太阳鱼脑乙酰胆碱酯酶的分离纯化

采用硫酸铵沉淀–普鲁卡因胺亲和柱层析方法,对太阳鱼(Lepomis gibbosus)脑部乙酰胆碱酯酶分离纯化,纯化倍数为234倍,回收率为25.67%,经SDS-PAGE电泳检测,呈现单一的条带,相对分子质量约为68 000,表明其纯度达到电泳纯.     

Photocatalytic degradation of phenol with mesoporous TiO2?xBx

We report a facile approach for preparing mesoporous boron-doped TiO₂ materials by combining the sol?Cgel process with the dehydration of glucose. Specifically a high surface carbon material was formed by dehydration of glucose, then used as template. This material and the TiO₂ dry gel were calcinated to produce porous TiO₂. The as-synthesized boron-doped TiO₂ was in pure anatase crystallite phase with high surface area. X-ray photoelectron spectroscopy (XPS) results showed that boron was incorporated into the anatase TiO₂ lattice to form TiO_2?xB_x. The absorption spectra of TiO_2?xB_x extended into the visible region to 460?nm. The TiO_2?xB_x exhibited much higher photocatalytic activity on phenol degradation than pure TiO₂. It showed that the phenol degradation by-products of TiO_2?xB_x were different from that of pure TiO₂. Mechanism of the photocatalytic degradation of phenol at TiO_2?xB_x was also proposed.     

花岗岩风化壳的不均一性与海岸带的可蚀性研究——以南海北大陆海岸带为例

海岸带岩土动力学特征的差异是影响海岸侵蚀过程与方向的重要因素之一。南海北大陆海岸带主要由花岗岩风化边坡组成。通过对该海岸带的北东翼及西南翼典型花岗岩风化壳剖面的黏土矿物及风化指标研究发现,两者存在不均一性：横向上,北东翼黏土矿物主要以高岭石、伊利石为主;西南翼黏土矿物主要以高岭石、伊利石和绿泥石为主,两翼均未见较明显的蒙脱石。相同层位比较,西南翼黏土矿物总量高于北东翼。垂向上,自地表到深部,北东翼黏土矿物组合及总量无明显的分层性,而西南翼则呈明显的分层性且地表含量明显高于深部。海岸带的风化作用也存在明显的不均一性：表现为横向上,北东翼海岸带风化程度要稍弱于西南翼;垂向上,北东翼化学风化指标n（Al2O3）/n（SiO2）,n（Fe2O3＋Al2O3）/n（SiO2）,n（TiO2）/n（Al2O3）、CIA在风化壳中呈无规律变化,而西南翼则呈明显的分层性,这种分层基本与表土层、红土层及砂土层成一定的对应关系。从化学可蚀性指标来看,由南海北大陆海岸带花岗岩风化壳演化而成的土壤均为强抗蚀性,但相同层位比较,北东翼可蚀性要稍弱于西南翼剖面。研究认为,组成南海北大陆海岸带的花岗岩风化壳之黏土矿物与风化作用的不均一性可很大程度影响海岸带的可蚀性。     

应用浅层地温测量法分析崩岗侵蚀与地下水分布关系

地下水是影响崩岗发生的重要驱动力之一,而地温场异常可以反映反推地下水分布。在野外调查的基础上,利用浅层地温法反演流动地下水脉分布的原理,分析并探讨了粤东五华典型崩岗侵蚀区的地下水分布、流向及与崩岗分布的空间关系。结果表明：地下水脉复杂多变的区域,其崩岗侵蚀程度也越严重。这种关系主要表现在3点：（1）较活跃和集中分布的崩岗侵蚀群常具有更多的浅层地温冷点;（2）零散分布的单个崩岗体,其水脉形态常呈不连续性,且总体流动方向较均一,与崩岗前进方向相反;（3）在崩岗群中,地下水脉则呈树枝状或网状展布。应用浅层地温法间接探讨崩岗侵蚀与地下水分布关系,是研究崩岗侵蚀过程与机理的新手段,具较好的应用前景。     

Assessment of cadmium exposure for neonates in Guiyu, an electronic waste pollution site of China

This study aimed to determine the levels of placental cadmium (PCd) and cord blood cadmium (CBCd) and the resulting expression of placental metallothionein (MT) in neonates and to investigate cadmium (Cd) exposure levels in neonates and mothers who live in Guiyu, China, an electronic waste (e-waste) pollution site. Among the 423 mothers included in the study from 2004/2005 to 2007, 289 lived in Guiyu (exposed group) and 134 lived in Chaonan, located 10 km away from Guiyu (controls) and had never been exposed to e-waste pollution. CBCd and PCd levels were measured by atomic absorption spectrometry. Placental MT was examined by immunohistochemistry. Information on maternal and neonatal characteristics and exposure conditions was obtained from hospital records and by personal interviews. For the 3 years, the median CBCd was higher for Guiyu neonates than for controls (3.61 vs. 1.25 ??g/L), with 25.61% of Guiyu subjects exhibiting a median CBCd that exceeded the safety limit defined by the World Health Organization (5 ??g/L), as compared with 14.18% of control neonates (p < 0.01). In Guiyu, the mean PCd was higher than that for controls (0.17 ± 0.48 vs. 0.10 ± 0.11 ??g/g, p ?? 0.01). The high levels of CBCd and PCd were significantly associated with parents?? occupational and environmental exposure to e-waste recycling pollutants. Staining for MT was positive and dense for 67.00% (67/100) of Guiyu neonates as compared with 32.69% (17/52) of controls (p < 0.01). Exposure to e-waste recycling pollutants increased Cd exposure in neonates, which was accompanied by increased placental MT expression.     

Water quantity and quality optimization modeling of dams operation based on SWAT in Wenyu River Catchment, China

Water quantity and quality joint operation is a new mode in the present dams?? operation research. It has become a hot topic in governmental efforts toward integrated basin improvement. This paper coupled a water quantity and quality joint operation model (QCmode) and genetic algorithm with Soil and Water Assessment Tool (SWAT). Together, these tools were used to explore a reasonable operation of dams and floodgates at the basin scale. Wenyu River Catchment, a key area in Beijing, was selected as the case study. Results showed that the coupled water quantity and quality model of Wenyu River Catchment more realistically simulates the process of water quantity and quality control by dams and floodgates. This integrated model provides the foundation for research of water quantity and quality optimization on dam operation in Wenyu River Catchment. The results of this modeling also suggest that current water quality of Wenyu River will improve following the implementation of the optimized operation of the main dams and floodgates. By pollution control and water quantity and quality joint operation of dams and floodgates, water quality of Wenyu river will change significantly, and the available water resources will increase by 134%, 32%, 17%, and 82% at the downstream sites of Sha River Reservoir, Lutong Floodgate, Xinpu Floodgate, and Weigou Floodgate, respectively. The water quantity and quality joint operation of dams will play an active role in improving water quality and water use efficiency in Wenyu River Basin. The research will provide the technical support for water pollution control and ecological restoration in Wenyu River Catchment and could be applied to other basins with large number of dams. Its application to the Wenyu River Catchment has a great significance for the sustainable economic development of Beijing City.     

两级序批式生物膜法对厌氧消化液的处理研究

采用两级序批式生物膜法(SBBR)处理猪场废水厌氧消化液,考察了不同类型的填料以及填料的不同组合方式对污染物的去除效果。试验结果表明:组合3(1级反应器中投加碳素纤维填料,2级反应器中投加组合填料)COD去除能力较好,可达93.7%,组合1(1级,2级反应器中均投加碳素纤维填料)NH4+-N和TN去除率最高,分别为69.2%、70.4%;此外对运行过程中的DO浓度和pH值的变化情况进行监测,DO浓度受有机物降解和硝化反应的共同影响,pH值受曝气量的影响较多。因此,可以通过DO浓度和pH值来判断反应系统中污染物的变化情况和反应所处阶段。     

基于GC-MS的烹调油烟VOCs的组分研究

挥发性有机物(VOCs)是PM2.5和臭氧生成的重要前体物之一,而VOCs组分不同,对大气反应的贡献也不同.烹调油烟排放的VOCs作为大气中VOCs的重要来源之一,其化学成分随所选用的食用油种类、食品种类、烹调方式、加热温度等的不同有很大差异.从对食用油的烧杯加热实验入手,简化模拟烹调油烟发生情景,以油温和油品为变量,采用Tenax吸附管采样,热脱附-气相色谱-质谱法(GC-MS)对不同油品在不同温度下加热产生的VOCs进行组分分析,根据谱库检索和图谱解析,利用面积归一化的半定量法,对各条件下油烟VOCs的具体组分进行了初步的定性和定量.     

Growth and nutrient accumulation of Phragmites australis in relation to water level variation and nutrient loadings in a shallow lake

Shallow lake eutrophication is a global environmental issue. This study investigated the effects of water level variation and nutrient loadings on the growth and nutrient accumulation of Phragmites australis (reed) by field samplings in Baiyangdian Lake, the largest shallow lake of northern China. The field samplings were conducted in two sites of different nutrient loadings during the whole growth period of reeds, and three types of zones with different water depths were chosen for each site, including the terrestrial zone with water level below the ground, the ecotone zone with the water level varying from belowground to aboveground, and the submerged zone with water level above the ground. The result showed that reed growth was more limited by water level variation than nutrient loadings. The average stem lengths and diameters in terrestrial zones were about 26.3%-27.5% and 7.2%-12.0% higher than those in submerged zones, respectively. Similarly, the terrestrial status increased the aboveground biomass of reeds by 36.6%-51.8% compared with the submerged status. Both the nutrient concentrations and storages in the aboveground reeds were mainly influenced by the nutrient loadings in surface water and sediment rather than the water level variation of the reed growth environment, and the nutrient storages reached their maxima in late August or early September. It was observed that the maximum nitrogen storage occurred in the terrestrial zone with higher nutrient loadings, with the value of 74.5 g/m 2 . This study suggested that water level variation and nutrient loadings should be considered when using reeds to control and remediate eutrophication of shallow lakes.     

Cr(VI) removal from aqueous solution with bamboo charcoal chemically modified by iron and cobalt with the assistance of microwave

Bamboo charcoal (BC) was used as starting material to prepare Co-Fe binary oxideloaded adsorbent (Co-Fe-MBC) through its impregnation in Co(NO3)2 , FeCl3 and HNO3 solutions simultaneously, followed by microwave heating. The low-cost composite was characterized and used as an adsorbent for Cr(VI) removal from water. The results showed that a cobalt and iron binary oxide (CoFe2O4 ) was uniformly formed on the BC through redox reactions. The composite exhibited higher surface area (331 m2/g) than that of BC or BC loaded with Fe alone (Fe-MBC). The adsorption of Cr(VI) strongly depended on solution pH, temperature and ionic strength. The adsorption isotherms followed the Langmuir isotherm model well, and the maximum adsorption capacities for Cr(VI) at 288 K and pH 5.0 were 35.7 and 51.7 mg/g for Fe-MBC and Co-Fe-MBC, respectively. The adsorption processes were well fitted by the pseudo second-order kinetic model. Thermodynamic parameters showed that the adsorption of Cr(VI) onto both adsorbents was feasible, spontaneous, and exothermic under the studied conditions. The spent Co-Fe-MBC could be readily regenerated for reuse.