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Search Results: 1 - 10 of 27577 matches for " 吕靖 "
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学术期刊网络化进程的思考与探索

中国科技期刊研究 , 2005,
Abstract: 学术期刊网络化是我国学术期刊出版界所面临的一大课题,借助期刊网络化的种种优势,推动我国期刊国际化、网络化的进程,必须解决当前网络出版过程中所面临的各种问题,要实事求是地评价期刊网络化的优势,对存在的问题提出切实可行的解决方案,才能推动学术期刊网络化的健康发展。
我国战略石油安全储备最优规模问题研究
王尧,
安全与环境工程 , 2014,
Abstract: 在分析我国石油储备现状的基础上,以社会福利最大化为目标,通过建立静态局部均衡模型,并结合我国石油储备实际数据对模型进行参数估计和数值模拟计算,以求得我国最优的战略石油安全储备规模。结果表明在目前我国石油进口需求价格弹性较小的情况下,应对十年一遇的石油进口中断危机最优的战略石油安全储备规模为80天进口量,而面对规模更大的石油进口危机则需要更多的石油安全储备量。
中国原油进口运输通道安全研究
王尧,
大连海事大学学报 , 2014,
Abstract: 从我国原油进口运输通道的现状出发,综合考虑海上运输和管道运输,从定性角度,对运输通道的风险因素进行分析.在此基础上,建立基于运输成本和风险最小化的多目标规划模型,对我国原油进口运输网络进行优化.结果表明,对于长距离的海上运输,VLCC型船舶具有明显的成本优势;而对比海上运输,管道运输则具有较高的安全系数.
海上通道突发事件应急方案选择
朱乐群,,
大连海事大学学报 , 2016,
Abstract: 为确保海上通道突发事件应急响应的及时有效,针对应急响应过程中的方案决策问题,在案例推理方法思路的基础上提出一种两阶段相似度匹配的应急方案选择方法.首先,分别建立海上通道突发事件类型特征因子与情境特征因子体系.其次,在现有相似度计算方法的基础上,采用广义相似度,将不同数据属性进行统一,寻找与目标事件相似度最大的案例,从而确立目标事件的应急方案.最后,运用该方法对实际海上通道突发事件进行实例分析.研究结果表明,该方法具有可行性与有效性,可以在充分借鉴以往应急工作经验的基础上,较好地解决缺乏有效应急预案的海上通道突发事件的应急方案选择问题.
In order to make the emergency response for sea lines of communication effective and timely, a two-stage similarity matching of emergency plan selection method was proposed based on case-based reasoning, which focused on the problem of decision making in the progress of emergency response. Firstly, two different series of factors were created separately, which were category factors and environment factors. Secondly, based on the existing calculated method of similarity, the generalized similarity was applied to unify different data attributes to search the case having the maximum similarity degree with target event. Finally, two real cases study was introduced. Results show that the method is feasible and valid, which can solve the problem of emergency plan selecting better for lacking effective emergency response plan based on the previous emergency experience.
Consideration and Exploration on Process of Academic Periodicals Realizing On-line Propagation
学术期刊网络化进程的思考与探索

U Jing,

中国科技期刊研究 , 2005,
Abstract: 学术期刊网络化是我国学术期刊出版界所面临的一大课题,借助期刊网络化的种种优势,推动我国期刊国际化、网络化的进程,必须解决当前网络出版过程中所面临的各种问题,要实事求是地评价期刊网络化的优势,对存在的问题提出切实可行的解决方案,才能推动学术期刊网络化的健康发展。
天津地区雨季降水异常的前期强影响信号研究
,江津
气象 , 2010, DOI: 10.7519/j.issn.1000-0526.2010.11.002
Abstract: 利用1958—2007年天津地区4站月降水资料以及ncep/ncar月平均再分析数据资料集,采用相关分析和合成分析,研究了天津地区雨季降水异常的前期强影响信号。结果表明:天津地区雨季降水量在很大程度上决定了全年的降水量,雨季降水存在显著的年际变化和一定的年代际变化。天津地区雨季降水与前期冬季2月nao存在显著的反相关关系,前期冬季2月异常的nao可能是天津地区雨季降水异常的前期强影响信号。nao偏弱年,天津地区上游有强低值系统发展,南亚高压、高空副热带西风急流和热带东风急流位置偏北,阿拉伯海到孟加拉湾一带有季风低压和季风槽发展。上述系统的配置有利于天津地区雨季降水偏多。nao偏强年上述情况则相反。
天津地区雨季降水异常年大气环流特征分析
,江津
气象 , 2011, DOI: 10.7519/j.issn.1000-0526.2011.8.006
Abstract: 利用1958—2009年天津地区和中国160站月总降水资料以及ncep/ncar月平均再分析数据资料集,采用相关分析和合成分析,分别研究了天津地区雨季降水的变化特征以及异常年同期(7—8月)和前期(前一年12月至当年6月)大气环流的特征。结果表明:天津地区的降水大部分集中于雨季且雨季降水存在着年际变化和年代际变化。天津地区雨季降水偏多年同期,西太平洋副热带高压主体偏北,天津地区西北部有低值系统发展,对流层低层有正涡度发展,辐合上升运动较强,南亚高压和高空副热带西风急流偏北,西南暖湿气流输送较强;雨季降水偏少年同期情况正好相反。此外,天津地区雨季降水与前期夏季6月sam(南半球环状模)存在显著的反相关关系,这为天津地区雨季降水的短期气候预测提供了有参考意义的前兆信号。
硫排放控制区和碳排放限制下的班轮航线配船模型
,毛鹤达
大连海事大学学报 , 2017,
Abstract:
The operating costs of container liners will increase by reason of the accomplishment of the SOx emission control areas(SECA)and the imposition of carbon emission tax. The fleet deployment was studied by selecting three typical lines through the SECA. Taking the ship types, the number of ships and the speed as decision variables, a nonlinear programming model was established to achieve the minimization of container fleet cost and the carbon emission cost. The Lingo11.0 software was used to solve the model. Case study verifies the validity of the model and algorithm. Under the background of “Green Shipping”, the study can help liner companies to reply the dual pressures from environmental protection and operating cost, which has great practical significance.
轴向变密度铝泡沫件的动态和静态压缩实验与有限元模拟分析
Dynamic and static compression tests and FEA analyses of aluminum foam specimen with variable density in the loading direction

振华,
- , 2017, DOI: 10.16511/j.cnki.qhdxxb.2017.25.033
Abstract: 针对工程中常见的厚度方向变密度的闭孔铝泡沫材料,该文通过动态和静态压缩实验与模拟分析,探讨了大尺度变密度铝泡沫部件变形与吸能特性分析的有限元模型构建方法。对变密度铝泡沫大试样的准静态压缩和冲击压缩实验研究表明:厚度方向变密度铝泡沫材料的压缩过程呈现从低密度层开始的逐层屈服变形伴随整体变形的特性,与密度均匀的铝泡沫材料的变形特性显著不同。该文建立了变密度铝泡沫大试样的分层变密度变尺度有限元模型和近似的密度和尺度均匀的有限元模型,计算结果对比分析表明:分层变密度变尺度有限元模型能够模拟实际材料的逐层屈服变形特性,计算的试样准静态和冲击压缩变形与吸能特性等与实验结果相符;而基于均匀模型的计算结果则不能模拟逐层变形特性,与实验结果及理论特性明显不相符。分层变密度变尺度有限元模型的单元尺度会影响逐层屈服变形特性模拟结果,基于单元尺度接近实际铝泡沫材料胞元尺度的分层有限元模型的计算结果与实验结果一致性较好。这些研究结果对各种结构的铝泡沫材料应用研究具有重要意义。
Abstract:Closed-cell aluminum foams with variable densities in the loading direction are widely used. A finite-element mode (FEM) is used to model the foam deformation and energy absorption characteristics with dynamic and quasi-static compression tests. The results show that large aluminum foam specimens with variable densities have density-dependent layered deformation characteristics, which differ from uniform-density aluminum foams. Predictions of an FEM model with a layered variable density and layered element sizes are compared with those of a conventional FEA model with uniform density and element size. The computation results show that the layered gradual deformation characteristics can be simulated by the layered models with quasi-static and dynamic compression simulation results agreeing well with experimental data. The uniform model cannot accurately predict the layered gradual deformation characteristics. The element size of the layered models influences the simulated layered gradual deformation characteristics with simulation results using the layered model with element sizes equal to the foam cell diameter agreeing best with the experimental data. These results will improve engineering designs using aluminum foam materials.
车辆受垂向强冲击时座椅安全带的防护效果比较分析与锚点位置优化
Protection performance simulation and anchoring optimization of seat safety belts of vehicle under vertical intensive shock

,振华
- , 2016, DOI: 10.16511/j.cnki.qhdxxb.2016.25.041
Abstract: 针对特种车辆受垂向强冲击时座椅安全带对乘员防护性能问题研究较少的情况,该文应用数值仿真方法分析评价了分别配置5种形式安全带的座椅-乘员系统模型的垂向强冲击响应,在此基础上进行了5点式、6点式安全带的锚点位置优化研究,并分析检验了该优化方案在车辆正面、侧面碰撞工况的防护效果。研究结果量化评价了多点式安全带结构形式差异对乘员防护效果的显著影响,实现了以乘员的垂向冲击防护为主要目标的座椅安全带锚点位置优化分析,对于特种车辆座椅安全带系统的综合优化设计具有技术指导意义。
Abstract:The passenger protection performance of seat belts in special-purpose vehicles subjected to vertical shocks has rarely been studied. This paper describes numerical simulations of the vertical shock response of seat-passenger systems equipped with 5 different types of safety belts. Anchoring systems of 5 or 6 anchor-point belts are optimized to improve the protection under strong performance vertical shocks, and the influences of the anchoring configuration changes for the two types of safety belts also numerically analyzed for frontal and lateral collisions. The results show the remarkable influence of the configuration of multi-anchor-point safety belts on the passenger protection performance and the optimized anchoring systems of safety belts significantly improve the passenger's vertical shock protection. The study gives a comprehensive optimal design method for safety belt systems of special-purpose vehicles.
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