淮南李咀孜矿煤中汞及其分布特征

系统采集了淮南李咀孜矿不同煤层中的13个煤样,采用美国Leco公司生产的"AMA汞分析仪器"测定所采集到的煤样中汞的含量.分析结果表明:李咀孜矿煤中汞的含量范围为0.082～0.251(ug/g),处于中国煤中汞的含量范围之内(0.01～1.00 ug/g;其算数平均值为0.177(ug/g),与华北石炭-二叠系和美国煤中汞的算数平均值相近(0.17 ug/g),略高于中国煤中汞的算数平均值(0.15 ug/g).不同成煤期煤层中汞的含量有较大差别,由大到小依次为:上石盒子组、下石盒子组、山西组.     

煤中砷的分布、赋存形态及对环境的影响

研究了煤中砷含量的分布规律、赋存形态及成因,简要分析了砷对环境的影响。结果表明,我国煤中砷含量算数平均值比美国、英国和世界平均水平都低,但比澳大利亚高。我国各省(直辖市)煤中砷含量各不相同,砷浓度在中国北方显著低于华南。我国不同成煤时代煤中砷的含量显著变化。不同煤种砷含量分布不均匀。砷的赋存形态主要是有机砷和无机砷。各种地质因素影响砷的富集,包括物源区母岩、成煤植物、成煤环境、煤化作用、构造运动等。     

皖东北部新元古代臼齿构造碳酸盐岩地球化学特征与成因研究

对皖东北部新元古代臼齿构造碳酸盐岩进行了主量元素与微量元素的测试分析,并结合前人研究的基础上,系统地研究了臼齿构造碳酸盐岩微亮晶与基质的主量元素与微量元素地球化学特征.结果表明:主量元素中微亮晶相对基质Ca CO3含量较高,微亮晶相对基质沉积环境较稳定,微量晶相比基质在主量元素含量上波动较小;稀土元素方面,Y/Ho比值在基质与微亮晶呈现正隆起性的相关性,推测臼齿构造碳酸盐岩形成于元古代Rodinia形成的前陆汇聚时期.微亮晶与基质稀土配分模式平坦,Eu正异常,Ce的负异常,具有同东太平洋13°海隆和冲绳海槽相似的稀土分配模式.同时结合该区域的研究成果分析表明:皖东北部新元古代臼齿构造碳酸盐岩形成于Rodinia超级大陆汇聚过程中华北板块东南缘弧后伸展条件下,热液活动有关.     

稀土元素对银镁镍合金的改性研究

为得到高稳定性的电接触材料,向Ag-Mg-Ni合金中添加稀土元素Ce、Y,研究稀土元素对内氧化型银镁镍合金组织、力学性能及电阻率的影响。实验表明,加入Ce、Y后的内氧化银镁镍合金的力学性能明显提高,电阻率略有升高。相对于Y元素,Ce元素的添加使合金强化程度更高,更有利于合金力学性能的提高。     

云、贵、川地区不同变质程度煤中稀土元素含量研究

以我国云、贵、川地区煤为研究对象,采用HR-ICP-MS法测试了三种不同变质程度煤中稀土元素含量,得知褐煤中稀土元素含量偏低,肥煤、无烟煤中稀土元素含量在正常水平。三种煤稀土元素的分布模式与华南煤、中国煤一致,稀土元素来源主要是陆源,与变质程度关系不大。     

生物质与煤共燃特性的研究

利用TG-DTG（热重-微分热重）热分析技术研究了生物质、煤及其混合物燃烧的燃烧性质.考察了它们各自的着火温度、最大失重速度和燃尽温度等燃烧特征参数,计算了着火性能指数和综合燃烧特性指数.结果表明,生物质的燃烧分为250～350℃之间和350～450℃之间两个阶段;生物质的燃烧性能相近,结构相似;生物质的综合燃烧特性指数明显高于煤的综合燃烧特性;生物质与煤样混燃可有效地降低着火温度,改善煤样的燃烧性能.     

偏最小二乘分光光度法同时测定混合稀土氧化物中的Eu、Sm、Pr、Ho、Tm和Nd

本文研究了EGTA和DTPA对稀土元素可见光区的吸收光谱的增敏作用.采用偏最小二乘(PLS)分光光度法拟定在DTPA—六次甲基四胺体系中测定Eu、Sm和Pr、Ho;在EGTA—六次甲基四胺体系中测定Tm.Nd.实验结果表明对合成样品的测定相对误差均小于6%,回收率为94～105%,混合稀土样品测定结果与x—荧光配分值相比较相对误差小于10%,本方法适合于一般的工业分析,用于测定指定的六个稀土元素,设备简单,操作方便.     

贵州织金中低品位磷块岩物质组成研究

本文以贵州织金地区中低品位含稀土磷块岩为研究对象,分别研究了磷块岩的化学组分、稀土元素的分布、矿石的扫描电镜及显微镜下矿石的结构分析.结论为矿物的物质组成为碳氟磷灰石、白云石和石英为主,含有少量方解石、黄铁矿和粘土矿物,原生矿中P2 O5一般在10.01％ ～ 19.90％,SiO2为19.05％ ～60.29％,CaO为20.75％～33.13％.稀土元素主要以钇(Y2O3)、钕(Nd2O3)、镧(La2O3)、铈(CeO2)等四种元素为主,占稀土总量13.53％～34.90％.通过综合分析测试,查明矿石的矿物组成、稀土元素的分布,为深入开展该类型磷块岩矿物加工工艺提供基础资料.     

无机玄武岩纤维微观结构的光谱学特征研究

利用多种光谱方法研究新制备的玄武岩纤维的组成和微观结构特征.X-射线探针分析表明其主要成份为硅酸盐和碱土金属氧化物.中红外光谱和显微远红外光谱研究表明纤维中含有Si-O,Si(Al)-O和金属与氧的振动模式;利用共焦激光显微拉曼光谱对比研究玄武岩和制备的玄武岩纤维的结构特征,结果表明纤维中含有[Si2O5]2-、[Si2O6]4-[、SiO4]4-等结构单元.广角X-射线衍射表明玄武岩纤维为非晶结构,具有短程有序的特点,计算的短程有序度为0.912 nm.详细解释了各种光谱变化的原因,据此提出了玄武岩纤维的非晶微观结构近程有序模型的特征.     

市政道路“黑+白”路面层间性能试验研究

已有研究表明层间性能对超薄水泥混凝土加铺路面性能的影响十分重要.本文通过直接剪切试验和拉伸试验综合确定市政道路"黑+白"路面层间处理方案为"1.8 kg/m~2的SBS改性沥青+13 kg/m~2 13.2mm级单粒径玄武岩碎石+轻压",层间具有良好的抗剪切能力和抗拉能力,层间性能满足市政道路"黑+白"路面要求.     

On Ugliness in Words,in Politics,in Tour-ism

Many educational theoretical approaches to cosmopolitanism tend towards an unconditional appreciation of mobility, diversity and rootlessness. The recent interest of educational philosophy in the rhizome, de-territorialization and diversity contributes to this understanding of cosmopolitanism as movement across a borderless and imperfect world. Without downplaying such insights (and related political education), this article displaces and de-temporalizes them. It takes the form of a parody of the rhizome to view those insights from a different perspective and make them strike a different pedagogical note.     

扎实扎好建配管努力搞好用教研

通过对小学师资队伍现状的分析，提出网络环境下小学教师应具备的基本素质并对小学师资队伍建设的途径进行探讨。     

Self-concept differences in student teachers in primary,elementary, secondary,and special education

Self-concept, intelligence and academic achievement were examined in students preparing to teach in primary, elementary, secondary, and special education (N = 267). The measures were the Tennessee Self-Concept Scale, a group intelligence test, and school grades. Differences in self-concept, but not in intelligence and academic achievement, were found among groups of student teachers. Secondary education majors reported a more positive self-concept than primary or elementary, with special education majors reporting the least positive self-concept of all.     

Genotypic and environmental variation in cadmium, chromium, arsenic, nickel, and lead concentrations in rice grains

Genotypic and environmental variation in Cd, Cr, As, Ni and Pb concentrations of grains, and the relationships between these heavy metals and Fe, Zn were investigated using 9 rice genotypes grown in 6 locations for two successive years. Significant genotypic variation was detected in the five heavy metal concentrations in grains, indicating the possibility to reduce the concentration of these heavy metals in grains through breeding approach. The environmental effect varied with metal, with Pb and Ni having greater variation than the other three metals. There was significant genotype-environment （location） interaction of the concentrations of all five heavy metals in grains, suggesting the importance of cultivar choice in producing rice with low heavy metal concentrations in grains for a given location. Correlation analysis showed that Cd and As, Cr and Ni, and As and Pb concentrations in rice grains were closely associated, and that Ni concentration in grains was negatively correlated with Zn concentration.     

江西婺源蓝尾石龙子形态特征的两性异形

报道了江西婺源地区蓝尾石龙子（Eumeces elegans）头、体大小的两性异形.蓝尾石龙子成体体长存在显著的两性差异（雄性大于雌性）,雄性个体有较大的头部（头长和头宽）,雄性头部增长速率明显大于雌性,表明成年雄体分配较多的能量用于头部和身体的生长;而成年雌体则相对延缓头部的生长,以维持躯干生长,增大腹腔容纳量,可提高其繁殖输出.     

Knowledge, Concepts, and Inferences in Childhood

The role of knowledge in children's inferences was investigated in 3 experiments. Experiment 1 examined developmental changes in the role of categorical membership, perceptual appearance, and item complexity in inferences for natural kind and artifact concepts. Preschoolers (5-year-olds), second graders (8-year-olds), and fourth graders (10-year-olds) were taught novel properties about target concepts and asked whether each of 4 probes had those properties. Probes varied in category membership and perceptual appearance relative to the target item. Item complexity also varied. Experiments 2 and 3 examined inferences with known and unknown concepts for familiar and unfamiliar properties. Older children's knowledge led to differential weighting of categorical information over appearance but only for known concepts and/or familiar properties. Preschoolers made no distinction between category and appearance for either known or unknown concepts. Additionally, as target item complexity increased, older children made more inferences than preschoolers. No differences between inferences about natural kind and artifact concepts were found. The role of theories and knowledge in children's drawing of inferences is discussed.