轻型柴油车尾气烟羽中颗粒数量与粒径分布

测量了轻型柴油车在高怠速和低怠速运转的条件下，其尾气烟羽中粒径范围在15nm到30μm的颗粒数量和粒径的分布。利用SMPS和APS测量装置测量尾气烟羽中心线和环境背景条件下的颗粒排放。测量结果表明，测试的柴油车在高怠速运转的条件下会排放出更多的颗粒。然而，在两种怠速条件下，总的颗粒数量浓度由于沉降的作用会随着远离排气管的距离而减少。测量结果还表明，柴油车排放的颗粒主要是粒径小于700nm的颗粒，这些细颗粒比粗颗粒更易长期悬浮于大气中，从而引发局部的颗粒物污染问题。     

太赫兹3D打印透镜综述

太赫兹波由于其独特的电磁特性可应用于超高速率无线通信、生物化学物质检测以及高分辨率成像等领域。但由于太赫兹波的物理波长小,传统适用于低频的加工工艺难以满足其加工精度的要求;而微纳米加工工艺又具有加工复杂、成本高等缺点。3D打印技术的发展为太赫兹器件的加工提供了新的选择和更多的设计灵活度。文章介绍了香港城市大学太赫兹与毫米波国家重点实验室在3D打印太赫兹透镜方面的最新研究动态和实验研究新成果,包括基于3D打印的太赫兹高增益圆极化透镜、近场聚焦圆极化透镜、贝塞尔波束生成透镜的设计,高精度3D打印方法的探索以及太赫兹天线测试方法等。太赫兹3D打印透镜天线具有低成本、低损耗、能快速成型等特点,可应用于不同的太赫兹场景中。     

桑黄子实体多糖、黄酮和多酚含量与抗氧化活性相关性

探讨子实体抗氧化的物质基础。通过提取和萃取得到7种组分:水提物(WE)、醇提物(AE)、粗多糖(CP)、醇沉上清干物(RL)和二氯甲烷(MCE)、乙酸乙酯(EAE)、正丁醇(n BE)萃取物,采用FRAP值法测定体外抗氧化能力,分光光度法测定多糖、黄酮和多酚含量。结果表明:抗氧化活性物存在于醇提物中,抗氧化活性和多酚、黄酮含量有关,并呈线性正相关(R2为0.9977和0.9950),多糖在抗氧化中所起作用小,酚类、黄酮类为其主要抗氧化活性物质。      

不同瓜类种子性状及其油中角鲨烯含量的分析比较

为探究不同瓜类种子性状与含油量及其油中角鲨烯含量的相关性,以苦瓜、瓜蒌、籽瓜和南瓜等15个品种的瓜类种子为实验材料,对单粒质量、百粒质量、长、宽、干基含油量和油中角鲨烯含量进行测定,并分析其相关性。结果表明：籽瓜种子单粒质量最大、长度最长、宽度最宽,分别为0.255 2 g、0.632 mm和0.383 mm;阿根廷蛇瓜种子百粒质量最大,为24.919 3 g;砍瓜种子的干基含油量和油中角鲨烯含量最高,分别为41.14%和2 525.8 mg/kg;相关性分析发现种子长度越长,宽度越宽有利于单粒质量和百粒质量的增加,油中角鲨烯含量与干基含油量呈显著正相关(p<0.05);西葫芦、青皮绿肉酥、砍瓜、早熟南瓜和南瓜在籽油角鲨烯含量选育中具有一定的参考价值。综上,砍瓜为种子高含油量及其油中高角鲨烯含量的瓜类品种。     

移动荷载识别的一种快速算法

基于移动荷载识别理论并根据移动常力轴载特点,提出了一种用于准确识别移动常力轴载的快速算法。两轴12种组合工况和多轴10种组合工况的荷载识别仿真计算结果表明：该快速方法的计算量不足时域法的1/2,识别精度很高且基本不受噪声影响,尤其对于多轴荷载识别,该快速算法效率更高,这对于桥梁移动荷载的在线识别十分有利。     

Describing function for servomechanism with backlash and multiple non-linearities †

The paper presents a new describing function for a servomechanism which employs a motor driving an inertia load subject to combined Coulomb and viscous frictions, through gearing having backlash. It is shown that describing functions for various types of backlash phenomena reported in the literature can be considered as special cases of the describing function obtained in this paper.     

Measurement of Papaya Maturity by Delayed Light Emission

Papaya at five stages of maturity were evaluated for differences in intensity of delayed light emission (DLE), chlorophyll, β-carotene and Hunter color values. Results showed there were high correlations between DLE intensity and chemical and physical properties that relate to papaya maturity. DLE has a high potential as a rapid screening technique for identifying papayas which are one-half ripe and riper.     

Novel electrically conducting polyheteroarylene azines

Abstracts are not published in this journal This revised version was published online in November 2006 with corrections to the Cover Date.     

GPS技术在采砂管理中的应用

为解决河道管理单位在采砂管理工作中的问题,郯城河道管理局将GPS技术应用在采砂管理中.介绍了GPS在砂场现场划界,采砂证办理和采砂日常管理工作中的应用,并提出对采砂管理的几点建议.通过应用GPS技术,解决了传统管理手段中的难题,使砂场管理更科学、规范.     

Development of a Colorimetric, Second Generation Nucleic Acid Hybridization Method For Detection of Salmonella in Foods and a Comparison With Conventional Culture Procedure

A new, highly specific colorimetric DNA hybridization method (cDNAH) for detection of Salmonella in foods was developed. It detected 355/362 strains representing 206/213 serovars of Salmonella, and showed no cross-reactivity with 32 different non-Salmonella species, including a variety of Enterobacter and Citrobacter species. The cDNAH method was compared with the BAM/AOAC culture method in two studies: (1) with 20 different inoculated and uninoculated foods overall agreement between the two methods was 99%. (2) with naturally contaminated foods at two independent sites agreement with culture was 99.8% where 9/404 samples were positive for Salmonella.