共沉淀富集火焰原子吸收光谱法测定固体弃物磷石膏中痕量镉

用ＣｕＳ作捕集沉淀剂共沉淀富集分离磷石膏中痕量Ｃｄ,研究了最佳沉淀条件,对溶液共沉淀酸度,沉淀试剂用量进行了讨论。平行６次测定Ｃｄ含量为０．０４４μｇ／ｇ的磷石膏样品,相对标准偏差为７．７９％,加标回收率在８８％～１１０％之间。     

浊点萃取-石墨炉原子吸收法测定高盐样品中的痕量铅

在pH 6～7的缓冲体系中,样品溶液中的痕量铅与加入的吡咯烷二硫代氨基甲酸铵(APDC)为络合剂形成稳定的配合物。通过70 ℃恒温水浴3 h,铅配合物被萃取到表面活性剂相并与水相分开。 分离后的表面活性剂相室温就可配成上机待测样液。 此法不但将大量基体离弃在水相,从而消除高盐带来的高背景信号干扰,并将水样或1%食盐溶液的痕量铅富集10～100倍。用氘灯校正背景石墨炉原子吸收法进行测定,方法检出限：食盐0.000 5 μg·g-1,水样0.01 μg·L-1。回收率为92.3%～104%。用于食盐、海水、井水中痕量铅的测定,结果令人满意。     

共沉淀富集火焰原子吸收光谱法法测定固体弃物磷石膏中痕量镉

用ＣｕＳ作捕集沉淀剂共沉淀富集分离磷石膏中痕量Ｃｄ,研究了最佳沉淀条件,对溶液共沉淀酸度,沉淀试剂用量进行了讨论。平行６次测定Ｃｄ含量为０．０４４μｇ／ｇ的磷石膏样品,相对标准偏差为７．７９％,加标回收率在８８％￣１１０％之间。     

印迹壳聚糖/凹土分离富集-火焰原子吸收光谱法测定中药中的痕量铅

建立了用离子印迹壳聚糖/凹凸棒石(MICA)分离富集-火焰原子吸收光谱法(FAAS)测定中药中痕量铅的新方法.在动态吸附条件下,系统地研究了溶液pH值、流速、洗脱条件和干扰离子对痕量铅分离富集的影响;在pH 4.5,上样流速为0.60mL/min的条件下,铅能被MICA定量富集;吸附的铅可用1.0mol/L HCl-0...     

APDC共沉淀分离富集—火焰原子吸收分光光度法测定明矾中的痕量铅

本文研究了ＡＰＤＣ－Ｃｕ（Ⅱ）共沉淀分离富集，开槽管原子捕集火焰原子吸收光谱测定铅的条件，发现痕量铅在ｐＨ值为２－８条件下能被ＡＰＤＣ－Ｃｕ（Ⅱ）定量共沉淀，方法的检出限可达１．５×１０＾－２μｇ／ｍＬ。用于明矾中痕量铅的分离富集和测定，共存物质不产生干扰，样品６次平行测定的相对标准偏差〈４％。加标回收率在９８％－１０３％之间。     

磷酸钇共沉淀分离富集原子吸收光谱测定氯化镍和硫酸锰中的痕量铅和铁

研究了采用磷酸钇(YPO4)作为共沉淀载体选择性分离富集NiCl2,MnSO4溶液中的痕量Pb2 和Fe3 ,并用火焰原子吸收光谱(FAAS)测定的方法.共沉淀受pH,YCl3和H3PO4溶液用量的影响.结果显示,在溶液pH 3.0～4.0时,YPO4能够定量共沉淀氯化Ni中的Pb和Fe以及硫酸Mn中的Pb.对于20mL溶液,Pb和Fe的检出限分别为1.63×10-2 mg·L-1和4.58×10-2mg·L-1.在NiCl2溶液中,Pb和Fe的标准加人回收率分别为100.91%和99.73%;在MnSO4溶液中,Pb和Fe的标准加入回收率分别为99.45%和98.98%.实验基本消除了基体干扰,取得了较满意的结果.     

有机共沉淀-火焰原子吸收光谱法测定高纯稀土氧化物中痕量铅镉钴镍铁铜

本文研究了吡咯啶二硫代氨基甲酸铵(APDC)共沉淀痕量铅镉钴镍铁铜的最佳条件;金属-PDC配合物的稳定性及共存元素的干扰等。沉淀溶解于小体积的甲基异丁酮(MIBK)中,采用微量进样技术,将有机相直接喷入空气-乙炔火焰,原子吸收光谱法测定之。该法已成功地应用于荧光级氧化镧和氧化钇中题示元素的测定。     

应用内标的APDC-Cu(Ⅱ)快速共沉淀分离富集和原子吸收光谱测定食盐中的铅

采用APDC(吡咯烷二硫代氨基甲酸铵)-Cu(Ⅱ)共沉淀体系,以Ni(Ⅱ)为内标,在pH 2.5的条件下快速共沉淀分离富集食盐中的铅,并用火焰原子吸收法(FAAS)测定。当试液为100 mL时方法的检测限为3.27×10-3 μg·mL-1,回收率为92%～101%,基本消除了基体干扰。该法快速、简便、重现性好。     

Fe-DDTC共沉淀分离富集ICP-AES摄谱法同时测定水中9个痕量元素

ICP—AES对许多元素的检出限远远低于地面水环境质量标准,直接测定即可以满足要求。然而ICP—AES摄谱法在直接分析天然水中痕量元素时,仍存在灵敏度不足的问题。目前关于富集分离技术的研究,已有许多报道。利用铁与铜试剂(二乙基二硫代氨基甲酸)(Fe—DDTC)的共沉淀作用,可同时分离富集水中多种痕量元素。本文在文献的基础上,进行了高倍数(100倍)富集,ICP—AES摄谱法的测定条件实验,选择了干扰较小的分析线,研究了铁工     

浊点萃取-火焰原子吸收光谱法测定痕量铅的研究

研究了浊点萃取-火焰原子吸收光谱法测定痕量铅的新方法.利用表面活性剂聚乙二醇辛基苯基醚(Triton X-100)和配合剂1-苯基-3-甲基-4-苯甲酰吡喹啉酮-5(PMBP)对试样中的Pb(Ⅱ)进行浊点萃取.并详细探讨了溶液pH值、试剂浓度等实验条件对浊点萃取及测定灵敏度的影响.在最佳条件下,铅的富集倍数为20,检出...     

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.     

Visualization and interferometry for cylindrical and spherical sample tomography and profilometry

A technique combining image processing and laser interferometry for visualizing and detecting the deformation of transparent cylindrical and spherical sample is proposed. This deformation includes geometric deformation such as volume transition in profilometry and physical deformation such as refractive index change in tomography. Phase contour lines are used for quantitative analysis and graphical representation of the deformation. This method allows us to visually detect the spatial variation of the deformation field and to evaluate the test quality such as misalignment of optical system. A theoretical analysis using phase contour map to characterize the deformation field is described in detail. A method using phase contour map to qualify the interferometric test is proposed. Analysis of test examples is carried out. Suggestions on using phase contour line method to ameliorate test system design are finally discussed.     

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.     

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.     

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。     

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。     

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.     

Geometry and Elasticity of Strips and Flowers

We solve several problems that involve imposing metrics on surfaces. The problem of a strip with a linear metric gradient is formulated in terms of a Lagrangian similar to those used for spin systems. We are able to show that the low energy state of long strips is a twisted helical state like a telephone cord. We then extend the techniques used in this solution to two–dimensional sheets with more general metrics. We find evolution equations and show that when they are not singular, a surface is determined by knowledge of its metric, and the shape of the surface along one line. Finally, we provide numerical evidence by minimizing a suitable energy functional that once these evolution equations become singular, either the surface is not differentiable, or else the metric deviates from the target metric.     

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.