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Dieback intensity but not functional and taxonomic diversity indices predict forest productivity in different management conditions: Evidence from a semi-arid oak forest ecosystem

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Journal of Arid Land 2022年第2期14卷 225-244页

作者： Mona KARAMI Mehdi hEYdaRI Ali ShEYKhOLESLAMI majid EShAGh NIMVARI Reza OMIDIPOUR YUAN Zuoqiang Bernard PREVOSTO Faculty of Natural Resources Chalus BranchIslamic Azad UniversityChalus 46615/397Iran Department of Forestry Chalous BranchIslamic Azad UniversityChalous 46615/397Iran Department of Rangeland and Watershed Management Faculty of Natural Resources and Earth SciencesShahrekord UniversityShahrekord ***Iran Key Laboratory of Forest Ecology and Management Institute of Applied EcologyChinese Academy of SciencesShenyang 110164China INRAE Aix Marseille UniversityUMR RECOVERMediterranean Ecosystems and RisksAix-en-Provence 13128France

The relationships between different aspects of diversity(taxonomic,structural and functional)and the aboveground biomass(AGB)as a major component of global carbon balance have been studied extensively but rarely under the simultaneous influence of forest dieback and *** this study,we investigate the relationships between taxonomic,functional and structural diversity of woody species(trees and shrubs)and AGB along a gradient of dieback intensity(low,moderate,high and no dieback as control)under two contrasted management conditions(protection by central government *** management by natives)in a semi-arid oak(Quereus brantii Lindl.)forest *** was estimated and taxonomic diversity,community weighted average(CWM)and functional divergence indices were *** found that the aerial biomass was significantly higher in the intensively used area(14.57(±1.60)t/hm^(2))than in the protected area(8.70(±1.05)t/hm^(2))due to persistence of some large trees but with decreasing values along the dieback intensity gradient in both *** of height(h),leaf nitrogen content(LNC)and leaf dry matter content(LDMC)were also higher in the traditional managed area than in the protected *** contrast,in the protected area,the woody species diversity was higher and the inter-specific competition was more intense,explaining a reduced h,biomass and *** to the results of CWM,none of the functional diversity traits(FDvar)was affected by dieback intensity and only FDvar values of LNC,leaf phosphorus content(LPC)and LDMC were influenced by *** also found significantly positive linear relationships of AGB with CWM and FDvar indices in the protected area,and with taxonomic and structural diversity indices in the traditional managed *** results emphasize that along a dieback intensity gradient,the leaf functional traits are efficient predictors in estimating the AGB in protected forests,while taxonomic and structural indices provide bett

关键词： environmental stress sudden oak dieback degradation conservation selection effect hypothesis

Michael Addition Reaction without Catalyst: The Synthesis of 2-Amino-5, 6, 7, 8-tetrahydro-5-oxo-4-aryl-7, 7-dimethyl- 4h-benzo-[b]-pyran Derivatives

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Chinese Chemical Letters 2002年第5期13卷 393-395页

作者： Shu Jiang TU Xiao hong LIU heng Jun MA da Qing ShI Fang LIU Department of Chemistry Xuzhou Normal UniversityXuzhou 221009

A series of tetrahydrobenzo-[b]-pyran derivative was synthesized by the reaction of arylmethylene malononitrile or arylmethylene cyanoacetate with dimedone in ethylene glycol at 80C without catalyst. The structures o... 详细信息

关键词： Benzo-[b]-pyran dimetone ethylene glycol.

植物系统发生海报——以演化视角介绍植物多样性的科教资料项目

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生物多样性 2025年

作者：蒋陈焜郁文彬饶广远黎怀成 Julien B.Bachelier hartmut h.hilger Theodor C.h.Cole 北京大学生命科学学院蛋白质与植物基因研究国家重点实验室北京大学前沿交叉学科研究院北京大学-清华大学生命科学联合中心中国科学院西双版纳热带植物园综合保护中心/云南省热带雨林与亚洲象保护重点实验室 dahlem Centre of Plant Sciences (DCPS)， Institute of Biology， Structural and Functional Plant Diversity， Freie Universit?t Berlin

中国的植物多样性保护行动虽然提升了公众对多样性的认识，但这些努力往往未能深入到理解植物多样性演化及其保护的深层意义。从演化的视角进行植物多样性宣传教育，有利于促进对多样性的综合理解，增进对多样性保护的认可。然而， ... 详细信息

中国的植物多样性保护行动虽然提升了公众对多样性的认识，但这些努力往往未能深入到理解植物多样性演化及其保护的深层意义。从演化的视角进行植物多样性宣传教育，有利于促进对多样性的综合理解，增进对多样性保护的认可。然而，现有资料多集中于物种的识别、鉴定与分类，缺乏从生物演化角度对植物多样性进行系统性介绍的内容。本文介绍了一个具有全球影响力的科教资料案例——由美裔德国植物学家Theodor C. h. Cole发起的植物系统发生海报(Plant Phylogeny Posters)项目。该项目通过整合最新的系统与演化植物学研究成果，以系统发生为线索介绍植物多样性及其亲缘关系，旨在利用系统发生树所蕴含的丰富演化思想内涵，启发读者理解植物多样性与演化。海报以系统发生树结合植物类群的形态、地理分布、物种数量等数据信息，直观展示了多个分类等级的重要类群的演化历史。在数十所大学和科研机构的45位研究人员的努力下， 70张系统发生海报已被翻译成中文，并向所有人免费开放获取。这一科教项目有望为增进公众深入理解植物多样性及其保护行动提供宝贵的资源和帮助。

关键词：植物多样性演化系统发生科教资料

[Na(DB18-C-6)(h2O)2][Na(DB18-C-6)(SCN)2]：Two-Di-mensional Network Complex Assembled by π-π Stacking Interactios,hydrogen Bonds and Electrostatic Interactions

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Chinese Journal of Chemistry 2002年第5期20卷 424-426页

作者： De‐Zhong Zhu Xing‐Min Song Jian‐Min Dou Ying Liu da‐Qi Wang Department of Chemistry Liaocheng Teacher's College Liaocheng 252000

A novel two‐dimensional network dibenzo‐18‐crown‐6 (DB18‐C6) complex: [Na (DB18‐C‐6) (h 2 O) 2 ] [Na (DB18‐C‐6) (SCN) 2 ] has been isolated and characterized by elemental, IR and X‐ray diffraction analysis. The crystal structure belongs to monoclinic, space group P 2 1 /c with cell dimensions a = 1.06178(7), b = 1.40243(8), c = 3.03496(19) nm, β = 90.4220(10)°, V = 4.5292(5) nm 3 , Z=4, D calcd =1.351 g/ cm 3 , F (000) = 1936, R 1 = 0.0369, wR 2 = 0.0821. The most interesting feature in this structure is that complex cation and complex anion form a two‐dimensional network via τ‐τ stacking interactions, hydrogen bonds and electrostatic interactions.

关键词： τ‐τ stacking interactions hydrogen bonds crown ether DB18‐crown‐6 crystal structure

Ghezeljeh nanoclay as a new natural adsorbent for the removal of copper and mercury ions: Equilibrium, kinetics and thermodynamics studies

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Chinese Journal of Chemical Engineering 2015年第11期23卷 1819-1833页

作者： majid Soleimani Zahra hassanzadeh Siahpoosh Department of Chemistry Imam Khomeini International University (IKIU)

heavy metal determination was carried out by applying the solid phase extraction （SPE） method in batch mode followed by atomic absorption spectroscopy （AAS） and inductively coupled plasma atomic emission spectrosco py （ICP-AES） from aqueous solutions using Ghezeljeh montmorillonite nanoclay as a new natural adsorbent. The Ghezeljeh clay is characterized by using Fourier Transform Infrared （FT-IR） Spectroscopy, Scanning Electron Mi- croscopy-Energy Dispersive Spectrometry （SEM-EDS） and X-ray Diffractometry （XRD） and X-ray Fluorescence （XRF）. The results of XRD and FT-IR of nanoclay confirm that montmorillonite is the dominant mineral phase. Based on SEM images of Ghezeljeh clay, it can be seen that the distance between the plates is Nano. The effects of varying parameters such as initial concentration of metal ions, ph and type of buffer solutions, amount of ad- sorbent, contact time, and temperature on the adsorption process were examined. The effect of various interfer- ing ions was studied. The adsorption data correlated with Freundlich, Langmuir, Dubinin-Radushkevich （D-R）, and Temkin isotherms. The Langmuir and Freundlich isotherms showed the best fit to the equilibrium data for hg（II）, but the equilibrium nature of Cu（ll） adsorption has been described by the Langmuir isotherm. The kinetic data were described with pseudo-first-order, pseudo-second-order and double-exponential models, The adsorp- tion process follows a pseudo-second-order reaction scheme, Calculation of AGσ, △hσ and ASσ showed that tilenature of hg（II） ion sorption onto the Ghezeljeh nanoclay was endothermic and was favored at higher temper- attire, and the nature of Cu（II） ion sorption was exothermic and was favored at lower temperature,

关键词： Montmorillonite Thermodynamic Kinetic Mercury Copper

A sample of active galactic nuclei with strong soft X-ray variabilities

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Science China(Physics,Mechanics & Astronomy) 2015年第4期58卷 101-108页

作者： BI da LIU Teng WANG JunXian CAS Key Laboratory for Research in Galaxies and Cosmology Department of AstronomyUniversity of Science and Technology of China

Large-amplitude X-ray variation is a special feature of AGN, reflecting possible extreme change in the central engine or the ab- sorption along the line of sight. Till now there are only a few relevant studies on individual sources or rather small samples. In this work we aim to perform a systematic study of AGNs with strong soft X-ray variations at timescale of 〉 10 years. To build the sample, we compare the soft X-ray fluxes of AGNs measured in ROSAT All-Sky Survey （RASS） during 1990-1991 with those measured by XMM-Newton during 2000-2009. This investigation bings forth to a sample of 13 AGNs, which appeared bright in RASS era, and went into low states （flux dropped by a factor of 〉 10） when they were caught by XMM-Newton. Most of the 13 sources are type I Seyfert galaxies. 5 of them are noticed to have strong X-ray vai＇iation for the first time. We study the nature of their variations through performing XMM-Newton spectral analyses and by collecting reports from the existing literature. We find the sample could be divided into three categories according to the possible causes of the strong X-ray variations. The variations in MRK 0478 and 1h 0419-557 are consistent with strong light-bending effect, i.e., the observed X-ray flux drops significantly as the X-ray emitting corona gets much closer to the central black hole. The variations in ESO 140-G043 and NGC 7158 are caused by absorption changes along the line of sight. For one special case MRK 0335, the variation can be explained by either light-bending or absorption variation. In the rest 8 sources （- 60%）, the strong soft X-ray variations are likely to exist due to intrinsic changes in the activities of the corona, although in some of them without high quality X-ray spectra we are unable to rule out alternative models. This sample provides good targets for future monitoring campaigns with more extensive studies.

关键词： soft X-ray active galactic nuclei variation

Assessing the prognosis of cirrhotic patients in the intensive care unit:What we know and what we need to know better

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World Journal of hepatology 2021年第10期13卷 1341-1350页

作者： Fernando da Silveira Pedro h R Soares Luana Q Marchesan Roberto S A da Fonseca Wagner L Nedel Programa de Pos-Graduacao em Pneumologia Universidade Federal do Rio Grande do SulPorto Alegre 91430835Brazil Intensive Care Unit Grupo Hospitalar ConceiçãoPorto Alegre 91430835Brazil Programa de Pos-Graduacao em Neurociencias Universidade Federal do Rio Grande do SulPorto Alegre 91430835Brazil Programa de Pos-Graduacao em Ciencias da Saude Universidade Federal de Santa MariaSanta Maria 97105900Brazil Programa de Pos-Graduacao em Bioquimica Universidade Federal do Rio Grande do SulPorto Alegre 91430835Brazil

Critically ill cirrhotic patients have high in-hospital mortality and utilize significant health care resources as a consequence of the need for multiorgan *** this fact,their mortality has decreased in recent decades due to improved care of critically ill ***-on-chronic liver failure(ACLF),sepsis and elevated hepatic scores are associated with increased mortality in this population,especially among those not eligible for liver *** score is superior to another in the prognostic assessment of these patients,and both liver-specific and intensive care unit-specific scores have satisfactory predictive *** sequential assessment of the scores,especially the Sequential Organ Failure Assessment(SOFA)and Chronic Liver Failure Consortium(CLIF)-SOFA scores,may be useful as an auxiliary tool in the decision-making process regarding the benefits of maintaining supportive therapies in this population.A CLIF-ACLF>70 at admission or at day 3 was associated with a poor prognosis,as well as SOFA score>19 at baseline or increasing SOFA score>*** studies addressing the prognostic assessment of these patients are necessary.

关键词： Cirrhosis Extrahepatic organ failure Organ replacement therapy Mortality Prognostic scores Chronic Liver Failure Consortium-Sequential Organ Failure Assessment Sequential Organ Failure Assessment Model for End-stage Liver Disease

Si/SiC hybrid 5-level Active NPC Inverter for Electric Aircraft Propulsion Drive Applications

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Chinese Journal of Electrical Engineering 2020年第4期6卷 63-76页

作者： majid T.Fard Mostafa Abarzadeh Kiavash A.Noghani Jiangbiao he Kamal Al-haddad Department of Electrical and Computer Engineering University of KentuckyLexingtonKY 40506USA Department of Electrical and Computer Engineering Marquette UniversityMilwaukeeWI 53233USA Department of Electrical Engineering Ecole de Technologie Superieure(ÉTS)MontrealH3C 1K3Canada

Medium voltage DC(MVDC)system is considered as a promising technology to improve the efficiency and power density of electric aircraft propulsion(EAP)*** adapt to the MVDC voltage level and achieve high drive performance,a five-level active neutral point clamped(5L-ANPC)inverter consisting of three-level ANPC and flying capacitor circuits is investigated,which possesses higher voltage capability,lower output harmonics,as well as mitigated dv/dt and common-mode *** fulfill the requirements of high-speed operation and pursue further enhanced efficiency and power density of the inverter for the next-generation EAP drives,Silicon Carbide(SiC)semiconductor devices are considered for implementing the 5L-ANPC ***,the large commutation loops associated with certain switching states of the inverter lessen the benefits of configuring all the switches as SiC *** a result,a hybrid Si/SiC 5L-ANPC inverter is developed with a synchronous optimal pulse(SOP)width modulation strategy for controlling the switches in cell 2 and finite-control-set model predictive controller(FCS-MPC)for those in cell 3 of the ***,in the proposed topology,the SiC devices are merely used for the high-frequency switches in cell 3 and the rest of the low-frequency switches are configured with Si *** Si/SiC hybrid ANPC inverter concurrently provides high efficiency and low implementation cost at high-speed operation *** and experimental results are provided to verify the effectiveness of the proposed hybrid inverter.

关键词： Five-level ANPC flying capacitor SOP FCS-MPC carrier-based modulation high efficiency MVDC electric aircraft propulsion

Fore-aft asymmetry of the ~2h(n,γ)~3h at very low energies

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Chinese Physics C 2013年第9期37卷 13-18页

作者： h.Khalili h.Sadeghi Department of Physics Faculty of ScienceArak University

We have used the recent effective field theory （EFT） which is constructed from two- and three-nucleon interactions, using minimal substitution in the momentum dependence of these interactions. We present the calcula- tions of the fore-aft asymmetry of γ-rays in the reaction 2h（n,γ）3h which are based on EFT up to next-to-next-to leading order （N2LO）. The results are compared with the recently reported calculations and measurements of the fore-aft asymmetry of T-rays from neutron-deuteron radiative capture. The calculated fore-aft asymmetry of the nd radiative capture process above deuteron breakup threshold is in good agreement with the available experimental data up to 20 MeV.

关键词： effective field theory neutron-deuteron radiative capture photonuclear observables fore-aft asymmetry