期刊文献+
共找到136,891篇文章
< 1 2 250 >
每页显示 20 50 100
Enhancing proton exchange membrane water electrolysis by building electron/proton pathways
1
作者 Liyan Zhu Hao Zhang +5 位作者 Aojie Zhang Tian Tian Yuhan Shen Mingjuan Wu Neng Li Haolin Tang 《Advanced Powder Materials》 2024年第4期103-112,共10页
Proton exchange membrane water electrolysis(PEMWE)plays a critical role in practical hydrogen production.Except for the electrode activities,the widespread deployment of PEMWE is severely obstructed by the poor electr... Proton exchange membrane water electrolysis(PEMWE)plays a critical role in practical hydrogen production.Except for the electrode activities,the widespread deployment of PEMWE is severely obstructed by the poor electron-proton permeability across the catalyst layer(CL)and the inefficient transport structure.In this work,the PEDOT:F(Poly(3,4-ethylenedioxythiophene):perfluorosulfonic acid)ionomers with mixed proton-electron conductor(MPEC)were fabricated,which allows for a homogeneous anodic CL structure and the construction of a highly efficient triple-phase interface.The PEDOT:F exhibits strong perfluorosulfonic acid(PFSA)side chain extensibility,enabling the formation of large hydrophilic ion clusters that form proton-electron transport channels within the CL networks,thus contributing to the surface reactant water adsorption.The PEMWE device employing membrane electrode assembly(MEA)prepared by PEDOT:F-2 demonstrates a competitive voltage of 1.713 V under a water-splitting current of 2 A cm^(-2)(1.746 V at 2A cm^(-2) for MEA prepared by Nafion D520),along with exceptional long-term stability.Meanwhile,the MEA prepared by PEDOT:F-2 also exhibits lower ohmic resistance,which is reduced by 23.4%and 17.6%at 0.1 A cm^(-2) and 1.5 A cm^(-2),respectively,as compared to the MEA prepared by D520.The augmentation can be ascribed to the superior proton and electron conductivity inherent in PEDOT:F,coupled with its remarkable structural stability.This characteristic enables expeditious mass transfer during electrolytic reactions,thereby enhancing the performance of PEMWE devices. 展开更多
关键词 proton exchange membrane water electrolysis Oxygen evolution reaction Mixed proton-electron conductivity Triple-phase boundaries Membrane electrode assembly
下载PDF
On the Possible Structures of Electron and Proton
2
作者 Wei-Xing Xu 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第4期1734-1742,共9页
In this work, the possible structures of electron and proton have been explored. Based on the potential expressions of electron and proton, we found that the electron and proton share the similar structure inside re a... In this work, the possible structures of electron and proton have been explored. Based on the potential expressions of electron and proton, we found that the electron and proton share the similar structure inside re and rn. And within re and rn, the conventional charge concept stops working, the same charge repelling force doesn’t exist anymore and as a result, the requirement of charge conservation is automatically removed. Whereas beyond re and rn, the potential expressions of electron and proton obey the point charge potentials as we normally understand. Therefore, the conventional charge concept can be applied and the requirement of charge conservation takes effect. Furthermore, a possible mechanism for the creations of electric monopole and magnetic monopole is discussed. In addition, to compare the particle size in micro-world, the balloon criterion is proposed. By this balloon criterion, the proton is determined about 10 times bigger than electron. From the physical picture about electron and proton described above, the stabilities of electron and proton can be explained quite well. 展开更多
关键词 Electromagnetic Spacetime Quantum Mechanics electron proton Standard Model Particle Physics “Yin-Yang” Philosophy Electric Monopole Magnetic Monopole Charge Conservation
下载PDF
Bioelectronic medicine in modulation of cortical spreading depolarization and beyond
3
作者 Khaled Alok Timothy G.White Chunyan Li 《Neural Regeneration Research》 SCIE CAS 2025年第2期481-482,共2页
Bioelectronic interventions,specifically trigeminal nerve st imulat ion(TNS),have attracted considerable attention in conditions where cortical spreading depolarizations(CSDs)accompanied by compromised cerebral perfus... Bioelectronic interventions,specifically trigeminal nerve st imulat ion(TNS),have attracted considerable attention in conditions where cortical spreading depolarizations(CSDs)accompanied by compromised cerebral perfusion may exacerbate neurological damage.While pharmacological interventions have demonstrated initial potential in addressing CSDs,a standardized treatment approach has not yet been established.The objective of this perspective is to explore emerging bioelectronic methodologies for addressing CSDs,particularly emphasizing TNS,and to underscore TNS’s capacity to enhance neurovascular coupling and cerebral perfusion. 展开更多
关键词 CEREBRAL PERFUSION electronic
下载PDF
Boosting high-performance in Zr-rich side protonic solid oxide electrolysis cells by optimizing functional interlayer
4
作者 Chunmei Tang Ning Wang +3 位作者 Sho Kitano Hiroki Habazaki Yoshitaka Aoki Siyu Ye 《Green Energy & Environment》 SCIE EI CAS 2025年第1期150-160,共11页
Protonic solid oxide electrolysis cells(P-SOECs)are a promising technology for water electrolysis to produce green hydrogen.However,there are still challenges related key materials and anode/electrolyte interface.P-SO... Protonic solid oxide electrolysis cells(P-SOECs)are a promising technology for water electrolysis to produce green hydrogen.However,there are still challenges related key materials and anode/electrolyte interface.P-SOECs with Zr-rich electrolyte,called Zr-rich side P-SOECs,possess high thermodynamically stability under high steam concentrations but the large reaction resistances and the current leakage,thus the inferior performances.In this study,an efficient functional interlayer Ba_(0.95)La_(0.05)Fe_(0.8)Zn_(0.2)O_(3-δ)(BLFZ)in-between the anode and the electrolyte is developed.The electrochemical performances of P-SOECs are greatly enhanced because the BLFZ can greatly increase the interface contact,boost anode reaction kinetics,and increase proton injection into electrolyte.As a result,the P-SOEC yields high current density of 0.83 A cm^(-2) at 600℃ in 1.3 Vamong all the reported Zr-rich side cells.This work not only offers an efficient functional interlayer for P-SOECs but also holds the potential to achieve P-SOECs with high performances and long-term stability. 展开更多
关键词 Functional interlayer Zr-rich side electrolyte protonic solid oxide electrolysis cells Current density Faradaic efficiency
下载PDF
Optimizing electronic structure through point defect engineering for enhanced electrocatalytic energy conversion
5
作者 Wei Ma Jiahao Yao +6 位作者 Fang Xie Xinqi Wang Hao Wan Xiangjian Shen Lili Zhang Menggai Jiao Zhen Zhou 《Green Energy & Environment》 SCIE EI CAS 2025年第1期109-131,共23页
Point defect engineering endows catalysts with novel physical and chemical properties,elevating their electrocatalytic efficiency.The introduction of defects emerges as a promising strategy,effectively modifying the e... Point defect engineering endows catalysts with novel physical and chemical properties,elevating their electrocatalytic efficiency.The introduction of defects emerges as a promising strategy,effectively modifying the electronic structure of active sites.This optimization influences the adsorption energy of intermediates,thereby mitigating reaction energy barriers,altering paths,enhancing selectivity,and ultimately improving the catalytic efficiency of electrocatalysts.To elucidate the impact of defects on the electrocatalytic process,we comprehensively outline the roles of various point defects,their synthetic methodologies,and characterization techniques.Importantly,we consolidate insights into the relationship between point defects and catalytic activity for hydrogen/oxygen evolution and CO_(2)/O_(2)/N_(2) reduction reactions by integrating mechanisms from diverse reactions.This underscores the pivotal role of point defects in enhancing catalytic performance.At last,the principal challenges and prospects associated with point defects in current electrocatalysts are proposed,emphasizing their role in advancing the efficiency of electrochemical energy storage and conversion materials. 展开更多
关键词 Point defect engineering DOPING VACANCY ELECTROCATALYSIS electronic structure
下载PDF
Proton pump inhibitors and all-cause mortality risk among cancer patients
6
作者 Arunkumar Krishnan Carolin Victoria Schneider Declan Walsh 《World Journal of Clinical Oncology》 2025年第1期34-42,共9页
BACKGROUND Proton pump inhibitors(PPIs)are widely used,including among cancer patients,to manage gastroesophageal reflux and other gastric acid-related disorders.Recent evidence suggests associations between long-term... BACKGROUND Proton pump inhibitors(PPIs)are widely used,including among cancer patients,to manage gastroesophageal reflux and other gastric acid-related disorders.Recent evidence suggests associations between long-term PPI use and higher risks for various adverse health outcomes,including greater mortality.AIM To investigate the association between PPI use and all-cause mortality among cancer patients by a comprehensive analysis after adjustment for various confounders and a robust methodological approach to minimize bias.METHODS This retrospective cohort study used data from the TriNetX research network,with electronic health records from multiple healthcare organizations.The study employed a new-user,active comparator design,which compared newly treated PPI users with non-users and newly treated histamine2 receptor antagonists(H2RA)users among adult cancer patients.Newly prescribed PPIs(esomeprazole,lansoprazole,omeprazole,pantoprazole,or rabeprazole)users were compared to non-users or newly prescribed H2RAs(cimetidine,famotidine,nizatidine,or ranitidine)users.The primary outcome was all-cause mortality.Each patient in the main group was matched to a patient in the control group using 1:1 propensity score matching to reduce confounding effects.Multivariable Cox regression models were used to estimate hazard ratios(HRs)and 95% confidence interval(CI).RESULTS During the follow-up period(median 5.4±1.8 years for PPI users and 6.5±1.0 years for non-users),PPI users demonstrated a higher all-cause mortality rate than non-users after 1 year,2 years,and at the end of follow up(HRs:2.34-2.72).Compared with H2RA users,PPI users demonstrated a higher rate of all-cause mortality HR:1.51(95%CI:1.41-1.69).Similar results were observed across sensitivity analyses by excluding deaths from the first 9 months and 1-year post-exposure,confirming the robustness of these findings.In a sensitivity analysis,we analyzed all-cause mortality outcomes between former PPI users and individuals who have never used PPIs,providing insights into the long-term effects of past PPI use.In addition,at 1-year follow-up,the analysis revealed a significant difference in mortality rates between former PPI users and non-users(HR:1.84;95%CI:1.82-1.96).CONCLUSION PPI use among cancer patients was associated with a higher risk of all-cause mortality compared to non-users or H2RA users.These findings emphasize the need for cautious use of PPIs in cancer patients and suggest that alternative treatments should be considered when clinically feasible.However,further studies are needed to corroborate our findings,given the significant adverse outcomes in cancer patients. 展开更多
关键词 All-cause mortality Cancer Histamine-2 receptor antagonists MORTALITY MALIGNANCY proton pump inhibitors CARCINOMA OUTCOME
下载PDF
Constructing Donor–Acceptor‑Linked COFs Electrolytes to Regulate Electron Density and Accelerate the Li^(+)Migration in Quasi‑Solid‑State Battery
7
作者 Genfu Zhao Hang Ma +5 位作者 Conghui Zhang Yongxin Yang Shuyuan Yu Haiye Zhu Yongjiang Sun Hong Guo 《Nano-Micro Letters》 SCIE EI CAS 2025年第1期456-471,共16页
Regulation the electronic density of solid-state electrolyte by donor–acceptor(D–A)system can achieve highly-selective Li^(+)transportation and conduction in solid-state Li metal batteries.This study reports a high-... Regulation the electronic density of solid-state electrolyte by donor–acceptor(D–A)system can achieve highly-selective Li^(+)transportation and conduction in solid-state Li metal batteries.This study reports a high-performance solid-state electrolyte thorough D–A-linked covalent organic frameworks(COFs)based on intramolecular charge transfer interactions.Unlike other reported COFbased solid-state electrolyte,the developed concept with D–A-linked COFs not only achieves electronic modulation to promote highly-selective Li^(+)migration and inhibit Li dendrite,but also offers a crucial opportunity to understand the role of electronic density in solid-state Li metal batteries.The introduced strong electronegativity F-based ligand in COF electrolyte results in highlyselective Li^(+)(transference number 0.83),high ionic conductivity(6.7×10^(-4)S cm^(−1)),excellent cyclic ability(1000 h)in Li metal symmetric cell and high-capacity retention in Li/LiFePO_(4)cell(90.8%for 300 cycles at 5C)than substituted C-and N-based ligands.This is ascribed to outstanding D–A interaction between donor porphyrin and acceptor F atoms,which effectively expedites electron transferring from porphyrin to F-based ligand and enhances Li^(+)kinetics.Consequently,we anticipate that this work creates insight into the strategy for accelerating Li^(+)conduction in high-performance solid-state Li metal batteries through D–A system. 展开更多
关键词 electronic modulation engineering Donor-acceptor-linked covalent organic frameworks Quasi-solid-state Li metal battery
下载PDF
Integration of wearable electronics and heart rate variability for human physical and mental well-being assessment
8
作者 Feifei Yin Jian Chen +4 位作者 Haiying Xue Kai Kang Can Lu Xinyi Chen Yang Li 《Journal of Semiconductors》 2025年第1期58-76,共19页
Heart rate variability(HRV)that can reflect the dynamic balance between the sympathetic nervous and parasympathetic nervous of human autonomic nervous system(ANS)has attracted considerable attention.However,traditiona... Heart rate variability(HRV)that can reflect the dynamic balance between the sympathetic nervous and parasympathetic nervous of human autonomic nervous system(ANS)has attracted considerable attention.However,traditional electrocardiogram(ECG)devices for HRV analysis are bulky,and hard wires are needed to attach measuring electrodes to the chest,resulting in the poor wearable experience during the long-term measurement.Compared with that,wearable electronics enabling continuously cardiac signals monitoring and HRV assessment provide a desirable and promising approach for helping subjects determine sleeping issues,cardiovascular diseases,or other threats to physical and mental well-being.Until now,significant progress and advances have been achieved in wearable electronics for HRV monitoring and applications for predicting human physical and mental well-being.In this review,the latest progress in the integration of wearable electronics and HRV analysis as well as practical applications in assessment of human physical and mental health are included.The commonly used methods and physiological signals for HRV analysis are briefly summarized.Furthermore,we highlighted the research on wearable electronics concerning HRV assessment and diverse applications such as stress estimation,drowsiness detection,etc.Lastly,the current limitations of the integrated wearable HRV system are concluded,and possible solutions in such a research direction are outlined. 展开更多
关键词 wearable electronics HRV analysis physical and mental well-being machine learning stress detection
下载PDF
SlPGR5/SlPGRL1 pathway-dependent cyclic electron transport regulates photoprotection and chloroplast quality in tomato plants
9
作者 Xiaolong Yang Yumeng Zhang +5 位作者 Ting Liu Jiali Shi Mingfang Qi Riyuan Chen Yufeng Liu Tianlai Li 《Horticultural Plant Journal》 2025年第1期211-226,共16页
The essential photoprotective role of proton gradient regulation 5(PGR5)-dependent cyclic electron flow(CEF)has been reported in Arabidopsis,rice,and algae.However,its functional assessment has not been performed in t... The essential photoprotective role of proton gradient regulation 5(PGR5)-dependent cyclic electron flow(CEF)has been reported in Arabidopsis,rice,and algae.However,its functional assessment has not been performed in tomato yet.In this study,we focused on elucidate the function of SlPGR5 and SlPGR5-like photosynthetic phenotype 1(PGRL1)in tomato.We performed RNA interference and found that SlPGR5/SlPGRL1-suppressed transformants exhibited extremely low CO_(2)assimilation capacity,their photosystem I(PSI)and PSII were severely photoinhibited and chloroplasts were obviously damaged.The SlPGR5/SlPGRL1-suppressed plants almost completely inhibited CEF and Y(ND),and PSII photoinhibition may be directly related to the inability to produce sufficient proton motive force to induce NPQ.The transgenic plants overexpressing SlPGR5 and SlPGRL1 driven by 35S promoter capable alleviate photoinhibition of plants under low night temperature.The transcriptomic and proteomic analyses suggested that the nuclear gene transcription and turnover of chloroplast proteins,including the plastoglobule-related proteins,were closely related to SlPGR5/SlPGRL1 pathway dependent CEF.The bridge relationship between CEF and chloroplast quality maintenance was a novel report to our knowledge.In conclusion,these results revealed the regulatory mechanism of the SlPGR5/SlPGRL1 pathway in photoprotection and maintenance of chloroplast function in tomato,which is crucial for reduce yield loss,especially under adverse environmental conditions. 展开更多
关键词 TOMATO Cyclic electron transport SlPGR5/SlPGRL1 PHOTOPROTECTION Chloroplast quality Plastoglobulus
下载PDF
Theoretical Studies on the Mechanism of the Proton-transfer-coupled Electron Transfer Reactions Between Menaquinone Q_A and Ubiquinone Q_B in the Bacterial Photosynthetic Reaction Center of Rhodopseudomona viridis 被引量:1
10
作者 马淑华 徐红 +3 位作者 张汝波 屈正旺 张兴康 张启元 《Acta Botanica Sinica》 CSCD 2002年第12期1409-1417,共9页
The mechanism of the proton_transfer_coupled electron transfer (PT_ET) reactions between the menaquinone Q A (MQ 1) and ubiquinone Q B (UQ 1) in the bacterial photosynthetic reaction center of Rhodopseudomona vi... The mechanism of the proton_transfer_coupled electron transfer (PT_ET) reactions between the menaquinone Q A (MQ 1) and ubiquinone Q B (UQ 1) in the bacterial photosynthetic reaction center of Rhodopseudomona viridis was studied by using the B3LYP/6_31G(d) method. The changes of standard Gibbs free energy ΔG 0 of all possible reactions followed the ET reaction (1) were calculated. The results indicated that: (1) according to the ΔG 0 values of corresponding reactions, UQ 1 could not accept two electrons from MQ - 1 continually without the coupled proton transfer reactions. Because of ΔG 0 2b 0, ΔG 0 3b 0 and ΔG 0 4b 0, the corresponding PT_ET reactions could take place along with reactions (2b), (3b) and (4b) sequentially; (2) on the gaseous condition, the first and second transferred protons (H +(1) and H +(2)) from the surrounding amino acid residues or water molecules will combine with the oxygen No.7 and oxygen No.8 of UQ 1, respectively. On the condition of protein surroundings (by SCRF model, ε =4.0), the results are converse but the energy difference between the combination of H +(1) and H +(2) with UQ - 1 is quite small. The difference of ΔG 0 values between the corresponding reactions in gaseous surroundings and the SCRF model is not significant; (3) the PT_ET reactions between MQ 1 - and UQ 1 - should be as follows: MQ 1 -+UQ 1→MQ 1+UQ 1 - (1) UQ 1 - ( O (7) )+H +( HisL 190)→UQ 1H(2b) ( Gas ) or UQ 1 - ( O (8) )+H +(H 2O)→UQ 1H (2b') ( SCRF ) or UQ 1 - ( O (8) )+H + ( ArgL 217)→UQ 1H(2b') ( SCRF ) MQ 1 -+UQ 1H→MQ 1+UQ 1H - (3b) ( Gas ) MQ 1 -+UQ 1H→MQ 1+UQ 1H -(3b') ( SCR F) UQ 1H -+H +(H 2O)→UQ 1H 2(4b) ( Gas ) or UQ 1H -+H + ( ArgL 217)→UQ 1H 2 (4b) ( Gas ) or UQ 1H -+H + ( HisL 190)→UQ 1H 2 (4b') ( SCRF ) 展开更多
关键词 Rhodopseudomena viridis electron transfer proton transfer Q A and Q B DFT
下载PDF
Analysis of the decrease of two-dimensional electron gas concentration in GaN-based HEMT caused by proton irradiation 被引量:2
11
作者 Jin-Jin Tang Gui-Peng Liu +2 位作者 Jia-Yu Song Gui-Juan Zhao Jian-Hong Yang 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第2期467-471,共5页
Gallium nitride(Ga N)-based high electron mobility transistors(HEMTs)that work in aerospace are exposed to particles radiation,which can cause the degradation in electrical performance.We investigate the effect of pro... Gallium nitride(Ga N)-based high electron mobility transistors(HEMTs)that work in aerospace are exposed to particles radiation,which can cause the degradation in electrical performance.We investigate the effect of proton irradiation on the concentration of two-dimensional electron gas(2 DEG)in Ga N-based HEMTs.Coupled Schr¨odinger’s and Poisson’s equations are solved to calculate the band structure and the concentration of 2 DEG by the self-consistency method,in which the vacancies caused by proton irradiation are taken into account.Proton irradiation simulation for Ga N-based HEMT is carried out using the stopping and range of ions in matter(SRIM)simulation software,after which a theoretical model is established to analyze how proton irradiation affects the concentration of 2 DEG.Irradiated by protons with high fluence and low energy,a large number of Ga vacancies appear inside the device.The results indicate that the ionized Ga vacancies in the Ga N cap layer and the Al Ga N layer will affect the Fermi level,while the Ga vacancies in the Ga N layer will trap the two-dimensional electrons in the potential well.Proton irradiation significantly reduced the concentration of 2 DEG by the combined effect of these two mechanisms. 展开更多
关键词 proton irradiation GaN-based HEMT two-dimensional electron concentration
下载PDF
The Phenomenon of Proton Dissolving in Vacuum and of Proton Condensation from Vacuum. Two Forms of Protons, Structure of Nuclei, Electrons and Atoms 被引量:1
12
作者 Kristina Zubow Anatolij Zubow Viktor A. Zubow 《Journal of Modern Physics》 2010年第3期175-184,共10页
It was investigated how react molecular clusters in water, starch, bio-matrices, polymers and in quartz on gravitation radiation from planets. Gravitation radiation (GR) was found to influence the proton jumping in hy... It was investigated how react molecular clusters in water, starch, bio-matrices, polymers and in quartz on gravitation radiation from planets. Gravitation radiation (GR) was found to influence the proton jumping in hydrogen bonds that stabilize the cluster structure. There was given a method calculating parameters of GR as well as a mechanism of its resonance interaction with weak GR from molecular matter (WGR). WGR has been defined as the result of proton dissolving in vacuum connected with its simultaneous condensation in the nearest free space. Both dissolving and condensation proceed with super light velocity. The gravitation wave length has been determined experimentally and it depends on the planet masses (between Earth and Sun λ ≥ 62 km, between Earth and Milky Way center λ ≥ 330 km). GR has been characterized with super light velocity. After analyzing the Sun influence on water two forms of protons were found: in a condensed and dissolved state. A new model for the atomic nucleus has been suggested according to which the protons in the nucleus oscillate between condensed and dissolved state, where in the case of isotopes this state is partially destroyed. The models for H2 and Be shall be given. Electron orbitals in atoms and molecules were found to be caused by a stationary front of shock waves from condensing protons. 展开更多
关键词 GRAVITATION Waves proton DISSOLVING VACUUM Planets electron Form of Matter
下载PDF
Proton Transmitting Energy Spectra and Transmission Electron Microscope Examinations of Biological Samples 被引量:2
13
作者 TAN Chun-yu XIA Yue-yuan +5 位作者 ZHANG Jian-hua MU Yu-guang WANG Rui-jin LIU Ji-tian LIU Xiang-dong YU Zeng-liang 《Chinese Physics Letters》 SCIE CAS CSCD 1999年第2期123-125,共3页
Transmission energy spectra of 530 keV H^(+) ion penetrating 140μm thick seed coat of maize and fruit peel of grape with thickness of 100μm were measured.The result indicates that these thick biological targets,as s... Transmission energy spectra of 530 keV H^(+) ion penetrating 140μm thick seed coat of maize and fruit peel of grape with thickness of 100μm were measured.The result indicates that these thick biological targets,as seen by the penetrating ions,are inhomogeneous,and there are open“channel like”paths along which the incidentions can transmit the targets easily.While most of the incident ions are stopped in the targets,some of the transmitting ions only lose a small fraction of their initial incident energy.The transmission energy spectra show a pure electronic stopping feature.Transmission electron microscope(TEM)micrographes taken from the samples of seed coat of maize and fruit peel of tomato with thickness of 60μm indicate that 150keV electron beam from the TEM can penetrate the thick samples to give very good images with clear contrasts. 展开更多
关键词 INCIDENT electron INHOMOGENEOUS
下载PDF
Two-temperature warm dense hydrogen as a test of quantum protons driven by orbital-free density functional theory electronic forces 被引量:2
14
作者 Dongdong Kang Kai Luo +1 位作者 Keith Runge S.B.Trickey 《Matter and Radiation at Extremes》 SCIE CAS 2020年第6期48-59,共12页
We consider a steady-state(but transient)situation in which a warm dense aggregate is a two-temperature system with equilibrium electrons at temperature T_(e),ions at T_(i),and T_(e)≠T_(i).Such states are achievable ... We consider a steady-state(but transient)situation in which a warm dense aggregate is a two-temperature system with equilibrium electrons at temperature T_(e),ions at T_(i),and T_(e)≠T_(i).Such states are achievable by pump–probe experiments.For warm dense hydrogen in such a twotemperature situation,we investigate nuclear quantum effects(NQEs)on structure and thermodynamic properties,thereby delineating the limitations of ordinary ab initio molecular dynamics.We use path integral molecular dynamics(PIMD)simulations driven by orbital-free density functional theory(OFDFT)calculations with state-of-the-art noninteracting free-energy and exchange-correlation functionals for the explicit temperature dependence.We calibrate the OFDFT calculations against conventional(explicit orbitals)Kohn–Sham DFT.We find that when the ratio of the ionic thermal de Broglie wavelength to the mean interionic distance is larger than about 0.30,the ionic radial distribution function is meaningfully affected by the inclusion of NQEs.Moreover,NQEs induce a substantial increase in both the ionic and electronic pressures.This confirms the importance of NQEs for highly accurate equation-of-state data on highly driven hydrogen.For Te>20 kK,increasing Te in the warm dense hydrogen has slight effects on the ionic radial distribution function and equation of state in the range of densities considered.In addition,we confirm that compared with thermostatted ring-polymer molecular dynamics,the primitive PIMD algorithm overestimates electronic pressures,a consequence of the overly localized ionic description from the primitive scheme. 展开更多
关键词 ORBITAL QUANTUM electronIC
下载PDF
The front-end electronics design of dose monitors for beam delivery system of Shanghai Advanced Proton Therapy Facility
15
作者 Bin-Qing Zhao Ming-Hua Zhao +2 位作者 Ming Liu Chong-Xian Yin Hang Shu 《Nuclear Science and Techniques》 SCIE CAS CSCD 2017年第6期154-160,共7页
A front-end electronics of dose monitor has been developed for measuring irradiation dose to the patient in Shanghai Advanced Proton Therapy Facility.The parallel plate ionization chamber is used for the dose monitori... A front-end electronics of dose monitor has been developed for measuring irradiation dose to the patient in Shanghai Advanced Proton Therapy Facility.The parallel plate ionization chamber is used for the dose monitoring.Unlike the traditional method of recycling capacitor integration and voltage-to-frequency conversion,this dose monitor electronics uses the trans-impedance amplifier and analog-to-digital conversion method.It performs satisfactorily,with the integral nonlinearity of less than ±0.04 nA in the range of-400 to 50 nA and the resolution of about±0.6 nA. 展开更多
关键词 FRONT-END electronics DOSE MONITOR proton therapy
下载PDF
Comparing Nasal Cavity Radiotherapy Using Electron, Photon, Proton and Photon-Electron Beams
16
作者 Navid Khaledi Foad Goli Ahmadabad +1 位作者 Susan Ebam Roghiye Bodaghi Hosseinabadi 《Journal of Cancer Therapy》 2018年第3期255-261,共7页
Aim: Electron, photon or proton beams are used in radiotherapy for cancer treatment while each one may be used depending on depth and the location of tumor and normal tissues around the treatment target as well as eco... Aim: Electron, photon or proton beams are used in radiotherapy for cancer treatment while each one may be used depending on depth and the location of tumor and normal tissues around the treatment target as well as economic issues. Materials and Methods: In this research, dose distribution by proton was measured by film dosimetry in nasal cavity Plexiglas phantom and Monte Carlo simulation. Then the DVH of treatment target and the posterior of treatment target of different beams were compared. The energies of electron, photon and proton were 9 MeV, 6 MV, and maximum 65 MeV, respectively. Due to a depth of 3.5 cm of CTV (Clinical Target Volume), Modulation Range was between 0 - 3.5 cm and SOBP (Spread-out Bragg Peak) was between 0 - 65 MeV. Results: Comparing the obtained DVH values, 95% dose coverage of target volume for electron, photon, proton and Photon-Electron beams were 88%, 98%, 98%, and 95%, respectively. However, doses above 40% that reached outside the target were 50%, 82%, 5%, and 44%, respectively. Conclusions: The results demonstrate the superiority of proton therapy in nasal cancer due to its better target volume coverage and the less amount of the dose reaching outside the target that is because of dose discharge in a small area and significant dose fall-off after Bragg peak. 展开更多
关键词 electron PHOTON proton Mixed Beam Monte Carlo Film DOSIMETRY NASAL Cavity Cancer
下载PDF
Towards electrochemical hydrogen storage in liquid organic hydrogen carriers via proton-coupled electron transfers 被引量:1
17
作者 Hamid Ghorbani Shiraz Mikhail Vagin +7 位作者 Tero-Petri Ruoko Viktor Gueskine Krzysztof Karon Mieczystaw tapkowski Tobias Abrahamsson Thomas Ederth Magnus Berggren Xavier Crispin 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2022年第10期292-300,I0007,共10页
Green hydrogen is identified as one of the prime clean energy carriers due to its high energy density and a zero emission of CO_(2).A possible solution for the transport of H_(2)in a safe and low-cost way is in the fo... Green hydrogen is identified as one of the prime clean energy carriers due to its high energy density and a zero emission of CO_(2).A possible solution for the transport of H_(2)in a safe and low-cost way is in the form of liquid organic hydrogen carriers(LOHCs).As an alternative to loading LOHC with H_(2)via a two-step procedure involving preliminary electrolytic production of H_(2)and subsequent chemical hydrogenation of the LOHC,we explore here the possibility of electrochemical hydrogen storage(EHS)via conversion of proton of a proton donor into a hydrogen atom involved in covalent bonds with the LOHC(R)via a protoncoupled electron transfer(PCET)reaction:2nH^(+)+2ne^(-)+Rox■n H_(2)^(0)Rred.We chose 9-fluorenone/fluorenol(Fnone/Fnol)conversion as such a model PCET reaction.The electrochemical activation of Fnone via two sequential electron transfers was monitored with in-situ and operando spectroscopies in absence and in presence of different alcohols as proton donors of different reactivity,which enabled us to both quantify and get the mechanistic insight on PCET.The possibility of hydrogen extraction from the loaded carrier molecule was illustrated by chemical activation. 展开更多
关键词 proton-coupled electron transfer Electrochemical hydrogen storage Hydrogen bonding agent Anion-radical Comproportionation
下载PDF
The Angular Momenta Dipole Moments and Gyromagnetic Ratios of the Electron and the Proton
18
作者 A. Georgiou 《Journal of Modern Physics》 2014年第14期1254-1257,共4页
We had previously obtained analytical formulae for the dipole moments and angular momenta of rotating spherical bodies. The resulting formulae were applied to the Sun, the star 78 Virginis and the Earth. The agreement... We had previously obtained analytical formulae for the dipole moments and angular momenta of rotating spherical bodies. The resulting formulae were applied to the Sun, the star 78 Virginis and the Earth. The agreement of the theoretical formulae with the actual real situations is indeed remarkable. In this note we apply the same formulae to the electron and the proton, using the classical values of the radii, so no quantum mechanical treatment is considered. 展开更多
关键词 ANGULAR MOMENTA DIPOLE MOMENTS electron proton
下载PDF
High energy electron beam generation during interaction of a laser accelerated proton beam with a gas-discharge plasma
19
作者 Wangwen XU Zhanghu HU +1 位作者 Dexuan HUI Younian WANG 《Plasma Science and Technology》 SCIE EI CAS CSCD 2022年第5期75-79,共5页
The study of the interaction between ion beam and plasma is very important to the areas of inertial fusion energy and high energy density physics. With detailed one-dimensional electromagnetic particle-in-cell simulat... The study of the interaction between ion beam and plasma is very important to the areas of inertial fusion energy and high energy density physics. With detailed one-dimensional electromagnetic particle-in-cell simulations, we investigate here the interaction of a laseraccelerated proton beam assuming an ideal monoenergetic beam with a gas-discharge plasma.After the saturation stage of the two-stream instability excited by the proton beam, significant high energy electrons are observed, with maximum energy approaching 2 MeV, and a new twostream instability occurs between the high energy electrons and background electrons. The trajectories of plasma electrons are studied, showing the process of electron trapping and detrapping from the wakefield. 展开更多
关键词 electron beam proton beam two-stream instability particle-in-cell simulation
下载PDF
A Generic Strategy to Create Mechanically Interlocked Nanocomposite/Hydrogel Hybrid Electrodes for Epidermal Electronics 被引量:2
20
作者 Qian Wang Yanyan Li +7 位作者 Yong Lin Yuping Sun Chong Bai Haorun Guo Ting Fang Gaohua Hu Yanqing Lu Desheng Kong 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第5期120-133,共14页
Stretchable electronics are crucial enablers for next-generation wearables intimately integrated into the human body.As the primary compliant conductors used in these devices,metallic nanostructure/elastomer composite... Stretchable electronics are crucial enablers for next-generation wearables intimately integrated into the human body.As the primary compliant conductors used in these devices,metallic nanostructure/elastomer composites often struggle to form conformal contact with the textured skin.Hybrid electrodes have been consequently developed based on conductive nanocomposite and soft hydrogels to establish seamless skin-device interfaces.However,chemical modifications are typically needed for reliable bonding,which can alter their original properties.To overcome this limitation,this study presents a facile fabrication approach for mechanically interlocked nanocomposite/hydrogel hybrid electrodes.In this physical process,soft microfoams are thermally laminated on silver nanowire nanocomposites as a porous interface,which forms an interpenetrating network with the hydrogel.The microfoam-enabled bonding strategy is generally compatible with various polymers.The resulting interlocked hybrids have a 28-fold improved interfacial toughness compared to directly stacked hybrids.These electrodes achieve firm attachment to the skin and low contact impedance using tissue-adhesive hydrogels.They have been successfully integrated into an epidermal sleeve to distinguish hand gestures by sensing mus-cle contractions.Interlocked nanocomposite/hydrogel hybrids reported here offer a promising platform to combine the benefits of both materials for epidermal devices and systems. 展开更多
关键词 Stretchable electronics Epidermal electronics Silver nanowire Conductive nanocomposites HYDROGEL
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部