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Search Results: 1 - 10 of 240832 matches for " 刘德 "
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气液两相节流数值模拟
Numerical Simulation of Gas-Liquid Two-Phase Flow in Throttling Process
 [PDF]


Mine Engineering (ME) , 2016, DOI: 10.12677/ME.2016.41005
Abstract:
本文研究气液两相流在节流嘴处的流动规律,利用Fluent计算流体动力学软件,对节流嘴附近的流体流动状况进行数值模拟。分析结果表明,流体的压力、温度在节流嘴入口处急剧减小,再经过能量衰减逐渐达到平衡,总的变化趋势是减小的,为现场预防水合物的生成提供参考依据。
In this paper, a simplified physical model at the throttle choke is established based on the Fluent Software. The flow properties of gas-liquid two-phase flow at the throttle nozzle are studied. As a result, the pressure and the temperature at the entrance of the throttle nozzle decrease sharply and then achieve a balance through the energy attenuation. The total variation trend is reduced. It provides a theoretical foundation to prevent the hydrate formation.
不同荷载形式下HCW耦连比计算
Calculation of the Coupling Ratio under Different Load Form of Hybrid Coupled Walls
 [PDF]

龙飞, 王育
Hans Journal of Civil Engineering (HJCE) , 2016, DOI: 10.12677/HJCE.2016.53007
Abstract:
混合连肢剪力墙(HCW)是采用钢连梁代替传统钢筋混凝土连梁的一种结构。文章提出了通用于双肢和多肢剪力墙的耦连比概念,即耦连比表示连梁剪力产生的总约束弯矩与结构外部水平荷载产生的倾覆力矩的比值。文章推导出了均布荷载、倒三角形荷载和顶点集中荷载形式下耦连比的计算公式。实际工程计算表明,与传统方法相比,该计算方法更加简便、准确,为后续研究提供了基本参考。
Hybrid Coupled Walls use steel coupling beams instead of the traditional reinforced concrete beams. We put forward the general concept about coupling ratio in both double shear walls and multiple shear walls. It presents the proportion of system overturning moment produced by the structural external load resisted by the total constraint bending moment produced by shear forces of coupling beams. We also deduced the calculation formula of coupling ratio under uniform load, reverse triangle load and concentrated load. Actual engineering calculation showed that, compared with the traditional method, this calculation formula is more simple and accurate. This study provides a basic reference for subsequent research.
基于4R’s营销理论的成品油营销策略探析
Analysis of Marketing Strategy of Oil Product based on 4R’s Theory
 [PDF]

, 孙永风
Modern Marketing (MOM) , 2011, DOI: 10.12677/mom.2011.11003
Abstract: 随着市场竞争主体的增加和消费者要求的提高,成品油市场竞争愈演愈烈,成品油营销工作受到越多越多的重视和关注。本文在分析当前成品油市场竞争特点的基础上,提出了基于4R’s营销理论的成品油营销策略,强调了市场分析、客户关系管理和快速反应在构建成品油销售企业核心竞争力中的重要性。
The competition is becoming increasingly sharp in oil product market, along with the increase in competitors and the advance of consumer’s needed. Then, the marketing of oil product gains more and more recognition and attention. Through a deeply analysis of the characteristics of oil product market, the paper advances a type of marketing strategy of oil product based on 4R’s theory, indicate how important of market analysis, management of customer relationship, and rapidly reaction in constructing the core-competitiveness of oil product marketing company.
基于免疫克隆算法的应急物资调运优化研究
Construction on the Immune Clonal Algorithm for Optimization Research of Emergency Material Scheduling
 [PDF]

成琳娜,
Open Journal of Transportation Technologies (OJTT) , 2013, DOI: 10.12677/OJTT.2013.22021
Abstract:
为了提高突发事件应急救援的效率,应急物资配送优化是应急救援的关键环节之一。本文结合应急物资的特殊性,分析了自然因素、事故性质和基础设施对应急物资配送方案选择的影响,构造出多应急点多种类物资条件下应急物资调运优化模型,并利用免疫克隆算法进行求解。最后,以某地区应急事件为例,分析了各应急点及各路段的受影响程度,采用Matlab计算平台,求解出最优的应急物资配送方案。结果表明:免疫克隆算法可以避免早熟收敛现象,能够快速有效地收敛到最优解,是求解应急物资配送问题的一种有效方法。
Emergency material scheduling is one of the key links in order to improve the efficiency of the emergency rescue. Combining with the particularity of the emergency material and analyzing the influence of natural factors, accident character and base installation to selecting emergency supplies distribution plan, emergency supplies scheduling optimization model that is based upon more emergencies points and more kinds supplies is constructed. In addition, this issue is solved by the immune clonal algorithm. Taking emergency events of one region as an example, this paper analyzes the influence degree of every emergency points and every road segments. And by using Matlab software, an optimal distribution scheme of emergency supplies is proposed. The results show that the immune clonal algorithm can avoid form the premature convergence problem and is more efficient in optimization of multi-variable function, moreover, it is an efficient method to resolve the problems of emergency supplies distribution.
DNA指纹图谱法及其应用

生物化学与生物物理进展 , 1990,
Abstract: DNA指纹图谱法是利用卫星DNA作探针,探测不同生物的卫星区,产生相应的DNA指纹图谱的杂交方法。它是八十年代中期发展起来的最新技术。短暂几年,该法得到迅速发展和完善,并在法医学、人类遗传学以及鸟类和其它哺乳类的遗传研究中得到广泛应用。
Developments on Self-regulated Learning abroad since 1990
90年代以来国外自主学习研究的若干进展

,陈琦
心理科学进展 , 2000,
Abstract: 20世纪90年代以来,国外关于自主学习的研究取得了若干重要进展。该文从自主学习的实质、自主学习的内在机制、自主学习与学习成绩的关系、自主学习能力的获得等四个方面对此作简要回顾。
战术导弹单发命中概率的数学统计模拟

系统工程理论与实践 , 1981,
Abstract: 单发命中概率是导弹最核心的战术技术指标,我们研究它的目的在于,在复杂的作战条件下如何能够获得最大的战斗效果。 单发命中概率与导弹的作战使用条件密切相关,其中包括目标距离r_0、目标类型、目标
论有关计算机辅助教学效果的研究

心理学报 , 1998,
Abstract: 有关CAI效果的研究经历了单纯的计算机教学功效研究、软件设计研究、CAI应用过程研究和综合研究等四个方面。这些研究都是以计算机辅助教学与传统教学的效果对比为基础的,从大量的元分析研究看,对于CAI是否比传统教学效果更好,人们的研究结果并不一致。之所以如此,不仅是因为影响CAI效果的因素非常复杂,也是因为效果对比实验在研究思想和设计上都存在较大的漏洞,如对比实验在本质上并没有什么意义、研究设计不够完
第一届全国“三束”学术年会简讯

半导体学报 , 1981,
Abstract: <正> 第一届全国“三束”学术年会已于1980年10月23日至29日在湖南长沙市召开.这次会议也是中国电子学会生产技术学会和半导体与集成技术学会分别建立“三束技术学组”和“三束及超精细加工专业组”的成立大会.出席会议的有领导机关、科研单位、高等院校和工厂等80个单位的专家、教授、工程技术人员和干部等240余名代表。
牛带绦虫早期虫卵的卵膜结构的扫描电镜观察

动物学研究 , 1982,
Abstract: 通过对牛带绦虫早期虫卵的冷冻断割,做扫描电镜观察,见到带科绦虫虫卵在早期阶段保留了典型的各层膜的结构。虫卵共有七个膜层,实际各层之间是互相沟通与渗透的完整体系。待到虫卵成熟时,绦虫的卵壳才破裂,卵黄细胞及卵黄膜层也有退行性变化,而胚膜(embryophore)及幼虫(六钩幼hcxacanth embryo)的发育则趋于更完整。 对带绦虫的成熟虫卵的超微结构,国内、外已有过较细的描述(Inatomi,S.1962;Ishii,Y.1972;王松山等 1980)。这些报告多侧重于对带绦虫的胚膜超微结构的研究,尤其是对胚膜微管系统的观察,这些观察对于了解虫卵的生理是很有意义的。此外,Ogren,R.E.(1953,55,56,57,67) Smyth,J.D.(1956) 曾分别对Linstowiidae 科绦虫的 Oochoristria symmetrica(=O,ratti)及假叶目绦虫(Pseudophyllidae)的Schistocephalus solides的虫卵的发育做了一系列的观察;森山(1961)也对未成熟的牛带绦虫卵做过观察。但这些研究的方法,主要是光学显微镜的观察,对一些虫卵的微细结构,仅是以示意模式图来表示,而不能直接地表达其观察结果。 本文试图应用冷冻断割法(freeze fracture)将牛带绦虫卵剖开,通过SEM观察绦虫卵的早期三维结构,对绦虫卵的膜结构做了进一步地了解。
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