提取野菊花中的精油

采用超临界CO₂萃取技术,研究了从野菊花中提取精油的工艺并鉴定其主要化学成分。对影响超临界CO₂萃取精油的各因素进行了单因素试验研究,得到较适宜的萃取工艺条件,萃取温度 35℃、分离温度 30℃、萃取时间 90 min、萃取压力 25 MPa、CO₂流量为 30 kg/h。在上述萃取工艺条件下,精油得率 9.65%。经GC-MS分析鉴定了野菊花精油成分43个,主要是萜类及其含氧衍生物、烷烃类化合物和酯类化合物等。     

萃取八角茴香精油的研究

用超临界CO₂萃取八角茴香精油。采用4因素4水平的正交试验,得出超临界CO₂萃取八角茴香精油的最佳工艺条件为:压力16 MPa、温度35℃、时间2 h、CO₂流量30 L/h。在此条件下,八角茴香萃取物得率为10.5%。采用水蒸气蒸馏提取精油,得率为7.5%。对两种不同提取方法得到的精油的品质和得率进行了比较。超临界CO₂萃取方法得到的八角茴香精油产品得率比水蒸气法高出40%,并且香气更全面。     

萃取红松种壳中抗氧化性物质的研究

对超临界CO₂萃取红松种壳中的抗氧化成分进行了研究。分析了其抗氧化成分与超临界CO₂提取的压力、时间、温度之间的关系,得出超临界CO₂萃取红松种壳中抗氧化性物质的最佳条件为压力40 MPa 、温度35℃ 、时间120 min,萃取物得率为2.4%,抗氧化性较强部分占其中的42.1%。并且发现红松种壳提取物对豆油具有明显的抗氧化作用,并具有剂量效应的关系,在添加量为0.6%时抗氧化效果最好。     

萃取山苍子核仁油的工艺研究

研究了用超临界CO₂流体萃取山苍子核仁油的萃取工艺,探讨了各种影响因素对山苍子核仁油萃取率的影响,通过正交试验确定了超临界萃取的最佳工艺为:萃取温度45℃、萃取压力25 MPa、CO₂流量220 L/h、萃取时间80 min。在此条件下,山苍子核仁油萃取率84.5%。研究证明了加入溶剂和剥壳均可提高山苍子核仁油的萃取率。     

萃取天然除虫菊 化学成分的GC-MS分析

采用GC-MS法对超临界CO₂萃取天然除虫菊的化学成分进行了分析,用归一化法测定了各组分的相对百分含量。结果共分离出53个组分,鉴定了31个成分,已鉴定的化合物组分占总馏出组分的58.5%。结果表明超临界CO₂萃取的天然除虫菊的主要成分为除虫菊酯类以及烷烃类、烯醇、烯酸、甾醇、脂肪酸,其中除虫菊酯的相对含量为50.70%。     

下Pd/C催化剂催化 松香加氢反应的研究

在超临界CO₂条件下采用Pd/C催化剂进行催化松香加氢反应的研究。超临界CO₂条件与常规条件下反应产物相比较,产品中枞酸、去氢枞酸含量都较常规条件下的氢化松香产品低。详细考察了反应温度、反应时间、催化剂用量、催化剂重复使用对反应的影响。结果表明Pd/C催化剂中Pd的流失是造成催化剂失活的主要原因。     

催化剂的制备及其 用于菜籽油制备生物柴油的研究

采用等体积浸渍法制备了纳米K₂CO₃/γ-Al₂O₃催化剂,并研究了该催化剂的制备条件对酯交换反应的影响。用TEM表征催化剂颗粒的大小,用TG-DSC表征催化剂的热性能。结果显示:催化剂粒径分布在30-50nm之间;催化剂的最佳制备条件是K₂CO₃负载率(K₂CO₃占γ-Al₂O₃质量分数)50%,焙烧温度600℃,焙烧时间4h。利用此催化剂,当醇油物质的量之比为12:1、催化剂用量为油质量的3%、反应时间3h 、反应温度70℃时,生物柴油的得率达到97.90%。生物柴油质量指标符合国家标准。     

负载型钾基CO2吸收剂的结构表征和碳酸化反应特性

The structure identification and carbonation characteristics of several potassium-based supported sorbents for CO₂ capture were investigated with TGA,XRD,XRF,SEM and N₂ adsorption method.Potassium-based sorbents were prepared by impregnation with potassium carbonate on supports,such as cocoanut activated charcoal（AC1）,coal active carbon（AC2）,silica gel（SG）and diatomite（DT）using the iso-volume impregnation method.The results showed that the K₂CO₃ loading amounts of AC1,AC2,SG and DT were 24.1%,22.5%,21.7% and 19.1% respectively.The surface area and pore volume of K₂CO₃/AC1 and K₂CO₃/AC2 were larger than others.In contrast,those of K₂CO₃/DT were small.For K₂CO₃/SG,pore volume was large but surface area was small.K₂CO₃/AC1 and K₂CO₃/AC2 showed excellent carbonation capacity.However,the carbonation capacities of K₂CO₃/SG and K₂CO₃/DT were low.The difference in carbonation capacity of those sorbents were attributed to the difference in pore structure,leading to different supported sorbents.     

PVAm/PAN复合膜的制备及其对CO2/CH4的分离性能

New polymeric membrane materials——polyvinyl amine (PVAm) with different primary amine contents were synthesized.By covering polyacrylonitrile(PAN) ultrafiltration membranes with PVAm, the PVAm/PAN composite membranes for CO₂/CH₄ separation were prepared. The composite membranes containing more primary amino groups have higher selectivity for CO₂/CH₄.The cross-linking of acid or glutaradehyde could improve the gas permselectivity of the composite membranes. With decreasing CO₂ content in the feed gas, the CO₂/CH₄ separation factor increased.When the feed gas was 25%(vol) CO₂ and 75%(vol) CH₄, the CO₂ permeation rate was 4.1×10^-9cm³(STP) •cm^-2•Pa^-1•s^-1, and the CO₂/CH₄ separation factor was 180.     

288 K下Li+,K+//CO2-3,B4O2-7-H2O四元体系的相平衡

Solubilities and properties (density, conductivity and pH value) of solutions in the quaternary system Li⁺,K⁺//CO^2-₃,B₄O^2-₇-H₂O at 288 K were experimentally studied with the isothermal equilibrium method. The phase diagram of the system consisted of two invariant points E and F, five univariant curves, and four crystallization fields that belonged to K₂CO₃·3/2H₂O,Li₂B₄O₇·3H₂O,K₂B₄O₇·4H₂O and Li₂CO₃. The composition of the solution corresponding to E was w（CO^2-₃）=2.27 %,w（B₄O^2-₇）=6.05 %,w（K⁺ ）=4.30%,w(Li⁺)=0.30 % and the equilibrium solids were Li₂B₄O₇· 3H₂O+K ₂B₄O₇·4H₂O+Li₂CO₃;The composition of the solution for F was w(CO^2-₃)=22.45%,w(B₄O^2-₇)=1.88%,w(K⁺ )=29.96%,w(Li⁺ )=0.03% and the equilibrium solids were K₂CO₃·3/2H₂O+K ₂B₄O₇·4H₂O+Li₂CO₃. K₂CO₃ possesses strong salting-out effect on K₂B₄O₇,Li₂CO₃ and Li₂B₄O₇.     

乙烯酮(双乙烯酮)下游产品废水的治理技术

乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。     

Semi-empirical equation of state of metals. Equation of state of aluminum

A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO₂) of density 0.08 g/cm³. __________ Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008.     

水泥水化热测定方法综述

水泥水化热是中、低热水泥和核电工程用水泥的一项关键的技术指标。全球范围内测定水泥水化热的方法有溶解法、直接法/半绝热法、等温传导量热法三种。本文总结了中、美、欧相关方法标准,对其测试原理、仪器设备、试验过程等方面进行了比对,并对其在领域的应用做了简单的概括。     

我国聚碳酸酯工业发展概况

介绍我国聚碳酸酯生产能力和消费需求,对聚碳酸酯在信息工业中的应用作了简短介绍     

Calorimetric and Computational Study of Enthalpy of Formation of Diperoxide of Cyclohexanone

A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out.     

Effect of degree of deacetylation of chitosan on the kinetics of ultrasonic degradation of chitosan

The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003     

气化给煤系统故障分析

气化给煤装置自投运以来,出现了气化煤仓堵煤、称重给煤机输送皮带因跑偏而损伤以及清扫装置故障频繁等问题,多次造成气化系统减负荷运行。通过对出现的各种问题进行分析,找到了产生这些问题的原因,并有针对性地采用配煤和改进清扫链等措施,使出现的问题得到了极大的改善。     

醋酸纤维素取代基分布与性质的关系

分析了以吡啶为溶剂的醋酸纤维素的13C-NMR核磁共振谱,得出了三种不同位置羟基的取代度。结合X—射线和DSC分析,初步说明具有相同取代度但未经水解和经过水解的醋酸纤维素(CA) 性质上的差异是由于三个羟基上的取代度分布不同及消晶程度差异所致。     

Generalization of vdW type of equations of state

1 INTRODUCTIONBecause of importance of equations of state (EOS)in science and industry,hundreds forms of EOS havebeen presented since latter 19th century.It seems impossible to develop a general equation covering vari-ous kinds of EOS.But for cubic EOS,several generalequations have been reported already. Martin presented the first general equation whichis following p=RT/V-α(T)/(υ β)(υ γ) δ(T)/υ(υ β)(υ γ) (1) Kumar et a1.presented an equation called the most general form of a density-cubic or, alterna tively,volume-cubic mathematical equation,the form of which is as follows     

船舶柴油机涡轮增压器的清洗

采用喷射清洗剂的方法，清洗涡轮叶片积炭。