期刊文献+
共找到421篇文章
< 1 2 22 >
每页显示 20 50 100
Hydration Characteristics and Mechanical Properties of Cement-Based Materials Modified by Calcined Zeolite and Montmorillonite
1
作者 Lingling Qin Mengya Zhou +5 位作者 Jiahao Yan Ping Duan Yingcan Zhu Wei Chen Zuhua Zhang Aiguo Wang 《Journal of Renewable Materials》 SCIE EI 2023年第5期2191-2207,共17页
Montmorillonite and clinoptilolite zeolite were used as representative materials to prepare calcined clay-cement binary cementitious materials in order to study the effect of calcination treatment on the activation of... Montmorillonite and clinoptilolite zeolite were used as representative materials to prepare calcined clay-cement binary cementitious materials in order to study the effect of calcination treatment on the activation of clay minerals and the activity difference between layered and framed clays in this research.The influence of different calcined clay content(2%,4%,6%,8%,10%)on the fluidity,compressive strength,microstructure,phase change,and hydration heat of cement-based materials were analyzed.The calcined clay improves the fluidity of cement-based materials as compared with the uncalcined group.The addition of calcined montmorillonite(CMT)improves the development of mechanical strength,and the optimal compressive strength reaches 85 MPa at 28 days with 8%CMT.However,the activity of calcined clinoptilolite zeolite(CZL)is weak with few reaction sites,which slightly reduced the mechanical strength as compared to the blank sample.The addition of CMT changes the microscopic morphology of hydration products such as C-S-H and C-A-H,leading to the formation and transformation of ettringite in the early stage.It promotes the gradual polymerization of Si-O bonds into Si-O-Si bonds simultaneously,which accelerates the early hydration process.However,CZL acts mainly as a filling function in the cementitious system.In brief,CMT as an admixture can improve the mechanical properties of cement,but CZL has little effect.This work provides a guideline for the applications of calcined clay in cement,considering the influence of clay type on workability and mechanical strength. 展开更多
关键词 Calcined clay cement MONTMORILLONITE clinoptilolite zeolite mechanical strength HYDRATION
下载PDF
Effect of Sc on Al_(3)Fe phase and mechanical properties of as-cast AA5052 aluminum alloy
2
作者 Yang Li Qing Yu +3 位作者 Feng-feng Chen Jia-wen He Hong-mei Yang Meng-nie Li 《China Foundry》 SCIE EI CAS CSCD 2024年第3期257-264,共8页
The AA5052 aluminum alloy is widely used in automobile and aerospace manufacturing,and with the development of light-weight alloys,it is required that these materials exhibit better mechanical properties.Previous stud... The AA5052 aluminum alloy is widely used in automobile and aerospace manufacturing,and with the development of light-weight alloys,it is required that these materials exhibit better mechanical properties.Previous studies have demonstrated that the addition of Sc to aluminum alloys can improve both the microstructure and properties of the alloys.In this study,the effect of Sc on the Fe-rich phase and properties of the AA5052 aluminum alloy was studied by adding 0%,0.05%,0.2%,and 0.3%Sc.The results show that with the increase of Sc,the coarse needle-like Fe-rich phase gradually transforms into Chinese-script and then nearly spherical particles,reduce the size of Fe-rich phase,and refine the grain with increase of high angle grain boundaries(HAGBs).These microstructure changes enhance the strength of the AA5052 alloy through Sc addition.The ductility of the alloy is obviously improved because the addition of a lower amount of Sc changes the morphology of Fe-rich phase from needle-like into a Chinese-script,and it is subsequently reduced as a result of significant increase in HAGBs with increasing Sc content. 展开更多
关键词 AA5052 aluminum alloy Al3Fe phase mechanical properties grain boundary
下载PDF
Microstructure and properties of LZQT600-3 HCCDIBs for plunger pump cylinder
3
作者 Chun-jie Xu Yuan-ying Jin +8 位作者 Dong Ma Zhen Zhao Jia-wei Qi Shang Sui Xiang-quan Wu Can Guo Zhong-ming Zhang Yong-hui Liu Dan Shechtman 《China Foundry》 SCIE EI CAS CSCD 2024年第2期197-204,共8页
It is important to improve the comprehensive performance of the ductile iron bars(DIBs)for the cylinder block of the extra high pressure hydraulic plunger pump and accelerate the industrial application.In this work,th... It is important to improve the comprehensive performance of the ductile iron bars(DIBs)for the cylinder block of the extra high pressure hydraulic plunger pump and accelerate the industrial application.In this work,the LZQT600-3 DIBs with the diameter of 145 mm were prepared by the horizontal continuous casting(HCC)process,that is,LZQT600-3 HCCDIBs.The microstructure and room temperature tensile properties of different sections[left-edge(surface layer),left-1/2R(left half of the radius),and the center of the HCCDIBs]were studied.The results show that the spheroidization of LZQT600-3 HCCDIBs matrix from the left-edge,left-1/2R to the center is at nodulizing grade II and above.As the cooling rate gradually decreases from surface to the center of the HCCIBs,the number of spheroidized graphite is gradually reduced,the size is gradually increased,the shape factor is decreased,and the pearlite content and lamellate spacing are increased.Along the horizontal direction of the section,the hardness of the material is distributed symmetrically around the center of the HCCDIBs.In the vertical direction,the hardness distribution in the center of the HCCDIBs is asymmetrical due to the gravity during the solidification process.Therefore,the microstructure in the lower part of the section solidifies relatively quickly.The left-edge has the best tensile mechanical properties,and the ultimate tensile strength,yield tensile strength and elongation are 597.3 MPa,418.5 MPa and 9.6%,respectively.The tensile fracture belongs to the ductile-brittle hybrid fracture.The comprehensive performances of LZQT600-3 HCCDIBs meet the actual application requirements of ultra-high pressure hydraulic plunger pump cylinder. 展开更多
关键词 horizontal continuous casting(HCC) nodular cast iron ductile iron bars microstructure mechanical properties
下载PDF
Low-temperature replacement construction of three-dimensional corrosion-resistant interface for deeply rechargeable Zn metal batteries
4
作者 Jinze Li Daniel Rohrens +8 位作者 Gianluca Dalfollo Xiaochao Wu Ziheng Lu Qiang Gao Bo Han Ruimin Sun Chenggang Zhou Jindi Wang Zhao Cai 《Nano Materials Science》 EI CAS CSCD 2024年第3期329-336,共8页
Aqueous Zn batteries are promising candidates for grid-scale renewable energy storage.Foil electrodes have been widely investigated and applied as anode materials for aqueous Zn batteries,however,they suffer from limi... Aqueous Zn batteries are promising candidates for grid-scale renewable energy storage.Foil electrodes have been widely investigated and applied as anode materials for aqueous Zn batteries,however,they suffer from limited surface area and severe interfacial issues including metallic dendrites and corrosion side reactions,limiting the depth of discharge(DOD)of the foil electrode materials.Herein,a low-temperature replacement reaction is utilized to in-situ construct a three-dimensional(3D)corrosion-resistant interface for deeply rechargeable Zn foil electrodes.Specifically,the deliberate low-temperature environment controlled the replacement rate between polycrystalline Zn metal and oxalic acid,producing a Zn foil electrode with distinct 3D corrosion-resistant interface(3DCI-Zn),which differed from conventional two-dimensional(2D)protective structure and showed an order of magnitude higher surface area.Consequently,the 3DCI-Zn electrode exhibited dendrite-free and anticorrosion properties,and achieved stable plating/stripping performance for 1000 h at 10 mA cm^(-2)and 10 mAh cm^(-2)with a remarkable DOD of 79%.After pairing with a MnO2cathode with a high areal capacity of 4.2 mAh cm^(-2),the pouch cells delivered 168 Wh L^(-1)and a capacity retention of 89.7%after 100 cycles with a low negative/positive(N/P)ratio of 3:1. 展开更多
关键词 Aqueous batteries Foil electrodes Depth of discharge DENDRITES Corrosion side reactions
下载PDF
High-performance magnesium/sodium hybrid ion battery based on sodium vanadate oxide for reversible storage of Na^(+)and Mg^(2+)
5
作者 Xiaoke Wang Titi Li +5 位作者 Xixi Zhang Yaxin Wang Hongfei Li Hai-Feng Li Gang Zhao Cuiping Han 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第9期79-88,共10页
Magnesium ion batteries(MIBs)are a potential field for the energy storage of the future but are restricted by insufficient rate capability and rapid capacity degradation.Magnesium-sodium hybrid ion batteries(MSHBs)are... Magnesium ion batteries(MIBs)are a potential field for the energy storage of the future but are restricted by insufficient rate capability and rapid capacity degradation.Magnesium-sodium hybrid ion batteries(MSHBs)are an effective way to address these problems.Here,we report a new type of MSHBs that use layered sodium vanadate((Na,Mn)V_(8)O_(20)·5H_(2)O,Mn-NVO)cathodes coupled with an organic 3,4,9,10-perylenetetracarboxylic diimide(PTCDI)anode in Mg^(2+)/Na^(+)hybrid electrolytes.During electrochemical cycling,Mg^(2+)and Na^(+)co-participate in the cathode reactions,and the introduction of Na^(+)promotes the structural stability of the Mn-NVO cathode,as cleared by several ex-situ characterizations.Consequently,the Mn-NVO cathode presents great specific capacity(249.9 mA h g^(−1)at 300 mA g^(−1))and cycling(1500 cycles at 1500 mA g^(−1))in the Mg^(2+)/Na^(+)hybrid electrolytes.Besides,full battery displays long lifespan with 10,000 cycles at 1000 mA g^(−1).The rate performance and cycling stability of MSHBs have been improved by an economical and scalable method,and the mechanism for these improvements is discussed. 展开更多
关键词 Aqueous battery Hybrid ion battery Mg^(2+)/Na^(+)co-intercalation High-rate performance Organic-water hybrid electrolyte
下载PDF
Coaxial Wet Spinning of Boron Nitride Nanosheet‑Based Composite Fibers with Enhanced Thermal Conductivity and Mechanical Strength
6
作者 Wenjiang Lu Qixuan Deng +3 位作者 Minsu Liu Baofu Ding Zhiyuan Xiong Ling Qiu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第2期126-138,共13页
Hexagonal boron nitride nanosheets(BNNSs)exhibit remarkable thermal and dielectric properties.However,their self-assembly and alignment in macroscopic forms remain challenging due to the chemical inertness of boron ni... Hexagonal boron nitride nanosheets(BNNSs)exhibit remarkable thermal and dielectric properties.However,their self-assembly and alignment in macroscopic forms remain challenging due to the chemical inertness of boron nitride,thereby limiting their performance in applications such as thermal management.In this study,we present a coaxial wet spinning approach for the fabrication of BNNSs/polymer composite fibers with high nanosheet orientation.The composite fibers were prepared using a superacid-based solvent system and showed a layered structure comprising an aramid core and an aramid/BNNSs sheath.Notably,the coaxial fibers exhibited significantly higher BNNSs alignment compared to uniaxial aramid/BNNSs fibers,primarily due to the additional compressive forces exerted at the core-sheath interface during the hot drawing process.With a BNNSs loading of 60 wt%,the resulting coaxial fibers showed exceptional properties,including an ultrahigh Herman orientation parameter of 0.81,thermal conductivity of 17.2 W m^(-1)K^(-1),and tensile strength of 192.5 MPa.These results surpassed those of uniaxial fibers and previously reported BNNSs composite fibers,making them highly suitable for applications such as wearable thermal management textiles.Our findings present a promising strategy for fabricating high-performance composite fibers based on BNNSs. 展开更多
关键词 Boron nitride nanosheets Coaxial fiber Interfacial compression Nanosheet aligning Wearable thermal management
下载PDF
Upcycling of phosphogypsum waste for efficient zinc-ion batteries 被引量:2
7
作者 Huanwen Wang Can Luo +9 位作者 Yinyin Qian Caihong Yang Xiaojun Shi Yansheng Gong Rui Wang Beibei He Jun Jin Aidong Tang Edison Huixiang Ang Huaming Yang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第6期157-166,I0006,共11页
Zinc metal is a promising anode material for next-generation aqueous batteries,but its practical application is limited by the formation of zinc dendrite.To prevent zinc dendrite growth,various Zn^(2+)-conducting but ... Zinc metal is a promising anode material for next-generation aqueous batteries,but its practical application is limited by the formation of zinc dendrite.To prevent zinc dendrite growth,various Zn^(2+)-conducting but water-isolating solid-electrolyte interphase(SEI)films have been developed,however,the required high-purity chemical materials are extremely expensive.In this work,phosphogypsum(PG),an industrial byproduct produced from the phosphoric acid industry,is employed as a multifunctional protective layer to navigate uniform zinc deposition.Theoretical and experimental results demonstrate that PG-derived CaSO_(4)2H_(2)O can act as an artificial SEI layer to provide fast channels for Zn^(2+)transport.Moreover,CaSO_(4)2H_(2)O could release calcium ions(Ca^(2+))due to its relatively high Kspvalue,which have a higher binding energy than that of Zn^(2+)on the Zn surface,thus preferentially adsorbing to the tips of the protuberances to force zinc ions to nucleate at inert region.As a result,the Zn@PG anode achieves a high Coulombic efficiency of 99.5%during 500 cycles and long-time stability over 1000 hours at 1 m A cm^(-2).Our findings will not only construct a low-cost artificial SEI film for practical metal batteries,but also achieve a high-value utilization of phosphogypsum waste. 展开更多
关键词 Upcycling Phosphogypsum waste Zinc-ion battery Solid-electrolyte-interface Protection layer
下载PDF
Construction of all-organic low dielectric polyimide hybrids via synergistic effect between covalent organic framework and cross-linking structure 被引量:2
8
作者 Wanjing Zhao Zhaoyang Wei +6 位作者 Chonghao Lu Yizhang Tong Jingshu Huang Xianwu Cao Dean Shi Robert KYLi Wei Wu 《Nano Materials Science》 EI CAS CSCD 2023年第4期429-438,共10页
Polyimide(PI)is a promising electronic packaging material,but it remains challenging to obtain an all-organic PI hybrid film with decreased dielectric constant and loss without modifying the monomer.Herein,a series of... Polyimide(PI)is a promising electronic packaging material,but it remains challenging to obtain an all-organic PI hybrid film with decreased dielectric constant and loss without modifying the monomer.Herein,a series of allorganic PI hybrid films were successfully prepared by introducing the covalent organic framework(COF),which could induce the formation of the cross-linking structure in the PI matrix.Due to the synergistic effects of the COF fillers and the cross-linking structure,the PI/COF hybrid film containing 2 wt%COF exhibited the lowest dielectric constant of 2.72 and the lowest dielectric loss(tanδ)of 0.0077 at 1 MHz.It is attributed to the intrinsic low dielectric constant of COF and a large number of mesopores within the PI.Besides,the cross-linking network of PI prevents the molecular chains from stacking and improves the fraction of free volume(FFV).The molecular dynamics simulation results are well consistent with the dielectric properties data.Furthermore,the PI/COF hybrid film with 5 wt%COF showed a significant enhancement in breakdown strength,which increased to 412.8 kV/mm as compared with pure PI.In addition,the PI/COF hybrid film achieve to reduce the dielectric constant and thermal expansion coefficient(CTE).It also exhibited excellent thermal,hydrophobicity,and mechanical performance.The all-organic PI/COF hybrid films have great commercial potential as next-generation electronic packaging materials. 展开更多
关键词 POLYIMIDE Covalent organic framework All-organic Cross-linking structure Dielectric property Hybrid film
下载PDF
A Comparative Investigation of Single Crystal and Polycrystalline Ni-Rich NCMs as Cathodes for Lithium-Ion Batteries 被引量:1
9
作者 Xianming Deng Rui Zhang +6 位作者 Kai Zhou Ziyao Gao Wei He Lihan Zhang Cuiping Han Feiyu Kang Baohua Li 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2023年第3期1-7,共7页
Nickel-rich LiNi_(1-x-y)Co_(x)Mn_(y)O_(2)(NCM,1-x-y≥0.6)is known as a promising cathode material for lithium-ion batteries since its superiority of high voltage and large capacity.However,polycrystalline Ni-rich NCMs... Nickel-rich LiNi_(1-x-y)Co_(x)Mn_(y)O_(2)(NCM,1-x-y≥0.6)is known as a promising cathode material for lithium-ion batteries since its superiority of high voltage and large capacity.However,polycrystalline Ni-rich NCMs suffer from poor cycle stability,limiting its further application.Herein,single crystal and polycrystalline LiNi_(0.84)Co_(0.07)Mn_(0.09)O_(2)cathode materials are compared to figure out the relation of the morphology and the electrochemical storage performance.According to the Li^(+)diffusion coefficient,the lower capacity of single crystal samples is mainly ascribed to the limited Li+diffusion in the large bulk.In situ XRD illustrates that the polycrystalline and single crystal NCMs show a virtually identical manner and magnitude in lattice contraction and expansion during cycling.Also,the electrochemically active surface area(ECSA)measurement is employed in lithium-ion battery study for the first time,and these two cathodes show huge discrepancy in the ECSA after the initial cycle.These results suggest that the single crystal sample exhibits reduced cracking,surface side reaction,and Ni/Li mixing but suffers the lower Li^(+)diffusion kinetics.This work offers a view of how the morphology of Ni-rich NCM effects the electrochemical performance,which is instructive for developing a promising strategy to achieve good rate performance and excellent cycling stability. 展开更多
关键词 cathodes electrochemically active surface area Li^(+)diffusion coefficient lithium-ion batteries single crystal
下载PDF
Influences of Multi-Component Supplementary Cementitious Materials on the Performance of Metakaolin Based Geopolymer
10
作者 Wu Jing Ren Luo +1 位作者 Sha Ding Ping Duan 《Journal of Renewable Materials》 SCIE EI 2022年第7期1813-1828,共16页
In this study,the workability and reaction mechanism of metakaolin(MK)based geopolymer blended with rice husk ash(RHA)and silica fume(SF)was investigated.The prepared samples were subjected to tests including compress... In this study,the workability and reaction mechanism of metakaolin(MK)based geopolymer blended with rice husk ash(RHA)and silica fume(SF)was investigated.The prepared samples were subjected to tests including compressive strength and fluidity tests.X-ray diffraction(XRD)and Scanning electron microscope(SEM)were employed to explore the phase composition and microstructure of geopolymers.The molecular bonding information of geopolymer was provided by Fourier transform infrared spectroscopy(FTIR).Meanwhile,the porosity of geopolymer was obtained by Mercury intrusion porosimeter(MIP)analysis.The high-activity RHA obtained after calcination at 600℃ was used as a supplementary cementitious material to prepare geopolymer.The properties of preventing morphology cracking and compressive strength are improved.The addition of RHA and SF changes the working performance of MK based geopolymer and provided a theoretical basis for future practical applications.Meanwhile,the high chemical activity of SF and RHA contributes to the healing of microcracks. 展开更多
关键词 Rice husk ash silica fume METAKAOLIN GEOPOLYMER
下载PDF
Structural stability and ion migration of Li_(2)MnO_(3) cathode material under high pressures
11
作者 谢泽仁 周思思 +5 位作者 贺贝贝 王欢文 公衍生 金俊 张祥功 汪锐 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第12期449-453,共5页
Some special fields,such as deep-sea exploration,require batteries and their electrode materials to withstand extremely high pressure.As the cathode material has the highest energy density,Li-excess Mn-based materials... Some special fields,such as deep-sea exploration,require batteries and their electrode materials to withstand extremely high pressure.As the cathode material has the highest energy density,Li-excess Mn-based materials are also likely to be utilized in such an environment.However,the effect of pressure on the crystal structure and migration barrier of this kind of material is still not clear at present.Therefore,in this study,we investigate the properties of the matrix material of Li-excess Mn-based material,Li_(2)MnO_(3),under high pressure.The equation of state,bulk modulus,and steady-state volume of Li_(2)MnO_(3) are predicted by the method of first principles calculation.The calculations of unit cells at different pressures reveal that the cell parameters suffer anisotropic compression under high pressure.During compression,Li-O bond is more easily compressed than Mn-O bond.The results from the climbing image nudged elastic band(CINEB)method show that the energy barrier of Li^(+)migration in the lithium layer increases with pressure increasing.Our study can provide useful information for utilizing Li-excess Mn-based materials under high pressure. 展开更多
关键词 lithium-ion battery Li_(2)MnO_(3) high pressure DFT computation
下载PDF
New carbon-nitrogen-oxygen compounds as high energy density materials
12
作者 沈俊宇 段青卓 +4 位作者 苗俊一 何适 何开华 戴伟 卢成 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第9期381-385,共5页
Molecular crystals are complex systems exhibiting various crystal structures,and accurately modeling the crystal structures is essential for understanding their physical behaviors under high pressure.Here,we perform a... Molecular crystals are complex systems exhibiting various crystal structures,and accurately modeling the crystal structures is essential for understanding their physical behaviors under high pressure.Here,we perform an extensive structure search of ternary carbon-nitrogen-oxygen(CNO)compound under high pressure with the CALYPSO method and first principles calculations,and successfully identify three polymeric CNO compounds with Pbam,C2/m and I4m2symmetries under 100 GPa.More interestingly,these structures are also dynamically stable at ambient pressure,and are potential high energy density materials(HEDMs).The energy densities of Pbam,C2/m and I4m2 phases of CNO are about2.30 kJ/g,1.37 kJ/g and 2.70 kJ/g,respectively,with the decompositions of graphitic carbon and molecular carbon dioxide andα-N(molecular N_(2))at ambient pressure.The present results provide in-depth insights into the structural evolution and physical properties of CNO compounds under high pressures,which offer crucial insights for designs and syntheses of novel HEDMs. 展开更多
关键词 molecular crystals high pressure structure searches first principles calculations high energy density materials
下载PDF
Self-adaptive bulk/surface engineering of Bi_(x)O_(y)Br_(z) towards enhanced photocatalysis:Current status and future challenges
13
作者 Zhiwei Wu Bidyut Kumar Kundu +5 位作者 Wanqiong Kang Lei Mao Sen Zhang Lan Yuan Fen Guo Chuang Han 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第7期387-413,I0009,共28页
The bulk/surface states of semiconductor photocatalysts are imperative parameters to maneuver their performance by significantly affecting the key processes of photocatalysis including light absorption,separation of c... The bulk/surface states of semiconductor photocatalysts are imperative parameters to maneuver their performance by significantly affecting the key processes of photocatalysis including light absorption,separation of charge carrier,and surface site reaction.Recent years have witnessed the encouraging progress of self-adaptive bulk/surface engineered Bi_(x)O_(y)Br_(z) for photocatalytic applications spanning various fields.However,despite the maturity of current research,the interaction between the bulk/surface state and the performance of Bi_(x)O_(y)Br_(z) has not yet been fully understood and highlighted.In this regard,a timely tutorial overview is quite urgent to summarize the most recent key progress and outline developing obstacles in this exciting area.Herein,the structural characteristics and fundamental principles of Bi_(x)O_(y)Br_(z)for driving photocatalytic reaction as well as related key issues are firstly reviewed.Then,we for the first time summarized different self-adaptive engineering processes over Bi_(x)O_(y)Br_(z)followed by a classification of the generation approaches towards diverse Bi_(x)O_(y)Br_(z)materials.The features of different strategies,the up-to-date characterization techniques to detect bulk/surface states,and the effect of bulk/surface states on improving the photoactivity of Bi_(x)O_(y)Br_(z)in expanded applications are further discussed.Finally,the present research status,challenges,and future research opportunities of self-adaptive bulk/surface engineered Bi_(x)O_(y)Br_(z)are prospected.It is anticipated that this critical review can trigger deeper investigations and attract upcoming innovative ideas on the rational design of Bi_(x)O_(y)Br_(z)-based photocatalysts. 展开更多
关键词 Bismuth oxybromide Self-adaptive engineering Pollutant degradation Energy application PHOTOCATALYSIS
下载PDF
In Situ Formation of LiF-Rich Carbon Interphase on Silicon Particles for Cycle-Stable Battery Anodes
14
作者 Yang Ni Shuibin Tu +3 位作者 Renmin Zhan Zhao Cai Xiaohong Wang Yongming Sun 《Transactions of Tianjin University》 EI CAS 2023年第2期101-109,共9页
Silicon(Si)is a potential high-capacity anode material for the next-generation lithium-ion battery with high energy density.However,Si anodes suff er from severe interfacial chemistry issues,such as side reactions at ... Silicon(Si)is a potential high-capacity anode material for the next-generation lithium-ion battery with high energy density.However,Si anodes suff er from severe interfacial chemistry issues,such as side reactions at the electrode/electrolyte interface,leading to poor electrochemical cycling stability.Herein,we demonstrate the fabrication of a conformal fl uorine-containing carbon(FC)layer on Si particles(Si-FC)and its in situ electrochemical conversion into a LiF-rich carbon layer above 1.5 V(vs.Li^(+)/Li).The as-formed LiF-rich carbon layer not only isolates the active Si and electrolytes,leading to the suppression of side reactions,but also induces the formation of a robust solid-electrolyte interface(SEI),leading to the stable interfacial chemistry of as-designed Si-FC particles.The Si-FC electrode has a high initial Coulombic effi ciency(CE)of 84.8%and a high reversible capacity of 1450 mAh/g at 0.4 C(1000 mA/g)for 300 cycles.In addition,a hybrid electrode consisting of 85 wt%graphite and 15 wt%Si-FC,and mass 2.3 mg/cm^(2) loading delivers a high areal capacity of 2.0 mAh/cm^(2) and a high-capacity retention of 93.2%after 100 cycles,showing the prospects for practical use. 展开更多
关键词 Lithium-ion batteries Silicon anode LiF-rich carbon interphase Capacity Cycling stability
下载PDF
Detection of a Quasiperiodic Phenomenon of a Binary Star System Using Convolutional Neural Network
15
作者 Denis Benka Sabína Vasová +1 位作者 Michal Kebísek Maximilián Strémy 《Intelligent Automation & Soft Computing》 SCIE 2023年第9期2519-2535,共17页
Pattern recognition algorithms are commonly utilized to discover certain patterns,particularly in image-based data.Our study focuses on quasiperiodic oscillations(QPO)in celestial objects referred to as cataclysmic va... Pattern recognition algorithms are commonly utilized to discover certain patterns,particularly in image-based data.Our study focuses on quasiperiodic oscillations(QPO)in celestial objects referred to as cataclysmic variables(CV).We are dealing with interestingly indistinct QPO signals,which we analyze using a power density spectrum(PDS).The confidence in detecting the latter using certain statistical approaches may come out with less significance than the truth.We work with real and simulated QPO data of a CV called MV Lyrae.Our primary statistical tool for determining confidence levels is sigma intervals.The aforementioned CV has scientifically proven QPO existence,but as indicated by our analysis,the QPO ended up falling below 1-σ,and such QPOs are not noteworthy based on the former approach.We intend to propose and ultimately train a convolutional neural network(CNN)using two types of QPO data with varying amounts of training dataset lengths.We aim to demonstrate the accuracy and viability of the classification using a CNN in comparison to sigma intervals.The resulting detection rate of our algorithm is very plausible,thus proving the effectiveness of CNNs in this scientific area. 展开更多
关键词 Convolutional neural network quasi-periodic oscillation cataclysmic variable simulation
下载PDF
Polarization Raman spectra of graphene nanoribbons
16
作者 许望伟 孙诗杰 +6 位作者 杨慕紫 郝振亮 高蕾 卢建臣 朱嘉森 陈建 蔡金明 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第4期568-573,共6页
The on-surface synthesis method allows the fabrication of atomically precise narrow graphene nanoribbons(GNRs),which bears great potential in electronic applications.Here,we synthesize armchair graphene nanoribbons(AG... The on-surface synthesis method allows the fabrication of atomically precise narrow graphene nanoribbons(GNRs),which bears great potential in electronic applications.Here,we synthesize armchair graphene nanoribbons(AGNRs)and chevron-type graphene nanoribbons(CGNRs)array on a vicinal Au(111112)surface using 10,10′-dibromo-9,9′-bianthracene(DBBA)and 6,12-dibromochrysene(DBCh)as precursors,respectively.This process creates spatially wellaligned GNRs,as characterized by scanning tunneling microscopy.AGNRs show strong Raman linear polarizability for application in optical modulation devices.Different from the distinct polarization of AGNRs,only weak polarization exists in CGNRs polarized Raman spectrum,which suggests that the presence of the zigzag boundary in the nanoribbon attenuates the polarization rate as an important factor affecting the polarization.We analyze the Raman activation mode of CGNRs using the peak polarization to expand the application of the polarization Raman spectroscopy in nanoarray analysis. 展开更多
关键词 graphene nanoribbons polarization Raman spectroscopy scanning tunneling microscopy
下载PDF
In-depth analysis of the influence of bio-silica filler(Didymosphenia geminata frustules)on the properties of Mg matrix composites
17
作者 Izabela B.Zgłobicka Anna Dobkowska +12 位作者 Aleksandra Zielińska Ewa Borucinska Mirosław J.Kruszewski RafałZybała Tomasz Płociński Joanna Idaszek Jakub Jaroszewicz Krystian Paradowski Bogusława Adamczyk-Cieślak Kostiantyn Nikiforow Bartosz Bucholc WojciechŚwięszkowski Krzysztof J.Kurzydłowski 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第8期2853-2871,共19页
A novel metal matrix composites(MMC)with Mg matrix reinforced with natural filler in the form of Didymosphenia geminata frustules(algae with distinctive siliceous shells)are presented in this work.Pulse plasma sinteri... A novel metal matrix composites(MMC)with Mg matrix reinforced with natural filler in the form of Didymosphenia geminata frustules(algae with distinctive siliceous shells)are presented in this work.Pulse plasma sintering(PPS)was used to manufacture Mg-based composites with 1,5 and 10 vol.%ceramic filler.As a reference,pure Mg was sintered.The results show that the addition of 1 vol.%Didymosphenia geminata frustules to the Mg matrix increases its corrosion resistance by supporting passivation reactions,and do not affect the morphology of L929 fibroblasts.Addition of 5 vol.%the filler does not cause cytotoxic effects,but it supports microgalvanic reactions leading to the greater corrosion rate.Higher content than 5 vol.%the filler causes significant microgalvanic corrosion,as well as increases cytotoxicity due to the greater micro-galvanic effect of the composites containing 10 and 15 vol.%diatoms.The results of contact angle measurements show the hydrophilic character of the investigated materials,with slightly increase in numerical values with addition of amount of ceramic reinforcement.The addition of Didymosphenia geminata frustules causes changes in a thermo-elastic properties such as mean apparent value of coefficient of thermal expansion(CTE)and thermal conductivity(λ).The addition of siliceous reinforcement resulted in a linear decrease of CTE and reduction in thermal conductivity over the entire temperature range.With the increasing addition of Didymosphenia geminata frustules,an increase in strength with a decrease in compressive strain is observed.In all composites an increase in microhardness was attained.The results clearly indicate that filler in the form of Didymosphenia geminata frustules may significantly change the most important properties of pure Mg,indicating its wide potential in the application of Mg-based composites with a special focus on biomedical use. 展开更多
关键词 Metal-matrix composites(MMCs) Pulse plasma sintering(PPS) Ceramic filler Microstructure Properties
下载PDF
New Carbon Nitride C_(3)N_(3) Additive for Improving Cationic Defects of Perovskite Solar Cells
18
作者 Zuhong Li Jiaxin Feng +8 位作者 Jinguo Cao Jiaren Jin Yijun Zhou Duoling Cao Zihui Liang Bicheng Zhu Ming Li Li Zhao Shimin Wang 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2023年第1期281-288,共8页
Due to the loss of organic amine cations and lead ions in the structure of the iodine-lead methylamine perovskite solar cell,there are a large number of defects within the film and the recombination loss caused by gra... Due to the loss of organic amine cations and lead ions in the structure of the iodine-lead methylamine perovskite solar cell,there are a large number of defects within the film and the recombination loss caused by grain boundaries,which seriously hinder the further improvement of power conversion efficiency and stability.Herein,a novel carbon nitride C_(3)N_(3) incorporated into the perovskite precursor solution is a multifunctional strategy,which not only increases the light absorption strength,grain size,and hydrophobicity of the perovskite film,but also effectively passivates the bulk and interfacial defects of perovskite and verified by the first-principles density functional theory calculations.As a result,the efficiency and stability of perovskite solar cells are improved.The device with 0.075 mg mL^(-1) C_(3)N_(3) additive delivers a champion power conversion efficiency of 19.91%with suppressed hysteresis,which is significantly higher than the 18.16% of the control device.In addition,the open-circuit voltage of the modified device with the maximum addition as high as 1.137 V is 90.96% of the Shockley–Queisser limit(1.25 V).Moreover,the power conversion efficiency of the modified device without encapsulation can maintain nearly 90% of its initial value after being stored at 25℃ and 60% relative humidity for 500 h.This work provides a new idea for developing additives to improve the power conversion efficiency and stability of perovskite solar cells. 展开更多
关键词 ADDITIVE C_(3)N_(3) humidity stability passivate defect perovskite solar cells
下载PDF
State-of-the-art advances in vacancy defect engineering of graphitic carbon nitride for solar water splitting
19
作者 Jie Li Kaige Huang +11 位作者 Yanbin Huang Yumin Ye Marcin Ziółek Zhijie Wang Shizhong Yue Mengmeng Ma Jun Liu Kong Liu Shengchun Qu Zhi Zhao Yanjun Zhang Zhanguo Wang 《Journal of Semiconductors》 EI CAS CSCD 2023年第8期16-34,共19页
Developing low-cost,efficient,and stable photocatalysts is one of the most promising methods for large-scale solar water splitting.As a metal-free semiconductor material with suitable band gap,graphitic carbon nitride... Developing low-cost,efficient,and stable photocatalysts is one of the most promising methods for large-scale solar water splitting.As a metal-free semiconductor material with suitable band gap,graphitic carbon nitride(g-C_(3)N_(4))has attracted attention in the field of photocatalysis,which is mainly attributed to its fascinating physicochemical and photoelectronic properties.However,several inherent limitations and shortcomings—involving high recombination rate of photocarriers,insufficient reaction kinetics,and optical absorption—impede the practical applicability of g-C_(3)N_(4).As an effective strategy,vacancy defect engineering has been widely used for breaking through the current limitations,considering its ability to optimize the electronic structure and surface morphology of g-C_(3)N_(4) to obtain the desired photocatalytic activity.This review summarizes the recent progress of vacancy defect engineered g-C_(3)N_(4) for solar water splitting.The fundamentals of solar water splitting with g-C_(3)N_(4) are discussed first.We then focus on the fabrication strategies and effect of vacancy generated in g-C_(3)N_(4).The advances of vacancy-modified g-C_(3)N_(4) photocatalysts toward solar water splitting are discussed next.Finally,the current challenges and future opportunities of vacancy-modified g-C_(3)N_(4) are summarized.This review aims to provide a theoretical basis and guidance for future research on the design and development of highly efficient defective g-C_(3)N_(4). 展开更多
关键词 g-C_(3)N_(4) vacancy defect water splitting PHOTOCATALYST charge carrier
下载PDF
Fabrication and Characterization of Lightweight Ceramic/Polyurethane Composites
20
作者 Paulina Chabera 《Journal of Civil Engineering and Architecture》 2023年第9期427-432,共6页
The paper presents the experimental results of fabrication and characterization of ceramic/polyurethane composites.The composites were fabricated from preforms with gradient of porosity and different pores size.The co... The paper presents the experimental results of fabrication and characterization of ceramic/polyurethane composites.The composites were fabricated from preforms with gradient of porosity and different pores size.The composites obtained via infiltration of porous Al_(2)O_(3)ceramics by urea-urethane elastomers poses a microstructure of percolated phases.In order to improve thermal resistance and mechanical properties of composites,fire retardants and silane coupling agent were used.The microstructure of ceramic/elastomer composites was characterized using X-ray tomography as well as Scanning Electron Microscopy(SEM).The microscopic observations proved that the matrix pores are filled with the elastomer.It was found that residual porosity of composites was up to 5vol.%.Such composites exhibit high initial strength with the ability to sustain large deformations due to combining the ceramic stiffness and rubbery elasticity of elastomer.Static compression tests for the obtained composites were carried out and the energy absorbed during compression was calculated as the area under the stress-strain curve.The dynamic behavior of the composite was investigated using the split Hopkinson pressure bar technique in conjunction with high-speed photography.It was found that ceramic-elastomer composites effectively absorb the energy.Moreover,ballistic test was carried out using armor piercing bullets. 展开更多
关键词 Composites ELASTOMER INFILTRATION SEM energy absorbing
下载PDF
上一页 1 2 22 下一页 到第
使用帮助 返回顶部