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A tunable ionic covalent organic framework platform for efficient CO_(2) catalytic conversion

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Frontiers of Chemical Science and Engineering 2024年第1期18卷 25-36页

作者： Ting Li ji xiong Minghui Chen Quan Shi Xiangyu Li Yu jiang Yaqing Feng Bao Zhang School of Chemical Engineering and Technology Tianjin UniversityTianjin 300350China Guangdong Laboratory of Chemistry and Fine Chemical Industry jieyang Center Jieyang 522000China Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192China

The cycloaddition reaction between epoxides and CO_(2) is an effective method to utilize CO_(2) resource.Covalent organic frameworks(COFs)provide a promising platform for the catalytic CO_(2) transformations on account of their remarkable chemical and physical properties.Herein,a family of novel vinylene-linked ionic COFs named TE-COFs(TTE-COF,TME-COF,TPE-COF,TBE-COF)has been facilely synthesized from N-ethyl2,4,6-trimethylpyridinium bromide and a series of triphenyl aromatic aldehydes involving different numbers of nitrogen atoms in the central aromatic ring.The resulting catalyst TTE-COF with excellent adsorption capacity(45.6 cm3·g^(-1),273 K)exhibited outstanding catalytic performance,remarkable recyclability and great substrate tolerance.Moreover,it was also observed that the introduction of nitrogen atom in the precursor led to a great improvement in the crystallinity and CO_(2) adsorption capacity of TE-COFs,thus resulting to a progressively improved catalytic performance.This work not only illustrated the influence of monomer nitrogen content on the crystallinity and CO_(2) adsorption capacity of TE-COFs but also provided a green heterogeneous candidate for catalyzing the cycloaddition between CO_(2) and epoxides,which shed a light on improving the catalytic performance of the CO_(2) cycloaddition reaction by designing the covalent organic frameworks structures.

关键词： CO_(2)cycloaddition nreaction covalent organic frameworks cyclic carbonate vinylene-linked synergetic effects

Effect of cermet substrate characteristics on the microstructure and properties of TiAlN coatings

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International Journal of Minerals,Metallurgy and Materials 2022年第3期29卷 547-556页

作者： Qianbing You ji xiong Tianen Yang Tao Hua Yunliang Huo Junbo Liu School of Mechanical Engineering Sichuan UniversityChengdu 610065China

The composition and structure of substrate materials have important influences on coating performance,especially in terms of bond-ing strength and coating hardness,which determine whether the coating can be used for a given application.In this study,a TiAlN coating is deposited on Ti(C,N)-based cermet(TC)substrates with 0wt%-20wt%WC by arc ion plating.The influence of cermet substrate characterist-ics on the structure and properties of the TiAlN coating is then researched.Results show that the TiAlN coating deposited on the TC substrate has a columnar grain structure.As WC increases,the strength ratio of I(111)/I(200)and adhesive strength of TiAlN gradually increases.In the ab-sence of WC in the substrate,the preferred orientation of the TiAlN coating is(200).As WC increases,the preferred orientation of the TiAlN coating becomes(111)and(200).Notable differences in adhesive strength between the coating and substrate could be attributed to the micro-structure and composition of the latter.Scratching results show that the adhesive strengths of the TiAlN coating on the 0wt%-20wt%WC cer-met substrate are 52-65 N.Among the coatings obtained that on the TC substrate with 15wt%WC presents the highest H/E and H3/E2,which indicates that this coating also features the best wear resistance.The failure mechanisms of the coated tools include coating peeling,adhesive wear,and abrasive wear.As the cutting speed increases,the degree of flank wear increases and the durability of the coating decreases accord-ingly.Increases in WC result in an initial decrease followed by a gradual increase in the flank wear of the coated cermet inserts.

关键词： cermet TiAlN coating characteristics structure properties

In-situ doping strategy for improving the photocatalytic hydrogen evolution performance of covalent triazine frameworks

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Science China Chemistry 2023年第8期66卷 2363-2370页

作者： Minghui Chen ji xiong Xiangyu Li Quan Shi Ting Li Yaqing Feng Bao Zhang School of Chemical Engineering and Technology Tianjin UniversityTianjin300350China Collaborative Innovation Center of Chemical Science and Engineering(Tianjin) Tianjin300072China Haihe Laboratory of Sustainable Chemical Transformations Tianjin300192China

A highly conjugated network of covalent triazine frameworks(CTFs)on the one hand promotes light-harvesting,but on the other hand,also results in high carrier recombination which eventually limits their photocatalytic hydrogen evolution reaction(HER)rates.Thus,strategies to favorably tune the electronic configuration of CTFs for efficient photocatalytic HERs need to be developed,but still remain challenging.Herein,a simple in-situ defect strategy involving element doping is developed for the first time to introduce a heteroatom including S and Se into CTF-1 via the condensation of aldehydes with the mixture of the terephthalimidamide and the S-or Se-substituted terephthalimidamide under mild conditions.The doping content(X)is varied,resulting in a series of S-and Se-doped CTFs,named CTFS-1-X and CTFSe-1-X,respectively.Interestingly,for the S-doped CTFs,CTFS-1-10 shows the most excellent HER rate(4,992.3μmol g^(-1)h^(-1))from water splitting,while for the Se-doped ones,CTFSe-1-10 exhibits a photocatalytic HER rate of 5,792.8μmol g^(-1)h^(-1),both of which far surpass undoped CTFs(693.3μmol g^(-1)h^(-1)).In-depth studies indicate that the introduction of S or Se atoms into CTFs could extend the light absorption and promote photo-generated electron-hole pairs migration.Meanwhile,S-or Se-doping could create heterogeneous electronic configuration in CTFs,which can help to suppress carrier recombination.

关键词： covalent triazine frameworks heteroatom doping hydrogen evolution

Design and preparation of gradient graphite/cermets self-lubricating composites

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Journal of Materials Science & Technology 2018年第8期34卷 1378-1386页

作者： Liming Zhou ji xiong Zhixing Guo Junliu Ye School of Manufacturing Science and Engineering Sichuan University

Based on the functionally graded materials （FGMs） design concept, the laminated-graded graphite/cermets self-lubricating composite was prepared to achieve the integration of mechanical prop- erties and lubrication performance of the cermet. The effects of the layer number and thickness of graded structure on residual stresses in the gradient composites were investigated by finite element method （FEM）. From the FEM analyses, the optimal gradient structure design was obtained correspond- ing to the following parameters： the number of graded layers n = 2 and the thickness of graded structure t = I ram. According to the optimum design, a graded graphite/cermets self-lubricating material with two layers was fabricated by a typical powder metallurgy technique. Compared with the homogenous graphite/cermets composite, the surface hardness and indentation fracture toughness of graded compos- ite were increased by approximately 15.9% and 6.3%, respectively. The results of X-ray diffraction （XRD） stress measurement identified the existence of residual compressive stress on the surface of graded com- posite. Additionally, the friction and wear tests revealed that the wear resistance of the graphite/cermets self-lubricating composite was improved significantly via the graded structural design, whereas the coefficient of friction changed slightly.

关键词： Graphite/cermets self-lubricating material Graded structure Finite element analysis Mechanical properties Tribological performance

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智慧公路毫米波雷达感知精度分析与验证

中国公路学报 2024年第1期37卷 205-214页

作者：赵聪师钰鹏丁德隆暨育雄杜豫川同济大学道路与交通工程教育部重点实验室上海201804

毫米波雷达是当前智慧公路中路侧感知系统的重要组成部分,在交通流运行态势感知与智能管控、车路协同与自动驾驶中广泛应用。然而,车辆与毫米波雷达之间的相对位置、相对姿态的变化会对雷达信号回波及点云分布产生影响,导致雷达对车辆... 详细信息

毫米波雷达是当前智慧公路中路侧感知系统的重要组成部分,在交通流运行态势感知与智能管控、车路协同与自动驾驶中广泛应用。然而,车辆与毫米波雷达之间的相对位置、相对姿态的变化会对雷达信号回波及点云分布产生影响,导致雷达对车辆的感知结果出现偏差,进而影响交通系统的管控决策。分析毫米波雷达感知精度的空间特征,对于指导毫米波雷达在智慧公路中的应用至关重要。为此,基于毫米波雷达的感知原理,综合考虑毫米波雷达信号处理与点云数据处理2个阶段中的感知误差来源,通过数值仿真与实测试验相结合的方式对目标在不同位置与姿态下毫米波雷达的感知精度特征进行分析与验证。研究表明:雷达纵向感知精度主要受到与车辆相对位置的影响,当车辆与雷达纵向距离小于30 m或大于200 m时,车辆位置感知结果会向车头或车尾方向显著偏移,相应产生的纵向感知误差通常超过0.5 m;雷达横向感知精度主要受到车辆横向位置及相对姿态的影响,当车辆横向位置偏离雷达中心光束超过5 m或车辆行驶的航向角超过40°时,车辆位置感知结果会向车身侧向偏移,相应产生的横向感知误差通常超过0.5 m。得到的影响因素分析结果,可进一步为智慧公路场景中毫米波雷达感知数据的应用与感知设备的部署提供建议。

关键词：交通工程感知精度数值仿真毫米波雷达智慧公路路侧感知

A Homogeneous Cloud Task Distribution Method Based on an Improved Leapfrog Algorithm

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Computer Modeling in Engineering & Sciences 2021年第7期128卷 359-379页

作者： Yunliang Huo ji xiong Zhixing Guo Qianbing You Yi Peng School of Mechanical Engineering Sichuan UniversityChengdu610065China Chengdu Yigao Intelligent Technology Co. Ltd.Chengdu610065China

Cloud manufacturing is a new manufacturing model with crowd-sourcing characteristics,where a cloud alliance composed of multiple enterprises,completes tasks that a single enterprise cannot accomplish by itself.However,compared with heterogeneous cloud tasks,there are relatively few studies on cloud alliance formation for homogeneous tasks.To bridge this gap,a novel method is presented in this paper.First,a homogeneous cloud task distribution model under cloud environment was constructed,where services description,selection and combination were modeled.An improved leapfrog algorithm for cloud task distribution(ILA-CTD)was designed to solve the proposed model.Different from the current alternatives,the initialization operator and the leapfrog operator in ILA-CTD can ensure that the algorithm always searches the optimal solution in the feasible space.Finally,the processing of task allocation for 1000 pieces of medical labeling machine bottom plates was studied as a case to show the feasibility of the proposed method.The superiority of ILA-CTD was also proven based on more optimal solutions found,compared with the three other methods.

关键词： Cloud manufacturing service composition tasks distribution intelligent optimization leapfrog algorithm

高依赖与协商自主:西部地方高校自主性现状、困境与突破

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黑龙江高教研究 2024年第6期42卷 38-43页

作者：谢冬平熊继承红河学院云南蒙自661199 湖南科技大学湖南湘潭411201

组织自主性是西部地方高校发展不可绕过的命题。通过搭建“组织-外部制度”互构分析框架,将制度与事件分析范式相结合,以一所西部新建本科高校(U1)向应用型转型改革为切入点,在“过程-事件”中窥探其自主性“原始面貌”,以期发现其中规... 详细信息

组织自主性是西部地方高校发展不可绕过的命题。通过搭建“组织-外部制度”互构分析框架,将制度与事件分析范式相结合,以一所西部新建本科高校(U1)向应用型转型改革为切入点,在“过程-事件”中窥探其自主性“原始面貌”,以期发现其中规律性结构。研究发现,在现行高等教育治理框架下,西部地方高校自主性尚不成熟。出现这种情况,既因现有制度结构限制,也因其自身发展惯习以及能力限制。基于此,初步构建“高支持下的协商自主模式”模型,以形成政府、市场与西部地方高校联动的多重协商机制:外部关键力量应持续增强对西部地方高校的高支持;西部地方高校要积极构建教师和学生主动参与的自主行为模式等,以促进其自主性的提升。

关键词：西部地方高校组织自主性高依赖协商自主

语文教师专业阅读悖论探究——基于知识分类学习论的解释和破解

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黄冈师范学院学报 2024年第1期44卷 69-76页

作者：熊纪涛海南热带海洋学院附属中学海南五指山572200

语文教师阅读专业书籍收效甚微,这同其以教人学读书为己任的身份就形成了一种悖论。采用知识分类学习论进行观照,其根本症结乃在于语文教师无法鉴明所读书籍蕴涵的知识类型,更无法清晰、准确地为学习该类知识创设适切的条件。知识分类... 详细信息

语文教师阅读专业书籍收效甚微,这同其以教人学读书为己任的身份就形成了一种悖论。采用知识分类学习论进行观照,其根本症结乃在于语文教师无法鉴明所读书籍蕴涵的知识类型,更无法清晰、准确地为学习该类知识创设适切的条件。知识分类学习论为透视和解决语文教师专业阅读悖论提供了理论资源。针对语文教师专业阅读的书籍,采用知识分类的标准对专业书籍分类,根据专业书籍的具体类型提出其有效阅读的策略,并对阅读策略产生效用的逻辑作以解释或例析。

关键词：语文教师专业阅读阅读低效阅读悖论知识分类阅读策略

Adherent coating on gradient cemented carbide with ultrafine Ti(C_(0.5),N_(0.5))

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Rare Metals 2015年第6期34卷 413-420页

作者： Tian-En Yang Lan Sun ji xiong Zhi-Xing Guo Lei Wang Ding Cao School of Manufacturing Science and Engineering Sichuan University Institute of System Engineering Chinese Academy of Engineering Physics

Gradient cemented carbide is usually employed as the snbstrate for coated carbide insert. In this work, gradient cemented carbide with ultrafine Ti（C0.5,N0.5） was prepared and its microstructure and properties were researched. Moreover, this novel substrate was coated to investigate cutting performance. It is found that the average WC grain size in the gradient zone is larger than that in the bulk. Owing to ultrafine Ti（C0.5,N0.5） introduction, gradient cemented carbide prepared by vacuum sintering exhibits full densification. By contrast, the gradient cemented carbide with ultrafine Ti（C0.5,N0.5） shows higher transverse rupture strength （TRS） and hardness than the homogenous one. Gradient cemented carbide suffers small TRS reduction after coating, and the bonding between coatings and gradient substrate is tidy and compact. The coated gradient cemented carbide shows much better endurance and impact resistance than the coated homogenous one. It confirms the superiority of gradient cemented carbide when used as the substrate for coating inserts.

关键词： Gradient cemented carbide UltrafineTi（C0.5,N0.5） Vacuum sintering Transverse rupturestrength Cutting performance