ICP—AES摄谱法的光谱分析检出限测定方法

本文分析了五种摄谱法检出限的测定方法,总结了其优缺点和可行性,并进行了实验,在比较的基础上。作者认为采用log(I_0/I_B)/-log C_0作图法,无论是从理论上,还是从实践上,都较其余四种方法优越,是一种值得推荐的方法。     

单缝石英管-巯基棉富集火焰原子吸收法测定水中微量硒

本文使用单缝石英管和巯基棉富集,两者结合的方法,提高火焰原子吸收法的灵敏度以测定水中硒的含量。回收率为95～104%,变异系数为3.0%,灵敏度可提高2～3个数量级,     

A model of grain refinement and strengthening of Al alloys due to cold severe plastic deformation

This paper presents a model which quantitatively predicts grain refinement and strength/hardness of Al alloys after very high levels of cold deformation through processes including cold rolling, equal channel angular pressing (ECAP), multiple forging (MF), accumulative roll bonding (ARB) and embossing. The model deals with materials in which plastic deformation is exclusively due to dislocation movement within grains, which is in good approximation the case for many metallic alloys at low temperature, for instance aluminium alloys. In the early stages of deformation, the generated dislocations are stored in grains and contribute to overall strength. With increase in strain, excess dislocations form and/or move to new cell walls/grain boundaries and grains are refined. We examine this model using both our own data as well as the data in the literature. It is shown that grain size and strength/hardness are predicted to a good accuracy.     

Robust automatic facial expression detection method based on sparse representation plus LBP map

Recently the sparse representation based classification (SRC) is successfully used to automatically recognize facial expression, well-known for its ability to solve occlusion and corruption problems. The results of those methods which using different features conjunction with SRC framework show state of the art performance on clean or noised facial expression images. Therefore, the role of feature extraction for SRC framework will greatly affect the success of facial expression recognition (FER). In this paper, we select a new feature which called LBP map. This feature is generated using local binary pattern (LBP) operator. It is not only robust to gray-scale variation, but also extracts sufficient texture information for SRC to deal with FER problem. Then we proposed a new method using the LBP map conjunction with the SRC framework. Firstly, we compared our method with state of the art published work. Then experiments on the Cohn–Kanade database show that the LBP map + SRC can reach the highest accuracy with the lowest time-consuming on clean face images than those methods which use different features such as raw image, Downsample image, Eigenfaces, Laplacianfaces and Gabor conjunction with SRC. We also experiment the LBP map + SRC to recognize face image with partial occluded and corrupted, the result shows that this method is more robust to occlusion and corruption than existing methods based on SRC framework.     

A hierarchical feature graph matching method for recognition of complex human activities

Complex human activities in natural videos are often composed of several atomic-level actions organized hierarchically. We should not only consider the appearance variability of these action units, but also model the spatiotemporal relationships between them when recognizing such high-level complex activities. In this paper, we focus on the problem of recognition of complex human activities in an example-based video retrieval framework and propose a new method based on hierarchical feature-graph matching. A video depicting an activity is represented as a high-level feature graph (HLFG), and each node of the HLFG is a mid-level feature graph (MLFG) constructed on a local collection of spatiotemporal interest points. MLFG, the first level of our two-level graph structure, describes the local feature contents and spatiotemporal arrangements of interest points. HLFG, the second level, describes the appearance variability and spatiotemporal arrangements of atomic-level actions in a way. Final recognition is accomplished by matching the HLFGs of the query and test videos, and matching two HLFGs involves matching the MLFGs between them. We use an efficient spectral method to solve these two graph-matching problems. Our method does not require any preprocessing and gives reasonable results with even a small number of query examples. We evaluate our approach with one publicly available complex human activity dataset and achieve results comparable to other systems that have studied this problem.     

Ξ型三能级原子玻色-爱因斯坦凝聚体单模光场系统中双模原子激光的压缩性质

研究了Ξ型三能级原子玻色-爱因斯坦凝聚体单模光场系统中双模原子激光的压缩性质.结果表明:双模原子激光能被周期性压缩,并且具有量子Rabi振荡和崩塌-回复现象两种形式的振荡.最大压缩深度和崩塌-回复振荡频率主要依赖于光场与原子间相互作用强度,量子Rabi振荡频率主要由光场圆频率决定.     

SiC过渡层制备温度对碳化硅/氟化类金刚石复合薄膜血液相容性的影响

以316L不锈钢为基底,SiC晶体为靶材,Ar为源气体,采用磁控溅射法在不同温度下制备出系列SiC过渡层.然后以高纯石墨作靶,Ar和CHF_3为源气体,在同一工艺条件下再续镀一层氟化类金刚石(F-DLC)薄膜,形成SiC/F-DLC复合薄膜.研究表明,相比于F-DLC薄膜,复合薄膜的附着力显著增加,血液相容性明显改善.通过样品的拉曼和红外光谱分析了不同温度下制备的SiC过渡层以及复合薄膜结构的演变.结果表明,控制SiC过渡层制备温度可以有效调制过渡层中C=C键的比例以及—C—C—不饱和键的密度,复合薄膜中保留较高比例的芳香环式结构以及合适的F/C比是薄膜的血液相容性得以进一步改善的原因,SiC过渡层制备温度控制在500℃左右效果尤为明显.SiC薄膜和F-DLC两种薄膜的界面处形成一定比例的Si—C键和C=C键是导致复合薄膜附着力显著上升的直接原因.适当条件下在316L不锈钢和F-DLC薄膜之间增加SiC过渡层对于增强薄膜的附着力、改善其血液相容性是可行、有效的.     

A ruthenium(II) complex with a methylated polypyridine ligand: synthesis,DNA binding,and antiproliferation activity

Transition Metal Chemistry - A ruthenium polypyridine complex, [Ru(mptpy)(Mmptpy)Cl][PF6]2 (Ru1, mptpy?=?4-(4-methylphenyl)-2,2′,6′,2″-mptpyridine,...     

Essential oil extracted from leaf of Phoebe bournei (Hemsl.) yang: chemical constituents,antitumor, antibacterial,hypoglycemic activities

Abstract

The essential oil were extracted from the leaf of Phoebe bournei (Hemsl.) Yang by a hydrothermal method and then analyzed by gas chromatography–mass spectrometry. The leaf oil mainly included α-copaene (5.44%), α-muurolene (7.32%), δ-cadinene (11.44%), 1s-calamenene (5.18%). Phoebe bournei (Hemsl.) Yang leaf essential oil had significant inhibitory activity against Epidermophyton floccosum and Microsporum gypseum, the potential antitumor activity towards leukemia, breast, and colon cancer cell lines was good. Phoebe bournei (Hemsl.) Yang leaf essential oil had weaker activity on the four tested bacteria, it exhibited a certain role in promoting glucose uptake by adipocytes.     

Complete 1H NMR spectral analysis of ten chemical markers of Ginkgo biloba

The complete and unambiguous ¹H NMR assignments of ten marker constituents of Ginkgo biloba are described. The comprehensive ¹H NMR profiles (fingerprints) of ginkgolide A, ginkgolide B, ginkgolide C, ginkgolide J, bilobalide, quercetin, kaempferol, isorhamnetin, isoquercetin, and rutin in DMSO‐d₆ were obtained through the examination of 1D ¹H NMR and 2D ¹H,¹H‐COSY data, in combination with ¹H iterative full spin analysis (HiFSA). The computational analysis of discrete spin systems allowed a detailed characterization of all the ¹H NMR signals in terms of chemical shifts (δ_H) and spin‐spin coupling constants (J_HH), regardless of signal overlap and higher order coupling effects. The capability of the HiFSA‐generated ¹H fingerprints to reproduce experimental ¹H NMR spectra at different field strengths was also evaluated. As a result of this analysis, a revised set of ¹H NMR parameters for all ten phytoconstituents was assembled. Furthermore, precise ¹H NMR assignments of the sugar moieties of isoquercetin and rutin are reported for the first time. Copyright © 2012 John Wiley & Sons, Ltd.