铵盐镍基电镀金刚石钻头     

王群英  杨凯华 《地质科技情报》2007,26(4):82-84

探讨了在普通镀镍溶液中加入铵离子后,电镀液成分和电镀工艺条件对镀层性能的影响,得到了一种用于钻进坚硬致密弱研磨性岩层的优化配方及工艺条件,讨论了铵离子引起的络合作用.实验表明,当氯化铵的质量浓度为18 g/L时可细化镀层晶粒,提高胎体的硬度和脆性,改变胎体与金刚石的包镶程度,从而改变电镀金刚石钻头的性能,得到一种能有效钻进坚硬致密弱研磨性岩石的新性能电镀金刚石钻头.  相似文献   

沙尘气溶胶粒子表面变性对云滴形成过程的影响   总被引：9，自引：2，他引：9  

黄蔚薇  杨军  凌士兵  牛生杰 《南京气象学院学报》2007,30(2):210-215

利用1997年5月14日辽宁省气溶胶和云滴谱航测资料,讨论了沙尘气溶胶粒子表面变性产生的不溶性沙尘粒子外包可溶性硫酸铵层的混合气溶胶粒子作为凝结核的增长规律,计算了由混和核形成的云滴谱特征,并与纯硫酸铵盐核进行对比.结果表明:混和核上初期形成的云滴谱型比纯硫酸铵盐核上初期形成的云滴谱型要宽,更接近实际观测到的云滴谱分布.  相似文献   

Nitrogen nutrition of the phytoplankton in the Oslofjord     

E. Paasche  S. Kristiansen 《Estuarine, Coastal and Shelf Science》1982,14(3):237-249

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Purification and characterization of lectin from humoral fluids of Charybdis feriatus     

戴聪杰王桂忠  何剑锋李少菁 黄辉洋 《中国海洋湖沼学报》2006,24(4):390-394

1 INTRODUCTION Lectins have been regarded as having a puta- tive role in non-self recognition in vertebrate and invertebrate immunities (Arason, 1996; Matsushita, 1996; Olafsen, 1996; Vasta et al., 1999; Wilson, et al., 1999; Marques and Barracco, 2000). …  相似文献   

Ammonium Photoproduction from Aquatic Humic and Colloidal Matter     

Weiwei Wang  Matthew A. Tarr  Thomas S. Bianchi  Erika Engelhaupt 《Aquatic Geochemistry》2000,6(3):275-292

It has recently been shown thatnitrogen contained in humic substances can be releasedas low molecular weight species through photochemicalprocesses or reactions. Nitrogen released in thismanner may then become available for biological useand chemical reactivity. This report providesadditional kinetic data for nitrogen photochemistry oforganic matter in natural waters from Louisiana andfor Suwannee River humic and fulvic acids. Naturalwater samples were fractionated into colloidal(>0.2 m, <1000 Dalton) and dissolved (>1000Dalton) fractions and the kinetics of these fractionsas well as 0.2 m filtered water samples weremeasured. For irradiations of less than 10 hours ofsimulated noon-time sun, samples showed linearproduction of ammonium and first-order fading at350 nm. Ammonium photoproduction was enhanced asmuch as three-fold by lowering pH, but linear kineticswere maintained. Light-dark cycling showed continuedrelease of ammonium immediately after irradiation,followed by uptake at longer post irradiation times.A two step mechanism was proposed to explain theobserved kinetics. Calculated net daytime release ofammonium from natural surface waters ranged from 0.33to 1.9 M h^-1 in the samples studied,corresponding to a photic zone conversion rate of9–20% of the total organic nitrogen per day intoammonium.  相似文献   

Variability of unsaturated Bromide fluxes as measured through a layered volcanic vadose zone in New Zealand          下载免费PDF全文

G. F. Barkle  Th Wöhling  R. Stenger 《水文研究》2014,28(25):6080-6097

The measured drainage fluxes through a layered volcanic vadose zone exhibited high spatial variability as a consequence of heterogeneous flow conditions. The drainage flux variability was quantified using automated equilibrium tension lysimeters, installed in close‐proximity and resulted in high variability in the Br masses recovered from a conservative tracer experiment. The primary cause of the heterogeneous flow was attributed to textural changes occurring at the interface between volcanic layers, resulting in development of funnel‐flow patterns, and further enhanced by the existence of hydrophobic conditions. The Br recoveries in individual automated equilibrium tension lysimeters were used to determine the corresponding variable sizes of the surface areas contributing drainage to the lysimeters. The tracer experiment confirmed the existence of unsaturated lateral transport occurring at the sloping interface of the coarse Taupo Ignimbrite material with the silty Palaeosol layer at approximately 4.2 m depth. This study demonstrates that measurements of both flux and solute concentrations at multiple locations are essential when heterogeneous flow is suspected to be present, to be able to determine reliable estimates of contaminant leaching through the vadose zone at the plot scale. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

Distribution,Origin and Development Status of Underground Brine Resource along the Coast of Laizhou Bay,Shandong Province     

LI Shouping  MENG Ye 《《地质学报》英文版》2014,88(Z1):222-222

正The underground brine resource along the coast of Laizhou Bay is the world’s rare shallow underground brine resource,which occurs in the Laizhou city in the east,and extends to the coastal area of the Binzhou city in  相似文献   

KBr-K₂SO₄-H₂O体系在318.15 K下的热力学性质和相平衡预测研究          下载免费PDF全文

符阳晓  桑世华  崔瑞芝 《盐湖研究》2022,30(4):72-82

本文采用电动势法对318.15 K下三元体系KBr-K₂SO₄-H₂O的热力学性质进行研究。首先,测定了KBr-H₂O溶液中KBr的电动势,线性回归出电极响应斜率κ和电极常数E⁰,结果表明实验所用离子选择性电极具有良好的能斯特响应。然后,对318.15 K下三元体系KBr-K₂SO₄-H₂O混合溶液中KBr的平均活度系数进行了研究,绘制了离子强度I及离子强度分数y_b与KBr的平均活度系数关系图,由图可得,当离子强度I一定,随着离子强度分数 y_b增大,KBr平均活度系数逐渐减小,且减小的趋势越来越大。当离子强度分数y_b是个定值时,KBr平均活度系数随着离子强度I的增大而减小。应用活度系数数据通过多元线性回归拟合出该温度条件下Pitzer模型混合离子作用参数θBr,SO₄和ψK,Br,SO₄,并计算了混合溶液中K₂SO₄的平均活度系数、渗透系数Φ,水活度a_w,超额吉布斯自由能GE。应用拟合的Pitzer混合离子相互作用参数和Pitzer模型计算了该三元体系在318.15 K下的溶解度数据,并对计算结果和其他温度下已经报道的KBr-K₂SO₄-H₂O三元体系的共饱和点处的溶解度数据进行比较,对比结果表明,溶解度计算结果可靠,拟合的离子相互作用参数具有较好的精度,可用于计算相关体系的热力学参数和相平衡的预测。  相似文献   

Ammonium occurrence in a salinized lowland coastal aquifer (Ferrara,Italy)   总被引：1，自引：0，他引：1  

M. Mastrocicco  B.M.S. Giambastiani  N. Colombani 《水文研究》2013,27(24):3495-3501

To understand the spatial distribution and the possible sources of high ammonium concentration in the unconfined coastal aquifer of the Po River Delta lowland (Italy), a detailed characterization of inorganic nitrogen species was completed. A total of 59 boreholes were drilled to collect core samples and groundwater samples of the aquifer. Among them, four piezometers, located along a representative flow line, were chosen to monitor the inorganic nitrogen concentrations with depth. Ammonium is the prevalent nitrogen inorganic species in groundwater, and its concentration increases with depth and salinity. Very high ammonium concentrations are found in coincidence with peaty sediments in the salinized anoxic aquifer and in the low‐lying aquitard. In particular, the elevated ammonium concentration derives from mineralization of organic matter present in fine sediments deposited in paleo‐marsh environments. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

过硫酸铵-丁二酮肟光度法测定红土镍矿中的镍   总被引：2，自引：1，他引：1  

褚宁  蒋晓光  李卫刚  王艳君 《岩矿测试》2012,31(3):479-483

红土镍矿样品用适宜比例的HCl-HNO3-HF-HClO4混合酸低温消解,待样品溶解完全后在NaOH介质中,以过硫酸铵作氧化剂将Ni2+氧化为Ni4+,使Ni4+与丁二酮肟生成可溶性酒红色络合物,采用分光光度法测定镍的含量。样品溶液中仅通过加入酒石酸钾钠作掩蔽剂,就可消除红土镍矿中其他基体元素对镍测定的干扰,避免了萃取分离操作和有机试剂对环境的污染。在优化的酸碱度、试剂加入顺序及用量、显色时间等实验条件下,镍的线性范围为0～2.0μg/mL,方法检出限为0.1 mg/g,精密度为(RSD)为0.75%～1.69%,加标回收率为95.4%～102.7%。方法用于分析红土镍矿中镍的含量,测定结果与电感耦合等离子体发射光谱法相符。该方法简便,稳定性好,仪器价格低廉,可用于批量红土镍矿样品中镍的快速准确测定。  相似文献