首页 | 官方网站   微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   43篇
  国内免费   1篇
  完全免费   12篇
工业技术   56篇
  2019年   1篇
  2018年   2篇
  2017年   3篇
  2016年   5篇
  2015年   4篇
  2014年   5篇
  2013年   5篇
  2012年   5篇
  2011年   5篇
  2010年   5篇
  2009年   4篇
  2008年   1篇
  2007年   4篇
  2006年   1篇
  2003年   1篇
  2001年   2篇
  2000年   1篇
  1999年   1篇
  1993年   1篇
排序方式: 共有56条查询结果,搜索用时 31 毫秒
1.
International regulations formerly focused on consumer safety. Now, attention is shifted towards the preservation of the global quality of goods. New control methods (HACCP) can increase the quality of the whole chain. A correct approach to weight losses is a primary goal in the cold chain. Direct fuel consumption (with respect to each mass unit transported) is reduced when the transported weight per vehicle is increased; indirect consumption is optimised when the efficiency of the refrigerating unit is increased and when the overall heat transfer coefficient of the insulated body is minimised. Ageing of the vehicles must be minimised. A voluntary energy labelling program of vehicles provides an excellent opportunity to reduce energy consumption. New insulating products can theoretically worsen the energy budget. Every effort should be made to improve the basic thermal characteristics of new insulating materials and new vehicle design should be studied. Energy and environmental benefits can be obtained by the optimisation of the logistic chain. Multi-temperature vehicles and mini-containers can solve certain specific problems.  相似文献   
2.
吸收稳定系统能耗分析及优化   总被引:1,自引:0,他引:1  
为了全面评价催化裂化装置吸收稳定系统工艺流程的优劣,不仅要对解析塔进行能耗分析,同时应实现以节能为目的的系统工艺最优化。应用HYSYS化工过程模拟软件对某炼油厂催化裂化装置吸收稳定系统进行模拟计算,并对多种进料工况进行研究分析。结果表明:冷进料工艺减少了系统的物料循环,提高了生产能力;另外,冷进料工艺也减少了系统的能量消耗,降低了生产成本,有利于装置的扩能增效。所以,冷进料是最合理的工艺流程。  相似文献   
3.
Hydrogen fueling stations are emerging around and in larger cities in Europe and United States together with a number of hydrogen vehicles. The most stations comply with the refueling protocol made by society of automotive engineers and they use a cascade fueling system on-site for filling the vehicles. The cascade system at the station has to be refueled as the tank sizes are limited by the high pressures. The process of filling a vehicle and afterward bringing the tanks in refueling station back to same pressures, are called a complete refueling cycle. This study analyzes power consumption of refueling stations as a function of number of tanks, volume of the tanks and the pressure in the tanks. This is done for a complete refueling cycle. It is found that the energy consumption decreases with the number of tanks approaching an exponential function. The compressor accounts for app. 50% of the energy consumption. Going from one tank to three tanks gives an energy saving of app. 30%. Adding more than four tanks the energy saving per extra added tank is less than 4%. The optimal numbers of tanks in the cascade system are three or four.  相似文献   
4.
We consider the problem of assigning transmission powers to the nodes of an ad hoc wireless network, so that the total power consumed is minimized and the resulting network is biconnected, i.e., there are at least two node-disjoint paths between any pair of nodes. Biconnected communication graphs are important to ensure fault tolerance, since ad hoc networks are used in critical application domains where failures are likely to occur. A mixed integer programming formulation of the problem can be exactly solved to optimality by a commercial solver only for moderately sized problems. We recall a mixed integer programming formulation that can be exactly solved to optimality by a commercial solver only for very moderately sized problems. We propose a quick greedy algorithm and a GRASP with path-relinking heuristic for solving real-life sized problems. Computational experiments involving practical issues such as energy consumption and interference have been performed and reported for problems with up to 800 nodes, illustrating the effectiveness and the efficiency of the new algorithms. Both the greedy algorithm and the GRASP heuristic outperformed the best heuristic in the literature for very large problem sizes.  相似文献   
5.
6.
降低网络系统能耗是当前计算机领域构建绿色网络迫切需要解决的关键问题.网络设备的传输服务速率自适应性为优化网络能耗和提高网络能效提供了有效的途径,文中提出一种基于速率自适应的全局性和分布式的能耗优化路由策略.该策略从网络全局路由的角度出发,根据网络系统的服务特征,将为数据提供传输服务的网络组件抽象为一个处理域.为求解处理域中速率自适应时的服务速率和工作状态平均转换次数,把处理域的服务过程视为可变服务速率的服务系统.然后以网络系统总能耗最小化为目标,并满足相关的路由和性能等约束条件,建立基于速率自适应的网络能耗优化路由模型,利用改进的蚁群算法对模型进行求解.在仿真实验中,将文中提出的能耗优化路由的分布式启发算法与相关文献的OSPF和GreenOSPF节能路由算法进行比较,给出算法在能耗和延时方面的对比结果.多种实验情况下的对比结果表明,文中提出的能耗优化路由策略能更有效地匹配速率自适应机制,具有较好的节能效果,从而达到优化和降低能耗的目的.  相似文献   
7.
三相流环状集输管网能量利用优化研究是通过环状集输管网的物理模型、管内油气水三相流之间的温降模型,建立了以最小能耗为目标函数的数学模型,分析出了掺水量、温度、压力与总能量消耗之间的变化关系,找到了影响总能耗的主要因素、次要因素及最小因素分别为掺水温度、掺水流量、压力,并得到管道总能耗的最优方案。在生产实际过程中尽量降低掺水温度以使总能量消耗最少。  相似文献   
8.
蒸汽是影响全厂能耗的主要因素,蒸汽系统优化是炼油厂节能降耗的重点.某炼油厂单系列千万吨级炼油项目通过不断实施优化技术和管理措施,对全厂蒸汽系统持续优化,节能成效明显,取得了良好的经济效益.该厂通过实施催化裂化装置余热锅炉改造、优化流程提高热供料温度、降低汽轮机背压蒸汽压力、优化塔的工艺参数、优化动力锅炉运行方式等措施,节约蒸汽83.9 t/h,创造经济效益2.08×10^8 RMB¥/a,炼油蒸汽单耗由2009年的64.7 kg/t降至34.5 kg/t,降幅达46.67%,全厂炼油实际能耗降低108.02 MJ/t,实际综合能耗由2009年的2 830.41MJ/t降低至2 392.45MJ/t,降幅为15.47%.  相似文献   
9.
片上网络作为未来多核处理器片上互连的发展趋势,其能耗优化问题越来越受到重视。动态电压频率调节是一种有效的运行时能耗管理手段,近年来已被许多研究者用在片上网络的能耗优化上。针对目前主流的分布式控制方案存在软硬件代价高的缺点,提出了一种全局控制的能耗优化方法,通过监控程序的关键性访存信息来动态调整片上网络的电压和频率。仿真结果表明,在允许性能损失5%的限制下,该方法可以实现约45%的能耗节省。  相似文献   
10.
陈树  徐圆 《计算机工程》2014,(11):97-100,105
针对传统LEACH协议中簇头数量自由度高以及分布不均所导致能量消耗过多的缺陷,提出一种基于优化分簇的、能耗均匀的改进LEACH协议。改进簇头选择机制,在常规能量阈值选取簇头节点的过程中,引入最优簇半径控制策略,改善簇头节点的物理分布位置,达到网络能量的均衡,同时引入网络覆盖率控制簇头数目,避免产生多余的簇头节点。该算法还在传统LEACH协议的基础上,使用CH-VCH交替轮寻策略简化计算量。仿真结果表明,该改进LEACH协议能解决传统LEACH协议存在的能量问题,使网络的能量消耗更加均匀,并在一定程度上延长网络的生存期限。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号