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Impacts of land conversion and management measures on net primary productivity in semi-arid grassland

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Ecosystem Health and Sustainability 2020年第1期6卷 434-449,433页

作者： Feifei Cao jiaxun li Xiao Fu Gang Wu State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijingChina University of Chinese Academy of Sciences BeijingChina

Ecological restoration measures implemented in China have profoundly impacted vegetation *** study aimed to estimate the effects of the land conversion and management measures on the grassland ecosystem in semi-arid *** use data were employed from 2000 to 2015 to compare land conversion and coverage changes in Xilingol ***,the contributions of land conversion and management policies were quantified by assessing the difference between actual NPP and climate-induced NPP *** results indicated that the grassland area had a net loss of 534.42 km^(2),and the net area of increased vegetation coverage was 74,683.05 km^(2).Furthermore,the total NPP increased by 8,010.73 Gg C·yr^(−1)(1 Gg=10^(9)g),of which the human activities,including grazing management measures(+6,809.40 Gg C·yr^(−1))and land conversion(45.72 Gg C·yr^(−1))contributed to 85.58%of the increase in *** from desert and farmland dominated grassland expansion and NPP increase,while urbanization and desertification caused large grassland reduction and NPP *** grazing management increased vegetation NPP in most regions except for some regions in the desert steppe and the farming-pastoral *** policies should be further adjusted to strengthen the management of the desert steppe and farming-pastoral regions.

关键词： Grassland degradation land use and land cover change management measures and policies net primary productivity(NPP) Xilingol grassland anthropogenic/human activities affects

Characterizing the capability of mesoscale eddies to carry drifters in the northwest Pacific

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Journal of Oceanology and limnology 2020年第6期38卷 1711-1728页

作者： WANG Huizan liU Ding ZHANG Weimin li jiaxun WANG Bo College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410073China Naval Research Academy Tianjin 300061China

Mesoscale eddies are common oceanic *** many related studies have been conducted,the ability for mesoscale eddies to carry real particles remains poorly *** considered the drifters as real particles to characterize the capability of mesoscale eddies to carry ***,mesoscale eddies in the northwest Pacific(99°E-180°E,0°-66°N)were identified using sea level anomaly(SLA)data from 1993 to ***,three important parameters(the carrying days,the number of circles the drifter revolving around the eddy center,and the carrying distances)were calculated by colocalizing eddy data with ***,statistical analysis and composite analysis were conducted,reflecting the capability of mesoscale eddies to carry *** mechanisms on the carrying capability of eddies were also *** show that(1)the motion of carried drifters reflects the upper limit of rotational speed of eddies that the drifters revolve around the eddy center by≤90°for one day in most cases;(2)the drifters tend to be carried for a longer time when their minimal distances to the eddy center measured with normalized distance are small;(3)there are two types of eddies(cyclonic and anticyclonic eddies)in different subregions of northwest Pacific,and each has a different carrying capability(on average,similar in the tropical ocean and Subtropical Countercurrent,cyclonic eddies tend to have stronger carrying capability in Southern Kuroshio Extension,and anticyclonic eddies tend to have stronger carrying capability in Northern Kuroshio Extension and Subarctic Gyre);(4)on average,the carried drifters tend to travel for a longer time around the normalized eddy radii ranging from 0.41 to 0.76;(5)the carrying days are related to the Rossby number of the eddy(in general when the Rossby number is smaller,the carrying days are longer).

关键词： mesoscale eddy drifter Rossby number composite analysis carrying capability

The long-term trend of the sea surface wind speed and the wave height (wind wave, swell, mixed wave) in global ocean during the last 44 a

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Acta Oceanologica Sinica 2013年第10期32卷 1-4页

作者： ZHENG Chongwei ZHOU lin HUANG Chaofan SHI Yinglong li jiaxun li Jing College of Meteorology and Oceanography People's Liberation Army (PLA) University of Science &Technology Meteorological Unit.No.92538 Army of PLA

Utilizing the 45 a European Centre for Medium-Range Weather Forecasts （ECMWF） reanalysis wave da- ta （ERA-40）, the long-term trend of the sea surface wind speed and （wind wave, swell, mixed wave） wave height in the global ocean at grid point 1.5°× 1.5° during the last 44 a is analyzed. It is discovered that a ma- jority of global ocean swell wave height exhibits a significant linear increasing trend （2-8 cm/decade）, the distribution of annual linear trend of the significant wave height （SWH） has good consistency with that of the swell wave height. The sea surface wind speed shows an annually linear increasing trend mainly con- centrated in the most waters of Southern Hemisphere westerlies, high latitude of the North Pacific, Indian Ocean north of 30°S, the waters near the western equatorial Pacific and low latitudes of the Atlantic waters, and the annually linear decreasing mainly in central and eastern equator of the Pacific, Juan. Fernandez Archipelago, the waters near South Georgia Island in the Atlantic waters. The linear variational distribution characteristic of the wind wave height is similar to that of the sea surface wind speed. Another find is that the swell is dominant in the mixed wave, the swell index in the central ocean is generally greater than that in the offshore, and the swell index in the eastern ocean coast is greater than that in the western ocean inshore, and in year-round hemisphere westerlies the swell index is relatively low.

关键词： ECMWF reanalysis wave data wind wave swell mixed wave long-term trend swell index

First report of Muyocopron laterale causing a new leaf disease of Camellia sinensis in China

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Beverage Plant Research 2022年第1期2卷 72-75页

作者： Hao Jiang Mengting Zhang Youjia Zhou Xuehui li jiaxun li Chuankui Song State Key Laboratory of Tea Plant Biology and Utilization Anhui Agricultural University130 West Changjiang RoadHefei 230036China

Tea plant(Camellia sinensis)diseases are one of the factors that reduce tea production yield and ***,a new leaf disease of tea plants was observed in tea plantations.A representative isolate was obtained from diseased leaf by the traditional fungus separation *** isolate identified was confirmed as Muyocopron laterale based on morphological and molecular results and phylogenetic tree *** tests were conducted on tea plant seedlings,and which is fulfilling Koch’s *** disease was first identified in *** leaves caused by *** in *** the future,the results of this studies will enrich our knowledge and help control tea leaf disease.

关键词： sinensis analysis Camellia

Screening and characterization of phenolic compounds by LC-ESI-QTOF-MS/MS and their antioxidant potentials in papaya fruit and their by-products activities

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Food Bioscience 2023年第2期52卷 1102-1117页

作者： Yufeng Zhou Yuanxiao Cao jiaxun li Osman Tuncay Agar Colin Barrow Frank Dunshea Hafiz A.R.Suleria School of Agriculture and Food Faculty of ScienceThe University of MelbourneParkvilleVIC3010Australia Centre for Chemistry and Biotechnology School of Life and Environmental SciencesDeakin UniversityWaurn PondsVIC3217Australia Faculty of Biological Sciences The University of LeedsLeedsLS29JTUK

Papaya(Carica papaya L.)is one of the most commonly planted and consumed fruits in the world,especially in tropical and subtropical *** recent years,due to the diverse range of nutritional value and medicinal properties of bioactive substances possessed in papaya,papaya fruit and their by-products have gained more *** present study aimed to characterize the different parts(pulp,peel,and seed)of two varieties of papaya(yellow-and red-fleshed)at different stages of ripeness(unripe and ripe)for their phenolic compounds using liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry(LC-ESI-QTOF-MS/MS).The phenolic content and antioxidant activity were detected through several ***-fleshed unripe papaya seed showed the highest total phenolic content(TPC)(4.73 mg GAE/g).Red-fleshed ripe papaya peel exhibited the highest level of total tannin content(TTC)with 1.98 mg CE/g,while red-fleshed unripe peel exhibited the highest total flavonoid content(TFC)with 2.78±0.04 mg QE/*** terms of antioxidant potential,yellow-fleshed unripe papaya peels had the highest radical scavenging activities for the DPPH,ABTS,and TAC ***-ESI-QTOF-MS/MS experiment successfully tentatively identified 118 phenolic compounds in total,including phenolic acids(35),flavonoids(61),stilbenes(3),lignans(7)and other polyphenols(12)in all papaya *** indicate that the three different parts of the papaya fruit are potential sources of phenolic compounds,particularly the *** results of this study provide practical data for the potential application of papaya fruit as a functional food ingredient in the food,pharmaceutical and medicinal industries.

关键词： Antioxidant activity LC-ESI-QTOF-MS/MS Phenolic compounds Papaya

LC-ESI-QTOF-MS/MS profiling of phenolic compounds in Australian native plums and their potential antioxidant activities

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Food Bioscience 2023年第2期52卷 179-192页

作者： jiaxun li Haoyao liu Muhammad Sohail Mazhar Salman Quddus Hafiz Ansar Rasul Suleria School of Agriculture and Food Faculty of Veterinary and Agricultural SciencesThe University of MelbourneParkvilleVIC3010Australia Department of Industry Tourism and Trade of the Northern Territory GovernmentDarwinNT0801Australia

Australian native plums are rich in phenolic compounds,which have significant health-promoting *** are limited recordings and information on the number of species and phenolic content of Australian native ***,the number of species and phenolic content of Australian native plums are not well *** research was conducted to identify and quantify phenolic compounds in the peel,pulp,and seed of three common Australian native plums(Kakadu plum,Davidson plum,Illawarra plum)for applying and promoting the commercial worth of these *** phenolic content(TPC),total flavonoid content(TFC),and total tannins content(TTC)were used to determine the amount of phenolic compounds in these Australian native plums and in vitro experiments,including total antioxidant capacity(TAC),2,2′-Diphenyl-2-picrylhydrazyl(DPPH),Ferric Reducing Antioxidant Power(FRAP),and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS)were used to analyze the antioxidant activities of the *** compounds in the samples were thoroughly analyzed by liquid chromatography-mass spectrometry(LC-ESI-QTOF-MS/MS),and preliminarily identified as phenolic acids(10),flavonoids(23),and other phenolic substances(11).These results show the potent antioxidant properties of the Australian native plums and provide evidence for their potential use as culinary,medicinal,and nutraceutical components.

关键词： Antioxidant activity Australian native plum LC-ESI-QTOF-MS/MS Phenolic compounds

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新形势下老旧小区更新的资金筹措模式探究

现代城市研究 2021年第11期36卷 115-120页

作者：李嘉珣住房和城乡建设部政策研究中心

老旧小区更新有助于改善人居环境、优化城市空间、推动经济发展,而资金筹措模式是更新的重要环节由于更新项目繁多、利益难以统一以及盈利性不佳,传统资金筹措模式难以持续大规模地推进项目进展研究提出“政金合作模式”和“社会资本自... 详细信息

老旧小区更新有助于改善人居环境、优化城市空间、推动经济发展,而资金筹措模式是更新的重要环节由于更新项目繁多、利益难以统一以及盈利性不佳,传统资金筹措模式难以持续大规模地推进项目进展研究提出“政金合作模式”和“社会资本自主维育模式”两种资金筹措模式,并分析其操作流程、经验和优势,提出相应的政策建议,为决策部门创新老旧小区更新资金筹措模式提供参考和依据。

关键词：老旧小区城市更新资金筹措

“双循环”格局下我国住房领域发展的反思与重构

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天津师范大学学报（社会科学版） 2021年第6期41卷 95-100页

作者：李嘉珣住房和城乡建设部政策研究中心北京100835

百年未有之大变局下,我国于2020年提出"构建国内国际双循环相互促进的新发展格局"。住房领域在我国经济结构中具有基础性、先导性、支撑性作用,也是供给侧结构性改革的重要领域。我们需要深入剖析"双循环"特征和科学内涵,提出"双循环"... 详细信息

百年未有之大变局下,我国于2020年提出"构建国内国际双循环相互促进的新发展格局"。住房领域在我国经济结构中具有基础性、先导性、支撑性作用,也是供给侧结构性改革的重要领域。我们需要深入剖析"双循环"特征和科学内涵,提出"双循环"背景下住房领域的发展格局和实施路径,推进我国住房和城市建设更高层次发展。

关键词：住房领域房地产双循环城镇化

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“新基建”下新型城镇化发展方向探析

建筑经济 2020年第10期41卷 5-8页

作者：李嘉珣住房和城乡建设部政策研究中心北京100835

“新基建”催生的技术和生产方式能够推动新型城镇化高质量发展。结合“新基建”的特点,梳理并提出“新基建”在新型城镇化发展方向中的应用,希望其推动城镇化发展的质量变革、效率变革和动力变革。

关键词：新基建新型城镇化数字化城市治理