1,3-丙二醇发酵过程中底物抑制及其对策的研究

研究了底物甘油浓度对Klebsiellapneumoniae发酵生产 1 ,3 丙二醇的影响 ,并通过实验确定了最佳的初始甘油浓度和甘油开始对产物生成产生抑制作用的浓度。针对底物抑制现象 ,提出了菌种驯化和流加甘油发酵两种解决途径。结果表明 :采用原始菌株发酵 ,适宜的甘油初始浓度为 642 .4mmol/L ,此时 1 ,3 丙二醇浓度和转化率分别可达 2 60mmol/L和 0 .492mol/mol;在较高甘油初始浓度 (789mmol/L)的情况下 ,经驯化培养获得的耐底物抑制菌株 ,可将最终 1 ,3 丙二醇浓度和转化率分别提高到 30 0 .9mmol/L和 0 .530mol/mol;采用流加甘油发酵工艺 ,1 ,3 丙二醇浓度和转化率分别可提高到 397.7mmol/L和 0 .62 5mol/mol。     

现代分析技术在食品添加剂检测中的应用

民以食为天,食以安为先,食品安全牵涉到全民的生活质量和身体健康,加强食品安全检测事关重大.对食品添加剂的检测也成为保证食品安全的重要手段.工欲善其事,必先利其器,借助现代科学仪器和分析技术,使得食品添加剂的检测得以长足的发展.多学科的研究成果的彼此渗透,也促进了分析技术水平的提高,使食品添加剂的检测更为便捷、快速、准确,介绍了现代分析技术在食品添加剂检测中的应用,包括样品预处理技术和测定方法的最新进展.     

Novel technology on preparation of double-layered pellets for sulfur and arsenic-bearing gold concentrates

Double-layered pellet （DLP） roasting is a novel pretreatment method for sulfur and arsenic-bearing gold concentrates. In this process, preparation of DLPs is a fundamental step which is required to produce DLPs with favorable mechanical strength and thermal stability. Studies were carried out to investigate the affecting factors and conditions on the preparation and properties of DLPs. The results show that moisture content has significant influence on DLPs preparation. With the increase of moisture content in the range of no more than 9.8%, drop resistance and compressive strength of green DLPs are raised and the pelletizing dynamics is improved accordingly. The optimum conditions are determined as moisture content of 9.8%, coating time of 14-16 min, drying temperature 〈80 ℃and drying gas velocity 〈1.2 m/s. When DLPs prepared under these conditions are roasted at 600 ℃ for 1 h, favorable removal and solidifying rates can be obtained, in which the removal rates of arsenic and sulfur are 94.38% and 82.55%, and the solidifying rates of arsenic and sulfur reach 99.62% and 99.79%, respectively. These results promise industrial application of DLP roasting.     

海水淡化工程海水预处理构筑物的选型及技术措施

海水淡化工程建设涉及到海水取水和预处理工艺及其构筑物的选择和施工管理．预处理构筑物的工艺选型和施工管理的好坏,将直接关系到整个海水淡化工程的投资、运转情况及淡化水的成本．以岱山本岛50130t／d绿苑海水淡化工程的海水预处理工艺及其构筑物的选择和施工管理为例,介绍了构筑物的钢筋工程、模板工程、混凝土工程及混凝土浇筑情况,工程实例对类似的海水淡化工程建设有一定借鉴作用．     

铁炭微电解法预处理印染废水

采用铁炭微电解法对印染废水进行预处理实验研究,考察了初始pH值、反应时间、铁炭加入量、曝气时间对预处理结果的影响。结果表明:反应初始pH值为3,反应时间为120min,铁炭加入量为100g.(100mL)-1,曝气时间为120min时,处理效果最好。经过铁炭预处理后的废水CODCr降到489mg.L-1,色度降到125倍,B/C值提高到0.37,为后续生化处理奠定了良好的基础。     

一种动态时间阈值的会话识别算法

会话识别是网络日志预处理中的重要环节,传统网络日志数据的预处理采用固定阈值会话识别算法,不能较好消除网络日志中的冗余信息。为更好提高后继数据挖掘的效率和精度,提出一种改进的预处理网络日志数据的会话识别算法,根据内容及站点结构确定其重要程度,对时间阈值进行动态控制调整,根据用户对访问内容的兴趣度删除不感兴趣的页面,消除冗余信息。     

化妆品中5种限用合成着色剂的分析方法研究进展

介绍了化妆品中5种限用有机合成着色剂CI12085（颜料红4）、C115630（颜料红49）、C142520（碱性紫2）、C145350（酸性黄73）和C145396（溶剂橙16）的性质,从样品前处理和检测技术两个方面叙述了化妆品中合成着色剂的分析方法研究进展,重点介绍了化妆品中有关这5种限用着色剂的分析方法。     

三油酸甘油酯的合成研究

详细论述了催化酯化合成三油酸甘油酯的方法，此合成分两步完成，避免了酯化反应的可逆性，高质量的产品符合医药用标准。     

Plasma-sprayed coatings as adherend surface pretreatments

As part of the National Center for Manufacturing Sciences contract on adhesive bonding of dissimilar materials, UTRC, as a sub-contractor, is evaluating environmentally acceptable surface preparation techniques for selected metals and composites. The selected processes are automatable and capable of being transferred into the manufacturing arena. One aspect of the programme is the evaluation of plasma-sprayed, microporous, thin coatings as surface pretreatments for both resin-based composites and metals. Mechanical test results are presented which demonstrate the viability of this approach to achieve acceptable joint strengths with steel, titanium and aluminium bonded to several types of resin-matrix composite. The environmental impact, by elimination of organic primer systems and strong acid etching and anodizing solutions, will be discussed.     

微污染原水生物预处理填料选型

介绍了生物预处理中两种新型填料的特点及部分处理效果。试验表明：轻质填料对氨氮的处理效果更稳定，而悬浮填料不需反冲洗，便于运行管理。