Burning Cave-Pipe Coil-Kang Coupled Heating System Research

Nowadays,people still rely on traditional heating methods in rural areas of northern China,such as Kang(bed-stoves) and burning caves in cold winter.Field measurements of indoor environment were carried out in several rural houses with burning-cave-coil-Kang coupling heating system in northern China.The results show that this system is able to realize the graded use of internal energy of burning cave.The temperature of supply pipe water ranged from 30 ℃ to 50 ℃ which met the demands in 74.7% of time.The surface temperature of Kang maintained at above 25 ℃.Compared with traditional burning cave,using burning-cave-coil-Kang coupled with heating system has a higher thermal efficiency of 48.9%,which is 8.32% higher than the traditional one.     

康有为教育思想评述

康有为是中国近代史上著名的教育家之一。他的教育思想主要有：教学内容和方法上的近代化尝试；主张男女平等，重视女子教育；提倡创立各级各类新式学堂，完善和优化学制等。他的教育思想对我们今天的教育改革仍具有启迪和借鉴的价值。     

严寒地区村镇住宅冬季室内热舒适环境研究

随着我国经济的发展、人们民生活水平的提高,人们们对住宅舒适性的要求也日益提高,日前舒适与健康已被提到了住宅设计的首位.在严寒地区,人们更加注重住宅冬季室内的热舒适问题.本文从影响热舒适环境的主要因素入手,分析严寒地区村镇住宅的特殊性,包括气候条件、地区特点、住宅现状、农民与生活习惯及火炕微热环境等;注重差异性研究,根据中西方的差异、城乡的差异,同时结合我国国情和严寒地区村镇居民的居住特点,提出适合严寒地区村镇住宅冬季室内舒适温度区间为15~18℃,为严寒地区村镇住宅节能计算、热舒适环境与绿色生态住宅的设计提供必要的理论依据.     

正戊烷异构化催化剂低温酸性改性

通过酸性改性制备正戊烷异构化低温非贵金属催化剂。结果表明正戊烷异构化遵循典型的双功能催化反应机理。金属含量一定时,通过酸性改性,催化剂活性、选择性均有明显提高,最佳反应温度从300℃降低到250℃。Ni-F/HM催化剂在Ni,F质量分数分别为4%,5%时,反应性能最佳,催化剂比表面积为327.63 m2/g,总孔容为0.238 2 mL/g,平面孔半径为1.088 4 nm。在温度为250℃,压力为2.0 MPa,空速为1.0 h-1,氢烃摩尔比为4∶1,正戊烷转化率为70.49%,异戊烷收率为68.27%,异戊烷选择性为96.85%,液体收率为97.78%。该结果优于目前国内外同类催化剂的应用结果。     

8-羟基喹啉萃取-氟试剂分光光度法测定氟

以８－羟基喹啉萃取分离干扰离子，用氟试剂－Ｌａ３＋显色体系测定氟。对萃取条件及固定剂的选择进行了考查。合成样品回收率９８．９％，样品加标回收率９７．７％。方法简便、准确。     

杭州市浅层地下水中氟含量分布特征的成因分析

本文从环境地球化学的角度,研究了杭州市浅层地下水中氟的含量分布特征及其成因。研究结果表明,该区地下水中氟的含量偏低,氟主要来自含水层中含氟矿物的镕解;平原区和山区地下水中氟的含量水平和分布特征的差异,主要是由于两者的原生地球化学环境和水文地质条件的不同所致。     

HDI trimer based fluorine containing urethane methacrylates for hydrophobic photocured coatings

In this work, hexamethylene diisocyanate (HDI) trimer based two urethane methacrylates were synthesized by reacting 2-hydroxyethyl methacrylate (HEMA) and a fluoroalcohol with HDI trimer. Due to the high viscosity of the fluorinated methacrylates, they were applied onto glass substrates after mixing with tripropylene glycol diacrylate (TPGDA). The performance of the fluorinated resins were compared to a fluorine free HDI trimer based trimethacrylate. The TPGDA diluted formulations were better in terms of surface wettability than the neat resins. TPGDA diluted fluorinated resins exhibited a water contact angle of 109°± 2. All coatings exhibited high surface hardness (4H and 5H) and good adhesion.     

New fluorinated acrylic polymers for improving weatherability of building stone materials

Acrylic polymers are widely used for their suitability to be shaped in different molecular structures. However, while very appropriate for many applications, these materials are characterized by a limited outdoor stability. In order to improve this last characteristic while maintaining the simple and flexible synthetic route, a study was performed based on the preparation of fluorinated polymers from acrylic monomers where several H-atoms in different positions were replaced with F-atoms. The structure design was aimed to optimize (e.g. minimize) the fluorine content of the final material while obtaining improved chemical and photochemical stability, good filmability and limited permeability to condensed water. The preparation of polymers of methacrylates derived from partially fluorinated alcohol by free radical mechanism is described. The fluorine content and distribution in the macromolecules is modulated by selecting different monomers and by copolymerization with nonfluorinated acrylates or vinylethers. The selection of the comonomers and their relative content in the polymer allows to control the glass transition temperature and the filmability as well as the protection efficiency of the coating. Polymers derived from more complex monomers such as -trifluoromethyl-methylacrylate are also described. The suitability of these new materials for protective coating of stones is tested by evaluating their stability to different chemical and physical agents and their selective permeability to water vapour vs. condensed water.     

Synthesis and the Structure to Property Relationship of Monoperfluoroalkyl Polyethylene Glycol

Monoprotected polyethylene glycols (PEG) react with epichlorohydrin to furnish PEGylated epoxides. The latter were converted into the corresponding α-(2-F-alkylethyl)thiomethyl polyethylene glycols by treatment with 2-F-alkylethanethiol. Surface activity of the obtained surfactants was investigated by evaluation of PEG and perfluoroalkyl chains length on the critical micelle concentration (CMC), surface and interfacial tensions.     

Morphologies of nanostructured TiO2 doped with F on Ti–6Al–4V alloy

The formation of nanotubes in sulphuric/hydrofluoric acid electrolyte at controlled voltage is investigated on Ti–6Al–4V alloy used for load-bearing prosthetic applications. The effects of anodizing time and voltage on film morphology, composition and microstructure are studied by scanning and transmission electron microscopy, Rutherford backscattering spectroscopy (RBS), and Raman spectroscopy. Fluorine content in the films was of a particular interest for enhancement of antibacterial properties of the surface. The efficiencies of film formation are determined as about 40% and 80% for anodizing at 20 V and 60 V respectively for shorter anodizing time and as about 1 and 5% for longer anodizing time. For 5 min of anodizing, higher voltage conditions results in a thicker barrier layer. At extended anodizing time a further disruption of the nanotubular morphology and formation of approximately 1.5 μm-thick nanoporous film is promoted. The films grown at 20 V contain from 4 at.% to 6 at.% of fluorine. RBS detects about 13 at.% of fluorine incorporated in the film formed at 60 V for 60 min, possibly associated with a greater film thickness. The oxide film material consists of amorphous titania matrix doped with V₂O₅ and Al₂O₃.