双奇核188Au的准粒子带结构研究

利用在束γ谱学实验技术, 通过¹⁷³Yb(¹⁹F,4nγ)反应 布居了¹⁸⁸Au的高自旋态, 并对其准粒子带结构进行了研究. 基于实验测量结果, 对原有的双奇核¹⁸⁸Au能级纲图做了较大的修改. 通过系统性比较, 对15⁺以上的能级结构进行了讨论.     

A study of the effect of ZrO2 on the magnetic properties of FePt/ZrO2 multilayer

Fe_xPt_100−x(30 nm) and [Fe_xPt_100−x(3 nm)/ZrO₂]₁₀ (x = 37, 48, 57, 63, 69) films with different ZrO₂ content were prepared by RF magnetron sputtering technique, then were annealed at 550 °C for 30 min. This work investigates the effect of ZrO₂ doping on the microstructural evolution, magnetic properties, grain size, as well as the ordering kinetics of FePt alloy films. The as-deposited films behaved a disordered state, and the ordered L1₀ structure was obtained by post-annealing. The magnetic properties of the films are changed from soft magnetism to hard magnetism after annealing. The variation of the largest coercivities of [Fe_xPt_100−x/ZrO₂]₁₀ films with the Fe atomic percentage, x and differing amounts of ZrO₂ content reveals that as we increase the ZrO₂ content we must correspondingly increase the amount of Fe. This phenomenon suggests that the Zr or O atoms of ZrO₂ preferentially react with the Fe atoms of FePt alloy to form compounds. In addition, introducing the nonmagnetic ZrO₂ can reduce the intergrain exchange interactions of the FePt/ZrO₂ films, and the interactions are decreased as the ZrO₂ content increases, the dipole interactions are observed in FePt/ZrO₂ films as the ZrO₂ content is more than 15%.     

Design and Fabrication of 1.06 μm Resonant-Cavity Enhanced Reflective Modulator with GaInAs/GaAs Quantum Wells

A resonant-cavity enhanced reflective optical modulator is designed and fabricated, with three groups of three highly strained InGaAs/GaAs quantum wells in the cavity, for low voltage and high contrast ratio operation. The quantum wells are positioned in antinodes of the optical standing wave. The modulator is grown in a single growth step in an molecular beam epitaxy system, using GaAs/AlAs distributed Bragg reflectors as both the top and bottom mirrors. Results show that the reflection device has a modulation extinction of 3 dB at -4.5 V bias.     

Rh／SiO_2上H_2的化学吸附

Ｒｈ／ＳｉＯ_２上Ｈ_２的化学吸附陈耀强，龚茂初，明虹，周建略，杜宗英，祝小红，陈豫（四川大学化学系，成都，６１００６４）关键词Ｒｈ／ＳｉＯ_２催化剂，Ｈ_２化学吸附，ＩＲＨ２在Ｒｈ上的化学吸附被认为是解离化学吸附［１］．而Ｒｈ－Ｈ的红外振动谱带是Ｈ２在...     

纳米SiO_2颗粒表面修饰的有机分子在介质中的光物理行为研究

利用Sol-Gel方法投篮了单分散性很好的球型二氧化硅纳米颗粒，通过表面化 学修饰法引入了带有荧光发色团的有机分子，通过稳态光物理方法研究了纳米颗粒 表面的有机分子在水、乙醇以及阴、阳离子表面活性剂悬浮液中的光物理行为。实 验表明，纳米颗粒表面有机分子的分散状态是决定其光物理行为的主要因素。这一 结果为设计和开发新型“壳-核”型纳米二氧化硅荧光传感器提供了有用的参考。     

On the ε-expansion procedure in the RNG theory of turbulence

Rescaling the equations of eliminating small scales, the physical justification for the-expansion procedure in the RNG theory of turbulence is proposed, in terms of that the inertial effects are small comparing with the viscous effects at the vicinity of the Kolmogorov dissipation wavenumber.We are grateful to Professor Chao-Hao Gu for numerous helpful suggestions. We would also like to acknowledge Professor Ke-Lin Wang and Bing-Hong Wang for many stimulating discussions of these problems.     

Versatile photosensitization system for 1O2-mediated oxidation of alkenes based on nafion-supported platinum(II) terpyridyl acetylide complex

[structure: see text] Platinum(II) terpyridyl acetylide complex (1) was incorporated into Nafion membranes as a photosensitizer, and the Nafion was immersed in an aqueous or organic solution of 7-dehydrocholesterol, alpha-pinene, or cyclopentadiene. This photosensitizer system can generate singlet oxygen ((1)O(2)) in high quantum yield to oxidize the alkenes in the solution outside the Nafion and can be easily removed from the reaction vessel at the end of the photooxidation.     

四甲氧基取代的二苯并并四苯(DBN)的合成, 晶体结构及聚集效应

本文从商品化的间溴苯甲醚和对甲氧基苯甲醛出发，通过傅-克酰基化反应、串联的羟醛缩合及1,4-迈克尔加成反应，得到三芳基取代的1,5-二酮，然后用查尔酮（Chalcone）作氧化剂，二酮与BF₃.Et₂O 反应形成吡喃鎓盐，再与苯基乙酸钠盐缩合得到芳香二溴代衍生物，产物的DMA溶液在DBU和钯催化剂的作用下，160°C 加热12 h进行脱卤化氢环化反应, 生成四甲氧基取代的二苯并并四苯（DBN）类衍生物。并报道了产物的晶体结构和在溶液中的聚集效应。     

纳米硅胶颗粒的制备及其对金属离子的识别

利用sol-gel方法制得了纳米级的硅胶悬浮液.通过表面化学修饰引入了具有发射荧光能力的萘基基团.在稳态荧光研究中清晰地观察到在微小粒子表面上萘基基团会因溶剂不同而发生重新排组,并呈现出激基缔合物发光.研究了不同过渡金属离子对粒子表面荧光的猝灭效应,发现只有Cu2＋对纳米微球荧光有强烈的猝灭特征,这种优良的选择能力使其有望发展成为一种分析检测Cu2＋的荧光化学敏感器.     

铂电极上异黄樟油和胡椒醛电氧化的SERS研究

采用循环伏安(CV)法和原位表面增强拉曼光谱(SERS)技术, 研究了非水体系中反应物异黄樟油和目标产物胡椒醛在粗糙铂电极上的电氧化行为, 发现胡椒醛在电位≥1.50 V时将进一步氧化, 而且从分子水平证实, 在胡椒醛的氧化电位(≥1.50 V) 下, 波长为632.8 nm的激光对胡椒醛的氧化有助催化作用. 由异黄樟油直接电氧化合成胡椒醛的电位(E)应控制在1.20 V相似文献