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571.
王旭 《南通航运职业技术学院学报》2005,4(3):38-40
为了加快高校基础设施建设,适应市场需求,高校越来越多地借助于银行贷款来谋求自身发展,形成了银行贷款的投资期限长、还款渠道单一、占建设资金比例大的特点,使银行贷款成为会计核算的常客.高校财务对银行贷款采用不同的会计方法进行核算,使银行贷款的信息披露不全面,文章试对不同的会计核算方法进行比较,以便选出最优核算方案. 相似文献
572.
电机噪声分析及抑制措施 总被引:3,自引:0,他引:3
本文主要对电机噪声的分类、形成原因以及抑制措施进行了论述,其中重点对电磁噪声的抑制措施进行了较为详细的分析。 相似文献
573.
Ice loads are important environmental loads that can influence the structural safety of ships during navigation in ice-covered waters. The identification of ice loads on ship hulls is the core of ice load monitoring. In this study, a new ice load identification model based on Green kernel and regularization methods is established. First, the forward model for ice load identification is developed through the discretised convolution integral of ice loads. Next, three commonly used regularization methods, including Tikhonov, truncated singular value decomposition, and least square QR-factorization (LSQR) are adopted to reduce solution errors. The LSQR method is thereafter selected as the optimal regularization operator, and its regular property is proved by numerical cases with ice-induced strains that contain noise. Finally, two load identification cases are conducted on an experimental rig to evaluate the feasibility of the model in ice load identification. The identified loads can determine the signal features of applied loads in the time domain with good accuracy. This identification model provides new insights for full-scale ice load monitoring. 相似文献
574.
[Objective]This paper studies the coupled damage effects of a ship's structure due to the internal blast loading of a warhead. [Methods]Blast tests with cased charge data are conducted to verify the effectiveness of the coupled SPH-FEM approach, and numerical calculations are then performed on real ship compartment scale model tests to analyze the coupled fragmentation and shockwave damage effects of an explosion in a confined cabin.[Results]The results show that the fragments caused by the detonation of the warhead will first cause local damage to the cabin structure. The shockwave will exacerbate the local damage, and blasted openings will further increase the space for the propagation and diffusion of the shockwave inside the chamber, which will in turn cause damage to the adjacent structures. The simple equivalence of the warhead to a bare charge does not give a true picture of the effect of the warhead on the ship's structure, and fragmentation plays a significant role in the detonation of the warhead.[Conclusions]The results of this study show that employing the coupled SPH-FEM numerical method to calculate the coupling damage effects on a ship's structure can accurately reproduce the warhead damage pattern in tests, thereby providing support for the improved assessment of the damage of naval structures under warhead detonation. © 2022 Chinese Journal of Ship Research. All rights reserved. 相似文献
575.
A methodology for estimating extreme response statistics for marine structures, that takes both the long-term variability of the metocean environment and the short-term variability of response into account is presented. The proposed methodology uses Gaussian process regression to estimate parameters of the short-term response distribution, based on output from computationally expensive hydrodynamic simulations. We present an adaptive design strategy for sequential updating of the model, focusing on the metocean conditions that contribute the most to the long-term extreme. With this approach, only a limited number of hydrodynamic simulations are needed.The suggested approach is demonstrated on the problem of estimating the 25-year extreme vertical bending moment on a ship. We show that a relatively small number of iterations (full hydrodynamic simulations) are needed to converge toward the “exact” results obtained by running a large number of simulations covering the entire range of sea states.The results suggest that the proposed method can be used as an alternative to contour-based methods or other methods that consider a few sea states using accurate numerical simulations, with little or no added complexity or computational effort. 相似文献
576.
577.
降雨入渗对土石坝边坡稳定性影响的分析研究 总被引:1,自引:0,他引:1
降雨入渗是土质边坡失稳的主要诱发因素,很多土石坝坝坡滑坡都与降雨有着密切的关系。在饱和-非饱和渗流理论及土石坝填土土—水特征曲线的基础上,对土石坝在降雨入渗情况下非饱和区基质吸力的变化及暂态饱和区的形成进行分析,结合工程实例,采用极限平衡法在考虑不同降雨强度及持续时间下对非饱和渗流土石坝下游坝坡稳定性的影响进行分析。计算结果表明,降雨入渗导致土石坝浸润线的升高,从而使得原浸润线以上区域出现暂态饱和区,孔隙水压力增加,最终导致坝坡稳定性的降低,降雨强度越大或降雨历时越长,坝坡安全系数降低越多,坝坡安全系数在降雨持续2~4 h时降低的最快。 相似文献
578.
579.
该文以深圳市机场南路新建工程(50+82+50)m钢-混凝土组合连续梁桥为例,对钢-混凝土组合梁负弯矩区施工控制方法进行分析研究。研究结论可供同类工程参考。 相似文献
580.
Planning, construction and operation of transport infrastructure are associated with a multitude of adverse effects on the environment. The Strategic Environmental Assessment (SEA) and Environmental Impact Assessment (EIA) are important legal instruments of the European Union's environmental policy that allows for identifying, predicting, preventing, and mitigating and or compensating for these adverse effects. As part of the environmental impact assessment, variants of planned activities and investment projects are considered in order to select the option, which is the most favourable from the environmental point of view. The primary goal of this work is to examine the possibility of using multi-criteria methods in order to select the route variant most favourable for the environment. In the first stage, a review of global literature from 2010 to 2019 was conducted on the subject of MCDM/MCDA (Multi-Criteria Decision Making/Multi-Criteria Decision Analysis) methods used in transportation. Based on the review, it was proven that the most popular methods used to solve multi-criteria decision problems in the field of transport are respectively: AHP with modifications, TOPSIS, DEMATEL, as well as methods encompassed in the so-called European trend, i.e. PROMETHEE and ELECTRE. Four selected methods were used in the empirical part of this work. They were used to select the variant of the expressway section in north-eastern Poland and compare the result of the analysis with the choice made in the analyzed environmental impact report. 相似文献