检索结果-南通市图书馆

Photonics Research 2024年第7期12卷 1395-1409页

作者： XIming li RUI XU XIAOFENG SUN YUAN zhao zhao YANG GUOHONG DU College of Electronic Engineering Chengdu University of Information TechnologyChengdu 610225China

Programmable metasurfaces have received a great deal of attention due to their ability to dynamically manipulate electromagnetic(EM) waves. Despite the rapid growth, most of the existing metasurfaces require manual control to switch among different functionalities, which poses severe limitations on practical applications. Here, we put forth an intelligent metasurface that has self-adaptive EM functionality switching in broadband without human participation. It is equipped with polarization discrimination antennas(PDAs) and feedback components to automatically adjust functionalities for the different incident polarization information.

关键词： equipped adjust polarization

Parsing Objects at a Finer Granularity: A Survey

在线全文

学校读者我要写书评

暂无评论

Machine Intelligence Research 2024年第3期21卷 431-451页

作者： Yifan zhao Jia li Yonghong Tian School of Computer Science Peking UniversityBeijing100871China State Key Laboratory of Virtual Reality Technology and Systems School of Computer Science and EngineeringBeihang UniversityBeijing100191China

Fine-grained visual parsing, including fine-grained part segmentation and fine-grained object recognition, has attracted considerable critical attention due to its importance in many real-world applications, e.g., agriculture, remote sensing, and space technologies. Predominant research efforts tackle these fine-grained sub-tasks following different paradigms, while the inherent relations between these tasks are neglected. Moreover, given most of the research remains fragmented, we conduct an in-depth study of the advanced work from a new perspective of learning the part relationship. In this perspective, we first consolidate recent research and benchmark syntheses with new taxonomies. Based on this consolidation, we revisit the universal challenges in fine-grained part segmentation and recognition tasks and propose new solutions by part relationship learning for these important challenges. Furthermore, we conclude several promising lines of research in fine-grained visual parsing for future research.

关键词： Finer granularity visual parsing part segmentation fine-grained object recognition part relationship

Beyond 1,4-addition of in-situ generated(aza-)quinone methides and indole imine methides

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第7期35卷 35-53页

作者： Yan-li li Zhi-ming li Kai-Kai Wang Xiao-Long He Medical College Xinxiang UniversityXinxiang 453000China School of Pharmacy Xinxiang UniversityXinxiang 453000China School of Food and Bioengineering Xihua UniversityChengdu 610039China

The conjugate addition of in-situ generated(aza-)quinone methides(QMs)and indole imine methides(IIMs)emerged as a powerful protocol to access densely functionalized benzenes and *** alcohols,aminobenzhydryl alcohols,and varied indolylmethanols served as most effective precursors for the in-situ generation of such reactive species under acid *** relevant propargylic alcohol has proven to be an elegant precursor to generate the propargylic-QMs and-IIMs via the acid promoted dehydration process,thus enabling diverse challenging remote activation to proceed conjugate1,6-and 1,***,the heteroarene has proven to be workable to transfer the LUMO of the p-QMs and 2-IIMs,thus inducing the remote nucleophilic dearomative *** conjugate additions of(aza-)p-QMs and varied IIMs has made significant contribution in the field of remote activation chemistry in past *** review summarizes the latest advances of the remote conjugate additions of the in-situ generated QMs and IIMs.

关键词： Conjugate addition QMs IIMs LUMO Remote activation Dearomative addition

An aptamer-driven DNA nanodevice for improved delivery of synthetic immunostimulants

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第10期17卷 9078-9083页

作者： Dejie Lu Zhenghan Di Lele li Jian zhao li Zheng Guangxi Engineering Center in Biomedical Materials for Tissue and Organ Regeneration Collaborative Innovation Centre of Regenerative Medicine and Medical BioResource Development and ApplicationGuangxi Key Laboratory of Regenerative MedicineThe First Affiliated Hospital of Guangxi Medical UniversityGuangxi Medical UniversityNanning 530021China CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety National Center for Nanoscience and TechnologyBeijing 100190China

Efficient delivery of therapeutics to immune cells remains a formidable challenge for cancer *** this work,we demonstrate that an aptamer-driven DNA nanodevice,constructed through linkage of a synthetic immunostimulant(Toll-like receptor 9 agonist:CpG motif)to an aptamer,could significantly enhance the immunostimulatory activity by facilitating the uptake and retention of therapeutics in *** administration of the DNA nanodevice results in efficient tumor growth inhibition in both breast cancer and melanoma mouse *** studies suggest that the DNA nanodevice leads to reeducation of tumor-associated macrophages and ultimately to reversing the tumor immune *** strategy for aptamer-mediated and vehicle-free delivery of immunostimulatory oligonucleotides provides a potential platform for cancer immunotherapy.

关键词： aptamer immunostimulatory oligonucleotides DNA nanodevice tumor-associated macrophages cancer therapy

An Environment‑Tolerant Ion‑Conducting Double‑Network Composite Hydrogel for High‑Performance Flexible Electronic Devices

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano-Micro Letters 2024年第5期16卷 352-369页

作者： Wenchao zhao Haifeng Zhou Wenkang li Manlin Chen Min Zhou Long zhao State Key Laboratory of Advanced Electromagnetic Technology School of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074People’s Republic of China School of Chemistry and Chemical Engineering Huazhong University of Science and TechnologyWuhan 430074People’s Republic of China

High-performance ion-conducting hydrogels(ICHs)are vital for developing flexible electronic ***,the robustness and ion-conducting behavior of ICHs deteriorate at extreme tempera-tures,hampering their use in soft *** resolve these issues,a method involving freeze–thawing and ionizing radiation technology is reported herein for synthesizing a novel double-network(DN)ICH based on a poly(ionic liquid)/MXene/poly(vinyl alcohol)(PMP DN ICH)*** well-designed ICH exhibits outstanding ionic conductivity(63.89 mS cm^(-1) at 25℃),excellent temperature resistance(-60–80℃),prolonged stability(30 d at ambient temperature),high oxidation resist-ance,remarkable antibacterial activity,decent mechanical performance,and ***,the ICH performs effectively in a flexible wireless strain sensor,thermal sensor,all-solid-state supercapacitor,and single-electrode triboelectric nanogenerator,thereby highlighting its viability in constructing soft electronic *** highly integrated gel structure endows these flexible electronic devices with stable,reliable signal output *** particular,the all-solid-state supercapacitor containing the PMP DN ICH electrolyte exhibits a high areal specific capacitance of 253.38 mF cm^(-2)(current density,1 mA cm^(-2))and excellent environmental *** study paves the way for the design and fabrication of high-performance mul-tifunctional/flexible ICHs for wearable sensing,energy-storage,and energy-harvesting applications.

关键词： Ionic liquids Double-network hydrogels Temperature tolerance Multifunctionality Flexible electronic devices

Singularity analysis and avoidance for an SSRMS-type reconfigurable space manipulator with a non-spherical wrist and two lockable passive telescopic links

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第8期37卷 435-459页

作者： Zhiyuan zhao Xiaohang YANG Yuntao li Zichun XU Jingdong zhao Hong liU State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China

This study focuses on addressing kinematic singularity analysis and avoidance issues for a space station remote manipulator system(SSRMS)-type reconfigurable space *** manipulator is equipped with a non-spherical wrist and two lockable passive telescopic links(LPTLs),which enable it to have both active revolute and passive prismatic joints and operate in two distinct *** begin with the kinematic singularity analysis,the study derives the differential kinematic equations for the manipulator and identifies the dominant Jacobian matrix that causes ***,an in-depth analysis of singularities from multiple perspectives is ***,a kinematic singularity map method is proposed to capture the distribution of singularities within the reachable ***,the influence of the two LPTLs on singularities is thoroughly ***,a new method based on the matrix rank equivalence principle is introduced to determine singularity conditions,enabling the identification of all the singular configurations for the SSRMS-type reconfigurable ***,this method significantly reduces computational complexity,and the singularity conditions obtained have more concise *** the singularity avoidance problem,a novel method is developed,which simultaneously addresses the requirements of real-time performance,high precision,and the avoidance of both kinematic singularities and joint limit *** from these excellent properties,the proposed method can effectively resolve the singularity issues encountered separately by the SSRMS-type reconfigurable manipulator in its two operational *** typical simulations validate the utility of all the proposed methods.

关键词： Reconfigurable space manipulator Redundant manipulator Kinematics Singularity analysis Singularity avoidance

Attention-Based CNN Fusion Model for Emotion Recognition During Walking Using Discrete Wavelet Transform on EEG and Inertial Signals

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Big Data Mining and Analytics 2024年第1期7卷 188-204页

作者： Yan zhao ming Guo Xiangyong Chen Jianqiang Sun Jianlong Qiu School of Communication Engineering Hangzhou Dianzi UniversityHangzhou 310018China School of Automation and Electrical Engineering Linyi UniversityLinyi 276000China

Walking as a unique biometric tool conveys important information for emotion *** in different emotional states exhibit distinct walking *** this purpose,this paper proposes a novel approach to recognizing emotion during walking using electroencephalogram(EEG)and inertial *** recognition of emotion is achieved by training in an end-to-end deep learning fashion and taking into account multi-modal *** wear virtual reality head-mounted display(VR-HMD)equipment to immerse in strong emotions during *** environment shows excellent imitation and experience ability,which plays an important role in awakening and changing *** addition,the multi-modal signals acquired from EEG and inertial sensors are separately represented as virtual emotion images by discrete wavelet transform(DWT).These serve as input to the attention-based convolutional neural network(CNN)fusion *** designed network structure is simple and lightweight while integrating the channel attention mechanism to extract and enhance *** effectively improve the performance of the recognition system,the proposed decision fusion algorithm combines Critic method and majority voting strategy to determine the weight values that affect the final decision *** investigation is made on the effect of diverse mother wavelet types and wavelet decomposition levels on model performance which indicates that the 2.2-order reverse biorthogonal(rbio2.2)wavelet with two-level decomposition has the best recognition *** experiment results show that the proposed method outperforms other existing state-of-the-art works with an accuracy of 98.73%.

关键词： walking multi-modal fusion virtual reality emotion recognition discrete wavelet transform attention mechanism

Plasma-exfoliated g-C_(3)N_(4) with oxygen doping: tailoring photocatalytic properties

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 Chemical Science and Engineering 2024年第2期18卷 27-39页

作者： Yuxin li Junxin Guo Rui Han zhao Wang National Engineering Research Centre of Industry Crystallization Technology School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China

Heteroatom doping and defect engineering have been proposed as effective ways to modulate the energy band structure and improve the photocatalytic activity of g-C_(3)N_(4). In this work, ultrathin defective g-C_(3)N_(4) was successfully prepared using cold plasma. Plasma exfoliation reduces the thickness of g-C_(3)N_(4) from 10 nm to 3 nm, while simultaneously introducing a large number of nitrogen defects and oxygen atoms into g-C_(3)N_(4). The amount of doped O was regulated by varying the time and power of the plasma treatment. Due to N vacancies, O atoms formed strong bonds with C atoms, resulting in O doping in g-C_(3)N_(4). The mechanism of plasma treatment involves oxygen etching and gas expansion. Photocatalytic experiments demonstrated that appropriate amount of O doping improved the photocatalytic degradation of rhodamine B compared with pure g-C_(3)N_(4). The introduction of O optimized the energy band structure and photoelectric properties of g-C_(3)N_(4). Active species trapping experiments revealed ·O_(2)^(–) as the main active species during the degradation.

关键词： graphitic carbon nitride cold plasma oxygen doping nitrogen defect visible-light photocatalysis

Classification of complete 3-dimensional self-shrinkers in the Euclidean space R^(4)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Mathematics 2024年第4期67卷 873-882页

作者： Qing-ming Cheng Zhi li Guoxin Wei Department of Applied Mathematics Faculty of ScienceFukuoka UniversityFukuoka 814-0180Japan College of Mathematics and Information Science Henan Normal UniversityXinxiang 453007China School of Mathematical Sciences South China Normal UniversityGuangzhou 510631China

In this paper,we completely classify 3-dimensional complete self-shrinkers with the constant norm S of the second fundamental form and the constant f3in the Euclidean space R^(4),where hij’s are components of the sec... 详细信息

关键词： mean curvature ow self-shrinker the generalized maximum principle

A multi-agent collaboration scheme for energy-efficient task scheduling in a 3D UAV-MEC space

在线全文

学校读者我要写书评

暂无评论

Frontiers of Information Technology & Electronic Engineering 2024年第6期25卷 824-838页

作者： Yang li Ziling WEI Jinshu SU Baokang zhao College of Computer National University of Defense TechnologyChangsha 410073China Academy of Military Sciences Beijing 100091China

Multi-access edge computing(MEC)presents computing services at the edge of networks to address the enormous processing requirements of intelligent *** to the maneuverability of unmanned aerial vehicles(UAVs),they can be used as temporal aerial edge nodes for providing edge services to ground users in ***,MEC environment is usually dynamic and *** is a challenge for multiple UAVs to select appropriate service ***,most of existing works study UAV-MEC with the assumption that the flight heights of UAVs are fixed;i.e.,the flying is considered to occur with reference to a two-dimensional plane,which neglects the importance of the *** this paper,with consideration of the co-channel interference,an optimization problem of energy efficiency is investigated to maximize the number of fulfilled tasks,where multiple UAVs in a threedimensional space collaboratively fulfill the task computation of ground *** the formulated problem,we try to obtain the optimal flight and sub-channel selection strategies for UAVs and schedule strategies for *** on the multi-agent deep deterministic policy gradient(MADDPG)algorithm,we propose a curiosity-driven and twin-networks-structured MADDPG(CTMADDPG)algorithm to solve the formulated *** uses the inner reward to facilitate the state exploration of agents,avoiding convergence at the sub-optimal ***,we adopt the twin critic networks for update stabilization to reduce the probability of Q value *** simulation results show that CTMADDPG is outstanding in maximizing the energy efficiency of the whole system and outperforms the other benchmarks.

关键词： Multi-access edge computing Multi-agent reinforcement learning Unmanned aerial vehicles Task scheduling