一类半线性抛物型方程组解的爆破速率估计

考虑一类带有齐次Dirichlet边界条件且反应项分别为指数形式和幂函数形式的半线性抛物型方程组,利用比较原理得到了方程解爆破的充分条件,由数学分析原理和最大值原理得到了爆破解的爆破速率估计.     

Supramolecular Aggregates: Hardness Plus Softness

The properties of supramolecular aggregates cross several disciplines, embracing the sciences of nature and joining theory, experiment, and application. There are few articles centering on the problems of interdisciplinarity, and this paper gives an alternative approach, starting with scientific divulgation, bringing concepts from their origin, to facilitate the access of young scientists to the scientific content. Didactic examples are taken from the experience of the author in changing directions of research due to several circumstances of life (including maternity), starting from the view of a rigorous student of physics and evolving to several subjects in chemistry. The scientific part starts with concepts related to nuclear interactions, using the technique of neutron scattering in reactors, and evolves to research in molecular physics. Finally, it arrives at the academic context, with research in condensed matter physics, with X-ray and other techniques, starting with detergents forming nematic lyotropic liquid crystals and the phase transition sequence of isotropic to nematics to hexagonal. The scientific subjects evolved to biological and bio-inspired liquid crystals, including DNA and also specific lipids and phospholipids in biomimetic membranes. Special attention is given to the question of distribution of matter in these complex systems and the non-trivial connections between biochemistry, structures, auto-aggregation, and biology.     

Concise synthesis of (-)-anisomycin

The antibiotic (-)-anisomycin was synthesized starting from D-tyrosine using Sharpless asymmetric epoxidation as a key reaction followed by formation and hydrolysis of oxazoline set up all chiral center.     

From Zn-Al layered double hydroxide to ZnO nanostructure:Gradually etching by sodium hydroxide

Zn-Al layered double hydroxide(LDH) was used as precursor to produce ZnO nanostructures through dissolution of aluminum hydroxide in caustic soda.The Zn-Al LDH could transform into different nanostructures of ZnO on LDH nanosheets and even pure ZnO nanorods under various NaOH concentration.The formed ZnO nanorods vertically aligned on both LDH sides.UV-vis diverse reflectance spectra show that the obtained ZnO nanorods have a band gap of approximately 3.05 eV.Such ZnO/LDH nanostructures might be used as photocatalyst in the organic pollutant decomposition.     

A highly selective solid-contact electrode for Ag~+ based on a monoazathiacrown ether ionophore

A new solid-contact Ag⁺-selective electrode was prepared with 9,10,12,13,24,25-hexahydro-5H,15H,23H-dibenzo [b,q][1,7,10,13,19,4,16]-entathiadiazacyclodocosine-6,16（7H,17H）-dione as ionophore,and cc,a>-dihexylsexithiophene（DH- 6T） ion-to-electron transducer.The sensor exhibited a working concentration range of 10⁸ to 10^-3 mol/L,with a near-Nernstian slope of 55.1±0.2 mV/dec and detection limit of 1.7×10^-9 mol/L.The fabricated electrodes demonstrated excellent selectivity over the most common monovalent and divalent cations.     

Asymmetric transfer hydrogenation of ketones catalyzed by nickel complex with new PNO-type ligands

The new polydentate mixed-N,P,O chiral ligands have been synthesized by the condensation of bis（o-formylphenyl）- phenylphosphane and R-phenylglycinol in CHCl₃,and fully characterized by IR,NMR and EIMS spectra.These ligands were employed with a simple Ni complex Ni（PPh_s）₂Cl₂ in situ as catalytic systems for asymmetric transfer hydrogenation of ketones,and the corresponding optical alcohols were obtained with up to 84%ee under mild conditions.     

变革型领导、知识共享与研发团队创造力:团队成员异质性的倒U型调节作用

本文基于变革型领导理论、知识共享理论、团队创造力理论及团队异质性理论,研究变革型领导对高新技术企业研发团队创造力的影响,及知识共享在这一作用过程中的中介效应,并提出带倒U型调节的混合模型,探索团队成员异质性的倒U型调节效应。通过对162家高新技术企业的实证研究,得出以下主要结论:变革型领导对研发团队创造力有显著正向影响;知识共享在变革型领导与研发团队创造力之间起部分中介作用;团队成员异质性在变革型领导与知识共享之间起倒U型调节作用,在知识共享与研发团队创造力之间起倒U型调节作用。     

Improving photoelectrochemical activity of dye sensitized solar cell by a bilayered electrode with an overlayer of mesoporous anatase TiO_2

For better performance of dye sensitized solar cells(DSSCs) ,a bilayer structured electrode was constructed by employing a mesoporous anatase TiO2 overlayer above a commercial P25 TiO2 nanoparticles underlayer. The mesoporous anatase TiO2,prepared through a facile surfactant-assisted sol-gel process,possessed large pore size and well inter-connected network structure,both beneficial for dye adsorption and electron transfer. The dye adsorption capability of the mesoporous TiO2 was nearly twice that of the P2...     

Synthesis and Crystal Structure of a New Tetracopper Complex [Cu(H_2O)_3Cu(HCDTA)]_2(ClO_4)_2·H_2O

A new tetracopper complex [Cu(H2O)3Cu(HCDTA)]2(ClO4)2·H2O (CDTA = transcyclohexane-1,2-diamine-N,N,N′,N′-tetraacetate) has been prepared and characterized by singlecrystal X-ray diffraction analysis. The crystal adopts space group C2/c with a = 16.990(10), b = 9.150(5), c = 29.318(17) , β = 104.289(9)°, V = 4417(4) 3, Z = 4, C28H52Cl2Cu4N4O31, Mr = 1265.80, Dc = 1.904 g/cm3, μ = 2.130 mm-1, F(000) = 2584, T = 293(2) K, the final R = 0.0328 and wR = 0.0809 for 4938 observed reflections (I 2σ(I)). The tetracopper units are interconnected by weak covalent bonds into a layered structure.     

Endomorphin analogues with balanced affinity for bothμ- andδ-opioid receptors

Analogues of endomorphin and tripeptidcs modified at positions 4 and 3,respectively,with various phenylalanine analogues were synthesized and their affinities for opioid receptors were evaluated.Most of the peptides exhibited potentμ-receptor affinity and selectivity,among them,compound 7(Dmt-Pro-Tmp-Tmp-NH_2) exhibited potent affinity for bothμ-andδ-receptors (K_iμ= 0.47 nmol/L,K_iδ= 1.63 nmol/L).