我国注蒸汽采油研究进展

注蒸汽采油方法是提高原油采收率的有效手段之一,我国蒸汽驱油和蒸汽吞吐技术已相对成熟,取得了较大发展。本文概述了注蒸汽采油主要方法,从基础理论研究、室内实验研究、现场试验及推广应用等方面对我国近年来注蒸汽采油研究现状进行综述,提出在进一步的研究中,要重视降低蒸汽成本、改善注入环境污染等问题。     

我国注蒸汽采油研究进展

注蒸汽采油方法是提高原油采收率的有效手段之一,我国蒸汽驱油和蒸汽吞吐技术已相对成熟,取得了较大发展,本文概述了注蒸汽采油主要方法,从基础理论研究、室内实验研究、现场试验及推广应用等方面对我国近年来注蒸汽采油研究现状进行综述,提出在进一步的研究中,要重视降低蒸汽成本、改善注入环境污染等问题。     

OCS表面活性剂在弱碱、无碱条件下的界面张力性能研究

研究了OCS表面活性剂中试产品在弱碱NaCO33及无碱条件下应用于不同油田原油的油-水界面张力特性。结果表明：对于大庆采油四厂原油，当表活剂浓度为0．1％-0．3％，Na2CO3浓度为0．6％-1．2％时，油-水界面张力可达到超低(-l0^-3mN／m数量级)；对于大庆采油二厂原油，当表面活性剂浓度为0．1％-0．3％，Na2CO3浓度为0．8％-1．4％时，油-水界面张力可达到超低；对于华北油田古-联原油，当表面活性剂浓度为0．2％，NaCO3浓度为0．6％-1．2％时，油-水界面张力可达到超低；对于胜利油田孤东采油厂原油，当表面活性剂浓度为0．2％，NaCO3浓度为0．8％-1．4％时，油-水界面张力可达到超低。在无碱条件下，对于大港油田枣园1256断块原油，当OCS表面活性剂浓度达到0．1％时，油-水界面张力即可达到超低；对于江苏油田原油，当OCS表面活性剂浓度在0．1％以上时，油-水界面张力均可以达到10^-2mN／m数量级。聚丙烯酰胺聚合物的加入对油-水超低界面张力的形成和稳定具有促进作用。     

hgcA/B基因介导的汞甲基化分子机制及其应用

作为一种强神经毒性物质,环境中的甲基汞(MeHg)主要由产甲烷菌、硫酸盐还原菌、铁还原菌等厌氧微生物产生,可通过水生食物链积累并作用于人体。汞甲基化基因hgcA/B明确以后,不仅扩大了可探知的汞甲基化微生物范围,也为汞甲基化生物分子机制的探索提供了新的方向。本文1)概述了hgcA/B及其表达产物HgcA、HgcB的预测结构和生物体内的汞甲基化分子机制,2)讨论了基于hgcA/B的环境汞甲基化研究进展,3)总结了现有hgcA/B研究存在的不足,4)对汞甲基化基因领域的研究方向进行了展望。     

非靶向尿液代谢组学方法研究五味子治疗精尿病并发症作用机制

采用超高效液相色谱-串联四级杆飞行时间质谱联用技术(Ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry,UPLC/Q-TOF-MS),结合主成分分析技术(Principal component analysis,PCA),进行了五味子治疗糖尿病并发症大鼠尿液代谢组学研究,对五味子治疗糖尿病并发症大鼠后尿液生物标志物变化进行了考察.采用UPLC/Q-TOF-MS方法分析了健康组、糖尿病并发症模型组和五味子给药组的大鼠尿液,采用偏最小二乘法-判别分析(Partial least squares discriminant analysis,PLS-DA)和正交偏最小二乘法-判别分析(Orthogonal partial least squares discriminant analysis,OPLS-DA)载荷图筛选,通过分析对各组分离贡献较大(VIP>1,P°0.05)化合物的串联质谱数据,再经Human Metabolome Data-base(HMDB)等数据库检索,进行质谱信息匹配,尿液中共鉴定出28种潜在生物标记物,其中正谱13种,负谱15种.这些生物标记物主要影响戊糖和葡糖醛酸相互转化通路、核黄素代谢、泛酸和CoA合成、精氨酸和脯氨酸代谢、肠内菌代谢、嘌吟代谢、Vc代谢胆酸合成、色氨酸代谢等通路,五味子从能量代谢、氨基酸代谢、肠内菌代谢、脂类代谢等各个角度发挥治疗糖尿病并发症的作用.从各个通路的相关生物功能分析,五味子治疗糖尿病肾病的作用较强,此外还具有降脂、抗氧化的功效.     

表面活性剂复合体系提高原油采收率研究

为了提高中后期油田原油的采收率,采用聚丙烯酰胺和非离子-阴离子型表面活性剂NPAC构建了一种二元复合驱油体系。以油水界面张力性能、黏度、老化稳定性、乳化能力、洗油率等作为评价指标,研究并优化NPAC活性剂复合体系对提高原油采收率的试验条件,为油田回注提供理论与实践参考。研究表明:聚丙烯酰胺和NPAC二元复合体系综合性能优异,原油洗油率达到32. 4%,乳化指数为2. 1。该研究对指导表面活性剂/聚合物二元复合体系对提高油田原油采收率具有重要意义。     

CTAB在硅胶表面吸附引起的润湿性变化和模拟驱油

用椭圆偏振法测定溴代十六烷基三甲胺（CTAB）水溶液在光滑的二氧化硅膜片上的吸附，其结果符合两阶段模型，即在不同浓度下发生单分子层和近似双分子层的吸附，并与其表面润湿性变化的数据吻合.用改进的Washburn方程测量改性硅胶粉末的润湿性, 研究了CTAB水溶液在硅胶粉末表面上吸附引起的润湿性变化.并由此探讨了CTAB水溶液在硅胶粉末表面的润湿性,表面活性剂的临界胶束浓度（CMC）与表面含油粉末脱油率的关系，对在非超低界面张力条件下通过改变固/液界面润湿性提高原油采收率作了实验探讨.     

基于修饰组和探针分子的重要途径代谢物筛选和注释新方法北大核心CSCD

植物次生代谢物在抵御生物/非生物胁迫、生物间互作以及信息传递等方面发挥重要作用,次生代谢途径解析对植物分子育种、天然产物合成等方面具有重要意义。液相色谱-高分辨串联质谱(LC-HRMS/MS)为次生代谢物鉴定及途径表征提供了技术手段。非靶向LC-HRMS/MS方法可获得丰富的质谱信号,包括一级质谱和二级质谱(MS,MS/MS),但受质谱数据库规模以及次生代谢物复杂性的制约,次生代谢物注释十分困难。该研究以玉米叶片中苯丙烷途径代谢物为例,发展用于非靶向代谢组数据中重要途径代谢物的高效筛选和注释新方法。首先,利用公共代谢途径数据库及文献获取参与苯丙烷代谢途径的61种修饰反应类型,进而从非靶向实验数据中筛选出修饰代谢组。其次,获取开源串联质谱数据中的苯丙烷类化合物作为探针分子,构建探针分子质谱数据库。将探针分子与修饰代谢组共建分子网络,锁定目标途径代谢物并注释结构。该方法在正、负离子模式下分别筛选出玉米叶片中392个和417个苯丙烷途径候选代谢物,去冗余后共注释出129个代谢物,涉及苯丙烷代谢的主要分支途径,如黄酮途径的8个类黄酮、19个氧苷类黄酮和32个碳苷类黄酮,31个羟基肉桂酸途径代谢物以及22个木脂素途径代谢物;其中26个在PubChem和SciFinder数据库中未见收录。该研究利用探针分子结合修饰组可快速锁定途径代谢物,且有助于快速、准确的网络传播注释,可显著提高目标途径代谢物筛选与注释效率,为植物次生代谢途径的深入解析提供分析手段。     

古菌脂质的前处理方法比较及超高效液相色谱-高分辨质谱分析

古菌是一类兼具真菌及细菌细胞特征、大多生活在极端环境下的单细胞微生物。由于膜结构及代谢通路的特殊性,研究古菌脂质对深入探究极端环境下生命的正常活动具有重要意义。前处理方法在组学分析中会极大影响最终结果的准确度及可靠性。该文基于超高效液相色谱-高分辨质谱联用（ultra-performance liquid chromatography-high resolution mass spectrometry,UPLC-HRMS）技术,以嗜热嗜压古菌Pyrococcus yayanosii为模式生物,采用Bligh-Dyer加酸法、Folch法、甲基叔丁基醚（methyl tert-butyl ether,MTBE）法及固相萃取（SPE）法提取脂质成分,从提取效率、重复性、歧视性等角度进行方法评价,并最终确定SPE法和MTBE法的提取重复性和提取效率最好,适合高通量古菌全脂质提取。利用SPE提取、高分辨质谱分析对P.yayanosii的常规脂质进行了全面分析,共鉴定到了1402种脂质。本研究旨在为古菌和其他极端微生物的非靶向脂质组学分析和脂质代谢研究提供方法参考。     

五味子治疗大鼠糖尿病肾病作用机制的血清代谢组学研究

采用基于超高效液相色谱与串联四级杆飞行时间质谱仪(Ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry,UPLC/Q-TOF-MS)联用技术的代谢组学方法,通过分析大鼠血清内源性代谢物的变化,研究五味子治疗糖尿病肾病的作用机制。利用高脂高糖饲料喂养并腹腔注射链脲佐菌素(STZ)建立糖尿病大鼠模型。给药12周后,采用试剂盒方法测定尿蛋白、尿肌酐的含量,结果表明五味子水提取物可以显著降低模型动物的尿蛋白含量(p<0.05),对糖尿病大鼠肾病并发症具有一定的改善作用。采用UPLC/Q-TOF-MS方法分析了五味子对糖尿病肾病大鼠的血清代谢轮廓,分析了健康组、模型组和五味子给药组的大鼠血清,采用偏最小二乘法-判别分析(Partial least squares discriminant analysis,PLS-DA)进行数据分析。PLS-DA得分图显示健康组、模型组和五味子组的代谢轮廓有显著差别,根据正交偏最小二乘法-判别分析(Orthogonal partial least squares discriminant analysis,OPLS-DA)载荷图筛选,将对各组分离贡献大的化合物的串联质谱分析数据,经Human Metabolome Database(HMDB)等数据库检索,进行质谱信息匹配,鉴定出黄尿酸、油酰胺、棕榈酰胺、尿酸、5-羟基己酸、硫酸对甲酚、对甲酚葡萄糖苷酸7种内源性代谢物为生物标记物。研究结果表明五味子通过影响色氨酸代谢、嘌呤代谢、肠内菌代谢、脂肪酸代谢等通路对糖尿病肾病发挥治疗作用,其中嘌呤代谢、肠内菌代谢通路可能是五味子发挥治疗作用的重要途径。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.