM)组分并探究其环境指示意义,恢复了区域13300 cal.a B.P.以来水文气候演化和人类活动。结果表明:EM1(5.0μm)与区域红... 对采自云南阳宗海的沉积岩芯(YZH-1)进行AMS^(14)C测年,在建立可靠年代序列的基础上,分析钻孔粒度端元(end-member,EM)组分并探究其环境指示意义,恢复了区域13300 cal.a B.P.以来水文气候演化和人类活动。结果表明:EM1(5.0μm)与区域红壤粒度特征相似,反映流域侵蚀强度;EM2(15.1μm)和EM3(30.2μm)反映湖泊水深,分别指示深湖相和浅湖相沉积。末次冰消期以来阳宗海水文气候和流域侵蚀演变过程可以分为5个阶段,阶段Ⅰ~Ⅳ[(13300—650) cal.a B.P.]阳宗海总体呈收缩趋势,与区域湿度变化规律一致;人类活动强度很低,流域侵蚀较弱,并具有先减小后增大特征,转折点出现在5500 cal.a B.P.前后,响应气候由暖湿向暖偏干转型。自1300年(阶段Ⅴ)以来EM1含量急剧升高,成为阳宗海沉积物的绝对优势粒度端元,反映快速增长的人口和农业规模破坏了植被,导致流域侵蚀加剧,与元朝1276年在西南边疆设“云南行中书省”,实行屯田制度,鼓励外省移民和农业生产的历史背景相吻合。自此,阳宗海流域环境的演变脱离了自然轨道,人类活动成为塑造地表景观、影响侵蚀强度的主要地质营力。 展开更多
关键词 阳宗海 全新世 粒度端元 环境演化 人类活动 流域侵蚀
原文传递
基于AERONET的喜马拉雅地区污染物气溶胶组成及时空变化研究
4
作者 张傲楠 董志文 +2 位作者 李芳洲 焦晓瑜 江聪 《中国环境科学》 北大核心 2026年第2期618-626,共9页
本文建立了气溶胶5成分模型(黑碳BC、吸收性有机碳BrC、硫酸铵AS、粉尘DU和水分AW),利用AERONET数据对喜马拉雅山及周边地区的气溶胶组分进行了反演计算.结果显示:多年平均来看,各个站点成分柱质量浓度占比相似,其中AS、DU、AW、BrC和A... 本文建立了气溶胶5成分模型(黑碳BC、吸收性有机碳BrC、硫酸铵AS、粉尘DU和水分AW),利用AERONET数据对喜马拉雅山及周边地区的气溶胶组分进行了反演计算.结果显示:多年平均来看,各个站点成分柱质量浓度占比相似,其中AS、DU、AW、BrC和AW依次占比53.49%、29.33%、10.63%、5.27%、1.28%.同时,喜马拉雅山南坡地区的气溶胶柱质量浓度(年平均390mg/m^(2))显著高于北坡(年平均49mg/m^(2)),主要原因是高海拔山脉大量阻挡了南亚污染物气溶胶跨越喜马拉雅的传输(仅通过约13%).总体上,喜马拉雅地区春季(多年平均)气溶胶柱质量浓度最高,而夏,秋,冬季表现出大幅降低,这主要是由于春季季风前大气污染物排放的不断累积效应,以及南亚沙漠释放的粉尘气溶胶大量传输造成的,而在夏天季风期随着大量降水的淋洗而大量降低.年际变化来看,2015~2024期间的气溶胶平均柱质量浓度(南坡平均370.83mg/m^(2))略低于较早的2006~2015年期间(南坡平均453.26mg/m^(2)),这反映出南亚地区近期污染状况有所改善,然而总体大气污染状况仍然十分严重.由于黑碳和棕碳等吸收性气溶胶可以显著影响冰川积雪的加速消融,南亚地区持续的高污染气溶胶排放,预估未来会继续影响喜马拉雅山冰川变化. 展开更多
关键词 AERONET 气溶胶组分 喜马拉雅山 污染排放 时空变化
在线阅读 下载PDF
Impacts as Triggers for Weather-Related Decision Making: Observations at the Berlin Fire Brigade Control and Dispatch Center
5
作者 Thomas Kox Catharina Lüder 《International Journal of Disaster Risk Science》 SCIE CSCD 2021年第4期610-615,共6页
This article presents the results of a series of ethnographic observations at the Berlin fire brigade control and dispatch center during routine and severe weather situations.The weather-related challenges of a fire b... This article presents the results of a series of ethnographic observations at the Berlin fire brigade control and dispatch center during routine and severe weather situations.The weather-related challenges of a fire brigade lie between the anticipation of events and their potential consequences,and the ad hoc reactions to actual impacts of weather.The results show that decisions and actions related to high impact weather are not necessarily motivated by weather warnings alone.Instead,they are reactions to the experience of impacts,for example,an increased number of missions or emergency calls.Impacts are the main trigger for the decision making.Weather is one additional external factor that influences the operational capability of a fire brigade.While commanding officers in a fire brigade control and dispatch center experience weather primarily through technical equipment,verified by ground truth,observations showed that direct personal contact with the regional weather service and colleagues on the ground takes on a greater role in actual severe weather situations.The observations point to the need for increased interagency communication between the emergency services,the weather service,and other organizations to integrate weather information,impacts,and non-weather-related tasks into coherent weather-related decision making. 展开更多
关键词 Berlin Emergency services Fire brigades Impact-based emergency response Interagency communication Weather-related decision making
原文传递
2025世界未来城市计划
6
作者 鲍里斯·沙德-宾索夫 《世界建筑》 2026年第1期4-5,共2页
世界未来城市计划(IUPA)于2019年正式启动。自那时起,《世界建筑》期刊(北京)与《建筑世界》杂志(柏林)每年联合颁发该奖项,旨在表彰那些将建筑与城市规划真正融合、产生积极社会影响的杰出实践。没有建筑的城市发展是不可想象的;同样,... 世界未来城市计划(IUPA)于2019年正式启动。自那时起,《世界建筑》期刊(北京)与《建筑世界》杂志(柏林)每年联合颁发该奖项,旨在表彰那些将建筑与城市规划真正融合、产生积极社会影响的杰出实践。没有建筑的城市发展是不可想象的;同样,脱离了规划与设计语境的建筑,亦将沦为孤立的物体——一种悬浮于现实之外、缺乏意义的“不明飞行物”。城市规划是对建筑的组织与协调,它决定了城市的整体品质。这一认知已成为全球建筑师与城市规划师之间的普遍共识,并在全球宜居且繁荣的城市中得以具体呈现。正因如此,本奖项面向全球开放征集。 展开更多
关键词 世界建筑期刊 世界未来城市计划 建筑世界杂志
在线阅读 下载PDF
石墨/陶瓷复合电阻材料的制备与性能
7
作者 聂京凯 韩钰 +6 位作者 周明瑜 姬军 祝志祥 李阳林 马金旭 杜君莉 何强 《陶瓷学报》 北大核心 2026年第1期113-121,共9页
碳陶瓷电阻材料因具有导电性能良好、抗脉冲能力强、过载能力出色和散热能力强等优点,已成为国外高性能合闸电阻产品的主要材料。本文在分析国外某产品的基础上,以高纯度氧化铝和氧化硅为主要原料,以石墨为导电填料,设计并制备了一系列... 碳陶瓷电阻材料因具有导电性能良好、抗脉冲能力强、过载能力出色和散热能力强等优点,已成为国外高性能合闸电阻产品的主要材料。本文在分析国外某产品的基础上,以高纯度氧化铝和氧化硅为主要原料,以石墨为导电填料,设计并制备了一系列样品,并对其物相组成、气孔率、体积密度和电阻率进行了分析与测试。同时,实验结合分析测试结果,系统研究了氧化铝/氧化硅质量比、烧结助剂种类、石墨粒度及其加入量对样品物相组成和性能的影响。结果表明,与氧化铁相比,碳酸钙更有助于石英向方石英的晶型转变,并促进莫来石的生成。在氧化铝/氧化硅质量比为3∶1、添加3%碳酸钙为烧结助剂、掺入11%~15%的800目石墨为导电填料的条件下,可制得以刚玉、方石英、莫来石、石墨为主要物相的复合电阻材料,其开口气孔率为33.2%~35.5%、体积密度为1.99 g·cm^(-3)~2.10 g·cm^(-3)、电阻率为0.11Ω·m~4.66Ω·m。本文的研究结果有望为碳陶瓷复合电阻材料研究提供数据支撑。 展开更多
关键词 石墨 陶瓷 物相组成 电阻材料 电阻率
在线阅读 下载PDF
“双减”背景下甘肃“影子教育”治理的现实挑战与破解路径
8
作者 武宇轩 《陇东学院学报》 2026年第1期128-133,共6页
“双减”政策旨在减轻义务教育阶段学生过重的作业负担和校外培训负担,推动教育回归育人本质。以西部欠发达省份甘肃为研究对象,深入剖析了“双减”背景下其“影子教育”治理的现实困境与破解路径。研究发现,甘肃“影子教育”呈现出鲜... “双减”政策旨在减轻义务教育阶段学生过重的作业负担和校外培训负担,推动教育回归育人本质。以西部欠发达省份甘肃为研究对象,深入剖析了“双减”背景下其“影子教育”治理的现实困境与破解路径。研究发现,甘肃“影子教育”呈现出鲜明的城乡二元特征:城市地区隐形变异培训屡禁不止,而农村地区则充斥着师资薄弱、监管困难的家庭作坊式补课。治理挑战主要源于多元主体协同不足、监管政策执行存在偏差、技术手段滞后以及部分家长教育焦虑未消等复杂因素。对此,强化政府主导下的多元协同治理机制,完善契合地方实际的法律法规;运用数字技术提升对隐形变异形态的监管效能;深化教育综合改革,提升校内教育质量、均衡资源配置及加强家校共育,从源头上疏导社会对“影子教育”的过度需求。 展开更多
关键词 “影子教育” “双减”政策 教育治理
在线阅读 下载PDF
Lysophosphatidic acid signaling:Transmembrane modulators in the central nervous system
9
作者 Alexandra Polyzou Alexandros Κ.Tsiouris +2 位作者 Charalampos Labrakakis Britta J.Eickholt George Leondaritis 《Neural Regeneration Research》 2026年第3期1104-1105,共2页
Lysophosphatidic acid(LPA)is a pleiotropic lipid agonist essential for functions of the central nervous system(CNS).It is abundant in the developing and adult brain while its concentration in biological fluids,includi... Lysophosphatidic acid(LPA)is a pleiotropic lipid agonist essential for functions of the central nervous system(CNS).It is abundant in the developing and adult brain while its concentration in biological fluids,including cerebrospinal fluid,varies significantly(Figure 1Α;Yung et al.,2014).LPA actually corresponds to a variety of lipid species that include different stereoisomers with either saturated or unsaturated fatty acids bearing likely differentiated biological activities(Figure 1Α;Yung et al.,2014;Hernández-Araiza et al.,2018). 展开更多
关键词 transmembrane modulators cerebrospinal fluidvaries variety lipid species lysophosphatidic acid biological fluidsincluding lysophosphatidic acid lpa saturated unsaturated fatty acids pleiotropic lipid agonist
暂未订购
Monolithic Integration of Redox-Stable Sn-Pb Halide Perovskite Single-Crystalline Films for Durable Near-Infrared Photodetection
10
作者 Rajendra Kumar Gunasekaran Jihoon Nam +9 位作者 Myeong-geun Choi Won Chang Choi Sunwoo Kim Doyun Im Yeonghun Yun Yun Hwa Hong Sang Hyeok Ryou Hyungwoo Lee Kwang Heo Sangwook Lee 《Nano-Micro Letters》 2026年第5期1-14,共14页
Tin-lead(Sn-Pb)halide perovskite single crystals combine narrow bandgaps,long carrier diffusion lengths,and low trap densities,positioning them as ideal candidates for near-infrared(NIR)optoelectronics.However,convent... Tin-lead(Sn-Pb)halide perovskite single crystals combine narrow bandgaps,long carrier diffusion lengths,and low trap densities,positioning them as ideal candidates for near-infrared(NIR)optoelectronics.However,conventional growth strategies rely on bulk crystallization at elevated temperatures,leading to uncontrolled nucleation,Sn^(2+)oxidation,and poor compatibility with planar integration.Here,we develop a coordination-engineered crystallization strategy that enables direct,lowtemperature growth of micrometer-thick Sn-Pb single-crystal thin films on device-compatible substrates.By modulating metal-solvent coordination strength using a low-donor number cosolvent system,we delineate a narrow processing window that stabilizes precursor speciation,lowers the nucleation barrier,and guides directional crystal growth under mild thermal conditions(<40℃).The resulting crystal films exhibit smooth morphology,high crystallinity,compositional uniformity,and ultralow trap densities(~3.98×10^(12)cm^(-3)).When integrated into NIR photodetectors,these films deliver high responsivity(0.51 A W^(-1)at 900 nm),specific detectivity up to 3.6×10^(12)Jones,fast response(~188μs),and>25,000 cycles of ambient operational stability.This approach establishes a scalable platform for redox-stable,low-temperature growth of Sn-Pb perovskite crystal films and expands the processing-structure-function landscape for next-generation infrared optoelectronics. 展开更多
关键词 Tin-lead perovskite Near-infrared photodetectors Single-crystal thin films Coordination chemistry Low-temperature crystallization
在线阅读 下载PDF
SNMR with short pulses:Optimizing the kernel calculation by considering the influence of pulse shape and phase
11
作者 Tobias Splith Thomas Hiller +1 位作者 Stephan Costabel Mike Müller-Petke 《Magnetic Resonance Letters》 2026年第1期43-52,共10页
In the past few years,efforts have been made to extend the sensitivity of surface nuclear magnetic resonance(SNMR)to short relaxation times,typical for strongly bound water,which,for example,occurs in partially satura... In the past few years,efforts have been made to extend the sensitivity of surface nuclear magnetic resonance(SNMR)to short relaxation times,typical for strongly bound water,which,for example,occurs in partially saturated soils.The two limiting factors for the sensitivity are the dead time after the excitation pulse and the duration of the pulse itself.To enable short pulses,while also achieving proper depths of investigation,high pulse amplitudes are needed.This makes it necessary to consider the Bloch-Siegert effect,i.e.the counter-rotating component and the parallel component of the excitation field have significant influence on the excitation.If an untuned transmitter circuit is used,the pulse shape will also be non-sinusoidal.In this paper,we demonstrate that this influences SNMR measurements with short pulses in two ways:On one hand,the pulse shape influences the phase of the fundamental frequency oscillation.On the other,at very high pulse amplitudes,other frequency components of the excitation field start to influence the excitation.The behavior of the macroscopic magnetizations in the subsurface during the pulse is simulated by solving the Bloch equations,using the pulse shape as an input.Since these calculations are computational expensive,we propose a lookup scheme that allows a time efficient modeling of the obtained SNMR data. 展开更多
关键词 Surface NMR Pulse shape Numerical modeling Bloch-Siegert effect
在线阅读 下载PDF
Performance Analysis of Bandwidth Aware Hybrid Powered 5G Cloud Radio Access Network
12
作者 Md.Al-Hasan Mst.Rubina Aktar +3 位作者 Fahmid Al Farid Md.Shamim Anower Abu Saleh Musa Miah Md.Hezerul Abdul Karim 《Computers, Materials & Continua》 2026年第4期2146-2160,共15页
The rapid growth in available network bandwidth has directly contributed to an exponential increase in mobile data traffic,creating significant challenges for network energy consumption.Also,with the extraordinary gro... The rapid growth in available network bandwidth has directly contributed to an exponential increase in mobile data traffic,creating significant challenges for network energy consumption.Also,with the extraordinary growth of mobile communications,the data traffic has dramatically expanded,which has led to massive grid power consumption and incurred high operating expenditure(OPEX).However,the majority of current network designs struggle to efficientlymanage a massive amount of data using little power,which degrades energy efficiency performance.Thereby,it is necessary to have an efficient mechanism to reduce power consumption when processing large amounts of data in network data centers.Utilizing renewable energy sources to power the Cloud Radio Access Network(C-RAN)greatly reduces the need to purchase energy from the utility grid.In this paper,we propose a bandwidth-aware hybrid energypowered C-RAN that focuses on throughput and energy efficiency(EE)by lowering grid usage,aiming to enhance the EE.This paper examines the energy efficiency,spectral efficiency(SE),and average on-grid energy consumption,dealing with the major challenges of the temporal and spatial nature of traffic and renewable energy generation across various network setups.To assess the effectiveness of the suggested network by changing the transmission bandwidth,a comprehensive simulation has been conducted.The numerical findings support the efficacy of the suggested approach. 展开更多
关键词 5G BANDWIDTH renewable energy energy efficiency spectral efficiency C-RAN
在线阅读 下载PDF
The satellite tracking of Great Snipes from European Russia reveals low migratory connectivity
13
作者 Tatiana V.Sviridova Anna A.Bazhanova +1 位作者 Stepan M.Soloviev Christoph Zockler 《Avian Research》 2026年第1期46-58,共13页
Great Snipe(Gallinago media) is a shore bird which has a Near Threatened status on the global scale.However,little is known about its migration strategy from the breeding range in Russia.This study is the first one ai... Great Snipe(Gallinago media) is a shore bird which has a Near Threatened status on the global scale.However,little is known about its migration strategy from the breeding range in Russia.This study is the first one aiming to reveal migration routes,stopovers and wintering grounds of adult Great Snipes from their breeding range in Russia using GPS devices.We also analyzed connectivity of Great Snipes from different breeding populations of this species during non-breeding season.In 2021,we equipped seven males and three females with satellite transmitters,ICARUS Basic Tags,in the breeding range in central European Russia(56°75′N,37°65 E).One female appeared later in tundra of north-eastern Europe.In the second half of July to early September,birds migrated to Africa in a fairly wide front and made stopovers in Europe before crossing seas and the Sahara.Our data allowed to suppose high mortality of birds on migration,especially during the trans-Saharan flight.Only four Great Snipes reached Africa alive during southward migration.These birds spread over across wide area from Eritrea to Ghana after the trans-Saharan flight,after which they moved in a general westward direction and made final prolonged stopovers in Ghana or to the south of Chad Lake.In October/December birds relocated to wintering grounds in Sub-Equatorial Afrotropics as far as the south of Democratic Republic of the Congo and Zambia;with intermediate winter sites in low and middle reaches of the Congo Basin.Together with other published results,our data showed wide overlap of African non-breeding grounds of birds coming from lowland Eastern European and mountain Scandinavian breeding populations.The results also indicated insufficient conservation status of migration stopovers and wintering sites,used by Great Snipes,and demonstrated high importance of West Africa for conservation of this species. 展开更多
关键词 Geographical population Great Snipe ICARUS Basic Tags Migration mortality Satellite tracking Southward migration Wintering grounds
在线阅读 下载PDF
Ligand- complex-based quantification of β2- integrin-mediated affinity and avidity of murine T cells
14
作者 M.Therre A.A.Kuhnle +3 位作者 H.M.Arndt N.Frey M.H.Konstandin N.V.Bogert 《Animal Models and Experimental Medicine》 2026年第2期319-328,共10页
Background:Integrins facilitate binding to the extracellular matrix and other cells.Their subunit β2 is exclusively expressed by leukocytes,binds to the intercellular cell adhesion molecule 1(ICAM-1),and is pivotal f... Background:Integrins facilitate binding to the extracellular matrix and other cells.Their subunit β2 is exclusively expressed by leukocytes,binds to the intercellular cell adhesion molecule 1(ICAM-1),and is pivotal for their recruitment to sites of inflammation such as the atherosclerotic plaque.Methods:To investigate β2-integrin-mediated adhesiveness,a well-established assay for human whole blood was adapted for the analysis of murine T cell subsets.Changes in avidity and affinity were assessed by incubation of murine complexes ICAM-1 in murine whole blood and consecutive stimulation with PMA and Mg^(2+)/EGTA.Underlying signaling pathways in β2-integrin-mediated adhesiveness upon chemokine stimulation with CCL-19 were identified by incubation with reducing substances,and a Ca^(2+)chelator and ROS and Ca^(2+)measurements were carried out.Results:Incubation of murine whole blood with PMA leads to 30-fold and Mg^(2+)/EGTA to 65-fold increase in β2-integrin-mediated adhesiveness of T cells.Specificity of the assay was proven by preincubation of a blocking antibody,leading to a 60%reduction in adhesion capacity.ROS species and Ca^(2+)are crucial for chemokine-mediated β2-integrin activation.In vivo relevance was proven by induction of T cell adhesiveness in whole blood of mice upon myocardial infarction.Conclusions:Our assay allows specific quantification of β2-integrin-mediated affinity and avidity of T cells in whole blood samples.In congruence to human adhesion,these mechanisms are ROS and Ca^(2+)dependent and significantly elevated after myocardial infarction.Our refined and robust assay may be of particular use in phenotyping involved mechanisms in T cell activation in atherosclerotic cardiovascular disease. 展开更多
关键词 AFFINITY AVIDITY ICAM-1 T cells T helper cells β2-integrin
暂未订购
From lab to forest:overcoming barriers to in vitro propagation of forest trees
15
作者 Tuija Aronen Valbona Sota +5 位作者 Branislav Cvjetković Bruce Christie Andrea Rupps Lucie Fischerova Dheeraj Singh Rathore Stefaan P.O.Werbrouck 《Journal of Forestry Research》 2026年第1期1-9,共9页
Reforestation initiatives are often limited by insufficient seeds,a problem exacerbated by natural variability in tree flowering and seed production and climate change and other environmental challenges.Innovative and... Reforestation initiatives are often limited by insufficient seeds,a problem exacerbated by natural variability in tree flowering and seed production and climate change and other environmental challenges.Innovative and adaptive solutions such as in vitro propagation are thus needed.Tissue culture can provide high-quality propagation material for tree conservation and mass propagation,but faces technical,economic,regulatory,and social barriers.Obstacles related to the academia-industry interface and to stakeholder concerns are discussed and actions suggested to overcome these barriers to realize the full potential of tree micropropagation.These include refining techniques to improve efficiency and reduce costs;establishing collaborations among researchers,industry,and foresters;and reducing points of contention and misinformation regarding genetic diversity and public perception.International collaborative initiatives,exemplified by the EU COST Action CA21157 COPYTREE,are elementary for achieving these goals. 展开更多
关键词 COMMERCIALIZATION Forest reproductive material Technology transfer Tissue culture
在线阅读 下载PDF
股债融合视域下对赌协议的本质属性与法律规制 被引量:4
16
作者 冉克平 张仪昭 《重庆大学学报(社会科学版)》 北大核心 2025年第1期247-258,共12页
伴随2023年《公司法》的颁布和适用,如何在新法视域下理解对赌协议的法律本质并处理对赌协议履行难题是对赌协议理论和实践研究的新面向。对赌协议目前仍存在理论疑难与实践困境:其一,对赌协议的认定和构成存在困惑,其与明股实债的区分... 伴随2023年《公司法》的颁布和适用,如何在新法视域下理解对赌协议的法律本质并处理对赌协议履行难题是对赌协议理论和实践研究的新面向。对赌协议目前仍存在理论疑难与实践困境:其一,对赌协议的认定和构成存在困惑,其与明股实债的区分是目前司法实践的核心问题;其二,对赌协议效力与履行区分存在悖论。目前,尽管对赌协议在原则上被认为有效,但在我国资本市场已经出现了首例因违反证券市场公共利益而被认定无效的案件。《九民纪要》所提出的“效力-履行区隔论”使对赌协议陷入“履行悖论”,实际履行面临法律和事实上的困境。针对这些问题,应当重新厘清对赌协议的法律本质,并在此基础上重塑对赌协议履行困难的规范解法。首先,对赌协议法律性质特殊,是股权和债权融合的产物。这反映在对赌协议承载的经济利益状态上,其存在趋同与分化的特点,对赌协议投资方的经济利益存在债权人化的倾向。对赌协议的作用场域复杂,受到公司、合同和会计准则、金融监管规则的约束和限制。对赌协议中各方主体的权利实现机制存在交叉竞合,在交易构造上符合股债结合型融资的特质,在外部关系上,投资人身份在公司登记材料上记载为股东,而在内部关系上,投资人实际的法律地位是债权人而非股东,这种身份的交叉与转化依靠合同法与公司法工具。其次,对赌协议履行不能的法律困境根植于其股债融合的本质中,契约规则、组织法规则、会计准则、监管规则应当实现在对赌协议纠纷处理和争议解决上的协调统一。最后,在股债融合视域下,应当通过解释2023年《公司法》中有关类别股的相关规范实现对赌协议的履行。在种类上,应当明确对赌协议可以被类推适用为144条第一款中规定的优先股;在行权上,应当适用优先股表决权行使的一般限制并要求董事、监事、高级管理人承担对投资方的特别信义义务。此外,还应当优化公司利润分配规则和减资规则的财源限制以及相关程序,促进公司在不丧失偿债能力的基础上灵活处理其资产以及公司法资本制度革新,解决中小企业融资难问题,促进营商环境优化。 展开更多
关键词 对赌协议 股债融合 2023年《公司法》 公司资本制度 中小企业融资
在线阅读 下载PDF
鄂尔多斯盆地西缘李105井奥陶系乌拉力克组笔石生物地层研究 被引量:1
17
作者 王传尚 胡勇 +1 位作者 Jörg MALETZ 危凯 《地球学报》 北大核心 2025年第2期273-282,共10页
本文通过对鄂尔多斯盆地西缘李105井奥陶系乌拉力克组的笔石化石的研究,划分出两个笔石生物带,即Nemagraptus gracilis带和Cilmacograptus bicornis带,其时限为桑比期。根据乌拉力克组的沉积学特征,结合最新的岩相古地理研究进展,认为... 本文通过对鄂尔多斯盆地西缘李105井奥陶系乌拉力克组的笔石化石的研究,划分出两个笔石生物带,即Nemagraptus gracilis带和Cilmacograptus bicornis带,其时限为桑比期。根据乌拉力克组的沉积学特征,结合最新的岩相古地理研究进展,认为原乌拉力克组的底界以一套特征的砾屑灰岩为标志欠妥,建议将克里摩里组上段的以黑色含笔石页岩为主的地层划归乌拉力克组,新厘定的乌拉力克组在盆地西缘北部露头区内蒙古乌海桌子山一带至少包含了Pterograptus elegans、Didymograptus murchisoni和Nemagraptus gracilis带等三个笔石带,其时限跨越中奥陶世达瑞威尔期晚期到晚奥陶世桑比期早期。可见,乌拉力克组在鄂尔多斯盆地西缘,其顶、底界线均存在明显的穿时。这一发现不仅为乌拉力克组的时限及其相变穿时提供了准确的生物地层约束,也为这一地区岩相古地理的重建及页岩气勘探有利相带的优选提供了依据。 展开更多
关键词 鄂尔多斯盆地西缘 乌拉力克组 笔石带 穿时 李105井
在线阅读 下载PDF
新质生产力视角下应用生态学的时代内涵与创新方向 被引量:1
18
作者 薛冰 李宏庆 任婉侠 《应用生态学报》 北大核心 2025年第6期1609-1615,共7页
新时代加快新质生产力的形成和发展,不仅是我国高质量发展阶段的必然要求,更是实现社会主义现代化与生态文明建设的重要历史使命。本文从应用生态学的视角阐释了新质生产力的时代内涵,即基于生态系统服务功能的优化与可持续利用,推动人... 新时代加快新质生产力的形成和发展,不仅是我国高质量发展阶段的必然要求,更是实现社会主义现代化与生态文明建设的重要历史使命。本文从应用生态学的视角阐释了新质生产力的时代内涵,即基于生态系统服务功能的优化与可持续利用,推动人与自然和谐共生的创新型生产能力,总结了应用生态学从生物应用生态学、社会应用生态学到数字应用生态学的发展历程,探讨了其在学科技术创新和生产资料配置中的重要孵化作用。面向未来,应用生态学应以生态系统为核心,通过加强对生物认知与人类活动的结合,重点关注新质生产力的生态学理论发展、构建绿色发展与创新融合的方法体系以及打造新质生产力的生态应用场景的实践等领域,实现生态系统的绿色健康发展。通过应用生态学的学科整合推动新质生产力的发展,为促进人与自然的和谐共生提供生态支撑。 展开更多
关键词 应用生态学 新质生产力 人地关系 生态治理
原文传递
教科书研究之方法论新探:基于现象学认识发生视域
19
作者 朱晓宏 宋玉博 王蒙 《北京教育学院学报》 2025年第6期1-8,共8页
教科书集中反映人类认识的优秀成果,从认识发生的视域看,适当汲取当代现象学哲学理论资源,可以开启教科书研究的新思路。遵循现象学“回到事情本身”的方法论原则,要基于教科书历史变迁看教科书之呈现方式;基于意识发生看教科书之构成;... 教科书集中反映人类认识的优秀成果,从认识发生的视域看,适当汲取当代现象学哲学理论资源,可以开启教科书研究的新思路。遵循现象学“回到事情本身”的方法论原则,要基于教科书历史变迁看教科书之呈现方式;基于意识发生看教科书之构成;基于学生认知特点看教科书之使用。由此尝试重构教科书研究的方法论体系,重新审视教科书编写与使用的理论前提,既为教科书研究开启新的教育学方法论视域,也助力教师拓展教科书使用的教育专业视域。 展开更多
关键词 教科书 方法论 学生认知 认识发生 现象学
在线阅读 下载PDF
村落尺度资源环境代谢分析发展路径及未来趋势 被引量:1
20
作者 李宏庆 许耀天 +2 位作者 徐月萍 任婉侠 薛冰 《自然资源学报》 北大核心 2025年第5期1227-1243,共17页
开展村落尺度的资源环境代谢研究不仅能够直观地观察到人类活动对资源的利用特征及环境的扰动影响,而且也为加快生态系统的良性循环提供了支撑。在对资源环境代谢概念辨析的基础上,基于CiteSpace6.3R1对当前国内外文献的分析建构了关键... 开展村落尺度的资源环境代谢研究不仅能够直观地观察到人类活动对资源的利用特征及环境的扰动影响,而且也为加快生态系统的良性循环提供了支撑。在对资源环境代谢概念辨析的基础上,基于CiteSpace6.3R1对当前国内外文献的分析建构了关键词共现图谱,深入探究了村落资源代谢在数据构成、模型模拟、账户设计和优化调控方面的现有问题,并针对性地提出了未来村落资源环境代谢良性发展的建议:部署村落尺度数据入库及共享调用机制,构建村落尺度资源环境代谢模型,建构村落尺度资源环境与社会经济代谢综合账户以及提升村落系统资源环境经济综合管理。通过全面考量乡村系统内资源环境等要素的影响,提升资源利用效率和环境质量,确保乡村地区实现平衡、持续的发展。 展开更多
关键词 资源环境代谢 人类活动 账户 资源管理 村落
原文传递
上一页 1 2 111 下一页 到第
使用帮助 返回顶部