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Siliceous mesocellular foam supported Cu catalysts for promoting non-thermal plasma activated CO_(2) hydrogenation toward methanol synthesis

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Frontiers of Chemical Science and Engineering 2024年第7期18卷 55-65页

作者： yi chen Shaowei chen Yan Shao Cui Quan Ningbo Gao Xiaolei Fan Huanhao chen State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical EngineeringNanjing Tech UniversityNanjing 211816China School of Environmental Science and Engineering Nanjing Tech UniversityNanjing 211816China School of Energy and Power Engineering Xi’an Jiaotong UniversityXi’an 710049China Department of Chemical Engineering School of EngineeringThe University of ManchesterManchester M139PLUK Nottingham Ningbo China Beacons of Excellence Research and Innovation Institute University of Nottingham Ningbo ChinaNingbo 315048China Institute of Wenzhou Zhejiang UniversityWenzhou 325006China

Electrified non-thermal plasma (NTP) catalytic hydrogenation is the promising alternative to the thermal counterparts, being able to be operated under mild conditions and compatible with green electricity/hydrogen. Rational design of the catalysts for such NTP-catalytic systems is one of the keys to improve the process efficiency. Here, we present the development of siliceous mesocellular foam (MCF) supported Cu catalysts for NTP-catalytic CO_(2) hydrogenation to methanol. The findings show that the pristine MCF support with high specific surface area and large mesopore of 784 m2·g−1 and ~8.5 nm could promote the plasma discharging and the diffusion of species through its framework, outperforming other control porous materials (viz., silicalite-1, SiO_(2), and SBA-15). Compared to the NTP system employing the bare MCF, the inclusion of Cu and Zn in MCF (i.e., Cu1Zn1/MCF) promoted the methanol formation of the NTP-catalytic system with a higher space-time yield of methanol at ~275 μmol·g_(cat)^(−1)·h^(−1) and a lower energy consumption of 26.4 kJ^(−1)·mmol_(CH_(3)OH)^(-1) (conversely, ~225 μmol·g_(cat)^(−1)·h^(−1) and ~71 kJ^(−1)·mmol_(CH_(3)OH)^(-1), respectively, for the bare MCF system at 10.1 kV). The findings suggest that inclusion of active metal sites (especially Zn species) could stabilize the CO_(2)/CO-related intermediates to facilitate the surface reaction toward methanol formation.

关键词： non-thermal plasma(NTP)catalysis Cu catalyst CO_(2)hydrogenation methanol siliceous mesocellular foam(MCF)

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A Region-Based Analysis for the Feature Concatenation in Deep Forests

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Chinese Journal of Electronics 2022年第6期31卷 1072-1080页

作者： LYU Shen-Huan chen yi-He ZHOU Zhi-Hua National Key Laboratory for Novel Software Technology Nanjing University

Deep forest is a tree-based deep model made up of non-differentiable modules that are trained without backpropagation. Despite the fact that deep forests have achieved considerable success in a variety of tasks, feature concatenation, as the ingredient for forest representation learning, still lacks theoretical understanding. In this paper, we aim to understand the influence of feature concatenation on predictive performance. To enable such theoretical studies, we present the first mathematical formula of feature concatenation based on the two-stage structure, which regards the splits along new features and raw features as a region selector and a region classifier respectively. Furthermore, we prove a region-based generalization bound for feature concatenation,which reveals the trade-off between Rademacher complexities of the two-stage structure and the fraction of instances that are correctly classified in the selected *** a consequence, we show that compared with the prediction-based feature concatenation(PFC), the advantage of interaction-based feature concatenation(IFC) is that it obtains more abundant regions through distributed representation and alleviates the overfitting risk in local regions. Experiments confirm the correctness of our theoretical results.

关键词： trees (mathematics) raw features pattern classification deep learning (artificial intelligence) deep forest prediction-based feature concatenation forest representation learning tree-based deep model learning (artificial intelligence) region-based generalization feature extraction region-based analysis backpropagation interaction-based feature concatenation

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Coherent State Projection Operator Representation of Symplectic Transformations as a Loyal Representation of Symplectic Group

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Communications in Theoretical Physics 2002年第8期38卷 147-150页

作者： FAN Hong-yi chen Jun-Hua Department of Material Science and Engineering University of Science and Technology of China Hefei 230026 China Department of Material Science and Engineering University of Science and Technology of China Hefei 230026 China

We find that the coherent state projection operator representation of symplectic transformation constitutesa loyal group representation of symplectic group. The result of successively applying squeezing operators on n... 详细信息

关键词： coherent state projection operator, symplectic transformation, squeezing operator

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Calculations of the Spin-Lattice Coupling Coefficients Fij and Zij for MgO:Co2+Crystal

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Communications in Theoretical Physics 2001年第10期36卷 487-490页

作者： ZHENG Wen-chen WU Shao-yi Department of Materials Science Sichuan University Chengdu 610064 China International Centre for Materials Physics The Chinese Academy of Sciences Shenyang 110015 China Department of Materials Science Sichuan University Chengdu 610064 China International Centre for Materials Physics The Chinese Academy of Sciences Shenyang 110015 China

According to a uniform and simple method of calculating spin-lattice coupling coefficients and the pert1rbation formulas of gi factors and hyperfine structure constants Ai based on the cluster approach for 3d7 ions in cubic,tetragonal and trigonal octahedral crystal fields, the spin-lattice coupling coefficients Fij (F11, Fl2, F44), Zij (Z11, Z12,Z44) and also g factor and hyperfine constant A for MgO:Co2+ are calculated by using the parameters obtained from the optical spectra without adjustable parameters. The calculated results show good agreement with the observed *** difiiculty in explaining the coeficients Fij and Zij is therefore removed.

关键词： spin-lattice coupling coefficients, electronic paramagnetic resonance, crystal- and ligand-field theory, Co2+, MgO crystal

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Overexpression of microRNA-124 promotes the neuronal differentiation of bone marrow-derived mesenchymal stem cells

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Neural Regeneration Research 2014年第12期9卷 1241-1248页

作者： Defeng Zou yi chen Yaxin Han chen Lv Guanjun Tu Department of Orthopedics First Affiliated Hospital of China Medical University Department of Orthopedics Jinhua Central Hospital of Zhejiang University

microRNAs （miRNAs） play an important regulatory role in the self-renewal and differentiation of stem cells. In this study, we examined the effects of miRNA-124 （miR-124） overexpression in bone marrow-derived mesenchymal stem cells. In particular, we focused on the effect of overexpression on the differentiation of bone marrow-derived mesenchymal stem cells into neurons. First, we used GeneChip technology to analyze the expression of miRNAs in bone marrow-derived mesen- chymal stem cells, neural stem cells and neurons, miR-124 expression was substantially reduced in bone marrow-derived mesenchymal stem cells compared with the other cell types. We con- structed a lentiviral vector overexpressing miR-124 and transfected it into bone marrow-derived mesenchymal stem cells. Intracellular expression levels of the neuronal early markers [3-III tu- bulin and microtubule-associated protein-2 were significantly increased, and apoptosis induced by oxygen and glucose deprivation was reduced in transfected cells. After miR-124-transfected bone marrow-derived mesenchymal stem cells were transplanted into the injured rat spinal cord, a large number of cells positive for the neuronal marker neurofilament-200 were observed in the transplanted region. The Basso-Beattie-Bresnahan locomotion scores showed that the motor function of the hind limb of rats with spinal cord injury was substantially improved. These re- sults suggest that miR-124 plays an important role in the differentiation of bone marrow-derived mesenchymal stem cells into neurons. Our findings should facilitate the development of novel strategies for enhancing the therapeutic efficacy of bone marrow-derived mesenchymal stem cell transplantation for spinal cord injury.

关键词： nerve regeneration microRNA-124 lentivirus overexpression bone marrow-de-rived mesenchymal stem cells neural stern cells spinal cord injury neurogenesis GeneChip motor function NSFC grant neural regeneration

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A novel adaptive harmonic balance method with an asymptotic harmonic selection

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Applied Mathematics and Mechanics(English Edition) 2023年第11期44卷 1887-1910页

作者： Rongzhou LIN Lei HOU yi chen Yuhong JIN N.A.SAEED Yushu chen School of Astronautics Harbin Institute of TechnologyHarbin 150001China Department of Physics and Engineering Mathematics Faculty of Electronic EngineeringMenoufia UniversityMenouf 32952Egypt Department of Automation Biomechanicsand MechatronicsFaculty of Mechanical EngineeringLodz University of TechnologyLodz 90924Poland Mathematics Department Faculty of ScienceGalala UniversityGalala 43511Egypt

The harmonic balance method(HBM)is one of the most widely used methods in solving nonlinear vibration problems,and its accuracy and computational efficiency largely depend on the number of the harmonics *** adaptive harmonic balance(AHB)method is an improved HBM *** paper presents a modified AHB method with the asymptotic harmonic selection(AHS)*** new harmonic selection procedure selects harmonics from the frequency spectra of nonlinear terms instead of estimating the contribution of each harmonic to the whole nonlinear response,by which the additional calculation is avoided.A modified continuation method is proposed to deal with the variable size of nonlinear algebraic equations at different values of path parameters,and then all solution branches of the amplitude-frequency response are *** experiments are carried out to verify the performance of the AHB-AHS *** typical nonlinear dynamic equations with different types of nonlinearities and excitations are chosen as the illustrative *** with the classical HBM and Runge-Kutta methods,the proposed AHB-AHS method is of higher accuracy and better *** AHB-AHS method proposed in this paper has the potential to investigate the nonlinear vibrations of complex high-dimensional nonlinear systems.

关键词： harmonic balance method(HBM) adaptive harmonic balance(AHB)method harmonic selection nonlinear vibration multi-frequency excitation

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Multiscale Fusion Transformer Network for Hyperspectral Image Classification

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Journal of Beijing Institute of Technology 2024年第3期33卷 255-270页

作者： Yuquan Gan Hao Zhang chen yi School of Telecommunication and Information Engineering Xi’an University of Posts and TelecommunicationsXi’an 710121China

Convolutional neural network(CNN)has excellent ability to model locally contextual ***,CNNs face challenges for descripting long-range semantic features,which will lead to relatively low classification accuracy of hyperspectral *** address this problem,this article proposes an algorithm based on multiscale fusion and transformer network for hyperspectral image ***,the low-level spatial-spectral features are extracted by multi-scale residual ***,an attention module is introduced to focus on the more important spatialspectral ***,high-level semantic features are represented and learned by a token learner and an improved transformer *** proposed algorithm is compared with six classical hyperspectral classification algorithms on real hyperspectral *** experimental results show that the proposed algorithm effectively improves the land cover classification accuracy of hyperspectral images.

关键词： hyperspectral image land cover classification multi-scale transformer

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Microstructure and texture evolution of a near β titanium alloy Ti-7333 during continuous cooling hot deformation

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Progress in Natural Science:Materials International 2019年第1期29卷 50-56页

作者： Jiahao chen Jinshan Li Bin Tang yi chen Hongchao Kou State Key Laboratory of Solidification Processing Northwestern Polytechnical University Key Construction Laboratory of Green Forming and Equipment from Jiangsu Province Jiangsu University of Technology

The microstructure and texture evolution during continuous cooling hot deformation(CCHD) in a near β titanium alloy, named Ti-7Mo-3Nb-3Cr-3Al(Ti-7333), were investigated by using the electron backscattered diffraction(EBSD). The results indicate that the precipitation of secondary α phase was restricted by CCHD, and the morphology of primary α phase nearly had no change with the deformation and temperature drop. In contrast, βphase underwent more deformation and the grains tended to refine. This may be due to the dynamic recrystallization(DRX) of β phase, including continuous dynamic recrystallization(CDRX) and discontinuous dynamic recrystallization(DDRX). In addition, the textures of {110} , {225} and{115} transformed to {100} and {001} during CCHD. Among these, the η-fiber component of {001} was the dominant deformation texture in the deformed Ti-7333 alloy. Finally,continuous cooling has an important effect on the work hardening and softening during CCHD, contributing to the different flow behaviors at different cooling rates.

关键词： Near β titanium alloy Thermo-mechanical processing Texture Dynamic recrystallization

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SSC:Gesture-based game for initial dementia examination

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第7期7卷 1253-1258页

作者： LIU Jun-fa chen yi-qiang XIE chen GAO Wen Institute of Computing Technology Chinese Academy of Sciences Beijing 100080 China Graduate School of the Chinese Academy of Sciences Beijing 100080 China College of Software Technology Zhejiang University Hangzhou 310027 China

This paper presents a novel system assisting medical dementia examination in a joyful way: the object just needs to play a popular game SSC against the computer during the examination. The SSC game’s target is to detect the player’s reacting capability, which is related closely with dementia. Our system reaches this target with some advantages: there are no temporal and spatial constraints at all. There is no cost, and it can even improve people’s mental status. Hand talk technology and EHMM gesture recognition approach are employed to realize the human computer interface. Experiments showed that this system can evaluate people’s reacting capability effectively and is helpful for initial dementia examination.

关键词： Human computer interface Hand talk Dementia Reaction capability

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A multiple template approach for robust tracking of fast motion target

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Applied Mathematics(A Journal of Chinese Universities) 2016年第2期31卷 177-197页

作者： SUN Jun HE Fa-zhi chen yi-lin chen Xiao State Key Laboratory of Software Engineering School of Computer Science Wuhan UniversityWuhan 430072 China Huanggang Polytechnic College Huanggang 438002 China

Target tracking is very important in computer vision and related areas. It is usually difficult to accurately track fast motion target with appearance variations. Sometimes the tracking algorithms fail for heavy appearance variations. A multiple template method to track fast motion target with appearance changes is presented under the framework of appearance model with Kalman filter. Firstly, we construct a multiple template appearance model, which includes both the original template and templates affinely transformed from original one. Generally speaking, appearance variations of fast motion target can be covered by affine transformation. Therefore, the affine tr templates match the target of appearance variations better than conventional models. Secondly, we present an improved Kalman filter for approx- imate estimating the motion trail of the target and a modified similarity evaluation function for exact matching. The estimation approach can reduce time complexity of the algorithm and keep accuracy in the meantime. Thirdly, we propose an adaptive scheme for updating template set to alleviate the drift problem. The scheme considers the following differences： the weight differences in two successive frames; different types of affine transformation applied to templates. Finally, experiments demonstrate that the proposed algorithm is robust to appearance varia- tion of fast motion target and achieves real-time performance on middle/low-range computing platform.

关键词： Target tracking Fast motion target Multiple template match Kalman filter forecast.

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