浅谈稠油脱水中破乳剂利用率的提高

破乳剂作为一种表面活性物质 ,在原油脱水生产中起着不可替代的作用 ,破乳剂成本也占脱水生产成本的很大部分 .因此 ,随着生产平稳运行与降低生产成本的需要 ,有必要对生产设备与工艺进行技术改造 ,以提高破乳剂利用率     

Biosynthesis, immunity, regulation, mode of action and engineering of the model lantibiotic nisin

This review discusses the state-of-the-art in molecular research on the most prominent and widely applied lantibiotic, i.e., nisin. The developments in understanding its complex biosynthesis and mode of action are highlighted. Moreover, novel applications arising from engineering either nisin itself, or from the construction of totally novel dehydrated and/or lanthionine-containing peptides with desired bioactivities are described. Several challenges still exist in understanding the immunity system and the unique multiple reactions occurring on a single substrate molecule, carried out by the dehydratase NisB and the cyclization enzyme NisC. The recent elucidation of the 3-D structure of NisC forms the exciting beginning of further 3-D-structure determinations of the other biosynthetic enzymes, transporters and immunity proteins. Advances in achieving in vitro activities of lanthionine-forming enzymes will greatly enhance our understanding of the molecular characteristics of the biosynthesis process, opening up new avenues for developing unique and novel biocatalytic processes. Received 9 April 2007; received after revision 31 August 2007; accepted 28 September 2007     

乙醇脱水反应的制约条件

乙醇脱水因条件不同可生成不同产物,本文讨论如何控制一定条件使脱水反应能生成不同产物。该实验提出了实验中的条件,分析了原因,因而可供同类研究参考。     

蔗糖脱水实验微型化探究

蔗糖脱水实验是一个典型的化学演示实验,但往往产生较多的有毒气体,既有损于身体健康,又污染环境。文章采用正交试验法对蔗糖脱水实验进行微型化探究,既可将污染降至最低程度,又有明显的实验现象。     

稀土硝酸盐高水合物脱水行为研究

制备11种稀土硝酸盐高水合物,研究它们在不同浓度H_2SO_4和P_4O_(10)干燥气氛中的脱水行为,探讨了晶体颜色、高水合物的脱水产物和熔点变化的规律。给出了它们的M·P,IR和x衍射特征值。     

Dehydration melting of UHP eclogite and paragneiss in the Dabie orogen: Evidence from laboratory experiment to natural observation

Dehydration melting of subducted continental crust is significant during exhumation, and its study from both experimental and petrological observations is of great importance to our understanding of continental geodynamics. Dehydration melting experi- ments were carried out on ultrahigh-pressure （UHP） eclogite from Bixiling in the Dabie orogen using a piston cylinder at 1.5-3.0 GPa and 800-950℃ to investigate partial melting of eclogite induced by phengite breakdown. The phengite-bearing eclogite started to melt at T≤800-850℃ and P=1.5-2.0 GPa and produced about 3% granitic melt. The products of dehydration melting vary with temperature and pressure. Such results provide valuable constraints on the micro-texture related to partial melting of UHP rocks in the Dabie-Sulu orogenic belt. Three types of polyphase inclusions were identified in garnet from the Shuanghe UHP eclogite. K-feldspar and quartz inclusions are interpreted to represent the products of segregation and crystallization of minor amounts of melt that formed during dehydration melting of phengite by the inferred reaction Phengite＋Omphacite＋Quartz Amphibole_＋Garnet＋Melt （K-feldspar＋Quartz＋Plagioclase）. Polyphase inclusions of phengite and K-feldspar＋Quartz inclusions were also found in zoisite/clinozoisite and garnet from the Shuanghe garnet-bearing paragneiss. These polyphase inclusions pro- vide evidence for a continuous process from sub-solidus dehydration to partial melting within the UHP gneissic rocks. The com- positional variation of garnets demonstrates that breakdown of epidote-group minerals may have played a crucial role during de- hydration melting reaction of phengite. The Ti-in-zircon thermometry and Si content of phengite in zircon suggest that partial melting would occur at 783-839℃ and 2.0-2.5 GPa. Therefore, both experimental results and petrological observations indicate that dehydration melting and fluid activity within the Dabie UHP rocks at micro-scale are controlled by the breakdown of phengite.     

跳汰洗选设备常见故障及处理方法

国家大力发展洁净煤技术,因此选煤技术需要不断提高.跳汰洗选是一种重要的洗选方法,本文讨论了洗选设备——空气脉动跳汰机、脱水设备和筛分设备的常见故障和处理方法。     

黑暗中脱水对银杏离体叶片光系统Ⅱ光化学活性的影响

以银杏叶片为材料,研究其在黑暗脱水条件下光系统Ⅱ（PSⅡ）光化学活性的变化。结果表明：在黑暗脱水过程中,银杏叶片的相对含水量（RWC）随时间的延长而下降,PSⅡ的潜在活性Fv/Fo和最大量子效率Fv/Fm的变化趋势相同。PSⅡ反应中心单位面积吸收（ABS/CS）的能量、捕获（TRo/CS）的能量和热耗散（DIo/CS）的能量都呈上升的变化趋势,而用于电子传递（ETo/CS）的能量则呈先上升后下降的变化趋势,说明银杏叶片没有受到明显的光抑制。     

气相色谱法分离和分析失水山梨醇

用气相色谱法分离和测定失水山梨醇各组分的相对含量.试样先用硅醚化试剂硅醚化,生成易挥发、低极性的三甲基硅醚衍生物,气相色谱分析使用柱内填充5%OV-17的101白色担体,氢火焰离子化检测器检测,检测温度260℃,汽化室温度270℃,柱温240℃,载气为氮气,氢气压力为0.05 Mpa,空气压力为0.1 Mpa.