检索结果-南通市图书馆

Field Evaluation of Soil Water Extraction of Cotton

在线全文

学校读者我要写书评

暂无评论

Open Journal of Soil Science 2017年第12期7卷 378-400页

作者： José O. payero Graham harris Geoff Robinson Edisto Research and Education Center Clemson University Blackville USA Department of Agriculture and Fisheries Toowoomba Australia

Water scarcity is often a major limiting factor in cotton (Gossypium hirsutum l.) production, and sustaining productivity and profitability with limited water is a major challenge for the cotton industry. A good understanding of the magnitude, timing and spatial distribution of cotton soil water extraction is important for proper irrigation management, and for development of accurate crop models and decision support systems. The overall objective of this study was to evaluate the water extraction distribution of cotton under different irrigation regimes. Specific objectives were to quantify: 1) the depth of soil water extraction as a function of time, 2) the percent of seasonal water extraction from each soil depth, and 3) the relationship between depth of soil water extraction and canopy height. To meet these specific objectives, daily and seasonal cotton soil water extraction were determined from continuous records of water content in the soil profile measured from four irrigation treatments during a field experiment. We found that cotton extracted soil water from as deep as 150 cm, but the percent of seasonal extraction sharply decreased with soil depth. The top 50 cm soil layer accounted for 75% of the seasonal extraction and the top 80 cm, for 90%. We also found that from 32 days after sowing (DAS) to 100 DAS, the depth of soil water extraction increased linearly at a rate of 1.89 cm·day-1 or 2.36 times the increase in crop canopy height. These findings suggest that cotton producers should manage irrigations to maintain adequate moisture in the top 80 cm of the soil profile rather than relying on moisture stored deeper in the profile.

关键词： Cotton Soil Water Water Use Evapotranspiration Root Development Effective Root Zone

THERE IS NO MATHEMATICAl VAlIDITY FOR USING FUZZY NUMBER CRUNCHING IN THE ANAlYTIC HIERARCHY PROCESS

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

Journal of Systems Science and Systems Engineering 2006年第4期15卷 457-464页

作者： Thomas l. SAATY University of Pittsburgh Pittsburgh PA 15260

Fuzzy logic has difficulty producing valid answers in decision-making. Absent are theorems to prove that it works to produce results already known that are being estimated with judgments by transforming such judgments numerically. The numerical representation of judgments in the AHP is already fuzzy. Making fuzzy judgments more fuzzy does not lead to a better more valid outcome and it often leads to a worse one. The compatibility index of the AHP is used to illustrate how the answers obtained by fuzzifying AHP judgments do not produce better results than direct derivation of the principal eigenvector. Other authors who did experiments with given data in decision making quoted in the conclusions section of the paper, have observed that fuzzy sets gives the poorest answers among all methods used to derive best decisions.

关键词： Analytic Hierarchy Process fuzzy logic compatibility index validity

在线全文

学校读者我要写书评

暂无评论

2-苯甲酰基嘧啶类化合物的合成与生物活性

有机化学 2015年第6期35卷 1260-1269页

作者：吕强芦昕婷戴明刘世梦朱为宏杜葩吕龙华东理工大学化学与分子工程学院上海200237 中国科学院上海有机化学研究所有机氟化学重点实验室上海200032 上海应用技术学院化学与环境工程学院上海201418

2-嘧啶氧基-N-芳基苄胺类化合物结构经过两次骨架结构优化后得到2-苯甲酰基嘧啶类化合物二次先导结构.在二次先导结构基础上,共设计并合成了36个化合物,所有化合物结构经1H NMR、13C NMR、HRMS确认,并进行了室内杀菌活性筛选,对各部位... 详细信息

2-嘧啶氧基-N-芳基苄胺类化合物结构经过两次骨架结构优化后得到2-苯甲酰基嘧啶类化合物二次先导结构.在二次先导结构基础上,共设计并合成了36个化合物,所有化合物结构经1H NMR、13C NMR、HRMS确认,并进行了室内杀菌活性筛选,对各部位取代基进行了逐次优化.结果表明2-苯甲酰基嘧啶类化合物中R1取代基以2位卤素或烷基取代的苯环或杂环活性最好;中间苯环6位引入氟原子活性保持;嘧啶环4,6位甲氧基取代活性较好,5位甲基取代活性大大降低;羰基被还原为羟基后活性消失.其中2,3-二氯-N-[2-(4,6-二甲氧基嘧啶-2-甲酰基)苯氧基]-N-甲基苯甲酰胺(4AHl)、2,5-二氯-N-[2-(4,6-二甲氧基嘧啶-2-甲酰基)苯氧基]-N-甲基苯甲酰胺(4AHn)及N-[2-(4,6-二甲氧基嘧啶-2-甲酰基)-3-氟苯氧基]-N,2-二甲基苯甲酰胺(4AFd)对黄瓜白粉病的杀菌活性与对照样苯菌酮相当.

关键词： 2-苯甲酰基嘧啶合成结构优化生物活性

在线全文

学校读者我要写书评

暂无评论

多点养猪体系的管理

当代畜禽养殖业 2003年第9期 17-21页

作者： D．l．harris 王永康不详上海市畜牧兽医站

管理者负责着多点体系全面的生产性能或效率。为了判断养猪场的财务状况,场主或场主兼管理者必须考虑三个因素,即效率、生产规模和债务结构。效率是管理者和场主管理技巧的直接反映。低效率并非是财务状况低下的唯一原因,但优异的生产... 详细信息

管理者负责着多点体系全面的生产性能或效率。为了判断养猪场的财务状况,场主或场主兼管理者必须考虑三个因素,即效率、生产规模和债务结构。效率是管理者和场主管理技巧的直接反映。低效率并非是财务状况低下的唯一原因,但优异的生产成绩则是取得令人满意的利润和资金流动的基本所在。

关键词：猪养殖体系日常管理生产性能工作效率生产规模债务结构

The Isentropic Exponent of Single-Ionized Mono-Atomic Plasmas

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2012年第8期14卷 699-701页

作者： K.T.A.l.BURM PlasmAIX for Plasma Research Heimerik 472440 GeelBelgium

The isentropic exponent of single-ionized mono-atomic plasmas in thermal equilib- rium is studied. Its behavior as a function of the ionization degree and temperature is examined for argon and zinc plasmas at two pressures （1 bar and 1 mbar, 1 mpa and 1 pa）, respectively. The results show that for the two sorts of plasma the isentropic exponent equals typically about 1.1-1.2 within a considerably wide range of the ionization degree （5%-80%）.

关键词： plasma modelling isentropic exponent

在线全文

学校读者我要写书评

暂无评论

美国内幕

美国内幕

1990年

作者：（美）哈里斯（harris l.）诗宓等译

书名原文:Inside America:本书揭示了美国的家庭、社会和政界以及许多社会现象背后所隐藏的公众心理,反映了各阶层美国人对家庭、婚姻、子女、学校教育、疾病死亡、社会经济、世界政局等方面问题的真实态度。

ISBN: (纸本)7

关键词：社会科学总论社会学社会调查和社会分析

来源：汇雅图书（南通市图书馆... 评论

在线全文

汇雅图书（南通市图书馆）

学校读者我要写书评

暂无评论

关于使用样线法估计种群密度

动物学报 2002年第6期48卷 812-818页

作者： Richard B.harris Kenneth P.BURNHAM University of Montana Colorado State University Missoula MT 59812 USAFort Collins CO 80523 USA

样线法是在大范围内估计野生动物种群密度的优良方法之一。我们在本文中说明了使用以平均垂直距离作为有效样带宽度来计算种群密度的简单数学公式一般不会得到可靠的结果。即使野外实施方式正确 ,使用该数学计算式估计出的密度结果也往... 详细信息

样线法是在大范围内估计野生动物种群密度的优良方法之一。我们在本文中说明了使用以平均垂直距离作为有效样带宽度来计算种群密度的简单数学公式一般不会得到可靠的结果。即使野外实施方式正确 ,使用该数学计算式估计出的密度结果也往往过于偏高。因此 ,我们建议最好使用计算机软件DISTANCE调查野生动物种群密度 ,并能熟悉样线距离取样法的理论基础。

关键词：样线法估计种群密度探测函数傅立叶级数负指数函数计算机软件 DISTANCE 野生动物

The effect of gas phase polydimethylsiloxane surface treatment of metallic aluminum particles： Surface characterization and flow behavior

在线全文

学校读者我要写书评

暂无评论

particuology 2017年第1期15卷 92-101页

作者： Bellamarie ludwia Jennifer l. Gray Applied Research laboratory The Pennsylvania State University North Atherton Street State College PA 16801 USA Materials Research Institute The Pennsylvania State University USA

Aluminum particles were exposed to gaseous polydimethylsiloxane （PDMS） to produce a hydropho- bic surface coating for enhanced flow and fluidity. Surface retention of the intact PDMS was confirmed through infrared and X-ray photoelectron spectroscopy. Transmission electron microscopy was used to image cross-sections of the treated particles and energy dispersive spectroscopy element maps demon- strated the presence of a surface layer consisting of silicon and oxygen. Density measurements provided evidence for improvements in the Hausner ratio and Carr index of the PDMS-treated aluminum, indicating a reduction in inter-particulate cohesion through increased bulk density. Stability, compressibility, shear, aeration, and permeability of the particles were assessed by powder rheometer. The compressibility was reduced by approximately 32% following surface treatment, revealing a reduction in void space, while Mohr＇s circle analysis and shear testing determined that the extrapolated cohesion value was reduced by approximately 53% and the flow factor at 6 kpa was doubled. Aeration testing showed that the air velocity required to obtain a fluidized bed was on the order of 0.35 mm/s for the treated powder, whereas the raw powder could not be uniformly fluidized. PDMS may be a viable option for the large-scale treatment of aluminum powder for flow applications.

关键词： Aluminum powder Polydimethylsiloxane X-ray photoelectron spectroscopy Diffuse reflectance infrared Fourier transform spectroscopy Flowability FT4 powder rheometer

AN ANAlYTIC HIERARCHY PROCESS MODEl OF GROUP CONSENSUS

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

Journal of Systems Science and Systems Engineering 2014年第3期23卷 363-375页

作者： Qingxing DONG Thomas l.SAATY School of Information Management Central China Normal University University of Pittsburgh PittsburghPA 15260USA

In group decision making, a certain degree of consensus is necessary to derive a meaningful and valid outcome. This paper proposes a consensus reaching model for a group by using the Analytic Hierarchy Process （AHP）. It supports people to improve their group consensus level through an updating of their judgments. In this model, a moderator suggests the most discoraant aeclslon manet to update his judgment in each step. The proposed consensus reaching model allows decision makers to accept or reject the suggestion from the moderator. This model ensures that the judgment updating is effective and the final solution will be of acceptable consistency. Finally, a numerical example is given to illustrate the validity of the proposed consensus reaching model.

关键词： Group decision making Analytic Hierarchy Process (AHP) consensus judgment updating