期刊文献+
共找到2,690篇文章
< 1 2 135 >
每页显示 20 50 100
Development and clinical evaluation of a supramolecular acid-enzyme complex for skin exfoliation,sebum control,and pore refinement 被引量:1
1
作者 Huwu Zhou Wenrong Zhang +3 位作者 Xuewan Li Rongrong Li Changzhi Dong Lifeng Tang 《Journal of Dermatologic Science and Cosmetic Technology》 2025年第3期37-44,共8页
Background:Enzyme fragility remains a major challenge in research and applications.Free enzymes are highly unstable,inactivated by heat,acid,alkali,or organic solvents,and often lose activity even under optimal storag... Background:Enzyme fragility remains a major challenge in research and applications.Free enzymes are highly unstable,inactivated by heat,acid,alkali,or organic solvents,and often lose activity even under optimal storage conditions.Limiting their use in cosmetics.Few commercial products combine acids and enzymes effectively.Objective:To investigate the physicochemical properties,in vitro exfoliation efficacy,and effects on facial skin parameters of a supramolecular acid-enzyme complex(SAE)composed of mandelic acid(MAN),betaine(BET),and composite enzymes(CE;papain and bromelain),thereby establishing a theoretical foundation for cosmetic applications.Methods:The supramolecular structure was characterized using Fourier transform infrared(FTIR)spectroscopy and proton nuclear magnetic resonance(1H NMR)spectroscopy.Dissolution experiments were conducted to compare the solubility of SAE and CE in aqueous solutions.Enzymatic activity assays evaluated the stabilizing effect of supramolecular deep eutectic technology on enzymes.In vitro exfoliation tests assessed acid-enzyme synergy in keratin removal.A 4-week clinical trial evaluated the efficacy of a 2%SAE essence aqueous solution on facial skin parameters.Results:Dissolution experiments confirmed that supramolecular deep eutectic technology significantly improved enzyme solubility.Enzymatic activity tests demonstrated that this technology effectively preserved protease activity,substantially enhancing its practical applicability.Furthermore,in vitro exfoliation efficacy tests revealed that this technology strengthened the synergistic interaction between acids and enzymes and exhibited superior stratum corneum-removing capability of the SAE.In clinical evaluations of efficacy,after 7 days of using the essence containing SAE,the formulation significantly enhanced cheek gloss(+8.08%),while reducing comedones volume(-16.25%).after 28 days,significantly enhanced cheek hydration(+25.0%,SCH),gloss(+15.93%),and smoothness(−7.78%SEsm),while reducing TEWL(−6.86%),sebum(−15.54%),roughness(+16.24%SEr),and pore metrics(volume:−39.98%;count:−30.64%),and decreased comedones(blackheads:−70.33%;Whiteheads:−52.42%;all p<0.05).Conclusion:The supramolecular acid-enzyme complex demonstrates enhanced stability,improved solubility,and superior exfoliation efficacy compared to free enzymes.Clinical results further confirm its multifunctional benefits,including enhancing skin hydration,sebum regulation,barrier repair,pore refinement,and comedolytic effects.This study provides both theoretical and practical foundations for developing stable acid-enzyme combinations in dermatological applications. 展开更多
关键词 Supramolecular acid-enzyme complex Acid-enzyme synergy Enzymatic stability Cosmetic exfoliation Sebum regulation Pore refinement Comedolytic effects
在线阅读 下载PDF
Prediction of temperature and strain rate dependent flow behaviors for AA6061-T4 sheet using phenomenology and machine learning-based approaches
2
作者 Zhi-hao WANG D.GUINES +2 位作者 Jia-shuo QI Xing-rong CHU L.LEOTOING 《Transactions of Nonferrous Metals Society of China》 2025年第11期3617-3637,共21页
The plastic flow behaviors of AA6061-T4 sheets at different temperatures(21-300°C)and strain rates(0.002-4 s^(-1))were studied.Significant nonlinear effects of temperature and strain rate on flow behaviors were r... The plastic flow behaviors of AA6061-T4 sheets at different temperatures(21-300°C)and strain rates(0.002-4 s^(-1))were studied.Significant nonlinear effects of temperature and strain rate on flow behaviors were revealed,as well as underlying micromechanical factors.Phenomenology and machine learning-based constitutive models were developed.Both models were formulated in the framework of a temperature-dependent linear combination regulated by a transition function to capture the evolution of strain-hardening behavior with increasing temperature.Novel mathematical functions for describing temperature and strain rate sensitivities were formulated for the phenomenological constitutive model.The threshold temperature related to microstructure evolution was considered in the modeling.A data-enrichment strategy based on extrapolating experimental data via classical strain hardening laws was adopted to improve neural network training.An efficient inverse identification strategy,focusing solely on the transition function,was proposed to enhance the prediction accuracy of post-necking deformation by both constitutive models. 展开更多
关键词 AA6061-T4 sheet thermo-visco-plasticity constitutive model machine learning strain rate and temperature effects
在线阅读 下载PDF
A Flexible Decision Method for Holonic Smart Grids
3
作者 Ihab Taleb Guillaume Guerard +2 位作者 Frédéric Fauberteau Nga Nguyen Pascal Clain 《Computer Modeling in Engineering & Sciences》 2025年第10期597-619,共23页
Isolated power systems,such as those on islands,face acute challenges in balancing energy demand with limited generation resources,making them particularly vulnerable to disruptions.This paper addresses these challeng... Isolated power systems,such as those on islands,face acute challenges in balancing energy demand with limited generation resources,making them particularly vulnerable to disruptions.This paper addresses these challenges by proposing a novel control and simulation framework based on a holonic multi-agent architecture,specifically developed as a digital twin for the Mayotte island grid.The primary contribution is a multi-objective optimization model,driven by a genetic algorithm,designed to enhance grid resilience through intelligent,decentralized decisionmaking.The efficacy of this architecture is validated through three distinct simulation scenarios:(1)a baseline scenario establishing nominal grid operation;(2)a critical disruption involving the failure of a major power plant;and(3)a localized fault resulting in the complete disconnection of a regional sub-grid.The major results demonstrate the system’s dual resilience mechanisms.In the plant failure scenario,the top-level holon successfully managed a global energy deficit by optimally reallocating shared resources,prioritizing grid stability over complete demand satisfaction.In the disconnection scenario,the affected holon demonstrated true autonomy,transitioning seamlessly into a selfsufficient islanded microgrid to prevent a cascading failure.Collectively,these findings validate the holonic model as a robust decision-support tool capable of managing both systemic and localized faults,thereby significantly enhancing the operational resilience and stability of isolated smart grids. 展开更多
关键词 Smart grid holonic architecture multi agent system energy management system OPTIMIZATION
在线阅读 下载PDF
Exercise-Induced Bronchospasm, Prevalence and Associated Factors in University Students in STAPS
4
作者 Paul Roger Mabounda Kounga Alain Boussana +1 位作者 Florent Nsompi Hue Olivier 《Journal of Biosciences and Medicines》 2025年第1期92-101,共10页
Background: There are links between physical exercise, fine particles and the prevalence of exercise-induced bronchospasm (EIB). Objective: The aim of this study was to assess the prevalence of exercise-induced bronch... Background: There are links between physical exercise, fine particles and the prevalence of exercise-induced bronchospasm (EIB). Objective: The aim of this study was to assess the prevalence of exercise-induced bronchospasm in students of sciences and techniques of physical activities and sports (STAPS) exercising in a hot, humid and relatively polluted environment. Methods: Twenty-two first-year undergraduate students, including 11 in PE and 11 in SPORT, aged 21.64 ± 1.80 years, participated in a football match. Resting spirometry was performed before and 5 minutes after the match. During the match, particulate matter (PM2.5 and PM10) was measured every 10 minutes around the football pitch. Ambient temperature and relative humidity were recorded. The diagnosis of EIB was based on a decrease in FEV1 of at least 10% after the match. If there was a decrease, the participant was considered susceptible to EIB. Results: Five subjects were positive for exercise-induced bronchospasm, a percentage of 22%. Ambient temperature and relative humidity were 34.22˚C ± 1.38˚C and 52.2% ± 4.97%, respectively. Concentrations of PM2.5 and PM10 were between 53.3 - 115.5 µg/m3 and 75.5 - 168.2 µg/m3, respectively, exceeding WHO limits. Conclusion: These results show a high incidence of exercise-induced bronchospasm in students without a history of asthma but exercising in a hot, humid and environment polluted by fine particles. 展开更多
关键词 BRONCHOCONSTRICTION Air Pollution Sports Health Respiratory Asthma ATHLETE
在线阅读 下载PDF
High-cycle fatigue life improvement of a PtAl-coated third-generation Ni-based single-crystal superalloy after thermal exposure
5
作者 Dong Sun Siliang He +4 位作者 Longfei Li Song Lu Weiwei Zheng Jonathan Cormier Qiang Feng 《International Journal of Minerals,Metallurgy and Materials》 2025年第9期2200-2210,共11页
The as-deposited coating-substrate microstructure has been identified to substantially influence the high-cycle fatigue(HCF)behavior of Ni-based single-crystal(SX)superalloys at 900℃,but the impact of degraded micros... The as-deposited coating-substrate microstructure has been identified to substantially influence the high-cycle fatigue(HCF)behavior of Ni-based single-crystal(SX)superalloys at 900℃,but the impact of degraded microstructure on the HCF behavior remains unclear.In this work,a PtAl-coated third-generation SX superalloy with sheet specimen was thermal-exposed at 1100℃ with different durations and then subjected to HCF tests at 900℃.The influence of microstructural degradation on the HCF life and crack initiation were clarified by analyzing the development of microcracks and coating-substrate microstructure.Notably,the HCF life of the thermal-exposed coated alloy increased abnormally,which was attributed to the transformation of the fatigue crack initiation site from surface mi-crocracks to internal micropores compared to the as-deposited coated alloy.Although the nucleation and growth of surface microcracks occurred along the grain boundaries in the coating and the interdiffusion zone(IDZ)for both the as-deposited and the thermal-exposed coated alloys,remarkable differences of the microcrack growth into the substrate adjacent to the IDZ were observed,changing the crack initiation site.Specifically,the surface microcracks grew into the substrate through the cracking of the non-protective oxide layers in the as-deposited coated alloy.In comparison,the hinderance of the surface microcracks growth was found in the thermal-exposed coated al-loy,due to the formation of a protective Al_(2)O_(3) layer within the microcrack and theγ′rafting in the substrate close to the IDZ.This study will aid in improving the HCF life prediction model for the coated SX superalloys. 展开更多
关键词 platinum-aluminide coating single-crystal superalloy high-cycle fatigue INTERDIFFUSION surface microcracks coating-substrate microstructure
在线阅读 下载PDF
Impact of COVID-19 care reorganization on the prognosis of patients with bladder urothelial carcinoma:a multicentric retrospective study
6
作者 Marie Chaumel Nicolas Brichart +1 位作者 Franck Bruyère Ali Bourgi 《The Canadian Journal of Urology》 2025年第4期359-366,共8页
Background:The COVID-19 pandemic disrupted healthcare systems globally,raising concerns about delayed cancer diagnosis and treatment.In France,transurethral resection of bladder tumors(TURBT)was prioritized in nationa... Background:The COVID-19 pandemic disrupted healthcare systems globally,raising concerns about delayed cancer diagnosis and treatment.In France,transurethral resection of bladder tumors(TURBT)was prioritized in national urology guidelines to ensure the timely management of urothelial carcinoma.This study aimed to assess the impact of care reorganization on tumor staging,recurrence,palliative care,and mortality in bladder cancer patients from the pre-pandemic through late-pandemic periods.Methods:We conducted a retrospective multicenter study including all patients who underwent TURBT with histologically confirmed urothelial carcinoma between April and December of 2019(pre-pandemic),2020(early pandemic),2021(mid-pandemic),and 2022(late pandemic)in two French institutions.TURBT indications were categorized as diagnostic,palliative,or staging.Clinical and pathological data were compared across the four periods.Statistical analyses included Chi-square tests,Estimated Annual Percentage Change(EAPC),and multivariable logistic regression adjusted for age,sex,ASA score,and center.Results:A total of 790 TURBT procedures were analyzed.The proportion of muscle-invasive bladder cancer(pT≥2)declined over time(18.7%in 2019 to 13.2%in 2022;p=0.63),while superficial tumors(pTa)increased(57.2%to 65.5%).All-cause mortality significantly decreased from 38.0%in 2019 to 22.0%in 2020,20.5%in 2021,and 19.5%in 2022(p=0.006).EAPC showed a significant annual decline in mortality(–24.3%,p=0.004).In multivariable analysis,2020,2021,and 2022 were each associated with significantly lower odds of mortality compared to 2019.Recurrence rates remained stable across all periods(p=0.93).Interhospital variation persisted in mortality and recurrence.Conclusions:Despite the pandemic,urothelial bladder cancer outcomes did not worsen through 2022.On the contrary,timely reorganization,prioritization of TURBT,and triage strategies were associated with reduced mortality and palliative care needs,highlighting the resilience of cancer care when guided by adaptive health policies. 展开更多
关键词 urothelial carcinoma bladder tumor transurethral resection of bladder tumors(TURBT) COVID-19 PANDEMIC cancer prognosis MORTALITY RECURRENCE
暂未订购
Social insects behind the microgranular structure of Ferralsols: Consequences for their physical fertility when cultivated
7
作者 Ary BRUAND 《Pedosphere》 2025年第1期17-19,共3页
It was long accepted that the microgranular structure of many Ferralsols was mainly related to physicochemical processes and to their mineralogical composition. It now appears, however, that this microgranular structu... It was long accepted that the microgranular structure of many Ferralsols was mainly related to physicochemical processes and to their mineralogical composition. It now appears, however, that this microgranular structure originates from the burrowing activity of termites and ants. Given its importance for the physical properties of Ferralsols, it will be necessary to study the different termite and ant species responsible for this microgranular structure and the characteristics of the burrowing activity associated with species. 展开更多
关键词 SPECIES structure composition
原文传递
OsEXO70L2 is required for large lateral root formation and arbuscular mycorrhiza establishment in rice
8
作者 Tongming Wang Kai Zhou +2 位作者 Bingxian Yang Benoit Lefebvre Guanghua He 《Journal of Integrative Agriculture》 2025年第6期2035-2045,共11页
As a major subunit of the exocyst complex,members of the EXO70 family have mainly been shown to play roles in cell polarity and morphogenesis in Arabidopsis,but their roles in plant endosymbiosis,such as with arbuscul... As a major subunit of the exocyst complex,members of the EXO70 family have mainly been shown to play roles in cell polarity and morphogenesis in Arabidopsis,but their roles in plant endosymbiosis,such as with arbuscular mycorrhizal fungi(AMF),have rarely been reported.Here,using knockout and overexpression lines,we show that OsEXO70L2,which encodes a divergent EXO70 protein in rice,controls the number of primary roots and is essential for large lateral root formation.Furthermore,the OsEXO70L2 mutant sr1 displayed rare internal AMF hyphaeand no arbuscules.We also found that AMF sporulation can occur in roots despite low colonization and that AMF colonization and sporulation are modulated by photoperiod and co-culture with clover.Finally,genes related to auxin homeostasis were found to be affected in the OsEXO70L2 knockout or overexpression lines,suggesting that auxin is at least partly responsible for the phenotypes.This study provides new perspectives on the role of the exocyst complex during root development and AM in rice. 展开更多
关键词 RICE EXO70 root formation arbuscular mycorrhizal SPORULATION
在线阅读 下载PDF
Synchronization of a fractional-order chaotic memristive system and its application to secure image transmission
9
作者 Lamia Chouchane Hamid Hamiche +2 位作者 Karim Kemih Ouerdia Megherbi Karim Labadi 《Chinese Physics B》 2025年第12期174-191,共18页
The dynamics of chaotic memristor-based systems offer promising potential for secure communication.However,existing solutions frequently suffer from drawbacks such as slow synchronization,low key diversity,and poor no... The dynamics of chaotic memristor-based systems offer promising potential for secure communication.However,existing solutions frequently suffer from drawbacks such as slow synchronization,low key diversity,and poor noise resistance.To overcome these issues,a novel fractional-order chaotic system incorporating a memristor emulator derived from the Shinriki oscillator is proposed.The main contribution lies in the enhanced dynamic complexity and flexibility of the proposed architecture,making it suitable for cryptographic applications.Furthermore,the feasibility of synchronization to ensure secure data transmission is demonstrated through the validation of two strategies:an active control method ensuring asymptotic convergence,and a finite-time control method enabling faster stabilization.The robustness of the scheme is confirmed by simulation results on a color image:χ^(2)=253/237/267(R/G/B);entropy≈7.993;correlations between adjacent pixels in all directions are close to zero(e.g.,-0.0318 vertically);and high number of pixel change rate and unified average changing intensity(e.g.,33.40%and 99.61%,respectively).Peak signal-to-noise ratio analysis shows that resilience to noise and external disturbances is maintained.It is shown that multiple fractional orders further enrich the chaotic behavior,increasing the systems suitability for secure communication in embedded environments.These findings highlight the relevance of fractional-order chaotic memristive systems for lightweight secure transmission applications. 展开更多
关键词 MEMRISTOR fractional-order chaotic system SYNCHRONIZATION finite-time control active control CRYPTOGRAPHY secure communications
原文传递
X-ray transition and K-edge energies in dense finite-temperature plasmas:Challenges of a generalized approach with spectroscopic precision
10
作者 X.Li F.B.Rosmej 《Matter and Radiation at Extremes》 2025年第2期1-15,共15页
The capacity to predict X-ray transition and K-edge energies in dense finite-temperatur plasmas with high precision is of primary importance for atomic physics of matter under extreme conditions.The dual characteristi... The capacity to predict X-ray transition and K-edge energies in dense finite-temperatur plasmas with high precision is of primary importance for atomic physics of matter under extreme conditions.The dual characteristics of bound and continuum states in dense matter are modeled by a valence-band-like structure in a generalized ion-sphere approach with states that are either bound,free,or mixed.The self-consistent combination of this model with the Dirac wave equations of multielectron bound states allows one to fully respect the Pauli principle and to take into account the exact nonlocal exchange terms.The generalized method allows very high precision without implication of calibration shifts and scaling parameters and therefore has predictive power.This leads to new insights in the analysis of various data.The simple ionization model representing the K-edge is generalized to excitation–ionization phenomena resulting in an advanced interpretation of ionization depression data in near-solid-density plasmas.The model predicts scaling relations along the isoelectronic sequences and the existence of bound M-states that are in excellent agreement with experimental data,whereas other methods have failed.The application to unexplained data from compound materials also gives good agreement without the need to invoke any additional assumptions in the generalized model,whereas other methods have lacked consistency. 展开更多
关键词 atomic physics matter dirac wave equations multielectron bound states spectroscopic precision x ray transitions k edge energies generalized approach valence band structure bound continuum states
在线阅读 下载PDF
Fostering hope and recovery:enhancing psychological resources in military personnel with post-traumatic stress disorder
11
作者 Bénédicte Aubet Charles Martin-Krumm Marion Trousselard 《Military Medical Research》 2025年第10期1670-1672,共3页
Dear Editor,Post-traumatic stress disorder(PTSD)is a major issue for military personnel,with prevalence rates between 1%and 35%in veterans^([1]),significantly higher than in the general population^([2]).Psychological ... Dear Editor,Post-traumatic stress disorder(PTSD)is a major issue for military personnel,with prevalence rates between 1%and 35%in veterans^([1]),significantly higher than in the general population^([2]).Psychological resources,particularly hope,can protect against PTSD and promote post-traumatic growth^([3]).Hope,conceptualized as both a trait and a state,contributes to well-being and resilience and is negatively associated with PTSD symptoms,representing a psychological factor while mitigating the impact of trauma by fostering resilience and adaptive coping mechanisms. 展开更多
关键词 Post-traumatic stress disorder(PTSD) HOPE SELF-ESTEEM Positive mental health WELL-BEING Military personnel REHABILITATION
原文传递
Preferential fatigue cracking at basal twist grain boundary (BTGB) in bimodal Ti-5Al-4V alloy: Dislocation activities and crack initiation
12
作者 Zhihong Wu Hongchao Kou +6 位作者 Jinshan Li Samuel Hémery Tong Li Carlo Franke Nana Chen Frédéric Prima Fan Sun 《Journal of Materials Science & Technology》 2025年第14期281-295,共15页
In recent years,(0001)twist grain boundaries(BTGBs)located in primary α grain clusters were identified as fatigue crack nucleation sites in different Ti alloys.In the present study,crack initiation was investigated i... In recent years,(0001)twist grain boundaries(BTGBs)located in primary α grain clusters were identified as fatigue crack nucleation sites in different Ti alloys.In the present study,crack initiation was investigated in a bimodal Ti-5Al-4 V alloy subjected to low-cycle fatigue and dwell-fatigue loadings at room temperature.The low fraction of primary α grains was not associated with a lack of sensitivity to BTGB cracking.Transmission electron microscopy and electron back-scattered diffraction were used to characterize BTGBs in the initial microstructure.The fatigue mechanisms were then analyzed with a focus on dislocation activity.α_(p) grains adjacent to cracked BTGBs contained a high dislocation density.It was primarily composed of planar slip bands of dislocations.In addition,<c+a>dislocations were noticed in the vicinity of cracked BTGBs.They supposedly pertain to crack tip plasticity during growth,and no evidence of a role of an incoming slip event in crack nucleation was obtained.Also,basal slip bands extending across adjacent grains were found to emerge from BTGBs.This feature provides an easier path for crack extension when growth along the grain boundary becomes difficult owing to a deviation from the basal plane.Atom probe tomography analyses evidenced V and Fe segregation at a grain boundary with a significant deviation from the BTGB configuration.This suggests a possible contribution of local solute segregation to the high cracking resistance of general α_(p)/α_(p) grain boundaries.This work provides new insights into the mechanisms involved in cracking of BTGB in Ti alloys subjected to cyclic loadings. 展开更多
关键词 Low cycle fatigue Titanium alloy Crack initiation Twist boundary Dislocations
原文传递
Secure Medical Image Transmission Using Chaotic Encryption and Blockchain-Based Integrity Verification
13
作者 Rim Amdouni Mahdi Madani +2 位作者 Mohamed Ali Hajjaji El Bay Bourennane Mohamed Atri 《Computers, Materials & Continua》 2025年第9期5527-5553,共27页
Ensuring the integrity and confidentiality of patient medical information is a critical priority in the healthcare sector.In the context of security,this paper proposes a novel encryption algorithm that integrates Blo... Ensuring the integrity and confidentiality of patient medical information is a critical priority in the healthcare sector.In the context of security,this paper proposes a novel encryption algorithm that integrates Blockchain technology,aiming to improve the security and privacy of transmitted data.The proposed encryption algorithm is a block-cipher image encryption scheme based on different chaotic maps:The logistic Map,the Tent Map,and the Henon Map used to generate three encryption keys.The proposed block-cipher system employs the Hilbert curve to perform permutation while a generated chaos-based S-Box is used to perform substitution.Furthermore,the integration of a Blockchain-based solution for securing data transmission and communication between nodes and authenticating the encrypted medical image’s authenticity adds a layer of security to our proposed method.Our proposed cryptosystem is divided into two principal modules presented as a pseudo-random number generator(PRNG)used for key generation and an encryption and decryption system based on the properties of confusion and diffusion.The security analysis and experimental tests for the proposed algorithm show that the average value of the information entropy of the encrypted images is 7.9993,the Number of Pixels Change Rate(NPCR)values are over 99.5%and the Unified Average Changing Intensity(UACI)values are greater than 33%.These results prove the strength of our proposed approach,demonstrating that it can significantly enhance the security of encrypted images. 展开更多
关键词 Medical image encryption chaotic maps blockchain substitution-Box security INTEGRITY
在线阅读 下载PDF
Evolutionary factors and habitat filtering affect the pattern of Gerbillinae diversity
14
作者 Yaqian Cui Jilong Cheng +6 位作者 Zhixin Wen Anderson Feijó Lin Xia Deyan Ge Emmanuelle Artige Laurent Granjon Qisen Yang 《Current Zoology》 2025年第1期65-78,共14页
How ecological and evolutionary factors affect small mammal diversity in arid regions remains largely unknown.Here,we combined the largest phylogeny and occurrence dataset of Gerbillinae desert rodents to explore the ... How ecological and evolutionary factors affect small mammal diversity in arid regions remains largely unknown.Here,we combined the largest phylogeny and occurrence dataset of Gerbillinae desert rodents to explore the underlying factors shaping present-day distribution patterns.In particular,we analyzed the relative contributions of ecological and evolutionary factors on their species diversity using a variety of models.Additionally,we inferred the ancestral range and possible dispersal scenarios and estimated the diversification rate of Gerbillinae.We found that Gerbillinae likely originated in the Horn of Africa in the Middle Miocene and then dispersed and diversified across arid regions in northern and southern Africa and western and central Asia,forming their current distribution pattern.Multiple ecological and evolutionary factors jointly determine the spatial pattern of Gerbillinae diversity,but evolutionary factors(evolutionary time and speciation rate)and habitat filtering were the most important in explaining the spatial variation in species richness.Our study enhances the understanding of the diversity patterns of small mammals in arid regions and highlights the importance of including evolutionary factors when interpreting the mechanisms underlying large-scale species diversity patterns. 展开更多
关键词 arid regions evolutionary time GERBILLINAE habitat filtering landcover speciation rate
原文传递
Effects of Zr^(4+)and Hf^(4+)co-doping on luminescence and scintillation properties of LuYAG:Pr^(3+)single crystals grown by micro-pulling-down technique
15
作者 Yufeng Tong Yunyun Li +6 位作者 Qingsong Song Jie Xu Xiaodong Xu Mikhail Korzhik Jun Xu Kheirreddine Lebbou Yuntao Wu 《Journal of Rare Earths》 2025年第4期701-706,I0003,共7页
In this study,we aim to clarify the luminescence and scintillation performance of 0.2 at%Pr^(3+)-doped LuYAG scintillators with either zirconium or hafnium co-doping obtained using the micro-pulling-down(μ-PD)method.... In this study,we aim to clarify the luminescence and scintillation performance of 0.2 at%Pr^(3+)-doped LuYAG scintillators with either zirconium or hafnium co-doping obtained using the micro-pulling-down(μ-PD)method.Under radiation excitation,scintillation properties such as light yield,decay time,and afterglow level were measured and compared to non-co-doped LuYAG:Pr^(3+).The positive effect of Zr and Hf co-doping is to significantly shorten the scintillation time response.The negative effect is the decrease of scintillation yield and increase of afterglow.We propose that the positively charged defects induced by Zr/Hf co-doping are responsible for the spatial correlated traps around Pr centers causing the shortened scintillation decay via non-radiative recombination processes,and the deep traps as well for the prolonged afterglow. 展开更多
关键词 LuYAG:Pr SCINTILLATORS CO-DOPING ZIRCONIUM HAFNIUM μ-PD
原文传递
Engineering core-shell-structured BaAl_(2)O_(4)overlaid Ni catalyst with strong metal-support interaction for durable and efficient CH_(4) dry reforming
16
作者 Qiangqiang Xue Kang Hui Lim +7 位作者 Zhehao Sun Binhang Yan Zongyou Yin Ange Nzihou Yujun Wang Guangsheng Luo Feng-Shou Xiao Sibudjing Kawi 《Journal of Energy Chemistry》 2025年第10期807-819,共13页
Dry reforming of methane(DRM)over Ni-based catalysts is an economically reasonable technology for large-scale CO_(2)utilization.However,prolonged Ni sintering and carbon deposition reduce the durability and efficiency... Dry reforming of methane(DRM)over Ni-based catalysts is an economically reasonable technology for large-scale CO_(2)utilization.However,prolonged Ni sintering and carbon deposition reduce the durability and efficiency of DRM,hindering its engineering application.Herein,we propose a facile approach by combining continuous microscale coprecipitation with solid-state reactions to construct a BaAl_(2)O_(4)-overlayer-confined Ni catalyst.The 5-wt%-Ni@BaAl_(2)O_(4)catalyst exhibited advanced CO_(2)and CH_(4)conversions of 96% and 86% at 800℃ and a GHSV of 144 L g_(cat)^(-1).h^(-1).Moreover,the k_(d)-CO_(2)and k_(d)-CH_(4)of Ni@BaAl_(2)O_(4)were 0.0063 and 0.0029 h^(-1);which are approximately half and one-thirds of those of Ni/BaAl_(2)O_(4)and slightly better than those of Ni@MgAl_(2)O_(4),underscoring the versatility of the proposed synthesis protocol for constructing core-shell structures.XAS,HAADF-STEM-EDS,and CO transmission-IR characterizations confirmed the SMSI of~2-nm amorphous BaAl_(2)O_(4)-overlaid~10 nm Ni with an overall mesoporous structure.After a long-term test,the sintering and coking inhibition effects of Ni@BaAl_(2)O_(4)(10→11 nm,0.55 mgCg_(cat)^(-1).h^(-1))outperformed Ni/BaAl_(2)O_(4)(13→22 nm,1.90 mgCg_(cat)^(-1).h^(-1))and Ni@MgAl_(2)O_(4).In situ time-resolved CH4→CO_(2)transient response,DRIFTS experiments,and DFT calculations suggested that Ni@BaAl_(2)O_(4)and Ni/BaAl_(2)O_(4)followed the Mars-van Krevelen and Langmuir-Hinshelwood redox mechanisms,respectively.The functional interfacial lattice oxygen promoted the removal of C_(ads)^(*)on Ni and core-shell structure induced fast CO_(2)adsorption and CO desorption.The present study provides a facile approach for constructing a stable and active Ni-based core-shell catalyst.Furthermore,it offers novel insights into the functionalities of non-reducible spinel overlayers in the DRM process. 展开更多
关键词 Heterogeneous catalysis OVERLAYER CORE-SHELL SINTERING Carbon deposition
在线阅读 下载PDF
UV to IR Continuous Photocatalytic Gas-Phase CO_(2)Hydrogenation Over Ni-Doped Molybdenum Oxysulfide:An Experimental and Mechanistic Study
17
作者 Arturo Sanz-Marco Javier Navarro‐Ruiz +6 位作者 Jose L.Hueso Iann CGerber Victor Sebastian Susanne Mossin David Nielsen Francisco Balas Jesus Santamaria 《Carbon Energy》 2025年第4期74-90,共17页
The reduction of CO_(2)toward CO and CH_(4)over Ni-loaded MoS_(2)-like layered nanomaterials is investigated.The mild hydrothermal synthesis induced the formation of a molybdenum oxysulfide(MoO_(x)S_(y))phase,enriched... The reduction of CO_(2)toward CO and CH_(4)over Ni-loaded MoS_(2)-like layered nanomaterials is investigated.The mild hydrothermal synthesis induced the formation of a molybdenum oxysulfide(MoO_(x)S_(y))phase,enriched with sulfur defects and multiple Mo oxidation states that favor the insertion of Ni^(2+)cations via photo-assisted precipitation.The photocatalytic tests under LED irradiation at different wavelengths from 365 to 940 nm at 250℃rendered 1%CO_(2)conversion and continuous CO production up to 0.6 mmol/(gcat h).The incorporation of Ni into the MoO_(x)S_(y)structure boosted the continuous production of CO up to 5.1 mmol/(gcat h)with a CO_(2)conversion of 3.5%.In situ spectroscopic techniques and DFT simulations showed the O-incorporated MoS_(2)structure,in addition to Ni clusters as a supported metal catalyst.The mechanistic study of the CO_(2)reduction reaction over the catalysts revealed that the reverse water-gas shift reaction is favored due to the preferential formation of carboxylic species. 展开更多
关键词 CO_(2)utilization DFT calculations DRIFTS EPR MoS_(2)
在线阅读 下载PDF
High-power laser drivers and fast neutron sources towards green energy applications
18
作者 Federico Canova Itamar Cohen +7 位作者 Leonida Antonio Gizzi Gerard Mourou Karoly Osvay Ales Necas Vincenzo Romanello Sidney Galès Ishay Pomerantz Jonathan Wheeler 《High Power Laser Science and Engineering》 2025年第5期136-170,共35页
Accelerator-driven systems(ADSs)may offer a promising technology for energy production and transmutation of nuclear waste.Here we introduce the concept of utilizing high-intensity laser acceleration technology in real... Accelerator-driven systems(ADSs)may offer a promising technology for energy production and transmutation of nuclear waste.Here we introduce the concept of utilizing high-intensity laser acceleration technology in realizing an ADS,with a focus on the use of thorium fuel in subcritical systems.We explore state-of-the-art laser-driven particle sources for neutron generation by nuclear fusion,spallation or photonuclear reactions and the prospect of reaching the flux of 10^(15)n/s required to drive a subcritical reactor.We review recent advances in high-power laser amplification and assess their technological readiness in view of integration in an ADS.Finally,we present a risk analysis of a laser-driven ADS in terms of laser and target development,radiation safety and operational stability.Our conclusion highlights the potential of laser-driven ADSs as a transformative approach to nuclear fission energy.With continued research and development,technological hurdles can be overcome to fully realize sustainable,green energy production that can meet global energy demands while addressing safety and environmental concerns. 展开更多
关键词 accelerator-driven systems high-intensity lasers laser-plasma acceleration
原文传递
Zeeman splitting observations in laser-produced magnetized blast waves
19
作者 A.Triantafyllidis J.-R.Marquès +10 位作者 S.Ferri A.Calisti Y.Benkadoum Y.De León A.Dearling A.Ciardi J.Béard J.-M.Lagarrigue N.Ozaki M.Koenig B.Albertazzi 《Matter and Radiation at Extremes》 2025年第4期70-79,共10页
We report the observation of Zeeman splitting in multiple spectral lines emitted by a laser-produced,magnetized plasma(1–3×10^(18)cm^(-3),1–15 eV)in the context of a laboratory astrophysics experiment under a c... We report the observation of Zeeman splitting in multiple spectral lines emitted by a laser-produced,magnetized plasma(1–3×10^(18)cm^(-3),1–15 eV)in the context of a laboratory astrophysics experiment under a controlled magneticfield up to 20T.Nitrogen lines(NII)in the visible range were used to diagnose the magneticfield and plasma conditions.This was performed by coupling our data with(563–574 nm)the Stark–Zeeman line-shape code PPPB.The excellent agreement between experiment and simulations paves the way for a non-intrusive experimental platform to get time-resolved measurements of the local magneticfield in laboratory plasmas. 展开更多
关键词 laboratory astrophysics experiment zeeman splitting diagnose magnetic eld plasma conditionsthis Zeeman splitting controlled magnetic eld nitrogen lines coupling our data laser produced magnetized plasma
在线阅读 下载PDF
Implementation of a double trigger condition system based on charge comparison and TOF measurement for the NEDA detector array
20
作者 J.M.Deltoro A.Goasduff +19 位作者 F.J.Egea V.González A.Gadea R.M.Pérez-Vidal I.Lazarus M.Kogimtzis L.McNicholl M.Palacz G.Jaworski J.J.Valiente-Dobón J.Nyberg S.Casans A.E.Navarro-Antón E.Sanchis A.Boujrad E.Clément T.Hüyük R.Illicachi O.Stezowski V.Modamio 《Nuclear Science and Techniques》 2025年第2期40-48,共9页
The NEutron Detector Array(NEDA)is designed to be coupled to gamma-ray spectrometers to enhance the sensitivity of the setup by enabling reaction channel selection through counting of the evaporated neutrons.This arti... The NEutron Detector Array(NEDA)is designed to be coupled to gamma-ray spectrometers to enhance the sensitivity of the setup by enabling reaction channel selection through counting of the evaporated neutrons.This article presents the implementation of a double trigger condition system for NEDA,which improves the acquisition of neutrons and reduces the number of gamma rays acquired.Two independent triggers are generated in the double trigger condition system:one based on charge comparison(CC)and the other on time-of-flight(TOF).These triggers can be combined using OR and AND logic,offering four distinct trigger modes.The developed firmware is added to the previous one in the Virtex 6 field programmable gate array(FPGA)present in the system,which also includes signal processing,baseline correction,and various trigger logic blocks.The performance of the trigger system is evaluated using data from the E703 experiment performed at GANIL.The four trigger modes are applied to the same data,and a subsequent offline analysis is performed.It is shown that most of the detected neutrons are preserved with the AND mode,and the total number of gamma rays is significantly reduced.Compared with the CC trigger mode,the OR trigger mode allows increasing the selection of neutrons.In addition,it is demonstrated that if the OR mode is selected,the online CC trigger threshold can be raised without losing neutrons. 展开更多
关键词 Neutron detector Neutron-gamma discrimination Pulse shape analysis TIME-OF-FLIGHT Charge comparison
在线阅读 下载PDF
上一页 1 2 135 下一页 到第
使用帮助 返回顶部