竖置管流中液固两相脉动特性和颗粒浓度分布

利用激光多普勒分相测量技术，考察了液固两相自下而上通过竖置矩形管时，固、液两相的时均速度、流向及横向有脉动强度和颗粒相的相对浓度分布，证实了颗粒浓度的横向分布主要取决于颗粒的横向脉动强度分布（即n_p↑—v'_p~2=常数）的分析结果。

On the influence zone and the prediction of tensile strength of particulate polymeric composites

An intended numerical investigation is carried out. The results indicate that, even if a perfect adhesive bond is preserved between the particles and matrix materials, the two-phase element cell model is unable to predict the strength increment of the particulate polymeric composites (PPC). To explore the main reinforcing mechanism, additional microscopic experiment is performed. An ''influence zone'' was observed around each particle which is measured about 2 to 10 micrometers in thickness for a glass-polyethylene mixture. Then, an improved computational model is presented to include the ''influence zone'' effect and several mechanical behaviors of PPC are well simulated through this new model.

库布齐沙漠油蒿群落水量平衡研究

鄂尔多斯高原位于中国北方敏感的生态过渡带，水分往往是制约该区域内植物生存、生长和生态系统结构与功能的最主要的限制因子。境内分布大面积的沙地，沙地天然植被以油蒿（Artemisia ordosica）灌丛为主，是重要的沙地牧场。油蒿在新固定沙地上和半流动沙地上长势良好，随着沙地的固定、地表土壤结皮的形成，生长变差，呈现出衰败的迹象。这种现象被认为是由于沙地土壤水分状况改变而驱动的自发演替。沙地土壤水分状况通常与降水量直接相关，降水格局影响植物根系层土壤水分的补充，植被、土壤结构及地表结皮、微地形等其它生物和非生物因素也会引起土壤水分在时间和空间上的再分配。降水只有克服植被和土壤表层的截留与直接蒸发，并下渗到根系层土壤中，才能有效地补充为土壤水分，进而为植物利用。因此，小雨量的降雨往往对土壤水分的补充，特别是对油蒿根系层土壤水分的补充效果有限。在该地区特定自然条件下，单次降雨雨量多大才能有效地补充沙地油蒿群落的土壤水分？在特定降雨格局下，一年内补充到土壤中且能被植物生长利用的有效降雨量究竟是多少？这些都直接影响土壤水分状况和群落的稳定以及长期演替。 为了解决以上两个问题，借助涡度相关技术对鄂尔多斯高原库布齐沙漠油蒿群落的蒸散过程及土壤水分状况进行观测，配合以地面植物群落、土壤物理特性调查，综合考虑生态系统水文平衡的各个环节，对沙地土壤水分状况以及降雨格局对土壤水分的补充进行了研究。 结果表明，2006年全年降水总量为229.4 mm，年蒸散量281.4 mm，降雨、蒸散主要集中在5～10月。5～10月间，降雨29次，总降雨量223.2 mm，各次降雨量、降雨历时、降雨强度变异较大。5.0 mm以下降雨16次，累计降雨量14.0 mm，5.0 mm以上降雨对总降雨量贡献大。雨后被植被和地表截留直接蒸发的水分和的有效降雨受降雨特性及其他气象条件共同影响，通常5.0 mm以上降雨能有效补充到油蒿根系层土壤，有效降雨量累计153.9 mm，降雨效率约68.9%。

蛇毒胶囊治疗海洛因成瘾临床疗效观察

使用华南亚种眼镜蛇纯化神经毒素胶囊治疗海洛因成瘾１６６例，并与美沙酮疗法平行对照（８ｏ例），结果表明，蛇毒胶囊对海洛因成瘾戒断症状具有明显缓解和一定控制作用，蛇毒加用适量美沙酮

Fabrication and Infrared Optical Properties of Nano Vanadium Dioxide Thin Films

Vanadium dioxide thin films were fabricated by ion beam sputtering on Si3N4/SiO2/Si after a post reductive annealing process in a nitrogen atmosphere. X-ray Diffraction (XRD), scanning electron microscope (SEM), and X-ray photoelectron spectroscopy (XPS) were employed to analyze the effects of post annealing temperature on crystallinity, morphology, and composition of the vanadium oxide thin films. Transmission properties of vanadium dioxide thin films were measured by Fourier transform-infrared (FT-IR) spectroscopy. The results showed that the as-deposited vanadium oxide thin films were composed of non-crystalline V2O5 and a tetragonal rutile VO2. After annealing at 400 degrees C for 2 h, the mixed phase vanadium oxide (VOx) thin film changed its composition and structure to VO2 and had a (011) oriented monoclinic rutile structure. When increasing the temperature to 450 degrees C, nano VO2 thin films with smaller grains were obtained. FT-IR results showed that the transmission contrast factor of the nano VO2 thin film was more than 0.99 and the transmission of smaller grain nano VO2 thin film was near zero at its switched state. Nano VO2 thin film with smaller grains is an ideal material for application in optical switching devices.

Experimental study of mode field evolution of dual-core photonic crystal fiber

The accurate mode field profile of high negative dispersion dual-core photonic crystal fiber (DCPCF) is measured. The mode field evolution of DCPCF with wavelength is studied experimentally for the first time. The measurement result shows that no individual inner core mode or outer core mode exists, but two modes coexist simultaneously, and either one of them is dominant. The mode field evolution versus wavelength indicates that the wavelength range where the modes coupling takes place between inner core and outer core is broader than that of theoretical design.

面向有差异群体的联合决策方案

公平性、透明性是联合决策的基本安全需求.结合多机构商务合作背景,利用具有同态性质的Paillier公钥密码系统和门限密码技术,提出了面向有差异群体的联合决策策略与方案,并对其安全性进行了分析和证明.

纳米二氧化钒薄膜的制备及红外光学性能

采用双离子束溅射方法在Si_3N_4/SiO_2/Si基底表面沉积氧化钒薄膜,在氮气气氛下热处理获得二氧化钒薄膜.利用x射线衍射(XRD)、扫描电子显微镜(SEM)和X射线光电子能谱(XPS)研究了热处理温度对氧化钒薄膜晶体结构、表面形貌和组分的影响,利用傅里叶变换红外光谱(FT-IR)对二氧化钒薄膜的红外透射性能进行了测试分析.结果表明,所制备的氧化钒薄膜以非晶态V_2O_5;和四方金红石结构VO_2为主,经400℃、2 h热处理后获得了(011)择优取向的单斜金红石结构纳米VO_2薄膜,提高热处理温度至450℃,纳米结构VO_2薄膜的晶粒尺寸减小.FT-IR结果显示,纳米VO_2薄膜透射率对比因子超过0.99,高温关闭状态下透射率接近0.小晶粒尺寸纳米VO_2:薄膜更适合在热光开关器件领域应用.

Wet Oxidation of AlxGa1-xAs/GaAs Distributed Bragg Reflectors

The wet oxidation of AlGaAs with high Al content in a distributed Bragg reflectors （DBR） is studied by scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. Some voids distribute along the oxide/GaAs interfaces due to the stress induced by the wet oxidation of the AlGaAs layers. These voids decrease the shrinkage of the Al2O3 layers to 8% instead of the theoretical 20% when compared to the unoxidized AlGaAs layers. With the extension of oxidation time, the reactants are more completely transported to the front interface and the products are more completely transported out along the porous interfaces. As a result,the oxide quality is better.