湘潭市土壤重金属地球化学特征的统计分析

运用相关性分析、聚类分析、因子分析及直方图分析对湘潭市土壤重金属地球化学特征进行了研究。结果表明：（1）As、Cd、Cu、zn与pH值呈显著正相关;As与Cd、Cu、Ph、zn呈显著正相关;Cd与As、Cu、Pb呈显著正相关;Cu与As、Cd、Pb、Zn呈显著正相关;Pb与As、Cu、zn呈显著正相关;Zn与As、Cd、Cu、Pb呈显著正相关;Hg与其他重金属及pH值不具有显著相关关系。（2）本区重金属分为两类,即Cr、pH、As、Zn、Cu、Cd;Hg、Pb。（3）区内重金属存在3种主要元素组合即As—Cd—Cu—Pb—Zn—pH;Cr—Hg;Cd—pH;（4）区内重金属As、Cd、Cr、Cu、Hg、Zn服从正态分布。（5）通过前人对湘潭市土壤重金属进行生态地球化学评价可知,区内Cd、Hg属重污染,从统计分析结果来看,Cd随着本区pH值变化而变化,并与As、Cu、Pb相关性显著;而Hg与pH值及其它重金属之间没有必然联系。     

长沙市公园土壤重金属调查与评价

根据对长沙市公园土壤的重金属含量测定结果,采用内梅罗综合污染指数对其进行了评价,并运用相关分析、聚类分析进行了统计分析。研究结果表明,岳麓山公园、烈士公园土壤重金属含量较低,月亮岛土壤重金属含量较高。通过内梅罗综合污染指数评价,认为岳麓山公园土壤属于安全级别,未发生重金属污染;烈士公园土壤中Cr、Hg、Cd属轻污染,其余重金属无污染;月亮岛中土壤重金属污染相对严重,其中Zn、Cd属重污染。通过相关分析表明,与pH值呈正相关的为Cr、Zn、Pb、As;聚类分析研究表明,在距离为20分为两大类Cr、Zn;Hg、Cd、Cu、As、Pb、pH。     

长株潭地区土壤环境地球化学研究

通过长株潭地区环境地球化学调查工作的实施,对长株潭地区土壤环境地球化学研究的工作方法进行了初步研究。结果显示,工业区重金属中Cu、Zn、Pb、As、Cd的污染较严重,尤其是Cd,这说明工业生产所产生的废水、废气、废渣是引起土壤中重金属污染的主要原因;各功能区重金属含量由高到低顺序为:工业区,居民区,商业办公区,休闲区,居民区和休闲区中重金属超标可能是由生活废水、生活垃圾和汽车尾气引起的。     

成都市农业土壤重金属污染特征初步研究

对成都市农业土壤中七种重金属元素Pb、Hg、Cr、As、Cu、Zn和Cd进行了测定和研究,并进行了潜在生态风险评价。结果表明,成都市农业土壤重金属元素含量分别为:Pb 77.27mg/kg,Hg 0.31 mg/kg,Cr 59.50 mg/kg,As 11.27 mg/kg,Cu 42.52 mg/kg,Zn 227.00 mg/kg,Cd0.36 mg/kg;重金属潜在的生态危害因子表明,Hg和Cd达到中等生态危害程度,Pb、As、Cu、Zn、Cr达到轻微生态危害;多种重金属的生态系统的潜在生态风险指数(RI)表明,成都市农业土壤生态危害级别为中等生态危害。     

重庆都市圈土壤重金属元素形态分析

选取重庆市表层土壤样品,采用Tessier A连续提取法研究了土壤中Hg、Cd、Cr、Cu、Zn、Ni等6种重金属元素进行形态分析。结果表明,在该区域表层土壤中Cd以离子交换态为主,其余的重金属元素均以残渣态为主,说明Cd较活泼,对环境有潜在的影响力,Hg、Cu、Zn、Ni、Cr相对比较稳定。     

湖南长沙城市土壤地质环境综合评价

对长沙市土壤重金属Cu、Pb、Zn、Cd、Cr、Hg、As污染现状进行了调查与评价。结果表明,长沙市110个样本中总体Cd、Cr污染程度已经属于重污染,Zn、As属于中污染,Cu、Pb、Hg属于轻度污染;不同母岩类型土壤中泥盆纪砂页岩、新生代沉积物、花岗岩的重金属含量较高。     

锦州市大气颗粒物中重金属形态分析及生物有效性评价

研究了锦州市秋冬季大气颗粒物中重金属元素Al、Cd、Cr、Cu、Zn、Pb的化学形态和生物有效性。结果表明锦州市主要商业街和交通主干道的PM10和PM2.5污染比较严重,冬季取暖期间PM2.5平均超标3.4倍,最高超标达8.1倍。PM10和PM2.5中重金属Zn、Pb和Cu的含量较高,在PM10中最大值分别为0.903、0.392、0.272μg·m-3。Cd、Cu、Pb、Zn在大气颗粒物中主要以酸可提取态(F1)和氧化物结合态(F2)存在,这两种形态在环境中易迁移和转化,特别是Cd的F1和F2形态含量之和占总量的95%,其毒性较大。Cd的含量较低(0.006~0.018μg·m-3),但富集因子高(1880~2819),表明Cd人为污染严重;Cu、Zn和Pb的富集因子较高(100),表明其受人类活动影响较大。Cd和Zn在PM2.5中生物有效性系数分别为0.56和0.58,对大气环境和人体健康危害较大。     

杭州西郊茶园土壤重金属的积累特点与来源分析

选择了杭州市西部近郊、远郊和农村等3个受人为不同程度影响的区块,分析了同为第四纪红土母质发育的茶园与附近林地土壤剖面中重金属垂直分布的特点,探讨了茶园土壤重金属的来源。结果表明,相同区块的茶园与附近林地土壤重金属Pb、Cd和Hg剖面分布相似,均随剖面深度下降,表土Pb、Cd和Hg含量随离城市距离增加而下降,说明研究区茶园土壤中重金属Pb、Cd和Hg的积累主要与大气沉降有关;茶园与附近林地土壤重金属Cu和Zn也随剖面深度而下降,但同一区块中茶园表土重金属Cu和Zn含量明显高于附近林地土壤,说明施肥等农业措施对茶园土壤Cu和Zn的积累有较大的影响;茶园土壤中Cu和Zn的积累与地理位置关系不大。茶园土壤中Cr和Co的积累不明显,并有淋失的趋势。     

微波消解-电感耦合等离子体质谱(ICP-MS)法同时测定畜禽粪便中7种重金属元素

粪便样品干燥、研磨后,称取0.25 g样品,加入8 mL硝酸,采用微波消解方法进行前处理.采用KED模式消除质谱干扰,采用内标校正消除非质谱干扰(Ge作为Cu、Zn、Cr的内标,Bi作为Hg和Pb的内标,Rh作为As和Cd的内标),建立了可同时测定畜禽粪便中Cu、Zn、Cr、As、Cd、Pb、Hg 7种重金属元素的微波...     

原子吸收光谱法测定烟叶中的重金属总量及形态分析

采用火焰原子吸收光谱法测定烟叶中Mn,Cu,Zn元素,石墨炉原子吸收光谱法测定Cd,Cr,Pb元素,以HNO3-H2O2微波消解法获取烟叶中的重金属总量,以超声水提取法获取水溶态重金属进行初级形态分析,以Tessier逐级提取法获取5种形态的重金属进行次级形态分析。实验结果表明,原子吸收光谱法检测6种重金属线性良好,相关系数(r2)不低于0.998 8,检出限为0.16~3.1μg·L-1。烟叶样品中Mn,Cu,Zn,Cd元素主要以可交换态和碳酸盐结合态的形式存在;Cr主要以残渣态的形式存在;而Pb主要以碳酸盐结合态和残渣态的形式存在。     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

Acid hydrolysis of carboxymethylcellulose of low degree of substitution

Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.     

恶臭嗅辨实验室建设探讨

针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

Estimation of Kinetic Parameters of Thermal Oxidation of Ilmenite

The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe₂O₃. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.     

Mechanism of action of base-catalyzed oxygenation of phenol derivatives

Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6.