茶叶中乙酰甲胺磷及甲胺磷对映体的气相色谱法分离与测定

建立了乙酰甲胺磷、甲胺磷对映体在茶叶基质中的手性拆分与定量方法。比较了2种手性柱对乙酰甲胺磷及甲胺磷对映体的分离效果,并对分离效果较优的BGB-176手性柱进行色谱条件优化。茶叶样品经改良QuEChERS法处理后,气相色谱测定,外标法定量。在0.04,0.08,0.4 mg/kg 3个加标水平下,甲胺磷、乙酰甲胺磷的回收率分别为58.3%~66.4%和50.8%~57.6%,相对标准偏差(n=5)均小于7%。方法检出限为0.003~0.01 mg/kg。该方法简便、可靠,满足分析要求。通过实际样品的检测,发现乙酰甲胺磷、甲胺磷对映体在茶树上存在一定的降解差异。     

中药微量元素数据（16）

＂中药微量元素数据＂分为植物药、动物药、生物甲壳药、矿物药和中成药刊出,其中又细分为解表药、泻下药、清热药、利水渗湿药、祛风湿药、温里祛寒药、芳香化湿药、理气药、理血药、补养药、固涩药、化痰止咳药、消导药、熄风镇痛药、养心安神药、芳香开窍药、外用药、驱虫药、各类中药煎煮液。 检测的中药747种,共6 780味。每种药包括药名、学名、科属、部位、产地、元素含量、分析方法和文献来源等8个内容。以表格形式表示。每味药物最多测定38种元素,最少测定4种元素,平均测定17种元素,共展示出的元素数据约12万个。 每一个数据含义非常深刻,如序号为113的黄芩,共测定河北、山西、辽宁、黑龙江、山东、云南、四川、河南、吉林、陕西、甘肃、内蒙古、江苏等50个不同产地黄芩中的20种元素。又如序号为114的猕猴桃,共测定其中花、果、叶、枝、茎、根、皮、汁等8个不同部位中的23种元素。从元素的角度去研究中药不同产地、不同部位的药用功效,很有科研价值和实用意义。还可以用模式识别法去研究微量元素与中药的解表、清热、理气、理血等药性的关系,指导合理用药和配伍,深入研究中药与元素数据的关系,可以发现其中许多意想不到的科学规律。 ＂数据＂所参考的1 036条文献,全是公开发表的论文和专著,是中国科研人员使用34种先进的分析测试方法所得的分析测试数据,是研究课题的＂数据＂,有高度的可靠性。对中药进行＂解剖＂测试,不但测定其＂全身＂中的元素,还测定其不同＂器官＂中的元素含量,如人参,既测定全参,又测定人参子、人参叶、人参皮、人参花、人参芦、人参茎、人参果、人参须等8个不同部位的元素含量,用元素功能指导临床用药很有帮助,甚至有些可用替代药,而且用中药治疗的阴虚、阳虚?     

采用CO吸附原位红外光谱研究Pt/TiO_2光催化体系中助催化剂作用

采用CO作为探针分子,将原位透射红外光谱应用于研究助催化剂Pt在Pt/TiO2光催化体系中的作用.实验发现,光照条件下,CO的覆盖度及样品温度没有明显变化,CO在Pt/TiO2上的吸附峰红移11 cm–1,在Pt/Al2O3上的吸附峰没有位移,表明CO在Pt/TiO2上的红移来源于TiO2上的光生电子转移到Pt上,这解释了为什么加入Pt助催化剂可提高光催化产氢活性.     

表面活性剂辅助共沉淀法制备Ni-Mg-Al固体碱催化剂用于CH_4-CO_2重整反应

采用表面活性剂辅助共沉淀法制备了Ni-Mg-Al固体碱催化剂并用于CH4-CO2重整反应,探讨了表面活性剂对Ni(111),Ni(200)晶面的择优取向作用,在800℃下比较了不同表面活性剂制备的催化剂的催化性能,详细考察了CTAB制备的催化剂CB-LDO在不同反应温度下的催化活性和稳定性.采用红外光谱、X射线衍射、程序升温还原、X射线光电子能谱、高分辨透射电镜和程序升温氧化等表征手段分析了催化剂的活性、稳定性和失活原因.结果表明,四丙基氢氧化铵(TPAOH)促进Ni(200)的生长,而聚氧乙烯-聚氧丙烯-聚氧乙烯(P123)、聚乙烯吡咯烷酮(PVP)和十六烷基三甲基溴化铵(CTAB)抑制Ni(200)晶面的生长;Ni(200)的结晶程度对CH4的活化起到关键的作用,催化剂CB-LDO在高温下反应会发生晶型的转化,Ni(200)晶面由于反应过程中生成NiAl2O4尖晶石而得到缓慢释放,使催化剂的活性得以维持较高的水平.     

采用CO吸附原位红外光谱研究Pt/TiO2光催化体系中助催化剂作用

采用CO作为探针分子,将原位透射红外光谱应用于研究助催化剂Pt在Pt/TiO2光催化体系中的作用.实验发现,光照条件下,CO的覆盖度及样品温度没有明显变化,CO在Pt/TiO2上的吸附峰红移11 cm–1,在Pt/Al2O3上的吸附峰没有位移,表明CO在Pt/TiO2上的红移来源于TiO2上的光生电子转移到Pt上,这解释了为什么加入Pt助催化剂可提高光催化产氢活性.     

Synthesis and Characterization of Two Binuclear Macrocyclic Zinc(Ⅱ) Complexes by Anion Exchange

Two macrocyclic zinc(II) complexes {[ZnL(VO3)2]·0.33H2O}n(1) and [ZnL(H2O)2][Ni(CN)4](2)(L = 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane) have been obtained from the reactions of [ZnL](ClO4)2 with NH4VO3 and K2[Ni(CN)4], respectively, and structurally characterized by elemental analysis, IR, XRPD, TG and X-ray diffraction. Single-crystal X-ray diffraction analyses indicated that the Zn(II) atom lies on an inversion center and is octahedrally coordinated by four nitrogen atoms of the tetradentate macrocyclic ligand in the equatorial plane and two oxygen atoms of [VO4] tetrahedra in the axial positions in 1, and two oxygen atoms of two water molecules in 2. Complex 1 shows a three-dimensional structure, which is constructed by the links of [VO3]nn- chains with [ZnL]2+, forming one-dimensional channels occupied by guest water molecules. The monomers of [ZnL(H2O)2]2+ and [Ni(CN)4]2- are connected through the intermolecular hydrogen bonds to form a two-dimensional sheet in complex 2.     

Synthesis,Crystal Structure and Luminescent Property of Cadmium Complex Based on 2-（2-（1Hbenzo[d]imidazol-2-yl）benzyl）-1H-benzo[d]-imidazole

The complex [Cd(bbb)Cl2]·DMF·H2O, where bbb is 2-(2-(1H-benzo[d]imidazol-2-yl)benzyl)-1H-benzo[d]imidazole, was synthesized and characterized by X-ray single-crystal structure analyses. For the complex: C24H25Cl2CdN5O2, Mr = 598.77, crystal system, triclinic, space group P1, a = 9.9878(12), b = 10.0008(12), c = 13.2217(15) , α = 80.674(2), β = 72.158(2), γ = 86.776(2)°, V = 1240.5(3) 3, Z = 2, Dc = 1.598 g/cm3, λ = 0.71073, μ(MoKα) = 1.127 mm–1, F(000) = 600, S = 1.04, R = 0.0905 and wR = 0.3088 for 4805 observed reflections with I 2σ(I). It is a neutral complex. The distorted tetrahedral geometry of cadmium ion is coordinated by two nitrogen atoms of ligand and two chloride ions. The complex emits blue green luminescence with emission peaks at 480 nm in DMF solution.     

Morphology Evolution of Poly（vinylidene fluoride） Membranes during Supercritical CO2 Assisted Phase Inversion

A supercritical carbon dioxide（Sc CO2） assisted phase inversion was developed to produce microporous poly（vinylidene fluoride）（PVDF） membranes whose morphology characteristics arise from both liquid-liquid demixing and solid-liquid demixing（crystallization）. This result was confirmed by Fourier transform infrared spectroscopy（FTIR）, from which both α and β crystals were found. As revealed by contact angle experiment, the PVDF membranes prepared via Sc CO2 assisted phase inversion were more hydrophobic compared with the control membrane produced via conventional immersionprecipitation technique. In particular, the sample with 15 wt% PVDF prepared at 45 °C and 13 MPa exhibited a contact angle of 142°, which was mainly caused by the multilevel micro- and nano- structure. The effects of polyethylene glycol（PEG）, polyvinyl pyrrolidone（PVP） and lithium chloride（Li Cl） on the structures and crystal form were investigated. PVP promoted the formation of β phase crystal form, while PEG boosts the evolution of α phase. Li Cl restrained the crystallization degree of PVDF membrane under Sc CO2.     

Rapid Isolation of a Facultative Anaerobic Electrochemically Active Bacterium Capable of Oxidizing Acetate for Electrogenesis and Azo Dyes Reduction

In this study, 27 strains of electrochemically active bacteria (EAB) were rapidly isolated and their capabilities of extracellular electron transfer were identified using a photometric method based on WO₃ nanoclusters. These strains caused color change of WO₃ from white to blue in a 24-well agar plate within 40 h. Most of the isolated EAB strains belonged to the genera of Aeromonas and Shewanella. One isolate, Pantoea agglomerans S5-44, was identified as an EAB that can utilize acetate as the carbon source to produce electricity and reduce azo dyes under anaerobic conditions. The results confirmed the capability of P. agglomerans S5-44 for extracellular electron transfer. The isolation of this acetate-utilizing, facultative EBA reveals the metabolic diversity of environmental bacteria. Such strains have great potential for environmental applications, especially at interfaces of aerobic and anaerobic environments, where acetate is the main available carbon source.     

Plasma-Induced Synthesis of CuO Nanofibers and ZnO Nanoflowers in Water

Fiber-shaped cupric oxide (CuO) nanoparticles and flower-shaped ZnO nanoparticles were facilely synthesized by plasma-induced technique directly from copper and zinc electrode pair in water, respectively. The phase composition, morphologies and optical property of nanoparticles have been investigated by energy dispersive X-ray analysis, X-ray powder diffraction, transmission electron microscopy and UV–vis. The in situ analysis by an optical emission spectroscopy clarified the formation mechanism. Plasma was generated from the discharge between a metal electrode pair in water by a pulse direct current power. CuO and ZnO nanoparticles were synthesized via almost the same formation mechanism, which were prepared via the rapid energetic radicals’ bombardment to electrodes’ surface, atom vapour diffusion, plasma expansion, solution medium condensation, and in situ oxygen reaction and further growth. This novel plasma-induced technique will become a potential application in nanomaterials synthesis.