排序方式: 共有7条查询结果,搜索用时 15 毫秒
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针对同时兼顾大范围搜索和精确识别目标的迫切需求,研制了一种大变倍比红外变焦成像系统,设计两片独立运动的变倍镜及一片补偿镜,通过两个变倍镜级联的方式获得大变倍比。结合系统运动镜片多及变焦曲线复杂的特点,采用直线运动机构实现镜片变焦运动,使用集成编码器及螺纹丝杆的直线电机作为驱动。通过有限元仿真开展了系统力学分析,所设计镜片最大位移为3.04×10-3 mm。成像系统适用于中波红外制冷式640×512焦平面阵列探测器,变倍比达到55倍。实验室成像及外场实景成像的结果表明,系统在焦距由6 mm至330 mm连续变化的过程中成像清晰、像质良好,验证了系统的连续变焦成像性能,该设计合理可靠。研究成果在搜索、跟踪、侦察、监视等方面有广阔的应用前景。 相似文献
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Taihu Lake, the third largest freshwater lake in China, is located in the Chanjiang Delta of the Yangtze River. Its waters are used by agriculture, industry and as major drinking water for several cities including Shanghai and Wuxi. The lake also is important for tourism, aquaculture and flood control. Taihu Lake and its surrounding areas are facing three major water-related threats: deteriorating water quality with inflow and runoff from its watershed; flooding during the rainy seasons; and water shortages during drier months. Noxious algae blooms are occurring with increasing frequency and water quality continues to decline. Remedial actions implemented to date have been ineffective. This paper proposes that the problems could be remedied by constructing a by-pass channel (BPC), which would divert low-quality water from the lake during low precipitation periods and allow better quality water to flow into the lake during high flow periods. This remedial action would simultaneously deal with the deteriorating water quality of Lake Taihu and maintain its water level at a desired level. A preliminary assessment of this strategy shows that, if the BPC were implemented, the water quality of Taihu Lake would be improved significantly in few years, the flood disaster would be greatly mitigated, and the water shortage problem in the basin would be alleviated. 相似文献
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众多的软件开发过程到底是为我们解决的问题多,还是造成的问题更多?它们是否真的能够为改进团队的工作方式提供深刻的见解和所需的指导?文中对当代软件开发过程所面临的问题做了深刻的分析,并指出为什么我们现在拥有如此多的过程。 相似文献
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非分散红外(NDIR)气体传感器是机动车尾气CO和CO2检测系统的核心部件,一般使用定标的方法来计算待测气体的浓度。针对传统定标方法生成的定标曲线在低于CO和CO2满量程10%范围内的拟合优度不能满足实际使用要求的问题,提出了一种基于最小二乘加权拟合法的定标方法,通过对低浓度点赋予更大的权重和增加定标点的数目来改善定标曲线在低浓度范围内的拟合优度。采用该方法的定标结果表明,定标曲线在整个量程范围内的定标误差均小于2%。所提出的定标方法具有较高的应用价值。 相似文献
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Ji-Long Yao;Zhen-Yu Zhang;Bo-Yu Xu;Ting Li;Pan-Wei Bai;Wen-Peng Liang;Tao Xie; 《American Institute of Chemical Engineers》2024,70(7):e18433
Solar methane dry reforming (MDR) reaction is a highly promising technology for long-term energy storage due to its eco-friendly nature and high-value-added product. Numerous present works mainly focused on the photo-thermal catalysts, few of them discussed photo-thermal coupled kinetics. Therefore, this article proposed a light-dependent kinetic model for MDR. In the model, not only the effect of temperature and species concentration were included, but also the radiation was considered, which is different from the conventional kinetic model. Solar radiation is divided into thermal-effect and light-promoted-effect part and coupled with the heat and mass transportation and chemical reaction. The average relative error of established model is only 0.97% under dark condition, and 13.2% under light condition. Then, the impacts of operating condition in a cavity reactor were investigated by established coupled optical-photo-thermal dynamics–computational fluid dynamic model to improve the efficiency of chemical conversion. The results show that when GHSV is 48.21 h−1, light increased the reaction rate by 1.59 times and thermochemical energy storage efficiency by 18.5%. When CH4/CO2 = 1, the formation rates of syngas and thermochemical energy storage efficiency are the highest. This work provides a highly coupled photo-thermal kinetic model and a method for modeling and condition optimization. 相似文献
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为了满足红外搜索跟踪应用对于红外导引装置进行精确识别与定位的迫切需求,本文进行了一种基于“猫眼效应”的主动探测中波红外搜跟系统(ADMWIRSTS)研制,该系统主要由光束控制分系统和红外搜跟分系统组成。光束控制分系统采用光机一体二维指向镜实现系统方位、俯仰方向控制功能,可覆盖360°×90°全空域范围。红外搜跟分系统采用两个中波红外制冷式640×512焦平面探测器进行了共孔径扩束、红外与照明激光合束、红外搜索、两级跟踪光机设计。本工作中,进行了系统集成设计及结构有限元分析,对外场景物进行了搜索成像及两级跟踪成像,并在实验室对主动探测技术进行了实验验证。实验结果显示,ADMWIRSTS可通过照明激光的回波实现对中波红外导引或红外探测系统进行红外搜索跟踪成像及精确识别定位。上述工作对于发展紧凑型高精度红外搜跟与激光压制一体化系统等具有重要的技术意义和实际应用价值,在装备、物资和基础设施防护方面有广阔的应用前景。 相似文献
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