回火处理对LiNi1/3Co1/3Mn1/3O2结构和电化学性能的影响

以硝酸锂、四水合乙酸镍、四水合乙酸钴、四水合乙酸锰、氨水和草酸为原料,通过共沉淀-燃烧法合成了锂离子电池正极材料LiNi1/3Co1/3Mn1/3O2,采用XRD、SEM和充放电试验对合成产物进行了表征,研究了回火处理对合成产物结构和电化学性能的影响.实验结果表明,嫩烧反应形成的LiNi1/3C1/3Mn31/3O2结...     

Synthesis,structure and DNA-binding studies of tetranuclear copper(II) complexes bridged by asymmetrical<Emphasis Type="Italic"> N</Emphasis>,<Emphasis Type="Italic">N′</Emphasis>-bis(substituted)oxamides

Two tetranuclear copper(II) complexes bridged by asymmetrical N,N′-bis(substituted)oxamides have been synthesized and characterized as [Cu₄(dmapob)₂(Me₂bpy)₂](pic)₂·6H₂O (1) and [Cu₄(oxbe)₂(dabt)₂](pic)₂ (2), where H₃dmapob and H₃oxbe denote N-benzoato-N′-[3-(dimethylamino)propyl]oxamido and N-benzoato-N′-(2-aminoethyl)oxamide, respectively; and Me₂bpy, dabt, and pic represent 4,4′-dimethyl-2,2′-bipyridine 2,2′-diamino-4,4′-bithiazole, and 2,4,6-trinitrophenol, respectively. Complex 1 was characterized by elemental analyses, IR and electronic spectra, and single-crystal X-ray diffraction. Its structure consists of two asymmetrical binuclear copper(II) units linked by carboxyl bridges into a circular tetranuclear copper(II) complex with an embedded center of inversion. The copper(II) centers are in square-planar and distorted square-pyramidal environments. Hydrogen bonds and aromatic stacking interactions link the tetranuclear copper(II) fragments into a 3D supramolecular structure. The interactions of complexes 1 and 2 with herring sperm DNA (HS-DNA) were investigated by electronic and fluorescence spectra and viscosity measurements. Both complexes bind to HS-DNA via the intercalative mode, and complex 2 displays a significant binding propensity to HS-DNA.     

Temperature dependent synthesis of micro- and meso-porous silica employing the thermo-responsive polymer of poly(<Emphasis Type="Italic">N</Emphasis>-isopropylacrylamide) as structure-directing agent

Temperature dependent synthesis of micro- and meso-porous silica employing the thermo-responsive homopolymer poly(N-isopropylacrylamide) or the random copolymer poly(N-isopropylacrylamide-co-acrylic acid) as structure-directing agent (SDA) and Na₂SiO₃ as silica source is proposed. The thermo-responsive character of the SDA provides the advantages including (1) temperature dependent synthesis of microporous silica, hierarchically micro-mesoporous silica, and mesoporous silica just by changing the aging temperature below or above the low critical solution temperature of the thermo-responsive SDA, and (2) elimination of the thermo-responsive SDA from silica matrix by water extraction. The synthesis mechanism is discussed, and the effect of the aging temperature and the weight radio of SDA/Na₂SiO₃ on the synthesis of micro- and meso-porous silica are studied. Microporous silica, hierarchically micro-mesoporous silica and mesoporous silica with the surface area at 3.5−9.0 × 10² m²/g and the pore volume at 0.28−1.13 cm³/g and the average pore size ranging from 1.1 to 9.0 nm are synthesized. The strategy affords a new and environmentally benign way to fabricate porous silica materials, and is believed to bridge the gap between the synthesis of microporous and mesoporous silica materials.     

介质阻挡放电中OH自由基对甲醛脱除的影响

对管线式介质阻挡放电中的甲醛脱除进行了实验研究, 测量了介质阻挡放电产生的OH (A²Σ→X ²Π, 0-0)自由基发射光谱. 研究了在一个大气压下不同放电峰值电压、放电频率、添加氩气和氧气时甲醛脱除率与OH自由基发射光谱强度的变化关系. 实验结果表明: 在氮气含甲醛体系中, 提高放电峰值电压、放电频率和增大氩气含量时, 甲醛脱除率随OH (A²Σ→X ²Π, 0-0)自由基发射光谱强度的增强而提高; 当在氮气含甲醛体系中增大氧气含量时, 甲醛脱除率随OH (A²Σ→X ²Π, 0-0)自由基发射光谱强度的减弱而降低. 在11.5 kV放电峰值电压和9 kHz放电频率下, 氮气含甲醛体系中甲醛脱除率达93.8%.     

Poly[tetra‐μ2‐l‐lactato‐indium(III)sodium(I)]

The asymmetric unit of the title compound, [InNa(C₃H₅O₃)₄]_n, consists of one In^III ion, one Na^I ion and four crystallographically independent l ‐lactate monoanions. The coordination of the In^III ion is composed of five carboxylate O and two hydroxy O atoms in a distorted pentagonal–bipyramidal coordination geometry. The Na^I ion is six‐coordinated by four carboxylate O atoms and two hydroxy O atoms from four l ‐lactate ligands in a distorted octahedral geometry. Each In^III ion is coordinated by four surrounding l ‐lactate ligands to form an [In(l ‐lactate)₄]⁻ unit, which is further linked by Na^I ions through Na—O bonds to give a two‐dimensional layered structure. Hydrogen bonds between the hydroxy groups and carboxylate O atoms are observed between neighbouring layers.     

Synthesis and biological evaluation of new mono naphthalimide platinum(IV) derivatives as antitumor agents with dual DNA damage mechanism

Naphthalimide has emerged as an interesting DNA intercalator and possessed attracting antitumor properties. In this context, naphthalimide group was linked to platinum(IV) core to construct a series of new mono naphthalimide platinum(IV) derivatives. The title compounds exert effective antitumor activities to the tested tumor cells lines in vitro, especially the one with propionyl chain displays comparable or even better bioactivities than platinum(II) reference drugs cisplatin and oxaliplatin. Moreover, the mono naphthalimide platinum(IV) derivative displays comparable tumor growth inhibitory competence against CT26 xenograft tumors in BALB/c mice in vivo without severe toxic effects in contrast to oxaliplatin. A dual DNA damage mechanism was proven for the title complex. Both naphthalimide ligand and the liberated platinum(II) moiety could generate DNA lesions to tumor cells synergistically and active the apoptotic pathway by up-regulating the expression of caspase 9 and caspase 3. Meanwhile, the conversion of platinum(II) drug into tetravalent form by incorporating naphthalimide moiety increases the uptake of platinum in whole cells and DNA remarkably. All these facts might be the factors for the title platinum(IV) complexes to overcome platinum(II) drug resistance. Additionally, the mono naphthalimide platinum(IV) complex could interact with human serum albumin by hydrogen bond and van der Waals force which would further influence their storage, transport and bioactivities.     

电感耦合等离子体原子发射光谱法(ICP-AES)测定金鸡胶囊中的7种无机元素

建立了测定金鸡胶囊中Ca、Mg、Mn、Fe、Cu、Zn和Sr 7种无机元素含量的分析方法.采用浓硝酸和高氯酸(8+2)的混合酸溶解样品,利用电感耦合等离子体原子发射光谱法(ICP-AES)对各种元素进行测定.金鸡胶囊含有丰富的对人体有益的无机元素,对待测样品的测定结果表明,Ca、Mg、Fe、Mn、Zn、Sr和Cu的含量...     

A Novel Phenoxazine-based Fluorescent Probe for the Detection of HOCl in Living Cells

Hypochlorous acid (HOCl), one of the reactive oxygen species (ROS), is a key microbicidal agent which is used for natural defense. However, it is also linked to varieties of human diseases owing to the overproduction of HOCl. Much effort has been made to exploit selective fluorescent sensors for the detection of HOCl, but most of them have some disadvantages such as short excitation wavelength, low selectivity, and slow response and so on. These restrict the biological application of the probes. In this work, BR-O was designed and synthesized on the base of phenoxazine for the detection of HOCl. BR-O exhibited a violent fluorescence enhancement in the presence of HOCl, showing excellent selectivity and high sensitivity. More importantly, the probe BR-O was capable of detecting exogenous and endogenous HOCl in living cells.     

Widely Adaptable Oil-in-Water Gel Emulsions Stabilized by an Amphiphilic Hydrogelator Derived from Dehydroabietic Acid

A surfactant, R-6-AO, derived from dehydroabietic acid has been synthesized. It behaves as a highly efficient low-molecular-weight hydrogelator with an extremely low critical gelation concentration (CGC) of 0.18 wt % (4 mm ). R-6-AO not only stabilizes oil-in-water (O/W) emulsions at concentrations above its critical micelle concentration (cmc) of 0.6 mm , but also forms gel emulsions at concentrations beyond the CGC with the oil volume fraction freely adjustable between 2 % and 95 %. Cryo-TEM images reveal that R-6-AO molecules self-assemble into left-handed helical fibers with cross-sectional diameters of about 10 nm in pure water, which can be turned to very stable hydrogels at concentrations above the CGC. The gel emulsions stabilized by R-6-AO can be prepared with different oils (n-dodecane, n-decane, n-octane, soybean oil, olive oil, tricaprylin) owing to the tricyclic diterpene hydrophobic structure in their molecules that enables them to adopt a unique arrangement in the fibers.