聚偏氟乙烯-六氟丙烯多孔隔膜的改性研究进展

聚偏氟乙烯-六氟丙烯材料具有良好的耐化学腐蚀性、耐热性、机械性能等特点,是聚合物锂离子电池中重要的隔膜材料。但由于该材料存在结晶度较高、玻璃化温度高、孔隙率低等问题,需要进行改性。对近几年来国内外学者对该材料的改性研究进行了综述,总结出该材料的5种改性方法,即:有机聚合物改性法、纳米无机材料改性法、有机聚合物和无机纳米材料共混改性、稀土氧化物改性法、表面接枝改性法。最后对材料的发展前景进行了展望。     

Water‐Dispersible,pH‐Stable and Highly‐Luminescent Organic Dye Nanoparticles with Amplified Emissions for In Vitro and In Vivo Bioimaging

A new strategy is presented for using doped small‐molecule organic nanoparticles (NPs) to achieve high‐performance fluorescent probes with strong brightness, large Stokes shifts and tunable emissions for in vitro and in vivo imaging. The host organic NPs are used not only as carriers to encapsulate different doped dyes, but also as fluorescence resonance energy transfer donors to couple with the doped dyes (as acceptors) to achieve multicolor luminescence with amplified emissions (AE). The resulting optimum green emitting NPs show high brightness with quantum yield (QY) of up to 45% and AE of 12 times; and the red emitting NPs show QY of 14% and AE of 10 times. These highly‐luminescent doped NPs can be further surface modified with poly(maleic anhydride‐alt‐1‐octadecene)‐polyethylene glycol (C18PMH‐PEG), endowing them with excellent water dispersibility and robust stability in various bio‐environments covering wide pH values from 2 to 10. In this study, cytotoxicity studies and folic acid targeted cellular imaging of these multicolor probes are carried out to demonstrate their potential for in vitro imaging. On this basis, applications of the NP probes in in vivo and ex vivo imaging are also investigated. Intense fluorescent signals of the doped NPs are distinctly, selectively and spatially resolved in tumor sites with high sensitivity, due to the preferential accumulation of the NPs in tumor sites through the passive enhanced permeability and retention effect. The results clearly indicate that these doped NPs are promising fluorescent probes for biomedical applications.     

基于行驶仿真试验的履带车辆传动箱疲劳寿命预测仿真研究

履带车辆传动箱在设计时采用静强度设计理论,由于无法准确反映其在不同任务工况下的各组成部件动态特性,同时由于传统测试手段及试验方法的局限性,使对随机载荷作用下的各组成部件的可靠性及寿命预测研究具有很大困难,导致实际寿命与设计寿命有很大差距,严重影响了履带车辆整车可靠性.通过建立基于MSC.ATV的行驶仿真试验平台,获得了...     

单井回灌地源热泵地下传热数值模型研究

在空间上将单井回灌系统地下传热问题分为井内与井外两部分,通过有限容积法(FVM)分别建立了井内与井外传热的数值模型。利用该数值模型对单井回灌系统的一些重要参数进行了研究,发现热传导和热对流是单井回灌地热换热器的主要传热方式,凡是影响热传导和热对流的地质参数和系统参数都对换热器的传热性能有明显影响。此外,利用现场测试的数据验证了计算结果的有效性。     

Efficiency of Vertical Geothermal Heat Exchangers in the Ground Source Heat Pump System

Taking the fluid temperature distribution along the borehole depth into account, a new quasi-three-dimensional model for vertical ground heat exchangers has been established, which provides a better understanding of the heat transfer processes in the geothermal heat exchangers. On this basis the efficiency of the borehole has been defined and its analytical expression derived. Comparison with the previous two-dimensional model shows that the quasi-three-dimensional model is more rational and more accurate to depict the practical feature of the conduction of geothermal heat exchanger, and the efficiency notion can be easily used to determine the inlet and outlet temperature of the circulating fluid inside the heat exchanger.     

融化和凝固温度对三水醋酸钠相变储热性能的影响

为了研究储热材料三水醋酸钠(含成核剂十二水磷酸氢二钠和增稠剂羧甲基纤维素)在实际贮能工程中应用的融化和凝固温度范围,通过不同水浴温度下的融化实验和不同冷却条件下的凝固实验,得到了储热材料的相变性能参数.实验结果表明,储热材料的过冷度随着加热水浴温度的升高有增大的趋势,水浴温度在83℃以内时其相变性能较稳定,超过这个温度,其储热性能就无法保证;冷却温度降低,其过冷度有增大的趋势,但只要是在常温条件下的水浴或空气浴中冷却,即使冷却温度变化较大,储热材料的相变性能仍比较稳定.     

基于广义S变换的吸收衰减分析技术在油气识别中的应用

广义S变换克服了小波基函数变化趋势固定不变的缺陷,具有较好的时频分析效果和较高的灵活性。将广义S变换引入到地震波吸收衰减分析中,应用最小二乘谱模拟方法消除地层反射系数对子波振幅谱的影响,突出含油气储层在地震记录上的响应;引入“低频增加、高频衰减”(LFR&HFA)面积差值法使得含油气储层的影响占主导地位,提高了油气识别的准确性。物理模型和实际地震资料的应用验证了上述方法的可行性;应用上述方法对实际地震资料进行油气识别,取得的结果与实际钻井结果吻合,证明了上述方法的实用性。     

Optical and electrical properties of porous silicon layer formed on the textured surface by electrochemical etching

Porous silicon(PS) layers were formed on textured crystalline silicon by electrochemical etching in HF-based electrolyte.Optical and electrical properties of the TMAH textured surfaces with PS formation are studied. Moreover,the influences of the initial structures and the anodizing time on the optical and electrical properties of the surfaces after PS formation are investigated.The results show that the TMAH textured surfaces with PS formation present a dramatic decrease in reflectance.The longer the anodizing time is,the lower the reflectance.Moreover,an initial surface with bigger pyramids achieved lower reflectance in a short wavelength range.A minimum reflectance of 3.86%at 460 nm is achieved for a short anodizing time of 2 min.Furthermore,the reflectance spectrum of the sample,which was etched in 3 vol.%TMAH for 25 min and then anodized for 20 min,is extremely flat and lies between 3.67%and 6.15%in the wavelength range from 400 to 1040 nm.In addition,for a short anodizing time,a slight increase in the effective carrier lifetime is observed.Our results indicate that PS layers formed on a TMAH textured surface for a short anodization treatment can be used as both broadband antireflection coatings and passivation layers for the application in solar cells.     

我国小城镇可持续发展评价研究

本文借鉴近年来国内外可持续发展研究成果,构建出小城镇可持续发展评价指标体系,以山东省相州镇为研究对象,在建立评价模型的基础上,计算得出其可持续发展目前处于优异状态,但资源要素的可持续性不容乐观,已在很大程度上制约了该城镇的整体可持续发展。     

不冻泉应急水源地水文地质特征及开发利用研究

不冻泉一带赋存第四系松散岩类孔隙潜水和构造裂隙水两种地下水类型,可建立孔隙水和构造裂隙水类型水源地.受研究区水文地质条件的制约,孔隙水类型水源地仅适用于每年的5～9月份暖季丰水期,水质较好,开采便利,允许开采量为1.5×104m3/d,;构造裂隙水虽埋藏较深,但不受季节限制,水质较好,可供全年开采.针对该区水资源利用现...