Characterizing scale- and location-dependent correlation of water retention parameters with soil physical properties using wavelet techniques

Understanding the correlation between soil hydraulic parameters and soil physical properties is a prerequisite for the prediction of soil hydraulic properties from soil physical properties. The objective of this study was to examine the scale- and location-dependent correlation between two water retention parameters (alpha and n) in the van Genuchten (1980) function and soil physical properties (sand content, bulk density [Bd], and organic carbon content) using wavelet techniques. Soil samples were collected from a transect from Fuxin, China. Soil water retention curves were measured, and the van Genuchten parameters were obtained through curve fitting. Wavelet coherency analysis was used to elucidate the location- and scale-dependent relationships between these parameters and soil physical properties. Results showed that the wavelet coherence between alpha and sand content was significantly different from red noise at small scales (8-20 m) and from a distance of 30 to 470 m. Their wavelet phase spectrum was predominantly out of phase, indicating negative correlation between these two variables. The strong negative correlation between alpha and Bd existed mainly at medium scales (30-80 m). However, parameter n had a strong positive correlation only with Bd at scales between 20 and 80 m. Neither of the two retention parameters had significant wavelet coherency with organic carbon content. These results suggested that location-dependent scale analyses are necessary to improve the performance for soil water retention characteristic predictions.     

An in-situ method of identifying ingredients of zeotropic refrigerants by inversion problem technique

An inversion method is applied to identify ingredients of zeotropic refrigerants in a circular duct. In the case of low Reynolds number and constant fluid pressure, the temperature distribution of direct heat transfer problem can be solved numerically. The thermophysical parameters of zeotropic refrigerants are determined by using inversion problem technique, the ingredients of refrigerants can be identified eventually. An in-situ experimental apparatus was proposed and three test samples with different composition refrigerants were conducted in this study. The experiment results show that the relative error of ingredients identification can be limited within 8.33%.     

Ecosystem-inspired model and artificial intelligence predicts pollutant consumption capacity by coagulation in drinking water treatment

Conventional methods for water and wastewater treatment are energy-intensive, notably at the stage of coagulation–flocculation, calling for new strategies to predict pollutant reduction because the amount of energy consumed is related to how much of the pollutant is treated. Here we developed a model, named Bio-logic, inspired by ecosystems, where pollutants represent organisms, coagulants are food, and the wider environmental conditions are the living environment. Artificial intelligence was used to learn the biological behavior, which enabled an accurate prediction of the amount of pollutant reduction. Results show that pseudo-biological objects that have a strong affinity for biological food, such as turbidity, total phosphorus, ammonia nitrogen and the potassium permanganate index, induced a strong correlation, between measured pollutant consumption capacity and predicted values. For instance, R² correlation coefficients are 0.97 for turbidity and 0.92 for the potassium permanganate index in the laboratory; and 0.99 for turbidity, 0.90 for total phosphorus, 0.75 for ammonia nitrogen and 0.63 for the potassium permanganate index in water treatment plants. Overall, our findings demonstrate that artificial intelligence can use the water Bio-logic model to predict the pollutant consumption capacity.

     

旅游演艺品牌形象的结构化与非结构化研究——以张家界“魅力湘西”为例

以张家界"魅力湘西"为例,利用结构法与非结构法研究了游客对旅游演艺品牌形象的感知状况。结果表明:旅游演艺品牌形象感知的内在维度存在差异,宣传策略宜多元化;旅游演艺品牌形象感知以具体象征物为载体的文化形象为主;产品体验前以传播形象对旅游演艺品牌形象的影响显著,产品体验后的功能形象影响显著。     

Application of an integrated biomarker response index to assess ground water contamination in the vicinity of a rare earth mine tailings site

We utilized a multi-biomarker approach (Integrated Biomarker Response version 2, IBRv2) to investigate the scope and dispersion of groundwater contamination surrounding a rare earth mine tailings impoundment. Parameters of SD rat included in our IBRv2 analyses were glutathione levels, superoxide dismutase, catalase, and glutathione peroxidase activities, total anti-oxidative capacity, chromosome aberration, and micronucleus formation. The concentration of 20 pollutants including Cl^?, SO₄ ^2?, Na⁺, K⁺, Mg²⁺, Ca²⁺, TH, COD_Mn, As, Se, TDS, Be, Mn, Co, Ni, Cu, Zn, Mo, Cd, and Pb in the groundwater were also analyzed. The results of this study indicated that groundwater polluted by tailings impoundment leakage exhibited significant ecotoxicological effects. The selected biomarkers responded sensitively to groundwater pollution. Analyses showed a significant relationship between IBRv2 values and the Nemerow composite index. IBRv2 could serve as a sensitive ecotoxicological diagnosis method for assessing groundwater contamination in the vicinity of rare earth mine tailings. According to the trend of IBRv2 value and Nemerow composite index, the maximum diffusion distance of groundwater pollutants from rare earth mine tailings was approximately 5.7 km.

     

薪柴和经济作物秸秆燃烧VOCs排放特征

薪柴及经济作物秸秆在中国农村地区仍普遍使用,其燃烧是挥发性有机物(VOCs)的重要排放源,当前对其排放特征研究仍比较薄弱.本研究选取了3种薪柴(白杨树、杉木和柑橘枝)和6种经济作物秸秆(黄豆秆、芝麻秆、玉米棒、棉花秆、花生秆和玉米秆),通过实验室模拟燃烧和稀释通道采样系统,采用Tedlar袋和Agilent 7820A/5977E气相色谱/质谱联用法采集和分析了烟气中102种VOCs组分组成,并对不同类型生物质燃烧排放VOCs的臭氧生成潜势进行分析.结果表明,不同类型的生物质燃烧排放的VOCs组分存在差异,乙烷(11.1%)、反-2-戊烯(15.4%)、乙烯(8.3%)和二氯甲烷(11.9%)是白杨树和杉木燃烧排放的主要VOCs组分;甲苯(49.8%)是柑橘枝燃烧排放的VOCs含量最丰富的物种;乙烯(11.8%～17.5%)和丙酮(9.2%～14.7%)是秸秆类燃料燃烧的主要VOCs组分.玉米秆、花生秆和柑橘枝具有相似的VOCs源成分谱,分歧系数小于0.1.本研究及已有报道中的生物质燃烧排放苯/甲苯比值范围是0.030～6.48,在开展源解析研究中,采用苯/甲苯比值大于1认定为受到生物质燃烧排放影响值得商榷.烯烃、含氧VOCs和芳香烃对生物质燃烧排放VOCs的臭氧生成潜势的贡献分别为30.6%～80.3%、 6.5%～21.0%和3.8%～56.5%,对臭氧生成潜势贡献比例超过10.0%的组分为乙烯、丙烯、反-2-戊烯、顺-2-戊烯、甲苯和丙醛.     

Cysteine-enhanced reductive degradation of nitrobenzene using nano-sized zero-valent iron by accelerated electron transfer

As an aliphatic amino acid, cysteine (CYS) is diffuse in the living cells of plants and animals. However, little is known of its role in the reactivity of nano-sized zero-valent iron (NZVI) in the degradation of pollutants. This study shows that the introduction of CYS to the NZVI system can help improve the efficiency of reduction, with 30% more efficient degradation and a reaction rate constant nine times higher when nitrobenzene (NB) is used as probe compound. The rates of degradation of NB were positively correlated with the range of concentrations of CYS from 0 to 10 mmol/L. The introduction of CYS increased the maximum concentration of Fe(III) by 12 times and that of Fe(II) by four times in this system. A comparison of systems featuring only CYS or Fe(II) showed that the direct reduction of NB was not the main factor influencing its CYS-stimulated removal. The reduction in the concentration of CYS was accompanied by the generation of cystine (CY, the oxidized form of cysteine), and both eventually became stable. The introduction of CY also enhanced NB degradation due to NZVI, accompanied by the regeneration of CYS. This supports the claim that CYS can accelerate electron transfer from NZVI to NB, thus enhancing the efficiency of degradation of NB.     

以基层队为核心的“13331”安全工程构建

针对干部员工安全意识淡薄,制度穿透力较弱,安全监管有效性不强等问题,结合石油工程专业作业战线长、野外作业多的特点,某石油工程公司将基层工作与HSE工作深度结合,管理重心前移至基层队,构建并实施"13331"安全工程,有效提升了基层安全管理水平。     

贵州省生态渔业(池塘养殖、流水养殖、设施养殖)对水生态环境影响初探

为掌握生态渔业对贵州省水生态环境可能造成的影响,选择省内9个典型渔场开展不同养殖模式(池塘、网箱、设施养殖)对水体环境的影响机制与生态效应研究.研究结果表明:影响渔场水质的主要环境因子是CODMn、Chl-a、NH4+及WT、pH、EC和DO.其中不同生态渔业养殖模式水体由于鱼类的高密度,均呈现不同状态的富营养化,如直排尾水均会对排入水体生态环境产生影响,如渔场采用循环用水或排水后做沉淀池、植物净化等措施,该影响将会降低,但也影响鱼塘周边土壤及养殖池自身水环境,后期需持续对土壤、周边地下水进行跟踪监测.     

土壤种子库特征及与地上植被的关系——以福建省三明市杉木人工林为例

以杉阔混交林和杉木人工纯林为研究对象,采用野外调查、取样和室内种子萌发法,研究土壤种子库的物种组成、密度、垂直分布特征及其与地上植被的关系.结果表明：混交林土壤种子库由24科30属的30种植物组成,纯林由20科24属的24种植物组成,种子密度分别为656.94±89.59粒/m²和486.11±77.66粒/m²,物种组成均以草本植物为主.两林分土壤种子库中的种子主要集中于0~2cm和2~5cm土层,占69.0%~75.2%.乔木种子主要分布于凋落物层中,灌木、草本和藤本植物的种子主要分布于0~2cm土壤层中.混交林和纯林土壤种子库与各自地上植被的相似性指数分别为0.40和0.33,整体相似程度较低.总体而言,杉木纯林和杉阔混交林林内种源充足,可满足林下植被更新的需求,混交林林下草本植被的更新潜力大于纯林.杉木种源不是其更新障碍的主要因素,林内较厚的凋落物以及林下较弱的光照可能是主要障碍因素,但尚需进一步研究.