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1.
张光宇  刘鑫 《山西化工》2011,31(3):49-51
通过对石油化工企业工程资料管理工作特点的分析,采取Flex技术实现了对各种资料的统一管理和灵活检索、展示,满足了工程资料管理数据量大、多方位检索以及安全性等方面的需求,实现了工程资料的高效管理。  相似文献   

2.
关联规则的数据挖掘在高校图书馆系统中的应用   总被引:1,自引:0,他引:1  
简要介绍了关联规则的数据挖掘以及Apriori算法,对Apriori算法优缺点和性能进行分析,并将Apriori算法应用于高校图书馆管理系统,给出了系统的完整实现过程。通过分析数据挖掘的结果,寻找各个学科领域中的一些相互关联的知识、辅助教师的教学工作,优化图书馆的馆藏布局。  相似文献   

3.
信息系统约简是个重要的课题 ,借鉴粗糙隶属度、最小分类规则及关联规则可信度等概念 ,推广了粗集理论中知识的核与简化的概念 ,使之能更好地描述决策表的属性约简 ;还从理论上研究了信息表数据浓缩与决策表数据浓缩的关系  相似文献   

4.
Hybrid lacquers that dry quickly in a low‐relative‐humidity environment were synthesized with the repeated kurome lacquer process and an organic silicone compound. An investigation by gel permeation chromatography showed that fractions with different molecular weights showed a lower monomer concentration than the pure kurome lacquer. Fourier transform infrared spectra of the hybrid lacquers revealed that absorption due to the ether of the quinone olefin and/or dibenzofuran appeared around 1470 and 1080 cm?1 and increased with the number of drying days. The gel fractions in the lacquer films increased according to the number of drying days, and this showed that the hybrid lacquers had higher gel fractions than the pure kurome lacquer in the initial stage of dryness. In addition, the drying mechanism of the hybrid lacquers was analyzed with an automatic drying time recorder and rigid‐body pendulum physical property testing measurements. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1055–1061, 2005  相似文献   

5.
The hybrid anaerobic solid–liquid (HASL) system was developed to be used in industrial‐scale operations to minimize the amount of food waste for disposal in Singapore. Thermal pre‐treatment of food waste at 70 °C for 2 h (experiment E1) or at 150 °C for 1 h (experiment E2) facilitated the hydrolytic and acidogenic processes in the acidogenic reactor and methanogenesis in the methanogenic reactor in the HASL system. The highest dissolved chemical oxygen demands in the effluents from the acidogenic reactors were 17 575, 19 980 and 24 235 mg dm?3 in the control with food waste without thermal pre‐treatment and experiments E1 and E2, respectively. The maximum concentrations of methanogens in the methanogenic reactor were 2.3 × 107, 3.8 × 107, 4.3 × 107 cells cm?3 for the control and experiments E1 and E2, respectively. However, the performances of the methanogenic phase in terms of specific activity of methanogens did not differ significantly for the control and experiments E1 and E2. Use of thermally pre‐treated food waste halved the time to produce the same quantity of methane in comparison with anaerobic digestion of fresh food waste. The fluorescent measurements of co‐enzyme F420 and oligonucleotide probe Arc915 specifically bound (hybridized) with 16S rRNA were used for monitoring of methanogens during anaerobic digestion of food waste. There was a linear correlation between these parameters and the concentration of methanogens in the effluent from the methanogenic reactor. Copyright © 2005 Society of Chemical Industry  相似文献   

6.
A new correction term was developed which allows the classical penetration theory to be applied successfully to kLa data obtained from oblate ellipsoidal bubbles formed in bubble columns operated in the homogeneous regime at various pressures . The correction factor is a function of both the Eötvös number Eo and dimensionless gas density ratio. The new correlation was compared with literature kLa data in 18 pure organic liquids, 14 adjusted liquid mixtures and tap water. In some of the liquids (tetralin, xylene and ethanol) not only air but also other gases (nitrogen, helium and hydrogen) were used. In total, 263 experimental kLa points are fitted with an average relative error of 10.4%.In the theoretical approach for the kLa prediction, the gas-liquid contact time (used in the penetration theory) is defined as the ratio of bubble surface to the rate of surface formation. All further calculations are based on the geometrical characteristics (bubble length and height) of an oblate ellipsoidal bubble. It was found that the new correction factor fc gradually reduces with the increase of both superficial gas velocity uG and gas density ρG (operating pressure P).  相似文献   

7.
根据所建立的味精企业"三环节"能量结构模型,对某味精生产企业的能量系统进行了热量平衡、火用平衡以及能量效率的计算和分析,并分别对能量利用环节、能量回收环节和能量转换环节的能量利用、能量回收和能量转换效率进行了评价,分析研究了该厂各环节能量效率低下的因素,指出了该厂存在着巨大的节能潜力。  相似文献   

8.
Statistical analysis of effects of experimental variables on volumetric mass transfer coefficient in a novel hybrid rotating and reciprocating perforated plate bubble column is studied. The novel bubble column is designed indigenously using bevel gear arrangement. Agitation level, superficial gas velocity, superficial liquid velocity, perforation diameter and plate spacing are the experimental variables. Air–sodium sulphite solution system is used in this investigation. The Box–Behnken design in response surface methodology is employed for statistical analysis. The relationship between experimental variables and the desired response of volumetric mass transfer coefficient is established for this novel hybrid column. The linear, quadratic and interactive effects of experimental variables are found to be significant on the desired response of volumetric mass transfer coefficient. Results show that the data adequately fit into the second‐order polynomial model. An F‐test and P‐value show the significance of parameters on volumetric mass transfer coefficient. © 2012 Canadian Society for Chemical Engineering  相似文献   

9.
Plant color landscape plays an important role in improving the quality of visual landscapes, regulating the emotion of landscape space, and highlighting the characteristics of urban landscapes. How to reasonably quantify and create rich plant color landscapes to achieve the best visual perception of the plant color landscape at different visual scales, so as to better meet the aesthetic needs of the public, has become a hot and difficult issue in the plant color design and application. Therefore, this article selects four typical urban parks in Nanjing to study the color characteristics of plant communities. The natural color system color card is used to extract plant color data. The color harmony and suitability degree of the plant community and external environment are quantitatively evaluated according to the Moon-Spencer (M-S) color harmony theory. The correlation between the chromaticity difference, color harmony, and color suitability of the plant landscape color is strong, whereas that between the chromaticity difference and lightness difference of the plant landscape color is weak. Among the four urban parks, the color harmony is the highest, and the appropriate color is the lowest in Xuanwu Lake Park. In addition, among the 12 selected plant community landscapes, the plant community number A3 in Xuanwu Lake Park has the highest color harmony and D3 in Gulin Park has the lowest color harmony. In short, the quantitative study of the plant community landscape color can provide new ideas for improving the optimal allocation of the plant community landscape color in urban parks.  相似文献   

10.
The effect of titanium oxide as an additive on the performance of a polyurethane/polysiloxane hybrid coating was characterized by an electrochemical approach. The performance evolution was quantified by exposing the hybrid coating on an aluminum substrate to NaCl solution at pH 5 over time. Real-time measurements were performed to quantify and correlate the mechanisms that occur at the coating/substrate interface. Electrochemical impedance spectroscopy (EIS) quantified the hybrid coating/substrate interface performance over the course of the 263 days of exposure, and electrically passive elements described and characterized the degradation/performance stages upon exposure to the acidic NaCl solution.The addition of TiO2 produced hydrophobicity functionality, and TiO2 acted as a physical barrier layer that influenced the initial damage stage. Different exposure times were associated the different stages of damage evolution for the hybrid coating and coating/substrate interfaces. Electrochemical testing with high-resolution techniques such as AFM (atomic force microscope) and IFM (infinite focus microscope) characterized the coating surface and the interface performance and resolved the surface and defect formation observed with different levels of TiO2 content. Of the systems tested, the system with 10 wt% TiO2 provided the best corrosion inhibition.  相似文献   

11.
介绍了某大型石化项目消防给水系统,针对其安全可靠性进行分析,并对GB 50974—2014《消防给水及消火栓系统技术规范》相关条文的适用性进行探讨,提出修订建议。  相似文献   

12.
以矿区规划环评导则以及相关法律法规的要求为基准,按照西南地区煤炭矿产资源分布现状及矿区规划特点,针对西南地区自然环境背景、矿区开采特点及已经存在的矿区环境问题,结合国内外研究成果提出了西南地区煤炭矿区规划环境影响评价指标体系及指标值。  相似文献   

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