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Wireless semantic communication based on semantic matching multiple access and intent bias multiplexing

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The Journal of China Universities of Posts and Telecommunications 2024年第1期31卷 26-36页

作者： Ren Chao He Zongrui Sun Chen Li Haojin Zhang Haijun University of science and technology Beijing Beijing 100083China research and development center Sony(China)LimitedBeijing 100027China

This paper proposes a multi-access and multi-user semantic communication scheme based on semantic matching and intent deviation to address the increasing demand for wireless users and *** scheme enables flexible management of long frames,allowing each unit of bandwidth to support a higher number of *** leveraging semantic classification,different users can independently access the network through the transmission of long concatenated sequences without modifying the existing wireless communication *** overcome the potential disadvantage of incomplete semantic database matching leading to semantic intent misunderstanding,the scheme proposes using intent deviation as an *** allows different receivers to interpret the same semantic information differently,enabling multiplexing where one piece of information can serve multiple users with distinct *** results show that at a bit error rate(BER)of 0.1,it is possible to reduce the transmission by approximately 20 semantic basic units.

关键词： semantic communication multiple access multiplexing multimodal communication

Diagnosing ratio of electron density to collision frequency of plasma surrounding scaled model in a shock tube using low-frequency alternating magnetic field phase shift

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Chinese Physics B 2024年第5期33卷 519-530页

作者：吴明兴谢楷刘艳徐晗张宝田得阳 School of Aerospace science and technology Xidian UniversityXi'an 710071China Hypervelocity Aerodynamics Institute China Aerodynamics Research and Development CenterMianyang 621000China

A non-contact low-frequency(LF)method of diagnosing the plasma surrounding a scaled model in a shock tube is *** method utilizes the phase shift occurring after the transmission of an LF alternating magnetic field through the plasma to directly measure the ratio of the plasma loop average electron density to collision *** equivalent circuit model is used to analyze the relationship of the phase shift of the magnetic field component of LF electromagnetic waves with the plasma electron density and collision *** applicable range of the LF method on a given plasma scale is *** upper diagnostic limit for the ratio of the electron density(unit:m^(-3))to collision frequency(unit:Hz)exceeds 1×10^(11),enabling an electron density to exceed 1×10^(20)m^(-3)and a collision frequency to be less than 1 *** this work,the feasibility of using the LF phase shift to implement the plasma diagnosis is also *** experiments on shock tube equipment are conducted by using both the electrostatic probe method and LF *** comparing the diagnostic results of the two methods,the inversion results are relatively consistent with each other,thereby preliminarily verifying the feasibility of the LF *** ratio of the electron density to the collision frequency has a relatively uniform distribution during the plasma *** LF diagnostic path is a loop around the model,which is suitable for diagnosing the plasma that surrounds the ***,the causes of diagnostic discrepancy between the two methods are *** proposed method provides a new avenue for diagnosing high-density enveloping plasma.

关键词： low-frequency alternating magnetic field phase shift shock-tube plasma diagnosis electron density collision frequency

Dehydration-triggered structural phase transition-associated ferroelectricity in a hybrid perovskite-type crystal

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Chinese Chemical Letters 2024年第10期35卷 487-490页

作者： Zhi-Yuan Yue Hua-Kai Li Na Wang Shan-Shan Liu Le-Ping Miao Heng-Yun Ye Chao Shi Chaotic Matter science research center Jiangxi University of Science and Technology

Since the appearance of Rochelle salt, ferroelectrics have received extensive attention from researchers due to they are playing an important role in sensors, memories, mechanical actuation, and so on. In recent years, with the rapid development of molecular ferroelectrics, high-performance molecular ferroelectrics have become effective complement to inorganic ferroelectrics. However, compared with inorganic ferroelectrics, the family of molecular ferroelectrics is relatively scarce, and exploring highperformance ferroelectric materials through new synthesis strategies has become the trend of molecular ferroelectrics. Here, we successfully transformed non-polar material 1（2-H2PCA）2（H2O）CdCl6（2-H2PCA = 2-picolylamine cation） into polar material 2（2-H2PCA）2CdCl6by single-crystal to single-crystal transformation（SCSCT）. Meanwhile, 2 exhibits clear ferroelectricity with a high-temperature Tcof 378 K,a Psof 1.18 μC/cm2at 300 K. This work not only realizes the purpose of synthesizing ferroelectrics by forming polar structures by SCSCT, but also realizes the reversibility of SCSCT, which provides ideas for the construction and exploration of new molecular ferroelectrics.

关键词： Ferroelectric materials Hybrid perovskite Phase transition Single-crystal to single-crystal transformation Stimulus-structure-response

Improvement in hydrogen storage performance of MgH_(2) by vanadium doped with ZIF-8 derived a single-atom catalyst V-N-C

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Rare Metals 2024年第6期43卷 2623-2635页

作者： Fei-Fan Hong Wei-Tao Shi Ruo-Lin Zhao Yi Fan Zi-Qi Liu Si-Zhi Ding Hai-Zhen Liu Wen-Zheng Zhou Jin Guo Zhi-Qiang Lan Guangxi Novel Battery Materials research center of Engineering technology and center on Nanoenergy research Guangxi Colleges and Universities Key Laboratory of Blue Energy and Systems IntegrationCarbon Peak and Neutrality Science and Technology Development InstituteSchool of Physical Science and TechnologyGuangxi UniversityNanning 530004China Nanning Engineering technology research center for Power Transmission System of New Energy Vehicle Transportation CollegeNanning UniversityNanning 530200China

Herein,the successful preparation of a singleatom catalyst V-N-C using vanadium-doped zeolitic imidazolate framework(ZIF)-8 as a precursor is *** experimental results showed that the V-N-C had a good promoting effect on the hydrogen storage performance of MgH_(2),and the optimal addition amount of V-N-C was 10wt%.The hydrogenation and dehydrogenation apparent activation energies of 10 wt%V-N-C-catalyzed MgH_(2)were reduced by 44.9 and 53.5 kJ·mol^(-1),respectively,compared to those of additive-free MgH_(2).The 10 wt%V-N-C-catalyzed MgH_(2)could reabsorb 5.92 wt%of hydrogen in 50 min at 150℃,with a capacity retention rate of 99.1%after 30 cycles of hydrogen absorption and *** analysis showed that V-N-C was partially transformed into VN and metallic V when it was milled with MgH_(2);the in-situ-formed VN and metallic V played an important role in improving the hydrogen storage performance of MgH_(2).This approach provides a potential solution for obtaining high-performance Mg-based hydrogen storage materials through synergistic interactions between V,N and C.

关键词： MgH_(2) Hydrogen storage materials Catalyst Hydrogen storage perormance

Study of inter-well interference in shale gas reservoirs by a robust production data analysis method based on deconvolution

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Petroleum science 2024年第4期21卷 2502-2519页

作者： Wen-Chao Liu Cheng-Cheng Qiao Ping Wang Wen-Song Huang Xiang-Wen Kong Yu-Ping Sun He-Dong Sun Yue-Peng Jia School of Civil and Resource Engineering University of Science and Technology Beijing PetroChina research Institute of Petroleum Exploration and development

In order to overcome the defects that the analysis of multi-well typical curves of shale gas reservoirs is rarely applied to engineering, this study proposes a robust production data analysis method based on deconvolution, which is used for multi-well inter-well interference research. In this study, a multi-well conceptual trilinear seepage model for multi-stage fractured horizontal wells was established, and its Laplace solutions under two different outer boundary conditions were obtained. Then, an improved pressure deconvolution algorithm was used to normalize the scattered production data. Furthermore, the typical curve fitting was carried out using the production data and the seepage model solution. Finally,some reservoir parameters and fracturing parameters were interpreted, and the intensity of inter-well interference was compared. The effectiveness of the method was verified by analyzing the production dynamic data of six shale gas wells in Duvernay area. The results showed that the fitting effect of typical curves was greatly improved due to the mutual restriction between deconvolution calculation parameter debugging and seepage model parameter debugging. Besides, by using the morphological characteristics of the log-log typical curves and the time corresponding to the intersection point of the log-log typical curves of two models under different outer boundary conditions, the strength of the interference between wells on the same well platform was well judged. This work can provide a reference for the optimization of well spacing and hydraulic fracturing measures for shale gas wells.

关键词： Shale gas Inter-well interference Deconvolution Production data analysis Typical curves Multi-stage fractured horizontal well

Active disturbance rejection distributed secondary control for DC microgrids

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High Voltage 2024年第1期9卷 241-251页

作者： Jianlin Li Honghao You Shuo Liu Xingchen Li Ziyang Ding Fei Zou National User-Side Energy Storage Innovation research and development center North China University of TechnologyBeijingChina

A novel control scheme is presented to eliminate the negative effects of communication disturbances,which introduces active disturbance rejection control(ADRC)in the control strategy design to achieve the objectives of the restoration of the bus voltage and the sharing of the power even in the presence of disturbances and delays in ***,its dynamic disturbance decoupling feature is used to realise the decoupling between power and voltage,so that the proposed controller only exchanges power information with its neighbours,reducing the communication burden and simplifying control *** control performance of the strategy is verified by employing steady-state *** impact of controller parameters is studied by establishing a small signal ***,both simulation cases and experimental tests prove the feasibility of this scheme.

关键词： Active disturbance establishing

research on the quasi-isentropic driving model of aluminized explosives in the detonation wave propagation direction

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Defence technology（防务技术） 2024年第2期32卷 596-618页

作者： Hongfu Wang Yan Liu Fan Bai Chao He Yingliang Xu Qiang Zhou Chuan Xiao Fenglei Huang State Key Laboratory of Explosion science and technology Beijing Institute of TechnologyBeijing100081China China research and development Academy of Machinery Equipment Beijing100089China Beijing Institute of technology Chongqing Innovation center Chongqing401120China

Taking CL-20(Hexanitrohexaazaisowurtzitane)-based aluminized explosives with high gurney energy as the research object, this research experimentally investigates the work capability of different aluminized explosive formulations when driving metal flyer plates in the denotation wave propagation *** research results showed that the formulations with 43 μm aluminum(Al) powder particles(The particle sizes of Al powder were in the range of 2~43 μm) exhibited the optimal performance in driving flyer plates along the denotation wave propagation direction. Compared to the formulations with Al powder 13 μm, the formulations with Al powder 2 μm delivered better performance in accelerating metal flyer plates in the early stage, which, however, turned to be poor in the later stage. The CL-20-based explosives containing 25% Al far under-performed those containing 15% Al. Based on the proposed quasi-isentropic hypothesis, relevant isentropy theories, and the functional relationship between detonation parameters and entropy as well as Al reaction degree, the characteristic lines of aluminized explosives in accelerating flyer plates were theoretically studied, a quasi-isentropic theoretical model for the aluminized explosive driving the flyer plate was built and the calculation methods for the variations of flyer plate velocity, Al reaction degree, and detonation product parameters with time and axial positions were developed. The theoretical model built is verified by the experimental results of the CL-20-based aluminized explosive driving flyer plate. It was found that the model built could accurately calculate the variations of flyer plate velocity and Al reaction degree over time. In addition, how physical parameters including detonation product pressure and temperature varied with time and axial positions was identified. The action time of the positive pressure after the detonation of aluminized explosives was found prolonged and the downtrend of the temperature was

关键词： Aluminized explosive Flyer plate experiment Quasi-isentropic theoretical model Al reaction Driving characteristics

A model reduction approach for discrete-time linear time-variant systems with delayed inputs

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science China(Information sciences) 2024年第4期67卷 197-217页

作者： Ai-Guo WU Guang-Ren DUAN Yu WANG Jie ZHANG School of Mechanical Engineering and Automation Harbin Institute of Technology(Shenzhen) HIT Wuhu Robot technology research Institute center for Control science and technology Southern University of Science and Technology

A model reduction approach is presented for discrete-time linear time-variant input-delayed systems. According to this proposed approach, a dynamical variable is constructed by taking advantage of the current state and historical information of input. It is revealed that the behavior of this dynamical variable is governed by a discrete-time linear delay-free system. It is worth noting that the presented variable transformation does not require the system matrix to be invertible. Based on the reduced delay-free models,stabilizing control laws can be easily obtained for the original delayed system. For the case with a single input delay, the constructed variable is an exact prediction for the future state, and thus the stabilizing control law could be designed by replacing the future state with its prediction. Finally, three discrete-time periodic systems with delayed input are employed to illustrate how to utilize the presented model reduction approaches.

关键词： reduction approach predictor-based feedback time-varying systems delayed input periodic system

High-speed penetration of ogive-nose projectiles into thick concrete targets:Tests and a projectile nose evolution model

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Defence technology（防务技术） 2024年第2期32卷 553-571页

作者： Xu Li Yan Liu Junbo Yan Zhenqing Shi Hongfu Wang Yingliang Xu Fenglei Huang State Key Laboratory of Explosion science and technology Beijing Institute of TechnologyBeijing100081China Beijing Institute of technology Chongqing Innovation center Chongqing401120China China research and development Academy of Machinery Equipment Beijing100089China

The majority of the projectiles used in the hypersonic penetration study are solid flat-nosed cylindrical projectiles with a diameter of less than 20 *** study aims to fill the gap in the experimental and analytical study of the evolution of the nose shape of larger hollow projectiles under hypersonic *** the hypersonic penetration test,eight ogive-nose AerMet100 steel projectiles with a diameter of 40 mm were launched to hit concrete targets with impact velocities that ranged from 1351 to 1877 m/*** erosion of the projectiles was observed during high-speed penetration of heterogeneous targets,and apparent localized mushrooming occurred in the front nose of recovered *** examining the damage to projectiles,a linear relationship was found between the relative length reduction rate and the initial kinetic energy of projectiles in different penetration ***,microscopic analysis revealed the forming mechanism of the localized mushrooming phenomenon for eroding penetration,i.e.,material spall erosion abrasion mechanism,material flow and redistribution abrasion mechanism and localized radial upsetting deformation ***,a model of highspeed penetration that included erosion was established on the basis of a model of the evolution of the projectile nose that considers radial upsetting;the model was validated by test data from the literature and the present *** upon the impact velocity,v0,the projectile nose may behave as undistorted,radially distorted or *** to the effects of abrasion of the projectile and enhancement of radial upsetting on the duration and amplitude of the secondary rising segment in the pulse shape of projectile deceleration,the predicted DOP had an upper limit.

关键词： High-speed penetration Concrete target Erosion Projectile nose evolution model