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A framework for considering ecological interactions for common non-timber forest product species:a case study of mountain date palm(Phoenix loureiroi Kunth)leaf harvest in South India

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Ecological Processes 2013年第1期2卷 212-220页

作者： Lisa Mandle Tamara Ticktin snehlata nath Siddappa Setty Anita Varg Botany Department University of Hawai'i at MānoaMānoaHawai'iUSA Ecology Evolution and Conservation Biology ProgramUniversity of Hawai'i at MānoaMānoaHawai'iUSA Keystone Foundation KotagiriTamil NaduIndia Ashoka Trust for Research in Ecology and the Environment BangaloreKarnatakaIndia Natural Capital Project Woods Institute for the EnvironmentStanford UniversityStanfordCAUSA.

Introduction:Many economically important non-timber forest products(NTFPs)come from widespread and common plant *** of these species often is assumed to be sustainable due to their ***,because of the ecological roles of common species,harvest may affect and be affected by ecological interactions at broader scales,which are rarely considered when evaluating the sustainability of *** use a case study of the mountain date palm(Phoenix loureiroi Kunth),harvested in South India to produce brooms,to present a conceptual framework illustrating how intensive harvest of a common species interacts with other anthropogenic management practices,plant-animal interactions and surrounding environmental ***:We apply this framework to understanding the impacts of mountain date palm harvest in the southern Western Ghats regions of the Indian states of Tamil Nadu and *** integrate data on the extent and levels of commercial harvest,local management practices,the ecological context in which harvest occurs,and research on harvest *** use this information to document the intensity and extent of mountain date palm harvest in the study area,identify the ecological implications of harvest,and demonstrate how a framework that considers harvest in the context of ecological communities and ecosystems is important for assessing the impacts of harvest of common NTFP ***:We show that mountain date palm leaves are heavily harvested from natural areas in the southern Western Ghats but that harvest levels have declined in recent *** date palm management and harvest occur within a network of ecological interactions,linking human activities to population-,community-,and ecosystem-level *** demonstrate that understanding the effects of return interval of anthropogenic fire,herbivory by wild animals and livestock,as well as the light environment in which harvest occurs are critical to assessing the sustainab

关键词： Non-timber forest product(NTFP) Western Ghats Savanna woodland Resource management Plant-animal interactions Fire Herbivory

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Perspectives on Higgs boson and supersymmetry

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Frontiers of physics 2013年第3期8卷 294-301页

作者： Pran nath Department of Physics Northeastern University Boston MA 02115-5005 USA

We review the recent discovery of the Higgs like particle at - 125 GeV and its implications for par- ticle physics models. Specifically the implications of the relatively high Higgs mass for the discovery of supersymmetry are discussed. Several related topics such as naturalness and supersymmetry, dark matter and unification are also discussed.

关键词： 125 GeV Higgs supersymmetry (SUSY) dark matter unification

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Propagation of a strong cylindrical shock wave in a rotational axisymmetric dusty gas with exponentially varying density

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Research in Astronomy and Astrophysics 2010年第5期10卷 445-460页

作者： Gorakh nath Department of Mathematics National Institute of Technology Raipur G. E. Road Raipur-492010 India

Non-similarity solutions are obtained for one-dimensional isothermal and adiabatic flow behind strong cylindrical shock wave propagation in a rotational ax-isymmetric dusty gas, which has a variable azimuthal and axial fluid velocity. The dusty gas is assumed to be a mixture of small solid particles and perfect gas. The equi-librium flow conditions are assumed to be maintained, and the density of the mixture is assumed to be varying and obeying an exponential law. The fluid velocities in the ambient medium are assumed to obey exponential laws. The shock wave moves with variable velocity. The effects of variation of the mass concentration of solid particles in the mixture, and the ratio of the density of solid particles to the initial density of the gas on the flow variables in the region behind the shock are investigated at given times. Also, a comparison between the solutions in the cases of isothermal and adia-batic flows is made.

关键词： shock wave — equation of state — stars: rotation — radiative transfer — interplanetary medium

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Efficient contraflow algorithms for quickest evacuation planning

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Science China Mathematics 2018年第11期61卷 2079-2100页

作者： Urmila Pyakurel Hari Nandan nath Tanka nath Dhamala Central Department of Mathematics Tribhuvan University Department of Mathematics Bhaktapur Multiple Campus Tribhuvan University

The optimization models and algorithms with their implementations on flow over time problems have been an emerging field of research because of largely increasing human-created and natural disasters *** an optimal use of transportation network to shift affected people and normalize the disastrous situation as quickly and efficiently as possible,contraflow configuration is one of the highly applicable operations research(OR)*** increases the outbound road capacities by reversing the direction of arcs towards the safe destinations that not only minimize the congestion and increase the flow but also decrease the evacuation time *** this paper,we sketch the state of quickest flow solutions and solve the quickest contraflow problem with constant transit times on arcs proving that the problem can be solved in strongly polynomial time O(nm^2(long n)~2)where n and m are number of nodes and number of arcs,respectively in the *** contraflow solution has the same computational time bound as that of the best min-cost flow ***,we also introduce the contraflow approach with load dependent transit times on arcs and present an efficient algorithm to solve the quickest contraflow problem *** the claim,our computational experiments on Kathmandu road network and on randomly generated instances perform very well matching the theoretical *** a sufficiently large number of evacuees,about double flow can be shifted with the same evacuation time and about half time is sufficient to push the given flow value with contraflow reconfiguration.

关键词： evacuation planning contraflow flow over time quickest flow load dependent transit time

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Development and experimental investigation of duplex turning process

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Advances in Manufacturing 2017年第2期5卷 149-157页

作者： Ravindra nath Yadav Department of Mechanical Engineering BBD National Institute of Technology and Management Lucknow 226028India

The aim of the present study was to develop a novel turning process with the simultaneous application of two cutting tools in place of a single cutting tool during machining of rotating surfaces. This process is referred to as duplex turning, and is used to eliminate the need for a secondary final cut operation following the turning process. To achieve this, a secondary （auxiliary） tool post is mounted on the cross slide of the centre lathe machine after fabrication. The secondary tool post is used to hold a secondary cutting tool that penetrates the workpiece from opposite side of the primary cutting tool to perform the finish cut operation during turn machining of the cylin- drical workpiece. The performance of the developed process was tested on AISI 1040 alloy steel, using two single point cutting tools made of high speed steel. The effects of cutting velocity, feed rate, primary depth of cut and secondary depth of cut were analyzed and discussed with regard to average surface roughness, and were also compared with normal turning process. From the results, it was concluded that duplex turning process was capable of providing better surface finishes compared to those generated by normal turning. It was also found that higher cutting velocity yielded better surface finishes within the determined ranges of the selected parameters.

关键词： Cutting Design of experiment Machining Surface roughness Turning

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Investigating the Dominant Source for the Generation of Gravity Waves during Indian Summer Monsoon Using Ground-based Measurements

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Advances in Atmospheric Sciences 2013年第1期30卷 153-166页

作者： Debashis nath 陈文 Center for Monsoon System Research Institute of Atmospheric PhysicsChinese Academy of Sciences

Over the tropics, convection, wind shear （i.e., vertical and horizontal shear of wind and/or geostrophic adjustment comprising spontaneous imbalance in jet streams） and topography are the major sources for the generation of gravity waves. During the summer monsoon season （June August） over the Indian subcontinent, convection and wind shear coexist. To determine the dominant source of gravity waves during monsoon season, an experiment was conducted using mesosphere-stratosphere-troposphere （MST） radar situated at Gadanki （13.5°N, 79.2°E）, a tropical observatory in the southern part of the Indian subcontinent. MST radar was operated continuously for 72 h to capture high-frequency gravity waves. During this time, a radiosonde was released every 6 h in addition to the regular launch （once daily to study low-frequency gravity waves） throughout the season. These two data sets were utilized effectively to characterize the jet stream and the associated gravity waves. Data available from collocated instruments along with satellite-based brightness temperature （TBB） data were utilized to characterize the convection in and around Gadanki. Despite the presence of two major sources of gravity wave generation （i.e., convection and wind shear） during the monsoon season, wind shear （both vertical shear and geostrophic adjustment） contributed the most to the generation of gravity waves on various scales.

关键词： convection wind shear gravity waves MST radar radiosonde

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Impedance Studies of La_2Mo_(2-x)Sn_xO(9-δ) Oxide Ion Conductors

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Acta Metallurgica Sinica(English Letters) 2013年第4期26卷 425-434页

作者： Lakhi nath Borah A.Pandey Department of Physics North Eastern Regional Institute of Science and Technology

A series of compounds La2Mo2-xSnxO9-6 （x=0-0.3） have been synthesized by solid-state reaction technique. Materials have been characterized by XRD, SEM, DSC and impedance study. In the temperature regime 520℃-590 ℃, the specimens with x〈0.05 have the conductivity higher than La2Mo2O9. Conductivity of Sn-doped compound decreases consistently with increasing Sn-doping, compared to the undoped compound both below and above phase transition, barring the specimens with x〈 0.05, where conductivity values remains almost same as that of undoped specimen in high temperature region. In the intermediate temperature regime （520℃-590℃）, the conductivity of doped compounds increases for x〈0.05 as compared to parent compound. Also, there is no indication of phase stabilization with Sn-doping in this compound even with the highest doping level, x=0.3. Electric modulus analysis suggests that thermally activated oxygen ion hopping mechanism is responsible for the conduction in Sn-doped compound.

关键词： Ionic conduction La2M0209 Oxide ion conductor Impedance spectroscopy Electric modulus

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Structural reliability analysis using a hybrid HDMR-ANN method

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Journal of Central South University 2017年第11期24卷 2532-2541页

作者： Bhaw nath Jha LI Hong-shuang Key Laboratory of Fundamental Science for National Defense-Advanced Design Technology of Flight Vehicles Nanjing University of Aeronautics and AstronauticsNanjing 210016China

A new hybrid method is proposed to estimate the failure probability of a structure subject to random parameters. The high dimensional model representation(HDMR) combined with artificial neural network(ANN) is used to approximate implicit limit state functions in structural reliability analysis. HDMR facilitates the lower dimensional approximation of the original limit states function. For evaluating the failure probability, a first-order HDMR approximation is constructed by deploying sampling points along each random variable axis and hence obtaining the structural responses. To reduce the computational effort of the evaluation of limit state function, an ANN surrogate is trained based on the sampling points from HDMR. The component of the approximated function in HDMR can be regarded as the input of the ANN and the response of limit state function can be regarded as the target for training an ANN surrogate. This trained ANN surrogate is used to obtain structural outputs instead of directly calling the numerical model of a structure. After generating the ANN surrogate, Monte Carlo simulation(MCS) is performed to obtain the failure probability, based on the trained ANN surrogate. Three numerical examples are used to illustrate the accuracy and efficiency of the proposed method.

关键词： high dimensional model representation structural reliability artificial neural network failure probability

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Impact of Planetary Wave Reflection on Tropospheric Blocking over the Urals–Siberia Region in January 2008

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Advances in Atmospheric Sciences 2016年第3期33卷 309-318页

作者： Debashis nath Wen CHEN Center for Monsoon System Research Institute of Atmospheric Physics Chinese Academy of Sciences

Planetary wave reflection from the stratosphere played a significant role in changing the tropospheric circulation pattern over Eurasia in mid-January 2008. We studied the 2008 event and compared with composite analysis （winters of 2002/2003, 200412005, 200612007, 200712008, 201012011 and 2011/2012）, when the downward coupling was stronger, by employing time-lagged singular value decomposition analysis on the geopotential height field. In the Northern Hemisphere, the geopo- tential fields were decomposed into zonal mean and wave components to compare the relative covariance patterns. It was found that the wavenumber 1 （WN1） component was dominant compared with the wavenumber 2 （WN2） component and zonal mean process. For the WNI field, the covariance was much higher （lower） for the negative （positive） lag, with a prominent peak around ＋15 days when the leading stratosphere coupled strongly with the troposphere. It contributed to the downward coupling due to reflection, when the stratosphere exhibited a partially reflective background state. We also analyzed the evolution of the WNI anomaly and heat flux anomaly, both in the troposphere and stratosphere, during January- March 2008. The amplitude of the tropospheric WN 1 pattern reached a maximum and was consistent with a downward wave coupling event influenced by the stratospheric WN1 anomaly at 10 hPa. This was consistent with the reflection of the WN1 component over Eurasia, which triggered an anomalous blocking high in the Urals-Siberia region. We further clarified the impact of reflection on the tropospheric WNI field and hence the tropospheric circulation pattern by changing the propagation direction during and after the event.

关键词： planetary wave reflection singular value decomposition (SVD) Eliassen-Palm (EP) flux blocking circulation

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Impact of Drought on Agriculture in the Indo-Gangetic Plain,India

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Advances in Atmospheric Sciences 2017年第3期34卷 335-346页

作者： Reshmita nath Debashis nath Qian LI Wen CHEN Xuefeng CUI Center for Monsoon System Research Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China School of System Sciences Beijing Normal UniversityBeijing 100875China Key Laboratory of Middle Atmosphere and Global Environmental Observations Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Meteorology and Climate Unit School of Mathematical ScienceUniversity College DublinDublin 4Ireland

In this study, we investigate the spatiotemporal characteristics of drought in India and its impact on agriculture during the summer season （April-September）. In the analysis, we use Standardized Precipitation Evapotranspiration Index （SPEI） datasets between 1982 and 2012 at the six-monthly timescale. Based on the criterion SPEI 〈 -1, we obtain a map of the number of occurrences of drought and find that the humid subtropical Upper Middle Gangetic Plain （UMGP） region is highly drought-prone, with an occurrence frequency of 40%-45%. This UMGP region contributes at least 18%-20% of India＇s annual cereal production. Not only the probability of drought, but the UMGP region has become increasingly drought-prone in recent decades. Moreover, cereal production in the UMGP region has experienced a gradual declining trend from 2000 onwards, which is consistent with the increase in drought-affected areas from 20%-25% to 50%-60%, before and after 2000, respectively. A higher correlation coefficient （-0.69） between the cereal production changes and drought-affected areas confirms that at least 50% of the agricultural （cereal） losses are associated with drought. While analyzing the individual impact of precipitation and surface temperature on SPEI at 6 month timescale [SPEI （6）] we find that, in the UMGP region, surface temperature plays the primary role in the lowering of the SPEI. The linkage is further confirmed by correlation analysis between SPEI （6） and surface temperature, which exhibits strong negative values in the UMGP region. Higher temperatures may have caused more evaporation and drying, which therefore increased the area affected by drought in recent decades.

关键词： drought agriculture SPEI Indo-Gangetic Plain temperature precipitation potential evapotranspiration

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