镍-磷/纳米碳管化学复合镀层的研究

采用化学复合镀方法,在基体铜片上进行Ni-P／纳米碳管复合镀．用金相显微镜、扫描电子显微镜、X射线衍射仪和显微硬度计等实验手段研究复合镀层的组织、结构和性能．结果表明:随着镀液中纳米碳管含量的增加,复合镀层表面的颗粒变小且密度增加;复合镀层的硬度随纳米碳管含量的增加而提高;此外,纳米碳管的加入,使镀层由非晶变成了纳米晶,促进了复合镀层的晶化．     

[CUⅡ(BTAH)2(NCS)2]·2H2O(BTAH=苯并三唑)的合成、晶体结构及其光学性能

通过水热法,合成了[CuⅡ(BTAH)2(NCS)2]·2H2O晶体.对其进行了元素分析、红外光谱以及热重分析,并通过单晶X射线衍射确定了其晶体结构.该晶体属于三斜晶系,空间群为Pi,晶胞参数为a=0.64174(6)nm,b=0.83749(8)nm,c=0.92831(5)nm,a=71.982(5)°,β=72.522(6)°,γ=77.068(4)°.通过UV-VIS-NIR反射光谱研究了其光学性质,能隙值为2.5eV,吸光系数(ε)为0.0294μm-1.     

Antioxidant,Antimicrobial and Antitumor Studies of Transition Metal Complexes Derived from N-(2-Aminoethyl)-1,3-Propanediamine with DFT Calculations and Molecular Docking Investigation

New expected biologically active complexes for some of the first (Mn (II), Ni (II), Cu (II) and Zn (II)) and second (Rh (III) and Cd (II)) transitional metals rows with N-(2-Aminoethyl)-1,3-propanediamine as a ligand (AEPD)have been synthesized. All synthesized complexes were formed with 1:1 (metal: AEPD) stoichiometry except Ni (II) 1:2 (Ni: AEPD). The compounds were characterized by different analysis tools such as; elemental analysis, Fourier transform infrared (FTIR), ¹H-NMR, mass spectra, thermal analysis, electronic spectra, magnetic measurement and molar conductance techniques. AEPD ligand interacted with all metal ions as tridentate ligand by using the nitrogen atoms. On the other hand, density functional theory (DFT) calculations have been performed to confirm the optimized geometrical structures for both AEPD and its complexes. Furthermore, coordination compounds were screened for their potential antibacterial activities against six pathogenic bacteria as well as one kind of fungi in comparison to standard antibiotics by agar well diffusion method. The results show that most of the complexes exhibit antibacterial and antifungal activities against these organisms. Rh (III)-AEPD complex exhibited the strongest antibacterial effect followed by the Cd (II) complex but as antifungal agents Cd (II) was the first and the second was Rh (III). Also, the anticancer activity was screened for these metal complexes against growth of human liver cancer HEPG2 tumor cell line and this inhibition activity of Cd (II) chelate was noticed to be more active with lowest IC₅₀ than that of all other synthesized complexes. Unfortunately, Mn (II) and Rh (III) chelates lacked anticancer activity. The docking active sites interactions were evaluated using the selected protein for anticancer activity. Finally, antioxidant activity was studied. Mn (AEPD) showed maximum activity followed by complex of Rh (III).     

Thermal energy storage: Challenges and the role of particle technology

Thermal energy is at the heart of the whole energy chain providing a main linkage between the primary and secondary energy sources. Thermal energy storage (TES) has a pivotal role to play in the energy chain and hence in future low carbon economy. However, a competitive TES technology requires a number of scientific and technological challenges to be addressed including TES materials, TES components and devices, and integration of TES devices with energy networks and associated dynamic optimization. This paper provides a perspective of TES technology with a focus on TES materials challenges using molten salts based phase change materials for medium and high temperature applications. Two key challenges for the molten salt based TES materials are chemical incompatibility and low thermal conductivity. The use of composite materials provides an avenue to meeting the challenges. Such composite materials consist of a phase change material, a structural supporting material, and a thermal conductivity enhancement material. The properties of the supporting material could determine the dispersion of the thermal conductivity enhancement material in the salt. A right combination of the salt, the structural supporting material, and the thermal conductivity enhancement material could give a hierarchical structure that is able to encapsulate the molten salt and give a substantial enhancement in the thermal conductivity. Understanding of the structure–property relationships for the composite is essential for the formulation design and fabrication of the composite materials. Linking materials properties to the system level performance is recommended as a key future direction of research.     

Eucleanal A and B:Two new napthalene derivatives from Euclea divinorum

Two new naphthalene derivatives named eucleanal A and B（1 and 2） were isolated from Euclea divinorum.The structures of the new compounds were elucidated by detailed spectroscopic analysis such as ¹H,¹³C NMR,COSY,HMQC,HMBC and HREIMS mass spectrometry.     

Synthesis and Crystal Structure of a Polymeric Heteronuclear Complex of Cadmium(II) and Silver(I)

A polymeric complex of Cd(II) and Ag(I) bridged by thiocyanate and ethylenediamine, [Cd(en)_1.5Ag(SCN)₃], has been prepared and its structure determined by X-ray diffraction methods. The complex crystallizes in space group P2₁/n with a =7.456(1), b =9.915(2), c =19.822(2)Å, β =98.94(1)°. The Cd(II) atom is octahedrally coordinated by three SCN^- anions and two en molecules, while the Ag(I) atom is tetrahedraly coordinated by four SCN^- anions. Both SCN^- anions and en molecules act as bridging ligands and link Ag(I) and Cd(II) atoms to form a three-dimensional polymeric structure. The distance between Ag(I) and the atom S of a 1,1,3-µ3-SCN^- anion is much longer than that between Ag(I) and the atom S of a 1,3-µ-SCN^- anion. The short Ag-Ag distance of 3.133 Å and small Ag-S-Ag angle of 70.92° strongly suggests the existence of an Ag-Ag bonding interaction in the complex.     

Effects of ultrasound on the structural and emulsifying properties and interfacial properties of oxidized soybean protein aggregates

Oxidative attack leads to the oxidative aggregation and structural and functional feature weakening of soybean protein. We aimed to investigate the impact of ultrasonic treatment (UT) with different intensities on the structure, emulsifying features and interfacial features of oxidized soybean protein aggregates (OSPI). The results showed that oxidative treatment could disrupt the native soy protein (SPI) structure by promoting the formation of oxidized aggregates with β1-sheet structures through hydrophobic interactions. These changes led to a decrease in the solubility, emulsification ability and interfacial activity of soybean protein. After low-power ultrasound (100 W, 200 W) treatment, the relative contents of β1-sheets, β2-sheets, random coils, and disulfide bonds of the OSPI increased while the surface hydrophobicity, absolute ζ-potential value and free sulfhydryl content decreased. Moreover, protein aggregates with larger particle sizes and poor solubility were formed. The emulsions prepared using the OSPI showed bridging flocculation and decreased protein adsorption and interfacial tension. After applying medium-power ultrasound (300 W, 400 W, and 500 W) treatments, the OSPI solubility increased and particle size decreased. The α-helix and β-turn contents, surface hydrophobicity and absolute ζ-potential value increased, the structure unfolded, and the disulfide bond content decreased. These changes improved the emulsification activity and emulsion state of the OSPI and increased the protein adsorption capacity and interfacial tension of the emulsion. However, after a high-power ultrasound (600 W) treatment, the OSPI showed a tendency to reaggregate, which had a certain negative effect on the emulsification activity and interfacial activity. The results showed that UT at an appropriate power could depolymerize OSPI and improve the emulsification and interfacial activity of soybean protein.     

A significant enhancement in thermoelectric power factor of In2Te3 thin films by Se doping and Te composition tuning

Thermoelectric power factor of a material significantly relies on its electrical conductivity, thermal conductivity, and Seebeck coefficient. Herein, an attempt has been made to enhance the thermoelectric power factor of In₂Te₃ thin films by tuning their Te composition and via Se doping. The optimum Se-doping concentration and Te composition enhanced the power factor of pristine In₂Te₃ films by 14 and 7.4 times, respectively. The modified chemical composition, structural characteristics, and surface morphological features of In₂Te₃ films are observed to be pivotal in improving their thermoelectric power factor. Overall, this study offers a facile approach to control the thermoelectric power factor of In₂Te₃ thin films which is significant for their futuristic applications.     

Structural,magnetic and electric behavior of the new Ba2TiMoO6 material

We report synthesis and characterization of the structural, morphologic and ferroelectric behavior of the complex perovskite Ba₂TiMoO₆. Samples of Ba₂TiMoO₆ were synthesized through standard solid state reaction methods. Crystalline structure was studied by means of X-ray diffraction experiments and Rietveld-like analysis. Results reveal that material crystallizes in a tetragonal structure, space group P4/mnm (#123), with cell parameters a=3.8557 Å and c=11.8678 Å. The tolerance factor of perovskite was determined to be 1.04. Surface morphology was examined using Scanning Electron Microscopy, which shows the micrometric granular character of samples with 1.0–5.0 μm mean grain size. Ferroelectric response of material was established from curves of polarization as a function of applied electric field. Our results reveal that Ba₂TiMoO₆ double perovskite evidences a ferroelectric hysteretic behavior at ambient temperature and paramagnetic ordering. © 2011 Elsevier Science. All rights reserved.