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Search Results: 1 - 10 of 241889 matches for " 李冬冬 "
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中国法律史学会2006年学术年会综述
王捷,冬冬
华东政法大学学报 , 2007,
Abstract:
四足机器人结构柔顺化设计与性能评价
Design and Evaluation of the Compliant Structure for a Quadruped Robot
 [PDF]

冬冬, 张秀丽, 周坤玲, 龚加庆
Artificial Intelligence and Robotics Research (AIRR) , 2013, DOI: 10.12677/AIRR.2013.21001
Abstract:
针对刚性四足机器人动态行走时的躯体姿态不平稳和地面冲击力大等问题,通过借鉴哺乳类四足动物的躯体结构,提出了一种以局部被动自由度为特征的四足机器人柔顺化结构,即,在刚性四足机器人腿部末端添加由压簧约束的直线移动副构成弹性腿部,在腰部添加由扭簧约束的横滚、偏转两个方向的转动副,形成柔性腰部。采用中枢模式发生器(CPG)方法建立了四足机器人的轨迹控制模型,结合力学分析和样机试验确定柔顺结构各个弹性自由度的刚度系数。物理样机运动实验表明,柔顺结构能够有效的降低四足机器人行走时的地面冲击力,减小躯干姿态变化程度,从而提高机器人行走的平稳性。
It can cause large ground impact force and postural instability when a rigid quadruped robot walks on the ground. To improve walking performances, a bio-inspired compliant structure was designed for a quadruped robot, which features four elastic legs and two flexible waist joints. The elastic legs are composed of a linear sliding pair con-strained by compression spring at the end of each leg. The flexible waist is constituted with two rotating joints in roll and yaw, which are constrained by torsion springs. A center pattern generator (CPG) model was established, used as the trajectory planner of the robot. Mechanical analysis and physcial experiments were combined to determine the stiffness of all the springs. Comparative experiments show that the elastic legs can effectively reduce the ground impact force and the flexible waist can decrease the swing of the body, which contribute to achieve higher postural stability when the quadruped robot walks on the ground.
配电变压器无弧有载自动调容技术探讨
Discussion on Arcless On-Load Automatic Capacity Regulating Distribution Transformer
 [PDF]

冬冬, 晓峰, 周科延
Transmission and Distribution Engineering and Technology (TDET) , 2014, DOI: 10.12677/TDET.2014.34012
Abstract:
该研究针对农村配电的特点,介绍了农村配电变压器的有载自动调容技术,探讨了农村配电变压器无弧有载自动调容的可行性,给出了无弧有载自动调容的技术方案和控制系统的设计。为农村电网实施有效的季节调容提供了解决办法。
The technology of the on-load automatic capacity regulating distributing transformer is dissertated according to the distribution characteristics of rural areas, the feasibility of arcless on-load automatic capacity regulating transformer is discussed, and the technology scheme of arcless on- load automatic capacity regulating and the design of the control system are put forward. All of these provide solution to the capacity regulating seasonally in country grid.
交互设计中的需求层次及设计策略
冬冬,世国
包装工程 , 2013,
Abstract: 以马斯洛需求层次理论为启示,分析了交互设计对于用户需求的满足,论述了交互设计中用户在可用性层面、易用性层面以及体验性层面上的多样化需求。在此基础上,提出了交互设计中满足用户需求应采取的设计策略。
凡德他尼的合成工艺研究
Study on Synthetic Process of Vandetanib
 [PDF]

张志鹏, 周艳红, 冬冬, 石伟, 王亚楼
Studies in Synthetic Chemistry (SSC) , 2015, DOI: 10.12677/SSC.2015.32005
Abstract:
目的:提供一条合成凡德他尼新工艺路线。方法:以香兰素为起始原料,经过酚羟基苄基保护、氧化、硝化、还原、环合和氯代反应得到7-苄氧基-4-氯-6-甲氧基喹唑啉,再与2-氟-4-溴苯胺发生取代反应,然后脱苄基生成4-(2-氟-4-溴苯胺基)-6-甲氧基-7-羟基喹唑啉(10),收率33.1%;以4-哌啶甲酸乙酯为原料,经Leuckart N-甲基化反应、酯基还原反应,然后和对甲苯磺酰氯反应生成磺酸酯(14),收率35.1%。最后将(10)和(14)在碱性条件下缩合得到目标产物凡德他尼(1)。(1)的总收率11.6% (以化合物(2)和(11)计)。结果:目标化合物及其中间体的化学结构都经过IR、1H-NMR和HR-MS图谱确证。结论:本方法缩短了反应步骤,反应条件温和、操作简便。
Objective: To develop a new synthetic route for Vandetanib. Methods: 4-(2-fluoro-4-bromo-ami- no)-6-methoxy-7-hydroxy-quinazoline (10) was prepared from vanillin (2) via phenolic hydroxyl protection, oxidation, nitration, reduction, cyclization and chlorination to afford 7-benzyloxy-4- chloro-6-methoxy-quinazoline (7), and then (7) coupled with 2-fluoro-4-bromoaniline, followed by debenzylation, yield 33.1%. (1-methylpiperidin-4-yl)methyl 4-methylbenzenesulfonate (14) was prepared from ethyl piperidine-4-carboxylate(11) by Leuckart reaction, reduction and then reacted with p-toluenesulfonyl chloride, yielding 35.1%. In addition, 10 was reacted with 14 to yield the antitumor drug vandetanib (1) with an overall yield of 11.6% (based on compound 2 and 11). Results: The structure of all products was confirmed by IR, 1H-NMR and HR-MS. Conclusion: The improved process has several advantages over those reported procedures, such as brief reac-tion steps, mild conditions, and simple operations.
云南少数民族地区肝硬化发病特点与防治措施的研究现状
The Research of the Disease Features and Preventive Measures of Liver Cirrhosis in Ethnic Areas of Yunnan Province
 [PDF]

冬冬, , 陈刚, 王帆, 胡宗强, 刘洪
Advances in Clinical Medicine (ACM) , 2015, DOI: 10.12677/ACM.2015.53029
Abstract:
长期接触各种能导致肝损伤的病因,使得肝细胞外基质大量聚积,引发肝纤维化,继而发展为肝硬化,出现肝功能衰竭,甚至是肝癌,危及生命。而云南作为我国少数民族最多的省份,该地区的居民肝硬化的发病情况具有自身的特点,本文就云南少数民族地区肝硬化的发病特点进行了总结,通过与全国其他地区相比,总结其所突显的特点,为云南少数民族地区肝硬化疾病的防治等相关研究提供理论基础。
Liver fibrosis is the excessive accumulation of extracellular matrix (ECM) in the liver, which is de-veloped by a long-term contact with various incentives of chronic liver injury, and moreover it can develop into liver cirrhosis with failure of liver functions, even into deadly liver cancer. Yunnan Province, with the largest number of ethnic groups, has specific features in the conditions of liver cirrhosis that residents in this area have. This paper summarizes the disease features of liver cirrhosis in ethnic areas of Yunnan Province, aiming to find out and make a comprehensive sum-mary of the disease features that hepatic fibrosis highlights by comparison with other areas of our country, which provides the theoretical basis for relevant studies on the prevention and medical treatment of liver cirrhosis patients in ethnic areas of Yunnan Province.
基于基频的情感语音聚类的说话人识别方法*
冬冬,吴朝晖,杨莹春
模式识别与人工智能 , 2009,
Abstract: 针对存在情感差异性语音情况下说话人识别系统性能急剧下降以及缺乏充足情感语音训练说话人模型的问题,提出一种基于基频的情感语音聚类的说话人识别方法,能有效利用系统可获取的少量情感语音.该方法通过对男女说话人设定不同的基频阈值,根据阈值,对倒谱特征进行聚类,为每个说话人建立不同基频区间的模型.在特征匹配时,选用最大似然度的基频区间模型的得分作为该说话人的得分.在中文情感语音库上的测试结果表明,与传统的基于中性训练语音的高斯混合模型说话人识别方法和结构化训练方法相比,该方法具有更高的识别率.
基于粮食安全的黑龙江省垦区耕地集约利用定量分析——以宝泉岭垦区为例
宋戈,国凤,冬冬
农业现代化研究 , 2011,
Abstract: 本文以黑龙江省宝泉岭垦区为研究区,基于粮食安全角度,以耕地投入强度、利用程度、利用效益以及持续状况为要素层,筛选具有代表性的21个指标,构建研究区耕地集约利用评价指标体系,综合主、客观赋权,运用多因素综合数学模型,定量测算黑龙江省宝泉岭垦区1999-2008年耕地集约利用状况,并进一步探讨耕地集约利用与粮食安全的关系。结果表明:1999-2008年,研究区耕地集约利用水平各不相同,不同指标和要素对研究区耕地集约利用程度的影响存在一定的差异,其中耕地利用效益对耕地集约利用水平影响最大。耕地投入强度、利用程度、利用效益以及持续状况间的协调性也是影响耕地集约利用的重要因素,同时粮食安全与耕地集约利用水平具有很强的相关度,表现为粮食总产量随耕地利用集约度的升高而增加,随耕地利用集约度的降低而减少。
多个布儒斯特窗大型光学元件的损伤在线检测
冬冬,曹益平,大海
强激光与粒子束 , 2007,
Abstract: ?针对高功率固体激光装置主放大器中以布儒斯特角放置的大型光学元件,设计了一套损伤在线检测系统。该系统利用望远系统倍率不变特性实现了多个光学元件在线等精度、等分辨率检测;采用景深理论,通过仔细调节孔径光阑的大小,以达到既能测量同一倾斜光学元件上的不同损伤点,又能减小相邻光学元件间损伤信息相互影响的目的。通过亮场成像纵向定位损伤位置,而利用暗场成像横向定位损伤的大小。实验证明了该方法的可行性和有效性。该检测方法适用于各种多个倾斜放置的光学元件的损伤在线检测。
基于乱序修正框架的物联网复杂事件检测模型
冬冬,袁凌云?,晶?
计算机科学 , 2015,
Abstract: 针对物联网应用系统中存在的时间戳乱序问题,给出了物联网语义事件定义,对时间戳乱序问题进行了描述,同时基于混合驱动的空间回收机制,构建了基于哈希结构的复杂事件乱序修正框架,并提出了一种基于乱序修正框架的复杂事件检测算法(orfced)。该算法提取事件的2个特征参数来计算哈希地址,利用时间戳特性将事件存入循环单链表进行局部排序,从而解决了时间戳乱序问题。仿真结果表明,所提出的orfced算法不仅具有较高的处理正确率和可靠性,而且可以对乱序流及时地作出反应,弥补了现有方法存在的不足。最后通过案例研究验证了所提算法的有效性和可行性。
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