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瓶颈效应还是马太效应?——数字鸿沟指数演化的跨国比较分析

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科学与社会 2013年第3期3卷 106-120页

作者：张伦祝建华中国科学院大学人文学院新闻与科学传播系香港城市大学媒体与传播系

基于香港互联网使用调查、美国常驻人口调查、皮尤"互联网与美国生活"项目调研和国际电信联盟对各国互联网扩散率调查等相关数据,本研究经验性地描述了香港、美国以及全球范围内1996年至2008年互联网"数字鸿沟"指数的发展趋势。研究表明... 详细信息

基于香港互联网使用调查、美国常驻人口调查、皮尤"互联网与美国生活"项目调研和国际电信联盟对各国互联网扩散率调查等相关数据,本研究经验性地描述了香港、美国以及全球范围内1996年至2008年互联网"数字鸿沟"指数的发展趋势。研究表明,香港地区、美国与世界平均水平的互联网数字鸿沟发展趋势与该地区互联网扩散率呈倒U字型关系,即随着互联网扩散率的增长,"数字鸿沟"指数在该地区互联网扩散率的中值处达到峰值,并随后下降。

关键词：数字鸿沟社会平等创新扩散互联网采纳

Stabilizing zinc anode using zeolite imidazole framework functionalized separator for durable aqueous zinc-ion batteries

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journal of Energy Chemistry 2024年第3期90卷 23-31,I0003页

作者： Weisong Zhang Xinyan zhu Ling Kang Ziyu Peng jing zhu Liang Pan Lei Dai Shude Liu Ling Wang Yongguang Liu Zhangxing he School of Chemical Engineering North China University of Science and TechnologyTangshan 063009HebeiChina Shanghai Key Laboratory of Multidimensional Information Processing East China Normal UniversityShanghai 201620China College of Textiles Donghua UniversityShanghai 201620China

Aqueous zinc-ion batteries(AZIBs) hold great promise as a viable alternative to lithium-ion batteries owing to their high energy density and environmental ***,AZIBs are consistently plagued by the formation of zinc dendrites and concurrent side reactions,which significantly diminish their overall service life,In this study,the glass fiber separator(GF) is modified using zeolite imidazole salt framework-8(ZIF-8),enabling the development of efficient ***-8,which is abundant in nitrogen content,efficiently regulates the desolvation of [Zn(h_(2)O)_(6)]^(2+) to inhibit hydrogen ***,it possesses abundant nanochannels that facilitate the uniform deposition of Zn~(2+) via a localized action,thereby hindering the formation of *** insulating properties of ZIF-8 help prevent Zn^(2+) and water from trapping electron reduction at the layer surface,which reduces corrosion of the zinc ***,ZIF-8-GF achieves the even transport of Zn^(2+) and regulates the homogeneous deposition along the Zn(002) crystal surface,thus significantly enhancing the electrochemical performance of the AZIBs,In particular,the Zn|Zn symmetric cell with the ZIF-8-GF separator delivers a stable cycle life at0.5 mA cm^(-2) of 2300 *** Zn|ZIF-8-GF|MnO_(2) cell exhibits reduced voltage polarization while maintaining a capacity retention rate(93.4%) after 1200 cycles at 1.2 A g^(-1) The unique design of the modified diaphragm provides a new approach to realizing high-performance AZIBs.

关键词： Aqueous zinc-ion batteries Separators modifications ZIF-8 Zn deposition Dendrite-free

Process intensification for the synthesis and purification of battery-grade Li_(2)CO_(3)with microfluidics

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Particuology 2024年第7期90卷 106-117页

作者： haodu Li jie Zhang Lin Dai Le Du jiqin zhu The State Key Laboratory of Chemical Resource Engineering College of Chemical EngineeringBeijing University of Chemical TechnologyBeijing 100029China

Battery-grade lithium carbonate(Li_(2)CO_(3))with a purity of higher than 99.5 wt%is of great importance as a high value-added lithium ***,influences of different reaction systems and process control on product purity remain ***,a membrane dispersion microreactor was used to enhance the mass transfer of preparation and purification processes in homogeneous and heterogeneous *** systems of Na_(2)CO_(3)–LiCl,Nh_(4)hCO_(3)–LiCl,and Nh_(3)·h_(2)O−CO_(2)−LiCl,CO_(2)purification based on carbonation and decomposition were *** Li_(2)CO_(3)purity was increased by the improvement of mixing *** carbonation time was reduced by 62.5%and 58.3%for the Nh_(3)·h_(2)O−CO_(2)and CO_(2)purification systems,*** the two ammonia-based systems,Li_(2)CO_(3)particles with a purity of 99.7–99.8 wt%were one-step prepared with a size of 3–5μm,which also met the requirement of the battery-grade *** purity was further increased to 99.9 wt%by CO_(2)purification and LihCO_(3)*** investigation could provide a feasible alternative for the controllable preparation of battery-grade Li_(2)CO_(3)in one or multiple steps.

关键词： Microfluidics Battery grade Li_(2)CO_(3) Process intensification high purity

Improved Efficiency and Stability of Organic Solar Cells by Interface Modification Using Atomic Layer Deposition of Ultrathin Aluminum Oxide

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Energy & Environmental Materials 2024年第3期7卷 282-290页

作者： Ai Lan Yiqun Li huiwen zhu jintao zhu hong Lu hainam Do Yifan Lv Yonghua Chen Zhikuan Chen Fei Chen Wei huang School of Flexible Electronics(Future Technologies)and Key Laboratory of Flexible Electronics(KLOFE)and Institute of Advanced Materials(IAM) Jiangsu National Synergetic Innovation Center for Advanced Materials(SICAM)Nanjing Tech UniversityNanjing 210009China Department of Chemical and Environmental Engineering University of Nottingham Ningbo ChinaNingbo 315000China Key Laboratory of Flexible Electronics of Zhejiang Province Ningbo Institute of Northwestern Polytechnical UniversityNingbo 315103China Frontiers Science Center for Flexible Electronics Xi'an Institute of Flexible Electronics(IFE)and Xi'an Institute of Biomedical Materials&EngineeringNorthwestern Polytechnical UniversityXi'an 710072China

The interfacial contacts between the electron transporting layers(ETLs)and the photoactive layers are crucial to device performance and stability for OSCs with inverted ***,atomic layer deposition(ALD)fabricated ultrathin Al_(2)O_(3)layers are applied to modify the ETLs/active blends(PM6:BTP-BO-4F)interfaces of OSCs,thus improving device *** ALD-Al_(2)O_(3)thin layers on ZnO significantly improved its surface morphology,which led to the decreased work function of ZnO and reduced recombination losses in *** simultaneous increase in open-circuit voltage(V_(OC)),short-circuit current density(j_(SC))and fill factor(FF)were achieved for the OSCs incorporated with ALD-Al_(2)O_(3)interlayers of a certain thickness,which produced a maximum PCE of 16.61%.Moreover,the ALD-Al_(2)O_(3)interlayers had significantly enhanced device stability by suppressing degradation of the photoactive layers induced by the photocatalytic activity of ZnO and passivating surface defects of ZnO that may play the role of active sites for the adsorption of oxygen and moisture.

关键词： atomic layer deposition interface modification organic solar cells stability

Improvement of Film Cooling Design for Turbine Vane Leading Edge Considering Combustor Outflow

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journal of Thermal Science 2024年第1期33卷 311-327页

作者： WANG Xinyu LIU Cunliang FU Zhongyi LI Yang zhu huiren School of Power and Energy Northwestern Polytechnical UniversityXi'an 710072China AECC hunan Aviation Powerplant Research Institute Zhuzhou 412002China

As the interaction between the combustor and the turbine in the aero-engine continues to increase,the film cooling design considering the combustor swirling outflow has become the research *** swirling inflow and high-temperature gas first affect the vane leading edge(LE).however,no practical improved solution for the LE cooling design has been proposed considering the combustor swirling *** this paper,the improved scheme of showerhead cooling is carried out around the two ways of adopting the laid-back-fan-shaped hole and reducing the coolant outflow *** film cooling effectiveness(η) and the coolant flow state are obtained by PSP(pressure-sensitive-paint) and numerical simulation methods,*** research results show that the swirling inflow increases the film distribution inhomogeneity by imposing the radial pressure gradient on the vane to make the film excessively gather in some *** showerhead film cooling adopts the laid-back-fan-shaped hole to reduce the momentum when the coolant flows *** this cooling scheme improves the film attachment and increases the surface-averaged film cooling effectiveness(η_(sur)) by as much as15.4%,the film distribution inhomogeneity *** reducing the coolant outlet angle,the wall-tangential velocity of the coolant increases,and the wall-normal velocity *** the swirl intake condition,both ηand the film distribution uniformity are significantly increased,and the growth of η_(sur) is up to 16.5%.This paper investigates two improved schemes to improve the showerhead cooling under the swirl intake condition to provide a reference for the vane cooling design.

关键词： turbine vane showerhead cooling swirling inflow laid-back-fan-shaped hole film hole inclination

Revealing the anti-sintering phenomenon on silica-supported nickel catalysts during CO_(2)hydrogenation

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journal of Environmental Sciences 2024年第6期140卷 270-278页

作者： Liuqingqing Yang Tiancheng Pu Feixiang Tian Yulian he Minghui zhu State Key Laboratory of Chemical Engineering School of Chemical EngineeringEast China University of Science and TechnologyShanghai 200237China University of Michigan-Shanghai jiao Tong University joint Institute Shanghai Jiao Tong UniversityShanghai 200240China School of Chemistry and Chemical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

The CO_(2)catalytic hydrogenation represents a promising approach for gas-phase CO_(2)utilization in a direct *** to its excellent hydrogenation ability,nickel has been widely studied and has shown good activities in CO_(2)hydrogenation reactions,in addition to its high availability and low ***,Ni-based catalysts are prone to sintering under elevated temperatures,leading to unstable catalytic *** the present study,various characterization techniques were employed to study the structural evolution of Ni/SiO_(2)during CO_(2)*** anti-sintering phenomenon is observed for both 9%Ni/SiO_(2)and 1%Ni/SiO_(2)during CO_(2)hydrogenation at 400℃.Results revealed that Ni species were re-dispersed into smaller-sized nanoparticles and formed Ni^(0)active *** interestingly,this anti-sintering phenomenon leads to distinct outcomes for two catalysts,with a gradual increase in both reactivity and Ch_(4)selectivity for 9%Ni/SiO_(2)presumably due to the formation of abundant surface Ni°from redispersion,while an apparent decreasing trend of Ch_(4)selectivity for 1%Ni/SiO_(2)sample,presumably due to the formation of ultra-small nanoparticles that diffuse and partially filled the mesoporous pores of the silica support over ***,the redispersion phenomenon was found relevant to the h_(2)gas in the reaction environment and enhanced as the h_(2)concentration *** finding is believed to provide in-depth insights into the structural evolution of Ni-based catalysts and product selectivity control in CO_(2)hydrogenation reactions.

关键词： Carbon dioxide utilization CO_(2)hydrogenation Nickel-based catalysts Anti-sintering Structural evolution

Small-sized Ni-Co/Mo_(2)C/Co_(6)Mo_(6)C_(2)@C for efficient alkaline and acidic hydrogen evolution reaction by an anchoring calcination strategy

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Frontiers of Chemical Science and Engineering 2024年第5期18卷 95-103页

作者： jianxia Gu Ying zhu haiyan Zheng Chunyi Sun Zhongmin Su Department of Chemistry Xinzhou Normal UniversityXinzhou 034000China School of Chemistry Northeast Normal UniversityChangchun 130024China

A novel,cheap and highly efficient Ni-Co/Mo_(2)C/Co_(6)Mo_(6)C_(2)@C nanocomposite has been successfully constructed through simple one-step carbonization method in a nitrogen *** in the precursor can effectively anchor molybdenum-based Keggin-type polyoxometallate and NiCo-layered double hydroxide through electrostatic and coordination interactions,which avoids the aggregation of catalyst particles during the pyrolysis *** optimization,the obtained Ni-Co/Mo_(2)C/Co_(6)Mo_(6)C_(2)@C possesses small size(3-8 nm),large specific surface area and hierarchical pore *** importantly,Ni-Co/Mo_(2)C/Co_(6)Mo_(6)C_(2)@C presents remarkable hydrogen evolution reaction activity with low overpotentials in 0.5 mol·L^(-1)h_(2)SO_(4)(102.3 mV)and 1 mol·L^(-1)KOh(95 mV)to afford the current density of 10 mA·cm^(-2),as well as small Tafel slopes of 82.49 and 99.92 mV·dec^(-1),***,this catalyst also shows outstanding stability for 12 h without a significant change in current *** excellent catalytic performance of Ni-Co/Mo_(2)C/Co_(6)Mo_(6)C_(2)@C can put down to the synergistic effect between multiple components and the small size of the *** work provides unique insights into the preparation of efficient transition metal-based catalysts for hER.

关键词： polyoxometallates layered double hydroxide transition metal-based electrocatalysts hydrogen evolution reaction

Effects of content and particle size of Tih2 powders on the energy output rules of RDX composite explosives

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Defence Technology（防务技术） 2024年第2期32卷 297-308页

作者： hao Wang Yangfan Cheng Shoujun zhu Zihan Li Zhaowu Shen School of Chemical Engineering Anhui University of Science and TechnologyHuainan 232001China Anhui Engineering Laboratory of Explosive Materials and Technology Anhui University of Science and TechnologyHuainan 232001China School of Engineering Science University of Science and Technology of ChinaHefei 230027China

In order to improve the detonation characteristics of RDX,a RDX-based composite explosive with Tih_(2)powders was *** effects of content and particle size of Tih_(2)powders on thermal safety,shock wave parameters and thermal damage effects of RDX-based composite explosive were studied with the C80 microcalorimeter,air blast experiment system and colorimetric thermometry *** results showed that Tih_(2)powders could enhance the thermal stability of RDX-based composite explosive and increase its ultimate decomposition *** content and particle size of Tih_(2)powders also had significant effects on the thermal safety,detonation velocity,shock wave parameters,fireball temperature and duration of RDX-based composite ***,the differences of Tih_(2)and Ti powders on the detonation energy output rules of RDX-based composite explosives were also compared,showing that Tih_(2)powders had better influences on improving the explosion power and thermal damage effect of RDX-based composite explosives than Ti powders,for the participation of free h_(2)released by Tih_(2)powders in the detonation ***_(2)powders have important research values as a novel energetic additive in the field of military composite explosives.

关键词： RDX hydrogen storage alloy Air blast After-burn reaction Colorimetric thermometry

Deposition of thin TiO_(2)films on fluorophlogopite particle surface by CVD in fluidized bed reactor to prepare silver pearlescent pigments

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Particuology 2024年第6期89卷 88-98页

作者： Ming Liu Guoqiang Shao Pengpeng Lv jun Li Qingshan zhu State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China

Two critical parameters:Glossiness and chromaticity space of pearlescent pigments were evaluated based on crystallinity and grain *** the roughness and the vertical distance evolution along the surface of deposited TiO_(2)film are affected by the *** optimal crystallinity of TiO_(2)was deposited at the temperature of 350℃.The TiCl4 concentration effectively changed the grain ***,the high flow rate of fluidizing gas and optimal gas–solid ratio(h))restricted the change of TiCl_(4)concentrations in fluidized bed *** this case,the grain size of the deposited TiO_(2)film was about 55 *** on the grain size,the color of pearlescent pigments was adjusted by controlling the film thickness based on TiO_(2)***,the silver pearlescent pigment with high glossiness was prepared by chemical vapor deposition method in a fluidized bed reactor.

关键词： Fluidized bed chemical vapor deposition TiO_(2)film deposition Pearlescent pigment Free powder restrain Crystal growth