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OPTIMUM OF PRESSURE RATIOS OF MULTI-STAGE RECIPROCATING COMPRESSOR WITH PRACTICAL INTER-COOLING 被引量:1
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作者 刘卫华 昂海松 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2002年第2期177-181,共5页
The optimum pressure ratio distribution of a multistage reciprocating compressor is presented based on the assumption, i.e. the inter stage cooling is perfect and there are no pressure losses. The optimization of the... The optimum pressure ratio distribution of a multistage reciprocating compressor is presented based on the assumption, i.e. the inter stage cooling is perfect and there are no pressure losses. The optimization of the two or three stage pressure ratio is analyzed in two cases of constant heat transfer rate for the inter cooler or constant inter stage inlet temperature, based on the minimum of the sum of theoretical compression power at each stage about a multi stage reciprocating compressor. Furthermore, with an example of two stage compressor the influence on the sum of the power of each stage is analyzed when practical pressure ratio deviates from the optimum value. It is obtained that under different cooling conditions the optimum pressure ratio distribution of the multi stage compression is various, and the change of the optimum pressure ratio within a small range has little influence on the sum of the power each stage. For the two stage compression, this range can be represented as ε 1=(0 96~1 06)ε 1j . 展开更多
关键词 inter cooler multi stage compressor pressure ratio optimum
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DYNAMICAL OPTIMUM DESIGN OF THE MECHANICAL OSCILLATION SYSTEM IN FLUIDIC GENERATOR
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作者 李福松 陈建军 《兵工学报》 EI CAS CSCD 北大核心 2000年第1期-,共4页
文中通过对射流发电机工作原理、结构特点及作用荷载的分析,建立了射流发电机机械振动系统的动力优化设计数学模型,以结构尺寸为设计变量,使结构重量极小化,满足动力位移、应力响应、基频以及尺寸限等约束条件,利用振型迭加法和复... 文中通过对射流发电机工作原理、结构特点及作用荷载的分析,建立了射流发电机机械振动系统的动力优化设计数学模型,以结构尺寸为设计变量,使结构重量极小化,满足动力位移、应力响应、基频以及尺寸限等约束条件,利用振型迭加法和复合形法求解。优化和试验结果表明:经优化后,既减轻结构重量,又显著地提高了射流发电机的输出功率。 展开更多
关键词 引信 射流技术 电源 有限元法 动力响应 动力优化 DYNAMICAL optimum DESIGN OF THE MECHANICAL
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Optimum Design of Impedance Simulator for Phased Array Antnnas
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作者 吕昕 李世智 《Journal of Beijing Institute of Technology》 EI CAS 1994年第1期63+59-63,共6页
The impedance of a solid state active phased array antenna varing with frequency and beam scanning scanning angle be matched with the solid state active matching network (SSAMN). In order to adjust and measure the rad... The impedance of a solid state active phased array antenna varing with frequency and beam scanning scanning angle be matched with the solid state active matching network (SSAMN). In order to adjust and measure the radar conveniently and Securely, it is necessary for the impedance of the simulator of the phased array antennas to be optimized.Having selected the PIN dilde controlling circuits and the circuit parameters optimized,the simulator circuit is determined through numerical computation The experiment is given in support of the simulation. 展开更多
关键词 phase array antennas impedance inatching simulation optimum design active circuits
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Zemax-Based Optimum Structural Design of Probe of an Optical-Fiber Sensor 被引量:1
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作者 Hang Tianyuan Wang Xiaolei +2 位作者 Liu Feng Ye Song Chen Zhentao 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2018年第2期309-317,共9页
Bubble plumes are important during the process of air-sea exchange,and optical-fiber phase detection is a suitable way to observe bubble plumes entrained by breaking waves.This paper designs a new optical-fiber probe(... Bubble plumes are important during the process of air-sea exchange,and optical-fiber phase detection is a suitable way to observe bubble plumes entrained by breaking waves.This paper designs a new optical-fiber probe(OFP)made of sapphire to overcome the limitations of existing materials(e.g.,high brittleness,poor corrosion resistance,and narrow bandwidth)and thereby enhance the detection performance of the OFP by improving its structure.Based on total internal reflection and light refraction,a simulation model of the probe is established in the Zemax optical design software to optimize the probe tip and matching mode of the two probe tips.The results show that the optimum OFP tip is a conical sapphire one with a cone angle of 35°.Tests are then conducted on a bespoke OFP sensor,the results of which are consistent with those predicted theoretically.The simulation results lay the foundation for the integrated design of OFP sensors and the optimization of their internal optics.The findings could also be applied to OFPs with multiple tips. 展开更多
关键词 BUBBLE measurement OPTICAL-FIBER PROBE optimum design light transmission test ZEMAX OPTICAL simulation
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Research on High-Efficiency Cyclone Separators and Their Optimum Design 被引量:1
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作者 Shi Mingxian, Jin Youhai, Wu Xiaolin, Chen Jianyi, Liu Junren (United Research Institute of Applied Chemistry and Chemical Engineering, University of Petroleum, Beijing 100083) 《石油学报(石油加工)》 EI CAS CSCD 北大核心 1997年第S1期19-27,共9页
ResearchonHighEficiencyCycloneSeparatorsandTheirOptimumDesignShiMingxian,JinYouhai,WuXiaolin,ChenJianyi,Liu... ResearchonHighEficiencyCycloneSeparatorsandTheirOptimumDesignShiMingxian,JinYouhai,WuXiaolin,ChenJianyi,LiuJunren(UnitedRese... 展开更多
关键词 CYCLONE SEPARATOR flow field distribution of particle concentration optimum DESIGN efficiency pressure DROP multicyclone SEPARATOR
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Research of PDC Bit Compact Die With FEM and Optimum Method
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作者 ZhouSizhu LiChenggang +1 位作者 CaoJiguang HuaJian 《Petroleum Science》 SCIE CAS CSCD 2004年第1期59-64,82,共7页
In mould design, it is necessary for a designer to ensure that the cylinder has enough intensity in both the prestressed and synthesis states. An individual layer cylindrical mould cannot withstand a very high pressur... In mould design, it is necessary for a designer to ensure that the cylinder has enough intensity in both the prestressed and synthesis states. An individual layer cylindrical mould cannot withstand a very high pressure needed in polycrystalline diamond composite (PDC) production. So, multi-layer prepressure combination assemble moulds are often used. The analysis conducted here is to study the interaction of cylindrical layers and to explain how to obtain enough load capability with the lowest requirement of material performance. The ratio of the pressure cylinder radius of synthetic diamond is 3.27, which is close to the optimal value and can be used as structure size in a design for PDC bit compact die. There is a linear relationship between the internal and external pressures under a special tangent stress on the inner wall of the pressure cylinder. So, when two of the three parameters (the internal pressure, external pressure, and the requirement value of the tangent stress on the inner wall of the pressure cylinder) are given, the third can be obtained. The sleeve acts as a bridge?between the pressure cylinder and the steel belts. The optimum model developed in this paper can be used in PDC bit compact die design and other similar prestressed cold extrusion die design. 展开更多
关键词 PDC bit COMPACT DIE optimum design finite element method
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Increasing the range accuracy of three-dimensional ghost imaging ladar using optimum slicing number method
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作者 杨旭 张勇 +4 位作者 徐璐 杨成华 王强 刘越豪 赵远 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第12期319-324,共6页
The range accuracy of three-dimensional(3D) ghost imaging is derived. Based on the derived range accuracy equation, the relationship between the slicing number and the range accuracy is analyzed and an optimum slici... The range accuracy of three-dimensional(3D) ghost imaging is derived. Based on the derived range accuracy equation, the relationship between the slicing number and the range accuracy is analyzed and an optimum slicing number(OSN)is determined. According to the OSN, an improved 3D ghost imaging algorithm is proposed to increase the range accuracy. Experimental results indicate that the slicing number can affect the range accuracy significantly and the highest range accuracy can be achieved if the 3D ghost imaging system works with OSN. 展开更多
关键词 ghost imaging range accuracy optimum slicing number
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Short Range Top Attack Trajectory Optimum Design Based on Genetic Algorithm
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作者 唐胜景 许晓霞 戴斌 《Journal of Beijing Institute of Technology》 EI CAS 2006年第1期13-16,共4页
A flying-body is considered as the reference model, the optimized mathematical model is established. The genetic operators are designed and algorithm parameters are selected reasonably. The scheme control signal in sh... A flying-body is considered as the reference model, the optimized mathematical model is established. The genetic operators are designed and algorithm parameters are selected reasonably. The scheme control signal in short range top attack flight trajectory is optimized by using genetic algorithm. The short range top attack trajectory designed meets the design requirements, with the increase of the falling angle and the decrease of the minimum range. The application of genetic algorithm to top attack trajectory optimization is proved to be feasibly and effectively according to the analyses of results. 展开更多
关键词 genetic algorithm short range top attack trajectory optimum design
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An Optimum Method for a Grooved 2D Planar Ion Trap Design
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作者 JI Wei-Bang WAN Jin-Yin +1 位作者 CHENG Hua-Dong LIU Liang 《Chinese Physics Letters》 SCIE CAS CSCD 2011年第7期111-113,共3页
We investigate an effective grooved 2D ion chip design and optimize the ratio between the size of the rf electrodes and the groove.We calculate the optimal size of the groove using the analytical model,which was intro... We investigate an effective grooved 2D ion chip design and optimize the ratio between the size of the rf electrodes and the groove.We calculate the optimal size of the groove using the analytical model,which was introduced by House,and the optimum result is obtained.We also obtain the simulated scattering points with the finite element analysis method.The analytical curve and simulated scattering points are coincident with each other.It is shown that this analytical model also fits for the grooved planar ion chip.Thus the optimum grooved 2D planar ion chip design could be obtained.It is effective for scalable quantum information processing. 展开更多
关键词 optimum PLANAR PROCESSING
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OPTIMUMDESIGNOFSTREAMLINEDEXTRUSIONDIESBASEDONUPPERBOUNDMETHODANALYSIS
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作者 Huang Xiang Chen Wenliang Zhou Rurong Department of Mechanical Engineering,NUAA29 Yudao Street, Nanjing 210016, P. R. China 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 1996年第1期105-111,共7页
A more universal and flexible method of constructing the streamlined die surfaces is presented. The streamlined die surfaces are interpolated by the arbitrarily cross sectional shapes of the die entrance and exit. Th... A more universal and flexible method of constructing the streamlined die surfaces is presented. The streamlined die surfaces are interpolated by the arbitrarily cross sectional shapes of the die entrance and exit. The boundaries of the die entrance and exit are represented by Ferguson curves with tension parameters. By adjusting the tension parameter, the cross sectional shapes of the die entrance and exit with line segments can be accurately constructed. The upper bound method is used to analyze the procedure of extrusion, the pseudo independent parameters in kinematically admissible velocity and die surface are computed by minimizing the extrusion load, so the optimum die surface is obtained. The effects of frictional condition, die length, area reduction and product shaped complexity are discussed in relation to the extrusion load. 展开更多
关键词 EXTRUSION extrusion dies optimum design upper bound method curved surface
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THE THEORY AND METHOD OF OPTIMUM PLANNING OF A MINING AREA
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作者 王玉浚 张先尘 韩可琦 《Journal of China University of Mining and Technology》 1991年第1期37-45,共9页
Being aimed at the vital decisive problems to be solved during.making long-term planning and overall planning of the development of coal mining areas of China, this paper presents comprehensive theories and methods fo... Being aimed at the vital decisive problems to be solved during.making long-term planning and overall planning of the development of coal mining areas of China, this paper presents comprehensive theories and methods for the choice of mining area optimum planning schemes by use of combining technic analysis with system simulation and system optimization.The main contents are as follows: the prediction of technic and economic indexes in the developing process of existing mining areas and new mining area, including computer simulation analysis of maximum possibility of output growth in a working mine, the effect of technic progress on productive development, and grey predictive model of the change of technic and economic indexes; the dynamic simulation model of the mining area system, including five subsystem models; mining area output, investment, economic benefit, number of workers and staff of a mining area, mining area population, and ecologic environmental dynamic change under different schemes;the 0--1 programming, the goal programming and the analytic hierarchy process for contrast analysis optimization of mining area planning schemes. 展开更多
关键词 technic analysis optimum planning dynamic simulation
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ON OPTIMUM DESIGN OF THE SHEARER DRUM
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作者 陶驰东 陈翀 《Journal of China University of Mining and Technology》 1996年第1期15-27,共13页
On the basis of the model experiments, a software for optimum design of the shearer drum has been developed, and the main parameters of a shearer drum also have been optimized. The combination of the techniques of opt... On the basis of the model experiments, a software for optimum design of the shearer drum has been developed, and the main parameters of a shearer drum also have been optimized. The combination of the techniques of optimization with the mod el experiment makes the designing and theoretical systems of the shearer drum more perfect. 展开更多
关键词 shearer drum model experiment optimum design
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Optimum PN Guidance Law for Maneuvering Target
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作者 孙宝彩 祁载康 《Defence Technology(防务技术)》 SCIE EI CAS 2007年第2期121-124,共4页
An optimum PN guidance law for maneuvering target is developed using optimal control theory.By estimating the target position and setting the cost function,the guidance law can be deduced even without knowing the miss... An optimum PN guidance law for maneuvering target is developed using optimal control theory.By estimating the target position and setting the cost function,the guidance law can be deduced even without knowing the missile lateral acceleration.Since the quadratic cost function can make a compromise between the miss distance and the control constraint,the optimum guidance law obtained is more general.Also,introduced line of sight rate as the input,a practical form of this guidance law is derived.The simulation results show the effectiveness of the guidance laws. 展开更多
关键词 控制 导航技术 飞机 机动性能
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Optimum thickness of Mssbauer absorber
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作者 CHEN Yi-Long YI Fan, ZHANG Fu-Liang(Department of Physics of Wuhan University,Wuhan 430072) 《Nuclear Science and Techniques》 SCIE CAS CSCD 2000年第2期91-95,共5页
If recoilless fraction fa is available, the optimum absorber thickness dopt can be calculated by maximizing the signal to noise ratio or Q factor. In this work,an approach presented is to get experimental Qexp as a fu... If recoilless fraction fa is available, the optimum absorber thickness dopt can be calculated by maximizing the signal to noise ratio or Q factor. In this work,an approach presented is to get experimental Qexp as a function of the thickness,andthen fitting Qexp by its theoretical expression gives fa value. At last the dopt value is deduced from a maximum on the fitted curve.In such a way, thicknesses of six specimens with quadrupole or magnetic hyperfinc splitting were optimized. 展开更多
关键词 穆斯堡尔光谱 穆斯保尔效应 信噪比 最佳吸收厚度 噪声 光谱吸收
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极端热湿气候区珊瑚砂外墙传热系数优化——以琼海为例
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作者 高圣迪 谢静超 +2 位作者 徐鑫 张广凯 刘加平 《建筑节能(中英文)》 2025年第2期67-75,共9页
极端热湿气候区以高温、高湿、强辐射为气候特征,以琼海为例的多数地区目前已经不充分满足夏热冬暖地区的区划,如果继续使用夏热冬暖地区的规范进行设计,可能会在一定程度上造成能量损耗。为了体现现有标准在极端热湿气候区的可优化性,... 极端热湿气候区以高温、高湿、强辐射为气候特征,以琼海为例的多数地区目前已经不充分满足夏热冬暖地区的区划,如果继续使用夏热冬暖地区的规范进行设计,可能会在一定程度上造成能量损耗。为了体现现有标准在极端热湿气候区的可优化性,以琼海为例,以珊瑚砂外墙为研究对象,通过模拟计算得到空调负荷特征与外墙传热特性,以此为基础考虑经济性指标计算珊瑚砂外墙最佳保温层厚度,并给出该地区外墙传热系数限值的优化方向。研究表明,琼海地区公共建筑全年需要供冷,在室内外温差、热流密度上均存在特殊的“双向流”特征,表明外墙传热系数并非越小越好;当保温层厚度由0 mm增加至80 mm时,全年累计冷负荷由117.6 kW·h/m^(2)降低至107.5 kW·h/m^(2),总成本先降低后升高,谷值为37.0元/m^(2),此时保温层最佳厚度为20 mm,投资回收期为7.8年;在20 mm保温层厚度下的外墙传热系数为0.98 W/(m^(2)·K),高于现有标准的限值,因此,若要实现保温层经济性最优,现有标准的外墙传热系数的限值应调大。研究结果为以琼海为代表的极端热湿气候区外墙结构设计提供数据支撑和优化参考。 展开更多
关键词 极端热湿气候区 珊瑚砂外墙 双向流 空调负荷特性 保温层最佳厚度
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一种确定吸振器最优阻尼的新型方法
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作者 田戚可人 《噪声与振动控制》 北大核心 2025年第1期269-275,共7页
采用独立完备振动变量,推导正弦谐波扰动力作用下2自由度系统主质量的四参数通用位移振幅放大倍数。为使最大的位移振幅放大倍数取得最小值,运用洛必达第一法则,统一求解3种阻尼动力吸振器的最优阻尼比。最大的位移振幅放大倍数与阻尼... 采用独立完备振动变量,推导正弦谐波扰动力作用下2自由度系统主质量的四参数通用位移振幅放大倍数。为使最大的位移振幅放大倍数取得最小值,运用洛必达第一法则,统一求解3种阻尼动力吸振器的最优阻尼比。最大的位移振幅放大倍数与阻尼比构成V字型关系。以固定点的有解析式的极大值近似代替无解析式的最大值,相对误差为0.266 8%至1.806 8%。 展开更多
关键词 振动与波 阻尼动力吸振器 独立完备振动变量 最大位移振幅放大倍数最小化 洛必达第一法则 最优阻尼
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技术进步能有效促进粮食安全与农民增收双目标实现吗?——来自全国省级面板数据的经验证据 被引量:1
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作者 马晓河 周婉冰 《农村金融研究》 北大核心 2024年第7期3-15,共13页
技术进步能显著提高粮食安全与农民增收双目标实现的有效性。论文基于2002—2022年全国31省的面板数据,通过耦合协调度模型、DEA-Malmquist指数模型及面板数据双向固定效应模型等进行实证分析。研究表明:技术进步能明显提高粮食安全与... 技术进步能显著提高粮食安全与农民增收双目标实现的有效性。论文基于2002—2022年全国31省的面板数据,通过耦合协调度模型、DEA-Malmquist指数模型及面板数据双向固定效应模型等进行实证分析。研究表明:技术进步能明显提高粮食安全与农民收入一致性水平,其中,技术变化对粮食安全与农民收入一致性水平的影响更为显著,该结论在经过一系列稳健性检验后依旧成立。在经济发展水平相对落后的西部地区以及地形更为崎岖的丘陵地区,技术进步对粮食安全与农民收入一致性水平的促进作用更强。此外,技术进步可以通过促进农业适度经营规模水平提升进而间接作用于粮食安全与农民增收双目标的实现。以此为基础,论文提出了相应的政策建议,以充分发挥技术进步对粮食安全与农民增收双目标实现的促进作用。 展开更多
关键词 技术进步 粮食安全与农民增收 耦合协调度 适度规模经营
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ATIS与收费策略下多用户随机均衡的效率损失
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作者 张俊婷 朱文龙 +1 位作者 叶顺强 陈华友 《运筹与管理》 CSSCI CSCD 北大核心 2024年第4期147-152,I0046,I0047,共8页
考虑ATIS作用的交通网络,用户具有交通信息接受程度的异质性;进一步,考虑实施道路收费策略情形下,用户具有时间价值的异质性;基于这两类异质性,研究了ATIS下异质性交通网络的效率损失问题。用户对ATIS系统的响应程度,亦即ATIS信息遵从率... 考虑ATIS作用的交通网络,用户具有交通信息接受程度的异质性;进一步,考虑实施道路收费策略情形下,用户具有时间价值的异质性;基于这两类异质性,研究了ATIS下异质性交通网络的效率损失问题。用户对ATIS系统的响应程度,亦即ATIS信息遵从率,是影响ATIS系统运行效率的关键因素。因此,通过ATIS信息遵从率参数的引入,将用户分为不同类型。假设用户均按照随机方式进行择路,建立了基于时间准则与基于费用准则的多用户Logit-随机均衡变分不等式。当系统总出行成本包含收费时,建立了多用户双准则系统最优模型,界定了多用户Logit-随机均衡相对于多用户系统最优的效率损失,推导出效率损失上界;进一步分析了当路段阻抗函数为多项式情形时,引入了自由流出行时间参数,给出了双准则下效率损失上界的解析式,分析了效率损失上界与各参数之间的关系。研究结论表明,双准则下效率损失上界为ATIS信息遵从率的减函数;此外,效率损失上界与路段阻抗函数、用户时间价值及其对路网的熟悉程度、路网本身复杂程度等因素有关。最后,通过算例验证了结论的有效性。 展开更多
关键词 ATIS 道路收费 多用户随机均衡 多用户系统最优 效率损失
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基于耦合辐射模型的太阳能集热器倾角优化研究
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作者 王恩宇 王天生 +2 位作者 张学友 沈海笑 黄运兴 《可再生能源》 CAS CSCD 北大核心 2024年第7期894-900,共7页
为了使太阳能集热器获得更多的太阳辐射量,须对集热器倾角进行优化。文章在建立倾斜面太阳辐射计算模型的基础上,分别优化直接辐射、散射辐射的计算过程。以太阳能集热器运行期间倾斜面接收最大辐射量为求解目标,借助MATLAB对集热器倾... 为了使太阳能集热器获得更多的太阳辐射量,须对集热器倾角进行优化。文章在建立倾斜面太阳辐射计算模型的基础上,分别优化直接辐射、散射辐射的计算过程。以太阳能集热器运行期间倾斜面接收最大辐射量为求解目标,借助MATLAB对集热器倾角进行优化分析,得到月度最佳倾角和年度最佳倾角。其中天津地区的太阳能集热器年度最佳倾角为36.3°,比当地纬度略小;月度最佳倾角为10~64°,表现为夏季小冬季大的特点。相较于水平放置,在年度最佳倾角和月度最佳倾角下,太阳能集热器接收的年太阳辐射量可分别增加12.4%,17.3%;相较当地纬度作为倾角时,以月度最佳倾角值逐月调整接收的太阳辐射量可增加5.0%。分别以广州、拉萨、济南和长春为例,计算得到上述地区的年、月最佳倾角。对不同地区进行对比分析发现,直接辐射占比较高的地区逐月改变最佳倾角可获得更高的能量增益。 展开更多
关键词 太阳辐射模型 集热器 最佳倾角 设计优化
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基于疫苗接种的SEIHRVI传染病模型分析与最优控制
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作者 薛亚奎 任亚鑫 《沈阳大学学报(自然科学版)》 CAS 2024年第1期77-85,F0003,共10页
为研究疫苗接种对控制传染病的影响,建立了具有标准发生率的传染病模型。通过推导得出模型的基本再生数,给出地方病平衡点的存在条件。借助构造Lyapunov函数证明了平衡点的全局稳定性。应用Pontryagin最大值原理分析了最优控制问题,得... 为研究疫苗接种对控制传染病的影响,建立了具有标准发生率的传染病模型。通过推导得出模型的基本再生数,给出地方病平衡点的存在条件。借助构造Lyapunov函数证明了平衡点的全局稳定性。应用Pontryagin最大值原理分析了最优控制问题,得出最优控制策略。结果表明:提高疫苗接种率和效力能有效控制疾病传播;注意自我保护,及时接种以及重视治疗一定程度上可减小疾病爆发的规模。 展开更多
关键词 稳定性理论 疫苗接种 传染病模型 最优控制 数值模拟
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