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Differential Effects of Ammonium and Nitrate on Growth Performance of Glechoma longituba under Heterogeneous Cd Stress

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Phyton-International Journal of Experimental Botany 2020年第3期89卷 667-679页

作者： Yanwei Feng Wen lei Rui Gu Ping Zhao Shijun Ni Ningfei Lei College of Earth Sciences Chengdu University of TechnologyChengdu610101China College of Landscape Architecture Sichuan Agricultural UniversityChengdu610101China College of Environment Chengdu University of TechnologyChengdu610101China Geological Party 105 Guizhou Provincial Bureau of Geology and Mineral Exploration and DevelopmentGuiyang550018China

Water,minerals,nutrients,etc.,can be shared by physiological integration among inter-connected ramets of clonal plants.Nitrogen plays an important role in alleviating cadmium(Cd)stress for clonal plants.But how different forms of nitrogen affect growth performance of clonal plants subjected to heterogeneous Cd stress still remains poorly understood.A pot experiment was conducted to investigate the differential effects of ammonium and nitrate on growth performance of Glechoma longituba under heterogeneous Cd stress.In the experiment,parent ramets of Glechoma longituba clonal fragments were respectively supplied with modified Hoagland solution containing 7.5 mM ammonium,7.5 mM nitrate or the same volume of nutrient solution without nitrogen.Cd solution with different concentrations(0,0.1 or 2.0 mM)was applied to offspring ramets of the clonal fragments.Compared with control(N-free),nitrogen addition to parent ramets,especially ammonium,significantly improved antioxidant capacity[glutathione(GSH),proline(Pro),peroxidase(POD,)superoxide dismutase(SOD)and catalase(CAT)],PSII activity[maximum quantum yield of PSII(F_(v)/F_(m))and effective quantum yield of PSII(ΦPSII)],chlorophyll content and biomass accumulation of the offspring ramets suffering from Cd stress.In addition,negative effects of nitrate on growth performance of whole clonal fragments were observed under Cd stress with high concentration(2.0 mM).Transportation or sharing of nitrogen,especially ammonium,can improve growth performance of clonal plants under heterogeneous Cd stress.The experiment provides insight into transmission mechanism of nitrogen among ramets of clonal plants suffering from heterogeneous nutrient supply.Physiological integration might be an important ecological strategy for clonal plants adapting to heterogeneous environment stress conditions.

关键词： Clonal plant physiological integration nitrogen form antioxidant capacity chlorophyll fluorescence

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异质光照条件下克隆整合对入侵植物南美蟛蜞菊化感作用的影响

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Journal of Plant Ecology 2022年第3期15卷 663-671页

作者： lei Pu Lang Cheng Ai Li Sha Liang Qing Wei Shulan Wu Linxuan He Xiangning Xu Ningfei Lei Jinsong Chen College of Ecology and Environment Chengdu University of TechnologyChengdu 610059China College of Life Science Sichuan Normal UniversityChengdu 610101China No.405 Geological Team Sichuan Bureau of Geology and Mineral ResourcesChengdu 610066China

植物入侵已成为全球生态系统最严重的威胁之一。当具有克隆生长能力的入侵植物入侵或定殖到新的生境时,它们相互连接的分株可能受到异质光照的影响。在异质光照条件下,克隆整合对入侵植物化感作用的影响尚不清楚。为研究异质光照条件下... 详细信息

植物入侵已成为全球生态系统最严重的威胁之一。当具有克隆生长能力的入侵植物入侵或定殖到新的生境时,它们相互连接的分株可能受到异质光照的影响。在异质光照条件下,克隆整合对入侵植物化感作用的影响尚不清楚。为研究异质光照条件下克隆整合对入侵植物南美蟛蜞菊(Wedelia trilobata)化感作用的影响,采用两个连续分株的克隆片段进行了盆栽试验。较老的分株暴露在全光下,而年轻的分株则受到20%的全光照。同时,每个克隆片段的年轻分株与目标植株(一个番茄苗)在盆栽中相邻生长。南美蟛蜞菊的两个连续分株之间的匍匐茎设置切断和不切断两种处理。另外,两株番茄幼苗(一株作为目标植株)在盆栽中相邻生长作为对照。研究结果表明,当与目标植物相邻生长的南美蟛蜞菊分株之间的匍匐茎保持完整时,目标植株的生物量积累、叶片叶绿素和氮含量、叶绿素荧光参数和净光合速率及其根长和活性相较于匍匐茎切断处理显著降低。异质光照条件下连续两个分株之间碳水化合物的运输或共享可以增强20%全光处理下年轻分株的化感作用。克隆整合在异质光照条件下对具有克隆生长能力的入侵植物的入侵或定殖具有重要意义。

关键词：匍匐茎植物克隆整合入侵机制异质环境化感作用

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Experimental and numerical study on pressure oscillation in a combustor with rotary valve

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Chinese Journal of Aeronautics 2021年第5期34卷 298-314页

作者： Yunzhi XI ningfei WANG Junwei LI Zhihui ZHANG lei HAN School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China

A rotary valve coupled in a combustor assembly can generate periodic pressure oscillations inside the combustor and can be used to study the combustion instability in the combustion chamber of a rocket engine.This paper proposes a cold gas flow experimental system based on a rotary valve and a corresponding rotation model.A 3 D numerical model is proposed to obtain the transient flow inside the rotary valve,and the dynamic mesh technique and User-Defined Functions(UDFs)are adopted to implement a swing motion instead of a rotary motion.Several cold gas flow experiments are carried out at rotating speeds of 75225,and 375 rpm to verify the validity of the numerical model.The effects of rotating speed,stroke length ratio and radius of the RED(Rotor Exhaust Duct)on the pressure oscillations are studied using this numerical model.The results show that the maximum and peak-to-peak values of the pressure oscillations gradually decrease with increasing rotating speed.The ratio of the corresponding peak-to-peak value to the maximum pressure(pressure amplitude ratio)is reduced from 1.81 to 0.6%.The stroke length ratio affects the pressure waveform because it leads to a change in the time spent in the non-exhaust stage.When the stroke length ratio is 0,the waveform closely resembles a sine wave.With the increase in the stroke length ratio,the pressure waveform exhibits a more square or a triangular wave shape.Finally,a high-frequency and high-amplitude pressure oscillation can be obtained by appropriately increasing the radius of the RED.

关键词： Cold gas test Dynamic mesh Numerical simulation Pressure oscillation Rotary valve

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Machine learning-based estimates of aboveground biomass of subalpine forests using Landsat 8 OLI and Sentinel-2B images in the Jiuzhaigou National Nature Reserve,Eastern Tibet Plateau

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Journal of Forestry Research 2022年第4期33卷 1329-1340页

作者： Ke Luo Yufeng Wei Jie Du Liang Liu Xinrui Luo Yuehong Shi Xiangjun Pei Ningfei Lei Ci Song Jingji Li Xiaolu Tang College of Earth Science Chengdu University of TechnologyChengdu 610059People’s Republic of China State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu 610059People’s Republic of China Jiuzhaigou Nature Reserve Administration Aba Tibetan and Qiang Autonomous PrefectureJiuzhai 623402People’s Republic of China College of Ecology and Environment Chengdu University of TechnologyChengdu 610059People’s Republic of China State Environmental Protection Key Laboratory of Synergetic Control and Joint Remediation for Soil&Water Pollution Chengdu Univer-Sity of TechnologyChengdu 610059People’s Republic of China China Railway Eryuan Engineering Group Co.LtdChengdu 610031People’s Republic of China

Accurate estimates of forest aboveground biomass(AGB)are critical for supporting strategies of ecosystem conservation and climate change mitigation.The Jiuzhaigou National Nature Reserve,located in Eastern Tibet Plateau,has rich forest resources on steep slopes and is very sensitive to climate change but plays an important role in the regulation of regional carbon cycles.However,an estimation of AGB of subalpine forests in the Nature Reserve has not been carried out and whether a global biomass model is available has not been determined.To provide this information,Landsat 8 OLI and Sentinel-2B data were combined to estimate subalpine forest AGB using linear regression,and two machine learning approaches–random forest and extreme gradient boosting,with 54 inventory plots.Regardless of forest type,Observed AGB of the Reserve varied from 61.7 to 475.1 Mg hawith an average of 180.6 Mg ha.Results indicate that integrating the Landsat 8 OLI and Sentinel-2B imagery significantly improved model efficiency regardless of modelling approaches.The results highlight a potential way to improve the prediction of forest AGB in mountainous regions.Modelled AGB indicated a strong spatial variability.However,the modelled biomass varied greatly with global biomass products,indicating that global biomass products should be evaluated in regional AGB estimates and more field observations are required,particularly for areas with complex terrain to improve model accuracy.

关键词： Aboveground biomass Linear regression Random forest Extreme gradient boosting Landsat 8 OLI Sentinel-2B

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Degree of Humification in Fresh Litter from a Subtropical Mixed Plantation Forest in Southwest China

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Phyton-International Journal of Experimental Botany 2021年第2期90卷 635-650页

作者： Fujia Wu Chengming You Jie Du Xiangjun Pei Ningfei Lei Bo Tan Huixing Song College of Landscape Architecture Sichuan Agricultural UniversityChengdu611130China Institute of Ecology&Forestry Sichuan Agricultural UniversityForestry Ecological Engineering in Upper Reaches of Yangtze River Key Laboratory of Sichuan ProvinceChengdu611130China Jiuzhaigou National Nature Reserve Administration Aba Tibetan and Qiang Autonomous PrefectureAba623402China Institute of Ecological Environment Chengdu University of TechnologyChengdu610059China

The humification degree of fresh litter directly controls the accumulation of soil humus derived from plant litter,but very little information on this process is available.Planted forests are well known to restrict soil fertility,which is often indicated by the soil humus level.In this study,fresh litter was collected during different plant phenological stages during 2016 and 2017 in a mixed plantation in Southwest China.The values of hue coefficientΔlogK(absorbance ratio of 400 nm and 600 nm on a logarithmic scale),optical density E4/E6(absorbance ratio of 400 nm and 600 nm)and A600/C(absorbance at 600 mm per mg of carbon per ml of extraction)and the concentration of extractable humus carbon(HC)were determined in four litter components(foliar,twigs,reproductive organs and miscellaneous)of the dominant species(Pterocarya stenoptera,Quercus acutissima,Cunninghamia lanceolata and Toxicodendron vernicifluum).All of the litter components exhibited obvious humification characteristics,and showed the highest concentration of extractable HC during the leaf maturation period.The miscellaneous and foliar litters showed greater humification than the other litter types.The components of Pterocarya stenoptera litter exhibited greater degrees of humification than those of the other species,with lowerΔlogK and E4/E6 values and higher A600/C values.The litter from coniferous and evergreen species showed lower humification than that from broad-leaf and deciduous species regardless of the litter component examined.The present results provide new insights into the management of plantations and theoretical data to accurately improve the quality of plantations and maintain soil fertility under a global change.

关键词： Fresh litter humification plantations extractable humus carbon

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Effects of Soil Nutrient Heterogeneity and Earthworms on Aboveground Biomass of Experimental Plant Communities

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Phyton-International Journal of Experimental Botany 2021年第4期90卷 1259-1271页

作者： Simei Yao Yu Jin Limin Zhang Ningfei Lei Wei Xue Jinsong Chen Qian Zhang Feihai Yu College of the Environment Chengdu University of TechnologyChengdu610059China Institute of Wetland Ecology&Clone Ecology Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and ConservationTaizhou UniversityTaizhou318000China College of Life Science Sichuan Normal UniversityChengdu610101China

Soil nutrients are commonly heterogeneously distributed and earthworms are one of the most common soil organisms.While effects of both soil nutrient heterogeneity and earthworms have been well studied,their interactive effect on plant community productivity has rarely been tested.In a greenhouse experiment,we constructed experimental plant communities by sowing seed mixtures of four grasses,two legumes and two forbs in either a heterogeneous soil consisting of low and high nutrient soil patches or a homogeneous soil where the low and high nutrient soil patches were evenly mixed.The earthworm Eisenia fetida was either added to these soils or not.Aboveground biomass of the whole communities,grasses and legumes did not differ between the homogeneous and heterogeneous soils or between the soils with and without earthworms.However,soil nutrient heterogeneity reduced aboveground biomass of forbs,and such an effect did not interact with earthworms.In response to soil heterogeneity and earthworms,biomass ratio of the three functional groups showed similar patterns as that of their biomass.At the patch level,aboveground biomass of the whole community,grasses and legumes were greater in the high than in the low nutrient soil patches within the heterogeneous soil.A similar pattern was found for the forbs,but this was only true in the absence of earthworms.Our results suggest that soil nutrient heterogeneity and earthworms may not influence aboveground biomass of plant communities,despite the fact that they may modify the growth of certain plant functional groups within the community.

关键词： Environmental heterogeneity foraging response functional group plant-animal interaction yield

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Wafer-scale fabrication of carbon-nanotube-based CMOS transistors and circuits with high thermal stability

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Nano Research 2022年第11期15卷 9875-9880页

作者： Nan Wei ningfei Gao Haitao Xu Zhen Liu lei Gao Haoxin Jiang Yu Tian Yufeng Chen Xiaodong Du Lian-Mao Peng Beijing HuaTanYuanXin Electronics Technology Ltd.Co. Beijing 101399China Research Center for Carbon-based Electronics Peking UniversityBeijing 100871China Beijing Institute of Carbon-based Integrated Circuits Beijing 100195China

Thanks to its single-atomic-layer structure,high carrier transport,and low power dissipation,carbon nanotube electronics is a leading candidate towards beyond-silicon technologies.Its low temperature fabrication processes enable three-dimensional(3D)integration with logic and memory(static random access memory(SRAM),magnetic random access memory(MRAM),resistive random access memory(RRAM),etc.)to realize efficient near-memory computing.Importantly,carbon nanotube transistors require good thermal stability up to 400℃ processing temperature to be compatible with back-end-of-line(BEOL)process,which has not been previously addressed.In this work,we developed a robust wafer-scale process to build complementary carbon nanotube transistors with high thermal stability and good uniformity,where AlN was employed as electrostatic doping layer.The gate stack and passivation layer were optimized to realize high-quality interfaces.Specifically,we demonstrate 1-bit carbon nanotube full adders working under 250℃ with rail-to-rail outputs.

关键词： carbon nanotube field-effect transistors complementary metal-oxide-semiconductor(CMOS) thermal stability waferscale integrated circuits

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Different Ablation Models for the Wall-plasma Interaction Process in Pulsed Plasma Thruster

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高电压技术 2013年第9期39卷 2301-2308页

作者： YANG lei LIU Xiangyang WANG Siyu XIE Kan WU Zhiwen WANG ningfei Beijing Institute of Technology School of Aerospace Engineering Beijing 100081 China

Ablation excited by current pulses is a very critical physical process in pulse plasma thrusters(PPT).Its effects on wall-plasma interaction directly determine the PPT performances.In order to reveal the process of the ablated wall interaction with the discharge plasma in PPT,ablation models formulated by three different boundary conditions at the wall-plasma interface are studied.These are the two widely used high-speed evaporation models(Model-L and Model-M),and the recently developed Keida-Zaghloul model(Model-K)of the Knudsen layer that takes into account the internal degrees of freedom on the energy flux conservation.First,fundamental mechanisms of the three ablation models are clarified by comparative analysis in order to gain a comprehensive understanding of the wall-plasma interaction.Then,the applicability of different ablation models with the numerical solutions of LES-6 PPT is investigated in detail using magnetohydrodynamic(MHD)modeling.Results show that Model-L and Model-M are actually special cases of Model-K when a simplified jump conditions limited by high velocity at the vapor/plasma interface is used;A ratio of ablation rate in Model-L to that in Model-M is about 0.8at the same wall surface temperature,while it rises to 1 at different surface temperature determined by Model-L and Model-M in PPT.Even though Model-K solution requires significant computational time,it shows more accurate ablation feature for the wall-plasma interaction and possesses better computing precision of impulse bit during post-pulse which is useful for future studies of the late time ablation.

关键词：等离子体推进器蒸发模型电流脉冲壁挂式脉冲等离子体推力器相互作用交互放电等离子体

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凹凸棒的研究现状——基于CiteSpace的可视化分析

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化工新型材料 2022年第2期50卷 51-57页

作者：梁莎刘金渠许向宁雷泞菲成都理工大学生态环境学院成都610059

应用文献计量可视化分析软件CiteSpace,立足于CNKI数据库中的主题为"凹凸棒"或"坡缕石"的2068篇文献,对其文献的发表时间特征、文献发表机构和关键词的知识图谱进行分析,整理和总结出关于该领域的研究进程、发展现状和未来趋势。结果显... 详细信息

应用文献计量可视化分析软件CiteSpace,立足于CNKI数据库中的主题为"凹凸棒"或"坡缕石"的2068篇文献,对其文献的发表时间特征、文献发表机构和关键词的知识图谱进行分析,整理和总结出关于该领域的研究进程、发展现状和未来趋势。结果显示:文献时间分布总体为缓慢发展后迅猛增长再回落到稳定状态;研究力量方面,凹凸棒领域具有突出贡献的作者和机构,并形成了稳点的研究团队和机构合作网络,但彼此的交流合作不够紧密,学术界整体的资源互置仍需加强;主题词和热点方面,吸附、改性和纳米材料是持续时间较长的研究重点,钝化、热处理等是目前研究的前沿趋势。

关键词：凹凸棒坡缕石可视化分析研究进展

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番茄对不同养分水平下南美蟛蜞菊和蟛蜞菊化感作用的响应

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广西植物 2021年第8期41卷 1354-1362页

作者：辜睿蒲磊李军亚赵平雷泞菲成都理工大学生态环境学院成都610059 四川省地质矿产勘查开发局四○五地质队四川都江堰611830 贵州省地质矿产勘查开发局一○五地质大队贵阳550018

外来入侵植物分泌的化感物质能够影响本地植物的生长生理特性,养分水平对入侵植物的化感潜力有重要影响。该文通过将番茄植株分别与同种番茄、南美蟛蜞菊、蟛蜞菊植株相邻原位种植,以15%、25%、50%、75%的Hoagland培养液模拟不同养分水... 详细信息

外来入侵植物分泌的化感物质能够影响本地植物的生长生理特性,养分水平对入侵植物的化感潜力有重要影响。该文通过将番茄植株分别与同种番茄、南美蟛蜞菊、蟛蜞菊植株相邻原位种植,以15%、25%、50%、75%的Hoagland培养液模拟不同养分水平开展温室控制实验,探究在不同养分水平下入侵植物南美蟛蜞菊及其亲缘植物蟛蜞菊的化感作用对本地植物番茄叶绿素荧光参数及生物量的影响。结果表明:(1)番茄在75%养分水平下的叶绿素荧光参数和生物量显著优于其余3个养分水平。(2)随着养分水平降低,番茄叶片的PSⅡ最大光化学效率(F v/F m)、PSⅡ实际光合量子产量[Y(Ⅱ)]、光化学淬灭系数(q p)及植株的总生物量显著减少,非光化学淬灭系数(NPQ)和植株根系生物量的分配比例增加。(3)在25%Hoagland培养液处理下,与南美蟛蜞菊混植番茄的F v/F m、Y(Ⅱ)、q p和总生物量显著低于与蟛蜞菊混植番茄,NPQ和根系生物量的分配比例显著高于与蟛蜞菊混植番茄。综上结果说明南美蟛蜞菊和蟛蜞菊可能通过根系分泌化感物质抑制番茄的生长发育,且南美蟛蜞菊的化感作用强于蟛蜞菊,而增加栽培基质中的养分水平可以显著降低南美蟛蜞菊和蟛蜞菊对番茄的化感胁迫作用。

关键词：化感作用养分水平叶绿素荧光参数总生物量生物量分配

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