Generation and Propagation of Optical Superoscillatory Vortex Arrays

Superoscillation is an intriguing wave phenomenon which enables subwavelength features propagating into far field and hence has potential applications in super‐resolution microscopy as well as particle trapping and manipulation. While previous demonstrations mostly concentrate on designing complicated nanostructures for generating uncontrollable superoscillatory functions, here a new technique which allows for creating polynomially shaped superoscillatory functions that contain phase singularity arrays is demonstrated both theoretically and experimentally. Such a technique is implemented in optical experiments for the first time and controllable superoscillatory lobes with feature much below the diffraction limit is achieved. More importantly, a general theoretical framework, which, to our knowledge, has not been reported before, is developed to show how the created superoscillations propagate to a distance of many Rayleigh ranges and eventually disappear when the distance is sufficiently larger. The validity of the model is confirmed by the experiments. The results may trigger further studies in light field shaping and manipulations in subwavelength scale.     

A Phenolic Glucoside from Alangium plantanifolium

Alangium, the sole genus in the family Alangiaceae, has a variety of about 20 species distributed in the tropical and subtropical area of the Eastern Hemisphere, and 13 species are known to occur in the south of China1. A. plantanifolium and A. chinense are used in chinese traditional medicine for the treatment of rheumatalgia, paralysis, cardianeuria, and wound2. Pharmacological studies of the extracts of these two species showed muscular relaxing activity, and anabasine was considered as t…     

Novel pressure and displacement sensors based on carbon nanotubes

We report newly designed pressure and displacement capacitive sensors based on a flexible paper–CNT structure.The carbon nanotube(CNT)powder was deposited on a thin paper substrate and was pressed at an elevated temperature.The sheet resistance of the paper–CNT films was in the range of 2–4 kΩ/cm2.The paper–CNT films were used to fabricate pressure and displacement sensors.The sensitivities of the pressure and the displacement sensors were found to be17.3 p F·m2/k N and 0.93 10-3p F/μm,respectively.The experimental results were compared with the simulated data and they found good agreement with each other.     

ICP-AES法同时测定饮用水中Pb, As等11种金属元素

本文建立了ICP AES(电感耦合等离子体发射光谱仪 )法同时测定生活饮用水中的铅、砷、铜、铁、锌、锰、铬、镉、银、铝、硒的分析方法 ,采用超声波雾化器 ,提高了雾化效率 ,同时提高分析的灵敏度。优化了ICP工作参数 ,研究了酸度对测定的影响 ,并进行了元素分析线的选择、背景扣除方式和共存元素干扰的试验。该法相关性好 (r为 0 9993～ 0 9998) ,线性范围广 ,精密度RSD <9 8% ,准确度好 ,样品加标回收率为 90 0 %～ 10 9 7% ,检出限低 ,具有分析速度快 ,多元素同时测定 ,操作简便等优点。应用于实际样品的测定 ,结果满意。     

铈(Ⅳ)与氟喹诺酮类抗生素相互作用的共振瑞利散射光谱及其分析应用

在pH4.0～5.0的弱酸性介质中,Ce(Ⅳ)能与诺氟沙星(NOR)、环丙沙星(CIP)、培氟沙星(PE)、洛美沙星(LOM)和司帕沙星(SPA)等氟喹诺酮类抗生素(FLQs)反应,并最终形成Ce(HL)(OH)4型的三元混配络合物.此时,仅能引起吸收光谱的微小变化和摩尔吸光系数(ε)的少量提高,但是却能导致共振瑞利散射(RRS)的显著增强,5种体系的最大散射波长均位于381nm附近,并在534nm处出现一个较小的散射峰,散射增强(ΔI)在一定范围内与FLQs的浓度成正比,方法有高灵敏度,对不同的FLQ其检出限(3σ)除SPA(16.0μgmL-1)之外,其余FLQs在1.9～5.3ngmL-1之间.研究了Ce(Ⅳ)与FLQs相互作用对RRS光谱的影响,反应的适宜条件和影响因素,考察了共存物质的影响,表明方法有良好的选择性,可用于某些样品中FLQs的测定.还结合吸收光谱的变化和量子化学计算,讨论了反应机理及散射增强的原因.     

A convenient synthesis of methyl 2-hydroxy-4-oxo-4-(substituted phenyl) butanoates from malic acid

A synthesis of methyl 2-hydroxy-4-oxo-4-(substituted phenyl)butanoates has been accomplished using Friedel-Crafts acylation of substituted benzenes with 2-acetoxybutanoyl chloride.The key feature of this strategy is that various 4-arylbutanoates can be obtained conveniently,which are important intermediates for the synthesis of biologically active compounds including ACE inhibitors.     

佛山市顺德区幼儿头发中六种元素含量水平的研究

测定了佛山市顺德区1100名1～7岁学龄前儿童头发中6种元素含量。结果表明,该区幼儿头发中的Zn为(85.25+20.12)×10~(-6);Fe为(30.13±5.30)×10~(-6),Cu为(9.08±2.35)×10~(-6),Ca为(520.70±98.62)×10~6,Mn为(1.87±0.89)×10~(-6),Pb为(11.79±6.85)×10~(-6),并与周边地区作了比较。     

微量元素硒治疗肝病138例的探讨

用西维尔(硒酵母片)治疗了肝病138例，对其疗效进行了观察和探讨。结果表明，硒对各种肝炎、肝肿大者疗效显著；对已患肝癌或肝硬化者疗效不明显。     

铬渣中铬,镍,锌,锰和铁的X射线荧光法测定

本文首次研究了用X射线荧光光谱法测定铬渣中Cr、Zn、Ni、Mn和Fe元素的模拟标样,样品直接压片不经化学处理。用稀释样品校正试样的基体效应。用人工模拟标样所建立的元素浓度与X射线强度间的线性函数关系令人满意,所试元素的线性相关系数均在0.99以上,测定结果与化学法基本一致。Cr的检测下限为0.036%;Fe为0.039%;Ni为35.33μg/g;Mn为498.18μg/g;Zn为55.61μg/g。各元素的相对标准偏差均低于2.48%。并首次用非线性方法研究了铬渣样品稀释比中Cr、Ni、Zn、Mn、Fe与X射线强度的线性关系。