米洛沙星的波谱特征与结构确证

采用紫外吸收光谱、红外光谱、质谱、核磁共振光谱和单晶X-射线衍射法对米洛沙星进行结构确证。讨论了紫外光谱和红外光谱的特征,详细归属了~1HNMR和~(13)CNMR谱信号,结合X-射线衍射分析结果,最终确证其分子结构。     

Systematic investigation of spectroscopic factors from (d,p) reactions for deuteron nuclear data evaluation

Spectroscopic factors for the (d,p) reactions on ¹²C, ²⁷Al, ⁴⁰Ca, and ⁵⁸Ni for incident deuteron energies up to 100 MeV were extracted systematically by fitting theoretical distorted wave Born approximation calculations to the existing experimental data. The extracted spectroscopic factors show similar incident energy dependence for all the target nuclei. An empirical expression describing the energy dependence has been deduced and implemented in a computational code system developed specially for deuteron-induced reactions. The calculation with the code system reproduces the measured ²⁷Al(d,p)²⁸Al cross sections in the incident energy range from the threshold to 20 MeV and the measured double-differential cross sections for (d,xp) reactions on ¹²C and ⁵⁸Ni at 56 and 100 MeV fairly well.     

椭圆偏振研究溅射气压对锰膜光学性质的影响

采用射频磁控溅射技术在Si(111)基片上制备金属锰膜,用椭圆偏振光谱在2.0~4.0 e V光子能量范围内研究了溅射压强对锰膜光学性质的影响.分别用德鲁得-洛伦兹模型以及有效介质模型对椭偏参数进行拟合,结果表明随压强增大薄膜致密度先增大后减少;折射率随压强增大先减少后增大;而消光系数随压强的变化与光子能量有关,在低能量区变化复杂,高能量区随压强增加与折射率规律一致.分析表明上述变化与薄膜的致密度密切相关.     

Role of the Chemical Environment beyond the Coordination Site: Structural Insight into FeIII Protoporphyrin Binding to Cysteine‐Based Heme‐Regulatory Protein Motifs

The importance of heme as a transient regulatory molecule has become a major focus in biochemical research. However, detailed information about the molecular basis of transient heme–protein interactions is still missing. We report an in‐depth structural analysis of Fe^III heme–peptide complexes by a combination of UV/Vis, resonance Raman, and 2D‐NMR spectroscopic methods. The experiments reveal insights both into the coordination to the central iron ion and into the spatial arrangement of the amino acid sequences interacting with protoporphyrin IX. Cysteine‐based peptides display different heme‐binding behavior as a result of the existence of ordered, partially ordered, and disordered conformations in the heme‐unbound state. Thus, the heme‐binding mode is clearly the consequence of the nature and flexibility of the residues surrounding the iron ion coordinating cysteine. Our analysis reveals scenarios for transient binding of heme to heme‐regulatory motifs in proteins and demonstrates that a thorough structural analysis is required to unravel how heme alters the structure and function of a particular protein.     

Preparation and spectroscopic, and thermal decomposition kinetic studies of europium(Ⅲ) complex [Eu(HNBD)3] (HNBD: 1-(6-hydroxy-1-naphthyl)-1,3-butanedione)

The complex of Eu(Ⅲ) with 1-(6-hydroxy-1-naphthyl)-1,3-butanedione (HNBD) was prepared for the first time and characterized by elemental analysis, IR, UV, fluorescence spectrum, and DTA-TG-DTG techniques. The IR and UV-visible spectra showed that Eu(Ⅲ) ion was coordinated to the HNBD ligand. The fluorescence spectrum showed the presence of Eu3+ characteristic emission. The TG-DTA-DTG curves showed that the thermal decomposition of the anhydrous complex was a two-stage process and the final residue was Eu2O3. The thermal decomposition kinetic parameters of the complex were evaluated from TG-DTG data by using three kinds of integral methods (Coat-Redfern equation, Horowitz and Metzger equation, Madhusudanan-Krishnan-Ninan equation). The kinetic parameters of the first stage are E* = 164.02 kJ·mol-1, A = 1.31 × 1015 s-1, △S*= 42.27 J·K-1·mol-1, △H*= 159.51 kJ·mol-1, △G*= 136.54 kJ·mol-1, and n = 3.1, those of the second stage are E*= 128.52 kJ·mol-1, A = 1.44 × 106 s-1, △S*= - 136.89 J·K-1·mol-1,△H*= 120.41 kJ·mol-1, △G*=283.85 kJ·mol-1, and n = 1.1.     

pH dependent spectral properties and electronic structure of benzothiazol containing cyanine dyes

The absorption and emission properties of some cyanine dyes over a range of 8 pH units are presented. Theoretical investigations of their electronic structure in the ground and excited states have been undertaken and the nature of the electronic transitions in the protonated and non-protonated forms is rationalised.     

Structural characterization of HfN<Subscript>x</Subscript>-based films grown by metal organic chemical vapor deposition

In this paper, HfN_x-based films on SiO₂/Si stack were grown by metal organic chemical vapor deposition (MOCVD), and one of them was ex-situ annealed at elevated temperature. The structural parameters of HfN_x-based films for the as-grown and the post-growth annealing samples were characterized by Rutherford back-scattering spectrometry (RBS), Spectroscopic Ellipsometry (SE) and atomic force microscopy (AFM). The measurements of the post-growth annealing sample by RBS demonstrated that the N: Hf ratio of HfN_x-based films would decrease with depth increase. In addition, The SE results for the structure of HfN_x-based nitride films were in good agreement with those determined by RBS.     

大天区面积多目标光纤光谱天文望远镜科学级CCD相机低嗓声设计和检测

结合实际测试结果,介绍了大天区面积多目标光纤光谱天文望远镜( LAMOST)低色散光谱仪所使用的科学级CCD相机的系统设计与检测技术。LAMOST科学级CCD相机系统由大面阵CCD芯片、相机头、制冷系统、控制器及其软件组成,其CCD控制器的设计实现低噪声、多路图像读出、像素合并及陷阱测试等功能,满足LAMOST工程的设计要求。介绍了科学级CCD相机增益、读出噪声、暗电流,满阱等指标的测试方法,该技术方法适用于其它领域同类型科学级CCD相机的研制和检测。     

Er3+/Yb3+共掺锗碲酸盐玻璃的热稳定性、 Judd-Ofelt理论分析和光谱性质

用高温熔融法制备了一种Er3 /Yb3 共掺的70TeO2-5Li2O-10B2O3-15GeO2玻璃.测试和分析了其热稳定性、吸收光谱、荧光光谱和上转换发光.应用Judd-Ofelt理论计算了玻璃中Er3 的强度参数、自发辐射跃迁几率、辐射寿命以及荧光分支比.结果表明:这种玻璃具有较好的热稳定性,较宽的荧光半高宽和较大的受激发射截面,位于532 nm、546 nm和659 nm的上转换绿光和红光,分别对应于Er3 离子2H11/2→4I15/2,4S3/2→4I15/2和4F9/2→4I15/2的辐射跃迁,是一种较为合适的宽带光纤放大器和上转换激光器的基质材料.     

Scattering of radiation by a fiber with a rough surface

We present a new theory on scattering of radiation by real fibers in engineering systems. The theory covers the scattering by fibers consistently over an entire range of fiber sizes from smaller to larger than the wavelength of radiation. A geometrical technique is presented for modeling a fiber with a rough surface of a three-dimensional homogeneous microstructure. Scattering characteristics of the fiber are described based on the electromagnetic wave theory of diffraction to investigate the relationship among three main factors of scattering: wavelength of radiation, fiber diameter, and fiber microstructure. With an increase in fiber diameter and a corresponding magnification of a rough fiber surface microstructure, the scattering changes from particle scattering to surface scattering. The transition occurs in a size parameter range of P = 100–300. © 1999 Scripta Technica, Heat Trans Asian Res, 28(4): 322–335, 1999