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101.
Yanan Wu Ling Zhou Xia Zhang Junbo Gong Hongxun Hao Qiuxiang Yin Zhao Wang 《Journal of solution chemistry》2018,47(5):950-973
The solubilities of acetylpyrazine in seven pure solvents and one binary solvent mixture were determined by a dynamic analytic method at temperatures ranging from 268.15 to 308.15 K under atmospheric pressure. For pure solvents, the solubility of acetylpyrazine increases with increasing temperature and solvent polarity. For the binary solvent mixture of ethyl acetate and isopropanol, the solubility increases with increasing temperature and mole fraction of ethyl acetate. The solubility data were correlated with some thermodynamic models, including the modified Apelblat model, λh model, CNIBS/R-K model, and NRTL model. In addition, the relationship between solubility and solvent polarity was investigated by using the Arrhenius equation. All the models or equations gave satisfactory correlation results. The results showed that the solubility of acetylpyrazine generally rises with the increase of solvent polarity at the same temperature. Moreover, the dissolution thermodynamic properties of acetylpyrazine in different solvents were calculated and are discussed based on the NRTL model. 相似文献
102.
Xiuting Chen Qingnuan Li Yu Gong 《Journal of the American Society for Mass Spectrometry》2018,29(12):2327-2332
Ligated tetrapositive metal ions are rare gas-phase species which tend to form complexes with lower charges due to the high 4th ionization energies of metals. We report the observation of tetrapositive Zr(TMPDA)34+ and Zr(TMOGA)34+ complexes in the gas phase by electrospray ionization of Zr(ClO4)4/TMPDA and Zr(ClO4)4/TMOGA mixtures. The Zr4+ center in both complexes is coordinated by nine atoms from three neutral diamide ligands forming nine-coordinate twisted tricapped trigonal prismatic geometry on the basis of DFT calculations. Collision-induced dissociation of both complexes resulted in the loss of protonated ligands to form tripositive Zr(TMPDA)(TMPDA-H)3+ and Zr(TMOGA)(TMOGA-H)3+ products which retain the IV oxidation state of zirconium at the cost of charge reduction from 4+ to 3+ of the whole complexes. The very high 4th ionization energy of zirconium (34.34 eV) makes tetrapositive zirconium complex the most challenging tetracation to be stabilized against charge reduction in the gas phase to date. 相似文献
103.
Influence of Functional Groups and Modi cation Sites of Metal-Organic Frameworks on CO2/CH4 Separation: A Monte Carlo Simulation Study 下载免费PDF全文
In order to explore the in uence of modification sites of functional groups on landfill gas (CO2/CH4) separation performance of metal-organic frameworks (MOFs), six types of organic linkers and three types of functional groups (i.e. -F, -NH2, -CH3) were used to construct 36 MOFs of pcu topology based on copper paddlewheel. Grand canonical Monte Carlo simulations were performed in this work to evaluate the separation performance of MOFs at low (vacuum swing adsorption) and high (pressure swing adsorption) pressures, respectively. Simulation results demonstrated that CO2 working capacity of the unfunctionalized MOFs generally exhibits pore-size dependence at 1 bar, which increases with the decrease in pore sizes. It was also found that -NH2 functionalized MOFs exhibit the highest CO2 uptake due to the enhanced Coulombic interactions between the polar -NH2 groups and the quadrupole moment of CO2 molecules, which is followed by -CH3 and -F functionalized ones. Moreover, positioning the functional groups -NH2 and -CH3 at sites far from the metal node (site b) exhibits more significant enhancement on CO2/CH4 separation performance compared to that adjacent to the metal node (site a). 相似文献
104.
105.
Guo Xue Feng Yurun Ma Li Yu Jincheng Jing Jie Gao Dezhi Khan Adil Saleem Gong Hongyu Zhang Yujun 《Journal of Radioanalytical and Nuclear Chemistry》2018,317(1):397-407
Nickel hydroxide solubility has been studied in this work in different cementitious systems. Our results indicate that once Glenium® 27, cement superplasticizer admixture, is added to water and then mixed with cement, this polymeric material is stabilized and not released back to the aqueous solution, with negligible effects on the mobility of nickel. Contrary to that, when Glenium® 27 is added directly in solution at high dosages, an important effect is observed on nickel behaviour. Thermodynamic calculations indicate that the effect of such component on Ni is likely the effect that other small organics could have over this element.
相似文献106.
Jin Kai Li Baowei Wang Kaixing Luo Huijuan Gong Zhijun Wu Wenfei 《Research on Chemical Intermediates》2018,44(11):6933-6943
Research on Chemical Intermediates - A rare-earth concentrate obtained from Bayan Obo tailings was used as catalyst for low-temperature selective catalytic reduction (SCR) of NOx. X-ray powder... 相似文献
107.
Yong-Hui Zhang Chun-Yan Liu Bei-Bei Jiu Yong Liu Fei-Long Gong 《Research on Chemical Intermediates》2018,44(3):1569-1578
ZnO and Pd nanoparticles (NPs) with average diameter of 38 and 10 nm were prepared in advance through a chemical solution method. Pd-functionalized ZnO nanoparticles (Pd@ZnO) were simply synthesized by adding ethanol solution of Pd NPs into ZnO powder, and annealing in argon atmosphere at 500 °C for 1 h after grinding for 30 min. The morphology and structure of the materials were systemically analyzed using Brunauer–Emmett–Teller (BET), X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) techniques. A weak peak in the XRD pattern of Pd@ZnO belonging to the (111) plane of elemental Pd indicated successfully loading of Pd. EDS and TEM results further confirmed successfully coating of Pd NPs onto the surface of ZnO. Sensors using ZnO NPs decorated with Pd (1 wt%) on the surface of exhibited highly elevated sensitivity of 76 in comparing with the response of 36 when based on pure ZnO NPs. In addition, such modification also resulted in a decrease in the operating temperature from 370 to 340 °C for 100 ppm acetone vapor. The sensing mechanism of the sensor based on Pd@ZnO NPs is discussed. Addition of Pd NPs can play an important role in improving the performance of gas sensors, including high sensitivity, good selectivity, and short response/recovery times. 相似文献
108.
Xiaoyu Chen Yushuang Liu Guangying Chen Chi Gong Shengge Li Huiming Hua Tao Yuan 《Tetrahedron letters》2018,59(26):2610-2613
A novel macrocyclic flavonoid glycoside, angustifolinoid A (1), featuring an unprecedented 13-membered heterocyclic ring moiety, along with a known flavonoid glycoside, tiliroside (2), were isolated from Elaeagnus angustifolia flowers. Their structures were determined by extensive spectroscopic analysis and electronic circular dichroism (ECD) calculation. Biosynthesis analysis indicated that compound 1 might be derived from compound 2 via a key enzymatic intramolecular oxidative coupling. Compounds 1 and 2 showed inhibitory activities against cyclooxygenases, COX-1 and COX-2. 相似文献
109.
Junyi Gong Peifa Wei Yuanan Su Ying Li Xing Feng Jacky W. Y. Lam Dongzhou Zhang Xiangzhi Song Ben Zhong Tang 《中国化学快报》2018,29(10):1493-1496
Three salicylaldehyde Schiff base (SSB) with AIE behavior were designed and facilely synthesized through a condensation reaction. In solid and aggregation states, these SSB dyes exhibited yellow to red emission with large Stokes shift. One of SSB dyes could specifically stain lipid droplets in living cells. 相似文献
110.
Baibai Liu Xinjuan Liu Lei Li Jianwei Li Can Li Yinyan Gong Lengyuan Niu Xinsheng Zhao Chang Q. Sun 《催化学报》2018,39(12):1901-1909
Development of efficient heterostructured photocatalysts that respond to visible light remains a considerable challenge. We herein show the synthesis of ZnIn2S4/carbon quantum dot hybrid photocatalysts with flowerlike microspheres via a facile solvothermal method. The ZnIn2S4/carbon quantum dot flowerlike microspheres display enhanced photocatalytic and photoelectrochemical activity compared with that of pure ZnIn2S4. With a content of only 0.5 wt % carbon quantum dots, 93% of Cr(VI) is reduced under visible-light irradiation at 40 min. As a co-catalyst, the carbon quantum dots improve the light absorption and lengthen the lifetime of charge carriers, consequently enhancing the photocatalytic and photoelectrochemical activity. 相似文献