水力压裂裂缝起裂延伸的试验研究

水力压裂模拟试验是认识裂缝扩展机制的重要手段,通过模拟地层条件下的压裂试验,可以对裂缝扩展的实际物理过程进行监测,并且对形成的裂缝进行直接观察。通过室内模拟实验可知:应力附加区作用范围通常在3倍~6倍井眼之间,先逐渐憋压到一个极值(即破裂压力),在这个区域内裂缝先起裂,在起裂之后存在一个压裂液蓄能的过程,然后裂缝再突破应力附加区;4块岩样产生的都是单一裂缝,裂缝形态类似,并符合力压裂裂缝起裂延伸机理,没有出现多裂缝扩展现象。     

基于COMSOL Multiphysic的CO变换反应的数值模拟与优化

利于多物理场耦合软件COMSOL Multiphysic,建立一个耦合CO变换反应传质、传热、动量传递和化学反应的二维轴对称拟均相固定床反应器模型。采用COMSOL Multiphysicl默认的反应流,稀物质传递(rfcs)模型和传热(ht)模型,通过内置的模型输入将二个模型耦合起来。催化动力学采用Langmuir-Hinshelwood方程,催化剂的性质及操作条件以Wei-Hsin Chen等的实验为基础。采用有限元法对模型进行稳态模拟,得到反应器内的速度场、浓度场、温度场,对反应床层内组分浓度、速度及温度进行可视化分析。将所得的结果与文献值进行对比,从而验证了模型的准确性。最后,采用COMSOL Multiphysic对催化反应条件进行灵敏度分析,分析了入口温度、催化剂失活因子、入口组成对床层温度及CO转化率的影响。     

表面改性多壁碳纳米管吸附水中Cu2+的研究

采用混酸对多壁碳纳米管(MWCNTs)进行表面改性,制备吸附性较好的吸附剂,用于去除水中低质量浓度的Cu2+离子。实验考察了pH为6时,溶液Cu2+的浓度、吸附时间、吸附剂量等因素对Cu2+吸附性能的影响。实验结果表明,利用混酸对多壁碳纳米管进行改性,可使其表面的-OH增多,且当温度为30℃、pH为6时,吸附量随着吸附浓度、吸附时间的增长而增大,而吸附率随着吸附剂量的增加而增大,并且混酸处理后增加效果更加明显。     

p-Chlorotetrafluorophenyl esters of N-protected amino acids

p-Chlorotetrafluorophenyl (Tfc) esters of protected amino acids and peptides are more reactive than are the well known pentafluorophenyl (Pfp) esters. Two reagents, p-chlorotetrafluorophenyltrifluoroacetate (Tfc-OTfa) and di-(p-chlorotetrafluorophenyl)carbonate (di-Tfc-carbonate), can be used for their syntheses, thereby avoiding use of the allergic dicyclohexylcarbodiimide. This is especially important for bulk preparations. Many Fmoc- and Boc-amino acid-OTfc esters have been synthesized and characterized. The hexadecameric tandem repeat H-(AlaAlaLysPro)4-OH was synthesized using di-Tfc-carbonate for the preparation of Tfc-esters.     

Regulation of PAX-6 gene transcription: alternate promoter usage in human brain

The physiological role of the catecholamines (CA), adrenaline and noradrenaline in fish has been frequently reviewed, but the metabolic consequences of these hormones have received less attention. The purpose of this review is to examine the recent literature dealing with CA actions on whole fish and tissue metabolism. The CA increase glucose production both in vivo and in vitro, at least in isolated hepatocytes. Although the data are less clear, lipid mobilization is also a consequence of elevated circulating CA. The difficulty with using the whole fish for such studies is that CA may alter other circulating hormone levels, CA turnover in the circulation quickly, and it is difficult to define precisely the tissue being affected. Much of our understanding is derived, therefore, from the study of isolated tissues, and especially the hepatocyte. Catecholamines stimulate both glycogenolysis and gluconeogenesis in hepatocytes isolated from a large number of fish species. This review examines the steps involved in the signal transduction system, from the binding of CA to alpha- and beta-adrenoceptors to the ultimate effects of specific enzyme phosphorylation. Recent literature demonstrates that the complexity of the adrenoceptor system noted for mammals, also is expressed in fish. Adrenoceptor subtypes are specific to species, to tissues and to function of the tissues, and these issues are discussed especially as they are related to external and to internal stressors. Future research will pursue better definitions of the adrenoceptor systems, molecular biology of the components of these receptor systems and development of alternative cell models. There still remains a poor explanation of the reason for the diversity of adrenoceptor systems, and there are a number of fish systems that may provide unique opportunities to understand this question.     

中药穿心莲的B-Z振荡反应研究

对于BrO-3-穿心莲-丙酮-Mn2+-H2SO4体系的化学振荡反应,测定了不同浓度,不同温度下,穿心莲的振荡反应行为,得到了不同温度、浓度下反应的诱导期,振荡周期,并由此计算出振荡∝c3.0786∝c2.7793反应的表观活化能及穿心莲的反应级数。并得到下列关系:100·exp-10405tinT;1tp,1∝c3.6650·exp-116900·exp-9847.1T。T;1tp,2