等离子体离子注入类金刚石多层膜机械特性

采用非平衡磁控溅射及等离子体离子混合注入方法在奥氏体不锈钢 1 Cr1 8Ni9Ti基体上制备 N/ Ti N/ Ti(N,C) / DLC梯度膜 .研究了类金刚石 (DLC)梯度膜的结构特征和力学性能 .试验结果表明 ,N/ Ti N/ Ti(N,C) / DLC梯度膜最外层为典型的 DLC层 .梯度膜的硬度、弹性模量、断裂韧性以及界面结合强度值分别为 1 9.84GPa、1 90 .0 3GPa、3.75MPa· m1/ 2和 5.68MPa·m1/ 2 .试验所制备的 DLC多层膜比 DLC单层膜具有更好的综合机械性能 .     

碳纤维表面特性对反硝化菌固着化的影响

通过对比反硝化菌在不同基体碳纤维表面的固着化及碳纤维表面含氧官能团对菌种的固着化实验,研究了碳纤维(基体、比表面积、循环利用性等)特性,尤其表面含氧官能团对反硝化菌固着化的影响。实验结果表明,反硝化菌在PAN基碳纤维上的平均挂膜厚度明显高于沥青基和粘胶基碳纤维。碳纤维表面适量的含氧官能团有助于较多、较牢固地固着反硝化菌。对三种PAN基碳纤维的XPS谱图分析表明碳纤维表面含氧官能团—O—CO对反硝化菌的固着化影响较大,当碳纤维表面含氧官能团—O—CO中碳原子占表面碳原子总量的3%左右时反硝化菌固着化效果较佳。经过比较表明PAN基碳纤维是一种生物相容性好、固着化程度高、再生能力强、耐微生物分解及化学腐蚀的优异的新型反硝化菌固着化载体。     

Na_2WO_4与BTA复配对碳钢的缓蚀作用

采用交流阻抗法和极化曲线法来研究环境友好型缓蚀剂钨酸盐和苯并三氮唑(BTA)、ZnSO4、D-葡萄糖酸钠等的复配对碳钢的缓蚀效果。研究发现,当缓蚀剂总浓度为5×10-4mol/L时,钨酸盐和BTA复配摩尔比为2∶1时缓蚀效果最好,当配方中含有4mg/LZnSO4,其缓蚀效果有一定增加;再加入10mg/LD-葡萄糖酸钠后缓蚀效果明显增加。     

Isotopic evolution of the terminal Neoproterozoic and early Cambrian carbon cycle on the northern Yangtze Platform, South China

Profound geotectonic, climatic and biological changes occur during the terminal Neoproterozoic and its transition into the early Cambrian. These are reflected in temporal variations of the chemical and isotopic composition of seawater. We are studying a sequence of sedimentary rocks at the Shatan section, northern Yangtze Platform, Sichuan Province of China. This succession comprises, in ascending stratigraphic order, predominantly calcareous sediments of the Sinian upper Dengying Formation and black shales of the lower Cambrian Guojiaba Formation (time equivalent of Niutitang Fm.). Paleoenvironmental setting represents shallow-water shelf deposits. The objective of our study is to provide temporal records for the isotopic compositions of organic and carbonate carbon throughout this time interval. Organic carbon isotope values display a range between -35.8‰ and -30.1‰ with clear stratigraphic variations. Carbonate carbon isotope data vary between -3.5‰ and +0.5‰. These secular variations are interpreted to reflect perturbations of the global carbon cycle, specifically changes in the fractional burial of organic carbon. However, local conditions have further affected the isotopic signals.     

活性炭纤维的表面功能设计和控制(Ⅰ)

文章系统阐述了活性炭纤维 (ACF)表面功能的设计和控制方法 ,介绍了ACF的比表面积、孔径分布、表面化学结构与吸附对象的关系;从ACF表面物理、化学结构的可设计化入手 ,全面阐述了ACF物理结构的设计和控制方法及表面化学的改性方法;并介绍了其应用效果     

碳钢粉末渗铝试验研究

对 2 0碳钢进行了粉末包埋渗铝试验 ,优化了渗剂配方及渗铝工艺。采用X射线衍射仪分析了渗铝层的相成分 ,并对渗铝层的微观组织和渗铝钢的力学性能进行了测试。结果表明 ,使用 3号渗剂的 2 0碳钢的表面渗铝效果最好。 2 0碳钢渗铝层内未出现高铝脆性相 (FeAl3 、Fe2 Al5等 ) ,这有利于改善渗铝钢的力学性能和焊接性能。 2 0碳钢经渗铝处理后 ,其机械性能略有降低 ,高温持久性能明显降低 ,而抗高温氧化性能大大提高。     

Climatic significance of stable carbon isotope in tree rings of Abies spectabibis in southeastern Tibet

The annually cross-dated stable carbon isotope of tree-ring a-cellulose of Abies spectabibis collected from the southeastern Tibetan Plateau is used to examine its rela-tionship with climatic parameters. The residual D13C series in treerings is constructed after removing the effects of age trend and rising CO2. We found a close relationship between D13C in tree rings and the relative humidity of September—November of the previous year measured at the nearby Ny-ingchi Meteorological Station, albeit a strong 搇agged effect? Thus we developed a transfer function to reconstruct the autumn relative humidity for the Nyingchi region, which explained 37.9% of the total variance (p < 0.001). Our results suggest a high frequency and moderate amplitude variance of the relative humidity before 1800, and the variance re-versed afterwards.     

铜离子在4-甲氧基-2,6-二(3,5-二甲基吡唑)-1,3,5-三嗪吸附型修饰电极上的电化学行为

用循环伏安法和方波伏安法研究了铜离子在4 甲氧基 2,6 二(3,5 二甲基吡唑) 1,3,5 三嗪(简称MBDT)吸附型修饰电极上的电化学行为.通过吸附在玻碳表面的配体与铜离子的配位作用,对Cu(Ⅱ)和Cu(Ⅰ)进行了电分析,结果表明,Cu(Ⅰ)在修饰电极上表现出比Cu(Ⅱ)高得多的灵敏度.     

离子选择性电极直接电位法测定牙膏中游离氟

利用氟离子选择性电极直接电位法测定了牙膏中的游离氟．讨论了总离子强度调节缓冲剂(TISAB)的组成及用量，氟电极在测定后快速恢复到空白值，以及不同空白值对测定结果的影响．实验结果表明游离氟的浓度在0．1000-9．000mg／ml范围内线性关系良好．方法的最低检出限为0．02000μg／ml，相对标准偏差RSD≤2．5％，加标平均回收率为100．8％～104．7％，方法简便，准确．     

碳纤维加固低配箍混凝土梁板柱节点的抗震试验

简要介绍了五个用碳纤维加固的混凝土低配箍梁板柱节点低周反复试验的情况 ,对试验结果进行了分析 ,发现加固后的节点极限承载力和抗震性能都有大幅度的提高 ,各项性能指标都达到并超过了我国现行抗震规范的要求 ,因此碳纤维加固混凝土节点技术是一个值得进一步深入研究的课题 .