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Search Results: 1 - 10 of 170063 matches for " 徐文修 "
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近51a伊犁河谷热量资源时空变化
娇媚,,李大平
干旱区研究 , 2014,
Abstract: 基于伊犁河谷10个气象站1960—2010年年平均气温、≥0℃和≥10℃积温及无霜冻期气象资料,采用线性趋势分析、[WTBX]t-检验、[WTBZ]Kriging空间插值等方法,对伊犁河谷近51a的热量资源时空变化特征进行分析。结果表明①热量资源的空间分布总体呈现平原地区多山区少的特点;②近51a伊犁河谷的热量资源呈增加趋势,年平均气温、≥0℃和≥10℃积温及持续日数、无霜冻期分别以0.43℃·(10a)-1、89.9℃·d·(10a)-1、88.0℃·d·(10a)-1、4.0d·(10a)-1、3.2d·(10a)-1和5.4d·(10a)-1的倾向率上升,51a来分别增加了2.2℃、458.5℃·d、448.8℃·d、20.4d、16.3d和27.5d。并且各热量资源要素在20世纪90年代中后期发生突变,突变后年平均气温、≥0℃持续日数和无霜冻期在平原地区增幅最大,在山间盆地增幅较小。≥0℃与≥10℃积温在丘陵地区增加最明显,在山间盆地增加最少。而≥10℃持续日数在山间盆地增加最多,在平原地区增加最少。
基于优势关系下的协调近似空间
伟华 张
计算机科学 , 2005,
Abstract: 在基于优势关系下的信息系统中引入了协调近似空间的概念,并证明了在优势关系下不协调目标信息系统也可以转化为一个协调近似空间,这进一步方便了基于优势关系下不协调目标信息系统的研究,丰富了粗糙集理论.
基于优势关系下不协调目标信息系统的知识约简
伟华 张
计算机科学 , 2006,
Abstract: 在基于优势关系下不协调目标信息系统中引入了分配约简和近似约简的概念,并讨论了它们二者之间的关系,进一步给出了知识约简的判定定理和辨识矩阵,从而提供了在优势关系下不协调目标信息系统知识约简的具体操作方法。
严寒地区村镇住宅屋顶双层复合保温模式初探
李桂,其态,
哈尔滨工业大学学报 , 2010, DOI: 10.11918/j.issn.0367-6234.2010.10.021
Abstract: 针对严寒地区村镇住宅屋顶能耗现状和保温技术特点,并基于对目前严寒地区村镇住宅屋顶保温和节能目标的要求,提出了符合当代村镇住宅特征的屋顶上层与下层分设保温层的复合保温构造模式;阐述了该模式的设计理念及模式内涵,建立了该模式下的吊顶封闭空间热平衡数学模型,给出了不同保温层选材的厚度参考值.该模式的提出为我国严寒地区村镇住宅屋顶保温和节能设计提供了新的设计对策.
遮光条件下氮肥用量对棉铃生长发育及产量的影响
Effect of Nitrogen Levels on the Growth and Yield of Cotton Bolls under Shading Conditions

苏丽丽,田彦君,新霞,
- , 2015, DOI: 10.7606/j.issn.1004-1389.2015.04.012
Abstract: 人工模拟果棉间作遮光条件下采用裂区试验方法,研究不同光照、施氮水平对棉铃生长发育及产量的影响。结果表明,光照和氮肥共同影响着棉铃生长发育和产量的高低,且光照比氮肥的影响更大;遮光使棉铃体积减小、棉铃干物质积累下降、发育推迟;遮光施氮量为0 kg/hm2(N0)、320 kg/hm2(N1)、480 kg/hm2(N2)处理棉铃体积分别比对照(光照处理)减少2.1%、5.6%、3.7%,铃壳、棉籽、纤维干物质最大积累量分别减少11.8%、8.1%、5.4%,适当增加施氮量会减少其降低程度;遮光条件下不同施肥处理的棉花平均产量比自然光照减少56.9%,中等施氮处理(N1)能获得相对最高皮棉产量(2 931.28 kg/hm2),其分别比未施肥处理N0和高施肥处理N2增产63.97%和17.94%。因此,在新疆果棉间作模式下,通过合理增施氮肥可以在一定程度上减轻因遮光导致的产量下降。
In order to study the effects of different light and nitrogen levels on growth and yield of cotton bolls,a split-plot-design experiment was conducted under shading conditions to simulate fruit-cotton intercropping.The results showed that both light and nitrogen had effects on the growth and yield of cotton bolls,but effect of light on cotton bolls was greater than fertilizer.Shading decreased boll volume,dry matter accumulation and delayed it’s growth.Compared with corresponding nitrogen treatments under natural light condition,the boll volume in the treatments of N0,N1,N2 under shading condition were decreased by 2.1%,5.6%,and 3.7%,and reduced by 11.8%,8.1%,5.4% on boll housing,cottonseed,maximum dry matter accumulation of fiber,respectively,which indicated that nitrogen fertilization could alleviate the effect of shading on cotton.The average yield of cotton in different fertilizer treatments under shading conditions decreased by 56.9% than under natural light condition,but the moderate nitrogen application (treatment N1) had the highest lint yield,2 931.28 kg/hm2,under all shading conditions,which was 63.97% and 17.94% higher than that of treatment N0 and N2.So,for fruit-cotton intercropping pattern in Xinjiang, rational nitrogen fertilization can reduce negative effect of shading on cotton yield.
新疆连作、轮作棉田可培养的土壤微生物区系及活性分析
韩 剑,张静,,罗 明,吴莉莉
棉花学报 , 2011, DOI: 1002-7807(2011)01-0069-06
Abstract: 研究了新疆连作、轮作棉田土壤可培养微生物区系及活性变化。结果表明,棉花多年连作造成土壤中可培养微生物数量减少,连作6~8年、9~12年、大于13年的棉田与连作小于5年的棉田相比,土壤微生物总量分别下降了40.2%,46.7%,52.4%。连作超过5年后,土壤微生物菌群结构逐渐从高肥的“细菌型”向低肥的“真菌型”转化,细菌/真菌(B/F)和放线菌/真菌(A/F)比值均降低,拮抗菌减少,病原菌积累。氮素生理群氨化细菌、硝化细菌、好气性自生固氮菌数量下降,反硝化细菌数量增加。连作还导致土壤呼吸强度、纤维素分解强度下降,微生物活性降低。连作棉田与草木樨、番茄、春麦、玉米倒茬轮作能使土壤微生物数量明显增长,有益于调节菌群平衡,提高微生物活性,固氮菌数量呈现显著增长。不同轮作作物的效应不同,以草木樨、番茄的效应更为突出。
Knowledge Systems and Cognitive Analysis
知识系统与认知分析

ZHANG Wen,|xiu,XU Zong,|ben,
,宗本

系统工程理论与实践 , 2002,
Abstract: In the paper, mathematical concept of knowledge system is introduced. General properties and attribute characteristic on knowledge system are discussed. We point out that divided knowledge base is foundation of deep cognitive process.
Knowledge Reductions in Inconsistent Information Systems Based on Dominance Relations
基于优势关系下不协调目标信息系统的知识约简

XU Wei-Hua,ZHANG Wen-Xiu,
伟华
,

计算机科学 , 2006,
Abstract: Knowledge reduction is one of the most important problems in rough set theory.However,most of informa tion systems are not only inconsistent,but also based on dominance reiations because of various factors.To acquire brief decision rules from inconsistent systems based on dominance relations,knowledge reductions are needed.The main aim of this paper is to study the problem.The assignment reduction and approximation reduction are introduced in inconsis- tent systems based on dominance relations,and relationships between them are examined.The judgment theorem and discernable matrix are obtained,from which we can provide new approach to knowledge reductions in inconsistent sys terns based on dominance relations.
Consistent Approximation Spaces Based on Dominance Relations
基于优势关系下的协调近似空间

XU Wei-Hu,ZHANG Wen-Xiu,
伟华
,

计算机科学 , 2005,
Abstract: In practices, most of information systems are not only inconsistent, but also based on dominance relations be- cause of various factors. It is every difficult to acquire brief decision rules from inconsistent systems based on domi- nance relations. Furthermore, how to turn an inconsistent system into a consistent one is extremely meaningful. The main objective of this paper is to study the problem. The concept of consistent approximation space based on dominance relation is proposed in the paper, and it is shown that the inconsistent system can be turned into a consistent approxi- mation space based on dominance, and any knowledge isn't lost. Using this approaches some problems can be simpli- fied.
网格单元形状对数值计算的影响
荣荣,明海,黄善波,
工程热物理学报 , 2004,
Abstract: 实现了二维非结构化网格上的N-S方程的离散,编制了非结构化同位网格上的SIMPLE程序,针对CFD/NHT中几个有基准解的问题进行了试算考核。结果表明,在步长基本相同的情况下,四边形网格的收敛速度和解的精度都优于三角形网格,尤其是收敛速度更明显;使用考虑边界贴体特性的边界层网格,解的精度优于均匀网格。
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