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Impact of Climate and Grazing on Biomass Components of Eastern Russia Typical Steppe

Journal of Integrative Agriculture 2014年第6期13卷 1183-1192页

作者： ubugunov leonid Rupyshev Yuriy ubugunov Vasiliy HOU Xiang-yang Vishnyakova Oxana Lavrentieva Irina ubugunova Vera REN Wei-bo DING Yong Institute of General and Experimental Biology Siberian Branch of Russian Academy of Sciences Grassland Research Institute Chinese Academy of Agricultural Sciences

Spatial and structural characteristics of plant communities in the steppe ecosystems of the Baikal region, Russian Federation have been researched in connection with climate change and grazing. The present study, based on a total of 15 typical steppe sampling plots, investigated above-ground biomass （AGB）, below-ground biomass （BGB）, total biomass （TB） and root：shoot ratios （R：S） and their relationships with climatic factors and grazing. All biomass components varied widely depending on the climatic parameters and the degree of grazing affected transformation. A strong negative correlation between mean annual temperature （MAT） and total plant biomass was revealed for all study area. Mean annual precipitation （MAP） signiifcantly affected communities productivity increasing only in the south of the region. Due to the large and mountainous territory, the inlfuence of latitude and elevation （mountain） factors on the components of the biomass were studied. Although all studied plant steppe communities were transformed by uncontrolled grazing, their productivity is signiifcantly reduced only at plots with maximum digression. Vegetation shift is an indicator of climate change, as well as providing a diagnostic tool to build predictive models. Based on the complex index of effective precipitation, it was revealed that at the end of last century in the steppes of the Baikal region the structural and production processes will be affected by an arid climate trend.

关键词： steppe productivity climate grazing transformation Baikal region

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气候变化背景下草原生态系统研究热点探讨

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中国草地学报 2013年第5期35卷 124-132页

作者：丁勇侯向阳吴新宏 leonid ubugunov 任卫波萨茹拉孙小龙刘朋涛中国农业科学院草原研究所/中国农业科学院欧亚温带草原研究中心内蒙古呼和浩特010010 俄罗斯科学院西伯利亚分院普通与实验生物学研究所布里亚特共和国乌兰乌德670047 内蒙古自治区生态与农业气象中心内蒙古呼和浩特010051

回顾了近年来关于气候变化与人类活动对草原生态系统的影响与系统响应及适应的研究前沿,并从自然系统维度指出,应该重视气候变化下草原生态系统,尤其是水分胁迫对生态系统的影响及植物生产层适应机制的研究,这将有助于破解草原退化的本... 详细信息

回顾了近年来关于气候变化与人类活动对草原生态系统的影响与系统响应及适应的研究前沿,并从自然系统维度指出,应该重视气候变化下草原生态系统,尤其是水分胁迫对生态系统的影响及植物生产层适应机制的研究,这将有助于破解草原退化的本质与趋势,以挖掘其适应气候变化的潜能;从人类干扰与管理的维度指出,研究人类活动与气候变化两大主要因素共同作用对生态系统的影响,是最符合现实状态的研究,在一个较短的时期内,人类无法阻止和控制气候变化,放牧利用作为主要人类活动是一高度人为可控的管理手段,通过建立放牧制度、放牧强度和放牧时间的多维调控网络,将承担起草原应对气候变化、促进退化草原恢复的重要责任。最后,将以上主要观点进行归纳,提出气候变化背景下草原生态系统研究的5个热点方向及需要突破的相关问题。

关键词：气候变化人类活动草原生态系统响应和适应研究热点

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气候变化对家庭牧场复合系统的影响及其牧民适应

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草业学报 2013年第1期22卷 148-156页

作者：李西良侯向阳 leonid ubugunov 丁勇丁文强尹燕亭运向军张勇中国农业科学院草原研究所内蒙古呼和浩特010010 俄罗斯科学院西伯利亚分院生物公共实验研究所兰州大学草地农业科技学院甘肃兰州730020

家庭牧场土-草-畜-人复合生态系统是北方草原应对气候变化的基本单元,研究其适应性是促进牧区可持续发展的科学基础之一。以草业系统论构建家庭牧场气候变化适应性的研究方法,基于问卷调查研究了内蒙古草原10个旗县599个家庭牧场对气候... 详细信息

家庭牧场土-草-畜-人复合生态系统是北方草原应对气候变化的基本单元,研究其适应性是促进牧区可持续发展的科学基础之一。以草业系统论构建家庭牧场气候变化适应性的研究方法,基于问卷调查研究了内蒙古草原10个旗县599个家庭牧场对气候变化的响应过程。结果表明,1)放牧地、打草场、饲料地、购草作为家庭牧场草料供给途径存在明显的区域分异,饲料地、购草之间具有替代效应;2)以干旱为主的极端气候是气候变化影响家庭牧场的关键因子,雪灾、沙尘暴、大风的影响在内蒙古各地呈现分异格局;3)牲畜、草场是气候变化作用于家庭牧场经营的主要介质,而通过土壤、人群、设施等要素对家庭牧场影响相对较小;4)购草、卖畜是牧户应对极端气候的主要适应行为,分别为保畜与减畜策略,比较而言,保畜策略更为常见。研究认为,家庭牧场复合系统对气候变化的响应发生于草畜-经营界面,草、畜2因子是反馈过程的关键节点。

关键词：家庭牧场气候变化牧民适应响应策略

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温带草原区气候变化及其对植被影响的研究进展

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中国农学通报 2012年第17期28卷 310-316页

作者：丁勇侯向阳 leonid ubugunov 吴新宏尹燕亭李西良运向军中国农业科学院草原研究所呼和浩特010010 俄罗斯科学院西伯利亚分院生物公共实验研究所乌兰乌德670047 兰州大学草地农业科技学院兰州730020

为了深入研究温带草原区气候变化及其对自然-社会-经济系统的影响、系统响应及适应,回顾了温带草原区气候主要要素(如温度、降雨)与旱灾的变化及未来区域气候趋势预测等方面的研究进展,重点总结了气候变化对温带草原植被影响的最新研究... 详细信息

为了深入研究温带草原区气候变化及其对自然-社会-经济系统的影响、系统响应及适应,回顾了温带草原区气候主要要素(如温度、降雨)与旱灾的变化及未来区域气候趋势预测等方面的研究进展,重点总结了气候变化对温带草原植被影响的最新研究成果。研究发现:温带草原区呈现总体气温明显升高,降水区域差异显著,干旱年份增多、旱灾增加的变化趋势。受此影响,植物物候、生理特征、生产力、覆盖度等发生明显的变化。最后指出,在气候变化核心要素预测、研究的时空尺度等方面还不完善,今后应重视开展大尺度气候变化的时空格局,微地形下气候变化的时空异质性等方面研究,同时加强气候变化对草原植被的影响与生态系统响应以及气候变化适应等方面的研究。

关键词：气候变化草原植被温带草原

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The Dependence of Stellar Activity Cycles on Effective Temperature

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Research in Astronomy and Astrophysics 2022年第12期22卷 198-210页

作者： leonid Kitchatinov Institute of Solar-Terrestrial Physics SB RAS Lermontov Str.126AIrkutsk 664033Russia

This paper proposes the idea that the observed dependence of stellar activity cycles on rotation rate can be a manifestation of a stronger dependence on the effective temperature. Observational evidence is recalled and theoretical arguments are given for the presence of cyclic activity in the case of sufficiently slow rotation only. Slow rotation means proximity to the observed upper bound on the rotation period of solar-type stars. This maximum rotation period depends on temperature and shortens for hotter stars. The maximum rotation period is interpreted as the minimum rotation rate for operation of a large-scale dynamo. A combined model for differential rotation and the dynamo is applied to stars of different mass rotating with a rate slightly above the threshold rate for the *** show shorter dynamo cycles for hotter stars. As the hotter stars rotate faster, the computed cycles are also shorter for faster rotation. The observed smaller upper bound for rotation period of hotter stars can be explained by the larger threshold amplitude of the α-effect for onset of their dynamos: a larger α demands faster rotation. The amplitude of the(cycling) magnetic energy in the computations is proportional to the difference between the rotation period and its upper bound for the dynamo. Stars with moderately different rotation rates can differ significantly in super-criticality of their dynamos and therefore in their magnetic activity, as observed.

关键词： dynamo stars:activity stars:magnetic field stars:solar-type stars:rotation

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Mechanisms Modeling the Double Rotation of the Elytra in Beetles （Coleoptera）

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Journal of Bionic Engineering 2011年第4期8卷 395-405页

作者： leonid Frantsevich Schmalhausen-Institute of Zoology B. Chmielnicki str. 15 Kiev-3 O 01601 Ukraine

We recorded transient movements, i.e. opening and closing, of beetle elytra. The beetles were tethered from below and filmed under a skew mirror; two markers were glued on each elytron at the apex and at the base. Body-fixed 3D traces of the apical and basal markers were reconstructed. The trace of the basal marker was, as a rule, non-parallel to the apical trace. The costal edge of the elytron uniformly supinated in the course of adduction of the apical marker. We found two essential attributes of double rotation：（1） the elytron to body articulation is approximately a spherical mechanism; （2） transient opening and closing possess single degree of freedom. The double rotation was modeled with two mechanisms：（1） a flexagon model of the Haas and Wootton＇s type simulated the elytral movement relative to the movement of one facet of the flexagon; （2） a screw and nut model provided traces as two sectors of a helical thread, one sector was phase shifted with respect to other one. Screw guideways in a spherical mechanism give rise to discrepancies. Exact solution for a spherical mechanism with two guideways was proposed. The modeling revealed the attribute （3）： the elytron is actuated by two linked but differently directed drives. Experimental investigations on the elytron to body articulation may be oriented at search of those mechanisms.

关键词： insect flight insect thorax flexagon screw and nut joint

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Computational study of laser fragmentation in liquid:Phase explosion,inverse Leidenfrost effect at the nanoscale,and evaporation in a nanobubble

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Science China(Physics,Mechanics & Astronomy) 2022年第7期65卷 99-114页

作者： Hao Huang leonid V.Zhigilei School of Mechanical Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China Department of Materials Science and Engineering University of VirginiaCharlottesville 22904-4745USA

Laser fragmentation in liquid is an effective and environment-friendly processing technique capable of yielding colloidal nanoparticles and atomic clusters with a narrow size distribution. The advancement of this technique can be facilitated by an improved understanding of processes that control the sizes, shapes, and structures of the produced nanoparticles. In this work, the dependence of the fragmentation mechanisms on the energy density deposited by the laser pulse is investigated in atomistic simulations performed for 20 nm Au nanoparticles irradiated in water by 10 ps laser pulses. The simulations reveal that the decrease in the absorbed laser energy leads to sequential transitions from the regime of “strong” phase explosion, when all products of an explosive phase decomposition of the irradiated nanoparticle are promptly injected into the water surrounding a nanobubble formed around the nanoparticle, to two distinct regimes of nanoparticle fragmentation leading to the formation of a large central nanoparticle surrounded by smaller satellite fragments. First, in the regime of “mild” phase explosion, the central nanoparticle is produced by the reflection of some of the hot metal droplets generated by the explosive decomposition of the nanoparticle from the boundary of the nanobubble. This reflection is attributed to the inverse Leidenfrost effect acting at the nanoscale. The reflected droplets converge in the center of the nanobubble and coalesce into a single droplet that solidifies shortly after the collapse of the nanobubble. Further decrease in the absorbed laser energy brings the irradiation conditions below the threshold for the phase explosion and results in the formation of a core-satellite structure of the fragmentation products through an interplay of the intense evaporation from the surface of the irradiated nanoparticle, evolution of the nanobubble, and condensation of the metal vapor into clusters and small satellite nanoparticles. The computationa

关键词： laser fragmentation in liquid molecular dynamics simulations phase explosion inverse Leidenfrost effect nanobubble nanoparticles

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Nonlinear interference in crystal superlattices

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Light(Science & Applications) 2020年第1期9卷 1239-1245页

作者： Anna V.Paterova leonid A.Krivitsky Institute of Materials Research and Engineering(IMRE) Agency for Science Technology and Research(A*STAR)138634 SingaporeSingapore

Nonlinear interferometers with correlated photons hold promise to advance optical characterization and metrology techniques by improving their performance and *** interferometers offer subshot noise phase sensitivity and enable measurements in detection-challenging regions using inexpensive and efficient *** sensitivity of nonlinear interferometers,defined by the ability to measure small shifts of interference fringes,can be significantly enhanced by using multiple nonlinear elements,or crystal ***,to date,experiments with more than two nonlinear elements have not been realized,thus hindering the potential of nonlinear ***,we build a nonlinear interferometer with up to five nonlinear elements,referred to as superlattices,in a highly stable and versatile *** study the modification of the interference pattern for different configurations of the superlattices and perform a proof-of-concept gas sensing experiment with enhanced *** approach offers a viable path towards broader adoption of nonlinear interferometers with correlated photons for imaging,interferometry,and spectroscopy.

关键词： spectroscopy nonlinear Nonlinear

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Utilization of Extrinsic Fabry-Perot Interferometers with Spectral Interferometric Interrogation for Microdisplacement Measurement

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Journal of Electronic Science and Technology 2020年第1期18卷 59-75页

作者： leonid Liokumovich Aleksandr Markvart Nikolai Ushakov Higher School of Applied Physics and Space Technologies Peter the Great St.Petersburg Polytechnic UniversitySt.Petersburg 195251

The paper presents a number of signal processing approaches for the spectral interferometric interrogation of extrinsic Fabry-Perot interferometers(EFPIs). The analysis of attainable microdisplacement resolution is performed and the analytical equations describing the dependence of resolution on parameters of the interrogation setup are derived. The efficiency of the proposed signal processing approaches and the validity of analytical derivations are supported by experiments. The proposed approaches allow the interrogation of up to four multiplexed sensors with attained resolution between 30 pm and 80 pm, up to three times improvement of microdisplacement resolution of a single sensor by means of using the reference interferometer and noisecompensating approach, and ability to register signals with frequencies up to 1 kHz in the case of 1 Hz spectrum acquisition rate. The proposed approaches can be used for various applications, including biomedical, industrial inspection, and others, amongst the microdisplacement measurement.

关键词： Absolute measurement dynamic measurement Fabry-Perot interferometer least-squares methods optical fiber sensors resolution analysis resolution enhancement sensor multiplexing spectral interferometry

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Computational fluid dynamics simulations of aerosol behavior in a high-speed (Heubach) rotating drum dustiness tester

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Particuology 2023年第1期72卷 68-80页

作者： Hongyu Chen Milind A.Jog leonid A.Turkevich Thermal-Fluids and Thermal Processing Lab Mechanical&Materials EngineeringUniversity of CincinnatiCincinnatiOH 45221-0072USA Division of Field Studies and Engineering(DFSE) National Institute for Occupational Safety&Health(NIOSH)The Centers for Disease Control&Prevention(CDC)Alice Hamilton Laboratory1090 Tusculum AvenueCincinnatiOH 45226USA

Potential exposure from hazardous dust may be assessed by evaluating the dustiness of the powders being *** is the tendency of a powder to aerosolize with a given input of *** we used computational fluid dynamics(CFD)to numerically investigate the flow inside the European Standard(EN15051)rotating drum dustiness tester during its *** present work extends those CFD studies to the widely used Heubach rotating *** flow characteristics are investigated within the Abe-Kondoh-Nagano k-epsilon turbulence model;the aerosol is incorporated via a Euler-Lagrangian multiphase *** air flow inside these drums consists of a well-defined axial jet penetrating relatively quiescent *** spreading of the Heubach jet results in a fraction of the jet recirculating as back-flow along the drum walls;at high rotation rates,the axial jet becomes *** flow behavior qualitatively differs from the stable EN15051 flow *** aerodynamic instability promotes efficient mixing within the Heubach drum,resulting in higher particle capture efficiencies for particle sizes d<80μm.

关键词： Rotating drum Dustiness Euler-Lagrangian multiphase AKN k-epsilon turbulence

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