O_2,H_2S和SO_2对氧硫化镧催化性能影响的原位IR研究

对比研究了O2,H2S和SO2对La2O2S和γ-Al2O3催化剂上羰基硫（COS）水解反应的影响,与传统的氧化铝催化剂相比,氧硫化镧显示出良好的抗氧性能和一定的耐硫能力．一定量的O2或O2与H2S共存气体对La2O2S的活性几乎没有影响,但却使γ-Al2O3的活性明显下降;SO2的存在会导致两种催化剂活性有不同程度的降低,但在La2O2S上随着温度的上升其影响程度逐渐减弱．利用原位IR技术表征了La2O2S表面物种,用程序升温脱附（TPD）技术分别考察了O2,H2S,SO2单独组分及混合组分在两种催化剂上的吸附行为．研究发现,由于各组分在两种催化剂上的吸附行为不同,使COS在γ-Al2O3和La2O2S催化剂上具有不同的水解反应机理,氧硫化镧催化剂上COS水解反应遵循Rideal机理．由于SO2本身对La2O2S中的品格S^2-起输送作用,因而稀土氧硫化物催化剂具有良好的抗SO2中毒性能．     

The Influence of Au-Doping on Morphology and Visible-Light Reflectivity of TiN Thin Films Deposited by Direct-Current Reactive Magnetron Sputtering

Ti, TiN and Au-TiN （Au content： from 0.5%to 7.7%） thin films were deposited on stainless steel substrates by dc reactive magnetron sputtering with a metal Ti target. The crystal structure, surface morphology and visiblelight reflectivity of the films for different film compositions are studied in detail. Distinctly different surface morphologies appear for the Ti, TiN and Au-TiN thin films. It can be observed that the surface morphology of the TiN film is affected by the Au-doping, when the Au content increases from 0% to 7.7%, surface roughness enlarges from 62.4 to 82.8 nm. Moreover, visible-light reflectivity varies significantly with increasing A u contents in the TiN films. However, the rettectivity of the TiN thin film at 550-800 nm is higher than that of the Au-TiN thin film. The present work illustrates the dependence of metal elements on the surface morphology and on the reflectivity of Au-TiN thin films. It is speculated that the addition of Au can suppress the formation and growth of TiN grains so that it changes the surface morphology and the Au-TiN thin film has potential applications in spectral selective coating.     

CaMoO_4:Tb~(3+)发光材料的制备和发光性质的研究

用共沉淀法制备了样品CaMoO_4:Tb~(3+)的前驱物,经TG-DTA测试表明:样品在850℃时有能量吸收峰,即达到样品反应的活化点。XRD谱图分析显示,焙烧后样品CaMoO_4:Tb~(3+)为CaMoO_4的白钨矿结构,但峰位发生了右移,说明晶体内部产生了微小的晶体缺陷,推测该缺陷可能是由晶胞内2个Tb~(3+)取代了3个Ca~(2+)形成空穴而引发的。通过对激发谱图的测试发现,此种缺陷结构有利于使MoO_4~(2-)发射特征峰(488 nm)的能量有效地传递给Tb~(3+),使Tb~(3+)的4f电子发生跃迁,特别使Tb~(3+)的~7F_6→~5D_4(488 nm)电子跃迁大大加强,因而在样品CaMoO_4:Tb~(3+)的发射谱图(λ_(ex)=488 nm)中,自激活荧光体MoO_4~(2-)的发射强度被大大减弱,而Tb~(3+)的~5D_4→~7F_5(544 nm)跃迁的绿光发光强度被大大增强,使该材料成为有潜在应用价值的发光材料。     

基于边缘几何特征和频域相关技术的图像匹配方法

提出了一种基于图像特征提取和变换域相关的图像匹配方法。借助提取图像的大边缘信息，以其几何特征构造边缘方向角曲线作为图像匹配的依据。通过对差分的计算，并比较两幅图像边缘方向曲线的相对链码，得到2幅图像之间可能的旋转角度。对旋转矫正后的图像进行2维傅里叶变换，计算频域内2图的相位相关矩阵，并从中找到相关系数最大的位置，这个位置就代表了2图的坐标位移量，通过平移达到图像间的精确匹配。实验表明：该方法匹配准确，速度快，减少了人为因素的干扰，对于图像间存在较小灰度差和噪声情况均有很好的匹配效果。     

去势手术对大鼠肾上腺中孕烯醇酮、17α-羟孕烯醇酮和脱氢表雄酮代谢的影响

雄激素阻断治疗作为临床上治疗前列腺癌的主要方式,已被证明能够引起肾上腺中CYP17α1基因表达的增强.由于该基因所编码的酶为肾上腺中的肾上腺雄激素合成的关键酶,因此去势后由该酶所催化的甾体激素合成途径中的孕烯醇酮、17a-孕烯醇酮以及脱氢表雄酮的含量应会出现相应变化.本文建立了一种适用于生物组织样品中上述3种激素的Gc...     

A new parametric equation of state and quark stars

It is still a matter of debate to understand the equation of state of cold matter with supra-nuclear density in compact stars because of unknown non-perturbative strong interaction between quarks. Nevertheless, it is speculated from an astrophysical view point that quark clusters could form in cold quark matter due to strong coupling at realistic baryon densities. Although it is hard to calculate this conjectured matter from first principles, one can expect that the inter-cluster interaction will share some general features with the nucleon-nucleon interaction successfully depicted by various models. We adopt a two-Gaussian component soft-core potential with these general features and show that quark clusters can form stable simple cubic crystal structure if we assume that the wave function of quark clusters have a Gaussian form. With this parametrization, the Tolman-Oppenheimer-Volkoff equation is solved with reasonably constrained parameter space to give mass-radius relations of crystalline solid quark stars. With baryon number densities truncated at 2_n0 at surface and the range of the interaction fixed at 2 fm we can reproduce similar mass-radius relations to that obtained with bag model equations of state. The maximum mass ranges from 0.5M_⊙ to 3M_⊙. The recently measured high pulsar mass ( 2M_⊙) is then used to constrain the parameters of this simple interaction potential.     

微通道板离子壁垒膜粒子阻透特性的蒙特卡罗模拟

在三代微光像管中,微通道板(MCP)输入面上覆盖一层超薄离子壁垒膜(IBF),目的是保护光电阴极,延长像管使用寿命.为了深入研究离子壁垒膜的特性,本文对Al2O3和SiO2两种离子壁垒膜的粒子阻透能力进行了蒙特卡罗模拟,结果表明:5 nm厚Al2O3和SiO2离子壁垒膜的死电压分别为230 ～240 V和220～230...     

纳米氢氧化钴原位修饰碳糊电极固-液微萃取及电化学检测辛硫磷

运用纳米氢氧化钴原位修饰碳糊电极微分脉冲伏安(DPV)法检测了辛硫磷。在外加电位下辛硫磷分子被萃取到电极表面,并与纳米氢氧化钴相互作用形成络合物,在-0.489 V处得到1还原峰,且还原峰电流随扫速线性增长,表明电极上的还原过程受吸附控制。吸附过程满足Temkin等温吸附模型。pH与电位的关系表明辛硫磷的还原过程为1电子1个质子反应。运用交流阻抗方法考察了反应过程,并辅以理论计算,表明反应为自发过程,计算结果与循环伏安法一致。采用该体系检测辛硫磷,其还原峰电流与辛硫磷浓度的对数分别在3.333×10~(-13)～3.333×10~(-8) mol/L和3.333×10~(-8)～3.333×10~(-6) mol/L范围内呈线性关系,检出限(S/N=3)可达3.333×10~(-13) mol/L。该方法具有良好的重现性及选择性,用于菠菜中辛硫磷农药的检测,结果满意。     

煤粉高温空气燃烧与氮氧化物生成特性

借助循环流化床在高过剩空气系数下燃烧提供高温低氧空气的工艺,在直径为220 mm高为3000 mm的实验台上研究褐煤、烟煤和无烟煤在高温低氧空气下的燃烧特性和氮氧化物生成特性.实验结果表明,褐煤、烟煤和无烟煤在高温低氧空气下燃烧稳定性好,温度波动小;高温低氧的气氛降低了褐煤、烟煤、尤其是无烟煤燃烧的氮氧化物排放;褐煤、烟煤和无烟煤燃烧的氮氧化物排放值分别为440 mg/m3,390 mg/m3和332 mg/m3.