文献检索
检索与阿拉丁产品相关的同行评审论文、DOI、PubMed 编号、期刊、作者、CAS 号及研究领域。
科研影响力快照
在搜索之前,这些指标可帮助访客快速了解产品关联科研的规模与质量。
参考指标 指标基于阿拉丁文献引用数据库及期刊影响因子记录。文献关联仅供科研参考,请以原始文献为准。
Recently, the incorporation of hydrophobicity on the surface of UiO-66(Zr) has received much attention due to the deactivation of hydrophilic active sites of UiO-66(Zr) upon water adsorption. In this work, we report UiO-66(Zr) catalysts with an assortment of surface hydrophobicities fabricated by the solvent-free method to elucidate the impact of the environment framing Lewis acid sites on their catalytic activity in the production of fatty acid methyl ester (biodiesel) via the esterification of fatty acids at room temperature with high selectivity (100%) and good recyclability. A detailed structural analysis of the materials by N2 sorption, FT-IR, SEM, XRD, water contact angle measurement, dynamic liquid scattering (DLS), NMR and TGA revealed the fabrication of stearic acid-grafted UiO-66(Zr) catalysts (10SA/UiO-66) with fine particle size and a highly hydrophobic network. 10SA/UiO-66(Zr) with enhanced hydrophobicity exhibited superior catalytic performance in the esterification of a fatty acid with a long alkyl chain compared with conventional solid acid catalysts and even liquid acid catalysts. Detailed kinetic studies corroborated that the adsorption of lipophilic acids at the Lewis acid sites besides the enhancement of wettability between the reactants was facilitated by the hydrophobic environment, thus significantly motivating the esterification reaction at room temperature. Furthermore, 10SA/UiO-66(Zr) showed good catalytic activity in the esterification of oleic acid in the presence of water (∼10% in the light of acid weight).
The solid–liquid phase equilibrium solubility of doxycycline hyclate (DH) in 10 pure organic solvents and cosolvent mixtures DMF (1) + ethanol (2), DMSO (1) + ethanol (2) and acetone (1) + ethanol (2) at a temperature range from 278.15 to 323.15 K was measured and discussed. The results indicated that the experimental mole fraction (x) of DH in 10 neat solvents followed this order: acrylic acid > acetic acid > 1-butanol > 1-pentanol > tetrahydrofuran > isobutyl alcohol > isopropyl alcohol> propanoic acid > acetone > acetonitrile, and temperature affected obviously the solubility especially in acetic acid. Moreover, the experimental mole fraction (x) of DH increased with mass concentration rising of DMF or DMSO in DMF (1) + ethanol (2) or DMSO (1) + ethanol (2), and decreased gradually with mass concentration rising of acetone in acetone (1) + ethanol (2). The experimental solubility in all solvents was correlated better by the modified Apelblat model according to lower values of RAD and RMSD.
Phosphorus sulfide cage molecule based on P 4 S 3 was investigated for the first time as anode material for the storage of alkali metal ions (Li + , Na + , K + ). Such P 4 S 3 sample was obtained in a large scale by a simple heating reaction of low-cost rep P and S. X-ray diffraction refinement analysis indicates that P 4 S 3 sample possesses a defect rich molecule crystal structure with S/P atom ratio of 0.74. The P 4 S 3 anode delivered a high reversible capacity of 1266 mAh g −1 for lithium-ion batteries at 0.1 A g −1 and good cycling performance. Experimental results demonstrated that the P 4 S 3 anode undergoes a reversible Li-storage reaction of P 4 S 3 + 11 Li + + 11 e − ↔ 0.5 Li 4 P 2 S 6 + 3 Li 3 P during cycling. It also exhibited a high capacity of 1002 and 378 mAh g −1 at 0.1 A g −1 for Na + and K + storage, respectively. These properties suggest the promising application of P 4 S 3 anode in high energy batteries.
Brassinolide is a new environmental protection plant growth regulator. With the aim of knocking down selfcost and scale up agriculture market-place emulation, come what will manufacture method is adopted, the final step crystallization is significant for getting exclusive substances. The purpose of this study is to provide some authentic and general energetics data for the actual industrial production of brassinolide. In the research, the solid–liquid equilibrium of brassinolide in twelve pure solvents (tetrahydrofuran, dimethyl sulfoxide, ethanol, acetone, methanol, trichloromethane, acetonitrile, 1-butanol, isopropanol, xylenes, n-hexane and n-heptane) and three binary solvent mixtures (trichloromethane + tetrahydrofuran, acetonitrile + tetrahydrofuran and n-hexane + tetrahydrofuran) were tested by the circumstance of atmosphere pressure at range temperatures between 278.15 K and 323.15 K. Four models like the Buchowski–Ksiazaczak λh model, the modified Apelblat model, the Jouyban-Acree-van't-Hoff model and the Redich-Kister (CNIBS/R-K) model were employed to describe the change trend of solubility. On the groundwork of a series of data analysis, tetrahydrofuran is a better organic solvent and n-hexane can be applied as an effective anti-solvent when separating out brassinolides. These solubility data are very important for optimizing the extraction process and recrystallization of brassinolide.
High-efficiency and far-red light phosphors based on Mn 4+ -doped inorganic luminescence materials are beneficial to plant cultivation. However, Mn 4+ -doped oxide phosphors have a common problem of low quantum efficiency. Alkali metal ion codoping can effectively improve the luminescence properties of Mn 4+ -activated oxide phosphors. Herein, a series of Sr 2 InSbO 6 :Mn 4+ , M (SISO:Mn 4+ , M) (M = Li + , Na + , and K + ) far-red-emitting phosphors codoped alkali metal ions were first synthesized. Density functional theory calculation indicated that SISO is a kind of indirect bandgap material with a bandgap of ∼1.60 eV. The SISO:Mn 4+ samples showed a far-red light at 698 nm upon 365 nm, which perfectly matched the absorption spectrum of the far-red-phytochrome (Pfr) of plants. The doping concentration of the SISO:Mn 4+ samples was optimized to be 0.006 mol. The concentration quenching mechanism was defined as dipole–dipole interaction by combining the Dexter theory and the Inokuti–Hirayama model. Optimizing the sintering temperature and codoped with alkali metal ions (Li + , Na + , and K + ) could improve the luminescent intensity of SISO:Mn 4+ . The optimum sintering temperature was 1300°C. The internal quantum efficiencies of SISO:0.006Mn 4+ and SISO:0.006Mn 4+ , 0.006Li + phosphors are 22.67% and 60.56%, respectively. SISO:Mn 4+ , Li + phosphors-based plant growth light-emitting diodes (LEDs) demonstrate excellent optical stability and long lifetime. Thus, these phosphors are promising candidates for plant cultivation LEDs.
High-performance cyanate ester (CE) resins with excellent dielectric properties are highly desired in the fields of information and communication technology . Herein, we present an efficient strategy for the preparation of low- k and wave-transparent CE resins modified with a novel kind of bismaleimide (BMI) hollow polymer microspheres (BMI-HPPs). Benefiting from both the superior properties of BMI and the unique hollow structure, BMI-HPPs can serve as an effective modifier to reduce dielectric constant (ε) of the CE resins and simultaneously improve their toughness. There are plenty of pendant vinyl groups and unreacted maleimide groups on the surface of BMI-HPPs, which could effectively copolymerize with CE monomer , leading to a lower curing temperature and better interfacial compatibility. The BMI-HPPs/CE resin with 7.5 wt% BMI-HPPs exhibited minimum values of ε and dielectric loss (tanδ) (2.46, 0.006) at 16 GHz, much lower than those of the pristine CE resin (2.92, 0.018), and the corresponding wave transmission was 93.8%–97.1% in the frequency range of 15–18 GHz. Moreover, the modified CE resin showed a maximum impact strength of 18.8 kJ/m 2 at 5 wt% loading of BMI-HPPs, which is 64% higher than that of the pristine CE resin. Because of low- k dielectric properties, superior wave-transparent performance and highly enhanced toughness , the BMI-HPPs/CE resins have great potential in the fields of microelectronics and aerospace.
Methyl hexanoate, which was found to be the simplest methyl ester to present a strong cool flame behavior, is expected to be one of the main components of biodiesels. Details of the experimental speeds of sound in methyl hexanoate are scarce up to now. Therefore, the speed of sound in liquid methyl hexanoate was measured by the Brillouin light scattering method in the temperature range of 297.83–588.07 K and at pressures of up to 10 MPa. The relative uncertainty of the speed of sound experimental system is estimated to be less than 0.43%, and when considering the impurity of the sample, the relative uncertainty is 0.47%. The variation of the speed of sound with the temperature and pressure was analyzed. Besides, the correlation for the speed of sound as a function of temperature and pressure is presented based on the experimental data. The absolute average of relative deviation between the experimental data and the calculated results is 0.44%.
Owing to the outstanding catalytic performance for higher alcohol synthesis, Ga-Co catalysts have attracted much attention. In view of their unsatisfactory stability and alcohol selectivity, herein, K-modulated Co nanoparticles trapped in La-Ga-O catalysts were prepared by the reduction of La1−xKxCo0.65Ga0.35O3perovskite precursor. Benefiting from the atomic dispersion of all the elements in the precursor, during the reduction of La1−xKxCo0.65Ga0.35O3, Co nanoparticles could be confined into the K-modified La-Ga-O composite oxides, and the confinement of La-Ga-O could improve the anti-sintering performance of Co nanoparticles. In addition, the addition of K modulated parts of La-Ga-O into La2O3, which ameliorated the anti-carbon deposition performance. Finally, the addition of K increased the dispersion of cobalt and provided more electron donors to metallic Co, resulting in a high activity and superior selectivity to higher alcohols. Benefiting from the above characteristics, the catalyst possesses excellent activity, good selectivity, and superior stability.Keywords:perovskite-type oxide (PTO);cobalt;gallium;potassium;higher alcohols;syngas
Benzenesulfonamide (BSA) is known as an important chemical material and intermediate in chemical industry. Information concerning solid–liquid equilibrium of BSA in different solvents is essential for the development of its separation and reaction process. In this work, the equilibrium solubility of BSA in 16 neat solvents, namely, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, n-pentanol, isopentanol, acetone, ethyl acetate, acetonitrile, cyclohexanone, cyclopentanone, methyl acetate, ethyl formate, and dichloromethane was determined by a static gravimetric method within the temperature range of 273.15–324.45 K under atmospheric pressure. The solubility of BSA increases with the rising temperature in all selected solvents. The obtained solubility was mathematically represented by using the Apelblat model, λh equation, nonrandom two-liquid (NRTL) equation, and the Wilson equation in order to correlate the experimental data with the adjustable parameters. The dissolution properties of BSA, including Gibbs energy (ΔdisG), molar enthalpy (ΔdisH), and molar entropy (ΔdisS) were determined according to the Wilson model and the solubility data. Positive values of the dissolution enthalpy and entropy illustrated that the dissolution processes of BSA in these solvents are endothermic and entropy-driven.
The rapid rise of electrode impedance and capacity decay of Ni-rich layered cathode materials during high-voltage cycling are rooted in their severe structural degradation. Here we present a feasible strategy, anchoring ∼1 % K + into the Li + sites of LiNi 0.8 Co 0.15 Al 0.05 O 2 as an excellent structural stabilizer, to overcome aforementioned issues, and the similarities and differences in terms of modification mechanism is compared with Na + . Showing difference with Na + that tends to migrate into electrolyte during high-voltage cycling, K + occupies in Li + site firmly because of its larger ionic radius and lower migrating ability, which sustainably prevent the irreversible phase transition between two hexagonal phases (H2 and H3) and impede the cation migration in highly delithiated state, thus suppressing the structural degradation. Benefiting from these merits, Li 0.99 K 0.01 Ni 0.8 Co 0.15 Al 0.05 O 2 delivers a large initial discharge capacity of 217 mAh g −1 at 0.1 C and maintains stable cycling at 1 C in a high voltage of 4.6 V (remaining 87.4 % of its initial capacity after 150 cycles). The mechanism proposed in this work, accounting for enhanced structural stability under high-voltage cycling by K + anchoring in Ni-rich cathode materials, provides a vital hint for rational designing advanced cathode materials to pursue high energy density Li-ion batteries.
2,5-Furandicarboxylic acid (FDCA) serves as a monomer in various polyesters and is often obtained through the oxidation of 5-hydroxymethylfurfural. The solubility data of FDCA are of great value for the reaction process analysis and separation technology. The experimental solubility of FDCA in eight pure solvents (water, methanol, acetonitrile, acetic acid, ethyl acetate, methyl isobutyl ketone (MIBK), 1-butanol, and isobutanol) and two binary solvent systems (water + acetonitrile and water + acetic acid) in the temperature range of 313.15–363.15 K was determined. In pure solvents and binary mixtures, the solubility of FDCA increased with the increasing temperature. The order from largest to smallest solubility in pure solvents was as follows: methanol, 1-butanol, isobutanol, acetic acid, water, MIBK, ethyl acetate, and acetonitrile. The mole fraction of FDCA in binary mixtures increased first and then decreased with the increasing mole fraction of water. The solubility data were correlated with the UNIQUAC model, NRTL model, and WILSON model.
文献关联基于可获得的产品、CAS、DOI 及引用记录。收录不代表作者或出版方对阿拉丁产品的背书,请以原始文献为准。
危险品化学品经营许可证（带存储）