圆环结构磁光光子晶体中的拓扑相变

二维圆环结构的三角晶格磁光光子晶体中可以呈现多重拓扑相.在不同的几何参数和磁场下,这些拓扑相包括正常光子带隙相、量子自旋霍尔相和反常量子霍尔相.与文献[1]类似,该结果展现了二维光子晶体丰富的拓扑相变现象.     

Hydrothermal Synthesis and Crystal Structure of a Novel Isophthalate-bridged Copper(Ⅱ) Polymer with Two-dimensional Network Structure: [Cu2(phen)(ipt)2]2n·nH2O (ipt = isophthalate, phen = 1,10-phenanthroline)

A novel metal-organic coordination polymer [Cu2(phen)(ipt)2]2n·nH2O 1 has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. The complex crystallizes in monoclinic, space group P21/c with a = 12.338(3), b = 12.167(3), c = 18.167(4)(A), β = 111.686(14)o, V = 2534.1(10) A)3, C28H18Cu2N2O9, Mr = 653.52, Dc = 1.713 g/cm3, μ(MoKα) = 1.740 mm-1, F(000) = 1320, Z = 4, the final R = 0.0443 and wR = 0.0853 for 3543 observed reflections (I > 2σ(I)). It exhibits a novel two-dimensional network with tetra- Cu-ipt- as building units.     

多羟基氮杂茋衍生物的化学合成

多羟基氮杂茋衍生物的化学合成;氮杂茋;氯甲基吡啶;合成     

The effects of vicinal sapphire substrates on the properties of AlGaN/GaN heterostructures

AlGaN/GaN heterostructures on vicinal sapphire substrates and just-oriented sapphire substrates (0001) are grown by the metalorganic chemical vapor deposition method. Samples are studied by high-resolution x-ray diffraction, atomic force microscopy, capacitance--voltage measurement and the Van der Pauw Hall-effect technique. The investigation reveals that better crystal quality and surface morphology of the sample are obtained on the vicinal substrate. Furthermore, the electrical properties are also improved when the sample is grown on the vicinal substrate. This is due to the fact that the use of vicinal substrate can promote the step-flow mode of crystal growth, so many macro-steps are formed during crystal growth, which causes a reduction of threading dislocations in the crystal and an improvement in the electrical properties of the AlGaN/GaN heterostructure.     

Preliminary analysis of impurity transport in HL-2A ohmic discharges

This paper describes the behaviour of impurity transport in HL-2A ohmic discharges. In 2005, small quantities of metallic impurities （A1, Ni and Ti） were successfully injected into HL-2A plasmas by laser blow-off technique, and their progression was followed by the soft x-ray cameras with good spatial and temporal resolutions. The impurity confinement time is estimated from the characteristic decay time of the soft x-ray signal of the injected impurities, and it is about 30-60 ms. The transport coefficients of impurities （including diffusion coefficient and convection velocity） in radial different region have been derived by using a one-dimenslonal impurity transport code, the results present that diffusion coefficient is much smaller in the central region of plasmas than the outside of it, and it is much larger than that of neoclassical theory predictions; namely, it is anomalous.[第一段]     

Enantioselective Construction of Si-Stereogenic Center via Rhodium-Catalyzed Intermolecular Hydrosilylation of Alkene

Catalytic, enantioselective synthesis of stereogenic silicon compounds remains a challenge. Herein, we report a rhodium-catalyzed regio- and enantio-selective intermolecular hydrosilylation of alkene with prochiral dihydrosilane. This new method features a simple catalytic system, mild reaction conditions and a wide functional group tolerance.     

A low-noise,high-SNR balanced homodyne detector for the bright squeezed state measurement in 1–100 kHz range

We report a low-noise, high-signal-to-noise-ratio(SNR) balanced homodyne detector based on the standard transimpedance amplifier circuit and the inductance and capacitance combination for the measurement of the bright squeezed state in the range from 1 kHz to 100 kHz. A capacitance is mounted at the input end of the AC branch to prevent the DC photocurrent from entering the AC branch and avoid AC branch saturation. By adding a switch at the DC branch,the DC branch can be flexibly turned on and off on different occasions. When the switch is on, the DC output provides a monitor signal for laser beam alignment. When the switch is off, the electronic noise of the AC branch is greatly reduced at audio-frequency band due to immunity to the impedance of the DC branch, hence the SNR of the AC branch is significantly improved. As a result, the electronic noise of the AC branch is close to -125 dBm, and the maximum SNR of the AC branch is 48 dB with the incident power of 8 mW in the range from 1 kHz to 100 kHz. The developed photodetector paves a path for measuring the bright squeezed state at audio-frequency band.     

Design,synthesis and neuroprotective effects of Fenazinel derivatives

In search of novel neuroprotective agents with higher potency and lower h ERG liability, a series of novel Fenazinel derivatives were designed and synthesized, among which compounds 8m–o containing amide moiety exhibited good neuroprotective effects in vitro and in vivo. Especially, the representative compound 8o showed lower activity in a patch clamp h ERG K+ion channel screen and could be considered as a lead compound for further development. These findings provided an alternative approach to the development of drugs more potent than Fenazinel for the intervention of ischemic stroke.     

两个由2-(4′-氯-苯甲酰基)苯甲酸和双咪唑基配体构筑的锰、镉配合物的合成及晶体结构(英文)

通过水热法合成了2个配位聚合物[Mn(cbba)2(bimb)]n(1)和[Cd(cbba)2(mbix)]2n(2)(Hcbba=2-(4′-氯-苯甲酰基)苯甲酸,bimb=1,4-双(咪唑基-1-基)丁烷,mbix=1,3-双(咪唑基-1-基)苯)。并对其进行了元素分析、红外光谱、热重和X-射线单晶衍射测定。这两个配合物通过氢键或π-π相互作用形成了三维超分子网状结构。此外,还研究了配合物1的紫外光谱和配合物2的荧光性质。