激发态酯类取代基季铵盐水溶铜卟啉与DNA相互作用的共振拉曼研究

本文采用４００ｎｍ和４４５ｎｍ脉冲激光激发测量了４－Ｎ－乙酸乙酯基──吡啶基铜卟啉和镍卟啉［简称Ｃｕ（ＮＥＡＥ）和Ｎｉ（ＮＥＡＥ）］及它们与ＤＺＡ复合物的共振拉曼光谱。分析表明，Ｃｕ（ＮＥＡＥ）与ＤＮＡ形成了电子激发态复合物而Ｎｉ（ＮＥＡＥ）则不能；激发态卟啉π电子与ＤＮＡ碱基π电子间的相互作用比基态时强得多，使卟啉骨架出现了明显畸变，而卟啉的吡啶取代基团变化较小。     

亚稳态He（2^3S）原子与C3H3CN分子传能产物的发光研究

本文在流动余辉装置上，研究了亚稳态Ｈｅ（２＾３Ｓ）原子与Ｃ２Ｈ３ＣＮ分子碰撞传能，观察到了激发态产物ＣＮ（Ａ，Ｂ）、ＣＨ（Ａ）Ｈ的发射光谱。     

从CN的高激发态化学发光谱研究F和N原子与卤代甲烷反应的动力学

从ＣＮ的高激发态化学发光谱研究Ｆ和Ｎ原子与卤代甲烷反应的动力学周士康，周金刚，詹明生，胡正发（中国科学院安徽光机所激光光谱开放实验室北京２３００３１）本文用Ｆ和Ｎ原子同时与甲烷或卤代甲烷（ＣＨｍＸ４－ｍ，Ｘ＝Ｃｌ，Ｂｒ；ｍ≤４）反应，在３７０～８８Ｄ...     

Eu~（3＋）－N~1－（对－异硫氰基苄基）－DTTA标记抗CEA McAb C＿（17）

Ｅｕ￣（３＋）－Ｎ￣１－（对－异硫氰基苄基）－ＤＴＴＡ标记抗ＣＥＡＭｃＡｂＣ＿（１７）赵启仁，张福华，刘洁，林汉，李美佳，庄湘莲，陈艾，胡壁（中国医学科学院放射医学研究所，天津，３００１９２）ＴＲＩＦＭＡ中，制备比活性高、免疫活性高的Ｅｕ３＋标记抗体...     

利用准分子激光制备Cu，Al化合物的纳米粒子

利用准分子脉冲激光（ＸｅＣｌ，λ＝３０８ｕｍ）对Ｃｕ，Ａｌ靶进行消融，从而得到Ｃｕ，Ａｌ化合物的纳米级粉末。ＣＵ的产物为（ＣｕＯ）６·Ｃｕ２Ｏ，Ａｌ的产物为Ａ１Ｎ。用透射电镜对粉末进行分析，并对消融产生的纳米颗粒在其颗粒大小及分布上予以分析统计。结果表明，（ＣｕＯ）６·Ｃｕ２Ｏ粒子的平均直径为１１ｕｍ，Ａ１Ｎ粒子的平均直径为６ｕｍ左右，基本符合对数正态分布。     

Ne^3P0,2）与乙腈的能量转移反应研究

在流动余辉装置上，我们研究了亚稳态原子Ｎｅ（＾３Ｐ０，２）与乙腈的能量转移反应，观察到了ＣＮ（Ａ－Ｘ），ＣＮ（Ｂ－Ｘ），ＣＨ（Ａ－Ｘ）的发射谱。计算了ＣＮ（Ａ，Ｂ）的相对振动粒子数布居，并对该反的机理进行了讨论。     

复合物p—C6H4F2...NH3（ND3）外部振动的共振双光子电离光谱

利用共振光电离技术和飞行时间质谱技术,观察到了复合物ｐ－Ｃ６Ｈ４Ｆ２．．．ＮＨ３（ＮＤ３）的共振双光子电离光谱。光谱分析表明,复合物分子间的伸 振动频率为８６．４ｃｍ＾－１;由复合物光解离机理以及伸缩模的失谐参数与键有的关系。获得了复合物电子激发态Ｓ１和基态Ｓ０的键能信息。Ａｂｉｎｉｔｉｏ计算表明,ｐ－Ｃ６Ｈ４Ｆ２．．．ＮＨ３（ＮＤ）复合物的几何结构是：ＮＨ３分子中的Ｎ原子位于垂直ｐ－Ｃ６Ｈ４Ｆ２     

NEC研究先进的Al─ Ge─ Cu工艺

ＮＥＣ研究先进的Ａｌ┐Ｇｅ┐Ｃｕ工艺据ＳｅｍｉｃｏｎｄＩｎｔｌ１９９６年第６期报道：ＮＥＣ公司的研究人员正在不断观察Ｇｅ加入Ａｌ－Ｃｕ互连后的作用，以得到一种有实际生产价值的低温回流溅射工艺。这种使用低温回流溅射和化学机械抛光金属平坦化的Ａｌ－Ｇｅ...     

取代苯基硫脲在Au表面自组装单分子膜的AFM观察

采用自组装（ＳＡ）技术制备了对甲苯基硫脲、对氯苯基脲和２，４，６－三溴苯基硫脲Ａｕ表面的自装单分子膜（ＳＡＭｓ）。在Ａｕ－溶液界面，硫脲Ｓ原子与Ａｕ－Ｓ键诱导吸附分子形成取向在序排列的单分子膜。用原子力显微镜（ＡＦＭ）对单分子膜进行了直接观察，ＡＦＭ所获得的结构信息与椭圆偏振测量、接触角测量和Ｘ－射线光电子能谱（ＸＰＳ）分析结果一致。     

热处理对96.5Sn3.5Ag焊点中Cu-Sn合金层的影响

在焊点与铜基之间形成的Ｃｕ－Ｓｎ合金成分对表面安装器件的疲劳寿命起着关键性的作用。本文着重研究了９３．５Ｓｎ３．５Ａｇ（简写为Ｓｎ－Ａｇ）焊料与Ｃｕ基界面间形成的合金层,通过电子扫描显微镜（ＳＥＭ）,Ｘ衍射（ＸＤＡ）及能谱Ｘ射线（ＥＤＸ）等分析发现,在Ｓｎ－Ａｇ与Ｃｕ基界面上存在Ｃｕ６Ｓｎ５及Ｃｕ３Ｓｎ两种合金成分,且随着热处理时间增加,Ｃｕ６Ｓｎ５合金层增厚,并在该处容易出现裂纹而导致焊点强度减弱,从而使焊点产生疲劳失效。     

Photoluminescence of CuGaTeAs and CuGaSnGa complexes in n-GaAs under resonance polarized excitation

Photoluminescence (PL) of n-type GaAs:Te:Cu and GaAs:Sn:Cu with an electron density of about 10¹⁸ cm^?3 was studied at 77 K. A broad band with a peak at the photon energy near 1.30 eV (GaAs:Te:Cu) or 1.27 eV (GaAs:Sn:Cu) was dominant in the PL spectrum under interband excitation. This band arose from the recombination of electrons with holes trapped by Cu_GaTe_As or Cu_GaSn_Ga complexes. It has been found that the low-energy edge of the excitation spectrum of this PL band at photon energies below ～1.4 eV is controlled by the optical ejection of electrons from a complex into the conduction band or to a shallow excited state. The PL polarization factors upon excitation by polarized light from this spectral range suggest that the complexes have no additional distortions caused by an interaction of a hole bound at the center in the light-emitting state with local phonons of low symmetry. This feature makes Cu_GaTe_As and Cu_GaSn_Ga complexes different from those with the Ga vacancy (V _Ga) instead of Cu_Ga. The dissimilarity arises from the difference in the intensity of interaction of a hole localized at the orbital of an isolated deep-level acceptor in the state corresponding to its preemission state in the complex (Cu _Ga ^? and V _Ga ^2? ) with low-symmetry vibrations of atoms. The perturbation of the hole orbital induced by the donor in the complex practically does not affect this interaction.     

Modeling of copper–carbon solid solutions

The atomistic simulations in the framework of the Generalized Simulated Annealing approach (GSA) and classical force fields lead to very reasonable relaxed geometries around the carbon interstitial in O-, T-, and TS-sites. We have thus shown that a highly efficient energy-sampling and relaxation scheme, implemented with tight constraints on a limited volume, provides a powerful steering mechanism for selection of geometries suitable for detailed investigation by first-principles methods. The results, based upon harmonic interactions between Cu atoms and a van der Waals interaction between Cu and C, predict the relaxed O-site to be more stable than the T-site by ∼1.2 eV, in accordance with general expectations. The TS barrier to OO diffusion is found to be ∼0.8 eV, at a temperature of 0 K; the TS exhibits a strong local axial distortion of the pseudo-octahedral environment. The Density Functional results indicate a charge transfer of ∼1 e to carbon, mostly from the first neighbor shell, in all relaxed environments studied. Bond-order data show the Cu–C interaction to be bonding in nature, despite the net ‘repulsive interaction’ leading to a surface state of lower net energy.     

Triplet Exciton Confinement in Green Organic Light‐Emitting Diodes Containing Luminescent Charge‐Transfer Cu(I) Complexes

The temperature dependence of luminescence from [Cu(dnbp)(DPEPhos)]BF₄ (dnbp = 2,9‐di‐n‐butylphenanthroline, DPEPhos = bis[2‐(diphenylphosphino)phenyl]ether) in a poly(methyl methacrylate) (PMMA) film indicates the presence of long‐life green emission arising from two thermally equilibrated charge transfer (CT) excited states and one non‐equilibrated triplet ligand center (³LC) excited state. At room temperature, the lower triplet CT state is found to be the predominantly populated excited state, and the zero‐zero energy of this state is found to be 2.72 eV from the onset of its emission at 80 K. The tunable emission maximum of [Cu(dnbp)(DPEPhos)]BF₄ in various hosts with different triplet energies is explained in terms of the multiple triplet energy levels of this complex in amorphous films. Using the high triplet energy charge transport material as a host and an exciton‐blocking layer (EBL), a [Cu(dnbp)(DPEPhos)]BF₄ based organic light‐emitting diode (OLED) achieves a high external quantum efficiency (EQE) of 15.0%, which is comparable to values for similar devices based on Ir(ppy)₃ and FIrpic. The photoluminescence (PL) and electroluminescence (EL) performance of green emissive [Cu(μI)dppb]₂ (dppb = 1,2‐bis[diphenylphosphino]benzene) in organic semiconductor films confirmed its ³CT state with a zero‐zero energy of 2.76 eV as the predominant population excited state.     

Influence of Heavy Atom Effect on the Photophysics of Coinage Metal Carbene-Metal-Amide Emitters

The effect of the heavy metal atom on the photophysics of carbene-metal-amide (CMA) photoemitters is explored, where the metal bridge is either Au, Ag, or Cu. Spectroscopic investigations reveal the coupling mechanism responsible for communication between the singlet and triplet manifolds. The photophysical properties do not reflect expected trends based upon the heavy atom effect, as both direct coupling between charge-transfer states and spin-vibronic coupling via a ligand-centered triplet state are present. Direct coupling is weakest for CMA(Ag), increasing the importance of the spin-vibronic pathway and rendering its properties more sensitive to inter-state energy gaps than for the Au and Cu-bridged analogues. The measured activation energy correlates with the expected exchange energy of the charge-transfer state, which is also closely related to the length of the bonds joining the carbene and amide ligands, and decreases in the order CMA(Cu) > CMA(Au) > CMA(Ag). These findings reveal that reducing interference between charge-transfer and ligand-centers excited, and minimizing exchange energy, are required for developing efficient luminescent CMA complexes.     

激光频率对DNA分子混沌态影响的研究

通过对激光与ＤＮＡ作用的运动方程迭代求解和关联维计算，讨论了不同激光频率对ＤＮＡ分子系统混沌行为的影响，并对较大的激光频率范围内均能引起生物的遗传变异现象进行了解释。     

Effect of annealing in Zn vapor and liquid Zn on photoluminescence of high-purity polycrystalline ZnTe

The photoluminescence from high-purity polycrystalline ZnTe has been studied. The evolution of the emission spectra upon annealing in Zn is analyzed. The effect of impurity aggregation is observed in the initial samples. This effect gives rise to an undulatory spectrum on the long-wavelength wing of the line associated with emission from an acceptor-bound exciton. It is demonstrated that annealing leads to homogenization of the impurity distribution, which results in the appearance of a rich structure of two-hole transitions. An analysis of these lines yields the energies of the ground and excited states of Li and Cu acceptor impurities.     

Pt–Cu Interaction Induced Construction of Single Pt Sites for Synchronous Electron Capture and Transfer in Photocatalysis

Single-atom photocatalysts have shown their fascinating strengths in enhancing charge transfer dynamics; however, rationally designing coordination sites by metal doping to stabilize isolated atoms is still challenging. Here, a one-unit-cell ZnIn₂S₄ (ZIS) nanosheet with abundant Cu dopants serving as the suitable support to achieve a single atom Pt catalyst (Pt₁/Cu–ZIS) is reported, and hence the metal single atom–metal dopant interaction at an atomic level is disclosed. Experimental results and density functional theory calculations highlight the unique stabilizing effect (Pt–Cu interaction) of single Pt atoms in Cu-doped ZIS, while apparent Pt clusters are observed in pristine ZIS. Specifically, Pt–Cu interaction provides an extra coordination site except three S sites on the surface, which induces a higher diffusion barrier and makes the single atom more stable on the surface. Apart from stabilizing Pt single atoms, Pt–Cu interaction also serves as the efficient channel to transfer electrons from Cu trap states to Pt active sites, thereby enhancing the charge separation and transfer efficiency. Remarkably, the Pt₁/Cu–ZIS exhibits a superb activity, giving a photocatalytic hydrogen evolution rate of 5.02 mmol g⁻¹ h⁻¹, nearly 49 times higher than that of pristine ZIS.     

Single Crystal Gallium Nitride Nanomembrane Photoconductor and Field Effect Transistor

Large‐area, free‐standing and single‐crystalline GaN nanomembranes are prepared by electrochemical etching from epitaxial layers. As‐prepared nanomembranes are highly resistive but can become electronically active upon optical excitation, with an excellent electron mobility. The interaction of excited carriers with surface states is investigated by intensity‐dependent photoconductivity gain and temperature‐dependent photocurrent decay. Normally off enhancement‐type GaN nanomembrane MOS transistors are demonstrated, suggesting that GaN could be used in flexible electronics for high power and high frequency applications.     

新型Ba_2ZnS_3∶Cu荧光粉的合成及其发光性能

采用双坩埚嵌套高温固相法在950℃下成功地合成了Ba2ZnS3∶Cu荧光粉,探讨了工艺条件和Cu掺杂量对样品发光亮度的影响,用X射线粉末衍射(XRD)、扫描电子显微镜(SEM)和荧光分光光度计分别对其结构、形貌和发光性能进行了表征。结果表明:样品具有单一的Ba2ZnS3晶相结构;与Ba2ZnS3基质不同,该荧光粉的激发光谱在近紫外区存在一个从275～350nm的宽激发带,归因于Cu发光中心的吸收;该荧光粉在近紫外光激发下发出明亮的黄光,发射中心波长位于560nm处,是一种良好的黄光材料。     

Wetting interaction between Sn-Zn-Ag solders and Cu

The wetting interaction of Sn-(7.1–9)Zn-(0–3)Ag solders with Cu was investigated from 230°C to 300°C. The wetting time, wetting forces, and activation energy of the wetting reaction were studied. The wetting time decreases with increasing temperature and increases with Ag content. The wetting force exhibits a disproportional correlation to temperature rise, while no trend was observed with respect to Ag content. The wetting behavior was ascribed to the interaction between Cu and Zn. The AgZn₃ compound was formed at the interface when the solder contains 0.3% Ag and above, while it was formed within the bulk solder at 2% Ag and above.