Radiation-induced degradation of methyl orange in aqueous solutions

Degradation of methyl orange under gamma-irradiation was investigated. The reactions followed pseudo first-order kinetics. Apparent degradation rate constant, estimated through linear regression analysis, increased with an increase of dose rate and a decrease of initial methyl orange concentration. Degradation of methyl orange was significantly accelerated under oxidative condition, but was slightly enhanced under reductive condition. However, the result of decoloration was better under reductive condition than oxidative one. An analysis on the intermediates using Fourier transform infrared and gas chromatography/mass spectrometry demonstrates that the radiolytic degradation of methyl orange was processed with different C-N cleavages under oxidative and reductive conditions.     

羊角月芽藻摄取磷形态的动力学研究

将湖水中的磷分成总溶解磷,溶解反应磷,总反应磷、溶解的水解性磷,溶解的光解性磷。研究其在羊角月芽过程中的变化。     

便携式分光光度计法快速测定水中砷方法研究

通过研究各仪器性能指标以及测定实际水质样品,对3种便携式分光光度计快速测定水中砷的方法进行了优化和比对研究。结果表明,ZZW-Ⅱ测试仪快速测定水中砷的方法检出限(0.2 mg/L)高于JH 916检测仪和PORS-15 V光谱仪的方法检出限(0.008和0.009 mg/L),在突发性环境污染事故应急监测中,JH 916检测仪和PORS-15 V光谱仪具有相对较高的灵敏度。ZZW-Ⅱ测试仪和JH 916检测仪快速测定水中砷的方法精密度相近,其测定结果相对标准偏差均未超过5.7%(n=6),PORS-15 V光谱仪快速测定水中砷的方法精密度稍差,其相对标准偏差最大值为17%。测定实际样品时,加标回收率分别为110%~126%(ZZW-Ⅱ测试仪),63%~108%(PORS-15 V光谱仪),78%~101%(JH 916检测仪)。3种便携式分光光度计与实验室分析方法相比,测定结果精密度均存在显著性差异,测定结果相对偏差亦较大,相对偏差最大值分别为-19.0%(ZZW-Ⅱ测试仪),17.0%(PORS-15 V光谱仪),-15.0%(JH 916检测仪)。     

Impacts of ecological water conveyance on groundwater dynamics and vegetation recovery in the lower reaches of the Tarim River in northwest China

The ecological water conveyance project (EWCP) in the lower reaches of the Tarim River provided a valuable opportunity to study hydro-ecological processes of desert riparian vegetation. Ecological effects of the EWCP were assessed at large spatial and temporal scales based on 13 years of monitoring data. This study analyzed the trends in hydrological processes and the ecological effects of the EWCP. The EWCP resulted in increased groundwater storage—expressed as a general rise in the groundwater table—and improved soil moisture conditions. The change of water conditions also directly affected vegetative cover and the phenology of herbs, trees, and shrubs. Vegetative cover of herbs was most closely correlated to groundwater depth at the last year-end (R?=?0.81), and trees and shrubs were most closely correlated to annual average groundwater depth (R?=?0.79 and 0.66, respectively). The Normalized Difference Vegetation Index (NDVI) responded to groundwater depth on a 1-year time lag. Although the EWCP improved the NDVI, the study area is still sparsely vegetated. The main limitation of the EWCP is that it can only preserve the survival of existing vegetation, but it does not effectively promote the reproduction and regeneration of natural vegetation.     

电子设备缓蚀剂对电子设备防护的应用研究

目的 研究DZ-1电子设备缓蚀剂用于电子设备防护的有效性.方法 参照MIL-PRF-81309G、MIL-L-87177A和Q/AVIC 03018中的试验方法,对自主研制的DZ-1电子设备缓蚀剂的性能进行全面评价.结果 DZ-1电子设备缓蚀剂没有闪点,在运输、储藏及使用过程中非常安全,使用性能良好,很容易去除,能够去...     

高频超声波降解4-氯酚的反应机理及试验研究

探讨了高频超声波（1.7MHz)降解4-氯酚的反应过程和反应机理，研究了高频超声波降解4-氯酚的效果及4-氯酚的初始浓度，高级氧化方法（AOPs)等因素对降解效果的影响。试验结果表明，高频超声波降解4-氯酚为一级反应，超声波空化效应在降解过程中起主导作用。超声波与其他氧化方法联用可大大提高降解效率。具有良好的工业应用前景。     

水资源供需平衡的安全分析

从中国发展的区域基础角度,考察经济核心区和6个大区在未来经济发展中的水资源供需安全问题.在分析中应用一般均衡的分析技术和线性规划逆问题分析技术相结合,研究表明,在未来发展中水资源最紧缺的地区是华北和西北,作为经济核心区的京津唐地区水资源问题最为严重.研究提出,只有结合开源节流和调整产业结构才能保证经济发展中的水资源供应安全.     

矿井通风网络解算可视化软件研究

采用面向对象编程语言Visual Basic6.0为开发工具,以Access为后台数据库,开发了具有风机优选功能的矿井通风网络解算软件。该软件承袭了Windows系统应用程序界面直观、交互性好的特点,集矿井通风网络解算、自然风压计算、风机自动选型以及经济断面优化等功能于一体,并辅以强大的数据管理系统,为矿山通风设计和管理工作提供了便利工具。     

流体混合状态对微生物的影响——以枯草芽孢杆菌为例

采用雷诺数表征液体环境的混合状态。利用一种自主研发的流体混合设备产生不同的液体流态,研究流态对枯草芽孢杆菌生长的影响。枯草芽孢杆菌是净化污水的一大主要细菌。结果发现,雷诺数越大,越有利于细菌的生长,具体表现为对数期时间缩短,到达平稳期时菌体浓度提高。此外,接种枯草芽孢杆菌后会消耗溶解氧,使培养基中的溶解氧维持在一个较低的水平(0~1mg/L)。