高性能生物质纤维基锂电池隔膜研究进展

隔膜是电池的重要组成部分,传统的商用聚烯烃隔膜不仅润湿性和热稳定性较差,并且原料不可再生.为了满足可持续发展的需求,具有较好热稳定性、可降解以及可再生等优点的生物质纤维基锂电池隔膜受到广泛关注.本文概述了纤维素微米纤维基隔膜、纤维素纳米纤维基隔膜以及其他种类生物质纤维基锂电池隔膜的研究进展,并对该领域未来的研究方法和发...     

Dynamic hierarchical collaborative caching scheme in ultra-dense networks

Pushing popular contents to the edge of the network can meet the growing demand for data traffic, reduce latency and relieve the pressure of the backhaul. However, considering the limited storage space of the base stations, it is impossible to cache all the contents, especially in ultra-dense network ( UDN). Furthermore, the uneven distribution of mobile users results in load imbalance among small base stations (SBSs) in both time and space, which also affects the caching strategy. To overcome these shortcoming, the impact of the changing load imbalance in UDN was investigated, and then a dynamic hierarchical collaborative caching (DHCC) scheme was proposed to optimize latency and caching hit rate. The storage of the SBS is logically divided into the independent caching layer and the collaborative caching layer. The independent caching layer caches the most popular contents for local users爷interest, and the collaborative caching layer caches contents as much as possible for the benefit of content diversity in the region. Different SBSs have respective storage space layer division ratios, according to their real-time traffic load. For SBSs with heavy load, the independent caching layers are allocated with more space. Otherwise, the collaborative caching layers could store more contents with larger space. The simulation results show that, DHCC improved both transmission latency and hit rate compared with existing caching schemes.     

前纵梁后段热成形数值模拟分析

对某车型前纵梁后段建立数值分析模型,利用AutoForm软件进行热成形模拟分析,针对分析结果中的起皱缺陷优化模型,再次进行模拟分析后起皱缺陷消除,经实际生产验证,按优化方案开发热成形模生产的零件质量与第二次分析结果趋势一致。     

冶金因素对低合金钢点蚀扩展过程的影响

通过室内间浸挂片与模拟闭塞腐蚀电池试验对4种常用N i-Cr系与Mn系低合金钢的点蚀扩展速率作了比较,研究了4种钢的腐蚀行为,从冶金因素上分析探讨了引起点蚀扩展速率差异的机理.结果表明:短期内N i-Cr系钢的点蚀扩展速率小于Mn系钢,而在模拟长期挂片的OCC试验中N i-Cr系钢的点蚀扩展速率却大于Mn系钢.初步分析认为钢中的夹杂物对钢的点蚀扩展有促进作用;Cr在点蚀扩展初期尚未完全活化对提高钢的点蚀扩展阻力有利,在中后期Cr的活化促进了点蚀的扩展.     

Owner-dominated building information modeling and lean construction in a megaproject

The integration of building information modeling (BIM) and lean construction (LC) provides a solution for the management of megaprojects. Previous studies have generally focused on the theoretical or empirical adoption of BIM and LC. Moreover, only a few studies have examined the approach of simultaneously using BIM and LC in megaprojects. Therefore, an intensive study on the application of BIM and LC in megaprojects, particularly to explore considerably effective integrated application modes of BIM and LC in megaprojects, will substantially promote the management efficiency of megaprojects. The current study describes a method that integrates owner-dominated BIM and LC that was developed in a case study. The proposed method provides a framework for all stakeholders to use BIM and LC in a megaproject dominated by the owner. The interactional relations among the owner, BIM, and LC were analyzed and positive interactions were identified. These positive interactions served as a basis for the implementation of this integrated approach in a case study and could be applied to other megaprojects. The megaproject (i.e., airport construction project) was examined to verify the performance of the developed method. Results showed that the integration of BIM and LC dominated by the owner can improve management performance and achieve high quality standard.     

氧化铁纳米棒的制备及其在光催化降解水溶性活性染料中的应用

采用均相沉淀法制备了半导体纳米材料α-Fe2O3.通过XRD、TEM等手段对该材料进行了分析.研究了烧结温度、光催化剂的用量、光照等因素对催化剂光催化降解活性染料的影响.并用红外和紫外的分析方法验证了光催化降解效果.结果表明,在适当的用量和350℃烧结并在紫外光照射下,α-Fe2O3对活性染料B-RN蓝、活性艳兰K-NR有极强的光催化降解活性.     

基于车辆成组的V2V协同计算卸载策略研究

在车联网中引入V2V计算卸载技术可以缓解当前车载计算卸载热点地区路边单元(RSU)计算资源不足的问题.然而,在计算卸载过程中,服务车辆可能因故障离组或自主选择离开车组.如何返回任务结果并高效地分配计算任务是需要进一步研究的关键问题.提出了一个车组内计算任务分配算法,考虑了可能导致车辆离开车组的因素影响,以及组中每辆车能...     

励磁系统中发电机调差系数试验及分析

依照行业标准的要求,通过现场实际试验,对某发电厂中各台机组的调差系数进行了测定分析,得出了相对准确的发电机调差率、并列点的调差率,并进行了各台机组之间调差配合试验,验证了测得的各台机组调差率的正确性。     

基于多模型随机组合的水文集合预报方法研究

准确、可靠的水文预报是水资源开发利用的基础.集合预报以概率或区间的形式表征预报的不确定性,是未来水文预报研究的重点发展方向.本文提出了一种基于多模型随机组合的水文集合预报方法.首先通过加权形式将多种预报模型进行组合;再采用多目标优化算法率定各成员模型权重的上、下限;最后在优化的上、下限内随机生成权重以构建集合预报.以汉...     

光伏组件测试的复现性详解

随着IEC 61215:2005标准的换版,依据此标准进行的光伏组件测试时的组件功率判定方法也出现了较大变化,其中一处的变化就是在最终功率判定(即Gate No.2判定)时引入了复现性的概念,针对复现性的定义、重要性及算法进行了推演和阐述.