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Effects of Haloxylon spp. of Different Age Classes on Vegetation Cover and Soil Properties on an Arid Desert Steppe in Iran

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Pedosphere 2019年第5期29卷 619-631页

作者： mahdieh EBRAHImI Fereshteh m0HAmmADI Akbar FAKHIREH Abolfazl BAmERI Department of Range and Watershed management University of ZabolZabol *** (Iran) Department of Range and Watershed management University of Gonbad KavosFalahi StreetBasirat BoulevardGonbad Kavos P.O. Box 163 (Iran) Department of Soil Sciences University of ZabolZabol *** (Iran)

In arid regions,afforestation has been considered as a method for ecological revival in terms of vegetation enrichment and soil *** this study,the effects of afforestation with Haloxylon *** vegetation cover and soil properties were measuredmples were collected at two depths(0-30 and 30-60 cm)under and between shrub *** succession significantly affected plant community *** total,16 species from 8families and 15 genera were observed along the afforestation successional *** species richness and diversity and vegetation cover increased slowly during the succession,and reached the maximum values in the area where Haloxylon had been planted for25 *** nutrient values gradually increased during the succession,and the levels of organic matter,total nitrogen,available potassium,and available phosphorus were significantly higher under Haloxylon canopies than between *** reduced soil pH under and between Haloxylon canopies during the succession,while soil electrical conductivity followed an opposite *** planting increased the silt content in the 0-30 cm soil *** results suggest that Haloxylon establishment plays an important role in the reestablishment of desertified ecosystems in arid regions.

关键词： afforestation succession arid land desertification control plant community soil amelioration species diversity species richness vegetation enrichment

A New Perspective of the Physical Processes Associated with the Clear-Sky Greenhouse Effect over High Latitudes

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Advances in Atmospheric Sciences 2004年第2期21卷 171-180页

作者： Zuohao CA0 Ronald E．STEWART m．K．YAU meteorologicalServiceofCanada，Ontario，Canada DepartmentofAtmosphericandOceanicSciences，mcGillUniversitymontreal，Quebec，Canada

The physical processes associated with the clear-sky greenhouse effect in the presence of water vapor are examined by including surface emissivity in the greenhouse effect formulation, and by introducing a new way to partition physical processes of the greenhouse effect. In this new framework, it is found that the clear-sky greenhouse effect is governed by three physical processes associated with (1) the temperature contrast between the surface and the atmosphere, (2) the interaction between the surface emissivity and the temperature contrast, and (3) the surface emissivity. The importance of the three physical processes is assessed by computing their vertical and spectral variations far the subarctic winter and summer standard atmosphere using the radiation model mODTRAN3 (moderate Resolution Transmittance code Version 3). The results show that the process associated with the temperature contrast between the surface and the atmosphere dominates over the other two processes in magnitude. The magnitude of this process has substantial variations in the spectral region of 1250 to 1880 cm-1 and in the far infrared region. Due to the low-level temperature inversion over the subarctic winter, there exists a negative contribution to the greenhouse trapping. The seasonal variations are, however, dominated by the processes associated with the interaction between the surface emissivity and the temperature contrast as well as the surface emissivity itself. The magnitudes of these two physical processes contributing to the greenhouse trapping over the subarctic winter are about 7 to 10 times of those over the subarctic summer, whereas the magnitude of the processes associated with the temperature contrast in the subarctic summer is only about 2 times of that in the subarctic winter.

关键词： greenhouse effect surface ernissivity physical processe high latitude seasonal variation

Glia-to-neuron reprogramming to the rescue?

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Neural Regeneration Research 2025年第5期20卷 1395-1396页

作者： Jack W.Hickmott Cindi m.morshead Department of Surgery University of TorontoTorontoONCanada Donnelly Centre for Cellular and Biomolecular Research TorontoONCanada Institute of Biomedical Engineering University of TorontoTorontoONCanada The KITE Research Institute Toronto Rehabilitation InstituteUniversity Health NetworkTorontoONCanada

Over the last two decades,the dogma that cell fate is immutable has been increasingly challenged,with important implications for regenerative *** brea kth rough discovery that induced pluripotent stem cells could be generated from adult mouse fibroblasts is powerful proof that cell fate can be *** exciting extension of the discovery of cell fate impermanence is the direct cellular reprogram ming hypothesis-that terminally differentiated cells can be reprogrammed into other adult cell fates without first passing through a stem cell state.

关键词： programming passing proof

Projected area and drag coefficient of high velocity irregular fragments that rotate or tumble

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Defence Technology（防务技术） 2017年第4期13卷 269-280页

作者： John F. moxnes 0yvind Fr0 yland Ivar J. 0ye Tom I. Brate Eva Friis Gard 0degardstuen Tallak H. Risdal Norwegian Defence Research Establishment Land Systems Division P.O. Box 25 2027 Kjeller Norway Nammo Raufoss AS P.O. Box 162 2831 Raufoss Norway HPVisTech AS Bj0rnstadgutua 21 2092 Minnesund Norway

3 degrees of freedom(DOF)exterior ballistic computer models are used in fragment studies to calculate individual trajectories of each fragment based on drag coefficient and the projected(presented)area in the direction of velocity of center of *** expectation of a randomly distributed projected area is commonly used for fragments that tumble(random rotation)during *** forecast a model where the expected drag coefficient is dependent of shape and mach *** or tumbling only affects the expected projected *** of projected areas during tumbling and rotation are *** examination of the data by mc Cleskey(1988)indicates that the volume of the fragment to the power of2/3 is a better parameter to characterize the drag coefficient of the fragments than the maximum projected *** simulations are used to verify results and to study projected area and drag coefficient of fragments.

关键词： Fragments Form factor mach number Drag coefficient Cauchy area Tumbling

Numerical simulations for G-Brownian motion

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Frontiers of mathematics in China 2016年第6期11卷 1625-1643页

作者： Jie YANG Weidong ZHA0 School of mathematics & Finance Institute Shandong University Jinan 250100 China

This paper is concerned with numerical simulations for the G- Brownian motion （defined by S. Peng in Stochastic Analysis and Applications, 2007, 541-567）. By the definition of the G-normal distribution, we first show that the G-Brownian motions can be simulated by solving a certain kind of Hamilton-Jacobi-Bellman （HJB） equations. Then, some finite difference methods are designed for the corresponding HJB equations. Numerical simulation results of the G-normal distribution, the G-Brownian motion, and the corresponding quadratic variation process are provided, which characterize basic properties of the G-Brownian motion. We believe that the algorithms in this work serve as a fundamental tool for future studies, e.g., for solving stochastic differential equations （SDEs）/stochastic partial differential equations （SPDEs） driven by the G-Brownian motions.

关键词： Nonlinear expectation G-Brownian motion G-normal distribu- tion Hamilton-Jacobi-Bellman (HJB) equation

Lattice-Boltzmann models for Heat Transfer

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Communications in Nonlinear Science and Numerical Simulation 1997年第4期2卷 212-216页

作者： Chenghai SUN,Zujun XU,Baoguo WANG &mengyu SHEN (Dept. of Engineering mechanics,Tsing- hua University,Beijing,1 0 0 0 84) Department of Engineering mechanics Tsinghua University Beijing 100084 China

A multispeed heat transfer lattice Boltzmann model is presented. The model possesses the perfect gas state equation with arbitrary special heat ratio. The macroscopic conservation equations are derived by the Chapman- Enskog *** one dimensional simulation for the sinusoidal energy distributions are compared with the theoretical results, showing good *** theoretical conductivity in the energy equation is in accordance with the simulations.

关键词： Lattice Boltzmann heat transfer perfect gas

Impact of Zika virus non-structural protein mutations on hippocampal damage

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Neural Regeneration Research 2025年第8期20卷 2307-2308页

作者： Larissa m.G.Cassiano Roney S.Coimbra Neurogenômica/Imunopatologia Instituto RenéRachouFiocruzBelo HorizonteBrazil Departamento de Bioquímica e Imunologia Instituto de Ciências BiológicasUniversidade Federal de Minas GeraisBelo HorizonteBrazil

The Zika virus(ZIKV),a member of the Flaviviridae family,attracted worldwide attention for its connection to severe neurological effects,notably microcephaly in newborns,first reported during the 2015 epidemic in ***,its impact goes beyond fetal and neonatal abnormalities,also affecting the central nervous system(CNS)in both children and adults,leading to enduring cognitive and behavioral impairments.

关键词： damage fetal neonatal

Classification of hypersurfaces with two distinct principal curvatures and closed mbius form in S^(m+1)

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Science China mathematics 2012年第7期55卷 1463-1478页

作者： LINLimiao GU0Zhen Departmentofmathematics EastChinaNormalUniversityShanghai200241China Departmentofmathematics YunnanNormalUniversityKunming650092China

Let x be an m-dimensional umbilic-free hypersurface in an （m＋1）-dimensional unit sphere Sm＋l （m≥3）. In this paper, we classify and explicitly express the hypersurfaces with two distinct princi- pal curvatures and closed mSbius form, and then we characterize and classify conformally flat hypersurfaces of dimension larger than 3.

关键词： moebius geometry principal curvature conformally fiat mSbius form

SOFTWARE-CONTROLLED SYSTEm OF ULTRA-PRECISION mACHINING AXISYmmETRIC ASPHERIC mIRROR

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Chinese Journal of mechanical Engineering 2006年第2期19卷 256-259页

作者： GU0 Yinbiao　 WEI Lizhen Department of mechanical and Electrical Engineering Xiamen UniversityXiamen 361005 China

In order to improve machining accuracy and efficiency, a software-controlled system of ultra-precision machining for axisymmetric aspheric mirror, using techniques of error compensation, remote transmission and modularization, is designed based on industrial PC, Windows 2000 work platform and Visual Basic 6.0. By experiments, this system realizes functions of ultra-precision machining, machining error compensation, remote data transmission and automatic data transformation among first machining, compensation machining and accuracy measurement. The actual application shows that error compensation improves machining accuracy, remote transmission improves machining efficiency while modularization avoids repeated work and improves design efficiency. Therefore, the system has met ultra-precision machining need for aspheric mirror.

关键词： Aspheric surface machining Error compensation Remote transmission Visual Basic