冲击环境后峰锯齿脉冲试验条件自动寻优方法

目的 通过自动寻优制定冲击环境后峰锯齿脉冲试验条件,避免冲击“过试验”。方法 根据冲击响应谱的基本原理和谱型特征,提出利用对数距离量化评价2条谱型的吻合度。对冲击环境和后峰锯齿脉冲分别进行冲击响应谱分析,将2条冲击响应谱之间的对数距离最小作为优化目标,将后峰锯齿脉冲的波形参数作为优化参数,基于自适应差分进化算法,提出冲击环境后峰锯齿脉冲试验条件自动寻优方法。结果 将所提方法分别应用于模拟冲击环境和实测冲击环境,均获得了合理的后峰锯齿脉冲试验条件,验证了所提方法的正确性。结论 提出的基于自适应差分进化算法的冲击环境后峰锯齿脉冲试验条件自动寻优方法正确可行。     

centrifugal用热控装置设计

目的 评估飞行器产品在飞行过程对热–离心综合环境的适应性,研制一套热–离心综合环境试验用热控装置。方法 从热–离心试验需求出发,完成综合试验系统总体研制目标及系统方案设计。针对高g值离心环境（离心加速度值≥90g）下的热载荷加载需求,开展基于热传导的热载荷加载方法研究,并完成适用于高g值环境的热控装置硬件布局优化设计。提出基于分段包络思想的产品响应温度梯度分布效应模拟方法及实现,减少过试验考核。结果 利用该热控装置完成了热–离心综合环境功能验证试验,设置最大加速度为92g,保载时间为3 min,最高加热温度为150℃,最大温升速率为3℃/min,3温区控制,升温过程中,温度误差优于±1.5℃。结论 该热–离心综合环境试验用热控装置可用于飞行器产品热–离心综合环境试验的考核。     

陕西省大旱年发生概率及可能发生的年份预测

应用数理统计方法及三元、四元、五元可公度法分别推算了21世纪陕西省大旱年发生的概率和预测了该省未来30多年间可能发生大旱灾的年份.运算结果显示:陕西省在21世纪的100年中,大旱年发生次数至少为一次、两次、三次、四次、五次的概率分别为94.52%、86.65%、72.91%、54.78%、35.57%;在未来30多年间陕西省有可能在2006年、2008年、2024年、2031年发生重大旱灾.     

气凝胶消防救援服内衬的热阻计算

为提高消防救援服在高温环境中的穿着热舒适性能,探究消防救援服内衬热阻的理论公式推导和数值计算,推导得出粒径、导热系数、填充角度和热阻之间的关系,用Matlab作出三维模型图,表示热阻和三者之间的关系.结果 表明:当粒径越小,填充角度越小和导热系数越小时,热阻值越大;当填充颗粒的粒径一定时,等热阻线呈现抛物线趋势,且随着...     

Optimization of carbon dioxide absorption in a continuous bubble column reactor using response surface methodology

Carbon dioxide absorption using amine based solvents is a well-known approach for carbon dioxide removal. Especially with the increasing concerns about greenhouse gas emissions, there is a need for an optimization approach capable of multifactor calibration and prediction of interactions. Since conventional methods based on empirical relations are not efficiently applicable, this study investigates use of Response Surface Methodology as a strong optimization tool. A bubble column reactor was used and the effect of solvent concentration (10.0, 20.0 and 30.0 vol%), flow rate (4.0, 5.0 and 6.0 L min⁻¹), diffuser pore size (0.5, 1.0 and 1.5 mm) and temperature (20.0, 25.0 and 30.0°C) on the absorption capacity and also overall mass transfer coefficient was evaluated. The optimization results for maintaining maximum capacity and overall mass transfer coefficient revealed that different optimization targets led to different tuned operational factors. Overall mass transfer coefficient decreased to 34.7 min⁻¹ when the maximum capacity was the desired target. High reaction rate along with the highest absorption capacity was set as desirable two factor target in this application. As a result, a third scenario was designed to maximize both mass transfer coefficient and absorption capacity simultaneously. The optimized condition was achieved when a gas flow rate of 5.9 L min⁻¹, MEA solution of 29.6 vol%, diffuser pore size of 0.5 mm and temperature of 20.6°C was adjusted. At this condition, mass transfer coefficient reached a maximum of 38.4 min⁻¹, with a forecasted achievable absorption capacity of 120.5 g CO₂ per kg MEA.     

River Basin Export Reduction Optimization Support Tool; a tool to screen options for reducing nutrient loads while minimizing cost

Excess loading of nitrogen and phosphorus to river networks causes environmental harm, but reducing loads from large river basins is difficult and expensive. We developed a new tool, the River Basin Export Reduction Optimization Support Tool (RBEROST) to identify the least-cost combinations of management practices that will reduce nutrient loading to target levels in downstream and mid-network waterbodies. We demonstrate the utility of the tool in a case study in the Upper Connecticut River Basin in New England, USA. The total project cost of optimized lowest-cost plans ranged from $18.0 million to $41.0 million per year over 15 years depending on user specifications. Plans include both point source and non-point source management practices, and most costs are associated with urban stormwater practices. Adding a 2% margin of safety to loading targets improved the estimated probability of success from 37.5% to 99%. The large spatial scale of RBEROST, and the consideration of both point and non-point source contributions of nutrients, make it well suited as an initial screening tool in watershed planning.     

降水概率模型在旱涝监测评价中的应用研究

选择正态、准正态和偏态Gamma多种理论概率分布模型对河南年、月、旬不同统计时段降水概率进行了模型拟合试验，推求了准正态概率分布密度函数的通用公式，提出了二参数Gam—ma分布参数Thom估计方法的修正方案，并对旱涝监测评价分析中有关概率特征量的数值计算方法进行了试验研究。     

高校碳排放核算与分析：以北京A高校为例

在双碳背景下,我国各行业正积极核算自身碳排放,以有效应对气候变化,大学校园也应积极参与其中.以北京A高校为例,采用排放因子法和理论计算法核算了2021年其校园碳排放量.结果表明,A高校净碳排放量（以CO2计,下同）为43 249.04 t,人均碳排放量为1.52 t.电力、通勤与差旅、热力、天然气和食物是碳排放的主要来源.热力和天然气的碳排放与月份密切相关,而电力碳排放在不同的功能区和月份都有所不同.食物的碳排放与饮食结构有关,而污水和垃圾处理的碳排放则与处理过程有关.使用蒙特卡洛模拟法讨论了碳排放清单的不确定性,发现碳排放总量的不确定性在-13.61%～26.08%之间.尽管计算结果相对科学可靠,但通勤和差旅、电力、天然气和食品是主要的不确定性来源.总体来说,研究结果为校园和其他复杂系统的碳排放核算和不确定性计算提供了参考.     

卫生填埋场防渗衬垫系统优化设计

根据已建卫生填埋场防渗衬垫设计的实践经验总结,指出垃圾卫生填埋场防渗衬垫设计应从结构稳定、污染防治、减压导排等几方面进行综合考虑。采用现代环境卫生技术和环境土工技术,对防渗衬垫系统进行优化设计,并将其应用至现代卫生填埋场防渗衬垫设计中。     

BP神经网络和遗传算法在红发夫酵母培养基优化中的应用

运用BP神经网络对红发夫酵母发酵培养基组成进行建模以及预测类胡萝卜素产量,在此基础上采用遗传算法对此模型进行全局寻优.得到红发夫酵母发酵培养基的最佳配比为:蔗糖45.10 g/L,硫酸铵3.00 g/L,硫酸镁0.80 g/L,磷酸二氢钾1.40 g/L,酵母膏3.00 g/L,氯化钙0.50 g/L,类胡萝卜素产量达到8.20 mg/L,干重达到9.47 g/L.采用上述方法优化后的培养基使类胡萝卜素的产量比起始培养基提高了95.90%.