检索结果-内蒙古大学图书馆

A Novel Sulfonated Polyimide Composite Membrane Containing Covalent Organic Frameworks for Iron-Chromium Redox Flow Battery Application

引用

INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH 2025年第11期64卷 5995-6003页

作者： Zhang, shuwen Wang, Gang Jing, Yangtian wei, Shiguo Wang, Bin Zhang, Qi Xie, Youcai Yin, Chunlin Zhou, Yufeng Zhang, Jie Chen, Jinwei Wang, Ruilin Sichuan Univ Coll Mat Sci & Engn Chengdu 610065 Peoples R China Sichuan Galaxy Chem Co Ltd Mianyang 611130 Peoples R China

Iron-chromium redox flow batteries (ICRFB), as the pioneering technology in flow battery energy storage, have regained research attention with advancements in the field. Despite their significant cost advantage, the capacity degradation due to ion crossover through ion exchange membranes remains a major barrier to commercialization. In addition, there are relatively few types of nonfluorinated ion exchange membrane materials currently reported in ICRFB. Herein, covalent organic frameworks, sulfonated Schiff base network type (SSNW), were introduced into sulfonated polyimide (SPI) to prepare a novel SPI/SSNW composite membrane for ICRFB. The hydrogen bonding network formed by the -SO3H group in SPI and SSNW, with the fluorine atoms in SPI and the nitrogen atoms in SSNW, as well as the size exclusion effect of the SSNW, effectively hinder the permeation of Cr3+ and Fe3+, which was further analyzed by electrostatic potential calculation. Single-cell performance tests revealed that ICRFB equipped with SPI/SSNW-1% membrane achieved 93.96% Coulombic efficiency and 76.40% energy efficiency at 80 mA cm-2. Compared with the Nafion212 membrane, the SPI/SSNW-1% membrane exhibited 17.74% higher capacity retention over 50 cycles. These results demonstrate that optimized sulfonated polyimide composite membranes are promising candidates for ICRFB applications.

关键词： Hydrogen bonds

来源：评论

学校读者我要写书评

暂无评论

An improved SegNet network model for accurate detection and segmentation of car body welding slags

引用

INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY 2022年第1-2期120卷 1095-1105页

作者： Zhu, Dahu Qian, Chen Qu, Chao He, Minqi Zhang, shuwen Tu, Qiuping wei, Wenting Wuhan Univ Technol Hubei Key Lab Adv Technol Automot Components Wuhan 430070 Peoples R China Wuhan Univ Technol Hubei Collaborat Innovat Ctr Automot Components T Wuhan 430070 Peoples R China

The prerequisite for realizing robotic self-adaptive grinding of the car body welding slags is to accurately identify the small and randomly distributed welding slags, and to segment their contour from the complex background. In this paper, an improved SegNet network model is proposed to address the challenging problems in small target detection and contour extraction. Both the ability to capture image features and to perceive global and local information is enhanced by adding the context extractor into the SegNet network. Furthermore, the residual structure and BN layer are used to optimize the decoder of the SegNet network, and the Dropout layer is employed to effectively avoid overfitting of the training model. Based on these strategies, the adaptability of the network to multi-scale targets is further enhanced. Experiments on car body welding slags detection indicate that the accuracy rate of the improved SegNet network model can reach 99.5%, which is 2.7% higher than that before improvement. Meanwhile, the boundary pixels at connection area among welding slags, metal plate, and background are accurately segmented, which provides data support for the subsequent robotic grinding of car body welding slags.

关键词： Car body welding slags Defect detection Semantic segmentation SegNet network Context extractor

来源：评论

学校读者我要写书评

暂无评论

Design of ultracompact polarimeters based on dielectric metasurfaces

引用

OPTICS LETTERS 2017年第8期42卷 1580-1583页

作者： wei, shuwen Yang, Zhenyu Zhao, Ming Huazhong Univ Sci & Technol Wuhan Natl Lab Optoelect Wuhan 430074 Hunan Peoples R China Huazhong Univ Sci & Technol Sch Opt & Elect Informat Wuhan 430074 Hunan Peoples R China Cent S Univ State Key Lab High Performance Complex Mfg Changsha 410083 Hunan Peoples R China

The state of polarization (SOP) is the key characteristic of light;its evaluation is typically based on measurements of the Stokes parameters. However, conventional approaches often have bulky and complex optical systems with long acquisition times. In this Letter, an ultracompact polarimeter based on dielectric metasurfaces is proposed. The pixel of the proposed metasuface has four areas;each area acts not only as a polarization separator, but also a flat focusing lens. It can acquire a certain polarization component of the incident light and focus the component on the receiver. Therefore, the Stokes parameters of the incident light can be immediately determined through the data from the receiver, fully describing its SOP. The incident waves with different SOPs are simulated to demonstrate that the reconstructed Stokes parameters are in good agreement with the original ones. (C) 2017 Optical Society of America

关键词： Polarimetry Metamaterials Polarization

来源：评论

学校读者我要写书评

暂无评论

MAINTENANCE DECISION OF REPAIRABLE SERIES SYSTEM WITH K-OUT-OF-N: F SUBSYSTEMS 13

MAINTENANCE DECISION OF REPAIRABLE SERIES SYSTEM WITH K-OUT-...

引用

13th International Conference on Quality, Reliability, Risk, Maintenance, and Safety Engineering, QR2MSE 2023

作者： Zhang, Yanzhe Liu, Yuxin wei, Lai Ye, shuwen Shen, Xue Zhang, Anming College of Mechanical and Electrical Engineering Wenzhou University Zhejiang325035 China

ISBN: (纸本)9781839539848

Series production systems are widely applied in production, and safety-critical components that play a key role in production are particularly important. The redundant design of safety-critical components can not only improve the reliability of the system but also save maintenance costs. Due to this fact, this paper proposed a maintenance strategy for the series production system by focusing on two objectives: maximization of system reliability and minimization of system maintenance cost. The system in view consists of k-out-of-n: F subsystems as well as single component subsystems that are connected in series. In redundant subsystems, the components are assumed to be independent and identical. By implementing this maintenance strategy, the goal is to improve the overall reliability of the system while minimizing the cost associated with maintenance activities. To analyze their performances, an iterative algorithm is used in numerical examples, and the result shows that the maintenance policy proposed is effective and practical. © The Institution of Engineering & Technology 2023.

关键词： Costs

来源：评论

学校读者我要写书评

暂无评论

Aging characteristics of colorectal cancer based on gut microbiota

引用

CANCER MEDICINE 2023年第17期12卷 17822-17834页

作者： Wu, Yinhang Zhuang, Jing Zhang, Qi Zhao, Xingming Chen, Gong Han, Shugao Hu, Boyang Wu, wei Han, shuwen Huzhou Univ Huzhou Cent Hosp Affiliated Cent Hosp Huzhou Peoples R China Key Lab Multi Res & Clin Transformat Digest Canc Huzhou Peoples R China Zhejiang Chinese Med Univ Affiliated Clin Med Coll 5 Huzhou Cent Hosp Huzhou Peoples R China Fudan Univ Inst Sci & Technol Brain Inspired Intelligence Shanghai Peoples R China Zhejiang Univ Affiliated Hosp 2 Sch Med Hangzhou Peoples R China Huzhou Univ Huzhou Cent Hosp Affiliated Cent Hosp 1558 Sanhuan North Rd Huzhou 313000 Zhejiang Peoples R China

Background: Aging is one of the factors leading to cancer. Gut microbiota is related to aging and colorectal cancer (CRC).Methods: A total of 11 metagenomic data sets related to CRC were collected from the R package curated Metagenomic Data. After batch effect correction, healthy individuals and CRC samples were divided into three age groups. Ggplot2 and Microbiota Process packages were used for visual description of species composition and PCA in healthy individuals and CRC samples. LEfSe analysis was performed for species relative abundance data in healthy/CRC groups according to age. Spearman correlation coefficient of age-differentiated bacteria in healthy individuals and CRC samples was calculated separately. Finally, the age prediction model and CRC risk prediction model were constructed based on the age-differentiated ***: The structure and composition of the gut microbiota were significantly different among the three groups. For example, the abundance of Bacteroides vulgatus in the old group was lower than that in the other two groups, the abundance of Bacteroides fragilis increased with aging. In addition, seven species of bacteria whose abundance increases with aging were screened out. Furthermore, the abundance of pathogenic bacteria (Escherichia_coli, Butyricimonas_virosa, Ruminococcus_bicirculans, Bacteroides_fragilis and Streptococcus_vestibularis) increased with aging in CRCs. The abundance of probiotics (Eubacterium_eligens) decreased with aging in CRCs. The age prediction model for healthy individuals based on the 80 age-related differential bacteria and model of CRC patients based on the 58 age-related differential bacteria performed well, with AUC of 0.79 and 0.71, respectively. The AUC of CRC risk prediction model based on 45 disease differential bacteria was 0.83. After removing the intersection between the disease-differentiated bacteria and the age-differentiated bacteria from the healthy samples, the AUC of CRC risk prediction mo

关键词： aging artificial intelligence colorectal cancer gut microbiota metagenomic sequencing

来源：评论

学校读者我要写书评

暂无评论

A stochastic predator-prey model with Holling II increasing function in the predator

引用

JOURNAL OF BIOLOGICAL DYNAMICS 2021年第1期15卷 1-18页

作者： Huang, Youlin Shi, Wanying wei, Chunjin Zhang, shuwen Jimei Univ Sch Sci Xiamen Peoples R China

This paper is concerned with a stochastic predator-prey model with Holling II increasing function in the predator. By applying the Lyapunov analysis method, we demonstrate the existence and uniqueness of the global positive solution. Then we show there is a stationary distribution which implies the stochastic persistence of the predator and prey in the model. Moreover, we obtain respectively sufficient conditions for weak persistence in the mean and extinction of the prey and extinction of the predator. Finally, some numerical simulations are given to illustrate our main results and the discussion and conclusion are presented.

关键词： Stochastic predator– prey model Holling II increasing function in the predator the global positive solution persistence and extinction

来源：评论

学校读者我要写书评

暂无评论

Steric Construction and Modulation of Co‒Nx Single-Atom Electrocatalysts Via Polyoxometalate Clusters Integration

SSRN

引用

SSRN 2024年

作者： Wu, Yunping Niu, shuwen wei, Zhengyu Meng, Lingzhe wei, wei Department of Applied Chemistry School of Chemistry Xi’an Jiaotong University Engineering Research Center of Energy Storage Materials and Devices Ministry of Education Xi’an Key Laboratory of Sustainable Energy Material Chemistry Xi’an710049 China

Single-atom catalysts (SACs) with nitrogen-coordinated transition metal sites (M-Nx) hold great promise for electrocatalytic oxygen reduction and oxygen evolution reactions. Despite substantial achievements based on the confinement pyrolysis and heteroatom-doping methods, the M-Nx SACs still suffer from low yield of atomic sites and less tenability of electronic states of M-Nx center. Here, an innovate synthesis methodology is proposed for surface integrating Co atoms onto polyoxometalate (POM) and its derivative clusters, which promise to regulate the atomic distribution and coordination environments of Co-Nx SACs at the sub-nanometer level. The synthetic procedures exhibit general applicability for a variety of POM clusters to achieve high atomic Co loading up to 9.9 wt%. Steric integration by POM-derived clusters also impart strengthened d-p orbital hybridization of Co-Nx SACs by the formation of Co-N-Mo bonding, which surpass common heteroatoms toward modulating the geometric and electronic structures of M-Nx SACs, leading to pronounced catalytic activity and durability. © 2024, The Authors. All rights reserved.

关键词： Integration

来源：评论

学校读者我要写书评

暂无评论

Partial characterization and lyoprotective activity of exopolysaccharide from Oenococcus oeni 28A-1

引用

PROCESS BIOCHEMISTRY 2021年 101卷 128-136页

作者： Shi, Kan An, wei Meng, Qiang Gu, Yajing Liu, shuwen Northwest Agr & Forestry Univ Coll Enol Xianyang 712100 Shaanxi Peoples R China Shaanxi Engn Res Ctr Viti Viniculture Xianyang Shaanxi 712100 Peoples R China State Forestry Adm Engn Res Ctr Viti Viniculture Xianyang 712100 Shaanxi Peoples R China Heyang Expt & Demonstrat Stat Grape Xianyang 715300 Shaanxi Peoples R China

Nowadays, microbial exopolysaccharide (EPS) have been extensively researched due to their multifunctional characteristics, especially the EPS from the lactic acid bacteria (LAB). However, the EPS from the Oenococcus oeni (O. oeni, a lactic acid bacteria commonly used in winemaking) have rarely been experimented. In this study, the EPS produced by O. oeni 28A-1 was obtained and characterized. The EPS had an average molecular weight of 7.73x10(4) Da and were composed of mannose, rhamnose, glucose, galactose, arabinose and galacturonic acid in a molar ratio of 13.6:1.3:8.8:5.6:1:1.4. The SEM images showed EPS appeared as irregular lamellar structure and coarse surface. The AFM image of the EPS showed that the irregular particle structure was dispersed in the solution, and some aggregation occurred in some areas. FT-IR analysis of the EPS revealed the characteristics of polysaccharide with the presence of specific functional groups. The EPS also exhibited higher thermal stability with a degradation temperature of 259.47 degrees C in DSC analysis. In addition, the EPS from O. oeni exhibited great lyoprotective ability during its freeze-drying process, which indicated its great potential to be developed as natural lyoprotectant for O. oeni.

关键词： Exopolysaccharide Oenococcus oeni Structure Physicochemical property Lyoprotective activity

来源：评论

学校读者我要写书评

暂无评论

Revealing the plasma confinement behavior of an axial ring cusp hybrid discharge in a miniature ion thruster using PIC/MCC simulation

引用

PLASMA SOURCES SCIENCE & TECHNOLOGY 2023年第8期32卷 085005-085005页

作者： Liu, wei Wang, weizong Li, Yifei Xue, shuwen Beihang Univ Sch Astronaut Adv Space Prop & Energy Lab ASPEL Beijing 100191 Peoples R China Beihang Univ Ningbo Inst Technol Aircraft & Prop Lab Ningbo 315832 Peoples R China Beihang Univ Shen Yuan Honors Coll Beijing 100191 Peoples R China

Micro direct current (DC) ion thrusters have broad application prospects as propulsion systems for micro spacecrafts due to their advantages of high discharge reliability and efficiency. Experiments in the literature show that the plasma discharge under the axial ring cusp hybrid (ARCH) magnetic field has higher discharge efficiency in the discharge chamber of micro DC ion thruster. In this paper, a 2d-3v axisymmetric particle-in-cell/Monte Carlo collision numerical model is developed for the ARCH discharge. This model takes the thermal electron emission including the Schottky effect, various collision processes including the Bohm-type anomalous conductivity and the uneven background gas density distribution in the cathode-anode gap into account. The spatial distributions of plasma characteristics are presented and the advantages of ARCH discharge compared with traditional 3-ring discharge in the discharge chamber of the micro DC ion thruster are analyzed. The longer electron path length and the change of ionization region improve the discharge efficiency in small-scale discharges. Two primary methods for the discharge confinement in the miniature ion thrusters, that is, the magneto-static 'cusp confinement' through magnetic cusps and the electrostatic 'sheath refection confinement' through the backplate with the lower potential are investigated. The sensitivity of macroscopic current characteristics and microscopic plasma characteristics in the ARCH discharge to the magnetic field strength and backplate biased potential are explored. It is found that there is an optimal magnetic field to maximize the utilization of propellant and minimize the discharge loss. The electrostatic 'sheath refection confinement' is conducive to the reduction of discharge loss, however, it is also accompanied by the decline of propellant utilization. The above results provide further support for the design optimization of the micro DC ion thruster discharge chamber.

关键词： PIC-MCC simulation axial ring cusp hybrid discharge micro ion thruster plasma confinement behavior discharge chamber

来源：评论

学校读者我要写书评

暂无评论

Self-Enhanced Antibacterial and Antifouling Behavior of Three-Dimensional Porous Cu2O Nanoparticles Functionalized by an Organic-Inorganic Hybrid Matrix

引用

ACS APPLIED MATERIALS & INTERFACES 2023年第32期15卷 38808-38820页

作者： Li, Huali Zhang, Liuqin Zhang, Xiaohu Zhu, Guangyu Zheng, Dongchen Luo, shuwen Wu, Min Li, wei-Hua Liu, Fa-Qian Sun Yat Sen Univ Sch Chem Engn & Technol Zhuhai 519082 Peoples R China Sun Yat Sen Univ Sch Mat Sci & Engn Guangzhou 510275 Peoples R China Offshore Oil Prod Plant Sinopec Shengli Oilfield C Dongying 257237 Peoples R China North China Univ Water Resources & Elect Power Sch Mat Zhengzhou 450045 Peoples R China

Cu2O is currently an important protective material fordomestic engineering and equipment used to exploit marine ***+ is considered to have more effective antibacterialand antifouling activities than Cu2+. However, disproportionationof Cu+ in the natural environment leads to its reducedbioavailability and weakened reactivity. Novel and functionalizedCu(2)O composites could enable efficient and environmentallyfriendly applications of Cu+. To this end, a series ofthree-dimensional porous Cu2O nanoparticles (3DNP-Cu2O) functionalized by organic (redox gel, R-Gel)-inorganic(reduced graphene oxide, rGO) hybrids 3DNP-Cu2O/rGO( x )@R-Gel at room temperature by immobilization-reductionmethod was prepared and applied for protection against marine biofouling.3DNP-Cu2O/rGO(1.76)@R-Gel includes rGO and R-Gelshape 3D porous Cu2O nanoparticles with diameters & SIM;177nm and strong dispersion and antioxidant stability. Compared withcommercial Cu2O (Cu2O-0), 3DNP-Cu2O/rGO(1.76)@R-Gel exhibited an & SIM;50% higher bactericidalrate, & SIM;96.22% higher water content, and & SIM;75% lower adhesionof mussels and barnacles. Moreover, 3DNP-Cu2O/rGO( x )@R-Gel maintains the same excellent, stable, andlong-lasting bactericidal performance as Cu2O-0@R-Gel whilereducing the average copper ion release concentration by & SIM;56to 76%. This was also confirmed by X-ray diffraction, X-ray photoelectricspectroscopy (XPS), atomic absorption spectroscopy, and antifoulingtests. In addition, XPS tests of rGO-Cu2+ and R-Gel-Cu2+, photocurrent tests of 3DNP-Cu2O/rGO(1.76)@R-Gel, and energy-dispersive spectrometry pictures of bacteria confirmthat R-Gel and rGO act as electron donors and transfer substratesdriving the reduction of Cu2+ (Cu2+ & RARR;Cu+) and the diffusion of Cu+. Thus, a self-growingantibacterial and antifouling system of 3DNP-Cu2O/rGO(1.76)@R-Gel was achieved. The mechanism of accelerated bacterialinactivation and resistance to mussel and barnacle adhesion by 3DNP-Cu2O/rGO(1.76)@

关键词： 3D porous Cu2O nanoparticle rGO nanosheet redox gel self-enhanced antibacterial antifouling

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：