贵州喀斯特山区植物叶片碳同位素组成研究

通过测定贵州喀斯特山区灌丛12 种主要植物叶片的δ13 C 值,研究了该区植物叶片碳同位素组成特征,以及种间、生境差异和时空变化特征。研究结果表明:该区植物叶片的碳同位素组成的变化范围为- 26. 98 ‰～ - 29. 15 ‰,平均值为- 28. 14 ‰。研究区δ13C 值的分布相对均匀,除高于我国热带雨林区植物外,低于其它地区。研究结果还表明,种间碳同位素组成存在较大的差异。生境的变化对蕨的碳同位素组成影响较大,而对渐尖毛蕨、盐肤木、火棘、马桑影响较小。盐肤木、渐尖毛蕨、云南鼠刺、火棘叶片的δ13C 值从生长初期到末期有降低的趋势,但降低的幅度存在差异。植物的δ13 C 值随小尺度海拔的变化规律与随大尺度海拔变化的规律一致,都是随着海拔的增加δ13C 值增大,但不同植物种间变化的幅度是不一样的。

湘西柳林汊金矿带钠长石的矿物学和地球化学研究

湘西雪峰山地区是湖南最重要的黄金产地，湖南省80%以上的金矿床均赋存在该区前寒武系的浅变质岩中。柳林汊金矿带位于湘西雪峰山中段的北部，尽管该金矿带发现较早，采矿历史很长，但地质工作程度较低。在系统野外调研的基础上，本课题组首次确认柳林汊一带金矿床为典型的钠长石-石英脉型金矿床，明显有别于雪峰山地区其它石英脉型金矿床。本学位论文以该区四个有典型代表性的钠长石-石英脉型金矿为研究对象，在系统野外地质考察和系统采样的基础上，利用矿物学、元素地球化学、同位素地球化学、流体地球化学等研究手段，对该区金矿床的载金矿物—钠长石进行了较详细的矿物学和地球化学研究。在此基础上初步探讨了柳林汊一带金矿床的成矿流体来源、成矿物质来源、成矿时代及矿床成因。本论文主要取得以下几点新认识： 1.柳林汊金矿带金矿床的矿脉中的这些长石呈肉红色，在镜下通常呈板条状、粒状，解理不发育，双晶以聚片双晶为主，负低突起，干涉色一级灰白到一级淡黄。本文首次确认了该区矿脉中的肉红色长石为低温、高有序度的钠长石，该区的金矿类型为典型的钠长石-石英脉型金矿。 2.该区钠长石具Ab含量高，An、Or含量极低等特征，接近纯钠长石。钠长石中Sr 含量相对较高而稀土含量普遍较低，通常为LREE富集型，无明显的Eu、Ce异常。 3.柳林汊一带金矿脉中钠长石的氧同位素组成为10.2‰～14.5‰，对应的成矿流体的δ18O‰为1.9‰～6.9‰。该区成矿流体可能主要来自经演化的大气降水。 4.与钠长石共生的石英中的包裹体主要以液体包裹体为主。其均一温度为140～300℃，盐度为1～8%NaCl，成矿流体的密度为0.60～0.99g/cm3。该区金矿床成矿流体具中低温、低盐度和中等密度等特征。 5.根据本区金矿床的地质特征，并结合前人对湘西地区金矿床的研究成果，提出该区金矿的成矿物质来源为元古宇板溪群，成矿时代为加里东期，矿床的成因类型为层控的热液改造型金矿床。 关键词：柳林汊金矿带 钠长石 矿物学 元素地球化学 流体包裹体 矿床成因

安顺大气降水中低分子有机酸及其与贵州其它地区对比研究

低分子有机酸是对流层大气的重要组成成分，广泛分布于大气中的气相、液相、气溶胶中。本文以贵州省安顺作为研究区域，在 2007 年 6 月~2008年 6月期间，收集大气降水样品118个，对降水中主要成份尤其是低分子有机酸及其对自由酸度的贡献进行了为期一年的研究。并通过与贵州其它3个地区的对比，重点讨论了大气降水中低分子有机酸时间和空间的变化规律、成因机制、对降水自由酸度的贡献以及来源等关键问题。得出的主要结论如下： （1） 安顺降水总体呈酸性，pH雨量加权平均值为 4.89，范围在3.57～7.09，酸雨频率为 57.0%。降水的电导率平均值为46.52μs•cm-1，变化范围为6.01～298.00 μs•cm-1，该值远远高于降水背景站点，表明该地区受到了明显的人为活动影响。 （2） 安顺大气降水中离子浓度的顺序依次为SO42->Ca2+>NH4+>NO3-> Mg2+>K+>Na+>Cl->H+>HCOOHt>CH3COOHt >(COOH)2(t)2-。大气降水中最重要的离子为SO42-、NO3-（阴离子）和Ca2+、NH4+ 和Mg2+（阳离子），平均浓度依次为140.9、46.1、124.2、45.4和36.2µmol/L。相关性分析和聚类分析表明，安顺SO2和NOx具有同源特征，且进入降水的途径相同。大气中的铵主要以硫酸铵与硝酸铵的形式存在于大气中，成为大气中重要的酸性气溶胶。另外，CaSO4、NaCl、MgCl2、(NH4)2SO4、NH4NO3、KNO3、H2SO4、HNO3是降水的主要化学组分。降水中Ca2+、NH4+、Mg2+和K+的中和因子分别为0.38、0.14、0.22、0.05，表明降水中最重要的中和物质是Ca2+，其次是Mg2+和NH4+。源分析表明，安顺大气降水中的K+和Ca2+主要来自以岩石和土壤为主的陆相输入，而SO42-和NO3-主要来自人为活动的贡献，其人为贡献量高达97.0%和94.3%。Mg2+主要来自陆源输入，仅有9.1%来自海水的贡献。Cl-属于海盐性离子，但在安顺降水中，仅有57.3%来自海相输入，小部分（1.3%）来自岩石和土壤风化的贡献，人类活动排放的Cl-也是该地区一个重要来源。 （3） 安顺大气降水中共检测出7种低分子有机酸，含量最高的有机酸组成依次是甲酸(HCOO-)、乙酸(CH3COO-)和草酸（(COO)22-），雨量加权平均浓度分别为8.77、6.90和2.84µmol/L。降水中所测有机酸的平均总含量为19.00µmol/L，对阴离子总和的贡献为12.6%。对于 pH<5 的降水，甲酸、乙酸和草酸对自由酸度的平均贡献值（按最大贡献率法计算）分别为 19.2%、5.9和7.8%，总有机酸（三者之和）对自由酸度的平均贡献值为32.9%。这些事实表明，安顺大气降水中的有机酸是降水化学物质的重要组成部分，会对降水的物理和化学特征产生重要的影响。采样期间，安顺甲酸、乙酸和草酸的湿沉降通量分别为10.81、10.46和3.94 mmol/m2/year。根据气液平衡理论，估算出甲酸和乙酸的干沉降量，分别为4.78和1.63mmol/m2/year。 （4） 安顺降水有机酸浓度存在着明显的季节性变化，四季的有机酸浓度由高到低分别为：冬季>春季>夏季>秋季；非生长季节>生长季节。这种季节变化特征显然与植物生长的季节变化特征不一致。表明安顺大气中的有机酸浓度的影响因素非常复杂；植物生长、降雨量（降雨强度和持续时间）和人为活动等因素的季节变化都会影响大气有机酸的组成和分布特征。在连续降雨过程的监测中发现甲酸和乙酸的浓度是随降雨过程（时间）同步变化，这说明甲酸与乙酸很可能存在相同的来源或者相似的源强，它们在大气中的清除方式也可能相同。而草酸的浓度与日照强度和温度有关，与降雨发生的时间有很重要的关系，表明草酸多来源于光化学反应为主的间接来源。另外，还发现降雨初期降水酸性要强于降雨后期，这表明降雨对大气中污染物质有明显的清除和稀释作用。 （5） 相关性分析表明，甲酸和乙酸之间存在显著的相关关系，相关系数为0.80，这种强烈的正相关表明甲酸和乙酸具有相似的排放源或者排放源不同但有相似的排放强度；草酸与甲酸和乙酸也都具有显著相关关系,这可能是因为草酸与甲酸和乙酸具有相同的排放源或者是草酸的前体物如甲醛与甲酸、乙酸具有相似的排放源；甲酸与NH4+、NO3- 和NO2-的相关关系也很高，表明甲酸的主要来源是农业活动或者生物质燃烧和汽车尾气排放等。乙酸和草酸的情况与甲酸类似。论文建立了甲酸与乙酸分析浓度比值(F/A)T的判定方程曲线，结果表明安顺有机酸主要来源于直接来源，包括植物直接释放，生物质燃烧，汽车尾气排放等；间接来源如不饱和碳烃化合物（如烯烃和异戊二烯）和醛类物质(如甲醛）的光化学氧化不是该地区有机酸的主要来源。 （6） 对比贵州其它3个监测站点的降雨数据后，发现大气降水对降水酸度的贡献，偏远地区（尚重）要远大于工业城市。另外，安顺和尚重大气有机酸以直接来源为主。其中，尚重有机酸的主要来源是植物释放，而安顺有机酸的主要来源是生物质燃烧、汽车尾气等人类活动的释放。贵阳市有机酸的主要来源是间接来源，即有机酸前体物的光化学氧化。遵义有机酸的来源具有明显的季节周期性，在夏秋以直接释放为主，而春冬季节以间接释放为主。

13万年以来洛川黄土剖面中营养元素的分布及演化规律

洛川剖面以其厚度大，沉积连续，并完整地记录了第四纪以来陆相环境、气候变化的信息而举世闻名，是陆相沉积序列中研究最为成熟的黄土剖面，被定为国际标准的黄土剖面。学者们对黄土剖面经过多年的研究，获得了许多宝贵的成果，例如，磁化率、粒度、地球化学等指标的建立，黄土物质来源问题的探讨，东亚季风变迁的研究，及大气环流模型的建立等等。这些成果在解释全球性尺度上的古气候变化以及在预测未来气候变化趋势上具有重要的理论指导意义。上述成果着重从物理和化学的角度来展开研究的，而如何从生物地球化学的角度来研究局部的气候环境变化及其对全球变化的响应问题，以便更好地弄清楚气候变化的机制、周期性及影响因素，预测未来气候的变化，科学防治环境污染，合理利用自然环境，促进人类社会进步呢。这是目前黄土研究中较薄弱的地方。因此，本文在前人工作的基础上，首次将营养元素的概念较系统地引入到黄土古气候的研究中来，初步讨论了营养元素（C，N，P，K）在洛川黄土剖面中的分布和演化规律，获得了如下凡点新的认识：1．13万年来洛川黄土剖面中有机碳的含量在0.14％-0.54％之间变化，平均含量为0.26％。在时间上，有机碳高一低值的变化特征对应不同的气候时期。干冷气候条件下形成的黄土L1有较低的有机碳含量，湿热气候条件下发育的古土壤有较高的有”机碳含量。在马兰黄土中，间冰阶形成的L1SS1中有机碳含量高于始冰阶和盛冰阶形成的L1LL1、L1LL2中的有机碳含量，表现出低的有机碳含量对应于冷期，高的有机碳含量对应于暖期。有机碳的这种变化特征，与磁化率的变化趋势一致，在一定程度上反映了不同时期植被的发育程度。通过洛川剖面（109°25′E，35°45·N）与段家坡剖面（109°12′E，34°25′N）有机碳的对比可知，在空间上，从黄土高原的西北到东南，同一时期黄土剖面中有机碳的含量呈逐渐增加的变化趋势，这与地理上的气候变化是一致的。因此，时空上有机碳的变化特征反映黄土高原地区东亚夏季风强弱周期性变化的特点。2．洛川黄土剖面中的氮由有机氮、固定钱态氮和速效态氮组成，其中前两者为主要部分，占总氮的95％以上。有机氮占总氮的55％-76％，在181μg·g-15689μg-1之，间变化平均值为299μg-1彭，其在剖面中的分布与有机碳极为相似，在黄土LI中有较低的有机氮，在古土壤S1中有较高的有机氮，并且在马兰黄土中，间冰阶形成的L1SS1中有机氮含量高于始冰阶和盛冰阶形成的L1LL1、L1LL2中的有机氮，其高一低值的分布与黄土一古土壤中冷一暖变化相互对应。有机氮的含量变化在一定程度上也反映了植被的生长发育程度，同样揭示了东亚夏季风对黄土高原的影响。速效性氮（交换性钱态氮和水溶性钱态氮）在洛川黄土剖面中的含量低，主要在Oμg·g-1-11.5μg·-1之间变化，在古土壤51和间冰阶时期形成的弱土壤化黄土LISSI中有较高的值，反映了速效性氮与土壤湿度和粘粒的含量有关。由于速效性氮和固定按态氮在黄土剖面中的振荡幅度不大，总氮的分布基本与有机氮一致，其在黄土剖面中的变化主要受有机氮变化的制约。3．黄土一古土壤层位中固定钱态氮占总氮的24％-43％，其含量在140μg·210μg·g-1之间变化。黄土层中的固定钱态氮含量低于相邻的古土壤。

本科实习男护生压力源、应对方式与心理健康关系的研究

Objectives:To investigate stressor and stress level,coping styles and mental health of male nursing undergraduates in clinical practice;To find out the factors that influence mental health of male nursing undergraduates in clinical practice and to put forward some suggestions to improve the mental health status of male nursing undergraduates. Methods: After doing many literaturere search both at home and abroad,I gather further consulting many nursing undergraduates in clinical practice,Finally I formulate the “Nursing Student's Clinical Stressor Scale”.80 male nursing ungraduates from Bengbu Medical Colledge were recruited. While 140 female nursing ungraduates who were in clinical practice in the same period of time were taken as a comparative group.The following questionnaire package including a background questionnair,Nursing Student's Clinical Stressor Scale NSCSS,Simplified Coping Style Questionnaire SCSQ,The Symptom Checklist 90 SCL-90 were distributed and collected together in the 14th week during the clinical practice.Of the 220 questionnaires were distributed and 198 were found to valid,the valid callback rate was 92%.The endudeed 77 were male and 121 were female .Statistices analysis was performed by SPSS13.0 and AMOS5.0 software. Results： 1.25% of male nursing undergraduates had a higher level of stress, mainly from employment,major,working nature,working contents and so on.Compared with female nursing undergraduates,male nursing undergraduates underwent a higher pressure in the employment and the profession aspect,but lower in their insufficient knowledge and ability.There was a significant negative correlation between the male undergraduates’ stress level and their satisfaction degree to clinical nursing teaching and the professional title of the clinical teachers,but it was positively correlated with their family monthly income. Stress level of female nursing undergraduates positively related with the number of children in their families,but negatively correlated with their family monthly income; 2.Male nursing undergraduates' coping style both positive and negative coping styles were adopted by male nursing undergraduates but mean at while positive coping styles.The positive coping styles adopted by male nursing undergraduates were significantly lower than that adopted by female nursing undergraduates; 3.The scores of depression,interpersonal sensitivity and anxiety in male nursing undergraduates were significantly higher than those of the nationwide youths norm.Alist all subscales scores of male nursing group were more than those of female nursing undergraduates except for fear subscale. Mental health of male nursing undergraduates was inversly correlated with the professional title of the clinical teachers and satisfaction of their majors; 4.Among male nursing undergraduates,the total score of stress and most subscale(except working nature and working contents,employment)scores of stress were positively correlated with the negative coping styles.The scores of stress level was positively correlated with the scores of SCL-90,Negative coping styles was positively correlated with the scores of SCL-90 among male nursing undergraduates,while positive coping styles were inversly correlated with most subscales(except phobic,paranoia,psychoticism)scores of SCL-90. Conclusions： 1.25% male nursing undergraduates have a higher level of stress,which is from employment, profession,working nature and working contents,financial difficulties and so on.The coping styles adopted by male nursing undergraduates were mainly positive coping styles.The mental health of male nursing undergraduates were lower; 2.Different genders have significant differences between stressors, coping style and mental health; 3.Stress,coping style,satisfaction degree to clinical nursing teaching and the professional title of the clinical teachers are predietors of mental health among male nursing undergraduates.

10-14岁超常儿童的亲社会行为特点及影响因素

Is prosocial behavior of supernormal children distinguished from normal children? Is there any difference between the supernormal children’s prosocial behavior from different educational placement? What are the mechanisms underlying the difference? The aim of this study was to examine these issues. With multiple methods of prosocial behavior, including other-rating, self-rating and hypothetical dilemma, we investigated the 10 to 14 year-old children. Firstly, the development of prosocial behavior and its relationship with prosocial behavior was examined. Secondly, we investigated the features of supernormal children’s prosocial behavior and analysed its difference with normal children. Finally, we tried to find the difference of supernormal children’s prosocial behaviour from different educational placement, and the mechanisms underlying the difference, such as social value orientation and peer relation. The results are as follows: 1)The altruistic and compliant prosocial tendency of 14 year-old children was obviously lower than those younger children. Intelligence was positively related with altruistic and emotional prosocial tendency for 10 year-olds, and with prosocial behaviour of peer nominated for 12 year-olds. 2)There was no significant difference of prosocial behaviour between supernormal and normal children. The peer nominated prosocial behaviour of 12 year-old supernormal children was higher than of 11 and 13 years old supernormal children. In addition, girls’ other-rating prosocial behaviour was significantly higher than boys’, but no gender difference was detected in the prosocial behaviour of self-rating and hypothetical dilemma. 3)With regard to the supernormal children’s prosocial behaviour in different educational placement, we found that the prosocial degree of the supernormal children of homogeneous groups was higher than that of heterogeneous groups in the role-change of ultimatum game. 4)The supernormal children from different educational placement had different social value orientation. More supernormal children of homogeneous groups belonged to the type of group enhancement, while more supernormal children of heterogeneous groups belonged to the type of equality. The types of social value orientation did not have impact on the supernormal children’s prosocial behaviour from different educational placement. 5)Peer relation moderated the impact of different educational placement on supernormal children’s prosocial behaviour.