微波无极灯:一种具有前景的高效光催化光源

微波无极灯具有制造容易、价格低廉、能耗小和光强大等优点。作为光催化氧化的光源时,由于微波的协同作用可有效提高光催化活性,并能简化反应器。从发光机理、微波协同作用、优缺点和影响因素等方面,对微波无极灯在光催化领域的研究进行详细阐述。     

TVS管失效原因分析

TVS管是一种常见的浪涌抑制器件,但如果使用不当容易损坏。本文从大量的调查研究中,选取几个典型的TVS管失效案例,详细分析失效原因,并将这些原因进行总结,提出有效的整改办法。     

综合评分法筛选水污染物排放控制因子

控制因子筛选是工业水污染物排放标准制定的重要环节。控制因子筛选应从工业原材料主要成分、排放污染物种类分析着手,逐步缩小备选名单范围。对进入初始名单的污染物,通过综合评分法评价其毒性和暴露水平两方面因素,选择潜在危害指数、年排放量和环境检出率三个指标,制定评分标准,根据各污染物得分情况确定其在排放标准中加以控制的必要性,并以此为主要参考依据确定控制因子。     

Estimating Annual Groundwater Evapotranspiration from Phreatophytes in the Great Basin Using Landsat and Flux Tower Measurements

Escalating concerns about water supplies in the Great Basin have prompted numerous water budget studies focused on groundwater recharge and discharge. For many hydrographic areas (HAs) in the Great Basin, most of the recharge is discharged by bare soil evaporation and evapotranspiration (ET) from phreatophyte vegetation. Estimating recharge from precipitation in a given HA is difficult and often has significant uncertainty, therefore it is often quantified by estimating the natural discharge. As such, remote sensing applications for spatially distributing flux tower estimates of ET and groundwater ET (ET_g) across phreatophyte areas are becoming more common. We build on previous studies and develop a transferable empirical relationship with uncertainty bounds between flux tower estimates of ET and a remotely sensed vegetation index, Enhanced Vegetation Index (EVI). Energy balance‐corrected ET measured from 40 flux tower site‐year combinations in the Great Basin was statistically correlated with EVI derived from Landsat imagery (r² = 0.97). Application of the relationship to estimate mean‐annual ET_g from four HAs in western and eastern Nevada is highlighted and results are compared with previous estimates. Uncertainty bounds about the estimated mean ET_g allow investigators to evaluate if independent groundwater discharge estimates are “believable” and will ultimately assist local, state, and federal agencies to evaluate expert witness reports of ET_g, along with providing new first‐order estimates of ET_g.     

Mineralization of aqueous pentachlorophenolate by anodic contact glow discharge electrolysis

Exhaustive mineralization of pentachlorophenolate ion (PCP) in phosphate buffer was carried out using anodic contact glow discharge electrolysis (CGDE), in which plasma was sustained between the electrolyte and anode. During CGDE, PCP degraded smoothly. The amount of total organic carbon decreased significantly, indicating the eventual conversion of the carbon atoms of benzene nucleus to inorganic carbons. Furthermore, chlorine atoms in PCP were liberated as chloride ions. As a primary intermediate product, 2,3,5,6- tetrachloro-1,4-benzoquinone was detected, and oxalate and formate as byproducts were also found. It was revealed that disappearance of PCP obeyed first-order kinetics. The reaction rate was generally unaffected by both O2 and inert gases in the cell, although it decreased by raising initial pH of solution. In addition, a plausible reaction pathway involving hydroxyl radical was proposed.     

电磁脉冲作用下单极子天线的超宽带响应

目的提出求解短波单极子天线在外界电磁脉冲作用下宽带响应的数值算法——基于利用矩量法的时域积分方法。方法为展开未知电流的时域系数,采用拉盖儿多项式作为整个时域空间中的展开基函数,对单极子天线的瞬态响应进行数值模拟,并和试验数据进行对比验证。结果文中提出的方法与试验数据匹配良好。结论试验结果验证了该方法的有效性,该分析方法可为天线或系统对外界有意电磁干扰的响应及防护研究提供输入条件。     

非平衡等离子体治理有机含磷气体的实验研究

采用脉冲电晕放电产生的等离子体对沙林毒剂的模拟剂甲基磷酸二甲酯进行消除研究.着重进行了脉冲峰压、脉冲频率、初始质量浓度、气体流量等对消除率的影响实验.结果发现,消除率随脉冲峰压和脉冲频率的增加而提高,随气体流量和初始质量浓度的增大而降低.同时发现产物中含有C02、H2O、丙酸、甲基磷酸甲酯和磷酸(或P2O5)等物质.     

垃圾焚烧发电厂烟气净化工艺及应用

本文介绍了引进的西格斯烟气净化技术的工艺流程和技术特点，并就采用该技术建设的深圳某垃圾焚烧发电厂烟气排放指标和国家标准及实测值进行了比较。     

当前排污费征收中的问题和发展方向

本文针对在2000年“一控双达标”工作后排污费征收中出现的问题，提出了相应的解决办法，同时对排污费今后的发展作了简要阐述。     

PREDICTION OF TWO-YEAR PEAK STREAM-DISCHARGES USING NEURAL NETWORKS1

ABSTRACT: The cascade correlation neural network was used to predict the two-year peak discharge (Q₂) for major regional river basins of the continental United States (US). Watersheds ranged in size by four orders of magnitude. Results of the neural network predictions ranged from correlations of 0.73 for 104 test data in the Souris-Red Rainy river basin to 0.95 for 141 test data in California. These results are improvements over previous multilinear regressions involving more variables that showed correlations ranging from 0.26 to 0.94. Results are presented for neural networks trained and tested on drainage area, average annual precipitation, and mean basin elevation. A neural network trained on regional scale data in the Texas Gulf was comparable to previous estimates of Q₂ by regression. Our research shows Q₂ was difficult to predict for the Souris-Red Rainy, Missouri, and Rio Grande river basins compared to the rest of the US, and acceptable predictions could be made using only mean basin elevation and drainage areas of watersheds.