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Influence of High-Pressure Induced Lattice Dislocations and Distortions on Thermoelectric Performance of Pristine SnTe

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Chinese Physics Letters 2024年第5期41卷 61-68页

作者：郑博文陈涛孙海瑞杨曼曼杨兵超陈欣张永胜刘晓兵 Laboratory of High-Pressure Physics and Materials Science School of Physics and Physical EngineeringQufu Normal UniversityQufu 273165China Advanced Research Institute of Multidisciplinary Sciences Qufu Normal UniversityQufu 273165China Key Lab of Photovoltaic and Energy Conservation Materials Institute of Solid State Physics HFIPSChinese Academy of SciencesHefei 230031China university of Science and Technology of China Hefei 230026China School of Electronic Engineering huainan normal university Huainan 232038China

As a sister compound of PbTe, SnTe possesses the environmentally friendly elements. However, the pristine SnTe compounds suffer from the high carrier concentration, the large valence band offset between the L and Σpositions and high thermal conductivity. Using high-pressure and high-temperature technology, we synthesized the pristine SnTe samples at different pressures and systemically investigated their thermoelectric *** pressure induces rich microstructures, including the high-density dislocations and lattice distortions, which serve as the strong phonon scattering centers, thereby reducing the lattice thermal conductivity. For the electrical properties, pressure reduces the harmful high carrier concentration, due to the depression of Sn ***, pressure induces the valence band convergence, reducing the energy separation between the L and Σpositions. The band convergence and suppressed carrier concentration increase the Seebeck coefficient. Thus, the power factors of pressure-sintered compounds do not deteriorate significantly under the condition of decreasing electrical conductivity. Ultimately, for a pristine SnTe compound synthesized at 5 GPa, a higher ZT value of 0.51 is achieved at 750 K, representing a 140% improvement compared to the value of 0.21 obtained using SPS. Therefore, the high-pressure and high-temperature technology is demonstrated as an effectively approach to optimize thermoelectric performance.

关键词： coefficient properties positions

Real-Time Detection and Instance Segmentation of Strawberry in Unstructured Environment

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Computers, Materials & Continua 2024年第1期78卷 1481-1501页

作者： Chengjun Wang Fan Ding Yiwen Wang Renyuan Wu Xingyu Yao Chengjie Jiang Liuyi Ling School of Artificial Intelligence Anhui University of Science and TechnologyHuainan232001China School of Mechanical Engineering Anhui University of Science and TechnologyHuainan232001China

The real-time detection and instance segmentation of strawberries constitute fundamental components in the development of strawberry harvesting ***-time identification of strawberries in an unstructured envi-ronment is a challenging *** instance segmentation algorithms for strawberries suffer from issues such as poor real-time performance and low *** this end,the present study proposes an Efficient YOLACT(E-YOLACT)algorithm for strawberry detection and segmentation based on the YOLACT *** key enhancements of the E-YOLACT encompass the development of a lightweight attention mechanism,pyramid squeeze shuffle attention(PSSA),for efficient feature ***,an attention-guided context-feature pyramid network(AC-FPN)is employed instead of FPN to optimize the architecture’s ***,a feature-enhanced model(FEM)is introduced to enhance the prediction head’s capabilities,while efficient fast non-maximum suppression(EF-NMS)is devised to improve non-maximum *** experimental results demonstrate that the E-YOLACT achieves a Box-mAP and Mask-mAP of 77.9 and 76.6,respectively,on the custom ***,it exhibits an impressive category accuracy of 93.5%.Notably,the E-YOLACT also demonstrates a remarkable real-time detection capability with a speed of 34.8 *** method proposed in this article presents an efficient approach for the vision system of a strawberry-picking robot.

关键词： YOLACT real-time detection instance segmentation attention mechanism strawberry

Temperature trends and its elevation-dependent warming over the Qilian Mountains

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Journal of Mountain Science 2024年第2期21卷 500-510页

作者： ZHAO Peng HE Zhibin MA Dengke WANG Wen QIAN Lihui School of Computer Science Huainan Normal UniversityHuainan 232038China Linze Inland River Basin Research Station Key Laboratory of Inland River Basin ScienceNorthwest Institute of Eco-Environment and ResourceChinese Academy of SciencesLanzhou 730000China university of Chinese Academy of Sciences Beijing 100049China

Understanding temperature variability especially elevation dependent warming(EDW)in high-elevation mountain regions is critical for assessing the impacts of climate change on water resources including glacier melt,degradation of soils,and active layer *** means that temperature is warming faster with the increase of *** this study,we used observed temperature data during 1979-2017 from 23 meteorological stations in the Qilian Mountains(QLM)to analyze temperature trend with Mann-Kendall(MK)test and Sen’s slope *** showed that the warming trends for the annual temperature followed the order of T_min>T_mean>T_max and with a shift both occurred in *** and summer temperature have a higher increasing trend than that in autumn and winter.T_mean shifts occurred in 1996 for spring and summer,in 1997 for autumn and winter.T_max shifts occurred in 1997 for spring and 1996 for summer.T_min shifts occurred in 1997 for spring,summer and winter as well as in 1999 for *** mean diurnal temperature range(DTR)shows a significant decreasing trend(-0.18°C/10a)from 1979 to *** mean DTR shows a significant decreasing trend(-0.26°C/10a)from 1979 to 2017 with a shift occurred in *** removing longitude and latitude factors,we can learn that the warming enhancement rate of average annual temperature is 0.0673°C/km/10a,indicating that the temperature warming trend is accelerating with the continuous increase of *** increase rate of elevation temperature is 0.0371°C/km/10a in spring,0.0457°C/km/10a in summer,0.0707°C/km/10a in autumn,and 0.0606°C/km/10a in winter,which indicates that there is a clear EDW in the *** main causes of warming in the Qilian Mountains are human activities,cloudiness,ice-snow feedback and El Nino phenomenon.

关键词： Climate change Qilian Mountains Warming rates DTR Elevation-dependent warming

Double quantum images encryption scheme based on chaotic system

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Chinese Physics B 2024年第4期33卷 305-320页

作者：蒋社想李杨石锦张茹 School of Computer Science and Engineering Anhui University of Science and TechnologyHuainan 232001China Anhui Key Laboratory of Mine Intelligent Equipment and Technology Anhui University of Science&TechnologyHuainan 232001China

This paper explores a double quantum images representation(DNEQR)model that allows for simultaneous storage of two digital images in a quantum superposition ***,a new type of two-dimensional hyperchaotic system based on sine and logistic maps is investigated,offering a wider parameter space and better chaotic behavior compared to the sine and logistic *** on the DNEQR model and the hyperchaotic system,a double quantum images encryption algorithm is ***,two classical plaintext images are transformed into quantum states using the DNEQR ***,the proposed hyperchaotic system is employed to iteratively generate pseudo-random *** chaotic sequences are utilized to perform pixel value and position operations on the quantum image,resulting in changes to both pixel values and ***,the ciphertext image can be obtained by qubit-level diffusion using two XOR operations between the position-permutated image and the pseudo-random *** corresponding quantum circuits are also *** results demonstrate that the proposed scheme ensures the security of the images during transmission,improves the encryption efficiency,and enhances anti-interference and anti-attack capabilities.

关键词： double quantum images encryption chaotic system pixel scrambling XOR operation

Construction of enhanced multi-polarization and high performance electromagnetic wave absorption by self-growing ZnFe_(2)O_(4)on Cu_(9)S_(5)

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International Journal of Minerals,Metallurgy and Materials 2024年第8期31卷 1922-1934页

作者： Wenxiong Chen Honglong Xing School of Chemical Engineering Anhui University of Science and TechnologyHuainan 232001China

The development of 3D structural composites with electromagnetic(EM)wave absorption could attenuate EM ***,magnetized flower-like Cu_(9)S_(5)/ZnFe_(2)O_(4)composites were fabricated through a multistep hydrothermal *** crystallographic and surface phase chemical information,morphological structure,and magnetic and EM parameters of the composites were *** prepared Cu_(9)S_(5)/ZnFe_(2)O_(4)composites have multiple loss paths for EM waves and present an overall 3D flower-like *** Cu_(9)S_(5)/ZnFe_(2)O_(4)composites exhibit a minimum reflection loss of-54.38 dB and a broad effective absorption bandwidth of 5.92 *** magnetization,ZnFe_(2)O_(4)particles are self-assembled and grown on the surfaces of Cu_(9)S_(5).Such a modification is conducive to the generation of additional cross-linking contact sites and the effective introduction of a large number of phase interfaces,crystalline defects,special three-dimensional flower-like structures,and magneto-electrical coupling loss ***,the synergistic effect of multiple loss strategies effectively improves EM wave absorption by the *** work can provide a strategy for the use of magnetizationmodified sulfide composite functional materials in EM wave absorption.

关键词： self-assembled material electromagnetic wave absorption enhanced multi-polarization effect Cu_(9)S_(5)/ZnFe_(2)O_(4)composites radar cross-section

Damage constitutive model of lunar soil simulant geopolymer under impact loading

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 1059-1071页

作者： Hanyan Wang Qinyong Ma Qianyun Wu School of Civil Engineering and Architecture Anhui University of Science and TechnologyHuainan232001China Engineering Research Center of Underground Mine Construction Ministry of EducationAnhui University of Science and TechnologyHuainan232001China

Lunar base construction is a crucial component of the lunar exploration program,and considering the dynamic characteristics of lunar soil is important for moon ***,investigating the dynamic properties of lunar soil by establishing a constitutive relationship is critical for providing a theoretical basis for its damage *** this paper,a split Hopkinson pressure bar(SHPB)device was used to perform three sets of impact tests under different pressures on a lunar soil simulant geopolymer(LSSG)with sodium silicate(Na_(2)SiO_(3))contents of 1%,3%,5%and 7%.The dynamic stressestrain curves,failure modes,and energy variation rules of LSSG under different pressures were *** equation was modified based on the ZWT viscoelastic constitutive model and was combined with the damage *** damage element obeys the Weibull distribution and the constitutive equation that can describe the mechanical properties of LSSG under dynamic loading was *** results demonstrate that the dynamic compressive strength of LSSG has a marked strain-rate strengthening ***_(2)SiO_(3) has both strengthening and deterioration effects on the dynamic compressive strength of *** Na_(2)SiO_(3) grows,the dynamic compressive strength of LSSG first increases and then *** a fixed air pressure,5%Na_(2)SiO_(3) had the largest dynamic compressive strength,the largest incident energy,the smallest absorbed energy,and the lightest *** ZWT equation was modified according to the stress response properties of LSSG and the range of the SHPB strain rate to obtain the constitutive equation of the LSSG,and the model’s correctness was confirmed.

关键词： Lunar soil simulant geopolymer(LSSG) Split hopkinson pressure bar(SHPB)test Constitutive model Energy analysis Failure mode

Effects of content and particle size of TiH2 powders on the energy output rules of RDX composite explosives

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Defence Technology（防务技术） 2024年第2期32卷 297-308页

作者： Hao Wang Yangfan Cheng Shoujun Zhu Zihan Li Zhaowu Shen School of Chemical Engineering Anhui University of Science and TechnologyHuainan 232001China Anhui Engineering Laboratory of Explosive Materials and Technology Anhui University of Science and TechnologyHuainan 232001China School of Engineering Science University of Science and Technology of ChinaHefei 230027China

In order to improve the detonation characteristics of RDX,a RDX-based composite explosive with TiH_(2)powders was *** effects of content and particle size of TiH_(2)powders on thermal safety,shock wave parameters and thermal damage effects of RDX-based composite explosive were studied with the C80 microcalorimeter,air blast experiment system and colorimetric thermometry *** results showed that TiH_(2)powders could enhance the thermal stability of RDX-based composite explosive and increase its ultimate decomposition *** content and particle size of TiH_(2)powders also had significant effects on the thermal safety,detonation velocity,shock wave parameters,fireball temperature and duration of RDX-based composite ***,the differences of TiH_(2)and Ti powders on the detonation energy output rules of RDX-based composite explosives were also compared,showing that TiH_(2)powders had better influences on improving the explosion power and thermal damage effect of RDX-based composite explosives than Ti powders,for the participation of free H_(2)released by TiH_(2)powders in the detonation ***_(2)powders have important research values as a novel energetic additive in the field of military composite explosives.

关键词： RDX Hydrogen storage alloy Air blast After-burn reaction Colorimetric thermometry

Deflagration characteristics of freely propagating flames in magnesium hydride dust clouds

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Defence Technology（防务技术） 2024年第1期31卷 471-483页

作者： Qiwei Zhang Yangfan Cheng Beibei Zhang Danyi Li Zhaowu Shen School of Chemical Engineering Anhui University of Science and TechnologyHuainan 232001AnhuiPR China School of Civil Engineering and Architecture Anhui University of Science and TechnologyHuainan 232001AnhuiPR China Anhui Engineering Laboratory of Explosive Materials and Technology Anhui University of Science and TechnologyHuainan 232001AnhuiPR China School of Engineering Science University of Science and Technology of ChinaHefei 230027AnhuiPR China

The flame propagation processes of MgH_(2)dust clouds with four different particle sizes were recorded by a high-speed *** dynamic flame temperature distributions of MgH_(2)dust clouds were reconstructed by the two-color pyrometer technique,and the chemical composition of solid combustion residues were *** experimental results showed that the average flame propagation velocities of 23μm,40μm,60μm and 103μm MgH_(2)dust clouds in the stable propagation stage were 3.7 m/s,2.8 m/s,2.1 m/s and 0.9 m/s,*** dust clouds with smaller particle sizes had faster flame propagation velocity and stronger oscillation intensity,and their flame temperature distributions were more even and the temperature gradients were *** flame structures of MgH_(2)dust clouds were significantly affected by the particle sinking velocity,and the combustion processes were accompanied by micro-explosion of *** falling velocities of 23μm and 40μm MgH_(2)particles were 2.24 cm/s and 6.71 cm/s,*** the falling velocities of 60μm and 103μm MgH_(2)particles were as high as 15.07 cm/s and 44.42 cm/s,respectively,leading to a more rapid downward development and irregular shape of the ***,the dehydrogenation reaction had a significant effect on the combustion performance of MgH_(2)*** combustion of H_(2)enhanced the ignition and combustion characteristics of MgH_(2)dust,resulting in a much higher explosion power than the pure Mg *** micro-structure characteristics and combustion residues composition analysis of MgH_(2)dust indicated that the combustion control mechanism of MgH_(2)dust flame was mainly the heterogeneous reaction,which was affected by the dehydrogenation reaction.

关键词： Magnesium hydride dust Flame combustion mechanism Particle size Dust explosion Two-color pyrometer

Load-bearing characteristics and energy evolution of fractured rock masses after granite and sandstone grouting

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Journal of Central South university 2024年第8期31卷 2810-2825页

作者： Wu, Xu-kun Zhao, Guang-ming Meng, Xiang-rui Liu, Chong-yan Liu, Zhi-xi Huang, Shun-jie Zhang, Qi-hang Key Laboratory of Safe and Effective Coal Mining Ministry of Education Anhui University of Science and Technology Huainan China National Key Laboratory of Safe Mining of Deep Coal and Environmental Protection Anhui University of Science and Technology Huainan China Joint National-Local Engineering Research Centre for Safe and Precise Coal Mining Anhui University of Science and Technology Huainan China

Experiments on grouting-reinforced rock mass specimens with different particle sizes and features were carried out in this study to examine the effects of grouting reinforcement on the load-bearing characteristics of fractured rock mass. The strength and deformation features of grouting-reinforced rock mass were analyzed under different loading manners; the energy evolution mechanism of grouting-reinforced rock mass specimens with different particle sizes and features was investigated; the energy dissipation ratio and post-peak stress decreasing rate were employed to evaluate the bearing stability of grouting-reinforced rock mass. The results show that the strength and ductility of granite-reinforced rock mass (GRM) under biaxial loading are higher than that of sandstone-reinforced rock mass (SRM) under uniaxial loading. Besides, the energy evolution characteristics of grouting-reinforced rock mass under uniaxial and biaxial loading mainly could be divided into early, middle, and late stages. In the early stage, total, elastic, and dissipation energies were quite small with flatter curves; in the middle stage, elastic energy increased rapidly, whereas dissipation energy increased slowly; in the late stage, dissipation energy increased sharply. The energy dissipation ratio was used to represent the pre-peak plastic deformation. Under uniaxial loading, this ratio increased as the particle size increased and the pre-peak plastic deformation of grouting-reinforced rock mass became larger; under biaxial loading, it dropped as the particle size increased, and the pre-peak plastic deformation of grouting-reinforced rock mass became smaller. The post-peak stress decline rate Av was used to assess the post-peak bearing performance of grouting-reinforced rock mass. Under uniaxial loading, parameter Av exhibited reduction as the particle size kept increasing, and the ability of post-peak of grouting-reinforced rock mass to allow deformation development was greater, and the bea

关键词： grouting-reinforced rock mass particle size energy dissipation ratio post-peak stress decreasing rate load-bearing characteristics