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Evaluating the quantum confinement effects modulating exciton and electronic band structures of two-dimensional layered MoSSe films and their photodetection potentials
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作者 Yifan Ding Xudan Zhu +8 位作者 Hongyu Tang Weiming Liu Shuwen Shen Jiajie Fan Yi Luo Yuxiang Zheng Chunxiao Cong Siyuan Luo Rongjun Zhang 《Science China Materials》 SCIE EI CAS CSCD 2024年第10期3087-3095,共9页
Emerging two-dimensional ternary transition metal dichalcogenide alloys have attracted much attention for their unique optical and optoelectronic properties,making them ideal candidates for optoelectronic applications... Emerging two-dimensional ternary transition metal dichalcogenide alloys have attracted much attention for their unique optical and optoelectronic properties,making them ideal candidates for optoelectronic applications.However,a comprehensive understanding of their quantum confinement effects and photoelectronic response characteristics remains crucial for device optimization and performance enhancement.In this study,we employed various spectroscopic techniques to investigate the optical properties and electronic band structures of molybdenum sulfide selenide(MoSSe)films with different layer numbers(4–11 layers).Our results revealed the splitting of Raman modes and shifting of phonon vibrational frequencies with increasing thickness,suggesting that MoSSe has strong interactions within the lattice.The A1g and E2g 1 modes were mainly shifted by internal strain and dielectric screening effect versus thickness,respectively.The redshift phenomenon of A and B excitons with increasing thickness was attributed to the leading effect of quantum confinement on exciton properties and optical band gaps.We observed a strong decrease in the direct bandgap spectral weight in photoluminescence(PL)when the layer number increased from 4 to 5.In addition,we have fabricated MoSSe photodetectors that exhibit a broadband response in the visible wavelength band of 350–800 nm.Furthermore,the observed enhancement in photocurrent and responsivity with increasing film thickness underscored the potential of MoSSebased devices for practical optoelectronic applications.This research contributes to advancing our fundamental understanding of MoSSe materials and paves the way for the design and development of high-performance optoelectronic devices. 展开更多
关键词 MoSSe alloy quantum confinement effects EXCITON electronic band structure PHOTODETECTION
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Size matters:quantum confinement-driven dynamics in CsPbI_(3)quantum dot light-emitting diodes 被引量:1
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作者 Shuo Li Wenxu Yin +1 位作者 Weitao Zheng Xiaoyu Zhang 《Journal of Semiconductors》 2025年第4期55-61,共7页
The quantum confinement effect fundamentally alters the optical and electronic properties of quantum dots(QDs),making them versatile building blocks for next-generation light-emitting diodes(LEDs).This study investiga... The quantum confinement effect fundamentally alters the optical and electronic properties of quantum dots(QDs),making them versatile building blocks for next-generation light-emitting diodes(LEDs).This study investigates how quantum confinement governs the charge transport,exciton dynamics,and emission efficiency in QD-LEDs,using CsPbI_(3) QDs as a model system.By systematically varying QD sizes,we reveal size-dependent trade-offs in LED performance,such as enhanced efficiency for smaller QDs but increased brightness and stability for larger QDs under high current densities.Our findings offer critical insights into the design of high-performance QD-LEDs,paving the way for scalable and energy-efficient optoelectronic devices. 展开更多
关键词 quantum confinement effect CsPbI_(3) quantum dot light-emitting diode
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Anti-Swelling Polyelectrolyte Hydrogel with Submillimeter Lateral Confinement for Osmotic Energy Conversion
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作者 Yongxu Liu Jiangnan Song +10 位作者 Zhen Liu Jialin Chen Dejuan Wang Hui Zhi Jiebin Tang Yafang Zhang Ningbo Li Weijia Zhou Meng An Hong Liu Guobin Xue 《Nano-Micro Letters》 2025年第4期96-110,共15页
Harvesting the immense and renewable osmotic energy with reverse electrodialysis(RED)technology shows great promise in dealing with the ever-growing energy crisis.One key challenge is to improve the output power densi... Harvesting the immense and renewable osmotic energy with reverse electrodialysis(RED)technology shows great promise in dealing with the ever-growing energy crisis.One key challenge is to improve the output power density with improved trade-off between membrane permeability and selectivity.Herein,polyelectrolyte hydrogels(channel width,2.2 nm)with inherent high ion conductivity have been demonstrated to enable excellent selective ion transfer when confined in cylindrical anodized aluminum pore with lateral size even up to the submillimeter scale(radius,0.1 mm).The membrane permeability of the anti-swelling hydrogel can also be further increased with cellulose nanofibers.With real seawater and river water,the output power density of a three-chamber cell on behalf of repeat unit of RED system can reach up to 8.99 W m^(-2)(per unit total membrane area),much better than state-of-the-art membranes.This work provides a new strategy for the preparation of polyelectrolyte hydrogel-based ion-selective membranes,owning broad application prospects in the fields of osmotic energy collection,electrodialysis,flow battery and so on. 展开更多
关键词 Ionic polymer HYDROGEL confinement effect Anti-swelling Osmotic energy conversion
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Improving CO_(2) solubility in a hybrid sorbent of 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide/mesoporous titanium dioxide/water with confinement effect
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作者 Haoran Yin Lili Mu +3 位作者 Yifeng Chen Licheng Li Kang Sun Xiaoyan Ji 《Chinese Journal of Chemical Engineering》 2025年第4期100-109,共10页
Confinement effect is an effective method to enhance carbon dioxide(CO_(2))solubility.In this study,a hybrid sorbent of 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide([Hmim][NTf_2])/mesoporous titanium ... Confinement effect is an effective method to enhance carbon dioxide(CO_(2))solubility.In this study,a hybrid sorbent of 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide([Hmim][NTf_2])/mesoporous titanium dioxide(M-TiO_(2))/water(H_2O)was developed,and its confinement effect was regulated by changing the pore structure of M-TiO_(2).CO_(2) solubility in the hybrid sorbent was measured experimentally,and the thermodynamic properties including Henry's constant and desorption enthalpy were calculated.Furthermore,the confinement effect in the hybrid sorbent was quantified.Additionally,the hybrid sorbent was recycled with a multi-cycle experiment.The results showed that M-TiO_(2) calcined at 773.2 K(MT500)could lead to an efficient confinement effect.CO_(2) solubility in the hybrid sorbent increased by 49.8%compared to that of H_2O when the mass fraction of[Hmim][NTf_2]/MT500 was 5.0%(mass),where the contribution of confinement effect on Gibbs free energy occupied 5.2%. 展开更多
关键词 Ionic liquid Carbon dioxide Mesoporous titanium dioxide confinement effect Thermodynamics
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β-Cyclodextrin inducing confinement effect enabling spherical Na_(3)V_(2)(PO_(4))_(3)with multielectron reaction and superior performance at extreme conditions for sodium-ion batteries
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作者 Shuming Zhang Tao Zhou +1 位作者 Hongen Shi Yanjun Chen 《Journal of Energy Chemistry》 2025年第9期138-153,I0006,共17页
Currently,simultaneous regulation of external morphology and internal electronic structure for Na_(3)V_(2)(PO_(4))_(3)(NVP)is rarely realized.Herein,complexes of β-cyclodextrin(βCD)and ethylenediaminetetraacetic aci... Currently,simultaneous regulation of external morphology and internal electronic structure for Na_(3)V_(2)(PO_(4))_(3)(NVP)is rarely realized.Herein,complexes of β-cyclodextrin(βCD)and ethylenediaminetetraacetic acid ferric sodium salt(EDTAFeNa)are utilized for the one-step preparation of NVP with spherical morphology as well as Fe substitution.βCD is initially hydrolyzed into glucose,and then carbon microspheres with numerous pores are formed through continuous dehydration and carbonization.The intermediate hydroxymethylfurfural is rich in active functional groups,which are attractive for the V/P-contained raw materials.Accordingly,the nucleation sites for NVP are successfully limited in the spherical framework,possessing a superior surface area of 97.15 g m^(-2).Furthermore,the beneficial Fe in EDTAFeNa enters into the NVP bulk to construct a novel Fe-doped Na_(3)V_(1.95)Fe_(0.05)(PO_(4))_(3)(NVP/β-ISC)material.Fe-substitution induces significant optimizations of electronic structure for NVP,which has been verified by the newly generated abundant oxygen vacancies and extended V-O bond length.Moreover,a multielectron reaction is activated,resulting from the V^(4+)/V^(5+)redox couple.The charge compensation mechanism of NVP/β-ISC is also deeply investigated.Density functional theory(DFT)calculations theoretically elaborate the mechanism of Fe-doping.Consequently,NVP/β-ISC reveals superior sodium storage performance in both half and full cells and even at different extreme conditions(needling,soaking,bending,and freezing). 展开更多
关键词 b-Cyclodextrin Spherical morphology confinement effect Multielectron reaction Na_(3)V_(2)(PO_(4))_(3)
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Photothermal effects of multidimensional confined MMC/TMs-MDCS catalyst for ultra-high photocatalytic hydrogen evolution
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作者 Huihua Luo Haifeng Zhu +4 位作者 Kehui Xue Chong Liu Nannan Chen Yaping Zhang Lianqing Yu 《Journal of Energy Chemistry》 2025年第5期655-669,共15页
Multidimensional confined structure systems are proposed and demonstrated by using MoO_(2)@MO_(2)C(MMC)to enhance the photothermal catalytic performance of the metal sulfides-multidimensional confined structure(TMs-MD... Multidimensional confined structure systems are proposed and demonstrated by using MoO_(2)@MO_(2)C(MMC)to enhance the photothermal catalytic performance of the metal sulfides-multidimensional confined structure(TMs-MDCS).Specifically,the MMC nanoparticles confined to the surface of the ZnIn_(2)S_(4)hollow tube-shell(MMC/HT-ZIS)achieve a hydrogen evolution rate of 9.72 mmol g^(-1)h^(-1),which is 11.2 times higher than that of pure HT-ZIS.Meanwhile,the MnCdS(MCS)nanoparticles are encapsulated within the two-dimensional MMC(2D MMC/MCS)through precise regulation of size and morphology.The 10-MMC/MCS lamellar network demonstrates the highest hydrogen evolution rate of 8.19 mmol g^(-1)-h^(-1).The obtained MMC/TMs-MDCS catalysts exhibit an enhanced photocatalytic hydrogen evolution rate,which can be attributed to the strong synergistic interaction between the multidimensional confinement and the photothermal effects.The confinement space and the strong interfacial relationship within the MMC/TMs-MDCS create abundant channels and active sites that facilitate electron migration and transport.Furthermore,the construction of a confined environment positions these materials as promising candidates for achieving exceptional photothermal catalytic performance,as MMC/TMs-MDCS enhance light absorption through light scattering and reflecting effects.Additionally,the capacity of MMC/TMsMDCS to convert solar light into thermal energy significantly reduces the activation energy of the reaction,thereby facilitating reaction kinetics and accelerating the separation and transport of photogenerated carriers.This work provides valuable insights for the development of highly efficient photothermal catalytic water-splitting systems for hydrogen production using multidimensional confined catalysts. 展开更多
关键词 Multidimensional confined effect Photothermal effect Photothermal catalytic hydrogen production
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Photoluminescence of carbon quantum dots:coarsely adjusted by quantum confinement effects and finely by surface trap states 被引量:2
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作者 Zexi Liu Hongyan Zou +5 位作者 Ni Wang Tong Yang Zhewei Peng Jian Wang Na Li Chengzhi Huang 《Science China Chemistry》 SCIE EI CAS CSCD 2018年第4期490-496,共7页
Photoluminescence(PL)mechanism of carbon quantum dots(CQDs)remains controversial up to now even though a lot of approaches have been made.In order to do that,herein a PL color ladder from blue to near infrared of CQDs... Photoluminescence(PL)mechanism of carbon quantum dots(CQDs)remains controversial up to now even though a lot of approaches have been made.In order to do that,herein a PL color ladder from blue to near infrared of CQDs with the absolute quantum yields higher than 70%were prepared via a one-pot hydrothermal synthesis route and separated by silica gel column.Time-correlated single photon counting measurements suggest that the electron transition takes in effect in the PL progress of the crystalline core-shell structured CQDs,and the PL properties could be coarsely adjusted by tuning the size of the crystalline carbon core owing to quantum confinement effects,and finely adjusted by changing the surface functional groups consisted shell owing to surface trap states,respectively.Both coarse and fine adjustments of PL,as optical and photoelectrical characterizations and density-functional theory(DFT)calculations have demonstrated,make it possible for top-level design and precise synthesis of new CQDs with specific optical properties. 展开更多
关键词 carbon quantum dots quantum confinement effects surface trap states electron transition
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Lamella-like electrode with high Br_(2)-entrapping capability and activity enabled by adsorption and spatial confinement effects for brominebased flow battery 被引量:1
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作者 Luyin Tang Tianyu Li +1 位作者 Wenjing Lu Xianfeng Li 《Science Bulletin》 SCIE EI CSCD 2022年第13期1362-1371,M0004,共11页
Bromine-based flow batteries(Br-FBs)are well suitable for stationary energy storage owing to their high energy density and low cost.However,their power density and lifespan are limited by relatively low reaction kinet... Bromine-based flow batteries(Br-FBs)are well suitable for stationary energy storage owing to their high energy density and low cost.However,their power density and lifespan are limited by relatively low reaction kinetics of Br_(2)/Br-couple and serious self-discharge caused by bromine migration.Herein,lamella-like porous carbon nitride nanosheets(PCNS)with adsorption and spatial confinement effects are used to modify cathodes for Br-FBs.The large specific surface area and plentiful N-containing groups enable PCNS with excellent adsorption capacity,which captures bromine species into the pores on PCNS layers.The captured bromine species is subsequently confined in PCNS interlayers due to the strong interaction between bromine species and N-containing groups,thus effectively depressing bromine diffusion/migration.Moreover,the strong bromine adsorption capacity significantly improves the electrochemical activity of PCNS.Consequently,a zinc-bromine flow battery(ZBFB)employing PCNS-modified cathode achieves a high current density of 180 m A cm^(-2),with an ultra-high coulombic efficiency of 99.22%.It also exhibits better self-discharge performance and a long cycle life of 500 cycles.Furthermore,a complexing agent-free ZBFB is successfully realized based on the superior bromineentrapping/retaining capacity of the PCNS-modified cathode.Consequently,this work provides a promising strategy toward electrode modifications for high-performance and long-lifespan Br-FBs. 展开更多
关键词 Bromine-based flow battery Lamella-like electrode Bromine-entrapping capability Strong adsorption capacity Spatial confinement effect
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Ultrasensitive detection of micro RNA-21 in human serum based on the confinement effect enhanced chemical etching of gold nanorods
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作者 Min Huang Ru Cheng +6 位作者 Shuai Wen Liangtong Li Jie Gao Xiaohui Zhao Chunmei Li Hongyan Zou Jian Wang 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第9期382-386,共5页
Natural enzymes,such as horseradish peroxidase(HRP),are a class of important biocatalysts with the high specificity,but their catalytic efficiency is usually unsatisfactory.Thus,the higher catalytic efficiency induced... Natural enzymes,such as horseradish peroxidase(HRP),are a class of important biocatalysts with the high specificity,but their catalytic efficiency is usually unsatisfactory.Thus,the higher catalytic efficiency induced by the confinement effect is promising in optical sensing systems.In this work,a dark-field light scattering sensing platform was fabricated by the confinement effect of HRP from hybridization chain reaction(HCR)and then released to solution by the toehold-mediated strand displacement reaction(TSDR).Then,HRP catalyzed the 3,3,5,5-tetramethylbenzidine(TMB)to TMB^(2+)with the assistance of hydrogen peroxide,which etched the gold nanorods(Au NRs)with the weakened light scattering.The single-particle assay was established based on the decreased light scattering intensity of AuNRs under dark-field microscope.The proposed assay revealed excellent analytical performance within a linear range from 25 pmol/L to 600 pmol/L,and a low limit of detection of 3.12 pmol/L.Additionally,it also manifested satisfactory recovery of mi RNA-21 in human serum samples.The high sensitivity,excellent specificity,and universal applicability make this sensing platform promising for disease diagnosis. 展开更多
关键词 confinement effect Hybridization chain reaction Toehold-mediated strand displacement REACTION MICRORNA-21 Gold nanorods Dark-field microscope
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Supramolecular confinement effect enabling light-harvesting system for photocatalytic α-oxyamination reaction
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作者 Xuanyu Wang Zhao Gao Wei Tian 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第11期309-313,共5页
The supramolecular F?rster resonance energy transfer(FRET)is seen as a promising approach for organic photocatalysis using dyes as catalysts,because it combines the high efficiency of energy transfer with the dynamic ... The supramolecular F?rster resonance energy transfer(FRET)is seen as a promising approach for organic photocatalysis using dyes as catalysts,because it combines the high efficiency of energy transfer with the dynamic responsiveness based on non-covalent interactions.Here we propose a supramolecular FRET photocatalysis strategy forα-oxyamination reaction based on supramolecular confinement effect.The well-designed benzothiadiazole-based cationic monomer as energy donor and the dyes of Nile Red as acceptor are doped into the amphiphilic surfactants of sodium dodecyl sulfate(SDS).Benefitting from the supramolecular confinement space provided by SDS in aqueous environment,the FRET process between the monomer and Nile Red is effectively achieved(exciton migration rate:3.99×10^(14)L mol^(-1)s^(-1)).On this basis,the supramolecular FRET system is used as an efficient energy source to catalyzeα-oxyamination reactions between a series of 1,3-dicarbonyl compounds and 2,2,6,6-tetramethylpiperidine-1-oxyl under white LED light,showing a yield as high as 94%and a turnover frequency value of 3.92 h^(-1).This photocatalytic result shows a great enhancement compared to that of Nile Red alone. 展开更多
关键词 Self-assembly Supramolecular chemistry Light harvesting Energy transfer confinement effect
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Theoretical study of the strain effects on CO activation by Fe_(2)C confined with graphene
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作者 ZHU Jialiang LI Zhe +2 位作者 ZHANG Yuhua LI Yongxiu LI Jinlin 《分子科学学报》 CAS 2024年第3期233-238,共6页
The intrinsic strains at the confinement interface of iron carbide with graphene play important roles in the catalytic Fischer-Tropsch synthesis.In this study,we performed theoretical study of the biaxial strain effec... The intrinsic strains at the confinement interface of iron carbide with graphene play important roles in the catalytic Fischer-Tropsch synthesis.In this study,we performed theoretical study of the biaxial strain effects on the CO adsorption and dissociation on the Fe_(2)C(121)surface covered by graphene(Fe_(2)C@graphene).By varying the lattice strains within a range of±5%,the apparent energy barriers(E_(a,app))correlate with the adsorption energies(E_(ad))in nonlinear scaling relations for the direct and H-assisted CO dissociation at the Fe_(2)C active sites,which is normal Br∅nsted-Evans-Polanyi relation for those at the graphene sites.The nonlinear scaling relations can be interpreted by the strain effects on the confinement distances in the adsorption and transition states.This study provides a deep understanding of the intrinsic strain effects of Fe_(2)C@graphene for CO activation. 展开更多
关键词 strain effect iron carbide confinement effect GRAPHENE Fischer-Tropsch synthesis
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Decouple the intermolecular interaction by encapsulating an insulating sheath
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作者 Saisai Yuan Yiming Chen +6 位作者 Xijuan Wang Degui Zhao Tengyang Gao Caiyun Wei Chuanxiang Chen Yang Yang Wenjing Hong 《Chinese Chemical Letters》 2025年第6期495-499,共5页
Single-molecule junctions are building blocks for constructing molecular devices.However,intermolecular interactions like winding bring additional interference among the surrounding molecules,which inhibits the intrin... Single-molecule junctions are building blocks for constructing molecular devices.However,intermolecular interactions like winding bring additional interference among the surrounding molecules,which inhibits the intrinsic coherent transport through single-molecule junctions.Here,we employed a nanocavity(dimethoxypillar[5]arene,DMP[5]),which is analogous to electric cables,to confine the conformation of flexible chains(1,8-diaminooctane,DAO)via host-vip interaction.Single-molecule conductance measurements indicate that the conductance of DAO encapsulated with DMP[5]is as high as that of pure DAO,as reproduced by theoretical simulations.Intriguingly,the molecular lengths of the DAO encapsulated with DMP[5]increase from 1.13 nm to 1.46 nm compared with the pure DAO,indicating that DMP[5]keeps DAO upright-standing via the confinement effect.This work provides a new strategy to decouple the intermolecular interaction by employing an insulating sheath,enabling the high-density integration of single-molecule devices. 展开更多
关键词 SINGLE-MOLECULE Molecule devices Host-vip interaction confinement effect Decouple
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Phase Behavior and Dew Point Pressure of Multicomponent Condensate Gas in Nanopores
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作者 Jichao Zhao Xu Yan +1 位作者 Jing Sun Sheng Li 《Fluid Dynamics & Materials Processing》 2025年第2期279-292,共14页
Shale gas reservoirs typically contain numerous nanoscale pores,with pore size playing a significant role in influencing the gas behavior.To better understand the related mechanisms,this study employs the Gauge-GEMC m... Shale gas reservoirs typically contain numerous nanoscale pores,with pore size playing a significant role in influencing the gas behavior.To better understand the related mechanisms,this study employs the Gauge-GEMC molecular simulation method to systematically analyze the effects of various pore sizes(5,10,20,and 40 nm)on the phase behavior and dew point pressure of the shale gas reservoir components.The simulation results reveal that when pore sizes are smaller than 40 nm,the dew point pressure increases significantly as the pore size decreases.For instance,the dew point pressure in 5 nmpores is 20.3%higher than undermacroscopic conditions.Additionally,larger hydrocarbon molecules exhibit a tendency to aggregate in smaller pores,particularly in the 5–10 nm range,where the relative concentration of heavy hydrocarbons(C_(4+))increases markedly.Moreover,as the pore size becomes larger,the component distribution gradually aligns with experimental results observed under macroscopic conditions.This study demonstrates that pore effects are more pronounced for smaller sizes,directly influencing the aggregation of heavy hydrocarbons and the rise in dew point pressure.These phenomena could significantly impact the diffusivity of shale gas reservoirs and the recovery of condensate gas.The findings provide new theoretical insights into phase behavior changes in nanopores,offering valuable guidance for optimizing shale gas reservoir extraction strategies. 展开更多
关键词 Condensate gas NANOPORES molecular simulation dew point pressure confinement effect
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Design of highly active meso–zeolite enveloping Pt–Ni bimetallic catalysts for degradation of toluene
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作者 Tianyao He Gan Li +9 位作者 Xiaoqiang Xie Dong Han Yunyue Leng Qiuli Zhang Wenming Liu Guobo Li Hongxiang Zhang Shan Huang Ting Huang Honggen Peng 《Chinese Chemical Letters》 2025年第4期403-408,共6页
Degrading volatile organic compounds at low temperatures and active sites aggregation are still challenging.In this study,a novel mesoporous zeolite silicalite-1(S-1–meso)enveloped Pt–Ni bimetallic catalysts(noted a... Degrading volatile organic compounds at low temperatures and active sites aggregation are still challenging.In this study,a novel mesoporous zeolite silicalite-1(S-1–meso)enveloped Pt–Ni bimetallic catalysts(noted as Pt1Ni1@S-1–meso)were synthesized via a facile in situ mesoporous template-free method.The Pt–Ni bimetallic nanoparticles were uniformly distributed and displayed a large specific surface area and enriched mesopores to facilitate the deep oxidation of toluene.The presence of the Pt–Ni O interface both increased the dispersion of the catalyst and improved its catalytic performance,thereby reducing the consumption of Pt.The Mars-van Krevelen mechanism and density function theory(DFT)calculations revealed that the Pt–Ni O interface effect changed the electronic structure of Pt and Ni species,reduced the activation potential for oxygen,formed reactive oxygen species,and facilitated the adsorption and activation of reactants in the direction favorable to the toluene oxidation.This study provides a guideline for minimizing the proportion of precious metals used in practical applications and a promising method for toluene elimination at low temperatures. 展开更多
关键词 Zeolite confinement effect Pt–Ni O interface Toluene deep oxidation Low temperature degradation Reducing noble metal consumption
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Dynamic tensile behaviour of rocks under confining pressure and high-rate loadings
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作者 Kai Liu Chunjiang Zou Jian Zhao 《Earth Energy Science》 2025年第1期9-21,共13页
Tensile cracking is a predominant mode of failure in rocks within underground resource excavation and engineering structures,where rocks are frequently subjected to dynamic disturbances while simultaneously experienci... Tensile cracking is a predominant mode of failure in rocks within underground resource excavation and engineering structures,where rocks are frequently subjected to dynamic disturbances while simultaneously experiencing in-situ stresses.This paper proposes a new dynamic split tension setup utilising a cubic specimen to investigate the dynamic behaviour of rocks across various tensile strain rates and confining pressures.The objective is to extend the applicability of the triaxial Hopkinson bar in studying dynamic behaviour of geomaterials.For comparison,the dynamic Brazilian disc(BD)tests were performed using three rock types(e.g.,sandstone,granite and marble)under different strain rates ranging from 10^(−3)∼10^(2) s^(−1).Besides,the Digital Image Correlation(DIC)technique was adopted to measure full-field real-time tensile strain of rocks and demonstrated that tensile crack initiated at the middle part and split the specimen into two similar halves.Effects of specimen size,geometry,loading rate as well as the confining pressure are investigated in detail.The dynamic fracture behaviours,including dynamic tensile strength,tensile strain,time to fracture and dynamic increase factor(DIF),were characterised for the rocks.It is found that dynamic tensile strength of rock minimal dependence on size and geometry but is significantly influenced by loading rate and confinement.It exhibited a linear increase with strain rate(10^(0)∼10^(2) s^(−1))and demonstrated a nonlinear growth with lateral confinement from 0 to 15 MPa.The nonlinear dependency on confinement can be attributed to the restriction imposed on the opening and propagation of tensile cracks due to the presence of confinement.These findings enhance our understanding of the safety aspects associated with underground rock excavations,particularly in situations where considering in-situ stress is crucial for evaluating the dynamic tensile failure of rocks. 展开更多
关键词 Triaxial Hopkinson Bar Split tension High strain rate loads confinement effect
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Dielectric Confinement Effect on Calculating the Band Gap of PbSe Quantum Dots
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作者 程文超 张铁强 张宇 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2011年第2期162-166,I0003,共6页
Considering the dielectric confinement effect on excitonics of PbSe quantum dots (QDs), a correction factor in the wave function was introduced to propose a new band gap calculation model for QDs. The modified model... Considering the dielectric confinement effect on excitonics of PbSe quantum dots (QDs), a correction factor in the wave function was introduced to propose a new band gap calculation model for QDs. The modified model showed great consistency with the experimental data, especially in small size range. According to the variation of confined barrier, the band gap calculation model of PbSe QDs was analyzed in different solvents. The calculating results showed that the modified model was almost solvent-independent, which was consistent with our experimental results and related reports. 展开更多
关键词 Dielectric confinement effect PBSE Band gap
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Phonon Confinement Effect in Two-dimensional Nanocrystallites of Monolayer MoS_2 to Probe Phonon Dispersion Trends Away from Brillouin-Zone Center 被引量:1
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作者 石薇 张昕 +4 位作者 李晓莉 乔晓粉 吴江滨 张俊 谭平恒 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第5期111-114,共4页
The fundamental momentum conservation requirement q - 0 for the Raman process is relaxed in the nanocrystal- lites (NCs), and phonons away from the Brillouin-zone center will be involved in the Raman scattering, whi... The fundamental momentum conservation requirement q - 0 for the Raman process is relaxed in the nanocrystal- lites (NCs), and phonons away from the Brillouin-zone center will be involved in the Raman scattering, which is well-known as the phonon confinement effect in NCs. This usually gives a downshift and asymmetric broadening of the Raman peak in various NCs. Recently, the A1 mode of 1L MoS2 NCs is found to exhibit a blue shift and asymmetric broadening toward the high-frequency side [Chem. Soc. Rev. 44 (2015) 2757 and Phys. Rev. B 91 (2015) 195411]. In this work, we carefully check this issue by studying Raman spectra of lL MoS2 NCs prepared by the ion implantation technique in a wide range of ion-implanted dosage. The same confinement coefficient is used for both E' and A'1 modes in 1L MoS2 NCs since the phonon uncertainty in an NC is mainly determined by its domain size. The asymmetrical broadening near the A'1 and E' modes is attributed to the appearance of defect-activated phonons at the zone edge and the intrinsic asymmetrical broadening of the two modes, where the anisotropy of phonon dispersion curves along Г-K and Г- M is also considered. The photoluminescence spectra confirm the formation of small domain size of 1L MoS2 nanocrystallites in the ion-implanted 1L MoS2. This study provides not only an approach to quickly probe phonon dispersion trends of 2D materials away from Г by the Raman scattering of the corresponding NCs, but also a reference to completely understand the confinement effect of different modes in various nanomaterials. 展开更多
关键词 of is NC as Phonon confinement Effect in Two-dimensional Nanocrystallites of Monolayer MoS2 to Probe Phonon Dispersion Trends Away from Brillouin-Zone Center mode in from
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Solid-gas interface thermal conductance for the thermal barrier coating with surface roughness:The confinement effect 被引量:1
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作者 Xue Zhao Jin-Wu Jiang 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第12期418-423,共6页
The yttria-stabilized zirconia(YSZ)is a famous thermal barrier coating material to protect hot-end components of an engine.As a characteristic feature of the YSZ,the surface roughness shall play an important role in t... The yttria-stabilized zirconia(YSZ)is a famous thermal barrier coating material to protect hot-end components of an engine.As a characteristic feature of the YSZ,the surface roughness shall play an important role in the interface thermal conductance between the YSZ and gas,considering that the gas is typically at an extremely high temperature.We investigate the effect of the surface roughness on the thermal conductance of the YSZ-gas interface with surface roughness described by nanoscale pores on the surface of the YSZ.We reveal two competitive mechanisms related to the microstructure of the pore,i.e.,the actual contact area effect and the confinement effect.The increase of the pore depth will enlarge the actual contact area between the YSZ and gas,leading to enhancement of the solid-gas interface thermal conductance.In contrast to the positive actual contact area effect,the geometry-induced confinement effect greatly reduces the interface thermal conductance.These findings shall offer some fundamental understandings for the microscopic mechanisms of the YSZ-gas interface thermal conductance. 展开更多
关键词 interface thermal conductance thermal barrier coating solid-gas interface confinement effect
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Exploiting quasi-one-dimensional confinement for proficient hydrogen production from formic acid at room temperature
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作者 Tao Jiang Peng Lu +4 位作者 Meng-Jiao Xu Jian-Dong Lin Yong-Mei Liu Yong Cao He-Yong He 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2020年第10期205-213,共9页
We describe herein that the quasi-one-dimensional confinement effect of functionalized nanoporous supports is particularly advantageous for boosting formic acid(FA)dehydrogenation efficiency over palladium nanoparticl... We describe herein that the quasi-one-dimensional confinement effect of functionalized nanoporous supports is particularly advantageous for boosting formic acid(FA)dehydrogenation efficiency over palladium nanoparticles(NPs).Benefiting from their unique structural merits that lead to significant lowering of the entropic barrier for FA activation,the Pd NPs interiorly located on the amino-modified MCM-41 offer the promise of more than an order of magnitude speedup of the initial activity in H2 production from FA over their exterior analogs.Under mild and additive-free conditions,ultrafine Pd NPs confined in aminomodified MCM-41 channels exhibit an initial turnover frequency as high as 46,677 h-1 and a turnover number up to 1,060,000 at 60℃.In conjunction with the enhancement and robust performance for efficient regeneration of FA via CO2 hydrogenation,the presented approach greatly contributes to the development of FA-based hydrogen storage and related technologies as viable means of enabling sustainable future energy prospects. 展开更多
关键词 confinement effect Formic acid Heterogeneous catalysis Hydrogen storage
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Anion type-dependent confinement effect on glass transitions of solutions of LiTFSI and LiFSI
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作者 张晋兵 王凤平 +1 位作者 曹则贤 王强 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第7期453-457,共5页
We present findings on the effect of nanometer-sized silica-based pores on the glass transition of aqueous solutions of lithium bis(trifluoromethane)sulfonimide(LiTFSI)and lithium difluorosulfimide(LiFSI),respectively... We present findings on the effect of nanometer-sized silica-based pores on the glass transition of aqueous solutions of lithium bis(trifluoromethane)sulfonimide(LiTFSI)and lithium difluorosulfimide(LiFSI),respectively.Our experimental results demonstrate a clear dependence of the confinement effect on the anion type,particularly for water-rich solutions,in which the precipitation of crystalized ice under cooling process induces the formation of freeze-concentrated phase confined between pore wall and core ice.As this liquid layer becomes thinner,the freeze-concentrated phase experiences glass transition at increasingly higher temperatures in solutions of LiTFSI.However,differently,for solutions of LiFSI and LiCl,this secondary confinement has a negligible effect on the glass transition of solutions confined wherein.These different behaviors emphasize the obvious difference in the dynamic properties’response of LiTFSI and LiFSI solutions to spatial confinement and particularly to the presence of the hydrophilic pore wall. 展开更多
关键词 anion type-dependent confinement effect glass transition Li salts aqueous solutions
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