Small range 文档类型:"3"

Totally found 4700 items.

  • [期刊] TritonX-100/正己醇/环己烷反相微乳液合成堇青石纳米粉体及其性能研究
    以Al(NO3)3·9H2O、Mg(NO3)2·6H2O和TEOS为前躯体原料,采用TritonX-100/n-Hexane/ Cyclohexane作为乳液反应体系合成了堇青石(2MgO· 2Al2O3·5SiO2)纳米粉体.采用目测法对形成稳定W/O型微乳液体系的拟三元相图进行了测试与绘制.结果表明:该粉体有效粒径为100nm,粉体团聚度较低,可于930℃下低温烧结,烧结体具有较高的致密度(大于理论密度的98%);烧结过程中a-堇青石直接从无定形态中析出;920℃烧结2h的陶瓷样品具有良好的介电性能(ε=2.87,tanδ=0.00011;1GHz),该材料具备与Ag电极低温共烧的条件,是应用于高频片式电感等电子元器件的理想介质材料.
  • [期刊] Nonisothermal Crystallization Kinetics of Poly(phenylene sulfide)/Poly(ethylene-co-cyclohexane 1,4-dimethanol terephthalate) Blend
  • [期刊] Study on Morphology and Non-isothermal Crystallization Behavior of Poly(phenylene sulfide)/Poly(ethylene-co-cyclohexane 1,4-dimethanol terephthalate) Blend
  • [期刊] Phase equilibria in the systems cyclohexane+2,2,4-trimethylpentane and ethyl 1,1-dimethylethyl ether plus cyclohexane+2,2,4-trimethylpentane at 94.00 kPa
    Consistent vapor-liquid equilibria data at 94 kPa have been determined for the ternary system ethyl 1,1-dimethylethyl ether + cyclohexane + 2,2,4-trimethylpentane and for its constituent binary cyclohexane + 2,2,4-trimethylpentane, in the temperature range 343 to 369 K. According to the experimental results, the systems exhibit slight positive deviations from ideal behavior and no azeotrope is present. The VLE data have been correlated with the mole fraction using the Redlich-Kister, Wilson, NRTL, UNIQUAC, and Wisniak-Tamir relations. These models, in addition to UNIFAC, allow good prediction of the VLE properties of the ternary system from those of the pertinent binary systems. [References: 24]
  • [期刊] Isobaric Vapor-Liquid Equilibrium for Two Binary Systems of 3,3-Dimethyloxetane plus Methyl Cyclohexane and 3-Chloro-2,2-dimethyl-1-propanol + Methyl Cyclohexane at 101.3 kPa
    The binary vapor-liquid equilibrium (VLE) data at the pressure of 101.3 kPa, which are 3,3-dimethyloxetane + methyl cyclohexane and 3-chloro-2,2-dimethyl-1-propanol + methyl cyclohexane, have been measured using a modified Rose vapor-recirculating equilibrium still. The reliability of VLE data was verified by thermodynamic consistency of area test of Herington and point test of Van Ness. The experimental data were regressed with activity coefficient models of Wilson, nonrandom two-liquid, and UNIQUAC, respectively, and the corresponding binary interaction parameters were obtained using the maximum likelihood method. The root-mean square deviations between calculated and experimental data for the vapor phase molar fraction and equilibrium temperature were less than 0.0119 and 0.58 K, which indicated that the fitted results for the three models were within acceptable limits.
  • [期刊] Dispiro[cyclohexane-1,1'-(1',7'-dihydrocyclopenta[f]azulenium)-7', 1"-cyclohexane] perchlorate, a new highly stable hydrocarbon cation
    The title cation was synthesized from 1,6-diacetylcyclohepta-1,3,5-triene by a six-step sequence involving an aldol reaction, the Nazarov cyclization, the Shapiro reaction and hydride abstraction, and its pK_(R+) value was found to be 13.2, providing a new access to highly stable hydrocarbon cations.
  • [期刊] Phase equilibria and interfacial tensions in the systems methyl tert-butyl ether plus acetone plus cyclohexane, methyl tert-butyl ether plus acetone and methyl tert-butyl ether plus cyclohexane
    Isobaric vapor-liquid equilibrium (VLE) data have been measured for the ternary system methyl tert-butyl ether + acetone + cyclohexane. and for its methyl tert-butyl ether based binaries, at 94 kPa and in the temperature range 323-340 K. Equilibrium determinations were performed in a vapor-liquid equilibrium still with circulation of both phases. The dependence of interfacial tensions of these mixtures on concentration was also determined, at atmospheric pressure and 303.15 K, using the maximum bubble pressure technique. From the experimental results, it follows that the investigated mixtures exhibit positive deviation from ideal behavior and azeotropy is present for the methyl tert-butyl ether + acetone system at 94 kPa. The application of a model-free approach allows concluding about the reliability of the present vapor-liquid equilibrium data for all the indicated mixtures. Furthermore, the determined interfacial tensions exhibit negative deviation from linear behavior for all the analyzed mixtures. The vapor-liquid equilibrium data of the binary mixtures were well correlated using the NRTL, Wilson and UNIQUAC equations, while their interfacial tensions were smoothed using the Redlich-Kister equation. Scaling of these models to the ternary mixture allows concluding that both the VLE data and the interfacial tensions can be reasonably predicted from binary contributions.
  • [期刊] Synthesis and assessment of compounds trans-N,N-bis(9-phenyl-9-xanthenyl)cyclohexane-1,4-diamine and trans-N,N-bis(9-phenyl-9-thioxanthenyl)cyclohexane-1,4-diamine as hosts for potential xylene and ethylbenzene guests
    In this work, two novel compounds, trans-N,N-bis(9-phenyl-9-xanthenyl)cyclohexane-1,4-diamine 1 and trans-N,N-bis(9-phenyl-9-thioxanthenyl)cyclohexane-1,4-diamine 2, were designed and successfully synthesized in our laboratories, and assessed for their host potential in the presence of potential xylene (Xy) isomer and ethylbenzene (EB) guests. Host 1 successfully formed complexes with all four of o-Xy, m-Xy, p-Xy and EB, while 2 only clathrated p-Xy and EB. Equimolar guest/guest competition experiments showed that hosts 1 and 2 possess very similar selectivities for these guests [p-Xy (73.9%)>EB (13.0%)>m-Xy (8.1%)>o-Xy (5.0%) and p-Xy (71.3%)>EB (20.2%)>m-Xy (6.0%)>o-Xy (2.5%) for 1 and 2, respectively]. Single crystal diffraction analyses revealed striking geometry changes for the sulfur host analogue: while the tricyclic fused ring system of the oxygen host remained planar when guest was absent or present, this fused system of the sulfur analogue experienced a dramatic geometry change from buckled (in the absence of guest) to planar (in guest presence). This observation explained the selectivity similarities of both hosts in the presence of these guests. Additionally, the relative thermal stabilities of the four complexes with host 1 were assessed by employing thermal analyses, and the results of these correlated exactly with the selectivity order, since the onset temperature of the guest release processes (T-on) was in the order p-Xy (88.0 degrees C)>EB (70.9 degrees C)>m-Xy (59.7 degrees C)>o-Xy (46.2 degrees C). T-on values also explained the significant preference of host 2 for p-Xy (115.5 degrees C) relative to EB (76.6 degrees C), respectively.
  • [期刊] Vapor-liquid equilibrium of ternary mixtures containing methyl tert-butyl ether and/or substitution hydrocarbons. Methyl tert-butyl ether plus heptane plus cyclohexane and methyl tert-butyl ether plus cyclohexane plus 1-hexene at 313.15 K
    Experimental isothermal P-x-y data for the ternary systems methyl tert-butyl ether + heptane + cyclohexane and methyl tert-butyl ether + cyclohexane + l-hexene at 313.15 K and for the binaries cyclohexane + heptane and cyclohexane + l-hexene at 313.15 K are reported. Data reduction by Barker's method provides correlations for GE, using the Margules equation for the binary systems and the Wohl expansion for the ternaries. Wilson, NRTL, and UNIQUAC models have been applied sucessfully to both the binary and the ternary systems presented here. [References: 20]
  • [期刊] Measurement and correlation of vapor-liquid equilibra for cyclohexane + ethylene glycol monoisopropyl ether and cyclohexane + ethylene glycol monoisobutyl ether systems
    Ethylene glycol monoisopropyl ether (iC3E1) and ethylene glycol monoisobutyl ether (iC4E1) are nonionic surfactants which have been attracting considerable attention due to inter and intra-molecular association, related to the presence of 0 and OH in the same molecule. Binary isothermal vapor + liquid equilibrium data were measured for cyclohexane + ethylene glycol monoisopropyl ether and cyclohexane + ethylene glycol monoisobutyl ether systems at four different temperatures ranging from 303.15 K to 333.15 K at 10 K intervals. A static apparatus was used in this study. Two systems show positive deviation from Raoult's law and no azeotrope. The experimental data were correlated well with Peng-Robinson-Stryjek-Vera equation of state using Wong-Sandier mixing rule.