981 resultados para 327.508


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通过40%的HF溶液、KOH饱和溶液和19mol/L的NaOH溶液这三种常用方法对大、小颗粒石英进行裂变径迹蚀刻实验的对比发现,用环氧树脂固定的小颗粒石英样品,不宜用KOH饱和溶液(150℃)和19mol/L的NaOH溶液(沸点,约120℃)作为裂变径迹的蚀刻剂,宜用40%的HF溶液;三种方法均适宜于大颗粒石英,但不同的蚀刻方法蚀刻效率不同,40%的HF溶液(29℃)的蚀刻效率最高,且操作简单、安全性高。40%的HF溶液最佳蚀刻时间为:温度在4℃左右(冬季)时为40min,温度在29℃左右(夏季)时为30min,可在全年室内常温条件下操作。

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贵州喀斯特山区是我国乃至世界喀斯特分布面积最大的片区之一,由于其生态系统的脆弱性,加之人类活动的干扰,使得该区的植被退化较为严重。文章选择该区的12 种主要植物作为研究对象,对其营养元素进行了研究。结果表明:>1 000μg·g-1 的元素有N、P、K、Ca、Mg、S,100~1 000 μg·g-1 的元素有Fe、Mn、Al,10~100 μg·g-1 的元素有Zn、Sr,<10 μg·g-1的元素为Cu、Mo,其中Mo 含量最低,仅为0.17 μg·g-1。这些元素中,Ca、P、K 元素高于所报道的陆生植物的含量范围。元素含量特点是Ca>K>Mg 型。N、P、K、Mg 元素的频数分布为正态分布,Ca、Al、Fe、Mn、Cu、Zn、Sr、S 元素为对数正态分布。变异系数大于100%的元素有Al、Fe、Mn、Sr,变异系数小于60%的元素有N、P、K、Ca、Mg、S、Cu,其中Ca 的变异系数最小,仅为11.8%。不同生境下相同植物的营养元素含量有较大的差异,石灰土上植物的N、P、K、Ca、Mg、Al、Cu、Mo 元素含量要高于黄壤上植物的。元素间的相关分析表明:P 和K、P 和Cu、Al 和Fe、Al 和Zn、Fe 和Zn 元素具有显著相关关系;N 和P、P 和Mg、K 和Al、K 和Cu、Ca 和Sr、S 和Mo 元素具有一般相关关系。

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织金新华磷矿是我国扬子地台西南缘早寒武世重要的海相沉积磷矿床。长期以来,织金磷块岩磷酸盐矿物成分被认为是碳氟磷灰石或低碳氟磷灰石,有学者认为,产于沉积岩中的磷灰石基本上都属于碳氟磷灰石。本文利用电子探针的微区成分定量分析技术和X射线衍射分析技术,确认织金磷矿碎屑磷灰石为氟磷灰石。

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应用原子吸收光谱(AAS),X射线衍射(XRD)和电子自旋共振(ESR)方法对工业及民用陶瓷釉进行了研究。实验表明:陶瓷釉的主要化学成分为Al2O3、SiO2,少量为K2O、Na2O、MgO、CaO和微量的TiO2、Fe2O3、S等;矿物相有石英、伊利石、方解石、长石、高岭石和滑石等。生釉经不同温度焙烧后,无论是化学成分、矿物相、微量杂南元素的价态及含量均发生的变化。讨论了在不同温度下的化学组分.

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成矿物质来源是研究矿床成因的关键问题之一,而地质体(地层和岩浆岩)成矿元素的含量高低是探讨成矿物质来源的基础.为了研究白牛厂超大型银多金属矿床主要成矿元素特征,本文系统测定了外围赋矿地层以及矿区花岗岩和花岗斑岩的成矿元素(Ag、Pb、Zn、Sn)含量,结果表明,Pb、Zn主要来源于矿区花岗岩,寒武系及下伏基底地层可能也提供了部分成矿物质,特别是Zn;由于矿区外围赋矿地层的Sn含量远低于Pb、Zn的含量,也远远低于地壳克拉克值,因此推测,Sn主要来源于花岗岩浆;Ag则主要来源于赋矿地层,花岗岩对其进行了后期的改造作用.

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镁铁岩-超镁铁岩侵人体中常常含有少量及微量硫化物,它们是硅酸盐岩浆与硫化物熔体不混溶作用的产物。由于岩石圈环境下铂族元素亲硫性的制约,当硅酸盐岩浆与硫化物熔体呈液态熔离时,铂族元素便被硫化物熔体所捕集和运载,尔后在重力分异过程中下沉到岩盆底部富集成矿。能否依据岩盆上部岩浆熔离硫化物的铂族元素丰度值来判断岩盆深部铂族元素潜在成矿能力呢?这是本文试图回答的问题.

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大气在汞的全球生物地球化学循环演化中占有重要的地位,而正确认识大气中汞的来源是准确理解和建立汞的生物地球化学循环模型的关键。大气汞的来源分为人为源和自然源。汞矿化带内土壤汞含量高于背景区几个数量级,是大气汞的重要自然释放源。 论文选取贵州省红枫湖地区作为对照区,滥木厂汞矿区,万山汞矿区和务川汞矿区为研究区,采用目前国际上广泛应用的大气自动测汞仪与动力学通量箱联用技术,对土壤/大气界面汞交换通量特征及机理进行了详细的研究。主要得到以下结论: (1)高汞区大气汞含量与土壤释汞通量高于对照区1 ~ 3个数量级,汞矿化带土壤是区域上重要的大气汞源; (2)土壤与大气界面间的汞交换是双向的,既有土壤汞向大气的释放,也有大气汞向土壤表面的干沉降; (3)在对照区和受人为因素影响较小的地区,土壤释汞通量具有显著的日变化和季节性变化规律,主要表现为白天高于夜间,暖季高于冷季;在人为污染较严重的地区或采样点,土壤与大气界面汞交换无明显变化规律,且表现出强烈的大气汞沉降; (4)影响土壤/大气界面汞交换的因素有土壤总汞含量、光照强度、降雨、土壤湿度、大气汞含量和植被覆盖情况等; (5)利用土壤释汞通量与光照强度之间的线性相关关系,建立了土壤释汞通量和光照强度的比值与土壤汞含量之间的对数相关关系,见下式: Ln (F/S) = (-1.155 ± 0.191) + (0.508 ± 0.036) LnC, r = 0.95, p < 0.0001 其中F为日平均土壤释汞通量,单位为ng m-2 h-1;S为日平均光照强度,单位为W m-2;C为各对应采样点土壤总汞含量,单位为mg kg-1。 滥木厂汞矿区土壤年平均释汞通量约为476 ng m-2 h-1 (326 ~ 694 ng m-2 h-1);贵阳市土壤年平均释汞通量为15 ng m-2 h-1 (13 ~ 17 ng m-2 h-1),高于模型预测值(1.1 ng m-2 h-1)1 ~ 2个数量级,这表明前期研究可能低估了汞矿化带土壤向大气的排汞通量。

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To study the relationship between mental-physical health and coping behavior,job stress and job motivation in medical laboratory scientists and technicians. A cross-section survey was conducted,using the anxiety rating scale(SAS), depression rating scale(SDS), coping behavior rating scale,self-rating subhealth scale,self-rating stress scale,and self-rating job motivation scale among 289 medical laboratory scientists and technicians with analysis of ANOVA and Regression. The study was carried out in three steps:step1 is to analyze the general situation of the mental-physical health.Step 2 is to analyze the features of the main influencial facotors.Step 3 is to study the influence of the relative factors on mental-physical health.The following are the results: 1.The anxiety and depression scores of the medical researchers and technicians were 30±6 and 37±8 respectively,both significantly lower than those of the national norm(34±6 and 42±11 respectively,both P<0.01),which are of significant difference. The depression score of the associate chief technician was 42±7, significantly higher than those of the medical researchers and technicians with any other professional titles (all P<0.05), and the anxiety score of the associate chief technicians was 32±7, significantly higher than that of the research fellows(28±4, P<0.05),with no significant difference to the score of the medical researchers and technicians with other professional titles. The depression score,anxiety score and the subhealth score of the age group of 36~49 were 39±9,31±7 and 32±9 respectively, both higher than that of the age group of 20~35 (36±8,29±6 and 29±7 respectively,both P<0.05),while there is much diference among other age groups. And the subhealth status has nothing to do with marital status,education background and professional titles. 2.The coping behaviors,job stress and motivation of the military medical laboratory scientists and technicians. 1)Coping behaviors:The seeking help score of the associate chief technicians was 2.8±0.5,not significantly different from that of the associate research fellows(2.8±0.5),but significantly lower than those of the medical researchers and technicians with other professional titles(all P<0.01),and whose self-blame score was higher than that of the research fellows,which is of significant difference.The self-blame score and the imagination score of the associate research fellows were 2.0±0.5 and 2.4±0.5 respectively, significantly higher than that of the research fellows(1.6±0.4, 2.1±0.4,both P<0.01). The seeking help score of the females was 3.1±0.5, significantly higher than that of the males(2.9±0.5, both P<0.01),and the solving problem score was 3.4±0.6,significantly lower than the male(3.6±0.7, both P<0.01).There is no any significant difference in coping behaviors among researchers and technicians of different marital status,education background and age groups. 2)Job stress: The score of job stress of the age group of 35~49 and 50~60 were 23±8 and 25±6 respectively,significantly higher than that of the 20~35(21±7,both P<0.05). There is no any significant difference in job stress among researchers and technicians of different marital status,gender,professional titles and education background. 3)The score of meeting personal desire for reputation and interests of the males was 19.6±5.4,significantly higher than that of the females(18.4±5.0, both P<0.05), while there is no significant difference in job motivation among researchers and technicians of different titles,education,age and marital status. 3.The relationship of the mental-physical health of the military medical laboratory scientists and technicians with their coping behaviors,job stress and motivations 1) Coping behaviors:Regression analysis showed that, the best predictors of subhealth were anxiety,depression and escaping (β=-0.40,β=0.23, β=0.14, both P<0.01).the best predictors of anxiety and depression were active coping behaviors and negative coping behaviors (β=-0.40,β=0.40, both P<0.01).The moderate(rational) coping behaviors is the best predictor only of anxiety and of significant difference. 2)job stress : Regression analysis demonstrated that anxiety,depression,job stress 2 and job stress 4 are the best predictor for subhealth;job stress 12 is the best retro-predictor for depression; job stress 3 and 8 are the best predictor for depression;and job stress 2 and 9 are the best predictor for anxiety ,which are of significant difference. 3)Motivation:Regression analysis demonstrated that depression is the best predictor for subhealth while motivation itself doesn't predict subhealth;with respect to the specific contents of motivation,"probing unknown rules and making contributions to the human society "is the best retro-predictor for depression and has nothing to do with anxiety prediction. 4) The combined influences of coping behaviors,job stress and motivations: Regression analysis showed that, the best predictors for subhealth were anxiety,depression and job stress(β=0.41,β=0.24, β=0.19, both P<0.01).the best predictors for anxiety and depression were active coping behaviors and negative coping behaviors (β=-0.40,β=0.40, both P<0.01).The moderate(rational) coping behaviors is the best predictor only for anxiety and of significant difference. CONCLUSIONS: Regression analysis showed that the best predictors for anxiety and depression were active coping behaviors and negative coping behaviors, the best predictors for subhealth were anxiety,depression and job stress.Coping behaviors, job stress and motivations have significant influences on the mental-physical health of the military medical researchers and and technicians. Among them,coping behavior is the most important factor while job stress and motivation follow. Seeking help more often,less self-blame ,imagination and job stress could help release the anxiety, depression and improve the subhealth of the medical researchers and technicians. The findings of this study indicate we should address the physical and mental health of the military laboratory researchers and technicians.

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