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Spectrum sensing based on angular reciprocity in cognitive satellite communication system

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Science China(Information Sciences) 2021年第8期64卷 117-126页

作者： Jiancun FAN yong ban Jie LUO Ying ZHANG Xinmin LUO School of Information and Communications Engineering Xi'an Jiaotong University Science and Technology on Communication Networks Laboratory

Satellite communication is attracting increasing attention owing to its freedom from geographical constraints. However, its spectrum resources are limited, and it is susceptible to interferences. Therefore,cognitive radio technology can be used to detect and prevent interferences as well as improve spectrum utilization.To improve the spectrum sensing performance, an angle reciprocity-based spectrum sensing(ARSS)scheme is proposed in this study. The scheme exploits the reciprocity between the known beam’s central angle and the unknown signal’s arrival angle, with the reciprocity controlled by the narrow characteristic of the satellite’s beam owing to long-distance propagation. In this scheme, we use the beam’s central angle instead of the signal’s actual angle to process the received signal, and then the processed data are used as the sensing statistics for spectrum sensing. The simulation results show that the proposed ARSS scheme exhibits better satellite spectral sensing performance compared with the energy detector(ED).

关键词： satellite communications spectrum sensing angle reciprocity energy detector

Simulation study of the performance of new micropattern gaseous detectors

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Radiation Detection Technology and Methods 2018年第1期2卷 144-150页

作者： Shaokun He Qianming Huang Hao Qiao Dayong Wang yong ban State Key Laboratory of Nuclear Physics and Technology Physics SchoolPeking UniversityBeijing 100871China

Background The micropattern gaseous detectors(MPGDs)are widely used in high-energy physics experiment,such as detector upgrade projects in LHC,due to its excellent performance on rate capability,spatial and time resolutions.Method In this paper,we studied the performances of GEM,FTM andμ-RWELL detectors on time and spatial resolutions using Monte Carlo simulation methods and compared their performances and characteristics at various working conditions.Result Result shows that time resolution of MPGDs improves with the increase of electric field intensity in drift region,while spatial resolution shows the reverse tendency.In addition,detectors operating with an electronegative gas mixture show better performances on both time and spatial resolution.Conclusion We studied the performance of triple-GEM,FTM andμ-RWELL detectors with Monte Carlo simulation.In this paper,ANSYS and GARFIELD are used to build full electric field model of the detector.The time resolution and spatial resolution are derived,which are very important for triggering performance and track reconstruction ability.These results will provide references on detector design and the technology chosen in LHC detector upgrade projects.

关键词： Monte Carlo simulation Micropattern gaseous detectors Time resolution Spatial resolution

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基于InSAR的城市建筑安全监测技术研究

工业建筑 2024年第2期54卷 51-57页

作者：朱茂葛春青班勇周宁远徐康李吉平北京东方至远科技股份有限公司北京100081

城市建筑安全涉及人民的生命财产,近年已有多起建筑局部坍塌造成严重损害。为实现“灾前预防”的现代化城市建筑设施安全监管,基于PS-InSAR技术,提出一种针对于城市建筑及基础设施的大范围安全风险评估方法。通过结合InSAR原理,提取建... 详细信息

城市建筑安全涉及人民的生命财产,近年已有多起建筑局部坍塌造成严重损害。为实现“灾前预防”的现代化城市建筑设施安全监管,基于PS-InSAR技术,提出一种针对于城市建筑及基础设施的大范围安全风险评估方法。通过结合InSAR原理,提取建筑PS点聚类,分析聚类点形变信息,根据建筑物风险相关指标提取有效形变,参考建筑类型及区域情况划分风险等级标准,进而评价区域内建筑设施的安全风险情况。以长春市为例,利用COSMO-SkyMed卫星时序数据,对主城区建筑物进行大范围安全风险监测试验,并对评价为D级需重点关注的建筑进行实地踏勘,发现均存在较为明显的隐患情况。证实了方法的可行性以及准确性,能够为大范围城市建筑设施定期“体检”提供技术支持,保障城市建筑安全。

关键词：城市建筑安全 PS-InSAR技术安全风险监测长春市

A new species of the genus Ethmolaimus de Man,1880(Nematoda,Ethmolaimidae)from intertidal zone of the Yellow Sea,China

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Zoological Systematics 2024年第2期49卷 175-180页

作者： Shuyan ban Ting Li yong Huang College of Life Sciences Liaocheng UniversityLiaocheng 252059ShandongChina

In order to investigate the biodiversity of free-living nematodes along the coast of the Yellow Sea,sediment samples were collected in a number of intertidal sites in recent years.In this area,the mean abundance of free-living nematodes is 1663±502 ind 10 cm^(-2),and more than 200 species have been found(Zhai et al.,2020;Hao et al.,2021,2022;Chu et al.,2023).Among them,species from the genera,Daptonema,Thalassomonhystera,Parodontophora and Bathylaimus,are the most common,while the species,Daptonema parabreviseta Huang&Sun,Parodontophora deltensis Zhang,Bathylaimus huanghaiensis Huang&Zhang and Thalassomonhystera siamensis Kito&Aryuthaka are in dominant.Here,a species belongs to the genus Ethmolaimus is identified as new to science,namely E.multispiralis sp.nov.It is also the first time for the genus reported in the Chinese sea area.

关键词： sp.nov biodiversity new

Strongly Coupled Ag/Sn-SnO_(2)Nanosheets Toward CO_(2)Electroreduction to Pure HCOOH Solutions at Ampere‑Level Current

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Nano-Micro Letters 2024年第3期16卷 212-226页

作者： Min Zhang Aihui Cao Yucui Xiang Chaogang ban Guang Han Junjie Ding Li‑yong Gan Xiaoyuan Zhou College of Physics and Center of Quantum Materials and Devices Chongqing UniversityChongqing 401331People’s Republic of China State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of Sciences(CAS)Fuzhou 350002People’s Republic of China College of Materials Science and Engineering Chongqing UniversityChongqing 400044People’s Republic of China Institute of New Energy Storage Materials and Equipment Chongqing 401135People’s Republic of China State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing 400044People’s Republic of China

Electrocatalytic reduction of CO_(2) converts intermittent renewable electricity into value-added liquid products with an enticing prospect,but its practical application is hampered due to the lack of high-performance electrocatalysts.Herein,we elaborately design and develop strongly coupled nanosheets composed of Ag nanoparticles and Sn-SnO_(2) grains,designated as Ag/Sn-SnO_(2) nanosheets(NSs),which possess optimized electronic structure,high electrical conductivity,and more accessible sites.As a result,such a catalyst exhibits unprecedented catalytic performance toward CO_(2)-to-formate conversion with near-unity faradaic efficiency(≥90%),ultrahigh partial current density(2,000 mA cm^(−2)),and superior long-term stability(200 mA cm^(−2),200 h),surpassing the reported catalysts of CO_(2) electroreduction to formate.Additionally,in situ attenuated total reflection-infrared spectra combined with theoretical calculations revealed that electron-enriched Sn sites on Ag/Sn-SnO_(2)NSs not only promote the formation of*OCHO and alleviate the energy barriers of*OCHO to*HCOOH,but also impede the desorption of H*.Notably,the Ag/Sn-SnO_(2)NSs as the cathode in a membrane electrode assembly with porous solid electrolyte layer reactor can continuously produce~0.12 M pure HCOOH solution at 100 mA cm^(−2)over 200 h.This work may inspire further development of advanced electrocatalysts and innovative device systems for promoting practical application of producing liquid fuels from CO_(2).

关键词： Electrochemical CO_(2)reduction Coupled Ag/Sn-SnO_(2)nanosheets Electronic structure Porous solid electrolyte Pure

支持性团体辅导对流浪儿童心理韧性与情绪行为问题的干预研究

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中国临床心理学杂志 2022年第4期30卷 991-995页

作者：班永飞孙霁孔风安顺学院教育科学学院安顺561000 陕西师范大学心理学院西安710062

目的:设计支持性团体干预方案,探究对流浪儿童的心理韧性与情绪行为的干预效果。方法:38名流浪儿童参与研究,实验组和对照组各19名,实验组开展6次团体干预,对照组不干预。结果:团体干预后,心理韧性实验组后测得分高于实验组前测,对照组... 详细信息

目的:设计支持性团体干预方案,探究对流浪儿童的心理韧性与情绪行为的干预效果。方法:38名流浪儿童参与研究,实验组和对照组各19名,实验组开展6次团体干预,对照组不干预。结果:团体干预后,心理韧性实验组后测得分高于实验组前测,对照组前后测无显著差异;情绪行为问题实验组后测得分低于实验组前测、对照组前后测无显著差异。通过斜率和R2分析,团体干预后心理韧性对情绪行为问题的影响增强。心理韧性在支持性团体干预与情绪行为问题的关系中起中介作用。结论:支持性团体辅导可有效提升流浪儿童的心理韧性,改善流浪儿童的情绪行为问题。

关键词：心理韧性情绪行为流浪儿童支持性团体辅导

一种应用于机载通信的VHF/UHF低剖面小型化垂直极化天线

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电子学报 2023年第10期51卷 2754-2764页

作者：王亚鹏班永灵孙强胡俊电子科技大学电子科学与工程学院

在机载通信领域，迫切需要一种具有垂直极化全向辐射模式的低剖面小型化天线，尤其是在甚高频(Very High Frequency,VHF)频段和特高频(Ultra High Frequency,UHF)频段的低频段.针对这一需求，本文提出了一种有着低剖面、电小尺寸的圆柱... 详细信息

在机载通信领域，迫切需要一种具有垂直极化全向辐射模式的低剖面小型化天线，尤其是在甚高频(Very High Frequency,VHF)频段和特高频(Ultra High Frequency,UHF)频段的低频段.针对这一需求，本文提出了一种有着低剖面、电小尺寸的圆柱腔天线.通过在圆柱腔内部引入短路柱和导电柱分别激励起TM01和TM02模，能够获得良好的垂直极化全向辐射模式.引入锥形套筒在改善输入阻抗的同时，有效降低TM01和TM02模的谐振频率，使两个模式的谐振频率工作在目标频段.另外，设计了4个状态的宽带匹配网络来进一步改善天线的阻抗匹配.本文提出的圆柱腔天线尺寸为π×(0.11λmax)2×0.045λmax(λmax是最低频率处的自由空间波长).仿真和实测结果之间有着良好的一致性.实测结果表明，本文提出的圆柱腔天线在低频段和高频段分别获得了47.3%(105～170 MHz)和52.3%(207～355 MHz)的阻抗带宽(|S11|<-10 d B)，并在宽频带内获得了稳定的垂直极化全向辐射模式.

关键词：圆柱腔低剖面小型化全向天线垂直极化

A Time-Domain Numerical Simulation for Free Motion Responses of Two Ships Advancing in Head Waves

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China Ocean Engineering 2024年第3期38卷 519-530页

作者： PAN Su-yong CHENG yong School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China

The constant panel method within the framework of potential flow theory in the time domain is developed for solving the hydrodynamic interactions between two parallel ships with forward speed.When solving problems within a time domain framework,the free water surface needs to simultaneously satisfy both the kinematic and dynamic boundary conditions of the free water surface.This provides conditions for adding artificial damping layers.Using the Runge−Kutta method to solve equations related to time.An upwind differential scheme is used in the present method to deal with the convection terms on the free surface to prevent waves upstream.Through the comparison with the available experimental data and other numerical methods,the present method is proved to have good mesh convergence,and satisfactory results can be obtained.The constant panel method is applied to calculate the hydrodynamic interaction responses of two parallel ships advancing in head waves.Numerical simulations are conducted on the effects of forward speed,different longitudinal and lateral distances on the motion response of two modified Wigley ships in head waves.Then further investigations are conducted on the effects of different ship types on the motion response.

关键词： ship motions time domain simulation forward speed different distances wave loads

Optimizing multi-parameter distributed fiber sensors:a hybrid Rayleigh-Brillouin-Raman System approach

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Light(Science & Applications) 2024年第3期13卷 393-395页

作者： Kwang yong Song Dept.of Physics Chung-Ang University84 Heukseok-roDongjak-guSeoul 06974Korea

An optimized single-end hybrid Rayleigh,Brillouin,and Raman distributed fiber sensing system has been developed for simultaneous measurement of multiple parameters.This system integrates 3-bit pulse coding for the Raman signal and the Brillouin amplification of the Rayleigh-backscattered signal,discriminating strain,temperature,and vibration using a single sensing fiber.

关键词： fiber Rayleigh signal