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Unique synergistic effects of ZIF-9（Co）-derived cobalt phosphide and CeVO4 heterojunction for efficient hydrogen evolution

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Chinese Journal of Catalysis 2020年第1期41卷 82-94页

作者： Lijun Zhang Xuqiang Hao Junke Li Yuanpeng Wang Zhiliang Jin School of Chemistry and Chemical Engineering North Minzu UniversityYinchuan 750021NingxiaChina Key Laboratory for Chemical Engineering and Technology State Ethnic Affairs CommissionNorth Minzu UniversityYinchuan 750021NingxiaChina Ningxia Key Laboratory of Solar Chemical Conversion Technology North Minzu UniversityYinchuan 750021NingxiaChina

The photocatalytic decomposition of water to produce hydrogen is an important process,through which solar energy can be converted to chemical ***-precious metal phosphides have quietly attracted attention as an emerging inexpensive *** this study,we reported that a CoP/CeVO4 hybrid photocatalyst exhibited high hydrogen evolution efficiency owing to EY(eosin Y)sensitization under visible light irradiation for the first time,and the amount of generated hydrogen reached 444.6μmol in 5 *** CoP/CeVO4 nanohybrids were synthesized by a simple chemical precipitation *** coupling of CoP and CeVO4 with ZIF-9 as a precursor could be completed in one *** CeVO4 particles were firmly attached to the surface of the CoP particles to form a"small point"to"big point"*** results of X-ray diffraction,X-ray photoelectron spectroscopy,scanning electron microscopy,EDX,and transmission electron microscopy showed the formation of CoP and CeVO4 nanoparticles and the structure of the *** on a detailed analysis of the Mott-Schottky plot,the UV-vis diffuse reflectance spectra,photocurrent-time(it)curve,Tafel curve,Nyquist curve(EIS),linear volt-ampere curve(LSV),and steady-state fluorescence spectra were *** time-resolved photoluminescence measurements indicated that the reason for the high-efficiency hydrogen evolution of CoP/CeVO4 was that the bands of CoP and CeVO4 were bent due to the existence of the Schottky barrier,and a heterojunction was formed between CoP and CeVO4,which generated an internal electric field and accelerated the charge *** addition,the synergistic effect between CoP and CeVO4 provided a new hydrogen-evolution activity center for each of *** improved carrier separation efficiency and the decrease in the photo-generated recombination rate led to the excellent photocatalytic hydrogen-evolution activity of the CoP/CeVO4 composite *** work provides a new strategy for modulating the el

关键词： Photocatalysis CoP CeVO4 Dye-sensitized Hydrogen production

Recommendation Method for Contrastive Enhancement of Neighborhood Information

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Computers, Materials & Continua 2024年第1期78卷 453-472页

作者： Hairong Wang Beijing Zhou Lisi Zhang He Ma School of Computer Science and Engineering North Minzu UniversityNingxia750021China

Knowledge graph can assist in improving recommendation performance and is widely applied in various person-alized recommendation ***,existing knowledge-aware recommendation methods face challenges such as weak user-item interaction supervisory signals and noise in the knowledge *** tackle these issues,this paper proposes a neighbor information contrast-enhanced recommendation method by adding subtle noise to construct contrast views and employing contrastive learning to strengthen supervisory signals and reduce knowledge ***,first,this paper adopts heterogeneous propagation and knowledge-aware attention networks to obtain multi-order neighbor embedding of users and items,mining the high-order neighbor informa-tion of users and ***,in the neighbor information,this paper introduces weak noise following a uniform distribution to construct neighbor contrast views,effectively reducing the time overhead of view *** paper then performs contrastive learning between neighbor views to promote the uniformity of view information,adjusting the neighbor structure,and achieving the goal of reducing the knowledge noise in the knowledge ***,this paper introduces multi-task learning to mitigate the problem of weak supervisory *** validate the effectiveness of our method,experiments are conducted on theMovieLens-1M,MovieLens-20M,Book-Crossing,and Last-FM *** results showthat compared to the best baselines,our method shows significant improvements in AUC and F1.

关键词： Contrastive learning knowledge graph recommendation method

Improved YOLOv8n Model for Detecting Helmets and License Plates on Electric Bicycles

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Computers, Materials & Continua 2024年第7期80卷 449-466页

作者： Qunyue Mu Qiancheng Yu Chengchen Zhou Lei Liu Xulong Yu The College of Computer Science and Engineering North Minzu UniversityYinchuan750021China The Key Laboratory of Images and Graphics Intelligent Processing of State Ethnic Affairs Commission North Minzu UniversityYinchuan750021China

Wearing helmetswhile riding electric bicycles can significantly reduce head injuries resulting fromtraffic *** effectively monitor compliance,the utilization of target detection algorithms through traffic cameras plays a vital role in identifying helmet usage by electric bicycle riders and recognizing license plates on electric ***,manual enforcement by traffic police is time-consuming and *** methods face challenges in accurately identifying small targets such as helmets and license plates using deep learning *** paper proposes an enhanced model for detecting helmets and license plates on electric bicycles,addressing these *** proposedmodel improves uponYOLOv8n by deepening the network structure,incorporating weighted connections,and introducing lightweight convolutional *** modifications aim to enhance the precision of small target recognition while reducing the model’s parameters,making it suitable for deployment on low-performance devices in real traffic *** results demonstrate that the model achieves an mAP@0.5 of 91.8%,showing an 11.5%improvement over the baselinemodel,with a 16.2%reduction in ***,themodel achieves a frames per second(FPS)rate of 58,meeting the accuracy and speed requirements for detection in actual traffic scenarios.

关键词： YOLOv8 object detection electric bicycle helmet detection electric bicycle license plate detection

EDA-assisted synthesis of multifunctional snowflake-Cu_(2)S/CdZnS S-scheme heterojunction for improved the photocatalytic hydrogen evolution

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Journal of Materials Science & Technology 2022年第26期121卷 28-39页

作者： Guorong Wang Yongkang Quan Kaicheng Yang Zhiliang Jin School of Chemistry and Chemical Engineering Ningxia Key Laboratory of Solar Chemical Conversion TechnologyKey Laboratory for Chemical Engineering and TechnologyState Ethnic Affairs CommissionNorth Minzu UniversityYinchuan 750021China

The charge separation efficiency is one of the main factors affecting the solar photocatalytic decomposition of water to produce *** a unique heterojunction can accelerate the separation and transfer of photo-generated charges,and effectively improve the photocatalytic efficiency,which is considered a potential ***,the 2%Cu_(2)S/CZS step-scheme(S-scheme)heterojunction based on morphology and electronic structure was successfully prepared via simple hydrothermal *** with the monomer Cu_(2)S and Cd Zn S,the hydrogen evolution rate of 2%Cu_(2)S/CZS samples is significantly *** particular,the 2%Cu_(2)S/CZS not only shows high hydrogen evolution rate of 5904μmol g^(-1)h^(-1)(3.19 times than original Cd Zn S),but also presents preferable cyclic *** to the characterization,we believe that the introduction of Cu_(2)S has the following three advantages:(i)The snowflake structure of Cu_(2)S reduces the agglomeration of granular Cd Zn S.(ii)The Cu_(2)S with narrow band gap broadens the light response range of the composite catalyst.(iii)The Cu_(2)S was introduced into Cd Zn S to form S-scheme heterojunction,which accelerated the separation and transfer of photo-generated *** work broadens the idea of designing efficient photocatalyst of hydrogen evolution.

关键词： S-scheme Heterojunction Multifunctional Snowflake-Cu_(2)S Photocatalyst

User Purchase Intention Prediction Based on Improved Deep Forest

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Computer Modeling in Engineering & Sciences 2024年第4期139卷 661-677页

作者： Yifan Zhang Qiancheng Yu Lisi Zhang School of Computer Science and Engineering North Minzu UniversityYinchuan750030China Laboratory of Graphics and Images of the State Ethnic Affairs Commission North Minzu UniversityYinchuan750030China

Widely used deep neural networks currently face limitations in achieving optimal performance for purchase intention prediction due to constraints on data volume and hyperparameter *** address this issue,based on the deep forest algorithm and further integrating evolutionary ensemble learning methods,this paper proposes a novel Deep Adaptive Evolutionary Ensemble(DAEE)*** model introduces model diversity into the cascade layer,allowing it to adaptively adjust its structure to accommodate complex and evolving purchasing behavior ***,this paper optimizes the methods of obtaining feature vectors,enhancement vectors,and prediction results within the deep forest algorithm to enhance the model’s predictive *** demonstrate that the improved deep forest model not only possesses higher robustness but also shows an increase of 5.02%in AUC value compared to the baseline ***,its training runtime speed is 6 times faster than that of deep models,and compared to other improved models,its accuracy has been enhanced by 0.9%.

关键词： Purchase prediction deep forest differential evolution algorithm evolutionary ensemble learning model selection

Facilitating efficient photocatalytic hydrogen evolution via enhanced carrier migration at MOF-on-MOF S-scheme heterojunction interfaces through a graphdiyne(C_(n)H_(2n-2))electron transport layer

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Chinese Journal of Structural Chemistry 2023年第12期42卷 11-23页

作者： Fei Jin Bolin Yang Xuanpu Wang Teng Li Noritatsu Tsubaki Zhiliang Jin School of Chemistry and Chemical Engineering Ningxia Key Laboratory of Solar Chemical Conversion TechnologyKey Laboratory for Chemical Engineering and TechnologyState Ethnic Affairs CommissionNorth Minzu UniversityYinchuan750021PR China Department of Applied Chemistry Graduate School of EngineeringUniversity of ToyamaGofuku3190Toyama930-8555Japan

Interface engineering of photocatalysts is an effective way to enhance their photocatalytic *** this work,the MOF-on-MOF strategy was used to construct the ZIF-9(Co)/Cu_(3)BTC_(2) photocatalyst in ***,graph-diyne,possessing an inherent capability to facilitate rapid electron transfer at the interface,has been introduced into the ZIF-9(Co)/Cu_(3)BTC_(2) interface to regulate the interfacial carrier *** photogenerated carrier transfer capability has been significantly enhanced by the interfacial synergy,while retaining the original active sites and high specific surface *** exceptional efficiency performance of the composite catalyst under identical conditions could be attributed to the following two key factors:(i)The interfacial S-scheme hetero-junction in ZIF-9(Co)/Cu_(3)BTC_(2) provides the composite catalyst with strong reduction activity,facilitating the involvement of additional electrons in the reduction reaction through bended bands and an internal electric field.(ii)Carrier dynamics analysis shows that graphdiyne,as an electron transport layer,accelerates the charge migration rate at the S-scheme heterojunction interface through the electron relay *** incorporation of graphdiyne greatly improves the catalytic activity of MOFs and also demonstrates the great potential of graph-diyne in *** work provides a feasible idea for the interface engineering design of graphdiyne in photocatalysts.

关键词： Graphdiyne S-scheme heterojunction MOFs Photocatalytic hydrogen evolution

Construction of CuO-modified zeolitic imidazolate framework-9 for photocatalytic hydrogen evolution

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Chinese Journal of Catalysis 2017年第12期38卷 2056-2066页

作者： Kai Fan Zhiliang Jin Hong Yuan Hongyan Hu Yingpu Bi School of Chemistry and Chemical Engineering North Minzu University Yinchuan 750021 Ningxia China State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou 730000Gansu China

An efficient CuO‐modified zeolitic imidazolate framework‐9(ZIF‐9)photocatalyst is successfully prepared at room temperature under mild *** is observed that the ZIF‐9/CuO photocatalyst is effective for H2generation under visible light with sacrificial agent *** the CuO is introduced,the photocatalytic properties of ZIF‐9are greatly improved and when the content of CuO is40%,the photocatalytic activity reaches a maximum of78.74μmol *** results from the200–300nm cube structure of ZIF‐9being able to adsorb more dye molecules and the CuO,which connects with ZIF‐9,greatly improving the electronic transmission ***,the interaction between the dye molecule Eosin Y(EY)and the catalyst is also studied by transient fluorescence spectroscopy.A series of characterizations,such as SEM,TEM,XPS,XRD,UV‐vis,FTIR,transient fluorescence and photocurrent,are conducted,and the results are in good agreement with the experimental *** addition,the possible reaction mechanism over EY‐sensitized ZIF‐9/CuO under visible light irradiation is proposed.

关键词： ZIF‐9 CuO Eosin Y Sensitized pathway Hydrogen evolution Reaction optimization

BIFURCATION ANALYSIS IN A PREDATOR-PREY MODEL WITH AN ALLEE EFFECT AND A DELAYED MECHANISM

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Acta Mathematica Scientia 2023年第3期43卷 1415-1438页

作者：李丹阳刘华张濠天马明叶勇魏玉梅 School of Mathematics and Computer Science Northwest Minzu UniversityLanzhou730000China School of Science Harbin Institute of Technology(Shenzhen)Shenzhen518055China Experimental Teaching Department Northwest Minzu UniversityLanzhou730030China

Regarding delay-induced predator-prey models, much research has been done on delayed destabilization, but whether delays are stabilizing or destabilizing is a subtle issue. In this study, we investigate predator-prey dynamics affected by both delays and the Allee effect. We analyze the consequences of delays in different feedback mechanisms. The existence of a Hopf bifurcation is studied, and we calculate the value of the delay that leads to the Hopf bifurcation. Furthermore, applying the normal form theory and a center manifold theorem, we consider the direction and stability of the Hopf bifurcation. Finally, we present numerical experiments that validate our theoretical analysis. Interestingly, depending on the chosen delay mechanism, we find that delays are not necessarily destabilizing. The Allee effect generally increases the stability of the equilibrium, and when the Allee effect involves a delay term, the stabilization effect is more pronounced.

关键词： delays Allee effect Hopf bifurcation stability

A multiscale transform denoising method of the bionic polarized light compass for improving the unmanned aerial vehicle navigation accuracy

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Chinese Journal of Aeronautics 2022年第4期35卷 400-414页

作者： Donghua ZHAO Jun TANG Xindong WU Jing ZHAO Chenguang WANG Chong SHEN Jun LIU Key Laboratory of Instrumentation Science&Dynamic Measurement Ministry of EducationSchool of Instrument and ElectronicsNorth University of ChinaTaiyuan 03005JPR China School of Information and Communication Engineering North University of ChinaTaiyuan 030051PR China

In recent years, the bionic polarized light compass has been widely studied for the unmanned aerial vehicle navigation. However, it is found from the obtained investigation results that a polarized light compass with a sensitive and high dynamic range polarimeter still provides inferior output precision of the heading angle due to the presence of the noise generating from the *** noise is existed not only in the angle of the polarization image acquired by polarimeters but also in the output heading data, which leads to a sharp reduction in the accuracy of a polarized light compass. Herein, we present noise analysis and a novel multiscale transform denoising method of a polarized light compass used for the unmanned aerial vehicle navigation. Specifically, a multiscale principle component analysis utilizing one-dimensional image entropy as classification criterion is directly implemented to suppress the noise in the acquired polarization image. Subsequently, a multiscale time–frequency peak filtering method using the sample entropy as classification criterion is applied for the output heading data so as to further increase the heading measurement accuracy from the denoised image above. These two approaches are combined to significantly reduce the heading error affected by different types of noises. Our experimental results indicate the proposed multiscale transform denoising method exhibits high performance in suppressing the noise of a polarized light compass used for the unmanned aerial vehicle navigation compared to existing prior arts.

关键词： Denoising Multi-scale transform Orientation Polarized light compass UAV navigation