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91.
92.
Stuart M. Barlow Anthony P. Bimbo Eric L. Miller Snorri Thorisson D. E. Walters 《Journal of the American Oil Chemists' Society》1997,74(9):1077-1083
Twenty-two laboratories participated in a collaborative test to determine the iodine value (IV) of eight samples of fish oil
(four with IV<150, four with IV>150) with either carbon tetrachloride (AOCS Official Method Cd 1–25) or cyclohexane (AOCS
Recommended Practice Cd 1b-87) as solvent and either 1 or 2 h of reaction time. Laboratories received coded duplicate samples
(hidden duplicates) and carried out duplicate determinations on each oil by each solvent-time combination (open duplicates).
Replacing carbon tetrachloride with cyclohexane resulted in a lower IV (P<0.001). The decrease averaged 1.6 IV units for low-IV oils and 3.8 IV units for high-IV oils; this difference in response
of 2.2 IV units between low- and high-IV oils was significant (P<0.001). Increasing the reaction time had a relatively small effect (0.34±0.18). There was no interaction of reaction time
with solvent or oil type. Cyclohexane caused emulsions, which made it difficult to titrate residual iodine and thus increased
the variability of the determination. The repeatability standard deviations (s
r
), based on hidden duplicates, for 1-h reaction time with carbon tetrachloride and cyclohexane were 2.17 and 3.35, respectively.
The corresponding reproducibility standard deviations were 2.73 and 4.53. 相似文献
93.
94.
95.
《自动化学报》2014,(11)
A linear transformation is proposed to deal with the consensus problem of high-order linear multi-agent systems(LMASs).In virtue of the linear transformation, the consensus problem is equivalently translated into a partial stability problem. We discuss three issues of the LMASs under a generalized linear protocol: 1) to find criteria of consensus convergence; 2) to calculate consensus function; 3) to design gain matrices in the linear consensus protocol. Precisely, we provide a necessary and sufficient criterion of consensus convergence in terms of Hurwitz stability of a matrix and give an analytical expression of the consensus function. In addition, we set up a relation between the gain matrices in the protocol and the convergence time and consensus accuracy of the agents, and then design the gain matrices with respect to a pre-specified convergence time and a required consensus accuracy. 相似文献
96.
Soybean oil (900 g) was heated by deep frying at 200°C for 1 h with the addition of 0, 50, 100, 150 and 200 mL water, and
then stored at 55°C for 26 weeks. Soybean oil, corn oil and lard were heated by stir frying and then stored at 55°C for 30
weeks. The volatiles and peroxide values of these samples were monitored. All samples contained aldehydes as major volatiles.
During heating and storage, total volatiles increased 260-1100-fold. However, aldehyde content decreased from 62–87% to 47–67%,
while volatile acid content increased from 1–6% to 12–33%; especially hexanoic acid which increased to 26–350 ppm in the oils
after the storage period was completed. Water addition to the oils heated by deep frying tended to retard the formation of
volatile compounds. The total amount of volatile constituents of lard heated by stir frying increased more during storage
than that of corn oil or soybean oil. Peroxide values did not reflect the changes of volatile content in the samples. 相似文献
97.
Oxidative stability of high-fatty acid rice bran oil at different stages of refining 总被引:2,自引:0,他引:2
The contents of natural antioxidants and the oxidative stability of rice bran oils at different refining steps were determined.
Tocopherols and oryzanols were constant in crude and degummed oils but decreased in alkali-refined, bleached and deodorized
oils. The process of degumming, alkali-refining, bleaching and deodorization removed 34% of the tocopherols and 51% of the
oryzanols. During storage of deodorized oil for 7 wk, 34% of the tocopherols and 19% of the oryzanols were lost. The maximum
weight gain, peroxide value and anisidine value were obtained from alkali-refined oil during storage. The order of oxidation
stability was crude ≥ degummed > bleached = deodorized > alkali-refined oil. 相似文献
98.
This paper introduces a certain graphical coalitional game where the internal topology of the coalition depends on a prescribed communication graph structure among the agents. The game Value Function is required to satisfy four Axioms of Value. These axioms make it possible to provide a refined study of coalition structures on graphs by defining a formal graphical game and by assigning a Positional Advantage, based on the Shapley value, to each agent in a coalition based on its connectivity properties within the graph. Using the Axioms of Value the graphical coalitional game can be shown to satisfy properties such as convexity, fairness, cohesiveness, and full cooperativeness. Three measures of the contributions of agents to a coalition are introduced: marginal contribution, competitive contribution, and altruistic contribution. The mathematical framework given here is used to establish results regarding the dependence of these three types of contributions on the graph topology, and changes in these contributions due to changes in graph topology. Based on these different contributions, three online sequential decision games are defined on top of the graphical coalitional game, and the stable graphs under each of these sequential decision games are studied. It is shown that the stable graphs under the objective of maximizing the marginal contribution are any connected graph. The stable graphs under the objective of maximizing the competitive contribution are the complete graph. The stable graphs under the objective of maximizing the altruistic contribution are any tree. 相似文献
99.
表层腐殖层土壤是大自然赐予人类的难以再生的宝贵财富。表土具有较高的经济生产力,属于难以再生的资源,是生态建设的基础。从资源、生态方面考虑,生产建设项目进行表土剥离保护利用十分必要。本文分析了巴彦淖尔市表土剥离存在的主要问题,提出了表土剥离利用主要措施及有关技术要求。 相似文献
100.
ExPosition is a new comprehensive R package providing crisp graphics and implementing multivariate analysis methods based on the singular value decomposition (svd). The core techniques implemented in ExPosition are: principal components analysis, (metric) multidimensional scaling, correspondence analysis, and several of their recent extensions such as barycentric discriminant analyses (e.g., discriminant correspondence analysis), multi-table analyses (e.g.,multiple factor analysis, Statis, and distatis), and non-parametric resampling techniques (e.g., permutation and bootstrap). Several examples highlight the major differences between ExPosition and similar packages. Finally, the future directions of ExPosition are discussed. 相似文献