南亚热带丘陵土壤水分循环及其有效性的研究──Ⅷ.丘陵赤红壤水分循环与平衡数学模型

依据田间实测资料,在分析丘陵赤红壤水分性质的基础上,建立了土壤有效含水量与土壤物理粘粒含量之间的数学模型、土壤水分特征曲线数学模型、土壤月均贮水量与月降雨总量之间的数学模型和径流率与土壤表层初始含水量之间的数学模型,研究了土壤水分循环与平衡数学模型及各分量与参数的确定方法.     

Sorption of polar and nonpolar aromatic compounds to four surface soils of eastern China

Improved predictions on the fate of organic pollutants in surface environments require a better understanding of the underlying sorption mechanisms that control their uptake by soils. In this study, we monitored sorption of nine aromatic compounds with varying physicochemical properties (hydrophobicity, electron-donor/acceptor ability and polarity), including two polycyclic aromatic hydrocarbons, two chlorobenzenes, two nitroaromatic compounds, dichlobenil, carbaryl and 2,4-dichlorophenol in aqueous suspension of four surface soils of eastern China. The tested soils were characterized with respect to organic carbon (OC) content, black carbon content, mineralogy, morphology and size fraction to assess the role of the diverse soil characteristics in sorption. The results of this study show that not only the solute hydrophobicity and the OC content of soil are important to the retention of organic pollutants, but also the solute molecular structure and the soil nature.     

4,4'-DDT全生命周期暴露对大型溞(Daphnia mag-na)生长、生殖、心率、行为、存活及基因转录的影响

大型溞(Daphnia magna)慢性毒性测试的毒理学数据是美国环境保护局水质基准(water quality criteria,WQC)制定中非常重要的数据来源,用以推导能有效保护水生生物的化学污染物浓度阈值.以往的研究表明,在部分生命周期暴露的基础上得出的最低观察效应浓度(lowest observed effe...     

化学工业园区规划环评指标体系初探

本文以某化工园区规划环评为例,根据化工区的行业特点,在总结国内外相关研究的基础上,探讨了化工园区规划环评指标体系设置原则和基本程序。在充分考虑了发展循环经济和生态工业、实现区域可持续发展、持续推进清洁生产等方面的基础上,通过基础指标初步筛选、多角度指标分析和专家咨询、公众参与等三个步骤的筛选,最终形成了一套适合于该化工园区规划环评指标体系。     

江苏省一次典型沙尘污染过程分析

2021年4月16日至4月18日江苏省经历了一次受沙尘影响的重污染过程.本次过程沙源地为蒙古国中南部及中国内蒙古中西部地区,在蒙古气旋后部西北大风影响下,沙尘气团自西北向东南影响了中国多个省市和地区.江苏省自16日起逐渐受到沙尘过程影响,苏北城市ρ(PM10)从凌晨开始迅速升高,浓度最高达569μg/m3,空气质量达严...     

基于Arrhenius模型和Peck模型的分段非线性加速模型

目的 解决Arrhenius模型无法估计湿度应力敏感产品和Peck模型试验时间较长的问题。方法 考虑温度应力和湿度应力对产品贮存寿命的综合影响,在产品激活能不变的假设下,将Arrhenius模型对产品激活能的估计和Peck模型对湿度应力参数的估计相结合,建立Arrhenius&Peck分段非线性加速寿命估计模型。基于此模型,在双应力恒加试验条件下,得到产品的寿命估计方程。结果 以弹上电子产品的恒定应力加速贮存试验为例,进行仿真分析,得到产品寿命的估计,并对比产品实际寿命。Arrhenius&Peck模型的寿命误差和失效率误差均控制在5%以内,准确度高于Arrhenius模型和Peck模型。结论 构建的Arrhenius&Peck分段非线性加速寿命模型可以充分利用温度和湿度条件下的试验数据,对温湿敏感产品的寿命估计有较好的应用效果,为导弹产品的寿命估计提供一种可选方法。     

Photo-degradation organic dyes by Sb-based organic-inorganic hybrid ferroelectrics

The organic-inorganic hybrid halide compounds have emerged as one of the most promising photoelectric material for their superior optoelectronic properties and hold great prospects for renewable energy substitutes and environmental protection as photocatalysis. Here, we report the optical properties of the Sb-based organic-inorganic hybrid ferroelectric materials: pyridine-4-aminium tetrachloroantimonate ((C₅H₇N₂)SbCl₄, sample 1), piperidin-1-aminium tetrachloroantimonate ((C₅H₁₃N₂)SbCl₄, sample 2) and tris(trimethylammonium) nonachlorodiantimonate (((CH₃)₃NH)₃Sb₂Cl₉, sample 3), which are a kind of exploited efficient photocatalysts. Samples 2 and 3 exhibit distinct photoelectric respond, which are mainly ascribed to their minor narrow band-gap compared with sample 1. For the ferroelectrics, the intrinsic of spontaneous polarization of sample 3 at room temperature is favourable for the separation of photogenerated electrons and holes within the photorespond process. Moreover, sample 3 shows the highest efficiency of photo-decomposed Rhodamine B (90.2% within 80 min) and Methyl Orange (MO) (97.4% within 50 min), thanks to the photo-excited electrons and holes promoting the formation of oxidative radical species during the photo-redox progress. These findings prove that the development of a novel Sb-based organic-inorganic hybrid halide compounds with good stability in the degradation of organic dyes paves a way to designing new photocatalyst.     

WCDMA网络基站安全防护距离理论计算与实测对比研究

根据HJ/T 10.2-1996中的微波远场轴向功率密度计算公式,对所选取典型WCDMA基站的安全防护距离进行了理论预测,并与实测得到的基站电磁辐射强度达标距离对比.结果表明,理论计算的安全防护距离在水平方向上较实测达标距离更为保守,在垂直方向上则较为接近.从发射功率、话务量、监测条件、建筑物干扰和WCDMA基站特点等方面分析了实测结果与理论计算差异的产生原因,并基于基站副瓣和后瓣实测电磁辐射强度远低于理论预测值的实践,认为WCDMA网络基站运行时的电磁辐射强度超标范围应远小于理论计算结果,其所造成的电磁辐射对环境影响较小.     

三维电极电Fenton氧化法处理染料废水

采用三维电极电Fenton氧化法处理实际染料废水,探究了染料废水处理效果的影响因素。实验结果表明：以钌铱镀层钛电极为阳极、不锈钢板为阴极、粉末活性炭为颗粒电极,在粉末活性炭投加量为2.0 g/L、电流密度为0.5 mA/mm²、极板间距为3 cm、pH为2.0、硫酸亚铁投加量为0.50 g/L的最优工艺条件下,反应2 h后COD、TOC、氨氮、色度的去除率达到最大,分别为62.80%、41.15%、42.48%和95.00%;粉末活性炭作为颗粒电极可使染料废水COD去除率提高18个百分点;重复使用10次的处理效果与第2次基本持平。     

Influence of calcium chloride on the thermal behavior of heavy and alkali metals in sewage sludge incineration

In order to separate and reuse heavy and alkali metals from flue gas during sewage sludge incineration, experiments were carried out in a pilot incinerator. The experimental results show that most of the heavy and alkali metals form condensed phase at temperature above 600 degrees C. With the addition of 5% calcium chloride into sewage sludge, the gas/solid transformation temperature of part of the metals (As, Cu, Mg and Na) is evidently decreased due to the formation of chloride, while calcium chloride seems to have no significant influence on Zn and P. Moreover, the mass fractions of some heavy and alkali metals in the collected fly ash are relatively high. For example, the mass fractions for Pb and Cu in the fly ash collected by the filter are 1.19% and 19.7%, respectively, which are well above those in lead and copper ores. In the case of adding 5% calcium chloride, the heavy and alkali metals can be divided into three groups based on their conversion temperature: Group A that includes Na, Zn, K, Mg and P, which are converted into condensed phase above 600 degrees C; Group B that includes Pb and Cu which solidify when the temperature is above 400 degrees C; and Group C that includes As, whose condensation temperature is as low as 300 degrees C.