2024

• Record 193 of
  
  Title:Rapid prediction of regenerator performance for regenerative cryogenics cryocooler based on convolutional neural network
  
  Author(s):Chen, Xiantong; Li, Shanshan; Yu, Jun; Yang, Sen; Chen, Hao
  Source: INTERNATIONAL JOURNAL OF REFRIGERATION  Volume: 158  Issue:   DOI: 10.1016/j.ijrefrig.2023.11.025  Published: 2024  
  Abstract:The regenerator is the core component of the regenerative cryogenic refrigerator, for its structure sizes, operating parameters and phase characteristics at the cold and hot ends co-determine the power and efficiency of the refrigerator, and the design parameters of other coupled components. Efficiently predicting the regenerator performance can reduce the design period of cryogenic refrigerators. Addressing the long computational time constraints in the traditional numerical simulation methods, a novel approach based on a one-dimensional convolutional neural network (1D-CNN) was proposed. Initially, a program capable of multi-threading and automatically running the specialized regenerator calculation software REGEN 3.3 was developed. The performance of the regenerators with various parameter combinations at the cold end temperature of 60-120 K were calculated and 181,440 pieces of data were obtained. Subsequently, the architecture and hyperparameters of the model were determined. The trained model exhibits an average relative error of 3.83% for predicting regenerator power, 0.13% for predicting pressure ratio at the hot end, and 1.55% for predicting the coefficient of performance (COP). The model's generalization ability was confirmed by generating data points beyond the original dataset. Additionally, the model allows for the simultaneous calculation of multiple sets of irregular regenerator parameters, and reduces the calculation time from 2500 min for 1000 pieces using REGEN 3.3 software to just 130 ms, representing a decrease by nearly six orders of magnitude. This approach effectively resolves the long computation time associated with traditional numerical simulation methods, and will present a new solution for the rapid and precise design of regenerators.
  Accession Number:
  ISSN: 0140-7007
  eISSN: 1879-2081
• Record 194 of
  
  Title:Multi-scale convolutional neural networks and saliency weight maps for infrared and visible image fusion
  
  Author(s):Yang, Chenxuan; He, Yunan; Sun, Ce; Chen, Bingkun; Cao, Jie; Wang, Yongtian; Hao, Qun

  Source: JOURNAL OF VISUAL COMMUNICATION AND IMAGE REPRESENTATION  

  Volume: 98  DOI: 10.1016/j.jvcir.2023.104015  Published: 2024  

  Abstract:Image fusion is the fusion of multiple images from the same scene to produce a more informative image, and infrared and visible image fusion is an important branch of image fusion. To tackle the issues of diminished luminosity in the infrared target, inconspicuous target features, and blurred texture of the fused image after the fusion of infrared and visible images. This paper introduces a novel effective fusion framework that merges multiscale Convolutional Neural Networks (CNN) with saliency weight maps. First, the method measures the source image features to estimate the initial saliency weight map. Then, the initial weight map is segmented and optimized using a guided filter before being further processed by CNN. Next, a trained Siamese convolutional network is used to solve the two key problems of activity measure and weight assignment. Meanwhile, a multilayer fusion strategy is designed to effectively retain the luminance of the infrared target and the texture information in the visible background. Finally, adaptive adjustment of the fusion coefficients is achieved by employing saliency. The experimental results show that the method outperforms the state-of-the-art algorithms in terms of both subjective visual quality and objective evaluation effects.

  Accession Number: 104015

  ISSN: 1047-3203

  eISSN: 1095-9076
• Record 195 of
  
  Title:A different view on the deactivation process of 3-hydroxy-salicylidene-methylamine system
  
  Author(s):Han, Guoxia; Wei, Hongyan; Yu, Xianghua; Zhang, Jialing; Ma, Yanbin; Liu, Peng
  Source: CHEMICAL PHYSICS LETTERS  Volume: 835  Issue:   DOI: 10.1016/j.cplett.2023.141004  Published: 2024  
  Abstract:Schiff bases stand out as a highly significant class of photochromic materials with widespread applications. The exploration of their photochromic mechanisms has garnered substantial interest over the past decades. In this work, we investigated the photochromic mechanism of 3-hydroxy-salicylidene methylamine (3-OH-SMA) by high-level electronic structure calculations and on-the-fly excited state dynamics simulations. Our investigation revealed the identification of three minimum energy conical intersections between S1 and S0 states, while only the one characterized by the central C = N bond twisting motion was involved in the deactivation process. This finding contrasts with previous reports, suggesting that the excited state intramolecular proton transfer (ESIPT) process was the main reaction channel in 3-OH-SMA. The proposed new decay mechanism provides valuable theoretical insights, paving the way for the further enhancement or rational design of photochromic materials.
  Accession Number: 141004
  ISSN: 0009-2614
  eISSN: 1873-4448
• Record 196 of
  
  Title:Constructing 1D/0D Sb2S3/Cd0.6Zn0.4S S-scheme heterojunction by vapor transport deposition and in-situ hydrothermal strategy towards photoelectrochemical water splitting
  
  Author(s):Liu, Dekang; Jin, Wei; Zhang, Liyuan; Li, Qiujie; Sun, Qian; Wang, Yishan; Hu, Xiaoyun; Miao, Hui
  Source: JOURNAL OF ALLOYS AND COMPOUNDS  Volume: 975  Issue:   DOI: 10.1016/j.jallcom.2023.172926  Published: 2024  
  Abstract:Antimony sulfide (Sb2S3) is widely used in photocatalysts and photovoltaic cells because of its abundant reserves, low toxicity, environmental friendliness, narrow band gap, and high light absorption capacity. Sb2S3 shows a quasi-one-dimensional structure composed of [Sb4S6]n nanoribbons, a lot of reported studies are focused on preparing Sb2S3 with [hk1] oriented dominant growth to improve the photogenerated carrier transport capacity of Sb2S3. However, there is relatively few research on the preparation of [hk1] oriented rod-like Sb2S3 by vapor transport deposition (VTD) method. In this work, the VTD method was used to prepare Sb2S3 with [hk1] oriented growth on the FTO substrate, and then composite with the ternary solid solution CdxZn1_xS. Finally, a novel Sb2S3/Cd0.6Zn0.4S S-scheme heterojunction with rod-like core-shell structure was successfully constructed, which could effectively improve the photoelectrochemical properties. Because the solid solution component x is adjustable, that is, CdxZn1_xS has continuously adjustable band gap width and energy level position, the Sb2S3/ CdxZn1_xS heterojunction type can be regulated from Type-II to S-scheme. Photoelectrochemical (PEC) tests indicated that the composite photoanode Sb2S3/Cd0.6Zn0.4S achieved a higher photocurrent density (2.54 mA center dot cm_ 2, 1.23 V vs. RHE), which is about 4.31 times that of pure Sb2S3 nanorod photoanode (0.59 mA center dot cm_ 2, 1.23 V vs. RHE).
  Accession Number: 172926
  ISSN: 0925-8388
  eISSN: 1873-4669
• Record 197 of
  
  Title:Multilevel-based algorithm for hyperspectral image interpretation
  
  Author(s):Qiu, Shi; Ye, Huping; Liao, Xiaohan; Zhang, Benyue; Zhang, Miao; Zeng, Zimu
  Source: COMPUTERS & ELECTRICAL ENGINEERING  Volume: 113  Issue:   DOI: 10.1016/j.compeleceng.2023.109033  Published: 2024  
  Abstract:Hyperspectral imagery contains spatial and spectral information, which can reveal the material properties of the target while intuitively displaying its spatial attributes. It has been applied in target recognition, search and rescue, and other fields. However, manual detection inevitably leads to missed detections and false alarms, necessitating the assistance of artificial intelligence for detection. To address this, we propose the multilevel-based algorithm for hyperspectral image interpretation. 1) From the spatial and spectral dimensions, we propose a semantic segmentation algorithm based on multidimensional information fusion to achieve semantic segmentation. 2) From the semantic and textual representation dimensions, we introduce a context interpretation module based on visual attention. We construct both real and simulated databases to validate the effectiveness of the algorithm. Experimental results demonstrate that the average accuracy of semantic segmentation achieved by the proposed algorithm is 74.3%. Additionally, the BLEU1 score reaches 71.2, outperforming mainstream algorithms by 1.4.
  Accession Number: 109033
  ISSN: 0045-7906
  eISSN: 1879-0755
• Record 198 of
  
  Title:Observation of three kinds of bound solitons in a black phosphorus-based erbium fiber laser
  
  Author(s):Li, Wenlei; Lin, Ruping; Chen, Guangwei; Geng, Gaoli; Xu, Peng; Yang, Yining; Wang, Xinliang; Xu, Jian
  Source: OPTICAL FIBER TECHNOLOGY  Volume: 82  Issue:   DOI: 10.1016/j.yofte.2023.103617  Published: 2024  
  Abstract:We describe the experimental finding of three kinds of bound solitons in the Erbium-doped fiber lasers based on saturable absorber of black phosphorus. The passively mode-locked laser can obtain stretched-pulse state, double-pulse and four-pulse bound state with the sech2-shaped pulse profile. The laser can also realize Lorentzian autocorrelation trace with the duration of approximately 562 fs and deliver Lorentzian double-pulse bound state with pulse separations of approximately 5.04 ps by properly adjusting the polarization state. This project demonstrates that the same fiber laser can obtain different types of bound state pulses, which lays a foundation for further research into bound state pulses.
  Accession Number: 103617
  ISSN: 1068-5200
  eISSN: 1095-9912
• Record 199 of
  
  Title:Influence of wavefront distortion on the measurement of pulse signal-to-noise ratio
  
  Author(s):Xing, Dingding; Yuan, Suochao; Kou, Jingwei; Da, Zhengshang
  Source: OPTICS COMMUNICATIONS  Volume: 554  Issue:   DOI: 10.1016/j.optcom.2023.130110  Published: 2024  
  Abstract:The high-fidelity measurement of the ultra-short and ultra-intense laser pulses' temporal signal-to-noise ratio (SNR) is of great significance. To the best of our knowledge, few studies have investigated the influence of wavefront distortion on the measurement of pulse SNR. In this work, a numerical model is constructed to study how wavefront distortion affects the measurement of ultra-short and ultra-intense pulse SNR by the single-shot third-order auto-correlation (TOAC) method. The nonlinear coupled-wave equations with wavefront distortion have been solved numerically by the split-step Fourier method and the fourth-order Runge-Kutta numerical algorithm. The wavefront distortion of the under-test fundamental wave will be transmitted to the second harmonic and third harmonic, leading to the phase mismatch in the second harmonic generation (SHG) and third harmonic generation (THG), further resulting in the deterioration of the measured SNR. We analyze the influence of different spatial frequencies and peak-to-valley (PV) values on the measurements of SNR. The larger the spatial frequency or PV value of the wavefront distortion, the more severe the degradation of the SNR.
  Accession Number: 130110
  ISSN: 0030-4018
  eISSN: 1873-0310
• Record 200 of
  
  Title:A truncated test scheme design method for success-failure in-orbit tests
  
  Author(s):Ding, Wenzhe; Bai, Xiang; Wang, Qingwei; Long, Fang; Li, Hailin; Wu, Zhengrong; Liu, Jian; Yao, Huisheng; Yang, Hong
  Source: RELIABILITY ENGINEERING & SYSTEM SAFETY  Volume: 243  Issue:   DOI: 10.1016/j.ress.2023.109782  Published: 2024  
  Abstract:Based on the success-failure test feature of in-orbit tests (IOTs) for typical space equipment, this paper presents a method for designing a truncated test scheme for success-failure in-orbit tests. With this method, a small upper boundary of the sample size for the IOT verification test can be obtained before the test starts. The method introduces the truncated Bayes-sequential mesh test (SMT) method into the design of the IOT verification test scheme and greatly compresses the continuous test area by incorporating optimization theory, resulting in a smaller upper limit of the IOT sample size. First, this paper derives a specific calculation formula for the BayesSMT critical line. Second, the Markov chain model is adopted to calculate the occurrence probabilities of each acceptance and rejection point through state transition. Finally, an optimal truncated test optimization algorithm based on the augmented lagrangian genetic algorithm is proposed. Simulation tests show that, compared with the classical single sampling method, the truncated sequential probability ratio test method, the truncated SMT method, and the truncated Bayes-SMT method based on step-by-step calculation, the method presented in this paper can be used to obtain a sequential test scheme with smaller truncated sample size.
  Accession Number: 109782
  ISSN: 0951-8320
  eISSN: 1879-0836
• Record 201 of
  
  Title:The deactivation effects of Nd3+ion for 2.85 μm laser in Ho3+/Nd3+co-doped fluorotellurite glass
  
  Author(s):Feng, Shaohua; Zhu, Jun; Liu, Chengzhen; Xiao, Yang; Cai, Liyang; Xu, Yantao; Xiao, Xusheng; Guo, Haitao
  Source: JOURNAL OF LUMINESCENCE  Volume: 266  Issue:   DOI: 10.1016/j.jlumin.2023.120308  Published: 2024  
  Abstract:The 2.85 mu m band has garnered significant attention for its wide range of applications in the mid-infrared region, and Ho3+ doped fluorotellurite fiber shows great promise as a gain medium for the 2.85 mu m fiber laser. To achieve efficient population inversion for Ho3+ ions at 2.85 mu m, Ho3+/Nd3+ co-doped fluorotellurite glasses with low hydroxyl were synthesized. The deactivation effect of Nd3+ ions to Ho3+: 5I7 levels was investigated through emission spectra and lifetime decay curves under 890 nm excitation. The results show that Nd3+ ions can effectively quench the Ho3+: 2.05 mu m emission and help the Ho3+: 5I6 -> 5I7 transition to overcome the bottleneck of particle population inversion. Ultimately, the particle population inversion corresponding to 2.85 mu m luminescence was realized in the Ho3+/Nd3+ co-doped fluorotellurite glass, and indicates that a maximum of 1.64 W laser at 2.85 mu m with a slope efficiency of 8.72 % can be realized under 890 nm pump by numerical simulations.
  Accession Number: 120308
  ISSN: 0022-2313
  eISSN: 1872-7883
• Record 202 of
  
  Title:Scale and pattern adaptive local binary pattern for texture classification
  
  Author(s):Hu, Shiqi; Li, Jie; Fan, Hongcheng; Lan, Shaokun; Pan, Zhibin
  Source: EXPERT SYSTEMS WITH APPLICATIONS  Volume: 240  Issue:   DOI: 10.1016/j.eswa.2023.122403  Published: 2024  
  Abstract:Local binary pattern (LBP) with a fixed sampling template is sensitive to scale changes. Furthermore, under rotation changes or noise corruptions, one uniform LBP pattern can be corrupted to fall into a non-uniform pattern which loses its discrimination power to describe the corresponding texture feature. To overcome these two main drawbacks, we propose a scale and pattern adaptive local binary pattern (SPALBP). Firstly, in the gradient-based sampling radius adaptive scheme, eight directional adaptive sampling radius of each center pixel can be obtained by using its eight Kirsch gradient values. Secondly, in the noise and rotation robust neighborhood sampling scheme, three neighborhood sampling templates are used to extract three kinds of averaging neighborhood pixels. Thirdly, for each center pixel, three kinds of LBPriu2 patterns can be extracted by sampling these three kinds of averaging neighborhood pixels along eight directional adaptive sampling radius. Finally, an optimal SPALBP uniform pattern can be adaptively selected from these three LBPriu2 patterns. Hence, all SPALBP patterns show more robustness against scale changes, rotation changes and noise corruptions. Extensive experiments are conducted on four standard texture databases: Outex, UIUC, CUReT and XU_HR. Comparing with state-of-the-art LBP-based variants, the proposed SPALBP method consistently shows superior performance both in dramatic environment changes and high-levels of noise conditions, meanwhile it maintains a lower texture feature dimension.
  Accession Number: 122403
  ISSN: 0957-4174
  eISSN: 1873-6793
• Record 203 of
  
  Title:A compact 51.6-W, 26-μ J, Yb-doped all-fiber integrated CPA system through quasi-rectangular pulse pre-shaping
  
  Author(s):Li, Qianglong; Li, Feng; Liu, Hongjun; Zhao, Wei; Zhao, Hualong; Wang, Yishan; Wen, Wenlong; Cao, Xue; Si, Jinhai
  Source: OPTICS AND LASER TECHNOLOGY  Volume: 170  Issue:   DOI: 10.1016/j.optlastec.2023.110300  Published: 2024  
  Abstract:A compact 51.6-W, 26-mu J all-fiber integrated Yb-doped femtosecond laser source with pulse durations of 692 fs despite similar to 18 pi nonlinear phase shift accumulation in the main amplifier is demonstrated by using fiber quasi-rectangular pulse pre-shaping. The numerical results are in good agreement with the experiment. Due to the advantages of an all-fiber spliced structure and a minimal pulse stretching ratio (from 26.3 ps to similar to 70 ps), just a small size of gratings and a short separation distance between the two gratings in the compressor is required. Therefore, the laser source is exceedingly compact, robust, cost-effective, and easy to assemble. This technique is anticipated to accelerate the use of fiber femtosecond lasers in industrial applications.
  Accession Number: 110300
  ISSN: 0030-3992
  eISSN: 1879-2545
• Record 204 of
  
  Title:Static spectroscopic ellipsometer based on division-of-amplitude polarization demodulation
  
  Author(s):Li, Siyuan; Deng, Zhongxun; Quan, Naicheng; Zhang, Chunmin
  Source: OPTICS COMMUNICATIONS  Volume: 552  Issue:   DOI: 10.1016/j.optcom.2023.130115  Published: 2024  
  Abstract:Theoretical and experimental demonstrations of a static spectroscopic ellipsometer are presented. It uses a linear polarizer for generating polarization states to interact with the sample, and three non-polarization beam splitters incorporating four achromatic quarter waveplate/linear analyzer pairs for analyzing the polarization states after the interaction. Compared to previous instruments, the most significant advantage of the described model is that it can obtain the spectral ellipsometric parameters with the same spectral resolution as the spectrometer in the system by a single snapshot.
  Accession Number: 130115
  ISSN: 0030-4018
  eISSN: 1873-0310