检索结果-南通市图书馆

The δ^(15)N values of foxtail millet(Setaria italica)and common millet(Panicum miliaceum)are reliable indicators of manuring practices

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第9期67卷 2910-2923页

作者： Jishuai yang Xiaoyan yang Ting YOU Fahu CHEN Key Scientific Research Base of Bioarchaeology in Cold and Arid Regions(National Cultural Heritage Administration) Key Laboratory of Western China’s Environmental Systems(Ministry of Education)College of Earth and Environmental SciencesLanzhou UniversityLanzhou 730000China Group of Alpine Paleoecology and Human Adaptation(ALPHA) State Key Laboratory of Tibetan Plateau Earth SystemResources and Environment(TPESRE)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems College of Pastoral Agriculture Science and TechnologyLanzhou UniversityLanzhou 730000China

Millet agriculture,which originated in northern China,alongside rice agriculture,have nurtured the Chinese *** manuring practices likely promoted and maintained sustainable millet agricultural production in the loess area of northern ***,ongoing controversy exists regarding the indicators of prehistoric manuring intensity of foxtail millet(Setaria italica)and common millet(Panicum miliaceum).Here,we present the results of pot and field fertilization experiments on two millet *** findings suggest that manuring can significantly increase the δ^(15)N values of foxtail millet,and its δ^(15)N values increase with increasing manuring *** δ^(15)N values of foxtail millet leaves are systematically greater than those of grains by approximately 1.6‰.Manuring could have a long-term residual impact on increasing the δ^(15)N values of soil and millet *** with previous crop fertilization experiment results,we propose that the impact of manuring on the δ^(15)N values of non-nitrogen-fixing crops is roughly *** δ^(15)N value and amount of manure are key factors determining the extent of change in plant δ^(15)N *** millet grain δ^(15)N values can serve as reliable indicators of manuring ***,we provide an interpretive framework for assessing the correlation between manuring levels and the δ^(15)N values of archaeological millet *** δ^(15)N values of ancient millet grains suggest widespread and intensive manuring practices in prehistoric millet agriculture in northern China,spanning from the early yangshao period to the Longshan period.

关键词： Millet farming Manuring experiment Farming system Archaeobotany North China

Pressure effects on metal/covalent-organic frameworks:structural and optical properties

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第9期67卷 2890-2903页

作者： Yixuan Wang Yunfeng yang Xinyi yang Bo Zou Synergetic Extreme Condition High-Pressure Science Center State Key Laboratory of Superhard MaterialsCollege of PhysicsJilin UniversityChangchun 130012China

Metal-organic frameworks(MOFs)and covalent organic frameworks(COFs)with highly ordered porous structure,tunable bandgap,large specific surface area and structural diversity,provide an appealing platform for the development of stimulus response,sensing,imaging and *** various tuning methods,pressure engineering using the diamond anvil cell is a highly powerful in-situ technique,which can efficiently modulate the structural and optical properties of MOFs/*** is beyond the realization of traditional chemical *** review outlines the research progress in the experimentoriented discovery of new phases or unique properties under high pressure,including phase transition,abnormal compression,photoluminescence(PL)discoloration and ***,the improvement of PL quantum yield in MOFs could be achieved by pressure-treated engineering and hydrogen-bonding cooperativity *** also propose and establish the relationship between structure and optical properties under high ***,the challenge and outlook of the current fields are *** hope that this review will supply guidance for comprehending the development of high-pressure MOF/COF-related research fields,and offer novel strategies for designing more high-performance MOF/COF materials to ultimately expand their applications.

关键词： metal/covalent-organic frameworks pressure engineering phase transition abnormal compressive behaviors piezochromic behaviors emission enhancement

Enhanced Ion-Selective Diffusion Achieved by Supramolecular Interaction for High Thermovoltage and Thermal Stability

在线全文

学校读者我要写书评

暂无评论

Energy & Environmental Materials 2024年第2期7卷 200-208页

作者： Jiale Ke Xing Zhao Jie yang Kai Ke Yu Wang Mingbo yang Wei yang College of Polymer Science and Engineering Sichuan UniversityState Key Laboratory of Polymer Materials EngineeringChengdu 610065China

Thermoelectric(TE)generators capable of converting thermal energy into applicable electricity have gained great popularity among emerging energy conversion ***-based ionic thermoelectric(i-TE)materials are promising candidates for energy conversion systems because of their wide sources,innocuity,and low manufacturing ***,common physically crosslinked biopolymer gels induced by single hydrogen bonding or hydrophobic interaction suffer from low differential thermal voltage and poor thermodynamic ***,we develop a novel i-TE gel with supramolecular structures through multiple noncovalent interactions between ionic liquids(ILs)and gelatin molecular *** thermopower and thermoelectric power factor of the ionic gels are as high as 2.83 mV K-1 and 18.33μW m^(-1)K^(-2),*** quasi-solid-state gelatin-[EMIM]DCA i-TE cells achieve ultrahigh 2 h output energy density(E_(2h)=9.9 mJ m^(-2))under an optimal temperature ***,the remarkable stability of the supramolecular structure provides the i-TE hydrogels with a thermal stability of up to 80℃.It breaks the limitation that biopolymer-based i-TE gels can only be applied in the low temperature range and enables biopolymer-based i-TE materials to pursue better performance in a higher temperature range.

关键词： biopolymer gel ionic liquid multiple noncovalent interactions supramolecular structure thermoelectric conversion

Atomic-level coupled RuO_(2)/BaRuO_(3) heterostructure for efficient alkaline hydrogen evolution reaction

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第1期88卷 356-362,I0009页

作者： Yueying Yan Tian Meng Yuting Chen yang yang Dewen Wang Zhicai Xing Xiurong yang State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022JilinChina School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026AnhuiChina

The slow water dissociation is the rate-determining step that slows down the reaction rate in alkaline hydrogen evolution reaction(HER).Optimizing the surface electronic structure of the catalyst to lower the energy barrier of water dissociation and regulating the binding strength of adsorption intermediates are crucial strategy for boosting the catalytic performance of *** this study,RuO_(2)/BaRuO_(3)(RBRO)heterostructures with abundant oxygen vacancies and lattice distortion were in-situ constructed under a low temperature via the thermal decomposition of *** RBRO heterostructures obtained at 550℃ exhibited the highest HER activity in 1 M KOH,showing an ultra-low overpotential of 16 mV at 10 mA cm^(-2)and a Tafel slope of 33.37 m V dec^(-1).Additionally,the material demonstrated remarkable durability,with only 25 mV of degradation in overpotential after 200 h of stability testing at 10 mA cm^(-2).Density functional theory calculations revealed that the redistribution of charges at the heterojunction interface can optimize the binding energies of H*and OH*and effectively lower the energy barrier of water *** research offers novel perspectives on surpassing the water dissociation threshold of alkaline HER catalysts by means of a systematic design of heterogeneous interfaces.

关键词： Heterostructure Hydrogen evolution reaction Interfacial electron transfer Oxygen vacancies

Study of 26 Galactic Open Clusters with Extended Main-sequence Turnoffs

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第6期24卷 28-37页

作者： yang-yang Deng Zhong-Mu Li Yunnan Observatories Chinese Academy of SciencesKunming 650216China University of Chinese Academy of Sciences Beijing 100049China Institute of Astronomy and Information Dali UniversityDali 671003China

Recent studies indicate that some Galactic open clusters(OCs)exhibit extended main-sequence turnoff(eMSTO)in their color–magnitude diagrams(CMDs).However,the number of Galactic OCs with eMSTO structures detected so far is limited,and the reasons for their formation are still *** work identifies 26 Galactic OCs with undiscovered eMSTOs and investigates the causes of these *** population types and fundamental parameters of cluster samples are acquired using CMD fitting *** them,the results of 11 OCs are reliable as the observed CMDs are *** propose the crucial role of stellar binarity and confirm the importance of stellar rotation in reproducing eMSTO *** results also show that the impact of age spread is important,as it can adequately explain the structure of young OCs and fit the observed CMDs of intermediate-age OCs better.

关键词： (stars:)binaries:general Galaxy:fundamental parameters (Galaxy:)open clusters and associations:general (stars:)Hertzsprung Russell and C-M-diagrams

Livelihood Vulnerability and Adaptation for Households Engaged in Forestry in Ecological Restoration Areas of the Chinese Loess Plateau

在线全文

学校读者我要写书评

暂无评论

Chinese Geographical Science 2024年第5期34卷 849-868页

作者： yang Qingqing CHEN yang LI Xiaomin yang Jie GAO Yanhui Northwest Land and Resources Research Center Global Regional and Urban Research InstituteShaanxi Normal UniversityXi’an 710119China School of Geographical Science and Tourism Shaanxi Normal UniversityXi’an 710119China School of Tourism and Research Institute of Human Geography Xi’an International Studies UniversityXi’an 710128China

Chinese Loess Plateau has achieved a win-win situation concerning ecological restoration and socio-economic ***,synergistic development may not be realized at the local *** areas undergoing ecological restoration,livelihood vulner-ability may be more pronounced due to the inflexibility,policy protection,and susceptibility to climate and market changes in forestry *** this issue has attracted academic interest,empirical studies are relatively *** study,centered on Jiaxian County,Shaanxi Province of China explored the households’livelihood vulnerability and coping strategies and group heterogeneity con-cerned with livelihood structures or forestry resources through field investigation,comprehensive index assessment,and nonparametric *** showed that:1)the percentage of households with high livelihood vulnerability indicator(LVI)(>0.491)reached 46.34%.2)Eight groups in livelihood structures formed by forestry,traditional agriculture,and non-farm activities were significantly different in LVI,land resources(LR),social networks(SN),livelihood strategies(LS),housing characteristics(HC),and socio-demo-graphic profile(SDP).3)The livelihood vulnerability of the groups with highly engaged/reliance on jujube(Ziziphus jujuba)forest demonstrated more prominent livelihood vulnerability due to the increased precipitation and cold market,where the low-engaged with reliance type were significantly more vulnerable in LVI,SDP,LR,and HC.4)The threshold of behavioral triggers widely varied,and farmers dependent on forestry livelihoods showed negative coping ***,the cutting behavior was strongly associated with lagged years and government subsidies,guidance,and high returns of ***,the findings can provide guidance on the dir-ection of livelihood vulnerability mitigation and adaptive government management in ecologically restored *** issue of farmers’livelihood sustainability in the context of ecologi

关键词： livelihood vulnerability forestry coping behaviors climate change market change Jiaxian County

Quantitative contributions of climate change and human activities to vegetation dynamics in the Zoige Plateau from 2001 to 2020

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2024年第9期21卷 3031-3046页

作者： GAO Bing LIU Enqin yang yang yang Man YAO yang GUAN Lei FENG Yiwen College of Geography and Planning Chengdu University of TechnologyChengdu 610059China Key Laboratory of Smart Earth Beijing 100029China Sichuan Provincial Soil and Water Conservation Ecological Environment Monitoring Station Chengdu 610041China College of Earth and Planetary Sciences Chengdu University of TechnologyChengdu 610059China

Climate change and human activities such as overgrazing and rapid development of tourism simultaneously affected the vegetation of the Zoige ***,the spatiotemporal variations of vegetation and the relative contributions of climate change and human activities to these vegetation dynamics remain ***,clarifying how and why the vegetation on the Zoige Plateau changed can provide a scientific basis for the sustainable development of the ***,we investigate NDVI trends using the Normalized Difference Vegetation Index(NDVI)as an indicator of vegetation greenness and distinguish the relative effects of climate changes and human activities on vegetation changes by utilizing residual trend analysis and the *** find a tendency of vegetation greening from 2001 to 2020,with significant greening accounting for 21.44%of the entire ***,browning area expanded rapidly after *** temperatures are the primary driver of vegetation changes in the Zoige *** variations and human activities were responsible for 65.57%and 34.43%of vegetation greening,and 39.14%and 60.86%of vegetation browning,respectively,with browning concentrated along the Yellow,Black and White *** to 2001-2010,the inhibitory effect of human activity and climate fluctuations on vegetation grew dramatically between 2011 and 2020.

关键词： Vegetation change Climate change Residual trend analysis Geodetector Human activities Zoige plateau

河控型河口盐度层化对悬沙的捕集机制--以洪季磨刀门河口为例

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

海洋学报 2021年第5期43卷 38-49页

作者：谢荣耀刘锋罗向欣牛丽霞蔡华阳杨清书中山大学海洋科学学院广东珠海519082 中山大学海洋工程与技术学院河口海岸研究所广东珠海519082 广东省海岸与岛礁工程技术研究中心广东广州510275 河口水利国家地方联合工程实验室广东广州510275

河控型河口盐度混合和层化是控制悬沙输移扩散的重要动力机制。以珠江磨刀门河口为研究对象,基于2017年洪季三船同步大、小潮水文泥沙观测数据,分析河控型河口水体盐度层化结构的时空变化对悬沙分布的影响机制。结果表明:受径潮动力耦... 详细信息

河控型河口盐度混合和层化是控制悬沙输移扩散的重要动力机制。以珠江磨刀门河口为研究对象,基于2017年洪季三船同步大、小潮水文泥沙观测数据,分析河控型河口水体盐度层化结构的时空变化对悬沙分布的影响机制。结果表明:受径潮动力耦合时空变化影响,河口盐度垂向分布表现出时空差异,即受径流主导的M1站(挂锭角),河口盐度在涨落潮周期内垂向混合均匀,受径潮控制的M2站(口门)在整个潮周期内盐度层化结构明显,口门外侧的M3站,潮动力作用较强,盐度垂向分布随涨落潮变化而变化;悬沙空间分布与盐度分布关系密切,盐度混合均匀利于悬沙垂向均匀分布,而盐度层化则使悬沙倾向于滞留在底层水体中,且在盐度层结界面之下出现高悬沙浓度,悬沙浓度垂向分布曲线呈L字型或抛线型,纵向上表现为高浓度悬沙团抑制在盐水楔前端,盐度层化对悬沙的捕集效应明显。通过对比水体标准化分层系数与水流垂向扩散强度系数发现,两者呈现负相关关系,即标准化分层系数愈大,垂向扩散强度愈小,表明水体层化抑制悬沙垂向扩散强度,而且水体层化程度越高,悬沙垂向扩散抑制程度越大,进而促进了河口水体盐度层化对悬沙捕集作用。本研究有助于揭示河口细颗粒泥沙运动机制及河口拦门沙演变机制,并为磨刀门河口拦门沙治理提供科学依据。

关键词：悬沙分布盐度层化泥沙捕集磨刀门河口河控河口

Evolutionary dynamics of tax-based strong altruistic reward andpunishment in a public goods game

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第9期33卷 247-257页

作者： Zhi-Hao yang Yan-Long yang Mathematics and Statistics School Guizhou UniversityGuiyang 550025China

In public goods games, punishments and rewards have been shown to be effective mechanisms for maintaining individualcooperation. However, punishments and rewards are costly to incentivize cooperation. Therefore, the generation ofcostly penalties and rewards has been a complex problem in promoting the development of cooperation. In real society,specialized institutions exist to punish evil people or reward good people by collecting taxes. We propose a strong altruisticpunishment or reward strategy in the public goods game through this phenomenon. Through theoretical analysis and numericalcalculation, we can get that tax-based strong altruistic punishment (reward) has more evolutionary advantages thantraditional strong altruistic punishment (reward) in maintaining cooperation and tax-based strong altruistic reward leads toa higher level of cooperation than tax-based strong altruistic punishment.

关键词： evolutionary game theory strong altruism punishment reward