改性活性炭对废水中Cr（VI）吸附的研究

研究了改性活性炭对水溶液中Cr（VI）的吸附作用,运用正交分析法考查活性炭用量、废水pH值及吸附时间对Cr（VI）去除率的影响.筛选出改性活性炭最佳工艺条件：改性活性炭单位吸附量为6.7 mg Cr6＋/g活性炭,吸附时间2 h,pH值4,净化率为99.97%.相比原活性炭,改性后活性炭的吸附性更强,净化率提高了20%,吸附平衡时间缩短了66%.     

Effect of 6H-SiC crystal growth shapes on thermo-elastic stress in the growing crystal

The effect of 6H-SiC crystal growth shapes on the thermo-elastic stress distribution in the growing crystal was systematically investigated by using a finite element method. The thermo-elastic stress distribution in the crystal with a flat growth shape was more homogeneous than that in the crystals with concave and convex growth shapes, and the value of thermo-elasticity in the crystal with a flat growth shape was also smaller than that in the two other types of crystals. The maximum values of thermo-elastic stress appeared at interfaces between the crystal and the graphite lid. If the lid was of the same properties as 6H-SiC, the thermo-elastic stress would decrease in two orders of magnitude. Thus, to grow 6H-SiC single crystals of high quality, a transition layer of SiC formed by deposition or reaction is suggested; meanwhile the thermal field in the growth chamber should be adjusted to maintain the crystals with flat growth shapes.     

Novel discrimination method of digital deceptive jamming in mono-pulse radar

A new polarization measurement algorithm by using the sum and difference beam differential property of mono-pulse radar is given.Based on the generation mechanism differences between the target scattering and multi-false-target jamming,the signal models of real targets and digital deceptive false target jamming for sum and delta channel are presented.The polarization discrimination parameters are designed,and the discrimination method and its performance are discussed.This novel method does not need the acc...     

金银花叶茎藤中黄酮与绿原酸同时提取分离工艺

超声辅助乙醇提取金银花叶茎藤中的绿原酸与黄酮,乙酸乙酯萃取分离黄酮与绿原酸,D101大孔树脂梯度洗脱绿原酸与黄酮,乙醇及正己烷分相法纯化黄酮与绿原酸.结果表明,乙酸乙酯萃取可将金银花叶茎藤中的黄酮与绿原酸较好的分离,经D101大孔树脂吸附、50%乙醇洗脱、浓缩过滤、沉淀用乙醇重结晶后得到的水溶型黄酮纯度达84.5%;经D101大孔树脂吸附、70%乙醇洗脱、浓缩干燥、pH值2.97条件下乙酸乙酯萃取、正己烷分相后,得到的绿原酸纯度达91.2%.方法已用于金银花叶藤中黄酮与绿原酸的同时提取、分离与纯化,结果满意.     

光腔衰荡光谱技术应用于痕量气体检测的研究进展

光腔衰荡光谱(CRDS)技术在对痕量气体的检测技术中占有重要的地位。对基于光腔衰荡光谱技术的痕量气体检测相关研究进行了综述,分析了光腔衰荡光谱技术的相关工作原理及技术特点。介绍了CRDS痕量气体检测在大气环境、生物医学、燃烧化学等方面的研究进展以及存在的问题;总结了CRDS痕量气体检测的发展趋势。     

单周动态补偿的光通信码间抑制抗干扰新方法

在对光通信码间进行抑制抗干扰的过程中,光信号会受温度、大气流动等不确定性因素的影响,干扰随机性较大,导致传统的调相阵列技术由于不能实时检测,从而无法有效实现光通信码间的干扰抑制。提出一种单周动态补偿的光通信码间抑制抗干扰方法,分析带有干扰的光通信系统,给出外部扰动向量的动态特性,分析无限时域的性能指标,将原系统和干扰系统和期望输出联立,获取光通信增广系统。在调制信号中引入直流偏置信号,将经调制的数据向量划分成不同子序列,赋予各子序列对应的加权系数,依据光通信码间安全工作区域信号范围对光信号进行限幅,通过正信号的切顶信号求出补偿信号。对正信号与翻转负信号进行符号拼接、偏置信号添加等操作,将光信号以光功率的形式传输至光无线信道。将加性高斯白噪声信道作为信道模型,将负信号置零,进而抑制光通信码间的干扰。仿真实验结果表明,所提方法具有很好的抗干扰性能。     

多粒度制造资源统一模型及其语义服务发现

为了实现企业间的业务流程协同,提出了多粒度资源统一模型及其语义化方法,并实现了语义发现算法。将业务流程片段抽象成不同粒度大小的流程复合资源和单粒度资源,基于扩展OWL-S对多粒度资源进行了语义封装,并构建了领域业务流程本体和功能活动本体,对多粒度资源进一步语义化。进而给出了功能、过程和服务质量的三阶段语义匹配算法,并比较了复合粒度和单粒度资源的匹配性能。结合一个制造业务流程任务实例说明了多粒度资源模型及其语义化的应用过程。最后,通过仿真实验验证了模型、语义化和算法的有效性。     

基于正位移解的DELTA机器人工作空间分析

针对DELTA并联机器人,基于空间机构学理论和矢量法,建立该并联机构位移模型,给出其正、逆向位移解数值求取方法,提出基于正位移解的工作空间分析方法,采用MATLAB软件进行了仿真,为DELTA机器人的轨迹规划奠定了良好的基础。     

Surface wetting processing on BNNT films by selective plasma modes

The wettability of boron nitride nanotube (BNNT) films was modified using a combination of pulsed and continuous wave (CW) mode plasma. The combined mode effectively modified the wettability of BNNT films and kept the nanostructures intact. The BNNT films changed from superhydrophobic to superhydrophilic after combined mode treatment at 600 W min. In contrast, the contact angle controllable decreased linearly in a controllable way with increasing energy input before eventually becoming superhydrophilic after 1000 W min of CW mode treatment. A high concentration of graft functional groups formed, along with point defects. More point defects formed when using combined modes and higher energy input. Mainly amine functional groups were grafted by combined mode plasma, while the CW mode plasma led to more formation of amide and imine on the BNNTs. Research into controllable wettability and selection of grafted functional groups should enable promising applications of BNNTs in composites and biology in the future.     

Optical turbulence profiling with single star SCIDAR technique

In order to characterize optical turbulence, we have developed a single star SCIDAR （SSS） for measurement of the distribution of Cn^2 with height. The SSS consists of a 40 cm telescope and a CCD camera for fast sampling of stellar scintillation pattern. Spatio- temporal auto and cross-correlation functions of the single star images are computed, providing vertical profiles of optical turbulence intensity C2（h） and wind speed V（h）. Using this new SSS experiment, profiles of turbulence can be obtained from the ground to the top of atmosphere, allowing the determination of seeing, isoplanatic angle and coherence time. Detailed characteristics of atmospheric optical turbulence are important for active and passive imaging, astronomical site testing, adaptive optics, laser communications, target tracking and designation, and laser beam control. We plan to improve the robotization of the SSS to be able to use it routinely even under harsh weather and altitude conditions that we expect to encounter on the high Tibetan plateau or at Dome A in Antarctica. SSS will also be applied for the site testing campaign of the future Chinese extremely large telescope.