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Variation of carbon and nitrogen stoichiometry along a chronosequence of natural temperate forest in northeastern China

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Journal of Plant Ecology 2018年第3期11卷 339-350页

作者： Xingyun Liang Shirong Liu Hui wang jingxin wang Key Laboratory of Forest Ecology and Environment China’s State Forestry AdministrationInstitute of Forest EcologyEnvironment and ProtectionChinese Academy of ForestryNo.1 DongxiaofuQinglongqiaoHaidian DistrictBeijing 100091China Division of Forestry and Natural Resources West Virginia UniversityP.O.Box 6215MorgantownWV 26506-6125USA

Aims Carbon(C)and nitrogen(N)stoichiometry contributes to under-standing elemental compositions and coupled biogeochemical cycles in ***,we know little about the temporal patterns of C:N stoichiometry during forest *** goal of this study is to explore the temporal patterns of intraspecific and ecosystem components’variations in C:N stoichiometry and the scaling relationships between C and N at different successional *** Along forest development in a natural temperate forest,northeastern China,four age gradients were categorized into ca.10-,30-,70-and 200-year old,respectively,and three 20 m×20 m plots were set up for each age ***,branches,fine roots and fresh litter of seven dominant species as well as mineral soil at depth of 0-10 cm were sampled.A Universal CHN Elemental Analyzer was used to determine the C and N concentrations in all *** Findings Intraspecific leaf C,N and C:N ratios remained stable along forest development regardless of tree species;while C,N concentrations and C:N ratios changed significantly either in branches or in fine roots,and they varied with tree species except Populus davidiana(P<0.05).For ecosystem components,we discovered that leaf C:N ratios remained stable when stand age was below ca.70 years and dominant tree species were light-demanding pioneers such as Betula platyphylla and Populus davidiana,while increased signifi-cantly at the age of ca.200 years with Pinus koraiensis as the dom-inant species.C:N ratios in branches and fresh litter did not changed significantly along forest development stages.C concentrations scaled isometrically with respect to N concentrations in mineral soil but not in other ecosystem *** results indicate that,leaf has a higher intraspecific C:N stoichiometric stability compared to branch and fine root,whereas for ecosystem components,shifts in species composition mainly affect C:N ratios in leaves rather than other *** stud

关键词： C:N stoichiometry forest succession isometric scaling plant organs soil temperate forest

Converter-Based Reconfigurable Real-Time Electrical System Emulation Platform

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Chinese Journal of Electrical Engineering 2018年第1期4卷 20-27页

作者： Yiwei Ma jingxin wang Fred wang Leon M.Tolbert CURENT The University of TennesseeKnoxvilleTN 37996USA Oak Ridge National Laboratory Oak RidgeTN 37831USA

A Hardware Testbed(HTB)is developed for accurate and flexible emulation and testing of electrical power system and their control,measurement,and protection *** the HTB,modular and programmable power electronics converters are used to mimic the static and dynamic characteristics of electrical power *** paper overviews the development,integration,and application of the HTB,covering emulation principle,hardware and software configuration,and example results of power system research using the *** advantages of the HTB,compared with real-time digital simulation and downscaled hardware-based testing platform are discussed.

关键词： Emulation modeling real-time simulation

STUDY ON THE LOG PRODUCTION LINE IN LOG YARD

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Journal of Northeast Forestry University 1991年第2期2卷 77-82页

作者： Pan Delu wang jingxin Northeast Forestry University 1. Northeast Forestry University China

The article deals with the prduction lines in log yard by investigating the utilizationof machines in forest areas,presents the methods and rules of differentiating the log productionlines and also summarizes the formation and development of three kinds of log production lines innortbeast forest areas of *** gives different combination types of log production lines andtheir applications, so it is significant for us to evaluate and standardize the log Production lines.

关键词： Log production line The machines combining types Log yard Forest logging operations

Liquefaction of bamboo biomass and production of three fractions containing aromatic compounds

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Journal of Bioresources and Bioproducts 2020年第2期5卷 114-123页

作者： Yan Ma Weihong Tan jingxin wang Junming Xu Kui wang Jianchun Jiang Institute of Chemical Industry of Forestry Products Chinese Academy of ForestryKey and Open Lab.of Forest Chemical EngineeringSFANational Engineering Laboratory for Chemical Utilization of BiomassKey Laboratory of Biomass Energy and Materials of Jiangsu ProvinceNanjing 210042China Division of Forestry and Natural Resources West Virginia UniversityMorgantownWV 26506United States Co-Innovation Center of Efficient Processing and Utilization of Forest Resources Nanjing Forestry UniversityNanjing 210037China

Depolymerization of lignin to produce value-added aromatic monomers has attracted increasing attention since these monomers can be used as phenol replacement in production of phenolic *** a one-pot depolymerization of bamboo lignin was investigated to obtain aromatic platforms with low molecular weight using acidic catalyst and *** fractions(1#,2#,and 3#)containing different molecular weight distributions of aromatic compounds could be efficiently extracted using water-organic solvent system via a stepwise fractionation process by gradual removal of *** fractions distribution was found to be primarily dependent on the reaction temperature and *** the temperature was increased from 160°C to 200°C,the yield of fractions containing aromatic products increased significantly from 19.1 wt%to 27 wt%,the same change trend was found by changing the time,and the yield of aromatic products increased from 22.4%to 26.7%with an increase of time from 10 min to 30 *** bioproducts were characterized by using gas chromatography/mass spectrometry(GC-MS),gel permeation chromatography(GPC)and two-dimensional heteronuclear single-quantum coherence(2D HSQC NMR).As evidenced by GC-MS spectra,the three fractions were mainly comprised of phenolic derivatives,and the relative contents of phenolic compounds took up about 80%of the total area of each *** the similar physiochemical properties of the fractions,aromatic platforms could provide a new paradigm of bamboo lignin utilization for renewable energy and value-added biochemicals.

关键词： Aromatic compound Fraction Liquefaction Biomass conversion Bioproduct

Characteristics of typhoon disturbed gaps in an old-growth tropical montane rainforest in Hainan Island, China

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Journal of Forestry Research 2017年第6期28卷 1224-1232页

作者： Huai Yang Shirong Liu Kunfang Cao jingxin wang Yide Li Han Xu Research Institute of Tropical Forestry Chinese Academy of Forestry Key Laboratory of Forest Ecology and Environment of State Forestry Administration Institute of Forest EcologyEnvironment and Protection Chinese Academy of Forestry State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources and College of ForestryGuangxi University Division of Forestry and Natural Resources West Virginia University

Disturbances that create gaps can shape the structure and function of forests. However, such disturbance regimes in Asian tropical montane rainforests remain largely unquantified. Least studied are typhoon disturbances that are attributable to climate change. We investigated gap characteristics in terms of size, age, and gap-maker to quantify the gap disturbance regimes in an intact old-growth tropical montane rainforest on Hainan Island, China. The intensity of typhoons has increased since 1949, and typhoon winds blow mostly (45.5%) from the northeast corner of Hainan Island, resulting in a higher frequency of gaps in the northeast. A total of 221 gap-makers (trees that fell to create canopy gaps) and 53 gaps were observed in a 3.16 ha old-growth rainforest. Most canopy gaps (85%) were < 200 m(2). The average size of canopy gaps was smaller in the rainforest than in other tropical forests, while the average size of expanded gaps was similar to those in other tropical forests. The maximum age of gaps was 23.5 years indicating that gaps had more rapid turnover than other parts of tropical forests. The frequency distribution of gap-makers followed a lognormal distribution with a distinctive peak at three gap-makers, which was different from the inverse J-shaped curve typical of other tropical forests. Gaps were recorded mainly on slopes between 20A degrees and 35A degrees and wood density of gap-makers was between 0.6 and 0.7 g cm(-3). Our results suggest that small-scale disturbance was the dominant agent of gap formation in this old-growth rainforest that is subject to increasing typhoon disturbances.

关键词： Gap characteristics Gap-makers Old-growth Slope Tropical montane rainforest Typhoon disturbance Wood density

Soil carbon dynamics in a Pinus massoniana plantation following clear-cutting and slash removal

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Journal of Plant Ecology 2016年第1期9卷 20-29页

作者： Yuan Wen Jamie LSchuler Shirong Liu Pu Mou Hui wang Haolong Yu jingxin wang College of Life Sciences Beijing Normal UniversityNo.19 Xin Jie Kou Wai StreetBeijing 100875China Key Laboratory of Forest Ecology and Environment China’s State Forestry AdministrationInstitute of Forest EcologyEnvironment and ProtectionChinese Academy of ForestryNo.2 DongxiaofuBeijing 100091China Division of Forestry and Natural Resources West Virginia UniversityPO Box 6215MorgantownWV 26506-6125USA The Experimental Center of Tropical Forestry Chinese Academy of ForestryGuangxi Youyiguan Forest Ecosystem Research StationPingxiangGuangxi 532600China

Aims Slash removal is a common practice to prepare recently harvested sites for ***,little is known about its impact on soil carbon(C)dynamics in subtropical *** study evaluates the effects of burning versus manual slash removal site preparation treatments on soil organic carbon(SOC),soil respiration and soil microbial community structure in a Pinus massoniana plantation in southern *** Three areas within a mature *** plantation were *** months following harvesting,slash on one-half of each area was burned(BURN),whereas slash was manually removed(MANR)on the other *** removal treatments were also compared with adjacent uncut plantation areas(UNCUT).Soil samples,and soil respiration measurements were used to characterize soil properties and microbial communities following slash removal *** Findings Mean soil respiration rates from the MANR and BURN treatments were 26%and 17%lower,respectively,than the UNCUT treatment over 1 *** MANR and BURN treatment resulted in soils with 27%and 9%reduction in total phospholipid fatty acids(PLFAs)and 18%and 10%reduction in bacterial PLFAs,respectively,compared with the UNCUT ***,no significant differences existed between slash removal treatments with respect to soil chemical properties,SOC chemical compositions,soil respiration and microbial communities;although PLFA patterns were notably different for the burned *** factors affecting C dynamics and microbial communities were not sensitive to the differences imparted to the ecosystem due to manual slash removal or *** results suggested that low-intensity burning after clear-cutting might have no significant effect on soil C pool and its dynamics compared with manual slash removal in subtropical plantations.

关键词： plantation management soil organic carbon chemical composition soil respiration soil microbial community fire

DESIGN AND APPLICATION OF MODEL DZI LOG GRAPPLE DRIVEN BY AN ELECTRIC DRUM

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Journal of Northeast Forestry University 1993年第1期4卷 36-40页

作者： wang jingxin Pan DeluNortheast Forestry University

This article introduces the history and development of log grapple in ***-cording to the special conditions of Chinese forest areas,we have selected log grapple driven byelectric drum,and have analyzed and calculated its parameters *** is the first loggrapple driven by an electric drum made successfully in *** Model DZ1 log grapple has alarge closing force,works safely and is suitable for the special forest working conditions inChina.

关键词： Log grapple Electric drum Design and application Forest operation

Identification of two glycerophosphodiester phosphodiesterase genes in maize leaf phosphorus remobilization

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The Crop Journal 2021年第1期9卷 95-108页

作者： jingxin wang Wenbo Pan Alexiy Nikiforov William King Wanting Hong Weiwei Li Yang Han Jana Patton-Vogt Jianbo Shen Lingyun Cheng Key Laboratory of Plant-Soil Interactions Ministry of Education/Key Laboratory of Plant NutritionMinistry of AgricultureDepartment of Plant NutritionChina Agricultural UniversityBeijing 100193China State Key Laboratory of Plant Genomics Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China Department of Biological Sciences Duquesne UniversityPittsburghPA 15282USA

Phosphate deficiency is one of the leading causes of crop productivity *** degradation liberates phosphate to cope with phosphate *** phosphodiesterases(GPX-PDEs)hydrolyse the intermediate products of phospholipid catabolism glycerophosphodiesters into glycerol-3-phosphate,a precursor of ***,the function of GPX-PDEs in phosphate remobilization in maize remains *** the present study,we characterized two phosphate deficiency-inducible GPX-PDE genes,ZmGPX-PDE1 and ZmGPX-PDE5,in maize ***-PDE1 and ZmGPX-PDE5 were transcriptionally regulated by ZmPHR1,a well-described phosphate starvation-responsive transcription factor of the MYB *** of the yeast GPX-PDE mutant gde1Δindicated that ZmGPX-PDE1 and ZmGPX-PDE5 functioned as GPX-PDEs,suggesting their roles in phosphate recycling from *** vitro enzyme assays showed that ZmGPX-PDE1 and ZmGPX-PDE5 catalysed glycerophosphodiester degradation with different substrate preferences for glycerophosphoinositol and glycerophosphocholine,***-PDE1 was upregulated during leaf senescence,and more remarkably,loss of ZmGPXPDE1 inmaize compromised the remobilization of phosphorus fromsenescing leaves to young leaves,resulting in a stay-green phenotype under phosphate *** results suggest that ZmGPX-PDE1 catalyses the degradation of glycerophosphodiesters in maize,promoting phosphate recycling from senescing leaves to new *** mechanism is crucial for improving phosphorus utilization efficiency in crops.

关键词： Glycerophosphodiester phosphodiesterases Maize Phosphate deficiency Phosphorus remobilization Phospholipid

Application of MET Technique after Upper Limb Dysfunction after Breast Cancer Surgery

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Journal of Advances in Medicine Science 2021年第2期4卷 8-11页

作者： Yanan Jin jingxin wang Huayun Liu JiameiZhen Zhengzhou Central Hospital Affiliated to Zhengzhou University ZhengzhouHenan450000China

Object:Explore the application and actual effect of MET(Muscle Energy)technology after breast cancer surgery with upper limb ***:Taking 40 female breast cancer patients who underwent surgical treatment in our hospital from September 2017 to June 2019 as the research objects,all of them successfully completed modified radical mastectomy for breast *** to different nursing methods,the patients were randomly divided into two *** experiment There were 20 cases in each group and the control *** control group was given routine functional recovery exercise intervention after the operation,and the experimental group added MET technology to the base of the control *** month after the operation,the functional recovery of the affected limbs of the two groups of patients was effectively *** upper limb dysfunction of the two groups was compared by statistical methods,and the shoulder joint range of motion(ROM)was used for ***:Through early functional recovery training and MET technology,19 cases of ROM in the experimental group showed compliance(95%),compared with only 14 cases(70%)in the control *** difference in upper limb dysfunction between the two groups is very obvious with statistical significance(P<0.05).Conclusions:Early functional recovery training combined with muscle energy technology can promote the recovery of upper limb dysfunction after breast cancer surgery faster and better,which is conducive to the recovery of patients as soon as possible and improve the quality of life.

关键词： MET,technology Muscle energy technology Breast cancer Upper limb dysfunction