差分拉曼光谱对眼药水塑料瓶的分类研究

目的 建立一种便捷精准无损检验眼药水塑料瓶的方法。方法 使用便携式差分拉曼光谱仪检测33个塑料眼药水瓶，根据获得的各样品数据，包括差分拉曼光谱图的峰位、峰数等对样品进行成分分析，并通过统计分析软件“统计产品与服务解决方案”(SPSS 26.0)对样品进行K均值聚类，利用轮廓系数优选K值。对分类结果中样品数目较多的一类样品进行填料分析，利用皮尔逊相关系数验证分析结果的准确性。结果 样品主要成分为聚乙烯和聚对苯二甲酸乙二醇酯，利用轮廓系数优选K值为2，K均值聚类算法对样品的分类结果与成分分析结果能够相互印证。以聚乙烯类样品为例，根据填料不同可将其分为7组。皮尔逊相关系数计算结果能够证明上述分类分组结果可靠。结论 利用该方法能够准确无损地检测眼药水塑料瓶，并对其进行分类研究。     

What modelling research on supply chain collaboration informs us? Identifying key themes and future directions through a literature review

Although research regarding supply chain collaboration has been increasing, studies reviewing supply chain collaboration remains limited. This review paper categorises supply chain collaboration and identifies different themes in this research field. Articles were collected based on a designed keywords list and specific subject restrictions in citation databases. Text-mining technology and conceptual criteria were used to categorise and screen articles into different categories. Finally, cluster analysis was used to group articles and identify emerging themes. From the year 1999 to 2017, a total of 678 articles regarding supply chain collaboration were found. These were sorted into six categories: levels of collaboration, industries, supply chain stages, company scales, forms/methods of collaboration and typology of article, and into corresponding sub-categories. 380 articles employing modelling approach where collaboration forms the core of analysis were screened for hierarchical cluster analysis, resulting in four clusters: information sharing paradigm, joint decision-making paradigm, resource sharing paradigm and coordinating contract paradigm. Eleven themes were finally identified based on the four clusters. The number of articles in the field of supply chain collaboration shows an increasing trend by year. However, most of the collaborations discussed were still at a low level. It is expected to explore a higher level of collaborations and related themes in future research.     

A comparison of two bibliometric methods for mapping of the research front

Summary This paper builds on previous research concerned with the classification and specialty mapping of research fields. Two methods are put to test in order to decide if significant differences as to mapping results of the research front of a science field occur when compared. The first method was based on document co-citation analysis where papers citing co-citation clusters were assumed to reflect the research front. The second method was bibliographic coupling where likewise citing papers were assumed to reflect the research front. The application of these methods resulted in two different types of aggregations of papers: (1) groups of papers citing clusters of co-cited works and (2) clusters of bibliographically coupled papers. The comparision of the two methods as to mapping results was pursued by matching word profiles of groups of papers citing a particular co-citation cluster with word profiles of clusters of bibliographically coupled papers. Findings suggested that the research front was portrayed in two considerably different ways by the methods applied. It was concluded that the results in this study would support a further comparative study of these methods on a more detailed and qualitative ground. The original data set encompassed 73,379 articles from the fifty most cited environmental science journals listed in Journal Citation Report, science edition downloaded from the Science Citation Index on CD-ROM.     

Gas chromatography

This review of the fundamental developments in gas chromatography (GC) includes articles published from 1996 and 1997 and an occasional citation prior to 1996. The literature was reviewed principally using CA Selects for Gas Chromatography from Chemical Abstracts Service, and some significant articles from late 1997 may be missing from the review. In addition, the online SciSearch Database (Institute for Scientific Information) capability was used to abstract review articles or books. As with the prior recent reviews, emphasis has been given to the identification and discussion of selected developments, rather than a presentation of a comprehensive literature search, now available widely through computer-based resources. During the last two years, several themes emerged from a review of the literature. Multidimensional gas chromatography has undergone transformation encompassing a broad range of activity, including attempts to establish methods using chromatographic principles rather than a totally empirical approach. Another trend noted was a comparatively large effort in chromatographic theory through modeling efforts; these presumably became resurgent with inexpensive and powerful computing tools. Finally, an impressive level of activity was noted through the themes highlighted in this review, and this was particularly true with detectors and field instruments.     

Interior induced fatigue of surface‐strengthened steel under constant and variable loading: Failure mechanism and damage modeling

Pulsating tension tests with constant amplitude (CA) and variable amplitude (VA) were conducted to investigate the interior failure mechanisms of a carburized Cr steel, and a cumulative damage model with the fine granular area (FGA) formation process was proposed in this study. Such a steel represents the continuously descending S‐N (stress‐number of cycles) curve characteristics associated with inclusion‐FGA‐fisheye induced failure even under variable amplitude. Due to crack growth retardations and accelerations resulted from the interaction effect between stepwise resets of the applied stress, the crack morphology under variable amplitude loading is much rougher. The interior failure mechanism was elucidated in combination with the determination of stress intensity factor values at different crack tips. Based on proposed damage model, the agreement between the predicted and experimental results is fairly good within the factor‐of‐two range.     

Homeland security literature in relation to terrorism publications: The source and the response

Summary The literature on Terrorism and National Security (NS), and Homeland Security (HS) presents two sides of a coin: one side demonstrates the problematic nature of terrorism and asks for solutions; the other side tries to find a response and solutions to the problem. It was expected that the NS literature would emanate from the same source material as the HS publications. Analysis of the literature of terrorism, homeland security, and national security on Science Citation Index (SCI) has shown that the material on terrorism and NS stems from the same scientific sources; that is, the Social Sciences. In contrast, the HS scientific literature originates in the exact sciences, engineering, and life and environmental sources. The three kinds of literature have grown remarkably in recent years; however, cross-section search strategy between terrorism and HS studies yields small retrieval sets. This means that few articles both present the problem and propose possible solutions. Currently, HS is on one side of the scholarly arena, and NS and terrorism literature on the other side; they advance mostly in lines parallel to each other, but as the researcher moves from observing the core scientific literature toward the more general material, this state of affairs changes. Another analysis of a multimedia database, WorldCatalog (which indexes mostly books, but also videos and computer materials, both scientific and popular) demonstrates a different trend; the same publications deal with both terrorism and HS counter-terrorism, and suggested solutions.     

考虑水体压缩性的椭圆柱体地震动水压力分析

地震作用下水与柱体结构的相互作用会对结构产生动水压力,该文研究椭圆柱体的地震动水压力。首先,基于椭圆坐标系推导了椭圆柱体地震动水压力的解析解;其次,通过ABAQUS声固耦合方法验证了提出的椭圆柱体地震动水压力的解析解,算例表明两者误差在1%左右;最后,引入无量纲参数数频率、宽深比和长短轴比,定量分析了水体压缩性对地震动水压力的影响。     

Blockchain applications in supply chains,transport and logistics: a systematic review of the literature

This paper presents current academic and industrial frontiers on blockchain application in supply chain, logistics and transport management. We conduct a systematic review of the literature and find four main clusters in the co-citation analysis, namely Technology, Trust, Trade, and Traceability/Transparency. For each cluster, and based on the pool of articles included in it, we apply an inductive method of reasoning and discuss the emerging themes and applications of blockchains for supply chains, logistics and transport. We conclude by discussing the main themes for future research on blockchain technology and its application in industry and services.     

Optical phase retrieval by use of first Born- and Rytov-type approximations

The first Born and Rytov approximations of scattering theory are introduced in their less familiar near-field versions. Two algorithms for phase retrieval based on these approximations are then described. It is shown theoretically and by numerical simulations that, despite the differences in their formulation, the two algorithms deliver fairly similar results when used for optical phase retrieval in the near and intermediate fields. The algorithms are applied to derive explicit solutions to four phase-retrieval problems of practical relevance to quantitative phase-contrast imaging and tomography. An example of successful phase reconstruction by use of the Born-type algorithm with an experimental x-ray image is presented.     

Video retrieval for shot cluster and classification based on key feature set

The proposed content-based video retrieval method in this study uses feature extraction, shot boundary detection, shot noise filter, shot cluster, the key feature set of shot extraction and shot classification. Shot boundary detection is conducted using a weight selection genetic algorithm. In order to verify the video retrieval method in this paper, three video databases were used in the experiment. These video databases are used to verify the shot boundary detection, the shot classification and video retrieval of this study. A series of comparisons and analyses were then conducted using the above video databases. The experiment results showed that the shot boundary detection method exhibits better performance than the other compared methods. Moreover, the video retrieval experiment results showed that the proposed method is able to precisely catch a shot in the search video, and do so with reduced video retrieval time.     

A guide to efficient keyword, sequence and classification search strategies for biopharmaceutical drug-centric patent landscape searches - A human recombinant insulin patent landscape case study

Searching biopharmaceutical drug-related patent information is generally considered to be challenging. In particular, setting up efficient search strategies for comprehensive retrieval of high amounts of patent documents related to processes and methods of use, that achieve a reasonable level of precision, but still remain within a particular search scope. While it is generally accepted that patent information cannot be searched using standardized approaches, it is desirable to have a basic rule set for successful biopharmaceutical drug-related patent information retrieval, particularly facing a steady flow of patent expirations for prominent biologic drugs. The present human recombinant insulin case study shows an assessment of keyword, sequence and classification search strategies for establishing biopharmaceutical drug-centric patent landscapes. The search results of both crude and sophisticated keyword search strategies, as well as of a sequence search strategy, were compared in terms of the key information retrieval quality indicators; the recall and the precision. Through analyses of the relevant retrieved documents, a quality assessment of keyword choice is provided, as well as determining focused IPC and Derwent Manual classification codes and terminology from original patent and Derwent documentation abstract titles. All of which can be used for setting up more efficient search strategies and facilitated document categorization.     

New classification quality estimators for analysis of documentary information: Application to patent analysis and web mapping

The information analysis process includes a cluster analysis or classification step associated with an expert validation of the results. In this paper, we propose new measures of Recall/Precision for estimating the quality of cluster analysis. These measures derive both from the Galois lattice theory and from the Information Retrieval (IR) domain. As opposed to classical measures of inertia, they present the main advantages to be both independent of the classification method and of the difference between the intrinsic dimension of the data and those of the clusters. We present two experiments on the basis of the MultiSOM model, which is an extension of Kohonen's SOM model, as a cluster analysis method. Our first experiment on patent data shows how our measures can be used to compare viewpoint-oriented classification methods, such as MultiSOM, with global cluster analysis method, such as WebSOM. Our second experiment, which takes part in the EICSTES EEC project, is an original Webometrics experiment that combines content and links classification starting from a large non-homogeneous set of web pages. This experiment highlights the fact that break-even points between our different measures of Recall/Precision can be used to determine an optimal number of clusters for web data classification. The content of the clusters obtained when using different break-even points are compared for determining the quality of the resulting maps. This revised version was published online in June 2006 with corrections to the Cover Date.     

Attainable Supersaturation of Superfluid 3He-4He Solutions and the Role of Quantized Vortices

The earlier systematic measurements of attainable supersaturations of superfliud ³ He- ⁴ He solutions depending on temperature and pressure have been continued. The experiments were carried out at continuously varied solution concentration and at constant temperature and pressure. The results obtained are analysed using various models of nucleation in supersaturated liquid solutions. The fast nucleation line which is constructed from experimental results is in strong contrast with the kinetic theory of homogeneous nucleation for supersaturated ³ He- ⁴ He solutions. It is shown that reasonable agreement with experimental results can be obtained assuming that completed centres of nucleation generated on quantized vortices in superfluid liquid are available.     

Stability and mechanical properties of electrochemically prepared conducting polypyrrole films

The stability and mechanical properties of polypyrrolep-toluene sulphonate films prepared under various preparation conditions were studied and are reported here. Relatively high retention of conductivity and flexibility properties in air at room temperature were found for the films. More stable films were produced from propylene carbonate diluent than from acetonitrile and solvent mixtures. Acid treatment caused conductivity to increase and the mechanical properties to decrease slightly. However, both properties decreased dramatically after exposure of the films to sodium hydroxide solution. The effect of solutions containing different vanadium ions was also observed, the films being stable in V³⁺ and V⁴⁺ acid solutions, but unstable in V⁵⁺ solutions. The thermal stability of polypyrrole films grown at different temperatures and from different solvents was considerably high and fairly constant. Anisotropy in the mechanical properties was also observed for the two directions (along and across) within the same plane of the film. Incorporation of the plasticizer, di-iso-butyl phthalate (DIBP) into the films improved the mechanical properties. A high extendable acrylic-polypyrrole composite film was also prepared, capable of straining over 100%.     

Evaluation of J1 and J2 integrals for curved cracks using an enriched boundary element method

This paper introduces an enriched Boundary Element Method in which functions are introduced that are known to model singularities or discontinuities from a priori knowledge of the solution space. Additional fundamental solutions are introduced to solve for the additional unknowns created by enrichment and a numerical integration routine is outlined for the evaluation of strongly singular and hypersingular enriched boundary integrals. The solution of a curved crack in an infinite domain by Muskhelishvili is used to assess the accuracy of the method. Using an appropriate technique to evaluate J₁ and J₂ integrals, it is found that very good agreement with the exact solution is seen with improvements in accuracy over similar FEM implementations.     

An hp‐adaptive finite element method for scattering problems in computational electromagnetics

An hp‐adaptive finite element (FE) approach is presented for a reliable, efficient and accurate solution of 3D electromagnetic scattering problems. The radiation condition in the far field is satisfied automatically by approximation with infinite elements (IE). Near optimal discretizations that can effectively resolve local rapid variations in the scattered field are sought adaptively by mesh refinements blended with graded polynomial enrichments. The p‐enrichments need not be spatially isotropic. The discretization error can be controlled by a self‐adaptive process, which is driven by implicit or explicit a posteriori error estimates. The error may be estimated in the energy norm or in a quantity of interest. A radar cross section (RCS) related linear functional is used in the latter case. Adaptively constructed solutions are compared to pure uniform p approximations. Numerical, highly accurate, and fairly converged solutions for a number of generic problems are given and compared to previously published results. Copyright © 2004 John Wiley & Sons, Ltd.     

Finite deformation finite element analyses of tensile growing crack fields in elastic-plastic material

Finite deformation finite element analyses of plane strain stationary and quasi-statically growing crack fields in fully incompressible elastic-ideally plastic material are reported for small-scale yielding conditions. A principal goal is to determine the differences between solutions of rigorous finite deformation formulation and those of the usual small-displacement-gradient formulation, and thereby assess the validity of the (nearly all) extant studies of ductile crack growth that are based on a small-displacement-gradient formulation. The stationary crack case with a significantly blunted tip is studied first; excellent agreement in stress characteristics at all angles about the crack tip and up to a radius of about three times the crack tip opening displacement is shown between Rice and Johnson's [1] approximate analytical solution and our numerical solution. Outside this radius, the numerical results agree very well with Drugan and Chen's [2] small-displacement-gradient analytical characteristics solution in the region of principal plastic deformation. Thus we identify accurate analytical representations for the stress field throughout the plastic zone of a blunted stationary crack. For the growing crack case, the macroscopic difference in crack tip opening profiles between previous small-displacement-gradient solutions and the present results is shown to be negligible, as is the difference in the stress fields in plastic regions. The stress characteristics again agree very well with analytical results of [2]. The numerical results suggest—in agreement with a recent analytical finite deformation study by Reid and Drugan [3]—that it is the finite geometry changes rather than the additional spin terms in the objective constitutive equation that cause any differences between the small-displacement-gradient and the finite deformation solutions, and that such differences are nearly indistinguishable for growing cracks.     

Validation of Bibliometric Indicators in the Field of Microbiology: A Norwegian Case Study

This paper addresses two related issues regarding the validity of bibliometric indicators for the assessment of national performance within a particular scientific field. Firstly, the representativeness of a journal-based subject classification; and secondly, the completeness of the database coverage. Norwegian publishing in microbiology was chosen as a case, using the standard ISI-product National Science Indicators on Diskette (NSIOD) as a source database. By applying an "author-gated" retrieval procedure, we found that only 41 percent of all publications in NSIOD-indexed journals, expert-classified as microbiology, were included under the NSIOD-category Microbiology. Thus, the set of defining core journals only is clearly not sufficient to delineate this complex biomedical field. Furthermore, a subclassification of the articles into different subdisciplines of microbiology revealed systematic differences with respect to representation in NSIOD's Microbiology field; fish microbiology and medical microbiology are particularly underrepresented.In a second step, the individual publication lists from a sample of Norwegian microbiologists were collected and compared with the publications by the same authors, retrieved bibliometrically. The results showed that a large majority (94%) of the international scientific production in Norwegian microbiology was covered by the database NSIOD. Thus, insufficient subfield delineation, and not lack of coverage, appeared to be the main methodological problem in the bibliometric analysis of microbiology.     

Cable coupling of detector and preamplifier as an alternative design of radiation hard electronics

It is shown that cable coupling between a detector of large capacitance and a fast amplifier does not degrade noise performance. The dependences of equivalent noise charge (ENC) on cable length, detector capacitance and output pulse duration are presented. There is a fairly good agreement between experiment and calculation.