超临界二氧化碳萃取技术

超临界流体萃取(Supercritical Fluid Extraction)技术是一种新型的化工分离技术.本文综述了超临界流体萃取技术的发展.超临界流体的特性,介绍了超临界二氧化碳萃取技术在中草药,食品工业,香料工业和环保技术方面的应用,并对超临界二氧化碳萃取技术的现状和前景进行了分析.     

超临界流体及其在萃取中的应用

综述了超临界流体、超临界流体萃取技术及其在工业生产中的应用等,着重介绍了超临界流体萃取的原理和萃取装置,并对超临界流体萃取的发展新趋势作了分析。     

超临界流体耦合技术的现状及发展

超临界流体萃取技术作为一种新兴的分离技术,目前已经得到广泛研究和应用,但也存在不足.本文在对超临界流体萃取技术介绍的基础上,针对其不足,提出了超临界流体萃取技术与其他分离技术进行耦合是发展趋势.并重点对超临界流体萃取技术与膜分离技术、蒸馏技术、色谱技术及结晶技术的耦合做全面阐述.认为超临界流体耦合技术具有广阔发展前景,应重視其研究.     

超临界流体萃取技术的应用与发展

介绍了国内外超临界流体萃取工艺及发展情况,在对超临界流体萃取原理及特点概述的基础上,就影响萃取效率的诸多因素：萃取压力、萃取温度、超临界流体流量及萃取时间等进行了阐述。分析了超临界流体技术的优越性,特别是在环境科学领域如废水处理、固体废物处理及污染监测中的应用。指出超临界流体技术是环境友好化学的发展趋势。     

超声强化超临界流体萃取海藻脱氢乙酸的研究

研究了超声强化超临界流体萃取海藻DHA技术,研究了萃取温度、萃取压力、流体流量以及萃取时间的影响.结果表明超声强化超临界流体萃取可以降低萃取温度、萃取压力以及超临界流体的流量,还可缩短萃取时间,提高萃取率.     

超临界流体萃取技术发展概况

对超临界流体及超临界流体萃取进行了概述;简要阐述了超临界流体萃取的发展简史及研究现状;对超临界流体萃取技术的应用前景进行了综述性的介绍和预测。     

超临界CO2流体萃取中的在线检测技术

综述了超临界CO2流体萃取中的在线检测技术,介绍了超临界CO2流体萃取与超临界流体色谱、气相色谱、高效液相色谱、核磁共振、近红外光谱等技术的联用在线检测,阐述了在线检测技术的优越性,提出了如何发展超临界CO2流体萃取中的在线检测技术。     

超临界流体萃取技术在中药提取的应用

超临界流体萃取技术(supercritical fluid extraction,简称SFE)是利用流体在临界点处特殊的溶解性能进行的物质提取分离技术,同时也是环境友好型的高效化工分离技术,尤其在中药领域,超临界流体萃取技术作为中药现代化的关键技术之一广泛应用于中药的提取分离。本文主要阐明了超临界流体萃取技术的基本技术原理及工艺特点,综述了超临界流体萃技术在中药有效成分提取的应用,概述了超临界流体萃取技术发展存在的局限性和应用前景。     

超临界流体萃取技术的发展现状

超临界流体萃取作为一种新型的分离技术,越来越受到各行业的关注和重视,并已广泛应用于医药、食品、化妆品及香料工业等领域.作者对超临界流体萃取技术进行了评述,主要从超临界CO2流体萃取技术的原理、工业应用及其强化过程等几个方面,介绍了国内外关于超临界流体分离技术的最新研究动态,最后针对超临界萃取技术应用现状,探讨了其目前存在的问题及应用前景.     

超临界流体萃取技术的应用

介绍了超临界CO2萃取技术的优点及使用的改性剂,对超临界流体萃取技术在医药工业、食品工业、环境保护中的应用进行了详细阐述,指出应加快超临界流体萃取技术应用的产业化步伐。     

底座连接口特征参数对显示器后壳注塑质量的影响分析

在Moldflow分析软件的基础上,对显示器后壳进行仿真研究,以翘曲变形量为质量指标,结合控制变量法进行单因素变动实验,保持注射工艺参数不变,研究显示器后壳底座连接口对制品翘曲变形的影响.对数据进行图表分析,结果表明显示器后壳尺寸定位68.58 cm(27英寸)时,底座连接口选用圆形,连接口位置距离底边26 mm,尺寸...     

The role of the symmetry and the flexibility of the anion on the characteristics of the nanostructures and the viscosities of ionic liquids☆

The transport properties of ionic liquids (ILs) are crucial properties in view of their applications in electrochem-ical devices. One of the most important advantages of ILs is that their chemical–physical properties and conse-quently their bulk performances can be well tuned by optimizing the chemical structures of their ions. This will require elucidating the structural features of the ions that fundamentally determine the characteristics of the nanostructures and the viscosities of ILs. Here we showed for the first time that the“rigidity”, the order, and the compactness of the three-dimensional ionic networks generated by the anions and the cation head groups determine the formation and the sizes of the nanostructures in the apolar domains of ILs. We also found that the properties of ionic networks are governed by the conformational flexibility and the symmetry of the anion and/or the cation head group. The thermal stability of the nanostructures of ILs was shown to be con-trolled by the sensitivity of the conformational equilibrium of the anion to the change of temperature. We showed that the viscosity of ILs is strongly related to the symmetry and the flexibility of the constitute ions rather than to the size of the nanostructures of ILs. Therefore, the characteristics of the nanostructures and the viscosities of ILs, especially the thermal stability of the nanostructures, can be fine-tuned by tailoring the symmetry and the conformational flexibility of the anion.     

浅谈设备的性能与操作对胎面压出质量的影响

简要介绍了胎面压出的工作原理及工艺过程，对设备的配置及操作对胎面压出质量的影响进行了分析，并对压出过程中常见的质量缺陷、造成的原因以及解决措施提出了自己的见解。     

Investigation of the effects of fatty acids on the compressive strength of the concrete and the grindability of the cement

In cement industry, a great energy consumption has been observed during grinding of clinker. To reduce this consumption, some waste products have been used as grinding aids.In this investigation, the effects of sunflower oil (SO), oleic acid (OA), stearic acid (SA), myristic acid (MA) and lauric acid (LA) on the fineness and strength of the cement have been examined. These aids were added into clinker in certain ratios based on the cement clinker weight and the grinding has been done for a definite time at the same condition.All of the fatty acids used increased the fineness as compared with the cement without the grinding additives. SO and OA decreased the strength significantly, LA decreased it to a lesser extent and SA increased it definitely according to the common cement. But MA did not alter the strength of the cement as much as SA. In addition, the covering of the balls influences the grinding of cement clinker unfavourably.     

煤粉流动性对GSP气化炉气力输送的影响研究

针对GSP气化装置煤粉气力输送在试车阶段出现的煤粉锁斗下料不畅、发料罐输送性能不佳等问题,从原料煤性质和工业装置的改进方面出发,通过煤粉的流动性参数的测量与研究,分析出现上述工程问题可能的内在原因,并提出工业装置改进方法,为保证GSP煤粉气力输送工业装置的正常运行提供解决办法。     

The effect of the length of the oxyethylene chain on the conductivity of the polyurethaneurea electrolyte

Polyurethaneureas (PUU), which were synthesized from 4,4′-diphenylmethane diisocyanate (MDI), poly(ethylene glycol) (PEG), and 3,5-diaminobanzoic acid (DABA), were used as polyelectrolytes in this study. Differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR) were used to monitor the effect of the various kinds of PEG on the changes in morphology of PUU electrolytes corresponding to the concentration of lithium perchlorate (LiClO₄) dopants. The results of DSC and FT-IR indicate the Li⁺ ions coordinate with the soft and hard segments. Additionally, the crystallinity of the PEG soft segment and the ordered hydrogen-bonded urea carbonyl groups decreased with increasing salt concentration. Impedance spectroscopy (IS) measurements show that the PUU electrolyte with the high phase separation degree has the high ionic conductivity. The hard-segment T_g and the soft-segment T_m influence the conductivity behavior of polyelectrolytes with increasing measurement temperature.     

Effect of the drafting force on the strength of the bottom of the spinneret

In spinning basalt fibres, the drafting force is in the same range as in spinning of glass fibres. The effect of the drafting force can not be considered in the calculation for the strength and rigidity of the bottom of the spinneret. __________ Translated from Khimicheskie Volokna, No. 5, pp. 47–50, September–October, 2007.     

煤的溶胀处理对药用腐植酸提取的影响研究

以气煤、肥煤、焦煤、瘦煤为样煤,进行了样煤的粉碎、有机溶剂溶胀和硝酸氧化处理,考察了处理后煤样中的药用腐植酸得率。结果表明,吡啶和N,N-二甲基吡咯烷酮是溶胀较好的溶剂;样煤粉碎后,随着粒度的减小,煤的溶胀率增加;粒度粉碎至200目的气、肥煤经吡啶溶胀和硝酸氧化后,煤样的药用腐植酸得率可达到73.0%和71.4%,而经甲醇溶胀和硝酸氧化的200目气煤药用腐植酸得率为56.4%和58.4%。实验结果表明,煤样经过溶胀和硝酸氧化处理,对药用腐植酸的提取有促进作用。     

转子挤压组合凹模的应力分析

组合凹模的应力分析是一个非常复杂的问题，对其进行精确分析是解决模具寿命的关键。本文采用有限元分析软件Ansys对转子的组合凹模进行了分析，为转子组合凹模的优化设计提供了依据。     

Effect of the density of the electronic states at the valence orbital of the bridge redox molecule on the dependence of the tunnel current on the overvoltage in the case of fully adiabatic electron transition

Effect of the density of the electronic states at the valence orbital of the bridge redox molecule on the dependence of the tunnel current on the overvoltage and on the width at half maximum of the current-overvoltage curve is studied. A number of the approximate expressions for the density of states, the tunnel current and the width are obtained in the fully adiabatic limit for different particular cases. It is shown that at small values of the coupling of the electronic levels of the electrodes with the valence orbital of the redox molecule and the small values of the bias voltage two regions of the reorganization Gibbs energy exist with different dependence of the width on the reorganization Gibbs energy. The results of calculations of the density of states, the tunnel current and the width are presented and used for the interpretation of the experimental data [N.G. Tao, Phys. Rev. Lett. 76 (1996) 4066, I. Visoly-Fisher, K. Daie, Y. Terazono, C. Herrero, F. Fungo, L. Otero, E. Durantini, J.J. Silber, L. Sereno, D. Gust, T.A. Moore, A.L. Moore, S.M. Lindsay, PNAS 103 (2006) 8686].