谈北京公馆的节能技术设计

北京公馆作为高档公寓,在设计中采用了钢结构、呼吸式玻璃幕墙、水源热泵系统、地板采暖系统、独立新风系统等多种节能措施。多种节能措施的综合运用,在建筑工程的可持续发展方面具有一定的探索意义。     

Floc-based sequential partial nitritation and anammox at full scale with contrasting N2O emissions

New Activated Sludge (NAS^®) is a hybrid, floc-based nitrogen removal process without carbon addition, based on the control of sludge retention times (SRT) and dissolved oxygen (DO) levels. The aim of this study was to examine the performance of a retrofitted four-stage NAS^® plant, including on-line measurements of greenhouse gas emissions (N₂O and CH₄). The plant treated anaerobically digested industrial wastewater, containing 264 mg N L⁻¹, 1154 mg chemical oxygen demand (COD) L⁻¹ and an inorganic carbon alkalinity of 34 meq L⁻¹. The batch-fed partial nitritation step received an overall nitrogen loading rate of 0.18-0.22 kg N m⁻³ d⁻¹, thereby oxidized nitrogen to nitrite (45-47%) and some nitrate (13-15%), but also to N₂O (5.1-6.6%). This was achieved at a SRT of 1.7 d and DO around 1.0 mg O₂ L⁻¹. Subsequently, anammox, denitrification and nitrification compartments were followed by a final settler, at an overall SRT of 46 d. None of the latter three reactors emitted N₂O. In the anammox step, 0.26 kg N m⁻³ d⁻¹ was removed, with an estimated contribution of 71% by the genus Kuenenia, which constituted 3.1% of the biomass. Overall, a nitrogen removal efficiency of 95% was obtained, yielding a dischargeable effluent. Retrofitting floc-based nitrification/denitrification with carbon addition to NAS^® allowed to save 40% of the operational wastewater treatment costs. Yet, a decrease of the N₂O emissions by about 50% is necessary in order to obtain a CO₂ neutral footprint. The impact of emitted CH₄ was 20 times lower.     

Long-range effect of cyanide on mercury methylation in a gold mining area in southern Ecuador

Small-scale gold mining in Portovelo-Zaruma, Southern Equador, performed by mercury amalgamation and cyanidation, yields 9-10 t of gold/annum, resulting in annual releases of around 0.65 t of inorganic mercury and 6000 t of sodium cyanide in the local river system. The release of sediments, cyanide, mercury, and other metals present in the ore such as lead, manganese and arsenic significantly reduces biodiversity downstream the processing plants and enriches metals in bottom sediments and biota. However, methylmercury concentrations in sediments downstream the mining area were recently found to be one order of magnitude lower than upstream or in small tributaries. In this study we investigated cyanide, bacterial activity in water and sediment and mercury methylation potentials in sediments along the Puyango river watershed, measured respectively by in-situ spectrophotometry and incubation with ³H-leucine and ²⁰³Hg²⁺.Free cyanide was undetectable (< 1 μg·L^− 1) upstream mining activities, reached 280 μg·L^− 1 a few km downstream the processing plants area and was still detectable about 100 km downstream. At stations with detectable free cyanide in unfiltered water, 50% of it was dissolved and 50% associated to suspended particles. Bacterial activity and mercury methylation in sediment showed a similar spatial pattern, inverse to the one found for free cyanide in water, i.e. with significant values in pristine upstream sampling points (respectively 6.4 to 22 μgC·mg wet weight^− 1·h^− 1 and 1.2 to 19% of total ²⁰³Hg·g dry weight^− 1·day^− 1) and undetectable downstream the processing plants, returning to upstream values only in the most distant downstream stations. The data suggest that free cyanide oxidation was slower than would be expected from the high water turbulence, resulting in a long-range inhibition of bacterial activity and hence mercury methylation. The important mercury fluxes resultant from mining activities raise concerns about its biomethylation in coastal areas where many mangrove areas have been converted to shrimp farming.     

Measuring and visualizing hot mix asphalt concrete paving operations

This paper presents AsphaltOpen, a visualization tool for Hot Mix Asphalt (HMA) paving operations and a data collection process to collect the input data for AsphaltOpen from HMA paving operations. In detail, AsphaltOpen visualizes collected site-specific GIS data and GPS path tracing data of equipments' motions together with the HMA's temperature behavior. In this way, AsphaltOpen allows HMA paving professionals to understand and learn about the relation of machine operations and HMA temperature and its impact on the HMA compaction. To ensure the practical usability, we developed AsphaltOpen and the data collection process by conducting action research with HMA paving operators. Overall, AsphaltOpen offers an easy-to-use tool for HMA paving companies to visualize previous asphalting operations. In this way, it opens up new ways for HMA paving contractors to improve and professionalize their paving operations.     

某行政中心办公楼数码涡旋多联机组设计

本文通过对吉安市吉州区行政中心办公楼中央空调方案进行对比,得出数码涡旋多联机在本项目中应用的优势。     

基于MATLAB复合形法的二级圆柱齿轮减速器的优化设计

传统的二级圆柱齿轮减速器的设计也会追求最优的设计结果,其一般依赖过去的经验确定。这样的设计虽然比较真实可靠,但往往达不到实际最佳的设计方案。在一般设计的基础上,以二级圆柱齿轮减速器的总中心距最小为优化目标,建立数学模型,以MATLAB软件平台,利用复合形法对二级圆柱齿轮减速器进行优化设计,所得结果表明比传统设计更为优越。     

太阳能热水远程监控与能耗计量系统开发

阐述了太阳能热水工程的研究发展及特点,提出了太阳能热水远程监控与能耗计量系统的设计与实现方案,并且依据技术经济指标计算公式得到系统的节能减排数据。配备了具有GPRS/以太网模块的数据采集装置,开发了基于.Net平台的数据中心软件以及web发布平台,具有数据接收、处理、分析、查询等功能。应用结果表明,系统运行稳定,操作简单,数据可靠性高。     

On the Relation between Morphology and FET Mobility of Poly(3‐alkylthiophene)s at the Polymer/SiO2 and Polymer/Air Interface

The influence of the interface of the dielectric SiO₂ on the performance of bottom‐contact, bottom‐gate poly(3‐alkylthiophene) (P3AT) field‐effect transistors (FETs) is investigated. In particular, the operation of transistors where the active polythiophene layer is directly spin‐coated from chlorobenzene (CB) onto the bare SiO₂ dielectric is compared to those where the active layer is first spin‐coated then laminated via a wet transfer process such that the film/air interface of this film contacts the SiO₂ surface. While an apparent alkyl side‐chain length dependent mobility is observed for films directly spin‐coated onto the SiO₂ dielectric (with mobilities of ≈10^?3 cm² V^?1 s^?1 or less) for laminated films mobilities of 0.14 ± 0.03 cm² V^?1 s^?1 independent of alkyl chain length are recorded. Surface‐sensitive near edge X‐ray absorption fine structure (NEXAFS) spectroscopy measurements indicate a strong out‐of‐plane orientation of the polymer backbone at the original air/film interface while much lower average tilt angles of the polymer backbone are observed at the SiO₂/film interface. A comparison with NEXAFS on crystalline P3AT nanofibers, as well as molecular mechanics and electronic structure calculations on ideal P3AT crystals suggest a close to crystalline polymer organization at the P3AT/air interface of films from CB. These results emphasize the negative influence of wrongly oriented polymer on charge carrier mobility and highlight the potential of the polymer/air interface in achieving excellent “out‐of‐plane” orientation and high FET mobilities.     

基于CERS的接处警系统的设计与应用

针对当前城市应急联动系统（CERS）在中小城市的快速发展和应用,其中接处警系统是城市应急联动系统的重要组成部分,为提高系统的稳定性,通过分析当前城市应急联动系统的基本结构,研究设计出适合现代社会应急需求的接处警系统的整体结构、系统的主要功能以及接处警流程,并进行了应用方面的分析研究,为城市应急联动系统的建设提供了很好的指导作用.     

MCT与Clustered IGBT在大功率应用中的比较研究

针对两种应用于大功率领域的半导体器件——栅控晶闸管(MCT)和组合式绝缘栅晶体管(CIGBT),采用数值仿真软件进行了比较研究。静态仿真结果表明MCT具有更低的正向压降,只有CIGBT的50%左右,而CIGBT得益于其电流饱和特性,具有更大的短路安全工作区。开关仿真结果表明CIGBT具有比MCT更短的关断时间和更小的关断能量,更适合应用于高频领域。同时研究了MCT和CIGBT在脉冲放电应用中的特性,结果表明MCT具有更大的脉冲峰值电流和更快的电流上升率,并首次论证了脉冲放电过程中器件物理机制的区别。