检索结果-南通市图书馆

Abandoned corrals: colonization and vegetation recovery of ephemeral habitats in silvo-pastoral systems

Journal of Plant Ecology 2020年第6期13卷 722-731页

作者： Arie Vinograd Eli Zaady jaime Kigel Institute of Plant Science and Genetics in Agriculture Robert H.Smith Faculty of AgricultureFood and EnvironmentHebrew University of JerusalemRehovot 76100Israel Department of Natural Resources Gilat Research CenterAROMobile Post Negev 85280Israel

Aims Management of silvo-pastoral systems in planted and natural forests in semi-arid Mediterranean regions often employs seasonal night corrals for animal *** management system changes the spatial distribution of animal excreta,resulting in a net transfer of soil mineral resources and their accumulation in the *** abandonment,corrals are colonized by ruderal species,becoming focal sources for their spread in the *** aimed to implement a rational management of seasonal sheep corrals based on a better understanding of the vegetation processes occurring in abandoned corrals,in order to alleviate their negative impact in the *** Relationships between temporal changes in the vegetation,the soil seed-bank and levels of soil nutrients were studied in a chronosequence of abandoned sheep corrals and compared with nearby reference plots in planted Eucalyptus forests grazed by sheep in the semi-arid North-Western Negev,*** region has a bi-seasonal Mediterranean climate,with high dominance of annual species in the grazing *** Findings Abandoned sheep corrals were colonized by seeds of ruderals originating in older abandoned *** successional changes occur at a slow rate,driven by the depletion of soil resources in the abandoned corrals,and were still in progress 20 years after *** were gradually replaced,first by taller grasses and followed by short grasses,but most forbs and particularly geophytes did not recover during this *** of the original herbaceous vegetation in the corrals was through seed dispersal from the surrounding vegetation,not from the original soil seed-bank remaining in the corrals after *** species in the grazed,planted forests behave as patch-tracking *** persistency depends on constant creation of new corrals compensating for the gradually dwindling populations in older abandoned corrals,and on the availability of dispersa

关键词： metapopulation ruderals seasonal grazing seed-bank sheep succession

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

GBP-WAHSN:A Group-Based Protocol for Large Wireless Ad Hoc and Sensor Networks

引用

Journal of Computer Science & Technology 2008年第3期23卷 461-480页

作者： jaime Lloret Miguel garcia Jesus Tomás Fernando Boronat Department of Communications Polytechnic University of ValenciaCamino Vera s/n46022ValenciaSpain

Grouping nodes gives better performance to the whole network by diminishing the average network delay and avoiding unnecessary message forwarding and additional overhead. Many routing protocols for ad-hoc and sensor networks have been designed but none of them are based on groups. In this paper, we will start defining group-based topologies, and then we will show how some wireless ad hoc sensor networks （WAHSN） routing protocols perform when the nodes are arranged in groups. In our proposal connections between groups are established as a function of the proximity of the nodes and the neighbor＇s available capacity （based on the node＇s energy）. We describe the architecture proposal, the messages that are needed for the proper operation and its mathematical description. We have also simulated how much time is needed to propagate information between groups. Finally, we will show a comparison with other architectures.

关键词： group-based protocol group-based architecture group-based routing algorithm large networks

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Incipient sexual isolation in Laupala cerasina： Females discriminate population-level divergence in acoustic characters

引用

Current Zoology 2012年第3期58卷 416-425页

作者： jaime L. GRACE Kerry L. SHAW Department of Biology University of Maryland College Park MD 20742 USA Department of Neurobiology and Behavior Cornel1 University Ithaca NY 14853 USA kls4@cornell.edu

Sexual selection by female choice can shape the evolution of male traits within populations, since the most attractive males experience an increase in fitness through elevated mating success. Speciation by sexual selection occurs when evolution in traits and preferences within populations causes differentiation among populations, such that females in alternative populations prefer sexual signals of their own population relative to others. Differentiated traits and preferences thereby play an active role in limiting gene flow between divergent populations. The effectiveness of differentiated preferences in maintaining differentiated male signals against the homogenizing effects of gene flow across populations will be limited by both the degree to which fe- males can discriminate against non-local males, and the breeding values of traits and preferences. Populations of the Hawaiian cricket Laupala cerasina have diverged in pulse rate, a sexually selected male signal, and female acoustic preference for pulse rate. Gene flow between neighboring populations may be reduced if migrants from sexually diverged populations experience re- duced mating success. We show that females discriminate among divergent songs characteristic of neighboring populations, that differences among populations in song and preference breed true in a common environment, and that mean preferences for each population closely match the mean pulse rates. Divergence in preference was observed only between populations that also dif- fered in song. Along with a striking ability to discriminate slight differences in song, correlated evolution of song and preference within populations could be a mechanism that promotes assortative mating among populations, thereby reducing gene flow, and leading to speciation in Laupala [Current Zoology 58 （3）： 416-425, 2012].

关键词： Sexual selection Phenotypic divergence Behavioral isolation Preference functions Speciation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Modeling egg development of the pest Clavipalpus ursinus （Coleoptera： Melolonthidae） using a temperature-dependent approach

引用

Insect Science 2012年第6期19卷 657-665页

作者： Andrea Escobar Rodrigo Gil Carlos Ricardo Bojaca jaime Jimenez Facultad de Ciencias Naturales e Ingenieria Departamento de Ciencias Basicas Universidad de Bogota Jorge Tadeo Lozano Bogota Direccion Tecnica de Sanidad Vegetal Instituto Colombiano Agropecuario Bogota Colombia

Predicting the population dynamics of insects in natural conditions is es- sential for their management or preservation, and temperature-dependent development models contribute to achieving this. In this research the effects of temperature and soil moisture content on egg development and hatching of Clavipalpus ursinus （Blanchard） were evaluated. The eggs were exposed to seven temperature treatments with averages of 7.2, 13.0, 15.5, 19.7, 20.6, 22.0 and 25.3~C, in combination with three soil moisture contents of 40%, 60% and 80%. A linear and two non-linear （Lactin and Briere） models were evaluated in order to determine the thermal requirements of this developmental stage. Temperature affected significantly the time of development and egg hatching, while no significant effect was observed for moisture content. Thermal requirements were set as： 7.2℃ for lower developmental threshold, 20.6℃ for optimum developmental threshold, 25.3℃ for maximum temperature and 344.83 degree-days for the thermal constant. The linear model described satisfactorily egg development at intermediate temperatures; nev- ertheless, a slightly better fit of the observed data was obtained with the Lactin model. Egg development took place inside a narrow range of temperatures. Consequently, an increment of soil temperature could generate a negative impact on the population size of this species or changes in its biological parameters.

关键词： egg development pests soil moisture thermal requirements

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Feeding on clean food?Potential effects of electric organ discharges by Torpedo spp.(Torpediniformes:Torpedinidae)on their trophically transmitted parasites

引用

Integrative Zoology 2022年第2期17卷 234-245页

作者： jaime PENADÉS-SUAY Tania REGACHO Francisco Javier AZNAR Marine Zoology Unit Cavanilles Institute of Biodiversity and Evolutionary BiologyUniversity of ValenciaValènciaSpain LAMNA Association for the study of elasmobranchs from the Valencian Community ValènciaSpain

Members of the Torpedinidae(torpedoes)and Hypnidae(coffin ray)use electric organ discharges(EOD)to stun or kill their prey before *** investigated whether EOD could also negatively affect the helminth larvae infecting these preys through a surrogate model:we applied electric discharges to individuals of blue whiting,Micromesistius poutassou,that harbored live larvae of *** mortality throughout a 6-h period was significantly higher in the treatment group,suggesting that EODs could significantly hamper helminth *** then tested whether torpedinids and hypnids(“strong-EOD”families)harbored species-poor helminth(cestode)assemblages compared with“weak-EOD”Torpediniformes(Narcidae and Narkidae)and other *** on comparisons on estimated species diversity and mean species richness of tapeworms at host individual level we found that(i)Torpediniformes had the lowest tapeworm diversity of all Batoidea orders;(ii)Torpedo *** had the lowest mean cestode richness at host individual level,and this could not be related to other host factors influencing cestode diversity in chondrichthyans,that is body size,trophic level or dietary ***,a preliminary comparison between“strong-EOD”and“weak-EOD”Torpediniformes did not detect clear differences of cestode ***,evidence supporting an unambiguous contribution of EODs to depauperate cestode assemblages requires further research.

关键词： Anisakis Batoidea cestode EOD behavior Torpediniform Torpedo

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A species-transport model for circulation in a leading-edge vortex

引用

Advances in Aerodynamics 2022年第1期4卷 762-779页

作者： Clara Giner-Morency jaime G.Wong Department of Mechanical Engineering University of AlbertaEdmontonT6G 1H9Canada

In this study,we propose a model to predict circulation growth along the span of a rotating wing,in which circulation transport is represented as species *** particles entering the vortex shear layer at the leading edge are initialized as vorticity-containing mass and are advected by the flow along the span.A circulation budget is presented,consisting of a generation and transport term,the latter derived from the vorticity transport equation,which leaves only two unknowns for the modeller to determine:the shear-layer thickness and the spanwise flow *** find that the model is insensitive to the value chosen for the shear-layer thickness,as varying the thickness by an order of magnitude only changes the output by a few ***,we use Bernoulli equation in a rotating coordinates system as a basic model for spanwise *** verify the accuracy of the model,the predicted circulation values are compared against experimental circulation values and show good agreement to measurements close to the axis of rotation,which corresponds to the spanwise locations at which the spanwise flow model best matches experimental *** is suggested,therefore,that this model produces accurate results subject to an appropriate spanwise flow model.

关键词： Leading-edge vortices Circulation transport Vortex growth Rotating wings

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Data-driven disturbance observer-based control: an active disturbance rejection approach

引用

Control Theory and Technology 2021年第1期19卷 80-93页

作者： Harvey Rojas-Cubides John Cortés-Romero jaime Arcos-Legarda Deparameno de Ingeniera Elétricay Electrónica Universidad Nacional de ColombiaAv.K30 No.45-03 Edif.453 Of.222BogoiáColombia Department of Mechatromies Engineering Universidad de San BuenaventuraBogotá.Colombia

In this paper,a data-driven method for disturbance estimation and rejection is *** proposed approach is divided into two stages:an inner stabilization loop,to set the desired reference model,together with an outer loop for disturbance estimation and *** by the active disturbance rejection control framework,the exogenous and endogenous disturbances are lumped into a lotal disturbance *** signal is estimaed using an on-line algorithm based on a data-driven predictor scheme,whose parameters are chosen Io salisfy high robustnessperformance *** above process is presented as a novel enhancement lo design a disturbance observer,w hich constitutes the main contribution of the *** addition,the control strategy is completely presented in discrete time,avoiding the use of discretization methods for its digital *** a case study,the voltage control of a DC-DC synchronous buck converter aflected by disturbances in the input voltage and the load is ***,experimental results that validate the proposed stralegy and some comparisons with the classical disturbance observer-based control are presented.

关键词： Active disturbance rejection control Data-driven disturbance observer Disturbance observer-based control Signal prediction

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A re-evaluation of the average chain length of lacustrine sedimentary n-alkanes as a paleoproxy on the Qinghai-Tibet Plateau

引用

Frontiers of Earth Science 2023年第4期17卷 905-919页

作者： Mingda WANG Qin LI jaime TONEY David HENDERSON Juzhi HOU School of Geography Liaoning Normal UniversityDalian 116029China Alpine Paleoecology and Human Adaptation(ALPHA)Group State Key Laboratory of Tibetan Plateau Earth SystemResources and EnvironmentInstitute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China School of Geographical and Earth Sciences University of GlasgowGlasgow G128QQScotlandUK CAS Center for Excellence in Tibetan Plateau Earth Sciences Beijing 100101China

Long-chain n-alkanes are one of the most common organic compounds in terrestrial plants and they are well-preserved in various geological archives.n-alkanes are relatively resistant to degradation and thus they can provide high-fidelity records of past vegetation and climate ***,previous studies have shown that the interpretation of n-alkane proxies,such as the average chain length(ACL),is often ambiguous since this proxy depends on more than one *** vegetation and climate could exert controls on the n-alkane ACL,and hence its interpretation requires careful consideration,especially in regions like the Qinghai-Tibet Plateau(QTP)where topography,biome type and moisture source are highly *** further evaluate the influences of vegetation and climate on the ACL in high-elevation lakes,we examined the n-alkane distributions of the surface sediments of 55 lakes across the *** results show that the ACL across a climatic gradient is significantly affected by precipitation,rather than by *** positive correlation between ACL and precipitation may be because of the effect of microbial degradation during ***,we suggest that more caution is needed in the interpretation of ACL data in different regions.

关键词： ACL average chain length n-alkanes leaf wax lake sediments Qinghai-Tibet Plateau

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Determination of Parameters of Time-delayed Embedding Algorithm Using Koopman Operator-based Model Predictive Frequency Control

引用

CSEE Journal of Power and Energy Systems 2021年第6期7卷 1140-1151页

作者： Xiawen Li Chetan Mishra Shichao Chen Yajun Wang jaime De La Ree Dominion Energy RichmondVAUSA Thorlabs Quantum Electronics. JessupMDUSA Department of Electrical and Computer Engineering Virginia Polytechnic Institute and State UniversityBlacksburgVAUSA

Power systems around the world have been registering a degenerating inertial response in view of the growth of inverter-based resources along with the withdrawal of conventional coal ***,there is a need for swift frequency support and its control,preferably by means of power electronic-interfaced storage devices,owing to their beneficial *** being particularly efficient,pragmatically,the traditional model-based non-linear control techniques are not highly popular in power system control design,primarily due to the complications faced in obtaining accurately suitable models for certain power system ***,the modelfree Koopman operator-based model predictive control(KMPC)has proven to be highly conducive for data-driven non-linear control *** principle behind KMPC is to change the coordinates in a manner to get an approximately linear model,which can then be controlled using a linear model predictive *** this study,we employed time-delayed embedding of measurements to reconstruct a new set of preferable coordinates,thereby suggesting an approach for finding the optimal number of time lags and the embedding dimensions which are the key parameters of this *** efficacy of this KMPC framework is established by adopting a decentralized frequency control problem through a decoupled synchronous machine system,which we proposed for both the Kundur two-area system as well as the IEEE 39-bus test system.

关键词： False nearest neighbors koopman operator model predictive control non-linear control time-delayed embedding

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The effect of ethylene inhibitors （AgNO3, AVG）, an ethyleneliberating compound （CEPA） and aeration on the formation of protocorm-like bodies of hybrid Cymbidium （Orchidaceae）

引用

Frontiers in Biology 2013年第6期8卷 606-610页

作者： jaime A. TEIXEIRA DA SILVA Faculty of Agriculture and Graduate School of Agriculture Kagawa University Miki-cho Kagawa 761-0795 Japan Present address. P O. Box 7 Miki-cho post office Ikenobe 3011-2 Kagawa-ken 761-0799 Japan

Protocorm-like bodies （PLBs） or thin cell layers （TCLs） derived from PLBs of hybrid Cymbidium Twilight Moon ＇Day Light＇ can induce new or neo-PLBs on Teixeira Cymbidium （TC） medium, which contains 0.1 mg/L a- naphthaleneacetic acid, 0.1 mg/L kinetin, 2 g/L tryptone and 20 g/L sucrose, and is solidified with 8 g/L Bacto agar. This study aimed to assess the response ofneo-PLB formation to an ethylene-liberating compound （2-chloroethylphosphonic acid （CEPA））, to two ethylene inhibitors （silver nitrate （AgNO3） and aminoethoxyvinylglycine （AVG））, and to aeration （made possible by using Milliseal~ or autoclaved filter paper）. AgNO3 at 1 or 2 mg/L in TC medium significantly increased the fresh weight of PLBs while 1 mg/L of AgNO3 also showed a significant increase in the number ofneo-PLB from both half-PLBs and from tTCLs. In contrast, AVG and CEPA inhibited neo-PLB formation. Neo-PLB formation from half-PLB or TCL explants in the presence of aeration resulted in significantly lower neo-PLB weight. The use of AgNO3 and aeration are alternative means to mass produce neo-PLBs for micropropagation purposes.

关键词： AgNO3 AVG CEPA PLB Teixeira Cymbidium (TC) medium

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：