检索结果-南通市图书馆

Annual mowing mitigates the negative legacy effects of N enrichment on grassland nutrient use efficiency

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Plant Ecology 2021年第5期14卷 959-969页

作者： Yan-Yu Hu Zhi-Wei Zhang shuang-li hou Jun-Jie Yang Xiao-Tao Lü Erguna Forest-Steppe Ecotonc Research Station CAS Key Laboratory of Forest Ecology and ManagementInstitute of Applied EcologyChinese Academy of SciencesShenyang 110016China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Vegetation of Environmental Change Institute of BotanyChinese Academy of SciencesBeijing 100093China

Aims Plant nutrient use efficiency,an important factor driving primary production,is sensitive to nitrogen(N)*** of strengthened regulations of N emissions,atmospheric N deposition is decreasing in many *** remains unknown whether historical N enrichment would alter plant nutrient use efficiency and whether such impacts would be mitigated by ecosystem management *** We assessed the effects of historical N addition and mowing on plant N and phosphorus use efficiency(NUE and PUE)at both functional group and community levels in a temperate steppe after the cessation of 6-year N *** Findings Historical N addition had negative legacy effects on plant NUE but not on PUE at the functional group *** were negative legacy effects of N addition on community-level NUE and PUE,but only in the unmown *** mitigated the negative legacy effects of N enrichment on community-level NUE and PUE by reducing the dominance of tall rhizomatous grass but enhancing that of tall *** results highlight the importance of community composition variations caused by mowing in driving the legacy effects of N enrichment on community-level nutrient use *** the slow recovery of community composition following cessation of N deposition,our findings suggest that the lower nutrient efficiency of plant community would be long-lasting.

关键词： community composition hay harvest legacy effect nutrient utilization plant functional type semiarid grassland

linking changes of forage production and digestibility with grassland community assembly under nitrogen enrichment

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Ecological Processes 2021年第1期10卷 441-448页

作者： Xiao-Tao Lü Zhuo-Yi liu Seeta Sistla Guo-Jiao Yang Yan-Yu Hu Zhi-Wei Zhang shuang-li hou Cong Ding Erguna Forest-Steppe Ecotone Research Station CAS Key Laboratory of Forest Ecology and ManagementInstitute of Applied EcologyChinese Academy of SciencesShenyang 110016China Natural Resources Management and Environmental Sciences California Polytechnic State UniversitySan Luis ObispoCA 93407USA Institute of Ecology and Biodiversity School of Life ScienceShandong UniversityQingdao 266237China.

Background:Forage production is the fundamental ecosystem service of *** forage consumption occurs at community level,most studies focused on species-level changes of forage *** quantitative and qualitative changes of forage production are driven by species-specific trait,intra-specific plasticity,and species *** examined the changes in forage production and digestibility after 5-year factorial treatments of nitrogen(N)addition and mowing in a temperate steppe and linked such changes to community assembly under the Price equation ***:Nitrogen addition significantly reduced species richness,increased forage production,but did not change forage digestibility(indicated by the total Ca+Mg concentrations).Mowing did not affect forage production and *** positive effects of N addition on forage production were driven by the enhancement of abundance of the remaining species following N enrichment,rather than by species loss or species *** species identity effects could offset the effects of species richness loss or gain on forage production and ***:Our results highlight the importance of a community perspective in addressing the quantitative and qualitative changes of forage production under global change pressure of N *** identity is important in determining the contribution of different processes of community assembly to ecosystem services.

关键词： Community composition Nitrogen deposition Species turnover Price equation Primary productivity

Mowing weakens the positive effects of nitrogen deposition on fundamental ecosystem service of grassland

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Ecological Processes 2021年第1期10卷 58-68页

作者： Cong Ding Guo-Jiao Yang Xiao-Guang Wang Zi-Jia Zhang Yan-Yu Hu Zhi-Wei Zhang shuang-li hou Xiao-Tao Lü Erguna Forest-Steppe Ecotone Research Station CAS Key Laboratory of Forest Ecology and ManagementInstitute of Applied EcologyChinese Academy of SciencesShenyang 110016China. University of Chinese Academy of Sciences Beijing 100049China Institute of Ecology and Biodiversity School of Life ScienceShandong UniversityQingdao 266237China. College of Environmental and Resource Sciences Dalian Minzu UniversityDalian 116600China.

Forage yield is the fundamental ecosystem service of *** the quantitative responses of forage yield to nitrogen(N)enrichment are well known,its qualitative responses remain *** less known is the relative contribution of changes in community composition to the quality of the yield at the community *** examined the quantitative and qualitative responses of forage yield at both plant functional group and community levels with factorial treatments of N addition and mowing in a temperate *** addition significantly enhanced the community-level yield by favoring the growth of rhizomatous *** tended to mediate the impacts of N addition on the *** addition increased the concentrations of crude protein and crude fat in forage at the community *** the main effects of mowing nor its interactive effects with N addition affected forage *** N-induced shifts in plant species composition significantly contributed to the effects of N addition on forage quality at the community *** results suggest that mowing wound weaken the positive effects of N deposition on the quantity but not the quality of forage *** in plant community composition are important in driving the qualitative responses of yield to N deposition.

关键词： Nitrogen enrichment Primary productivity Forage quality Forage yield Semi-arid grassland

Electronic structure engineering of single atomic sites by plasmoninduced hot electrons for highly efficient and selective photocatalysis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2024年第8期17卷 6960-6967页

作者： Xiaoya Huang Xinyuan li Akang Chen Hongfei Gu Shouyuan li Tailei hou Shuwen Zhu shuang Yu Yin Song Jiatao Zhang Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications MIIT Key Laboratory of Medical Molecule Science and Pharmaceutical EngineeringMOE Key Laboratory of Cluster ScienceSchool of Chemistry and Chemical EngineeringSchool of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081China MIIT Key Laboratory of Complex-field Intelligent Exploration School of Optics and PhotonicsBeijing Institute of TechnologyBeijing 100081China

Single atom(SA)catalysts have achieved great success on highly selective heterogeneous catalysis due to their abundant and homogeneous active *** electronic structures of these active sites,restrained by their localized coordination environments,significantly determine their catalytic performances,which are difficult to ***,we investigated the effect of localized surface plasmon resonance(LSPR)on engineering the electronic structures of single atomic ***,core–shell structures consisted of Au core and transition metal SAs loaded N-doped carbon(CN)shell were constructed,namely Au@M-SA/CN(M=Ni,Fe,and Co).It was demonstrated that plasmon-induced hot electrons originated from Au were directionally injected to the M-SAs under visible light irradiation,which significantly changed their electronic structures and meanwhile facilitated improved overall charge separation *** as-prepared Au@Ni-SA/CN exhibited highly efficient and selective photocatalytic CO_(2) reduction to CO performance,which is 20.8,17.5,and 6.9 times those of Au nanoparticles,Au@CN,and Ni-SA/CN,*** spectroscopy analysis and theoretical calculations confirmed that the plasmon enhanced Ni-SA/CN sites featured increased charge density for efficient intermediate activation,contributing to the superb photocatalytic *** work provides a new insight on plasmon and atomic site engineering for efficient and selective catalysis.

关键词： single atom catalysts plasmon enhancement coupling effect photocatalysis CO_(2) reduction

Exploring the Predominant Factors Influencing the Oxygen Reduction Performance of PtCo/C Catalysts

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2024年第4期40卷 753-760页

作者： li Jinrong YU Xianghui SUN Qi PENG Yong CAO shuang hou Chun-Chao XU Qiang College of Chemistry and Chemical Engineering Institute for Sustainable Energy and ResourcesQingdao UniversityQingdao266071P.R.China Leibniz Institute for Catalysis e.V. Albert-Einstein-Strasse 29aRostock18059Germany School of Materials Science and Engineering Ocean University of ChinaQingdao266100P.R.China Shenzhen Key Laboratory of Micro/Nano-Porous Functional Materials(SKLPM) SUSTech-Kyoto University Advanced Energy Materials Joint Innovation Laboratory(SKAEM-JIL)Key University Laboratory of Highly Efficient Utilization of Solar Energy and Sustainable Development of GuangdongDepartment of Chemistry and Department of Materials Science and EngineeringSouthern University of Science and Technology(SUSTech)Shenzhen518055P.R.China

PtCo nanoalloys(NAs)deposited on carbon black are emerging as robust electrocatalysts for addressing the sluggish kinetic issue of oxygen reduction reaction(ORR).However,developing a simple and low-cost method to synthesize PtCo/C with excellent performance is still a great *** this work,a one-pot method was used to successfully obtain the PtCo NAs on commercial carbon supports of acetylene black and Ketjenblack ECP600JD,*** with those grown on Ketjenblack ECP600JD,the PtCo NAs grown on acetylene black exhibited higher electrochemical surface area(ECSA)and mass activity(MA),which may be attributed to the different particle sizes of PtCo NAs,distinct hydrophilicity,electroconductivity and charge distribution between the carbon supports and PtCo *** study provides valuable insights into the optimal design of carbon-supported ORR electrocatalysts with exceptional activity and durability.

关键词： Oxygen reduction reaction PtCo nanoalloy Carbon-supported nanostructure Acetylene black

The Crystallization Behavior of L-Poly(lactic acid)/Polypropylene Blends:The Acceleration for Both L-Poly(lactic acid)and Polypropylene

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第6期42卷 775-786页

作者： shuang-Cheng li Wei-Jia Zhou Wen-Jie Wu Jun Shao Shui-liang Chen Hao-Qing hou Sheng Xiang College of Chemistry&Chemical Engineering and Nanofiber Engineering Center of Jiangxi Province Jiangxi Normal UniversityNanchang330022China National Engineering Research Center for Carbohydrate Synthesis/Key Lab of Fluorine and Silicon for Energy Materials and Chemistry of Ministry of Education Jiangxi Normal UniversityNanchang330022China Wenzhou Institute University of Chinese Academy of SciencesWenzhou325001China

For a polymer/polymer dismissible blend with two crystallizable components,the crystallization behavior of different components and the reciprocal influences between different crystals are interesting and important,but did not investigate in *** this study,the L-poly(lactic acid)/polypropylene(PLLA/PP)blends with different weight ratios were prepared by melt mixing and the crystallization behavior of the blends were *** showed that the crystalline structures of PLLA and PP were not altered by the *** the crystallization of PLLA,both the diffusion of chain segments and crystallization rate were enhanced under the existence of PP *** the crystallization of PP,its crystallization rate was depressed under the existence of amorphous PLLA molecular *** the PP crystallized from the existence of PLLA crystals,although the diffusion rate of PP was reduced by PLLA crystals,the nucleation positions were obviously enhanced,which accelerated the formation of PP *** investigation would supply more basic data for the application of PLLA/PP blend.

关键词： L-poly(lactic acid) Polypropylene Blends Crystalization behavior Crystallization acceleration

Perturbation to Symmetries and Adiabatic Invariants for Generalized Birkhoffian Systems on Time Scales

在线全文

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural Sciences 2024年第3期29卷 263-272页

作者： hou shuang SONG Chuanjing School of Mathematical Sciences Suzhou University of Science and TechnologySuzhou 215009JiangsuChina

Time scale is a new and powerful tool for dealing with complex dynamics problems. The main result of this study is the exact invariants and adiabatic invariants of the generalized Birkhoffian system and the constrained Birkhoffian system on time scales. Firstly, we establish the differential equations of motion for the above two systems and give the corresponding Noether symmetries and exact invariants. Then, the perturbation to the Noether symmetries and the adiabatic invariants for the systems mentioned above under the action of slight disturbance are investigated, respectively. Finally, two examples are provided to show the practicality of the findings.

关键词： time scale generalized Birkhoffian system Noether symmetry perturbation and adiabatic invariants

Toll-like receptor 4-related regulation of Ornithogalum caudatum extract on inflammatory responses in LPS activated macrophages

在线全文

学校读者我要写书评

暂无评论

中国药理学与毒理学杂志 2018年第4期32卷 284-285页

作者： Xin HAN Jian SONG Jing ZHANG Ya-mei li Ying FAN Dan-yang SHAO li-shuang hou li-hua liAN Ji-xing NAN Yan-ling WU Key Laboratory for Natural Resource of Changbai Mountain & Functional Molecules Ministry of Education College of Pharmacy Yanbian University Yanji 133002 China

OBJECTIVE To investigate toll-like receptor 4(TLR4)-related the regulation of Ornithogalum caudatum extract(OCE) on inflammatory responses in lipopolysaccharide(LPS) activated *** Primary peritoneal macrophage,Raw 264.7,and THP-1 were incubated in 96-well plate for 24 h and treated with OCE of the concentration of 0-400 μg/ml for 4 *** viability of cells was measured by MTT *** concentrations of OCE were added into the medium of primary *** macrophage,Raw 264.7,and THP-1,respectively,then following with lipopolysaccharides(LPS).Cells were harvested and the total cellular protein and nuclear protein were extracted,and the protein content was determined using BCA protein assay *** expressions of TLR4,inducible nitric oxide synthase(iNOS),cyclooxygenase 2(COX-2),α-inhibitor of NF-κB(IκB-α) and nuclear factor-κB(NF-κB) were assayed by Western *** expressions of interleukin-1α(IL-1α),interleukin-1β(IL-1β),interleukin-18(IL-18),and tumor necrosis factor-α(TNF-α) were measured by *** The results of MTT showed that OCE has no cytotoxicity in Raw 264.7 cells between 1.56 μg/ml and 400 μg/*** with normal group,the expressions of TLR4,iNOS,COX-2,NF-κB and IL-1α,IL-1β,IL-18,TNF-α,the level of nitric oxide(NO) were significantly increased by LPS stimulation,while OCE *** reduced these increase induced by ***,OCE pretreatment reversed the reduction of IκB-α after LPS *** OCE might suppress TLR4 expression and block the *** process of NF-κB and iNOS,further decrease the expression of COX-2 and inhibit the release of inflammatory factors.

关键词：尾砂提取物巨噬细胞炎症临床分析治疗方法

Flocking of a Cucker–Smale Type Model with Compactly Supported Interaction Functions

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第9期40卷 2285-2296页

作者： Chun Yin JIN shuang Zhi li College of Science China Agricultural UniversityBeijing 100083P.R.China

How to analyze flocking behaviors of a multi-agent system with local interaction functions is a challenging problem in *** and Tadmor in 2011 also stressed the significance to assume that the interaction function is rapidly decaying or cut-off at a finite distance(*** and Tadmor in ***.2011).In this paper,we study the flocking behavior of a Cucker–Smale type model with compactly supported interaction *** properties of a connected stochastic matrix,together with an elaborate analysis on perturbations of a linearized system,we obtain a sufficient condition imposed only on model parameters and initial data to guarantee ***,it is shown that the system achieves flocking at an exponential rate.

关键词： Cucker-Smale model local interaction flocking stochastic matrix neighbor graph