Hydrolysis of cephanone in the micelles with different charges

The hydrolysis of cephanone in water and micelles with different charges was studied by UV-vis absorption spectroscopy. The change of pH with the hydrolysis of cephanone was determined. The mechanism of the hydrolysis and the effect of the acidity of the media on the hydrolysis were studied. The results show that the hydrolysis rate of cephanone increases with the acidity. Compared with water, SDS micelles accelerate this hydrolysis, whereas CTAB and Triton X-100 micelles suppress it. The effects of the micelles with different charges on the hydrolysis are explained by the proton concentration of the micro-environment where cephanone exists and by the charge density of the polar group of the cephanone molecules.     

DFT study and Monte Carlo simulation on proton transfers of 2-amino-2-oxazoline, 2-amino-2-thiazoline, and 2-amino-2-imidazoline in the gas phase and in water

Density functional theory (DFT) and Monte Carlo (MC) simulation with free energy perturbation (FEP) techniques have been used to study the tautomeric proton transfer reaction of 2-amino-2-oxazoline, 2-amino-2-thiazoline, and 2-amino-2-imidazoline in the gas phase and in water. Two reaction pathways were considered: the direct and water-assisted transfers. The optimized structures and thermodynamic properties of stationary points for the title reaction system in the gas phase were calculated at the B3LYP/6-311+G(d, p) level of theory. The potential energy profiles along the minimum energy path in the gas phase and in water were obtained. The study of the solvent effect of water on the proton transfer of 2-amino-2-oxozoline, 2-amino-2-thiazoline, and 2-amino-2-imidazoline indicates that water as a solvent is favorable for the water-assisted process and slows down the rate of the direct transfer pathway.     

Fast electron transfer repair of oxidizing OH adduct of dGMP by chlorogenic acid

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制备方法对Mg1.9Al0.1Ni合金储氢性能的影响

文中采用机械合金化(MA)和氢化燃烧法(HCS)制备了Mg1.9Al0.1Ni,通过对它们储氢性能的对比研究发现,MA优于HCS.采用MA制得的Mg1.9Al0.1Ni储氢合金具有较高的活性和高储氢量,对PCT结果进行计算,得出温度和氢平衡压的关系式.Mg1.9Al0.1Ni(MA)553K时100s内吸放氢量分别为2.67和2.54 mass%H.用XRD方法进行物相分析,表明添加适量Al没有改变Mg2Ni的物相结构,由于MA能够制备出纳米晶粒,使得Mg1.9Al0.1Ni合金具有更好的储放氢动力学性能.     

LyP-1 peptide-functionalized gold nanoprisms for SERRS imaging and tumor growth suppressing by PTT induced-hyperthermia

The gold nanoprisms (GNPs) have exhibited special plasmonic properties for biomedical applications because of their unique shapes and dimensions. Based on their optical performance, the NIR dye IR780 not only enabled the GNPs-based nanosystem as SERRS nanoparticles for Raman-encoded molecular imaging, but also enhanced the plasmonic photothermal property by laser irradiation. Meanwhile, the GNPs/IR780-Lyp-1 by introduction of tumor-homing peptide segment LyP-1, which presents high affinity to p32 protein, demonstrated the increased enrichment in tumor region and enhanced photothermal therapy efficacy.     

电化学方法对两性接枝星形聚合物LB膜屏蔽效应的研究

本文将自制Y式玻碳电极拉上两性接枝星形聚合物(GPSMA)的LB膜,用循环伏安法研究谈膜的屏蔽效应,讨论了接枝量、成膜条件等对膜缺陷的影响,并提出了减少缺陷的办法。     

Longistylumphyllines A–C,Three New Alkaloids from Daphniphyllum longistylum

Three new alkaloids, longistylumphyllines A–C (1–3), together with the six known alkaloids deoxycalyciphylline B, deoxyisocalyciphylline B, methyl homosecodaphniphyllate, daphnicyclidin A, daphnicyclidin B, and daphnicyclidin F, were isolated from the stems and leaves of Daphniphyllum longistylum. Their structures and relative configuration were elucidated on the basis of spectroscopic data, especially 1D and 2D NMR techniques.     

Study of Structures and Electronic Properties of Pdn–1Pb and Pdn （n≤8） Clusters

Geometric and electronic properties of Pdn–1Pb and Pdn (n≤8) clusters have been studied by using density functional theory with effective core potentials, focusing on the differences between mono- and bimetallic clusters. The average bond length of Pdn–1Pb (n≤8) bimetallic clusters is longer than that of pure palladium clusters except for n = 2 and 3. The most stable structure of Pdn–1Pb (n≤7) is the singlet where there is at least a Pd or Pb atom on its excited state. The energy gaps of Pd–Pb binary clusters are narrower than those of Pdn clusters, and then the chemical activity is strengthened when Pdn clusters are doped with Pb.     

Maximum overlap symmetry molecular orbital model

This paper provides a brief and systematic presentation of the basic principle and method of the maximum overlap symmetry molecular orbital (MOSMO ) model and its application to simplification of molecular orbital calculation and to calculation of molecular structures and properties, together with some new results about the MOSMO calculation and new insights concerning the further extension of the principle and method. It has been shown that the theoretical method of the MOSMO model is very simple, reliable, and useful and can be employed to study the structure–property relation in even very large molecular systems. The numerical results obtained from the MOSMO calculation on various semiempirical molecular orbital approximation levels show that when the same parametrization, such as one of those employed in EHMO , CNDO /2, and HMO methods, is adopted, the MOSMOS are very close to the canonical molecular orbitals obtained from the customary LCAO method and the MOSMO calculation requires less computing time than does the LCAO method. The MOSMO calculation can be used for rapidly obtaining reasonably good molecular geometries, vibrational frequencies, and other properties of molecules by employing a simple improved semiempirical parametrization. Equilibrium geometries, vibrational frequencies, and other results are in good agreement with the experimental data and the results obtained from ab initio molecular orbital calculation. The basic calculational procedure of the MOSMO model can be extended further and has been employed to give some new results, to propose some new theoretical schemes and principles, and to introduce some new interesting theoretical problems that deserve to be studied further.     

铜对钌改性尖晶石催化剂结构和氧化性能的影响

通过湿化学法制备钌改性的纳米尖晶石MnFe1.95Ru0.05O4催化剂, 考察了添加助剂铜对该催化剂的影响.通过比表面积和孔径分布表征结果证实, 铜助剂的添加有效地增大了比表面积和孔容.XPS的测试结果表明, 钌的改性大大改变了尖晶石中各元素如锰和铁的化学环境；助剂铜的添加对于锰和铁等原子的影响不大, 但对钌原子的影响显著；EXAFS表征结果显示了铜助剂的导入影响了钌的周围环境, 形成了活性Ru=O键.以桂皮醇和苯甲醇的氧化反应为典型反应考察了添加助剂铜前后的影响.