焦炭高温反应炉温度控制系统的改进

介绍了焦炭高温反应炉的温控工艺及程控曲线，给出了程控曲线的控制结构、主回路以及实现多套PI参数控制的方法。     

一种分数阶PI~αD~β控制器的设计与化简

针对分数阶PIαDβ控制器数字实现相对复杂、结构调整相对困难这一情况,依据分数阶微积分算子最佳有理逼近原理,提出了一种逼近频带可选择的分数阶PIαDβ控制器设计与化简方法。这种分数阶控制器设计与化简方法可以方便地用程序来实现,为分数阶控制器的工程化应用提供了一个途径。     

有机特种纤维介绍(二)

对有机特种纤维中的超高相对分子质量聚乙烯(UMHWPE)纤维、聚对苯撑苯并二噁唑(PBO)纤维、聚酰亚胺(P)I纤维、聚(2,5-二羟基-1,4-苯撑吡啶并二咪唑)(PIPD)纤维的结构与性能、发展情况、制备方法以及主要应用领域进行了简要介绍,最后简要展望了这4种特种纤维的发展前景。     

模型算法控制与常规PI调节规律的关系

介绍了模型算法控制的基本原理 ,通过在单变量情况下对模型算法控制和常规PI调节规律进行了比较 ,揭示了模型算法控制的优越性。     

民用电网谐波电流检测方法及仿真研究

针对民用电网中存在的电压不稳、三相不平衡和中线电流大等问题,在传统的ip-iq法基础上,采用对称分量法和零序电流分离法研究电流中的零序分量问题,并结合PI调节器建立数学模型对其谐波、基波负序和零序电流进行了实时检测。结果表明,该方法可准确地检测出电网电流中含有的谐波、基波负序和零序电流,且检测精度高、实时性好。     

基于前馈控制的交流伺服系统精确定位的研究

介绍了交流伺服电动机数学模型,叙述了伺服控制系统的设计原理和具体方法,在位置环、速度环和电流环的3环PI伺服控制系统的基础上,引进位置前馈控制来提高定位控制的性能,研究了前馈PI的控制方法.通过仿真进行了与普通伺服控制系统的对比,未加前馈控制跟踪误差较大,在位置环加前馈控制恒速段跟踪误差较小,但在加减速度段,误差成单调变化,在速度环上再加上前馈控制,位置跟踪误差会更接近于零.结果表明,引进前馈控制的PI交流伺服系统可以实现高精度位置控制,验证了前馈控制在指令信号跟踪性和抗干扰性方面的良好效果.     

三层复合PI薄膜厚度比对其介电性能影响

利用微乳化-热液法制备纳米分散液,制备了掺杂层与中间纯聚酰亚胺（PI）层厚度比不同的三层复合薄膜.在相同环境条件下通过透射电镜（TEM）、击穿场强和耐电晕测试分别对三层复合薄膜的微观结构和纳米掺杂层厚度比例的变化与介电性能的影响进行了分析.TEM测试结果表明纳米粒子在有机基体中的分散均匀;介电强度测试和耐电晕测试表明随掺杂层厚度比例的增加,击穿场强逐渐下降,耐电晕性能呈先上升后下降趋势.     

模糊控制在聚合装置的应用

介绍了模糊控制在我厂聚丙烯聚合装置的投用,并结合聚合的工艺特点详细介绍了模糊控制的理论和对聚合的模糊控制方案。     

miR-223 Inhibits Lipid Deposition and Inflammation by Suppressing Toll-Like Receptor 4 Signaling in Macrophages

Atherosclerosis and its complications rank as the leading cause of death with the hallmarks of lipid deposition and inflammatory response. MicroRNAs (miRNAs) have recently garnered increasing interests in cardiovascular disease. In this study, we investigated the function of miR-223 and the underlying mechanism in atherosclerosis. In the atherosclerotic ApoE^−/− mice models, an obvious increase of miR-223 was observed in aortic atherosclerotic lesions. In lipopolysaccharide (LPS) activated macrophages, its expression was decreased. The miR-223 overexpression significantly attenuated macrophage foam cell formation, lipid accumulation and pro-inflammatory cytokine production, which were reversed by anti-miR-223 inhibitor transfection. Mechanism assay corroborated that miR-223 negatively regulated the activation of the toll-like receptor 4 (TLR4)-nuclear factor-κB (NF-κB) pathway. Pretreatment with a specific inhibitor of NF-κB (pyrrolidinedithiocarbamate, PDTC) strikingly abrogated miR-223 silence-induced lipid deposition and inflammatory cytokine production. Furthermore, PI3K/AKT was activated by miR-223 up-regulation. Pretreatment with PI3K/AKT inhibitor {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002 strikingly ameliorated the inhibitory effects of miR-223 on the activation of TLR4 and p65, concomitant with the increase in lipid deposition and inflammatory cytokine production. Together, these data indicate that miR-223 up-regulation might abrogate the development of atherosclerosis by blocking TLR4 signaling through activation of the PI3K/AKT pathway, and provides a promising therapeutic avenue for the treatment of atherosclerosis.     

Effect of alumina on the structure and properties of polyimide matrix films

To improve the properties of polyimide (PI), different mass fractions of alumina (Al₂O₃) nanoparticles, unmodified or modified by KH550, were incorporated into PI matrix to form PI/Al₂O₃ hybrid films by in situ polymerisation. The effects of Al₂O₃ additives on the structure, dielectric and mechanical properties of the films were studied. Fourier transform infrared spectroscopy confirmed the successful preparation of PI/Al₂O₃ hybrid films, and the microstructures of the samples showed a more uniform dispersion of the modified Al₂O₃ nanoparticles than the unmodified ones in the matrix. The dielectric constant of the films increased with increasing filler content, and the maximum electrical breakdown strength of 311 MV m^?1 was obtained with a filler content of 8.0 wt-% modified Al₂O₃ in the matrix. Both unmodified and modified Al₂O₃-reinforced PI hybrids demonstrated improved mechanical properties compared with the PI matrix. Moreover, the properties of films with Al₂O₃ modified by KH550 were better.