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排序方式: 共有146条查询结果,搜索用时 31 毫秒
81.
介绍了机舱声响仿真系统的组成,说明了数据通信原理和声音波形件的处理步骤,详细地叙述了声响仿真计算机程序软件设计方法。 相似文献
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83.
选择了两种有代表性级配的红层软岩土石混合料,进行了长期蠕变性能模拟试验.持续6个月的模拟试验研究表明,红层软岩土石混合料的长期蠕变性能除了与岩块特性、成型密度、上覆荷载及干湿循环有关外,细料含量是影响其长期蠕变性能的主要因素. 相似文献
84.
综合考虑了土压平衡式盾构机的直径、刀盘开口率、刀盘与土体的摩擦系数、盾构机的埋深、盾构机施工地层的土性、盾构机和地层之间的相互关系、盾构机推进速度以及螺旋输送机转速等参数的影响因素,推导出刀盘扭矩的理论模型。在盾构机模拟试验平台上进行试验,分析了两种典型开口率的刀盘在3种典型土层中扭矩的变化及土仓压力对刀盘扭矩的影响。分析结果表明,刀盘扭矩的理论模型与试验结果相符,并能满足盾构机实际施工的要求。 相似文献
85.
Widespread uptake of battery electric, plug-in hybrid, and hydrogen fuel-cell vehicles (collectively zero-emissions vehicles or ZEVs) could help many regions achieve deep greenhouse gas mitigation goals. Using the case of Canada, this study investigates the extent to which increasing ZEV charging and refuelling availability may boost ZEV sales relative to other ZEV-supportive policies. We adapt a version of the Respondent-based Preferences and Constraints (REPAC) model using 2017 survey data from 1884 Canadian new vehicle-buyers to simulate the sales impacts of increasing electric vehicle charging access at home, work, public destinations, and on highways, as well as increasing hydrogen refuelling station access. REPAC is built from a stated preference choice model and represents constraints in supply and consumer awareness, as well as dynamics in ZEV policy out to 2030. Results suggest that new ZEV market share from 2020 to 2030 does not substantially benefit from increased infrastructure. Even when electric charging and hydrogen refuelling access are simulated to reach “universally” available levels by 2030, ZEV sales do not rise by more than 1.5 percentage points above the baseline trajectory. On the other hand, REPAC simulates ZEV market share rising as high as 30% by 2030 with strong ZEV-supportive policies, even without the addition of charging or refuelling infrastructure. These findings stem from low consumer valuation of infrastructure found in the stated preference model. Results suggest that achieving ambitious ZEV sale targets requires a comprehensive suite of policies beyond a focus on charging and refueling infrastructure. 相似文献
86.
This paper focuses on comparing the frameworks and projections from four global transportation models with considerable technology details. We analyze and compare the modeling frameworks, underlying data, assumptions, intermediate parameters, and projections to identify the sources of divergence or consistency, as well as key knowledge gaps. We find that there are significant differences in the base-year data and key parameters for future projections, especially for developing countries. These include passenger and freight activity, mode shares, vehicle ownership rates, and energy consumption by mode, particularly for shipping, aviation and trucking. This may be due in part to a lack of previous efforts to do such consistency-checking and “bench-marking.” We find that the four models differ in terms of the relative roles of various mitigation strategies to achieve a 2 °C/450 ppm target: the economics-based integrated assessment models favor the use of low carbon fuels as the primary mitigation option followed by efficiency improvements, whereas transport-only and expert-based models favor efficiency improvements of vehicles followed by mode shifts. We offer recommendations for future modeling improvements focusing on (1) reducing data gaps; (2) translating the findings from this study into relevant policy implications such as gaps of current policy goals, additional policy targets needed, regional vs. global reductions; (3) modeling strata of demographic groups to improve understanding of vehicle ownership levels, travel behavior, and urban vs. rural considerations; and (4) conducting coordinated efforts in aligning historical data, and comparing input assumptions and results of policy analysis and modeling insights. 相似文献
87.
基于在线仿真的穿浪船推进智能控制及系统优化研究 总被引:1,自引:0,他引:1
为了增加优化过程的实时性,本文提出了一种基于在线仿真的穿浪船可调桨推进智能控制及其系统优化方法。首先建立了可调桨推进的数学模型,再以MATLAB为平台,使用其仿真软件Simulink建立了仿真模型,又使用查表模糊控制器实现了对穿浪船可调桨推进的智能控制。然后,建立了系统优化的数学模型。基于仿真模型,应用MATLAB的遗传算法工具箱GAOT实现了该系统的优化设计。最后给出了算例。计算结果表明:仿真和优化的准确性和可靠性都较好,该方法是有效且可行的。 相似文献
88.
王红升 《国防交通工程与技术》2007,5(4):64-67
为保证荷麻溪特大桥在施工过程中结构的受力和线形符合设计要求,运用ANSYS软件对施工过程进行数值分析,介绍了预应力的处理方法、单元生死特性的应用,计算出的桥梁各断面应力、索力和桥梁线形与测量结果十分接近,说明使用ANSYS可以很好的对部分预应力混凝土斜拉桥施工过程进行仿真分析。 相似文献
89.
首先介绍以燃气发生器为水下鱼雷管发射动力源的假海模型弹发射原理试验,然后对模型弹内测系统记录数据等结果进行综合分析,最后给出对有关进一步研究工作的启示和建议. 相似文献
90.
对某改扩建的油码头,首先采用基于设计规范的设计方式对泊位年通过能力进行初步计算。由于任意泊位停靠船舶的船型大小会对其它泊位停靠船舶的船型大小产生一定约束(即船舶靠泊具有组合约束),考虑到这类船舶组合靠泊对码头泊位年通过能力的影响,引入仿真技术对船舶靠泊组合约束下的码头泊位年通过能力进行仿真计算,并将仿真数据与基于设计规范方式得到的数据进行比较和分析,为船舶靠泊组合约束下的泊位年通过能力的计算提供新思路。 相似文献