PVP/Zn（CH3COO）2复合纤维电纺丝条件的研究

采用静电纺丝法在18~32kV、PVP/Zn(CH3COO)2前驱体浓度为15%、20%、24%和28%,纺丝距离为6~15cm的条件下,制备了直径为200~500nm的微纳米纤维。通过扫描电子显微镜(SEM)分析得出在纺丝电压为25~28kV,纺丝距离为10~12cm,溶液质量浓度为24%时纺出的微纳米纤维结构较为均一。     

基于IMS的移动通信专网认证和密钥协商方法研究

为适应行业移动通信专网发展和保密通话业务需求,文章针对专网独立业务控制特点,在应用IMS技术架构的移动通信专网中,提出一种向前兼容的专网功能结构模型.文章研究分析了多个可应用于IMS专网的认证和密钥协商方案,并根据归属地服务器是否参与认证过程,分端到端、端到服务器两类应用场景,综合比较各类认证和密钥协商方案的安全性能和...     

我国城镇污水厂运行管理中存在的问题及对策

城镇污水处理厂的运行管理是指将接纳符合城镇下水道排放标准的污水经处理后达标排放的全过程管理,其运行管理中存在的问题将直接或间接影响污水处理厂的节能减排效果。对我国华北、华东、西北、东北、中南、西南、华南等地区污水处理厂进行了大量调研和走访,分析了目前我国城镇污水处理厂运行管理中存在的问题,并提出了相应的解决对策。     

再生水处理工艺CMF-S优化运行的中试研究

通过中试试验装置,结合夏季进水水质及高、中、低负荷3种运行工况对浸没式连续微滤(CMF-S)工艺运行参数进行优化研究。结果表明,CMF-S优化运行可减缓膜污染,提高运行效率,降低运行费用;利用运行数据建立跨膜压差TMP增长数学模型,确定主要影响因素,根据不同的工况条件,调控运行参数,实现微滤系统运行优化。     

Design of a large scale multimedia storage server

Large scale multimedia storage servers will be an integral part of the emerging distributed multimedia computing infrastructure. However, given the modest rate of improvements in storage transfer rates, designing servers that meet the demands of multimedia applications is a challenging task that needs significant architectural innovation.Our research project, called Massively-parallel And Real-time Storage (mars) architecture, is aimed at the design and prototype implementation of a large scale multimedia storage server. It uses some of the well-known techniques in parallel I/O, such as data striping and Redundant Arrays of Inexpensive Disks (raid) and an innovative atm based interconnect inside the server to achieve a scalable architecture that transparently connects storage devices to an atm-based broadband network. The atm interconnect within the server uses a custom asic called ATM Port Interconnect Controller (apic) currently being developed as a part of an arpa sponsored gigabit local atm testbed. Our architecture relies on innovative data striping and real-time scheduling to allow a large number of guaranteed concurrent accesses, and uses separation of metadata from real data to achieve a direct flow of the media streams between the storage devices and the network. This paper presents our system architecture; one that is scalable in terms of the number of supported users and the throughput.     

基于行为发展的纸质儿童绘本多感官体验设计

目的试图探究如何能够在繁荣的信息时代革新纸质儿童绘本的产品设计,挖掘纸质儿童绘本多感官体验设计思路;方法首先分析了纸质儿童绘本不可取代的优点与急需解决的痛点;接着,通过对儿童行为发展的身心变化规律进行梳理,确定符合学龄前儿童的多感官阅读需求;而后,试图探究纸质绘本的视觉动态化、感官多样性、体验沉浸化3个层次面向0～3岁、3～6岁两大阶段纸质儿童绘本多感官体验设计思路;结论未来纸质儿童绘本市场会不断壮大,而多感官体验设计也将越来越多地体现在纸质儿童绘本的设计开发中,视觉动态化、感官多样性、体验沉浸化设计思路既能发扬纸质绘本不可取代的优点,又改善纸质绘本急需解决的痛点,为儿童阅读启蒙和亲子共读提供更丰富的阅读体验效果。     

无线传感网络安全防护路径激光追踪方法

为了提高无线传感网络安全防护能力,需要进行网络安全防护路径设计,提出基于联合节点行为覆盖的无线传感网络安全防护路径激光追踪方法.构建无线传感网络安全防护路径的覆盖关系模型,根据传感器节点与目标节点从属关系进行无线传感网络安全防护的路径空间规划设计,采用最短路径寻优方法进行无线传感网络安全防护路径的激光控制,采用激光扫描...     

In-field detection of multiple pathogenic bacteria in food products using a portable fluorescent biosensing system

Foodborne diseases caused by pathogenic bacteria have increasingly become a major public health issue worldwide. Rapid, simple, and accurate detection methods are urgently needed for in-field screening of bacterial pathogens. In our previous work, rapid detection methodologies have been established based on fluorescent nanobiosensors for simultaneous separation and detection of multiple foodborne pathogenic bacteria. In this research, a portable fluorescent biosensing system was designed and built and further assessed for in-field detection of three main types of bacterial pathogens that have been associated with the outbreaks of foodborne illness. Using the developed fluorescent nanobiosensor coupled with nanobead-based immunomagnetic separation, we conducted blind tests with the portable device to simultaneously detect E. coli O157:H7, L. monocytogenes, and S. Typhimurium in different food products in three cities selected from three big agricultural provinces in China. Specificity tests showed low interference of this multiplex biosensor from non-targets in food samples. The detection could be done from sampling to results within 60 min. Limits of detections of this method for E. coli O157:H7, L. monocytogenes, and S. Typhimurium were determined to be 10², 10³, and 10³ CFU/mL in lettuce, shrimp, and ground beef, respectively. Recovery tests were also investigated and this method was evaluated to be accurate comparing with the gold standard culturing method. Therefore, it is feasible for this portable fluorescence biosensing system to be used in rapid and in-field screening of multiple foodborne pathogenic bacteria in foods, such as vegetables, livestock meat, and sea food. And together with fluorescent nanobiosensors, it provides a promising alternative tool to traditional culturing method, or even conventional ELISA and PCR based methods.     

乳化剂剂量对改性乳化沥青性能的影响研究

改性乳化沥青作为一种新型的高速公路沥青路面养护材料,备受人们关注。沥青种类、改性剂的种类及剂量、乳化剂的种类及剂量、皂液的pH值、乳化时间、稳定剂CaCl2剂量、沥青固含量的变化等都影响着改性乳化沥青的性质。以室内试验研究为基础,重点研究了乳化剂剂量对改性乳化沥青性能的影响。     

多孔介质内复合对流传热传质的数值分析

采用数值方法分析了具有非均匀内热源的竖直套管中复合对流传热传质,考查内热源分布系数M和热质二浮力比N对速度、温度、浓度分布以及Nusselt数和Sherwood数的影响。结果表明：当N〉1时速度V为正,其值随N的增加而增大;当N〈-1.5时,V则先负后正。随着M增大,等温线和等浓度线分布更加密集,传热和传质过程更加明显。