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Effects of desert plant communities on soil enzyme activities and soil organic carbon in the proluvial fan in the eastern foothills of the Helan Mountain in Ningxia,china

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Journal of Arid Land 2024年第5期16卷 725-737页

作者： SHEN Aihong SHI Yun MI Wenbao YUE Shaoli SHE Jie ZHANG Fenghong GUO Rui HE Hongyuan WU Tao LI Hongxia ZHAO Na College of Forestry and Prataculture of Ningxia University Yinchuan 750021China School of Geography and Planning of Ningxia University Yinchuan 750021China Ningxia Hui Autonomous Region Agricultural Comprehensive development center Yinchuan 750002China Ningxia Helan Mountain National Nature Reserve Administration Yinchuan 750021China Yinchuan Yinxi Ecological Protection Forest management center Yinchuan 750002China

It is of great significance to study the effects of desert plants on soil enzyme activities and soil organic carbon(SOC)for maintaining the stability of the desert ecosystem.In this study,we studied the responses of soil enzyme activities and SOC fractions(particulate organic carbon(POC)and mineral-associated organic carbon(MAOC))to five typical desert plant communities(Convolvulus tragacanthoides,Ephedra rhytidosperma,Stipa breviflora,Stipa tianschanica var.gobica,and Salsola laricifolia communities)in the proluvial fan in the eastern foothills of the Helan Mountain in Ningxia Hui Autonomous Region,china.We recorded the plant community information mainly including the plant coverage and herb and shrub species,and obtained the aboveground biomass and plant species diversity through sample surveys in late July 2023.Soil samples were also collected at depths of 0–10 cm(topsoil)and 10–20 cm(subsoil)to determine the soil physicochemical properties and enzyme activities.The results showed that the plant coverage and aboveground biomass of S.laricifolia community were significantly higher than those of C.tragacanthoides,S.breviflora,and S.tianschanica var.gobica communities(P<0.05).Soil enzyme activities varied among different plant communities.In the topsoil,the enzyme activities of alkaline phosphatase(ALP)andβ-1,4-glucosidas(βG)were significantly higher in E.rhytidosperma and S.tianschanica var.gobica communities than in other plant communities(P<0.05).The topsoil had higher POC and MAOC contents than the subsoil.Specifically,the content of POC in the topsoil was 18.17%–42.73%higher than that in the subsoil.The structural equation model(SEM)indicated that plant species diversity,soil pH,and soil water content(SWC)were the main factors influencing POC and MAOC.The soil pH inhibited the formation of POC and promoted the formation of MAOC.Conversely,SWC stimulated POC production and hindered MAOC formation.Our study aimed to gain insight into the effects of desert plant communities on soil enzyme activities and SOC fra

关键词： proluvial fan desert plant community soil enzyme activity particulate organic carbon mineral-associated organic carbon Helan Mountain

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Effects of simulated gut pH environment on bacterial composition and pheromone production of Dendroctonus valens

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Insect Science 2024年第1期31卷 225-235页

作者： Qingjie Cao Yu Zhao Tuuli-Marjaana Koski Huiping Li Jianghua Sun College of Forestry Hebei Agricultural UniversityBaodingHebei ProvinceChina State Key Laboratory of Integrated management of Pest Insects and Rodents Institute of ZoologyChinese Academy of SciencesBeijingChina College of Life Science/Hebei Basic Science center for Biotic Interactions Institute of Life Science and Green DevelopmentHebei UniversityBaodingHebei ProvinceChina

Bark beetles are an economically and ecologically important insect group,with aggregation behavior and thus host colonization success depends on pheromone-mediated communication.For some species,such as the major invasive forest pest in china,red turpentine beetle(Dendroctonus valens),gut microbiota participates in pheromone production by converting tree monoterpenes into pheromone products.However,how variation in gut microenvironment,such as pH,affects the gut microbial composition,and consequently pheromone production,is unknown.In this study,we fed wild caught D.valens with 3 different pH media(main host diet with natural pH of 4.7;a mildly acidic diet with pH 6 mimicking the beetle gut pH;and highly acidic diet with pH 4),and measured their effects on the gut pH,bacterial community and production of the main aggregation and anti-aggregation pheromone(verbenone).We further tested the verbenone production capacity of 2 gut bacterial isolates in different pH environments(pH 6 and 4).Compared to natural state or main host diet,feeding on less acidic diet(pH 6)diluted the acidity of the gut,whereas feeding on highly acidic diet(pH 4)enhanced it.Both changes in gut pH reduced the abundance of dominant bacterial genera,resulting in decreased verbenone production.Similarly,the highest pheromone conversion rate of the bacterial isolates was observed in pH mimicking the acidity in beetle gut.Taken together,these results indicate that changes in gut pH can affect gut microbiota composition and pheromone production,and may therefore have the potential to affect host colonization behavior.

关键词： Dendroctonus valens gut bacteria gut pH verbenone

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Spatiotemporal characteristics of cultivated land use eco-efficiency and its influencing factors in china from 2000 to 2020

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Journal of Arid Land 2024年第3期16卷 396-414页

作者： LI Shaoting MU Na REN Yanjun Thomas GLAUBEN College of Economics and management Northwest A&F UniversityYangling 712100China Sino-German center for Agricultural and Food Economics Northwest A&F UniversityYangling 712100China Leibniz Institute of Agricultural development in Transition Economies(IAMO) Halle 06120Germany

Improving cultivated land use eco-efficiency(CLUE)can effectively promote agricultural sustainability,particularly in developing countries where CLUE is generally low.This study used provincial-level data from china to evaluate the spatiotemporal evolution of CLUE from 2000 to 2020 and identified the influencing factors of CLUE by using a panel Tobit model.In addition,given the undesirable outputs of agricultural production,we incorporated carbon emissions and nonpoint source pollution into the global benchmark-undesirable output-super efficiency-slacks-based measure(GB-US-SBM)model,which combines global benchmark technology,undesirable output,super efficiency,and slacks-based measure.The results indicated that there was an upward trend in CLUE in china from 2000 to 2020,with an increase rate of 2.62%.The temporal evolution of CLUE in china could be classified into three distinct stages:a period of fluctuating decrease(2000-2007),a phase of gradual increase(2008-2014),and a period of rapid growth(2015-2020).The major grain-producing areas(MPAs)had a lower CLUE than their counterparts,namely,non-major grain-production areas(non-MPAs).The spatial agglomeration effect followed a northeast-southwest strip distribution;and the movement path of barycentre revealed a"P"shape,with Luoyang City,Henan Province,as the centre.In terms of influencing factors of CLUE,investment in science and technology played the most vital role in improving CLUE,while irrigation index had the most negative effect.It should be noted that these two influencing factors had different impacts on MPAs and non-MPAs.Therefore,relevant departments should formulate policies to enhance the level of science and technology,improve irrigation condition,and promote sustainable utilization of cultivated land.

关键词： cultivated land use eco-efficiency(CLUE) slacks-based measure(SBM)model barycentre model standard deviation ellipse(SDE) panel Tobit model carbon emissions nonpoint source pollution

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A Study on the Current Situation, Problems and Responsive Measures of Building china's National Carbon Market

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Chinese Journal of Urban and Environmental Studies 2022年第3期10卷 7-16页

作者： XIA Yingzhe FENG Chao YUAN Xiaohua china clean development mechanism fund management center

Carbon emissions trading is a major innovation in the practice of using market mechanism to control and reduce greenhouse gas(GHG) emissions and promote green and low-carbon development. It is an important way to achieve china's carbon peaking and carbon neutrality goals(the“dual carbon” goals) at a relatively low cost. Starting late and having gone through three development stages, china's national carbon market has entered a new stage. However, given the problems such as incomplete institutional, regulatory and carbon emissions verification systems,less balanced and vibrant market, limited transaction entities and trading products, and lack of voice due to insufficient participation in relevant international affairs, continuous efforts are still required to further improve this market by deepening reform, strengthening capacity building and increasing international cooperation.

关键词： Climate change carbon neutrality carbon market MRV

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The impact of demographic dynamics on food consumption and its environmental outcomes:Evidence from china

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Journal of Integrative Agriculture 2024年第2期23卷 414-429页

作者： Shaoting Li Xuan Chen Yanjun Ren Thomas Glauben College of Economics and management Northwest A&F UniversityYangling 712100China Leibniz Institute of Agricultural development in Transition Economies(IAMO) Halle(Saale)06120Germany Sino-German center for Agricultural and Food Economics Northwest A&F UniversityYangling 712100China

With increasing population and changing demographics,food consumption has experienced a significant transition in quantity and quality.However,a dearth of knowledge remains regarding its environmental impacts and how it responds to demographic dynamics,particularly in emerging economies like china.Using the two-stage Quadratic Almost Demand System(QUAIDS)model,this study empirically examines the impact of demographic dynamics on food consumption and its environmental outcomes based on the provincial data from 2000 to 2020 in china.Under various scenarios,according to changes in demographics,we extend our analysis to project the long-term trend of food consumption and its environmental impacts,including greenhouse gas(GHG)emissions,water footprint(WF),and land appropriation(LA).The results reveal that an increase in the proportion of senior people significantly decreases the consumption of grain and livestock meat and increases the consumption of poultry,egg,and aquatic products,particularly for urban residents.Moreover,an increase in the proportion of males in the population leads to higher consumption of poultry and aquatic products.Correspondingly,in the current scenario of an increased aging population and sex ratio,it is anticipated that GHG emissions,WF,and LA are likely to decrease by 1.37,2.52,and 3.56%,respectively.More importantly,in the scenario adhering to the standards of nutritional intake according to the Dietary Guidelines for Chinese Residents in 2022,GHG emissions,WF,and LA in urban areas would increase by 12.78,20.94,and 18.32%,respectively.Our findings suggest that changing demographics should be considered when designing policies to mitigate the diet-environment-health trilemma and achieve sustainable food consumption.

关键词： demographic dynamics food consumption environmental impacts nutrition intakes

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The Role of Childhood Circumstances in Healthy Aging Inequalities Among Older Adults—china,2011–2020

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china CDC weekly 2024年第11期6卷 208-212,I0004-I0007页

作者： Peng Nie Xili Lin Lanlin Ding School of Economics and Finance Xi’an Jiaotong UniversityXi’an CityShaanxi ProvinceChina Global Health Institute Xi’an Jiaotong University Health Science CenterXi’an CityShaanxi ProvinceChina National School of development Peking UniversityBeijingChina

What is already known about this topic?Addressing health disparities is a worldwide priority,with a well-established acknowledgment of the influence of childhood circumstances on these discrepancies.In china,particularly among the elderly,health inequalities are a notable concern.What is added by this report?The inequality in healthy aging has increased from 2011 to 2020,both in general and concerning childhood factors.Nevertheless,the impact of early-life healthcare access and parental health behaviors on healthy aging gaps has reduced among older adults in better health within the top segment of healthy aging.What are the implications for public health practice?Efforts towards reducing regional health disparities and improving healthcare access for children,along with promoting the health and well-being of parents,especially in economically disadvantaged households,are crucial policy considerations.

关键词： ledgment inequalities circumstances

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High-speed penetration of ogive-nose projectiles into thick concrete targets:Tests and a projectile nose evolution model

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Defence Technology（防务技术） 2024年第2期32卷 553-571页

作者： Xu Li Yan Liu Junbo Yan Zhenqing Shi Hongfu Wang Yingliang Xu Fenglei Huang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China Beijing Institute of Technology Chongqing Innovation center Chongqing401120China china Research and development Academy of Machinery Equipment Beijing100089China

The majority of the projectiles used in the hypersonic penetration study are solid flat-nosed cylindrical projectiles with a diameter of less than 20 mm.This study aims to fill the gap in the experimental and analytical study of the evolution of the nose shape of larger hollow projectiles under hypersonic penetration.In the hypersonic penetration test,eight ogive-nose AerMet100 steel projectiles with a diameter of 40 mm were launched to hit concrete targets with impact velocities that ranged from 1351 to 1877 m/s.Severe erosion of the projectiles was observed during high-speed penetration of heterogeneous targets,and apparent localized mushrooming occurred in the front nose of recovered projectiles.By examining the damage to projectiles,a linear relationship was found between the relative length reduction rate and the initial kinetic energy of projectiles in different penetration tests.Furthermore,microscopic analysis revealed the forming mechanism of the localized mushrooming phenomenon for eroding penetration,i.e.,material spall erosion abrasion mechanism,material flow and redistribution abrasion mechanism and localized radial upsetting deformation mechanism.Finally,a model of highspeed penetration that included erosion was established on the basis of a model of the evolution of the projectile nose that considers radial upsetting;the model was validated by test data from the literature and the present study.Depending upon the impact velocity,v0,the projectile nose may behave as undistorted,radially distorted or hemispherical.Due to the effects of abrasion of the projectile and enhancement of radial upsetting on the duration and amplitude of the secondary rising segment in the pulse shape of projectile deceleration,the predicted DOP had an upper limit.

关键词： High-speed penetration Concrete target Erosion Projectile nose evolution model

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Experimental study on the activation of coal gasification fly ash from industrial CFB gasifiers

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Chinese Journal of Chemical Engineering 2024年第1期65卷 8-18页

作者： Qiyao Yang Xiaobin Qi Qinggang Lyu Zhiping Zhu North china Electric Power University Beijing 102206China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China Shanxi Key Laboratory of Coal Flexible Combustion and Thermal Conversion Datong 037000China University of Chinese Academy of Sciences Beijing 100049China Shanxi Engineering Research center of Coal clean Efficient Combustion and GasificationDatong 037000China

Coal gasification fly ash(CGFA)is an industrial solid waste from the coal circulating fluidized bed(CFB)gasification process,and it needs to be effectively disposed to achieve sustainable development of the environment.To realize the application of CGFA as a precursor of porous carbon materials,the physicochemical properties of three kinds of CGFA from industrial CFB gasifiers are analyzed.Then,the activation potential of CGFA is acquired via steam activation experiments in a tube furnace reactor.Finally,the fluidization activation technology of CGFA is practiced in a bench-scale CFB test rig,and its advantages are highlighted.The results show that CGFA is characterized by a high carbon content in the range of 54.06%–74.09%,an ultrafine particle size(d50:16.3–26.1 μm),and a relatively developed pore structure(specific surface area SSA:139.29–551.97 m^(2)·g^(-1)).The proportion of micropores in CGFA increases gradually with the coal rank.Steam activation experiments show that the pore development of CGFA mainly includes three stages:initial pore development,dynamic equilibrium between micropores and mesopores and pore collapse.The SSA of lignite fly ash(LFA),subbituminous fly ash(SBFA)and anthracite fly ash(AFA)is maximally increased by 105%,13%and 72%after steam activation;the order of the largest carbon reaction rate and decomposition ratio of steam among the three kinds of CGFA is SBFA>LFA>AFA.As the ratio of oxygen to carbon during the fluidization activation of LFA is from 0.09 to 0.19,the carbon conversion ratio increases from 14.4%to 26.8%and the cold gas efficiency increases from 6.8%to 10.2%.The SSA of LFA increases by up to 53.9%during the fluidization activation process,which is mainly due to the mesoporous development.Relative to steam activation in a tube furnace reactor,fluidization activation takes an extremely short time(seconds)to achieve the same activation effect.It is expected to further improve the activation effect of LFA by regulating the carbon conversion ratio range of 27%–35%to create por

关键词： Circulating fluidized bed Coal gasification fly ash Steam activation Pore structure evolution Fluidization activation

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R2R3-type Lo MYB21 affects jasmonate-regulated development and dehiscence of anthers in lily(Lilium oriental hybrids)

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Horticultural Plant Journal 2024年第1期10卷 239-251页

作者： Zheng Tong Tingting Dong Qiuhua Li Rui Wang Junna He Bo Hong Institute of Tropical Bioscience and Biotechnology Chinese Academy of Tropical Agricultural Sciences&Hainan Institute for Tropical Agricultural ResourcesHaikouHainan 571101China Beijing Key Laboratory of development and Quality Control of Ornamental Crops Department of Ornamental HorticultureChina Agricultural UniversityBeijing 100193China Beijing Garden Expo management center Beijing 100072China

Lilies are widely cultivated for cut flowers,but their large anthers carry a considerable amount of colored pollen that is dispersed easily.Studying the molecular mechanism of anther development and dehiscence could help solve this problem.LoMYB21,encoding a putative R2R3v-myb avian myeloblastosis viral oncogene homolog(MYB)transcription factor,was identified from oriental lilies(Lilium‘Siberia’).Real-time quantitative PCR analysis showed that LoMYB21 was mainly expressed in the anther,filament and stigma and had high expression during the late stages of lily anther development.LoMYB21 had transactivation activity and was located in the nucleus through yeast one-hybrid assays and transient expression in Nicotiana benthamiana.Suppression of LoMYB21 by virus-induced gene silencing(VIGS)in Lilium‘Siberia’led to anther indehiscence and reduced the expression of genes related to Jasmonate acid(JA)biosynthesis and signal transduction.Induction of LoMYB21 in DEX::LoMYB21 transgenic Arabidopsis caused procumbent inflorescences that became infertile,accompanied by higher expression of JA biosynthetic and signaling genes.These results demonstrated that JA content and signaling were abnormal in silenced lily and transgenic LoMYB21 Arabidopsis,which affected anther development.Our study indicated that LoMYB21 could regulate lily anther dehiscence through JA biosynthesis and signaling during the late stages of anther development.

关键词： Lilium LoMYB21 Anther dehiscence Jasmonate acid

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Isotopic insights on quantitative assessments of interaction of eco-hydrological processes in multi-scale karst watersheds

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International Soil and Water Conservation Research 2024年第1期12卷 156-170页

作者： Zhuo Hao Yang Gao Qingwen Zhang Wen Wen Agricultural clean Watershed Research Group Institute of Environment and Sustainable Development in AgricultureCAASBeijing100081China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchCASBeijing100101China School of Humanities and Social Sciences Beijing Institute of TechnologyBeijing100081China

The dynamics of hydrological processes and the storage mechanisms of karst water resources are the most important issues in karst hydrology.The impact of environmental changes on water quantity,and the evaluation and quantification of eco-hydrological processes remain poorly addressed.In this study,high-frequency continuous monitoring in multi-scale karst watersheds in Southwest china combined the approaches of water isotopes and the hybrid single-particle lagrangian integrated trajectory(HYSPLIT)model to identify the recharge mechanisms between atmospheric vapor,rainfall,surface water,and groundwater,and to reveal the interaction of eco-hydrological processes.The dominant moisture sources in Puding(PD)County were the Indian Ocean(43-69%)and local moisture(24-33%).Theδ^(18)O and deuterium excess(d-excess)values showed a positive correlation indicating that secondary or sub-cloud evaporation was prominent in the wet seasons.Karst water line-conditioned excess(lc-excess)indicated that karst water interacted with recent precipitation,groundwater,and evaporation across seasons.Owing to its specific hydrogeological structure,surface water and rainwater have a higher contribution rate to groundwater replenishment.The Chenqi stream replenished the Houzhai River mainly in the form of groundwater,with percentages ranging from 38.1 to 93.5%in the wet season,and 47.8-80.1%in the dry season.In the Houzhai outlet,surface water and groundwater interconverted frequently with a percentage of 45.6-49.1%.We believe this is the first systematic study to quantify the supply relationship between water vapor transport,rainfall,surface water and groundwater in the Chinese karst zone,making a significant move forward in the field of karst hydrological processes and improving the efficiency of water resource evaluation and management.

关键词： Stable isotope Moisture sources Water cycle Karst watersheds

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