丙烯酸分散体多元醇的制备及其性能

以异丙醇为溶剂,通过先溶液聚合再水分散的方法,得到粒径小、性能优的丙烯酸多元醇分散体。在实验中考察了反应单体用量、引发剂用量以及配方中丙烯酸含量对生成的分散体多元醇粒径以及贮藏稳定性的影响;同时探讨了配方中丙烯酸羟丙酯含量对丙烯酸分散体多元醇粒径和流变性能的影响;最后讨论了不同羟基含量的丙烯酸分散体多元醇的稀释流变性能。结果表明:随着单体用量的提高,得到的丙烯酸分散体多元醇粒径不断减小,贮存稳定性不断提高;当引发剂用量为1%时,得到的分散体多元醇粒径较小,贮存稳定性较好;随着羟基含量的增加,丙烯酸分散体多元醇的黏度呈现"奇异"的下降趋势。

聚醚多元醇大分子单体的合成及其接枝共聚物的稳定性

目的 研究制备分散体的中间产物大分子单体的合成方法和条件 ;考察分散体的稳定性。方法 测定动力学曲线选择合成条件 ;分别用离心和冷冻分散体来观察其稳定性。结果 适宜催化剂作用下 ,在 12 0℃反应 3小时可合成符合要求的大分子单体 ;分散体的机械稳定性与粘度和粒径有关 ,热稳定性与体系内外温差有关。结论 适宜的反应条件下 ,可以制备三羟基聚醚单酯化产物———大分子单体 ;

甲醇分离器内件改造及低压醇分水洗塔的应用

针对甲醇合成装置中闪蒸槽闪蒸气携带甲醇量过多和甲醇分离器分离效果差的实际情况,增设低压醇分水洗塔并在甲醇分离器内增设立式翅片分离器。改造后,低压醇分水洗塔可回收甲醇约1.0 t/h,甲醇分离器可多分离甲醇约1.6 t/h,经济效益显著。

溶剂型80%高固体分聚丙烯酸酯多元醇树脂的分子量对涂膜物性的影响

探讨了树脂分子量对80%高固体分聚丙烯酸酯多元醇树脂涂膜性能的影响。试验结果表明,分子量控制在Mw=4 155、Mn=1 902时涂膜耐化学性不受影响。

水性双组分聚氨酯用丙烯酸酯分散体的合成

采用溶液聚合法合成了水性双组分聚氨酯用丙烯酸酯分散体。系统地研究了溶剂种类、聚合温度、引发剂种类及用量、链转移剂用量对丙烯酸酯多元醇分散体性能的影响,确定了制备低黏度丙烯酸分散体的合成工艺。

新技术在φ800 mm联醇装置中的应用

采用多项新技术,对闲置不用的φ800 mm合成氨装置进行生产甲醇改造,增加了精脱硫;合成塔采用JW均温型内件,GDC207催化剂;除油及分醇采用聚结式内件,实现了平衡生产和扩产、降耗的目的。

不同类型PTX治疗复发性卵巢癌的临床效果分析

目的探讨白蛋白结合型紫杉醇(PTX)与PTX脂质体分别联合奈达铂化疗治疗复发性卵巢癌的临床效果及不良反应。方法回顾性分析本院妇科近年来化疗的97例晚期复发性卵巢癌患者临床资料。其中51例患者采用白蛋白结合PTX加奈达铂治疗(白蛋白组)、46例患者采用PTX脂质体加奈达铂治疗(脂质体组),对比两组的临床效果、毒副反应及预后差异。结果白蛋白组患者的缓解率52.94%显著高于脂质体组32.61%(P<0.05);白蛋白组的总有效率84.31%高于脂质体组73.91%,但差异无统计学意义(P>0.05);两组的各种严重毒副反应发生率差异均无统计学意义;白蛋白组与脂质体组患者治疗后第1年、2年生存率(78.43%、47.06%vs 67.39%、30.43%)间差异无统计学意义(P>0.05);但3年生存率白蛋白组显著高于脂质体组(29.41%vs 13.04%)。结论白蛋白结合PTX加用奈达铂治疗复发性卵巢癌患者的效果优于PTX脂质体加用奈达铂,且不会增加毒副反应。

Machine learning molecular dynamics simulations of liquid methanol

As the simplest hydrogen-bonded alcohol,liquid methanol has attracted intensive experimental and theoretical interest.However,theoretical investigations on this system have primarily relied on empirical intermolecular force fields or ab initio molecular dynamics with semilocal density functionals.Inspired by recent studies on bulk water using increasingly accurate machine learning force fields,we report a new machine learning force field for liquid methanol with a hybrid functional revPBE0 plus dispersion correction.Molecular dynamics simulations on this machine learning force field are orders of magnitude faster than ab initio molecular dynamics simulations,yielding the radial distribution functions,selfdiffusion coefficients,and hydrogen bond network properties with very small statistical errors.The resulting structural and dynamical properties are compared well with the experimental data,demonstrating the superior accuracy of this machine learning force field.This work represents a successful step toward a first-principles description of this benchmark system and showcases the general applicability of the machine learning force field in studying liquid systems.

Sulfated Sterols Isolated from Starfish Asterias amurensis Lutken

Aim To study the chemical constituents of starfish Asterias amurensis. Methods The constituents were separated and purified by different chromatographic methods, and their structures were elucidated by MS and NMR. Results Six compounds were isolated from Asterias amurensis Lutken. Their structures were identified as 3β-O-sulfated-cholest-5-en sodium salt （1）, 3β-O-sulfated-6α-ol- pregn-9（ 11 ） -en-20-one sodium salt （ 2 ）, 3β-O-sulfated-6α-ol-cholest-9 （ 11 ） -en-23-one sodium salt （3）, 3β-O-sulfated-6α, 20β-diol-cholest-9 （ 11 ）-en-23-one sodium salt （ 4 ）, 3β-O-sulfated-6α-ol- cholesta-9 （ 11 ）, 20 （ 22 ） -dien-23-one sodium salt （ 5 ）, and 3β-O-sulfated-6ct-ol-ergost-9 （ 11 ） -en-23- one sodium salt （6）. Conclusion Compounds 1 - 6 were obtained from this species for the first time.

Shear Thickening Fluids Based on Additives with Different Concentrations and Molecular Chain Lengths

Shear thickening fluids （STFs） based on additives with different concentrations and molecular chain lengths were investigated. STF samples were prepared with silica and additive dispersed in polyethylene glycol （PEG） 400, where three types of additives with different molecular chain lengths of PEG4000, PEG6000, and PEG10000 were used. For PEG10000, different concentrations, including 0, 1%, 3%, and 5%, were selected to study the influences of additive concentrations. Rheological properties of the samples were measured with a rheometer. The results show that the shear thickening effect was significantly enhanced with the increase of the concentration and the molecular chain length of additives. The mechanism of enhancement was quantitatively explained with the formation of large particles clusters.

银耳多糖醇沉级分对酪氨酸酶的抑制作用

采用分步醇沉法得到4种银耳多糖级分--STP 20、STP 40、STP 60、STP 80,分析其得率、纯度和相对分子质量及纯化STP 60的单糖组成,研究其对酪氨酸酶的抑制作用及作用类型。结果表明,STP 60的得率和纯度均为最高,分别为19.28%和81.12%;4种银耳多糖级分均具有一定酪氨酸酶抑制作用,其中STP 60的抑酶作用最大,质量浓度1 mg/mL时对酪氨酸酶活性的抑制率为37.55%;STP 60对酪氨酸酶的抑制作用属于非竞争性可逆抑制。银耳多糖在美白类化妆品中具有潜在应用价值。

Synthesis and characterization of an unusual snowflake-shaped ZSM-5 zeolite with high catalytic performance in the methanol to olefin reaction

The ZSM-5 zeolite with an unusual snowflake-shaped morphology was hydrothermally synthesized for the first time,and compared with common ellipsoidal and boat-like shaped samples.These samples were characterized by N2 adsorption-desorption,X-ray fluorescence spectroscopy,scanning electron microscopy,X-ray diffraction,magic angle spinning nuclear magnetic resonance,temperature-programmed desorption of ammonia,and infrared spectroscopy of pyridine adsorption.The results suggest that the BET surface area and SiO2/Al2O3 ratio of these samples are similar,while the snowflake-shaped ZSM-5 zeolite possesses more of the（101） face,and distortion,dislocation,and asymmetry in the framework,resulting in a larger number of acid sites than the conventional samples.Catalysts for the methanol to olefin（MTO） reaction were prepared by loading Ca on the samples.The snowflake-shaped Ca/ZSM-5 zeolite exhibited excellent selectivity for total light olefin（72%） and propene（39%） in MTO.The catalytic performance influenced by the morphology can be mainly attributed to the snowflake-shaped ZSM-5 zeolite possessing distortion,dislocation,and asymmetry in the framework,and lower diffusion limitation than the conventional samples.

(-)-氧基乙酸的合成

（－）－氧基乙酸的合成ＳＹＮＴＨＥＳＩＳＯＦ（－）┐ＭＥＮＴＨＯＸＹＡＣＥＴＩＣＡＣＩＤ林汉森＊邓益暖△（广东药学院药化教研室，广州５１０２２４）ＬＩＮＨａｎ－Ｓｅｎ＊，ＤＥＮＧＹｉ－Ｎｕａｎ（Ｄｅｐｔ．ｏｆＭｅｄｉｃｉｎａｌＣｈｅｍｉｓｔｒｙ，Ｇ...

Analysis of Active Components of Hexane Extractives of Morus alba Leaves

[Objective]The aim was to explore the active compound of Morus alba leaves with the analysis of active components of hexane extractives of M.alba leaves.[Method]Antibacterial assays of hexane extractives of M.alba leaves were done and the volatile components of hexane extractives of M.alba leaves with the strongest antibacterial activity were analyzed by gas chromatography-mass spectrometry（GC-MS）.[Result]The results of inhibitory effect of hexane extractives of M.alba leaves on Staphylococcus aureus and Escherichia coli showed that hexane extractives of M.alba leaves collected in June,July and August had antibacterial activity against S.aureus and had no antibacterial effect against E.coli.Furthermore,hexane extractives of M.alba leaves collected in June had the strongest antibacterial activity against S.aureus（inhibition diameter 10.95 mm）.The hexane extractives of M.alba leaves collected in June was analyzed by GC-MS,the main volatile components were tetradecane（16.76%）,dodecane（13.20%）,diisobutyl phthalate（10.26%）,decane（9.10%）,hexadecane（8.71%）,linolenyl alcohol（7.25%）,octadecane（5.88%）,eicosane（3.26%）,dibutyl phthalate（2.59%）.[Conclusion]Linolenyl alcohol was the potential antibacterial compound.

Chemical Constituents of Silene jenisseensis Root

从旱麦瓶草（ＳｉｌｅｎｅｊｅｎｉｓｓｅｅｎｓｉｓＷｉｌｌｄ．）的根中分出３种化合物，根据理化常数及波谱分析鉴定了其中２个为α—菠菜甾醇葡萄糖甙（１），蜕皮甾酮（２）。这两个化合物均为首次从该植物中分得。

The Chemical Constituents of Amoora yunnanensis

Two new sterols, 3 beta, 7 alpha, 16 beta -trihydroxy-stigmast-5,22-diene (1), 3 beta, 7 alpha, 16 beta -trihydroxy-stigmast-5-ene (2), were isolated together with six known compounds, ergosta-5, 24(28)-dien-3 beta, 7 alpha -diol (3), ergosta-5,24(28)-dien-3 beta, 7 beta, 16 beta -triol (4), beta -amyrone (5), beta -amyrin (6), 11 alpha, 12 alpha -epoxy-14-taraxeren-3-one (7), and 6-guaiene-4 alpha, 10 alpha -diol (8) from the EtOH extract of the bark of Amoora yunnanensis (H. L. Li) C. Y. Wu. Their structures were deduced on the basis of spectral data.

Alkylation of toluene with tert-butyl alcohol over HPW-modified Hβ zeolite

An Hβ-supported heteropoly acid （H3PW12O40 （HPW）/Hβ） catalyst was successfully prepared by wetness impregnation, and investigated in the alkylation of toluene with tert-butyl alcohol for the synthesis of 4-tert-butyltoluene （PTBT）. X-ray diffraction, scanning electron microscopy, transmis- sion electron microscopy, fourier-transform infrared spectroscopy, inductively coupled plas- ma-optical emission spectrometry, the brunauer emmett teller （BET） method, tempera- ture-programmed NH3 desorption, and pyridine adsorption infrared spectroscopy were used to characterize the catalyst. The results showed that loading HPW on Hβ effectively increased the B acidity and decreased the pore size of Hβ. The B acidity of HPW/Hβ was 142.97 μmol/g, which is 69.74% higher than that of Hβ （84.23 μmol/g）. The catalytic activity of the HPW/Hβ catalyst was much better than that of the parent Hβ zeolite because of its high B acidity. The toluene conversion over HPW/Hβ reached 73.1%, which is much higher than that achieved with Hβ （54.0%）. When HPW was loaded on Hβ, the BET surface area of Hβ decreased from 492.5 to 379.6 m2/g, accompa- nied by a significant decrease in the pore size from 3.90 to 3.17 nm. Shape selectivity can therefore play an important role and increase the product selectivity of the HPW/Hβ catalyst compared with that of the parent Hβ. PTBT （kinetic diameter 0.58 nm） can easily diffuse through the narrowed pores of HPW/Hβ, but 3-tert-butyltoluene （kinetic diameter 0.65 nm） diffusion is restricted because of steric hindrance in these narrow pores. This results in high PTBT selectivity over HPW/Hβ （around 81%）. The HPW/Hβ catalyst gave a stable catalytic performance in reusability tests.

Chemical Constituents of Hedysarum gmelinii

To study the chemical constituents of Hedysarum gmelinii. Methods Theconstituents were separated and purified by different methods of chromatography, and theirstructures were elucidated by DR, MS and NMR. Results Eight compounds were isolated from Hedysarumgmelinii, including three triteipenoids, two flavonoids and two other compounds. Their structureswere identified as squasapogenol (1), soyasapogenol (2), lupeol (3), 3, 9-dihydroxy coumestan (4),3-hydroxy-9-me-thoxy pterocarpan (5), β-sitosterol (6), palmatic acid (7), and hexadecanoic acid 2,3-dihydroxypropyl ester (8). Conclusion All the compounds have been isolated from this plant forthe first time. Compounds 1 — 4 and 8 were obtained from this genus for the first time. The NMRdata of 1 are reported for the first time.

STUDY ON BIFURCATION BEHAVIOR IN CONTINUOUS FERMENTATION OF ETHANOL

As a typical biochemical reaction, the process of continuous fermentation of ethanol is studied in this paper. An improved model is set forward and in agreement with experiments. Nonlinear oscillations of the process are analyzed with analytical and numerical methods. The Hopf bifurcation region is fixed and further analyses are given.