高温高压下流体中电解质活度系数的确定

高温高压下流体中电解质的活度系数在地球化学领域有着广泛的应用。本实验测量了100—500℃、0．11—12GPa下0．01mol／L KCl溶液的电导率,并利用Hueckel方程由实验确定的摩尔电导和极限摩尔电导计算出了KCl的平均摩尔活度系数。平均摩尔活度系数随温度升高而减小,随压力升高而增大,而在高温高压下随温度压力的升高几乎保持恒定。     

山东刚玉巨晶中包裹体研究Ⅱ：氯化物与地幔液相的物质组成

利用电子探针,扫描电镜在山东碱性玄武岩中产出的刚玉巨晶中发现了许多氯化物包裹体,这些氯化物可能以石盐为主,它的发现表明在较浅深度的地幔液相中也存在较多的氯。     

High chloride concentrations in the soil and groundwater under an oak hedge in the West of France: an indicator of evapotranspiration and water movement

Chloride is a major anion in soil water and its concentration rises essentially as a function of evapotranspiration. Compared to herbaceous vegetation, high transpiration rates are measured for isolated trees, shelterbelts or hedgerows. This article deals with the influence of a tree hedge on the soil and groundwater Cl^? concentrations and the possibility of using Cl^? as an indicator of transpiration and water movements near the tree rows. Cl^? concentrations were measured over 1 year at different depths in the unsaturated zone and in the groundwater along a transect intersecting a bottomland oak hedge. We observed a strong spatial heterogeneity of Cl^? concentrations, with very high values up to 2 g l^?1 in the unsaturated zone and 1·2 g l^?1 in the upper part of the groundwater. This contrasts with the low and homogeneous concentrations (60–70 mg l^?1) in the deeper part of the groundwater. Cl^? accumulation in the unsaturated zone at the end of the vegetation season allows us to identify the active root zone extension of trees. In winter, upslope of the tree row, downwards leaching partly renews the soil solution in the root zone, while the slow water movement under the trees or farther downslope results in Cl^? accumulation and leads to a salinization of the soil and groundwater. This salinization is of the same order as experimental conditions produce negative effects on oak seedlings. The measurement of Cl^? concentrations in the unsaturated zone under tree rows at the end of the vegetation season would indicate whether certain topographic, pedological or climatic conditions are likely to favour a strong salinization of the soil, as observed in the present study. Copyright © 2009 John Wiley & Sons, Ltd.     

青海盐湖氯化镁资源开发

青海盐湖中有丰富的氯化镁资源 ,由氯化镁可生产多种镁产品 ,特别是以青海盐湖卤水提钾老卤中的镁资源开发镁产品 ,既可获得经济效益 ,又可治理氯化镁老卤造成的危害与污染 ;开展高值镁产品的研究可为盐湖开发的纵深发展打基础     

Chloride source delineation in an urban-agricultural watershed: Deicing agents versus agricultural contributions

Analyses (n = 525) of chloride (Cl⁻), bromide (Br⁻), nitrate as nitrogen (NO₃-N), sodium (Na⁺), calcium (Ca²⁺) and potassium (K⁺) in stream water, tile-drain water and groundwater were conducted in an urban-agricultural watershed (10% urban/impervious, 87% agriculture) to explore potential differences in the signature of Cl⁻ originating from an urban source as compared with an agricultural source. Only during winter recharge events did measured Cl⁻ concentrations exceed the 230 mg/L chronic threshold. At base flow, nearly all surface water and tile water samples had Cl⁻ concentrations above the calculated background threshold of 18 mg/L. Mann–Whitney U tests revealed ratios of Cl⁻ to Br⁻ (p = .045), to NO₃-N (p < .0001), to Ca²⁺ (p < .0001), and to Na⁺ (p < .0001) to be significantly different between urban and agricultural waters. While Cl⁻ ratios indicate that road salt was the dominant source of Cl⁻ in the watershed, potassium chloride fertilizer contributed as an important secondary source. Deicing in watersheds where urban land use is minimal had a profound impact on Cl⁻ dynamics; however, agricultural practices contributed Cl⁻ year-round, elevating stream base flow Cl⁻ concentrations above the background level.     

不同氮源对微小亚历山大藻生长和毒素产生的影响

通过尿素、氯化铵、酵母浸出粉和硝酸钠等氮源对微小亚历山大藻(Alexandrium minutum)生长及毒素产生的影响研究,分析了微小亚历山大藻对不同氮源利用状况的差异.结果表明,在氮饥饿条件下,加入硝酸钠和酵母浸出粉能显著促进微小亚历山大藻的生长;高浓度的氯化铵在加入后对微小亚历山大藻有一定的毒性效应,表现为生长停滞,但毒性效应在5 d后消失,并得到与添加硝酸钠及酵母浸出粉相似的增长速率0.21 d-1;添加尿素对微小亚历山大藻的生长没有显著促进作用.在四种氮源中,尿素对微小亚历山大藻毒素产生的刺激作用也最弱,在稳定期每个细胞藻细胞毒素含量维持在6.00~8.00 fmol;添加硝酸钠、氯化铵和酵母浸出粉的藻细胞在稳定期毒素含量分别达到11.85,12.86和14.64 fmol.硝酸钠和氯化铵刺激藻毒素产生的效果比酵母浸出粉更为直接.四种含氮营养盐对微小亚历山大藻毒素组成的影响都很小.     

三元体系CaCl2?SrCl2?H2O的相平衡及其在钙锶分离中的应用

采用等温溶解平衡法研究了三元体系CaCl₂?SrCl₂?H₂O温度从323.15 K到353.15 K范围内的相平衡。基于该三元体系多温下的相平衡数据,设计开展了实验室模拟南翼山油田卤水中氯化钙和氯化锶在温度323.15 K下的分离实验。实验室模拟钙锶分离实验结果表明,在323.15 K下时分离一次固相产品中的钙锶摩尔比可以从25.46:1降至1.73:1,SrCl₂的回收率为52.47 %,所得一次固相产品在323.15 K下溶解并再次蒸发。钙和锶的摩尔比从1.73:1降至1.1:1,SrCl₂的回收率为78.67 %。     

Time-variant fragility analysis of the bridge system considering time-varying dependence among typical component seismic demands

This paper presents a copula technique to develop time-variant seismic fragility curves for corroded bridges at the system level and considers the realistic time-varying dependence among component seismic demands. Based on material deterioration mechanisms and incremental dynamic analysis, the time-evolving seismic demands of components were obtained in the form of marginal probability distributions. The time-varying dependences among bridge components were then captured with the best fitting copula function, which was selected from the commonly used copula classes by the empirical distribution based analysis method. The system time-variant fragility curves at different damage states were developed and the effects of time-varying dependences among components on the bridge system fragility were investigated. The results indicate the time-varying dependence among components significantly affects the time-variant fragility of the bridge system. The copula technique captures the nonlinear dependence among component seismic demands accurately and easily by separating the marginal distributions and the dependence among them.     

氯化钙对河蟹肝胰腺中几种酶活性的影响

在盐度为12的海水中,添加不同浓度的CaCl2(2、4、6、8、10g/L)可对中华绒螯蟹肝胰腺中超氧化物歧化酶(SOD)、碱性磷酸酶(AKP)、酸性磷酸酶(ACP)、过氧化氢酶(CAT)以及溶菌酶(LZM)的活性产生影响.结果表明:在实验海水中浸泡4h后,实验组与对照组河蟹肝胰腺中5种酶的活性随着CaCl2浓度的上升均出现了不同程度的降低,当CaCl2浓度为10g/L时,活性最低;ACP和AKP分别为对照组的56.72％和40.76％;SOD与CAT的活性在10g/L时为对照组的20.11％和7.32％;LZM的活性为对照组的60.14％;该结果说明:正常海水中CaCl2浓度的提高会导致河蟹体内自由基代谢的紊乱,从而影响机体的正常生理功能和免疫力.除LZM外,当CaCl2浓度为4g/L时,其它免疫酶的活性均表现出向下的拐点.因此,继续提高海水中的CaCl2浓度,将对河蟹成活率产生不利的影响.     

农用地土壤中7种重金属可提取态的测定

该文以氯化钙溶液进行提取,采用电感耦合等离子体质谱法和原子荧光光谱法,测定农用地土壤中Cd,As,Pb,Cr,Cu,Zn,Ni等7种重金属可提取态,检出限在0.003~0.06 mg/kg之间。该方法用于4个可提取态质控样品的测定,测定值与推荐值基本相符,测定的相对标准偏差(n=8)在3.3%~9.1%之间。基于800余件农用地土壤样品的测定数据,对7种重金属可提取态与土壤pH值及重金属总量之间的关系进行了初步考察。结果表明,7个重金属可提取态和总量关系无明显相关性,仅在土壤酸性条件下可提取态Cd与总量Cd呈正相关性。7种重金属提取率大小顺序为Cd>Zn>Ni>Cu,As>Pb>Cr,其中Cd,Zn,Ni,Cu,Pb的提取率随土壤pH值的增大而迅速下降,而As,Cr在土壤碱性条件下的提取率略高于中酸性条件下的提取率。