从玫瑰花渣中提取玫瑰精油的技术研究

玫瑰鲜花用水蒸气蒸馏提取玫瑰油后,玫瑰花渣中还残留相当多的玫瑰精油。新鲜的玫瑰花渣经离心脱水后,用有机溶剂浸提,经浓缩、纯化,得到浓缩液,然后用分子蒸馏分离,可将花渣中残留的玫瑰精油提取出来。分子蒸馏采用二级蒸馏法。分子蒸馏脱除残留溶剂时,预热温度40℃,真空度10Pa,蒸馏柱温度45℃,蒸馏速度1.0mL/min,刮膜机转速300r/min;分子蒸馏脱除高分子物质时宜采用预热温度60℃,冷却温度25℃,蒸馏柱温度120℃,真空度1.0Pa,蒸馏速度1.0mL/min,刮膜机转速300～350r/min。     

分子蒸馏处理丁香亚临界萃取物制备烟用香料

为了更好的精制丁香亚临界萃取物,采用分子蒸馏技术对亚临界制备的丁香油进行分离,并对馏分进行GC/MS分析。实验表明,分子蒸馏能很好地脱除色素,分离出高级脂肪酸等不溶于酒精的成分。另外,作为烟用香料最好的丁香油分子蒸馏处理工艺为蒸馏压力10Pa,物料流速6mL/min,刮板转速400r/min,蒸馏温度45℃。     

草甘磷废水预处理实验研究

采用多效氧化偶联蒸馏-强制性电化学反应工艺对草甘膦废水进行预处理实验研究；实验过程中研究了直接蒸馏与多效偶合催化氧化蒸馏相对比的方法,探讨出氧化偶联蒸馏与直接蒸馏的区别；并采用强制性电化学反应后废水B/C值大大提高,为后续生化反应奠定了良好的基础.强制性电化学反应考察了电解时间与B/C的关系,废水COD与电解时间的关系,pH值与COD之间的关系等.     

分子蒸馏技术分离纯化橘皮油中苧烯的研究

为探讨用分子蒸馏技术从橘皮油中提取高品质苧烯的最优工艺条件,采用二级蒸馏分离,以苧烯的得率和纯度为考察指标,在单因素试验的基础上,采用L_9(3~4)正交试验来确定蒸馏压力、蒸馏温度、进料速度、刮膜转速四个因素的最佳组合工艺条件。在二级分子蒸馏选择蒸馏压力为40 Pa,进料速度1.5 mL/min,蒸馏温度为80℃,刮膜转速为280 r/min的条件下,可获得纯度高达99%,得率达到86.54%的苧烯。该工艺操作稳定可靠,便于控制,环保且易于实现工业化。     

基于分子蒸馏的丙硫醚提纯工艺研究

采用分子蒸馏技术对市售的丙硫醚进行了分离提纯，考察了分离提纯的刮膜速度、蒸馏温度和蒸馏压力对丙硫醚纯度的影响，经过单因素分析，通过设计L₉(3⁴)正交实验，得到了分子蒸馏分离提纯丙硫醚的最佳工艺参数。     

从山苍子油中提取柠檬醛新工艺的研究

采用分子蒸馏技术对从天然产物山苍子油中分离纯化柠檬醛工艺条件进行研究.结果表明:在蒸馏压力0.2 kPa、蒸馏温度45 ℃、物料流量1滴/s、刮膜蒸馏转速370～390 r/min、冷却水温度4～5 ℃,提取的柠檬醛质量分数可达到95.08%,收率为80.02%.经过二次分子蒸馏可得到纯度为100%的柠檬醛.     

利用MD技术纯化玫瑰精油的正交实验研究

超临界CO2萃取所得的玫瑰粗油含蜡质较高,影响品质,采用无毒、无害、高效的分子蒸馏技术对其进行脱蜡,避免了传统有机溶剂法对精油品质的破坏,精油得率可达20.6%。正交实验表明分子蒸馏法提纯玫瑰精油最佳工艺条件为：蒸馏压力3.0Pa、蒸馏温度110℃、物料流量2mL/min、刮膜转速480r/min。     

C_9石油树脂装置的技术改造

对原C9石油树脂装置进行改造设计 ,将乙烯裂解C9馏分的处理量由 1万t/a扩大到 3万t/a ,同时提高了产品的质量。将原料预处理部分的间歇反应蒸馏工艺改造为连续蒸馏工艺 ,深色C9芳烃石油树脂仍采用间歇减压反应蒸馏工艺 ,而浅色C9芳烃石油树脂采用釜式连续聚合工艺。另外 ,浅色C9芳烃石油树脂及芳烃溶剂油的分离采用两级闪蒸工艺分离。     

分子蒸馏法提高丁香花蕾油品质的工艺研究

乙酸丁香酚酯含量的高低是衡量丁香花蕾油品质的重要参考指标。采用分子蒸馏技术对丁香花蕾油进行纯化,得到乙酸丁香酚酯含量更高的产品。采用单因素试验确定蒸馏温度、进料速度、蒸馏压力及刮膜转速的操作范围,并用正交试验法优化分子蒸馏技术纯化丁香花蕾油的最佳工艺参数。得到的优化工艺参数为:蒸馏温度95℃、进料速度500 g/h、蒸馏压力100 Pa及刮膜转速400 r/min,在此工艺条件下,产品中乙酸丁香酚酯的质量分数由9.13%提高到49.23%,得油率为5.6%。该工艺稳定、可行,易于实现工业化生产。     

分子蒸馏技术纯化玫瑰精油工艺研究

超临界CO2萃取所得的玫瑰粗油含蜡质较高,影响品质,采用无毒、无害、高效的分子蒸馏技术对其进行脱蜡,避免了传统有机溶剂法对精油品质的破坏,精油得率可达20.6%.正交试验表明分子蒸馏法提纯玫瑰精油最佳工艺条件为: 蒸馏压力3.0 Pa、蒸馏温度110℃、物料流量2 mL/min、刮膜转速480 r/min.     

Some Properties of the Oxides of Vanadium and Their Compounds

Vanadium tetroxide and vanadium pentoxide were prepared and some of their physical properties were measured. A brief survey was then made of some of their binary oxide compounds. Various mixtures of V₂O₄ or V₂O₆ and BeO, MgO, CaO, SrO, BaO, Al₂O₃, SiO₂, TiO₂, CeO₂, ZrO₂, Nb₂O₆, and U₃O₈ were heated. When compounds were formed, some of their properties were determined. Refractoriness, thermal expansion, and optical properties were considered of special interest. Vanadium pentoxide was found to have a linear thermal expansion of only 0.63 × 10⁻⁶ per °C. from 30° to 450°C.     

Growth and Properties of Single Crystals of Hexagonal Ferrites

Single crystals of hexagonal ferrites up to 1/2 in. long were grown from the system NaFeO₂-Fe₂O₃-BaO-MeO, where Me = divalent Zn, Co, Ni, or Mg. NaFeO₂ was the flux from which crystals were grown in platinum crucibles from a maximum temperature of 1250° to 1375°C. More than 150 single-crystal growth experiments were attempted and the reaction products were studied by X-ray diffraction and optical microscopy. Stability data for the principal single-crystal products are given for initial compositions lying in quaternary planes. Such planes were considered for BaO/MeO ratios corresponding to the compounds 1/1 for Ba₂Me₂Fe₁₂O₂₂ (Y) and Ba₂Me₂Fe₂₈O₄₆ (X) , 3/2 for Ba₃Me₂Fe₂₄O₄₁ (Z) , 2/1 for Ba₄Me₂Fe₃₆O₆₀ (U) , and 1/2 for BaMe₂-Fe₁₆O₂₇ (W) (Me = Zn, Co, Ni, or Mg). A number of adjoining planes were also considered. All the five known structure types were grown as single crystals. A series of four new hexagonal ferrite structures was discovered. These were derived from Z by systematically adding blocks of Y. Magnetization as a function of temperature and field was investigated for crystals of two structure types. The room-temperature ferromagnetic resonance and effective anisotropy were studied for substituted crystals of the same two structure types.     

Effect of composition and processing on rheological properties of multicomponent polymer melts

Polyamide and polyether maleic anhydride were blended with carbon black at various compositions and processing conditions. The compositions were varied from 0/92/8 percent, 23/69/8 percent, 46/46/8 percent, 69/23/8 percent to 92/0/8 percent of polyamide/polyether maleic anhydride/carbon black. The polymer blends were processed by a Banbury roll mill and an extruder under various conditions and were spray dried. The effects of composition and processing conditions on steady state and dynamic viscoelastilc properties were determined. These effects were compared with the thermal and morphological properties of the blends.     

温度影响印楝素A及同系物降解动力学研究

研究温度对印楝素A、6-deacetylnimbin、6-deacetylsalannin、nimbin和salannin 5种同系物稳定性的影响。建立在不同温度条件下印楝素A及同系物的一级降解动力学模型,计算印楝素A及同系物降解反应的反应速率常数、温度效应系数(Q)、活化能(Ea)、活化焓(?H)和活化熵(?S)。结果表明,印楝素A及同系物在25℃条件下较为稳定,大于35℃时降解速率明显增大。印楝素A、6-deacetylnimbin、6-deacetylsalannin、nimbin和salannin 5种同系物的活化能分别为98.49kJ/mol、92.43kJ/mol、96.76kJ/mol、95.23kJ/mol和104.79kJ/mol,活化焓分别为95.84kJ/mol、89.78kJ/mol、94.11kJ/mol、92.58kJ/mol和102.14kJ/mol,活化熵分别为10.68kJ/mol·K、1.60kJ/mol·K、19.58kJ/mol·K、4.76kJ/mol·K和27.32kJ/mol·K。印楝素A及同系物在环境中的降解反应是自发反应,在环境中易自然降解。     

Surface Roughness of Yttria-Containing Aluminosilicate Glass-Ceramics as Indicative of Their Machinability

Several series of Y₂O₃-containing aluminosilicate glasses were prepared by an ordinary melting method, and their physical properties, such as density and Vickers hardness, were measured. Heat treatment of these glasses at 1200°C precipitated tubular and hexagonal Ca₄Y₆O(SiO₄)₆ oxyapatite crystals which were characterized by scanning electron microscopy and X-ray diffraction analysis. The homogeneously crystallized glass-ceramics were lathed, and the machinabilities of these samples were estimated by measuring the lathed surface roughness. Then, the relationship between surface roughness and other properties was analyzed to optimize the glass composition. Substitution of BaO for CaO was conducted and the physical properties were examined.     

Characterization of Alkoxy-Derived Yttria-Stabilized Hafnia

High-purity submicron HfO₂−Y₂O₃ powders were prepared by the simultaneous hydrolytic decomposition of hafnium and yttrium alkoxides. Compositions of 1 to 7 mol% Y₂O₃ in HfO₂ were studied by high-temperature X-ray diffraction, electron microscopy, BET surface area measurements, emission spectrographic analysis, TGA, and DTA. X-ray diffraction and atomic absorption were used to determine the Y₂O₃ concentration. Hot-pressing or cold-pressing and sintering of the powders resulted in nearly theoretically dense bodies with uniform microstructure containing grains 1 to 5 μm in size. Surface reflection ir spectra were obtained for monoclinic, tetragonal, and cubic specimens. Fully cubic HfO₂ with 7 mol% Y₂O₃ additions was obtained at a relatively low temperature. The hot-pressed specimens, initially slightly oxygen-deficient or gray HfO_{2- x} , were reoxidized at 1000°C with no deleterious effects; thin sections were translucent to incident light.     

Effect of carrier type on coupled transport kinetics of thiocyanate ions through liquid membranes

Coupled transport of thiocyanate ions through a liquid membrane containing quaternary ammonium chloride salts in chloroform was examined. The influences of the carrier type in the membrane phase on the coupled transport of thiocyanate ions were investigated. The kinetics of the coupled transport were analyzed in the formalism of two consecutive irreversible first-order reactions and the kinetic parameters (k_1d, k_2m, k_2a, R_m^max, t_max, J_d^max, J_amax) were also calculated. For the coupled transport of thiocyanate ions, quaternary ammonium chloride salts having different carbon atom numbers (C_n) used as carriers were found to increase thiocyanate ions transport efficiency with increasing carbon atom numbers. Tetradecyl trimethylammonium chloride (TDTMACl), hexadecyl trimethylammonium chloride (HDTMACl), and tetraoctyl ammonium chloride (TOACl) were found to be the most effective carrier types for transport of thiocyanate ions when C_n is greater than 16. The activation energies for maximum membrane entrance and exit fluxes were calculated as 32.45 kJ/mol and 34.75 kJ/mol, respectively. The values of the activation energy indicate that the process is controlled by species diffusion.     

含能材料合成中的氮链扩增方法

综述了含能材料合成中的氮链扩增化学反应方法,总结了氮-卤键的叠氮化取代、叠氮离子的电催化氧化、伯胺重氮转移、二氮烯的二聚、N氨基化及硝化、氨基氧化偶联、氨基重氮偶联等共性反应,介绍了典型氮链扩增反应的机理。重点讨论了N₅⁺、[N₇O]⁺、N^-₈等离子型氮链,以及具有N₃/N₄/N₅/N₆/N₇/N₈/N₁₀/N₁₁链等全氮片段的有机化合物的结构演进过程,提出了N^-₇、N₁₀、N₁₂长氮链化合物的可能合成路线,最后提出了该领域后续发展的趋势和建议。附参考文献65篇。     

锰氧化物制备及其对锰和氨氮的去除研究

为制备具有优艮吸附性能的材料,采用高锰酸钾氧化(分别在酸性条件和中性条件下进行)和空气自然氧化水中2价锰,制备了3种锰氧化物(ORIG-MnOx、Na2CO3-MnOx、O2-MnOx),对其结构进行了表征,并探究了对水中NH4+-N和Mn2+污染的去除特性及影响因素.结果表明,所制备的ORIG-MnOx与Na2CO3...     

Constrained Densification of Alumina/Zirconia Hybrid Laminates, I: Experimental Observations of Processing Defects

Various forms of damage were observed in pressure-less-sintered Al₂O₃/ZrO₂symmetric laminates and asymmetric laminates (bilayers) fabricated by tape casting and lamination. These defects included channel cracks in the ZrO₂ layers, Al₂O₃ edge-effect cracks parallel to the layers, delamination in the Al₂O₃layers, and debonding between the Al₂O₃and ZrO₂layers. Based on detailed microscopic observations, the defects were attributed to sintering rate and thermal expansion mismatch between the layers. Cracks or cracklike defects were formed in the early stages of densification, and these cracks either opened during sintering or acted as preexisting flaws for thermal expansion mismatch cracks. Consequently, the extent of cracking could be reduced or even eliminated by decreasing mismatch stresses during the sintering and cooling stages. This can be accomplished by reducing the heating and/or cooling rates or by adding Al₂O₃in the ZrO₂layers. The sintering mismatch stresses were estimated from the degree of curling in asymmetric laminates and from layer viscosities that were obtained by cyclic loading dilatometry. The measured curvature was an indication of the mismatch in sintering strain between Al₂O₃and ZrO₂and were consistent with the dilatometric data that were obtained for the component layers.