The Mechanism for Air pollution compleX version 1.0(MAX1),describing detailed tropospheric chemical processes,has been developed based on the latest knowledge.MAX1 contains 940 reactions,including photolysis,gaseous r...The Mechanism for Air pollution compleX version 1.0(MAX1),describing detailed tropospheric chemical processes,has been developed based on the latest knowledge.MAX1 contains 940 reactions,including photolysis,gaseous reactions,and heterogeneous reactions of 300 species,which is adequate for both box model and climate transport model(CTM)applications.Detailed chemical processes of chlorine chemistry,chemistry of Criegee intermediates,and heterogeneous uptake of HO_(2) and N_(2)O_(5) have been implemented and updated.With this level of explicitness,MAX1 can support investigations into the quantification of secondary pollutant productions and the chemical behavior of the crucial intermediates,such as organic peroxy radicals.Box model and CTM tests were conducted to evaluate the performance of MAX1 from different perspectives.Simulations of MAX1 successfully captured the variation of ozone in all cases tested.Meanwhile,significant improvement was made on predictions of radicals compared to other mechanisms,especially under the low NO_(x) environment,with good similarity to simulations of a nearly explicit chemical mechanism(i.e.,Master Chemical Mechanism)that contains over 17000 reactions.The computational expense of MAX1 is acceptable and it can be applied in atmospheric scientific research and air quality prediction.MAX1 introduces new dimensions in atmospheric chemistry modeling,and its potential application in policymaking is a promising yet exploratory step.It offers improved insights into air quality dynamics,which could assist policymakers in making more informed decisions.However,the translation of its detailed chemical understanding into practical strategies remains an area for further investigation.This model suggests a path towards more nuanced air pollution control methods,contributing to ongoing efforts in environmental management.展开更多
In recent years,with the rapid advancement of artificial intelligence,object detection algorithms have made significant strides in accuracy and computational efficiency.Notably,research and applications of Anchor-Free...In recent years,with the rapid advancement of artificial intelligence,object detection algorithms have made significant strides in accuracy and computational efficiency.Notably,research and applications of Anchor-Free models have opened new avenues for real-time target detection in optical remote sensing images(ORSIs).However,in the realmof adversarial attacks,developing adversarial techniques tailored to Anchor-Freemodels remains challenging.Adversarial examples generated based on Anchor-Based models often exhibit poor transferability to these new model architectures.Furthermore,the growing diversity of Anchor-Free models poses additional hurdles to achieving robust transferability of adversarial attacks.This study presents an improved cross-conv-block feature fusion You Only Look Once(YOLO)architecture,meticulously engineered to facilitate the extraction ofmore comprehensive semantic features during the backpropagation process.To address the asymmetry between densely distributed objects in ORSIs and the corresponding detector outputs,a novel dense bounding box attack strategy is proposed.This approach leverages dense target bounding boxes loss in the calculation of adversarial loss functions.Furthermore,by integrating translation-invariant(TI)and momentum-iteration(MI)adversarial methodologies,the proposed framework significantly improves the transferability of adversarial attacks.Experimental results demonstrate that our method achieves superior adversarial attack performance,with adversarial transferability rates(ATR)of 67.53%on the NWPU VHR-10 dataset and 90.71%on the HRSC2016 dataset.Compared to ensemble adversarial attack and cascaded adversarial attack approaches,our method generates adversarial examples in an average of 0.64 s,representing an approximately 14.5%improvement in efficiency under equivalent conditions.展开更多
Background Internet gaming disorder(IGD)is an ideal model to study the mechanisms underlying synaptic deficits in addiction as it eliminates the confounding effects of substance use.Synaptic loss and deficits are hypo...Background Internet gaming disorder(IGD)is an ideal model to study the mechanisms underlying synaptic deficits in addiction as it eliminates the confounding effects of substance use.Synaptic loss and deficits are hypothesised to underlie the enduring maladaptive behaviours and impaired cognitive function that contribute to IGD.Aims This study aimed to determine whether subjects with IGD have lower synaptic density than control subjects and the relationship between synaptic density and IGD severity.Methods Eighteen unmedicated subjects diagnosed with current IGD according to the Diagnostic and Statistical Manual of Mental Disorders,Fifth Edition criteria and 16 demographically matched healthy controls(HCs)participated in the study and underwent 18F-labelled difluoro-analogue of UCB-J(18F-SynVesT-1)positron emission tomography scans to assess the density of synaptic vesicle glycoprotein 2A(SV2A).The Internet Gaming Disorder Scale-Short Form(IGDS9-SF),Hamilton Rating Scale for Depression(HAMD),Hamilton Anxiety Rating Scale(HAMA),Barratt Impulsiveness Scale Version 11(BIS-11),Stroop Colour-Word Test(SCWT),stop-signal paradigms and N-back tasks were administered to all subjects.Results Patients with IGD had significantly higher scores on the IGDS9-SF,HAMD,HAMA and BIS-11 than HCs.HCs performed better on the two-back and SCWT tests as well as in terms of stop-signal reaction times(SSRTs)in the stop-signal paradigms than patients with IGD.Lower uptake was found in the bilateral putamen,right pregenual anterior cingulate cortex and Rolandic operculum of patients with IGD compared with HCs.Furthermore,in the IGD group,IGDS9-SF scores and daily gaming hours were negatively correlated with the standardised uptake value ratios of 18F-SynVesT-1 in the bilateral putamen.Longer SSRTs were significantly associated with lower SV2A density in the right pregenual anterior cingulate cortex and right Rolandic operculum.Conclusions The in vivo results in this study suggest that lower synaptic density contributes to the severity and impairments in inhibitory control of IGD.These findings may provide further incentive to evaluate interventions that restore synaptic transmission and plasticity to treat IGD.展开更多
Binuclear complexes have attracted extensive attention in fields such as catalysis because of their likely bimetallic synergistic effect;however,the mechanism and factors influencing this synergism remain unclear.In t...Binuclear complexes have attracted extensive attention in fields such as catalysis because of their likely bimetallic synergistic effect;however,the mechanism and factors influencing this synergism remain unclear.In this work,six bis-β-ketoimine binuclear titanium complexes4a-4f containing different alkylthio sidearms and configurations were synthesized and characterized by nuclear magnetic resonance hydrogen spectrum(~1H-NMR),nuclear magnetic resonance carbon spectrum(^(13)C-NMR),Fourier transform infrared spectrum(FTIR),and elemental analysis.The intermetallic distances of isomeric complexes 4a,4d,4e and 4f determined through density functional theory(DFT)optimization were in the order 4a<4d<4e<4f and were found to significantly influence the catalytic performance for ethylene(co)polymerization.These complexes could efficiently catalyze ethylene polymerization and ethylene/1-hexene or ethylene/1-octene copolymerization with high activity to produce highmolecular-weight ethylene homo-and co-polymers.Among the three binuclear titanium complexes 4a-4c with similar structures but different lengths of alkylthio sidearms,complex 4a,which contained the shortest methylthio sidearm,exhibited the highest activity for ethylene polymerization and copolymerization with 1-hexene or 1-octene.Additionally,for ethylene/1-hexene or ethylene/1-octene copolymerization,it showed the highest comonomer incorporation compared with propylthio(4b)and octylthio(4c)derivatives because of the smaller steric hindrance of the methyl group in 4a and the more open coordination space for vinyl monomers.Furthermore,among the isomeric complexes 4a,4d,4e and4f,complex 4a with the shortest bimetallic distance also exhibited the highest activity towards ethylene(co)polymerization,and the highest 1-hexene or 1-octene incorporation in comparison with its regioisomeric counterparts 4d,4e and p-phenyl-bridged analog 4f,owing to a more appropriate bimetallic distance that is conducive to a synergistic effect.展开更多
Long-term levodopa administration can lead to the development of levodopa-induced dyskinesia.Gamma oscillations are a widely recognized hallmark of abnormal neural electrical activity in levodopa-induced dyskinesia.Cu...Long-term levodopa administration can lead to the development of levodopa-induced dyskinesia.Gamma oscillations are a widely recognized hallmark of abnormal neural electrical activity in levodopa-induced dyskinesia.Currently,studies have reported increased oscillation power in cases of levodopa-induced dyskinesia.However,little is known about how the other electrophysiological parameters of gamma oscillations are altered in levodopa-induced dyskinesia.Furthermore,the role of the dopamine D3 receptor,which is implicated in levodopa-induced dyskinesia,in movement disorder-related changes in neural oscillations is unclear.We found that the cortico-striatal functional connectivity of beta oscillations was enhanced in a model of Parkinson’s disease.Furthermore,levodopa application enhanced cortical gamma oscillations in cortico-striatal projections and cortical gamma aperiodic components,as well as bidirectional primary motor cortex(M1)↔dorsolateral striatum gamma flow.Administration of PD128907(a selective dopamine D3 receptor agonist)induced dyskinesia and excessive gamma oscillations with a bidirectional M1↔dorsolateral striatum flow.However,administration of PG01037(a selective dopamine D3 receptor antagonist)attenuated dyskinesia,suppressed gamma oscillations and cortical gamma aperiodic components,and decreased gamma causality in the M1→dorsolateral striatum direction.These findings suggest that the dopamine D3 receptor plays a role in dyskinesia-related oscillatory activity,and that it has potential as a therapeutic target for levodopa-induced dyskinesia.展开更多
Due to the lack of the three-dimensional structure of the Zhaoji Salt Basin,the salt mining enterprises have obvious clustering when choosing sites.Production capacity declines rapidly as mining deepens,and the enterp...Due to the lack of the three-dimensional structure of the Zhaoji Salt Basin,the salt mining enterprises have obvious clustering when choosing sites.Production capacity declines rapidly as mining deepens,and the enterprises are entering a stage of stagnation in production.In this study,a dense seismic array of 125 short-period stations was deployed around the core mining area and its vicinity of the salt mine industry,we used the ambient noise tomography(ANT)method to image the three-dimensional shear wave velocity structure at the depth shallower than 3 km.The results indicate:(1)The overall shear wave velocity in the study area is relatively lower,ranging from 0.8 to 1.8 km/s,which could be related to the loose and thick deposition of the Zhaoji sub-depression.(2)The three-dimensional shear wave velocity structure reveals that the sedimentary thickness of the Zhaoji sub-depression is deeper in the southeast and shallower in the northwest,with the sedimentary center located around Heping Town and Dahuangzhuang Town.(3)The Zhaoji salt mine is a low-velocity anomalous zone in the shear wave velocity structure with an inverse‘C'character spreading along Nanchenji Town and Zhaoji Town,with a depth ranging from approximately 1.2 to 2.8 km,it may be caused by the development of rock fissures due to water extraction and injection.The surrounding rock exhibits relatively high velocity,which reflects the morphological characteristics of the Zhaoji Salt Basin.The three-dimensional shear wave velocity model obtained in this study provides scientific guidance for the industrial exploitation of the Zhaoji salt mine and reference for salt exploration of the Hongze Salt Basin.It also provides an important basis for the seismic risk assessment of the salt basins.Simultaneously,it holds significant implications for exploring the application of ambient noise tomography method in spatial detection of salt mine belt.展开更多
This study provides different opinion for exploring the mechanism of catechin(CAT)relieving nonalcoholic steatohepatitis(NASH),it is more innovative to explore from the perspective of intestinal microorganism.Through ...This study provides different opinion for exploring the mechanism of catechin(CAT)relieving nonalcoholic steatohepatitis(NASH),it is more innovative to explore from the perspective of intestinal microorganism.Through in vitro fermentation experiments,CAT could improve the abundance of Enterococcus,and Enterococcus faecalis(EF)accounts for the vast majority of Enterococcus in human gut.The experimental results in vivo showed that EF group and CAT+EF group could reduce the body weight,liver index and epididymal fat index of NASH mice,and improve the changes of serum and liver indexes.Hematoxylin-eosin staining observation showed that these two groups have greatly improved the fatty degeneration,balloon degeneration and necrotic focus caused by NASH.The alleviation of CAT+EF group was more obvious.Results of targeted metabonomics showed that CAT could promote EF to produce more methyl palmitate(C_(16:0)),which plays a great role in relieving NASH.Our results indicated that EF could alleviate NASH and CAT+EF group had better alleviation may due to more production of methyl palmitate(C_(16:0))by EF.This study provides a new idea for CAT to alleviate NASH.展开更多
Grain size,which encompasses length,width,and thickness,is a critical agricultural trait that influences both grain yield and quality in rice.Although numerous grain size regulators have been identified,the molecular ...Grain size,which encompasses length,width,and thickness,is a critical agricultural trait that influences both grain yield and quality in rice.Although numerous grain size regulators have been identified,the molecular mechanisms governing grain size and the lignin content remain largely elusive.In this study,we clone and characterize GRAIN LENGTH AND GRAIN WIDTH 10(GLGW10),a regulator of grain size in rice.Loss-of-function mutations in GLGW10 result in reduced grain size.GLGW10 encodes an evolutionarily conserved protein,the function of which has not been previously characterized in higher plants.Biochemical assays reveal that GLGW10 may interact with the transcription factor OsMYB108,which acts as a negative regulator of the lignin content.Knockout of OsMYB108 leads to longer and slender grain size,accompanied by increased lignin content,indicating that OsMYB108 negatively regulates both grain size and lignin content.Analysis of natural variations and haplotypes in GLGW10 reveals an association with grain size,suggesting an artificial selection on GLGW10 during rice domestication.In summary,our findings identify regulators of grain size and elucidate potential mechanisms linking grain size and lignin metabolism in rice,thereby providing essential insights for improving crop yields.展开更多
The complexity of living environment system demands higher requirements for the sensitivity and selectivity of the probe.Therefore,it is of great importance to develop a universal strategy for highperformance probe op...The complexity of living environment system demands higher requirements for the sensitivity and selectivity of the probe.Therefore,it is of great importance to develop a universal strategy for highperformance probe optimization.Herein,we propose a novel“Enrichment-enhanced Detection”strategy and use carbon dots-dopamine detection system as a representative model to evaluate its feasibility.The composite probe carbon dots (CDs)-encapsulated in glycol-chitosan (GC)(i.e.,CDs@GC) was obtained by simply mixing GC and CDs through noncovalent interactions,including electrostatic interactions and hydrogen bonding.Dopamine (DA) could be detected through internal filter effect (IFE)-induced quenching of CDs.In the case of CDs@GC,noncovalent interactions (electrostatic interactions) between GC and the formed quinone (oxide of DA) could selectively extract and enrich the local concentration of DA,thus effectively improving the sensitivity and selectivity of the sensing system.The nanosensor had a low detection limit of 3.7 nmol/L,which was a 12-fold sensitivity improvement compared to the bare CDs probes with similar fluorescent profiles,proving the feasibility of the“Enrichment-enhanced Detection”strategy.Further,to examine this theory in real case,we designed a highly portable sensing platform to realize visual determination of DA.Overall,our work introduces a new strategy for accurately detecting DA and provides valuable insights for the universal design and optimization of superior nanoprobes.展开更多
Arabinoxylan(AX)has been found to improve an imbalanced gut microbiota.Lactobacillus gasseri is a beneficial endogenous bacterium that has been shown to have several health benefits in the human gut,particularly its l...Arabinoxylan(AX)has been found to improve an imbalanced gut microbiota.Lactobacillus gasseri is a beneficial endogenous bacterium that has been shown to have several health benefits in the human gut,particularly its lipid-lowering activity.However,it is not known whether AX can promote the action of L.gasseri.The results of in vitro experiments showed that AX promoted biofilm formation in L.gasseri,its acid and bile salt resistance could be enhanced,and enabled better colonization of L.gasseri in the intestinal tract of mice.In vivo experiments showed that the AX+L.gasseri group could effectively ameliorate weight gain and fat accumulation in high-fat diet-induced obese mice,and the L.gasseri group or AX+L.gasseri alleviated liver injury in mice.16S rRNA sequencing showed that L.gasseri can colonize the mice intestine and AX+L.gasseri can ameliorate gut microbiota dysbiosis in obese mice by increasing Lactobacillus spp.and Coriobacteriaceae_UCG-002,and decreasing Peptococcaceae.In addition,metabolomics results indicated that the L.gasseri group and the AX+L.gasseri group could alleviate metabolic disorders by decreasing the levels of L-phenylalanine,L-tyrosine,kynurenine acid,and arachidonic acid in obese mice.The effect of AX+L.gasseri group was better than that of the L.gasseri group,suggesting that AX promotes the lipid-lowering activity of L.gasseri,and the mechanism may be due to the activation of retrograde endocannabinoid signaling.AX can be used as a functional food ingredient to potentially alleviate obesity and metabolic syndrome.展开更多
Objective:Strabismus is associated with a higher prevalence of idiopathic thoracic scoliosis(ITS)in children.This study aims to investigate whether superior oblique palsy(SOP)poses a higher risk for developing ITS amo...Objective:Strabismus is associated with a higher prevalence of idiopathic thoracic scoliosis(ITS)in children.This study aims to investigate whether superior oblique palsy(SOP)poses a higher risk for developing ITS among children and adolescents.Methods:A cross-sectional study.The study group comprised 347 consecutive candidates for SOP surgery aged 4 to 18 years;Patients within the same age range with ocular trauma were enrolled as the control group.Preoperative chest plain radiographs were used to measure the Cobb angle.Demographic information and clinical data,including diopter,best corrected visual acuity,deviation degree,and binocular function,were analyzed.Results:A significantly higher prevalence of ITS was found in study group compared with control group(12.68%vs 4.18%,P<0.001).Additionally,the mean Cobb angle was lagger in SOP group than that in control group(5.02°±3.87°vs 3.84°±3.09°,P<0.001).Males in SOP group showed a higher prevalence of ITS(12.9%vs 2.87%,P=0.007),but there was no significant difference in females between two groups(12.3%vs 7.69%,P=0.295).Good near stereopsis acuity was significantly associated with high prevalence of thoracic scoliosis(P<0.001).Multivariate logistic regression analysis revealed that a large distant magnitude of deviation(>20 PD)and near stereoacuity were significantly associated with ITS.Conclusions:Patients with SOP have a significantly higher risk of developing idiopathic thoracic scoliosis,especially those with good near stereoscopic and large distant magnitude of deviation.展开更多
Developing ultrabroad radar-infrared compatible stealth materials has turned into a research hotspot,which is still a problem to be solved.Herein,the copper sulfide wrapped by reduced graphene oxide to obtain three-di...Developing ultrabroad radar-infrared compatible stealth materials has turned into a research hotspot,which is still a problem to be solved.Herein,the copper sulfide wrapped by reduced graphene oxide to obtain three-dimensional(3D)porous network composite aerogels(CuS@rGO)were synthesized via thermal reduction ways(hydrothermal,ascorbic acid reduction)and freeze-drying strategy.It was discovered that the phase components(rGO and CuS phases)and micro/nano structure(microporous and nanosheet)were well-modified by modulating the additive amounts of CuS and changing the reduction ways,which resulted in the variation of the pore structure,defects,complex permittivity,microwave absorption,radar cross section(RCS)reduction value and infrared(IR)emissivity.Notably,the obtained CuS@rGO aerogels with a single dielectric loss type can achieve an ultrabroad bandwidth of 8.44 GHz at 2.8 mm with the low filler content of 6 wt%by a hydrothermal method.Besides,the composite aerogel via the ascorbic acid reduction realizes the minimum reflection loss(RL_(min))of−60.3 dB with the lower filler content of 2 wt%.The RCS reduction value can reach 53.3 dB m^(2),which effectively reduces the probability of the target being detected by the radar detector.Furthermore,the laminated porous architecture and multicomponent endowed composite aerogels with thermal insulation and IR stealth versatility.Thus,this work offers a facile method to design and develop porous rGO-based composite aerogel absorbers with radar-IR compatible stealth.展开更多
In order to explore the total-pressure distortion test assessment method for a turbofan engine, a Controlled Variable Double-Baffle Distortion Generator(CVDBDG) with a horizontal symmetry moving form was developed, wh...In order to explore the total-pressure distortion test assessment method for a turbofan engine, a Controlled Variable Double-Baffle Distortion Generator(CVDBDG) with a horizontal symmetry moving form was developed, which can adjust the steady-state and time–variant distortion separately in real time. The inlet total-pressure distortion test was conducted on an afterburner turbofan engine. The distortion parameters of CVDBDG and the instability characteristics of the engine were measured. The experimental data were modeled and analyzed by using back propagation artificial neural networks, and the work envelope of CVDBDG was obtained. Based on the analysis of the data on the engine’s instability, the properties of CVDBDG used for the stability assessment were preliminarily evaluated. The results show that CVDBDG can simulate both steady-state and time–variant distortions simultaneously in a range determined by three envelopes.Under the condition of symmetric double baffles, a critical depth of insertion exists, beyond which the symmetric baffles will generate an asymmetric flow field. In the case of double baffles, compared to a single baffle, the engine exhibited different instability characteristics. Based on CVDBDG, it is expected that more efficient engine stability and durability assessment methods can be developed.展开更多
In conventional modeling of a cable-pulley system, the cable must be finely meshed with Lagrangian elements for valid contact detections with pulleys, leading to extremely low efficiency. The sliding joint method base...In conventional modeling of a cable-pulley system, the cable must be finely meshed with Lagrangian elements for valid contact detections with pulleys, leading to extremely low efficiency. The sliding joint method based on the arbitrary-Lagrangian- Eulerian （ALE） formulation still lacks an efficient cable element, and in particular, modeling of friction between a sliding joint and the cable has not been studied. This paper presents efficient multi-body modeling of a cable-pulley system with friction. A variable- length cable element with a node movable along the cable, which is described with ALE, is developed to mesh the cable. A transitional cable element is then proposed to model the contact part of the cable by fixing its two nodes to the two corresponding locations of the pulley. Friction of the cable-pulley is derived as a simple law of tension decay and embedded in the multi-body system modeling. It is simplified as a generalized friction force acting only on the arc-length coordinate. This approach can use a rough mesh on the cable, and is free of contact detections, thus significantly saving computation time. Several examples are presented to validate the proposed method, and show its effectiveness in real engineering applications.展开更多
Wearable devices with efficient thermal management and electromagnetic interference(EMI) shielding are highly desirable for improving human comfort and safety. Herein, a multifunctional wearable carbon fibers(CF) @ po...Wearable devices with efficient thermal management and electromagnetic interference(EMI) shielding are highly desirable for improving human comfort and safety. Herein, a multifunctional wearable carbon fibers(CF) @ polyaniline(PANI)/silver nanowires(Ag NWs) composites with a “branch-trunk” interlocked micro/nanostructure were achieved through "three-in-one" multi-scale design. The reasonable assembly of the three kinds of one-dimensional(1D) materials can fully exert their excellent properties i.e., the superior flexibility of CF, the robustness of PANI, and the splendid conductivity of Ag NWs. Consequently, the constructed flexible composite demonstrates enhanced mechanical properties with a tensile stress of 1.2 MPa, which was almost 6 times that of the original material. This is mainly attributed to the fact that the PNAI(branch) was firmly attached to the CF(trunk) through polydopamine(PDA), forming a robust interlocked structure. Meanwhile, the composite possesses excellent thermal insulation and heat preservation capacity owing to the synergistically low thermal conductivity and emissivity. More importantly, the conductive path of the composite established by the three 1D materials greatly improved its EMI shielding property and Joule heating performance at low applied voltage. This work paves the way for rational utilization of the intrinsic properties of 1D materials, as well as provides a promising strategy for designing wearable electromagnetic protection and thermal energy management devices.展开更多
Reliability assessment of the braking system in a high?speed train under small sample size and zero?failure data is veryimportant for safe operation. Traditional reliability assessment methods are only performed well ...Reliability assessment of the braking system in a high?speed train under small sample size and zero?failure data is veryimportant for safe operation. Traditional reliability assessment methods are only performed well under conditions of large sample size and complete failure data,which lead to large deviation under conditions of small sample size and zero?failure data. To improve this problem,a new Bayesian method is proposed. Based on the characteristics of the solenoid valve in the braking system of a high?speed train,the modified Weibull distribution is selected to describe the failure rate over the entire lifetime. Based on the assumption of a binomial distribution for the failure probability at censored time,a concave method is employed to obtain the relationships between accumulation failure prob?abilities. A numerical simulation is performed to compare the results of the proposed method with those obtained from maximum likelihood estimation,and to illustrate that the proposed Bayesian model exhibits a better accuracy for the expectation value when the sample size is less than 12. Finally,the robustness of the model is demonstrated by obtaining the reliability indicators for a numerical case involving the solenoid valve of the braking system,which shows that the change in the reliability and failure rate among the di erent hyperparameters is small. The method is provided to avoid misleading of subjective information and improve accuracy of reliability assessment under condi?tions of small sample size and zero?failure data.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.22325601,92044302,42377105)the National Key Scientific and Technological Infrastructure project“Earth System Science Numerical Simulator Facility”.
文摘The Mechanism for Air pollution compleX version 1.0(MAX1),describing detailed tropospheric chemical processes,has been developed based on the latest knowledge.MAX1 contains 940 reactions,including photolysis,gaseous reactions,and heterogeneous reactions of 300 species,which is adequate for both box model and climate transport model(CTM)applications.Detailed chemical processes of chlorine chemistry,chemistry of Criegee intermediates,and heterogeneous uptake of HO_(2) and N_(2)O_(5) have been implemented and updated.With this level of explicitness,MAX1 can support investigations into the quantification of secondary pollutant productions and the chemical behavior of the crucial intermediates,such as organic peroxy radicals.Box model and CTM tests were conducted to evaluate the performance of MAX1 from different perspectives.Simulations of MAX1 successfully captured the variation of ozone in all cases tested.Meanwhile,significant improvement was made on predictions of radicals compared to other mechanisms,especially under the low NO_(x) environment,with good similarity to simulations of a nearly explicit chemical mechanism(i.e.,Master Chemical Mechanism)that contains over 17000 reactions.The computational expense of MAX1 is acceptable and it can be applied in atmospheric scientific research and air quality prediction.MAX1 introduces new dimensions in atmospheric chemistry modeling,and its potential application in policymaking is a promising yet exploratory step.It offers improved insights into air quality dynamics,which could assist policymakers in making more informed decisions.However,the translation of its detailed chemical understanding into practical strategies remains an area for further investigation.This model suggests a path towards more nuanced air pollution control methods,contributing to ongoing efforts in environmental management.
文摘In recent years,with the rapid advancement of artificial intelligence,object detection algorithms have made significant strides in accuracy and computational efficiency.Notably,research and applications of Anchor-Free models have opened new avenues for real-time target detection in optical remote sensing images(ORSIs).However,in the realmof adversarial attacks,developing adversarial techniques tailored to Anchor-Freemodels remains challenging.Adversarial examples generated based on Anchor-Based models often exhibit poor transferability to these new model architectures.Furthermore,the growing diversity of Anchor-Free models poses additional hurdles to achieving robust transferability of adversarial attacks.This study presents an improved cross-conv-block feature fusion You Only Look Once(YOLO)architecture,meticulously engineered to facilitate the extraction ofmore comprehensive semantic features during the backpropagation process.To address the asymmetry between densely distributed objects in ORSIs and the corresponding detector outputs,a novel dense bounding box attack strategy is proposed.This approach leverages dense target bounding boxes loss in the calculation of adversarial loss functions.Furthermore,by integrating translation-invariant(TI)and momentum-iteration(MI)adversarial methodologies,the proposed framework significantly improves the transferability of adversarial attacks.Experimental results demonstrate that our method achieves superior adversarial attack performance,with adversarial transferability rates(ATR)of 67.53%on the NWPU VHR-10 dataset and 90.71%on the HRSC2016 dataset.Compared to ensemble adversarial attack and cascaded adversarial attack approaches,our method generates adversarial examples in an average of 0.64 s,representing an approximately 14.5%improvement in efficiency under equivalent conditions.
基金supported by the STI2030-Major Projects(grant number 2022ZD0211100,NZ)Foundation of Shanghai Mental Health Center(grant number 2021-YJ15,JL)+5 种基金National Natural Science Foundation of China(grant number 82272045,SH)National Natural Science Foundation of China(grant number 82201702,QX)Science and Technology Innovation Program of Hunan Province(grant number 2021RC4056,SH)Key Program of Ministry of Industry and Information Technology of China(grant number CEIEC-2022-ZM02-0219,SH)National Natural Science Foundation of China(grant number 82001405,HD)Hunan Natural Science Foundation Youth Program(grant number 2021JJ40979,HD).
文摘Background Internet gaming disorder(IGD)is an ideal model to study the mechanisms underlying synaptic deficits in addiction as it eliminates the confounding effects of substance use.Synaptic loss and deficits are hypothesised to underlie the enduring maladaptive behaviours and impaired cognitive function that contribute to IGD.Aims This study aimed to determine whether subjects with IGD have lower synaptic density than control subjects and the relationship between synaptic density and IGD severity.Methods Eighteen unmedicated subjects diagnosed with current IGD according to the Diagnostic and Statistical Manual of Mental Disorders,Fifth Edition criteria and 16 demographically matched healthy controls(HCs)participated in the study and underwent 18F-labelled difluoro-analogue of UCB-J(18F-SynVesT-1)positron emission tomography scans to assess the density of synaptic vesicle glycoprotein 2A(SV2A).The Internet Gaming Disorder Scale-Short Form(IGDS9-SF),Hamilton Rating Scale for Depression(HAMD),Hamilton Anxiety Rating Scale(HAMA),Barratt Impulsiveness Scale Version 11(BIS-11),Stroop Colour-Word Test(SCWT),stop-signal paradigms and N-back tasks were administered to all subjects.Results Patients with IGD had significantly higher scores on the IGDS9-SF,HAMD,HAMA and BIS-11 than HCs.HCs performed better on the two-back and SCWT tests as well as in terms of stop-signal reaction times(SSRTs)in the stop-signal paradigms than patients with IGD.Lower uptake was found in the bilateral putamen,right pregenual anterior cingulate cortex and Rolandic operculum of patients with IGD compared with HCs.Furthermore,in the IGD group,IGDS9-SF scores and daily gaming hours were negatively correlated with the standardised uptake value ratios of 18F-SynVesT-1 in the bilateral putamen.Longer SSRTs were significantly associated with lower SV2A density in the right pregenual anterior cingulate cortex and right Rolandic operculum.Conclusions The in vivo results in this study suggest that lower synaptic density contributes to the severity and impairments in inhibitory control of IGD.These findings may provide further incentive to evaluate interventions that restore synaptic transmission and plasticity to treat IGD.
基金financially supported by the National Natural Science Foundation of China(No.21172269)the Fundamental Research Funds for the Central Universities,SouthCentral Minzu University(No.CZH24005)。
文摘Binuclear complexes have attracted extensive attention in fields such as catalysis because of their likely bimetallic synergistic effect;however,the mechanism and factors influencing this synergism remain unclear.In this work,six bis-β-ketoimine binuclear titanium complexes4a-4f containing different alkylthio sidearms and configurations were synthesized and characterized by nuclear magnetic resonance hydrogen spectrum(~1H-NMR),nuclear magnetic resonance carbon spectrum(^(13)C-NMR),Fourier transform infrared spectrum(FTIR),and elemental analysis.The intermetallic distances of isomeric complexes 4a,4d,4e and 4f determined through density functional theory(DFT)optimization were in the order 4a<4d<4e<4f and were found to significantly influence the catalytic performance for ethylene(co)polymerization.These complexes could efficiently catalyze ethylene polymerization and ethylene/1-hexene or ethylene/1-octene copolymerization with high activity to produce highmolecular-weight ethylene homo-and co-polymers.Among the three binuclear titanium complexes 4a-4c with similar structures but different lengths of alkylthio sidearms,complex 4a,which contained the shortest methylthio sidearm,exhibited the highest activity for ethylene polymerization and copolymerization with 1-hexene or 1-octene.Additionally,for ethylene/1-hexene or ethylene/1-octene copolymerization,it showed the highest comonomer incorporation compared with propylthio(4b)and octylthio(4c)derivatives because of the smaller steric hindrance of the methyl group in 4a and the more open coordination space for vinyl monomers.Furthermore,among the isomeric complexes 4a,4d,4e and4f,complex 4a with the shortest bimetallic distance also exhibited the highest activity towards ethylene(co)polymerization,and the highest 1-hexene or 1-octene incorporation in comparison with its regioisomeric counterparts 4d,4e and p-phenyl-bridged analog 4f,owing to a more appropriate bimetallic distance that is conducive to a synergistic effect.
基金supported by the National Natural Science Foundation of China,No.82071254(to WZ).
文摘Long-term levodopa administration can lead to the development of levodopa-induced dyskinesia.Gamma oscillations are a widely recognized hallmark of abnormal neural electrical activity in levodopa-induced dyskinesia.Currently,studies have reported increased oscillation power in cases of levodopa-induced dyskinesia.However,little is known about how the other electrophysiological parameters of gamma oscillations are altered in levodopa-induced dyskinesia.Furthermore,the role of the dopamine D3 receptor,which is implicated in levodopa-induced dyskinesia,in movement disorder-related changes in neural oscillations is unclear.We found that the cortico-striatal functional connectivity of beta oscillations was enhanced in a model of Parkinson’s disease.Furthermore,levodopa application enhanced cortical gamma oscillations in cortico-striatal projections and cortical gamma aperiodic components,as well as bidirectional primary motor cortex(M1)↔dorsolateral striatum gamma flow.Administration of PD128907(a selective dopamine D3 receptor agonist)induced dyskinesia and excessive gamma oscillations with a bidirectional M1↔dorsolateral striatum flow.However,administration of PG01037(a selective dopamine D3 receptor antagonist)attenuated dyskinesia,suppressed gamma oscillations and cortical gamma aperiodic components,and decreased gamma causality in the M1→dorsolateral striatum direction.These findings suggest that the dopamine D3 receptor plays a role in dyskinesia-related oscillatory activity,and that it has potential as a therapeutic target for levodopa-induced dyskinesia.
基金supported by the National Key R&D Program of China(No.2024YFC3012902)the National Natural Science Foundation of China(No.42074070)supported by the Huai’an Earthquake Prevention and Disaster Reduction Service Center“Salt Cavern Exploration Project”(No.HAZC-2021050155-001)。
文摘Due to the lack of the three-dimensional structure of the Zhaoji Salt Basin,the salt mining enterprises have obvious clustering when choosing sites.Production capacity declines rapidly as mining deepens,and the enterprises are entering a stage of stagnation in production.In this study,a dense seismic array of 125 short-period stations was deployed around the core mining area and its vicinity of the salt mine industry,we used the ambient noise tomography(ANT)method to image the three-dimensional shear wave velocity structure at the depth shallower than 3 km.The results indicate:(1)The overall shear wave velocity in the study area is relatively lower,ranging from 0.8 to 1.8 km/s,which could be related to the loose and thick deposition of the Zhaoji sub-depression.(2)The three-dimensional shear wave velocity structure reveals that the sedimentary thickness of the Zhaoji sub-depression is deeper in the southeast and shallower in the northwest,with the sedimentary center located around Heping Town and Dahuangzhuang Town.(3)The Zhaoji salt mine is a low-velocity anomalous zone in the shear wave velocity structure with an inverse‘C'character spreading along Nanchenji Town and Zhaoji Town,with a depth ranging from approximately 1.2 to 2.8 km,it may be caused by the development of rock fissures due to water extraction and injection.The surrounding rock exhibits relatively high velocity,which reflects the morphological characteristics of the Zhaoji Salt Basin.The three-dimensional shear wave velocity model obtained in this study provides scientific guidance for the industrial exploitation of the Zhaoji salt mine and reference for salt exploration of the Hongze Salt Basin.It also provides an important basis for the seismic risk assessment of the salt basins.Simultaneously,it holds significant implications for exploring the application of ambient noise tomography method in spatial detection of salt mine belt.
基金supported by the National Natural Science Foundation of China(32202200)Shanghai Excellent Academic/Technical Leaders Project(23XD1430500).
文摘This study provides different opinion for exploring the mechanism of catechin(CAT)relieving nonalcoholic steatohepatitis(NASH),it is more innovative to explore from the perspective of intestinal microorganism.Through in vitro fermentation experiments,CAT could improve the abundance of Enterococcus,and Enterococcus faecalis(EF)accounts for the vast majority of Enterococcus in human gut.The experimental results in vivo showed that EF group and CAT+EF group could reduce the body weight,liver index and epididymal fat index of NASH mice,and improve the changes of serum and liver indexes.Hematoxylin-eosin staining observation showed that these two groups have greatly improved the fatty degeneration,balloon degeneration and necrotic focus caused by NASH.The alleviation of CAT+EF group was more obvious.Results of targeted metabonomics showed that CAT could promote EF to produce more methyl palmitate(C_(16:0)),which plays a great role in relieving NASH.Our results indicated that EF could alleviate NASH and CAT+EF group had better alleviation may due to more production of methyl palmitate(C_(16:0))by EF.This study provides a new idea for CAT to alleviate NASH.
基金supported by grants from the National Key R&D Program of China(2023YFF1000500)the Fundamental Research Funds for the Central Universities(226-2024-00102)the Hundred-Talent Programof Zhejiang University,China to M.Z.
文摘Grain size,which encompasses length,width,and thickness,is a critical agricultural trait that influences both grain yield and quality in rice.Although numerous grain size regulators have been identified,the molecular mechanisms governing grain size and the lignin content remain largely elusive.In this study,we clone and characterize GRAIN LENGTH AND GRAIN WIDTH 10(GLGW10),a regulator of grain size in rice.Loss-of-function mutations in GLGW10 result in reduced grain size.GLGW10 encodes an evolutionarily conserved protein,the function of which has not been previously characterized in higher plants.Biochemical assays reveal that GLGW10 may interact with the transcription factor OsMYB108,which acts as a negative regulator of the lignin content.Knockout of OsMYB108 leads to longer and slender grain size,accompanied by increased lignin content,indicating that OsMYB108 negatively regulates both grain size and lignin content.Analysis of natural variations and haplotypes in GLGW10 reveals an association with grain size,suggesting an artificial selection on GLGW10 during rice domestication.In summary,our findings identify regulators of grain size and elucidate potential mechanisms linking grain size and lignin metabolism in rice,thereby providing essential insights for improving crop yields.
基金the financial support from the National Natural Science Foundation of China(No.21904007)the Fundamental Research Funds for the Central Universities(China,No.2412022QD008)+1 种基金the Jilin Provincial Department of Education(China),the Key Laboratory of Nanobiosensing and Nanobioanalysis at Universities of Jilin Province(China)the Analysis and Testing Center of Northeast Normal University(China)。
文摘The complexity of living environment system demands higher requirements for the sensitivity and selectivity of the probe.Therefore,it is of great importance to develop a universal strategy for highperformance probe optimization.Herein,we propose a novel“Enrichment-enhanced Detection”strategy and use carbon dots-dopamine detection system as a representative model to evaluate its feasibility.The composite probe carbon dots (CDs)-encapsulated in glycol-chitosan (GC)(i.e.,CDs@GC) was obtained by simply mixing GC and CDs through noncovalent interactions,including electrostatic interactions and hydrogen bonding.Dopamine (DA) could be detected through internal filter effect (IFE)-induced quenching of CDs.In the case of CDs@GC,noncovalent interactions (electrostatic interactions) between GC and the formed quinone (oxide of DA) could selectively extract and enrich the local concentration of DA,thus effectively improving the sensitivity and selectivity of the sensing system.The nanosensor had a low detection limit of 3.7 nmol/L,which was a 12-fold sensitivity improvement compared to the bare CDs probes with similar fluorescent profiles,proving the feasibility of the“Enrichment-enhanced Detection”strategy.Further,to examine this theory in real case,we designed a highly portable sensing platform to realize visual determination of DA.Overall,our work introduces a new strategy for accurately detecting DA and provides valuable insights for the universal design and optimization of superior nanoprobes.
基金The following funding sources are gratefully acknowledged:National Key Research and Development Program Project of China(2022YFF1100102)the Cross-Innovation Open Project of Food Flavor and Health,Beijing Technology&Business University(FFHCI-2025071).
文摘Arabinoxylan(AX)has been found to improve an imbalanced gut microbiota.Lactobacillus gasseri is a beneficial endogenous bacterium that has been shown to have several health benefits in the human gut,particularly its lipid-lowering activity.However,it is not known whether AX can promote the action of L.gasseri.The results of in vitro experiments showed that AX promoted biofilm formation in L.gasseri,its acid and bile salt resistance could be enhanced,and enabled better colonization of L.gasseri in the intestinal tract of mice.In vivo experiments showed that the AX+L.gasseri group could effectively ameliorate weight gain and fat accumulation in high-fat diet-induced obese mice,and the L.gasseri group or AX+L.gasseri alleviated liver injury in mice.16S rRNA sequencing showed that L.gasseri can colonize the mice intestine and AX+L.gasseri can ameliorate gut microbiota dysbiosis in obese mice by increasing Lactobacillus spp.and Coriobacteriaceae_UCG-002,and decreasing Peptococcaceae.In addition,metabolomics results indicated that the L.gasseri group and the AX+L.gasseri group could alleviate metabolic disorders by decreasing the levels of L-phenylalanine,L-tyrosine,kynurenine acid,and arachidonic acid in obese mice.The effect of AX+L.gasseri group was better than that of the L.gasseri group,suggesting that AX promotes the lipid-lowering activity of L.gasseri,and the mechanism may be due to the activation of retrograde endocannabinoid signaling.AX can be used as a functional food ingredient to potentially alleviate obesity and metabolic syndrome.
基金the National Natural Science Foundation of China grant NSFC(82070995).
文摘Objective:Strabismus is associated with a higher prevalence of idiopathic thoracic scoliosis(ITS)in children.This study aims to investigate whether superior oblique palsy(SOP)poses a higher risk for developing ITS among children and adolescents.Methods:A cross-sectional study.The study group comprised 347 consecutive candidates for SOP surgery aged 4 to 18 years;Patients within the same age range with ocular trauma were enrolled as the control group.Preoperative chest plain radiographs were used to measure the Cobb angle.Demographic information and clinical data,including diopter,best corrected visual acuity,deviation degree,and binocular function,were analyzed.Results:A significantly higher prevalence of ITS was found in study group compared with control group(12.68%vs 4.18%,P<0.001).Additionally,the mean Cobb angle was lagger in SOP group than that in control group(5.02°±3.87°vs 3.84°±3.09°,P<0.001).Males in SOP group showed a higher prevalence of ITS(12.9%vs 2.87%,P=0.007),but there was no significant difference in females between two groups(12.3%vs 7.69%,P=0.295).Good near stereopsis acuity was significantly associated with high prevalence of thoracic scoliosis(P<0.001).Multivariate logistic regression analysis revealed that a large distant magnitude of deviation(>20 PD)and near stereoacuity were significantly associated with ITS.Conclusions:Patients with SOP have a significantly higher risk of developing idiopathic thoracic scoliosis,especially those with good near stereoscopic and large distant magnitude of deviation.
基金financial support from the National Nature Science Foundation of China(No.51971111).
文摘Developing ultrabroad radar-infrared compatible stealth materials has turned into a research hotspot,which is still a problem to be solved.Herein,the copper sulfide wrapped by reduced graphene oxide to obtain three-dimensional(3D)porous network composite aerogels(CuS@rGO)were synthesized via thermal reduction ways(hydrothermal,ascorbic acid reduction)and freeze-drying strategy.It was discovered that the phase components(rGO and CuS phases)and micro/nano structure(microporous and nanosheet)were well-modified by modulating the additive amounts of CuS and changing the reduction ways,which resulted in the variation of the pore structure,defects,complex permittivity,microwave absorption,radar cross section(RCS)reduction value and infrared(IR)emissivity.Notably,the obtained CuS@rGO aerogels with a single dielectric loss type can achieve an ultrabroad bandwidth of 8.44 GHz at 2.8 mm with the low filler content of 6 wt%by a hydrothermal method.Besides,the composite aerogel via the ascorbic acid reduction realizes the minimum reflection loss(RL_(min))of−60.3 dB with the lower filler content of 2 wt%.The RCS reduction value can reach 53.3 dB m^(2),which effectively reduces the probability of the target being detected by the radar detector.Furthermore,the laminated porous architecture and multicomponent endowed composite aerogels with thermal insulation and IR stealth versatility.Thus,this work offers a facile method to design and develop porous rGO-based composite aerogel absorbers with radar-IR compatible stealth.
基金supported by the Beijing Aeronautical Technology Research Center
文摘In order to explore the total-pressure distortion test assessment method for a turbofan engine, a Controlled Variable Double-Baffle Distortion Generator(CVDBDG) with a horizontal symmetry moving form was developed, which can adjust the steady-state and time–variant distortion separately in real time. The inlet total-pressure distortion test was conducted on an afterburner turbofan engine. The distortion parameters of CVDBDG and the instability characteristics of the engine were measured. The experimental data were modeled and analyzed by using back propagation artificial neural networks, and the work envelope of CVDBDG was obtained. Based on the analysis of the data on the engine’s instability, the properties of CVDBDG used for the stability assessment were preliminarily evaluated. The results show that CVDBDG can simulate both steady-state and time–variant distortions simultaneously in a range determined by three envelopes.Under the condition of symmetric double baffles, a critical depth of insertion exists, beyond which the symmetric baffles will generate an asymmetric flow field. In the case of double baffles, compared to a single baffle, the engine exhibited different instability characteristics. Based on CVDBDG, it is expected that more efficient engine stability and durability assessment methods can be developed.
基金Project supported by the National Natural Science Foundation of China(No.11302114)the Major State Basic Research Development Program(No.2012CB821203)the Guangdong Provincial Key Laboratory Construction Project of China(No.2011A060901026)
文摘In conventional modeling of a cable-pulley system, the cable must be finely meshed with Lagrangian elements for valid contact detections with pulleys, leading to extremely low efficiency. The sliding joint method based on the arbitrary-Lagrangian- Eulerian （ALE） formulation still lacks an efficient cable element, and in particular, modeling of friction between a sliding joint and the cable has not been studied. This paper presents efficient multi-body modeling of a cable-pulley system with friction. A variable- length cable element with a node movable along the cable, which is described with ALE, is developed to mesh the cable. A transitional cable element is then proposed to model the contact part of the cable by fixing its two nodes to the two corresponding locations of the pulley. Friction of the cable-pulley is derived as a simple law of tension decay and embedded in the multi-body system modeling. It is simplified as a generalized friction force acting only on the arc-length coordinate. This approach can use a rough mesh on the cable, and is free of contact detections, thus significantly saving computation time. Several examples are presented to validate the proposed method, and show its effectiveness in real engineering applications.
基金supported by the National Nature Science Foundation of China (Nos. 51971111, 52273247)the facilities in the Center for Microscopy and Analysis at Nanjing University of Aeronautics and Astronautics and the Fund of Prospective Layout of Scientific Research for NUAA (Nanjing University of Aeronautics and Astronautics (No. ILA220461A22)。
文摘Wearable devices with efficient thermal management and electromagnetic interference(EMI) shielding are highly desirable for improving human comfort and safety. Herein, a multifunctional wearable carbon fibers(CF) @ polyaniline(PANI)/silver nanowires(Ag NWs) composites with a “branch-trunk” interlocked micro/nanostructure were achieved through "three-in-one" multi-scale design. The reasonable assembly of the three kinds of one-dimensional(1D) materials can fully exert their excellent properties i.e., the superior flexibility of CF, the robustness of PANI, and the splendid conductivity of Ag NWs. Consequently, the constructed flexible composite demonstrates enhanced mechanical properties with a tensile stress of 1.2 MPa, which was almost 6 times that of the original material. This is mainly attributed to the fact that the PNAI(branch) was firmly attached to the CF(trunk) through polydopamine(PDA), forming a robust interlocked structure. Meanwhile, the composite possesses excellent thermal insulation and heat preservation capacity owing to the synergistically low thermal conductivity and emissivity. More importantly, the conductive path of the composite established by the three 1D materials greatly improved its EMI shielding property and Joule heating performance at low applied voltage. This work paves the way for rational utilization of the intrinsic properties of 1D materials, as well as provides a promising strategy for designing wearable electromagnetic protection and thermal energy management devices.
基金Supported by National Natural Science Foundation of China(Grant No.51175028)Great Scholars Training Project(Grant No.CIT&TCD20150312)Beijing Recognized Talent Project(Grant No.2014018)
文摘Reliability assessment of the braking system in a high?speed train under small sample size and zero?failure data is veryimportant for safe operation. Traditional reliability assessment methods are only performed well under conditions of large sample size and complete failure data,which lead to large deviation under conditions of small sample size and zero?failure data. To improve this problem,a new Bayesian method is proposed. Based on the characteristics of the solenoid valve in the braking system of a high?speed train,the modified Weibull distribution is selected to describe the failure rate over the entire lifetime. Based on the assumption of a binomial distribution for the failure probability at censored time,a concave method is employed to obtain the relationships between accumulation failure prob?abilities. A numerical simulation is performed to compare the results of the proposed method with those obtained from maximum likelihood estimation,and to illustrate that the proposed Bayesian model exhibits a better accuracy for the expectation value when the sample size is less than 12. Finally,the robustness of the model is demonstrated by obtaining the reliability indicators for a numerical case involving the solenoid valve of the braking system,which shows that the change in the reliability and failure rate among the di erent hyperparameters is small. The method is provided to avoid misleading of subjective information and improve accuracy of reliability assessment under condi?tions of small sample size and zero?failure data.
