检索结果-南通市图书馆

Science China Chemistry 2024年

作者： Ying-Qi Zhang gan-Lu Qian Yun Liu Jia-Hui Li Xin Hong Zhou Xu Bo Zhou Long-Wu ye State Key Laboratory of Physical Chemistry of Solid Surfaces Key Laboratory of Chemical Biology of Fujian Province and College of Chemistry and Chemical Engineering Xiamen University Center of Chemistry for Frontier Technologies Department of Chemistry State Key Laboratory of Clean Energy Utilization Zhejiang University Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy School of Pharmacy Xuzhou Medical University State Key Laboratory of Elemento-Organic Chemistry Nankai University State Key Laboratory of Organometallic Chemistry Chinese Academy of Sciences

Herein, we disclose a highly regio-/chemoselective tandem asymmetric dearomatized halofunctionalization reaction of phenoltethered ynamides with diverse electrophilic halogenation sources in a catalyst-free manner for the practical and rapid assembly of a series of halogenated spirocyclic enones. Besides, the related dearomatized selenation and protonation are also achieved,affording the corresponding selenated and protonated spirocycles in high efficiency. Moreover, the enantioselectivities of these products can be perfectly induced by Evans auxiliaries (99%ees). Significantly, this protocol not only represents the first tandem asymmetric halofunctionalization reaction of phenol derivatives, but also constitutes the first asymmetric halogenation/selenation of ynamides. Theoretical calculations indicate a remote induction model of Evans chiral auxiliary-attached keteniminium.

关键词：

CNN-LSTM based incremental attention mechanism enabled phase-space reconstruction for chaotic time series prediction

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Electronic Science and Technology 2024年第2期22卷 77-90页

作者： Xiao-Qian Lu Jun Tian Qiang Liao zheng-Wu Xu Lu gan Bidding and Purchasing Center University of Electronic Science and Technology of ChinaChengdu611731China Yibin Research Institute University of Electronic Science and Technology of ChinaYibin644000China School of Information and Communication Engineering University of Electronic Science and Technology of ChinaChengdu611731China

To improve the prediction accuracy of chaotic time series and reconstruct a more reasonable phase space structure of the prediction network,we propose a convolutional neural network-long short-term memory(CNN-LSTM)prediction model based on the incremental attention ***,a traversal search is conducted through the traversal layer for finite parameters in the phase ***,an incremental attention layer is utilized for parameter judgment based on the dimension weight criteria(DWC).The phase space parameters that best meet DWC are selected and fed into the input ***,the constructed CNN-LSTM network extracts spatio-temporal features and provides the final prediction *** model is verified using Logistic,Lorenz,and sunspot chaotic time series,and the performance is compared from the two dimensions of prediction accuracy and network phase space ***,the CNN-LSTM network based on incremental attention is compared with long short-term memory(LSTM),convolutional neural network(CNN),recurrent neural network(RNN),and support vector regression(SVR)for prediction *** experiment results indicate that the proposed composite network model possesses enhanced capability in extracting temporal features and achieves higher prediction ***,the algorithm to estimate the phase space parameter is compared with the traditional CAO,false nearest neighbor,and C-C,three typical methods for determining the chaotic phase space *** experiments reveal that the phase space parameter estimation algorithm based on the incremental attention mechanism is superior in prediction accuracy compared with the traditional phase space reconstruction method in five networks,including CNN-LSTM,LSTM,CNN,RNN,and SVR.

关键词： Chaotic time series Incremental attention mechanism Phase-space reconstruction

Pyramid diffractive optical networks for unidirectional image magnification and demagnification

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第9期13卷 1841-1864页

作者： Bijie Bai Xilin Yang Tianyi gan Jingxi Li Deniz Mengu Mona Jarrahi Aydogan Ozcan Electrical and Computer Engineering Department University of CaliforniaLos AngelesCAUSA Bioengineering Department University of CaliforniaLos AngelesCAUSA California NanoSystems Institute(CNSI) University of CaliforniaLos AngelesCAUSA

Diffractive deep neural networks(D2NNs)are composed of successive transmissive layers optimized using supervised deep learning to all-optically implement various computational tasks between an input and output ***,we present a pyramid-structured diffractive optical network design(which we term P-D2NN),optimized specifically for unidirectional image magnification and *** this design,the diffractive layers are pyramidally scaled in alignment with the direction of the image magnification or *** P-D2NN design creates high-fidelity magnified or demagnified images in only one direction,while inhibiting the image formation in the opposite direction—achieving the desired unidirectional imaging operation using a much smaller number of diffractive degrees of freedom within the optical processor ***,the P-D2NN design maintains its unidirectional image magnification/demagnification functionality across a large band of illumination wavelengths despite being trained with a single *** also designed a wavelength-multiplexed P-D2NN,where a unidirectional magnifier and a unidirectional demagnifier operate simultaneously in opposite directions,at two distinct illumination ***,we demonstrate that by cascading multiple unidirectional P-D2NN modules,we can achieve higher magnification *** efficacy of the P-D2NN architecture was also validated experimentally using terahertz illumination,successfully matching our numerical simulations.P-D2NN offers a physics-inspired strategy for designing task-specific visual processors.

关键词： unidirectional illumination opposite

Numerical Simulation of the Mass Movement Process of the 2018 Sedongpu Glacial Debris Flow by Using the Fluid-Solid Coupling 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

Journal of Earth Science 2024年第2期35卷 583-596页

作者： Xing-Yu Long Yu-Xiang Hu Bin-Rui gan Jia-Wen Zhou State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan UniversityChengdu610065China College of Water Resource and Hydropower Sichuan UniversityChengdu610065China

In the context of global warming and intensified human activities,glacier instability in plateau regions has increased,and glacier debris flows have become active,which poses a significant threat to the lives and property of people and socioeconomic *** mass movement process of glacier debris flows is extremely complex,so this paper uses the 2018 Sedongpu glacier debris flow event on the Qinghai-Tibet Plateau as an example and applies a numerical simulation method to invert the whole process of mass *** view of the interaction between phases in the process of motion,we use the fluid-solid coupling method to describe the mass *** granular-flow model and drift-flux model are employed in FLOW3D software to study the mass movement process of glacier debris flows and explore their dynamic *** results indicate that the glacier debris flow lasted for 700 s,and the movement process was roughly divided into four stages,including initiation,scraping,surging and deposition;the depositional characteristics calculated by the fluid-solid coupling model are consistent with the actual survey results and have good reliability;strong erosion occurs during the mass movement,the clear volume amplification effect,and the first wave climbs 17.8 m across the *** fluid-solid coupling method can better simulate glacier debris flows in plateau regions,which is helpful for the study of the mechanism and dynamic characteristics of such disasters.

关键词： glacial debris flow Qinghai-Tibet Plateau fluid-solid coupling FLOW3D mass movement depositional characteristics disasters engineering geology

Quantum Spin Exchange Interactions to Accelerate the Redox Kinetics in Li–S Batteries

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2024年第5期16卷 370-383页

作者： Yu Du Weijie Chen Yu Wang Yue Yu Kai Guo gan Qu Jianan Zhang Key Laboratory of Advanced Energy Catalytic and Functional Materials Preparation of zhengzhou City College of Materials Science and EngineeringZhengzhou UniversityZhengzhou 450001People’s Republic of China

Spin-engineering with electrocatalysts have been exploited to suppress the“shuttle effect”in Li–S *** selec-tion,spin-dependent electron mobility and spin potentials in activation barriers can be optimized as quantum spin exchange interactions lead-ing to a significant reduction of the electronic repulsions in the orbitals of ***,we anchor the MgPc molecules on fluorinated carbon nanotubes(MgPc@FCNT),which exhibits the single active Mg sites with axial *** to the density functional theory calculations,the electronic spin polarization in MgPc@FCNT not only increases the adsorption energy toward LiPSs intermediates but also facilitates the tunneling process of electron in Li–S *** a result,the MgPc@FCNT provides an initial capacity of 6.1 mAh cm^(-2) even when the high sulfur loading is 4.5 mg cm^(-2),and still maintains 5.1 mAh cm^(-2) after 100 *** work provides a new perspective to extend the main group single-atom catalysts enabling high-performance Li–S batteries.

关键词： Metal phthalocyanines Spin polarization Electrocatalysis Li–S batteries

Oral peptide therapeutics for diabetes treatment: State-of-the-art and future perspectives

在线全文

学校读者我要写书评

暂无评论

Acta Pharmaceutica Sinica B 2024年第5期14卷 2006-2025页

作者： Bingwen Ding Zhu Zhu Cong Guo Jiaxin Li Yong gan Miaorong Yu State Key Laboratory of Drug Research and Center of Pharmaceutics Shanghai Institute of Materia MedicaChinese Academy of SciencesShanghai 201203China University of Chinese Academy of Sciences Beijing 100049China School of Pharmacy Henan UniversityKaifeng 475004China NMPA Key Laboratory for Quality Research and Evaluation of Pharmaceutical Excipients National Institutes for Food and Drug ControlBeijing 100050China

Diabetes,characterized by hyperglycemia,is a major cause of death and disability ***,such as insulin and glucagon-like peptide-1(GLP-1)analogs,have shown promise as treatments for diabetes due to their ability to mimic or enhance insulin's actions in the *** to subcutaneous injection,oral administration of anti-diabetic peptides is a preferred ***,biological barriers significantly reduce the efficacy of oral peptide *** advancements in drug delivery systems and formulation techniques have greatly improved the oral delivery of peptide therapeutics and their efficacy in treating *** review will highlight(1)the benefits of oral anti-diabetic peptide therapeutics;(2)the biological barriers for oral peptide delivery,including pH and enzyme degradation,intestinal mucosa barrier,and biodistribution barrier;(3)the delivery platforms to overcome these biological ***,the review will discuss the prospects in this *** information provided in this review will serve as a valuable guide for future developments in oral anti-diabetic peptide therapeutics.

关键词： Oral peptides Diabetes Delivery platforms Insulin Glucagon-like peptide-1 Biodistribution Biological barriers Targeted delivery

Detrital Zircon of Devonian Sandstones in ChangningMenglian Suture Zone, Yunnan, SW China: Implications for the Early Evolution of Paleo-Tethys

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 Earth Science 2024年第3期35卷 786-796页

作者： zhengqin gan Qinglai Feng Yuehua Wei Guichun Liu Xiaomei Nie Tianyu Zhao State Key Laboratory of Geological Processes and Mineral Resources China University of GeosciencesWuhan 430078China School of Earth Sciences China University of GeosciencesWuhan 430074China

The Changning-Menglian suture zone is a critical tectonic belt pivotal to the evolution of the *** Wenquan Formation,characterized as turbidite deposited on the western side of the Changning-Menglian suture zone as well as the eastern edge of the Baoshan *** of detrital zircons from the Wenquan Formation reveals two significant age peaks approximately at 440 and 980 Ma,with additional age populations around 600,780,and 2500 *** major age peak at about 440 Ma is come from the andesitic-dominant volcanic arc within the Lancang Block and the western Simao Block,corroborated by the presence of andesite fragments in thin section ***,the zircons that form the secondary age peak at~980 Ma and other older age groups probably originate from the Baoshan *** on the western side of the Paleo-Tethyan ophiolites,the Wenquan Formation received detrital materials from the continental margin on the opposite ***,the main Paleo-Tethyan Ocean basin was not sufficiently broad enough to cut off the transference of detrital *** was a relatively narrow basin in the Early Devonian.

关键词： Changning-Menglian suture zone sandstone zircon Paleo-Tethys Devonian tectonics.

在线全文

学校读者我要写书评

暂无评论

中国新材料科学技术的创新发展研究

Engineering 2024年第1期32卷 10-13页

作者： Yong gan China Iron and Steel Research Institute Group Co. Ltd.Beijing 100081China

New materials,which are also known internationally as"advanced materials,"refer to newly emerging materials with excellent performance and special functions or traditional materials with significantly improved performance or new functions after improvement and *** present,the multidisciplinary cooperation of information technology,biotechnology,new energy technology,and new materials technology is triggering a new round of scientific and technologicalrevolution and industrial transformation[1].

关键词：材料科学技术 performance functions

Perception Enhanced Deep Deterministic Policy Gradient for Autonomous Driving in Complex Scenarios

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第7期140卷 557-576页

作者： Lyuchao Liao Hankun Xiao Pengqi Xing zhenhua gan Youpeng He Jiajun Wang Fujian Provincial Key Laboratory of Automotive Electronics and Electric Drive Fujian University of TechnologyFuzhou350118China Fujian Provincial Universities Engineering Research Center for Intelligent Driving Technology Fuzhou350118China

Autonomous driving has witnessed rapid advancement;however,ensuring safe and efficient driving in intricate scenarios remains a critical *** particular,traffic roundabouts bring a set of challenges to autonomous driving due to the unpredictable entry and exit of vehicles,susceptibility to traffic flow bottlenecks,and imperfect data in perceiving environmental information,rendering them a vital issue in the practical application of autonomous *** address the traffic challenges,this work focused on complex roundabouts with multi-lane and proposed a Perception EnhancedDeepDeterministic Policy Gradient(PE-DDPG)for AutonomousDriving in the ***,themodel incorporates an enhanced variational autoencoder featuring an integrated spatial attention mechanism alongside the Deep Deterministic Policy Gradient framework,enhancing the vehicle’s capability to comprehend complex roundabout environments and make ***,the PE-DDPG model combines a dynamic path optimization strategy for roundabout scenarios,effectively mitigating traffic bottlenecks and augmenting throughput *** experiments were conducted with the collaborative simulation platform of CARLA and SUMO,and the experimental results show that the proposed PE-DDPG outperforms the baseline methods in terms of the convergence capacity of the training process,the smoothness of driving and the traffic efficiency with diverse traffic flow patterns and penetration rates of autonomous vehicles(AVs).Generally,the proposed PE-DDPGmodel could be employed for autonomous driving in complex scenarios with imperfect data.

关键词： Autonomous driving traffic roundabouts deep deterministic policy gradient spatial attention mechanisms

MCP-1 and IL-4 encapsulated hydrogel particles with macrophages enrichment and polarization capabilities for systemic lupus erythematosus treatment

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 Research 2024年第9期17卷 8316-8324页

作者： Shengjie Zhu Danqing Huang Qichen Luan Yang Li Jingjing gan Yuanjin Zhao Lingyun Sun Department of Rheumatology and Immunology Nanjing Drum Tower HospitalClinical Medical College of Traditional Chinese and Western MedicineNanjing University of Chinese MedicineNanjing 210096China State Key Laboratory of Bioelectronics School of Biological Science and Medical EngineeringSoutheast UniversityNanjing 210096China

Macrophages play a pivotal role in systemic lupus erythematosus(SLE)*** have been made to develop multifunctional drug delivery systems capable of directing macrophage ***,we present a novel hyaluronic acid methacrylate(HAMA)hydrogel microparticle encapsulating multiple cytokines for SLE remission though enhancing macrophage *** HAMA microparticles loaded with monocyte chemotactic protein-1(MCP-1)and interleukin-4(IL-4)were fabricated by using a microfluidic *** released MCP-1 facilitates the aggregation of inflammatory macrophages,after which IL-4 induces the macrophage phenotype shift from inflammatory M1 to immune-protective M2,thus restoring immune *** have demonstrated in MRL/lpr mice that the hydrogel microparticles could improve their efficacy of intraperitoneal drug delivery,modulate immune function,and attenuate the disease *** results suggest that our proposed microparticles delivery platform has potential clinical value for treating autoimmune diseases.

关键词： microfluidics M2 polarization hydrogel drug delivery systemic lupus erythematosus(SLE)