2,4,4′-三羟基苯基苄酮的合成

2,4,4′-三羟基苯基苄酮是合成大豆苷元的重要中间体,也是合成大豆苷元的技术难点,工艺路线的优劣决定大豆苷元合成方法能否工业化的关键。同时它本身有非常强的抑制酪氨酸酶活性,抑制效果较好、性质稳定、对皮肤刺激小是非常有潜力的皮肤增白剂[4]。本文论述了2,4,4′-三羟基苯基苄酮的合成方法,在原有文献的基础上,通过正交设计优化及反应溶剂的合理选取,提高了产品质量,降低了生产成本。     

基于F-C反应的天然产物大豆黄素合成工艺

引言 大豆黄素(又名大豆苷元、大豆黄酮,daid-zein),化学名为4',7-二羟基异黄酮,是从大豆中提取得到的一种异黄酮活性组分,是大豆异黄酮的一种,属大豆苷类中的游离型的苷元,因豆科植物中的大豆异黄酮大多以糖苷形式存在,故以游离型苷元形式存在的大豆黄素在豆科植物中的含量非常低,大约为0.1%,提取、分离过程都很困难,存在生产成本高、投资较大、工艺复杂、产品纯度低等问题.大豆黄素及其糖苷的结构如下     

大肠杆菌偏利共培养系统合成大豆苷元

大豆苷元是一种植物雌激素,具有多种生物活性,但在大肠杆菌中的生物全合成还未见报道。基于大豆苷元合成途径的三个模块（对香豆酸、甘草素和大豆苷元模块）,构建大肠杆菌共培养系统从头合成大豆苷元。将对香豆酸和甘草素模块分配到两株大肠杆菌中构建双菌共培养系统,合成甘草素。在此基础上,探索了三种共培养模式合成大豆苷元,结果显示,三菌共培养系统比其他两种双菌共培养系统的产量更高,达到27.8 mg/L。共培养菌株间通过苯丙氨酸的单向流动形成了偏利共生的关系,有助于平衡代谢途径,提高大豆苷元产量。该共培养系统在大肠杆菌中实现大豆苷元的从头合成,为其他黄酮类化合物的生物合成提供了即插即用的平台。     

大肠杆菌偏利共培养系统合成大豆苷元

大豆苷元是一种植物雌激素，具有多种生物活性，但在大肠杆菌中的生物全合成还未见报道。基于大豆苷元合成途径的三个模块（对香豆酸、甘草素和大豆苷元模块），构建大肠杆菌共培养系统从头合成大豆苷元。将对香豆酸和甘草素模块分配到两株大肠杆菌中构建双菌共培养系统，合成甘草素。在此基础上，探索了三种共培养模式合成大豆苷元，结果显示，三菌共培养系统比其他两种双菌共培养系统的产量更高，达到27.8 mg/L。共培养菌株间通过苯丙氨酸的单向流动形成了偏利共生的关系，有助于平衡代谢途径，提高大豆苷元产量。该共培养系统在大肠杆菌中实现大豆苷元的从头合成，为其他黄酮类化合物的生物合成提供了即插即用的平台。     

大豆苷元合成

报道了以间苯二酚和对羟基苯乙酸为原料,经过缩合,环合两步反应获得大豆苷元新方法。合成收率可达43．O％,产品质量符合药典标准。     

大豆苷元的水溶性改性研究进展

大豆苷元来源于自然界,是异黄酮化合物中很重要的一种,其具有重要的药理活性。近年来,国内外学者通过化学改性以提高其应用性进行了深入的研究。综述了大豆苷元的水溶性改性的最新研究进展,以促进对其的研究和应用。     

大豆甙元的合成方法

利用化学合成方法制造大豆活动物质大豆甙元,大豆中大豆甙元含量很低,而大豆甙元在农业,畜牧业,医药上用途日益广泛,本合成路线具有工序短,成本低的优势。     

大豆苷元在混合有机溶剂中溶解度的测定和关联

采用动态法利用激光监视技术测定了大豆苷元在乙醇和N,N-二甲基甲酰胺混合有机溶剂中配比为0.000、0.100、0.181、0.273、0.358、0.460、0.547、0.649、0.812、1.000,温度范围在280~340 K的溶解度;将溶解度实验数据用Apelblat方程进行关联。结果表明,大豆苷元在混合有机溶剂中的溶解度随温度的升高增大,随乙醇比例的增大而降低,关联结果良好,Apelblat方程关联溶解数据的平均相对误差小于1.652%,实验结果和关联方程为大豆苷元分离结晶过程提供基础数据。     

生物活性物质大豆苷元的量子化学研究

采用PM3-MO方法，对大豆苷元进行了量子化学计算，给出了分子轨道及其能级、电荷密度、键长、二面角参数等。结果表明：大豆苷元分子中苯并吡喃环（A环和C环）带较强的正电荷，易与受体的负电荷中心结合；B环是负电子区域，易与受体的正电荷中心结合；其他部分通过氢键与受体发生作用，从而发挥生物活性。     

新月弯孢霉KA-91转化异羟基洋地黄毒苷元的研究

考察了新月弯孢霉(Curvularialunata)KA-91对地高辛和异羟基洋地黄毒苷元的生物转化反应。结果发现,新月弯孢霉KA-91对地高辛不具有转化能力,对异羟基洋地黄毒苷元转化产生一个产物,经结构鉴定产物为3-羰基-异羟基洋地黄毒苷元。确定了转化异羟基洋地黄毒苷元反应的最优工艺参数为:发酵培养基的初始pH值6.0,装液量50 mL.(250 mL)-1,底物浓度0.60 mmol.L-1,转化温度28℃,180 r.min-1振荡培养24 h,转化54 h。此时,转化率为40%。     

关于陶瓷墙地砖的深加工及其机械

本文简要回顾了陶瓷墙地砖深加工的工艺理论和机械设备。对陶瓷墙地砖深加工的自动抛光生产线和组成生产线的工艺单机作了一般介绍。指出设计陶瓷墙地砖深加工工艺单机时要注意的主要问题,并提供了解决这些问题的方法。     

Solid-State Organic Batteries Based on Polymer Composites of Charge-Transfer Materials

Solid-state organic batteries based on charge-transfer complexes have been extensively used. However, the low mechanical strengths of these materials have restricted their applications. The polymer composite of these materials have been prepared and used in fabrication of solid-state batteries to overcome this problem. The pressed pellets of the polymer composite of o-tolidine–iodine (1:0.75) charge-transfer complex in poly(vinyl chloride) and polystyrene have been used as cathodes in contact with zinc as anode metal. The electrochemical characterization of these cells such as open-circuit voltages, short-circuit currents, their time and temperature dependence and rechargeability of these cells have been studied. The impedance analyses have been done to understand the nature of the electrode reaction.     

Structural,mechanical, and gas barrier properties of poly(ethylene terephthalate) nanohybrid using nanotalc

Amorphous poly(ethylene terephthalate) (PET)/nanotalc nanohybrids have been prepared through solution casting route. The fine dispersion of nanotalc clay in the polymer matrix has been examined through transmission electron microscopy (TEM). The intercalation and interaction of nanoclay have further been confirmed using X-ray diffraction, ultraviolet, and Fourier transform infrared techniques. The thermal stability has been tested via thermogravimetric analysis and nanohybrids have been found thermally stable. The glass-transition temperature has been further confirmed through DTA and differential scanning calorimetry analysis which has been increased in the presence of nanotalc arising from greater interaction. The nanohybrids have been tested for their mechanical performances and have been found to have improved mechanical responses for nanotalc-filled nanohybrids. The modulus has been increased whereas toughness has been compromised meagerly. The modulus values have been theoretically predicted using various micromechanical models. The microhardness of the nanohybrids has been examined through Vicker hardness test. The theoretical prediction of the hardness values has been done using different micromechanical models. The structural development upon uniaxial stretching of the samples has been studied using small-angle X-ray scattering and wide-angle ray diffraction. The stretched samples have found to have short-range ordering as well as increased blob size and better coherency in the presence of nanotalc. The aspect ratio has been increased upon stretching. The inclusion of nanotalc has induced high barrier for gas permeation as compared to pure PET. The oxygen transmission rate has been found to decrease up to 64% for 8 wt % of filler concentration. The prediction of the permeability data has been done using different models considering different aspect ratios. The permeability values have been predicted very closely and nanohybrids have been found suitable for practical applications such as packaging. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 137, 48607.     

A Review of Contemporary Views of Theories of Adhesion

The once distinct and independent theories of adhesion have been losing their isolation and converging. Ideas of the effects of surface roughness, once dismissed as irrelevant except in the case of textiles, have been revised; albeit on a smaller scale as details of surfaces have been revealed by sophisticated techniques. Electrostatic interactions across an interface have been more deeply explored and their significance recognised and expounded. Diffusion of groupings and chain segments within a polymer have been related to the possibilities of interaction with a variety of surfaces. Perhaps most important, theories of adsorption have been extended in depth. The precise nature of the molecular interactions have been recognised and quantified. In doing this the contribution of diffusion and elastoplastic phenomena have been integrated. These developments are collated and analysed to present the present understanding of the concepts.     

含氯离子废水化学需氧量分析方法比较

含氯离子废水化学需氧量的分析方法的研究是当前环境监测研究的热点之一，各种文献报道也较多，但各自使用的效果不一。采用试验的方法对含氯离子废水中CODCr的分析进行了初步研究，比较了硫酸汞加入法、稀释法、硝酸银滴定法、氯气校正法、氯离子校正法等方法在不同化学需氧量不同氯离子浓度下的分析结果，利用分析结果与配置的标准溶液浓度相比较，分析了各种方法的优缺点，结果表明硝酸银滴定法是比较理想的适应范围较广的方法。     

Characterization of Europium Complex-doped PMMA and PMMA-EVA Polymer Networks

Europium-β-diketone chelate doped poly(methyl methacrylate) and poly(methyl methacrylate)/poly(ethylene co-vinyl acetate) blends have been successfully prepared and characterized. The mechanical properties of the PMMA-EVA systems have been assessed in terms of tensile strength and impact strength. The thermal characteristics and the energy involved in thermal decomposition have been studied. The structural properties of the complex doped polymeric systems reveal that the complex exists in the same crystalline state in the doped systems as it does in the pure state. The orientations of the groups in the host matrix have been found to be affected by the complex loading. The optical properties of the system have been studied by photo luminescence spectroscopy. The fluorescence lifetime have been observed to decrease at greater loadings of the complex; an effect that has been attributed to concentration quenching. The complex doped PMMA/EVA polymer network developed is considered to be a potential candidate for the development of optoelectronic devices those possess superior mechanical properties.     

短流程炼钢工艺用耐火材料

简述了电炉短流程工艺的特点，介绍了超高功率电炉、LF精炼炉及连铸中间包各部位用耐火材料的选择与应用。实践表明，超高功率电炉一精炼炉一连铸用耐火材料已完全国产化，国产耐火材料取得了良好的使用效果。     

A Review of Contemporary Views of Theories of Adhesion

The once distinct and independent theories of adhesion have been losing their isolation and converging. Ideas of the effects of surface roughness, once dismissed as irrelevant except in the case of textiles, have been revised; albeit on a smaller scale as details of surfaces have been revealed by sophisticated techniques. Electrostatic interactions across an interface have been more deeply explored and their significance recognised and expounded. Diffusion of groupings and chain segments within a polymer have been related to the possibilities of interaction with a variety of surfaces. Perhaps most important, theories of adsorption have been extended in depth. The precise nature of the molecular interactions have been recognised and quantified. In doing this the contribution of diffusion and elastoplastic phenomena have been integrated. These developments are collated and analysed to present the present understanding of the concepts.     

SIGNIFICANCE OF THE CENTRAL PLUME VELOCITY FOR THE CORRELATION OF LIQUID PHASE MIXING IN BUBBLE COLUMNS

The knowledge of the flow patterns of each phase of bubble column reactors is of considerable importance for the rational design and scale-up. The hydrodynamic models for the liquid phase have been reviewed. The models have been based on some form of pressure balance or energy balance. These two approaches have been compared and recommendations have been made regarding the range of applicability of the individual models. A comparison between the predicted and the experimental liquid velocities has been presented whenever possible. The range of variables has been pointed out for which further investigations are needed. The empirical and theoretical models for the mixing behavior of the different phases of bubble column reactors have also been reviewed.     

氯碱工业60年发展变化与新格局

全面分析了建国60年来我国氯碱工业的发展变化情况:采用高新技术和先进技术;装置向规模化、大型化发展;企业向工业园区集中,向资源、能源丰富的地区发展;氯碱行业外的企业大举加盟氯碱产业,使氯碱工业格局发生新的变化。