下保护层开采覆岩卸压及瓦斯运移规律

为了研究中远距离下保护层开采覆岩卸压及瓦斯运移规律,以寺河矿和海天煤业为试验矿井,采用FLAC3D对开采覆岩卸压特征进行分析,采用COMSOL对开采被保护层瓦斯运移规律进行研究,并进行了现场实测验证。研究结果表明,保护层开采后,覆岩应力呈分区式分布,随着距煤层距离的增加,应力集中系数和卸压程度逐渐减少;保护层开采后,3#煤层应力降到最小值3.4 MPa,降幅达到57.8%;以膨胀变形量0.3%作为临界指标,被保护层的走向和倾向卸压角分别是59°,62°;保护层开采后,瓦斯质量浓度由7.82~9.75m~3/t降到4.12~4.36 m~3/t,瓦斯压力由0.37~0.46 MPa降到0.22~0.26 MPa,透气性系数增加了500多倍,被保护层产生的次生裂隙对于瓦斯解析具有促进作用,大大提高了煤体透气性。     

两种能源草田间条件下对镉和锌的吸收累积

大生物量能源草对镉污染土壤的修复潜力如何还未知.本研究采用两种能源草杂交狼尾草(Pennisetum americanum×P.purpureum)和紫色象草(P.purpureum 'Purple')以及马蔺(Iris lactea var.chinensis)和镉的超累积植物遏蓝菜(Noccaea caerules...     

土壤汞污染及修复措施研究进展

土壤汞污染已经严重危害到人类健康和生态环境,成为一个世界性问题,对其治理的各种修复措施也成为当前研究的一个热点。本文对土壤汞污染的来源、危害和修复措施等方面进行综述,指出了当前存在的问题,并对今后治理的研究方向提出了相关建议。     

Au nanoring arrays as surface enhanced Raman spectroscopy substrate for chemical component study of individual atmospheric aerosol particle

Monolayer-ordered gold nanoring arrays were prepared by ion-sputtering method and used as surface enhanced Raman spectroscopy (SERS) substrates to test the individual atmospheric aerosols particle. Compared to other methods used for testing atmospheric aerosols particles, the collection and subsequent detection in our work is performed directly on the gold nanoring SERS substrate without any treatment of the analyte. The SERS performance can be tuned by changing the depth of the gold nanoring cavity as originating from coupling of dipolar modes at the inner and outer surfaces of the nanorings. The electric field exhibits uniform enhancement and polarization in the ordered Au nanoring substrate, which can improve the accuracy for detecting atmospheric aerosol particles. Combined with Raman mapping, the information about chemical composition of individual atmospheric aerosols particle and distribution of specific components can be presented visually. The results show the potential of SERS in enabling improved analysis of aerosol particle chemical composition, mixing state, and other related physicochemical properties.     

Tetrasomy 12p—unusual presentation in CVS

CVS direct preparations usually achieve limited resolution and are better at detecting numerical rather than structural abnormalities. A CVS direct preparation analyzed using G-banding revealed a 47,XY,+G karyotype in 5 of 11 cells and was reported as mosaic for trisomy 21. Subsequent analysis of the CVS culture found only normal male cells. Amniocentesis revealed both normal male cells and cells with an extra F-group chromosome. Fluorescence in situ hybridization (FISH) identified this chromosome to be an isochromosome from the short arm of chromosome 12 [i(12)(p10)]. The amniocyte karyotype was reported as 47,XY,+i(12)(p10)[12]/46,XY[8].ish i(12)(p10)(wcp12+), which is associated with Pallister–Killian syndrome. Reexamination of the CVS direct preparation by FISH with a chromosome 12 centromere probe confirmed the karyotype of this tissue to be 47,XY,+mar[5]/46,XY[6].nuc ish 12cen(D12Z3 × 3)/12cen(D12Z3 × 2). Thus, multiple studies, including amniocentesis and fluorescence in situ hybridization, may be required to fully and accurately evaluate abnormalities detected by CVS. This case also indicates that mosaicism for supernumerary isochromosomes may have a complex origin. Copyright © 2003 John Wiley & Sons, Ltd.     

黄浦江上游原水强化处理选炭试验研究

以黄浦江上游水源为原水,通过煤质炭、竹质炭、椰壳炭等炭种筛选小试和中试试验,研究了黄浦江上游原水中有机污染物强化去除的最佳炭种及其最佳投加量。结果表明黄浦江上游原水中投加PAC能够改善处理后水质,提高原水中有机物的去除效果;并且随着PAC投加量的增加,原水中有机物去除效果增强;综合性价比、碳源等因素确定竹质炭较为经济合理;当竹质炭投加量为10～15mg/L时,处理后出水CODMn可达到3mg/L或以下。     

A new apparatus to enhance the rate of gas hydrate formation: Application to capture of carbon dioxide

A new apparatus employing a modular, mechanically agitated gas-inducing crystallizer is used to demonstrate the capture of CO₂ via hydrate crystallization. The crystallizer enhances the contact of hydrate forming gases with water and thus the rate of hydrate crystallization increases. Flue gas (CO₂/N₂) and fuel gas (CO₂/H₂) mixtures were used to represent post- and precombustion capture. A comparison between the rates of hydrate formation in different crystallizers is presented by defining a metric called the normalized rate of hydrate formation. The gas uptake and the separation efficiency for the fuel and flue gas mixtures were found to be greater compared to the results obtained in a smaller scale stirred tank reactor (Kumar et al., 2009c, Linga et al., 2008). The gas uptake and CO₂ recovery for flue gas mixture in the presence of THF obtained in this work was higher than that reported in the literature with tetra-n-butyl ammonium bromide and tetra-n-butyl ammonium fluoride (Fan et al., 2009, Li et al., 2009). Although hydrate crystallization is able to capture CO₂, the power required for mechanical agitation was found to be very significant. If the hydrate process is to be used industrially then hydrate crystallization must be carried out without mechanical agitation.     

温州城市降雨径流中BOD5和COD污染特征及其初始冲刷效应

为研究温州降雨径流污染情况,监测了温州2个采样区4场较为典型的降雨过程,测定了不同下垫面径流中BOD5和COD的浓度,并且计算出污染物的EMC值、M(V)曲线和BOD5/COD值等.结果表明,温州城市降雨径流中BOD5和COD的含量分别介于ND～69.21 mg.L-1和ND～636 mg.L-1之间,不同城市下垫面径流中BOD5和COD的含量均随着降雨历时的延长而呈下降趋势,处理初期径流水样对减少耗氧性有机污染具有重要意义.从COD和BOD5的EMC值来判断,部分城市下垫面降雨径流中污染物浓度超出地表五类水标准,甚至高于污水排放二级标准,此类降雨径流若直接入河将对下级受纳水体造成耗氧性有机污染的压力.根据M(V)累积曲线判断,COD初期冲刷效应在城市降雨径流中是较为普遍的,城市降雨径流中的BOD5表现出与COD类似的初始冲刷情况,该结果亦表明径流初期耗氧性有机污染严重.城市降雨径流中COD和BOD5的浓度受下垫面类型和降雨条件的影响,而BOD5/COD指标的变化特征则指出生物降解是削减有机污染负荷的有效途径之一,但不同下垫面径流有机污染的治理工作应采用不同的最佳管理方案(BMPs).     

土地利用变化的水土资源平衡效应研究——以西辽河流域为例

北方农牧交错带作为我国传统农区与牧区的交汇和过渡地带,是我国东、中部地区的重要生态屏障地区。选取北方农牧交错带东缘的西辽河流域为案例区,运用遥感、地理信息系统等方法,构建水分亏缺模型,定量计算了西辽河流域不同土地利用情景下的水分亏缺态势,揭示了北方农牧交错带土地利用变化的水土资源平衡效应,研究表明:①1995-2005年,西辽河流域土地利用整体特征未发生重大改变,土地利用表现为耕地面积有所增加、草地面积相对减少的局面;②西辽河流域水土资源平衡总体呈现中度水分亏缺的特征,亏水量较大的区域相对集中在西辽河冲积平原中部地区;③1995-2005年10 a间的土地利用变化使得西辽河流域严重缺水地区面积增加1/4,水分亏缺态势进一步加剧。     

Fe0/荧光假单胞菌联合处理直接耐晒黑的脱色特性

采用荧光假单胞菌(Pseudomonas fluorescen,简称pf菌)与Fe0微粒构建Fe0/pf菌联合体系,处理了含偶氮类染料-直接耐晒黑(C.I.Direct black 19,简称DB19)废水.在中温((35±2)℃)条件下,比较了纯pf菌、纯Fe0微粒和Fe0/pf菌联合体系的脱色能力,并探讨了联合体系中供氧条件、初始pH值、Fe0投加量和染料初始浓度等因素对DB19脱色的影响.结果表明,在微需氧、菌接种量为5％(体积比)的条件下,染料初始浓度为100 mg·L-1、初始pH =7.0、Fe0投加量为500 mg·L-1时,联合体系内脱氢酶活性最高,处理约30 h后可实现90％以上的脱色率;与纯pf菌比较,Fe0/pf菌联合体系达到该脱色率的时间可提前约40 h.UV-vis和FT-IR光谱分析表明,联合体系中DB19染料的脱色过程是通过偶氮键断裂来实现的,而且部分含苯环或萘环结构的中间产物也可被降解.