Investigation of Nitrite Production Pathway in Integrated Partial Denitrification/Anammox Process via Isotope Labelling Technique and the Relevant Microbial Communities

In this study,the nitrogen removal performance of partial denitrificaiton/anammox(PDA) process was investigated by using an UASB reactor.High total nitrogen(TN) removal efficiency(91.97%) was achieved at an influent nitrogen loading rate of 0.64 kg/(m³·d).Anammox bacteria did execute the function of converting nitrate to nitrite in PDA system according to ¹⁵N isotope labeling experiments and the contribution was approximately 36.3%.Candidatus＿Brocadia,Candidatus＿Kuenenia an...     

氨氯地平对高血压患者颈动脉内膜中层厚度的影响

目的:观察氨氯地平对原发性高血压病人颈动脉内膜中层厚度的影响.方法:选择134例1、2级高血压病人,随机分为两组,A组氨氯地平5-10mg,每日1次;B组吲哒帕胺1.5g,每日1次;治疗12周.如血压不达标可加用ACEI或ARB类药物.结果:治疗2周后两组血压均明显下降,4周后血压趋于达标并稳定,两组的降压幅度无显著差别.12周后与治疗前比较,两组IMT均降低,A组IMT降低更明显,两组比较有显著差异.结论:氨氯地平对逆转原发性高血压病人颈动脉IMT的效果显著.     

Cloud service provisioning in two types of DCN with awareness of delay and link failure probability

Cloud service based on data center network (DCN) has become an attractive choice for various applications. Traditionally, multiple DCs are distributed at different nodes across a given optical network, and users access DCs through predefined routes (this architecture is named as Multiple Independent DCN, MI-DCN). However, as there exist transmission delay and failure probability on each link, such a network may not be a good choice for the service providers from the perspective of service reliability and cost. Therefore, we propose the idea of regrouping all the racks and distributing each rack group on a special node, where there exists a gateway (this architecture is named as Integrated Distributed DCN, ID-DCN). As each group can provide service independently, by properly grouping and routing, the whole network can work more efficiently with lower cost and higher reliability. In this paper, we study the service provision in the above two types of DCN. With the given failure probability and transmission delay on each link, we aim to minimize the total service cost and design the access routes for the demands originated from each node. To integrate the system cost, we introduce two cost scaling factors for delay and failure probability, which can be flexibly adjusted to control their relative importance (i.e., the weights). Based on mathematical approximation, a novel method is proposed to compute the failure probabilities of individual service paths. This translates our objective function into a linear expression. Then, we formulate two integer linear programs (ILP) to compare the solutions of the two scenarios. Via extensive numerical experiments, the performance of the two schemes is properly verified.     

Dynamic hierarchical collaborative caching scheme in ultra-dense networks

Pushing popular contents to the edge of the network can meet the growing demand for data traffic, reduce latency and relieve the pressure of the backhaul. However, considering the limited storage space of the base stations, it is impossible to cache all the contents, especially in ultra-dense network ( UDN). Furthermore, the uneven distribution of mobile users results in load imbalance among small base stations (SBSs) in both time and space, which also affects the caching strategy. To overcome these shortcoming, the impact of the changing load imbalance in UDN was investigated, and then a dynamic hierarchical collaborative caching (DHCC) scheme was proposed to optimize latency and caching hit rate. The storage of the SBS is logically divided into the independent caching layer and the collaborative caching layer. The independent caching layer caches the most popular contents for local users爷interest, and the collaborative caching layer caches contents as much as possible for the benefit of content diversity in the region. Different SBSs have respective storage space layer division ratios, according to their real-time traffic load. For SBSs with heavy load, the independent caching layers are allocated with more space. Otherwise, the collaborative caching layers could store more contents with larger space. The simulation results show that, DHCC improved both transmission latency and hit rate compared with existing caching schemes.     

基于透传的IPv6个人区域网无线网关设计

主干网络设备和操作系统支持IPv6协议的请况下,大量的个人区域网网关仅使用IPv4地址转换的方式连接互联网,不能支持IPv6,提出一种数据链路层透传的数据包处理方式,使IPv6数据直接通过网关,减少地址转换或者中间代理的过程,实现内部网直接接入IPv6网络。经分析和实验,该设计方法在不影响IPv4使用的情况下使个人区域网内部设备顺利接入IPv6网络。     

基于Qt的显控系统图形显示的研究

作为显控系统不可或缺的功能之一,在图形显示的过程中,如何保证嵌入式系统能够在所拥有硬件资源相对有限的前提下,频繁切换的画面仍旧能够具有相应的稳定性,是相关人员主要研究的课题之一.本文则以此为核心内容,对Qt显示、绘图的机制以及导致画面出现闪烁问题的原因进行了系统、深入的分析,并提出了具有针对性的解决策略,希望能够在某些方面为Qt显控系统所显示图形质量的提高提供一定的帮助.     

电信基站用新风冷却换热装置的开发应用研究

电信基站的人工降温、空气净化及其运行管理是电信维护部门的工作重点之一.本研究提出新型的新风冷却换热装置,然后通过实验验证和数值模拟手段对该装置的性能与地区适用性进行了系统研究.初步结果表明该装置的研制开发,不仅具有显著的节能、节电效果,大幅降低了电信行业的运行管理成本,而且有利于国家的环保工作,对于促进电信行业的可持续发展,增强企业市场竞争力,具有非常重要的经济效益和社会发展意义.     

手持式超高频RFID读写器天线设计技术综述

天线作为手持式超高频射频识别技术(Radio frequency identification technology,RFID)读写器中的关键部件,其性能直接影响到RFID系统的读写距离和读写器体积大小.论文分析研究各种手持式超高频RFID读写器天线的设计技术,重点介绍应用最广的微带天线设计方法、技巧及发展趋势.     

灵巧噪声干扰对主动雷达导引头干扰效能评估

现役第四代主动雷达型空空导弹普遍采用被动跟踪干扰源技术应对噪声压制性干扰,为对其进行有效对抗,研究了一种新的灵巧噪声干扰信号——扫频锯齿波信号。干扰信号通过在原有雷达回波上附加一个窄带线性调频信号产生,用较小的功率在目标回波附近产生类似高斯噪声的特性。以最小干扰距离和脱靶量为评估指标进行建模分析,仿真结果表明,该灵巧噪声干扰能够有效干扰导引头,具有很高的功率利用率。