科创中国

为了改进目前检测雷达告警设备的多波段分立式雷达射频信号模拟器,采用PC104+ CPLD设计了一种通用雷达射频信号模拟器,创新地设计了分频功率回退谐波抑制方法.根据电子对抗接收机的工作特性,模块化雷达射频信号模拟器的结构组成,并对各模块进行了优化设计.实践证明该模拟器具有良好的通用性和可扩展性.

空空雷达主动弹已成为打击防区外预警机、空中加油机、电子干扰机等目标的重要杀手.针对该类型导弹,分析了对其告警探测的技术可行性,以无源引导思想为牵引,提出了采用机载无源定位技术进行导弹告警探测的思想,建立了导弹运动及定位模型.仿真结果表明,该方法具有较好的探测性能.

By recording nocturnally migrating passerines with tracking radar we have investigated how coastlines affect the migrants' flight paths. Birds could use coastlines as an orientation aid or as a reference cue to compensate for wind drift while mi- grating. However, on the small scale of Falsterbo Peninsula in southern Sweden, we found very little effect of coastlines on migrants flight paths, irrespective of altitude. We tracked 2 930 migrants in three autumn and two spring seasons, at altitudes from 60 up to 3 000 meters. We compared tracks of migrants flying in three different areas, which correspond to the three main coastlines, and can demonstrate that the orientation of the tracks did not differ in a way consistent with the coastlines between the areas in autumn, and showed only a slight effect in spring. This is in accordance with earlier infrared device monitoring in Falsterbo, but contrary to earlier visual observations. It supports the view of nocturnally migrating passerines as mainly broad-front migrants. Even though the coastlines on the scale of the peninsula affected the flight paths very little, it is possible that the coastline has an effect on a larger regional scale, by migrants avoiding long sea crossings and thereby being funneled towards the peninsula, but this remains to be investigated [Current Zoology 60 (5): 660-669, 2014].

有效掩护区是定量研究对星载SAR干扰效能比较简洁的手段.通过定义对星载SAR压制式干扰的有效掩护距离和有效掩护区,并结合雷达干扰统一方程,研究建立了对星载SAR干扰的仿真模型,并根据不同时期SAR所采取的天线,引入二种三维天线增益模型进行了仿真,可以得到不同输入条件下干扰掩护区,仿真结果验证了模型的合理性,有利于定量分析和评估对星载SAR的干扰效能.

随着舰载超视距武器系统的广泛应用,舰载火控雷达的效能对武器系统的影响越来越明显,大气是影响火控雷达作用距离的最主要原因之一,因此研究大气对舰载火控雷达效能的影响很有必要.该文从电磁衰减出发研究了大气对电磁波能量的影响;从电磁折射入手分析了大气对电磁波传播路径的影响.

C3I系统是实现指挥、控制、通信和情报的军事电子综合信息系统,雷达作为系统中的重要组成部分,对C3I系统作战效能的发挥有重要影响.针对雷达对目标探测生成的目标航迹问题,基于航迹质量随着目标距离增加而减小的假设,依据雷达性能确定航迹质量服从指数分布,首先提出了基于雷达烧穿距离的航迹质量评估模型;其次,根据历史航迹数据,依据马尔可夫线性估计理论枸建误差协方差估升矩阵,建立了航迹质量预测模型;由航迹质量是随着航迹误差减少而提高的原则以分段形式建立航迹误差与航迹质量的映鼽由映射表确定航迹质量值;最后通过Mallab进行仿真,保证了模型的有效性.

Migrating landbirds are known to follow coast lines and concentrate on peninsulas prior to crossing water bodies, es- pecially during daylight but also at night, creating enhanced potential collision hazards with man-made objects. Knowing where these avian migration "hot-spots" occur in time and space is vital to improve flight safety and inform the spatial planning process (e.g. environmental assessments for offshore windfarms). We developed a simple spatial model to identify avian migration hot- spots in coastal areas based on prevailing migration orientation and coastline features known, from visual and radar observations, to concentrate migrating landbirds around land masses. Regional scale model validation was achieved by combining nocturnal passerine movement data gathered from two tier radar coverage (long-range dual-polarization Doppler weather radar and short- range marine surveillance radar) and standardised bird ringing. Applied on a national scale, the model correctly identified the ten most important Danish coastal hot-spots for spring migrants and predicted the relative numbers of birds that concentrated at each site. These bird numbers corresponded well with historical observational data. Here, we provide a potential framework for the es- tablishment of the first three-dimensional avian airspace sanctuaries, which could contribute to more effective conservation of long-distance migratory birds [Current Zoology 60 (5): 680-691, 2014].

"西环"除尘还你一片蓝天无锡市西漳环保设备有限公司创建于1978年,是全国铸造行业综合百强企业、高新技术企业,是一家以设计、生产除尘设备为主的专业环保产品制造厂家.公司具有三十多年铸造行业环保设备设计、制造经验,拥有雄厚的技术力量和高素质的管理团队,具备齐全的检测手段和强有力的售后

本文采用了包括地质雷达在内的多种勘察手段对西安城墙某段海墁病害进行了研究.研究思路逐步深入并根据阶段性成果调整研究方案,以获得解决城墙病害的针对性成果.基于研究成果阐明了病害产生的原因,并提出了治理方案.同时对研究手段和治理方法进行归纳,为文物病害勘察提供了可以借鉴的思路和经验.

"西环"除尘还你一片蓝天无锡市西漳环保设备有限公司创建于1978年,是全国铸造行业综合百强企业、高新技术企业,是一家以设计、生产除尘设备为主的专业环保产品制造厂家.公司具有三十多年铸造行业环保设备设计、制造经验,拥有雄厚的技术力量和高素质的管理团队,具备齐全的检测手段和强有力的售后服务保障.公司通过了ISO9001国际质量管理体系和ISO14001环境管理体系认证.公司与同济