沙质土壤热红外高光谱特征及其含沙量预测研究

为明确土壤热红外高光谱数据反演土壤含沙量的应用潜力,利用102F型便携式傅里叶变换红外光谱仪对沙质土壤进行测量,在进行相关分析和主成分分析的基础上,对土壤发射率光谱特征进行了分析,并采用偏最小二乘回归和主成分回归两种建模方法预测土壤含沙量.结果表明,沙质土壤发射率光谱中二氧化硅的Reststrahlen特征表现明显,在...     

Synthesis and Crystal Structure of Isobutyl-substituted Tetramethylcyclopentadienyl Tetracarbonyldiiron Complex

Abstract  The synthesis of the new ligand, (C₅Me₄ ⁱ Bu)H was described and its reaction with Fe(CO)₅ to prepare (C₅Me₄ ⁱ Bu)₂Fe₂(CO)₄ was presented. The structure of complex was characterized by IR, ¹H NMR, elemental analysis and single crystal X-ray diffraction. It confirms the complex is a dimer with bridging and terminal CO groups. The Fe–Fe bond distance is 2.5508(9) ?. (C₅Me₄ ⁱ Bu)₂Fe₂(CO)₄ belongs to triclinic: space group P ī, with a = 8.5468(17) ?, b = 8.8997(18) ?, c = 9.4044(19) ?, α = 89.52(3)°, β = 74.11(3)°, γ = 86.42(3)°, V = 686.6(2) ?³, Z = 2, Dc = 1.399 g cm⁻³, μ (MoKα) = 1.090 mm⁻¹, F(000) = 306, and final R ₁ = 0.0324, wR ₂ = 0.0852 for observed reflections 2,396 (I > 2σ(I)). Graphical Abstract  The synthesis of the new ligand, (C₅Me₄ ⁱ Bu)H was described and its reaction with Fe(CO)₅ to prepare (C₅Me₄ ⁱ Bu)₂Fe₂(CO)₄ was presented. Single crystal X-ray diffraction analysis reveals that the molecular structure of this complex is a dimmer.      

Enhancement in Thermoelectrical Power Factor of N-Type Si80Ge20 Alloys

Influences of the carrier concentration and mobility of heavily doped n-type Si80 Ge20 alloys on the thermoelectrical power factor are investigated. The experimental results indicate that thermoeleetrieal power factors of 32- 36μWem-1K^-2 eouM be consistently achieved with carrier concentrations of 2.1-2.9 × 10^20cm^-3 and carrier mobilities of 36-40 cm^2 V^-1s^-1. However, many samples with suitable carrier concentrations do not always have high mobilities and high power factors. Some possible explanations for this behaviour are discussed.     

入射光的偏振特性对全内反射荧光显微术中荧光激发的影响

基于麦克斯韦的电磁场理论，研究了在全内反射荧光显微术中不同偏振态的入射光所产生的 不同偏振的隐失场以及对不同取向的荧光分子荧光发射的影响.理论分析结果表明，p偏振的 入射场将产生椭圆偏振的隐失场，s偏振的入射场将产生s偏振的隐失场.随着荧光分子三维 取向的不同，这两种隐失场的激发荧光效率也将不同，由此引起荧光发射强度的各向异性分 布.据此特性，可以实现对膜表面分子三维取向的成像. 关键词： 全内反射 荧光显微术 隐失波 偏振态     

磁场作用下的有机电致发光

分别制备了荧光器件ITO/NPB/Alq₃/LiF/Al和磷光器件ITO/NPB /CBP: Ir（ppy）₃/BCP/Alq₃/LiF/Al, 测试了50 mT磁场作用下器件的I-V和L-V特性. 与零磁场相比荧光器件和磷光器件的效率分别增加了44%和7%. 从有机电致发光的机制出发对该现象进行了解释, 认为外加磁场可以使三重态激子发生塞曼分裂, 进而在荧光器件中引起了三重态激子T     

Solitons with Periodic Behavior in an SBN：75 Photorefractive Crystat

We study the formation of spatial solitons in an SBN： 75 photorefractive crystal by a 532 nm continuous-wave laser beam. The output beam from the crystal cannot be compressed proportionally to the voltage of the applied electric field. Quasi-steady-state spatial solitons are formed instantaneously at a voltage of 900 V. Interestingly, the quasi- steady-state solitons exhibit a periodic behavior consisting of formation/broken/reformation cycles. If we increase the input intensity of the soliton beam but keep the same signal-to-background intensity ratio, the solitons stay for a longer time in the quasi-steady state and a longer period of soliton formation/broken/reformation cycle is also observed.     

基于细菌视紫红质膜的全光逻辑门

基于在细菌视紫红质膜中的自衍射，我们提出了全光非、异或、半加器及同或门逻辑操作。利用衍射光与记录光偏振状态之间的关系，我们演示了非门和同或门逻辑操作。 通过衍射光，记录光和读出光之间的偏振状态的关系，我们实现了异或逻辑操作和具有三个输入端的半加器逻辑操作。所用方法简单实用。     

HPLC同时测定烤肉中的丙烯酰胺和杂环胺

建立了高效液相色谱法同时测定烤肉中丙烯酰胺和杂环胺的新方法.选择适宜的样品前处理方法提取和净化样品,经TSK-gel ODS-80TM柱分离并以配备二极管阵列和紫外检测器的HPLC对丙烯酰胺和杂环胺进行测定.结果表明,该方法的线性范围为0.02-32.0μg/mL,检出限为0.2-0.4ng/g;回收率为67.3％-9...     

室温下磁场对基于Alq3的有机电致发光器件的影响

制备了ITO/NPB/LiF/Alq₃/LiF/Al的器件,测量了该组器件效率和亮度的磁效应.结果表明,在50 mT磁场中,当LiF缓冲层厚度为0.8 nm时,器件的效率最大增加了12.4%,磁致亮度最大变化率17%.同时,制备的磷光器件ITO/NPB/LiF/CBP:6 wt% Ir(ppy)₃/BCP/Alq₃/ LiF/Al,在50mT磁场作用下,当LiF缓冲层的厚度为0.8 nm时,器件的效率最大增加12.1%.在Alq_{3 关键词： 有机发光 磁场 效率 磁致亮度}     

A potassium-encapsulated Preyssler-based structure modified by binuclear cyclic copper(II) clusters: photocatalytic and electrochemical properties

Transition Metal Chemistry - Through the use of a flexible ligand 1,1′-bis(3,5-dimethyl-1H-pyrazolate)methane (H2bdpm), a K-encapsulated Preyssler-based complex,...