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Evolution of defect polarization under external fields in potassium sodium niobate-based ceramics with excess bismuth

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Ceramics International 2025年

作者： Tao, Hong Wu, Wenjuan Zhao, Chunlin Zhang, Yiting Song, Xilong Feng, Jiaqing Xing, Zhipeng Wu, Chaofeng Zhao, Lin Wu, Bo Ma, Jian Xu, Ze Sichuan Prov Key Lab Informat Mat Southwest Minzu University Chengdu610041 China Sichuan Province Key Laboratory of Information Materials and Devices Application Chengdu University of Information Technology Chengdu610225 China College of Materials Science and Engineering Fuzhou University Fuzhou350108 China State Key Laboratory of New Ceramics and Fine Processing School of Materials Science and Engineering Tsinghua University Beijing100084 China Tongxiang Tsingfeng Technology Co. Ltd Jiaxing314500 China

Piezoelectric ultrasonic motors play a pivotal role in advancing intelligent and high-tech applications, drawing significant attention to the study of defects in piezoelectric materials. Defect modulation, achieved through the incorporation of appropriate additives, stands out as a proven and effective strategy for enhancing the performance of ceramics. Herein, defect structure and the orientation behavior under external fields has been emphasized on in potassium sodium niobate ceramics with excess bismuth. Elevated defect polarization is revealed with increased A-site vacancy and decreased oxygen vacancy when bismuth is strongly excessive, along with lowered orthorhombic-tetragonal phase transition temperature. The defect polarization is oriented under a high electric field and depolarized under a strong thermal field. This is evidenced by asymmetric ferroelectric hysteresis loops and a large internal bias field in poled ceramics, while unpoled and depolarized samples display nearly symmetrical loops. Additionally, asymmetric bipolar strain curves with a notable deviation between positive and negative electric fields are observed in poled samples, whereas annealing reduces this asymmetry. Meanwhile, the domain switching becomes more difficult in the poled state compared to the virgin state due to the pinning effect induced by oriented defect polarization during pre-poling. Then, large Qm and d33 as well as decreasing and increasing tendencies respectively, are gained simultaneously with increased defect, generated by the strong promoted domain switching from elevated A-site vacancy and lowered phase transition temperature, with respect to the impeded effect from pinning effect of defect dipoles. Therefore, this study demonstrated the defect evolution under external fields and the impact on macro-performance, accelerating the material development for piezoelectric motors. © 2025 Elsevier Ltd and Techna Group S.r.l.

关键词： Piezoelectric motors

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An Image Semantic Communication System Based on GAN and Relative Position-Encoding

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IEEE Communications Letters 2025年

作者： Zhang, Ziqi Tan, Weijie Li, Chunguo Guizhou University College of Big Data and Information Engineering Guiyang550025 China Guizhou University State Key Laboratory of Public Big Data College of Computer Science and Technology Guiyang550025 China Advanced Cryptography and System Security Key Laboratory of Sichuan Province Chengdu610025 China Ministry of Industry and Information Technology Laboratory of Cryptography Application Technology Innovation and Testing Verification Beijing100015 China Southeast University School of Information Science and Engineering Nanjing210096 China

In image semantic communication, the complex wireless channel environment leads to the loss of image details and performance degradation during transmission. To address this issue, we propose an image semantic communication system based on Generative Adversarial Networks (GAN) and Relative Position-Encoding (RPE), named GAN-RpeSC. Specifically, in the system design, we introduce the GAN network at the output of the semantic communication framework to enhance the image restoration. We integrate the RPE module into the Visual Transformer (ViT) module, adding the RPE module to its Multihead Self Attention (MHSA), so that the model can better capture the spatial location information of the image. Experimental results show that the proposed GAN-RpeSC has significant advantages in improving image transmission quality, with a 0.3 dB improvement in peak signal-to-noise ratio (PSNR) compared to the ViT module alone. © 1997-2012 IEEE.

关键词： Encoding (symbols)

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Revealing Packing Structure in Benzimidazole-Containing Polyimides: Anti-Parallel Offset Π-Π Stacking

SSRN

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SSRN 2024年

作者： Luo, Junhui Jin, Yaxin Li, Xin Luo, Longbo Zuo, Zhijun Liu, Xiangyang College of Polymer Science and Engineering State Key Laboratory of Polymer Material and Engineering Sichuan University Chengdu610065 China College of Materials Science and Engineering Henan Key Laboratory of Advanced Nylon Materials and Application Zhengzhou University Zhengzhou450001 China Key Laboratory of Coal Science and Technology of Ministry of Education and Shanxi Province Taiyuan University of Technology Shanxi Taiyuan030024 China

Aromatic polyimides (PIs) exhibit excellent properties due to the charge transfer (CT) interactions. The introduction of benzimidazole with hydrogen interactions is a notably effective strategy for yielding exceptional superheat resistance and high thermal dimensional stability of PIs. Decoupling the stacking behavior under CT interactions and hydrogen interactions is crucial for elucidating the behavior of PIs macromolecules. Herein, the packing structure of PIs guided by hydrogen interactions was visualized using three plausible model compounds and theoretical simulations. The phthalimide fragment exhibited a preference for anti-parallel offset stack π-π stacking, while the phenylbenzimidazole fragment formed a shoulder-to-shoulder arrangement, resulting in the adoption of a Mixed Layer Packing (MPL) conformation, which is not the common Preferred Layer Packing (PLP) conformation. The CT interactions of phthalimide served as the primary stacking driving force, rather than the hydrogen interaction of benzimidazole. The intrinsic nature of packing behavior was that the minima and maxima parts of the electron density deviated from the midperpendicular of benzene and succinimide, where the LOL-π map, ESP map and SAPT calculations provided insights into the microscopic electronic structure. Finally, experimental PI fibers was prepared and their XRD pattern further confirmed the presence of an anti-parallel offset π-π stack conformation. © 2024, The Authors. All rights reserved.

关键词： Polyimides

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Addressing Class Imbalance in Skin Lesion Classification with Dynamic Multi-Output Convolutional Neural Network

SSRN

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SSRN 2023年

作者： Zhao, Jiaqi Zhou, Yingyue Zhong, Ruiqiang Li, Chi Li, Xiaoxia Qin, Jiamin Zhuang, Ming Wen, Liming School of Information Engineering Southwest University of Science and Technology Sichuan Mianyang6210102 China School of Materials Science and Engineering Southwest University of Science and Technology Sichuan Mianyang6210102 China Robot Technology Used for Special Environment Key Laboratory of Sichuan Province Sichuan Mianyang6210102 China Sichuan Mianyang 404 Hospital Sichuan Mianyang621053 China

Skin cancer is a major global public health concern with high incidence and mortality rates. The Convolutional Neural Networks (CNNs) models have been proven effective in improving the performance in skin lesion image classification. This kind of artificial intelligence (AI) based method reduces the medical burden to some extent. However, class imbalance about the training data, resulting from the challenge of collecting dermoscopy images, leads to categorical over-fitting and constraints the performance of these data-driven models in recognizing few-shot categories. To address this issue, we propose a Dynamic Multi-Output Convolutional Neural Network (DMO-CNN) model, which enhances feature representation ability through the introduction of multi-scale sub-feature maps and the reduction of inter-layer dependencies during backpropagation. DMO-CNN is achieved by incorporating exit nodes into the standard CNN structure and equipping with Feature Refinement Layers (FRLs) and an Adaptive Output Scheduling (AOS) module. The FRLs enable efficient and low-loss down-sampling, while the AOS module utilizes a trainable layer selection mechanism to refocus the model's attention on few-shot lesion categories. Furthermore, a novel correction factor (CF) loss is introduced to supervise and promote AOS convergence. Our evaluation of DMO-CNN model on the HAM10000 dataset demonstrated its effectiveness in multi-class skin lesion classification tasks, outperforming some typical models in recognizing few-shot categories. Specifically, DMO-CNN achieved superior performance of 0.885 in BACC and 0.983 in weighted AUC, approaching the first place on the leaderboards of the ISIC 2018 challenge. © 2023, The Authors. All rights reserved.

关键词： Convolutional neural networks

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A Novel Colorimetric and Fluorometric Dual-Signal Identification of Crude Baijiu Based on La-Cds

SSRN

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SSRN 2024年

作者： Zhao, Peng Xia, Xuhui Zheng, Jia Yuan, Zirui Luo, Yiyao Luo, Huibo Ma, Yi Huo, Danqun Hou, Changjun Key Laboratory for Biorheological Science and Technology Ministry of Education Bioengineering College Chongqing University Chongqing400044 China Liquor Making Biology Technology and Application of Key Laboratory of Sichuan Province College of Bioengineering Sichuan University of Science and Engineering 188 University Town Yibin644000 China Strong-flavor Baijiu Solid-state Fermentation Key Laboratory of China Light Industry Wuliangye Group Co. Ltd Yibin644007 China

In this work, we developed a novel optical sensing array using lanthanum-doped carbon dots (La-CDs). By combining La-CDs with three metal complex dyes—chromium black T, alizarin red, and dimethylphenol orange—we achieved, for the first time, simultaneous colorimetric and fluorescent dual-signal detection of organic acids and tannins (TA) in crude baijiu. Based on the indicator displacement (IDA) principle, organic acids competitively replace the dyes' binding sites on La3+, causing the dye colors to change to varying degrees. Tannins quench the fluorescence of quantum dots via an internal filtering effect. We analyzed the data using pattern recognition algorithms such as HCA, PCA, and LDA, successfully classifying and identifying 16 types of strong-flavored crude baijiu, which included 10 types of carboxylic acids and various grades. In blind tests of 32 crude baijiu samples, the colorimetric method achieved a 94% accuracy rate, while the fluorescence method achieved 100%. © 2024, The Authors. All rights reserved.

关键词： Cadmium sulfide

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Experimental Study on Fracture Properties of Heat-Treated Granite in I-Ii Mixed Mode Suffered from Water and Liquid Nitrogen Cooling Methods

SSRN

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SSRN 2024年

作者： Li, Yao Zhou, Lei Xiao, Xiaodong Liang, Xian Wang, Haohan Liu, Junjie Liu, Bang State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering College of Architecture and Environment Sichuan University Chengdu610065 China Applied Mechanics and Structure Safety Key Laboratory of Sichuan Province School of Mechanics and Aerospace Engineering Southwest Jiaotong University Chengdu610031 China Department of International Application Technology Yibin University Yibin644000 China

Hot dry rock (HDR) development is significant for solving energy problems and realizing energy conservation and emission reduction. Liquid nitrogen (LN2) fracturing and hydraulic fracturing can form cracks in the HDR and improve the efficiency of geothermal energy mining. Therefore, it is necessary to study the fracture characteristics of high-temperature granite under different cooling methods. In this study, the deterioration of the physical and mechanical properties of granite subjected to high-temperature treatment under water cooling and LN2 cooling was studied. Two I/II mixed modes (tensile orientation mode and shear orientation mode) and a pure II mode fracture characteristics of cracked straight-through Brazilian disc (CSTBD) specimens made of granite were explored. The displacement and strain fields of cracked granite specimens were measured by using a digital image correlation (DIC) method. The results show that the peak load decreases with the increase of loading angle β, the deterioration degrees of specimens cooled by water cooling and LN2 cooling β=5° are 0 and 1.57% under room temperature, respectively. When the CSTBD specimen with β=23° under room temperature, deterioration degrees of 7.24% and 17.96%, respectively. When the temperature is 600ºC, regardless of the water cooling method or LN2 cooling method for granite, high temperature becomes the main factor affecting the variations of the physical and mechanical properties of granite. © 2024, The Authors. All rights reserved.

关键词： Cooling

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Preliminary Research on the Flavor Substance and Antioxidant Capacity of Beers Produced with Baking Qingke

SSRN

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SSRN 2024年

作者： Ao, Feng Wu, Jianhang Qiu, Ran Zhao, Haifeng Li, Li Zong, Xuyan Liquor Brewing Biotechnology and Application Key Laboratory of Sichuan Province Sichuan University of Science and Engineering Sichuan Yibin644000 China College of Bioengineering Sichuan University of Science and Engineering Sichuan Yibin644000 China China Resources Snow Breweries Co. Ltd Beijing010 100000 China School of Food Science and Engineering South China University of Technology Guangzhou510640 China

The addition of baked Qingke improves the flavor profile of beer. In this study, beer was brewed using Qingke baked at various temperatures. The beer produced with Qingke baked at 180 °C achieved the highest sensory score (40/50), an alcohol content of 6.92% (v/v), a total phenolic content of 446.42 mg/L, melanoidin concentration of 98.22 g/L, a color value of 10.88 EBC, and exhibited satisfactory antioxidant activity. Analysis of volatile compounds using HS-SPME-GC-MS revealed 48 compounds, of which esters accounted for 63% and alcohols accounted for 27% of the total content. The flavor profile of the beer varied across different baking temperatures. Pyrazines and aldehydes were predominantly present in samples baked at higher temperatures (T3, T4, and T5). Correlation analysis showed that the baking flavor in the beer was primarily correlated with 2, 5-dimethyl-pyrazine, trimethyl-pyrazine, phenylacetaldehyde, and ethyl 9-decenoate (R > 0.9) © 2024, The Authors. All rights reserved.

关键词： Beer

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Hardness Recognition of Fruit and Vegetable Based on robot Tactile Perception

Hardness Recognition of Fruit and Vegetable Based on Robot T...

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robotics, Artificial Intelligence and Intelligent Control (RAIIC), International Conference on

作者： Huijuan Lan Dunfeng Zhang Jingyi Wei Shuang Liang School of Information Engineering Southwest University of Science and Technology Mianyang China Robot Technology Used for Special Environment Key Laboratory of Sichuan Province Southwest University of Science and Technology Mianyang China School of Northwestern Polytechnical University Xian China

Aiming at the inaccurate recognition of fruit and vegetable hardness in the damage-free grasping operation of picking robot, we propose a method called proper orthogonal decomposition-artificial neural network (POD-ANN) in this paper. First, the symmetrical clamping mechanism of two fingered manipulator is constructed, and the pressure series data set is established through the fingertip flexible tactile sensor. Second, the classification and recognition results of the collected tactile feature sequences are compared with support vector machine (SVM) and K - nearest neighbor (KNN) algorithms. The comparison results show that the POD-ANN algorithm achieves a recognition rate of 88.1% on the two finger robotic arm platform, which has higher recognition accuracy compared to the other two methods. Simultaneously, it also shows great potential in tactile classification tasks.

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Optimal Subband Adaptive Filtering Algorithm Over Functional Link Neural Network

Optimal Subband Adaptive Filtering Algorithm Over Functional...

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IEEE Workshop on Machine Learning for Signal Processing

作者： Jianhong Ye Yi Yu Badong Chen Zongsheng Zheng School of Information Engineering Robot Technology Used for Special Environment Key Laboratory of Sichuan Province Southwest University of Science and Technology Mianyang China Institute of Artificial Intelligence and Robotics Xi’an Jiaotong University Xi’an China School of Electrical Engineering Sichuan University Chengdu China

Recently, to overcome the slow convergence of the functional link neural network (FLNN) for highly auto-correlated input signals, the delayless multi-sampled multiband-structured subband over FLNN (DMSFLNN) algorithm was proposed. However, this algorithm exists a performance tradeoff between convergence and steady-state behaviors, due to the fact that it uses a fixed step-size. Therefore, to obtain fast convergence and low steady-state misadjustment at the same time, this paper develops an optimal DMSFLNN (ODMSFLNN) algorithm that minimizes the trace of the covariance matrix of the weight deviation vector. Intrinsically, the ODMSFLNN algorithm is an extension of the Kalman filtering theory over the subband-based FLNN structure. In addition, we design the vectorized implementation of the ODMSFLNN algorithm to reduce the computational complexity from $O(L^{2})$ to $O(L)$. Simulations on nonlinear system identification and nonlinear acoustic echo cancellation have been conducted to demonstrate that the proposed ODMSFLNN algorithm outperforms the existing state-of-art algorithms.

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From Discoloration to Color Enhancement: A Novel Approach to High-Concentration Tannin Detection Based on Vco-N-C Bimetallic Nanozyme

SSRN

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SSRN 2024年

作者： Hou, Changjun Qiao, Cailin Wang, Xinrou Luo, Huibo Ma, Yi Yang, Ping Huo, Danqun Zhang, Suyi Key Laboratory for Biorheological Science and Technology of Ministry of Education Bioengineering College of Chongqing University Chongqing400044 China Liquor Making Biology Technology Application of Key Laboratory of Sichuan Province College of Bioengineering Sichuan University of Science and Engineering 188 University Town Yibin644000 China National Engineering Research Center of Solid-State Brewing Luzhou Laojiao Group Co. Ltd. Luzhou646000 China

Direct and rapid detection of high-concentration tannins is crucial for food quality monitoring. This study developed a tannin detection system based on a bimetallic nanozyme VCo-N-C with laccase-like activity, innovatively shifting the conventional detection approach from the 3,3',5,5'-tetramethylbenzidine (TMB) discoloration principle to the 4-aminoantipyrine(4-AP) color enhancement principle. In the presence of VCo-N-C, 4-AP specifically bound to the oxidation products of tannins, resulting in a brown-red compound. By utilizing the bimetallic active centers of VCo-N-C and its multi-valent state conversions, the laccase-like activity was further enhanced, reducing the detection time to 10 min and extending the detection range to 0.1-3000 mg/L, enabling direct detection of high-concentration samples without pretreatment. Ultimately, the VCo-N-C&4-AP system was successfully applied to detect tannin content in high-concentration real samples such as brandy, white liquor, and tea beverages. This study providing a new and powerful tool for food quality control and monitoring. © 2024, The Authors. All rights reserved.

关键词： Discoloration

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