Fe-Cr-Co系永磁合金结构与性能

Fe-Cr-Co系合金是一类可加工的永磁材料，具有较好的综合磁性能，本文对该合金的相结构与相转变，磁性能、三步热处理工艺、形变时效工艺以及添加元素对合金的重要影响等方面作了较为全面的概述，介绍了Fe-Cr-Co系永磁合金的研究进展情况。     

CPE、ACR等加工助剂对PVC—U流变性能的影响

研究了CPE、ACR等加工助剂及填料对PVC—U流变性能的影响。结果表明：CPE和ACR都能促进PVC的塑化,但作为冲击改性剂的CPE所起的塑化作用较ACR要小,硬脂酸的加入延长了PVC的塑化时间,在本体系中起到了外润滑剂的作用,填料的加入延缓了共混体系的塑化。     

Guanabenz Downregulates Inflammatory Responses via eIF2α Dependent and Independent Signaling

Integrated stress responses (ISR) may lead to cell death and tissue degeneration via eukaryotic translation initiation factor 2 α (eIF2α)-mediated signaling. Alleviating ISR by modulating eIF2α phosphorylation can reduce the symptoms associated with various diseases. Guanabenz is known to elevate the phosphorylation level of eIF2α and reduce pro-inflammatory responses. However, the mechanism of its action is not well understood. In this study, we investigated the signaling pathway through which guanabenz induces anti-inflammatory effects in immune cells, in particular macrophages. Genome-wide mRNA profiling followed by principal component analysis predicted that colony stimulating factor 2 (Csf2, or GM-CSF as granulocyte macrophage colony stimulating factor) is involved in the responses to guanabenz. A partial silencing of Csf2 or eIF2α by RNA interference revealed that Interleukin-6 (IL6), Csf2, and Cyclooxygenase-2 (Cox2) are downregulated by guanabenz-driven phosphorylation of eIF2α. Although expression of IL1β and Tumor Necrosis Factor-α (TNFα) was suppressed by guanabenz, their downregulation was not directly mediated by eIF2α signaling. Collectively, the result herein indicates that anti-inflammatory effects by guanabenz are mediated by not only eIF2α-dependent but also eIF2α-independent signaling.     

A Macro‐Damaged Viscoelastoplastic Model for Thermomechanical and Rate‐Dependent Behavior of Glassy Polymers

The primary objective of this paper is to develop a macro‐damaged viscoelastoplastic constitutive model to describe large deformation mechanical behavior for glassy polymers at various kinds of experimental conditions. First of all, quasi‐static and dynamic tension and compression tests were carried out to obtain stress–strain responses over wide range of rates and temperatures for two glassy polymeric materials, polymethylmethacrylate and polycarbonate. Then a phenomenological macroscopic damage model, covering effects of strain rates, temperatures, and effective strain, is incorporated into the constitutive model in the previous work. Furthermore, two distinct criteria are applied to predict the damage evolution affected by strain rate and temperature at elastic phase and plastic phase, respectively. The validations of the novel developed damaged model are made by the better matches with the testing data compared with the original undamaged model, and excellent agreements with the experimental result in all cases.

     

回质回热吸附式制冷循环的热力学分析与方案优选

吸附式制冷是一种能利用低品位热能的节能环保的制冷方式。在空调工况下,硅胶-水回质回热系统应用最多。为了解在特定工况下选择何种循环能提升系统性能,应用热力学第一与第二定律评价指标分析了基本循环、回质循环、回质回热循环的COP、(火用)效率、循环熵产。分析表明,回质循环存在推荐最高热源温度和最优热源温度,回质回热循环存在推荐最低热源温度和最优热源温度。例如对于典型夏季空调工况热源温度90℃、蒸发温度10℃、冷凝温度40℃,回质循环的推荐最高热源温度为93℃,高于实际热源温度90℃,选用回质循环更合适而非回质回热循环。最后,对制冷机组的分析表明给出的方法和推荐工作温度区间能针对实际系统给出方案优选和系统控制的指导性建议。     

Mechanical and electret properties of polypropylene unwoven fabrics reinforced with POSS for electret filter materials

A novel polypropylene/Polyhedral oligomeric silsesquioxanes (PP/POSS) composite unwoven fabric with permanent electret was prepared through melt-blown process with corona charging. Field-emission scanning electron microscope (FESEM) and wide-angle X-ray diffraction (WAXRD) were employed to investigate the morphology of the composite fibers and the distribution of POSS nanoparticles on the surface of the fibers, respectively. POSS acted as nucleating agent and accelerated the crystallization process during nonisothermal cooling. The utmost stable charge density of PP/POSS melt-blown unwoven fabric was improved by 78.4% compared with the neat PP unwoven fabric. The maximum value of collection efficiency measured by monodisperse polystyrene aerosol (PSL) (particle size: 0.3 μm) collection could reach 97.36% for PP/POSS composite melt-blown unwoven fabric, which improved by 9% compared with neat PP melt-blown unwoven fabric. Moreover, both stress and elongation at break of the PP/POSS melt-blown unwoven fabrics were improved compared with PP unwoven fabric.     

狄舍尔穿孔调整参数计算方法的研究

基于狄舍尔穿孔机轧辊开度的分析，讨论了调整参数的计算方法，提出将送进角作为改善毛管横向壁厚均匀性的手段。     

浅析重组形势下的煤炭企业集团产业链整合

在中央提出加快培育煤炭大集团决策的推动下,各主要产煤省区纷纷重组、整合大型煤炭企业。大型煤企组建后,将面临多种复杂的问题,最突出的当数主业与辅业、一元主导与多元发展的问题,而影响大型煤企长远发展大计的当聚焦在其产业链的设计、延展和闭合上。初步分析和探讨了重组后的煤炭企业应当构建什么样的产业链以及产业链整合的相应对策。     

新型电控柴油喷射系统的仿真模型与参数优化

电控泵－管－阀－嘴（PPVI）柴油喷射系统是一种新型的电磁阀溢流控制式直列泵供油系统,在此前已建立其物理与数学模型的基础上,利用SIMULINK软件,建立了系统的仿真计算模型。根据该模型对系统 计算机辅助仿真计算,经与油泵台试验结果的对照表明,使有该模型可以方便灵活地对系统参数进行优化匹配,为电控泵－管－阀－嘴系统的深入研究提供了有效的工具。     

太阳电池及方阵的模型与仿真

介绍了太阳电池及方阵的数学模型和电路模型,特别针对用于计算机解析计算的模型进行了详细地描述。介绍了利用模型对太阳电池及方阵的特性,并进行了初步仿真,结果表明该模型能够模拟太阳电池及方阵的特性。