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71.
将混沌理论应用到弱信号的测量中已获得了初步的成功,降低因电子开关的频繁通断而引起的测量噪声是目前需要解决的主要问题.提出了一种新的混沌测量电路设计方法,它利用DSP仿真电子开关,与已有的测量方法相比,具有更好的线性度和更小的误差.给出了新方法与目前已有方法的测量结果对比,表明该方法具有更良好的前景. 相似文献
72.
Aurora Valdez-Fragoso Hugo M??jica-Paz Jorge Welti-Chanes J. Antonio Torres 《Food and Bioprocess Technology》2011,4(6):986-995
Consumers demand, in addition to excellent eating quality, high standards of safety and nutrition in ready-to-eat food. This
requires a continuous improvement in conventional processing technologies and the development of new alternatives. Prevailing
technologies such as thermal processing can cause extensive and undesirable chemical changes in food composition while minimal
processing strategies cannot eliminate all microbial pathogens. This review focuses on pressure-assisted thermal processing,
a new alternative for shelf-stable foods. Its implementation requires an analysis of reaction kinetics at high pressure and
elevated temperature. Acceleration of the inactivation of bacterial spores by the synergistic effect of pressure and temperature
is expected to allow processing at lower temperature, shorter process time, or a combination of both. Therefore, thermal degradation
of quality is expected to be lower than that of conventional thermal processes. However, few studies have focused on the effect
of the conditions required for the inactivation of bacterial spores on the kinetics of chemical reactions degrading food quality,
particularly at the high temperatures required for the processing of low-acid foods. 相似文献
73.
Differential scanning calorimetry (DSC) was used to investigate the protein denaturation characteristics of pork muscles from
four quality groups namely RFN (red, firm, and non-exudative), RSE (red, soft, and exudative), PFN (pale, firm, and non-exudative),
and PSE (pale, soft, and exudative). The thermograms indicated three endothermic peaks between 45°C to 90°C, corresponding
to denaturation of myosin (peak I), sarcoplasmic proteins (peak II), and actin (peak III). The myosin peak was much reduced
in PSE samples, while the actin peak remained almost identical in all groups. RFN and RSE samples were found to have very
similar protein denaturation characteristics and were not significantly different in their thermodynamic protein denaturation
parameters. PFN samples showed similar myofibrilar protein denaturation but significantly different sarcoplasmic protein denaturation
characteristics compared to normal (RFN) samples according to their DSC thermograms. Based on these findings, it was suggested
that the pale color in PFN pork is linked to sarcoplasmic protein denaturation. 相似文献
74.
Ana Caroline Lustosa de Melo Carvalho Thiago de Sousa Fonseca Marcos Carlos de Mattos Maria da Concei??o Ferreira de Oliveira Telma Leda Gomes de Lemos Francesco Molinari Diego Romano Immacolata Serra 《International journal of molecular sciences》2015,16(12):29682-29716
Biocatalysis offers an alternative approach to conventional chemical processes for the production of single-isomer chiral drugs. Lipases are one of the most used enzymes in the synthesis of enantiomerically pure intermediates. The use of this type of enzyme is mainly due to the characteristics of their regio-, chemo- and enantioselectivity in the resolution process of racemates, without the use of cofactors. Moreover, this class of enzymes has generally excellent stability in the presence of organic solvents, facilitating the solubility of the organic substrate to be modified. Further improvements and new applications have been achieved in the syntheses of biologically active compounds catalyzed by lipases. This review critically reports and discusses examples from recent literature (2007 to mid-2015), concerning the synthesis of enantiomerically pure active pharmaceutical ingredients (APIs) and their intermediates in which the key step involves the action of a lipase. 相似文献
75.
Heng?Li Tse-Hsun??Chen Weiyi?Shang Ahmed?E.?Hassan 《Empirical Software Engineering》2018,23(5):2655-2694
Software developers insert logging statements in their source code to record important runtime information; such logged information is valuable for understanding system usage in production and debugging system failures. However, providing proper logging statements remains a manual and challenging task. Missing an important logging statement may increase the difficulty of debugging a system failure, while too much logging can increase system overhead and mask the truly important information. Intuitively, the actual functionality of a software component is one of the major drivers behind logging decisions. For instance, a method maintaining network communications is more likely to be logged than getters and setters. In this paper, we used automatically-computed topics of a code snippet to approximate the functionality of a code snippet. We studied the relationship between the topics of a code snippet and the likelihood of a code snippet being logged (i.e., to contain a logging statement). Our driving intuition is that certain topics in the source code are more likely to be logged than others. To validate our intuition, we conducted a case study on six open source systems, and we found that i) there exists a small number of “log-intensive” topics that are more likely to be logged than other topics; ii) each pair of the studied systems share 12% to 62% common topics, and the likelihood of logging such common topics has a statistically significant correlation of 0.35 to 0.62 among all the studied systems; and iii) our topic-based metrics help explain the likelihood of a code snippet being logged, providing an improvement of 3% to 13% on AUC and 6% to 16% on balanced accuracy over a set of baseline metrics that capture the structural information of a code snippet. Our findings highlight that topics contain valuable information that can help guide and drive developers’ logging decisions. 相似文献
76.
Ale??Popovi?Email authorView authors OrcID profile Ray?Hackney Rana?Tassabehji Mauro?Castelli 《Information Systems Frontiers》2018,20(2):209-222
Big Data Analytics (BDA) is an emerging phenomenon with the reported potential to transform how firms manage and enhance high value businesses performance. The purpose of our study is to investigate the impact of BDA on operations management in the manufacturing sector, which is an acknowledged infrequently researched context. Using an interpretive qualitative approach, this empirical study leverages a comparative case study of three manufacturing companies with varying levels of BDA usage (experimental, moderate and heavy). The information technology (IT) business value literature and a resource based view informed the development of our research propositions and the conceptual framework that illuminated the relationships between BDA capability and organizational readiness and design. Our findings indicate that BDA capability (in terms of data sourcing, access, integration, and delivery, analytical capabilities, and people’s expertise) along with organizational readiness and design factors (such as BDA strategy, top management support, financial resources, and employee engagement) facilitated better utilization of BDA in manufacturing decision making, and thus enhanced high value business performance. Our results also highlight important managerial implications related to the impact of BDA on empowerment of employees, and how BDA can be integrated into organizations to augment rather than replace management capabilities. Our research will be of benefit to academics and practitioners in further aiding our understanding of BDA utilization in transforming operations and production management. It adds to the body of limited empirically based knowledge by highlighting the real business value resulting from applying BDA in manufacturing firms and thus encouraging beneficial economic societal changes. 相似文献
77.
近年来建设的高坝大库越来越多,下泄低温水的影响日趋严重,对水库下泄低温水的影响和减缓措施的研究应给予关注和不断加强。本文是对已投入运行的漫湾水电站库区的水温结构进行研究。通过2004年2月对漫湾水库进行水温分布现场观测,并辅以三维数值模型计算,获得了较详细的水温分布成果。研究结果表明,漫湾水库的水温结构既不属于典型分层型又不属于完全混合型,应属于局部分层型或过渡型。该成果对于流域梯级水电开发对水环境的影响研究,具有一定的代表性,可用于类比分析研究与漫湾水库条件类似的其它水电站。 相似文献
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