烟草甲虫性信息素(7S)-(-)-4,6-二甲基-7-羟基-3-壬酮的立体选择性合成

手性试剂;烟草甲虫性信息素(7S)-(-)-4;6-二甲基-7-羟基-3-壬酮的立体选择性合成     

2-氨基-10-羟基-5,10-二氢磷杂吖嗪-10-氧化物的合成、诱变性及应用

2-氨基-10-羟基-5;10-二氢磷杂吖嗪-10-氧化物的合成、诱变性及应用;二氢磷杂吖嗪; 吡唑啉酮; 合成; 结构鉴定; 诱变性     

3,7-二甲基-2-十三碳醇乙酸酯的全合成

松叶蜂;性信息素;3;7-二甲基-2-十三碳醇乙酸酯的全合成     

聚羟乙谷氨酰胺-5-氟尿嘧啶-1-乙酸的合成、表征与缓释性

聚羟乙谷氨酰胺-5-氟尿嘧啶-1-乙酸的合成、表征与缓释性;高分子前药     

甘薯象鼻虫信息素(E)-2-丁烯酸-(Z)-3-十二烯基酯的全合成

性信息素;甘薯象鼻虫信息素(E)-2-丁烯酸-(Z)-3-十二烯基酯的全合成     

含二苯并-18-冠-6冠醚环的偶氮型液晶冠醚的合成

含二苯并-18-冠-6冠醚环的偶氮型液晶冠醚的合成;偶氮型;冠醚;热致性液晶;合成     

席夫碱的合成及热色性研究Ⅲ——二取代苯甲醛-二-对-氨基苯甲烷类席夫碱

本文合成了二取代苯甲醛-二-对-二氨基苯基甲烧类席夫碱类的7个化合物,并应用物理方法进行了表征.通过加热显微观察,这些化合物都具热色性,而其中4种具有可逆热色性.此外应用差热分析阐述了这类席夫碱的吸热峰的ΔH(ΔS)与其结构的关系.     

CTAB透性化酵母细胞生物催化合成(S)-(+)-3-羟基丁酸乙酯

 利用十六烷基三甲基溴化铵(CTAB)透性化啤酒酵母细胞中高活性的脱氢酶,借助于辅助底物乙醇和葡萄糖,对3-羰基丁酸乙酯(EOB)不对称还原合成(S)-(+)-3-羟基丁酸乙酯((S)-(+)-3-EHB)进行了研究. 结果表明,CTAB透性化酵母细胞中的醇脱氢酶和6-磷酸葡萄糖脱氢酶的活性分别比未经处理的酵母细胞高482倍和6.5倍. 在相同条件下,CTAB透性化细胞对EOB的还原比未经处理的酵母细胞快. 细胞浓度对反应有明显影响,当透性化酵母细胞浓度＜90 mg/ml时,(S)-(+)-3-EHB的产率和对映体过量值都较低; 当酵母细胞浓度≥90 mg/ml,在最佳进料速率、最适温度和pH条件下,振摇速度为125 r/min时, (S)-(+)-3-EHB的浓度达到最大值314 mmol/L. 在反应开始的6 h内,(S)-(+)-3-EHB的产率可达94%,对映体过量值≥98%,但24 h后产率和对映体过量值分别降低到85%和91%.     

溶液聚合的α-烯烃高分子减阻剂的表征

高分子减阻剂;抗剪切性;胶粒浓度;α-烯烃     

聚(D,L)-乳酸的合成及生理盐水降解性

聚(D; L)-乳酸的合成及生理盐水降解性;聚(D; L)-乳酸;D; L-丙交酯;生理盐水;降解性     

壳聚糖季铵化衍生物的吸湿性与保湿性

壳聚糖季铵化衍生物的吸湿性与保湿性许晨，卢灿辉（福建师范大学高分子研究所福州３５０００７）关键词壳聚糖季铵盐，壳聚糖衍生物，吸湿性，保湿性壳聚糖是从虾、蟹等废弃甲壳中提取得到的一种生物活性物质［１，２］，由于其特有的直链聚阳离子结构，成膜附于角蛋白与...     

Optimization by factorial design of focused microwave assisted extraction of polycyclic aromatic hydrocarbons from marine sediment

The Focused Microwave (FMW) assisted extraction for organic contaminant analysis, such as polycyclic aromatic hydrocarbons (PAHs), in environmental matrices, was studied and optimized using a factorial design. The effects and interactions of five parameters on the extraction recovery were investigated in a few experiments with a good accuracy: irradiation power and time, volume and nature of solvent, and percentage of moisture of the matrix. The results show that the percentage of water added to the freeze-dried matrix can significantly increase the extraction recovery. The irradiation power has also a positive effect. The choice of solvent is significant: a mixture of heptane/ethanol (80/20, v/v) allows better results than dichloromethane. Some interactions between percentage of moisture and the two previous parameters have been demonstrated: the effect of power and nature of solvent depends on the water content. Some optimal conditions have been established: 10 mL of heptane/ethanol (80/20, v/v), extraction time of 2 min, and different possible pairs of moisture content and irradiation power (140 W and 0% of moisture or 20 W and 40% of moisture) according to the need and wish of the experimentalist; or 10 mL of dichloromethane, extraction time of 2 min, 20 W and 40% of moisture. These optimized conditions provide very good recoveries compared to conventional extraction such as Soxhlet (near 100%) for the model matrix (a marine sediment) used for the factorial design. FMW extraction is a good alternative to Soxhlet extraction with reduction of time and reduction of solvent volume. This study shows that it is possible to substitute chlorinated solvent by a less toxic solvent, like a mixture of heptane and ethanol.     

Graft polymerization of vinyl monomers onto cotton fibres pretreated with amines

The influence of treating cotton fibres with several amines on the mechanical properties, moisture sorption ability before and after graft polymerization, and on graft yields for various water-soluble and water-insoluble vinyl monomers were analysed. As compared to water, the treatment with amines, ethylenediamine (EDA) in particular, resulted in a decrease in the crystallinity and tensile strength of the cotton fibres, and an increase in the moisture sorption. The graft yields of amine-treated cotton fibres using water-soluble monomers, acrylic acid (AA), methacrylic acid (MAA) and acrylamide (AM) were greater than those observed for water-treated cotton fibres, whereas the graft yields using water-insoluble monomers, methyl acrylate (MA), methyl methacrylate (MMA) and vinyl acetate (VA) were lower. The moisture sorption ability was improved by the graft polymerization with water-soluble monomers. The improvement was enhanced for MA and MAA by treatment with sodium hydroxide to form the corresponding sodium carboxylate derivatives. The tensile strength of EDA-treated cotton was slightly reduced by grafting, while that of the water-activated cotton yarn was barely changed. These results suggest that the graft polymerization of amine-treated cotton fibres with certain vinyl monomers increased the moisture sorption ability without resulting in increased fibre rigidity.     

Study on the moisture absorption of zwitterionic copolymers for moisture‐sensitive shape memory applications

This study develops a new type of moisture‐sensitive shape memory polymer based on zwitterionic copolymers synthesized with acrylic acid (AA) and 3‐Dimethyl (methacryloyloxyethyl) ammonium propane sulfonate (DMAPS). The moisture absorption properties of zwitterionic copolymers are particularly investigated in this paper. The results demonstrate that the DMAPS/AA copolymers possess a sulfobetaine structure and form a two‐phase separation structure. The zwitterionic copolymers show both good hydrophilic properties and moisture absorption properties. Both AA and DMAPS segments influence the hydrophilic properties and moisture absorption of the composite copolymer. The moisture absorption process is well modeled by Fick's second law in its initial stage. The moisture absorption is mainly determined by immersion conditions and the given materials' structure. Moisture absorption speed and saturated moisture absorption both increase with an increase in DMAPS content as well as the immersion temperature. The increased moisture absorption rate and higher saturated moisture absorption results from the higher activation energy of diffusion. The DMAPS/AA copolymers demonstrate adequate moisture‐sensitive shape memory effects. Stain recovery is faster in the zwitterionic copolymers containing higher DMAPS content, whereas the final shape recovery decreases with an increase of DMAPS content. Finally, it is proposed that not only good moisture absorption units are required but also physical crosslinks should be improved for moisture‐sensitive shape memory polymers. Copyright © 2017 John Wiley & Sons, Ltd.     

Quantitative Analysis of Uncoated Eszopiclone Tablets by Near-Infrared Spectroscopy

This study employed near-infrared (NIR) spectroscopy to analyze content uniformity, moisture content, compression force, tablet hardness, average particle size, and particle-size distribution. The content uniformity, moisture content, compression force, tablet hardness, and average particle size models yielded high correlation coefficients (R²) of 0.99582, 0.99725, 0.99620, 0.96294, and 0.98421, respectively, whereas the particle size distribution models showed good predictive ability. Conventional criteria such as R², root-mean-square error of calibration, and the root-mean-square error of prediction were used to evaluate the accuracy and precision of the model. To ensure the accuracy and predictability of the content model for low-dose tablets, additional validation and reliability evaluations were performed using 70%, 80%, 100%, 120%, and 130% drug concentrations as well as 90% and 110% active content formulations. Near-infrared spectroscopy with multivariate modeling is a rapid, nondestructive technique for the characterization of the manufacturing process.     

Versatile use of ytterbium(III) triflate and acid washed molecular sieves in the activation of glycosyl trifluoroacetimidate donors. Assemblage of a biologically relevant tetrasaccharide sequence of Globo H

The nonreducing tetrasaccharide terminus of Globo H has been assembled in good yield and excellent stereocontrol exclusively by using mild and moisture stable agents such as Yb(OTf)(3) and acid washed molecular sieves for the activation of glycosyltrifluoroacetimidate donors in the glycosylation steps.     

Interferometrische Bestimmung des Feuchtigkeitsgehaltes einiger organischer Lösungsmittel

Zusammenfassung Zwischen den interferometrischen Daten und dem Feuchtigkeitsgehalt von Methanol, Äthanol, n-Butanol, Aceton und Äthyläther besteht eine lineare Abhängigkeit. Auf dieser Grundlage wurde eine Methode zur Bestimmung kleiner Feuchtigkeitsmengen in den angeführten Lösungsmitteln erarbeitet. Diese zeichnet sich bei schneller und einfacher Ausführbarkeit durch hohe Empfindlichkeit (0,01% Feuchtigkeitsgehalt) und gute Reproduzierbarkeit (relativer Fehler 3%) aus.

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Interferometric determination of the moisture content of some organic solvents

Summary There exists a linear relation between the interferometric data and the moisture content of methanol, ethanol,n-butanol, acetone and ethyl ether. On this basis there has been developed a method for the determination of small amounts of moisture in the solvents named above. This procedure which can be carried out rapidly and with simplicity is characterized by high sensitivity (0.01% moisture content) and good reproducibility (relative error3%).

     

Synthesis of guar gum-based hydrogel for sugarcane field solid conditioning

The water crisis is increased everywhere in recent years, which has affected the water demand in different sectors like industries, agriculture, residential, etc. The present research aims to the development of superabsorbent polymer (SAP) using bio-material. The hydrogel is synthesized by grafting Guar gum (GG) with methyl methacrylate (MMA) and crosslinking with polyethylene glycol (PEG). The developed GG-based hydrogelwas characterized by various analytical instruments. The Scanning Electron Microscopy (SEM) demonstrated hydrogels havepores of size 50 ​μm–10 ​μm. The Transmission Electron Microscopy (TEM) analysis has shownthat thematerial consists of spherical shapesand particles of size 141.11nm–182.19 ​nm.The Fourier-Transform Infrared Spectroscopy (FTIR) and Thermogravimetric analysis (TGA) study have confirmedthepresence of functional groups of material, and thermal resistivity. The absorption capacity of developed hydrogelwas found to be 110 ​ml per gram (110% of its dry weight). The hydrogelwasapplied in the field of sugarcane crop and measured soil moisture content after 20 days of application. A better resultwas found of moisture content in the area of hydrogel application (28%) compared to the area without hydrogel application (10%). Moreover, the comparison of different hydrogels is also shown in a study, and the developed hydrogel proves good moisture retention capacity. This technology could be promising in terms of improving perennial crop productivity and combating moisture stress in agriculture. As a soil conditioning material for agricultural applications, the synthesized hydrogel showed tremendous potential.     

海藻酸钠-羧甲基纤维素钠共混纤维的制备及其吸湿性能

以海藻酸钠(ALG)和羧甲基纤维素钠(CMC)两种天然高分子材料为纺丝原料,氯化钙水溶液为凝固浴,制得了吸湿性能优异、力学性能良好的海藻酸钠-羧甲基纤维素钠共混纤维。采用离心脱水法,系统研究了纺丝工艺条件、吸收环境对共混纤维吸湿性的影响,并在此基础上获得了海藻酸钠-羧甲基纤维素钠共混纤维的吸湿动力学模型。     

Effect of moisture content on the heat-sealing property of starch films from different botanical sources

In this study, we investigated the differences in the crystallinity of starch films (mung bean, water chestnut, sweet potato, and cassava starches) with different moisture contents stored in different humidity conditions (11%, 22%, 33%, 43%, 54%, 75%, and 84%) and evaluated their thermal adhesion and sealing properties. X-ray diffraction analysis revealed an association between the degree of crystallinity and the moisture content in starch films: crystallinity decreased with an increase in the moisture content. Field Emission Scanning Electron Microscopy (FE-SEM) analysis showed that films with low moisture content failed to completely adhere, but films with a high moisture content and lower crystallinity showed good adherence, with two films perfectly adhered at the same temperature because water molecules acted as a mobility enhancer. The peeling test demonstrated the failure modes of the heat-bound films. The cassava starch film, which had a low amylose content and crystallinity, showed better adhesion compared to other starch films.