激光能量对反钙钛矿GaCMn_3薄膜结构与物性的影响

本文采用脉冲激光沉积方法在LaAlO3(001)单晶衬底上制备了反钙钛矿GaCMn3薄膜,通过控制制备过程中脉冲激光的能量,研究了不同激光能量条件对GaCMn3薄膜结构与物理性能的影响.分别利用X射线衍射仪、原子力显微镜、超导量子干涉仪和物理性能测试系统,对所制备的薄膜的晶体结构、表面形貌和磁性、电输运性质进行了研究.结果表明,制备的样品均为具有多个晶面取向的反钙钛矿薄膜,且薄膜结构和物性明显随制备激光能量的变化而变化.当激光能量为450mJ时,制备的薄膜多晶面取向性最弱,结晶性和表面形貌最优良.实验所得的薄膜均表现出顺磁-铁磁-反铁磁相转变,然而转变过程比块材较平缓,同时薄膜的电阻率并未表现出块材中的突变特征,我们推测该现象很可能是由衬底的应力及衬底的晶格膨胀对薄膜反常晶格变化的抑制作用造成的.     

电流并联负反馈放大器实验的研究

用实验的方法，研究电流并联负反馈对放大器性能的改善，提出电流型、并联型负反馈放大器性能参数的测量方法。     

Proton-exchanged optical waveguides fabricated by glutaric acid

In this paper, we first report that a new proton source, glutaric acid, has been used to fabricate optical waveguides in Z-cut lithium niobate crystals. The relationship was experimentally established between proton-exchanged (PE) waveguide parameters and fabrication conditions. It is shown that this new organic acid can be used to obtain deep PE waveguides in fast diffusion speed (0.275 μm²/h at 221°C) and with low loss (0.2 dB/cm). It provides an alternative approach for fabricating PE waveguides in lithium niobate substrate.     

群色散光纤中高强度光脉冲传输与压缩的研究

考虑非线性四阶折射率,推导了光脉冲在群色散单模光纤中传输的非线性方程,并得到孤子型解析解.同时指出在Sech型光纤脉冲压缩实验中,光强度的阈值.     

Photo-induced effect in the layered perovskite manganite La<Subscript>1.2</Subscript>Sr<Subscript>1.8</Subscript>Mn<Subscript>1.8</Subscript>Co<Subscript>0.2</Subscript>O<Subscript>7</Subscript>

It is helpful to study the photo-induced effect in the perovskite manganites not only for elucidating the mechanism of colossal magnetoresistance (CMR) effect but also for potential applications in technology. The laser-induced effect in the Co doping layered perovskite manganites La_1.2Sr_1.8Mn_1.8Co_0.2O₇, is studied in this paper and the obtained results are also compared with that gained in the Nd-doping manganites with cubic perovskite structure.     

添加助剂的钙钛矿型氧化物NdMO_3上的甲烷氧化偶联——Ⅱ.15% Li_2O/NdMO_3(M=Cr、Mn、Fe、Co、Ni)上的OCM反应研究

在添加了15%Li_2O的NdMO_3(M=Cr、Mn、Fe、Co、Ni)上进行了甲烷氧化偶联(OCM)反应研究.通过改变反应气中CH_4:O_2浓度比,在氧化态和“脱氧态”催化剂上的CH_4脉冲反应,探讨了表面吸附氧和晶格氧在OCM反应中的作用以及NdMO_3中不同金属离子(M)对OCM反应活性的影响等.     

免疫亲和柱净化/柱前衍生化-高效液相色谱荧光检测法测定粮谷中的T-2毒素

建立了免疫亲和柱净化/柱前衍生化-高效液相色谱荧光检测器测定粮谷中T-2毒素含量的方法。样品经甲醇-水(体积比为80∶20)混合溶剂提取,通过免疫亲和柱(IAC)净化,以氰酸蒽(1-AN)为衍生化试剂、4-二甲基氨基吡啶(DMAP)为催化剂进行衍生,以ZORBAX Eclipse XDB-C18 柱为分离柱,乙腈-水(体积比为80∶20)为流动相进行高效液相色谱分离及荧光检测，荧光检测的激发波长为381 nm，发射波长为470 nm。T-2毒素的质量浓度为0.01~1.5 mg/L时与峰高呈良好的线性,相关系数为0.9985。在0.01~1.5 μg/g添加水平下，回收率为79.7%~94.5%,相对标准偏差小于7%；检出限（S/N＝3）为0.01 μg/g。该方法净化效果好,灵敏度高,操作简便快速。     

脊髓小脑变性疾病病人血清铜,锌,铝,铁含量的研究

脊髓小脑变性疾病（ＳＣＤ）的病因可能与遗传、神经生化紊乱、感染、微量元素平衡障碍及自由基损伤等因素有关，其中微量元素平衡障碍的研究具有重要意义。检测了ＳＣＤ中发病率较高的橄榄桥小脑萎缩症（ＯＰＣＡ）及晚发性小脑皮质萎缩症（ＬＣＣＡ）病人１５例血清中铜、锌、铝、铁等微量元素含量。发现病人比对照组铜明显降低，Ｐ〈０．０１；锌明显降低，Ｐ〈０．０１；铝明显升高，Ｐ〈０．０１；铁无明显差别。     

The Mutual Conversion of CO2 and CO in Dielectric Barrier Discharge (DBD)

Non-equilibrium plasma, which was engendered by dielectric barrier discharge (DBD) was used to analyze the mutual conversion between CO₂ and CO. The results showed that the conversion ratio of CO increased monotonously with the increasing voltage. But CO₂ was not so. Its conversion ratio reached maximum when the voltage was 3600 V in Ar system. It also showed that the existence of water molecules was more advanageous for the conversion of CO to CO₂ in Air system than in oxygen system, and the conversion ratio could reach 75.8% when the relative humidity was 100%. We also discussed the energy yield and energy efficiency, and the result was that high voltage and high concentration of reactant was disadvantageous for energy utilization.     

氢化物石墨炉原子吸收光谱法应用研究——Ⅱ.超痕量汞的测定

本文使用涂金石墨管,自制氢化物石墨炉进样系统及连续流动氢化物发生器,直接测定了粮食,植物及水中的痕量汞。该法实用性强,线性范围宽,精密度好,准确度高。灵敏度为1.1ng/L,检出限(3σ)为0.8ng/L。