电致发光色纯性增强的硅基有机微腔

报道了硅基有机微腔的电致发光（EL）.该微腔由上半透明金属膜、中心有源多层膜和多孔硅分布Bragg反射镜（PS DBR）组成.半透明金属膜由Ag（２０nm）构成，充当发光器件的负电极和微腔的上反射镜.有源多层膜由Al (1 nm) / LiF(05 nm) /Alq3/Alq3:DCJTB/NPB/CuPc/ITO/SiO2组成，其中的Al/LiF为电子注入层，ITO为正电极，SiO2为使正、负电极电隔离的介质层.该PS DBR是采用设备简单、成本低廉且非常省时的电化学腐蚀法用单晶Si来制备的；该PS 关键词： 电化学腐蚀 电致发光 窄峰发射 硅基有机微腔     

Simulation and fabrication of carbon nanotubes field emission pressure sensors

A novel field emission pressure sensor has been achieved utilizing carbon nanotubes (CNTs) as the electron source. The sensor consists of the anode sensing film fabricated by wet etching process and multi-wall carbon nanotubes (MWNTs) cathode in the micro-vacuum chamber. MWNTs on the silicon substrate were grown by thermal CVD. The prototype pressure sensor has a measured sensitivity of about 0.17-0.77 nA/Pa (101-550 KPa). The work shows the potential use of CNTs-based field-emitter in microsensors, such as accelerometers and tactile sensors.     

A brief semi-quantitative discussion on electrical conductance through resonant states in metallic electrochemical nanowires

Some aspects of electrical conduction through resonant states in metallic electrochemical nanowires are briefly discussed in a semi-quantitative way by means of concepts associated with electron gas, conductance quantization, and Fermi energy level. Aspects related to some experimental data are also discussed.     

Optimal Path Planning Based on Visibility

Various problems associated with optimal path planning for mobile observers such as mobile robots equipped with cameras to obtain maximum visual coverage of a surface in the three-dimensional Euclidean space are considered. The existence of solutions to these problems is discussed first. Then, optimality conditions are derived by considering local path perturbations. Numerical algorithms for solving the corresponding approximate problems are proposed. Detailed solutions to the optimal path planning problems for a few examples are given.     

Tunable narrow-band infrared emitters from hexagonal lattices

In this work, we present both the theoretical basis as well as supporting experimental measurements for development of a novel mid-infrared thermally stimulated narrow band emitter with a spectral bandwidth of less than 10%. To achieve this, we utilize a metallized-surface 2D photonic crystal of air voids in a silicon background with hexagonal structure symmetry. Our results are based on the generation of discrete surface plasmon (SP) modes in the thin metallized layer residing on the top surface. This yields a series of adequately spaced discrete peaks in the reflection spectrum, dominated by a single sharp feature corresponding to the lowest plasmon order, in an otherwise uniform highly reflective spectrum (>90%) over most of the IR spectrum. This, in turn, gives rise to a sharp absorption feature with a correspondingly narrow thermal emission peak in the emission spectrum. Transfer matrix calculations simulate well both the position and strengths of the absorption peaks. By altering the period of the surface photonic lattice, the SP peak and emissive band can be tuned to the desired wavelength. These devices promise a new class of tunable infrared emitters with high power in a narrow spectral bandwidth. Such narrow band sources are critical to achieving high efficiency gas sensors.     

Organic synthesis based on cathodic deprotonation of acids

The results of studies on electrosynthesis involving carb- and heteroanions generated by cathodic deprotonation of acids (CDA), carried out in the laboratory headed by the author, are surveyed. These studies resulted in the elaboration of efficient electrochemical versions of the known Michaelis-Becker, Wittig-Horner, and Perkin reactions; electrochemical analogs of homolytic aromatic substitution, alkylation, heterocyclization,etc. were developed. Based on CDA, convenient and promising methods for preparing variousN-, O-, P-, S-, andC-alkylated and arylated substances have been developed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1411–1422, August, 1995.The author is grateful to Professor V. A. Dorokhov, Professor V. P. Litvinov, and researchers from the laboratories of N. D. Zelinsky Institute of Organic Chemistry headed by them, who participated in joint studies.The work was carried out with financial support from the International Science Foundation (Grant No. MHYOO).     

Study of intermediates formed in the oxidation of thiols

The oxidation of aminoethanethiol (1) was investigated in acid solutions on a glass carbon anode. It was shown that at relatively low anode potentials thiyl radicals RS^· are released into the solution, but this does not lead to binding of the oxygen in the solution. Raising the anode potential leads to binding of oxygen, which is probably due to the formation of the intermediate RS⁺. The oxidation of 1 was studied in Ce(SO₄)₂+H₂SO₄ solution. It was shown that under certain conditions the intermediate is RS⁺, which subsequently converts to a product that could not be identified as any previously described product of the oxidation of thiols. Proposals are made regarding its structure and conversion pathways.B. P. Konstantinov Institute of Nuclear Physics, Russian Academy of Sciences, 188350 Leningrad. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 2, pp. 278–288, February, 1992.     

应用LiNbO_3声表面波驱动的全光纤声光频移器

介绍一种工作在10.7MHz的全光纤声光频移器.它由在LiNbO_3基片上制作的叉指电极换能器产生的声表面波驱动.当驱动电功率1.5W时,频移光转换效率达35％.     

Electrochemical co-oxidation of C-H acids and methanol as a new route to functionalized cyclopropanes

Electrolysis of dimethyl malonate or methyl cyanoacetate in methanol in the presence of LiCl in an undivided cell leads to formation of 1,1,2,2-cyclopropanetetracarboxylic derivatives.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1835–1836, October, 1994.This work was supported by the International Science Foundation (Grant No MHY 000).     

Single LED based dual wavelength referenced optical fibre sensor system using intensity modulation

An intensity-modulated optical fibre sensor system is described which employs a single LED source to provide the measurand and the reference signals with two separate wavelength bands. The allocated wavelength bands are selected to minimize any differential intensity effects that may arise from LED thermal variations. The sensor system, comprising a transceiver unit connected to an optical displacement sensor using a single optical fibre, provides an output fully referenced for all major common-mode variations that are likely to occur. Performance characteristics for the prototype system are reported which show a linear displacement range of over 20 mm.