白光和红绿蓝光LED可调光源研制

为了提高LED光源色温和亮度的调节精度和准确度,结合色温由低向高变化时光色所呈现的渐变特点,提出了一种低色温白光LED灯珠、高色温白光LED灯珠加红绿蓝光LED灯珠补偿式调光的方法.将色温分成三个部分进行调节,每个部分选用不同的LED灯珠组合来进行调光.实验结果表明:不同组合情况下的LED光源的初始输出色温相对于目标值的偏差范围在1％以内;亮度可以在保证色温不变的情况下独立进行调节,初始输出值与目标值的偏差范围在1％以内;经过微调之后可以达到目标值;达到了色温和亮度独立调节的要求;光源发光稳定,不会因为长时间工作而影响调节精度.     

国外超导材料技术研究政策和方向

超导材料技术是21世纪具有战略意义的高新技术,极具发展潜力和市场前景。世界各发达国家纷纷制定研发计划,给予高度重视和大力支持,加快超导材料技术的基础研究和产业化发展。主要从美国、日本、欧洲国家、韩国等国家的相关研发计划、政策以及主要科研机构的研发概况出发,阐明目前国外超导材料技术的研究政策和方向。     

黑克、布劳、及伯曼-温采尔代数的诱导及分导系数和量子经典李代数的耦合与重新耦合系数

本文总结了计算黑克、布劳、及伯曼 温采尔代数在各种工数链下诱导及分导系数的线性方程方法(LEM)。特别强调了关于A,B,C,D型李代数及其量子情形与其中心代数之间的舒尔 魏尔 布劳双关性关系。这一关系使我们能够利用相应中心代数的诱导及分导系数计算出经典李代数及其量子情形的耦合与重新耦合系数。讨论了从该方法得到B,C,D型李代数不可约表示克罗内克积分解的应用。基于LEM还得到了处理对应于置换群CG系列问题的黑克代数张量积的方法。     

Quantum and Classical Disparity and Accord

Discrepancies and accords between quantum (QM) and classical mechanics (CM) related to expectation values and periods are generally found for both the harmonic oscillator (SHO) and a free particle in a box (FPB), which may apply generally. These indicate non-locality is expected throughout QM. The FPB energy states violate the Correspondence Principle. Previously unexpected accords are found and proven that 〈x ²〉 _CM =〈x ²〉 _QM and τ _CM =τ _QMb (beat period i.e. beats between the phases for adjoining energy states) for the SHO for all quantum numbers, n. However, for the FPB the beat periods differ at small n. It is shown that a particle’s velocity in an infinite square well varies, no matter how wide the box, nor how far the particle is from the walls. The quantum free particle variances share an indirect commonality with the Aharonov-Bohm and Aharonov-Casher effects in that there is a quantum action in the absence of a force. The concept of an “Expectation Value over a Partial Well Width” is introduced. This paper raises the question as to whether these inconsistencies are undetectable, or can be empirically ascertained. These inherent variances may need to be fixed, or nature is manifestly more non-classical than expected.     

激光跟瞄仿真系统及两种跟瞄方法

基于OpenGL和大气传输光学分析的3维全数字仿真是激光跟瞄系统的重要研究手段。为提高跟踪和瞄准精度,从激光跟瞄仿真系统整体出发,研究了目标成像中的投影变换、成像与跟踪的关系、高精度跟踪现有算法的控制过程仿真等内容,并提出了基于大视口、目标大气传输图像序列的跟瞄仿真技术。说明了仿真系统中跟瞄精度分析的特点。就某仿真场景,设计了"头部顶点"和"两点提取"两种跟瞄方法,在不同大气湍流条件下得到了它们的跟瞄精度,说明应用该激光跟瞄仿真系统,能够预先设计、测试和验证一些跟瞄方法,帮助进行算法分析和改进,从而提高工作效率和节约成本。     

Spectroscopy and Photophysics of Iso- and Alloxazines: Experimental and Theoretical Study

We present a systematic study of the effect of methyl substitution on iso- and alloxazines in acetonitrile solutions. Substitution patterns have profound effects on both spectral and photophysical properties, with fluorescence quantum yields varying by more than an order of magnitude. TD-DFT calculation were used for the first time to correlate electronic structure changes with the substitution patterns, with good agreement between calculated and theoretical band positions and oscillator strengths. Both n-pi* and pi-pi* states in these compounds are predicted, with the oscillator strengths indicating that only the pi-pi* states should be observable in the absorption spectra. Substitution patterns are shown to be responsible for energy order inversion between these states.     

X-ray point- and line-projection microscopy and diffraction

A theoretical framework is presented to treat both imaging and diffraction experiments performed with point-focus and line-focus X-ray sources, with particular emphasis on two-dimensional and planar X-ray waveguides. In particular, point-projection and line-projection microscopy has been approached within the Huygens-Fresnel formalism; point-projection and line-projection diffraction, such as spatially-resolved Bragg/Laue diffraction of crystalline samples in a regime of dynamical scattering, has been treated both by means of the Huygens-Fresnel formalism and of the Takagi-Taupin dynamical theory. Both in point- and line- projection geometry, simply rotating the investigated crystalline samples, it is possible to switch from Fresnel self-imaging to Bragg/Laue diffraction conditions. This means to image, within the same experiment, either morphological features, with a sub-micrometric resolution, out of the exact diffraction condition, or the structure order on an atomic scale if placing the sample in diffraction.     

Spectral and photosensitizing properties of bacteriochlorin a and its monomethyl and dimethyl esters

We have carried out a comparative study of the photosensitizing activity of bacteriochlorin a (BCA) and its methylated derivatives: monomethyl and dimethyl esters of BCA (BCA MME and BCA DME). We have shown that BCA and its derivatives are bound to the erythrocyte membranes in monomolecular form, and upon photoexcitation in the region of their long-wavelength Q_y absorption band, they sensitize oxidation of the major membrane components: proteins and lipids. We have established that despite greater binding of the methylated BCA derivatives to the membranes, their specific activity in photosensitization of peroxide oxidation of membrane lipids and membrane protein tryptophanyls is lower than for BCA. At the same time, BCA MME and BCA DME sensitize oxidation of a larger number of SH groups in membrane proteins, which suggests methylated BCA is predominantly localized in the erythrocyte membrane close to the protein sulfhydryl groups. We also show that the rate of erythrocyte photohemolysis sensitized by BCA MME and BCA DME is significantly faster than for sensitization by BCA. This correlates with the lipophilicity of BCA, BCA MME, and BCA DME, which is responsible for the ability of bacteriochlorins to bind to cell membranes and cells. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 1, pp. 98–105, January–February, 2006.     

高分辨和超分辨光学成像技术在空间和生物中的应用

大到天文光学望远镜观察浩瀚的宇宙, 小到光学显微镜探察细微的纳米世界, 光学成像技术在人类探索和发现未知世界奥秘的活动中扮演着至关重要的角色. 看得更远、看得更细、看得更清楚是人们不断追求的目标. 传统光学理论已证明所有经典光学系统都是一个衍射受限系统, 即光学系统空间分辨率的物理极限是由光的波长和系统的相对孔径(或数值孔径)决定的. 能否突破这个极限？能否不断提高光学系统的成像分辨率？围绕着这个问题, 本文综述了近年来开展的各种光学高分辨和超分辨成像技术, 及其在空间探测和生物领域中的应用.     

Divergence- and Curl-Preserving Prolongation and Restriction Formulas

We present new second-order prolongation and restriction formulas which preserve the divergence and, in some cases, the curl of a discretized vector field. The formulas are suitable for adaptive and hierarchical mesh algorithms with a factor-of-2 linear resolution change. We examine both staggered and collocated discretizations for the vector field on two- and three-dimensional Cartesian grids. The new formulas can be used in combination with numerical schemes that require a divergence-free solution in some discrete sense, such as the constrained transport schemes of computational magnetohydrodynamics. We also obtain divergence-preserving interpolation functions which may be used for streamline or field line tracing.     

激光与计量基准

激光以它的良好的物理性质（单色性好、方向性强、能量大等）而被广泛应用到科学与技术许多领域。激光应用于计量科学和利用激光变更计量基本单位的定义和复现其定。都为计量科学的发展起到革命性的作用，文章介绍了激光与米定义及其复现，激光与秒定义，激光与国际温标，激光与质量自然基准和一系列激光在计量测试中的应用。     

Interactions Between an Ionic Liquid and Silica,Silica and Silica,and Rubber and Silica and Their Effects on the Properties of Styrene-Butadiene Rubber Composites

An investigation of the effect of an ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate (BMI), on the properties of silica reinforced styrene-butadiene rubber (SBR), aimed to correlate the interactions between the ionic liquid and silica, silica and silica, and silica and rubber with the macro-properties and microstructure of SBR and SBR/silica vulcanizates is described. The interaction between the ionic liquid and silica was characterized by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR), the interaction between silica and silica was characterized by a rubber processing analyzer (RPA), and the interaction between rubber and silica was characterized by the bound rubber content. The FTIR analysis revealed that BMI can react with the hydroxyl groups on the surface of silica, improving the compatibility between the rubber and silica. The RPA and bound rubber testing indicated that the interactions between silica and silica particles were weakened and the interaction between silica and rubber increased with the incorporation of BMI into the SBR rubber. The bound rubber content showed a maximum with a BMI content of 3 phr. At the same time, the dispersion of silica in SBR was improved with the incorporation of BMI. With the increase of BMI content, the curing rate was greatly improved and the crosslink density increased. BMI also increased the tensile strength and abrasion resistance of the SBR vulcanizates. Most important, the BMI significantly improved the dynamic properties of the rubber composites, especially the wet-skid resistance and rolling resistance. However, excessive BMI (beyond 3 phr) acted as a plasticizer and was detrimental to the mechanical properties, resulting in a decrease of tensile strength and abrasion resistance.     

Non-stoichiometric oxide and metal interfaces and reactions

We have employed a combination of experimental surface science techniques and density functional calculations to study the reduction of TiO₂(110) surfaces through the doping with submonolayer transition metals. We concentrate on the role of Ti adatoms in self doping of rutile and contrast the behaviour to that of Cr. DFT+U calculations enable identification of probable adsorption structures and their spectroscopic characteristics. Adsorption of both metals leads to a broken symmetry and an asymmetric charge transfer localised around the defect site of a mixed localised/delocalised character. Charge transfer creates defect states with Ti 3d character in the band gap at ∼1-eV binding energy. Cr adsorption, however, leads to a very large shift in the valence-band edge to higher binding energy and the creation of Cr 3d states at 2.8-eV binding energy. Low-temperature oxidation lifts the Ti-derived band-gap states and modifies the intensity of the Cr features, indicative of a change of oxidation state from Cr³⁺ to Cr⁴⁺. Higher temperature processing leads to a loss of Cr from the surface region, indicative of its substitution into the bulk.     

Nylon and nylon blend nanotubes and nanorods

Nylon nanorods and nanotubes (200 nm diameter) were fabricated by the membrane wetting technique (solvent and melt wetting) from a range of nylons (6; 6,6; 6,9; 6,10; 6,12; 11; 12, 6(3)T) and nylon blended with different dyes (Nylon Cast Blue, Nylon 6/6 Black) or with molybdenum disulfide (Nylon cast MDS). The 65-μm long nylon nanotubes and nanorods were characterized by scanning electron microscopy. The nanoscale nylon 6,6 served as an effective high surface area alternative to a nylon membrane as a solid support in a chemiluminescent assay for nylon-bound biotinylated nucleic acids based on streptavidin- alkaline phosphatase and chemiluminescent detection of the bound alkaline phosphatase label with the dioxetane substrate, CDP-Star. Layer-by-layer deposition of the cationic polymer (Sapphire-II™; Tropix) onto the nylon 6,6 nanostructures prior to UV-cross-linking with biotinylated DNA resulted in further enhancement of binding and detection of biotinylated DNA.     

Interfacing DNA and Polydopamine Nanoparticles and Its Applications

Polydopamine (PDA) is polymerized from dopamine under oxidative and basic conditions. PDA is a biocompatible material with great versatility for coating various surfaces and it can also form nanoparticles. DNA oligonucleotides are highly stable, and they can recognize a diverse range of molecules from complementary nucleic acids, proteins to small molecules and metal ions. To enhance the molecular recognition function of PDA, it is interfaced with DNA and the conjugates have achieved a wide range of applications in biomedical and analytical science. In this review, the chemistry of some catecholamines, including dopamine and PDA, is first briefly introduced and variables in the PDA synthesis are highlighted. Strategies to promote DNA adsorption on PDA are then discussed including the use of low pH and polyvalent metal ions. In addition, covalent attachment of DNA to PDA can be achieved by using amino or thiol-modified DNA, forming highly stable conjugates. The specific applications of PDA–DNA conjugate are also delineated, including DNA extraction, biosensing, intracellular delivery, and DNA origami. Finally, some problems in the field are discussed, along with a few future research opportunities.     

水合物研制、结构与性能及其在能源环境中的应用

天然气水合物是与能源和环境相关的物质,可以进行甲烷等能源气体的存储和提取,也可以用于对二氧化碳等废气的封存.天然气水合物主要分为三种结构:sI, sII和sH,在本文中对其稳定性、水笼类型和大小以及可俘获气体进行了论述.中子衍射技术是研究水合物的重要手段之一,有着独特的优势.如中子的穿透性可以研究在高压状态下压力腔体内的大块样品;中子对于轻元素的敏感性可以很好地确定水合物当中的碳、氢、氧元素.通过中子衍射和非弹散射可以得到水合物中H/D原子的位置、各向异性振动因子、不同温度压力下的客体分子的水笼占据率、客体分子在水笼中的无序分布、原子核密度分布(通过最大熵方法);通过时间分辨中子,可以检测水合物形成及分解过程的热力学和动力学过程.而利用非弹中子可以得到气体分子平移和旋转振动模式以及分子的量子态转变.通过二氧化碳气体注入对天然气水合物的开采可以实现能源气体甲烷的开采和废气二氧化碳的水合物封存,在减小地质灾害和开采成本上有着独特的优势.     

Combustion synthesis of ZnO and Ag-doped ZnO and their bactericidal and photocatalytic activities

The combustion synthesized ZnO and 0.9 at.% Ag-doped ZnO have been characterized by powder X-ray diffraction and energy dispersive X-ray, UV-visible diffuse reflectance, photoluminescence and impedance spectroscopies. Doping sharpens the band gap absorption, displays surface plasmon resonance, suppresses the blue emission, enhances the near band gap emission and increases the charge transfer resistance and capacitance. Ag-doping by combustion method improves significantly the bactericidal activity but not the photocatalytic activity.     

Escort entropies and divergences and related canonical distribution

We discuss two families of two-parameter entropies and divergences, derived from the standard Rényi and Tsallis entropies and divergences. These divergences and entropies are found as divergences or entropies of escort distributions. Exploiting the nonnegativity of the divergences, we derive the expression of the canonical distribution associated to the new entropies and a observable given as an escort-mean value. We show that this canonical distribution extends, and smoothly connects, the results obtained in nonextensive thermodynamics for the standard and generalized mean value constraints.     

Rapid and flexible laser marking and engraving of tilted and curved surfaces

We present a novel method for rapid and flexible laser marking and engraving of tilted, curved and freeform work-piece surfaces. The method is based on integrating a three-dimensional (3D) laser measurement system into a 3D laser marking system. We use the same laser source and optics for measurement and processing with a minimum of additional hardware components. A low power CW laser regime is used to measure the 3D shape of a work-piece surface while a high-peak power-pulsed laser regime is used for processing. The acquired 3D surface data are used to determine the 3D trajectory of the processing beam focus. Neither the 3D shape of the work-piece nor its orientation needs to be known in advance as long as the processed surface lies within the working range of the 3D laser processing system. This eliminates the need for exact work-piece positioning before processing and substantially improves processing flexibility (allowing, e.g. variations in work-piece shape or/and orientation from mark to mark). This paper discusses key issues concerning an implementation of the method and presents typical examples of markings and engravings, which demonstrate the advantages of the method with respect to the existing industrial 2D and 3D laser marking and engraving methods. The method can also be applied to flexible laser structuring and microprocessing of curved surfaces.     

Nanomaterials and Water Purification: Opportunities and Challenges

Advances in nanoscale science and engineering suggest that many of the current problems involving water quality could be resolved or greatly ameliorated using nanosorbents, nanocatalysts, bioactive nanoparticles, nanostructured catalytic membranes and nanoparticle enhanced filtration among other products and processes resulting from the development of nanotechnology. Innovations in the development of novel technologies to desalinate water are among the most exciting and promising. Additionally, nanotechnology-derived products that reduce the concentrations of toxic compounds to sub-ppb levels can assist in the attainment of water quality standards and health advisories. This article gives an overview of the use of nanomaterials in water purification. We highlight recent advances on the development of novel nanoscale materials and processes for treatment of surface water, groundwater and industrial wastewater contaminated by toxic metal ions, radionuclides, organic and inorganic solutes, bacteria and viruses. In addition, we discuss some challenges associated with the development of cost effective and environmentally acceptable functional nanomaterials for water purification.