Simultaneous degradation of nitroaromatic compounds TNT,RDX, atrazine,and simazine by Pseudomonas putida HK‐6 in bench‐scale bioreactors

BACKGROUND: Environmental contamination by nitroaromatic compounds such as 2,4,6‐trinitrotoluene (TNT), hexahydro‐1,3,5‐trinitro‐1,3,5‐s‐triazine (RDX), atrazine, and/or simazine (TRAS) generated as waste from military and agricultural activities is a serious worldwide problem. Microbiological treatment of these compounds is an attractive method because many explosives and herbicides are biodegradable and the process can be made cost‐effective. We explored the feasibility of using cultures of Pseudomonas putida HK‐6 for simultaneous degradation of TRAS with the aim of microbial application in wastewater treatment in bench‐scale bioreactors. RESULTS: Experiments were conducted to study the effects of supplemental carbons, nitrogens, and Tween‐80 on the degradation of Ps. putida HK‐6 in media containing TRAS as target substrate(s). The most effective TRAS degradation was shown in the presence of molasses. Addition of nitrogen sources produced a delayed effect for the target substrate(s). Tween‐80 enhanced the degradation of target substrate(s). Simultaneous degradation of these compounds proceeded to completion within the given period. CONCLUSIONS: Ps. putida HK‐6 was capable of growth with TRAS, and the effects of supplements on TRAS degradation and simultaneous TRAS degradation were evaluated in bench‐scale bioreactors. The results of this study have practical applications in the processes of industrial waste stream treatment where the disposal of TRAS may be problematic. Copyright © 2008 Society of Chemical Industry     

Signed line intercept count

Elements of surfaces that bound a phase (β) in a two phase mixture (α+β) may be classified as: (a) convex (++) if both principal curvatures are positive; (b) concave (? ?) if both are negative; and (c) saddle (+ ?) if one is positive and the other negative. This classification excludes the limiting cases for which one or both of the principal curvatures is zero. The traces of these surfaces that form the boundaries of the β areas on a representative two dimensional section may also be: (a) convex (+) if the local curvature is positive; or (b) concave (?) if it is negative. Line intercepts may be tabulated separately for intersections with convex (+) and concave (?) segments of boundary. This paper presents a derivation of fundamental stereological formulae that relate these counting measurements to three-dimensional geometric properties of the structure they sample.     

基于数字线性化技术的高性能光载无线链路

针对光载无线(Radio over fiber, ROF)链路中的固有非线性,研究了多种数字线性化技术,来提高链路性能。下行链路针对多频段多制式场景,提出采用多维数字预失真技术,最大输入射频功率增加了3 dB,进而提高了下行链路的射频功率传送效率。同时,提出了多维预失真在2倍过采样率,考虑5阶非线性,无记忆时有最佳的链路性能改善。上行链路采用基于输出截断点获取的数字后补偿技术,仅需确定系统三阶截断点(Output third-order intercept point,OIP3)即可完成非线性补偿函数的确定与失真的补偿,无杂散动态范围(Spurious free dynamic range,SFDR)可提高到128.3 dB·Hz2/3;上行链路针对多频段多 制式架构采用盲估计数字后补偿技术,动态范围提高了3 dB。     

积雪草多糖的脱脂工艺研究

为优选并确立积雪草的最佳脱脂工艺,考察积雪草不同脱脂溶剂对多糖得率和脱脂率的影响,通过单因素试验和正交试验对脱脂工艺进行优化.最佳脱脂工艺为：料液比（g/mL）1∶10,乙醚-乙醇溶液（V乙醚∶V乙醇=2∶3）在35℃下脱脂6h.在此脱脂方案下,积雪草多糖平均得率为2.69％（n=5）,RSD为2.23％,脱脂率为15.87％（n=5）.该脱脂方案稳定,可使多糖得率更高.     

金属的脱脂与除锈技术（1）

介绍金属表面前处理的脱脂与除锈对镀层质量的影响;脱脂方法的分类,金属表面沾污物的种类、碱液浸泡脱脂技术;除锈方法的分类,金属表面生锈的机构和不同种类金属的腐蚀产物,酸洗除锈和电解酸洗除锈技术.     

2～5GHz 0.18μm CMOS宽带低噪声放大器设计

本文设计实现了一个2～5GHz的两级CMOS低噪声放大器(LNA),可应用在超宽带的下半频段(3.1～5GHz)。LNA由两级组成,第一级是一个共栅级,保持良好的线性度并完成较好的输入匹配;第二级是一个共源级堆叠一个电流源,在保持低噪声系数的同时降低功耗。通过级联共栅和共源结构进行增益补偿,所设计的LNA具有近似恒定的增益和噪声系数。采用0.18μm CMOS工艺实现后,模拟结果表明,增益和噪声系数在2～5GHz频率范围内分别为11.5dB和5.1dB,输入反射系数低于-22dB。在4GHz时,模拟得到的三阶交调点为-10dBm。在1.8V电源电压下,LNA的功耗约为11mW。     

基于NDIS Hook的网络数据包拦截和发送技术研究

结合实际项目经验,主要介绍了目前个人防火墙最为广泛使用的技术——NDIS Hook技术,重点探讨了如何使用NDIS Hook技术在NDIS层实现数据包的拦截与发送。     

香港地区残疾人社会福利制度及其启示

香港残疾人福利制度采用精简型社会福利模式,社会福利实施机制健全,主体多元且彼此良性互动,社会福利服务高度专业化.但其福利模式无法应对社会现实需求且欠缺人权角度的考量.借鉴香港正反两方面经验,内地残疾人社会福利应以赋权型、发展型福利模式为理性选择,建立多元、持续、高质量的福利供给与服务机制,妥善处理政府与公益类民间组织的关系,提高福利保障的法治化程度.     

铝及铝合金铬酸阳极氧化工艺研究

本文针对铝及铝合金铬酸阳极氧化工艺中出现的问题，论述并分析了除油、水洗、铬酸阳极氧化、封闭等工艺方法和试验结果。试验结果表明，改进除油、水洗、铬酸阳极氧化工艺和封闭处理方法后，工艺质量有了明显提高。     

Internet网络上合法侦听模型的研究

本文根据ETSI标准,从合法侦听的角度分析了网络数据传输模型,给出了该传输模型下侦听点的设置规则。根据网络联接方式和侦听点设置的不同,设计出了相应的合法侦听模型。