Research on accelerator-based atomic physics at the Lawrence Berkeley Laboratory super-HILAC and Bevalac accelerators is described. This research covers several important topics in collisions of fast, highly charged i...Research on accelerator-based atomic physics at the Lawrence Berkeley Laboratory super-HILAC and Bevalac accelerators is described. This research covers several important topics in collisions of fast, highly charged ions with atoms: charge transfer, ionization, and excitation. Multiple - electron processes are emphasized. Electron correlation is important in some of these processes, e.g., resonance transfer and excitation (RTE) multiple-electron capture in close collisions. A variety of experiments and results for energies from 1 to 420 MeV/u are presented.展开更多
Heat dissipation performance is critical to the design of high-end equipment,such as integrated chips and high-precision machine tools.Owing to the advantages of artificial intelligence in solving complex tasks involv...Heat dissipation performance is critical to the design of high-end equipment,such as integrated chips and high-precision machine tools.Owing to the advantages of artificial intelligence in solving complex tasks involving a large number of variables,researchers have exploited deep learning to expedite the optimization of material properties,such as the heat dissipation of solid isotropic materials with penalization(SIMP).However,because the approach is limited by discrete datasets and labeled training forms,ensuring the continuous adaptation of the condition domain and maintaining the stability of the design structure remain major challenges in the current intelligent design methodology for thermally conductive structures.In this study,we propose an innovative intelligent design fram-ework integrating Conditional Deep Convolutional Generative Adversarial Networks(CDCGAN)with SIMP,capable of creating topology structures that meet prescribed thermal conduction performance.This proposed design strategy significantly reduces the computational time required to solve symmetric and random heat sink problems compared with existing design approaches and is approximately 98%faster than standard SIMP methods and 55.5%faster than conventional deep-learning-based methods.In addition,we benchmarked the design performance of the proposed framework against theoretical structural designs via experimental measurements.We observed a 50.1%reduction in the average temperature and a 28.2%reduction in the highest temperature in our designed topology compared with those theoretical structure designs.展开更多
High-resolution transmission electron microscopy(HRTEM)promises rapid atomic-scale dynamic structure imaging.Yet,the precision limitations of aberration parameters and the challenge of eliminating aberrations in Cs-co...High-resolution transmission electron microscopy(HRTEM)promises rapid atomic-scale dynamic structure imaging.Yet,the precision limitations of aberration parameters and the challenge of eliminating aberrations in Cs-corrected transmission electron microscopy constrain resolution.A machine learning algorithm is developed to determine the aberration parameters with higher precision from small,lattice-periodic crystal images.The proposed algorithm is then validated with simulated HRTEM images of graphene and applied to the experimental images of a molybdenum disulfide(MoS_(2))monolayer with 25 variables(14 aberrations)resolved in wide ranges.Using these measured parameters,the phases of the exit-wave functions are reconstructed for each image in a focal series of MoS_(2)monolayers.The images were acquired due to the unexpected movement of the specimen holder.Four-dimensional data extraction reveals time-varying atomic structures and ripple.In particular,the atomic evolution of the sulfur-vacancy point and line defects,as well as the edge structure near the amorphous,is visualized as the resolution has been improved from about 1.75?to 0.9 A.This method can help salvage important transmission electron microscope images and is beneficial for the images obtained from electron microscopes with average stability.展开更多
Crocuta and Pachycrocuta are widely regarded as the most prevalent and emblematic hyenas across Eurasia during Quaternary.They are easily distinguished by their distinctive carnassial teeth.However,the disparities in ...Crocuta and Pachycrocuta are widely regarded as the most prevalent and emblematic hyenas across Eurasia during Quaternary.They are easily distinguished by their distinctive carnassial teeth.However,the disparities in non-carnassial elements are less pronounced and have received minimal attention in previous studies.This has resulted in erroneous identifications when dealing with fragmented specimens,particularly in cases where carnassial teeth are poorly preserved or absent.Such misidentifications have the potential to give rise to erroneous inferences regarding the paleozoogeography and biochronology of the animals in question.The bone-cracking hyena specimens from Huainan,Anhui(Tseng et al.,2008)are re-examined and re-evaluated here through a series of morphological comparisons and data analyses(univariate,bivariate,and multivariate analyses etc.).The results provide unequivocal confirmation that the specimens from Xiliexi are not spotted hyenas,but belong to Pachycrocuta perrieri instead.Conversely,the specimen from Dadingshan is the only genuine representative of the spotted hyena,which is supposed to be a possible earliest fossil record for Crocuta ultima thus far in China.Furthermore,the disparities in dentognathic morphology between Crocuta and Pachycrocuta are systematically summarized and analyzed,with an explanation of their eco-functional significance.The present study hypothesizes that Pachycrocuta retains a certain degree of active predatory capability,attributable to the robustness of the canine and the symphysis of the jaw,among other factors.This finding indicates that Pachycrocuta exhibits a form of flexible foraging behavior,combining opportunistic scavenging and active hunting in a manner analogous to Crocuta.Finally,the dynamic evolutionary history of hyenas in East China since Pleistocene has also been broadly reconstructed.展开更多
The Neogene interval witnessed three major waves of intercontinental dispersals by carnivoran mammals,mainly migrating from Eurasia to North America but with rare occurrences going in the opposite direction(e.g.,Sthen...The Neogene interval witnessed three major waves of intercontinental dispersals by carnivoran mammals,mainly migrating from Eurasia to North America but with rare occurrences going in the opposite direction(e.g.,Sthenictis,Leptarctus).The timing and composition of dispersers are thought to be controlled by filter-bridge mechanisms,but it is unclear what types of regional conditions promoted occasional dispersals outside of the three major waves.We study and report on new occurrences of small-bodied carnivorans from late Clarendonian-aged Black Hawk Ranch and Cuyama Valley fossil mammal assemblages in California.The relatively late occurrences of the mustelids Sthenictis and Hoplictis and the ailurid Alopecocyon in coastal regions of western North America suggest that nearshore dispersal corridors both facilitate and preserve faunal elements later than they might otherwise occur further inland.The availability of both marine-and terrestrially-derived food resources may be an important factor in allowing coastally dispersing taxa to be accommodated in those ecological communities compared to less heterogenous environments further inland.展开更多
1.Introduction.The ever-increasing demands for high-energy-density power supply systems have driven the rapid development of conventional lithium-ion batteries,of which properties are approaching to the ceiling.In the...1.Introduction.The ever-increasing demands for high-energy-density power supply systems have driven the rapid development of conventional lithium-ion batteries,of which properties are approaching to the ceiling.In the meantime,the safety of lithium-ion batteries also grabs more attention as their wide application in consumer electronics and electric vehicles.The safety of battery system can be enhanced inherently by replacing the flammable liquid electrolytes with inorganic solid electrolytes,which makes solid-state battery one of the most promising candidates of next-generation energy storage systems[1-3].Additionally,the improvements in energy density are foreseen as solid electrolytes enable lithium metal anode[4-11]and high-voltage cathodes[12-15].展开更多
An important challenge in ensuring the long-term effectiveness of geological nuclear waste disposal is predicting the transportation of decay heat and gases released from nuclear waste canisters.In this study,thermo-h...An important challenge in ensuring the long-term effectiveness of geological nuclear waste disposal is predicting the transportation of decay heat and gases released from nuclear waste canisters.In this study,thermo-hydromechanical(THM)coupled simulations were conducted using the TOUGH + FLAC3D simulator to predict the THM behaviors of a generic nuclear waste repository over 100,000 years following closure.The designed engineered barrier system(EBS)consists of the waste canister,backfill,and concrete liner.The objective of this study is to evaluate the long-term performance of the repository in the presence of continued hydrogen(H_(2))and heat release around the canister.The simulation results show that thermal pressurization and gas accumulation significantly raise the pore pressure within the EBS and surrounding host rock,while the peak pore pressure is not likely to exceed the lithostatic stress so that there is no risk of widespread hydro-fracturing in the host rock.However,tension failure and fracturing can occur at the tunnel scale because of internal gas buildup.Meanwhile,the generated H_(2) continuously migrates outward and tends to accumulate in the concrete liner and excavation disturbed zone surrounding the tunnel because of lower capillary pressure.Nevertheless,the fluids that may contain radionuclides will not leach into the confining units over a 100,000-year time frame.Our analysis indicates that for the assumed disposal system in Opalinus Clay,the generated heat and gas can gradually be transported through the host rock without significantly disturbing the isolation characteristics of the repository.展开更多
The accurate state of health(SOH)estimation of lithium-ion batteries is crucial for efficient,healthy,and safe operation of battery systems.Extracting meaningful aging information from highly stochastic and noisy data...The accurate state of health(SOH)estimation of lithium-ion batteries is crucial for efficient,healthy,and safe operation of battery systems.Extracting meaningful aging information from highly stochastic and noisy data segments while designing SOH estimation algorithms that efficiently handle the large-scale computational demands of cloud-based battery management systems presents a substantial challenge.In this work,we propose a quantum convolutional neural network(QCNN)model designed for accurate,robust,and generalizable SOH estimation with minimal data and parameter requirements and is compatible with quantum computing cloud platforms in the Noisy Intermediate-Scale Quantum.First,we utilize data from 4 datasets comprising 272 cells,covering 5 chemical compositions,4 rated parameters,and 73operating conditions.We design 5 voltage windows as small as 0.3 V for each cell from incremental capacity peaks for stochastic SOH estimation scenarios generation.We extract 3 effective health indicators(HIs)sequences and develop an automated feature fusion method using quantum rotation gate encoding,achieving an R2of 96%.Subsequently,we design a QCNN whose convolutional layer,constructed with variational quantum circuits,comprises merely 39 parameters.Additionally,we explore the impact of training set size,using strategies,and battery materials on the model’s accuracy.Finally,the QCNN with quantum convolutional layers reduces root mean squared error by 28% and achieves an R^(2)exceeding 96% compared to other three commonly used algorithms.This work demonstrates the effectiveness of quantum encoding for automated feature fusion of HIs extracted from limited discharge data.It highlights the potential of QCNN in improving the accuracy,robustness,and generalization of SOH estimation while dealing with stochastic and noisy data with few parameters and simple structure.It also suggests a new paradigm for leveraging quantum computational power in SOH estimation.展开更多
The development of an analytical method for determining the properties of quantum dots(QDs)is crucial for improving the optical performance of QD-based displays.Therefore,synchrotron-based X-ray photoelectron spectros...The development of an analytical method for determining the properties of quantum dots(QDs)is crucial for improving the optical performance of QD-based displays.Therefore,synchrotron-based X-ray photoelectron spectroscopy(XPS)is designed here to accurately characterize the chemical and structural differences between different QDs.This method enables the determination of the reason for the minimal differences between the optical properties of different QDs depending on the synthesis process,which is difficult to determine using conventional methods alone.Combined with model simulations,the XPS spectra obtained at different photon energies reveal the internal structures and chemical-state distributions of the QDs.In particular,the QD synthesized under optimal conditions demonstrates a relatively lower degree of oxidation of the core and more uniformly stacked ZnSe/ZnS shell layers.The internal structures and chemical-state distributions of QDs are closely related to their optical properties.Finally,the synchrotron-based XPS proposed here can be applied to compare nearly equivalent QDs with slightly different optical properties.展开更多
BACKGROUND Posterior reversible encephalopathy syndrome(PRES)is a complex neurological disorder characterized by symptoms such as headaches,seizures,confusion,and visual disturbances.The pathophysiology of PRES involv...BACKGROUND Posterior reversible encephalopathy syndrome(PRES)is a complex neurological disorder characterized by symptoms such as headaches,seizures,confusion,and visual disturbances.The pathophysiology of PRES involves endothelial dysfunction,disrupted cerebral autoregulation,and resulting vasogenic edema.Hypertension and other factors that alter cerebral autoregulation are critical in its development.Corticosteroids,widely used for their anti-inflammatory and immunosuppressive properties,play a controversial role in PRES.AIM To elucidate the dual role of corticosteroids in the context of PRES by critically evaluating the existing literature.Specifically,it seeks to assess the results of PRES induced by corticosteroid therapy and the efficacy and safety of corticosteroids in the treatment of PRES.By synthesizing case reports and series,this review aims to provide a comprehensive understanding of the mechanisms,clinical presentations,and management strategies associated with corticosteroid-related PRES.METHODS The review was carried out according to the PRISMA guidelines.The databases searched included Science Direct,PubMed,and Hinari.The search strategy encompassed terms related to corticosteroids and PRES.Studies were included if they were peer-reviewed articles examining corticosteroids in PRES,excluding non-English publications,reviews,and editorials.Data on patient demographics,clinical characteristics,imaging findings,corticosteroid regimens,and outcomes were extracted.The risk of bias was evaluated using the Joanna Briggs Institute tool for case reports.RESULTS A total of 56 cases of PRES(66.1%women,33.9%men)potentially induced by corticosteroids and 14 cases in which corticosteroids were used to treat PRES were identified.Cases of PRES reportedly caused by corticosteroids showed a mean age of approximately 25.2 years,with seizures,headaches,hypertension,and visual disturbances being common clinical sequelae.Magnetic resonance findings typically revealed vasogenic edema in the bilateral parieto-occipital lobes.High-dose or prolonged corticosteroid therapy was a significant risk factor.On the contrary,in the treatment cases,corticosteroids were associated with positive outcomes,including resolution of vasogenic edema and stabilization of symptoms,particularly in patients with underlying inflammatory or autoimmune diseases.CONCLUSION Corticosteroids have a dual role in PRES,capable of both inducing and treating the condition.The current body of literature suggests that corticosteroids may play a greater role as a precipitating agent of PRES rather than treating.Corticosteroids may induce PRES through hypertension and subsequent increased cerebral blood flow and loss of autoregulation.Corticosteroids may aid in the management of PRES:(1)Enhancing endothelial stability;(2)Antiinflammatory properties;and(3)Improving blood-brain barrier integrity.Mechanisms which may reduce or mitigate vasogenic edema formation.展开更多
Identifying the factors that contribute to individual susceptibility to cancer is essential for both prevention and treatment.The advancement of biotechnologies,particularly next-generation sequencing,has accelerated ...Identifying the factors that contribute to individual susceptibility to cancer is essential for both prevention and treatment.The advancement of biotechnologies,particularly next-generation sequencing,has accelerated the discovery of genetic variants linked to cancer susceptibility.While hundreds of cancer-susceptibility genes have been identified,they only explain a small fraction of the overall cancer risk,a phenomenon known as"missing heritability".Despite progress,even considering factors such as epistasis,epigenetics,and gene-environment interactions,the missing heritability remains unresolved.Recent research has revealed that an individual's microbiome composition plays a significant role in cancer susceptibility through several mechanisms,such as modulating immune cell activity and influencing the presence or removal of environmental carcinogens.In this review,we examine the multifaceted roles of the microbiome in cancer risk and explore gene-microbiome and environment-microbiome interactions that may contribute to cancer susceptibility.Additionally,we highlight the importance of experimental models,such as collaborative cross mice,and advanced analytical tools,like artificial intelligence,in identifying microbial factors associated with cancer risk.Understanding these microbial determinants can open new avenues for interventions aimed at reducing cancer risk and guide the development of more effective cancer treatments.展开更多
AIM:To investigate short-term changes in choroidal thickness in response to peripheral myopic defocus induced by two designs of multifocal corneal gas permeable contact lenses(MFGPCL)in young adults.METHODS:Seventeen ...AIM:To investigate short-term changes in choroidal thickness in response to peripheral myopic defocus induced by two designs of multifocal corneal gas permeable contact lenses(MFGPCL)in young adults.METHODS:Seventeen participants,with a mean age of 24.5±4y,underwent choroidal thickness and vascularity index measurements using enhanced depth imaging optical coherence tomography(EDI OCT)at baseline,one day,and one week following MFGPCL wear.Two center-distance MFGPCL designs with similar center zone diameters of 3.0 mm but different peripheral add powers(low add:+1.5 D and high add:+3.0 D)were tested.Each participant was randomly assigned to wear one of the two MFGPCL designs.Measurements of total,luminal,and stromal choroid thickness were obtained in five eccentric regions(6 mm towards the periphery)in all quadrants.RESULTS:Significant thickening in total choroidal thickness were observed after one week of wearing both high add(+10±6µm)and low add(+7±5µm)MFGPCLs,with no statistically significant difference between the two groups(P=0.42).Choroidal thickening was consistent across eccentric regions and quadrants,with no significant differences based on eccentricity or quadrant(all P>0.05).Both lens designs induced choroidal thickening,with no significant difference between them in total choroidal thickness(P=0.18 for quadrants,P=0.51 for eccentric regions).CONCLUSION:Peripheral myopic defocus induced by MFGPCLs lead to significant choroidal thickening,including total,luminal,and stromal components.This study highlights the need for future research to explore the dose-response relationship between peripheral myopic defocus and choroidal thickening,utilizing choroidal response as a potential biomarker.展开更多
Early risk detection and management are essential for cognitive preservation.While particulate matter with a diameter smaller than 2.5μm(PM_(2.5))is considered harmful to cognition,the effect of smaller,more penetrat...Early risk detection and management are essential for cognitive preservation.While particulate matter with a diameter smaller than 2.5μm(PM_(2.5))is considered harmful to cognition,the effect of smaller,more penetrative particulate matter with a diameter smaller than 1μm(PM_(1))requires further evidence and explicit safety thresholds.In this study,we explored the effects of long-term PM_(1) exposure on early cognitive impairment and longitudinal cognitive changes in middle-aged and older populations.This study assessed data from two large-scale longitudinal surveys:the China Health and Retirement Longitudinal Study(CHARLS)and UK Biobank(UKB).Cross-sectional,longitudinal,and trajectory analyses were conducted to investigate the association between long-term PM_(1) exposure and cognition.Additionally,the expo sure-response curves were fitted to determine the customized thresholds.The findings indicated that sustained PM_(1) exposure may lead to mild cognitive impairment,particularly at concentrations exceeding 30 and 5.6μg·m^(-3) in CHARLS and UKB participants,respectively.Furthermore,we found that long-term PM_(1) exposure can contribute to rapid cognitive decline at concentrations exceeding 23 and 5.5μg·m^(-3) in CHARLS and UKB participants,respectively.In conclusion,reducing PM_(1) exposure can improve the cognitive health of middle-aged and older adults.展开更多
High-resolution photoelectron spectra of cryogenically cooled TiO_(2)CH_(3)OH^(−)anions obtained with slow electron velocity-map imaging are reported and used to explore the reactions of TiO_(2)^(−/0)with methanol.The...High-resolution photoelectron spectra of cryogenically cooled TiO_(2)CH_(3)OH^(−)anions obtained with slow electron velocity-map imaging are reported and used to explore the reactions of TiO_(2)^(−/0)with methanol.The highly structured spectra were compared with results from DFT calculations to determine the dominant structure to be cis-CH_(3)OTi(O)OH^(−),a dissociative adduct in which CH3OH is split by TiO_(2)^(−).The experiment yields an electron affinity of 1.2152(7)eV for TiO_(2)CH^(3)OH as well as several vibrational frequencies for the neutral species.Comparison to Franck−Condon(FC)simulations shows that while most experimental features appear in the simulations,several are not and are assigned to FC-forbidden transitions involving non-totally symmetric vibrational modes.The FC-allowed and forbidden transi-tions also exhibit different photoelectron angular distributions.The FC-forbidden transitions are attributed to Herzberg−Teller(HT)coupling with the A^(2)A″excited state of the anion.The results are compared to previous cryogenic slow electron velocity-map imaging(cryo-SE-Ⅵ)studies of bare TiO_(2)^(−)and the water-split adduct TiO_(3)H_(2)^(−).展开更多
Methyl methoxyacetate(MMAc)and methyl formate(MF)can be produced directly by heterogeneous zeolite-catalyzed carbonylation and disproportionation of dimethoxymethane(DMM),with near 100%selectivity for each process.Des...Methyl methoxyacetate(MMAc)and methyl formate(MF)can be produced directly by heterogeneous zeolite-catalyzed carbonylation and disproportionation of dimethoxymethane(DMM),with near 100%selectivity for each process.Despite continuous research efforts,the insight into the reaction mechanism and kinetics theory are still in their nascent stage.In this study,ZEO-1 material,a zeolite with up to now the largest cages comprising 16×16-MRs,16×12-MRs,and 12×12-MRs,was explored for DMM carbonylation and disproportionation reactions.The rate of MMAc formation based on accessible Brönsted acid sites is 2.5 times higher for ZEO-1(Si/Al=21)relative to the previously investigated FAU(Si/Al=15),indicating the positive effect of spatial separation of active sites in ZEO-1 on catalytic activity.A higher MF formation rate is also observed over ZEO-1 with lower activation energy(79.94 vs.95.19 kJ/mol)compared with FAU(Si/Al=30).Two types of active sites are proposed within ZEO-1 zeolite:Site 1 located in large cages formed by 16×16-MRs and 16×12-MRs,which is active predominantly for MMAc formation,and Site 2 located in smaller cages for methyl formate/dimethyl ether formation.Kinetics investigation of DMM carbonylation over ZEO-1 exhibit a first-order dependence on CO partial pressure and a slightly inverse-order dependence on DMM partial pressure.The DMM disproportionation is nearly first-order dependence on DMM partial pressure,while it reveals a strongly inverse dependence with increasing CO partial pressure.Furthermore,ZEO-1 exhibits good catalytic stability,and almost no deactivation is observed during the more than 70 h test with high carbonylation selectivity of above 89%,due to the well-enhanced diffusion property demonstrated by intelligent-gravimetric analysis.展开更多
INTRODUCTION Reports indicating that culturally and linguistically diverse(CALD)people-often with migrant backgrounds-in Australia and New Zealand are more likely to be placed in compulsory community treatment(CCT)hav...INTRODUCTION Reports indicating that culturally and linguistically diverse(CALD)people-often with migrant backgrounds-in Australia and New Zealand are more likely to be placed in compulsory community treatment(CCT)have rightlyraised concernsthat such action might be discriminatory.展开更多
Autologous bone marrow-derived mesenchymal stem cells(BMSCs)have been shown to promote osteogenesis;however,the effects of allogeneic BMSCs(allo-BMSCs)on bone regeneration remain unclear.Therefore,we explored the bone...Autologous bone marrow-derived mesenchymal stem cells(BMSCs)have been shown to promote osteogenesis;however,the effects of allogeneic BMSCs(allo-BMSCs)on bone regeneration remain unclear.Therefore,we explored the bone regeneration promotion effect of allo-BMSCs in 3D-printed autologous bone particle(ABP)scaffolds.First,we concurrently printed scaffolds with polycaprolactone,ABPs,and allo-BMSCs for appropriate support,providing bioactive factors and seed cells to promote osteogenesis.In vitro studies showed that ABP scaffolds promoted allo-BMSC osteogenic differentiation.In vivo studies revealed that the implantation of scaffolds loaded with ABPs and allo-BMSCs into canine skull defects for nine months promoted osteogenesis.Further experiments suggested that only a small portion of implanted allo-BMSCs survived and differentiated into vascular endothelial cells,chondrocytes,and osteocytes.The implanted allo-BMSCs released stromal cell-derived factor 1 through paracrine signaling to recruit native BMSCs into the defect,promoting bone regeneration.This study contributes to our understanding of allo-BMSCs,providing information relevant to their future application.展开更多
Digital transformation,as a recent trend in socioeconomic development,is considered as a critical pathway for urban carbon reduction because of its potential to increase productivity and energy efficiency.However,few ...Digital transformation,as a recent trend in socioeconomic development,is considered as a critical pathway for urban carbon reduction because of its potential to increase productivity and energy efficiency.However,few studies have explored the relationship between urban digitalization and carbon emissions(CE).Therefore,this study systematically analyzed the spatiotemporal distribution and interaction mechanism between digitalization and CE in the Yangtze River Delta(YRD)urban agglomerations of China during 2006-2020 based on a multidimensional indicator system,including digitalization industry level,digitalization application level,and urban green digitalization willingness.The findings revealed that both digitalization and CE in the YRD exhibit a significant and synchronously evolving“core-periphery”spatial pattern.Core cities generated substantial positive spillover effect on periphery cities through technology diffusion and policy demonstration,advancing both regional digitalization and the collaborative governance of CE.However,digitalization had dual impact on CE.On the one hand,it promoted the reduction of CE by enhancing energy efficiency,optimizing industrial structures,and promoting the application of green technologies.On the other hand,the expansion of digital infrastructure introduced a potential risk of increased energy consumption.Therefore,targeted policy recommendations are proposed to facilitate the coordination of environmental sustainability and digitalization in the YRD.This study provides empirical support and policy insights for advancing the coordinated development of regional digital transformation and green low-carbon initiatives.展开更多
基金This work was supported by the director Office of Energy Research, Office of Basic Energy Sciences, Materials Sciences Division of the U.S. Department of Energy under Contract No. DE - AC08 - 76SF 00098
文摘Research on accelerator-based atomic physics at the Lawrence Berkeley Laboratory super-HILAC and Bevalac accelerators is described. This research covers several important topics in collisions of fast, highly charged ions with atoms: charge transfer, ionization, and excitation. Multiple - electron processes are emphasized. Electron correlation is important in some of these processes, e.g., resonance transfer and excitation (RTE) multiple-electron capture in close collisions. A variety of experiments and results for energies from 1 to 420 MeV/u are presented.
基金Supported by National Natural Science Foundation of China(Grant Nos.52222508 and 52335011)。
文摘Heat dissipation performance is critical to the design of high-end equipment,such as integrated chips and high-precision machine tools.Owing to the advantages of artificial intelligence in solving complex tasks involving a large number of variables,researchers have exploited deep learning to expedite the optimization of material properties,such as the heat dissipation of solid isotropic materials with penalization(SIMP).However,because the approach is limited by discrete datasets and labeled training forms,ensuring the continuous adaptation of the condition domain and maintaining the stability of the design structure remain major challenges in the current intelligent design methodology for thermally conductive structures.In this study,we propose an innovative intelligent design fram-ework integrating Conditional Deep Convolutional Generative Adversarial Networks(CDCGAN)with SIMP,capable of creating topology structures that meet prescribed thermal conduction performance.This proposed design strategy significantly reduces the computational time required to solve symmetric and random heat sink problems compared with existing design approaches and is approximately 98%faster than standard SIMP methods and 55.5%faster than conventional deep-learning-based methods.In addition,we benchmarked the design performance of the proposed framework against theoretical structural designs via experimental measurements.We observed a 50.1%reduction in the average temperature and a 28.2%reduction in the highest temperature in our designed topology compared with those theoretical structure designs.
基金financial support from the National Natural Science Foundation of China(Grant No.61971201)。
文摘High-resolution transmission electron microscopy(HRTEM)promises rapid atomic-scale dynamic structure imaging.Yet,the precision limitations of aberration parameters and the challenge of eliminating aberrations in Cs-corrected transmission electron microscopy constrain resolution.A machine learning algorithm is developed to determine the aberration parameters with higher precision from small,lattice-periodic crystal images.The proposed algorithm is then validated with simulated HRTEM images of graphene and applied to the experimental images of a molybdenum disulfide(MoS_(2))monolayer with 25 variables(14 aberrations)resolved in wide ranges.Using these measured parameters,the phases of the exit-wave functions are reconstructed for each image in a focal series of MoS_(2)monolayers.The images were acquired due to the unexpected movement of the specimen holder.Four-dimensional data extraction reveals time-varying atomic structures and ripple.In particular,the atomic evolution of the sulfur-vacancy point and line defects,as well as the edge structure near the amorphous,is visualized as the resolution has been improved from about 1.75?to 0.9 A.This method can help salvage important transmission electron microscope images and is beneficial for the images obtained from electron microscopes with average stability.
文摘Crocuta and Pachycrocuta are widely regarded as the most prevalent and emblematic hyenas across Eurasia during Quaternary.They are easily distinguished by their distinctive carnassial teeth.However,the disparities in non-carnassial elements are less pronounced and have received minimal attention in previous studies.This has resulted in erroneous identifications when dealing with fragmented specimens,particularly in cases where carnassial teeth are poorly preserved or absent.Such misidentifications have the potential to give rise to erroneous inferences regarding the paleozoogeography and biochronology of the animals in question.The bone-cracking hyena specimens from Huainan,Anhui(Tseng et al.,2008)are re-examined and re-evaluated here through a series of morphological comparisons and data analyses(univariate,bivariate,and multivariate analyses etc.).The results provide unequivocal confirmation that the specimens from Xiliexi are not spotted hyenas,but belong to Pachycrocuta perrieri instead.Conversely,the specimen from Dadingshan is the only genuine representative of the spotted hyena,which is supposed to be a possible earliest fossil record for Crocuta ultima thus far in China.Furthermore,the disparities in dentognathic morphology between Crocuta and Pachycrocuta are systematically summarized and analyzed,with an explanation of their eco-functional significance.The present study hypothesizes that Pachycrocuta retains a certain degree of active predatory capability,attributable to the robustness of the canine and the symphysis of the jaw,among other factors.This finding indicates that Pachycrocuta exhibits a form of flexible foraging behavior,combining opportunistic scavenging and active hunting in a manner analogous to Crocuta.Finally,the dynamic evolutionary history of hyenas in East China since Pleistocene has also been broadly reconstructed.
文摘The Neogene interval witnessed three major waves of intercontinental dispersals by carnivoran mammals,mainly migrating from Eurasia to North America but with rare occurrences going in the opposite direction(e.g.,Sthenictis,Leptarctus).The timing and composition of dispersers are thought to be controlled by filter-bridge mechanisms,but it is unclear what types of regional conditions promoted occasional dispersals outside of the three major waves.We study and report on new occurrences of small-bodied carnivorans from late Clarendonian-aged Black Hawk Ranch and Cuyama Valley fossil mammal assemblages in California.The relatively late occurrences of the mustelids Sthenictis and Hoplictis and the ailurid Alopecocyon in coastal regions of western North America suggest that nearshore dispersal corridors both facilitate and preserve faunal elements later than they might otherwise occur further inland.The availability of both marine-and terrestrially-derived food resources may be an important factor in allowing coastally dispersing taxa to be accommodated in those ecological communities compared to less heterogenous environments further inland.
文摘1.Introduction.The ever-increasing demands for high-energy-density power supply systems have driven the rapid development of conventional lithium-ion batteries,of which properties are approaching to the ceiling.In the meantime,the safety of lithium-ion batteries also grabs more attention as their wide application in consumer electronics and electric vehicles.The safety of battery system can be enhanced inherently by replacing the flammable liquid electrolytes with inorganic solid electrolytes,which makes solid-state battery one of the most promising candidates of next-generation energy storage systems[1-3].Additionally,the improvements in energy density are foreseen as solid electrolytes enable lithium metal anode[4-11]and high-voltage cathodes[12-15].
基金Funding was provided by the U.S.Department of Energy,Office of Nuclear Energy,Spent Fuel and Waste Disposition,under Contract Number DE-AC02-05CH11231 with Lawrence Berkeley National Laboratory(LBNL).
文摘An important challenge in ensuring the long-term effectiveness of geological nuclear waste disposal is predicting the transportation of decay heat and gases released from nuclear waste canisters.In this study,thermo-hydromechanical(THM)coupled simulations were conducted using the TOUGH + FLAC3D simulator to predict the THM behaviors of a generic nuclear waste repository over 100,000 years following closure.The designed engineered barrier system(EBS)consists of the waste canister,backfill,and concrete liner.The objective of this study is to evaluate the long-term performance of the repository in the presence of continued hydrogen(H_(2))and heat release around the canister.The simulation results show that thermal pressurization and gas accumulation significantly raise the pore pressure within the EBS and surrounding host rock,while the peak pore pressure is not likely to exceed the lithostatic stress so that there is no risk of widespread hydro-fracturing in the host rock.However,tension failure and fracturing can occur at the tunnel scale because of internal gas buildup.Meanwhile,the generated H_(2) continuously migrates outward and tends to accumulate in the concrete liner and excavation disturbed zone surrounding the tunnel because of lower capillary pressure.Nevertheless,the fluids that may contain radionuclides will not leach into the confining units over a 100,000-year time frame.Our analysis indicates that for the assumed disposal system in Opalinus Clay,the generated heat and gas can gradually be transported through the host rock without significantly disturbing the isolation characteristics of the repository.
基金funded by the Research on SOC/SOH Joint Estimation Technology of Electric Vehicle Battery System State Based on Online Parameter Identification Project(2019)the National Natural Science Foundation of China(Grant No.51877120)。
文摘The accurate state of health(SOH)estimation of lithium-ion batteries is crucial for efficient,healthy,and safe operation of battery systems.Extracting meaningful aging information from highly stochastic and noisy data segments while designing SOH estimation algorithms that efficiently handle the large-scale computational demands of cloud-based battery management systems presents a substantial challenge.In this work,we propose a quantum convolutional neural network(QCNN)model designed for accurate,robust,and generalizable SOH estimation with minimal data and parameter requirements and is compatible with quantum computing cloud platforms in the Noisy Intermediate-Scale Quantum.First,we utilize data from 4 datasets comprising 272 cells,covering 5 chemical compositions,4 rated parameters,and 73operating conditions.We design 5 voltage windows as small as 0.3 V for each cell from incremental capacity peaks for stochastic SOH estimation scenarios generation.We extract 3 effective health indicators(HIs)sequences and develop an automated feature fusion method using quantum rotation gate encoding,achieving an R2of 96%.Subsequently,we design a QCNN whose convolutional layer,constructed with variational quantum circuits,comprises merely 39 parameters.Additionally,we explore the impact of training set size,using strategies,and battery materials on the model’s accuracy.Finally,the QCNN with quantum convolutional layers reduces root mean squared error by 28% and achieves an R^(2)exceeding 96% compared to other three commonly used algorithms.This work demonstrates the effectiveness of quantum encoding for automated feature fusion of HIs extracted from limited discharge data.It highlights the potential of QCNN in improving the accuracy,robustness,and generalization of SOH estimation while dealing with stochastic and noisy data with few parameters and simple structure.It also suggests a new paradigm for leveraging quantum computational power in SOH estimation.
基金Advanced Light Source,which is a DOE Office of Science User Facility under contract no.DE-AC02-05CH11231the Basque Government for funding through a PhD Fellowship(Grant no.PRE_2018_2_0285)+1 种基金through Egonlabur Travel Fellowship(Grant no.EP_2018_1_0004)partially supported by an Early Career Award in the Condensed Phase and Interfacial Molecular Science Program,in the Chemical Sciences Geosciences and Biosciences Division of the Office of Basic Energy Sciences of the U.S.Department of Energy under Contract No.DE-AC02-05CH11231.
文摘The development of an analytical method for determining the properties of quantum dots(QDs)is crucial for improving the optical performance of QD-based displays.Therefore,synchrotron-based X-ray photoelectron spectroscopy(XPS)is designed here to accurately characterize the chemical and structural differences between different QDs.This method enables the determination of the reason for the minimal differences between the optical properties of different QDs depending on the synthesis process,which is difficult to determine using conventional methods alone.Combined with model simulations,the XPS spectra obtained at different photon energies reveal the internal structures and chemical-state distributions of the QDs.In particular,the QD synthesized under optimal conditions demonstrates a relatively lower degree of oxidation of the core and more uniformly stacked ZnSe/ZnS shell layers.The internal structures and chemical-state distributions of QDs are closely related to their optical properties.Finally,the synchrotron-based XPS proposed here can be applied to compare nearly equivalent QDs with slightly different optical properties.
文摘BACKGROUND Posterior reversible encephalopathy syndrome(PRES)is a complex neurological disorder characterized by symptoms such as headaches,seizures,confusion,and visual disturbances.The pathophysiology of PRES involves endothelial dysfunction,disrupted cerebral autoregulation,and resulting vasogenic edema.Hypertension and other factors that alter cerebral autoregulation are critical in its development.Corticosteroids,widely used for their anti-inflammatory and immunosuppressive properties,play a controversial role in PRES.AIM To elucidate the dual role of corticosteroids in the context of PRES by critically evaluating the existing literature.Specifically,it seeks to assess the results of PRES induced by corticosteroid therapy and the efficacy and safety of corticosteroids in the treatment of PRES.By synthesizing case reports and series,this review aims to provide a comprehensive understanding of the mechanisms,clinical presentations,and management strategies associated with corticosteroid-related PRES.METHODS The review was carried out according to the PRISMA guidelines.The databases searched included Science Direct,PubMed,and Hinari.The search strategy encompassed terms related to corticosteroids and PRES.Studies were included if they were peer-reviewed articles examining corticosteroids in PRES,excluding non-English publications,reviews,and editorials.Data on patient demographics,clinical characteristics,imaging findings,corticosteroid regimens,and outcomes were extracted.The risk of bias was evaluated using the Joanna Briggs Institute tool for case reports.RESULTS A total of 56 cases of PRES(66.1%women,33.9%men)potentially induced by corticosteroids and 14 cases in which corticosteroids were used to treat PRES were identified.Cases of PRES reportedly caused by corticosteroids showed a mean age of approximately 25.2 years,with seizures,headaches,hypertension,and visual disturbances being common clinical sequelae.Magnetic resonance findings typically revealed vasogenic edema in the bilateral parieto-occipital lobes.High-dose or prolonged corticosteroid therapy was a significant risk factor.On the contrary,in the treatment cases,corticosteroids were associated with positive outcomes,including resolution of vasogenic edema and stabilization of symptoms,particularly in patients with underlying inflammatory or autoimmune diseases.CONCLUSION Corticosteroids have a dual role in PRES,capable of both inducing and treating the condition.The current body of literature suggests that corticosteroids may play a greater role as a precipitating agent of PRES rather than treating.Corticosteroids may induce PRES through hypertension and subsequent increased cerebral blood flow and loss of autoregulation.Corticosteroids may aid in the management of PRES:(1)Enhancing endothelial stability;(2)Antiinflammatory properties;and(3)Improving blood-brain barrier integrity.Mechanisms which may reduce or mitigate vasogenic edema formation.
基金Supported by The United States Department of Defense Breast Cancer Research Program,No.BC190820the National Institutes of Health,No.R01ES031322.
文摘Identifying the factors that contribute to individual susceptibility to cancer is essential for both prevention and treatment.The advancement of biotechnologies,particularly next-generation sequencing,has accelerated the discovery of genetic variants linked to cancer susceptibility.While hundreds of cancer-susceptibility genes have been identified,they only explain a small fraction of the overall cancer risk,a phenomenon known as"missing heritability".Despite progress,even considering factors such as epistasis,epigenetics,and gene-environment interactions,the missing heritability remains unresolved.Recent research has revealed that an individual's microbiome composition plays a significant role in cancer susceptibility through several mechanisms,such as modulating immune cell activity and influencing the presence or removal of environmental carcinogens.In this review,we examine the multifaceted roles of the microbiome in cancer risk and explore gene-microbiome and environment-microbiome interactions that may contribute to cancer susceptibility.Additionally,we highlight the importance of experimental models,such as collaborative cross mice,and advanced analytical tools,like artificial intelligence,in identifying microbial factors associated with cancer risk.Understanding these microbial determinants can open new avenues for interventions aimed at reducing cancer risk and guide the development of more effective cancer treatments.
基金Supported by Ongoing Research Funding Program(No.ORF-2025-1160),King Saud University,Riyadh Saudi Arabia.
文摘AIM:To investigate short-term changes in choroidal thickness in response to peripheral myopic defocus induced by two designs of multifocal corneal gas permeable contact lenses(MFGPCL)in young adults.METHODS:Seventeen participants,with a mean age of 24.5±4y,underwent choroidal thickness and vascularity index measurements using enhanced depth imaging optical coherence tomography(EDI OCT)at baseline,one day,and one week following MFGPCL wear.Two center-distance MFGPCL designs with similar center zone diameters of 3.0 mm but different peripheral add powers(low add:+1.5 D and high add:+3.0 D)were tested.Each participant was randomly assigned to wear one of the two MFGPCL designs.Measurements of total,luminal,and stromal choroid thickness were obtained in five eccentric regions(6 mm towards the periphery)in all quadrants.RESULTS:Significant thickening in total choroidal thickness were observed after one week of wearing both high add(+10±6µm)and low add(+7±5µm)MFGPCLs,with no statistically significant difference between the two groups(P=0.42).Choroidal thickening was consistent across eccentric regions and quadrants,with no significant differences based on eccentricity or quadrant(all P>0.05).Both lens designs induced choroidal thickening,with no significant difference between them in total choroidal thickness(P=0.18 for quadrants,P=0.51 for eccentric regions).CONCLUSION:Peripheral myopic defocus induced by MFGPCLs lead to significant choroidal thickening,including total,luminal,and stromal components.This study highlights the need for future research to explore the dose-response relationship between peripheral myopic defocus and choroidal thickening,utilizing choroidal response as a potential biomarker.
基金supported by the National Key Research and Development Program of China(2021YFC2701102)the China-US Program for Biomedical Collaborative Research(NSFC-NIH)(81961128022)+1 种基金the US National Institute for Environmental Health Sciences(NIEHS)(R01ES031322)the National Science Fund for Young Scholars(82304095)。
文摘Early risk detection and management are essential for cognitive preservation.While particulate matter with a diameter smaller than 2.5μm(PM_(2.5))is considered harmful to cognition,the effect of smaller,more penetrative particulate matter with a diameter smaller than 1μm(PM_(1))requires further evidence and explicit safety thresholds.In this study,we explored the effects of long-term PM_(1) exposure on early cognitive impairment and longitudinal cognitive changes in middle-aged and older populations.This study assessed data from two large-scale longitudinal surveys:the China Health and Retirement Longitudinal Study(CHARLS)and UK Biobank(UKB).Cross-sectional,longitudinal,and trajectory analyses were conducted to investigate the association between long-term PM_(1) exposure and cognition.Additionally,the expo sure-response curves were fitted to determine the customized thresholds.The findings indicated that sustained PM_(1) exposure may lead to mild cognitive impairment,particularly at concentrations exceeding 30 and 5.6μg·m^(-3) in CHARLS and UKB participants,respectively.Furthermore,we found that long-term PM_(1) exposure can contribute to rapid cognitive decline at concentrations exceeding 23 and 5.5μg·m^(-3) in CHARLS and UKB participants,respectively.In conclusion,reducing PM_(1) exposure can improve the cognitive health of middle-aged and older adults.
基金funded by the Air Force Office of Scientific Research (AFOSR) under Grant (No.FA955023-1-0545)。
文摘High-resolution photoelectron spectra of cryogenically cooled TiO_(2)CH_(3)OH^(−)anions obtained with slow electron velocity-map imaging are reported and used to explore the reactions of TiO_(2)^(−/0)with methanol.The highly structured spectra were compared with results from DFT calculations to determine the dominant structure to be cis-CH_(3)OTi(O)OH^(−),a dissociative adduct in which CH3OH is split by TiO_(2)^(−).The experiment yields an electron affinity of 1.2152(7)eV for TiO_(2)CH^(3)OH as well as several vibrational frequencies for the neutral species.Comparison to Franck−Condon(FC)simulations shows that while most experimental features appear in the simulations,several are not and are assigned to FC-forbidden transitions involving non-totally symmetric vibrational modes.The FC-allowed and forbidden transi-tions also exhibit different photoelectron angular distributions.The FC-forbidden transitions are attributed to Herzberg−Teller(HT)coupling with the A^(2)A″excited state of the anion.The results are compared to previous cryogenic slow electron velocity-map imaging(cryo-SE-Ⅵ)studies of bare TiO_(2)^(−)and the water-split adduct TiO_(3)H_(2)^(−).
文摘Methyl methoxyacetate(MMAc)and methyl formate(MF)can be produced directly by heterogeneous zeolite-catalyzed carbonylation and disproportionation of dimethoxymethane(DMM),with near 100%selectivity for each process.Despite continuous research efforts,the insight into the reaction mechanism and kinetics theory are still in their nascent stage.In this study,ZEO-1 material,a zeolite with up to now the largest cages comprising 16×16-MRs,16×12-MRs,and 12×12-MRs,was explored for DMM carbonylation and disproportionation reactions.The rate of MMAc formation based on accessible Brönsted acid sites is 2.5 times higher for ZEO-1(Si/Al=21)relative to the previously investigated FAU(Si/Al=15),indicating the positive effect of spatial separation of active sites in ZEO-1 on catalytic activity.A higher MF formation rate is also observed over ZEO-1 with lower activation energy(79.94 vs.95.19 kJ/mol)compared with FAU(Si/Al=30).Two types of active sites are proposed within ZEO-1 zeolite:Site 1 located in large cages formed by 16×16-MRs and 16×12-MRs,which is active predominantly for MMAc formation,and Site 2 located in smaller cages for methyl formate/dimethyl ether formation.Kinetics investigation of DMM carbonylation over ZEO-1 exhibit a first-order dependence on CO partial pressure and a slightly inverse-order dependence on DMM partial pressure.The DMM disproportionation is nearly first-order dependence on DMM partial pressure,while it reveals a strongly inverse dependence with increasing CO partial pressure.Furthermore,ZEO-1 exhibits good catalytic stability,and almost no deactivation is observed during the more than 70 h test with high carbonylation selectivity of above 89%,due to the well-enhanced diffusion property demonstrated by intelligent-gravimetric analysis.
文摘INTRODUCTION Reports indicating that culturally and linguistically diverse(CALD)people-often with migrant backgrounds-in Australia and New Zealand are more likely to be placed in compulsory community treatment(CCT)have rightlyraised concernsthat such action might be discriminatory.
基金supported by the Science and Technology Development Fund of the Fourth Military Medical University(No.2016XB051)the Military Medical Promotion Plan of the Fourth Military Medical University(No.2016TSA-005)+2 种基金the Science and Technology Program of Guangzhou(No.201604040002)the Youth Development Project of Air Force Medical University(No.21QNPY072)the Xijing Hospital Booster Program(No.XJZT24CZ10).
文摘Autologous bone marrow-derived mesenchymal stem cells(BMSCs)have been shown to promote osteogenesis;however,the effects of allogeneic BMSCs(allo-BMSCs)on bone regeneration remain unclear.Therefore,we explored the bone regeneration promotion effect of allo-BMSCs in 3D-printed autologous bone particle(ABP)scaffolds.First,we concurrently printed scaffolds with polycaprolactone,ABPs,and allo-BMSCs for appropriate support,providing bioactive factors and seed cells to promote osteogenesis.In vitro studies showed that ABP scaffolds promoted allo-BMSC osteogenic differentiation.In vivo studies revealed that the implantation of scaffolds loaded with ABPs and allo-BMSCs into canine skull defects for nine months promoted osteogenesis.Further experiments suggested that only a small portion of implanted allo-BMSCs survived and differentiated into vascular endothelial cells,chondrocytes,and osteocytes.The implanted allo-BMSCs released stromal cell-derived factor 1 through paracrine signaling to recruit native BMSCs into the defect,promoting bone regeneration.This study contributes to our understanding of allo-BMSCs,providing information relevant to their future application.
文摘Digital transformation,as a recent trend in socioeconomic development,is considered as a critical pathway for urban carbon reduction because of its potential to increase productivity and energy efficiency.However,few studies have explored the relationship between urban digitalization and carbon emissions(CE).Therefore,this study systematically analyzed the spatiotemporal distribution and interaction mechanism between digitalization and CE in the Yangtze River Delta(YRD)urban agglomerations of China during 2006-2020 based on a multidimensional indicator system,including digitalization industry level,digitalization application level,and urban green digitalization willingness.The findings revealed that both digitalization and CE in the YRD exhibit a significant and synchronously evolving“core-periphery”spatial pattern.Core cities generated substantial positive spillover effect on periphery cities through technology diffusion and policy demonstration,advancing both regional digitalization and the collaborative governance of CE.However,digitalization had dual impact on CE.On the one hand,it promoted the reduction of CE by enhancing energy efficiency,optimizing industrial structures,and promoting the application of green technologies.On the other hand,the expansion of digital infrastructure introduced a potential risk of increased energy consumption.Therefore,targeted policy recommendations are proposed to facilitate the coordination of environmental sustainability and digitalization in the YRD.This study provides empirical support and policy insights for advancing the coordinated development of regional digital transformation and green low-carbon initiatives.
