Modeling agricultural non-point source pollution in a high-precipitation coastal area of China

Non-point source （NPS） pollution simulation in the high-precipitation coastal areas of China is difficult because varying annual typhoon incidence leads to highly contrasting rainfall patterns in dry years and wet years. An IMPULSE （Integrated Model of Non-point Sources Pollution Processes） based NPS model of the Changtan Reservoir watershed, which is a typical high-precipitation coastal area in China, was established based on the analysis of point and NPS pollution data, a digital elevation model, and data on land-use, soil, meteorology, economy, and agricultural management practice. Pre-processed pre-rain- fall soil moisture levels were introduced during the simulation to model the effects of typhoons on hydrology. Rainfall events were simulated sequentially through the year and the model was calibrated and verified using hydrological and water quality data. Accuracy of the simulated rainfall runoff and water quality in the Changtan watershed was found to be acceptable. The study showed that the NPS modeling system could be applied to the simulation and prediction ofNPS loadings in the Changtan Reservoir watershed.     

Higher nitrates, P and lower pH in soils under medicinal plants versus crop plants

This report shows a higher soil quality under medicinal plants versus food-crop plants. Long-term continuous cultivation of food crops induces changes of soil properties that can lead to fertility loss and, in turn, decline of food productivity. Effect of cropping on soil changes has been studied mainly for food crops and vegetables worldwide, whereas soil changes in herbal fields are scarcely known. Therefore, we compared here soil nutrients and soil chemical properties of herbal fields, cultivated with Chinese medicinal plants, and food-crop fields. Fields are located at the famous traditional planting base of Chinese medicinal plants in Anguo, China. The results showed that in herbal fields, soil nitrate, available P, soil organic matter (SOM), and electrical conductivity decreased with soil depth, whereas soil pH and soil water content increased with depth. In herbal fields, soil nitrate, available P contents, and soil electrical conductivity were higher than those of food-crop fields at various soil layers. SOM and soil water content were similar in herbal and food-crop fields. Soil pH of herbal fields at 0–20 cm was lower than those of food-crop fields. Findings show overall that soil nutrient accumulation and changes under medicinal plants are higher than food-crop fields.     

城市大气颗粒物毒性效应及机制的研究进展

大气颗粒物（PM）严重影响人体的健康,其与人类多种疾病的发生存在着明显的暴露-效应关系.本文简述了大气颗粒物的组分和来源,从大气颗粒物的呼吸系统毒性、心血管毒性、免疫毒性、神经毒性、遗传毒性等方面,系统地阐述了其对人体健康的危害,并对大气颗粒物的毒性机制进行了总结和讨论,指出了目前相关研究中存在的问题,展望了该领域的研究趋势,为后续研究和控制大气颗粒物的健康危害提供相应的科学参考依据.     

2-巯基噻唑啉与过氧化氢酶的相互作用机理研究

2-巯基噻唑啉是一种被广泛应用的抗腐蚀剂和光亮剂,然而它的一些残留物会对环境造成损坏,为探究2-巯基噻唑啉的毒性作用,采用光谱学技术和分子对接技术来考察2-巯基噻唑啉和过氧化氢酶的相互作用影响,其中酶活性实验表明2-巯基噻唑啉会抑制过氧化氢酶的活性,分子对接结果显示2-巯基噻唑啉会结合在过氧化氢酶的活性位点处,并最终导致过氧化氢酶空间结构和微环境的变化,根据荧光测试结果,表明2-巯基噻唑啉和过氧化氢酶之间的猝灭方式为静态猝灭。通过测量不同温度下的结合位点数、结合常数以及热力学常数,显示2-巯基噻唑啉与过氧化氢酶主要通过氢键和范德华力相结合。该研究从分子水平上考察了2-巯基噻唑啉对蛋白质的毒性作用,对于阐明污染物的毒性机理具有重要意义。     

TiO2-Bi2O3纳米粒子气相光催化降解对二甲苯

采用沉淀法制备了TiO2-Bi2O3纳米粒子,并对其进行结构表征.以制得的TiO2-Bi2O3为光催化剂,以对二甲苯为目标污染物,研究了对二甲苯气相光催化氧化降解的影响因素.实验结果表明:经750 ℃焙烧的光催化剂对对二甲苯的催化效果最好;随氧气加入量的增加,对二甲苯的降解率增大;少量水蒸气的加入,可增大对对二甲苯降解率;采用L-H动力学模型得到对二甲苯光催化降解的反应速率常数和吸附常数分别为0.089 5 μmol/(L· min)和0.000785 L/μmol.     

极限定义的新理解

针对“极限”概念提出了一些见解,并从理论上描述和给出了“极限”的精确定义,从该定义出发,更有助正确理解和掌握“极限”的内在含义。     

A novel pharmacophore model on PAEs’ estrogen and thyroid hormone activities using the TOPSIS and its application in molecule modification

Environmental Science and Pollution Research - In the proposed model, the estrogen activity values and thyroid hormone activity values of PAEs molecules were normalized using the TOPSIS method by...     

实施科技兴企战略提升煤企竞争实力

山东新汶矿业集团翟镇煤矿通过不断引进、消化和吸收国内外先进生产技术,走科技创新之路,这个昔日饱受顶板破碎干扰、生产条件复杂的大型矿井在短短几年的时间内实现了采掘机械化、辅助自动化、控制智能化,先后有136项科技项目首开国内先河,其中32项达到了国际先进水平。为推动“科技兴矿”战略的实施,翟镇煤矿采取了一系列有效措施：     

Application of Composite Water Quality Identification Index on the water quality evaluation in spatial and temporal variations: a case study in Honghu Lake,China

Composite Water Quality Identification Index (CWQII) and multivariate statistical techniques were used to investigate the temporal and spatial variations of water quality in Honghu Lake. The aims are to explore the characteristics of water quality trends in annual, monthly, and site spatial distribution and to identify the main pollution factors. The results showed that the values of CWQII increased from 2.0 to 4.0 from the years 2001 to 2005, then decreased from 2006 and kept a balance between 2.0 and 3.0 from 2006 to 2011, indicating that the water quality of Honghu Lake deteriorated from 2001 to 2005 and has gradually improved since 2006, which were likely achieved after water protection measurements taken since 2004. The monthly change rules of water quality were influenced by a superposition of natural processes and human activities. In samples numbered 1–9 from upstream to downstream, the maximum values of CWQII often occurred in sample site 9 while the minimum ones often occurred in sample site 2, indicating that the water quality near the upstream tributary was the poorest and that in the core zone was the best. Incoming water from the trunk canal of the Sihu area upstream was the largest pollution source. The sensitive pollution nutrients were mainly caused by the total nitrogen, followed by the total phosphorus.     

Near-shore distribution of heavy metals in the Albanian part of Lake Ohrid

The heavy metal contamination in Lake Ohrid, a lake shared between Albania and Macedonia, was studied. Lake Ohrid is believed to be one of the oldest lakes in the world, with a large variety of endemic species. Different anthropogenic pressures, especially heavy metal influxes from mining activities, might have influenced the fragile equilibrium of the lake ecosystem. Heavy metal concentrations in water, sediment, emergent vegetation, and fish were investigated at selected sites of the lake and a study of the heavy metals in five tributaries was conducted. The lake surface water was found to have low levels of heavy metals, but sediments contained very high levels mostly near river mouths and mineral dump areas with concentrations reaching 1,501 mg/kg for Ni, 576 mg/kg for Cr, 116.8 mg/kg for Co and 64.8 g/kg for Fe. Sequential extraction of metals demonstrates that heavy metals in the sediment are mainly present in the residual fraction varying from 75% to 95% in different sites. High heavy metal levels (400 mg/kg Ni, 89 mg/kg Cr, and 39 mg/kg Co) were found in plants (stem of Phragmites australis), but heavy metals could not be detected in fish tissue (gill, muscle, and liver of Salmo letnica and Salmothymus ohridanus).