易破碎粒状材料本构研究

粒状材料被广泛地应用到土木工程的各个领域。大部分粒状材料在外力作用下较容易产生颗粒破碎,颗粒破碎对材料的力学性能有很大的影响。为了更好地描述易破碎粒状材料的力学特性,基于弹塑性力学和临界状态土力学开发了一种能够考虑颗粒破碎效应的本构模型。此本构模型能够考虑在剪应力和压应力作用下引起的颗粒破碎对粒状材料力学性能的影响。为了考虑颗粒破碎的影响,基于对Cambria 砂的高压试验,得出了临界状态线位置与消耗塑性功之间的关系,并称之为“破碎方程”。此本构模型拥有双屈服面,分别考虑剪切和等向压缩产生的塑性变形。通过试验结果与数值计算结果的对比得出,新的本构模型能较好地描述易破碎粒状材料的力学特性     

地震应急救援物资最优分配问题初探

本文从我国现有的地震应急救援和技术支持系统出发,提出如何解决救援物资最优分配的问题,并借鉴供销问题的路径最短模型,通过表上作业的计算方法来探讨解决这个问题,使救援物资得到最优分配。     

预拌干料辅助灌浆法在抗浮锚杆施工中的应用

在泰汶地区多个岩溶发育地基高层建筑建设项目中,运用预拌干料法辅助锚杆注浆,成功解决了岩溶地基场地条件下抗浮锚杆注浆中的漏失问题,保证了锚杆注浆锚固体质量,提高了注浆效率,取得了很好的经济效益和社会效益。本文介绍了预拌干料(水泥、砂、外加剂混合物)施工法在岩溶发育漏失场地抗浮锚杆施工中的成功运用,具有较好的示范作用和参考价值。     

1220铀矿田同位素地球化学和矿床成因研究

1220铀矿田分布于中生代后地台构造-岩浆活化带中1220破火山口周围。成矿过程中有三期热液活动和两期矿化作用。第一期是碱交代型矿他,第二期是萤石-水云母型矿化。将沥青铀矿的~(238)U/~(204)Pb—~(206)Pb/~(204)Pb等时年龄作为成矿年龄,它略低于火山活动年龄。通过氧、碳、硫、铅和锶同位素研究,对成矿溶液来源及演化、成矿过程和成矿物质来源等问题进行了探讨,得出了成矿溶液由岩浆水和大气降水混合组成,成矿物质主要来源于火山岩浆的结论。     

福建省上杭-大田地区中生代成岩成矿作用与构造环境演化

本文所研究的四个中生代花岗岩体具不同的同位素年代:汤泉岩体为183～158Ma,紫金山岩体为157-145Ma。才溪岩体为133Ma,四方岩体为108～105Ma,汤泉和紫金山岩体分别属于早中生代中、晚侏罗世,才溪和四方岩体时代为晚中生代早白垩世。汤泉和四方岩体为A/CNK<1.0的准铝质花岗岩类,因富Ba、Sr,贫HREE、Y、Yb而具埃达克岩地球化学特征,是最具铜矿成矿潜力的含矿母岩;紫金山花岗岩体为A/CNK>1.1的强过铝花岗岩,并富K、Rb、Th、Y、HREE,贫Sr、Ba、Ti,具地壳泥质岩石熔融的特征。才溪岩体为A/CNK1.0～1.1的弱过铝花岗岩,其元素地球化学特征介于四方岩体和紫金山岩体之间。富Na2O的汤泉岩体是地幔起源的基性岩浆底侵作用,促使加厚的元古代下地壳基性岩石部分熔融所形成,是铜、铁多金属矿床成矿系列的主要含矿母岩;富K2O的四方岩体是地幔起源的富钾基性岩浆与中下地壳物质部分熔融形成的花岗质混合岩浆,使岩浆中的K2O含量增高,并从地幔中获取大量铜及其它金属和硫,而成为斑岩型铜金多金属矿床成矿系列的主要含矿母岩。研究区自早-中侏罗世(180Ma)以来已有岩石圈伸展的岩石学记录。紫金山强过铝花岗岩是这种伸展机制延续的结果。随时间推移,岩石圈伸展减薄作用和底侵作用增强,地幔组分在花岗质岩浆的形成过程中贡献     

Determination of Boron Concentration in Geochemical Reference Materials Extracted by Pyrohydrolysis and Measured by ICP‐MS

This article presents new boron concentrations for nine geochemical reference materials (GS‐N, FK‐N, GL‐O, BX‐N, DT‐N, AN‐G, GH, Mica‐Fe, Mica‐Mg). After extraction by a modified pyrohydrolysis technique, boron concentrations were measured by ICP‐MS. The blank levels for the whole procedure were 0.091 ± 0.020 ng ml^?1 or 14 ± 5 ng of boron in total. The method was first validated by measuring nine reference materials with known boron concentrations. The determined boron concentrations are all within the range of recommended or published values, which means that the yields were 100%, and show precisions below 10% for samples containing over 2 μg g^?1 of boron.     

铝土矿中锂同位素分离提纯方法的建立

铝土矿是极端风化作用的产物,也是锂的重要载体,由于其资源量巨大,对铝土矿中锂的富集机制和分布规律的研究将有利于找矿预测。锂同位素的高效准确分析是深入认识矿物中锂的富集机制和分布规律的基础。铝土矿样品由于化学稳定性较强,溶样过程较为复杂,且Al、Na、Ca、K等基体元素含量远高于锂,给锂的纯化增加不少难度。本文采用内径5mm、柱长190mm的聚四氟乙烯离子交换柱和AG50W-X12阳离子交换树脂,以0.5mol/L硝酸为淋洗液淋洗34mL,收集最后的12mL,即可完成对铝土矿中锂的完全纯化回收。该纯化方法减少了淋洗液的使用量,提高了实验效率。采用该方法对国际标样L-SVEC、RGM-2、GSP-2进行锂的纯化,通过多接收电感耦合等离子体质谱仪(MC-ICP-MS)测试锂同位素组成,得到的δ~7Li测试值分别为-0.26‰±0.09‰(2SD,n=3)、3.19‰±0.37‰(2SD,n=3)、-0.78‰±0.22‰(2SD,n=3),与前人报道一致,验证了该方法的可靠性。此外,采用本方案对铝土矿国家标样(GBW07182)进行锂的纯化,δ~7Li测定值为10.16‰±0.21‰(2SD,n=3)。     

An Evaluation of Methods for the Chemical Decomposition of Geological Materials for Trace Element Determination using ICP-MS

Complete dissolution is essential to obtain accurate analytical results using ICP-MS. In this study, decomposition techniques (i.e. acid digestions using Savillex Teflon vials, a high pressure digestion system and microwave oven, a combined lithium tetraborate fusion - HF/HNO3 acid decomposition and sodium peroxide sinter) for the total dissolution of different types of geological reference materials have been investigated. Savillex Teflon vial HF/HNO3 digestion is effective for basaltic samples. The high pressure HF/HClO4 digestion (PicoTrace TC-805 digestion system, Bovenden, Germany) allows dissolution of basalts and ironstones. Granites and magnetite-rich samples can be dissolved using a high pressure HF/H₂SO₄ method. Geological samples cannot be effectively attacked by microwave acid digestion. A combined lithium tetraborate fusion - HF/HNO3 acid digestion method allows complete dissolution of many different types of geological materials; however, this method precludes the determination of volatile elements due to the high fusion temperature (1000 °C). A sodium peroxide sinter method at 480 °C has the potential for the rapid determination of Y, Sc and REE in different types of geological materials. However, the lack of ultra-pure reagents precludes the use of lithium tetraborate fusion and sodium peroxide sinter methods for the measurement of geological samples with low trace element abundances.     

Determination of Chlorine in Nine Rock Reference Materials by Isotope Dilution Mass Spectrometry

A procedure for the determination of chlorine by the isotope dilution technique (ID) using negative thermal ionisation mass spectrometry (N-TIMS) is described. Silicate samples of about 10 mg were spiked and decomposed with hydrofluoric acid, and chlorine was isolated by precipitation of silver chloride after neutralisation with Ca(OH)₂. The ammonical solution of AgCl was then subjected to N-TIMS. Replicate analyses of rock reference materials, typically of JB-1 and JR-1, demonstrated the high quality of the analyses (precision for Cl was ± 1-2%). We present here the most precise data sets of chlorine concentrations in nine igneous rock reference materials, three basalts (JB-1, JB-2, JB-3), two andesites (JA-3, AGV-1), two rhyolites (JR-1, JR-2) and two granodiorites (JG-3, GSP-1). The chlorine concentrations found ranged from 152 μg g-1 in AGV-1 to 1008 μg g^-1 in JR-1. Our results presented here are partly (but not completely) in agreement with recommended values, where they are available. The N-TIMS ID technique can thus be used as a means of determining low chlorine contents in silicate materials to high precision.     

羟基铝镍多孔粘土材料的表面酸性及其孔容

把羟基铝镍聚合物引入蒙脱石层间,制备多孔粘土材料,利用XRD、IR及非水溶液滴定法研究了制备方法及条件变化对材料表面酸性及孔容的影响。结果表明,制备方法及Al／Ni、(Al Ni)／土、老化温度等条件对表面酸性及孔容均有影响,材料在400℃以下热稳定性较好。