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51.
随着时代的发展,我国对现代化建设方面的要求也在不断提高.经济的发展与建筑施工项目有很大的联系,故对其安全管理体系的要求也越来越高.所以为使我国经济的发展更上一层楼,应更注重提高建筑施工项目的安全管理和安全生产监控. 相似文献
52.
EPC工程总承包自20世纪80年代开始,在石油化工、水电工程等大型工程项目中EPC得到了较为广泛的应用,从2003年开始我国住房与城乡建设部下发了有关工程总承包的明确制度与规定,至此工程总承包正式得到了各行业的推广性应用.现就市政工程项目实施过程中的风险及成本控制进行详细的论述,对比了地基处理工程的三种方案:空心方桩,管桩和真空预压联合堆载预压. 相似文献
53.
EPC工程总承包自20世纪80年代开始,在石油化工、水电工程等大型工程项目中EPC得到了较为广泛的应用,从2003年开始我国住房与城乡建设部下发了有关工程总承包的明确制度与规定,至此工程总承包正式得到了各行业的推广性应用.现就市政工程项目实施过程中的风险及成本控制进行详细的论述,对比了地基处理工程的三种方案:空心方桩,管桩和真空预压联合堆载预压. 相似文献
54.
55.
Qin-yu Zhou Shan Zhao Yan-yan Huang Jin-shuang Hu Jia-hua Kuang Dong-mei Liu Charles S. Brennan 《International Journal of Food Science & Technology》2021,56(6):2992-3003
Yogurt preserves and enhances nutritional value of milk. In this study, we have compared several strains to determine the physicochemical, sensory, rheological and aroma characteristics of different yogurts. We used Lactobacillus gasseri LGZ 1029 (LG), commercial probiotic L. rhamnosus (LGG) and traditional fermentation strains Streptococcus thermophilus and L. bulgaricus (SL). Results showed that the flavour and texture characteristics of mixed-strain yogurts were obviously better than in single-strain yogurts. Addition of LG increased pseudoplastic behaviour, as shown by Herschel–Bulkley model analysis of rheological behaviour. The LG + SL group also had both the highest viscosity consistency index and thickening ability. In addition, a total of 57 volatile compounds were detected in yogurts and the fermentation with the addition of LG was mainly affected by ketones. Our study suggested that a yogurt with new attributes can be produced by using LGZ 1029. 相似文献
56.
Bin Zhang Xuesong Jiang Fei Shen Xueming He Yong Fang Qiuhui Hu 《International Journal of Food Science & Technology》2021,56(6):2588-2595
This work intends to develop an online experimental system for screening of deoxynivalenol (DON) contamination in whole wheat meals by visible/near-infrared (Vis/NIR) spectroscopy and computer vision coupling technology. Spectral and image information of samples with various DON levels was collected at speed of 0.15 m s−1 on a conveyor belt. The two-type data were then integrated and subjected to chemometric analysis. Discriminant analysis showed that samples could be classified by setting 1000 μg kg−1 as the cut-off value. The best correct classified rate obtained in prediction was 93.55% based on fusion of spectral and image features, with reduced prediction uncertainty as compared to single feature. However, quantification of DON by quantitative analysis was not successful due to poor model performance. These results indicate that, although not accurate enough to provide conclusive result, this coupling technology could be adopted for rapid screening of DON contamination in cereals and feeds during processing. 相似文献
57.
Hang Shi Qiuyang Yu Guoliang Liu Xiaohong Hu 《International Journal of Hydrogen Energy》2021,46(33):17097-17105
Transition metal phosphides (TMPs) have been considered as cheap alternatives of precious metal platinum for electrochemical hydrogen evolution reaction (HER). In the past decades, many reports have indicated that the engineering of heterointerfaces between different components could efficiently enhance the activity of HER catalysts. Here, we report a facile method to construct Ni12P5–Ni2P heterostructure by using a low temperature phosphorization strategy. The obtained Ni12P5–Ni2P heterostructure shows high activity toward HER with an overpotential value of 166 mV at 10 mA cm?2 and a Tafel slope of 60 mV dec?1 in 0.5 M H2SO4. Compared with pure Ni2P and Ni12P5, the Ni12P5–Ni2P heterostructure has more active sites and faster HER kinetics due to the presence of the interfaces between Ni12P5 and Ni2P. Furthermore, we used the obtained Ni12P5–Ni2P as cathodic catalyst and IrO2/Ti as anodic material to set up a proton exchange membrane (PEM) electrolyzer which shows good stability after 120 h continuous constant current electrolysis at 200 mA cm?2. This work demonstrates the positive effect of heterostructure for HER catalysts and provides a feasible strategy for constructing earth-abundant electrocatalysts. 相似文献
58.
A series of ZnxNiyCrOm±δ catalysts were synthesized via a typical co-precipitation method, in which Zn-Cr layered double hydroxides (LDHs) were found and Ni-Zn intermetallic compound (IMC) was formed after reduction in hydrogen. During auto-thermal reforming (ATR) of acetic acid (HAc), the Ni-Zn IMC was transformed into Ni/(amorphous-ZnO)-ZnCr2O4 species with uniformed distribution and appropriate interaction within these Ni-Zn-Cr-O species; besides, the adsorbed oxygen promoted the activation and transfer of oxygen species; therefore, deactivation by oxidation, sintering and coking was inhibited. And the optimized Zn2.37Ni0.63CrO4.5±δ catalyst presented high activity and stability in a 45-h ATR test with HAc conversion near 100% and hydrogen yield at 2.7 mol-H2/mol-HAc, showing potential for hydrogen production via ATR of HAc. 相似文献
59.
60.
Wei-Fei Hu Shuo Chen Hong-Chao Hao Hong Jiang 《American Institute of Chemical Engineers》2022,68(11):e17879
Herein, we propose a novel method to enhance the photoreactivity of an MOF catalyst by grafting isocyanate bonds ( NCO) and sulfhydryl-complexed copper ( SCu) onto ZIF-8 (NIF-SCu). The grafting process intercalated interlayer bands between the conduction and valence bands of ZIF-8, thereby providing a “ladder” for facile electron transition. The extreme improvement in the photoreactivity of NIF-SCu could be attributed to the enhancement in light responses in the range of 350–450 nm by NCO groups and the widening of the visible light range of the MOF by SCu groups. The formation of staggered energy levels in NIF-SCu could also narrow the band gap, lower the resistance, and facilitate the transfer of photogenerated carriers, thereby generating electrons with strong reduction potential in the SCu conduction band. This study provides a new strategy for improving or even endowing the photoactivity of environmental functional materials with wide bandgaps. 相似文献