自聚焦透镜光斑直径,分辨率测试研究

通过显微镜放大、ＣＣＤ图像接收采集、计算机数据处理技术来测量自聚焦透镜（ＧＲＩＮ透镜）光斑直径、分辨率。重点对误差进行分析。通过对样品５２０－０２５－０８３的测试，表明该系统光斑直径、分辨率测试不确定度优于±０．１μｍ及１％，与误差分析相吻合。     

NN-模式识别中条件误差概率收敛性的充要条件

Let (θ₁,X₁),…, (θ_n,X_n), (θ, X) be iid random vectors ,where θ∈{0,1},X∈R^d Denote by θ′_n the nearest neighbour discriminator of θ based on the training samples (θ₁,X₁),…, (θ_n,X_n) and the observed X; put(?). This paper gives a sufficient and necessary condition for (?) as n→∞, namely (P(θ=0, X=x)-P(θ=1, X=x))²·P(θ=0, X=x)·P(θ=1, X=x)=0 for every x∈R^d.This generalizes a previous result of the authors [5] and improves a result of Wagner, T.J. [2].     

H MAS and H[Na] double resonance NMR studies on the modification of surface hydroxyl groups of γ-alumina by sodium

The modification of surface hydroxyl groups with sodium in a series of Na₂CO₃-γ-Al₂O₃ catalysts was investigated as a function of both the Na₂CO₃ loading and the calcination temperature by means of ¹H magic angle spinning (MAS) and ¹H[²³Na] spin-echo double resonance NMR techniques. The ¹H NMR experiments revealed that sodium ions are homogeneously distributed over the alumina surface and closely coordinated with the surface hydroxyl groups. In the catalysts calcined at 250 °C, the acidic hydroxyl groups (with a chemical shift of 2.0 ppm) are preferentially associated with sodium ions at low Na₂CO₃ coverages (5 and 10%), while both the acidic and the basic (0 ppm) hydroxyl groups are accessible for sodium ions at high coverages (15 and 20%). The coordination causes a low-field shift of about 2 ppm in the ¹H MAS spectra, and a broad signal at 4.5 ppm appears. It is interesting that the 4.5 ppm signal is completely suppressed in the ¹H[²³Na] MAS experiments, providing direct evidence that a strong interaction exists between adsorbed sodium ions and the surface hydroxyl groups. Increasing the calcination temperature to 450 °C results in preferential removal of the acidic hydroxyl groups, and only the most basic hydroxyl groups remain when the calcination temperature is raised to 600 °C. This is attributed to the formation of the coordinated species which enhances the acidity of the surface hydroxyl groups and prompts their dehydroxylation, especially at high calcination temperature. Correlation of the ¹H MAS NMR results and catalytic activity measurements indicates that the basic hydroxyl groups are essential for the carbonyl sulfide hydrolysis reaction.     

非晶硅薄膜的光膨胀效应

利用“差分电容膨胀计”方法，首次发现氢化非晶硅（ａ－Ｓｉ∶Ｈ）在光照下体积增大．著名的Ｓｔａｅｂｌｅｒ－Ｗｒｏｎｓｋｉ效应（ａ－Ｓｉ∶Ｈ的光致亚稳变化）很可能是这种“光膨胀”的后效应     

焙烧温度对La2O3—NiO体系结构和导电性及某些催化性能的影响

稀土氧化物特别是La2O3作为助催化剂，对CO甲烷化反应有促进作用，已为人们所知［‘j．研究焙烧温度对La。O。－NIO催化剂结构、导电性，特别是对其在不同类型反应中催化性能的影响，目前文献报道较少．本文通过多晶X射线衍射（XRD），差热一热重分析（DTA－TG），导电性测量，CO甲烷化及二甲苯完全氧化反应活性测定等手段，考察了所制备的La。Os－NIO催化剂经不同温度焙烧后，结构、热效应、导电性的变化，并研究了该体系催化剂在上述两种不同类型反应中的催化性能．用分析纯试剂La（NO3)·6H2O和La（NO3）3·6H2O（北京化工…     

铁电体爆电换能器的匹配研究

 本文根据冲击加载PZT铁电陶瓷材料的电响应理论，讨论了垂直模式的矩形和柱形铁电陶瓷样品含电感负载时的最佳匹配关系、最佳状态的某些特性及最佳装置的设计方法。计算举例表明，理论同已做过的矩形爆电换能实验符合很好。     

邻醌式同系物的DSC研究

丹参(Salvia miltirrohiza)和红根草(S.Prionitis)均含有治疗冠心病有效成分—丹参酮Ⅱ-A等二萜醌类化合物,它们的扩冠作用,抑制血小板聚集,抑菌等活性常与该类化合物的结构、晶型、极性、溶解度、熔点有密切的相关性,如前报所述A环为脂环的化合物其熔化热低于芳环的化合物.丹参中的丹参醌Ⅱ-A(1),丹参醌Ⅱ-B(2)和红根草邻醌(3),其抗菌和抗肿瘤活性强度是3>2>1,为探究其晶型结构与药效的内在联系,本文对该类化     

A Suberato-Pillared Mn(II) Coordination Polymer: Hydrothermal Synthesis, Crystal Structure, and Magnetic Properties of Mn2(H2O)[O2C(CH2)6CO2]2

A suberato-pillared Mn(II) coordination polymer Mn₂(H₂O)(C₈H₁₂O₄)₂ was hydrothermally synthesized at 170°C for 3 days and characterized by single-crystal X-ray diffraction. Crystal data: monoclinic, C2/c, Z=4, a=26.544(5), b=7.617(2), c=9.187(2) Å, β=105.38(2)°, V=1791.0(7) ų, R₁=0.064 and wR₂=0.162. The compound shows a layered structure consisting of inorganic Mn oxygen polyhedral layers and organic regions. The inorganic Mn oxygen layers are generated from Mn₂O₁₀ bioctahedral units, which share corners with neighbors to form zigzag chains along the [001] direction and are, along the [010] direction, further connected by carboxylate groups of the suberato ligands and hydrogen bonds. The magnetic studies indicated that the compound becomes antiferromagnetic at low temperatures with T_Néel=12 K and follows Curie-Weiss law χ_m(T+22.429)= 4.48 cm³ mol⁻¹ K between 25 and 300 K. Upon heating in Ar stream, Mn₂(H₂O)(C₈H₁₂O₄)₂ decomposes in three steps.