两种水生植物处理重金属废水的FTIR比较研究

利用傅里叶变换红外光谱仪(FTIR)测定一定重金属浓度梯度处理下水芹和黄菖蒲根、茎、叶的红外光谱,并对这些红外光谱进行了比较分析。结果表明：植物各组分吸附重金属前后的峰形基本不变,只有某些参与重金属吸附的官能团如羟基(3 328～3 361 cm-1)、羧基(1 402～1 440 cm-1)、酰胺基(1 620～1 645 cm-1)等的吸收峰发生了不同程度的位移。两种水生植物根中与植物生理有关的化学成分的特征峰大多数随重金属浓度增加而降低。水芹茎、叶在各浓度重金属处理下与植物生理有关的化学成分的特征峰大多数都比对照低,黄菖蒲则相反。综合分析,黄菖蒲对重金属废水的修复效果和耐受能力均强于水芹。采用FTIR法鉴别水生植物对重金属的处理效果比常规方法更具代表性,为植物修复的开展提供了有力的证据支持。     

结构声强技术测量墙体结构中弯曲波耦合功率流

虽然结构声强技术已成功地应用于匀质薄壁结构，但在建筑结构的应用研究只是一些定性的探讨，本文应用结构声强技术研究建筑结构中弯曲波声强的测量，以传统方法获得的结构总损耗能量测量值为参考，基于９５％合成置信区间研究弯曲波声强的测量精度，初步探讨了结构声强技术在建筑中应用的可行性。     

高温液滴外延生长先进光电材料

分子束液滴外延生长三维纳米结构不仅适用于晶格失配,也适用于晶格匹配材料系统。在高温条件时,这种技术制备的结构具有相对高的光学和电学性能,也表现出丰富多彩的形貌特征,包括量子环、量子点分子和纳米孔等。将着重介绍高温液滴外延生长技术的最新进展,同时讨论这种技术应用在光电材料领域的前景和挑战。     

全息制作不同晶面取向光子晶体模板

用单向光入射和单次曝光的激光全息技术制作了类金刚石结构, 此类金刚石结构有宽完全带隙和低介质折射率要求等优点. 在同一种光束配置下，引入恰当的匹配棱镜，用激光全息技术制作了大面积的类金刚石光学晶格不同晶面取向的亚微米周期结构. 满足如负折射效应等研究中所需的特殊晶面取向要求. 关键词： 激光全息技术 光学晶格 光子晶体     

准晶结构的激光全息人工制作

报道了用激光全息刻写技术结合感光聚合材料体系制作介观尺度二维准周期结构(准晶). 并在前期工作的基础上，研究了不同曝光量对二维空气柱孔径的影响，不同偏振对准晶结构花样的影响. 实验结果显示，可以制作的二维准晶的空气柱孔径可达100nm，而且结构均匀，无缺陷面积大. 用此实验系统可以制作多种花样二维甚至是三维准晶结构. 目前，除激光全息刻写技术外，用其他传统精密机械加工技术来人工制作介观准晶体尚存在很大挑战性. 关键词： 准晶结构 光子晶体 激光全息技术     

MATLAB图形技术在物质结构教学中的应用

本文结合物质结构的特点，简要介绍了MATLAB图形技术的内容、功能及其在物质结构教学中的应用。     

NMR波谱技术在两亲分子聚集体研究中的应用

通过近年来NMR技术在两亲分子聚集体研究中的应用实例,特别在弛豫时间、自扩散系数测定、谱线宽度、化学位移等方面取得的研究结果,对确定的两亲分子聚集性质、聚集体结构和聚集体性质的研究进行了较为详细的介绍.主要侧重点在于介绍1HNMR、13CNMR、19FNMR及2H四极分裂谱等技术在两亲分子聚集体结构及结构演变研究中的应用,特别在胶束、囊泡和微乳液结构确定上的应用.     

微纳米加工技术及其应用综述

材料与结构在微纳米尺度展现了许多不同于宏观尺度的新特征，纳米技术已经成为当前科学研究与工业开发的热门领域之一。微小型化依赖于微纳米尺度的功能结构与器件，实现功能结构微纳米化的基础是先进的微纳米加上技术，文章对微纳米加上技术做了一个综合的介绍，简要说明了微纳米加工技术与传统加工技术的区别，在微纳米加工技术的应用方面提出了一些合理选择加工技术的原则，并对当前微纳米加工技术面临的挑战和今后发展的趋势作了预测。     

基于RBF网络的光纤荧光海水叶绿素a含量在线监测系统的研究

介绍了能够实现对海水中叶绿素a含量在线监测的光纤荧光系统。系统将荧光技术、光纤技术和基于RBF(Radial Basis Function Neural Network)神经网络的标定方法相结合，建立了用于海水叶绿素a含量在线监测的最佳RBF网络结构，系统具有结构简单，探头无源及高灵敏度等特点。     

混成式热释电非制冷红外焦平面探测器技术

介绍了混成式热释电焦平面探测器的基本结构和主要制备工艺流程以及国内外研究现状。混成式热释电焦平面探测器的关键制备技术主要包括热释电材料的优选与减薄技术,铟柱倒装焊混成技术、热隔离技术和读出集成电路技术等。指出了混成式热释电焦平面探测器的发展趋势。     

Electronic-structure calculations for complex crystals

Summary We discuss some new ideas for improving first-principle muffin-tin orbital-type electronic-structure calculations for complex crystals such as ternary and multinary compounds. The new ideas include construction of generalized muffin-tin orbitals and energy-dependent double MTO basis sets, cellular decomposition based on strongly overlapping atomic spheres and evaluation of matrix elements in the residual interstitial region by extrapolation. Supported in part by the Office of Naval Research, Contract Number N00014-79-C-0814.     

High-frequency electric-field trap for micron and submicron particles

Summary Four e-beam-processed, planar electrodes with gaps between 0.5 and 4 μm were used to create quadrupole electric-field trap. The electrodes were immersed in an aqueous particle suspension and driven by kHz to MHz signals of several volts amplitude. Micron and submicron particles could be stably trapped by negative dielectrophoresis. Latex beads of 1000, 600, 100 and 14 nm diameter could be concentrated between the electrodes (positive dielectrophoresis) or levitated as condensed cloud (negative dielectrophoresis). The results are surprising since polarisation forces depend on the volume of the particle and, up to now, it was expected that thermal forces would dominate the behaviour of particles with diameters <100 nm. However, micron-scaled electrode configurations allow the application of extremely strong fields (up to 20 MV/m) and open up new perspectives for microparticle handling and macromolecule trapping.     

Comparison of spatial resolution in internal and external electro-optic probing

A new method, based on zero point of longitudinal electric field, was used to determine the spatial resolution of internal and external electro-optic (EO) probing systems. An interdigital structure electrode was fabricated on GaAs substrate to examine the spatial resolution of internal and external EO probing system. Considering the air gap between the electrode under test and the probe tip, the result of EO probing was simulated which is well accorded with experiment. The result indicates that spatial resolution of less than 0.5 and 1 m are obtained in internal and external EO probing system respectively.     

1,8-二羟基-3-甲基-苯并［d,e］蒽酮的2D NMR研究

从中药芦荟(Aloe vera)中分离得到一个蒽酮类新化合物. 通过UV、IR、HREI-M S、¹H NMR和¹³C NMR及2D NMR(¹H-¹H COSY、HMBC、HMQC和J -resolved)方法， 鉴定其结构为：1,8- 二羟基-3-甲基-苯并［d,e］蒽酮. 文章的侧重点在于讨论该化合物的¹H和¹³C NMR信号的全归属.     

Experimental Overview of Mass Measurements

Nuclear masses and binding energies are an important input for nuclear models, constituting strong constraints far from the β-stability valley. During the last decade, new experimental techniques for the production of exotic nuclei and the measurement of their mass were developed. The present paper gives an overview of these techniques. This revised version was published online in July 2006 with corrections to the Cover Date.     

The Evaluation of the Flow of Agents with Isotopic Tracers through Tanks

In this paper the existing methods of evaluating the effectiveness of mixing processes are presented. Starting from the results of experiments based on the use of isotopic technique, a new criterion for the mixing effect of the component flowing through a tank has been found. For this reason, model tests in aerated rooms have been carried out. Properties of the new criterion as well as the relationships to the existing methods of evaluation are given.     

Hyperfine-structure measurements and new levels evaluation in singly ionized praseodymium

Results of systematic studies of the hyperfine structure of singly ionized praseodymium are presented. For many of the known energy levels the hyperfine constants A and B have been measured more precisely and found consistent with previous literature data. Identification of some new energy levels has also been performed. The hyperfine structure of some unclassified lines has been recorded by the method of laser induced fluorescence in a hollow cathode discharge. J quantum numbers and A-values for upper and lower levels have been determined. Identification has been achieved through comparison of the obtained results with those for known levels. Three new low-lying levels in singly ionized praseodymium have been discovered. Some of the recorded unclassified lines involve two new levels and their identification requires further investigations. Received 28 February 2001 and Received in final form 3 July 2001     

自锁模钛宝石超短脉冲激光器的新进展

本文综述了自锁模钛宝石超短脉冲激光器的发展概况及最新进展,分析了这种超短脉冲技术的应用前景,在综述的基础上指出了这一技术的发展趋势.     

Nonlinear Fourier analysis of localized wave fields

Summary The Fourier transform (FT) has long served as an indispensable means for analysing wave motion described by linear evlution equations. The methods are well known and include not only mathematical analysis but also the analysis of data as well. In recent years new spectral methods have been developed for analysing nonlinear evolution equations. Such methods are generalizations of the FT to specific nonlinear wave systems and are referred to as the spectral or scattering transform (ST). Herein we use numerical procedures for applying the ST directly to the analysis of localized data described by the Kortewegde Vries (KdV) equation on the infinite interval,i.e. the Cauchy problem in shallow water. In this context we emphasize the importance of the direct spectral transform (DST) as a wave number domain representation of nonlinear data. The numerical methods discussed for the KdV equation should be extendible to the large class of systems considered by Ablowitzet al., Calogero and Degasperis. We give examples of the spectral analysis of nonlinear, computer-generated data.

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Riassunto La ben nota trasformata di Fourier (FT) è di uso commune per analizzare moti ondosi descritti da equazioni di evoluzione lineari. Negli ultimi anni sono stati sviluppati nouvi metodi (detti trasformate spettrali o di scattering, ST) per l'analisi di equazioni di evoluzione non lineari basati sulla generalizzazione della FT agli specifici sistemi ondosi non lineari. Qui usiamo procedimenti numerici per applicare la ST direttamente all'analisi di dati localizzati descritti dall'equazione di Korteweg-deVries nell'intervallo infinito, cioè al problema di Cauchy in acqua bassa. In questo contesto sottolineiamo l'importanza della trasformata specttrale diretta come rappresentazione nel campo dei numeri d'onda di dati non lineari. I metodi numerici discussi, che a titolo di esempio sono qui applicati all'analisi spettrale di dati non lineari generati dal calcolatore, hanno l'interessante possibilità di essere estendibili ai problemi piú generali di propagazione ondosa.

     

Liouville operator resolvent method applied to the hubbard dimer

Summary The problem of two hydrogenlike atomic sites (s-shells only) coupled via a hopping matrix is considered. We employ a new formalism, the Liouville operator resolvent method, to evaluate the single-particle thermodynamic Green’s function for this system. Details of the method are also discussed. To speed up publication, the authors of this paper have agreed to not receive the proofs for correction.