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排序方式: 共有1028条查询结果,搜索用时 15 毫秒
61.
张建军 《中国材料科技与设备》2007,4(6):112-113
本文主要讨论奥港联芬兰VAIF烧结专家系统(SPSS)与马钢第三炼铁总厂烧结控制系统(AB控制器)OPC通讯方式的优化和改进。该方案中包括系统结构和软硬件组成,通过改进,使得烧结专家系统结构更加合理,通讯质量明显提高。为AB系统过程控制系统提供一套较好的解决思路。 相似文献
62.
Sophie Couture Thomas G. Brown Jacques Tremblay N.M.K. Ng Ying Kin Marie Claude Ouimet Louise Nadeau 《Accident; analysis and prevention》2010,42(1):307-312
A first driving while impaired by alcohol (DWI) conviction is a key opportunity to identify offenders who are at high risk for recidivism. Detection of alcohol use disorder (AUD) is a major target of current DWI assessments. However, offenders frequently underreport their alcohol consumption, and use of biomarkers has been proposed as a more objective indicator. Among the best established are aspartate aminotranferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT), mean corpuscular red blood cell volume (MCV), carbohydrate-deficient transferrin (CDT), and thiamine. To our knowledge, no research has directly verified whether AUD biomarkers predict DWI recidivism status. Using a cross-sectional design, this study tested three hypotheses related to the utility of biomarkers in DWI assessment.
Hypotheses
(1) DWI recidivists possess biomarkers indicative of greater prevalence of AUD compared to first-time offenders; (2) multiple biomarkers better differentiate first-time offenders from recidivists compared to individual biomarkers; and (3) biomarkers add significantly to the prediction of recidivism over and above psychosocial questionnaires.Methods
First-time offenders (n = 49) and recidivists (n = 95) participated in the study. In addition to self-reported information on sociodemographic and driving characteristics, data from several AUD questionnaires were gathered: Michigan Alcoholism Screening Test, Alcohol Use Disorders Identification Test, Composite International Diagnostic Interview, and Timeline Follow-Back. Blood samples were collected to measure AST, ALT, GGT, MCV, CDT, and thiamine.Results
AUD biomarkers, taken individually or in combination, did not indicate that recidivists had more frequent AUD compared to first-time offenders. Also, they failed to significantly differentiate first-time offenders from recidivists or predict recidivism status. Finally, the superiority of biomarkers over psychosocial AUD questionnaires was not supported in the laboratory setting.Conclusion
The present findings suggest that biomarkers of chronic patterns of heavy drinking may not be adequate to capture the multiple processes that appear to promote recidivism (e.g., binge drinking, other risky behavioural and personality features). Despite their objectivity, caution is warranted in the interpretation of a positive score on these biomarkers in DWI assessment. Longitudinal research is needed to more comprehensively explore the relationship between positive biomarkers in first-time offenders and their risk of becoming recidivists. 相似文献63.
64.
Thermal conductivity measurements on the vapors of methanol, ethanol, isopropanol, and t-butanol are reported as a function of temperature (330–420 K) and pressure (11–240 kPa). The thermal conductivity versus pressure isotherms for all four alcohols exhibit upward curvatures at the lower temperatures and nearly linear increases at higher temperatures. This behavior is indicative of a dimeric species and one or more polymeric clusters in the vapor in addition to the monomer. Quantum mechanical calculations have indicated that tetramers are the most likely polymeric species. Detailed analyses of the data provide thermodynamic data (H,S) for the dimerization and tetramerization reactions and show interesting correlations with the size of the monomer unit. 相似文献
65.
Ramesh Borade Oliver Bruemmer Anil Guram Howard Turner Xiao Wang 《Chemical Engineering Communications》2013,200(12):1621-1635
High-throughput synthesis and screening of libraries consisting of redox zeolites and molecular sieves have been developed for the selective oxidation of 2-butyl-5-hydroxymethyl-imidazole to the corresponding aldehyde in the liquid phase. Libraries consisting of 96 catalysts were prepared and screened for catalytic activity using high-throughput software, robotics, reactor, and screening technologies. The integrated synthesis and screening workflow allowed ~5000 samples to be screened in less than one month. Promising hits identified in the high-throughput primary screens were successfully scaled up and optimized in conventional laboratory test units. Best results have been obtained with doubly or triply doped mesoporous sieves containing both an impregnated and framework-substituted metal. PtBi-doped framework-substituted V-MCM-41 redox mesoporous sieves were found to be efficient catalysts for aerobic oxidation under relatively mild reaction conditions (100–150°C, 15–400 psi air, 4–10 h reaction time). MIBK/H2O/t-BuOH mixtures were identified as efficient solvent systems for this reaction. Isolated yields confirm high selectivities of more than 90% with quantitative conversions. Spent catalysts were shown to be fully regenerable by high temperature calcination in air. 相似文献
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工厂车间通风、空调系统的运行效果会直接影响室内空气的成分和性质,进而影响产品质量和生产效率.本文对河南轮胎厂子午胎车间通风、空调系统存在的问题进行了分析和探讨,并结合现场测试结果,提出了优化和改造方案,经过运行调试,达到了满意的效果. 相似文献
68.
69.
陈火文 《可编程控制器与工厂自动化(PLC FA)》2005,(7):51-53
本文着重介绍了利用永宏FBs系列可编程控制器实现自动三维弯管机控制系统的设计。重点阐述了该系统的工作原理、硬件结构和软件设计,实践证明该弯管机系统实用性强、使用方便。 相似文献
70.