基于状态反馈精确线性化变结构控制的SSSC控制器设计

提出一种基于状态反馈精确线性化变结构控制的静止同步串联补偿器(SSSC)控制器设计方法.考虑到SSSC交流侧电压幅值和相角以及直流侧电容电压的动态调节过程,建立了SSSC在同步旋转dq坐标系下的非线性数学模型,在此模型的基础上,采用状态反馈精确线性化方法将原非线性系统转化为线性系统.然后,应用变结构控制原理设计SSSC控制器,同时通过PI控制稳定直流侧电容电压.最后,利用MATLAB仿真软件搭建了装设有SSSC的110kV输电系统的仿真模型,仿真结果表明了所设计的控制器能够很好地根据需求来改善电网输电能力,具有良好的暂态控制性能.     

基于不同故障情况的特高压变压器差动保护仿真研究

介绍了当前中国在建的特高压变压器的结构和参数,并建立了相应的动态仿真模型。根据特高压变压器的结构和运行特性,提出了针对特高压容量大,分体式结构的差动保护配置。通过模拟不同故障情况下差动保护的反应,对各种差动保护的灵敏性进行分析比较。仿真结果表明单独对调压绕组和补偿绕组分别配置差动保护能提高其匝间故障的灵敏性,故障分量差动保护可以提高重负荷情况下变压器内部发生轻微故障的灵敏性,分侧差动保护则可以避免励磁涌流和过励磁的影响,零序差动保护可以提高单相接地故障保护的灵敏性,尤其是接地点离中性点很近的轻微接地故障。     

Antiviral Effects of ABMA and DABMA against Influenza Virus In Vitro and In Vivo via Regulating the Endolysosomal Pathway and Autophagy

Influenza virus is an acute and highly contagious respiratory pathogen that causes great concern to public health and for which there is a need for extensive drug discovery. The small chemical compound ABMA and its analog DABMA, containing an adamantane or a dimethyl-adamantane group, respectively, have been demonstrated to inhibit multiple toxins (diphtheria toxin, Clostridium difficile toxin B, Clostridium sordellii lethal toxin) and viruses (Ebola, rabies virus, HSV-2) by acting on the host’s vesicle trafficking. Here, we showed that ABMA and DABMA have antiviral effects against both amantadine-sensitive influenza virus subtypes (H1N1 and H3N2), amantadine-resistant subtypes (H3N2), and influenza B virus with EC₅₀ values ranging from 2.83 to 7.36 µM (ABMA) and 1.82 to 6.73 µM (DABMA), respectively. ABMA and DABMA inhibited the replication of influenza virus genomic RNA and protein synthesis by interfering with the entry stage of the virus. Molecular docking evaluation together with activity against amantadine-resistant influenza virus strains suggested that ABMA and DABMA were not acting as M2 ion channel blockers. Subsequently, we found that early internalized H1N1 virions were retained in accumulated late endosome compartments after ABMA treatment. Additionally, ABMA disrupted the early stages of the H1N1 life cycle or viral RNA synthesis by interfering with autophagy. ABMA and DABMA protected mice from an intranasal H1N1 challenge with an improved survival rate of 67%. The present study suggests that ABMA and DABMA are potential antiviral leads for the development of a host-directed treatment against influenza virus infection.     

一种基于维度加权盲K近邻算法的数字预失真技术

传统的数字预失真(DPD)模型通常在所有的输入信号功率上采用单一多项式模型和单一记忆深度对功率放大器(PA)进行线性化矫正。然而,功率放大器在不同的功率水平下会呈现出不同的非线性特性,并产生不同的记忆效应。针对这一问题,该文提出一种基于维度加权盲K近邻(KNN)算法的数字预失真模型,所提模型根据功放当前输入信号以及记忆输入信号的幅度进行维度加权的KNN分类,组成维度加权盲KNN记忆多项式(WKMP)模型,并为每一类输入信号序列建立子模型。所提方法用Doherty功率放大器进行实验验证,使用带宽为30 MHz、频点为2.2 GHz的3载波长期演进(LTE)信号作为输入,反馈端使用122.88 MHz的采样率进行采样。实验结果表明,所提维度加权盲KNN分类方法与记忆多项式(MP)模型结合时,功放正向建模效果和数字预失真效果均超过了广义记忆多项式(GMP)模型,并远超记忆多项式模型的效果,实验结果验证了所提模型的优良性能。     

既有建筑物楼板结构和地基基础承载力检测技术的探讨

随着既有建筑物的改造和加固日益增多 ,如何对这些工程的结构性能和地基基础或桩基础承载力进行检测是当前建筑工程检测的一个主要课题。以工程实例为基础 ,对既有建筑物楼板结构和地基基础承载力检测技术进行了探讨 ,在此与同行们进行交流     

一种大孔超深穿透射孔器的设计

针对低孔低渗油气井射孔器穿孔孔径小、穿透力弱的问题,通过仿真和实验优化设计参数,设计了新型大孔超深穿透射孔器。在保证穿孔深度足够的前提下,穿孔孔径比同类射孔器的最大穿孔孔径提高15%以上,有利于正确评价油气藏和提高油气井产能,对低孔低渗储层的开发有着重要的意义。     

环境中邻苯二甲酸酯类污染物的检测方法

邻苯二甲酸酯类化合物(PAEs)是一类重要的化学危害物,广泛存在于水体、土壤、大气环境当中。文章介绍了近年来环境介质中PAEs检测的前处理技术和分析方法,并展望了其发展趋势。     

Adhesion Behavior of <Emphasis Type="Italic">Escherichia coli</Emphasis> on Plasma-Sprayed Zn and Ag Co-incorporated Calcium Silicate Coatings with Varying Surface Roughness

Our previous work demonstrated the good biocompatibility and bactericidal activity of a plasma-sprayed Zn and Ag co-incorporated calcium silicate ceramic coating (Ag-Ca₂ZnSi₂O₇), namely Ag-HT. In this work, we evaluated the influence of the surface roughness of Ag-HT coatings for Escherichia coli adhesion behavior, considering that surface topography is an important factor that regulates bacterial responses to biomaterials. Surface characteristics of as-sprayed and satin-finished Ag-HT coatings were investigated by scanning electron microscopy and measured using a surface roughness tester. Bacterial adhesion experiments showed that the number of viable E. coli cells on the as-sprayed or satin-finished coating surfaces was substantially lower than on the Ti-6Al-4V control surface, which can be explained by the antimicrobial effect of Ag and/or Zn. Moreover, the density of E. coli on the as-sprayed Ag-HT coating was considerably lower than on the satin-finished derivative. We attribute this difference to the fact that the as-sprayed coating surface was relatively smooth at a scale comparable to the size of an individual bacterium, while the satin-finished surface was slightly rough at this length scale and thus favored bacterial adhesion.     

TAs-15型FCC汽油脱砷剂的研究

极少量的砷化物可使加氢催化剂发生永久性中毒,为了保护加氢催化剂长期稳定运行,必须对催化裂化汽油中的砷化物进行脱除。对研制的TAs-15型FCC汽油脱砷剂进行原料适应性、1 600 h以上稳定性试验以及工艺条件对脱砷剂性能影响评价。结果表明,TAs-15脱砷剂具有较好的原料适应性及较高的脱砷性能,在反应温度（10～50） ℃、反应压力（0.5～2.0） MPa和空速（0.5～3.0） h^-1条件下,出口汽油中砷含量≤10×10^-9,完全可用于催化裂化汽油中砷化物的脱除。