长庆油田陕北区原油破乳剂的筛选和复配

实验考察了8种市售水溶性破乳荆对长庆油田陕北区有代表性的宝塔区、安塞和子长原油(均为低硫中间基-石蜡基原油)的脱水效果(加量100mg／L，脱水温度55℃，时间3h)。目前长庆采油一厂使用的YT-100和延炼集团使用的GT-940对这3种原油的脱水效果均较好，但对子长原油的脱水率不高，分别为69．7％和58．9％。在由所选性能较好的破乳刺组成的4种二元复配物中，GT-940 HQ96-1对3种原油的脱水效果均高于单剂，最佳配比分别为4：1，4：1，3：2；其余3种复配物则对原油有选择性，其中GT-940 YT-100相近(97．5％)；YT-100 HQ96-1仅能改善子长原油的脱水效果，配比为4：1时脱水率最高(76．4％)；SP-169 HQ96-1仅能改善宝塔区原油的脱水效果．配比3：2和2：3时脱水率最高(92．9％)。表5参6。     

基于神经网络的导弹变结构制导律

导弹的打击精度容易受干扰的影响.针对这些未知干扰的存在,利用RBF神经网络具有自学习的能力,并结合变结构控制方法的鲁棒性,提出了一种基于RBF神经网络的滑模变结构控制的导弹制导律.利用RBF神经网络对干扰进行在线估计,克服了未知干扰对制导精度的不利影响,并且分析了闭环系统的稳定性.仿真结果表明,RBF神经网络能够很好地估计出干扰,所设计的制导律能够不受干扰的影响,从而快速精确地打击到目标,验证了该制导律的有效性和鲁棒性.     

社区建成环境与中国居民体力活动的关联性研究综述与展望

Physical inactivity poses growing threats to the Chinese population,associated with booming urbanization and unfriendly living environment in recent years.This paper is a systematic review to investigate the neighborhood built environment factors correlated with physical activity in the Chinese population,including children and adolescents,adults,and the elderly.The Web of Science has been searched for articles in English,and the China National Knowledge Infrastructure has been searched for articles in Chinese.A total of 35 articles published before January 2020 have been included in this review.Then these articles are studied with a focus on six major aspects-transportation,density,design,diversity,amenity,and walkability–finding that the neighborhood built environment factors related to physical activity vary across age groups and different types of neighborhoods.In the context of refined community governance,future research should make further explorations from aspects including different resident groups,local characteristics of neighborhoods,built environment characteristics,research design,and other relevant variables.     

粉末活性炭和超滤组合工艺处理低温低浊水试验研究

通过浸没式超滤试验考察了粉末活性炭和超滤组合工艺对低温低浊水的净水效能以及对膜污染的缓解作用,并对其机理进行探讨.试验结果表明,粉末活性炭和超滤组合工艺处理低温低浊水时,能够降低膜表面的负荷,对可逆污染和不可逆污染具有一定的缓解作用;粉末活性炭投加量为10mg/L时,粉末活性炭和超滤组合工艺出水的浊度低于0.06NTU,对CODMn,UV254的平均去除率分别为20.9%,25%,比单纯的超滤工艺的去除率分别提高了10%,15%.     

非线性大弹性材料的位移分析

本篇短文阐述混合有限元理论在非线性，大变形和大应变条件下的运动关系及常用虚位移原理，并采用随机拉格朗日－欧拉方程分析有限元网格和材料单元的位移。     

基于ZigBee的电机故障诊断系统设计

针对目前集群现场电机故障诊断采用有线传感网络的诸多局限性,提出了一种利用ZigBee无线传感网络构建电机故障诊断系统的设计方案.设计了无线模块的硬件系统和软件系统以及上位机诊断界面,以ZigBee组建的无线传感网络实现电机的电压、电流和温度数据的采集,结合基于数学模型的电机故障诊断算法进行电机故障诊断.结果表明,该系统能准确地采集电机工作电压、电流和温度数据,并可以诊断电机的工作状态以及能对故障电机实施紧急停机操作,为工程应用提供了重要的依据.     

VFTO下SF_6间隙及绝缘子沿面预放电电流特性

对SF6气体间隙及绝缘子沿面的预放电电流进行了测量。测量结果证实 ,正极性VFTO作用下SF6的击穿遵从先导击穿机理 ;而负极性VFTO作用下SF6的击穿一般遵从茎先导机理或流注放电导致直接击穿。气压大小直接影响先导的起始电压及先导的间隔时间。存在绝缘子时 ,先导形成时间间隔及步长变短 ,且在快速振荡冲击电压作用下会出现“逆放电”现象 ,这有利于先导形成 ,从而降低了闪络电压。     

在线预决策紧急控制系统中的若干问题

探讨“在线预决策、实时匹配”暂态稳定紧急控制技术中的伪量测量设置问题和暂态后的静态安全分析问题。针对紧急控制系统的量测量有限的困难,利用EMS提供的信息和典型方式信息,采用二次规划法补充伪量测量。除了保证整个系统的暂态稳定性外,还考虑了系统在实施紧急控制后的静态安全性。这两种算法的可行性和有效性已在山东电网和广东韶关电网的在线预决策系统中得到工业验证。     

Characteristic of filamentous fungal diversity and dynamics associated with wheat Qu and the traditional fermentation of Chinese rice wine

Chinese rice wine, a traditional alcoholic beverage, is fermented from steamed rice with a starter culture of wheat Qu which is either inoculated spontaneously with various microorganisms in natural environment or inoculated artificially with certain microorganisms. The diversity of filamentous fungi in wheat Qu and the fermentation mashes of Chinese rice wine was studied by high‐throughput sequencing. The results indicated that filamentous fungi varied in wheat Qu and fermentation periods. Moreover, Aspergillus was the dominant filamentous fungi at genus levels. On that basis, quantitative real‐time PCR was used to quantify some dominant Aspergillus species. It was found that Aspergillus species in wheat Qu were more abundant than that in various fermentation mashes and continually decreased until the end of rice wine fermentation. Furthermore, it was found that different organic acids were produced by microorganisms at different fermentation stages might due to the changes of oxygen and nutrient content.     

基于硫化铋低温碱性熔炼的熔体物化性质分析

基于硫化铋精矿低温碱性熔炼技术,采用半球点法、旋转柱体法、阿基米德法和拉筒法,测定Bi2S3-NaOH体系的熔化温度、高温密度以及熔体的粘度和表面张力,研究不同NaOH含量和温度对Bi_2S_3-NaOH体系物化性质的影响,结果表明,随着温度的升高,Bi_2S_3-NaOH体系熔化过程分为缓慢收缩,快速收缩和流动阶段,熔化温度随着NaOH含量的增加先减小,达到最低共熔温度后逐渐增大;Bi_2S_3-NaOH熔体的高温密度、表面张力、粘度在NaOH含量一定条件下都随着温度的升高增加而减小,温度一定条件下随着氢氧化钠含量的增加而减小。研究结果可为硫化铋精矿低温清洁冶金技术的优化提供基础数据参考。