Negative refraction with low absorption using EIT in a four-level left-handed atomic system

We suggest a scheme for obtaining negative refraction with low absorption in a left-handed atomic system. Under the appropriate conditions, the atomic system displays negative refraction with negative permittivity and permeability (left-handedness) in a common frequency range, simultaneously. And the imaginary parts of permittivity and permeability show transparently propagate in the same frequency range. Finally, the negative refraction show low absorption due to the EIT effect, and the figure of merit demonstrated this in this resonant atomic system.     

Design of a dual-output fluorescent DNA logic gate and detection of silver ions and cysteine based on graphene oxide

In the presence of graphene oxide, upon formation of cytosine-Ag-cytosine the fluorescence wavelength of FAM-labeled DNA exhibited a red shift, and its intensity significantly increased. A novel fluorescent DNA sensor for Ag(+) and cysteine detection, and a dual-output fluorescent DNA INHIBIT logic gate are designed.     

Design, synthesis and inhibitory activities of 8-(substituted styrol-formamido)phenyl-xanthine derivatives on monoamine oxidase B

The design and synthesis of two series of 8-(substituted styrol-formamido)phenyl-xanthine derivatives are described. Their in vitro monoamine oxidase B (MAO-B) inhibition were tested and the effect of substituents on the N-7, phenyl and the substituted positions are discussed. It was observed that compound 9b displayed significant MAO-B inhibition activity and selectivity, fluorine substitution plays a key role in the selectivity of MAO-B inhibition, and the styrol-formamido group at position-3' may enhance the activity and selectivity of 8-phenyl-xanthine analogues. These results suggest that such compounds may be utilized for the development of new candidate MAO-B inhibitors for treatment of Parkinson's disease.     

PNIPAM线性链与凝胶在二元溶剂中相变的变温NMR研究

通过对聚N-异丙基丙烯酰胺（PNIPAM）水溶液和凝胶在水和甲醇混合溶剂中的¹H NMR谱图以及弛豫时间(T₁与T₂)等多种NMR参数随温度变化的研究,发现PNIPAM大分子的基团质子NMR信号、溶剂的弛豫时间都可以用来灵敏表征PNIPAM在二元溶剂中的相变行为. 在PNIPAM凝胶中,温度升到LSCT以上,溶剂峰由单峰变为双峰,分别对应于受限在大分子网络内的受限溶剂和排除到大分子网络外的自由溶剂,两者的弛豫时间存在明显差异. 在PNIPAM溶液中,溶剂峰在相变前后并没有显著变化. 通过PNIPAM溶胀在water/alcohol混合溶剂中的相变研究进一步证实了PNIPAM与不同溶剂之间的相互作用强弱.      

Photoinduced Electron Transfer Reaction between Poly-guanylic Acid (5`) with Anthraquinone-2-sulfonate

TheinteractionofquinonephotonucleasewithDNAhasbeenwidelystUdied.Anthraquinonederivatives,inparticularthatofanhraquinone-2-sulfonatehasbeenusedascleavingagentforduPlexDNA1-5.Howevef,directobservationofexcitedionpairsofbiomoleculesespeciallytheStabilizedradicalcationofbiomoleculeishamPeredbytheoverwhelmingtransientabsorPtionofhydrogenbondedradicalanionofquinone.lnthiswork,theinteractionofpolylG]withtripletanthraquinone-2-sulfonateinCH,CN-H:O(97f3)viaelectrontransferreactionhasbeenachieved…     

Polyaniline Formed in Alkaline Solution─A New Luminous Material

IntroductionPolyaniline (PAN) prepared in acidic aqueous media has received a great deal of interestas one of the conductive polymers due to its straightforward methods of preparation andthe stability of its conductive form in airl'2. Its applications as energy storage media3 andas electrochromic device4 have been discussed. But there are few reports about theelectropolymerization of aniline in alkaline solutions.In this paper, we report the results of an ellipsometric study of theelectropol…     

Synthesis and magnetic properties of lanthanum orthovanadate nanorods

In the present paper, single‐crystalline lanthanum orthovanadate (LaVO₄) nanorods were synthesized by an ethylenediaminetetraacetic acid (EDTA)‐mediated hydrothermal method. The resulting products were characterized using XRD, SEM, TEM and HRTEM. The experimental results illustrated that the morphologies and microstructures of LaVO₄ nanorods were influenced by EDTA and pH value of the precursor solution. The magnetic properties measurements showed that the magnetocrystalline anisotropy was greatly strengthened by the strong effect of the one‐dimensional anisotropy, and the magnetic properties of LaVO₄ nanorods are better than that of LaVO₄ nanoparticles. The growth mechanism of LaVO₄ nanorods was also discussed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

2(1H)-喹啉-2,4-二酮类化合物抗小麦锈病的3D-QSAR研究

用比较分子力场分析(CoMFA)方法和比较分子相似性指数分析(CoMSIA)方法研究了21个2(1H)-喹啉-2,4-二酮类化合物抗小麦锈病的三维定量构效关系(3D-QSAR),发现用CoMFA方法可以找到最佳的3D-QSAR模型,并通过量子化学从头计算的方法研究了不同活性化合物的前线轨道及静电势分布图的差异.所得构效关系模型为发现更高活性的化合物提供理论指导.     

Ultraviolet emission of ZnO film prepared by electrophoretic deposition

We deposited high quality ZnO film by electrophoretic deposition (EPD) using high quality ZnO powder prepared by solid-state pyrolytic reaction. X-ray photoelectron spectroscopy (XPS) and the infrared (IR) absorption spectrum clearly indicate that the ZnO phase powder has been prepared. Transmission electron microscope (TEM) imaging and x-ray diffraction (XRD) show that the average grain size of the powder is about 20nm. XRD and selected-area electron diffraction (SAED) reveal that the ZnO film has a polycrystalline hexagonal wurtzite structure. Only a strong ultraviolet emission peak at 390nm can be observed at room temperature.     

Autonomous conveyer gel driven by frontal polymerization

Autonomous mechanical mass transportation for cargos on the microscale with no need of continuous external powering is of great scientific and technological interest due to their extensive applications. However, it is still challenging to create a self‐driven system applicable to diverse micromaterial transportation demands. In this work, we developed a novel autonomous conveyer gel driven by frontal polymerization (FP). The chemical wave produced in FP was stable, and self‐propagating with a constant velocity, which can be easily monitored by thermal imaging or fluorescence labeling. We investigated the influence of the initiation temperature, swelling ratio of the gel substrate, and the size of the cargos on the motion of driven behavior. Results showed that the driving velocity can be well controlled by altering the initiation temperatures of FP. The swelling ratio and the size of the cargos had a key impact on the feasibility of self‐driven behavior. In addition, powerful driven capability by FP was demonstrated by successfully transporting cargos in series, and further applied for targeted synthesis of CdS nanocrystals. The methodology developed here provides an effective way to convert chemical energy to mechanical work, and may be useful in energy conversion and utilization, mass transportation and other applications. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1323‐1331