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Switched-capacitor Based Seven-level boost Inverter with a Reduced Number of Devices

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CSEE Journal of Power and Energy Systems 2024年第1期10卷 381-391页

作者： Weijie Lin Jun Zeng bo Fu Zhixing yan.Junfeng Liu School of Electric Power Engineering South China University of TechnologyGuangzhou 510641China WISDRI Engineering&Research Incorporation Limited Wuhan 430074China Department of Energy Aalborg UniversityAalborg 9220Denmark School of Automation Science and Engineering South China University of TechnologyGuangzhou 510641China

The conventional multilevel inverters(MLIs)have the disadvantages of numerous devices,incapacity of boost,unbalance for capacitor’s voltage,high complexity for control,and *** by this issue,a seven-level boost inverter(7LBI)based on a switched capacitor is presented for singlephase applications in this *** proposed 7LBI using only seven transistors can achieve seven output levels,1.5 voltage gain,and natural balance of capacitors’voltages without sensors or other auxiliary methods,which illustrates its suitability for the applications of renewable energy *** configuration of topology and operating principles are illustrated in *** natural balance of capacitors and capacitance calculations are deduced as ***,the comparative study is conducted for different types of *** results illustrate the merits of the proposed 7LBI with respect to reduced devices,lower voltage stress,and less power ***,a simulation for the proposed 7LBI with PWM modulation is realized based on the theoretical analysis;an experimental prototype is also implemented,verifying multilevel output,boost ability,natural balance for switched capacitors,and performance of transient response.

关键词： Multilevel inverters voltage gain natural balance renewable energy generation reduced number of elements

Scenarios analysis and performance assessment of blockchain integrated in 6G scenarios

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Science China(Information Sciences) 2024年第7期67卷 5-26页

作者： bo LI Guanjie CHENG Honghao GAO Xueqiang yan.Shuiguang DENG College of Computer Science and Technology Zhejiang University College of Computer Science and Technology Shanghai University 2012 Lab Huawei Technologies Co. Ltd.

Emerging applications such as smart city infrastructures and virtual reality landscapes are setting rigorous benchmarks for 6G mobile networks, requiring elevated levels of confidentiality, integrity, nonrepudiation, authentication, and stringent access controls. Blockchain technology is heralded as a transformative enabler for meeting 6G standards, owing to its intrinsic attributes. However, a gap exists in the holistic investigation of blockchain's applicability in 6G realms, particularly addressing the “whether”, “when”, and“how” of its deployment. Present research trails in developing robust methodologies to gauge blockchain's efficacy within 6G use cases. Addressing this, our study introduces a novel confluence of blockchain with 6G networks, where data resides in distributed Hash tables(DHTs) while their hashes are secured in distributed ledger technology(DLT), harnessing blockchain's core strengths-immutability, traceability, and fortified security. We delineate seven specific 6G use cases poised for enhancement through blockchain integration,and scrutinize the rationale, nature, and timing of this convergence. Furthermore, we devise a comprehensive methodology for assessing blockchain's performance metrics and scalability in 6G environments. Our extensive experimental analyses evaluate the synergistic performance of this integration, revealing that the Quorum blockchain satisfactorily supports 80% of 6G scenarios. The findings suggest that, with appropriate configurations, consortium blockchains are well-equipped to fulfill the demanding performance and scalability requisites of 6G networks.

关键词： blockchain distributed ledger technology (DLT) 6G performance assessment 6G scenarios analysis transaction arrival rate

Macrocyclic peptides:up-and-coming weapons to combat antimicrobial resistance

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Signal Transduction and Targeted Therapy 2024年第5期9卷 1786-1787页

作者： Wen-Jing Wang Xiang-min Dong Guo-bo L Department of Biotherapy Cancer Center and State Key Laboratory of BiotherapyWest China HospitalSichuan UniversityChengduSichuanChina Key Laboratory of Drug Targeting and Drug Delivery System of ministry of Education Department of Medicinal ChemistryWest China School of PharmacySichuan UniversityChengduSichuanChina

Recently,two companion papers published in Nature reported a first-in-class tethered macrocyclic peptide antibiotic targeting carbapenem-resistant ***(CRAB)and unveiled their unique antibacterial mechanism,which invol... 详细信息

关键词： outer macrocyclic Macrocyclic

An adaptive physics-informed deep learning method for pore pressure prediction using seismic data

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Petroleum Science 2024年第2期21卷 885-902页

作者： Xin Zhang Yun-Hu Lu yan.Jin Mian Chen bo Zhou State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Beijing)Beijing102249China College of Petroleum Engineering China University of Petroleum(Beijing)Beijing102249China College of Artificial Intelligence China University of Petroleum(Beijing)Beijing102249China PetroChina Tarim Oilfield Company KorlaXinjiang841000China

Accurate prediction of formation pore pressure is essential to predict fluid flow and manage hydrocarbon production in petroleum *** deep learning technique has been receiving more interest due to the great potential to deal with pore pressure ***,most of the traditional deep learning models are less efficient to address generalization *** fill this technical gap,in this work,we developed a new adaptive physics-informed deep learning model with high generalization capability to predict pore pressure values directly from seismic ***,the new model,named CGP-NN,consists of a novel parametric features extraction approach(1DCPP),a stacked multilayer gated recurrent model(multilayer GRU),and an adaptive physics-informed loss *** machine training,the developed model can automatically select the optimal physical model to constrain the results for each pore pressure *** CGP-NN model has the best generalization when the physicsrelated metricλ=0.5.A hybrid approach combining Eaton and bowers methods is also proposed to build machine-learnable labels for solving the problem of few *** validate the developed model and methodology,a case study on a complex reservoir in Tarim Basin was further performed to demonstrate the high accuracy on the pore pressure prediction of new wells along with the strong generalization *** adaptive physics-informed deep learning approach presented here has potential application in the prediction of pore pressures coupled with multiple genesis mechanisms using seismic data.

关键词： Pore pressure prediction Seismic data 1D convolution pyramid pooling Adaptive physics-informed loss function High generalization capability

Intelligent representation method of image flatness for cold rolled strip

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Journal of Iron and Steel Research International 2024年第5期31卷 1177-1195页

作者： yan.-huan Xu Dong-cheng Wang Hong-min Liu bo-wei Duan National Engineering Research Center for Equipment and Technology of Cold Strip Rolling Yanshan UniversityQinhuangdao066004HebeiChina National Key Laboratory of Metal Forming Technology and Heavy Equipment China National Heavy Machinery Research Institute Co.Ltd.Xi’an710018ShaanxiChina State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao066004HebeiChina

Real flatness images are the bases for flatness detection based on machine vision of cold rolled *** characteristics of a real flatness image are analyzed,and a lightweight strip location detection(SLD)model with deep semantic segmentation networks is *** interference areas in the real flatness image can be eliminated by the SLD model,and valid information can be *** this basis,the concept of image flatness is proposed for the first *** image flatness representation(IFAR)model is established on the basis of an autoencoder with a new *** optimal structure of the bottleneck layer is 16×16×4,and the IFAR model exhibits a good representation ***,interpretability analysis of the representation factors is carried out,and the difference and physical meaning of the representation factors for image flatness with different categories are *** flatness with new defect morphologies(bilateral quarter waves and large middle waves)that are not present in the original dataset are generated by modifying the representation factors of the no wave ***,the SLD and IFAR models are used to detect and represent all the real flatness images on the test *** average processing time for a single image is 11.42 ms,which is suitable for industrial *** research results provide effective methods and ideas for intelligent flatness detection technology based on machine vision.

关键词： Cold rolled strip Image flatness Location detection Representation learning bottleneck layer

Influence of friction-lubrication characteristics varying with rolling speed on instability of chatter and slip in cold tandem rolling process

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Journal of Iron and Steel Research International 2024年第4期31卷 894-908页

作者： yan.li Xin Zhi-ying Gao bo Tian Qing-dong Zhang School of Mechanical Engineering University of Science and Technology BeijingBeijing 100083China

In the high-speed cold tandem rolling process of thin plate,chatter or slip instability gives rise to the deterioration of equipment and product *** instability behavior is closely related to interfacial friction-lubrication con-dition which is generally characterized by the friction ***,with higher and higher speed requirements,the commonly used model of friction coefficient is no longer applicable and accurate.A novel approach is suggested to calculate the speed-dependent friction coefficient,in which the viscosity-pressure-temperature effects of the lubricant,surface roughness states of work rolls and rolled piece are comprehensively involved and the mixed flm lubrication theory is ***,the influences of friction coefficient on the instability of slip and chatter are investigated for a five-stand cold tandem rolling *** one side,the critical friction coefficient for each stand is determined by calculating the corresponding slip factor;on the other hand,the friction coefficient varying with rolling speed is combined with the model of theoretical critical rolling speed presented under constant friction coefficient,so that the speed threshold is ***,the stable and unstable regions corresponding to the rear three stands are individually discussed,and the technical strategies are proposed to suppress both slip and chatter frequently occurring in the actual rolling process.

关键词： Cold tandem rolling:Oil film thickness Speed-dependent friction coefficient-Slip:Chatter

Hydrothermal hydrogenation/deoxygenation of palmitic acid to alkanes over Ni/activated carbon catalyst

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Chinese Journal of Chemical Engineering 2024年第2期66卷 8-18页

作者： min Lin Yuhao yan.Xiaoxian Li Rui Li Yulong Wu MOE Engineering Center of Forestry Biomass Materials and Bioenergy Beijing Forestry UniversityBeijing 100083China Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084China Key Laboratory of Advanced Reactor Engineering and Safety of ministry of Education Tsinghua UniversityBeijing 100084China

To produce paraffin from hydrogenation/deoxygenation of palmitic acid,model compound of bio-oil obtained by hydrothermal liquefaction(HTL)of microalgae has been an attractive focus in recent *** order to avoid energy-intensive separation process of water and bio-oil,it is of importance that deoxygenation upgrading of fatty acids under hydrothermal conditions similar to HTL ***,it is the first time to explore the application of activated carbon(AC)-supported non-noble-metal catalysts,such as Ni,Co,and Mo,and so on,in the hydrothermal hydrogenation/deoxygenation of long-chain fatty acids,and the obtained Ni/AC-H(the Ni/AC was further H_(2)pre-reduced)is one of the best *** addition,it is found that the catalytic activity can be further improved by H_(2)pre-reduction of *** results that are more low valences of nickel and oxygen vacancy can be obtained after H_(2)pre-reduction,thus significant promoting the deoxygenation especially the decarbonylation pathway of fatty *** total alkanes yield can reaches 95.9%at optimal conditions(280℃,360 min).This work confirmed that the low-priced AC-supported non-noble-metal catalysts have great potential compared with the noble-metal catalyst,in hydrothermal upgrading of bio-oil.

关键词： Bio-oil Fatty acids Deoxygenation Hydrothermal upgrading

Data-driven surrogate model for aerodynamic design using separable shape tensor method

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Chinese Journal of Aeronautics 2024年第9期37卷 41-58页

作者： bo PANG yan. ZHANG Junlin LI Xudong WANG min CHANG Junqiang BAI State Key Laboratory for Srrenglh and Vibration of Mechanical Structures Xi'an Jiaotong UniversityXi'an 710049China Unmanned System Research Institute Northwestern Polytechmical UniversityXi'an 710072China

In the context of increasing dimensionality of design variables and the complexity of con-straints,the effcacy of Surrogate-Based Optimization(Sbo)is *** traditional linear and nonlinear dimensionality reduction algorithms are mainly to decompose the mathematical matrix composed of design variables or objective functions in various forms,the smoothness of the design space cannot be guaranteed in the process,and additional constraint functions need to be added in the optimization,which increases the calculation *** study presents a new parameterization method to improve both problems of *** new parameterization is addressed by decoupling affine transformations(dilation,rotation,shearing,and translation)within the Grassmannian sub-manifold,which enables a separate representation of the physical information of the airfoil in a high-dimensional *** upon this,Principal Geodesic Analysis(PGA)is employed to achieve geometric control,compress the design space,reduce the number of design variables,reduce the dimensions of design variables and enhance predictive performance during the surrogate optimiza-tion *** comparison,a dimensionality reduction space is defined using 95%of the energy,and RAE 2822 for transonic conditions are used as *** method significantly enhances the optimization efficiency of the surrogate model while effectively enabling geometric *** three-dimensional problems,it enables simultaneous design of planar shapes for various components of the aircraft and high-order perturbation *** was applied to the ONERA M6 wing,achieving a lift-drag ratio of 18.09,representing a 27.25%improvement com-pared to the baseline *** comparison to conventional surrogate model optimization methods,which only achieved a 17.97%improvement,this approach demonstrates its superiority.

关键词： Aerodynamicdesign Grassmannian manifold Shape parameterization Surrogate-based optimiza-tion Data dimensionality reduction

Cu-Based Materials for Enhanced C_(2+) Product Selectivity in Photo-/Electro-Catalytic CO_(2) Reduction: Challenges and Prospects

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Nano-Micro Letters 2024年第4期16卷 25-66页

作者： Baker Rhimi min Zhou Zaoxue yan.Xiaoyan.Cai Zhifeng Jiang Institute for Energy Research School of Chemistry and Chemical EngineeringJiangsu UniversityZhenjiang 212013People’s Republic of China School of Materials Science and Physics China University of Mining and TechnologyXuzhou 221116People’s Republic of China

Carbon dioxide conversion into valuable products using photocatalysis and electrocatalysis is an effective approach to mitigate global environmental issues and the energy shortages. Among the materials utilized for catalytic reduction of CO_(2), Cu-based materials are highly advantageous owing to their widespread availability, cost-effectiveness, and environmental sustainability. Furthermore, Cu-based materials demonstrate interesting abilities in the adsorption and activation of carbon dioxide, allowing the formation of C_(2+) compounds through C–C coupling process. Herein, the basic principles of photocatalytic CO_(2) reduction reactions(PCO_(2)RR) and electrocatalytic CO_(2) reduction reaction(ECO_(2)RR) and the pathways for the generation C_(2+) products are introduced. This review categorizes Cu-based materials into different groups including Cu metal, Cu oxides, Cu alloys, and Cu SACs, Cu heterojunctions based on their catalytic applications. The relationship between the Cu surfaces and their efficiency in both PCO_(2)RR and ECO_(2)RR is emphasized. Through a review of recent studies on PCO_(2)RR and ECO_(2)RR using Cu-based catalysts, the focus is on understanding the underlying reasons for the enhanced selectivity toward C_(2+) products. Finally, the opportunities and challenges associated with Cu-based materials in the CO_(2) catalytic reduction applications are presented, along with research directions that can guide for the design of highly active and selective Cu-based materials for CO_(2) reduction processes in the future.

关键词： Photocatalytic CO_(2)reduction Cu-based materials Electrocatalytic CO_(2)reduction