石墨衬底生长高质量金刚石膜的优势

石墨衬底上可以沉积出晶体取向性较强的(220)织构的金刚石膜,这种金刚石膜的热导率高、断裂强度大;石墨衬底上沉积金刚石形核致密、速度快;石墨上沉积的金刚石膜纹理缺陷少。对石墨衬底的这些优势做了比较详尽的分析。     

石墨炉原子吸收法测定动物组织中痕量铬的研究

本文报导了在酸性介质中，用石墨炉原子吸收法测定动物组织中痕量铬的最佳实验条件。系统的论述了消化剂的选择，消化时间控制，进样酸度以及共存元素对测定结果的影响。实验结果表明，采用ＨＮＯ３－ＨＣｌＯ４进行动物组织样品消化效果优于ＨＮＯ３－ＨＣｌ－Ｈ２Ｏ２。本文给出了动物组织的最佳消化条件及分析方法。     

Gradient distribution of radial structure of PAN-based carbonfi ber treated by high temperature

High-performance graphite fibers were prepared and analyzed. The gradient distribution of radial structure of PAN-based carbon fibers was characterized by two different Raman test methods(incident laser beam perpendicular to and parallel to the fiber axis) and studied by the distribution of graphitization degree. Meanwhile difference between the two Raman test methods was used to describe the orientation of the graphite crystallite along the fiber axis. The results showed that the radial structure of PAN-based carbon fiber presented different gradient distribution states at different heat treatment temperatures,and the graphitization degree in the skin region changed more rapidly compared with the core region since the skin region was more affected by temperature which resulted in the obvious difference between skin and core structures.The difference of graphitization degree(Δg) characterized by two different Raman test methods increased with heat treatment temperature,indicating that the high temperature treatment(HTT) promoted further stacking of graphite crystallite,and the orientation degree of the graphite crystallite along the fiber axis was continuously increased.     

新型组合式端面油封的结构设计

设计的端面油封由静圈和动圈组成,按采用弹簧的不同,分为圆柱形弹簧组合油封和别针形弹簧组合油封,其特点是用弹簧力压缩静环与动环端面,贴合至最小间隙实现密封,在长期工作中,能以弹簧的弹力来对间隙进行自动补偿,延长其使用寿命,提高密封性能。     

Catalytic performance of nano-hybrid graphene and titanium dioxide modified cathodes fabricated with facile and green technique in microbial fuel cell

Finite resources of the world''s fossil fuel give rise to the irresistible urge to explore alternative renewable energy routes such as microbial fuel cells (MFCs). The limited productivity is one of the main obstacles for MFC scalability. In this study, a dual-chamber MFC was assembled and equipped with fabricated modified cathodes with titanium dioxide (TiO2) or hybrid graphene (HG) which mainly improved the catalytic activity of the cathode. The graphite paste (GP) bare electrode was modified by both nanomaterials using a green and facile technique. The results showed that the modified cathodes resulted in a considerable improvement for the MFC performance, i.e., the power density reaching levels of 80 mW/m2 for GP-TiO2 and 220 mW/m2 for GP-HG compared to 30 mW/m2 for GP electrode. Additionally, the modified electrodes exhibited lower charge transfer resistance (Rct) compared to the bare electrode. Therefore, these modified electrodes, fabricated by an eco-friendly method, could be used as alternatives to the precious expensive metals like Pt.     

Cu-Ni/C催化剂的低温制备及其催化合成碳酸二甲酯的研究

 采用氧化石墨（GO）作为碳素载体前驱体,金属氨配合物作为金属前驱体,用水合肼以低温液相还原的方式制备了碳负载铜镍合金催化剂（Cu-Ni/C）。通过FTIR、XRD、SEM、TEM和微反技术来研究催化剂的微观结构和反应性能。结果表明,90 ℃下还原得到碳负载的铜镍合金催化剂的合金粒径小于50 nm,能很好的分散于载体表面。在140 ℃,0.6 MPa的条件下,CH₃OH和CO₂在催化剂的金属活性位上发生反应,生成碳酸二甲酯（DMC）,甲醇的最高转化率为4.2%,DMC的选择性达到84.5%。     

石墨炉原子吸收法测定饮用水中铝含量

本文研究了石黑炉原子吸收法测定饮用水中铝含量的条件和方法。其方法简便、快速、准确,灵敏度高。回收率在92～110％,相对标准偏差的1.8％～2.6％。定用于饮用水的监测分析。     

石墨炉原子吸收法测定地球化学样品中的痕量金

试料经高温焙烧后,用王水（50%）在电热板上加热溶解,在王水溶液的体积分数φ（王水）为10～15%和少量三氯化铁的介质中,用聚氨酯泡沫塑料吸附,再用硫脲—盐酸（10g/L）溶液解脱,所得溶液用Z-2000石墨炉原子吸收测定痕量金。根据实验得到的最佳分析条件,方法检出限（3S）为0.1ng/g,精密度（RSD,n=12）低于8.0%,经国家一级标准物质（GAu-2、GBW07243～GBW07248）分析验证,结果与标准值相符。     

智能石墨炉原子吸收光谱法直接测定尿镉

目的建立快速有效的减少尿镉测定中尿基体干扰的预处理方法，改善尿镉原子吸收光谱测定的效果。方法通过比较不同稀释剂、基体改进剂、升温程序及温度对尿镉测定的影响，选择0．25％Mg（NO3）2-0．5％TritonX-100作为样品稀释剂，0．1％Pdcl2-0．125％Mg（N03）2-0．5％TritonX-100-1％HNO3为基体改进剂，采用三步匀速干燥的石墨炉升温程序。该方法灵敏度b=0．21370A（μg/L），检测限为0．0716μg/L，相对偏差为0．8％～1．5％，回收率为98．8％～99．2％，线性范围0～10Ixg／L，样品稳定性〉10天。检测某电池厂镉作业工人60人，同时检测非镉接触的某单位工作人员79人，尿镉测定结果分别为（7．31±4．37）μg/gcr和（1．23±1．11）μg/gcr，两组比较，差异有统计学意义（P〈0．000）。结论该方法尿样可直接稀释测定，简单、快速、灵敏、准确、可靠，可满足大批量检测的要求。     

碳纤维的X射线显微结构分析

本文利用 X 射线衍射方法(包括小角散射方法)研究了四种碳纤维的显微结构,其中包括“乱层石墨”结构的层间距 C_0,层面堆垛的平均高度 L_c、层面的平均宽度厶、取向度 W_(1/2)以及碳纤维的平均显微孔洞等的测定,文中还提出了关于小角散射数据处理的计算程序。