Compact operators which factor through subspaces of lp

Let 1 ≤ p ≤ ∞. A subset K of a Banach space X is said to be relatively p ‐compact if there is an 〈x_n 〉 ∈ l^s _p (X) such that for every k ∈ K there is an 〈α_n 〉 ∈ l_{p ′} such that k = σ^∞_n=1 α_n x_n . A linear operator T: X → Y is said to be p ‐compact if T (Ball (X)) is relatively p ‐compact in Y. The set of all p ‐compact operators K_p (X, Y) from X to Y is a Banach space with a suitable factorization norm κ_p and (K_p , κ_p ) is a Banach operator ideal. In this paper we investigate the dual operator ideal (K^d _p , κ^d _p ). It is shown that κ^d _p (T) = π_p (T) for all T ∈ B (X, Y) if either X or Y is finite‐dimensional. As a consequence it is proved that the adjoint ideal of K^d _p is I_{p ′}, the ideal of p ′‐integral operators. Further, a composition/decomposition theorem K^d _p = Π_p K is proved which also yields that (Π^min _p )^inj = K^d _p . Finally, we discuss the density of finite rank operators in K^d _p and give some examples for different values of p in this respect. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Classification of the distribution of trace impurities by spark source mass spectrometry analysis

Spark source mass spectrometry in combination with principal component analysis and clustering analysis was used to investigate the trace element distributions in metallic samples. The analysis of Zn and Cu samples and a comparison with direct imaging secondary ion microscopy demonstrated the consistency of the approach.On leave from Department of Chemistry, Nanjing Normal University, Nanjing, People's Republic of China.     

Performance evaluation of a wave-front displacement system for vectorial shearing interferometer

We describe a wave-front displacement system using a novel configuration of a pair of wedge prisms. The wave-front propagation, through the displacement system, is analyzed using the exact ray trace. The main advantage, of this configuration, is that the shearing (direction and magnitude) is constant from the displacement system to the image plane. The direction of the shearing depends on the relative orientation of the prisms. The magnitude of the shearing is proportional to the distance between prisms. The proportionality constant depends on the wedge angle and the material of fabrication of the prisms, and it gives the sensitivity to the displacement of the system. The deviation of the shearing due to the difference between the wedge angles is larger than that the produced by the oblique incidence of the wave-front. The experimental results confirm the theoretical data.     

On the relaxation time of Gauss's continued-fraction map I. The Hilbert space approach (Koopmanism)

It is shown thatU ^*, the adjoint of Koopman's isometric operatorUf(x) =f(Tx) corresponding to the mapTx=x ^–1 (mod 1) of the unit interval, is isomorphic to a symmetric integral operator when restricted to a Hilbert space of holomorphic functionsf This result, also obtained by Babenko in a different setting, allows us to derive new trace formulas. Using generalized Temple's inequalities, we determine the relaxation time of the above system with great accuracy. In contrast to a widespread belief, it appears to be unrelated to the entropy of the mapT.     

大剂量补充微量元素治疗“胃溃疡型腺癌伴广泛转移”一例

阐述了一例胃底溃疡型腺癌伴周边器官淋巴组织广泛转移患者，行“贲门MT术”姑息治疗后，经九个月大剂量多种微量元素制剂补充达到很好的临床效果。     

Elemental Analysis of Phytotherapeutic Products by Inductively Coupled Plasma–Tandem Mass Spectrometry

A procedure for the determination of As, Cd, Cr, Ni, Pb, and V in phytotherapy medicines by inductively coupled plasma–tandem mass spectrometry is reported. The use of tandem mass spectrometry with oxygen into an octopole reaction system at various gas flow rates and the combination of on-mass and mass-shift modes was evaluated. Cadmium, Cr, Ni, and Pb were determined as free atomic ions while As and V were determined as the oxides AsO⁺ and VO⁺ in the same run. Samples were prepared by microwave-assisted digestion with dilute nitric acid and hydrogen peroxide. Two plant-certified reference materials (apple leaves and tomato leaves) were used to check the accuracy. For tandem mass spectrometry with 0.5?mL min^?1 O₂, recoveries in the 85–113% were typically obtained and no statistical differences were observed at the 95% confidence level (t-test) in comparison with the certified values. Using these conditions, the limits of detection for the method were 0.01, 0.0002, 0.008, 0.008, 0.003, and 0.002?µg g^?1 for As, Cd, Cr, Ni, Pb, and V, respectively. The procedure was used for the analysis of four phytotherapic drugs and the determined concentrations were up to 0.168?µg g^?1 As, 0.03?µg g^?1 Cd, 0.82?µg g^?1 Cr, 1.18?µg g^?1 Ni, 0.52?µg g^?1 Pb, and 2.4?µg g^?1 V with average precision values of 8% as the relative standard deviation. The found concentrations were compared with limits proposed in official guidelines and, in most cases, the values were below the maximum limits allowed.     

Determination of selected trace elements in marine biota samples with the application of fast temperature programs and solid sampling continuous source high resolution atomic absorption spectroscopy: method validation

Analytical procedure for the determination of As, Cd, Cu, Ni, Co and Cr in marine biota samples using solid sampling high-resolution continuum source atomic absorption spectrometry (HR CS AAS) and accelerated fast temperature programmes has been developed. Calibration technique based on the use of solid certified reference materials similar to the nature of the analysed sample and statistics of regression analysis were applied. A validation approach in line with the requirements of ISO 17025 standard and Eurachem guidelines was followed. Accordingly, blanks, selectivity, calibration, linearity, working range, trueness, repeatability and reproducibility, limits of detection and quantification and expanded uncertainty for all investigated elements were assessed. The major contributors to the combined uncertainty of the analyte mass fractions were found to be the homogeneity of the samples and the microbalance precision. Traceability to the SI system of units of the obtained with the proposed analytical procedure results was also demonstrated. The potential of the proposed analytical procedure based on solid sampling HR CS AAS technique was demonstrated by direct analysis of marine reference biota samples. Overall, the use of solid sampling HR CS AAS permits obtaining significant advantages for the determination of selected trace elements in marine biota samples, such as straightforward calibration, a high sample throughput, sufficient precision, a suitable limit of detection and reduced risk of analyte loss and contamination.     

主应力迹线的自动绘制

主应力迹线是代表主应力方向的曲线簇。在土木建筑工程中主应力迹线是布筋方向的依据,但是在工程中通常都是徒手或用曲线板近似绘制主应力迹线。作者提出一种新的主应力迹线自动的绘制方法。该方法是根据主应力迹线满足过任意三条等倾线的主应力都可以用二次曲线来描述这一条件,再利用主应力迹线本身所具有的性质列出方程组解算出描述主应力迹线的一元二次方程,然后根据方程描绘出所求的主应力迹线。实验证明这种方法对于工程上进行主应力迹线的绘制很有效。     

工具痕迹鉴定中的光学技术研究

工具痕迹由于形成的原因不同，其表面形成的原因不同，其表面形貌呈现多样性，从尺度范围上，大致可分为两类；一类痕迹尺度范围较大，一般在毫米级以上，可称为宏观痕迹；第二类痕迹尺度范围较小，一般在微米级，可称为微观痕迹，利用光学投影，缩束显微，二维调制图像模数转换及低通滤波去噪算法，小波变换，智能模板相位复原等处理技术。可精确，快速地得到工具痕迹鉴定所需的形貌信息，这成为用于识别，诊断领域中的光学图像处理新技术。本文介绍上述技术特点。并且提供了典型的应用实例。     

原子吸收光谱法测定粽叶中微量元素

用火焰原子吸收光谱法直接测定了粽叶中Fe、Cu、Zn、K、Ca、Na 6种微量元素的含量。结果表明,粽叶中含有丰富的人体必需微量元素。该法简单、准确,回收率在95.0%~105.0%之间,相对标准偏差(RSD)小于2.68%,结果令人满意。