石英挠性加速度计二元调宽数字脉冲控制系统的研制

本文介绍了石英挠性加速度计二元调宽数字脉冲控制系统的研制及其应用。提出了通过提高系统采样频率来抑制石英挠性加速度计摆片摆幅，从而最大限度地减小其疲劳强度的方法。并基于这一思想设计了石英挠性加速度计二元调宽数字脉冲控制模型，对模型进行了模拟仿真，证明该方案是合理可行的。其已成功地应用于各新型导航产品中     

Nanoporous ZnO nanostructures for photocatalytic degradation of organic pollutants

ZnO porous bamboo-leave-like nanorods and nanoporous networks were prepared by thermal conversion from Zn₂CO₃(OH)₂?H₂O bamboo-leave-like nanorods, Zn(OH)₂ nanoparticle networks and Zn(OH)₂ long nanostrand networks, respectively. Among them, the ZnO nanoporous networks prepared from Zn(OH)₂ nanostrands had the highest surface area of 78.57 m²/g and presented the best photocatalytic decomposition of organics. The morphologies of the Zn(OH)₂ nanostructures significantly depended on the solvent used for the precursors of aminoethanol and Zn(NO₃)₂ and then determined the corresponding structures and properties of the final ZnO nanostructures. The ethanol/water mixture solvent dramatically increased the stability of Zn(OH)₂ nanostrands. This is very beneficial for the collection and application of Zn(OH)₂ nanostrands.     

4H‐SiC: a new nonlinear material for midinfrared lasers

Nonlinear optical (NLO) frequency conversion is commonly used for generating midinfrared (MIR) lasers that offer light sources for a variety of applications. However, the low laser damage thresholds of NLO crystals used so far seriously limit the output power of MIR lasers. Here, a new nonlinear material 4H‐SiC is demonstrated for producing MIR laser. Broadband MIR radiation ranging from 3.90 to 5.60 μm is generated in 4H‐SiC by phase‐matched difference‐frequency generation for the first time. The results may open a door to practically utilize wide‐bandgap semiconductors with high laser damage thresholds as NLO materials for high power output of MIR lasers.     

Common-path interferometer with a tri-window

A common-path interferometer is proposed with a tri-window. It is built using a 4f optical system with Ronchi ruling as a spatial filter. The input rectangular aperture is formed by three windows; the central window supports a phase object, and the other two are used for reference beams. Using an appropriate grating period relative to input aperture size, an interferogram containing three patterns can be obtained in the output plane. The object phase can then be reconstructed from the three patterns using just one interferogram. The experiments are carried out to demonstrate the feasibility and reliability of the proposed scheme.     

Direct reductive amination of aromatic aldehydes catalyzed by gold(I) complex under transfer hydrogenation conditions

The direct reductive amination of aromatic aldehydes has been achieved with excellent isolated yields (89-96%) using readily accessible Ph(3)PAuCl/AgOTf catalyst along with ethyl Hantzsch ester as hydrogen source under mild reaction conditions.     

Vinylation of Alkyl Halides Catalyzed by Palladium Catalyst

The palladium catalyzed vinylation of alkyl halides, especially benzyl chlorides, with a variety of olefins has been studied. A possible free radical mechanism was proposed.     

A polarization interference imaging spectrometer and its calibration

A polarization interference imaging spectrometer for remote sensing is developed. Its operation principle and typical configuration are introduced. A polarization beam-splitter is its key component of the spectrometer. The advantages and disadvantages of the instrument are discussed compared with those of other instruments, which are based on the principle of active exploration for remote targets. The principles, strategies, methods, contents, aspects, and steps of calibration for the instrument are introduced. The experimental result of relative calibration for the CCD detector of a PIIS is given. Some applications and expectations of polarization interference imaging spectroscopy are put forward.     

以q空间法研究水分子在水晶体中之扩散及其结构

在核磁共振中的脉冲梯度自旋回响法(pulsed gradient spin echo,PGSE)常用来测量溶液中分子或离子的扩散现象,近年来利用PGSE q空间法对多孔隙物质的系统扩散研究。观察到类似绕射效应,在此工作中我们尝试以q空间法直接观察眼球水晶体中的纤维细胞组织和水分子扩散间的关系,实验结果显示,从类似绕射纹图可了解纤维细胞蜂巢式排列结构。     

A Versatile Oxidizing Agent: Tetrakis-pyridino-cobalt(II) Dichromate Py4Co(HCrO4)2 (TPCD). Oxidations of Alcohols,Halides and Amines to Their Corresponding Carbonyl Compounds

The preparation of a versatile oxidizing agent tetrakis-pyridino-cobalt (II) dichromate Py₄Co(HCrO₄)₂ (TPCD) is presented and its structure is confirmed by x-ray crystal data. Alcohols, halides and amines are oxidized smoothly to their corresponding carbonyl compounds in good yields with TPCD.     

The Aromatization of Hantzsch 1,4-Dihydropyridines by Tetrakis-Pyridine Cobalt (II) Dichromate (TPCD)

Aromatization of Hantzsch 1,4-dihydropyridines (la-n) were promoted by tetrakis-pyridine cobalt (11) dichromate to yield corresponding pyridine derivatives (2a-n) in moderate to high yields (70-87%). The reaction was carried out under mild and convenient conditions.