AlCl3-季戊四醇络合催化剂催化１-辛烯齐聚工艺

聚α-烯烃是高品质的润滑油基础油。使用AlCl₃-季戊四醇络合催化剂,对1-辛烯齐聚反应进行研究,考察催化剂物质的量分数、季戊四醇与A1Cl₃物质的量比、反应温度和反应时间对聚烯烃收率及不同聚合物选择性的影响。结果表明,1-辛烯齐聚合成聚α-烯烃最佳工艺条件：AlCl3物质的量分数为2％,季戊四醇与AlCl₃物质的量比为0.5,反应温度为50 ℃,反应时间为4 h,聚烯烃收率约为93.4％,合成的聚α-烯烃产品中润滑油的理想组分三聚体和四聚体选择性较好。     

新型树枝状镍系催化剂的合成、表征及催化乙烯聚合的性能

合成了一种含有强供电子、较大空间位阻的新型树枝状水杨醛亚胺配体及其镍配合物,利用1H NMR、元素分析、FT-IR、UV进行了表征。以配合物为催化剂,甲基铝氧烷（MAO）为助催化剂对乙烯齐聚反应进行了研究,详细考察了聚合反应温度、Al/Ni摩尔比、反应压力及时间对催化剂活性及产物分布的影响。结果表明,齐聚产物为不同碳链的烯烃,在温度为25℃、Al/Ni=500、压力为0.5MPa、时间为0.5h的条件下,树枝状催化剂的活性最高,达到4.93?105g/(mol Ni?h),C10～C18的含量为54.17%。     

1-C12烯烃齐聚制备高性能润滑油基础油

采用Et3NHCl AlCl3离子液体催化剂催化1 C12烯烃齐聚反应,考察了反应时间和温度对齐聚反应的影响。用色谱 质谱仪和红外光谱仪表征了产物的组成和结构,并按照石油和石油产品试验方法国家标准测定了产物的性能。结果表明,在反应时间为1~4 h、温度为25~75℃的范围内,1 C12烯烃齐聚反应的产物主要是其三聚体、四聚体和五聚体,是具有长侧链的聚α 烯烃。该混合物具有高黏度（ν100为321~532 mm2/s）、较高黏度指数（169~189）、低倾点（-33℃~-42℃）、适中相对分子质量（645~740）的特性,可作为高性能合成润滑油基础油。     

新型超支化镍系催化剂的合成及对乙烯齐聚的催化性能

以直链十二胺为核的0.5代超支化大分子（R₁₂-0.5G）和丁二胺为原料,合成出一种新型的1.0代超支化大分子（R₁₂-1.0G）。然后以R₁₂-1.0G、水杨醛和NiCl₂·6H₂O为原料,依次经过希夫碱反应和络合反应合成了一种新型的超支化水杨醛亚胺镍系催化剂。FTIR、¹H NMR、UV和MS证实合成产物的结构与理论结构相符。在合成的基础上,并对该催化剂催化乙烯齐聚的性能进行了研究。考察了溶剂种类、反应温度、反应压力、Al/Ni比等条件对该催化剂催化乙烯齐聚性能的影响。结果表明,该催化剂具有良好催化乙烯齐聚的性能,当以甲苯为溶剂,在甲基铝氧烷（MAO）活化下,随着反应压力和Al/Ni比增加,催化活性增加;而催化活性随着反应温度的增加先升高后下降;在反应温度为25℃、反应压力为0.5MPa、Al/Ni比为1500时,该催化剂的活性可达5.03×10⁵g/（molNi·h）,聚合产物主要是C₆以下的低碳烯烃,含量高达89%以上。相同条件下,其催化乙烯齐聚的活性低于与其具有类似结构的“扫帚型”镍系催化剂。     

利用钴基低温费-托合成油生产喷气燃料

介绍了钴基低温费-托合成油的特点及用其生产喷气燃料的工艺流程和加工技术。为生产符合标准的喷气燃料,需要采用叠合、芳烃烷基化、芳构化、加氢裂化、加氢异构等技术。叠合将小分子的低碳烃转化为汽油和煤油馏分;芳构化或重整技术将直链烃转变为芳烃;加氢裂化将大分子的烃断链成为汽油和煤油馏分。利用这些技术,设计了以生产喷气燃料为目标的低温费-托合成油加工方案。模拟计算结果表明,喷气燃料收率可达65.7%,汽油收率达18.3%。     

镍配合物催化乙烯齐聚合成α-烯烃的研究进展

综述了近几年国内外乙烯齐聚用镍配合物催化剂的研究进展。该类催化剂易于合成,齐聚反应条件温和,催化剂活性为1×10~5～1×10~7g/(mol·h),产物主要是C4和C6等短链α-烯烃。二齿配体[N,N]、[N,P]和三齿配体[N,N,N]镍配合物催化剂是目前研究的热点。。     

不同锆源合成ZrHZSM-5分子筛及其丙烯齐聚催化性能

 分别采用硝酸锆、硫酸锆、氧氯化锆为锆源,以正丁胺(NBA)为模板剂,水热法直接合成了ZrHZSM-5分子筛。通过XRD、SEM、NH3-TPD、BET等手段对分子筛进行了结构和性质等测试,以不同锆源ZrHZSM-5分子筛的结构和性质以及对烯烃齐聚制备液体燃料过程中的催化性能的影响. 实验考察了不同锆源对ZrHZSM-5分子筛催化活性和选择性的影响并对其原因进行了探讨。结果表明,不同的锆源合成的分子筛有所不同,以硝酸锆为锆源合成的ZrHZSM-5分子筛结晶度良好,表面规整,孔径和酸性分布较好,在丙烯齐聚反应中有很好的催化活性、选择性和稳定性,为较佳的烯烃齐聚反应催化剂。     

Comparative Analysis of Single-Molecule Dynamics of TRPV1 and TRPV4 Channels in Living Cells

TRPV1 and TRPV4, members of the transient receptor potential vanilloid family, are multimodal ion channels activated by various stimuli, including temperature and chemicals. It has been demonstrated that TRPV channels function as tetramers; however, the dynamics of the diffusion, oligomerization, and endocytosis of these channels in living cells are unclear. Here we undertook single-molecule time-lapse imaging of TRPV1 and TRPV4 in HEK 293 cells. Differences were observed between TRPV1 and TRPV4 before and after agonist stimulation. In the resting state, TRPV4 was more likely to form higher-order oligomers within immobile membrane domains than TRPV1. TRPV1 became immobile after capsaicin stimulation, followed by its gradual endocytosis. In contrast, TRPV4 was rapidly internalized upon stimulation with GSK1016790A. The selective loss of immobile higher-order oligomers from the cell surface through endocytosis increased the proportion of the fast-diffusing state for both subtypes. With the increase in the fast state, the association rate constants of TRPV1 and TRPV4 increased, regenerating the higher-order oligomers. Our results provide a possible mechanism for the different rates of endocytosis of TRPV1 and TRPV4 based on the spatial organization of the higher-order structures of the two TRPV channels.     

Hetero/Homo-Complexes of Sucrose Transporters May Be a Subtle Mode to Regulate Sucrose Transportation in Grape Berries

The sugar distribution mechanism in fruits has been the focus of research worldwide; however, it remains unclear. In order to elucidate the relevant mechanisms in grape berries, the expression, localization, function, and regulation of three sucrose transporters were studied in three representative Vitis varieties. Both SUC11 and SUC12 expression levels were positively correlated with sugar accumulation in grape berries, whereas SUC27 showed a negative relationship. The alignment analysis and sucrose transport ability of isolated SUCs were determined to reflect coding region variations among V. vinifera, V. amurensis Ruper, and V. riparia, indicating that functional variation existed in one SUT from different varieties. Furthermore, potentially oligomerized abilities of VvSUCs colocalized in the sieve elements of the phloem as plasma membrane proteins were verified. The effects of oligomerization on transport properties were characterized in yeast. VvSUC11 and VvSUC12 are high-affinity/low-capacity types of SUTs that stimulate each other by upregulating V_max and K_m, inhibiting sucrose transport, and downregulating the K_m of VvSUC27. Thus, changes in the distribution of different SUTs in the same cell govern functional regulation. The activation and inhibition of sucrose transport could be achieved in different stages and tissues of grape development to achieve an effective distribution of sugar.