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Vapor-phase postsynthetic amination of hypercrosslinked polymers for efficient iodine capture 被引量:1
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作者 Pengcheng Su Shizheng Chen +3 位作者 Zhihong Yang Ningning Zhong Chenzi Jiang Wanbin Li 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第9期320-325,共6页
Hypercrosslinked polymers(HCPs)with large surface areas,high intrinsic porosities and low production costs may be available platforms for iodine capture.However,the lack of iodine-philicity binding sites limits their ... Hypercrosslinked polymers(HCPs)with large surface areas,high intrinsic porosities and low production costs may be available platforms for iodine capture.However,the lack of iodine-philicity binding sites limits their adsorption capacity.Here we use vapor-phase postsynthetic amination strategy to introduce electron-donating amino groups into the prefabricated HCPs for enhancing their iodine capture performance.Through simple vapor-phase exposure,the halogen-containing HCPs can be grafted by amines through nucleophilic substitution toward chloro groups.Combining with the abundant amino groups and high porosities,the amino-functionalized porous polymers show substantially increased iodine adsorption capacity,about 221%as that of original one,accompanied by excellent recyclability.Mechanism investigations reveal the key roles of the electron-donor amino groups andπ-conjugated benzene rings along with structure characteristics of porous polymer frameworks in iodine capture.Moreover,this vapor-phase amination strategy shows good generality and can be extended to various amines,e.g.,ethylenediamine,1,3-diaminopropane and diethylenetriamine.Our work proves that this simple vapor-phase postsynthetic functionalization strategy may be applied in other porous polymers with wide application prospects in adsorption,separation and storage. 展开更多
关键词 Porous polymers Postsynthetic amination Hypercrosslinked polymers vapor-phase grafting Iodine capture
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Synthesis of 4-Phenylphthalonitrile by Vapor-Phase Catalytic Ammoxidation of Intermediate 4-Phenyl-<i>o</i>-Tolunitrile: Reaction Kinetics 被引量:3
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作者 G. A. Bagirzade D. B. Tagiyev M. R. Manafov 《Modern Research in Catalysis》 2014年第1期6-11,共6页
Kinetic regularities of 4-phenyl-o-tolunitrile ammoxidation on V-Sb-Bi-Zr/γ-Al2O3 oxide catalyst in the temperature interval 633 - 673 K have been studied. It has been established that rates of conversion of 4-phenyl... Kinetic regularities of 4-phenyl-o-tolunitrile ammoxidation on V-Sb-Bi-Zr/γ-Al2O3 oxide catalyst in the temperature interval 633 - 673 K have been studied. It has been established that rates of conversion of 4-phenyl-o-tolu- nitrile into the aimed 4-phenylphthalonitrile and CO2 are described by half-order equation on concentration of substratum and to be independent of the oxygen and ammonia partial pressures. It has been revealed that formation of 4-phenylphthalimide from byproducts is due to hydrolysis of 4-phenylphthalonitrile;carbon dioxide is produced by oxidation of 4-phenyl-o-tolunitrile and decarboxylation of 4-phenylphthalimide, and 4-phenylben- zonitrile is produced from 4-phenyl-o-tolunitrile and 4-phenylphthalimide. 展开更多
关键词 CATALYTIC AMMOXIDATION Partial Pressures 4-Phenylphthalimide vapor-phase Electron-Donorship Kinetic Measurements
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Vapor-Phase Transport Synthesis of MnSAPO-34 and Its Catalytic Properties 被引量:1
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作者 Shao Hui Chen Xia +2 位作者 Wang Binbin Zhong Jing Yang Chao 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2012年第3期68-74,共7页
MnSAPO-34 molecular sieves were synthesized by vapor-phase transport (VPT) method using triethylamine (Et3N) as a structure directing agent (SDA), and were characterized by XRD, BET, SEM, UV-Vis, FT-IR, and TG a... MnSAPO-34 molecular sieves were synthesized by vapor-phase transport (VPT) method using triethylamine (Et3N) as a structure directing agent (SDA), and were characterized by XRD, BET, SEM, UV-Vis, FT-IR, and TG analy- ses. The influence of the zeolite crystallization conditions and the dry-gel composition were investigated. The results showed that the synthesis conditions had an effect on the crystalline phase. Pure MnSAPO-34 had been obtained when it was crystallized at 140 C for 18 hours. The ratio of MnO/A1203 in the starting gel ranging from 0.1 to 0.2 resulted in pure MnSAPO-34 with a CHA topology. Beyond this scope, MnSAPO-5 with an AFI topology structure was obtained as an impurity substance. UV-Vis spectroscopy and FT-IR spectroscopy study indicated that manganese was incorporated into the framework of the molecular sieve. The catalytic performance of MnSAPO-34 molecular sieve was tested by ketalization reaction of l, 2-propanediol with cyclohexanone. High yield of cyclohexanone-1, 2-propanediol ketal was obtained. 展开更多
关键词 MnSAPO-34 vapor-phase transport (VPT) KETALIZATION
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Expired drugs as vapor-phase corrosion inhibitors of copper in simulated marine atmospheric environment
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作者 WANG Xin-wei ZHANG Tian-long +4 位作者 LI Yan-tao YANG Li-hui XU Wei-chen DISNA Ratnasekera HAN Tao 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第10期3570-3582,共13页
Urea,paracetamol and glutamine(based on the expired drugs)were selected as vapor-phase corrosion inhibitors(VCIs)to study their corrosion protection effect on red copper in simulated marine atmospheric environment by ... Urea,paracetamol and glutamine(based on the expired drugs)were selected as vapor-phase corrosion inhibitors(VCIs)to study their corrosion protection effect on red copper in simulated marine atmospheric environment by using weight loss,electrochemical measurement techniques(specially designed electrochemical testing device for simulating marine atmospheric environments)and surface morphology characterization analysis(SEM/EDS,XRD,RAMAN,XPS).Weight loss results show that the three corrosion inhibitors have good corrosion inhibition effect on red copper,and the corrosion inhibition efficiency in the order of glutamine(83.62%)>urea(68.46%)>paracetamol(61.47%).Surface morphology characterization analysis provides evidence of adsorption of corrosion inhibitors molecules on the red copper surface,thus forming a protective film that blocked the red copper surface from the aggressive chloride ion attack. 展开更多
关键词 marine corrosion and protection vapor-phase corrosion inhibitor(VCI) COPPER expired drugs marine atmospheric environment
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Vapor-phase Nitration of Benzene to Nitrobenzene over Supported Sulfuric Acid Catalyst
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作者 Jing Lin CHEN Wei Guo CHENG +2 位作者 Hong Feng LIU Qing Song LIN Lian Hai LU 《Chinese Chemical Letters》 SCIE CAS CSCD 2002年第4期311-314,共4页
Vapor-phase nitration of benzene over solid acid catalyst is expected to be a clean process with no sulfuric acid waste. We investigated this process over solid acidic catalysts utilizing diluted nitric acid (60-70%)... Vapor-phase nitration of benzene over solid acid catalyst is expected to be a clean process with no sulfuric acid waste. We investigated this process over solid acidic catalysts utilizing diluted nitric acid (60-70%) as nitrating agent, and found that supported sulfuric acid catalyst exhibited a very high catalytic activity. Under the conditions of reaction temperature 160-170℃, space velocity (SV) 1200 h-1, the yield and the space-time yield (STY) of nitrobenzene (NB) based on HNO3 were more than 98% and 0.75 kg穔gcat-1穐-1 over 10% H2SO4/SiO2 (by weight) catalyst respectively. 展开更多
关键词 Nitration (vapor-phase) sulfuric acid (supported catalyst) NITROBENZENE
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Silicalite-1 zeolite nanosheets with rich H-bonded silanols for boosting vapor-phase Beckmann rearrangement:One-pot synthesis and theoretical investigation
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作者 Tianming Zai Wei Chen +10 位作者 Jiamin Yuan Ye Ma Qinming Wu Xianfeng Yi Zhiqiang Liu Xiangju Meng Weiliao Liu Na Sheng Han Wang Anmin Zheng Feng-Shou Xiao 《Chinese Journal of Catalysis》 CSCD 2024年第12期82-90,共9页
Design and preparation of highly efficient zeolite catalysts for gas-phase Beckmann rearrangement of cyclohexanone oxime to caprolactam are attractive but still challenging.Herein,we show a one-pot synthesis of silica... Design and preparation of highly efficient zeolite catalysts for gas-phase Beckmann rearrangement of cyclohexanone oxime to caprolactam are attractive but still challenging.Herein,we show a one-pot synthesis of silicalite-1 zeolite nanosheets with rich H-bonded silanols.The key to this success is the use of urea in the synthetic system.Catalytic tests of cyclohexanone oxime gas-phase Beckmann rearrangement show that the silicalite-1 zeolite nanosheets with H-bonded silanols exhibit higher selectivity for caprolactam and longer reaction lifetime than those of the conventional silicalite-1 zeolite.Theoretical simulations reveal that the ammonium decomposed by urea is a critical additive for the formation of H-bond silanols.Obviously,one-pot synthesis of silicalite-1 zeolite nanosheets with rich H-bonded silanols plus excellent catalytic performance in the Beckmann rearrangement offer a new opportunity for development of highly efficient zeolites for catalytic applications in the future. 展开更多
关键词 Silicalite-1 zeolite nanosheets Rich H-bonded silanols One-pot synthesis vapor-phase Beckmann rearrangement Theoretical investigation
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Preparation of nanometer δ- and β-bismuth trioxide by vacuum vapor-phase oxidation 被引量:3
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作者 胡汉祥 丘克强 徐国富 《中国有色金属学会会刊:英文版》 CSCD 2006年第1期173-177,共5页
A stable δ- and β-bismuth trioxide was prepared at room temperature by vacuum vapor-phase oxidation. The average crystal size of products was 14.6 nm (by XRD), the d(0.5) value was in the range from 62 nm to 69 nm, ... A stable δ- and β-bismuth trioxide was prepared at room temperature by vacuum vapor-phase oxidation. The average crystal size of products was 14.6 nm (by XRD), the d(0.5) value was in the range from 62 nm to 69 nm, and geometric standard deviation(GSD) was from 1.42 to 1.64. The results show that δ-Bi2O3 is formed when quenching rates is rapid and β-Bi2O3 is formed when it is slow. The size of grains increases with rising reaction temperature, flow rate of carrier gas, residual pressure of system and longer growing time of grains. 展开更多
关键词 三氧化铋 真空气相氧化 纳米粒子 XRD 生长周期
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Lanthanum-Promoted Nickel Catalyst for Vapor-Phase Methanol Carbonylation
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作者 LI Fengbo, ZOU Jin, YUAN Guoqing (Institute of Chemistry, The Chinese Academy of Sciences, Beijing 100080, China) 《催化学报》 SCIE CAS CSCD 北大核心 2003年第4期239-240,共2页
关键词 Ni-La催化剂 催化反应 镍镧催化剂 甲醇 气相碳基化反应
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Compositional engineering nanoparticles and microwave absorption tuning of C-coated high-entropy alloy nanoparticles via vapor-phase synthesis
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作者 Sibt ul Hassan Sana Zafar +4 位作者 Lizhen Hou Tauqeer Haidar Qamar Yang Yang Daitao Kuang Shiliang Wang 《Science China Materials》 2025年第6期2056-2070,共15页
The tunable dielectric and magnetic properties of high entropy alloy(HEA)nanoparticles have attracted considerable interest in realizing optimal impedance matching and microwave absorption performance.However,the comp... The tunable dielectric and magnetic properties of high entropy alloy(HEA)nanoparticles have attracted considerable interest in realizing optimal impedance matching and microwave absorption performance.However,the compositional engineering of HEA nanoparticles in regulating their dielectric-magnetic balance to achieve high-performance microwave absorption remains challenging.Herein,a vaporphase synthesis method is employed to prepare C-coated CoNiFeCuCr_(x)HEA nanoparticles with tunable Cr content.The prepared HEA nanoparticles,with a size of less than 10 nm,exhibited typical soft ferromagnetic characteristics.In conjunction with the additional contributions of interfacial polarization,graphitization of the C-shell,and tunable Cr content to the regulation of electromagnetic parameters,the C-coated CoNiFeCuCr_(0.5) nanoparticles exhibit a minimum reflection loss(RL_(min))of−63.9 dB and an effective absorption bandwidth(EAB)of 5.52 GHz,with an optimal thickness of 2.1 mm.Moreover,by employing a gradient three-layer architectural design,the EAB can be further extended to 12.22 GHz.Simultaneously,the simulated radar cross-section(RCS)results highlight its exceptional radar stealth performance,with RCS values remaining below−20 dBm^(2) across a wide angular range of−85°to 85°.This study offers valuable perspectives on designing high-performance HEA-based electromagnetic wave absorbing materials,achieving outstanding microwave absorption and radar stealth capabilities through careful compositional engineering. 展开更多
关键词 high entropy alloy nanoparticles vapor-phase synthesis microwave absorption interfacial polarization radar cross-section
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Vapor-phase hydrothermal growth of single crystalline NiS2 nanostructure film on carbon fiber cloth for electrocatalytic oxidation of alcohols to ketones and simultaneous H2 evolution 被引量:5
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《Nano Research》 SCIE EI CAS CSCD 2018年第2期1004-1017,共14页
Electrocatalytic synthesis of value-added chemicals is attracting significant research attention owing to its mild reaction conditions, environmental benignity, and potentially scalable application to organic syntheti... Electrocatalytic synthesis of value-added chemicals is attracting significant research attention owing to its mild reaction conditions, environmental benignity, and potentially scalable application to organic synthetic chemistry. Herein, we report the preparation of a single-crystalline NiS2 nanostructure film of N 50 nm thickness grown directly on a carbon fiber doth (NiSJCFC) by a facile vapor-phase hydrothermal (VPH) method. NiSJCFC as an electrocatalyst exhibits activity for both the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER) in alkaline media. Furthermore, a series of alcohols (2-propanol, 2-butanol, 2-pentanol, and cyclohexanol) were electrocatalytically converted to the corresponding ketones with high selectivity, efficienc and durability using the NiSJCFC electrode in alkaline media. In the presence of 0.45 M alcohol, a remarkably decreased overpotential (- 150 mV, vs. RHE) at the NiS2/CFC anode compared with that for water oxidation to generate O2, i.e., the OER, in alkaline media leads to significantly improved H2 generation. For instance, the H2 generation rate in the presence of 0.45 M 2-propanol is almost 1.2-times of that obtained for pure water splitting, but in a system that employs an applied voltage at least 280 mV lower than that required for water splitting to achieve the same current density (20 mA-crn-2). Thus, our results demonstrate the applicability of our bifunctional non-precious-metal electrocatalyst for organic synthesis and simultaneous H2 production. 展开更多
关键词 vapor-phase hydrothermal single-crystalline NiS2 film carbon fiber cloth electrocatalytic oxidationof alcohols to ketones H2 generation
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Vapor-phase growth of high-quality wafer-scale two-dimensional materials 被引量:9
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作者 Xin Tong Keli Liu +1 位作者 Mengqi Zeng Lei Fu 《InfoMat》 SCIE CAS 2019年第4期460-478,共19页
Emerging two-dimensional(2D)materials have stimulated tremendous scientific and industrial interests due to their diverse and tunable physical,chemical,and mechanical properties.The scalable production of high-quality... Emerging two-dimensional(2D)materials have stimulated tremendous scientific and industrial interests due to their diverse and tunable physical,chemical,and mechanical properties.The scalable production of high-quality wafer-scale 2D materials has become significantly essential to bring us closer to practical industrial applications,particularly in electronic devices.Vapor-phase growth provides attractive opportunities for the synthesis of large-area and high-quality 2D materials.In this review,we will emphasize vapor-phase growth strategies from three aspects,including suppressing nucleation,seamless stitching,and evolutionary selection growth.We discuss the general understanding of the related fundamental mechanism and specific parameter optimization from precursors and substrate design to the adjusting of growth parameters(temperature and pressure).Meanwhile,we present other strategies to produce various kinds of wafer-scale 2D materials.Finally,we conclude the current challenges and future directions in this developing field.This work may inspire researchers to better design routes in the synthesis of wafer-scale 2D materials with high quality. 展开更多
关键词 two-dimensional materials vapor-phase growth wafer scale
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Enhanced conductivity and stability of Prussian blue cathodes in sodium-ion batteries by surface vapor-phase molecular selfassembly 被引量:3
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作者 Tao Yuan Xiaopan Fu +4 位作者 Yuan Wang Mingjie Li Shuixin Xia Yuepeng Pang Shiyou Zheng 《Nano Research》 SCIE EI CSCD 2024年第5期4221-4230,共10页
With many merits such as facile synthesis,economy,and relatively high theoretical capacity,Prussian blue analogs(PBAs)are considered promising cathode materials for sodium-ion batteries(SIBs).However,their practical a... With many merits such as facile synthesis,economy,and relatively high theoretical capacity,Prussian blue analogs(PBAs)are considered promising cathode materials for sodium-ion batteries(SIBs).However,their practical applications still suffer from a low actual specific capacity and inferior stability owing to the imperfect crystallinity,irreversible phase transition,and low intrinsic conductivity.Herein,a surface-modification technique for vapor-phase molecular self-assembly was developed to prepare Fe-based PBAs,specifically sodium iron hexacyanoferrate(NaFeHCF),with a uniform conductive polymer protective layer of polypyrrole(PPy)on the surface,resulting in NaFeHCF@PPy.The incorporation of a PPy protective layer not only improves the electronic conductivity of NaFeHCF@PPy,but also effectively mitigates the dissolution of Fe-ions during cycling.Specifically,this advanced vapor-phase technique avoids Fe^(2+)oxidation and Na^(+)loss during liquid-phase surface modification.The NaFeHCF@PPy exhibited a remarkably enhanced cycling performance,with capacity retentions of 85.6%and 69.1%over 500 and 1000 cycles,respectively,at 200 mA/g,along with a superior rate performance up to 5 A/g(fast kinetics).Additionally,by adopting this strategy for Mn-based PBAs(NaMnHCF@PPy),we further demonstrated the universality of this method for PBA cathodes in SIBs. 展开更多
关键词 sodium-ion battery CATHODE Prussian blue analogs surface modification vapor-phase molecular self-assembly
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Rational construction of multiple hollow silicalite-1 zeolite with enhanced quasi acidity for robust vapor-phase Beckmann rearrangement 被引量:3
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作者 Peng Zhang Xianfeng Yi +9 位作者 Changjiu Xia Xinxin Peng Shuai Zhang Chengxiang Li Anmin Zheng Xiaoxin Zhang Yibin Luo Lifeng Cui Fuhong Yu Xingtian Shu 《Nano Research》 SCIE EI CSCD 2023年第5期7958-7966,共9页
Developing efficient and stable zeolites for vapor-phase Beckmann rearrangement of cyclohexanone oxime is still a great challenge to realizeε-caprolactam(CPL)green production.In this work,the hierarchical porous sili... Developing efficient and stable zeolites for vapor-phase Beckmann rearrangement of cyclohexanone oxime is still a great challenge to realizeε-caprolactam(CPL)green production.In this work,the hierarchical porous silicalite-1 zeolites with multiple hollow structure(S-1-M)are explored by in-situ desilication−recrystallization post-treatment of spongy highway-like zeolites(S-1-S),which are synthesized through silanization synthesis of conventional bulky silicalite-1(S-1).Compared to S-1,S-1-M achieves superior catalytic performance,with improving the CPL selectivity from 85.7%to 94.1%and prolonging the catalyst lifetime from 74 to 126 h at a weight hourly space velocity(WHSV)of 6 h^(−1).Comprehensive physiochemical studies demonstrate that the highly dispersed intracrystalline cavities within S-1-M endow greater mass diffusion and better quasi acidity inducing by the enhanced H-bonds among abundant H-bonded silanols,which is cooperatively responsible for its superior catalytic performance. 展开更多
关键词 hollow silicalite-1 H-bonded silanols quasi acidity vapor-phase Beckmann rearrangement
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丙酸丙酯与正戊醇二元体系在101.3 kPa压力下气液相平衡研究
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作者 王琳 王思茜 +1 位作者 张雪珂 李入林 《南阳师范学院学报》 2026年第1期42-46,共5页
使用气液相平衡测量装置和阿贝折光仪,采用折光率分析法对101.3 kPa下的丙酸丙酯-正戊醇二元体系气液相平衡关系进行研究,得到了其在101.3 kPa下的气液相平衡数据。采用Herington面积积分法对实验数据进行热力学一致性检验,在此基础上... 使用气液相平衡测量装置和阿贝折光仪,采用折光率分析法对101.3 kPa下的丙酸丙酯-正戊醇二元体系气液相平衡关系进行研究,得到了其在101.3 kPa下的气液相平衡数据。采用Herington面积积分法对实验数据进行热力学一致性检验,在此基础上绘制了该二元体系的t-x-y、x-y相图。采用Wilson活度系数模型对实验数据进行模拟,得到了二元作用参数。结果表明,Wilson模型对应的气相组成平均相对偏差为0.1632%,平衡温度t平均相对偏差为0.03251%,预测数据与实验数据吻合良好,该模型适合模拟常压下丙酸丙酯-正戊醇体系的分离工艺。 展开更多
关键词 丙酸丙酯 正戊醇 气液相平衡 WILSON方程
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Vapor Deposition Engineering for Thin-Film Microbatteries:From Nanoscale Ionics to Interface-Integrated Architectures
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作者 Mingming Zheng Xinrui Xu +5 位作者 Xiaofei Wang Haibin Lin Changmin Hou Mustafa Khan Jinlong Zhu Songbai Han 《Nano-Micro Letters》 2026年第5期445-487,共43页
The rapid proliferation of microelectronics,coupled with the advent of the internet ofthings(IoT)era,has created an urgent demand for miniaturized,integrable,and reliable on-chip energystorage systems.All-solid-state ... The rapid proliferation of microelectronics,coupled with the advent of the internet ofthings(IoT)era,has created an urgent demand for miniaturized,integrable,and reliable on-chip energystorage systems.All-solid-state thin-film microbatteries(TFMBs),distinguished by their intrinsicsafety,compact design,and compatibility with microfabrication techniques,have emerged as promisingcandidates to power next-generation IoT devices.Nevertheless,in contrast to the well-establisheddevelopment of conventional lithium-ion batteries,the advancement of TFMBs remains at an earlystage,facing persistent challenges in materials innovation,interface optimization,and scalable manufacturing.This review critically examines the pivotal role of vapor deposition technologies,includingmagnetron sputtering,pulsed laser deposition,thermal/electron-beam evaporation,chemical vapordeposition,and atomic layer deposition,in the fabrication and performance modulation of TFMBs.We systematically summarize recent progress in thin-film electrodes and solid-state electrolytes,withparticular emphasis on how deposition parameters dictate crystallinity,lattice orientation,and ionictransport in functional layers.Furthermore,we highlight strategies for solid-solid interface engineering,three-dimensional structural design,andmultifunctional integration to enhance capacity retention,cycling stability,and interfacial compatibility.Looking ahead,TFMBs are expectedto evolve toward multifunctional platforms,exhibiting mechanical flexibility,optical transparency,and hybrid energy-harvesting compatibility,thereby meeting the heterogeneous energy requirements of future IoT ecosystems.Overall,this review provides a comprehensive perspective onvapor-phase-enabled TFMB technologies,delivering both theoretical insights and technological guidelines for the scalable realization of highperformancemicroscale power sources. 展开更多
关键词 Thin-film microbatteries vapor-phase deposition techniques Nanoscale ionic conductivity Interfacial engineering Microdevice integration
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基于Ga-Ga_(2)O_(3)反应的OVPE法GaN生长研究
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作者 武文潇 于翔宇 +4 位作者 甘云海 李悦文 郑有炓 张荣 修向前 《人工晶体学报》 北大核心 2026年第2期217-222,共6页
高速率外延生长是制备大尺寸氮化镓(GaN)衬底的关键。本研究提出了一种简洁无额外副产物的氮化镓高速外延生长策略,即利用金属Ga与Ga_(2)O_(3)高温反应生成Ga_(2)O作为镓源的氧化物气相外延(OVPE)法,结合热力学计算和生长实验分析,验证... 高速率外延生长是制备大尺寸氮化镓(GaN)衬底的关键。本研究提出了一种简洁无额外副产物的氮化镓高速外延生长策略,即利用金属Ga与Ga_(2)O_(3)高温反应生成Ga_(2)O作为镓源的氧化物气相外延(OVPE)法,结合热力学计算和生长实验分析,验证了其可行性,为高速率生长GaN提供了新的技术路径和理论支撑。热力学计算分析确定了Ga-Ga_(2)O_(3)生成Ga_(2)O反应的吉布斯自由能与温度关系,该反应在1073~1273 K具有显著的自发性,且Ga_(2)O饱和蒸气压随温度升高呈指数增长,利于Ga_(2)O高效生成。基于Ga_(2)O完全转化假设建立了GaN生长速率模型,计算了不同温度下Ga-Ga_(2)O_(3)反应及生成GaN的理论生长速率,并进行了OVPE生长验证。结果显示,理论与实测生长速率在镓源温度依赖性趋势上高度一致,但理论值约为实验值的5倍,据此推算实际转化效率约为20%。通过拟合分析,推导出更高温度(1100~1300℃)下Ga_(2)O的生成速率和GaN的理论生长速率,结合实验结果,可以得出:在1 mol Ga_(2)O_(3)与4 mol GaN的标准反应配比下,镓源温度为1300℃时,2英寸(1英寸=2.54 cm)GaN衬底实际生长速率可达约1080μm/h,6英寸可达约120μm/h。 展开更多
关键词 氮化镓 氧化物气相外延法 Ga_(2)O 热力学计算 高生长速率
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气相热缩合法生产苯基三氯硅烷
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作者 黄乐 金知会 +4 位作者 胡家啟 黄亮兵 许更新 刘迎新 魏作君 《应用化工》 北大核心 2026年第1期109-112,共4页
综述了苯基三氯硅烷的多种合成方法,重点分析了氯苯与三氯氢硅的气相热缩合反应的研究进展与反应机理。通过对不同催化剂和反应条件的深入探讨,特别是自由基引发剂在反应中的作用,揭示了影响产率的关键因素。基于上述分析,提出了优化建... 综述了苯基三氯硅烷的多种合成方法,重点分析了氯苯与三氯氢硅的气相热缩合反应的研究进展与反应机理。通过对不同催化剂和反应条件的深入探讨,特别是自由基引发剂在反应中的作用,揭示了影响产率的关键因素。基于上述分析,提出了优化建议,包括开发新型高效催化剂和引发剂、优化工艺条件,以进一步提升苯基三氯硅烷的产率,减少副产物积碳的形成,并扩展其在高性能材料等领域的应用前景。 展开更多
关键词 三氯氢硅 氯苯 苯基三氯硅烷 气相热缩合法 有机硅
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气相CO_(2)腐蚀下纳米SiO_(2)形态对油井水泥性能的影响规律及机理
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作者 崔曦月 谭慧静 +4 位作者 魏继军 谢兰兰 王胜 陈瑶 郑云天 《油田化学》 北大核心 2026年第1期45-53,共9页
高温高压含水气相CO_(2)环境下,传统硅酸盐水泥易受酸性环境腐蚀,出现强度衰退、结构劣化现象。在水泥中掺入纳米SiO_(2),可降低水泥石的Ca/Si比值和渗透性,从而提高材料的抗高温、耐腐蚀性能。纳米二氧化硅颗粒(NS)和溶胶(SS)是最常见... 高温高压含水气相CO_(2)环境下,传统硅酸盐水泥易受酸性环境腐蚀,出现强度衰退、结构劣化现象。在水泥中掺入纳米SiO_(2),可降低水泥石的Ca/Si比值和渗透性,从而提高材料的抗高温、耐腐蚀性能。纳米二氧化硅颗粒(NS)和溶胶(SS)是最常见的纳米SiO_(2)类型,但两种材料在水泥浆中的应用效果各有利弊。本文基于高温高压气相CO_(2)腐蚀实验,开展抗压强度、XRD、FTIR和SEM等测试,以探究不同类型纳米SiO_(2)对高温及腐蚀后水泥石力学强度、腐蚀产物和水化产物种类及微观结构的影响规律。结果表明,150℃高温养护后,掺入1%、2%和3%NS后,水泥石的抗压强度依次增加了1.82%、9.1%和15%,而掺入1%、2%和3%SS后抗压强度分别降低了7.73%、4.09%和2.73%。相对于G级油井水泥,分别掺入3%NS和3%SS,高温养护后水化产物中C-S-H凝胶的Ca/Si比分别降低了33.23%和24.37%,Ca(OH)_(2)含量降低,其中掺入NS使得水化产物Ca(OH)_(2)(001)晶面的衍射峰强度降低明显,改善Ca(OH)_(2)的晶面取向;腐蚀后水泥石抗压强度的衰退率依次降低了10.35个百分点和10.98个百分点,腐蚀产物CaCO_(3)减少,水泥颗粒之间胶结作用更强,水泥石耐腐蚀性能提高。综合对比腐蚀前后水泥石的力学强度及微观结构测试结果,NS对水泥石耐高温及耐腐蚀性能的改善作用优于SS。 展开更多
关键词 高温高压 CO_(2) 气相腐蚀 纳米SiO_(2)
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内孔空化发生单元相变模型研究
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作者 王成军 韩桂华 +1 位作者 李大尉 朱宜鹏 《哈尔滨理工大学学报》 北大核心 2026年第1期103-110,共8页
为探究内孔空化发生单元相变模型,首先,建立空化发生单元几何模型,根据旋转空化器的空化机理,推导了空化发生单元底部压力数学模型。当底部压力低于饱和蒸汽压力时就会产生空化,从而得到相变模型及气相体积的数学表达式,可知气相体积与... 为探究内孔空化发生单元相变模型,首先,建立空化发生单元几何模型,根据旋转空化器的空化机理,推导了空化发生单元底部压力数学模型。当底部压力低于饱和蒸汽压力时就会产生空化,从而得到相变模型及气相体积的数学表达式,可知气相体积与空化发生单元孔径二次方成正比,与孔深和转速成正相关。为验证理论模型,借助数值模拟得到气相云图及气相体积值,得出孔径和孔深与气相体积的关系。最后,通过实验得出转速与空化性能表征参数电导率的关系。数值模拟和实验结果表明:相变模型中,空化发生单元孔径的二次方与气相体积成正比;孔深、转速与气相体积成正相关。 展开更多
关键词 内孔空化 空化发生单元 相变模型 气相体积 电导率
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三级自复叠制冷系统实验研究
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作者 曹嘉旭 芮胜军 +3 位作者 刘冬喜 冯廷康 周璐瑶 贺滔 《低温与超导》 北大核心 2026年第2期77-82,共6页
通过搭建三级自复叠制冷循环实验台,采用环境友好非共沸混合制冷工质R1234yf/R116/R14,实验分析了三级自复叠制冷系统开机后压缩机运行特性与节流降温特性。研究表明:在环境温度32℃,混合工质配比0.5/0.4/0.1条件下,系统开机后压缩机运... 通过搭建三级自复叠制冷循环实验台,采用环境友好非共沸混合制冷工质R1234yf/R116/R14,实验分析了三级自复叠制冷系统开机后压缩机运行特性与节流降温特性。研究表明:在环境温度32℃,混合工质配比0.5/0.4/0.1条件下,系统开机后压缩机运行状态良好,系统稳定时压缩机排气温度为100℃,排气压力为1.48 MPa,升压比7.79。系统节流降温速率较快,开机20 min后节流温度逐渐达到稳定。稳定时蒸发器进口温度最低为-78.04℃,与箱内温度保持5℃左右的温差。各级毛细管的节流温度分别为-17.85℃、-40.28℃、-78.04℃。 展开更多
关键词 自复叠制冷 非共沸 混合工质 气液相平衡
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