农产品中农药残留化学降解方法研究进展

农药的大量使用,对环境和农产品造成的污染不可忽视,农产品中的农药残留问题是食品安全领域的研究热点。在诸多降解农药残留的方法中,化学降解方法受到研究者更多的关注。综述了几种化学降解农产品农药残留的典型方法,包括臭氧降解、过氧化氢降解和光催化降解的最新研究进展。对于油菜素内酯降解法和电生功能水降解法这2种新型降解农产品农药残留的方法也进行了重点介绍。  

有机磷农药生物降解研究进展

综述了有机磷农药的种类和毒性、有机磷农药生物降解技术、有机磷农药降解菌的种类、降解菌的获得、降解机理以及有机磷降解酶的应用6个方面的研究进展,并对有机磷农药生物降解存在的问题和研究方向提出了建议。  

纤维素酶的应用研究进展

植物纤维原料是地球上极为丰富、廉价而又可再生的资源,它的利用一直是国内外的研究热点。纤维素酶是一种高活性生物催化剂,是一组能够降解纤维素生成葡萄糖的酶的总称,在食品、饲料、酿酒、纺织、中药提取和造纸等众多的工业领域有广泛的应用价值。  

微生物法去除高氯酸盐的研究进展

基于高氯酸盐污染问题,阐述了高氯酸盐的生物降解机理,分析了影响高氯酸盐降解的因素,如氧、pH值、温度、电子供体和硝酸盐等,介绍了目前高氯酸盐微生物法降解技术的应用案例,并展望了高氯酸盐生物降解技术的未来方向。  

Agricultural productivity and natural resource use in southern Africa

This paper examines the natural resource status of southern Africa and analyzes the critical linkages between the performance of southern African agriculture and natural resource use patterns. The implication of on-going natural resource use trends on poverty, food insecurity, and environmental degradation are also analyzed. The challenges that must be addressed including, how best to intensify agricultural production, the types of technologies to promote and the imperatives of production efficiency and intra-regional trade are examined. The paper concludes with some suggestions on how best to proceed in the future to be able to successfully address the challenges identified.  

合成骨质瓷负载TiO_2光催化性能的研究

采用合成骨炭为主要原料制备的多孔陶瓷,能将纳米TiO_2催化活性与陶瓷载体的吸附性有机结合在一起,制备具有催化活性并能循环使用的载体型光催化剂,可有效催化降解水中有机污染物。通过实验研究了镀膜层数、多孔陶瓷球直径、致孔剂质量分数、骨炭合成中CaHPO_4和CaCO_3的质量比值等因素对催化性能的影响。试验结果表明:陶瓷球直径为3 mm,镀膜层数为4层,致孔剂质量分数为4%,CaHPO_4和CaCO_3的质量比值为2.6时,催化剂具有较好的催化活性。  

Internet peering as a network of relations

This paper applies results from recent theoretical work on networks of relations to analyze optimal peering strategies for asymmetric Internet Service Providers (ISPs). From a network of relations perspective, ISPs’ asymmetry in bilateral peering agreements need not be a problem, since when these form a closed network, asymmetries are pooled and information transmission is faster. Both these effects reduce the incentives for opportunism in general, and interconnection quality degradation in particular. The paper also explains why bilateral monetary transfers between asymmetric ISPs (Bilateral Paid Peering), though potentially good for bilateral peering, may have negative effects on the sustainability of the overall peering network.  

降解胆固醇马红球菌F21-1的分离、鉴定及其特性研究

利用以胆固醇为唯一碳源的选择性培养基,从豚鹿粪便样品中分离出1株降解胆固醇良好的菌株。经生理生化鉴定和16S rDNA基因序列分析,该菌株为马红球菌(Rhodococcus equi)。该菌株降解胆固醇的最佳碳源为胆固醇,最佳氮源为蛋白胨、硝酸铵复合氮;最佳培养条件:温度为32℃,初始pH值为8.0,胆固醇质量浓度为1.50 g/L。在该培养条件下培养24 h,胆固醇的降解率可达到71.95%。  

环糊精在环境污染治理中的应用

针对环糊精在环境污染治理领域越来越广泛的应用前景,介绍了环糊精在环境污染治理方面的应用,主要包括环糊精对弱极性有机污染物的增溶作用、环糊精对环境中有机污染物的富集和治理、环糊精对有机污染物降解过程的影响、环糊精对污染物生物活性的影响等几个方面。  

Knowledge management through the development of knowledge repositories: towards work degradation

This paper questions the consequences of the use of electronic knowledge repositories for work and employment. Drawing on critical research suggesting that knowledge management associated with such tools presents similarities to scientific management principles, it proposes to examine the following key research question: how do employees experience the transformation of the employment relationship when a knowledge repository is introduced to the workplace? The inquiry is grounded in an exploratory qualitative case study of a knowledge management system designed to foster knowledge‐sharing in a Belgian public administration. The findings illustrate two complementary outcomes: this system resulted in employees experiencing deskilling and work degradation, and was met with resistance. Significantly, this paper considers work degradation as a reflexive phenomenon in the context studied, where knowledge‐sharing systems produced deskilling and resistance as part of a specific re‐regulation process.