2 kPa下均三甲苯-偏三甲苯与均三甲苯-邻甲乙苯体系二元汽液相平衡数据研究及精馏模拟

均三甲苯是一种重要的化工原料,通常存在于重整重芳烃中,其中均三甲苯与偏三甲苯、邻甲乙苯的分离较为困难。测定了2 kPa下均三甲苯(1)-偏三甲苯(2)、均三甲苯(1)-邻甲乙苯(3)两个体系的汽液相平衡数据,并分别采用NRTL和UNIQUAC活度系数模型对相平衡数据进行关联,回归获得二元交互参数,并进行了热力学一致性检验。结果表明,在2 kPa下,均三甲苯与邻甲乙苯无法通过普通精馏实现分离。通过对均三甲苯-偏三甲苯-邻甲乙苯体系进行烷基化反应,而后分别采用单塔减压精馏和双塔减压精馏对反应产物的分离进行精馏模拟,得出较优工艺为双塔连续减压精馏,两塔塔板数分别为50,回流比分别为7和8,此时均三甲苯纯度可达98%(质量)。该研究不仅补充了汽液相平衡数据库,也为低压下C₉体系的分离工艺设计提供参考。     

蛋氨酸在KCl溶液中的解离常数与活度系数

采用改变pH法在25、30和35℃下测定了质量浓度为0.25~4.0 mol/kg的KCl水溶液中蛋氨酸的解离常数,计算得到了蛋氨酸的质子化焓;采用电动势法在25℃测量了0.025~0.200 mol/kg蛋氨酸溶液中浓度为0.1~1 mol/kg的KCl的活度系数,计算得到了KCl溶液中蛋氨酸的活度系数。结果表明,蛋氨酸在KCl水溶液中的解离常数随温度上升而减小、随KCl浓度增加而增大;25℃下,蛋氨酸在KCl水溶液中的活度系数随蛋氨酸浓度增大先减小后增大。运用德拜-休克尔模型和Pitzer模型对解离常数和活度系数的实验数据进行拟合,得到了相关参数,结果表明Pitzer模型的可靠性较好。     

硒化二氢杨梅素的制备及抗肿瘤活性

以DMY为基底物、Na2SeO3为硒化剂制备硒化DMY。采用UV、FTIR、NMR、XRD、TG、原子荧光光度计表征其结构和性能，CCK-8法检测对HSC-3细胞增殖的影响，划痕实验研究对HSC-3细胞迁移的影响。结果表明，硒化DMY中仍存在黄酮基本母核、并新形成C-Se键，其中硒含量为6.54%±0.22%；DMY和硒化DMY均对HSC-3细胞的增殖和迁移有良好的抑制作用、抑制效果与浓度呈正相关，且DMY和硒化DMY对HSC-3细胞的半数抑制浓度（IC50）分别为25.27 μg/mL、21.27 μg/mL，DMY的硒化有效提高了对HSC-3细胞增殖和迁移的抑制能力。     

乙炔氢氯化反应铜基催化剂研究进展

开发乙炔氢氯化无汞催化剂对我国聚氯乙烯(PVC)工业具有重要意义,目前以金为代表的贵金属催化剂已经接近工业化应用,但其生产成本高限制了其市场推广,因此相对价廉的铜基催化剂受到广泛关注。主要从配体和载体改性等方面综述了科研人员对金属铜基催化剂在乙炔氢氯化反应中性能提升所做的工作,并且总结了含铜多金属催化剂在乙炔氢氯化反应中的研究进展,最后对铜催化剂工业发展前景进行了展望。     

改性工艺对电石渣乳液活性的影响

利用煅烧与超声工艺分别对电石渣乳液进行改性处理。研究了不同改性工艺及条件对电石渣乳液活性的影响,通过采用测定消解速率、沉降体积、酚酞变红时间、粒度分布等手段对电石渣乳液进行了分析与表征。结果表明,与未改性电石渣乳液相比,煅烧和超声改性工艺均使电石渣乳液活性度有明显的提高;800℃保温2h煅烧的电石渣经80℃、12倍的去离子水消解后搅拌30min可制得活性高的电石渣乳液;电石渣乳液经超声4h改性后活性显著提高。     

功能化聚六亚甲基盐酸胍的合成与表征

将带有胍基抗菌官能团的聚六亚甲基盐酸胍(PHGC)与甲基丙烯酸环氧丙酯(GMA)反应,制备了含碳碳双键官能团的功能化聚六亚甲基盐酸胍。利用紫外分光光度法测定了反应转化率,并考察了溶剂、反应物配比、反应时间及温度对反应转化率的影响规律。采用FT-IR、Raman、NMR和TG对功能化聚六亚甲基盐酸胍的组成、结构和热稳定性进行了表征。结果表明,在DMSO溶剂中,当GMA与PHGC摩尔比为1:1,在60℃下反应60 h后,反应转化率可达75%,且合成的功能化聚六亚甲基盐酸胍具有良好的热稳定性。功能化聚六亚甲基盐酸胍可用作大分子单体,与其他单体共聚制备具有抗菌性能的聚合物和微球。     

Experimental study of improved two step synthesis for DME production

Dimethyl ether (DME) has received growing attention due to its potential use as a multi-purpose fuel. A new technical route of improved two step synthesis is proposed for DME production, which is composed of methanol synthesis and methanol dehydration in a fixed-bed reactor. The influences of the operating conditions including reaction pressure, temperature, H₂/CO mole ratio in the syngas and space velocity on CO conversion, selectivity and yield of DME are investigated. CO conversion and DME yield both increase monotonically with the pressure increase. The optimal reaction temperatures for the synthesis and dehydration of methanol are different. CO conversion increases at first and keeps constant when the H₂/CO mole ratio is above 2. DME yield increases obviously and then decreases gradually with the space velocity increase. The optimal conditions are obtained to maximize the CO conversion and DME selectivity. The reaction temperatures of the top and bottom stage are in the range of 270-280 °C and 235-245 °C, respectively. The optimal ratio of H₂/CO is above 2, and the space velocity is in the range of 1000-1300 h^− 1.     

Specific Inhibitors of the Breast Cancer Resistance Protein (BCRP)

A new class of specific breast cancer resistance protein (BCRP) inhibitors was identified, showing no inhibition of the ATP binding cassette (ABC) transporters P‐gp and MRP1. Some of these modulators inhibit BCRP with high potency; they are only slightly less potent than Ko143 and could serve as promising lead structures for the design of novel effective BCRP inhibitors. These inhibitors are structurally related to tariquidar (XR9576) and belong to a library of multidrug‐resistance modulators synthesized by our research group. The absence of the tetrahydroisoquinoline substructure appears to play a crucial role for specificity; we found that the presence of this substructure is not essential for interaction with BCRP. To determine the type of interaction between pheophorbide A and compounds with and without the tetrahydroisoquinoline substructure, various substrate pheophorbide A concentrations were used in enzyme kinetics assays. The resulting data show that these compounds share a noncompetitive‐type interaction with pheophorbide A. Experiments with imatinib and pheophorbide A revealed a mixed‐type interaction. The combination of imatinib and compounds with and without the tetrahydroisoquinoline substructure resulted in a positive cooperative effect, indicating that imatinib engages a binding site distinct from that of the new compounds on one side and distinct from that of pheophorbide A on the other side as well. The results of this study suggest that the category of BCRP‐specific inhibitors, which includes only fumitremorgin C, Ko143 and analogues, and novobiocin needs to be extended by this new class of inhibitors, which possess three key characteristics: specificity, potency, and low toxicity.     

响应曲面法优化TiO_2/Cu复合粒子的制备工艺

以甲基橙的降解为研究目标,通过一阶响应曲面试验设计,研究主要因素对复合粒子的可见光活性影响规律,通过二阶模型建立了回归模型,获得了最优的实验条件是：SnC l4的量0.086 g;H2O的量6.72 mL;HCl的量0.007 mol;在最优条件下的可见光活性研究表明,复合粒子具有明显的可见光活性,能够有效降解甲基橙,降解率达到90%以上,且可以重复使用。     

具有除草活性的三唑啉酮类衍生物的研究进展

介绍了三唑啉酮类除草剂的发展现状及其研究进展,并根据结构类型的不同介绍了稠环三唑啉酮类、氨基三唑啉酮类、磺酰脲类、磺酰胺类化合物的结构特点和生物活性。