高土壤电阻率变电站降阻措施分析及降阻目标选择

采用接地系统辅助设计软件包CDEGS,结合工程实例对局部换土、深井接地、引外接地和敷设接地极(接地模块或离子接地棒) 4种高土壤电阻率变电站常用降阻措施进行了仿真计算。基于计算结果分析了每种降阻措施的降阻特性,并提出了工程应用建议。此外,在确保人身和设备安全前提下,探讨了如何合理选择降阻目标避免过度设计。     

基于多分量融合的调度端小电流接地选线策略

针对中性点不接地的配电系统站端接地选线方式投资大、维护成本高,零序电流采样监测运行维护困难的问题,提出一种基于多分量融合的调度端小电流接地选线方法。首先,在现有调度自动化系统监测数据集中,针对性分析了对接地故障较为敏感的单分量特征及其影响因素;其次,综合考虑实际运行可靠性和判断准确性,提出了基于三角模融合的接地选线判据;进而通过归一化计算各线路接地概率,实现在调度端远程的故障线路准确选线;最后,通过在某电力公司实际部署基于所提方法的小电流接地选线功能模块进行实测验证。运行结果显示,所提方法具有良好的选线成功率,能够较好支撑调度端的远程故障定位,具有较高的推广价值。     

覆膜滤料用聚四氟乙烯微孔膜的制备及其性能研究

针对市场上常用4种SSG范围的聚四氟乙烯(polytetrafluoroethylene,简称PTFE)树脂原料,采用双向拉伸法制备PTFE微孔膜,分析微孔膜性能的差异,并确定最适用于覆膜滤料用PTFE树脂原料.分析了不同分子量PTFE树脂原料的相对标准密度(SSG)、粒径、挤出压力和含水率等参数,采用不同分子量树脂原料来制备PTFE微孔膜,并表征PTFE微孔膜力学、厚度、结晶度、孔径、孔隙率和透气性能.研究表明:SSG的大小会影响PTFE微孔膜的力学性能(最大力、断裂伸长率)和孔结构(孔径、孔隙率),随SSG的增大呈现先上升后下降的趋势,在2.170～2.189范围内达到最优;结晶度与SSG的大小成正相关,而微孔膜透气性能主要与其孔结构有关,与孔径和孔隙率的变化趋势具有一致性.得出结论:PTFE树脂原料SSG分布在2.170～2.189范围时,制备的PTFE微孔膜最适用于覆膜滤料领域.     

镀膜玻璃研究进展

镀膜玻璃作为一种深加工玻璃,是建筑领域不可或缺的材料之一.通过对镀膜玻璃的性能、分类以及制备方法进行阐述,对镀膜玻璃的传热系数、遮蔽系数和太阳能总透射比进行分析,对磁控溅射法、化学气相沉积法、喷雾热解法和溶胶-凝胶法等制备技术进行分析讨论,为镀膜玻璃的应用发展提供应用基础和先决条件.     

基于多端口能量路由器的多能互补系统研究与测试

针对旅游旺季期间某地区负荷出现较严重的过载现象,且当地可再生能源存在功率波动较大、难以消纳的问题,依托云南省某配电网智能化改造升级示范项目,研制了一套多能(含小水电、光伏、储能)、多端口的能量路由器装置及其能量管理系统,并对基于多端口能量路由器的多能互补系统进行了研究与测试.首先对多端口能量路由器的拓扑结构和技术参数进行了介绍;其次对能量管理系统的功能进行了阐述;最后在对各端口分别进行调试后,进行全端口联合运行功能测试.测试结果表明,各端口能分别正常运行,全端口联合运行功能正常,能有效平抑直流母线电压波动,实现上层功率指令跟踪,同时在大功率运行状态下,输出波形畸变率较低,效率基本满足要求,能用于解决当地负荷过载问题,实现能量的合理配置与利用.     

基于有限元方法的CeCl3和NdCl3在LiCl-KCl熔盐中的电极动力学模拟

充分理解锕系元素和镧系元素在熔盐中的行为和性质是实现反应堆乏燃料熔盐电解后处理的关键,然而熔盐电解实验所需的高温环境、腐蚀性熔盐甚至放射性物质等条件限制了实验的广泛开展。为寻求一种低成本且可靠的获取元素在熔盐中性质的途径,采用有限元方法在不同温度下模拟了不同浓度的三氯化铈和三氯化钕在LiCl-KCl熔盐中的循环伏安曲线,并与实验数据做了对比。结果表明,有限元方法能够较为准确地反映实际电化学过程,继而为乏燃料熔盐电解后处理提供数据支持。     

Genome-Wide Analysis Identified a Set of Conserved lncRNAs Associated with Domestication-Related Traits in Rice

Crop domestication, which gives rise to a number of desirable agronomic traits, represents a typical model system of plant evolution. Numerous genomic evidence has proven that noncoding RNAs such as microRNAs and phasiRNAs, as well as protein-coding genes, are selected during crop domestication. However, limited data shows plant long noncoding RNAs (lncRNAs) are also involved in this biological process. In this study, we performed strand-specific RNA sequencing of cultivated rice Oryza sativa ssp. japonica and O. sativa ssp. indica, and their wild progenitor O. rufipogon. We identified a total of 8528 lncRNAs, including 4072 lncRNAs in O. rufipogon, 2091 lncRNAs in japonica rice, and 2365 lncRNAs in indica rice. The lncRNAs expressed in wild rice were revealed to be shorter in length and had fewer exon numbers when compared with lncRNAs from cultivated rice. We also identified a number of conserved lncRNAs in the wild and cultivated rice. The functional study demonstrated that several of these conserved lncRNAs are associated with domestication-related traits in rice. Our findings revealed the feature and conservation of lncRNAs during rice domestication and will further promote functional studies of lncRNAs in rice.     

负荷功率模型的最优特征选择研究

负荷功率呈现时空多样的变化特性,其影响因素众多,构建负荷功率模型的关键之一是确定模型的输入特征量。文中着重研究短期负荷功率模型的特征选择,旨在从历史负荷、气象、日期等众多特征中选出最优特征集。首先,采用最大信息系数、基于支持向量机的递归特征消除法和随机森林3种不同特征选择方法分别对输入特征集进行选择;然后,根据对比分析结果提出基于遗传算法的最优特征集搜索策略,选定XGBoost预测模型的误差指标作为适应性函数进行迭代优化搜索;最终,确定负荷功率模型的最优特征输入集。采用某地区220 kV变电站母线负荷数据进行算例分析,对比各方法所选特征集作为功率模型输入得到的负荷预测效果,验证了文中方法的有效性和准确性。     

Robust Superhydrophobic Fabric for Durability,Self-Cleaning,and Oil/Water Separation via Thiol–Acrylate Polymerization

In recent years, highly efficient oil/water separation materials have brought much attention. It requests superhydrophobic surfaces with a rapid and facile separation process, excellent durability, and large-scale fabrication. Herein, a facile vapor-liquid sol-gel, and free radical polymerization reaction method to prepare the durable and robust superhydrophobic cotton fabric is proposed. Moreover, the fabric can be used for highly efficient and various oil/water separation. It is prepared via a simple two-step process, including a vapor-liquid sol-gel process to deposit with thiols particles, and then followed a free radical polymerization reaction to graft 2,2,3,4,4,4-hexafluorobutyl methacrylate. Scanning electron microscopy and Fourier transform infrared spectrometry prove that the rough structures are generated from the hydrolysis condensation reaction between tetraethyl orthosilicate and 3-mercaptopropyltriethoxysilane. As a result, the synthetic chemical composition provided by the natural fabric and silica nanoparticles synergistically construct a superhydrophobic surface with water contact angles and shedding angle of 158° and 9°, respectively. Additionally, the treated fabric exhibits excellent chemical resistance and self-cleaning ability. Remarkably, the fabric still retains superhydrophobic and excellent mechanical robustness after 30 cycles of various oil/water separation. In summary, the resultant fabrics with excellent chemical resistance, remarkable mechanical robustness, and versatile separation abilities have potential applications in various oil/water separations.