旧城商业街道景观与户外广告的共生

户外广告是城市街道景观环境中的一个要素,是文化信息的载体,而如何将其与具有深厚历史文化底蕴的旧城商业街景观进行良好的结合是文章探讨的重点。首先提出了存在的问题,接下来归纳了旧城商业街户外广告设计的5点原则,并且从5个方面分析讨论了街道空间中的户外广告设置,由此得出户外广告与旧城商业街道景观共生的方法。     

沥青混凝土路面摊铺用料动态监控

文章以信阳至九里关高速公路沥青路面工程项目第2合同段沥青混凝土路面的施工为例。谈谈如何在确保路面面层质量的前提下，使用“用料核算表”动态地控制路面面层的用料数量。     

A Comparative Study on Open Circuit Voltage Models for Lithium-ion Batteries

The current research of state of charge(SoC) online estimation of lithium-ion battery(LiB) in electric vehicles(EVs)mainly focuses on adopting or improving of battery models and estimation filters. However, little attention has been paid to the accuracy of various open circuit voltage(OCV) models for correcting the SoC with aid of the ampere-hour counting method. This paper presents a comprehensive comparison study on eighteen OCV models which cover the majority of models used in literature. The low-current OCV tests are conducted on the typical commercial LiFePO_4/graphite(LFP) and LiNiMnCoO_2/graphite(NMC) cells to obtain the experimental OCV-SoC curves at different ambient temperature and aging stages. With selected OCV and SoC points from experimental OCV-SoC curves, the parameters of each OCV model are determined by curve fitting toolbox of MATLAB 2013. Then the fitting OCV-SoC curves based on diversified OCV models are also obtained. The indicator of root-mean-square error(RMSE) between the experimental data and fitted data is selected to evaluate the adaptabilities of these OCV models for their main features, advantages,and limitations. The sensitivities of OCV models to ambient temperatures, aging stages, numbers of data points,and SoC regions are studied for both NMC and LFP cells. Furthermore, the influences of these models on SoC estimation are discussed. Through a comprehensive comparison and analysis on OCV models, some recommendations in selecting OCV models for both NMC and LFP cells are given.     

电液制动系统轮缸压力调节特性试验研究

电液制动系统轮缸压力变化特性直接影响制动器夹紧力控制,由于存在机、电、液严重耦合现象,难以精确建模表达。考虑轮缸初始压力和占空比两个因素,以稳态压力变化值代表压力变化率进行试验研究,绘制了轮缸压力变化MAP 图,并对MAP 图进行分析。结果显示:轮缸稳态压力变化值随轮缸初始压力变化存在拐点,该拐点为轮缸活塞运动终止压力,本系统中该压力为2. 8 MPa;轮缸稳态压力变化值与占空比之间呈线性关系,但由于开关阀开关特性的差异,直线未经过原点,增压过程中,直线与横轴交于占空比3% 附近;减压过程中,直线与横轴交于占空比-5%附近。该压力特性研究以MAP 图的形式表达了系统的非线性特性,并找出了系统中具有线性关系的部分,有助于下一步的制动器夹紧力控制研究。     

Perfluorosulfonated ionomers membranes: Melt‐processing and characterization for ion exchange applications

Perflurosulfonated ionomers membranes with different ionic‐exchange capacity were successfully fabricated via melt‐extruding and casting of their –SO₂F precursors. A systematical investigation of the thermal stability, crystallinity, and rheological properties of the precursors was performed to secure their optimized processing conditions. The tensile properties of acid‐form membranes are found to increase with base‐hydrolysis time, where a tensile strength of 38.2 MPa is readily obtained after 24 h's base‐hydrolysis. The content of –SO₂F or –SO₃H containing side‐chains plays an important role in the thermal stability, rheological, and mechanical properties of the precursor or the acid‐form membranes. The strong ionic interactions, attributed to the –SO₃H groups, lead to decreased crystallinity and tensile strength for different IEC membranes. The acid‐form membranes exhibit good proton conductivity and low methanol crossover in comparison with reference Nafion membrane. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39944.     

Selective hydrogenation of furfural to cyclopentanone over Cu-Ni-Al hydrotalcite-based catalysts

A series of Cu-Ni-Al hydrotalcites derived oxides with a (Cu+Ni)/Al mole ratio of 3 with varied Cu/Ni mole ratio (from 0.017 to 0.5, with a Cu ratio of 0.0125 to 0.25) were prepared by co-precipitation method, then applied to the hydrogenation of furfural in aqueous. Their catalytic performance for liquid phase hydrogenation of furfural to prepare cyclopentanone was described in detail, considering reaction temperature, catalyst composition, reaction time and so on. The yield of cyclopentanone was influenced by the mole ratio of Cu-Ni-Al based heterogeneous catalyst and depended on the reaction conditions. The yield of cyclopentanone was up to 95.8% when the reaction was carried out under 413 K with H₂ pressure of 40 bar for 8 h. The catalysts were characterized by X-ray powder diffraction (XRD), scanning electron microscope (SEM) and H₂ temperature-programmed reduction (H₂-TPR).     

化学沉淀法处理水中氟硅酸的研究

以水中氟硅酸的去除为研究对象,首先对氟离子选择电极法测量氟硅酸浓度的适用范围进行了分析,并在此基础上探讨了氟硅酸与熟石灰在不同反应条件下的动力学特征,同时给出了熟石灰及聚合氯化铝加入量对于脱氟效果的影响规律,并通过XRD表征证明了溶液中的氟是以氟化钙的形式析出。     

Long-Term Spinal Ventral Root Reimplantation,but not Bone Marrow Mononuclear Cell Treatment,Positively Influences Ultrastructural Synapse Recovery and Motor Axonal Regrowth

We recently proposed a new surgical approach to treat ventral root avulsion, resulting in motoneuron protection. The present work combined such a surgical approach with bone marrow mononuclear cells (MC) therapy. Therefore, MC were added to the site of reimplantation. Female Lewis rats (seven weeks old) were subjected to unilateral ventral root avulsion (VRA) at L4, L5 and L6 levels and divided into the following groups (n = 5 for each group): Avulsion, sealant reimplanted roots and sealant reimplanted roots plus MC. After four weeks and 12 weeks post-surgery, the lumbar intumescences were processed by transmission electron microscopy, to analyze synaptic inputs to the repaired α motoneurons. Also, the ipsi and contralateral sciatic nerves were processed for axon counting and morphometry. The ultrastructural results indicated a significant preservation of inhibitory pre-synaptic boutons in the groups repaired with sealant alone and associated with MC therapy. Moreover, the average number of axons was higher in treated groups when compared to avulsion only. Complementary to the fiber counting, the morphometric analysis of axonal diameter and “g” ratio demonstrated that root reimplantation improved the motor component recovery. In conclusion, the data herein demonstrate that root reimplantation at the lesion site may be considered a therapeutic approach, following proximal lesions in the interface of central nervous system (CNS) and peripheral nervous system (PNS), and that MC therapy does not further improve the regenerative recovery, up to 12 weeks post lesion.     

Sterols from Mytilidae Show Anti-Aging and Neuroprotective Effects via Anti-Oxidative Activity

For screening anti-aging samples from marine natural products, K6001 yeast strain was employed as a bioassay system. The active mussel extract was separated to give an active sterol fraction (SF). SF was further purified, and four sterol compounds were obtained. Their structures were determined to be cholesterol (CHOL), brassicasterol, crinosterol, and 24-methylenecholesterol. All compounds showed similar anti-aging activity. To understand the action mechanism involved, anti-oxidative experiments, reactive oxygen species (ROS) assays, and malondialdehyde (MDA) tests were performed on the most abundant compound, CHOL. Results indicated that treatment with CHOL increases the survival rate of yeast under oxidative stress and decreases ROS and MDA levels. In addition, mutations of uth1, skn7, sod1, and sod2, which feature a K6001 background, were employed and the lifespans of the mutations were not affected by CHOL. These results demonstrate that CHOL exerts anti-aging effects via anti-oxidative stress. Based on the connection between neuroprotection and anti-aging, neuroprotective experiments were performed in PC12 cells. Paraquat was used to induce oxidative stress and the results showed that the CHOL and SF protect the PC12 cells from the injury induced by paraquat. In addition, these substance exhibited nerve growth factor (NGF) mimic activities again confirmed their neuroprotective function.