The volcanic rocks hosting the iron deposits in the Aqishan–Yamansu metallogenic belt are sodium-rich.The geochronology,petrography,and geochemistry of minerals and sodium-rich rocks as well as the relationship betwe...The volcanic rocks hosting the iron deposits in the Aqishan–Yamansu metallogenic belt are sodium-rich.The geochronology,petrography,and geochemistry of minerals and sodium-rich rocks as well as the relationship between these rocks and the iron deposits are studied.Geochemically,the ore-hosting volcanic rocks are sodiumrich(the averages of Na2O and Na2O/K2O are 4.31 wt.%and 8.56,respectively)and belong to the calc-alkaline series.They are enriched in LREEs and LILEs(Ba,U,K,and Sr),but depleted in HFSEs(Nb,Ta,and Ti).SHRIMP zircon U–Pb dating of the crystal tuff in the Aqishan Formation and the dacite in the Tugutu Bulak Formation yields ages of 337.52.3 Ma(n?15,MSWD?0.85)and 313.03.3 Ma(n?13,MSWD?0.74),respectively,indicating that the sodium-rich volcanic rocks formed from the early–late Carboniferous.Electron microprobe data from plagioclases demonstrate that albites and/or oligoclases were formed in the basic–intermediate–acid volcanic rocks.Two stages of albitization are identified,and the latter is likely attributed to the dissolution of iron in the Aqishan–Yamansu belt.The sodium-rich volcanic rocks probably formed by the interaction between volcanic lava and seawater after volcanoes erupted on the seafloor;meanwhile,the albites formed by element substitution in a low-metamorphic environment.The spatiotemporal coupling relationship between sodium-rich volcanic rocks and iron deposits in the Aqishan–Yamansu belt is favorable.Iron dissolved from the dark minerals of basic–intermediate volcanic rocks through sodium metasomatism is one of the material sources for the iron deposits.展开更多
In recent years evidence has emerged suggesting that Mini-basketball training program(MBTP)can be an effec-tive intervention method to improve social communication(SC)impairments and restricted and repetitive beha-vio...In recent years evidence has emerged suggesting that Mini-basketball training program(MBTP)can be an effec-tive intervention method to improve social communication(SC)impairments and restricted and repetitive beha-viors(RRBs)in preschool children suffering from autism spectrum disorder(ASD).However,there is a considerable degree if interindividual variability concerning these social outcomes and thus not all preschool chil-dren with ASD profit from a MBTP intervention to the same extent.In order to make more accurate predictions which preschool children with ASD can benefit from an MBTP intervention or which preschool children with ASD need additional interventions to achieve behavioral improvements,further research is required.This study aimed to investigate which individual factors of preschool children with ASD can predict MBTP intervention out-comes concerning SC impairments and RRBs.Then,test the performance of machine learning models in predict-ing intervention outcomes based on these factors.Participants were 26 preschool children with ASD who enrolled in a quasi-experiment and received MBTP intervention.Baseline demographic variables(e.g.,age,body,mass index[BMI]),indicators of physicalfitness(e.g.,handgrip strength,balance performance),performance in execu-tive function,severity of ASD symptoms,level of SC impairments,and severity of RRBs were obtained to predict treatment outcomes after MBTP intervention.Machine learning models were established based on support vector machine algorithm were implemented.For comparison,we also employed multiple linear regression models in statistics.Ourfindings suggest that in preschool children with ASD symptomatic severity(r=0.712,p<0.001)and baseline SC impairments(r=0.713,p<0.001)are predictors for intervention outcomes of SC impair-ments.Furthermore,BMI(r=-0.430,p=0.028),symptomatic severity(r=0.656,p<0.001),baseline SC impair-ments(r=0.504,p=0.009)and baseline RRBs(r=0.647,p<0.001)can predict intervention outcomes of RRBs.Statistical models predicted 59.6%of variance in post-treatment SC impairments(MSE=0.455,RMSE=0.675,R2=0.596)and 58.9%of variance in post-treatment RRBs(MSE=0.464,RMSE=0.681,R2=0.589).Machine learning models predicted 83%of variance in post-treatment SC impairments(MSE=0.188,RMSE=0.434,R2=0.83)and 85.9%of variance in post-treatment RRBs(MSE=0.051,RMSE=0.226,R2=0.859),which were better than statistical models.Ourfindings suggest that baseline characteristics such as symptomatic severity of 144 IJMHP,2022,vol.24,no.2 ASD symptoms and SC impairments are important predictors determining MBTP intervention-induced improvements concerning SC impairments and RBBs.Furthermore,the current study revealed that machine learning models can successfully be applied to predict the MBTP intervention-related outcomes in preschool chil-dren with ASD,and performed better than statistical models.Ourfindings can help to inform which preschool children with ASD are most likely to benefit from an MBTP intervention,and they might provide a reference for the development of personalized intervention programs for preschool children with ASD.展开更多
The Yamansu iron deposit is hosted in submarine volcanic rocks in the Aqishan–Yamansu belt of Eastern Tianshan,NW China.A geological cross-section for the Carboniferous strata in the ore district shows that ore bodie...The Yamansu iron deposit is hosted in submarine volcanic rocks in the Aqishan–Yamansu belt of Eastern Tianshan,NW China.A geological cross-section for the Carboniferous strata in the ore district shows that ore bodies in the Yamansu deposit are hosted in andesitic crystal tuff of the third cycle of the Carboniferous Yamansu Formation.This indicates an association between mineralization and volcanism.The orebodies are strata bound and lensoid and generally share the occurrence state of the host rocks.Magnetite mineralization mainly occurs asbreccia ores,ores in the mineralized volcanic rocks,massive ores,and sulfide-rich ores according to their structures and sequences of formation.Trace element compositions of magnetite from various types of ores were determined by LA-ICP-MS.The dataset indicates thatdifferent types of magnetite havedistinct trace element contents correlated to their formation environments.Magnetite crystals from breccia ores have high Ti,Ni,V,Cr,and Co and low Si,Al,Ca,and Mg contents,indicating crystallization from a volcanic magmatic eruption,which is consistent with field evidence of coexisting altered volcanic breccia.Magnetite crystals from ores in the mineralized volcanic rocks have moderate Ti,Ni,V,Cr,and Co contents.In contrast,magnetite from massive ores and sulfide-rich ores have low concentrations of Ti,Cr,Ni,and V,high concentrations of Si,Al,Ca,and Mg,and evidence of hydrothermal magnetite.In-situ magnetite compositions imply a magmatic-hydrothermal process.Although d18 O values for magnetite grains from Yamansu vary(?1.3 to?7.0%),they all plot in the range field of volcanic iron deposits,and they also record a magmatic-hydrothermal process.The compositions of Yamansu magnetites are interpreted as controlled mainly by temperature,fluid,host rock buffering,oxygen fugacity,and sulfur fugacity.The metallogenic conditions of the Yamansu deposit changed from high temperature and low oxygen fugacity to low temperature and high oxygen fugacity.However,more fluid-rock reactions and higher sulfur fugacity were involved during the deposition of massive ores and sulfiderich ores.展开更多
Two bridged purine dinucleosides, bis(2-N-acetyl-6-N-alkylylene-2,6-diaminopurine-2',3',5'-triacetyl-beta-D-ribofuranoside), were synthesized fi om the reaction of the key medium 3, 2-acetylamino-6-[1-(1,2...Two bridged purine dinucleosides, bis(2-N-acetyl-6-N-alkylylene-2,6-diaminopurine-2',3',5'-triacetyl-beta-D-ribofuranoside), were synthesized fi om the reaction of the key medium 3, 2-acetylamino-6-[1-(1,2,4-triazolyl)]-purine-2',3',5'-triacetyl-beta-D-ribofuranoside with dialkylamine.展开更多
Bulk-rock elements,isotopes,and zircon U–Pb ages are reported for magmatic rocks in the Dongzi–Changhanboluo Pb–Zn ore district in Chifeng,Inner Mongolia,China.Zircon U–Pb dating identified four stages of magmatis...Bulk-rock elements,isotopes,and zircon U–Pb ages are reported for magmatic rocks in the Dongzi–Changhanboluo Pb–Zn ore district in Chifeng,Inner Mongolia,China.Zircon U–Pb dating identified four stages of magmatism:Late Silurian gabbroic diorite(*420 Ma),Middle Permian monzonite(*274 Ma),Late Jurassic quartz porphyry and ignimbrite,breccia tuff(153–158 Ma)and Early Cretaceous andesitic porphyrite(*127 Ma).Integrating field observations,geochronology,and element and isotope geochemistry indicated a complex petrogenetic history of the magmatic rocks.The gabbroic diorite may have been sourced from EM1-type mantle.The source of the monzonite may have been mantle metasomatized by melt from the subducting plate.The Jurassic volcaniclastic rocks formed in a medium-pressure,high-temperature environment,possibly in the background of crustal thickening in a syncollisional stage and an early postcollisional stage.During this process,shaly sedimentary rocks were brought into the deep crust and heated,followed by the rapid isostatic uplift of the crust,which caused partial melting of the sedimentary rocks.Quartz monzonite porphyry and quartz porphyry formed by partial melting of mantle metasomatized by subducted sediments,but the quartz porphyry experienced high-degree differentiation and evolution.The andesitic porphyrite has characteristics similar to those of Permian monzonite,indicating that its source area was also the zone of mantle metasomatized by subducted sediment.The late Silurian and Permian magmatic rocks in this area most likely formed against a continental arc background related to the subduction of the Paleo-Asian Ocean Plate beneath the North China Plate.The Late Jurassic magmatic rocks suggest that the northern margin of the North China Craton may have been in a postcollisional setting during the Late Jurassic,with no obvious crustal thinning.The Cretaceous andesitic porphyrite may have formed against the background of lithospheric extension and thinning.According to the comprehensive analysis of geological characteristics,diagenetic and metallogenic epochs,and Pb isotope data,the formation of ore bodies in the Dongzi–Changhanboluo ore district was closely related to the Jurassic quartz porphyry.展开更多
Benefitting from the interlaced networking structure of carbon nanotubes(CNTs),the composites of CNTs/polydimethylsiloxane(PDMS)have found extensive applications in wearable electronics.While hierarchical multiscale s...Benefitting from the interlaced networking structure of carbon nanotubes(CNTs),the composites of CNTs/polydimethylsiloxane(PDMS)have found extensive applications in wearable electronics.While hierarchical multiscale simulation frameworks exist to optimize the structure parameters,their wide applications were hindered by the high computational cost.In this study,a machine learning model based on the artificial neural networks(ANN)embedded graph attention network,termed as AGAT,was proposed.The datasets collected from the micro-scale and the macro-scale simulations are utilized to train the model.The ANN layer within the model framework is trained to pass the information from micro-scale to macro-scale,while the whole model is aimed to predict the electro-mechanical behavior of the CNTs/PDMS composites.By comparing the AGAT model with the original multiscale simulation results,the data-driven strategy is shown to be promising with high accuracy,demonstrating the potential of the machine-learning-enabled approach for the structure optimization of CNT-based composites.展开更多
In this paper, we present textures, trace element compositions, and sulfur isotope data for pyrite from the Honghai volcanogenic massive sulfide deposit to place new constraints on the source and evolution of the ore-...In this paper, we present textures, trace element compositions, and sulfur isotope data for pyrite from the Honghai volcanogenic massive sulfide deposit to place new constraints on the source and evolution of the ore-forming fluids and provide insights into the ore genesis with implications for future exploration. The Honghai deposit consists of upper lenticular ores comprising massive sulfides that are underlain by stockwork and disseminated sulfides. The textural and isotopic characteristics of the synsedimentary framboidal pyrite(Syn-Py) indicate its formation by biogenetic processes. Coarse-grained pyrite generations(M-Py1, M-Py2, and M-Py3) from the massive sulfides have high Au, Ag, Cu, Zn, Pb, Sb, and Tl concentrations and low Co, Se, Te, Ti, and Sn concentrations, indicating that they precipitated from metal-rich, low-to intermediate-temperature,oxidizing fluids. The high Te, Ti, and Sn concentrations and high Co/Ni ratios in the massive pyrite(M-Py4) associated with magnetite in the massive sulfide lenses, as well as the high Ti, V, Cr, and Ni concentrations and low Al, Mn, and Zn concentrations in the magnetite, suggest that the coexisting M-Py4 and magnetite precipitated under oxidizing and hightemperature(300℃ to 500℃) conditions. In contrast, pyrite grains from the underlying stockwork and veins(V-Py1, V-Py2, and V-Py3) are characterized by low Au, Ag, Cu, Zn, Pb, Sb, and Tl concentrations coupled with high Co, Se, Te, and Ti concentrations and high Co/Ni ratios, which are interpreted in terms of reducing and high-temperature ore-forming fluids. The large variations in δ^(34)S values from-6.4‰ to +29.9‰ suggest that the ore-forming fluids were derived from magmatic source that were significantly modified by seawater. The spatial variations of trace element assemblages of pyrite from different levels of the main massive orebodies can be used as an indicator for mineral exploration of Cu-Zn ores in the Honghai deposit.Although no significant difference in δ34S values is observed between the upper massive sulfide lenses and lower stockwork/vein zone, the spiky δ34S pattern noted in the massive pyrite can be used as a marker for the main massive orebodies.展开更多
Optical-resolution photoacoustic microscopy(OR-PAM)has rapidly developed and is capable of characterizing optical absorption properties of biological tissue with high contrast and high resolution(micrometer-scale late...Optical-resolution photoacoustic microscopy(OR-PAM)has rapidly developed and is capable of characterizing optical absorption properties of biological tissue with high contrast and high resolution(micrometer-scale lateral resolution).However,the conventional excitation source of rapidly diverging Gaussian beam imposes limitations on the depth of focus(DOF)in OR-PAM,which in turn affects the depth-resolving ability and detection sensitivity.Here,we proposed a flexible DOF,depth-invariant resolution photoacoustic microscopy(FDIR-PAM)with nondiffraction of Airy beams.The spatial light modulator was incorporated into the optical pathway of the excitation source with matched switching phase patterns,achieving the flexibly adjustable modulation parameters of the Airy beam.We conducted experiments on phantoms and intravital tissue to validate the effectiveness of the proposed approach for high sensitivity and highresolution characterization of variable topology of tissue,offering a promising DOF of 926μm with an invariant lateral resolution of 3.2μm,which is more than 17-fold larger compared to the Gaussian beam.In addition,FDIR-PAM successfully revealed clear individual zebrafish larvae and the pigment pattern of adult zebrafishes,as well as fine morphology of cerebral vasculature in a large depth range with high resolution,which has reached an evident resolving capability improvement of 62%mean value compared with the Gaussian beam.展开更多
Single-layer MoSi_(2)N_(4),a high-quality two-dimensional material,has recently been fabricated by chemical vapor deposition.Motivated by this latest experimental work,herein,we apply first principles calculations to ...Single-layer MoSi_(2)N_(4),a high-quality two-dimensional material,has recently been fabricated by chemical vapor deposition.Motivated by this latest experimental work,herein,we apply first principles calculations to investigate the electronic,optical,and photocatalytic properties of alkali-metal(Li,Na,and K)-adsorbed MoSi_(2)N_(4) monolayer.The electronic structure analysis shows that pristine MoSi_(2)N_(4) monolayer exhibits an indirect bandgap(E_(g)=1.89 eV).By contrast,the bandgaps of one Li-,Na-,and K-adsorbed MoSi_(2)N_(4) monolayer are 1.73 eV,1.61 eV,and 1.75 eV,respectively.Moreover,the work function of MoSi_(2)N_(4) monolayer(4.80 eV)is significantly reduced after the adsorption of alkali metal atoms.The work functions of one Li-,Na-,and K-adsorbed MoSi_(2)N_(4) monolayer are 1.50 eV,1.43 eV,and 2.03 eV,respectively.Then,optical investigations indicate that alkali metal adsorption processes substantially increase the visible light absorption range and coefficient of MoSi_(2)N_(4) monolayer.Furthermore,based on redox potential variations after alkali metals are adsorbed,Li-and Na-adsorbed MoSi_(2)N_(4) monolayers are more suitable for the water splitting photocatalytic process,and the Li-adsorbed case shows the highest potential application for CO_(2) reduction.In conclusion,alkali-metal-adsorbed MoSi_(2)N_(4) monolayer exhibits promising applications as novel optoelectronic devices and photocatalytic materials due to its unique physical and chemical properties.展开更多
System health management,which aims to ensure the safe and efficient operation of systems by reducing uncertain risks and cascading failures during their lifetime,is proposed for complex transportation systems and oth...System health management,which aims to ensure the safe and efficient operation of systems by reducing uncertain risks and cascading failures during their lifetime,is proposed for complex transportation systems and other critical infrastructures,especially under the background of the New Infrastructure Projects launched in China.Previous studies proposed numerous approaches to evaluate or improve traffic reliability or efficiency.Nevertheless,most existing studies neglected the core failure mechanism(i.e.,spatio-temporal propagation of traffic congestion).In this article,we review existing studies on traffic reliability management and propose a health management framework covering the entire traffic congestion lifetime,from emergence,evolution to dissipation,based on the study of core failure modes with percolation theory.Aiming to be"reliable,invulnerable,resilient,potential,and active",our proposed traffic health management framework includes modeling,evaluation,diagnosis,and improvement.Our proposed framework may shed light on traffic management for megacities and urban agglomerations around the world.This new approach may offer innovative insights for systems science and engineering in fiiture intelligent infrastructure management.展开更多
We propose a new discontinuous Galerkin method based on the least-squares patch reconstruction for the biharmonic problem. We prove the optimal error estimate of the proposed method. The two-dimensional and three-dime...We propose a new discontinuous Galerkin method based on the least-squares patch reconstruction for the biharmonic problem. We prove the optimal error estimate of the proposed method. The two-dimensional and three-dimensional numerical examples are presented to confirm the accuracy and efficiency of the method with several boundary conditions and several types of polygon meshes and polyhedral meshes.展开更多
The discontinuous Galerkin method by divergence-free patch reconstruction is proposed for Stokes eigenvalue problems.It utilizes the mixed finite element framework.The patch reconstruction technique constructs two cat...The discontinuous Galerkin method by divergence-free patch reconstruction is proposed for Stokes eigenvalue problems.It utilizes the mixed finite element framework.The patch reconstruction technique constructs two categories of approximation spaces.Namely,the local divergence-free space is employed to discretize the velocity space,and the pressure space is approximated by standard reconstruction space simultaneously.Benefit from the divergence-free constraint;the identical element patch serves two approximation spaces while using the element pair Pm+1/Pm.The optimal error estimate is derived under the inf-sup condition framework.Numerical examples are carried out to validate the inf-sup test and the theoretical results.展开更多
In this paper,we propose hierarchical absorbing interface conditions to solve the problem of wave propagation in domains with a non-uniform space discretization or grid size inhomogeneity using Pad´e Via Lanczos(...In this paper,we propose hierarchical absorbing interface conditions to solve the problem of wave propagation in domains with a non-uniform space discretization or grid size inhomogeneity using Pad´e Via Lanczos(PVL)method.The proposed interface conditions add an auxiliary variable in the wave system to eliminate the spurious reflection at the interface between regions with different mesh sizes.The auxiliary variable with proper boundary condition can suppress the spurious reflection by cancelling the boundary source term produced by the space inhomogeneity in variational perspective.The new hierarchical interface conditions with the help of PVL implementation can effectively reduce the degree of freedom in solving the wave propagation problem.展开更多
Toll-like receptors(TLRs)and glucocorticoid receptor(GR)act as effectors of innate immune system and neuroendocrine system,respectively.The crosstalk between these two receptors is important to maintain homeostasis du...Toll-like receptors(TLRs)and glucocorticoid receptor(GR)act as effectors of innate immune system and neuroendocrine system,respectively.The crosstalk between these two receptors is important to maintain homeostasis during immune response.It is well known that vaccination can boost adaptive immune responses to specific pathogens.However,it remains elusive whether and展开更多
基金supported by the National Key R&D Program of China (Nos. 2018YFC0604006, 2017YFC0601204)the National Basic Research Program of China (973 Program, No. 2014CB440803)
文摘The volcanic rocks hosting the iron deposits in the Aqishan–Yamansu metallogenic belt are sodium-rich.The geochronology,petrography,and geochemistry of minerals and sodium-rich rocks as well as the relationship between these rocks and the iron deposits are studied.Geochemically,the ore-hosting volcanic rocks are sodiumrich(the averages of Na2O and Na2O/K2O are 4.31 wt.%and 8.56,respectively)and belong to the calc-alkaline series.They are enriched in LREEs and LILEs(Ba,U,K,and Sr),but depleted in HFSEs(Nb,Ta,and Ti).SHRIMP zircon U–Pb dating of the crystal tuff in the Aqishan Formation and the dacite in the Tugutu Bulak Formation yields ages of 337.52.3 Ma(n?15,MSWD?0.85)and 313.03.3 Ma(n?13,MSWD?0.74),respectively,indicating that the sodium-rich volcanic rocks formed from the early–late Carboniferous.Electron microprobe data from plagioclases demonstrate that albites and/or oligoclases were formed in the basic–intermediate–acid volcanic rocks.Two stages of albitization are identified,and the latter is likely attributed to the dissolution of iron in the Aqishan–Yamansu belt.The sodium-rich volcanic rocks probably formed by the interaction between volcanic lava and seawater after volcanoes erupted on the seafloor;meanwhile,the albites formed by element substitution in a low-metamorphic environment.The spatiotemporal coupling relationship between sodium-rich volcanic rocks and iron deposits in the Aqishan–Yamansu belt is favorable.Iron dissolved from the dark minerals of basic–intermediate volcanic rocks through sodium metasomatism is one of the material sources for the iron deposits.
基金supported by grants from the National Natural Science Foundation of China(31771243)the Fok Ying Tong Education Foundation(141113)to Aiguo Chen.
文摘In recent years evidence has emerged suggesting that Mini-basketball training program(MBTP)can be an effec-tive intervention method to improve social communication(SC)impairments and restricted and repetitive beha-viors(RRBs)in preschool children suffering from autism spectrum disorder(ASD).However,there is a considerable degree if interindividual variability concerning these social outcomes and thus not all preschool chil-dren with ASD profit from a MBTP intervention to the same extent.In order to make more accurate predictions which preschool children with ASD can benefit from an MBTP intervention or which preschool children with ASD need additional interventions to achieve behavioral improvements,further research is required.This study aimed to investigate which individual factors of preschool children with ASD can predict MBTP intervention out-comes concerning SC impairments and RRBs.Then,test the performance of machine learning models in predict-ing intervention outcomes based on these factors.Participants were 26 preschool children with ASD who enrolled in a quasi-experiment and received MBTP intervention.Baseline demographic variables(e.g.,age,body,mass index[BMI]),indicators of physicalfitness(e.g.,handgrip strength,balance performance),performance in execu-tive function,severity of ASD symptoms,level of SC impairments,and severity of RRBs were obtained to predict treatment outcomes after MBTP intervention.Machine learning models were established based on support vector machine algorithm were implemented.For comparison,we also employed multiple linear regression models in statistics.Ourfindings suggest that in preschool children with ASD symptomatic severity(r=0.712,p<0.001)and baseline SC impairments(r=0.713,p<0.001)are predictors for intervention outcomes of SC impair-ments.Furthermore,BMI(r=-0.430,p=0.028),symptomatic severity(r=0.656,p<0.001),baseline SC impair-ments(r=0.504,p=0.009)and baseline RRBs(r=0.647,p<0.001)can predict intervention outcomes of RRBs.Statistical models predicted 59.6%of variance in post-treatment SC impairments(MSE=0.455,RMSE=0.675,R2=0.596)and 58.9%of variance in post-treatment RRBs(MSE=0.464,RMSE=0.681,R2=0.589).Machine learning models predicted 83%of variance in post-treatment SC impairments(MSE=0.188,RMSE=0.434,R2=0.83)and 85.9%of variance in post-treatment RRBs(MSE=0.051,RMSE=0.226,R2=0.859),which were better than statistical models.Ourfindings suggest that baseline characteristics such as symptomatic severity of 144 IJMHP,2022,vol.24,no.2 ASD symptoms and SC impairments are important predictors determining MBTP intervention-induced improvements concerning SC impairments and RBBs.Furthermore,the current study revealed that machine learning models can successfully be applied to predict the MBTP intervention-related outcomes in preschool chil-dren with ASD,and performed better than statistical models.Ourfindings can help to inform which preschool children with ASD are most likely to benefit from an MBTP intervention,and they might provide a reference for the development of personalized intervention programs for preschool children with ASD.
基金supported by the National Key R&D Program of China(2018YFC0604006 and 2017YFC0601204)the National Basic Research Program of China(973 Program,2014CB440803)。
文摘The Yamansu iron deposit is hosted in submarine volcanic rocks in the Aqishan–Yamansu belt of Eastern Tianshan,NW China.A geological cross-section for the Carboniferous strata in the ore district shows that ore bodies in the Yamansu deposit are hosted in andesitic crystal tuff of the third cycle of the Carboniferous Yamansu Formation.This indicates an association between mineralization and volcanism.The orebodies are strata bound and lensoid and generally share the occurrence state of the host rocks.Magnetite mineralization mainly occurs asbreccia ores,ores in the mineralized volcanic rocks,massive ores,and sulfide-rich ores according to their structures and sequences of formation.Trace element compositions of magnetite from various types of ores were determined by LA-ICP-MS.The dataset indicates thatdifferent types of magnetite havedistinct trace element contents correlated to their formation environments.Magnetite crystals from breccia ores have high Ti,Ni,V,Cr,and Co and low Si,Al,Ca,and Mg contents,indicating crystallization from a volcanic magmatic eruption,which is consistent with field evidence of coexisting altered volcanic breccia.Magnetite crystals from ores in the mineralized volcanic rocks have moderate Ti,Ni,V,Cr,and Co contents.In contrast,magnetite from massive ores and sulfide-rich ores have low concentrations of Ti,Cr,Ni,and V,high concentrations of Si,Al,Ca,and Mg,and evidence of hydrothermal magnetite.In-situ magnetite compositions imply a magmatic-hydrothermal process.Although d18 O values for magnetite grains from Yamansu vary(?1.3 to?7.0%),they all plot in the range field of volcanic iron deposits,and they also record a magmatic-hydrothermal process.The compositions of Yamansu magnetites are interpreted as controlled mainly by temperature,fluid,host rock buffering,oxygen fugacity,and sulfur fugacity.The metallogenic conditions of the Yamansu deposit changed from high temperature and low oxygen fugacity to low temperature and high oxygen fugacity.However,more fluid-rock reactions and higher sulfur fugacity were involved during the deposition of massive ores and sulfiderich ores.
文摘Two bridged purine dinucleosides, bis(2-N-acetyl-6-N-alkylylene-2,6-diaminopurine-2',3',5'-triacetyl-beta-D-ribofuranoside), were synthesized fi om the reaction of the key medium 3, 2-acetylamino-6-[1-(1,2,4-triazolyl)]-purine-2',3',5'-triacetyl-beta-D-ribofuranoside with dialkylamine.
基金financially supported by the National Natural Science Foundation of China(No.41602101)。
文摘Bulk-rock elements,isotopes,and zircon U–Pb ages are reported for magmatic rocks in the Dongzi–Changhanboluo Pb–Zn ore district in Chifeng,Inner Mongolia,China.Zircon U–Pb dating identified four stages of magmatism:Late Silurian gabbroic diorite(*420 Ma),Middle Permian monzonite(*274 Ma),Late Jurassic quartz porphyry and ignimbrite,breccia tuff(153–158 Ma)and Early Cretaceous andesitic porphyrite(*127 Ma).Integrating field observations,geochronology,and element and isotope geochemistry indicated a complex petrogenetic history of the magmatic rocks.The gabbroic diorite may have been sourced from EM1-type mantle.The source of the monzonite may have been mantle metasomatized by melt from the subducting plate.The Jurassic volcaniclastic rocks formed in a medium-pressure,high-temperature environment,possibly in the background of crustal thickening in a syncollisional stage and an early postcollisional stage.During this process,shaly sedimentary rocks were brought into the deep crust and heated,followed by the rapid isostatic uplift of the crust,which caused partial melting of the sedimentary rocks.Quartz monzonite porphyry and quartz porphyry formed by partial melting of mantle metasomatized by subducted sediments,but the quartz porphyry experienced high-degree differentiation and evolution.The andesitic porphyrite has characteristics similar to those of Permian monzonite,indicating that its source area was also the zone of mantle metasomatized by subducted sediment.The late Silurian and Permian magmatic rocks in this area most likely formed against a continental arc background related to the subduction of the Paleo-Asian Ocean Plate beneath the North China Plate.The Late Jurassic magmatic rocks suggest that the northern margin of the North China Craton may have been in a postcollisional setting during the Late Jurassic,with no obvious crustal thinning.The Cretaceous andesitic porphyrite may have formed against the background of lithospheric extension and thinning.According to the comprehensive analysis of geological characteristics,diagenetic and metallogenic epochs,and Pb isotope data,the formation of ore bodies in the Dongzi–Changhanboluo ore district was closely related to the Jurassic quartz porphyry.
基金supported by the National Key R&D Program of China(2023YFE0111500 and 2023YFC3040900)the National Natural Science Foundation of China(52222313,22075296,52321006,T2394480,T2394484 and 52203247)+2 种基金the China Postdoctoral Science Foundation(2022TQ0340)Beijing National Laboratory for Molecular Sciences(BNLMS-CXXM-202005)Junior Fellow Program of Beijing National Laboratory for Molecular Sciences(2021BMS20063)。
基金supported by the National Key R&D Program of China(2022ZD0117501)the National Natural Science Foundation of China(62201441)
文摘Benefitting from the interlaced networking structure of carbon nanotubes(CNTs),the composites of CNTs/polydimethylsiloxane(PDMS)have found extensive applications in wearable electronics.While hierarchical multiscale simulation frameworks exist to optimize the structure parameters,their wide applications were hindered by the high computational cost.In this study,a machine learning model based on the artificial neural networks(ANN)embedded graph attention network,termed as AGAT,was proposed.The datasets collected from the micro-scale and the macro-scale simulations are utilized to train the model.The ANN layer within the model framework is trained to pass the information from micro-scale to macro-scale,while the whole model is aimed to predict the electro-mechanical behavior of the CNTs/PDMS composites.By comparing the AGAT model with the original multiscale simulation results,the data-driven strategy is shown to be promising with high accuracy,demonstrating the potential of the machine-learning-enabled approach for the structure optimization of CNT-based composites.
基金supported by the National Key R&D Program of China(Grant No.2018YFC0604006)the National Natural Science Foundation of China(Grant No.41572077)the Geological Survey Project of China(Grant No.1212011140056)。
文摘In this paper, we present textures, trace element compositions, and sulfur isotope data for pyrite from the Honghai volcanogenic massive sulfide deposit to place new constraints on the source and evolution of the ore-forming fluids and provide insights into the ore genesis with implications for future exploration. The Honghai deposit consists of upper lenticular ores comprising massive sulfides that are underlain by stockwork and disseminated sulfides. The textural and isotopic characteristics of the synsedimentary framboidal pyrite(Syn-Py) indicate its formation by biogenetic processes. Coarse-grained pyrite generations(M-Py1, M-Py2, and M-Py3) from the massive sulfides have high Au, Ag, Cu, Zn, Pb, Sb, and Tl concentrations and low Co, Se, Te, Ti, and Sn concentrations, indicating that they precipitated from metal-rich, low-to intermediate-temperature,oxidizing fluids. The high Te, Ti, and Sn concentrations and high Co/Ni ratios in the massive pyrite(M-Py4) associated with magnetite in the massive sulfide lenses, as well as the high Ti, V, Cr, and Ni concentrations and low Al, Mn, and Zn concentrations in the magnetite, suggest that the coexisting M-Py4 and magnetite precipitated under oxidizing and hightemperature(300℃ to 500℃) conditions. In contrast, pyrite grains from the underlying stockwork and veins(V-Py1, V-Py2, and V-Py3) are characterized by low Au, Ag, Cu, Zn, Pb, Sb, and Tl concentrations coupled with high Co, Se, Te, and Ti concentrations and high Co/Ni ratios, which are interpreted in terms of reducing and high-temperature ore-forming fluids. The large variations in δ^(34)S values from-6.4‰ to +29.9‰ suggest that the ore-forming fluids were derived from magmatic source that were significantly modified by seawater. The spatial variations of trace element assemblages of pyrite from different levels of the main massive orebodies can be used as an indicator for mineral exploration of Cu-Zn ores in the Honghai deposit.Although no significant difference in δ34S values is observed between the upper massive sulfide lenses and lower stockwork/vein zone, the spiky δ34S pattern noted in the massive pyrite can be used as a marker for the main massive orebodies.
基金supported by the National Natural Science Foundation of China(Grant Nos.62105255 and 62275210)the Xidian University Specially Funded Project for Interdisciplinary Exploration(Grant No.TZJH2024043)+1 种基金the Key Research and Development Program of Shaanxi Province(Grant No.2023-YBSF-293)the National Young Talent Program and Shaanxi Young Top-notch Talent Program,and the Fundamental Research Funds for CentralUniversities(Grant No.ZYTS23187).
文摘Optical-resolution photoacoustic microscopy(OR-PAM)has rapidly developed and is capable of characterizing optical absorption properties of biological tissue with high contrast and high resolution(micrometer-scale lateral resolution).However,the conventional excitation source of rapidly diverging Gaussian beam imposes limitations on the depth of focus(DOF)in OR-PAM,which in turn affects the depth-resolving ability and detection sensitivity.Here,we proposed a flexible DOF,depth-invariant resolution photoacoustic microscopy(FDIR-PAM)with nondiffraction of Airy beams.The spatial light modulator was incorporated into the optical pathway of the excitation source with matched switching phase patterns,achieving the flexibly adjustable modulation parameters of the Airy beam.We conducted experiments on phantoms and intravital tissue to validate the effectiveness of the proposed approach for high sensitivity and highresolution characterization of variable topology of tissue,offering a promising DOF of 926μm with an invariant lateral resolution of 3.2μm,which is more than 17-fold larger compared to the Gaussian beam.In addition,FDIR-PAM successfully revealed clear individual zebrafish larvae and the pigment pattern of adult zebrafishes,as well as fine morphology of cerebral vasculature in a large depth range with high resolution,which has reached an evident resolving capability improvement of 62%mean value compared with the Gaussian beam.
基金This research was supported by the National Natural Science Foundation of China(Grant No.11774054,12075036)the talents and high-level paper cultivation plan from the School of Optoelectronic Engineering,Yangtze University.
文摘Single-layer MoSi_(2)N_(4),a high-quality two-dimensional material,has recently been fabricated by chemical vapor deposition.Motivated by this latest experimental work,herein,we apply first principles calculations to investigate the electronic,optical,and photocatalytic properties of alkali-metal(Li,Na,and K)-adsorbed MoSi_(2)N_(4) monolayer.The electronic structure analysis shows that pristine MoSi_(2)N_(4) monolayer exhibits an indirect bandgap(E_(g)=1.89 eV).By contrast,the bandgaps of one Li-,Na-,and K-adsorbed MoSi_(2)N_(4) monolayer are 1.73 eV,1.61 eV,and 1.75 eV,respectively.Moreover,the work function of MoSi_(2)N_(4) monolayer(4.80 eV)is significantly reduced after the adsorption of alkali metal atoms.The work functions of one Li-,Na-,and K-adsorbed MoSi_(2)N_(4) monolayer are 1.50 eV,1.43 eV,and 2.03 eV,respectively.Then,optical investigations indicate that alkali metal adsorption processes substantially increase the visible light absorption range and coefficient of MoSi_(2)N_(4) monolayer.Furthermore,based on redox potential variations after alkali metals are adsorbed,Li-and Na-adsorbed MoSi_(2)N_(4) monolayers are more suitable for the water splitting photocatalytic process,and the Li-adsorbed case shows the highest potential application for CO_(2) reduction.In conclusion,alkali-metal-adsorbed MoSi_(2)N_(4) monolayer exhibits promising applications as novel optoelectronic devices and photocatalytic materials due to its unique physical and chemical properties.
基金This work was supported by the National Natural Science Foundation of China(Grants Nos.71822101,71890973/71890970,71771009,and 61961146005).
文摘System health management,which aims to ensure the safe and efficient operation of systems by reducing uncertain risks and cascading failures during their lifetime,is proposed for complex transportation systems and other critical infrastructures,especially under the background of the New Infrastructure Projects launched in China.Previous studies proposed numerous approaches to evaluate or improve traffic reliability or efficiency.Nevertheless,most existing studies neglected the core failure mechanism(i.e.,spatio-temporal propagation of traffic congestion).In this article,we review existing studies on traffic reliability management and propose a health management framework covering the entire traffic congestion lifetime,from emergence,evolution to dissipation,based on the study of core failure modes with percolation theory.Aiming to be"reliable,invulnerable,resilient,potential,and active",our proposed traffic health management framework includes modeling,evaluation,diagnosis,and improvement.Our proposed framework may shed light on traffic management for megacities and urban agglomerations around the world.This new approach may offer innovative insights for systems science and engineering in fiiture intelligent infrastructure management.
基金the National Natural Science Foundation of China for Distinguished Young Scholars 11425106National Natural Science Foundation of China Grants 91630313+1 种基金CAS NCMISthe National Natural Science Foundation of China Grants 91630313 and 11671312.
文摘We propose a new discontinuous Galerkin method based on the least-squares patch reconstruction for the biharmonic problem. We prove the optimal error estimate of the proposed method. The two-dimensional and three-dimensional numerical examples are presented to confirm the accuracy and efficiency of the method with several boundary conditions and several types of polygon meshes and polyhedral meshes.
基金supported by the National Key Research and Development Program of China(Grant No.2020YFA0714200)by the National Natural Science Foundation of China(Grant Nos.12125103,12071362,12101062)+1 种基金the China Postdoctoral Science Foundation(Grant No.2019M660558)by the Natural Science Foundation of Hubei Province(Grant No.2019CFA007)。
文摘The discontinuous Galerkin method by divergence-free patch reconstruction is proposed for Stokes eigenvalue problems.It utilizes the mixed finite element framework.The patch reconstruction technique constructs two categories of approximation spaces.Namely,the local divergence-free space is employed to discretize the velocity space,and the pressure space is approximated by standard reconstruction space simultaneously.Benefit from the divergence-free constraint;the identical element patch serves two approximation spaces while using the element pair Pm+1/Pm.The optimal error estimate is derived under the inf-sup condition framework.Numerical examples are carried out to validate the inf-sup test and the theoretical results.
基金supported by the National Key Research and Development Program of China(Grant No.2020YFA0714200)by the National Natural Science Foundation of China(Grants No.12125103,12071362,12101062)+1 种基金by China Postdoctoral Sci-ence Foundation(Grant No.2019M660558)by the Natural Science Foundation of Hubei Province(Grant No.2019CFA007)。
文摘In this paper,we propose hierarchical absorbing interface conditions to solve the problem of wave propagation in domains with a non-uniform space discretization or grid size inhomogeneity using Pad´e Via Lanczos(PVL)method.The proposed interface conditions add an auxiliary variable in the wave system to eliminate the spurious reflection at the interface between regions with different mesh sizes.The auxiliary variable with proper boundary condition can suppress the spurious reflection by cancelling the boundary source term produced by the space inhomogeneity in variational perspective.The new hierarchical interface conditions with the help of PVL implementation can effectively reduce the degree of freedom in solving the wave propagation problem.
文摘Toll-like receptors(TLRs)and glucocorticoid receptor(GR)act as effectors of innate immune system and neuroendocrine system,respectively.The crosstalk between these two receptors is important to maintain homeostasis during immune response.It is well known that vaccination can boost adaptive immune responses to specific pathogens.However,it remains elusive whether and