检索结果-南通市图书馆

Controlled drainage in the Nile River delta of Egypt:a promising approach for decreasing drainage off-site effects and enhancing yield and water use efficiency of wheat

引用

Journal of Arid Land 2023年第4期15卷 460-476页

作者： mohamed K EL-GHANNAm Fatma WASSAR Sabah mORSY mohamed HAFEZ Chiter m PARIHAR Kent O BURKEY Ahmed m ABDALLAH Soil Water and Environment Research InstituteAgricultural Research CenterGiza 12112Egypt Higher Institute of Water Sciences and Techniques of Gabès University of GabèsGabès 6072Tunisia Institute of Arid Regions Medenine 4119Tunisia Crop Science Department Faculty of AgricultureDamanhour UniversityDamanhour 22516Egypt Land and Water Technologies Department Arid Lands Cultivation Research InstituteCity of Scientific Research and Technological ApplicationsNew Borg El-Arab 21934Egypt Indian Council of Agricultural Research(ICAR)-Indian Agricultural Research Institute(IARI) New Delhi 110012India United States Department of Agriculture(USDA)-Agricultural Research Services(ARS) Plant Science Research UnitNorth Carolina 27607USA Natural Resources and Agricultural Engineering Department Faculty of AgricultureDamanhour UniversityDamanhour 22516Egypt

North Africa is one of the most regions impacted by water *** implementation of controlled drainage(CD)in the northern Nile River delta of Egypt is one strategy to decrease irrigation,thus alleviating the negative impact of water *** study investigated the impacts of CD at different levels on drainage outflow,water table level,nitrate loss,grain yield,and water use efficiency(WUE)of various wheat *** levels of CD,i.e.,0.4 m below the soil surface(CD-0.4)and 0.8 m below the soil surface(CD-0.8),were compared with subsurface free drainage(SFD)at 1.2 m below the soil surface(SFD-1.2).Under each drainage treatment,four wheat cultivars were grown for two growing seasons(November 2018–April 2019 and November 2019–April 2020).Compared with SFD-1.2,CD-0.4 and CD-0.8 decreased irrigation water by 42.0%and 19.9%,drainage outflow by 40.3%and 27.3%,and nitrate loss by 35.3%and 20.8%,*** CD treatments,plants absorbed a significant portion of their evapotranspiration from shallow groundwater(22.0%and 8.0%for CD-0.4 and CD-0.8,respectively).All wheat cultivars positively responded to CD treatments,and the highest grain yield and straw yield were obtained under CD-0.4 *** the initial soil salinity as a reference,the soil salinity under CD-0.4 treatment increased two-fold by the end of the second growing season without negative impacts on wheat *** the drainage system by raising the outlet elevation and considering shallow groundwater contribution to crop evapotranspiration promoted water-saving and *** responses could be obtained based on the different plant tolerance to salinity and water stress,crop characteristics,and growth ***-specific soil salinity management practices will be required to avoid soil salinization due to the adoption of long-term shallow groundwater in Egypt and other similar agroecosystems.

关键词： drainage ratio nitrate loss water use efficiency yield soil salinity Nile River delta

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

A new cluster validity index using maximum cluster spread based compactness measure

引用

International Journal of Intelligent Computing and Cybernetics 2016年第2期9卷 179-204页

作者： m.Arif Wani Romana Riyaz Postgraduate Department of Computer Science University of KashmirSrinagarIndia

Purpose-The most commonly used approaches for cluster validation are based on indices but the majority of the existing cluster validity indices do not work well on data sets of different *** purpose of this paper is to propose a new cluster validity index(ARSD index)that works well on all types of data ***/methodology/approach-The authors introduce a new compactness measure that depicts the typical behaviour of a cluster where more points are located around the centre and lesser points towards the outer edge of the cluster.A novel penalty function is proposed for determining the distinctness measure of *** linear search-algorithm is employed to evaluate and compare the performance of the five commonly known validity indices and the proposed validity *** values of the six indices are computed for all nc ranging from(nc_(min),nc_(max))to obtain the optimal number of clusters present in a data *** data sets used in the experiments include shaped,Gaussian-like and real data ***-Through extensive experimental study,it is observed that the proposed validity index is found to be more consistent and reliable in indicating the correct number of clusters compared to other validity *** is experimentally demonstrated on 11 data sets where the proposed index has achieved better ***/value-The originality of the research paper includes proposing a novel cluster validity index which is used to determine the optimal number of clusters present in data sets of different complexities.

关键词： Clustering Cluster analysis Cluster validity Compactness measure Optimal number Distinctness measure

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

Effect of fibre orientations on the mechanical properties of kenaf–aramid hybrid composites for spall-liner application

引用

Defence Technology（防务技术） 2016年第1期12卷 52-58页

作者： R.YAH AYA S.m.SAPUAN m.JAWAID Z.LEmAN E.S.ZAINUDIN Department of mechanical and manujacturing Engineering Universiti Putra Malaysia 43400 UPM Serdang Selangor Malaysia Science and Technology Research Institutejbr Dejence (STRIDE) 43000 Kajang Selangor Malaysia Laboratory of Biocomposite Technology Institute of Tropical Forestry and Forest Products (INTROP) Universiti Putra Malaysia 43400 UPM Serdang Selangor Malaysia Aerospace manujacturing Research Centre (AmRC) Faculty of Engineering Universiti Putra Malaysia 43400 UPM Serdang Selangor Malaysia Department of Chemical Engineering College of Engineering King Saud University Riyadh Saudi Arabia

This paper presents the effect of kenaf fibre orientation on the mechanical properties of kenaf–aramid hybrid composites for military vehicle's spall liner application. It was observed that the tensile strength of woven kenaf hybrid composite is almost 20.78% and 43.55% higher than that of UD and mat samples respectively. Charpy impact strength of woven kenaf composites is 19.78% and 52.07% higher than that of UD and mat kenaf hybrid composites respectively. morphological examinations were carried out using scanning electron microscopy. The results of this study indicate that using kenaf in the form of woven structure could produce a hybrid composite material with high tensile strength and impact resistance properties.

关键词：芳纶复合材料材料力学性能纤维取向红麻应用剥落编织复合材料扫描电子显微镜

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

Design optimization of a slotless Pm brushless motor with helical edge wound laminations for rim driven thrusters

引用

High Technology Letters 2010年第1期16卷 70-79页

作者： Sharkh S m Lai S H School of Engineering Sciences University of Southampton Highfield Southampton SO17 1BJ UK Applied materials South East Asia Pte Ltd Changi Business Park Vista 486051 Singapore

This paper discusses the analysis and design of a very thin slotless permanent magnet （Pm） brushless motor whose stator laminations are manufactured from a single strip of steel that is edge wound into a spiral （like a ＂Slinky＂） and then fitted over the windings that are preformed on the outside surface of a non-conducting former. Analytical and finite element analysis （FEA） are used to determine the con- strained optimum dimensions of a motor used to drive a rim driven thruster in which the motor rotor is fit- ted onto the rim of the propeller and the stator is encapsulated in the thin Kort nozzle of the thruster. The paper describes the fabrication of a demonstrator motor and presents experimental results to validate the theoretical calculations. Experimental motor performance results are also reported and compared with those of a slotted motor that fits within the same active radial dimensions as the slotless motor. The slotless motor, which has longer active length and endwindings, and thicker magnets than the slotted motor, was found to be less efficient and more expensive （prototype cost） than the slotted machine.

关键词： slotless brushless permanent magnet (Pm) motor edge-wound laminations rim driven thruster

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

ON THE INVARIANT SUBmANIFOLDS OF RIEmANNIAN PRODUCT mANIFOLD

引用

Acta mathematica Scientia 2004年第4期24卷 549-558页

作者： m.Atceken S.Keles Department of mathematics Faculty of Arts and Sciences Inonu University 44069 Malatya/TURKEYDepartment of Mathematics Faculty of Arts and Sciences Inonu University 44069 Malatya/TURKEY

In this paper, the vertical and horizontal distributions of an invariant sub-manifold of a Riemannian product manifold are discussed. An invariant real space form in a Riemannian product manifold is researched. Finally, necessary and sufficient conditions are given on an invariant submanifold of a Riemannian product manifold to be a locally symmetric and real space form.

关键词： Riemannian product manifold mixed geodesic submanifold real space form and almost Riemannian product structure

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

Dynamic analysis of a fractional order system

引用

International Journal of Biomathematics 2015年第6期8卷 157-173页

作者： m. Javidi N. Nyamoradi Faculty of mathematical SciencesUniversity of Tabriz Tabriz Iran Department of mathematics Faculty of Sciences Razi University 67149 Kermanshah Iran

In this paper, we investigate the dynamical behavior of a fractional order phytoplankton- zooplankton system. In this paper, stability analysis of the phytoplankton zooplankton model （PZm） is studied by using the fractional Routh-Hurwitz stability conditions. We have studied the local stability of the equilibrium points of PZm. We applied an efficient numerical method based on converting the fractional derivative to integer derivative to solve the PZm.

关键词： Phytoplankton-zooplankton model Routh-Hurwitz stability conditions numerical simulation.

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

How Reliable Are Surface Tension Data?

引用

Accounts of materials Research 2022年第9期3卷 894-899页

作者： Bernette m.Oosterlaken Gijsbertus de With Laboratory of Physical Chemistry Department of Chemical Engineering and ChemistryEindhoven University of Technology5600 MB EindhovenThe Netherlands

Surface(Gibbs or Helmholtz)energy is of importance in many areas of science and technology but notoriously difficult to *** one time,it was thought that cleavage experiments could yield proper surface energy values because surface energy is related to the(reversible)energy needed to create a unit area of *** reported in his classic paper,Obreimoff1 was only in a few cases able,after“healing”a cleavage crack,to measure a similar cleavage energy along the same plane as needed in the initial experiment.

关键词： surface. experiment. measure.

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

Stricter national standards are required for credentialing of endoscopic-retrograde-cholangiopan-creatography in the United States

引用

World Journal of Gastroenterology 2019年第27期25卷 3468-3483页

作者： mitchell S Cappell David m Friedel Division of Gastroenterology and Hepatology William Beaumont HospitalRoyal OakMI 48073United States Oakland University William Beaumont School of medicine William Beaumont HospitalMI 48073United States Division of Gastroenterology New York University Winthrop Medical CenterMineolaNY 11501United States

Endoscopic-retrograde-cholangiopancreatography(ERCP) is now a vital modality with primarily therapeutic and occasionally solely diagnostic utility for numerous biliary/pancreatic disorders. It has a significantly steeper learning curve than that for other standard gastrointestinal(GI) endoscopies, such as esophagogastroduodenoscopy or colonoscopy, due to greater technical difficulty and higher risk of complications. Yet, GI fellows have limited exposure to ERCP during standard-three-year-GI-fellowships because ERCP is much less frequently performed than esophagogastroduodenoscopy/colonoscopy. This led to adding an optional year of training in therapeutic endoscopy. Yet many graduates from standard three-year-fellowships without advanced training intensely pursue independent/unsupervised ERCP privileges despite inadequate numbers of performed ERCPs and unacceptably low rates of successful selective cannulation of desired(biliary or pancreatic) duct. Hospital credentialing committees have traditionally performed ERCP credentialing, but this practice has led to widespread flouting of recommended guidelines(e.g., planned privileging of applicant with 20% successful cannulation rate, or after performing only 7 ERCPs);and intense politicking of committee members by applicants, their practice groups, and potential competitors. Consequently, some gastroenterologists upon completing standard fellowships train and learn ERCP 'on the job' during independent/unsupervised practice, which can result in bad outcomes: high rates of failed bile duct cannulation. This severe clinical problem is indicated by publication of ≥ 12 ERCP competency studies/guidelines during last 5 years. However, lack of mandatory, quantitative, ERCP credentialing criteria has permitted neglect of recommended guidelines. This work comprehensively reviews literature on ERCP credentialing;reviews rationales for proposed guidelines;reports problems with current system;and proposes novel criteria for competenc

关键词： Endoscopic retrograde cholangiopancreatography Privileges Credentialing Gastroenterology fellowship training Advanced gastrointestinal endoscopy training Certification Standards

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

Strategies and challenges to increase the precision in feeding zinc to monogastric livestock

引用

Animal Nutrition 2017年第2期3卷 103-108页

作者： Daniel Brugger Wilhelm m.Windisch TUm School of Life Sciences Weihenstephan Technical University of Munich

Practical diets for monogastric livestock must be supplemented with zinc(Zn) due to their high contents of antagonistic substances like phytates. Current feeding recommendations include quite generous safety margins because of uncertainties regarding the gross Zn requirements under varying rearing ***, the use of pharmacological Zn doses to stabilise animal performance and wellbeing is widespread. Taken together, modern diets for pigs and poultry contain considerably more Zn than necessary to meet animal requirements, which is associated with concerns related to the environment as well as animal and consumer safety. Therefore, European authorities most recently reduced the allowed upper limits for Zn in complete feed. To maintain animal productivity and wellbeing while reducing the Zn load in complete feed, all measures that stabilize feed Zn bioavailability must be applied. most importantly, reliable information on the gross Zn requirement under practical conditions must be provided, considering the bioavailability of native or supplemented feed Zn, antagonisms with dietary factors as well as the physiological status of the animal.

关键词： Zinc Requirement Recommendation Pharmacological Pig Poultry

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

Color change in a marine isopod is adaptive in reducing predation

引用

Current Zoology 2015年第4期61卷 739-748页

作者： Kristin m. HULTGREN Hannah mITTELSTAEDT Department of Biology Seattle University 901 12^th ave. Seattle WA 98122

Although background matching is a common form of camouflage across a wide diversity of animals, there has been surprisingly little experimental work testing the fitness consequences of this camouflage strategy, especially in marine ecosystems. In this study, we tested whether color camouflage enhances survival of the intertidal marine isopod Pentidotea （Idotea） wosnesenskii, quantified patterns of camouflage in different algal habitats, and examined how algal diet affected color change and growth using laboratory assays. In the field, isopods collected from two differently colored algal habitats （the brown alga Fucus distichus and the red alga Odonthaliafloccosa） matched the color of their respective algal habitats, and also differed significantly in body size： smaller red isopods were found on red algae, while larger brown isopods were found on brown algae. Predation ex- periments demonstrated these color differences had fitness benefits： brown isopods that matched their brown algae habitats sur- vived at higher rates than red unmatched isopods. Surprisingly, despite the propensity of isopods to match their algal habitats, algal diet had no effect on color change in color change experiments. Instead, isopods in all treatments turned browner, matching the color of the algal habitat that many isopods are found on as adults. In summary, our data supported our hypothesis that back- ground matching serves an adaptive function in reducing predation, with important evolutionary implications for explaining the wide variation in color change mechanisms in idoteid isopods [Current Zoology 61 （4）： 739-748, 2015].

关键词： Isopod Pentidotea wosnesenskii. Camouflage Crypsis Background matching Color change

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：