检索结果-南通市图书馆

Science China Mathematics 2021年第11期64卷 2539-2562页

作者： Hongshuai Dai Yiqiang q.zhao School of Statistics Shandong University of Finance and EconomicsJinan 250014China School of Mathematics and Statistics Carleton UniversityOttawaON K1S 5B 6Canada

Sticky Brownian motions can be viewed as time-changed semimartingale reflecting Brownian motions,which find applications in many areas including queueing theory and mathematical *** this paper,we focus on stationary distributions for sticky Brownian *** results obtained here include tail asymptotic properties in the marginal distributions and joint *** kernel method,copula concept and extreme value theory are the main tools used in our analysis.

关键词： sticky Brownian motion queueing model stationary distribution exact tail asymptotic kernel method extreme value distribution

维普期刊数据库

Explicit Stationary Distribution of the(L,1)-reflecting Random Walk on the Half Line

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2014年第3期30卷 371-388页

作者： Wen Ming HONg Ke ZHOU Yi qiang q.zhao School of Mathematical Sciences & Laboratory of Mathematics and Complex Systems Beijing Normal University School of Mathematics and Statistics Carleton University

In this paper,we consider the（L,1） state-dependent reflecting random walk（RW） on the half line,which is an RW allowing jumps to the left at a maximal size *** this model,we provide an explicit criterion for（positive） recurrence and an explicit expression for the stationary *** an application,we prove the geometric tail asymptotic behavior of the stationary distribution under certain *** main tool employed in the paper is the intrinsic branching structure within the（L,1）-random walk.

关键词： Random walk multi-type branching process recurrence positive recurrence stationarydistribution tail asymptotic

维普期刊数据库

A review on biodegradable biliary stents: materials and future trends

在线全文

学校读者我要写书评

暂无评论

Bioactive Materials 2022年第11期7卷 488-495页

作者： ge Song Hugh q.zhao qing Liu Zhongyong Fan Beijing Advanced Medical Technologies Ltd Inc26 Yongwang West RoadBuilding 11DaxingBeijing102609PR China The Institute for Translational Nanomedicine Shanghai East HospitalThe Institute for Biomedical Engineering&Nano ScienceTongji University School of MedicineShanghai200092PR China Department of Materials Science Fudan UniversityShanghai200433PR China

Biliary stricture is defined as the reduction and narrowing of the bile duct lumen, which can be caused by many factors such as cancer and inflammation. Biliary stent placement can effectively alleviate benign and malignant biliary strictures. However, the commonly used plastic or metallic biliary stents are far from ideal and do not satisfy all clinical requirements,although several types of biodegradable biliary stents have been developed and used clinically. In this review, we summarized current development status of biodegradable stents with the emphasis on the stent materials. We also presented the future development trends based on the published literature.

关键词： Biodegradable biliary stent Biliary strictures Polydioxanone Poly(L-lactic acid) Drug-eluting stent

Approximations for a queueing game Model with Join-the-Shortest-queue Strategy

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 the Operations Research Society of China 2023年第3期11卷 489-504页

作者： qi-Hui Bu Li-Wei Liu Jia-Shan Tang Yi-qiang q.zhao School of Science Nanjing University of Posts and TelecommunicationsNanjing210023JiangsuChina School of Science Nanjing University of Science and TechnologyNanjing210094JiangsuChina School of Mathematics and Statistics Carleton UniversityOttawaONK1S 5B6Canada

This paper investigates a partially observable queueing system with N nodes in which each node has a dedicated arrival *** is an extra arrival stream to balance the load of the system by routing its customers to the shortest *** addition,a reward-cost structure is considered to analyse customers'strategic *** equilibrium and socially optimal strategies are derived for the partially observable mean field limit ***,we show that the strategies obtained from the mean field model are good approximations to the model with finite N ***,numerical experiments are provided to compare the equilibrium and socially optimal behaviours,including joining probabilities and social benefits for different system parameters.

关键词： game theory queueing systems Mean field limit Markov process

A functional cathode sodium compensation agent for stable sodium-ion batteries

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

green Energy & Environment 2025年第1期10卷 173-182页

作者： Wei Wu Zhenglin Hu Zhengfei zhao Aoxuan Wang Jiayan Luo Key Laboratory for green Chemical Technology of Ministry of Education School of Chemical Engineering and TechnologyTianjin UniversityTianjin300072China State Key Laboratory of Metal Matrix Composites School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai200240China Shanghai Jiao Tong University Shaoxing Research Institute of Renewable Energy and Molecular Engineering Shaoxing312000China

Hard carbon(HC)is widely used in sodium-ion batteries(SIBs),but its performance has always been limited by lowinitial Coulombic efficiency(ICE)and cycling *** compensation agent is a favorable strategy to make up for the loss of active sodium ions consumed *** it lacks agent that effectively decomposes to increase the active sodium ions as well as regulate carbon defects for decreasing the irreversible sodium ions ***,we propose 1,2-dihydroxybenzene Na salt(NaDB)as a cathode compensation agent with high specific capacity(347.9 mAh g^(-1)),lower desodiation potential(2.4–2.8 V)and high utilization(99%).Meanwhile,its byproduct could functionalize HC with more C]O groups and promote its reversible ***,the presodiation hard carbon(pHC)anode exhibits highly reversible capacity of 204.7 mAh g^(-1) with 98%retention at 5 C rate over 1000 ***,with 5 wt%NaDB initially coated on the Na3V2(PO4)3(NVP)cathode,the capacity retention of NVP t NaDBjHC cell could increase from 22%to 89%after 1000 cycles at 1 C *** work provides a new avenue to improve reversible capacity and cycling performance of SIBs through designing functional cathode compensation agent.

关键词： Hard carbon ICE Cathode compensation agent Reversible capacity Stability

Rapid and scalable preparation of highly quaternized polymer networks to achieve efficient simultaneous adsorption of iodide and pertechnetate

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 Chemistry 2025年第1期68卷 337-349页

作者： Meiyun Xu Song gu Fulong Chen Zhe zhao Peng Liu Daoben Hua State Key Laboratory of Radiation Medicine and Protection School of Radiological and Interdisciplinary Sciences (RAD-X) Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions Soochow University

The efficient separation of fission products,such as TcO4-and I-,holds strategic significance for the management of radioactive wastes and environmental *** this study,we propose an ultrafast strategy for scalable preparation of a highly quaternized organic network to facilitate efficient and synchronous separation of iodide and *** network can be prepared within a few minutes at room temperature,using polyethylenimine and 1,2,4,5-tetrakis（bromomethyl）benzene as building *** chlorine replacement,the network,abundantly decorated with quaternary ammonium groups （Cl@qPN）,exhibits an ultrahigh positive charge density of 7.6 mmol/*** enables the rapid and efficient enrichment of target anions through strong electrostatic Coulomb *** a result,Cl@qPN exhibits significantly higher adsorption rate constants of 0.830 g/（mg min） for ReO4-（a nonradioactive surrogate of TcO4-） and 0.677 g/（mg min） for I-compared to other ***,it possesses high adsorption capacities,reaching 1,681 mg/g for ReO4-and 917.4 mg/g for I-.Cl@qPN also demonstrates good selectivity towards target ions and shows efficient adsorption for99TcO4-.Additionally,Cl@qPN exhibits high dynamic processing capacities,handling up to 3,100 and 7,400 kg of simulated streams per kilogram of material for I-and ReO4-,respectively.

关键词： quaternized polymer networks adsorption pertechnetate iodide liquid radioactive streams

Inside-Out 3D Reversible Ion-Triggered Shape-Morphing Hydrogels

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Research 2019年第1期2019卷 1237-1248页

作者： X.Du H.Cui q.zhao J.Wang H.Chen Y.Wang Institute of Biomedical&Health Engineering Shenzhen Institutes of Advanced Technology(SIAT)Chinese Academy of Sciences(CAS)Shenzhen518035China

Shape morphing is a critical aptitude for the survival of organisms and is determined by anisotropic tissue composition and directional orientation of micro-and nanostructures within cell walls,resulting in diferent swelling *** eforts have been dedicated to mimicking the behaviors that nature has perfected over billions of *** present a robust strategy for preparing 3D periodically patterned single-component sodium alginate hydrogel sheets cross-linked with Ca^(2+)ions,which can reversibly deform and be retained into various desirable inside-out shapes as triggered by biocompatible ions(Na^(+)/Ca^(2+)).By changing the orientations of the patterned microchannels or triggering with Na^(+)/Ca^(2+)ions,various 3D twisting,tubular,and plantinspired architectures can be facilely *** only can the transformation recover their initial shapes reversibly,but also it can keep the designated shapes without continuous *** inside-out 3D reversible ion-triggered hydrogel transformations shall inspire more attractive applications in tissue engineering,biomedical devices,and sof robotics felds.

关键词： swelling preparing attractive

Dual‑Donor‑Induced Crystallinity Modulation Enables 19.23% Efficiency Organic Solar Cells

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 2025年第3期17卷 376-388页

作者： Anhai Liang Yuqing Sun Sein Chung Jiyeong Shin Kangbo Sun Chaofeng Zhu Jingjing zhao Zhenmin zhao Yufei Zhong guangye Zhang Kilwon Cho Zhipeng Kan Center On Nanoenergy Research Institute of Science and Technology for Carbon Peak&NeutralitySchool of Physical Science&TechnologyGuangxi UniversityNanning 530004People’s Republic of China Department of Chemical Engineering Pohang University of Science and TechnologyPohang 37673South Korea College of New Materials and New Energies Shenzhen Technology UniversityShenzhen 518118People’s Republic of China Zhejiang Engineering Research Center for Fabrication and Application of Advanced Photovoltaic Materials School of Materials Science and EngineeringNingboTech UniversityNingbo 315100People’s Republic of China State Key Laboratory of Featured Metal Materials and Life-Cycle Safety for Composite Structures Nanning 530004People’s Republic of China

Trap-assisted charge recombination is one of the primary limitationsof restricting the performance of organic solar cells. However, effectivelyreducing the presence of traps in the photoactive layer remains ***, wide bandgap polymer donor PTzBI-dF is demonstrated as an effectivemodulator for enhancing the crystallinity of the bulk heterojunction active layerscomposed of D18 derivatives blended with Y6, leading to dense and orderedmolecular packings, and thus, improves photoluminescence quenching *** a result, the photovoltaic devices exhibit reduced trap-assisted charge recombinationlosses, achieving an optimized power conversion efficiency of over 19%.Besides the efficiency enhancement, the devices comprised of PTzBI-dF as athird component simultaneously attain decreased current leakage, improved chargecarrier mobilities, and suppressed bimolecular charge recombination, leading toreduced energy losses. The advanced crystalline structures induced by PTzBI-dFand its characteristics, such as well-aligned energy level, and complementaryabsorption spectra, are ascribed to the promising performance *** findings suggest that donor phase engineering is a feasible approach to tuning the molecular packings in the active layer, providingguidelines for designing effective morphology modulators for high-performance organic solar cells.

关键词： Trap-assisted charge recombination Photoluminescence Miscibility Current leakage Power conversion efficiency

维普期刊数据库

Satellite-assisted 6g wide-area edge intelligence:dynamics-aware task offloading and resource allocation for remote IoT services

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2025年

作者： Di zhao Rui DINg Bin SONg State Key Laboratory of Integrated Services Networks Xidian University Hangzhou Institute of Technology Xidian University China Satellite Network group Co. Ltd.

Future 6g networks will integrate non-terrestrial communication with mobile edge computing to enable wide-area edge intelligence, providing ubiquitous communication and computation services for everyone and everything. In this paper, we introduce the intelligent cloud-edge-device architecture into low Earth orbit (LEO) satellite-supported remote Internet of Things(IoT) networks to facilitate latency-sensitive and compute-intensive IoT applications. However, the dynamic spatio-temporal characteristics inherent in LEO satellite networks, such as the high volatility of task traffic and the high mobility of space nodes, pose severe challenges. For efficient task execution, we investigate the joint optimization of cross-region task offloading and cross-domain resource allocation, and innovatively propose a spatio-temporal attention-based proximal policy optimization(STA-PPO) algorithm. Specifically, the temporal attention-based actor network analyzes the timing dependencies of task arrival and makes time-variant decisions. Simultaneously, the spatial attention-based critic network captures the spatial variations of satellite motion and evaluates the topology-related value. We verify the effectiveness of the cloud-edge-device collaboration through extensive simulations. Numerical results demonstrate that the STA-PPO algorithm outperforms benchmarks, showing the lowest system delay and the highest link throughput.

关键词：

Reversible phase transition between amorphous and crystalline in Zr41.2Ti13.8Cu12.5Ni10Be22.5 under high pressure at room temperature

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

同步辐射装置用户科技论文集 2000年第1期 407-409页

作者： LilingSun q.zhao 等