基于有机羧酸配体的Co(Ⅲ)/Cu(Ⅱ)配合物的合成、结构及表征

在溶剂热条件下,以含卤素有机羧酸3-溴-吡啶-2,6-二甲酸(H₂L)为配体,以硝酸钴、硝酸铜为金属源,合成了两例配合物:[Co(L′)₃](1)和[Cu(L′)₂]_n(2)(HL′=5-溴-吡啶-2-甲酸),通过元素分析(EA)、X射线单晶衍射(SXRD)、X射线粉末衍射(PXRD)、红外光谱(IR)和热重分析(TGA)进行结构表征。X射线单晶衍射结果表明,配体H₂L在反应过程中发生脱羧现象,生成单羧酸配体5-溴-吡啶-2-甲酸。在配合物1中,每个Co(Ⅲ)都位于略微扭曲的八面体几何构型中,不对称单元中含有两个单核单元,单核单元通过C—H…O氢键形成三维超分子结构。配合物2的不对称单元中含有一个Cu(Ⅱ),两个脱质子的L′^-配体,每个Cu(Ⅱ)都是六配位的,位于扭曲的八面体几何构型中。Cu(Ⅱ)由配体连接生成1D链结构,通过C—H…O氢键形成三维超分子结构。此外,研究了两例配合物的热稳定性能。     

量子点在生物化学传感中的应用研究进展

综述了荧光量子点在生物化学传感中的研究应用进展,重点介绍离子、酶以及糖类的传感,并展望了其发展趋势和应用前景。     

Effects of novel hybrid nanofluid (TiO2–Cu/EG) and geometrical parameters of triangular rib mounted in a duct on heat transfer and flow characteristics

Journal of Thermal Analysis and Calorimetry - Heat transfer and flow characteristics have been numerically analyzed by using four different fluids [pure ethylene glycol (EG), TiO2/EG and Cu/EG...     

要掌握物理量定义的方法

建立物理量的目的是通过该量来表征物质或物体的状态或性质，并通过探求各量之间所表征的全部内容，集中地包含在它的定义式中．因此，掌握物理量定义的方法，对物理教学具有重要意义．     

The structure of N-(1H-benzo[d]imidazol-2-ylmethyl)-N-(2,6-dichlorophenyl)amine

The N-(1H-benzo[d]imidazol-2-ylmethyl)-N-(2,6-dichlorophenyl)amine, C₁₄H₁₁N₃Cl₂, M _r = 292.17, crystallizes in the orthorhombic space group Pbca with unit cell parameters a = 10.707(2), b = 9.615(2), c = 25.944(6) Å. The benzimidazole ring system is planar and makes a dihedral angle of 77.8(1)° with the phenyl ring. The structure is stabilized by an N–H···N hydrogen bond.     

亚临界情形下非线性裂纹转子的分叉与浑沌

分析非线性涡动裂纹转子中刚度变化比ΔＫ，裂纹角β，不平衡参数Ｕ对系统分叉及浑沌行为的影响。在转速区Ω＝２Ωｃ／３附近，当ΔＫ较大时，会出现分叉及浑沌现象，β对这些行为有很大影响，在Ω＝Ωｃ／２附近，当ΔＫ很大时，无论β为何值，将由拟周期通向浑沌，Ｕ作为一种外部因素，将使系统的非线性行为得到激发或抑制。     

The parameters affecting the differences between the solutions corresponding to two different definitions of the reference surface of deformed rubber-like shells of revolution

The parameters affecting the differences between the solutions to problems related with incompressible rubber—like shells of revolution, undergoing axisymmetric finite strains and rotations, corresponding to two different definitions of the reference surface of deformed rubber-like shells of revolution are obtained through an asymptotic analysis.     

Hydrothermal Carbonization of Microalgae (<Emphasis Type="Italic">Chlorococcum</Emphasis> sp.) for Porous Carbons With High Cr(VI) Adsorption Performance

Polygonum tinctorium Lour (indigo plant) has been regarded as a useful medicinal plant for traditional herbal medicine. The polyphenolic fraction of indigo leaves exhibited anti-inflammatory activities as determined by the suppressed synthesis of nitric oxide (NO) in cultured RAW264 macrophage cells. The acid hydrolysate of the fraction showed much more potent effect than the unhydrolyzed one. In sharp contrast, those fractions of indigo stems had almost no effect. 3,5,4′-Trihydroxy-6,7-methylenedioxyflavone (TMF)-O-glycosides and tryptanthrin were detected exclusively in the extracts of the leaves. The isolated flavonol species were furthermore tested for their anti-inflammatory activities against the synthesis of NO and prostaglandin E₂ in the cultured macrophage cells. More potent anti-inflammatory effects were recognized with different aglycones of flavonols than their flavonol O-glycosides. Although the inhibitory effects of TMF were less effective than those of tryptanthrin, the levels of flavonol O-glycosides with TMF were much more abundant than those of tryptanthrin in the leaves. Oral administration of the fraction containing flavonol O-glycosides with TMF into mice revealed the detection of free TMF in the blood circulation, indicating that the aglycone moiety can be cleaved by digestive enzymes and absorbed in the gut. Alternatively, the assay of hydrophilic oxygen radical absorbance capacity revealed that the isolated species of flavonol O-glycosides with TMF and their aglycone had appreciable antioxidant activities. Taken together, our findings suggest that the predominant flavonol O-glycosides with TMF as an aglycone could be promising natural agents for the application to herbal medicine, nutraceuticals, and food additives.     

A new metaheuristic approach based on orbit in the multi-objective optimization of wireless sensor networks

Wireless Networks - Wireless sensor networks (WSNs) is a research area which has been used in various applications and has continuously developed up to now. WSNs are used in many applications,...     

Boosting the Photocatalytic Ability of Cu2O Nanowires for CO2 Conversion by MXene Quantum Dots

MXene quantum dots (QDs) are emerging 0D nanomaterials. Here, a new heterostructure is developed based on a 1D photoactive semiconductor and a 0D MXene QD for improved photocatalytic reduction of CO₂ into methanol. Specifically, Ti₃C₂ QDs are incorporated onto Cu₂O nanowires (NWs) through a simple self‐assembly strategy. It is demonstrated that Ti₃C₂ QDs not only significantly improve the stability of Cu₂O NWs but also greatly improve their photocatatlytic performance by enhancing charge transfer, charge transport, carrier density, light adsorption, as well as by decreasing band bending edge and charge recombination. The energy level diagram derived from both experimental measurements and theoretical calculations provide further insights of such hierarchical photocatalysis system.