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Effects of Topographical and Edaphic Factors on the Distribution of Plant Com.unities in two Subtropical Karst Forests,Southwestern China

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Journal of m.untain Science 2013年第1期10卷 95-104页

作者： ZHANG Zhong-hua HU Gang ni Jian School of Chem.stry and Life Science Guangxi Teachers Education University Key Laboratory of Beibu Gulf Environm.nt Change and Resources Utilization of m.nistry of Education Guangxi Teachers Education University State Key Laboratory of Environm.ntal Geochem.stry Institute of GeochemistryChinese Academy of Sciences Departm.nt of Environm.ntal Science East China Normal University

Relationships between topography,soil properties and the distribution of plant com.unities on two different rocky hillsides are exam.ned in two subtropical karst forests in the m.olan National Natural Reserve,southwestern *** of two 1-ha perm.nent plots at each forest,and m.asurem.nts of four topographic and thirteen edaphic factors on the slopes were *** Indicator Species Analysis(TWINSPAN) and Detrended Canonical Correspondence Analysis(DCCA) were used for the classification of plant com.unities and for vegetation ordination with environm.ntal *** hundred 10m.10m.quadrats in each plot were classified into four plant com.unity types.A clear altitudinal gradient suggested that elevation was im.ortant in com.unity *** topography and soil explained 51.06% and 54.69% of the variability of the distribution of plant species in the two forest plots,respectively,indicating both topographic factors(***,slope and rock-bareness rate) and edaphic factors(*** P,K and exchangeable Ca) were the im.ortant drivers of the distribution of woody plant species in subtropical karst ***,our results suggested that topographical factors were m.re im.ortant than edaphic ones in affecting local plant distribution on steep slopes with extensive rock outcrops,while edaphic factors were m.re influential on gentle slope and relatively thick soil over rock in subtropical karst *** relationships between vegetation and environm.ntal factors in karst forest ecosystem. would enable us to apply these findings in vegetation m.nagem.nt strategies and restoration of forest com.unities.

关键词： Karst forest Classification Ordination Edaphic factor Topography Rock outcrop

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Calcium.Im.erm.able Nm.A Receptor:A Novel Target for Addiction

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Neuroscience Bulletin 2017年第3期33卷 357-358页

作者： Xiaodan Huang Wei ni Changzheng Zhang School of Psychology Nanjing Normal UniversityNanjing 210097China

Drug addiction results in long-term.synaptic potentiation at excitatory synapses in the brain reward circuitry,especially in the ventral tegm.ntal area（VTA）and nucleus accum.ens（NAc）,central parts of the m.solim.i... 详细信息

关键词： potentiation excitatory dopam.ne addiction synaptic cortical Nm.A ventral Receptor nucleus

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基于一维模型的椒盐噪声去除方法

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数据采集与处理 2007年第2期22卷 172-177页

作者：曹荣倪林苗原中国科学技术大学电子工程与信息科学系合肥230026 维多利亚大学计算机科学与数学学院澳大利亚墨尔本***

提出了一种基于一维信号处理去除图像椒盐脉冲噪声的方法,该算法给出了4种二维信号转换为一维信号的模型,用线性处理代替块处理去除图像椒盐脉冲噪声。经过实验仿真并与其他滤波算法比较表明,该算法可以有效地去除图像中的椒盐脉冲噪声... 详细信息

提出了一种基于一维信号处理去除图像椒盐脉冲噪声的方法,该算法给出了4种二维信号转换为一维信号的模型,用线性处理代替块处理去除图像椒盐脉冲噪声。经过实验仿真并与其他滤波算法比较表明,该算法可以有效地去除图像中的椒盐脉冲噪声,尤其是在计算复杂度上表现了很好的性能,同时也降低了图像边界点处理的边界效应。

关键词：图像处理一维模型椒盐噪声去除噪声

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10 watt-level tunable narrow linewidth 1.5μm.all-fiber am.lifier

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High Power Laser Science and Engineering 2018年第2期6卷 149-153页

作者： ni Tang Zhiyue Zhou Zhixian Li Zefeng Wang College of Advanced Interdisciplinary StudiesNational University of Defense TechnologyChangsha 410073China Hunan Provincial Collaborative Innovation Center of High Power Fiber Laser Changsha 410073China Hunan Provincial Key Laboratory of High Energy Laser Technology Changsha 410073China

We report here a high-power, wavelength tunable and narrow linewidth 1.5 μm.all-fiber laser am.lifier based on a tunable diode laser and Er-Yb co-doped fibers. The laser wavelength can be precisely tuned from.1535 nm.to 1580 nm. which covers m.ny absorption lines of m.d-infrared laser gases, such as C2 H2, HCN, CO, and HI. The m.xim.m.laser power is >11 W, and the linewidth is about 200–300 m.z, which is close to the absorption linewidth of the above-m.ntioned gases. This work provides a suitable pum. source for high-power wavelength tunable m.d-infrared fiber gas lasers based on low-loss hollow-core fibers.

关键词： Er-doped fibers fiber am.lifier fiber lasers high power narrow linewidth

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Two-phase sink vortex suction m.chanism.and penetration dynam.c characteristics in ladle teem.ng process

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Journal of Iron and Steel Research International 2017年第7期24卷 669-677页

作者： Da-peng Tan Ye-sha ni Li-bin Zhang Key Laboratory of E & m Ministry of Education & Zhejiang ProvinceZhejiang University of Technology

At the late stage of continuous casting（CC）ladle teem.ng,sink vortex can suck the liquid slag into tundish,and cause negative influences on the cleanliness of m.lten *** address this issue,a twophase fluid m.chanical m.deling m.thod for ladle teem.ng was ***,a dynam.c m.del for vortex suction process was built,and the profiles of vortex flow field were ***,based on the level set m.thod（LSm.,a two-phase 3Dinterface coupling m.del for slag entrapm.nt was ***,in com.ination with high-order essentially non-oscillatory（ENO）and total variation dim.nishing（TVD）m.thods,a LSm.based num.rical solution m.thod was proposed to obtain the 3Dcoupling evolution regularities in vortex suction *** results show that the vortex with higher kinetic energy can form.an expanded sandglass-shape region with larger slag fraction and lower rotating velocity;there is a pressure oscillation phenom.non at the vortex penetration state,which is caused by the energy shock of two-phase vortex penetration coupling.

关键词： Ladle teem.ng Sink vortex Suction m.chanism.Two-phase coupling Level set m.thod Pressure oscillation

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Influence of topography,soil properties and plant com.unity on the biom.ss of Abies georgei *** seedlings in Southeast Tibet

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Journal of m.untain Science 2022年第9期19卷 2664-2677页

作者： ZHANG Xin-sheng ZHOU Chen-ni LU Jie Institute of Tibet Plateau Ecology Tibet Agricultural&Animal Husbandry UniversityNyingchi 860000China Key Laboratory of Forest Ecology in Tibet Plateau Tibet Agricultural&Animal Husbandry UniversityMinistry of EducationNyingchi 860000China Linzhi National Forest Ecosystem.Observation&Research Station of Tibet Nyingchi 860000China Key Laboratory of Alpine Vegetation Ecological Security in Tibet Nyingchi 86000China

Biom.ss of seedlings at different developing stages of growth is im.ortant inform.tion for studying the response of species to site *** objectives of this study was to explore the distribution characteristics of AGB(above-ground biom.ss)and BGB(below-ground biom.ss)of Abies georgei *** seedlings of different ages,and investigate the effects of topography(slope aspect,altitude),plant com.unity characteristics(crown density,species diversity,etc.),and soil properties(soil physical and chem.cal properties)on the biom.ss and its *** in five age classes(1–2,3–4,5–6,7–8,and 9–10 years old)were collected by full excavation from.6 elevations(3800 m.3900 m.4000 m.4100 m.4200 m.4300 m.on the north and south slopes of Sejila m.untain in Tibet.15seedlings of each age class were investigated at one *** individual effects of seedling age(SA)and the interaction effects of SA,slope aspect(SL),and elevation(EG),nam.ly,SL×EG,SL×SA,EG×SA,and SL×EG×SA,had significant effects on the AGB of the seedlings(pnificantly affected by SA(pm.al growth trend with the increase in seedling age,and had an allom.tric relationship at different elevations,α(allom.tric exponential)varied from.0.913 to 1.046 in the northern slope,and from.1.004 to 1.268 in the southern *** biom.ss of seedlings on the northern slope was rem.rkably affected by stand factors,with a contribution rate of 47.8%,whereas that on the southern slope was considerably affected by soil factors with a contribution rate of 53.2%.The results showed that age was the m.st im.ortant factor affecting seedling *** allom.tric pattern of seedling biom.ss was relatively stable,but in a highaltitude habitat,*** *** seedlings increased the input of *** seedling biom.ss allocation and its influencing factors is useful for evaluating plants’ability to acquire resources and surviv

关键词： Biom.ss allocation Allom.tric relationship Stand characteristic Soil factors Abies georgei var.sm.thii seedlings Sejila m.untain,Tibet

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Two m.DS-box proteins,AGL9 and AGL15,recruit the FIS-PRC2 com.lex to trigger the phase transition from.endosperm.proliferation to em.ryo developm.nt in Arabidopsis

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m.lecular Plant 2024年第7期17卷 1110-1128页

作者： Shen Zhang Devasantosh m.hanty Adnan m.zaffar m.n ni Departm.nt of Plant and m.crobial Biology University of Minnesota at Twin CitiesSaint PaulMinnesota MN 55108United States of AmericaUSA

Spatiotem.oral regulation of gene expression by polycom. repressive com.lex 2(PRc2)is critical for anim.l and plant *** Arabidopsis fertilization independent seed(FIS)-PRC2 com.lex functions specifically during plant reproduction from.gam.togenesis to seed *** a double fertilization event,triploid endosperm.proliferates early,followed by the growth of a diploid em.ryo,which replaces the endosperm.in Arabidopsis and m.ny *** genes critical for endosperm.proliferation such as IKkU2 and m.ni3 are activated after *** we report that two m.DS-box AGAm.US-LIKE(AGL)proteins associate with the key endosperm.proliferation loci and recruit the FIS-PRC2 repressive com.lex at 4-5 days after pollination(DAP).Interestingly,AGL9 and AGL15 only accum.late toward the end of endosperm.proliferation at 4-5 DAP and prom.te the deposition of H3K27m.3 m.rks at key endosperm.proliferation *** of AGL9 and AGL15 or overexpression of AGL9 or AGL15 significantly influence endosperm.proliferation and ***-wide analysis with cleavage Under Targets and tagm.ntation(CUT&Tag)sequencing and RNA sequencing revealed the landscape of endosperm.H3K27m.3 m.rks and gene expression profiles in Col-0 and agl9 ***&Tag qPCR also dem.nstrated the occupancy of the two m.DS-box proteins and FIS-PRC2 on a few representative target *** studies suggest that m.DS-box proteins could potentially recruit PRc2 to regulate m.ny other developm.ntal processes in plants or even in fungi and anim.ls.

关键词： AGL9 AGL15 em.ryo endosperm IKU2 m.DEA m.ni3

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Near surface velocity and Q_s structure of the Quaternary sedim.nt in Bohai basin,China

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Earthquake Science 2009年第5期22卷 451-458页

作者： Jiajun Chong Sidao ni m.ngcheng National Geophysical Observatory University of Science and Technology of China Hefei 230026 China

Heavily populated by Beijing and Tianjin cities, Bohai basin is a seism.cally active Cenozoic basin suffering from.huge lost by devastating earthquakes, such as Tangshan earthquake. The attenuation （Qp and Qs） of the surficial Quaternary sedim.nt has not been studied at natural seism.c frequency （1-10 Hz）, which is crucial to earthquake hazards study. Borehole seism.c records of m.cro earthquake provide us a good way to study the velocity and attenuation of the surficial structure （0-500 m.. We found that there are two pulses well separated with sim.le waveform. on borehole seism.c records from.the 2006 m.4.9 Wen＇an earthquake sequence. Then we perform.d waveform.m.deling with generalized ray theory （GRT） to confirm.that the two pulses are direct wave and surface reflected wave, and found that the average vp and Vs of the top 300 m.in this region are about 1.8 km.s and 0.42 km.s, leading to high ve/vs ratio of 4.3. We also m.deled surface refleeted wave with propagating m.trix m.thod to constrain Qs and the near surface velocity structure. Our m.deling indicates that Qs is at least 30, or probably up to 100, m.ch larger than the typically assum.d extrem.ly low Q（-10）, but consistent with Qs m.deling in m.ssissippi em.aym.nt. Also, the velocity gradient just beneath the free surface （0-50 m. is very large and velocity increases gradually at larger depth. Our m.deling dem.nstrates the im.ortance of borebole seism.c records in resolving shallow velocity and attenuation structure, and hence m.y help in earthquake hazard sim.lation.

关键词： Bohai basin Quaternary sedim.nt near surface velocity Qs borehole records

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ABRUPT DEFLECTED SUPERCRITICAL WATER FLOW IN SLOPED CHANNELS

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Journal of Hydrodynam.cs 2008年第3期20卷 293-298页

作者： LIU Ya-kun ni Han-gen State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian 116024China

The effect of the bottom.slope on abrupt deflected supercritical water flow was experim.ntally and theoretically studied. m.del tests were conducted in a flum. of 1.2 m.wide and 2.6 m.long with sloped bottom.at an angle 35.54°, its length of deflector was 0.2 m.and the deflection angles were 15° and 30°. An approxim.te m.thod for calculating the shock wave angle and depth ratio of the abrupt deflected supercritical water flow was suggested, and a correction coefficient for the hydrodynam.c pressure was introduced to generalize the m.m.ntum.equation in the direction perpendicular to the shock front. It m.st be noticed that in the sloped channel the shock wave angle and the depth ratio are no longer constant as those in the horizontal channels, but slowly change along the shock front. The calculated results are in good agreem.nt with m.asured data.

关键词： shock wave abrupt deflection of supercritical water flow slopping channel

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Serrated chip characteristics and form.tion m.chanism.in high-speed m.chining of selective laser m.lted Ti6Al4V alloys

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Science China(Technological Sciences) 2023年第5期66卷 1435-1450页

作者： LIU DeJian WANG YouQiang ni ChenBing ZHU LiDa ZHENG ZhongPeng School of m.chanical and Autom.tive Engineering Qingdao University of TechnologyQingdao266520China Key Lab of Industrial Fluid Energy Conservation and Pollution Control Ministry of EducationQingdao266520China School of m.chanical Engineering and Autom.tion Northeastern UniversityShenyang110819China School of m.chanical Engineering Tsinghua UniversityBeijing100084China

Serrated chips,consisting of extrem.ly uneven plastic deform.tion,are a prom.nent feature of high-speed m.chining of difficultto-m.chine *** paper focuses on the evolution of chip form.chip m.rphology features(chip free surface,tool-chip contact surface,and chip edge),and chip segm.nt param.ters in subsequent high-speed(vc=50 and 150 m.m.n-1)m.chining of selective laser m.lted(SLm.d)Ti6Al4V alloys,which are significantly different from.conventional Ti6Al4V alloy in m.crostructure,m.chanical properties and *** effect of laser beam.scanning schem.s(0°,67.5°,and 90°),m.chined surfaces(top and front),and cutting speeds on serrated chip characteristics of SLm.d Ti6Al4Valloys was *** on the Johnson-Cook constitutive m.del of SLm.d Ti6Al4Valloys,an orthogonal cutting m.del was developed to better understand the effect of physical-m.chanical properties on the shear localization,which dom.nates the form.tion m.chanism.of serrated chips in post-m.chining of SLm.d Ti6Al4V *** results showed that the critical cutting speed(CCS)for chip serration of SLm.d Ti6Al4V alloy is lower than that for serrated chips of conventional Ti6Al4V alloy,and the serrated profile of SLm.d Ti6Al4V chips was m.re regular and ***,due to anisotropic m.crostructure and m.chanical properties of SLm.d Ti6Al4Valloys,the serration degree of chips produced on the top surfaces of SLm.d Ti6Al4Valloys is m.re prom.nent than that of chips generated on the front *** addition,because of the poor deform.tion coordination and high plastic flow stresses of needle-like m.rtensiteα′,the plastic flow and grain distortion in the adiabatic shear band(ASB)of SLm.d Ti6Al4V chips are significantly sm.ller than those in the ASB of conventional Ti6Al4V with equiaxed grains.

关键词： serrated chips selective laser m.lted Ti6Al4V alloys high-speed m.chining chip characteristics anisotropic properties

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