189 resultados para 302-M0004B


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在对大量数据进行系统分析的基础上,将贵州遵义下寒武牛蹄塘组黑色岩系中多元素富集层矿化元素按富集系数分为三组。超富集元素:富集系数大于1000,包括Mo、As、Se、Re等;强富集元素:富集系数介于100~1000,包括Ni、U、Au、Ag、Pt、Pd、Tl等;弱富集元素:富集系数近于5~100,包括V、Co、Cu、Pb、Zn、Y、Cd等。结合上述元素的地球化学性质和矿化岩石类型,指出贵州牛蹄塘组多元素富集层综合了岩浆作用、热水沉积和机械沉积作用的特点,是深部岩浆活动强烈喷发期的产物,提出了可能的成矿模式:早期岩浆(火山)活动伴随热水沉积,形成磷块岩(和硅质岩);中期岩浆活动减弱,表现为剥蚀沉积;晚期火山爆发,除大量射气元素的富集,还带出深部的成矿物质,然后通过水流机械富集成矿。

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和平、羊儿坝和猪草河剖面是南秦岭槽区巴山组的三个典型剖面,从南向北,这三个剖面的硅质岩厚度逐渐增大。通过对三个剖面硅质岩各种地球化学特征参数的研究分析,结果表明:猪草河剖面最接近火山弧带,为与大陆火山岛弧相邻的弧后盆地,受火山活动的控制很强烈,热水沉积的控制占主要地位;相应的硅质岩和碳酸盐岩都具有强烈的Eu正异常,其中具有高正Eu异常的碳酸盐岩在华南下寒武统尚属首次发现。羊儿坝剖面相当于大陆边缘的深水盆地,热水与海水处于相对平衡的状态。和平剖面最接近大陆边缘,热水的影响很弱,以海水的正常沉积为主,陆源碎屑物质增多。三个剖面沉积相从早到晚的变化体现了南秦岭断陷海槽从拉张到闭合的过程。

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目前测定铂族元素的方法主要有中子活化法和等离子体质谱法。后者具有灵敏度高、检出限低、质谱图简单的特点,是铂族元素测定的有力工具。同位素稀释法具有准确度高、灵敏度好,不需要对分析元素进行严格的定量回收,已应用于铂族元素的测定。由于铂族元素在地质样品中含量极低,且分布不均匀,因此必须进行分离富集。目前国内外对铂族元素的富集方法主要有火试金法、

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新疆北部地区属于中亚造山带的关键部位,有独特的构造岩浆活动和成矿作用,自二十世纪八十年代早期以来一直是国内外地质研究的热点地区之一。准噶尔盆地两侧大面积出露的A型花岗岩及相关矿床是该区的重要研究对象。尽管已有的研究积累了一定成果,但对一些关键问题,特别是对于A型花岗岩形成时代和成因的认识还存在较大争议。另一方面,传统观点认为锡矿床主要与演化的过铝质S型花岗岩有关,但在东准噶尔卡拉麦里构造带,多个中小型锡矿床产于A型花岗岩体内或岩体与围岩的接触带附近,花岗岩与锡矿的成因联系有待深入研究。 本论文以准噶尔盆地两侧的三条A型花岗岩带(包括东准噶尔的卡拉麦里和乌伦古河A型花岗岩带、西准噶尔的达拉布特A型花岗岩带)为研究对象,对其中的一些A型花岗岩体开展了详细的年代学和地球化学研究,并以这些资料为基础,探讨了A型花岗岩的岩石成因及其构造和成矿意义。概括起来,主要得到以下结论性认识: (1)锆石U-Pb年代学结果显示,卡拉麦里铝质和碱性A型花岗岩都形成于302~310Ma左右;乌伦古河碱性A型花岗岩形成于305~320Ma,而铝质A型花岗岩形成于270~280Ma;西准噶尔达拉布特铝质A型花岗岩形成于295~305Ma。这些高精度的同位素年龄资料进一步确证了准噶尔地区大面积发育的A型花岗岩是该区后碰撞阶段的岩浆作用产物。 (2)三个构造带的碱性花岗岩和碱长花岗岩都具有典型A型花岗岩的矿物学和地球化学特征。在主量元素上它们富硅、富碱、低铝、贫钙镁,在微量元素上它们明显富集Rb、K、Th等大离子亲石元素及Zr、Hf等高场强元素和稀土元素而亏损Ba、Sr、Eu。根据地球化学组成,苏吉泉黑云母碱长花岗岩是典型的铝质A型花岗岩,而不是前人提出的S型花岗岩。 (3)三个构造带的A型花岗岩均有较高的正Nd(T)值和大于成岩年龄的两阶段Nd同位素模式年龄,它们的地质特征和地球化学组成难以用幔源岩浆高度分异的成岩模式解释。这些A型花岗岩的岩浆很可能是花岗闪长质岩浆分异结晶作用的产物,而花岗闪长质岩浆则起源于具亏损地幔同位素组成的玄武质洋壳和少量陆壳物质的部分熔融。 (4)东准噶尔早二叠世A型花岗岩的发育表明该区后碰撞阶段的花岗岩浆作用持续时间较长(约60Ma),这些花岗岩与晚石炭世A型花岗岩在地球化学组成上的差异揭示了东准噶尔乃至新疆北部在早二叠世的陆壳垂向生长。 (5)萨惹什克锡矿石中辉钼矿的Re-Os同位素年龄值(307Ma)与赋矿的萨北碱性花岗岩中锆石的U-Pb年龄值(306Ma)有很好的一致性,而且辉钼矿的Re含量低,表明成矿物质可能主要源于地壳。时间和物源的证据反映该区A型花岗岩与锡矿床具有密切的成因联系。

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Job Burnout has been a focus of the Occupational Stress Research. As a typical,helping occupation, teacher has attracted widely attention and researches in the areas of pedagogy and psychology. The special subgroup of teacher, headmasters who are the elites of the Basic Education, is ignored. The research about principals’ Job Burnout is nearly blank after analyzing related documents and information. With the development of the society, people pay more and more attention to the education and put more demands on the headmasters, especially middle-school principals. They are required not only to be good educators, who are equipped with all the inner qualities as a teacher, but also good managers. So the main purpose of this research was to compare the principal group with ordinary teacher group, and reveal underling factors, such as background variables and psychological protection variables. A representative sample of Wenzhou middle school principals sized 192 and a sample of middle school teacher sized 302 were sampled from various schools. The educational version of burnout inventory, self consistency scale, and interpersonal trust scale were administrated to the two samples, together with some demographic variables of interest. The applicability and equivalence of the three instruments used in this study were checked. Based on well-established reliability and cross-sample congruence of measures, the difference between principals and teachers was test. Then the contributing factors were analysis gradually. The five background variables were examined one by one in the two samples separately. A multiple covariance analysis was conducted to test whether there remained any difference between these two samples on the variables of interest. Regression analysis was used to further control the effect of self harmony and interpersonal trust to test the difference between two samples. Mediating analysis was conducted to build the relationship among the three constructs. The main results of the research were stated as following: 1. The internal consistency coefficients of all the scales were good, and no difference exited between the two groups. The measurement equivalence of three instruments was established well. The measures could be applied to and comparing the two samples. 2. The self-harmony, and interpersonal trust of principals were better than the ordinary middle-school teachers. Job Burnout of principals was significant lower than teachers. 3. Demographic variables like the gender, age groups, income levels, disricts, and the type of school, were important influencing factors. The difference patterns of the variables on these five variables in two samples had similarity and distinction. 4. After controlling the background variables, there remained significant difference between principals and teachers on the variables of interest. 5. Job Burnout negatively correlated with self-harmony and interpersonal trust. That is to say,the lower the degree of self-harmony and interpersonal are, the serious of the Job Burnout is, The correlation between the self-harmony and the interpersonal trust was positive. 6. After statistically controlling the background variables and psychological variables, there still exited significant difference between two groups of this study. Also, self harmony and interpersonal trust were significant protection predictors to different aspect of job burnout. 7. Mediating analysis was conducted to the residual score of the three constructs after controlling the five variables and group membership. Self harmony partially mediated the relationship between interpersonal trust and job burnout. That is, interpersonal trust had indirect effect to burnout mediated by self harmony, also had direct effect to burnout.