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21.
N. A. Khan W. E. Tolberg D. H. Wheeler W. O. Lundberg 《Journal of the American Oil Chemists' Society》1954,31(11):460-466
- It has been confirmed that the principal products formed in the oxidation of methyl oleate by oxygen under a variety of conditions are predominantlytrans hydroperoxides. However no inversion of the double bond occurs in unoxidized oleate. Hence the conversion ofcis totrans double bonds and peroxide formation occur together in the same molecules.
- The autoxidation of methyl linoleate at low temperature yields predominantlycis,trans conjugated hydroperoxides. Autoxidation at 25°C., oxidation catalyzed by visible light, or ultraviolet light and copper soap catalyzed oxidation at temperatures appreciably above 0°C., lead to the formation primarily oftrans,trans conjugated hydroperoxides. The inversion of the second double bond in this case appears to be independent of the peroxide-forming reactions.
- The photochlorophyll oxidation of methyl linoleate leads to the formation of some unconjugated hydroperoxides, some of which containtrans double bonds.
- Under all of the conditions employed in the present investigation, the oxidation of methyl oleate and linoleate led primarily to the formation of monomeric peroxides which retained most of the unsaturation of the parent compound.
22.
Said Ghaout Alain Louveaux Anne Marie Mainguet Max Deschamps Youssef Rahal 《Journal of chemical ecology》1991,17(8):1499-1515
A field study of the food eaten by solitary desert locusts was carried out in a winter breeding area in Mauritania. The food eaten, determined by the plant epidermis found in fecal pellets, was compared to the plant's availability in the habitat.Schouwia purpurea, well represented in the diets, was dominant at the study site. Adults had a preference forTribulus terrester. Growth and feeding on these two plants were compared. The high water content ofS. purpurea leaves limited the dry matter eaten and slowed down growth. Glucosinolates were separated and quantified by gas chromatography. There are 132mol/g dry matter in green leaves. In multiple choice tests, with paper disks, glucosinolate extracts were phagostimulant at a low concentration (21mol/g dry matter) and repulsive at a higher one (214mol/ g dry matter). Biting behavior onS. purpurea was recorded and analyzed on video. The importance ofSchouwia purpurea in desert locust habitats and its defenses is discussed. 相似文献
23.
Kinetics of alkaline hydrolysis of mica-acrylonitrile graft copolymers was studied. The dependence of alkali concentration and the time of hydrolysis on the degree of saponification was determined. Chemical and spectroscopical techniques were used to determine the mechanism of hydrolysis. 相似文献
24.
Summary The rates of polymerization of alpha and beta eleostearates agree with second order kinetics, as would be expected for a bimolecular
Diels-Alder addition. The all-trans, beta isomer reacts faster than thecis, trans, trans alpha isomer, in agreement with knowncis, trans effects on diene activity.
The polymerization of normal linoleate follows an apparent first order reaction. It is suggested that conjugation is the slow
rate determining monomolecular reaction, as has been proposed for the non-conjugated linoleate isomers.
Paper No. 177, Journal Series, Research Laboratories, General Mills Inc. Presented at the 28th fall (Paul Bunyan) meeting
of the American Oil Chemists’' Society, Oct. 12, 1954, Minneapolis, Minn. 相似文献
25.
One of today's grand societal challenges is to replace the current ‘take‐make‐waste’ economic model with a circular economic model that allows a gradual decoupling of economic activities from the consumption of finite virgin resources. While circular economy (CE) scholars have long lauded digital technologies such as sensors, distributed ledgers, or platforms as key enablers, our own community has not fully explored the potentials of information systems (IS) for a CE. Considering recent technological advances in software and hardware and our history of helping address wicked challenges, we believe the time is ripe to mobilise IS scholarship for a CE. Our findings from an interdisciplinary literature review show that research has primarily examined IS potentials for increasing efficiency of isolated intra‐organisational processes while neglecting the larger sustainability potential of IS to establish circular material flows—that is, slow down and close material loops across entire product lifecycles. In response, we propose directions for IS research that develop our knowledge of how IS can help understand and enact circular material flows to intensify and extend use of products and components and recycle waste materials. Our directions offer pathways to building and evaluating the problem‐solution pairing that could characterise a prolific CE‐IS relationship. 相似文献
26.
Lina Yao Quan Z. Sheng Anne H. H. Ngu Byron J. Gao Xue Li Sen Wang 《World Wide Web》2016,19(6):1125-1149
Automatic annotation is an essential technique for effectively handling and organizing Web objects (e.g., Web pages), which have experienced an unprecedented growth over the last few years. Automatic annotation is usually formulated as a multi-label classification problem. Unfortunately, labeled data are often time-consuming and expensive to obtain. Web data also accommodate much richer feature space. This calls for new semi-supervised approaches that are less demanding on labeled data to be effective in classification. In this paper, we propose a graph-based semi-supervised learning approach that leverages random walks and ? 1 sparse reconstruction on a mixed object-label graph with both attribute and structure information for effective multi-label classification. The mixed graph contains an object-affinity subgraph, a label-correlation subgraph, and object-label edges with adaptive weight assignments indicating the assignment relationships. The object-affinity subgraph is constructed using ? 1 sparse graph reconstruction with extracted structural meta-text, while the label-correlation subgraph captures pairwise correlations among labels via linear combination of their co-occurrence similarity and kernel-based similarity. A random walk with adaptive weight assignment is then performed on the constructed mixed graph to infer probabilistic assignment relationships between labels and objects. Extensive experiments on real Yahoo! Web datasets demonstrate the effectiveness of our approach. 相似文献
27.
Johnny Jiung-Yee Lee Taylor Randall Paul Jen-Hwa Hu Anne Wu 《Information Systems Management》2013,30(4):340-352
Prior research has documented that IT investment increases market returns. Economic theories predict such returns to be recognized in accounting profitability; this relationship remains ambiguous in prior literature. We reexamine the relationship between IT investment and firm profitability. Our approach is unique in that we examine complementarities between distinct IT components. We document that a firm’s investments in IT components exhibit different impacts on its profitability conditional on the level of investments in complementary components. 相似文献
28.
Dynamic composition and optimization of Web services 总被引:1,自引:0,他引:1
Liangzhao Zeng Anne H. H. Ngu Boualem Benatallah Rodion Podorozhny Hui Lei 《Distributed and Parallel Databases》2008,24(1-3):45-72
Process-based composition of Web services has recently gained significant momentum for the implementation of inter-organizational business collaborations. In this approach, individual Web services are choreographed into composite Web services whose integration logics are expressed as composition schema. In this paper, we present a goal-directed composition framework to support on-demand business processes. Composition schemas are generated incrementally by a rule inference mechanism based on a set of domain-specific business rules enriched with contextual information. In situations where multiple composition schemas can achieve the same goal, we must first select the best composition schema, wherein the best schema is selected based on the combination of its estimated execution quality and schema quality. By coupling the dynamic schema creation and quality-driven selection strategy in one single framework, we ensure that the generated composite service comply with business rules when being adapted and optimized. 相似文献
29.
Timo Baur Rebecca Breu Tibor Kálmán Tobias Lindinger Anne Milbert Gevorg Poghosyan Helmut Reiser Mathilde Romberg 《Journal of Grid Computing》2009,7(3):319-333
In many Grid infrastructures different kinds of information services are in use, which utilize different incompatible data structures and interfaces to encode and provide their data. Homogeneous monitoring of these infrastructures with the monitoring data being accessible everywhere independently of the middleware which provided it, is the basis for a consistent status reporting on the Grids’ resources and services. Thus, interoperability or interoperation between the different information services in a heterogeneous Grid infrastructure is required. Monitoring data must contain the identity of the affected Virtual Organization (VO) so that it can be related to the resources and services the VO has allocated to enable VO-specific information provision. This paper describes a distributed architecture for an interoperable information service, which combines data unification and categorization with policies for VO membership, VO resource management and data transformations. This service builds the basis for an integrated and interoperating monitoring of Grids, which provide their data to more than one VO and utilize heterogeneous information services. 相似文献
30.
Roldão Luis de Charette Raoul Verroust-Blondet Anne 《International Journal of Computer Vision》2022,130(8):1978-2005
International Journal of Computer Vision - Semantic scene completion (SSC) aims to jointly estimate the complete geometry and semantics of a scene, assuming partial sparse input. In the last years... 相似文献