Subjects: Geosciences >> Geography submitted time 2024-03-01 Cooperative journals: 《干旱区研究》
Abstract： To study the important effects of the water-holding capacity of litter in plantation plants in coal minedumps on soil and water conservation and ecosystem restoration in mining areas, litter accumulation amount, thethickness, water-holding rate, water-holding capacity, and water absorption rate of different decomposition stageswere investigated in four typical plantations of the same age (Populus simonii, Ulmus pumila, Pinustabulaeformis, and Robinia pseudoacacia forests) in the Antaibao opencast coal mine reclamation area, throughfield investigation and soaking extraction. The results showed that the litter accumulation amount in the P.simonii forest was higher than that in the R. pseudoacacia and U. pumila forests (P < 0.05). The water-holdingcapacity and litter rate at different decomposition degrees changed logarithmically with immersion time (P <0.01). The order of the water absorption rate of litter was R. pseudoacacia forest > U. pumila forest > P. simoniiforest > P. tabulaeformis forest, and the water absorption rate showed a significant power function withimmersion time (P < 0.01). In conclusion, the litter of the P. simonii forest had the strongest water- holdingcapacity, whereas the R. pseudoacacia forest had the fastest water absorption rate. Therefore, from theperspective of the water conservation capacity of litter, P. simonii forest should be prioritized and mixed with theR. pseudoacacia forest, which is more conducive to water conservation in the reclamation area of opencast coalmines.
Subjects: Statistics >> Social Statistics submitted time 2023-08-12 Cooperative journals: 《中国科学院院刊》
Abstract： Ruminant livestock such as cattle and sheep can provide high-quality beef, mutton and milk, which are high-quality protein sources meeting the increasingly diverse food consumption needs for human being. Developing high-quality herbivorous animal husbandry is a concrete practice of practicing the “Greater Food” approach. The precise supply of forages and concentrates meeting the requirements of all nutrients in the whole life cycle is vital for cost saving and efficiency increasing of ruminant livestock industry, which is an important way to high-quality development. The whole life cycle nutrition is developed on the basis of traditional ruminant nutrition and new technologies made breakthroughs in understanding life and health. Its essence lies in optimizing the ration formulation based on the theory of systematic nutrition regulation and the theory of short-term and long-term effects of early life nutrition, with a final goal to establish precision nutrition system in combination with technologies in big data and artificial intelligence. Compared with the traditional technology in ration formulation, it is obviously scientific, systematic, and progressive. In this study, the concept, significance, and goals of whole life cycle nutrition in ruminants are briefly introduced. This paper elaborates the key scientific issues and technological problems in the development of whole life cycle nutrition system of ruminant livestock in China, and summarizes the research progress on nutrition regulation, diet formulation, and fundamental research on the long-term impact of early life nutrition in ruminants. Finally, taking the development of modern grassland sheep industry in Hulun Buir State Farm Conglomerate as an example, the concept of building whole life cycle nutrition and promoting high-quality development of ruminant livestock industry is discussed from the aspects of whole life cycle division, whole diet formula, and whole industry chain.
Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2022-05-10 Cooperative journals: 《计算机应用研究》
Abstract： Absrtact: Aiming at the shortcomings of SBO(School Based on Optimization) algorithm, such as poor search performance and local optimization, this paper proposed SBO algorithm integrated with educational psychology(SBO based Educational Psychology, SBO-EP) . The teaching stage used the theory of "zone of proximal development" to carry out dynamic teaching for students in groups to improve the exploration ability of algorithms; It introduced the theory of "achievement motivation" into the self-study stage, and designed dynamic self-study methods according to the achievement motivation of each group of students to improve the development ability of algorithms; After each round of learning process, refer to the "peer effect" theory, to set up the class reorganization operation to increase the diversity of solutions. This paper used 40 CEC2021 test functions and 20 other types of test functions for numerical experiments, and compared SBO-EP algorithm with ant colony optimization algorithm, spherical vector-based particle swarm optimization, Archimedes optimization algorithm, gray wolf optimization algorithm, teaching and learning algorithm, cognitive psychology teaching-learning-based optimization and student psychology based optimization algorithm. The results show that SBO-EP algorithm has obvious advantages in convergence speed, optimization accuracy and stability. Finally, conducted a comparative experiment on the combination of the three strategies, verify the effectiveness of the improved strategy.
Subjects: Civil Engineering and Building Construction >> Basic Disciplines of Civil Engineering and Building Construction submitted time 2018-10-26 Cooperative journals: 《土木建筑工程信息技术》
Abstract：虚拟现实、增强现实、混合现实是新兴的多维可视化沟通技术，在各个领域都有广泛的应用，他们与建筑工程领域的BIM技术的结合应用，能发挥出两者的优势，相辅相成。他们在建筑全生命期都有极大的价值空间可供挖掘。本文从基础理论开始，深入探讨了BIMVR/AR这一创新融合技术在建筑规划与设计阶段、工程施工阶段、项目营销阶段、运维管理阶段等全生命期的应用需求、落地应用模式、应用现状以及未来发展方向和潜力。最后本文分析了技术进一步发展所面临的障碍及突破口。
Subjects: Civil Engineering and Building Construction >> Basic Disciplines of Civil Engineering and Building Construction submitted time 2018-10-26 Cooperative journals: 《土木建筑工程信息技术》
Abstract：虚拟现实、增强现实、混合现实是新兴的多维可视化沟通技术，在各个领域都有广泛的应用，他们与建筑工程领域的BIM技术的结合应用，能发挥出两者的优势，相辅相成。他们在建筑全生命期都有极大的价值空间可供挖掘。本文从基础理论开始，深入探讨了BIMVR/AR这一创新融合技术在建筑规划与设计阶段、工程施工阶段、项目营销阶段、运维管理阶段等全生命期的应用需求、落地应用模式、应用现状以及未来发展方向和潜力。最后本文分析了技术进一步发展所面临的障碍及突破口。
Subjects: Geosciences >> Space Physics submitted time 2016-05-04
Abstract： Coronal mass ejections (CMEs) and corotating interaction regions (CIRs) are two significant contributors to interplanetary disturbances and geomagnetic disturbances, which also play as major drivers of geomagnetic storms to modulate the geo-space environment. In order to comprehensively investigate the characteristic temporal features of the solar wind activity and associated geomagnetic activity, a large amount of solar wind data and geomagnetic activity indices are analyzed in detail. Firstly, using the public data of solar wind parameters and geomagnetic activity indices provided by the NASA OMNIWeb, the MATLAB codes are developed to deal with a number of key parameters including IMF B-z solar wind velocity, solar wind proton density, solar wind dynamic pressure, Dst, AE, and Kp for the entire Solar Cycle 23 from 1996 to 2008. The complete database with a full list of 269 CME events and 456 CIR events is identified. Case event studies and superposed epoch analyses are implemented to carefully investigate the statistical features of four important solar wind parameters (IMF 13,, solar wind speed, solar wind proton density, and solar wind dynamic pressure) and three major geomagnetic indices (Dst, AE, and Kp) associated with the two types of solar disturbances. Secondly, the minimum of Dst index is utilized to differentiate 355 isolated geomagnetic storms occurring during the Solar Cycle 23. These storms are further categorized according to the magnitude of Dst minimum into 145 weak storms, 123 moderate storms, 70 strong storms, 12 severe storms, and 5 extreme storms. Finally, superposed epoch analysis is applied to evaluate the statistics of solar wind parameters and geomagnetic indices corresponding to magnetic storms with different intensities. It is found that in general the linearly fitted slope of N-sw/P-dyn (where N-sw is the solar wind proton density and P-dyn the dynamic pressure) with respect to epoch time remains positive for CME events but negative for CIR events, which can act as a feasible means to distinguish CME and CIR events. On average, compared to CIR events, CME events have larger magnitudes of southward IMF B solar wind dynamic pressure, AE and Kp indices but smaller Dst(min). In principle, CMEs bear higher possibility to drive extremely intense (i. e., super) geomagnetic storms. The overall variations of Dst tend to be similar to some extent for different levels of geomagnetic storms, however, Dst decreases faster for stronger storms. There are a large number of differences between CME and CIR events and their driven geomagnetic storms as well. Therefore, CME-driven storms and CIR-driven storms should be studied separately. The established database of CME and CIR events and geomagnetic storms and the quantitative statistical information in combination can provide a useful aid for better understanding the responses of Earth's plasma sheet, radiation belts, and ring current to various solar activities.
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