长江口盐度梯度下有色溶解有机物的分布、来源与季节变化

通过测定有色溶解有机物（CDOM）的吸收光谱和荧光光谱研究了2015年3月和7月长江口盐度梯度下CDOM的分布、组成、来源及河口混合行为等。利用激发发射矩阵荧光光谱（EEMs）并结合平行因子分析（PARAFAC）,研究了CDOM的荧光组分特征,共识别出两类4个荧光组分组成,即类腐殖质荧光组分C1（260,375/490 nm）、C2（365/440 nm）、C3（330/400 nm）及类蛋白质荧光组分C4（295/345 nm）。结果表明,3月和7月,4种荧光组分的分布模式与总荧光强度都基本一致:从口内到口外,先升高后降低,且4种组分都在河口呈现不保守混合行为,在最大浑浊带处存在添加过程,达到峰值,在口外有去除过程。3月腐殖化指数HIX范围在1.12~7.19,而7月HIX的范围在0.87~6.71;生物指数BIX在3月范围在0.76~1.11,7月为0.62~1.15,表明3月CDOM的腐殖化程度较7月高,而自生贡献比例较7月略低。3月吸收系数α（355）的平均值为0.55 m-1 ,7月的略高,为0.61 m-1,表明7月长江口CDOM的含量略高。光谱斜率比值S_R的季节性变化不大,都是近岸低,远岸高,表明CDOM的平均分子质量从口内到口外在逐渐增加。     

Determination of Ca,K, Mg and Fe in four fish species by FAAS

A method for determining calcium(Ca),potassium(K),magnesium(Mg) and iron(Fe) in four fish species was optimized and validated.It included microwave mineralization of the samples and subsequent quantification by flame atomic absorption spectroscopy(FAAS) with Zeeman-effect background correction.Using HNO3(65%) and H2O2(33%) as extraction solutions,the optimal conditions of extraction were established as follows:0.5 g of sample mass;microwave time program of 300 W/5 min and 600 W/5 min.The method was free of matrix interferences.The linear correlation coefficients were ≥0.9991,the recovery percentage of analytes was from 99.31% to 103.70% and the RSD(relative standard deviation) was lower than 2.06%.The detection limits obtained were 32.3,43.2,14.0 and 68.6 ng mL-1 for Ca,K,Mg and Fe in FAAS respectively.It is shown that the method is rapid,simple,sensitive and accurate.The method was applied to the studies of digestibility and measurement of these nutrients in samples of fish collected from Norway,Japan and China.     

运用防屈曲支撑的混凝土框架结构的抗震性能研究

简要介绍地震安全社区的实现途径以及防屈曲支撑的构成和性能参数。运用ABAQUS软件对有无安装防屈曲支撑的钢筋混凝土框架模型进行动力时程分析,总结分析防屈曲支撑对钢筋混凝土框架结构的减震效果。结果表明,防屈曲支撑能大大降低钢筋混凝土框架结构在罕遇地震作用下的层间位移角,提高建筑物抗震性能,使地震安全社区中抗震设防烈度为Ⅶ度的建筑物能够抵御Ⅷ度罕遇地震。     

近红外分析提取蚀变信息及其找矿实践——以甘肃岗岔金矿为例

甘肃岗岔金矿位于秦岭造山带西段北侧之夏河—礼县成矿带西段,属构造破碎蚀变岩型金矿床,目前探明储量已达中型。采用近红外矿物分析技术对矿区蚀变特征的研究结果表明,从远矿到近矿(矿体)存在3个明显特征:①远矿蚀变矿物组合主要为高岭石+地开石+蒙脱石±伊利石,近矿蚀变矿物组合主要为白云母+伊利石±次生石英;②1 400 nm结晶水特征吸收峰、1 910 nm吸附水特征吸收峰和2 200 nm Al-OH特征吸收峰均表现出由远矿至近矿峰型变浅的趋势;③普遍存在的蚀变矿物伊利石,在近矿位置其结晶度高,远矿位置结晶度低。上述分带特征对于进一步找矿具有重要的指导意义。     

水平孔某型喷反装置的结构优化实验

通过类比相关喷反机具设计,设计并制造了某型喷反装置模型。之后进行了结构优化实验研究,得到了一系列适于现场工况的喷反装置关键器件优化组合,并认识到该类喷反装置中,喉管喷嘴组合模式对吸水效率的影响最大,而流量参数m、间距S对吸水效率的影响较小;喷嘴喷速大于40 m/s时,其吸水效率急剧下降。      

Novel Polymeric Resin for Solid Phase Extraction and Determination of Lead in Waters

Interest in preconcentration techniques for the determination of metals at ultratrace levels still continues increasingly because of some disadvantages of flameless atomic absorption spectrometry and the high costs of other sensitive methods in compared to flame atomic absorption spectrometry (FAAS). Among preconcentration techniques, solid‐phase extraction is the most popular because of a number of advantages. In this work, thiol‐containing sulfonamide resin was synthesized, characterized, and applied as a new sorption material for solid phase extraction and determination of lead in natural water samples. The optimization of experimental conditions was performed using the parameters including pH, contact time, and volumes of initial and elution solutions. After preconcentration procedure, FAAS was used for determinations. The synthesized resin exhibits the superiority in compared to the other adsorption reagents because of the fact that there is no necessity of any complexing reagent as well as high sorption capacity. Consequently, 280‐fold improvement in the sensitivity of analytical scheme was achieved by combining the slotted tube atom trap‐atomic absorption spectrometry (STAT‐FAAS) and the developed preconcentration method. The limit of detection was found to be 0.15 ng mL^?1. The Pb²⁺ concentrations in the studied water samples were found to be in the range of 0.9–6.7 ng mL^?1.     

爆破地震效应主控因素分析及减震措施探讨

爆破地震动机制复杂,影响因素众多,为找出影响爆破地震效应的主控因素,引入灰色系统中灰色关联理论。通过实例分析,得到了影响爆破地震效应的主次关系,指出钻孔超深、孔网参数是影响爆破地震效应的主控因素,通过优化这些爆破参数是降低爆破地震效应最有效的方法。灰色关联分析方法计算简单、结果可靠、使用简便,在爆破工程中有一定的应用价值。     

高分辨连续光源原子吸收光谱法测定植物中的磷

利用连续光源原子吸收光谱法,通过测定磷元素在乙炔-空气火焰条件下形成的PO双原子分子的吸光度,从而确定植物样品中磷含量。实验研究了乙炔-空气比例和燃烧器高度对PO分子吸光度的影响及其他共存元素的光谱干扰和化学干扰。通过对植物标准物质中磷的测定比对证明:利用连续光源原子吸收光谱法,在乙炔-空气火焰条件下以PO分子测定植物样品中的磷是一种简单、快速、有效的方法。     

泡塑吸附-电感耦合等离子体发射光谱法测定矿石中的金

试样在650℃烧制、王水溶解、泡塑振荡吸附、硫脲解脱,用电感耦合等离子体发射光谱法测定矿石中的金量,克服了原子吸收光谱法对低含量金测定稳定性和精密度差、对高含量金测定分取误差大和返工率高等不足,缩短了分析时间。方法经国家一级标准物质分析验证,结果与标准值相符。对二级标准物质测定的方法精密度(RSD,n=12)为6.45%。方法检出限为0.138μg/g,线性范围宽,适用于矿石中0.2μg/g以上金的测定。     

Searching for the missing baryons in theWarm‐Hot Intergalactic Medium

At low redshift (z < 2), almost half of the baryons in the Universe are not found in bound structures like galaxies and clusters and therefore most likely reside in a Warm‐Hot Intergalactic Medium (WHIM), as predicted by simulations. Attempts to detect WHIM filaments at cosmological distances in absorption towards bright background sources have yielded controversial results that I review here. I argue that a secure detection of absorption features by the WHIM is at the limit of the XMM‐Newton capabilities, but feasible. A proper characterisation of the whole WHIM belongs to the realm of future X‐ray missions. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)