一种UUV集群抵近目标侦测决策效率评估方法研究          下载免费PDF全文

齐嘉慧  崔培  姜楷娜  吕俊军 《数字海洋与水下攻防》2024,(2):231-235

为实现对不同 UUV 集群自主抵近目标侦测任务中决策效率的评估,分析了被测目标采取不同策略时 UUV 集群决策灵活度,提出了评估 UUV 集群决策效率的 5 个指标：任务准备时间、目标停车集群响应时间、目标转向集群响应时间、目标旋回集群响应时间和目标加速集群响应时间,并建立了评估指标体系。 参考已有试验测试结果,基于字典序法对 5 种类型的 UUV 集群决策效率进行综合评估,并分析了该方法的优缺点,为不同类型 UUV 集群决策效率评估提供了研究思路。  相似文献   

东秦岭中段板厂铜钼矿床S、Pb同位素对成矿物质来源的示踪作用          下载免费PDF全文

吴帅吉  陈建立  陈守余  李照义  昝培 《地质找矿论丛》2020,35(1):42-51

东秦岭钼矿带是我国最重要的钼多金属成矿带,近年来在东秦岭板厂地区取得了新的找矿突破。本文利用区域成矿动力学、硫化物的硫、铅同位素组成研究,结合成矿地质特征,对板厂铜钼多金属矿床成矿物质来源进行示踪,并以板厂矿床为基点总结东秦岭钼矿带的稳定同位素时空分布特征。板厂矿床12件硫化物样品δ(34S)范围为1.2×10-3~5.7×10-3,平均值0.6×10-3,与地幔(0±3×10-3)硫同位素值相近;东秦岭钼矿床δ(34S)位素值有随成矿时代渐新而逐渐升高的趋势,印支期钼矿床(221~226Ma)δ(34S)同位素值偏负,燕山期第一阶段钼矿床(138~151Ma)δ(34S)值由"0"值向正值变化,燕山期第二阶段钼矿床(113~131 Ma)δ(34S)值较高(平均4.93‰)。板厂矿床深部硫化物206Pb/204Pb值为17.121~17.798,207Pb/204Pb值为15.369~15.433,208Pb/204Pb值为36.867~37.485,具有明显的低放射性成因铅特征,其铅同位素组成与华北克拉通南缘的类熊耳群和太华群相似,幔源特征明显;浅部硫化物铅同位素值相对较高,206Pb/204Pb值为18.266~18.392,207Pb/204Pb值为15.560~15.622,208Pb/204Pb值为37.611~38.438,反映了造山带混合铅特征。板厂矿床形成于中国东部构造体制转折阶段,深部构造体制重新调整导致地幔物质上侵以及壳幔混合物的重新熔融,岩浆沿着深大断裂上涌,并将一定规模的含矿流体运移至浅部,由于物理化学条件的变化以及浅部流体的混合,成矿流体在最终构造薄弱带沉淀Cu、Mo等金属,形成板厂铜钼多金属矿床。综上,在晚侏罗世-早白垩世,东秦岭地区地幔熔体活动强烈,板厂铜钼多金属矿床成矿物质来源以幔源为主,有少量壳源物质混入。  相似文献   

Acoustic backscattering measurement from sandy seafloor at 6–24 kHz in the South Yellow Sea     

Guangming Kan  Baohua Liu  Zhiguo Yang  Shengqi Yu  Lehua Qi  Kaiben Yu  Yanliang Pei 《海洋学报(英文版)》2019,(5)

The acoustic bottom backscattering strength was measured at the frequency range of 6–24 kHz on a typical sandy bottom in the South Yellow Sea by using omnidirectional sources and omnidirectional receiving hydrophones. In the experiment, by avoiding disturbances due to scattering off the sea surface and satisfying the far-field condition, we obtained values of acoustic bottom backscattering strength ranging from –41.1 to –24.4 dB within a grazing angle range of 18°–80°. In the effective range of grazing angles, the acoustic scattering strength generally increases with an increase in the grazing angles, but trends of the variation were distinct in different ranges of frequency, which reflect different scattering mechanisms. The frequency dependence of bottom backscattering strength is generally characterized by a positive correlation in the entire frequency range of 6–24 kHz at the grazing angles of 20°, 40° and 60° with the linear regression slopes of 0.222 9 dB/kHz, 0.513 0 dB/kHz and 0.174 6 dB/kHz, respectively. At the largest grazing angle of 80°, the acoustic backscattering strength exhibits no evident frequency dependence.  相似文献   

Fingerprints of the Kerguelen Mantle Plume in Southern Tibet: Evidence from Early Cretaceous Magmatism in the Tethyan Himalaya     

LIAN Dongyang  YANG Jingsui  LIU Fei  WU Weiwei  XU Zhiqin 《《地质学报》英文版》2020,94(Z1):29-29

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Disruption of bacterial balance in the gut of Portunus trituberculatus induced by Vibrio alginolyticus infection     

Xia  Mengjie  Pei  Feng  Mu  Changkao  Ye  Yangfang  Wang  Chunlin 《中国海洋湖沼学报》2018,36(5):1891-1898

Journal of Oceanology and Limnology - Gut microbiota impacts the health of crustaceans. Vibrio alginolyticus is a main causative pathogen that induces the vibriosis in farmed swimming crabs,...  相似文献   

Transpiration and evaporation of grassland using land surface modelling     

Wenchao Ma  Zhongwang Wei  Pei Wang  Jun Asanuma 《水文研究》2020,34(17):3656-3668

Partitioning transpiration (T) from evapotranspiration (ET) is a key process for understanding the interaction between land surfaces and the atmosphere. This paper reports daily partitioning results for a grassland over a 10-year period, obtained using the Community Land Model 3.5 (CLM3.5) land surface model. Hourly forcing data were collected from a long-term observation system located in the northeast of Japan ( http://doi.org/10.24575/0001.198108 ). To test the model behavior, total ET was validated using eddy correlation measurements combined with the energy balance method. The results were compared with previous research using an isotope approach for partitioning. The results demonstrate that our model can capture the dynamics of ET and its components at this location. Evaporation (E), originating from the ground and canopy, varied inter-annually, and from 2006 to 2015, average annual E was approximately 285 mm/year from the ground and 45 mm/year from the canopy. Average, T, was approximately 302 mm/year, accounting for approximately 48% of the total ET. Inter-annual results demonstrate that the water flux transported by vegetation ranges from 17 to 83% during the April–October period. A sensitivity test conducted with forcing data indicates air temperature, incident solar radiation, and longwave radiation exhibited a notable effect on all ET components. Relative humidity exhibited the only negative feedback to both evaporation and transpiration, contrary to the other forcing parameters. Our study reemphasized the effectiveness of CLM3.5 in partitioning T from ET and in understanding the complex interaction between land surfaces and the atmosphere.  相似文献   

低速缓动滑坡滑带土剪切蠕变特性          下载免费PDF全文

周静静  赵法锁  祝艳波  吴博  陈沛  宋飞  杨一帆 《中国地质灾害与防治学报》2020,31(1):107-112

滑带土的蠕变特性对低速缓动滑坡的形成演化过程起着控制性作用。本文选取典型的低速缓动滑坡—二庄科北区滑坡的滑带土为研究对象,在不同正应力水平作用下,通过对该滑带土的饱和试样进行直剪蠕变试验,研究了它的剪切蠕变特性。结果表明:该滑带土具有明显的蠕变特性,均包括瞬时变形、衰减蠕变和稳态蠕变3个阶段;随着剪切荷载的增大,衰减蠕变阶段及瞬时变形阶段的变形量均增大,衰减蠕变持续时间更长;其等时应力—应变曲线呈现出非线性特征,且曲线具有明显拐点;在长期荷载作用下出现强度损失,且正应力越大,强度损失越大;随着时间增大,衰减蠕变阶段的剪应变率越来越小,且剪应力越大,剪应变率越大;在蠕变破坏前的阶段,剪应变率随正应力增大而减小,即滑坡埋深越深,滑速越慢。  相似文献   

Geological Evidence does not Support a Shallow Origin for Diamonds in Ophiolite     

YANG Jingsui  LIAN Dongyang  Paul T ROBINSON  QIU Tian  XIONG Fahui  WU Weiwei 《《地质学报》英文版》2020,94(Z1):70-72

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基于天文开源软件的卫星干涉测量数据处理系统          下载免费PDF全文

朱梦祎  吴元伟  姚当  弓剑军  刘佳  李西顺  马浪明  韦沛  雷辉  杨旭海 《天文学报》2021,62(4):40

VLBI (Very Long Baseline Interferometry)技术观测卫星需要对干涉测量数据进行相关和后处理,通过相关、时延校准、条纹搜索,最终得到卫星的基线几何时延.基于天文开源软件建立起一套卫星干涉测量数据处理系统.该系统可工作在实时和事后两种状态,实现相关、中性大气、电离层、钟模型以及仪器硬件的时延校准、条纹搜索、生成基线时延和时延率序列.使用该系统处理北斗GEO (Geosynchronous Earth Orbit)卫星的干涉测量试验数据,得到了精度在1–2 ns量级的卫星基线时延序列.  相似文献   

Vegetation dynamics dominate the energy flux partitioning across typical ecosystem in the Heihe River Basin: Observation with numerical modeling   总被引：1，自引：1，他引：0  

Wang  Pei  Li  Xiaoyan  Tong  Yaqin  Huang  Yongmei  Yang  Xiaofan  Wu  Xiuchen 《地理学报(英文版)》2019,29(9):1565-1577

Journal of Geographical Sciences - Understanding the controls on seasonal variation of energy partitioning and separation between canopy and soil surface are important for qualifying the vegetation...  相似文献