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991.
综述了现阶段表面活性剂型防结块剂的特点和种类,不同种表面活性剂以及将不同种表面活性剂复合在防结块剂中的应用,目前防结块剂的防结块机理,防结块剂的性能测试方法及评价,并介绍了表面活性剂型防结块剂近年来在各领域的综合应用,尤其是在化肥中有着广泛的应用。提出了通过加入不同类型的表面活性剂及表面活性剂的复配使用对生活、生产等的方方面面的影响,展望了表面活性剂未来的发展方向。 相似文献
992.
The effect of initial gas pressure on Al–water reaction was investigated systematically. It was found that there is a non-monotonic relationship between the initial pressure and the induction time for the beginning of Al–water reaction. The induction time decreases with decreasing the initial pressure at the first stage from atmospheric pressure, then reaches a minimum, and finally increases with further decreasing the initial pressure. The mechanism analyses revealed that the special vacuum pressure corresponding to the minimum induction time is close to the saturated vapor pressure, below which probably there are some vapor bubbles passing or adsorbing on Al particle surfaces due to boiling, retarding the hydration process of Al surface oxide film and increasing the reaction induction time. The present results imply that a suitable initial gas pressure should be chosen for Al–water reaction to generate hydrogen. 相似文献
993.
994.
山西省娄烦县尖东铁矿地质特征及矿床成因 总被引:1,自引:0,他引:1
通过对山西省娄烦县尖东铁矿区域地质背景、矿区地质特征、矿体特征等的综合分析,阐述了该区铁矿的成因类型,总结其成矿规律,为铁矿的进一步勘查开发提供地质依据。 相似文献
995.
Abstract An explicit three-dimensional calculation of c.w. modulated photothermal deflection (PTD) with obliquely crossed geometry, including optical thin film and substrate absorption, has been presented. Theoretical results show that the obliquely crossed PTD technique is feasible to separate the thin film and substrate absorption, and to measure low thin film absorption under high substrate absorption by appropriately adjusting the cross-point position of the excitation and probe beams. Measurement of the thin film absorption is not affected by the thermal properties of the substrate. The obliquely crossed PTD also provides a method for real-time monitoring of thin film generation. 相似文献
996.
997.
Tensile properties and failure mechanism of 3D woven hollow integrated sandwich composites are investigated experimentally, theoretically and numerically in this paper. Firstly, the tensile properties are obtained by quasi-static tensile tests on the specimens in two principal directions of the sandwich panels, called warp and weft. The experimental results shows that the tensile performances of the warp are better than that of the weft. By observing the broken specimens, it is found that the touch parts between yarns are the main failure regions under tension. Then, a theoretical method is developed to predict the tensile properties. By comparing with the experimental data, the accuracy of the theoretical method is verified. Simultaneously, a finite element model is established to predict the tensile behavior of the composites. The numerical results agree well with the experimental data. Moreover, the simulated progressive damages show that the contact regions in the warp and weft tension are both the initial failure areas. 相似文献
998.
999.
High‐pressure microfluidisation pretreatment disaggregate peanut protein isolates to prepare antihypertensive peptide fractions 下载免费PDF全文
Kuijie Gong Lei Deng Aimin Shi Hongzhi Liu Li Liu Hui Hu Benu Adhikari Qiang Wang 《International Journal of Food Science & Technology》2017,52(8):1760-1769
High‐pressure microfluidisation (HPM) pretreatment was applied to increase in vitro antihypertensive activity of peanut peptide fractions (PPF). The morphology of protein in aqueous dispersion revealed that peanut protein isolate (PPI) disaggregated at relatively low pressure (≤120 MPa) and re‐aggregated at relatively high pressures (150–210 MPa). The treated pressure of 120 MPa could lead to the most disaggregation of PPI. Small peptides contents, trichloroacetic acid‐nitrogen soluble index (TCA‐NSI) and degree of hydrolysis (DH) of peanut protein hydrolysates (PPH) all reached the highest at 120 MPa. Consequently, it possessed the highest angiotensin converting enzyme (ACE) and renin inhibitory activity. The highest surface hydrophobicity occurred at 120 MPa pretreatment samples. Thirty‐nine oligopeptides at 120 MPa pretreatment were identified by ultra‐performance liquid chromatography‐quadrupole time‐of‐flight (UPLC‐Q‐TOF) mass spectrometer combined with Progenesis QI for Proteomics software compared with 29 and 35 at control and 210 MPa, respectively. This meant that disaggregation of PPI at 120 MPa resulted in the release of new hydrophobic peptide. 相似文献
1000.
Ke Deng Ling Wang Zheng-Hai Xia Yu-Hua Ma Lai-Lai Qin Qin Zhang Jia-Yu Liu Jian Yao Wei Liu 《核技术(英文版)》2018,(5)
Tritium concentrations in precipitation can be used as a criterion to evaluate the tritium baseline of the environment. The tritium concentration in precipitation in Shanghai during 2014-2015 was determined. Values ranged from 0.68 ± 0.04 to 4.11 ± 0.39 Bq/L, and it showed a decreasing trend compared with historical data; however,the values were slightly higher than the natural background tritium level. Additionally, the tritium concentration shows a seasonal variation: It was higher in autumn and winter and lower in summer and spring. A comparison of concentrations in precipitation in Shanghai and around the Qinshan Nuclear Power Plant reveals no correlation,implying that the nuclear power plant operations may not affect the environment of Shanghai. Thus, the raised tritium concentrations in Shanghai might be due to the effects of monsoons, spring leak, raindrop, or other activities that generate tritium there. Those activities may include chemistry research that uses tritium as a tracer. 相似文献