A new 3D Cd(II) metal–organic framework with discrete (H2O)6 clusters based on flexible cyclohexane-1,2,4,5-tetracarboxylic acid ligand

A 3D metal–organic framework (MOF), {[Cd₂(CTA)(bpp)₂(H₂O)₂] (H₂O)₃}_n (1) (H₄CTA = cyclohexane-1,2,4,5-tetracarboxylic acid, bpp = 1,3-bis(4-pyridyl)propane), has been synthesized and structurally characterized by elemental analysis, IR and powder X-ray diffraction. Single-crystal X-ray measurement reveals that the complex presents three-dimensional frameworks with 1D channels which are filled by unique (H₂O)₆ clusters. Noteworthily, the H₄CTA ligands keep exclusive conformation, where the carboxyl groups adopt different coordination modes, and the bpp ligands perform two different conformations. Thermogravimetric analysis demonstrates that 1 features favorable thermal stability. Photoluminescence property of 1 is investigated in the solid state at room temperature as well.     

红土酸浸的最佳条件研究

采用单因素试验安排方法对影响红土酸浸的主要因素(酸浸温度、酸浸时间、硫酸浓度和液固比)进行研究,实验表明酸浸温度、酸浸时间、硫酸浓度和液固比分别为90℃2、h、25%~35%和1~5∶1时红土的酸浸率最高。     

Synthesis,crystal structure and anticancer activity of 2D-coordination polymer of cerium(III) with chiral Schiff base trans-N,N′-bis-(2-hydroxy-1-naphthalidehydene)-(1R,2R)-cyclohexanediamine

The chiral Schiff base coordination polymer [Ce(H₂L)₃(NO₃)₃Ce(H₂L)₃(NO₃)₃(H₂O)]_n [H₂L: trans-N,N′-bis-(2-hydroxy-1-naphthalidehy-dene)-(1R,2R)-cyclohexanediamine] was synthesized and characterized by infrared spectroscopy, elemental analysis and single-crystal X-ray diffraction analysis. X-ray crystallography shows that the Ce(III) coordinates with three neutral Schiff base ligands and three nitrates. One Ce(III) is nine-coordinated by three oxygen atoms from three different Schiff base ligands and six oxygen atoms from three nitrates, the other Ce(III) is ten-coordinated because of the coordination of an additional water molecule. Each Schiff base ligand serves as a bridging ligand to link Ce(III) ions through oxygen atoms, leading to a coordination polymer. The Ce(III) coordination polymer displays two dimensional plane grid network structure. The antiproliferation activities of the ligand H₂L and its Ce(III) coordination polymer on MDA-MB-231 breast cancer cells were also studied by MTT (3-[4,5-dimethyltiazol-2-yl]-2,5-diphenyl-tetrazolium bromide) method. The results indicate that H₂L and [Ce(H₂L)₃(NO₃)₃Ce(H₂L)₃(NO₃)₃(H₂O)]_n can inhibit the cellularproliferation. Moreover, the coordination polymer had higher antiproliferative activity than that of the ligand.     

氯代铬酸吡啶盐在有机合成中的应用

氯代铬酸吡啶盐作为一种温和的、选择性的氧化剂,用于有机合成中,其效果是明显的,应用范围也越来越大。     

Dual-responsive polymer–drug nanoparticles for drug delivery

A well-defined, dual temperature- and pH-responsive drug carrier was synthesized through the radical copolymerization of methacrylic acid, N-isopropylacrylamide, and an N-(methacryloyl)glycylglycine 4-nitrophenyl ester. When the anticancer agent gemcitabine or antibiotic sulfamethoxazole was conjugated with a polymer and heated beyond its low critical solution temperature (40 °C), a dual temperature- and pH-induced phase transition was observed. This temperature was considered ideal for activating drug aggregation under hyperthermic and acidic conditions. The structure and properties of polymer drugs were investigated using nuclear magnetic resonance, Fourier transform infrared spectrometry, ultraviolet–visible absorption, transmission electron microscopy, and gel permeation chromatography. At a critical micelle concentration of 1 mg/mL, both polymer drugs formed micellar structures with diameters ranging from 50 nm to 150 nm, based on TEM image. These micelles exhibited higher pharmacological efficacy than the free drug alone did, and the cytotoxicity at the target site was substantially enhanced compared with that of the polymer–drug conjugate formed under normal physiological conditions.     

马来酸酐接枝改性竹纤维及其增强复合材料的性能

采用热化学酚化技术对竹粉进行液化,分离得到竹纤维素微粉(BCMP),对获得的BCMP表面进行马来酸酐(MAH)接枝改性,研究了反应温度和时间对酯化度的影响.结果表明,在二甲苯回流反应温度为140℃,反应时间为4 h的条件下,获得了高酯化度(16.2%)、低羟值(15.6 mKOH/g)的BCMP.与未接枝改性的BCMP...     

阀门启闭扭矩试验标准的研究

介绍了目前国内外阀门扭矩测试的现状,分析了阀门扭矩测试装置的主要内容及其操作规范,提出了制订阀门扭矩测试相关标准的必要性和紧迫性。     

Synergistic effect of Cu2O/TiO2 heterostructure nanoparticle and its high H2 evolution activity

Cu₂O/TiO₂ nanoparticles were prepared by solvothermal method, which formed the heterostructure of Cu₂O/TiO₂. Due to the heterostructure, the H₂ evolution rate under simulated solar irradiation was increasingly promoted. Meanwhile a certain amount of Cu particles which were confirmed by Transmission Electro Microscopy (TEM) and X-Ray Photoelectron Spectroscopy (XPS), formed on the surface of Cu₂O/TiO₂, and the photoactivity was accordingly further enhanced. The stabilized activity was maintained after many times irradiation. It is interesting that after a few hours irradiation the amount of Cu particles on the surface kept unchanged in the presence of Cu₂O and TiO₂. The Cu particles that formed during hydrogen generation reaction play a key role in the further enhancement of the hydrogen production activity. In this study, it is the first time to study the details on the formation of the stable ternary structure under simulated solar irradiation and their synergistic effect on the photoactivity of the water splitting.     

祁白术多酚提取工艺及抗氧化、抑菌活性研究

为研究表面活性剂十二烷基苯磺酸钠(sodium dodecyl sulfonate,SDS)协同超声波提取祁白术多酚的工艺参数,以多酚含量为指标,在单因素试验的基础上,采用响应面法优化提取工艺条件,并对祁白术多酚的体外抗氧化、抑菌活性进行研究。结果表明,祁白术多酚的最优工艺条件为:SDS添加量0.47%,超声波功率150 W,超声温度48℃,乙醇浓度64%,超声时间15 min,料液比1:25(g/mL),该条件下提取的多酚含量高达(38.53±0.51)mg/g。祁白术多酚具有显著的抗氧化活性,其对DPPH、ABTS自由基清除作用的半数抑制浓度(IC_(50))分别为0.056,0.050mg/mL。祁白术多酚对4种受试菌均有显著的抑制作用,多酚的质量浓度与抑制作用呈量效关系,其对大肠杆菌、金黄色葡萄球菌、绿脓杆菌的最低抑制浓度(MIC)为0.25mg/mL,对枯草芽孢杆菌的MIC为0.50mg/mL。     

合成环境友好型亚油酸镁清净剂

This paper mainly covers a method for preparing a highly alkaline magnesium linoleate solution with a totalbase number （TBN） value of 328 mg KOH/g using linoleic acid as the biodegradable raw material, which can substitute fortraditional lubricant detergents as an environmentally friendly detergent. Reaction conditions, including the molar ratio ofmagnesium oxide to linoleic acid, the molar ratio of methanol to magnesium oxide, the carbonation temperature, the molarratio of water to magnesium oxide, the flow rate of CO2 gas and the duration for injection of CO2 to magnesium oxide system,were optimized.