Effects of various pretreatment methods on mixed microflora to enhance biohydrogen production from corn stover hydrolysate

Effects on mixed microflora to enhance biohydrogen production from corn stover hydrolysate was studied.     

In vitro fluorescence displacement investigation of thyroxine transport disruption by bisphenol A

Bisphenol A (BPA) is a chemical with high production volume and wide applications in many industries. Although BPA is known as an endocrine disruptor, its toxic mechanisms have not been fully characterized. Due to its structural similarity to thyroid hormones thyroxine (T4) and triiodothyronine (T3), one possible mechanism of BPA toxicity is disruption of hormone transport by competitive binding with the transport proteins. In this study, the binding interactions of BPA, T4, and T3 with three thyroid hormone transport proteins, human serum albumin (HSA), transthyretin (TTR), and thyroxine-binding globulin (TBG) were investigated by fluorescence measurement. Using two site-specific fluorescence probes dansylamide and dansyl-L-proline, the binding constants of BPA with HSA at drug site I and site II were determined as 2.90 104 and 3.14 104 L/mol, respectively. By monitoring the intrinsic fluorescence of tryptophan, a binding constant of 4.70 103 L/mol was obtained. Similarly, by employing 8-anilino-1-naphthalenesulfonic acid as fluorescence probe, the binding a nity of BPA with TTR and TBG was measured to be 3.10 105 and 5.90 105 L/mol, respectively. In general, BPA showed lower binding a nity with the proteins than T3 did, and even lower a nity than T4. Using these binding constants, the amount of BPA which would bind to the transport proteins in human plasma was estimated. These results suggest that the concentrations of BPA commonly found in human plasma are probably not high enough to interfere with T4 transport.     

基于3S技术的呼和浩特市土地利用／覆盖变化研究

本文以呼和浩特市为研究对象,利用遥感（RS技术）、地理信息系统（GIS技术）以及全球定位系统技术（GPS技术）——简称3S技术,对呼和浩特市2000、2004年遥感影像进行了综合技术处理,获得2期土地利用现状图,据此对呼和浩特市土地利用变化幅度及变化速度、土地利用变化程度、土地利用变化空间动态进行了分析,为区域土地资源科学管理及实现区域土地资源可持续利用提供科学依据。     

Preliminary study of groundwater denitrification using a composite membrane bioreactor

A composite membrane bioreactor (CMBR) integrating the immobilized cell technique and the membrane separation technology was developed for groundwater denitrification. The CMBR had two well mixed compartments with one filled with the nitrate-containing influent and the other with a dilute ethanol solution; the compartments were separated by the composite membrane consisting of a microporous membrane facing the influent and an immobilized cell membrane facing the ethanol solution. Nitrate and ethanol molecules diffused from the respective compartments into the immobilized cell membrane where nitrate was reduced to gaseous nitrogen by the denitrifying bacteria present there with ethanol as the carbon source. The microporous membrane was attached to one side of the immobilized cell membrane for retention of the disaggregated bacteria. Relative to the single dose of external ethanol, the two-dose supplementation produced better treatment results as evidenced by the lower concentrations of NO₃⁻-N and ethanol (as measured by total organic carbon) of the effluent. The batch treatment in CMBR removed most of the nitrate in the influent and attained a stable denitrification rate of 0.1 g·m⁻²·h⁻¹ for most of the 96-h cycles during the 30-cycle study. The effluent was essentially free of ethanol and nitrite nitrogen.     

染整废水深度处理纳滤工艺膜污染成因分析

为调查棉针织染整废水纳滤脱盐系统膜污染的类型和成因,使用电感耦合等离子发射光谱仪、扫描电子显微镜-EDX能谱仪、傅里叶变换红外光谱仪、热重分析仪、高倍光学显微镜和X射线荧光光谱仪,从膜进水水质、膜过程污染状况和膜清洗效果等三方面进行了联合互补检测和综合分析.结果表明,棉针织染整废水脱盐过程中纳滤膜的污染类型包括无机污染、有机污染和微生物污染;干燥(105℃)的污染物成分组成中结合水所占质量分数约8.2%,有机成分所占质量分数约41.0%,无机成分所占质量分数约50.8%;在无机污染物中铁盐污染较为突出,有机污染物所包含的主要官能团为—OH、—CH和—CC,微生物污染物中包含原生动物和后生动物;短期膜污染和长期膜污染分析结果表明有机污染和微生物污染的形成需要长时间的累积效应;纳滤膜清洗试验结果表明,有机污染和微生物污染是引起膜通量下降的主要原因,两者对膜通量影响的贡献率约53.3%.     

冶金企业含铁固体废弃物的基本特征与资源化综合利用

重点介绍了冶金企业包括瓦斯泥、瓦斯灰、转炉泥、选矿废渣、高炉矿渣、转炉钢渣在内的固体废弃物的基本特征以及对环境的污染情况。并对其有效元素回收和资源化利用提出建议。     

Analytical prediction of stepped feature generation in multi-pass single point incremental forming

Single point incremental forming (SPIF) is a new sheet metal forming process characterized by higher formability, product independent tooling and greater process flexibility. The inability of conventional single pass SPIF to form vertical walls without failure is overcome by forming multiple intermediate shapes before forming the final component, i.e., multi-pass single point incremental forming (MSPIF). A major issue with MSPIF is significant geometric inaccuracy of the formed component, due to the generation of stepped features on the base. This work proposes analytical formulations that are shown to accurately and quantitatively predict the stepped feature formation in MSPIF. Additionally, a relationship is derived among the material constants used in these analytical equations, the yield stress and thickness of the blank material, such that the computational effort required for the calibration of these constants can be minimized. Finally, the physical effects of yield stress and sheet thickness on the rigid body translation are further discussed.     

香根草人工湿地处理生活污水的试验研究

通过建立香根草人工湿地系统,研究该系统对生活污水的COD、TP、TN的处理效果以及系统的耐污性。在水力停留时间（HRT）为6h的条件下,COD、TP、TN的去除率分别为63.5%、88.3%、72.4%。研究表明,香根草人工湿地系统对城镇生活污水具有较好的净化效果,且系统在该试验条件下耐污性良好。     

榆林市环境信息综合办公一体化的设想

为提高环保部门环境监管的效率和决策水平,实现现代化环境信息管理,在分析榆林市环境信息化建设的基础上,从环境管理的角度出发,结合榆林市环境信息化建设现状,将环境信息系统(EIS)的专业性和综合办公系统(OA)的大众性相结合,使两大系统在国家环境信息化建设的总架构下实现共享,设想环境信息与综合办公一体化,并对该一体化系统核心单元及其功能进行了叙述。     

Urbanization in Western China

China has experienced considerable urbanization in the past 60 years,especially since the implementation of the Economic Reform and Opening-up Policy in 1978.In 1949,there were only 132 cities with an urban population of 27.4 million,while in 2008 China had 652 cities with a total urban population of 606 million.Such urbanization is attributed to the boost in the number of cities and the urban population.Urban expansion enhanced geographic inequality between the three major regions in China.Compared with the eastern and central regions,western China only has 19%of the total cities and 18%of the urban population.The urbanization rate was 37.2%for the western region in 2008,while it reached 53.3%for the eastern regions and 45.3%for central China.Using a geographic information system(GIS)and statistical analyses,this study aims at explaining the structure and spatial development of urbanization,and highlighting the current issues of urban inequality in western China during the past two decades.The paper drew following conclusions:(1)Urbanization disparities between eastern and western China have become increasingly obvious,but seem to be evolving slowly since the establishment of the government’s Western Development Priority Policy in 2000.(2)Cities of various sizes were expanded in western China,and the main factors affecting the urbanization are population numbers and density,government investment and geographic conditions.(3)Current patterns of urbanization in the western region are distributed unevenly between provinces.