液位系统的辅助变量复合建模方法研究

针对发电过程控制策略设计和计量方法研究过程中,对系统模型要求越来越高的现状,基于辅助变量最小二乘(RIVLS)辨识方法,提出一种分别以一阶惯性加纯滞后模型(FOPDT)和二阶惯性加纯滞后模型(SOPDT)为基本组成部分,以建模误差的均方差为加权因子的复合建模方法,并通过实验室液位系统建模仿真过程,证明新算法的有效性。仿真结果表明:该方法具有提高建模准确性的作用,该建模方法可以扩展应用于其它对模型精度要求较高的生产过程中。     

Evaluation of the RAMS continuous monitor for determination of PM2.5 mass including semi-volatile material in Philadelphia,PA

The real-time ambient mass sampler (RAMS) is a continuous monitor based on particle concentrator, denuder, drier, and tapered element oscillating microbalance (TEOM) monitor technology. It is designed to measure PM2.5 mass, including the semi-volatile species NH4NO3 and semi-volatile organic material, but not to measure PM2.5 water content. The performance of the RAMS in an urban environment with high humidity was evaluated during the July 1999 NARSTO-Northeast Oxidant and Particles Study (NEOPS) intensive study at the Baxter water treatment plant in Philadelphia, PA. The results obtained with the RAMS were compared to mass measurements made with a TEOM monitor and to constructed mass obtained with a Particle Concentrator-Brigham Young University Organic Sampling System (PC-BOSS) sampler designed to determine the chemical composition of fine particles, including the semi-volatile species. An average of 28% of the fine particulate material present during the study was semi-volatile organic material lost from a filter during particle collection, and 1% was NH4NO3 that was also lost from the particles during sampling. The remaining mass was dominantly nonvolatile (NH4)2SO4 (31%) and organic material (37%), with minor amounts of soot, crustal material, and nonvolatile NH4NO3. Comparison of the RAMS and PC-BOSS results indicated that the RAMS correctly monitored for fine particulate mass, including the semivolatile material. In contrast, the heated filter of the TEOM monitor did not measure the semi-volatile material. The comparison of the RAMS and PC-BOSS data had a precision of +/-4.1 microg/m3 (+/-9.6%). The precision of the RAMS data was limited by the uncertainty in the blank correction for the reversible adsorption of water by the charcoal-impregnated cellulose sorbent filter of the RAMS monitor. The precision of the measurement of fine particulate components by the PC-BOSS was +/-6-8%.     

灭幼脲Ⅲ号杀虫剂在大白菜和土壤中持久性及残留的研究

本文报道灭幼脲Ⅲ号杀虫剂在大白菜和土壤中的残留试验结果.经在南北两地连续两年的田间试验表明,灭幼脲Ⅲ号属非持久性农药,在作物和土壤中都较快地消失,在大白菜上的半衰期为3.8—14.0d,在土壤中为8.8—27.0d.用25％灭幼脲Ⅲ号胶悬剂稀释2500倍,每亩每次按常规用药10g或加倍药量20g(有效成分)施药,喷施2或3次,距最后一次施药三周时,灭幼脲Ⅲ号杀虫剂在大白菜的最大残留量为2.67ppm,在土壤中为13.81ppm.建议该农药在大白菜上的最高允许残留量(MRL)为3ppm,安全间隔期为21d.     

柴油车排气微粒捕集用复合金属丝网的制备与性能研究

论述了用于柴油车排气微粒捕集器的复合金属丝网的制备和测试过程 ,讨论了丝网层数和涂层负载对复合金属丝网过滤性能的影响 ,并分析了其捕集机理     

Institutional Arrangements for Flood Hazards in Malaysia: An Evaluation Using the Criteria Approach

Institutional aspects of flood hazards significantly affect their outcomes in Malaysia. Institutional arrangements to deal with floods include: legislative activity, organisational structures, attitudes and sub-culture, and policies and instruments. When assessed in terms of four specific criteria, institutional aspects of flood hazards are found to be largely inadequate. Disaster reduction programmes are over-dependent on a reactive approach based largely on technology and not even aimed at floods specifically. Structual flood reduction measures are the predominant management tool and, although the importance of non-structural measures is recognised, thus far they have been under-employed. Current laws and regulations with regard to flood management are also insufficient and both the financial and human resources of flood hazard organisations are generally found to be wanting. Finally, economic efficiency, equity and public accountability issues are not adequately addressed by institutional arrangements for flood hazards.     

建设海峡西岸高效持续农业示范区的基本思路与技术对策——以福建省龙海市为例

本文以福建省龙海市为例,分析了龙海市农业发展优势与存在的问题,提出了建设海峡西岸高效持续农业示范区的基本思路与技术对策     

中国水利水电工程开发与区域可持续发展

本文论述了中国水利水电工程开发与区域可持续发展的关系,并提出了中国实现可持续的水利水电工程开发的主要对策。     

Sampling and analysis of ambient dioxins in northern Taiwan

In this study, ambient air samples were taken concurrently in the vicinity area of a large-scale municipal waste incinerator (MWI) and the background area for measuring polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) concentrations from November 1999 through July 2000 in northern Taiwan. The results obtained from eighteen ambient air samples indicate that the mean PCDD/F concentration of seventeen 2,3,7,8-substituted congeners in wintertime (188–348 fg-I-TEQ/m³) is significantly higher than that measured in summertime (56–166 fg-I-TEQ/m³). In addition, the seasonal PCDD/F concentrations are compared with the ambient air quality data including CO, NO₂, PM₁₀ and TSP sampled from Taipei area to gain better insights. It indicates that the variation of ambient air PCDD/F concentrations is closely correlated with that of PM₁₀ concentrations. Besides, the results indicate that the I-TEQ concentration of ambient air in sampling site B (directly downwind of the MWI) is of the highest while the sampling site A (upwind of MWI) is of the lowest among all sampling sites. This implies that existing MWI can be a significant emitter of PCDD/Fs in this area. Furthermore, the patterns of the PCDD/F congener distribution at all sampling sites (including the background site in Taoyuan) are quite similar. OCDD concentration is of the highest among seventeen PCDD/F congeners investigated and accounts for about 35% of the total concentration. As for the I-TEQ concentrations, 2,3,4,7,8-PeCDF is the most significant contributor, generally being responsible for 30–45% of the total I-TEQ values depending on the sampling sites and seasons.     

CuxFe1-x@γ-Al2O3催化剂湿式氧化陶瓷印花废水的性能及表征

采用常温浸渍法制备催化剂CuxFe1-x@γ-Al2O3,并用于陶瓷印花废水的催化湿式氧化处理,考察组分构成对催化剂CuxFe1-x@γ-Al2O3活性和稳定性的影响。结果表明：在4种样品Cu0.5Fe0.5@γ-Al2O3,Cu@γ-Al2O3,Fe@γ-Al2O3和γ-Al2O3中,Cu0.5Fe0.5@γ-Al2O3的催化活性和稳定性最高。催化剂Cu0.5Fe0.5@γ-Al2O3中的Fe促进Cu进入γ-Al2O3载体内部并形成稳定的固溶体Al2CuO4,故此催化剂的硬度和稳定性最高;此催化剂应用前后的SEM图无明显的形貌变化,XRD谱图无明显的物相变化,证实了其稳定性的存在。在优化的操作条件下,催化剂Cu0.5Fe0.5@γ-Al2O3催化湿式氧化陶瓷印花废水的COD及色度分别为280 mg·L-1、20倍,达到《污水综合排放标准》（GB 8978-1996）中染料类废水的三级排放标准。     

基于三维非稳态模型的车载加油油气回收系统碳罐结构优化

以车载加油油气回收系统(ORVR)碳罐吸附过程的传质传热过程为研究对象,以正丁烷/氮气模拟挥发油气,采用固定床吸附实验测试和CFD数值模拟相结合的方法,结合物种转移模型、层流模型和多孔介质模型,建立了三维非稳态ORVR碳罐的数值模型,以穿透时间和温度为特征量,从腔体体积比和进出口直径两个方面对其结构进行初步优化设计。结果表明,吸附过程床层温度模拟值与实验值偏差率低于7%,双腔体体积比为5∶3时,ORVR碳罐吸附过程中温度升高值相比其他结构低0.9~1.6 ℃,安全性高;进出口直径为12 mm时,在吸附穿透时间和床层温度升温方面综合性能最好。本研究可为ORVR碳罐结构优化设计提供参考。