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

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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

Small-signal Stability Criteria in Power Electronics-dominated Power Systems:A Comparative Review

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Journal of Modern Power Systems and Clean Energy 2024年第4期12卷 1003-1018页

作者： Qifan Chen Siqi Bu Chi Yung Chung Department of Electrical and Electronic Engineer The Hong Kong Polytechnic UniversityHong KongChina Department of Electrical and Electronic Engineering Shenzhen Research InstituteCentre for Grid ModernisationInternational Centre of Urban Energy NexusCentre for Advances in Reliability and SafetyResearch Institute for Smart Energyand Policy Research Centre for Innovation and TechnologyThe Hong Kong Polytechnic UniversityHong KongChina

To tackle emerging power system small-signal stability problems such as wideband oscillations induced by the large-scale integration of renewable energy and power electronics,it is crucial to review and compare existing small-signal stability analysis *** this basis,guidance can be provided on determining suitable analysis methods to solve relevant small-signal stability problems in power electronics-dominated power systems(PEDPSs).Various mature methods have been developed to analyze the small-signal stability of PEDPSs,including eigenvalue-based methods,Routh stability criterion,Nyquist/Bode plot based methods,passivity-based methods,positive-net-damping method,lumped impedance-based methods,bifurcation-based methods,*** this paper,the application conditions,advantages,and limitations of these criteria in identifying oscillation frequencies and stability margins are reviewed and compared to reveal and explain connections and discrepancies among ***,efforts are devoted to mathematically proving the equivalence between these small-signal stability ***,the performance of these criteria is demonstrated and compared in a 4-machine 2-area power system with a wind farm and an IEEE 39-bus power system with 3 wind farms.

关键词： Impedance-based method oscillation analysis power electronic converter power electronics-dominated power system renewable power generation small-signal stability

High performance in Zintl thermoelectrics via reduction in crystal field splitting energy

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Science China Materials 2024年第10期67卷 3424-3425页

作者： Anustoop Das Kanishka Biswas New Chemistry Unit School of Advanced Materials and International Centre for Materials ScienceJawaharlal Nehru Centre for Advanced Scientific Research(JNCASR)Jakkur P.O.Bangalore 560064India

Sustainable thermoelectric materials open an avenue of emission-free as well as fast-responding recycling of energy in terms of heat to *** efficiency(η)of such conversion is primarily guided by the dimensionless the... 详细信息

关键词： splitting energy crystal

A new view of the local Universe

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Science China(Physics,Mechanics & Astronomy) 2024年第3期67卷 167-168页

作者： Lister Staveley-Smith international centre for Radio Astronomy research(ICRAR) University of Western AustraliaCrawley WA 6009Australia ARC centre of Excellence for All Sky Astrophysics(ASTRO 3D) Crawley WA 6009Australia

The distribution and kinematics of gas in and around dark matter halos, the formation of stellar populations from the gravitational collapse of gas clouds, and the interaction of stars and their remnants with interste... 详细信息

关键词： galaxies stars galactic

Grassland-type ecosystem stability in China differs under the influence of drought and wet events

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Journal of Arid Land 2024年第5期16卷 615-631页

作者： CAO Wenyu BAI Jianjun YU Leshan School of Geography and tourism Shaanxi Normal UniversityXi'an 710119China international Business School Shaanxi Normal UniversityXi'an 710119China

Ecological stability is a core issue in ecological research and holds significant implications forhumanity. The increased frequency and intensity of drought and wet climate events resulting from climatechange pose a major threat to global ecological stability. Variations in stability among different ecosystemshave been confirmed, but it remains unclear whether there are differences in stability within the sameterrestrial vegetation ecosystem under the influence of climate events in different directions and ***'s grassland ecosystem includes most grassland types and is a good choice for studying this *** study used the Standardized Precipitation Evapotranspiration Index-12 (SPEI-12) to identify thedirections and intensities of different types of climate events, and based on Normalized DifferenceVegetation Index (NDVI), calculated the resistance and resilience of different grassland types for 30consecutive years from 1990 to 2019 (resistance and resilience are important indicators to measurestability). Based on a traditional regression model, standardized methods were integrated to analyze theimpacts of the intensity and duration of drought and wet events on vegetation stability. The resultsshowed that meadow steppe exhibited the highest stability, while alpine steppe and desert steppe had thelowest overall stability. The stability of typical steppe, alpine meadow, temperate meadow was at anintermediate level. Regarding the impact of the duration and intensity of climate events on vegetationecosystem stability for the same grassland type, the resilience of desert steppe during drought was mainlyaffected by the duration. In contrast, the impact of intensity was not significant. However, alpine steppewas mainly affected by intensity in wet environments, and duration had no significant impact. Ourconclusions can provide decision support for the future grassland ecosystem governance.

关键词： grassland ecosystem stability resistance resilience different climate types drought climate event wet climate event

Does back cooling improve human thermal comfort in warm environments?A device for heat conduction by the semiconductor Peltier effect

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Building Simulation 2024年第8期17卷 1253-1271页

作者： Mengyuan He Hong Liu Lianggen Shao Baizhan Li Yuxin Wu Joint international research Laboratory of Green Building and Built Environments(Ministry of Education) Chongqing UniversityChongqingChina National centre for international research of Low-carbon and Green Buildings(Ministry of Science and Technology) Chongqing UniversityChongqingChina School of Civil Engineering and Architecture Zhejiang Sci-Tech UniversityHangzhouChina

The hot environment and the metabolic heat of commuting in summer caused individual overheating and intense thermal *** cooling presents huge potential for optimizing thermal *** study investigates the performance of a back cooling device,based on the semiconductor Peltier effect,in improving thermal comfort after summer *** studied one case without cooling,and three cases with surface temperatures of the cooling device of 29,27,and 25℃using a simulated summer commute at a moderate activity *** results showed that thermal sensation,perceived sweating rate,and skin temperature decreased markedly in the cooling cases compared to the non-cooling case,with the changes being most notable in the lower back,in contact with the cooling *** decrease in overall thermal sensation and mean skin temperature was approximately 0.52 score and 0.31℃on average,respectively,with a 1.71 score increase in overall thermal *** contend that the surface temperature of local contact cooling devices should not be lower than 22℃to minimize local *** cooling devices present a huge potential for building energy-savings at ambient air temperature exceeding 30℃.Moreover,the functional paradigms for individual comfort predict improved comfort performance in future *** study contributes to the understanding on the well-being and physiological recovery of individuals after a summer commuting.

关键词： back cooling heat conduction summer commuting thermal comfort prediction

Insights into the pre-game legacy of the Paris 2024 Summer Olympics

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The Innovation 2024年第5期5卷 7-8页

作者： Haibin Xu Yiyi Jiang Yan Fang Tian Li Ning Wang Xujia Huang Hailong Li School of Leisure Sports and tourism Beijing Sport UniversityBeijing 100084China Beijing Winter Olympics Culture and Ice&Snow Sports Development research Base Beijing 100084China Alberta international School of Recreation Sportand Tourism of Beijing Sport UniversityHainan 572423China

In July 2024,the 33rd Summer Olympic Games will take place in *** the bidding phase for the Paris Olympics,extensive planning was undertaken to explore and utilize the Olympic legacy.1 This article examines the design and distinctive aspects of the Olympic legacy in Paris and summarizes the insights for utilizing legacies in future Games.

关键词： utilize utilizing Summer

Remote copper-catalyzed enantioselective substitution of yne-thiophene carbonates

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Science China Chemistry 2024年第4期67卷 1175-1180页

作者： Hao-Dong Qian Xiang Li Tingrui Yin Wei-Feng Qian Chunhui Zhao Cuiju Zhu Hao Xu CCNU-uOttawa Joint research centre Key Laboratory of Pesticides&Chemical Biology of Ministry of EducationInternational Joint Research Center for Intelligent Biosensing Technology and HealthCollege of ChemistryCentral China Normal UniversityWuhan 430079China

Here,we describe a strategy for the copper-catalyzed asymmetric heteroarylation of yne-thiophene carbonates with indoles via remote *** key to the success of this strategy lies in the design of the alkynyl group at the ortho-position of the heterocycle thiophene,enabling the formation of a triarylmethane moiety via very remote ***,the concept of remote copper-catalyzed asymmetric transformation extends not only to yne-allylic esters but also to yne-aryl *** reaction readily provides a diverse array of chiral triarylmethanes with high efficiency,enantioselectivity,and excellent functional group ***,facile follow-up transformations underscore their potential utility in the synthesis of various enantioenriched building *** mechanistic studies support the plausibility of the remote substitution pathway.

关键词： remote substitution copper catalyst asymmetric catalysis triaryl methanes

Application of plant DNA metabarcoding of lake sediments for monitoring vegetation compositions on the Tibetan Plateau

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Science China Earth Sciences 2024年第11期67卷 3594-3609页

作者： Kai WU Kai LI Weihan JIA Kathleen R.STOOF-LEICHSENRING Ulrike HERZSCHUH Jian NI Mengna LIAO Fang TIAN College of Life Sciences Zhejiang Normal University Polar Terrestrial Environmental Systems research Group Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research Institute of Environmental Science and Geography University of Potsdam Institute of Biochemistry and Biology University of Potsdam College of Resource Environment and tourism Capital Normal University

Benefiting from the rapid development of environmental DNA(eDNA) technologies, sedimentary DNA(sedDNA)emerges as a promising tool for monitoring plant compositions in remote regions. The Tibetan Plateau(TP), renowned for its harsh environment and numerous ponds and lakes, presents a potentially demanding region for the application of sedDNA on vegetation investigations. Here, we used the g and h universal primers for the P6 loop region of the chloroplast trn L(UAA)intron to amplify plant DNA in surface sediments from 59 ponds and small lakes on the southwestern TP. The applicability and limitations of using plant DNA metabarcoding for modern vegetation monitoring and palaeo-vegetation reconstructions have been assessed by comparing sedDNA, pollen, and vegetation survey data. Our results showed that plant DNA metabarcoding recorded 186 terrestrial taxa, of which 30.1% can be identified at the species level. The plant sedDNA approach can effectively disclose the dominant plant taxa(including Asteraceae, Cyperaceae and Poaceae) and significant vegetation assemblages in the vicinity of the investigated sites. The number of taxa and taxonomic resolution of plant sedDNA exceeded that of pollen analysis(75 taxa detected, 5.3% can be identified at species level). Unlike pollen that retains a broad spectrum of regional plant signals(including Pinus and Artemisia), plant sedDNA mirrors very local plants, underscoring its utility in local vegetation monitoring and reconstructions. To conclude, plant DNA metabarcoding of(small) lake sediments warrant increased attention in the future for local vegetation monitoring and reconstructions on the TP.

关键词： Sedimentary DNA (sedDNA) Metabarcoding Pollen Vegetation composition Tibetan Plateau