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1.
根据对桂北九毛锡矿区岩浆岩野外地质、岩石学、岩石化学、微量元素及稀土元素地球化学等方面的工作,结合成矿大地构造背景,本文着重讨论了与该锡矿成矿有关的超基性岩和花岗岩的含矿性及成因。在本区基性—超基性岩形成过程中锡元素的分异聚集作用,为锡矿成矿奠定了物质基础。花岗岩的形成和演化为成矿带来了大量热流体及部分成矿元素。主要与超基性岩有关的九毛锡矿是一种新的锡矿类型。  相似文献   

2.
本文根据九毛锡矿产出的地质地球化学环境,定量计算了成矿作用的物理化学参数。首次提出并讨论了锡矿的中低温成矿作用,从而打破了锡矿元素只在高温条件下才能成矿的传统观念。成矿作用主要在中低温(260~160℃)热液阶段,压力500×10~5~340×10~5pa,氧逸度log fo_2=-29.2~-42.5,硫逸度log fo_2=-7.7~-19.25,pH=6.1~4.5。运用络合物化学原理和方法,定量计算了成矿流体中锡主要呈羟基络合物形式迁移。  相似文献   

3.
低温下多孔硅电学性质研究   总被引:3,自引:2,他引:3  
在低温下(10-300K)对多孔硅(Al/多孔硅/单晶硅结构)的I-U特性进行了测量,得到了I-U特性随温度的变化曲线,结果表明,低温下多孔硅的电阻率远大于单晶硅,当温度变化时,电阻率的变化不是单调的,其原因一是电流的主要输运机制随温度的降低发生变化,二是多孔硅中的缺陷态俘获载流子的能力随温度降低而变弱。  相似文献   

4.
目的:研究低温条件下山莨菪三兔肾缺血再灌注损伤期肾内前列腺素的影响及肾功能的保护作用。方法:在兔肾缺血再灌注损伤模型上,分别 检测假手术(无缺血组)、对照组(缺血再灌注损伤组)、山莨菪硷治疗组、低温治疗组低温条件下山莨菪碱组缺前和恢复血液灌注24h的肾组织血栓素B2(TXB2),6-酮-前列腺素F1α(6-Keto-PGF1α)的含量以及检测各组恢复血液灌注24h各组血肌酐)SCr)、尿素氯(BuN)含量。结果:山莨菪 硷组和低温组、低温条件下山莨菪碱治疗组TXB、6-Keto-PGF1α、血肌酐(SCr),、尿素氮(BuN)及6-Keto-PGF1α/TXB2(K/T)与对照组相比较有显著性差异(P<0.05),低温条件下山莨菪碱治疗组优于山菪硷组和低温(P<0.05)。结论菪硷 与低低温改善肾内前列环素(PGI2()-血栓素A2(TXA2)平衡紊乱,对兔肾缺血再灌注损伤均有一定的保护作用。低温条件下山莨菪碱更能够有效纠正肾内PGI2-TXA2平衡紊乱,改善肾内微循环,明显优于山劳苦 硷或低温单独应用。  相似文献   

5.
低温钢种的研究及其炼钢制管工艺的优化洪连山(成都无缝钢管厂成都610069)1前言-45℃,-50℃,-70℃和-101℃级钢及其低温压力容器用无缝管,分别于1987,1989,1992年通过了专家技术鉴定。-40℃和-80℃级钢及其低温压力容器用无...  相似文献   

6.
低温烧结PZT压电陶瓷的研究   总被引:7,自引:0,他引:7  
对PZT压电陶瓷的低温烧结进行了研究。实验发现,在PZT陶瓷中添加少量低 熔玻璃(xB2O3-чBi2O3-zCdO)可使烧结温度从1250℃降低至960℃。其性能参数: Kp≥0.52~0.56,Qm≥1000,ε33T/ε0=800~1200, tgδ≤5×10-3.借助于扫描电镜 (SEM)、电子探针微区分析(EPMA)、X光光电子能谱分析(XPS)和体积烧缩速率的 测量,对陶瓷显微结构、烧结机理和添加剂的作用进行了讨论,所研制的低温烧结瓷料 巳用于制备独石压电陶瓷变压器,其空载交流升压比可高达 9 000以上。  相似文献   

7.
低温下等强橡胶集料混凝土的脆性初探   总被引:2,自引:0,他引:2  
脆性是混凝土性能的重要指标,尤其在低温环境中.为研究低温下橡胶集料混凝土(CRC)的脆性特征,配制了橡胶集料体积掺量分别为0、5%、10%和15%,强度等级相等的橡胶集料混凝土,测试了其在常温(20℃)和低温(-25℃)环境下的力学性能,从力学和断裂面两个角度分析了低温下橡胶集料混凝土的脆性特征.结果表明,橡胶集料混凝土的断裂面粗糙度比普通混凝土大,低温下能够吸收更多的非弹性变形能,屈服强度增加,脆性降低,延性增强.  相似文献   

8.
秋格明塔什-黄山韧性剪切带构造变形序列   总被引:1,自引:0,他引:1  
运用构造解析方法和应变测量与显微构造分析方法,研究了秋格明塔什-黄山韧性剪切带的构造样式,建立了其变形序列。该带依次经历了:(1)中深部构造层次的紧闭同斜褶皱作用;(2)中深部构造层次的顺层(片)韧性剪切变形;(3)中部构造层次的右行走滑脆-韧性剪切变形;(4)中浅构造层次的膝折作用。  相似文献   

9.
滇西锡矿带地质特征与成矿构造背景   总被引:2,自引:0,他引:2  
通过对滇西锡矿带矿床的野外地质特征、区域地质演化、时空分布、地球化学特征、成因、物质来源与成矿地球动力学背景等方面的研究,综合探讨滇西锡矿带的成矿地质特征与区域成矿构造背景,并浅析其找矿前景。结果表明滇西主要锡矿床类型为云英岩型、热液脉型和矽卡岩型;燕山晚期—喜马拉雅早期花岗岩体与锡矿关系最为密切;含锡岩浆岩主要是富硅、富碱、基性组分低及高分异的深层重熔型花岗岩;同位素年龄资料显示,锡矿床主要形成于110~50Ma B.P.,与中—新特提斯封闭碰撞时期吻合。结合三江多岛弧盆-碰撞造山构造演化分析,认为滇西地区锡矿床及成矿花岗岩主要形成于陆-陆碰撞体制。  相似文献   

10.
报道了N-Ga_(1-x)Al_xAs低温光伏的异常特性.在暗条件下降温的样品,其低温光伏的初始强度比受光照的样品的光伏初始强度大得多,对这两种不同初始条件,当样品加热到大约100~150K时,其低温光伏强度发生跳跃.这些异常特性归因于N-Ga_(1-x)Al_xAs(x>0.22)中的DX中心的电荷态变化.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

15.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

16.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

19.
20.
<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has  相似文献   

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