Plant Uptake/Bioavailability of Heavy Metals from the Contaminated Soil after Treatment with Humus Soil and Hydroxyapatite

Cellulose nitrate membrane filter was used for the preconcentration-separation of Cu, Co, Cd, Pb and Cr ions. The analyte ions were collected on the membrane filter by the aid of carmine. Then membrane filter was dissolved by using nitric acid. The levels of the analytes in the final solutions were determined by flame atomic absorption spectrometry (FAAS). The analytical parameters including pH, amounts of carmine, sample volumes etc. have been optimized. No influences have been observed from the matrix ions. The detection limits for analytes were in the range of 0.08 μg/l-0.93 μg/l. The validation of the procedure was checked by the analysis of standard reference sediment (GBW 07309). The present method has been successfully applied for the FAAS determinations of analyte ions in real samples including black tea and magnesium salts.     

不同虫压下转Bt基因水稻与非转基因水稻生态适合度差异

为了解转基因水稻的基因扩散效率和潜在生态风险,以转Bt抗虫水稻Bt63、R1、R2和非转基因常规水稻Ⅱ优838为试材,采用高、低两个不同虫害胁迫水平和转基因与非转基因水稻相间种植方式,通过观察水稻植株营养生长、结实以及对螟虫危害的抗性表现等差异,研究比较了Bt外源基因插入后对水稻植株适合度的影响.结果表明:在低虫害胁迫条件下,转Bt基因水稻在植株分蘖数、生物量鲜重等营养生长指标方面与非转基因对照品系间无明显差异,但株高、穗长、穗重等指标不及对照,且R2和Bt63与对照间差异显著;在高虫害胁迫条件下,3个转Bt基因水稻品系的分蘖数、穗长、穗重等指标明显高于对照.而不同转基因品系株高适合度效应不同,这可能与受体本身的特性相关.3种转基因水稻的单株结实粒数、千粒重与对照在两种虫害胁迫条件下均无显著性差异,Bt基因对受体植株的结实影响不明显.在高虫害胁迫条件下,3种转Bt基因水稻的抗虫能力均显著优于非转基因水稻,表明Bt基因对受体植株的抗虫性影响显著.同时,本研究结果还表明转Bt基因水稻的适合度代价较小,预示了抗虫转基因水稻外源Bt基因在一定环境条件下具有逃逸的可能,但这种风险比较小.     

Determination of Cd,Cr, Cu,Pb and Zn from various water samples with use of FAAS techniques after the solid phase extraction on rice bran

A facile and novel method has been developed for the determination of cadmium, chromium, copper, lead, and zinc from various water samples using FAAS. In the present investigation, a syringe was loaded with sorbent (rice bran) for the separation and enrichment of cadmium, chromium, copper, lead, and zinc, prior to their analysis by flame atomic absorption spectrometry which was described to substitute the batch and column techniques. The syringe was loaded with 2.0 g of sorbent in order to retain the analyte elements. Six milliliter of sample solution (pH 8.0 ± 0.2) was drawn into the syringe in 15 s and discharged over a period of 15 s. Then, 2.0 M HCl eluent was drawn into the syringe and ejected back to desorb the analyte elements. At the optimum conditions, the percentage recoveries of Cd, Cr, Cu, Pb, and Zn was in the range of 95.5–99.4% with SD of 0.10%. The elements could be concentrated by drawing and discharging several portions of sample successively. The detailed study of various interferences made the confirmation of the method highly selective. The risk of contamination is less than that with the column technique. The method was successfully applied for the determination of Cd, Cr, Cu, Pb, and Zn in spiked and natural water samples. The results obtained are in good agreement with the reported methods at the 95% confidence level.     

APDC-MIBK萃取火焰原子吸收分光光度法测定生活垃圾堆肥产品中铅、镉的研究

通过试验研究,建立了硝酸-氢氟酸-高氯酸消解、APDC-MIBK萃取火焰原子吸收分光光度法测定生活垃圾堆肥产品中的铅、镉.该方法铅的检出限为2mg/kg,镉的检出限为0.2mg/kg(按称取0.5g试样消解定容至50ml计算),用于不同地域堆肥样品测定,铅、镉的相对标准偏差(RsD)分别为2.29%～8.16%和5.17%～11.7%,加标回收率介于86.8%～107.2%和88.0%～108.0%之间.     

上拔水平力组合荷载作用下混凝土扩展基础承载性能试验

介绍了2个相同尺寸混凝土扩展基础分别在上拔、上拔与水平力组合荷载作用下的室内足尺试验概况,并根据加载过程中的基顶荷载位移、基础主柱纵筋应变、扩大端钢筋和混凝土应变等试验数据,分析了2种荷载工况下混凝土扩展基础的承载变形特性及混凝土裂缝发展规律。结果表明:①上拔和水平力组合荷载作用下,基础上拔荷载位移曲线呈现出两阶段特性,而水平位移曲线随水平力增加近似呈线性增加,水平荷载降低了扩展基础的抗拔承载性能;②上拔和水平力组合荷载作用下,基础主柱横截面部分受拉、部分承压,在基础立柱与底板连接处的拉应力最大,混凝土裂缝未贯穿全截面,而在上拔荷载作用下,混凝土扩展基础主柱全断面受拉,裂缝贯穿全断面。     

正态信息扩散法在确定河冰抗压强度概率分布中的应用

将正态信息扩散法应用于小样本条件下河冰抗压强度概率密度函数的确定,建立了小样本条件下河冰抗压强度概率分布,并结合K-S检验法和河冰抗压强度试验数据,分析了该方法的合理性。结果表明,本文方法可以较好解决小样本情况下河冰抗压强度概率分布的确定问题,正态信息扩散分布更加接近河冰抗压强度的真实分布,并优于经典分布的拟合方法。     

萃取富集—火焰原子吸收法测定环境水中痕量砷

联合应用高效雾化器、缝式石英管火焰原子吸收法,采用萃取富集技术测定砷,使砷的灵敏度改善267倍,同时消除了大量盐类的干扰,避免了钠、铝等对石英管的损坏。考察了溶液酸度、碘化钾用量、共存离子等因素对实验的影响。该方法的线性范围为0～25μg／L,检出限为。3μg／L,相对标准偏差为3．2％,回收率为97．8％～101．0％,用于环境水样中痕量砷的监测,结果令人满意。     

气相色谱——火焰光度法测定废水中黄磷的方法研究

研究了以苯为萃取剂，用气相色谱－－火焰光度法测定废水中的微量黄磷。结果色谱分离良好，萃取率大于９４％，水样易于保存，溶剂和杂质不干扰测定，水样加标回收率大于８８．４８％，精密度重复测定的变异系数不大于３．２％，定性检出限为２μｇ／Ｌ，定性检出限为６μｇ／Ｌ。     

一种分离培养硫酸盐还原菌的改进方法

On the base of the characteristics of sulfate-reducing bacteria (SRB) growth and dish cultivated method, a new method for isolation and cultivation of SRB is established. It is dilution spread and repeat dish sandwish cultivated method with the exellence of dilution spread and embeded growth, and it can help separation and identification of SRB. The method has simple operation and less equipment. And using this method, the natural SRB drop was successfully gained, and small agar pieces containing SRB drop were acquired in easiness. The brief SRB transfering operation in strict anaerobic condition was in-deed realized. Fig 1, Ref 7.     

特长公路隧道内的横通道间距和车行间距研究

隧道火灾,尤其是长大公路、铁路隧道火灾,往往是灾难性的。因此,基于性能化防火设计原理,对雪峰山特长公路隧道的横通道间距和车行间距进行了研究。对中等规模20 MW的火灾,按照规范建议的3 m/s的风速进行通风的情况下,先用CFD软件模拟计算火灾危险时间Tfire,然后由疏散模型中的经验公式计算人员疏散时间Tevac,比较分析不同横通道间距下人员疏散的安全性;同时为了避免隧道内车辆间的引燃,利用辐射换热原理,对车辆间的火灾蔓延性进行了分析。模拟结果为:最佳横通道间距约为290 m,最小引燃间距为6 m。考虑到建设成本的问题,建议雪峰山隧道的横通道间距改为300 m;同时,考虑到后继车辆的刹车及不同的行车速度等因素,建议特长隧道内车距最好要大于110 m;