共查询到20条相似文献,搜索用时 31 毫秒
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根据水雷隐身需要,分析了不同外形水雷的目标强度与隐身之间的关系,并对一些典型外形进行了目标强度计算.同时.在非消声水池中对按比例缩小的外形样品进行了声脉冲测量,将试验测得的目标强度值与理论计算的目标强度值相比较,认为波纹盒形水雷有较好的外形隐身效果. 相似文献
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本文提出了几个潜艇目标强度测量方法。这些方法只需利用船上声纳。无需特殊设备.而实施则易于常规法,精度接近应答法,因而很有实用价值。 相似文献
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本文是对某次海上试验的总结。用常规方法测量了某常规动力潜艇的目标强度与舷角的关系,取得了较满意的结果。 相似文献
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水下机动目标跟踪技术研究 总被引:2,自引:0,他引:2
水下目标跟踪是海洋国土监视、反潜战等环境下的关键技术。以往的跟踪滤波算法主要基于卡尔曼滤波、扩展卡尔曼滤波等算法,这些方法实现比较复杂,滤波精度不高。最近出现了不敏卡尔曼滤波、粒子滤波、转换瑞利滤波、双多基地跟踪算法等,需要研究这些算法在水下目标跟踪中的性能。总结对比了国内外学者在此领域的研究成果,得出了这些滤波算法在水下目标跟踪中的优缺点。重点论述了纯角度跟踪和非线性滤波算法的发展、在水下目标跟踪中的应用以及多基地声纳跟踪水下目标技术的发展,回顾了机动目标跟踪和多目标数据互联算法。研究表明,非卡尔曼滤波算法能够更高精度地跟踪水下目标,双多基地声纳是今后发展的重点。为今后的研究提供参考。 相似文献
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水下运动目标的被动测量和测量的实时性是水声测量设备的难点所在。设计了一套水下运动目标被动测量数据实时处理系统,它综合利用水声技术、计算机技术、电子技术等手段,采用球面内插法实现对水下运动目标被动测量数据的实时处理,并实时显示水下目标运动轨迹。可应用于不同类型水下目标海上试验的定位跟踪测量,具有良好的通用性和海上适应性,并可推广应用于舰船、潜艇等其它水中运动目标的定位跟踪测量,具有明显的军事、经济效益。 相似文献
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高压喷嘴作为高压水射流系统中的一个重要元件,其构造和特性直接影响高压水射流清洗系统性能的优劣,因此对高压喷嘴结构的研究具有非常重要的意义。文章通过对高压喷嘴进行结构设计、模型建立、数值模拟、结果分析,将靶面打击压强及打击面积作为主要的分析参数,对不同喷嘴结构和靶距下的高压水射流特性进行分析,得出最优的高压喷嘴结构以及打击距离。结果表明:渐缩形喷嘴的出口流量比锥形喷嘴出口流量增加了4.2%,比流线形喷嘴出口流量增加了1.6%;渐缩形喷嘴冲击靶距由50.68 mm减小到10 mm时,射流大于10 MPa的平均动压力值由27.2 MPa增加到31.9 MPa,射流大于40 MPa的平均动压力值由47.9 MPa增加到66.9 MPa;对应射流靶距为30 mm时,大于10 MPa的有效冲击面积最大,可达到8.3 cm2。
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Simulation of soft smart hydrogels responsive to pH stimulus: Ionic strength effect and case studies
Hua Li Yong Kin Yew 《Materials science & engineering. C, Materials for biological applications》2009,29(7):2261-2269
In this paper, the influence of the ionic strength of surrounding bath solution is presented and discussed on the responsive performance of soft pH-sensitive hydrogels to environmental change in solution pH. The numerical simulations are based on a chemo-electro-mechanical formulation previously termed the multi-effect-coupling pH-stimulus (MECpH) model. It is improved further in this paper via incorporation of the finite deformation theory into the mechanical equilibrium governing equation. The MECpH model is composed of coupled nonlinear partial differential equations and solved by a meshless numerical approach called the Hermite-cloud method with the modified Newton iteration technique. After examination of the improved MECpH model by comparing the simulation results with experiments available in literature, several case studies are carried out to discuss the effects of the ionic strength of surrounding solution on the distributive variations of the diffusive ion concentrations and electric potential as well as the deformation of the pH-stimulus-responsive hydrogels, when the hydrogels are immersed in buffered bath solutions. 相似文献
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Daniel Fay Neville A. Stanton Aaron P. J. Roberts 《Theoretical Issues in Ergonomics Science》2019,20(5):632-658
The quickening pace of technological advancement will require submarine command teams of the future to process greater volumes of data, potentially with fewer operators. User interfaces (UIs) have evolved to meet current requirements, but this iterative process has propagated legacy design paradigms that may be unsuitable for future system specifications. To understand where improvements may be made, a review of current submarine control room operation is presented, using a sociotechnical systems approach. The social (command team: work, structure, and communication) and technical (combat systems) components are presented for context. An emphasis is placed on Sonar and Target Motion Analysis due to their prevalence within the control room. It was found that current UIs place increased cognitive requirements on operators due to the complexity and quantity of information presented. It is proposed that adopting an Ecological Interface Design (EID) approach could reduce such issues, facilitating effective resource allocation to manage increased data volumes. EID has been demonstrated to be effective across many domains, however, its exploitation in submarine control rooms is limited. Advances in modern submarine combat systems have promoted greater flexibility, providing an opportunity to utilise contemporary design philosophies for designing intuitive interfaces to maintain effective control room performance. 相似文献
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首先建立了脉冲激励下车辆-包装物的动力学方程,然后运用Newmark和Rungekutta数值积分法获得该动力学方程的数值解,最后讨论了冲击脉冲大小对运输包装产品加速度幅值的影响. 相似文献
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A mathematical model of two-dimensional flows of PIM derived from the momentum, continuity equations and theheat transfer equation is obtained. The formula of calculating the flow conductance and the pressure equation arededuced when the no slip boundary 相似文献
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Based on a transient temperature distribution of a 45 steel cylinder workpiece during magnetic quenching, which was obtainedby solving the governing equations with nonlinear boundary on the condition of coupling effects of heat-magnetism. Accordingto the 相似文献
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The research on numerical simulation for combinative process of SPF/DB is carried out in this paper. The contacting problem of sheets is analyzed by using the penalty method. In order to solve the contact problem of different parts of the sheet, a new alg 相似文献