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A model framework for discovering the spatio-temporal usage patterns of public free-floating bike-sharing system

Transportation Research Part C: Emerging Technologies 2019年 103卷 39-55页

作者： Yuchuan Du fuwen deng Feixiong Liao Key Laboratory of Road and Traffic Engineering of the Ministry of Education Tongji University Shanghai China Urban Planning Group Eindhoven University of Technology Eindhoven the Netherlands

Public bike-sharing has gained much attention with the tide of sharing economy. Empowered by modern technologies (e.g., GPS devices and smartphone-based APPs), a new generation of free-floating bike-sharing systems has recently become popular. Usage data generated by such systems produce rich information. This study presents a model framework to explore the spatio-temporal usage patterns of free-floating shared bikes using the usage data. The framework includes modules of probability fitting, Random Forest, a cluster-based time-domain analysis, and a visualization toolset. A case study is discussed based on the usage data from Mobike, one of the largest operating bike-sharing systems in Shanghai (China). The daily usage dynamics is modeled using log-normal distributions. Random Forest is adopted to explore the impact of factors on the usage frequency in different districts. It is found that residential area, park & green area, and population size are the top three factors influencing the frequency. Particularly, usage near metro stations is delved using the hierarchical clustering method, resulting in three typical usage modes. Visualization analysis is demonstrated to understand the time-varying flow patterns and the spatial distribution of shared bikes. This study improves our understanding of the usage patterns of this emerging transport mode and provides insights for the promotion and dynamic deployment of the bike-sharing system in urban areas.

关键词： Free-floating Bike-sharing Dynamics Spatial-temporal patterns

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Minimally invasive approach to managing brachiocephalic trunk cannulation complicating central venous catheterization: a case report

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INTERNATIONAL JOURNAL OF EMERGENCY MEDICINE 2024年第1期17卷 1-6页

作者： deng, Haihui Chen, Bin Peng, Deti Pang, fuwen Shenzhen Tradit Chinese Med Hosp Dept Intervent Radiol 1 Fuhua Rd Shenzhen 518033 Peoples R China Shenzhen Tradit Chinese Med Hosp Dept Liver Dis Shenzhen 518033 Peoples R China

BackgroundCentral venous catheterization, crucial for device insertion, monitoring, medication, and fluid resuscitation, commonly uses the subclavian, internal jugular, and femoral veins. Despite its general safety, complications like arterial puncture can be life-threatening, requiring rapid diagnosis and *** presentationA 74-year-old woman in the recovery phase of cerebral infarction underwent right subclavian vein catheterization. The catheter was mistakenly placed in the brachiocephalic trunk, with its tip in the ascending aorta, as confirmed by computed tomography (CT) and digital subtraction angiography (DSA). With the high surgical risk and the complexity of endovascular treatment, catheter replacement was chosen. One month after the initial placement, the catheter was replaced with a smaller one, and another month later, it was retracted without complications. Follow-up CT and DSA revealed no leakage, with the patient's vitals remaining stable. A three-month post-discharge phone follow-up confirmed the patient's continued *** case demonstrates the effective use of a catheter replacement technique as a minimally invasive repair method when other options are impractical. Ultrasound guidance is also recommended to improve the procedure's accuracy and safety.

关键词： Central venous catheterization Brachiocephalic trunk Cannulation Catheter replacement

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Advanced Self-Improving Ramp Metering Algorithm based on Multi-Agent Deep Reinforcement Learning

Advanced Self-Improving Ramp Metering Algorithm based on Mul...

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International Conference on Intelligent Transportation

作者： fuwen deng Jiandong Jin Yu Shen Yuchuan Du College of Transportation Engineering Tongji University Shanghai China School of Electronics Engineering and Computer Science Peking University Beijing China

We proposed a novel ramp metering algorithm embedding multi-agent deep reinforcement learning (DRL) techniques, based on the data of loop detectors. A multi-agent DRL framework is adopted to generate proper ramp metering scheme for each ramp meter in real time to improve the operation efficiency of urban freeway with less investment. A simulation platform is developed to simplify the implementation and training of the algorithm. A set of simulation experiments - encompassing both single and multi-ramp scenarios with various traffic demand profiles - are conducted. Comparing with the state-of-the-practice ramp metering methods, the simulation results demonstrate that the proposed DRL-based algorithm outperforms in a comprehensive evaluation index considering mainstream speed at bottleneck and queue size on ramp. The method presents robustness, scalability, and the capability of further improvement by online learning during implementation.

关键词： Traffic control Training Detectors Inference algorithms Optimization Approximation algorithms Machine learning

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Theranostic radionuclides labeled biodegradable microspheres for the treatment of hepatocellular carcinoma with radioembolization

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RADIATION PHYSICS AND CHEMISTRY 2025年 232卷

作者： Pang, fuwen deng, Haihui Peng, Deti He, Jian Zhao, Weicheng Yu, Liqian Chen, Tuantuan Xie, Zonggui Cai, Huawei Chen, Bin Shenzhen Tradit Chinese Med Hosp Dept Intervent Radiol 1 Fuhua Rd Shenzhen 518033 Peoples R China Shenzhen Tradit Chinese Med Hosp Dept Liver Dis Shenzhen 518033 Peoples R China West China Hosp Dept Nucl Med 37 Guoxue Alley Chengdu 610041 Peoples R China

Liver cancer, predominantly hepatocellular carcinoma (HCC), is the third leading cause of cancer-related deaths worldwide. Unfortunately, curative options like surgery and ablation are limited to 20% of cases due to the frequent diagnosis of HCC at intermediate or advanced stages. Taking advantage of the liver's dual blood supply, transarterial radioembolization (TARE) serves as a viable option when surgery is not possible. It entails the therapeutic intra-arterial injection of microspheres containing radioisotopes during hepatic embolization procedures. While TARE using Yttrium-90 (90Y) labeled resin or glass microspheres has demonstrated promising results in HCC treatment, challenges persist, including non-biodegradability impeding re-embolization, high density causing improper occlusion in capillaries, inherent imaging issues, and high costs. Within the dynamic landscape of advancing research in HCC treatment, this article aims to deliver a thorough review of biodegradable microspheres labeled with theranostic radionuclides in the clinical setting for HCC and addresses new developments, presenting the most relevant findings.

关键词： Hepatocellular carcinoma Transarterial radioembolization Theranostic radionuclides Biodegradable microspheres

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Luminescent and thermometric properties of dual emitting Eu^(2+)/Sm^(3+) co-doped Sr_(4)La(PO_(4))_(3)O phosphor based on energy transfer

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Journal of Rare Earths 2021年第3期39卷 261-268,I0001页

作者： fuwen Liu Degang deng Ming Wu Bowen Chen Liuyan Zhou Shiqing Xu Institute of optoelectronic Materials and Devices China Jiliang UniversityHangzhou 310018China

Eu^(2+)/Sm^(3+)co-doped dual-emitting Sr_(4)La(PO_(4))_(3)O phosphors were synthesized through a convenient high temperature solid state reaction in reductive *** structure,luminescence,energy transfer and temperature-dependent luminescence properties of Eu^(2+)/Sm^(3+)co-doped Sr_(4)La(PO_(4))_(3)O phosphors were researched and analyzed in *** blue emission of Eu^(2+)and the red emission of Sm^(3+)can work together as FIR *** on the different response characteristics of these two ion emissions to temperature,Sr_(4)La(PO_(4))_(3)O:Eu^(2+)/Sm^(^(3+))phosphor achieves the relative sensitivity of0.48384%/K and a wide range of temperature measurements from room temperature to 573 *** results reveal that the Sr_(4)La(PO_(4))_(3)O:Eu^(2+)/Sm^(3+)phosphor has application prospect in the field of high temperature optical *** energy transfer mechanism is proved to be the dipole-dipole interaction between Eu^(2+)and Sm^(3+)ions.

关键词： Sr_(4)La(PO_(4))_(3)O FIR Optical thermometry Energy transfer Rare earths

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Designing Superhydrophilic Hydrogels as Binder-Free Catalysts for Enhanced Oxygen Evolution Performance (vol 62, pg 5543, 2023)

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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH 2023年第17期62卷 6806-6806页

作者： Yan, Yong Zhang, Chenyang deng, Xin Zhang, Jin Xue, Yali Zhang, Jie Luo, Yingjian Yang, fuwen Wang, Gang Wang, Ruilin Chen, Jinwei College of Materials Science and Engineering Sichuan University Chengdu 610065 China Engineering Research Center of Alternative Energy Materials & Devices Ministry of Education Sichuan University Chengdu 610065 China

Water electrolysis is an environmentally friendly and sustainable hydrogen production method. The proper design of the catalyst surface is essential for the oxygen evolution reaction (OER) in the water electrolysis process because the catalytic effect is highly dependent on contact surface properties such as the homogeneity of the coating and the stability of the catalyst, as well as the wettability of the electrolyte. Herein, hydrogel [consisting of poly(vinyl alcohol) (PVA) cross-linked with quaternized chitosan (HACC)] loaded on nickel foam (NF) was chosen to study the OER properties of iron (Fe) in organic molecules. Owing to the unique hydrophilicity, uniformity, and stability of hydrogel, the superhydrophilic Fe-HACC-PVA/NF exhibits a low overpotential of 225 mV versus reversible hydrogen electrode at 10 mA cm–2 and shows favorable stability (only 2.3% loss of current density after 24 h at 100 mA cm–2), which outperforms most Fe-based transition-metal OER catalysts. This work demonstrates that introducing a superhydrophilic catalyst surface structure to dissociate the adsorbed water is a productive strategy to enhance the performance of OER. Furthermore, the rational design of hydrophilic interface materials in this work provides a facile method to developing OER catalysts.

关键词： Catalysts Electrolytes Hydrogels Radiology Stability

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An optical thermometer with high sensitivity and superior signal discriminability based on dual-emitting Ce^(3+)/Eu^(2+)co-doped La5Si2BO13 thermochromic phosphor

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Journal of Rare Earths 2021年第11期39卷 1311-1319,I0001页

作者： fuwen Liu Ying Tian Degang deng Ming Wu Bowen Chen Liuyan Zhou Shiqing Xu Institute of Optoelectronic Materials and Devices China Jiliang UniversityHangzhou 310018China

A novel non-contact optical thermometer,qualified with high sensitivity and temperature resolution,is urgently needed for temperature measuring of micro devices,moving objects and specific severe ***,a series of dual-emitting La_(5)Si_(2)BO_(13):Ce^(3+),Eu^(2+)phosphors were *** two ions show diverse responses with the changing in *** variational emissions of Ce^(3+)and Eu^(2+)can be converted to FIR(fluorescence intensity ratio)*** maximal absolute sensitivity Sa and relative sensitivity Sr reach up to 0.07526%/K and 3.2241%/K,*** is worthy noting that the Sa and Sr possess the same variation tendency and both have high values in the low temperature region(293-373 K),showing the great temperature measuring property especially in low temperature *** temperature sensing characteristics are superior to the results of most previous *** energy transfer(ET)process is certified to occur from Ce^(3+)to Eu^(2+)*** studies indicate that La_(5)Si_(2)BO_(13):Ce^(3+),Eu^(2+)phosphor could have a good prospect for optical thermometry.

关键词： La_(5)Si_(2)BO_(13) FIR Optical thermometry Energy transfer Rare earths

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Preferred location strategy for self-equilibrium of free-floating bike-sharing systems 22

Preferred location strategy for self-equilibrium of free-flo...

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22nd International Conference of Hong Kong Society for Transportation Studies: Transport and Society, HKSTS 2017

作者： Du, Yuchuan deng, fuwen Key Laboratory of Road and Traffic Engineering of the Ministry of Education Tongji University China

ISBN: (纸本)9789881581464

Bike-sharing is becoming increasingly important with the promotion of sustainable alternatives to private cars in urban areas. Compared with traditional station-based bike-sharing, free-floating bike-sharing model is adopted more often by newly-built systems due to convenience for users. However, the model may lead to imbalance of the fleet and hence enormous cost will be spent on manual redistribution. In this paper, a novel user-based strategy, preferred parking location, is proposed to achieve self-equilibrium of bike-sharing system. More specifically, users can get pricing benefits if they return shared bicycles in specific stations. The semi-constraint mechanism is expected to decrease the refusing rate caused by fleet imbalance. A simulation-based optimization method is designed to determine the location and capacity of stations then a computational experiment is carried out on a small-scale network to evaluate the effectiveness of this strategy. The proposed strategy can be used in bike-sharing operation and system planning. © 2017 Hong Kong Society for Transportation Studies Limited. All rights reserved.

关键词： Location

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Dual-mode optical thermometry based on Bi³⁺/Eu³⁺ co-activated BaGd₂O₄ phosphor with high sensitivity and signal discriminability

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CERAMICS INTERNATIONAL 2021年第21期47卷 30221-30233页

作者： Fu, Jie Liu, fuwen Zhou, Liuyan Ye, Renguang deng, Degang Xu, Shiqing China Jiliang Univ Inst Optoelect Mat & Devices Hangzhou 310018 Peoples R China

A series of BaGd2O4:Bi3+,Eu3+ phosphors with dual-emitting centers were prepared by high-temperature solidstate method. X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), fluorescence spectroscopy, lifetime decay curve and variable temperature emission spectroscopy were used to systematically study the structure, luminescence performance and temperature characteristics. Under ultraviolet (UV) excitation, the BaGd2O4:Bi3+,Eu3+ phosphor showed a broad-band emission in the blue region corresponding to transitions of Bi3+ ions and the sharp red light emission corresponding to Eu3+ ions. The Bi3+ and Eu3+ ion emission peaks were well-separated, which meets a prerequisite for efficient temperature signal resolution measurement. The fluorescence intensity ratio (FIR) technique was used to measure the different temperature response characteristics between Bi3+ blue emission and Eu3+ red emission. When the temperature varies from 293 K to 473 K, the relative temperature sensitivity (Sr) of BaGd2O4:Bi3+,Eu3+ phosphors is obtained, was determined as 1.0182% K-1. In addition to calculating the relative sensitivity by FIR technology, we can also obtain the value of Sr through experiments and formulas related to the decay life, and found to be 1.0651% K-1. Therefore, BaGd2O4: Bi3+,Eu3+ phosphor is an excellent non-contact optical temperature measurement material.

关键词： BaGd2O4 Luminescence performance FIR Non-contact optical temperature measurement

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Balancing miscibility and crystallinity enables high-efficiency organic solar cells via ternary copolymerization

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JOURNAL OF POWER SOURCES 2024年 613卷

作者： deng, Haojie Bai, Yahui Shen, Xingxing He, Dan Zhang, Yajie Zhang, Jianqi Zhao, fuwen Cent South Univ Coll Chem & Chem Engn State Key Lab Powder Met Changsha 410083 Peoples R China Hebei Normal Univ Sci & Technol Coll Chem Engn Qinhuangdao 066004 Peoples R China Natl Ctr Nanosci & Technol CAS Ctr Excellence Nanosci CAS Key Lab Nanosyst & Hierarch Fabricat Beijing 100190 Peoples R China

Due to the limited exciton diffusion length and relatively low charge carrier mobilities of organic photovoltaic materials, donor/acceptor blends in organic solar cells (OSCs) have to form nanoscale interpenetrating network morphology with orderly molecular stacking to simultaneously ensure exciton diffusion to donor/acceptor interfaces and charge carrier transport to electrodes. Herein, two terpolymer donors, XD1 and XD2, are developed via inserting N-ethyl-2,2 '-bithiophene-3,3 '-dicarboximide (BTI) unit into the molecular skeleton of D18 on account of the traits of BTI. The crystallinity and miscibility of terpolymer donors increase along with the BTI ratio. The dual functions of introducing BTI make polymer:Y6 blend films exhibit the tendency of first improving then deteriorating in crystallinity, phase separation, trap density and thus charge carrier dynamics, resulting in shortcircuit current density and fill factor of OSCs to present the same trend. Among them, XD1:Y6 based OSCs well balance the dual functions of introducing BTI to acquire the optimized morphology, and thus achieve an impressive power conversion efficiency (PCE) of 19.13 %, which is among the highest values of OSCs. This work not only affords guidelines for developing high-performance terpolymer donors, but also demonstrates the importance of juggling crystallinity and miscibility of organic photovoltaic materials to boost PCEs of OSCs.

关键词： Organic solar cells Ternary copolymerization Miscibility Crystallinity Morphology

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