盐酸在硫酸镉水溶液中热力学性质的研究

在HCl-CdSO4-H2O体系中,恒定溶液总离子强度为I=0.2,0.4,0.6,0.8,1.0,1.5 mol.kg-1,CdSO4在溶液中的离子强度分数恒定为yB=0.00,0.10,0.20,0.30,0.50和0.70条件下,应用经典的电动势方法,测定无液体接界电池在278.15~318.15 K温度范围内的电动势。由于体系中存在硫酸的二级解离,应用数学迭代方法确定平衡体系中氢离子的浓度,AgCl-Ag电极的标准电极电势应用Bates方法确定,根据测得电池的电动势数据计算了混合溶液中HCl的活度系数γA。结果表明,在溶液中总离子强度保持恒定时,HCl的活度系数服从Harned规则,混合物中HCl的活度系数lgγA对热力学温度T作图是一条直线。     

英国ICT与IT学科的整合

英国IT学科起源于计算机科学学科.20世纪60年代英国中学开设了计算机科学课程.之后,IT学科逐渐发展起来.80年代后期,IT学科的课程体系进一步充实发展.90年代以后,信息与传播技术(ICT)新概念在英国教育界受到广泛的重视,但是它并没有取代IT学科,IT课程依然是英国重要的课程,贯穿于大、中、小学.     

聚丙烯腈纤维在水浴牵伸过程中应力-应变曲线的研究

主要考察了聚丙烯腈纤维在水浴牵伸过程中的应力—应变曲线，以及温度、牵伸速率、水分对应力—应变曲线的影响。结果表明：聚丙烯腈纤维在水温为室温(26℃)、30℃～70℃时属于细颈牵伸，在80℃、90℃时是类橡胶牵伸，当水温低于60℃和牵伸速率太快时纤维易产生毛丝。所以在牵伸过程中，水温不能低于60％，牵伸速率要适中，在本实验条件下，200mm／min、500mm／min比较合适，而且在水中牵伸比在空气中牵伸效果好，可获得较大的牵伸率。     

碳气凝胶的充放电性能研究

以碳气凝胶作锂离子模拟电池的正极,金属锂作模拟电池的负极进行电化学实验,通过改变催化剂和质量百分比来控制碳气凝胶的结构.采用恒流充放电模式对碳气凝胶结构和电化学性能间关系进行了研究.研究表明碳气凝胶的充放电曲线与碳气凝胶的结构间存在密切的联系.     

浅谈如何提升局域网安全

随着科技的发展，互联网的普及，企业的网络应用需求越来越频繁，随之产生的安全问题也变得越来越重要。如果单位局域网系统遭遇安全袭击，那么可能会给企业各方面带来严重的损失。ARP攻击、黑客入侵、非法窃取等越来越多的安全问题摆放在我们的面前，怎样有效地保护企业网络运行安全已成为企业管理者或网络管理员迫切需要解决的问题，下面我给大家介绍几种常用的办法，以提高企业局域网的安全性能。     

Research on image segmentation of Miao costume patterns based on the RSKP-UNet model北大核心CSCD

The Miao nationality is the sixth largest ethnic group in China which has a history of thousands of years. It has created a unique material culture and spiritual culture in its development process and the Miao costume is a highly condensed collection of the material and spiritual culture of the Miao nationality. As one of the unique symbols of Miao culture the Miao costume has profound cultural heritage and cultural connotations. The patterns of the Miao costume are particularly eye-catching as they not only symbolize the wisdom of the Miao people in thousands of years of production and life but also symbolize the pursuit of the good spirit of the Miao people. However under the impact of modern pop culture and foreign culture these cultural symbols are gradually disappearing. In order to protect and inherit them the Miao costume pattern segmentation has become the most important work. However the Miao costume pattern segmentation is quite difficult. At present there are few studies on the extraction classification identification and preservation of the features of Miao costume pattern segmentation. With the excellent segmentation performance of the U-Net model and the advantages of easy deployment the paper improves the basic structure of the U-Net model and proposes a Miao costume pattern segmentation algorithm based on the RSKP-UNet Residual Selective-Kernel Parallel U-Net model. The algorithm adds Residual modules in the encoder part of the U-Net model to improve the feature extraction capability of the model and embeds the SKNet modules and ParNet modules in the decoder part to enhance the feature expression capability of the model. The paper uses evaluation metrics to measure the segmentation performance of the model and compares it with four segmentation models based on deep learning. The paper not only combines the current research focus-deep learning and attention mechanism but also introduces the Lovász-hinge loss function to effectively solve the problem of class imbalance in the Miao costume patterns. The RSKP-UNet model is better than other models in various segmentation indicators. Compared with the benchmark model U-Net the Dice coefficient IoU precision recall and accuracy are improved by 6. 98% 11. 07% 2. 89% 6. 75% and 3. 92% . The segmentation algorithm proposed in this paper realizes the extraction of the element content of the Miao costume patterns through image segmentation of Miao costume patterns which can be used to build the Miao costume pattern database in this way thus helping designers relevant researchers and organizations to provide research foundation and completing the protection and inheritance of the Miao costume culture. The paper also provides some reference for the segmentation research of other minority costume patterns. © 2022 Authors. All rights reserved.     

中欧标准在水泥胶砂强度测试中的对比研究

随着中国建筑企业海外业务开拓,中外标准在建筑材料质量、测试方法及性能评价方面的差异给中国建筑施工带来了巨大困扰。本文通过对比中欧标准水泥胶砂强度测试,分析其在仪器设备、实验步骤、结果处理等内容的异同点,为中国建筑企业在水泥性能检测及评价方面提供借鉴依据,规避海外业务风险,并对水泥标准建设的提出几点建议。     

递进式干油集中润滑系统在风电设备中的应用

风电机组的润滑点数量在20～80个不等,使用递进式集中润滑系统是性价比较优的选择。风电机组变桨润滑系统是一种典型的递进式集中润滑系统。风电机组变桨润滑系统采用间隙式定量注脂方式,注脂间隙和单元排量根据风电机组需求订制,间隙时间一般由系统自带PLC进行设置,单元排量由分配器内油腔容积决定。     

电力通信光缆的运行及维护探讨

作为电力系统维护重要组成部分,通信光缆的运行与维护对于提高电力通信光缆的运行质量具有重要作用。文章首先介绍了电力通信光缆故障处理原则,然后具体阐述了电力通信光缆的运行维护措施,以期为相关技术与维护人员提供参考。     

含亚胺结构片段的喹唑啉酮衍生物的合成与抗肿瘤活性研究

设计并合成了一系列含亚胺结构片段的新型喹唑啉酮衍生物,最终的15个化合物结构经¹HNMR、¹³CNMR和HR-MS确证,并评价了它们对野生型表皮生长因子受体酪氨酸激酶(EGFR^wt)和两种人癌细胞株(A549、HepG2)的体外抗肿瘤活性。结果表明,部分化合物具有良好的活性,特别是化合物(E)-2-((4-((3,4-二氟亚苄基)氨基)苯氧基)甲基)-3-甲基喹唑啉-4(3 H)-酮对EGFR^wt激酶的IC₅₀达到0.037μmol/L,对A549和HepG2两种肿瘤细胞的IC₅₀值优于吉非替尼。