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Search Results: 1 - 10 of 251886 matches for " 陈伟成 "
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内循环流化床循环流率预测模型及试验验证
鸿,
热力发电 , 2014,
Abstract: 提出了终端速度法和滑移系数法2种内循环流化床循环流率的计算模型,并搭建了内循环流化床试验台,利用容积测量法得到循环流率试验值。对比模型预测值和试验值,发现以滑移系数计算颗粒相速度的模型预测值与试验值较吻合。
典型海(咸)水入侵防治措施机理数学解析
Mathematical Analysis on Mechanism of Typical Sea (Salt) Water Intrusion Prevention Measures
 [PDF]

学群, 李福林, , 田婵娟, 管清花,
Journal of Water Resources Research (JWRR) , 2016, DOI: 10.12677/JWRR.2016.55058
Abstract:
海(咸)水入侵是一种自然灾害,入侵过程遵循能量守恒定律、动量守恒定律及牛顿第二定律。在自然状态和人为干预状态下海(咸)水入侵过程中的影响因子之间并非单一的线性关系。本文利用量纲一致的原则从海(咸)水入侵的数学机理上进行研究分析,分别对自然状态条件、淡水水体帷幕防治措施条件以及地下坝刚性防治措施条件下的海(咸)水入侵的动态平衡进行了数学描述。本文提出了各种防治措施条件下的基础因子与关键因子,建立了海(咸)水入侵防治措施基础因子和关键因子的无量纲关系。通过实例分析,结果表明:不同的人工防治工程措施对应不同的关键性指标,其无量纲关系曲线表明淡水帷幕运移的时间、距离与淡水回灌流量呈现较好的规律性。因子之间的无量纲关系曲线也为海(咸)水入侵的防治和机理研究提供新的思路。
It is well known that sea (salt) water intrusion is a natural disaster, and its process follows the law of energy conservation, the law of conservation of momentum and the Newton’s second law. It is not a single linear relationship between sea (salt) water intrusion factors both in the natural state and human intervention state. In this paper, using dimensional homogeneity theory, the mathematic representation of seawater intrusion dynamic balance is made under both natural conditions and typical prevention measure conditions. The foundation factors and key factors under all sorts of seawater intrusion pre-vention measure conditions are proposed, and the dimensionless relationship between the foundation factors and key factors is built. The result shows that different artificial control projects correspond to different key indicators, and the dimensionless relation indicates that the water curtain migration time distance and fresh water injection flow present a good regularity. The dimensionless relation will also provide a technical support for seawater intrusion prevention and research in the future.
基于八叉树的全局接触搜索算法研究 Development of global contact searching method based on octree algorithm
Development of global contact searching method based on octree algorithm

,柳明,,
- , 2017, DOI: 10.7511/jslx201703009
Abstract: 接触搜索是接触-碰撞问题有限元模拟中最为耗时的部分,高效的接触搜索算法是提高数值分析效率的关键。以面心坐标和特征长度表征接触主片,并引入树包围盒和从节点包围盒的概念,基于八叉树算法发展了一种高效的全局接触搜索方法,计算复杂度为 O(Nlog8M),其中 N 为从节点数,M 为接触主片数。程序实现时,通过引入接触预搜索和相邻搜索方式加速搜索速度。本文算法基于PANDA-Impact软件实现,并进行了算例验证分析。结果表明,本文算法具有很好的接触搜索效率与适用性,与桶排序算法相比,当接触复杂且规模较大时,本文算法表现出较大的优势。
In finite element simulations,contact searching is the most time-consuming part in the problems involving contact-impact,therefore it is significant to develop an efficient contact-pairs searching method.In this paper a new global searching method based on octree algorithm is developed and implemented in PANDA-Impact program.In the proposed method,centroid of the master segment and relevant characteristic length are used to represent its true geometry.Two new concepts,tree-bounding-box and slave-bounding-box,are presented.The cost of the new contact searching method is of the order of O(Nlog8M),where N is the number of the slave nodes,and M is the number of master segments.In implementation,pre-searching and neighbor-searching are introduced to accelerate the efficiency of contact-searching.The results of typical numerical experiments show that the new contact searching method is very efficient.In dealing with problems involving complex and large amount of contact pairs,the new method has an apparent observable advantage over the bucket sorting method.
细长尖头刚性弹对金属靶板的斜侵彻/穿甲分析
,李维,
爆炸与冲击 , 2005, DOI: 10.11883/1001-1455(2005)05-0393-07
Abstract: ?给出细长尖头刚性弹(如尖卵、尖锥形)斜侵彻/穿甲金属靶的一个分析模型。在细长尖头弹对中厚度金属靶的斜穿甲中,韧性孔洞扩张为主要的穿甲机理;着靶初期,发生方向角的改变。研究表明,金属靶的斜穿甲仅由4个量纲一参数控制,即冲击函数I、弹体几何函数N、量纲一靶厚χ和撞击斜角β。分析得到显式的侵彻深度、终点弹道极限、剩余速度和撞击方向改变角表达式。该模型可预期跳飞发生的临界条件。理论预期与实验结果吻合较好。
基于“评价-模拟-优化”的流域环境经济决策模型研究
,,郭怀
环境科学学报 , 2014,
Abstract: 流域管理是一个具有经济、社会与水环境等多维发展目标的复杂系统,不同目标之间存在复杂的非线性响应关系,如何模拟、协调、优化各种目标,是长期制约流域环境经济优化决策的关键技术瓶颈之一.当前在构建流域模型时往往缺乏全局性和系统性的考虑,采用线性单向建模思路,忽略了流域环境经济问题的复杂性、综合性和整体性,难以实现最优决策.针对这一不足,结合现有流域模型的建模经验与流域量化管理的需求,从系统优化发展的角度出发,基于环境经济协调度模型、系统动力学模拟模型和Powell优化模型提出了流域环境经济优化决策模型(简称ASO模型).该模型弥补了现有流域模型仅能在概念上描述因果反馈关系的不足,在数值模型上实现流域经济-社会-水环境各子系统中反馈回路的闭合,提供了一种对流域系统复杂反馈关系的模拟方法.最后,基于该模型对抚仙湖流域进行了案例研究.
ERP软件中的组织结构与BPR的实现
,
计算机集成制造系统 , 2002,
Abstract: 以SAPR/3为例,讨论了企业资源计划软件中组织结构框架,指出了该软件中的组织构架是按功能设立的,各个不同功能有自己的组织结构,各个不同模块有自己的权力控制设置,这是一个虚体企业的结构。企业资源计划软件在企业的实施,可以按企业的虚体和实体的映射实现业务过程重构。本文最后给出一个观点,即企业虚体结构的优化也是业务过程重构的一种形式,参考企业资源计划软件的模型,有助于系统低风险、快速地实施。
两步法制备具有自愈合能力的纯sic涂层
,,
物理化学学报 , 2012,
Abstract:
光合作用光能转换过程中与耗能代谢有关的光保护机制(综述)
,贻竹?
热带亚热带植物学报 , 2000, DOI: 10.3969/j.issn.1005-3395.2000.4.012
Abstract: 对近年来光合电子传递过程中各种耗能代谢(包括光呼吸、mehler反应、循环电子传递、硝酸还原代谢等)的运转对光合机构的保护作用作一简要综述。
外耳道腺样囊性癌1例
Adenoid Cystic Carcinoma of External Auditory Canal: A Report of One Case
 [PDF]

, 晓平, 薛晓, 姚文昊
Asian Case Reports in Otolaryngology (ACRO) , 2013, DOI: 10.12677/ACRO.2013.12005
Abstract:

目的:探讨外耳道腺样囊性癌的临床及病理特点,以提高诊断和治疗水平。方法:回顾性分析1例外耳道腺样囊性癌患者自首诊8年来连续的临床表现,病程进展,治疗及随访结果。结果:患者术后随访半年无复发。结论:外耳道腺样囊性癌生长缓慢,可长期带瘤生存但远期预后不佳,首次治疗应该采用扩大根治性手术,术后结合临床病理分期辅以放射治疗以提高治愈率。
Objective: To detect the clinical and pathological features of the adenoid cystic carcinoma of external audi-tory canal, and to improve its diagnosis and treatment level. Method: A retrospective analysis has been performed on patients with ACCEAC by their clinical manifestation, the therapy and follow-up results since 8 years ago as well as the combination with there view of related literature. Result: Patients without recurrence of postoperative follow-up of six months. Conclusion: Adenoid cystic carcinoma of external auditory canal, which is rarely seen in clinic, is not easy to exact diagnosis in early stage. It progresses slowly and tends to invade parotid and even intracranial cavity. It also has the tendency of recurrence and pulmonary metastasis. So, it’s necessary to do both aggressive surgery and postoperative irradiation. The long term follow-up indicates that the tumor has a poor prognosis.

中国海海浪波周期季节特征的精细化模拟分析
Meticulous Simulation of Seasonal Characteristics of the China Sea Wave Period
 [PDF]

郑崇, 黎鑫,, 苏轼鹏,
Adances in Marine Sciences (AMS) , 2014, DOI: 10.12677/AMS.2014.12007
Abstract:
海浪波周期是波浪能资源开发、舰船航行安全等重点关注的要素之一,也是目前海浪研究的瓶颈。由于资料稀缺的限制,针对海浪波周期的研究可谓凤毛麟角。本文以CCMP风场驱动目前国际先进的第三代海浪数值模式WW3 (WAVEWATCH-III),模拟得到首份覆盖整个中国海、长时间序列、高时空分辨率、高精度的海浪场数据,首次实现了中国海海浪波周期季节特征的精细化研究,期望可以为“海之梦”、“中国梦”尽绵薄之力。研究结果表明中国海的海浪波周期存在较大的季节性、区域性差异,且与季风存在密切的关系:1) 中国海的波周期在1月和10月整体大于4月和7月。渤海的波周期在各个季节都小于其余海域。1月、4月和10月,海浪波周期的大值区主要分布在25?N以南,而7月主要分布于15?N以北。2) 从年平均海浪波周期的分布特征来看,南中国海大部分海域、东海大部分海域以及菲律宾以东近海的年平均波周期明显大于其余海域,高值中心分布于南海北部海域。3) 在季风期间(包含冬季风和夏季风),季风影响明显的区域波周期较小,而其余海域的波周期则偏高。
The wave period is close to the development of wave energy resource, navigation, ocean engineering, prevents and reduces sea wave calamity, and so on. In this study, the first China Sea wave data were obtained, using WW3 wave model forced by CCMP (Cross-Calibrated, Multi-Platform) wind field. Then the seasonal characteristics of the China Sea wave period were analyzed. Results showed that, 1) Wave period in January and October was greater than that in April and July. Wave period in the Bohai Sea was smaller than that in other waters all year round. In January, April and October, large area of wave period was mainly located in the south of 25?N, while in the north of 15?N in July. 2) From annual average wave period, values in the South China Sea, East Sea, and east of Philippine was greater than that in other waters. 3) During the period of monsoon, wave period in the area affected by the monsoon was larger than in the area not affected by the monsoon.
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