Synthesis, Crystal Structure and Electrochemical Properties of One-dimensional Chain Coordination Polymer [Co(Ⅱ)(C6H5CH=CHCOOH)2(4,4''-bipy)(H2O)5]n

A one-dimensional chain coordination polymer [Co(Ⅱ)(C6H5CH=CHCOOH)2(4,4'-bipy)(H2O)5]n has been synthesized with cinnamylic acid, 4,4'-bipy and cobaltous chloride as raw materials. Crystal data for this complex: monoclinic, space group P21/c, a - 1.1481(3), b =1.1230(2), c = 1.1759(3) nm, β = 97.054(4)°, V = 1.5046(6) nm3, Mr= 617.50, Dc = 1.363 g/cm3, Z= 2, μ(MoKα) = 0.627 mm-1, F(000) = 646, S = 1.062, R 0.0443 and wR = 0.1178. The crystal structure shows that two neighboring cobalt(Ⅱ) ions are linked together by one 4,4'-bipy, and the whole complex molecule adopts a one-dimensional chain structure. Each cobalt(Ⅱ) ion is coordinated with two nitrogen atoms from two 4,4'-bipy molecules and four oxygen atoms from four water molecules, giving a distorted octahedral coordination geometry. The electrochemical properties were analyzed by combining with the crystal structure.     

固相萃取-液质联用法同时测定饮用水中双酚A和邻苯二甲酸二丁酯

建立了饮用水中痕量双酚A和邻苯二甲酸二丁酯同时测定的LC/MS-MS快速分析方法.水样中双酚A和邻苯二甲酸二丁酯经HLB固相萃取小柱富集,以V(乙腈)∶V(水)＝90∶10为流动相,选择双酚A m/z 227/212、邻苯二甲酸二丁酯m/z 301/228为检测离子对,利用多反应监测(MRM)和扫描时间分段检测技术实现正、负离子不同扫描模式一次完成.该方法对水样体积为250 mL时双酚A和邻苯二甲酸二丁酯的线性范围为0.4～40 ng/L,检出限分别为0.16和0.10 ng/L,低中高3个不同水平的加标平均回收率均在90%以上.应用于5种不同来源的饮用水及原水中双酚A和邻苯二甲酸二丁酯的测定.     

环境水样中百菌清残留的单滴微萃取-反相液相色谱测定

应用单滴微萃取(SDME)-反相液相色谱(RPLC)检测了环境水样中的百菌清残留.优化了单滴微萃取条件:环己烷萃取剂6 μL、单滴体积2 μL、搅拌速率350 r/min、萃取时间40 min、水溶液温度35 ℃、无盐度.水样经单滴微萃取后,使用Hypersil C18柱反相液相色谱分离测定百菌清.反相液相色谱条件:100%甲醇流动相、流速1.0 mL/min、柱温25 ℃、224 nm检测.方法的线性范围、检出限、相对标准偏差和富集倍数分别为1.0 ～50 μg/L、0.02 μg/L、6.1%和427倍.采用该法对环境水样中的百菌清残留进行了测定,环境水样的加标回收率为98% ～106%.     

金属锂二次电池锂负极改性

本文综述了金属锂二次电池中提高锂负极性能的研究进展。分别介绍了以下改性方法:对金属锂表面进行预处理,使其表面预先形成性能良好的固体电解质界面膜,或直接在其表面制备保护膜;在电解液中加入添加剂对锂电极进行表面改性;采用新型有机溶剂、离子液体、聚合物电解质、玻璃态固体电解质、塑晶固体电解质等电解质体系提高界面相容性;改进金属锂电极的制备工艺,如制备金属锂粉末多孔电极和电沉积锂电极、制备全固态薄膜锂电池以及利用物理方法处理锂电极。并在此基础上对今后的发展趋势进行了展望。     

某城区地下水环境质量评价

在对某研究区进行环境调查的基础之上,质予以评价,查明研究区内地下水环境质量现状。源合理利用和规划需要提供一定的依据。对区内地下水进行了取样分析,并对地下水水为该区域地下水资源利用、环境保护、土地资     

An overview of analytical methodologies for the determination of antibiotics in environmental waters

The widespread occurrence of antibiotics as contaminants in the aquatic environment has increased attention in the last years. The concern over the release of antibiotics into the environment is related primarily to the potential for the development of antimicrobial resistance among microorganisms. This article presents an overview of analytical methodologies for the determination of quinolone (Qs) and fluoroquinolone (FQs), macrolide (MLs), tetracycline (TCs), sulfonamide (SAs) antibiotics and trimethoprim (TMP) in different environmental waters. The analysis of these antibiotics has usually been carried out by high-performance liquid chromatography (HPLC) coupled to mass spectrometry (MS) or tandem mass spectrometry (MS/MS) and to a lesser extent by ultraviolet (UV) or fluorescence detection (FD). A very important step before LC analysis is sample preparation and extraction leading to elimination of interferences and prevention of matrix effect and preconcentration of target analytes.     

Identification of Hydroxyl on Ni(111)

Hydroxyl (OH) is identified and characterized on the Ni(111) surface by high‐resolution electron energy loss spectroscopy. We find clear evidence of stretching, bending, and translational modes that differ significantly from modes observed for H₂O and O on Ni(111). Hydroxyl may be produced from water by two different methods. Annealing of water co‐adsorbed with atomic oxygen at 85 K to above 170 K leads to the formation of OH with simultaneous desorption of excess water. Pure water layers treated in the same fashion show no dissociation. However, the exposure of pure water to 20 eV electrons at temperatures below 120 K produces OH in the presence of adsorbed H₂O. In combination with temperature‐programmed desorption studies, we show that the OH groups recombine between 180 and 240 K to form O and immediately desorbing H₂O. The lack of influence of co‐adsorbed H₂O at 85 K on the O? H stretching mode indicates that OH does not participate in a hydrogen‐bonding network.     

高效液相色谱-电喷雾串联质谱法检测环境水样中22种抗生素类药物

建立了高效液相色谱-电喷雾串联质谱(HPLC-ESI MS/MS)分析环境水样中22种抗生素类药物的方法。采用HLB固相萃取柱对环境水样中的目标化合物进行富集、净化,然后以6 mL氨水-甲醇(5:95, v/v)溶液洗脱。收集的洗脱液经氮气吹干至1 mL,然后进行HPLC-ESI MS/MS分离分析。色谱流动相A相为甲醇-乙腈(1:1, v/v), B相为0.3%(体积分数)甲酸水溶液(含0.1%(体积分数)甲酸铵,pH 2.9);色谱柱为XTerra MS C18柱。质谱检测采用正离子扫描,多反应监测模式。分别以自来水和污水作为基质,22种抗生素类药物的加标平均回收率分别为54.9%～130%和57.4%～138%,相对标准偏差(n=3)分别为2.85%～28.6%和2.02%～23.2%;方法的检出限为0.05～0.5 ng/L。将建立的方法应用于北京市高碑店湖和小清河水样的分析,结果表明在两个水样中均有部分抗生素类药物检出。     

Water transfer characteristics in the vertical direction during methane hydrate formation and dissociation processes inside non-saturated media

In order to study water transfer characteristics inside non-saturated media during methane hydrate formation and dissociation processes, water changes on the top, middle and bottom locations of experimental media during the reaction processes were continuously followed with a novel apparatus with three pF-meter sensors. Coarse sand, fine sand and loess were chosen as experimental media. It was experimentally observed that methane hydrate was easier formed inside coarse sand and fine sand than inside loess. Methane hydrate formation configuration and water transfer characteristics during methane hydrate formation processes were very different among the different non-saturated media, which were important for understanding methane hydrate formation and dissociation mechanism inside sediments in nature.     

纳米零价铁去除水中重金属离子的研究进展

重金属离子危害严重.本文综述了近几年纳米零价铁去除水中重金属离子的研究,总结了纳米零价铁去除水中重金属离子的机理,主要包括:纳米零价铁的表面吸附-配合、还原、吸附-还原,并对纳米零价铁在这一领域的应用进行了展望.