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Attrition resistant catalyst for dimethyl ether synthesis in fluidized-bed reactor

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第9期9卷 1288-1295页

作者： li-hua teng Institute of Biology and Environmental Science Zhejiang Wanli University Ningbo 315100 China

Fluidized-bed reactor is a candidate for dimethyl ether （DME） synthesis from syngas because of its excellent heat removal capability. In order to improve the attrition resistance of catalyst, an amount of silica sol as binder was added to the catalyst composed of methanol synthesis component CuO/ZnO/Al2O3 and methanol dehydration component HZSM-5, which was prepared by coprecipitation and shaped by spray drying to get spherical particles. The effect of silica sol on the catalytic activity was investigated in a fixed-bed flow microreactor. Based on the experiment results, silica sol in the range of 0-20wt% had small effect on the catalytic activity. Generally, the CO conversion and DME yield decreased with the increase in concentration of silica sol, while the attrition resistance of catalysts increased with increasing silica sol, indicating that it was feasible to improve the attrition resistance without greatly sacrificing the activity of catalyst. In addition, the characterizations of catalysts were carried out using Brunauer-Emmett-Teller （BET）, X-ray powder diffraction （XRD） and temperature programmed reduction （TPR）.

关键词： Dimethyl ether (DME) Attrition resistance Catalytic activity Silica sol

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基于车桥耦合振动的连续梁桥动力特性研究

公路交通科技 2024年第4期41卷 73-79页

作者：王俊霞左新黛申林李华腾李舟山西工程职业学院山西太原030009 交通运输部公路科学研究院北京100088 中路高科交通检测检验认证有限公司北京100088 太原科技大学车辆与交通工程学院山西太原030024

为获取连续梁桥在行车荷载作用下的动力特性规律,基于虚功原理,建立了24自由度典型四轴拖挂车动力学模型。采用模态叠加法建立三跨连续梁桥动力特性模型,通过模态综合法建立了车轮-桥面间的力学和位移耦合关系。组建了四轴拖挂车和连续... 详细信息

为获取连续梁桥在行车荷载作用下的动力特性规律,基于虚功原理,建立了24自由度典型四轴拖挂车动力学模型。采用模态叠加法建立三跨连续梁桥动力特性模型,通过模态综合法建立了车轮-桥面间的力学和位移耦合关系。组建了四轴拖挂车和连续梁桥动力耦合分析模型,通过逐步迭代法建立了车桥耦合时变矩阵方程。以某三跨连续梁桥为工程示例,进行车桥耦合动力特性的敏感性分析,重点分析了车辆行车速度、桥面不平度和车辆载重变化对桥梁关键位置处的动力响应影响。结果表明:随着行车速度的增大,桥梁竖向位移时程响应曲线整体呈增大趋势,其中边跨跨中竖向位移幅值增幅相对较小,为3.40%,中跨跨中竖向位移幅值呈先减小后增大的变化趋势,最大增幅为7.10%;随着桥面状况的恶化,桥梁边跨跨中和中跨跨中截面的竖向位移响应增幅相对较大,分别为38.60%和54.95%,为桥梁动力响应的主要敏感参数;当车辆载重相对较小时(从空载至40%满载),桥梁位移动力响应变化较为敏感,但随着车辆载重增长率的逐步增大,桥梁动力响应结果对车辆载重的敏感性逐步降低。

关键词：桥梁工程车桥耦合模态综合法连续梁桥四轴拖挂车动力特性桥面不平度

IR study on surface chemical properties of catalytic grown carbon nanotubes and nanofibers

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第5期9卷 720-726页

作者： li-hua teng Tian-di TANG Institute of Biology and Environmental Science Zhejiang Wanli University Ningbo 315100 China College of Chemistry Northeast Normal University Changchun 130024 China）

In this study, the surface chemical properties of carbon nanotubes (CNTs) and carbon nanofibers (CNFs) grown by catalytic decomposition of methane on nickel and cobalt based catalysts were studied by DRIFT (Diffuse Reflectance Infrared Fourier Transform) and transmission Infrared (IR) spectroscopy. The results show that the surface exists not only carbon-hydrogen groups, but also carboxyl, ketene or quinone (carbonyl) oxygen-containing groups. These functional groups were formed in the process of the material growth, which result in large amount of chemical defect sites on the walls.

关键词： Carbon nanotubes (CNTs) Carbon nanofibers (CNFs) Functional surface groups Infrared (IR) spectroscopy

S-scheme heterojunction in photocatalytic hydrogen production

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Journal of Materials Science & Technology 2024年第2期169卷 82-104页

作者： teng li Noritatsu Tsubaki Zhiliang Jin School of Chemistry and Chemical Engineering North Minzu UniversityYinchuan 750021China Department of Applied Chemistry Graduate School of EngineeringUniversity of ToyamaGofuku 3190Toyama 930-8555Japan

As an ideal secondary energy source,hydrogen has the title of clean energy and the product of its complete combustion is only water,which is not polluting to the *** hydrogen production technology is an environmentally friendly,safe,and low-cost strategy that requires only an inexhaustible amount of solar energy and water as *** paper provides a detailed and detailed review of S-scheme heterojunction photocatalysts for photocatalytic hydrogen production,mainly including TiO_(2)-based,Perovskite-based,CdS-based,Graphitic phase carbon nitride-based,COF-based graphdiyne-based,ZnO-based,and ZnIn_(2)S_(4)-based S-scheme heterojunction *** classification of S-scheme heterojunctions is ***’s more,various characterizations for direct verification of the charge migration mechanism of S-scheme heterojunctions are *** on the present study,the future potential challenges and future research trends for S-scheme heterojunctions in photocatalytic hydrogen evolution technology are pointed out,which provides feasible strategies for the development and design of S-scheme heterojunction photocatalysts in the field of photocatalytic hydrogen evolution.

关键词： S-scheme heterojunction Photocatalysis Charges migration Hydrogen evolution

A Stroke-limitation AMD Control System with Variable Gain and limited Area for High-Rise Buildings

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工程与科学中的计算机建模(英文) 2024年第1期138卷 865-884页

作者： Zuo-hua li Qing-Gui Wu Jun teng Chao-Jun Chen School of Civil and Environmental Engineering Harbin Institute of Technology(Shenzhen)Shenzhen518055China Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityHong Kong100872China

Collisions between a moving mass and an anti-collision device increase structural responses and threaten structural *** active mass damper(AMD)with stroke limitations is often used to avoid ***,a strokelimited AMD control system with a fixed limited area shortens the available AMD stroke and leads to significant control *** solve this problem,the design approach with variable gain and limited area(VGLA)is proposed in this ***,the boundary of variable-limited areas is calculated based on the real-time status of the moving *** variable gain(VG)expression at the variable limited area is deduced by considering the saturation of AMD ***,numerical simulations of a stroke-limited AMD control system with VGLA are conducted on a high-rise building *** numerical simulations show that the proposed approach has superior strokelimitation performance compared with a stroke-limited AMD control system with a fixed limited ***,the proposed approach is validated through experiments on a four-story steel frame.

关键词： High-rise buildings active control stroke limitations variable gain variable limited area

April-September minimum temperature reconstruction based on Sabina tibetica ring-width chronology in the central eastern Tibetan Plateau,China

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Journal of Forestry Research 2024年第2期35卷 134-145页

作者： teng li Jianfeng Peng Tsun Fung Au Jinbao li School of Geography and Remote Sensing Guangzhou UniversityGuangzhou 510006People’s Republic of China College of Geography and Environmental Science Henan UniversityKaifeng 475004People’s Republic of China Institute for Global Change Biology School for Environment and SustainabilityUniversity of MichiganAnn ArborMIUSA Department of Ecology and Evolutionary Biology University of MichiganAnn ArborMIUSA Department of Geography University of Hong KongHong Kong SARPeople’s Republic of China HKU Shenzhen Institute of Research and Innovation Shenzhen 518057People’s Republic of China

Minimum temperatures have remarkable impacts on tree growth at high-elevation sites on the Tibetan Plateau,but the shortage of long-term and high-resolution paleoclimate records inhibits understanding of recent minimum temperature *** this study,a warm season(April–September)reconstruction is presented for the past 467 years(1550–2016)based on Sabina tibetica ring-width chronology on the lianbaoyeze Mountain of the central eastern Tibetan *** warm periods and eight cold periods were ***-term minimum temperature variations revealed a high degree of coherence with nearby *** correlations between our reconstruction and global sea surface temperatures suggest that warm season minimum temperature anomalies in the central eastern Tibetan Plateau were strongly influenced by large-scale ocean atmospheric circulations,such as the El Ni?o-Southern Oscillation and the Atlantic Multidecadal Oscillation.

关键词： Tree-ring analysis Sabina tibetica Minimum temperatures Central eastern Tibetan Plateau Climate change

Effects of interstitial cluster mobility on dislocation loops evolution under irradiation of austenitic steel

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Nuclear Science and Techniques 2024年第8期35卷 69-78页

作者： Xin‑hua Yan Lu Sun Du Zhou teng Xie Chang Peng Ye‑Xin Yang li Chen Zhen‑Feng Tong North China Electric Power University Beijing 102206China China Nuclear Power Operations Co. LtdShenzhen 518000China

The evolution of dislocation loops in austenitic steels irradiated with Fe^(+)is investigated using cluster dynamics(CD)simulations by developing a CD *** CD predictions are compared with experimental results in the *** number density and average diameter of the dislocation loops obtained from the CD simulations are in good agreement with the experimental data obtained from transmission electron microscopy(TEM)observations of Fe~+-irradiated Solution Annealed 304,Cold Worked 316,and HR3 austenitic steels in the *** CD simulation results demonstrate that the diffusion of in-cascade interstitial clusters plays a major role in the dislocation loop density and dislocation loop growth;in particular,for the HR3 austenitic steel,the CD model has verified the effect of temperature on the density and size of the dislocation loops.

关键词： Cluster dynamics Dislocation loops In-cascade interstitial clusters Austenitic steels

Dendroclimatological study of Sabina saltuaria and Abies faxoniana in the mixed forests of the Qionglai Mountains,eastern Tibetan Plateau

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Journal of Forestry Research 2024年第1期35卷 72-82页

作者： teng li Jianfeng Peng Tsun Fung Au Jingru li Jinbao li Yue Zhang School of Geography and Remote Sensing Guangzhou UniversityGuangzhou 510006People’s Republic of China College of Geography and Environmental Science Henan UniversityKaifeng 475004People’s Republic of China Institute for Global Change Biology School for Environment and SustainabilityUniversity of MichiganAnn ArborMIUSA Department of Ecology and Evolutionary Biology University of MichiganAnn ArborMIUSA Department of Geography University of Hong KongHong Kong SARPeople’s Republic of China HKU Shenzhen Institute of Research and Innovation Shenzhen 518057People’s Republic of China

Tree-ring chronologies were developed for Sabina saltuaria and Abies faxoniana in mixed forests in the Qionglai Mountains of the eastern Tibetan ***-growth relationship analysis indicated that the two co-exist-ing species reponded similarly to climate factors,although *** was more sensitive than *** strong-est correlation was between *** chronology and regional mean temperatures from June to *** on this relationship,a regional mean temperature from June to November for the period 1605-2016 was *** explained 37.3%of the temperature variance during th period *** major warm periods and five major cold periods were *** analysis detected significant interannual and multi-decadal *** also revealed the influence of the Atlantic Multi-decadal Oscillation,confirming its importance on climate change on the eastern Tibetan Plateau.

关键词： Tree-ring analysis Mixed forests Dendroclimatology Qionglai Mountains

Eutectogel-based self-powered wearable sensor for health monitoring in harsh environments

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Nano Research 2024年第6期17卷 5559-5568页

作者： Junpeng Wu Xinru teng Lu liu Hongzhi Cui Xiaoyi li College of Materials Science and Engineering Ocean University of ChinaQingdao 266100China Key Lab for Special Functional Materials of Ministry of Education School of Materials Science and EngineeringHenan UniversityKaifeng 475004China

Triboelectric nanogenerators(teng)have emerged as a highly promising energy harvesting technology,attracting significant attention in recent years for their broad ***-based tengs,with superior stretchability and sensitivity,have been widely reported as wearable ***,the traditional hydrogel-based tengs suffer from freezing at low temperatures and drying at high temperatures,resulting in *** this study,we introduce an anti-freezing eutectogel,which uses a deep eutectic solvent(DES),to improve the stability and electrical conductivity of tengs in harsh environmental *** eutectogel-based teng(E-teng)produces an open-circuit voltage of 776 V,a short-circuit current of 1.54μA,and a maximum peak power of 1.1 ***,the E-teng exhibits exceptional mechanical properties with an elongation at a break of 476%under ***,it maintains impressive performances across a wide temperature range from−18 to 60℃,with conductivities of 2.15 S/m at−10℃and 1.75 S/m at−18℃.Based on the excellent weight stability of the E-teng sensor,motion sensing can be achieved in the air,and even ***,the versatility of the E-teng can serve as a wearable sensor,by integrating it with Bluetooth *** self-powered E-teng can monitor various human motion signals in real-time and send the health signals directly to mobile *** research paves a new road for the applications of tengs in harsh environments,offering wireless flexible sensors with real-time health signal monitoring capabilities.

关键词： triboelectric nanogenerators self-powered harsh environment health monitoring Eutectogel