检索结果-南通市图书馆

Rehabilitation of Semi-Arid Grasslands through the Perennialization of Lots by Implementing Perennial Forage Exotic Grass

引用

Phyton-International Journal of Experimental Botany 2024年第8期93卷 2115-2125页

作者： Delfina Arancio Sidoti juan manuel zeberio Guadalupe Peter Universidad Nacional de Río Negro Sede AtlánticaCEANPaViedma8500Argentina Consejo Nacional de Investigaciones Científicas y Técnicas CONICETCABABuenos Aires1425Argentina Chacra Experimental Patagones Ministerio de Desarrollo Agrario de la Provincia de Buenos AiresCarmen de Patagones8504Argentina

Argentina is the country with the highest proportion of arid and semi-arid ecosystems in Latin *** the rangelands of Southwestern Buenos Aires(Patagones Department),there is a clear advancement of the agricultural frontier to the detriment of the native forest in this *** to rainfall variation and seed acquisition,Thinopyrum ponticum is cultivated as a forage perennial crop in this *** objective was to evaluate the performance of *** as a facilitating crop for the medium-term rehabilitation of natural grasslands in semi-arid *** working hypotheses were that:1)native perennial grass cover increases over the years and 2)diversity and specific richness of the vegetation are enhanced by the duration of Tall Wheatgrass *** were collected from commercial plots where *** was shown:recent implantation(5–8 years,RI);medium implantation(13–15 years,MI);and old implantation(20–22 years,OI).Thirty-four species were identified and classified into seven functional groups:Annual grasses,annual herbs,perennial herbs,exotic perennial herbs,perennial forage grasses,exotic perennial forage grasses,perennial forage exotic grasses,and nonforage perennial *** ponticum’s total cover was between RI and *** cover,species richness,and Shannon-Weaver diversity index showed no differences among *** forage grasses exhibited higher cover values in sites with greater implantation age and annual grasses showed the opposite *** results indicated that *** does not invade the sampled plots and enhances the colonization of the planted plots by perennial forage native ***,even though the herbaceous cover had been recovered,the woody layer which could provide environmental services and specific values for conservation was not.

关键词： Wheatgrass clearing vegetation monte Thinopyrum ponticum

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

Rehabilitation of degraded areas in northeastern Patagonia, Argentina: Effects of environmental conditions and plant functional traits on performance of native woody species

引用

Journal of Arid Land 2020年第4期12卷 653-665页

作者： juan M zeberio Carolina A PÉREZ National University of Río Negro Atlantic HeadquartersCenter for Environmental Studies from Norpatagonia(CEANPa)Viedma 8500Argentina National Council of Scientific and Technical Research(CONICET) Viedma 8500Argentina Ecological and Environmental Systems Research Laboratory(LISEA) National University of La PlataLa Plata 1900Argentina

Degradation processes affect a vast area of arid and semi-arid lands around the world and damage the environment and people′s health. Degradation processes are driven by human productive activities that cause direct and indirect effects on natural resources, such as species extinction at regional scale, reduction and elimination of vegetation cover, soil erosion, etc. In this context, ecological rehabilitation is an important tool to recover key aspects of the degraded ecosystem. Rehabilitation trials rely on the use of native plant species with characteristics that allow them to obtain high survival and growth rates. The aim of this work was to assess the survival and growth of native woody species in degraded areas of northeastern Patagonia and relate them to plant functional traits and environmental variables. We observed high early and late survival rates, and growth rates in Prosopis flexuosa DC. var. depressa F.A. Roig and Schinus johnstonii F.A. Barkley, and low values in Condalia microphylla Cav. and Geoffroea decorticans(Gillies ex Hook. & Arn.) Burkart. Early survival rates were positively associated with specific leaf area(SLA) and precipitation, but negatively associated with wood density, the maximum mean temperature of the warmest month and the minimum mean temperature of the coldest month. Late survival rates were positively associated with SLA and soil organic matter, but negatively associated with plant height and precipitation. The temperature had a positive effect on late survival rates once the plants overcame the critical period of the first summer after they were transplanted to the field. Prosopis flexuosa and S. johnstonii were the most successful species in our study. This could be due to their functional traits that allow these species to acclimatize to the local environment. Further research should focus on C. microphylla and G. decorticans to determine how they relate to productive conditions, acclimation to environmental stress, auto-eco

关键词： arid lands Condalia microphylla Geoffroea decorticans Prosopis flexuosa Schinus johnstonii survival rates height growth basal diameter growth

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

Models and observations of sunspot penumbrae

引用

Science China(Physics,Mechanics & Astronomy) 2009年第11期52卷 1670-1677页

作者： BORRERO juan manuel Max Planck Institut fr Sonnensystemforschung Max Planck Strasse 2 D 37191 Katlenburg-Lindau Germany

The mysteries of sunspot penumbrae have been under an intense scrutiny for the past 10 years. During this time, some models have been proposed and refuted, while the surviving ones had to be modified, adapted and evolved to explain the ever-increasing array of observational constraints. In this contribution I will review two of the present models, emphasizing their contributions to this field, but also pinpointing some of their inadequacies to explain a number of recent observations at very high spatial resolution (0.32 ). To help explaining these new observations I propose some modifications to each of those models. These modifications bring those two seemingly opposite models closer together into a general picture that agrees well with recent 3D magneto-hydrodynamic simulations.

关键词： sunspots magnetic fields spectropolarimetry magnetohydrodynamics

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

Virtual Conductance Based Cascade Voltage Controller for VSCs in Islanded Operation Mode

引用

Journal of Modern Power Systems and Clean Energy 2022年第6期10卷 1704-1713页

作者： Francisco Jesús Matas-Díaz manuel Barragán-Villarejo juan Carlos Olives-Camps juan manuel Mauricio JoséMaría Maza-Ortega Department of Elec‐trical Engineering Universidad de SevillaSeville 41092Spain

Voltage source converters have become the main enabler for the integration of distributed energy resources in *** the case of islanded operation,these devices normally set the amplitude and frequency of the network voltage by means of a cascade controller composed of an outer voltage control loop and an inner current control *** strategies to compute the gains of both control loops have been proposed in the literature in order to obtain a fast and decoupled response of the voltages at the point of common *** paper proposes an alternative and simple methodology based on the introduction of a virtual conductance in the classic cascade *** strategy allows to design each control loop independently,obtaining a closed-loop response of a first-order *** this way,the gains of each control loop are easily derived from the parameters of the LC coupling filter and the desired closed-loop time ***,a state observer is included in the controller to estimate the inductor current of the LC filter in order to reduce the number of required measurements.A laboratory testbed is used to validate and compare the proposed *** experimental results demonstrate the effectiveness of the proposal both in steady-state and transient regimes.

关键词： Voltage source converter microgrid cascade controller virtual conductance

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

Hot corrosion mechanism of yttria-stabilized zirconia powder in the presence of molten Na_(2)SO_(4)+V_(2)O_(5) salts

引用

Rare Metals 2021年第5期40卷 1307-1316页

作者： Jhonattan De la Roche juan manuel Alvarado-Orozco Alejandro Toro Tribology and Surfaces Group Universidad Nacional de ColombiaMedellin 050041Colombia Centro de Ingeniena y Desarrollo Industrial-CIDESI Queretaro 76125Mexico Consorcio de Manufactura Aditiva-CONMAD Queretaro 76125Mexico

The hot corrosion behavior of yttria-stabilized zirconia(YSZ)powder specimens exposed to Na_(2)SO_(4)/V_(2)O_(5) salts mixtures at high temperature was *** tests were carried out at 1000℃ for 10 h,the salt concentrations varied from 0.1 wt%to 1.00 wt%,and the Na_(2)SO_(4)/V_(2)O_(5) mass ratios were between 0.20 and 0.44 following a factorial design 22.X-ray diffraction(XRD)analyses of the tested samples showed with a confidence of95%that the mixture composed of 32 wt%Na_(2)SO_(4)+68 wt%V_(2)O_(5),and 1.00 wt% salt concentration led to high destabilization of the t’-YSZ phase and formation of YVO_(4) products.A second set of experiments were conducted to assess the influence of temperature on the hot corrosion response of the YSZ in the range between 490 and 1100℃.Thermogravimetric analysis(TGA)experiments and Rietveld adjustments of XRD patterns showed that the mass loss of the samples varied with testing temperature and also that the major destabilization of tetragonal phase occurred at 900℃.

关键词： Hot corrosion Molten salts Yttria-stabilized zirconia Thermal barrier coatings

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

HEART RATE VARIABILITY DURING HIGH-INTENSITY EXERCISE

引用

Journal of Systems Science & Complexity 2013年第1期26卷 104-116页

作者： SARMIENTO Samuel GARCIA-MANSO juan manuel MARTIN-GONZALEZ juan manuel VA-AMONDE Diana CALDERóN Javier DA SILVA-GRIGOLETTO Marzo Edir Department of Physical Education University of Las Palmas de Gran Canaria Spain. Physics Department University of Las Palmas de Gran Canaria Spain. Department of Morphological Sciences School of Medicine University of Cdrdoba Spain. Physical Activity Sciences Faculty Polytechnic University of Madrid Spain. Andalusian Centre of Sports Medicine Cdrdoba Spain.

The aim of this paper is to describe and analyse the behaviour of heart rate variability(HRV)during constant-load,high-intensity exercise using a time frequency analysis(Wavelet Transform).Eleven elite cyclists took part in the study(age:18.6±3.0 years;VO_(2max):4.88±0.61 litres·min^(-1)).Initially,all subjects performed an incremental cycloergometer test to determine load power in a constant load-test(379.55±36.02 W;89.0%).HRV declined dramatically from the start of testing(p<0.05).The behaviour of power spectral density within the LF band mirrored that of total energy,recording a significant decrease from the outset LF peaks fell rapidly thereafter,remaining stable until the end of the ***-VHF fell sharply in the first 20 to 30 *** relative weighting(%) of HF-VHF was inverted with the onset of fatigue,[1.6%at the start,7.1(p<0.05) at the end of the first phase,and 43.1%(p<0.05) at the end of the test].HF-VHF_(peak) displayed three phases:a moderate initial increase,followed by a slight fall,thereafter increasing to the end of the *** LF/HF-VHF ratio increased at the start,later falling progressively until the end of the first phase and remaining around minimal values until the end of the test.

关键词： Cycling heart rate variability wavelet.

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

BASKETBALL SCORING IN NBA GAMES:AN EXAMPLE OF COMPLEXITY

引用

Journal of Systems Science & Complexity 2013年第1期26卷 94-103页

作者： DE SA GUERRA Yves MARTíN GONZALEZ juan manuel SARMIENTO MONTESDEOCA Samuel RODRIGUEZ RUIZ David ARJONILLA LóPEZ Nieves GARCíA-MANSO juan manuel Departament of Phisical Education University of Las Palmas de Gran Canaria Departament of Physics University of Las Palmas de Gran Canaria

Scoring in a basketball game is a highly dynamic, non-linear process. NBA teams try to be more and more competitive each season. For instance, they incorporate into their rosters the best players in the world. This and other mechanisms concur to make the scoring process in NBA games exciting and rarely predictable. This paper is to study the behavior of timing and scoring in basketball gaines. The authors analyze all the games in five NBA regular seasons （2005-06, 2006-07, 2007-08, 2008-09, 2009-10）, for a total of 6150 games. Scoring does not behave uniformly; therefore, the authors also analyze the distributions of the differences in points in the basketball games. To further analyze the behavior of the tail of the distribution, the authors also carry out a semilog-plot and a log-log plot to verify whether this trend approaches a Poisson distribution or a PL. This paper reveals different areas of behavior related to the score, with specific instances of time that could be considered tipping points of the game. The presence of these critical points suggests that there are phase transitions where the dynamic scoring of the games varies significantly.

关键词： Complexity NBA non-linear Poisson power law.

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

Hepatopulmonary syndrome: What we know and what we would like to know

引用

World Journal of Gastroenterology 2016年第25期22卷 5728-5741页

作者： Israel Grilo-Bensusan juan manuel Pascasio-Acevedo Digestive Diseases Department HAR écija APS Bajo Guadalquivir Unit for the Clinical Management of Digestive Diseases IBIS CIBERehd Virgen del Rocío University Hospital

Hepatopulmonary syndrome (HPS) is characterized by abnormalities in blood oxygenation caused by the presence of intrapulmonary vascular dilations (IPVD) in the context of liver disease, generally at a cirrhotic stage. Knowledge about the subject is still only partial. The majority of the information about the etiopathogenesis of HPS has been obtained through experiments on animals. Reported prevalence in patients who are candidates for a liver transplantation (LT) varies between 4% and 32%, with a predominance of mild or moderate cases. Although it is generally asymptomatic it does have an impact on their quality of life and survival. The diagnosis requires taking an arterial blood gas sample of a seated patient with alveolar-arterial oxygen gradient (AaO2) ≥ 15 mm Hg, or ≥ 20 mm Hg in those over 64 years of age. The IPVD are identified through a transthoracic contrast echocardiography or a macroaggregated albumin lung perfusion scan (99mTc-MAA). There is currently no effective medical treatment. LT has been shown to reverse the syndrome and improve survival rates, even in severe cases. Therefore the policy of prioritizing LT would appear to increase survival rates. This paper takes a critical and clinical look at the current understanding of HPS, as well as the controversies surrounding it and possible future research.

关键词： Hepatopulmonary syndrome Liver cirrhosis Liver transplantation Contrast echocardiography Macroaggregated albumin lung perfusion scan

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

Oxidative effects of glyphosate on the lipophobic intracellular environment in the microalgae Chlorella vulgaris

引用

BIOCELL 2022年第3期46卷 795-802页

作者： juan manuel OSTERA SUSANA PUNTARULO GABRIELA MALANGA Fisicoquímica Facultad de Farmacia y BioquímicaUniversidad de Buenos AiresBuenos AiresCP 1113Argentina Instituto de Bioquímica y Medicina Molecular(IBIMOL) CONICET-Universidad de Buenos AiresBuenos AiresCP 1113Argentina

The studied hypothesis is that the herbicide glyphosate(GLY)can affect the oxidative balance in the hydrophobic intracellular medium in non-target Chlorella vulgaris *** GLY and RoundUp(RUP)supplementation,affected the growth profile.A significant 42%decrease in the cellular biomass in stationary(St)phase was observed in cultures supplemented with either 5μM of GLY or RUP,as compared to control *** treatment with 0.3μM of GLY generated non-significant effects on the oxidation rate of 2’,7’dichlorofluorescein diacetate(DCFH-DA),neither in exponential(Exp)nor in St phase of development,as compared to control ***,the treatment with either 5μM GLY or 0.3 and 5μM RUP lead to a significant decrease in the DCFH-DA oxidation rate,as compared to control *** lipid radical(LR●)generation rate,detected by Paramagnetic Resonance Spectroscopy(EPR),was significantly increased in the presence of RUP,in Lag and Exp phase of *** non-enzymatic antioxidants,α-Tocopherol(α-T)andβ-Carotene(β-C),are aimed to protect membranes against the damage produced by the radical *** content ofβ-C was not significantly affected,as compared to control cultures,by any of the treatments,in both growth phases of cellular *** content ofα-T was significantly decreased by the supplementation with either 0.3 or 5μM of RUP or 5μM *** LR●/α-T ratio,used as indicator of the oxidative balance in the hydrophobic cellular media,was significantly different between samples obtained from control and RUP-exposed microalgae in both,Exp and St phase of development,with either 0.3 or 5μM *** data presented here showed evidence that suggested that oxidative balance in the hydrophobic environment was affected by either GLY or RUP.

关键词： 2’,7’dichlorofluorescein diacetate oxidation rate Lipid soluble antioxidants Round up Redox balance

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

Improved organs at risk segmentation based on modified U‐Net with self‐attention and consistency regularisation

引用

CAAI Transactions on Intelligence Technology 2024年第4期9卷 850-865页

作者： Maksym Manko Anton Popov juan manuel Gorriz Javier Ramirez Electronic Engineering Department Igor Sikorsky Kyiv Polytechnic InstituteKyivUkraine Department of Signal Theory Telematics and CommunicationsUniversity of GranadaGranadaSpain

Cancer is one of the leading causes of death in the world,with radiotherapy as one of the treatment *** planning starts with delineating the affected area from healthy organs,called organs at risk(OAR).A new approach to automatic OAR seg-mentation in the chest cavity in Computed Tomography(CT)images is *** proposed approach is based on the modified U‐Net architecture with the ResNet‐34 encoder,which is the baseline adopted in this *** new two‐branch CS‐SA U‐Net architecture is proposed,which consists of two parallel U‐Net models in which self‐attention blocks with cosine similarity as query‐key similarity function(CS‐SA)blocks are inserted between the encoder and decoder,which enabled the use of con-sistency *** proposed solution demonstrates state‐of‐the‐art performance for the problem of OAR segmentation in CT images on the publicly available SegTHOR benchmark dataset in terms of a Dice coefficient(oesophagus-0.8714,heart-0.9516,trachea-0.9286,aorta-0.9510)and Hausdorff distance(oesophagus-0.2541,heart-0.1514,trachea-0.1722,aorta-0.1114)and significantly outperforms the *** current approach is demonstrated to be viable for improving the quality of OAR segmentation for radiotherapy planning.

关键词： 3‐D computer vision deep learning deep neural networks image segmentation medical image processing object segmentation

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：