利用集总L-C元件构造的一维metamaterials特性的实验研究

在普通微带传输线中周期性地加载集总L C元件能够构造一维特异性材料(metamaterials)，它具有与众不同的特异性质.通过实验证实了波在这种结构中传播具有相速度与群速度方向相反的左手性通带，其折射率为负值，并发现平均折射率为零的能隙.这种结构具有结构紧凑，参数可调，制作简单的优点. 关键词： 负折射率 特异性材料 周期性结构 微带线     

A Photonic Bandgap Filter Using Metallic Hilbert Curves

We theoretically suggest that a metallic plate with Hilbert curves can possesses multiple resonances in a linear scale, leading to multiple stop bands and pass bands for electromagnetic waves over a wide frequency range.The forward transmission from a line source nearby a small plate covered by four cells with Hilbert curves is checked by a probe at the far field, the results agree well with the multiple resonance frequencies calculated by the plane wave incidence under a periodic boundary condition, the return loss spectra show that radiations of a line antenna working at 4.5 GHz can be greatly enhanced, which results from the interaction of the antenna and the subwavelength metallic plate. This kind of metallic pattern is very practical in multi-frequency functioned wave devices with sub-wavelength sizes.     

一类新型高荧光性类水滑石（Al-HTLc）的合成与性能

采用共沉淀法,合成、组装得到一类将铝离子（Al^3＋）量减少到一定值的镁铝型类水滑石,并使分散于其镁铝水滑石板层上的铝离子与板层间溶于亲油性阴离子中的计量8-羟基喹啉（8-HQ）配位,获得一类新型高荧光性类水滑石（Al-HTLc）．采用荧光光谱、红外光谱、紫外光谱、XRD、XPS和热分析等对其进行了表征．研究结果表明,该Al-HTLc在紫外光下可发出荧光强度高达4．9×10^5（a．u.）的强烈蓝绿色荧光（487nm）,荧光寿命为21．24ns,光量子产率为67％,高于纯8-羟基喹啉铝（Alq3）,且具有更高热稳定性,有望作为一类高性能的新型荧光材料而获得应用．     

Efficient and stable wireless power transfer based on the non-Hermitian physics

As one of the most attractive non-radiative power transfer mechanisms without cables,efficient magnetic resonance wireless power transfer(WPT)in the near field has been extensively developed in recent years,and promoted a variety of practical applications,such as mobile phones,medical implant devices and electric vehicles.However,the physical mechanism behind some key limitations of the resonance WPT,such as frequency splitting and size-dependent efficiency,is not very clear under the widely used circuit model.Here,we review the recently developed efficient and stable resonance WPT based on non-Hermitian physics,which starts from a completely different avenue(utilizing loss and gain)to introduce novel functionalities to the resonance WPT.From the perspective of non-Hermitian photonics,the coherent and incoherent effects compete and coexist in the WPT system,and the weak stable of energy transfer mainly comes from the broken phase associated with the phase transition of parity-time symmetry.Based on this basic physical framework,some optimization schemes are proposed,including using nonlinear effect,using bound states in the continuum,or resorting to the system with high-order parity-time symmetry.Moreover,the combination of non-Hermitian physics and topological photonics in multi-coil system also provides a versatile platform for long-range robust WPT with topological protection.Therefore,the non-Hermitian physics can not only exactly predict the main results of current WPT systems,but also provide new ways to solve the difficulties of previous designs.     

噻吩并嘧啶酮衍生物的合成及其抑菌活性

利用三组分氮杂Wittig反应,以磷亚胺2、对氯苯基异氰酸酯和酚,合成了16个未见文献报道的2-芳氧基-3-对氯苯基-3,5,6,7-四氢-4H-环戊二烯并[4,5]噻吩并[2,3-d]-嘧啶-4-酮衍生物,产率52～74%。通过IR、1H NMR、MS和元素分析对目标化合物的结构进行了表征。初步探讨了所合成化合物的抑菌活性,结果显示所合成的化合物对真菌的抑制活性优于对细菌的抑制活性,对桔青霉菌的抑制活性在65.2%以上,其中5n的抑菌率最高,达到89.1%。在化合物对细菌的抑制活性中,对绿脓杆菌的抑菌率较好,在52.8～73.0%之间,对金黄色葡萄球菌的抑制活性最低,在43.3～65.5%之间。     

β—环糊精及其包结物作为气相色谱固定相分离混合物研究

β-环糊精由于其特殊的分子结构,对某些物质具有包结作用,并形成较稳定的复合物,极化能力大大增强,在色谱中具有更大的保留值,气相色谱固定相分离混合物过程中,β-环糊精包结物较β-环糊精具有更强的分离能力。分别对β-环糊精及其包结了某些物质后的β-环糊精作气相色谱固定相,对一系列低佛点有机化合物的分离和保留行为进行研究,比较了β-环糊精包结前后的不同的分离效果,并初步探讨了有关的形成机理和分离机制。     

spin-Peierls系统低能量激发谱的理论研究

用玻色化技术和量子自洽方法研究了spin-Peierls系统的低能量激发谱,计算了二聚化相的基态、单粒子激发态和双粒子束缚态的能量、阻挫对其低能量行为的影响及其各自的自旋-自旋关联函数.结果表明,随着阻挫的增大,spin-Peierls系统中的基态能会逐渐减小,单粒子激发态能隙和双粒子束缚态能隙却会增大.双粒子束缚态和基态的关联函数具有类似的短程关联,而单粒子激发态的关联函数具有长程关联.因此导出,单粒子激发态为自旋三重态,双粒子束缚态与基态类似为自旋单态,它存在于双粒子连续激发态的下边.该结果与Ain等 关键词： spin-Peierls系统 束缚态 关联函数     

Localized Mode Enhanced Coupler Based on Quasi-One-Dimensional Photonic Crystal Microstrip

We propose a novel localized mode enhanced (LME) coupler based on quasi-one-dimensional photonic crystal microstrips, which is promising to be applied in wavelength division multiplexed microwave communication systems. Compared to the traditional microstrip coupler, the LME structure has two advantages: high efficiency and frequency selectivity. Even in a relatively far coupling distance, this structure can still achieve a high efficiency about 50%. The frequency selectivity can be realized by simply tuning the distance between two transmission lines.     

ICP—AES法同时测定硅铁中铝、锰、铬、钙

本文介绍ICP-AES法同时测定硅铁中Al、Mn、Cr、Ca,试样用HF-HNO_3-H_2-SO_4分解,酸不溶残渣用Na_2CO_3-H_3BO_3混合熔剂熔融,稀盐酸浸取与滤液合并,定容后用Plasma Ⅱ型原子发射光谱仪测定,精密度小于5%,对标样进行十一次测定,对均值与标准值作t检验,证明均值与标准值无显著性差异,方法本身不存在系统误差。