检索结果-南通市图书馆

嵌段共聚物与阳离子表面活性剂混合模板合成介孔SiO_2

在线全文

学校读者我要写书评

暂无评论

化学学报 2003年第10期61卷 1675-1678页

作者：马玉荣齐利民马季铭程虎民北京大学化学学院分子动态与稳态结构国家重点实验室北京100871

利用三嵌段共聚物EO2 0 PO70 EO2 0 与阳离子表面活性剂CTAB作为混合模板合成了内部孔结构与外观形貌同时受到调控的介孔氧化硅 .与使用单一共聚物模板制备的介孔氧化硅相比 ,在混合模板作用下得到的介孔氧化硅的孔结构有序度降低 ,而... 详细信息

利用三嵌段共聚物EO2 0 PO70 EO2 0 与阳离子表面活性剂CTAB作为混合模板合成了内部孔结构与外观形貌同时受到调控的介孔氧化硅 .与使用单一共聚物模板制备的介孔氧化硅相比 ,在混合模板作用下得到的介孔氧化硅的孔结构有序度降低 ,而孔径则随混合模板中共聚物的质量分数的降低而减小 .在EO2 0 PO70 EO2 0 与CTAB质量比为 1∶1时可得到形貌完好、表面光滑的介孔氧化硅微米球 (1 5～ 4μm) ,其平均孔径为 3 2nm ,比表面积为 972m2

关键词：嵌段共聚物阳离子表面活性剂混合模板合成介孔氧化硅

Envisioning Water-Resilient Cities Through the Lens of Blue-Green-Grey Solutions

在线全文

学校读者我要写书评

暂无评论

Engineering 2024年第5期36卷 1-2页

作者： Nan-qi Ren Glen Daigger School of Civil and Environmental Engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China State Key Laboratory of Urban Water Resource and Environment Harbin Institute of TechnologyHarbin 150090China Department of Civil and Environmental Engineering University of MichiganAnn ArborMI 48109USA

Cities are dynamic systems,and the urban water systems within them can be evolved to provide water services to both humans and the environment while also enhancing the broader urban *** is done by embracing innovation and technological advancement while focusing on increased service to the human population and the local and broader *** the contemporary era,characterized by the rise of low-carbon and intelligent technologies,the swift pace of socioeconomic expansion highlights the critical need to address issues of urban water security and environmental *** escalating resource and environmental constraints,adopting holistic blue-green-grey strategies becomes imperative for the sustainable governance of urban water *** integrated approach is needed to navigate the intricate challenges of urban water dynamics while fostering enhanced ecological performance and resilience.

关键词： services urban advancement

A Review of NILM Applications with Machine Learning Approaches

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第5期79卷 2971-2989页

作者： Maheesha Dhashantha Silva qi Liu School of Electronic and Information Engineering Nanjing University of Information Science and TechnologyNanjing210044China

In recent years,Non-Intrusive LoadMonitoring (NILM) has become an emerging approach that provides affordableenergy management solutions using aggregated load obtained from a single smart meter in the power ***, by integrating Machine Learning (ML), NILM can efficiently use electrical energy and offer less ofa burden for the energy monitoring process. However, conducted research works have limitations for real-timeimplementation due to the practical issues. This paper aims to identify the contribution of ML approaches todeveloping a reliable Energy Management (EM) solution with NILM. Firstly, phases of the NILM are discussed,along with the research works that have been conducted in the domain. Secondly, the contribution of machinelearning approaches in three aspects is discussed: Supervised learning, unsupervised learning, and *** highlights the limitations in the applicability of ML approaches in the field. Then, the challenges in the realtimeimplementation are concerned with six use cases: Difficulty in recognizing multiple loads at a given time,cost of running the NILM system, lack of universal framework for appliance detection, anomaly detection andnew appliance identification, and complexity of the electricity loads and real-time demand side ***, options for selecting an approach for an efficientNILMframework are suggested. Finally, suggestionsare provided for future research directions.

关键词： Non-intrusive load monitoring transfer learning machine learning feature extraction

Dynamic motion of quadrupedal robots on challenging terrain:a kinodynamic optimization approach

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Mechanical Engineering 2024年第3期19卷 23-40页

作者： qi LI Lei DING Xin LUO Engineering Research Center of Hubei Province for Clothing Information Wuhan 430200China School of Computer Science and Artificial Intelligence Wuhan Textile UniversityWuhan 430200China State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China

The dynamic motion of quadrupedal robots on challenging terrain generally requires elaborate spatial–temporal kinodynamic motion planning and accurate control at higher refresh rate in comparison with regular ***,conventional quadrupedal robots usually generate relatively coarse planning and employ motion replanning or reactive strategies to handle terrain *** resultant complex and computation-intensive controller may lead to nonoptimal motions or the breaking of locomotion *** this paper,a kinodynamic optimization approach is *** generate long-horizon optimal predictions of the kinematic and dynamic behavior of the quadruped robot on challenging terrain,we formulate motion planning as an optimization problem;jointly treat the foot’s locations,contact forces,and torso motions as decision variables;combine smooth motion and minimal energy consumption as the objective function;and explicitly represent feasible foothold region and friction constraints based on terrain *** track the generated motions accurately and stably,we employ a whole-body controller to compute reference position and velocity commands,which are fed forward to joint controllers of the robot’s *** verify the effectiveness of the developed approach through simulation and on a physical quadruped robot *** show that the quadruped robot can successfully traverse a 30°slope and 43% of nominal leg length high step while maintaining the rhythm of dynamic trot gait.

关键词： quadrupedal robot kinodynamic planning nonlinear optimization challenging terrain whole-body control

Buckling optimization of curvilinear fiber-reinforced composite structures using a parametric level set method

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Mechanical Engineering 2024年第1期19卷 149-160页

作者： Ye TIAN Tielin SHI qi XIA State Key Laboratory of Intelligent Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China

Owing to their excellent performance and large design space,curvilinear fiber-reinforced composite structures have gained considerable attention in engineering fields such as aerospace and *** addition to the stiffness and strength of such structures,their stability also needs to be taken into account in the *** study proposes a level-set-based optimization framework for maximizing the buckling load of curvilinear fiber-reinforced composite *** the proposed method,the contours of the level set function are used to represent fiber *** a composite laminate with a certain number of layers,one level set function is defined by radial basis functions and expansion coefficients for each ***,the fiber angle at an arbitrary point is the tangent orientation of the contour through this *** the finite element of buckling,the stiffness and geometry matrices of an element are related to the fiber angle at the element *** study considers the parallelism constraint for fiber *** the sensitivity calculation of the objective and constraint functions,the method of moving asymptotes is utilized to iteratively update all the expansion coefficients regarded as design *** numerical examples under different boundary conditions are given to validate the proposed *** show that the optimized curved fiber paths tend to be parallel and equidistant regardless of whether the composite laminates contain holes or ***,the buckling resistance of the final design is significantly improved.

关键词： buckling optimization curvilinear fiber composite structure level set method manufacturing constraint

ANALYSIS OF THE IMPLICIT-EXPLICIT ULTRA-WEAK DISCONTINUOUS GALERKIN METHOD FOR CONVECTION-DIFFUSION PROBLEMS

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2024年第1期42卷 1-23页

作者： Haijin Wang Anping Xu qi Tao School of Science Nanjing University of Posts and TelecommunicationsNanjing 210023China Beijing Computational Science Research Center Beijing 100193China

In this paper,we first present the optimal error estimates of the semi-discrete ultra-weak discontinuous Galerkin method for solving one-dimensional linear convection-diffusion ***,coupling with a kind of Runge-Kutta type implicit-explicit time discretization which treats the convection term explicitly and the diffusion term implicitly,we analyze the stability and error estimates of the corresponding fully discrete *** fully discrete schemes are proved to be stable if the time-stepτ≤τ0,whereτ0 is a constant independent of the mesh-size ***,by the aid of a special projection and a careful estimate for the convection term,the optimal error estimate is also obtained for the third order fully discrete *** experiments are displayed to verify the theoretical results.

关键词： The ultra-weak discontinuous Galerkin method Convection-diffusion Implicitexplicit time discretization Stability Error estimate

π-conjugated chromophore functionalized high-nuclearity titanium-oxo clusters containing structural unit of anatase for photocatalytic selective oxidation of sulfides

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2024年第4期43卷 1736-1746页

作者： Ling-Rong Liao Dong-Chun Zheng Pin-Xi Ou qi-Xin Zhao Wei-Min Xuan qi Zheng State Key Laboratory for Modification of Chemical Fibers and Polymer Materials&College of Materials Science and Engineering Donghua UniversityShanghai201620China State Key Laboratory for Modification of Chemical Fibers and Polymer Materials and College of Chemistry and Chemical Engineering Donghua UniversityShanghai 201620China

N-doping has significant influence in manipulating the properties of TiO_(2),and this has stimulated the development of N-donor-functionalized titanium-oxo clusters(TOCs)as molecular models to study the structure-property ***,the structural type and photoresponsive application are still limited for such TOCs,especially regarding the high-nuclearity TOCs that contain structure unit of TiO_(2)for ***,we showed the synthesis of a series of high-nuclearity TOCs 1-3 compounds usingπ-conjugated 1,10-phenanthroline(phen)as chromophore and N-donor functional *** 1 features cocrystal structure composed of one[Ti_(26)]~(2+)and half[Ti_(22)]~(2+),which renders it as the first cocrystallized TOC containing two positively charged species and phen-functionalized TOC showing the highest nuclearity up to 37 Ti *** adjusting the synthetic conditions,the individual{Ti_(22)}and{Ti_(26)}clusters can also be isolated as Compounds 2 and 3,*** core structure of{Ti_(22)}is mainly constructed from four lacunary{Ti_(4)}derived from pentagonal{Ti(Ti)_5}unit,while{Ti_(26)}is built from four complete{Ti(Ti)_5}***,a{Ti_8O_(14)}structure unit of anatase TiO_(2)can be identified in{Ti_(26)}.Based on the unique structural features and proper photophysical and photochemical properties of Compounds 1-3,they are applied for photocatalytic *** to the presence of anatase structure unit in{Ti_(26)}and the synergistic effect from{Ti_(22)}and{Ti_(26)},the catalytic performance presents in the order of Compound 1>Compound 3>Compound *** work provides excellent models to understand the structureproperty relationship from the perspective of cocrystallization and Ti-O binding model and will further promote the application of TOCs as functional catalysts for organic transformation.

关键词： Titanium-oxo cluster Molecular model of anatase TiO_(2) High nuclearity π-conjugated chromophore Photocatalytic sulfoxidation

Optimal AP Deployment in Cell-Free Massive MIMO Systems with LoS/NLoS Transmissions:A Stochastic Geometry Approach

在线全文

学校读者我要写书评

暂无评论

China Communications 2024年第9期21卷 146-158页

作者： Jiang Ling Zhang qi Zhu Hongbo Jiangsu Key Laboratory of Wireless Communications Nanjing University of Posts and TelecommunicationsNanjing 210003China

Cell-free massive multiple-input multipleoutput(MIMO)is a promising technology for future wireless communications,where a large number of distributed access points(APs)simultaneously serve all users over the same time-frequency *** users and APs may locate close to each other,the line-of-sight(Lo S)transmission occurs more frequently in cell-free massive MIMO ***,in this paper,we investigate the cell-free massive MIMO system with Lo S and non-line-of-sight(NLo S)transmissions,where APs and users are both distributed according to Poisson point *** tools from stochastic geometry,we derive a tight lower bound for the user downlink achievable rate and we further obtain the energy efficiency(EE)by considering the power consumption on downlink payload transmissions and circuitry *** on the analysis,the optimal AP density and AP antenna number that maximize the EE are *** is found that compared with the previous work that only considers NLo S transmissions,the actual optimal AP density should be much smaller,and the maximized EE is actually much higher.

关键词： cell-free massive MIMO energy efficiency LoS/NLoS transmissions stochastic geometry

One-shot Face Reenactment with Dense Correspondence Estimation

在线全文

学校读者我要写书评

暂无评论

Machine Intelligence Research 2024年第5期21卷 941-953页

作者： Yunfan Liu qi Li Zhenan Sun School of Artificial Intelligence University of Chinese Academy of SciencesBeijing100049China Center for Research on Intelligent Perception and Computing Institute of AutomationChinese Academy of SciencesBeijing100190China

One-shot face reenactment is a challenging task due to the identity mismatch between source and driving *** existing methods fail to completely eliminate the interference of driving subjects’identity information,which may lead to face shape distortion and undermine the realism of reenactment *** solve this problem,in this paper,we propose using a 3D morphable model(3DMM)for explicit facial semantic decomposition and identity *** of using 3D coefficients alone for reenactment control,we take advantage of the generative ability of 3DMM to render textured face *** proxies contain abundant yet compact geometric and semantic information of human faces,which enables us to compute the face motion field between source and driving images by estimating the dense *** this way,we can approximate reenactment results by warping source images according to the motion field,and a generative adversarial network(GAN)is adopted to further improve the visual quality of warping *** experiments on various datasets demonstrate the advantages of the proposed method over existing state-of-the-art benchmarks in both identity preservation and reenactment fulfillment.

关键词： Generative adversarial networks face image manipulation face image synthesis face reenactment 3D morphable model