高阻值Cd1-xZnxTe晶体的生长及其性能测试

通过适当的工艺措施，采用Bridgman法生长了直径为30mm的X射线及γ射线探测器级的Cd.9Zn0．1Te晶锭．测试结果表明：该晶锭结晶质量良好，位错密度低，成分均匀，杂质含量低，红外透过率和电阻率都十分接近本征Cd.9Zn0．1Te的值．并从晶体的生长特性、缺陷和杂质的角度，分析了生长高性能晶体的条件，研究了生长Cdl-xZnxTe晶体的x值与缺陷和杂质浓度之间的关系．     

Preparation of fluoroacrylate nanocopolymer by miniemulsion polymerization used in textile finishing

Latex based on fluoroacrylate (TAN) and other comonomers was prepared via miniemulsion polymerization in the presence of stearyl trimethyl ammonium chloride (STAC) and 2, 2′‐azobis (2‐amidinopropane) dihydrochloride (ABAP) as a water soluble initiator. Light transmittance studies demonstrated that the light transmittance of prepared emulsions increases with the amount of TAN, STAC, cosolvent DPM, and hydrophobe DM. Given suitable reaction temperature and quantities of TAN, STAC, DPM, and DM, a copolymer emulsion of fluoroacylate with a particle size of 50 nm was produced. The water repellency tested on polyester fabrics displayed greater effectiveness than that of commercial products with higher fluorine content. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1466–1472, 2004     

半透明氮化硅陶瓷的放电等离子烧结制备及性能

用放电等离子烧结(spark plasma sintering,SPS)技术,以质量分数(下同)为9%氮化铝(A1N),3%氧化镁(MgO)为烧结助剂,在1850℃烧结5min,成功制备了半透明氮化硅(Si3N4)陶瓷.半透明Si3N4陶瓷在中红外波段表现出良好的透过率,最大透过率为66.4%.SPS的快速致密化过程保证了烧结体具有良好的晶体结构,有利于提高透过率.SPS快速的烧结过程和A1N和MgO的加入能够有效抑制烧结过程中Si3N4陶瓷由α相向β相的转变,是制备光学性能良好的Si3N4陶瓷的关键.报道了半透明Si3N4陶瓷的其他性能.光学性能与其他性能的结合,势必大大拓宽Si3N4陶瓷的应用领域.     

Synthesis and Characterization of Hydrophobic TMES/TEOS Based Silica Aerogels

The experimental results on the effect of adding trimethylethoxysilane (TMES) as a co-precursor on the hydrophobicity and physical properties of tetraethoxysilane (TEOS) based silica aerogels, are reported. The molar ratio of TEOS, ethanol (EtOH), water (0.001 M oxalic acid catalyst) was kept constant at 1:5:7 respectively, while the molar ratio of TMES/TEOS (A) was varied from 0 to 0.6. It has been observed that as the A value increases, the gelation time increases. The hydrophobicity was tested by measuring the contact angle, and the surface chemical modification was confirmed by the FTIR spectroscopy studies. The thermal stability of the hydrophobic aerogels was studied in the temperature range from 25 to 800°C. The hydrophobic nature of the aerogel could be maintained up to a temperature of 287°C and above this temperature the aerogels become hydrophilic. The bulk density and the optical transmittance of the aerogels have been found to decrease with increase in A value. The aerogels have been characterized by Fourier transform infrared spectroscopy (FTIR), Optical transmittance, Scanning electron microscopy (SEM), Differential thermal analysis (DTA) and Thermogravimetric analysis (TGA), and Contact angle measurements.     

溶胶-凝胶法制备掺镧钛酸钡薄膜及其光学性质研究

以硝酸镧、醋酸钡、钛酸四丁酯为原料,采用溶胶一凝胶旋涂法制备掺La的钛酸钡薄膜,研究薄膜的晶体结构、表面形貌、紫外-可见光吸收性能及光学带隙。研究结果表明,纯钛酸钡和掺La钛酸钡薄膜均为单一四方钙钛矿结构,La3＋的引入可以使钛酸钡薄膜在可见光区的透过率和光学带隙有一定程度下降,而退火温度对掺镧钛酸钡薄膜光学带隙基本无...     

高分2号图像业务化大气校正查找表的设计与实现

为实现高分2号图像(GF2)业务化大气校正,利用矢量6S模型(6SV)将辐射传输散射与吸收进行分离计算,其中散射部分采用涵盖各种大气模式、气溶胶类型、成像几何等条件下的大气校正查找表(look-up tables,LUTs)表示,大气吸收部分采用6SV拟合计算的6种大气模式下大气透过率的经验公式表示,这种处理有效简化了查找表大小.在内存4 GB、主频3.10 GHz条件下,通过比较基于本查找表方法和基于FLAASH大气校正软件对北京地区一景GF2数据处理.结果表明:以6SV模型直接大气校正法结果作为真值,两者的绝对误差分别为0.8%和2.6%,处理时间分别为77 s和240 s,该大气校正查找表在处理精度和效率更加适合业务化大气校正.     

Chemical,thermal, and mechanical properties and ultraviolet transmittance of novel nano-hydroxyapatite/polyethylene terephthalate milk bottles

Polyethylene terephthalate (PET)/nano-hydroxyapatite (nHAp) composite granules were obtained using twin-screw extruder. Preforms were prepared by injection molding and then PET/nHAp bottles were produced by blow molding. For PET bottles with nHAp, the migration amounts of carboxylic acid (COOH), acetaldehyde (AA), diethylene glycol (DEG), and isophthalic acid (IPA); glass transition temperature (T_g); melting temperature (T_m); and the maximum crystallization temperature (T_cry) were measured. The load-carrying capacity, burst strength, stress cracking, and regional material distribution tests were carried out on the bottles. X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, and ultraviolet transmittance analyses were conducted to explain the changes in mechanical, chemical, physical properties, and light transmission of bottles. It was found out that the COOH amount increased and the AA content decreased with increasing nHAp amount. On the other hand, no change was observed in the amounts of DEG and IPA. Although the mechanical properties such as load-carrying capacity and burst strength of the bottles have improved, it has been determined that the standard environmental stress crack resistance test procedure cannot be applied to such a composite. Experimental findings indicate that nHAp disrupts the chemical structure of PET and it isolates harmful chemicals such as AA by forming intermolecular bonds. Moreover, with the addition of up to 0.8% nHAp, PET bottles block the light transmission approximately 80% within 400–700 nm wave length zone. The study demonstrates that the PET/nHAp composite bottles can be used in the food industry, particularly in the packaging of milk and milk products which are vulnerable to light exposure.     

纯Ar气氛中退火对Al掺杂ZnO薄膜性能的影响

用射频磁控溅射技术制备了高度择优取向的Al掺杂ZnO(ZAO)薄膜,并对薄膜在纯氩气中进行了400～600℃的退火处理.利用X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)、光谱仪和四探针测试仪等对退火前后薄膜进行了表征和光学、电学性能研究.研究表明,纯氩气中退火处理对ZAO薄膜的晶体、光学和电学性能有影响.原位沉积的薄膜电阻率2.59Ωcm,可见光区透过率约70%.500℃纯Ar气氛中退火1h后,ZAO薄膜的平均晶粒有所长大,薄膜内应力达到最小,接近于松弛状态;薄膜可见光区平均透过率从70%提高到80%左右;而薄膜的电阻率变化不明显,从2.59Ωcm降低到1.13Ωcm.     

A new optical elasticity resin for mobile LCD modules

Abstract— The display used in current cell phones has an air gap between the cover glass and the liquid‐crystal‐display (LCD) module to prevent the LCD glass from being damaged. Reflections at the boundaries of the air gap cause a reduction in the LCD luminance and contrast. To address this problem, a newly proposed LCD structure has been investigated. The “Super View Resin (SVR),” a transparent elastic resin which improves the shock resistance and visibility of the LCD, has been developed. Filling the air gap between the cover glass and LCD module with a refractive‐index‐matching resin solves the light‐reflection problem inherent in the use of a reinforced cover‐glass lens. Moreover, the elastic filler works as a damper, reducing any external shock, which prevents not only the cover glass and LCD module from being damaged, but also the glass from being shattered when it is broken.     

微通道板BeO防离子反馈膜粒子阻透率的模拟研究

带有防离子反馈膜的微通道板是第三代微光像增强器件中的核心部件。文章阐述了防离子反馈膜的电子透过、离子阻止特性,利用Monte-Carlo模拟方法计算了氧化铍和三氧化二铝防离子反馈膜电子透过率和离子阻止率在不同条件下的变化曲线。模拟结果表明,氧化铍薄膜比三氧化二铝薄膜的电子透过特性好,而三氧化二铝薄膜比氧化铍薄膜的离子阻止本领好,证实了氧化铍作为防离子反馈膜的可行性。