Objective To investigate the epidemiological characteristics of human papillomavirus （HPV） infection in men attending a sexually transmitted diseases （STD） clinic in Hangzhou area. Methods Male subjects （n=375） ...Objective To investigate the epidemiological characteristics of human papillomavirus （HPV） infection in men attending a sexually transmitted diseases （STD） clinic in Hangzhou area. Methods Male subjects （n=375） aged 18-70 years, attending the STD clinic were recruited. Urethral swabs were assessed for HPV DNA using polymerase chain reaction （PCR） with the consensus primers MY09/11. HPV genotypes of positive PCR products were determined by restriction fragment length polymorphisms and direct sequence analysis. Results Of the 375 swabs collected, 305 （81.3%） yielded sufficient DNA for the subsequent HPV analysis. Among the 305 subjects, the prevalence of HPV was 13.8%. Nononcogenic HPV types were found in 8.5% （26/305） of subjects, oncogenic types in 4.3% （13/305）, and multiple types in 1.0% （3/305）. The prevalence of HPV infection was higher in subjects from urban area than in those from rural area （P〈0.05）. The prevalence was also higher in those who received fewer years of education （P〈0.05） and those who had more sex partners （P〈0.05）. Conclusions HPV infection among men at high risk is not uncommon. The detection rate of HPV DNA is significantly related to some sociodemographic factors, such as residence, educational level and the number of sex partners.展开更多
Image segmentation is attracting increasing attention in the field of medical image analysis.Since widespread utilization across various medical applications,ensuring and improving segmentation accuracy has become a c...Image segmentation is attracting increasing attention in the field of medical image analysis.Since widespread utilization across various medical applications,ensuring and improving segmentation accuracy has become a crucial topic of research.With advances in deep learning,researchers have developed numerous methods that combine Transformers and convolutional neural networks(CNNs)to create highly accurate models for medical image segmentation.However,efforts to further enhance accuracy by developing larger and more complex models or training with more extensive datasets,significantly increase computational resource consumption.To address this problem,we propose BiCLIP-nnFormer(the prefix"Bi"refers to the use of two distinct CLIP models),a virtual multimodal instrument that leverages CLIP models to enhance the segmentation performance of a medical segmentation model nnFormer.Since two CLIP models(PMC-CLIP and CoCa-CLIP)are pre-trained on large datasets,they do not require additional training,thus conserving computation resources.These models are used offline to extract image and text embeddings from medical images.These embeddings are then processed by the proposed 3D CLIP adapter,which adapts the CLIP knowledge for segmentation tasks by fine-tuning.Finally,the adapted embeddings are fused with feature maps extracted from the nnFormer encoder for generating predicted masks.This process enriches the representation capabilities of the feature maps by integrating global multimodal information,leading to more precise segmentation predictions.We demonstrate the superiority of BiCLIP-nnFormer and the effectiveness of using CLIP models to enhance nnFormer through experiments on two public datasets,namely the Synapse multi-organ segmentation dataset(Synapse)and the Automatic Cardiac Diagnosis Challenge dataset(ACDC),as well as a self-annotated lung multi-category segmentation dataset(LMCS).展开更多
Accurate fine-grained geospatial scene classification using remote sensing imagery is essential for a wide range of applications.However,existing approaches often rely on manually zooming remote sensing images at diff...Accurate fine-grained geospatial scene classification using remote sensing imagery is essential for a wide range of applications.However,existing approaches often rely on manually zooming remote sensing images at different scales to create typical scene samples.This approach fails to adequately support the fixed-resolution image interpretation requirements in real-world scenarios.To address this limitation,we introduce the million-scale fine-grained geospatial scene classification dataset(MEET),which contains over 1.03 million zoom-free remote sensing scene samples,manually annotated into 80 fine-grained categories.In MEET,each scene sample follows a scene-in-scene layout,where the central scene serves as the reference,and auxiliary scenes provide crucial spatial context for fine-grained classification.Moreover,to tackle the emerging challenge of scene-in-scene classification,we present the context-aware transformer(CAT),a model specifically designed for this task,which adaptively fuses spatial context to accurately classify the scene samples.CAT adaptively fuses spatial context to accurately classify the scene samples by learning attentional features that capture the relationships between the center and auxiliary scenes.Based on MEET,we establish a comprehensive benchmark for fine-grained geospatial scene classification,evaluating CAT against 11 competitive baselines.The results demonstrate that CAT significantly outperforms these baselines,achieving a 1.88%higher balanced accuracy(BA)with the Swin-Large backbone,and a notable 7.87%improvement with the Swin-Huge backbone.Further experiments validate the effectiveness of each module in CAT and show the practical applicability of CAT in the urban functional zone mapping.The source code and dataset will be publicly available at https://jerrywyn.github.io/project/MEET.html.展开更多
In this study,to enhance the coercivity and high-temperature stability of hot-deformed PrNd-Fe-B magnets,the NdHoAlGa alloy was utilized as a diffusion source and a dual-alloy diffusion process was employed to enhance...In this study,to enhance the coercivity and high-temperature stability of hot-deformed PrNd-Fe-B magnets,the NdHoAlGa alloy was utilized as a diffusion source and a dual-alloy diffusion process was employed to enhance the room temperature coercivity from 1.72 to 2.28 T.For the magnet doped with7 wt%Nd_(72.3)Ho_(13).8Al_(2.3)Ga_(11.7),within the temperature range from 20 to 200℃,the remanence temperature coefficient a increases from-0.16%/℃to-0.14%/℃,and the coercivity temperature coefficientβincreases from-0.49%/℃to-0.43%/℃.By controlling grain boundary(GB)phases and optimizing the main phase simultaneously,Ga was induced to motivate the formation of non-ferromagnetic GB phases,reducing the size of grains and intergranular exchange coupling.Additionally,Ho was diffused into the main phase,forming(Pr,Nd,Ho)-Fe-B phase,which enhances the magnetic crystalline anisotropy field of the main phase grains at high temperatures.展开更多
The metamaterial based on external meshing gears(MEG)is designed based on the principle of external meshing gear transmission.Based on the meshing transmission principle of external meshing gears and planetary gear tr...The metamaterial based on external meshing gears(MEG)is designed based on the principle of external meshing gear transmission.Based on the meshing transmission principle of external meshing gears and planetary gear trains,the internal and external gear rings are designed.Based on the internal and external gear rings,the metamaterial based on inner and outer planetary gear trains(MIP)is designed to study the shear modulus,Young's modulus,and amplitude-frequency characteristics of the metamaterial based on gears at different angles.The effects of the number of planetary gears on the physical characteristics of the MIP are studied.The results show that the MEG can be continuously adjusted by adjusting the shear modulus and Young's modulus due to its meshing characteristics.With the same number of gears,the adjustment range of the MIP is larger than the adjustment range of the MEG.When the number of planetary gears increases,the adjustment range of the MIP decreases.Moreover,when the metamaterial based on gears rotates,the harmonic response changes with the change of the angle.展开更多
Piperidine is a crucial pharmacophore and a special scaffold in the realm of drug discovery.Its flexibility increases the molecule’s capability to bind to the receptor.The piperidine-containing compounds are distingu...Piperidine is a crucial pharmacophore and a special scaffold in the realm of drug discovery.Its flexibility increases the molecule’s capability to bind to the receptor.The piperidine-containing compounds are distinguished by their remarkable activity,and are increasingly becoming a vital category of pesticides.In this review,the research progress of piperidines in the discovery of pesticides was updated according to their active characteristics.The structure-activity relationships(SARs),and mechanisms of action of piperidine-containing compounds were also discussed.This article is meant to enable readers to quickly understand piperidines,while providing ideas for creating piperidines with novel structures and unique mechanisms of action.展开更多
This study explored the connection between childhood psychological maltreatment and online trolling,as well as the influence of moral disengagement and mindfulness in that relationship.A total of 984 college students(...This study explored the connection between childhood psychological maltreatment and online trolling,as well as the influence of moral disengagement and mindfulness in that relationship.A total of 984 college students(54%females,Mean age=20.9 years,SD=1.57 years)took part in the current research.The students responded to standardized measures of childhood psychological maltreatment,online trolling,moral disengagement,mindfulness.Results following the regression and the mediation analyses showed that childhood psychological maltreatment was associated with higher online trolling among college students.Moral disengagement played a mediating role in the link between childhood psychological maltreatment and online trolling,predicting to increased trolling behavior.Furthermore,mindfulness moderated the direct connection between moral disengagement and online trolling.Specifically,compared to those with high mindfulness,individuals with high moral disengagement were more inclined to engage in online trolling when they had low mindfulness.These findings add to our understanding of how and when childhood psychological maltreatment relates to online trolling of which moral engagement and mindfulness would be protective.展开更多
Additive manufacturing provides an opportunity to efficiently produce the structure-performance integrated forming of aluminum alloy components,which has long been a primary objective in the aerospace and automobile i...Additive manufacturing provides an opportunity to efficiently produce the structure-performance integrated forming of aluminum alloy components,which has long been a primary objective in the aerospace and automobile industries.However,achieving nearly fully dense additive manufacturing of high-strength aluminum alloys remains a major challenge because of their high cracking sensitivity.In this study,an Al-Fe-V-Si-Sc alloy was designed and prepared by laser powder bed fusion(LPBF).The extremely high cooling rate and thermal gradient during the LPBF process facilitate the formation of a unique hierarchical heterostructure.The amorphous/crystal composite structure,located at the molten pool center,along with various nanoscale precipitates present at the molten pool boundary,can provide strengthening effects to this alloy,thereby conferring ultrahigh strength on the alloy at both room temperature and elevated temperatures.These findings offer valuable insights into the design of additively manufactured aluminum alloys,holding great promise for the advancement of aerospace components.展开更多
Grain boundary diffusion process(GBDP)was first proposed for sintered Nd-Fe-B magnets to achieve the high utilization efficiency of heavy rare earth elements.Recent success of fabricating high performance nanocomposit...Grain boundary diffusion process(GBDP)was first proposed for sintered Nd-Fe-B magnets to achieve the high utilization efficiency of heavy rare earth elements.Recent success of fabricating high performance nanocomposite magnets by GBDP indicates that this method also exerts huge applicable potential on hot-deformed Nd-Fe-B magnets.In this review,the development and magnetic property enhancement mechanisms of different diffusion methods proposed on hot-deformed magnets were thoroughly elucidated.Moreover,the improve room for further property enhancement and the accompanying problems of GBDP on hot-deformed magnets are also discussed in this article.展开更多
New samples returned by China Chang’e-5(CE-5)mission offer an opportunity for studying the lunar geologic longevity,space weathering,and regolith evolution.The age determination of the CE-5 samples was among the firs...New samples returned by China Chang’e-5(CE-5)mission offer an opportunity for studying the lunar geologic longevity,space weathering,and regolith evolution.The age determination of the CE-5 samples was among the first scientific questions to be answered.However,the precious samples,most in the micrometer size range,challenge many traditional analyses on large single crystals of zircon developed for massive bulk samples.Here,we developed a non-destructive rapid screening of individual zirconium-containing particle for isotope geochronology based on a Micro X-ray fluorescence analysis(μXRF).The selected particles were verified via scanning electron microscopy(SEM),3D X-ray microscopy(XRM),and focused ion beam scanning electron microscopy(FIB-SEM)techniques,which showed that zirconium-bearing minerals with several microns were precisely positioned and readily suitable for site-specific isotopic dating by second ion mass spectrometry(SIMS).Such protocol could be also appli-cable in non-destructively screening other types of particles for different scientific purposes.We there-fore proposed a correlative workflow for comprehensively studying the CE-5 lunar samples from single particles on nanometer to atomic scales.Linking various microscopic and spectromicroscopic instru-ments together,this workflow consists of six steps:(1)single-particle selection with non-destructive μXRF technique,(2)2D/3D morphological and structural characterization with a correlative submicron 3D XRM and nanoscale resolution FIB-SEM imaging methods,(3)SEM analysis of the surface morphology and chemistry of the selected particle,(4)a series of microscopic and microbeam analyses(e.g.,SEM,electron probe microanalysis,and SIMS)on the cross-section of the selected particle to obtain structural,mineralogical,chemical,and isotopic features from the micron to nanometer scale,(5)advanced 2D/3D characterization and site-specific sample preparation of thin foil/tip specimens on a microregion of inter-est in the selected particle with FIB-SEM technique,and(6)comprehensive analyses on the FIB-milled specimens at nanometer to atomic scale with synchrotron-based scanning transmission X-ray micro-scopy,analytic transmission electron microscopy,and atom probe tomography.Following this technical roadmap,one can integrate multiple modalities into a uniform frame of multimodal and multiscale cor-related datasets to acquire high-throughput information on the limited or precious terrestrial and extraterrestrial samples.展开更多
With the frequent fluctuations of international crude oil prices and China＇s increasing dependence on foreign oil in recent years, the volatility of international oil prices has significantly influenced China domesti...With the frequent fluctuations of international crude oil prices and China＇s increasing dependence on foreign oil in recent years, the volatility of international oil prices has significantly influenced China domestic refined oil price. This paper aims to investigate the transmission and feedback mechanism between international crude oil prices and China＇s refined oil prices for the time span from January 2011 to November 2015 by using the Granger causality test, vector autoregression model, impulse response function and variance decomposition methods. It is demonstrated that variation of international crude oil prices can cause China domestic refined oil price to change with a weak feedback effect. Moreover, international crude oil prices and China domestic refined oil prices are affected by their lag terms in positive and negative directions in different degrees. Besides, an international crude oil price shock has a signif- icant positive impact on domestic refined oil prices while the impulse response of the international crude oil price variable to the domestic refined oil price shock is negatively insignificant. Furthermore, international crude oil prices and domestic refined oil prices have strong historical inheri- tance. According to the variance decomposition analysis, the international crude oil price is significantly affected by its own disturbance influence, and a domestic refined oil price shock has a slight impact on international crude oil price changes. The domestic refined oil price variance is mainly caused by international crude oil price disturbance, while the domestic refined oil price is slightly affected by its own disturbance. Generally, domestic refined oil prices do not immediately respond to an international crude oil price change, that is, there is a time lag.展开更多
Eutectic high entropy alloy(EHEA)possesses promising prospects for industrial application due to its controllable and near-equilibrium dual-phase structure.Due to the advantages of high material utiliza-tion,efficient...Eutectic high entropy alloy(EHEA)possesses promising prospects for industrial application due to its controllable and near-equilibrium dual-phase structure.Due to the advantages of high material utiliza-tion,efficient production,and design freedom,the laser powder bed fusion(LPBF)technique provides a new path to prepare EHEA components with complex structure and excellent performance.In this study,near fully dense AlCoCrFeNi_(2.1) samples were obtained by adjusting the process parameters of LPBF.Con-sidering the balling phenomenon and powder splashing during the LPBF process,laser remelting was selected as an optimized scanning strategy to further improve the forming quality of AlCoCrFeNi21.The microstructure of remelted AlCoCrFeNi_(2.1) sample exhibited regular eutectic lamellae consisting of nano-scale face-centered-cubic(FCC)and B2 phases,in which the FCC phase accounted for a higher proportion.By investigating the tensile behavior and deformation mechanism,it was revealed that the ultrafine eu-tectic lamellae could induce a strong dual-phase synergistic strengthening,thereby significantly improv-ing the strength of the sample.Compared with the vacuum induction melted(VIM)sample,the remelted sample showed a 54%increase in ultimate tensile strength(UTS-1518 MPa)and a 130%increase in yield strength(YS-1235 MPa)with reasonable plasticity.This study indicates that by combining the design and manufacturing freedom of LPBF with the EHEA,it is expected to fabricate high-property 3D EHEA parts,expanding the application field of EHEA.展开更多
To restrict grain growth in coarse grain regions caused by the diffusion of Nd-Cu eutectic alloys,the Nb element was introduced into the precursor alloy to regulate the microstructure of melt-spun powder and die-upset...To restrict grain growth in coarse grain regions caused by the diffusion of Nd-Cu eutectic alloys,the Nb element was introduced into the precursor alloy to regulate the microstructure of melt-spun powder and die-upset magnets.The magnetic properties and thermal stability of die-upset magnets were appreciably improved through the addition of Nb.For the Nb-doped diffusion die-upset magnet,the grains inside the ribbons were refined and the coarse non-oriented surface crystallite got suppressed on the interface of ribbons during the hot-deformation process to form the anisotropic magnet.Moreover,Nd gathers at the intergranular phases,which is considered to enforce domain wall pinning force.The Nb-modified microstructure is advantageous to thermal stability and coercivity enhancement.High-resolution transmission electron microscopy images revealed that the Nb element gathered on the grain boundary and triple grain boundary to form c-Nb and h-Nb Fe B to hinder the grain growth during the hot-deformation process,which led to direct enhancement in the coercivity.Furthermore,the c-Nb and h-Nb Fe B are nonmagnetic phases that strengthened the magnetic isolation.However,the h-Nb Fe B precipitated from the hard magnetic phase and formed crystal defects which led to remanence deterioration.展开更多
基金This study was supported by the Educational Department of Zhejiang Province, China (Grant No. 20040689) and Hangzhou Science and Technology Bureau, Zhejiang Province, China (Grant No. 2004433Q05)
文摘Objective To investigate the epidemiological characteristics of human papillomavirus （HPV） infection in men attending a sexually transmitted diseases （STD） clinic in Hangzhou area. Methods Male subjects （n=375） aged 18-70 years, attending the STD clinic were recruited. Urethral swabs were assessed for HPV DNA using polymerase chain reaction （PCR） with the consensus primers MY09/11. HPV genotypes of positive PCR products were determined by restriction fragment length polymorphisms and direct sequence analysis. Results Of the 375 swabs collected, 305 （81.3%） yielded sufficient DNA for the subsequent HPV analysis. Among the 305 subjects, the prevalence of HPV was 13.8%. Nononcogenic HPV types were found in 8.5% （26/305） of subjects, oncogenic types in 4.3% （13/305）, and multiple types in 1.0% （3/305）. The prevalence of HPV infection was higher in subjects from urban area than in those from rural area （P〈0.05）. The prevalence was also higher in those who received fewer years of education （P〈0.05） and those who had more sex partners （P〈0.05）. Conclusions HPV infection among men at high risk is not uncommon. The detection rate of HPV DNA is significantly related to some sociodemographic factors, such as residence, educational level and the number of sex partners.
基金funded by the National Natural Science Foundation of China(Grant No.6240072655)the Hubei Provincial Key Research and Development Program(Grant No.2023BCB151)+1 种基金the Wuhan Natural Science Foundation Exploration Program(Chenguang Program,Grant No.2024040801020202)the Natural Science Foundation of Hubei Province of China(Grant No.2025AFB148).
文摘Image segmentation is attracting increasing attention in the field of medical image analysis.Since widespread utilization across various medical applications,ensuring and improving segmentation accuracy has become a crucial topic of research.With advances in deep learning,researchers have developed numerous methods that combine Transformers and convolutional neural networks(CNNs)to create highly accurate models for medical image segmentation.However,efforts to further enhance accuracy by developing larger and more complex models or training with more extensive datasets,significantly increase computational resource consumption.To address this problem,we propose BiCLIP-nnFormer(the prefix"Bi"refers to the use of two distinct CLIP models),a virtual multimodal instrument that leverages CLIP models to enhance the segmentation performance of a medical segmentation model nnFormer.Since two CLIP models(PMC-CLIP and CoCa-CLIP)are pre-trained on large datasets,they do not require additional training,thus conserving computation resources.These models are used offline to extract image and text embeddings from medical images.These embeddings are then processed by the proposed 3D CLIP adapter,which adapts the CLIP knowledge for segmentation tasks by fine-tuning.Finally,the adapted embeddings are fused with feature maps extracted from the nnFormer encoder for generating predicted masks.This process enriches the representation capabilities of the feature maps by integrating global multimodal information,leading to more precise segmentation predictions.We demonstrate the superiority of BiCLIP-nnFormer and the effectiveness of using CLIP models to enhance nnFormer through experiments on two public datasets,namely the Synapse multi-organ segmentation dataset(Synapse)and the Automatic Cardiac Diagnosis Challenge dataset(ACDC),as well as a self-annotated lung multi-category segmentation dataset(LMCS).
基金supported by the National Natural Science Foundation of China(42030102,42371321).
文摘Accurate fine-grained geospatial scene classification using remote sensing imagery is essential for a wide range of applications.However,existing approaches often rely on manually zooming remote sensing images at different scales to create typical scene samples.This approach fails to adequately support the fixed-resolution image interpretation requirements in real-world scenarios.To address this limitation,we introduce the million-scale fine-grained geospatial scene classification dataset(MEET),which contains over 1.03 million zoom-free remote sensing scene samples,manually annotated into 80 fine-grained categories.In MEET,each scene sample follows a scene-in-scene layout,where the central scene serves as the reference,and auxiliary scenes provide crucial spatial context for fine-grained classification.Moreover,to tackle the emerging challenge of scene-in-scene classification,we present the context-aware transformer(CAT),a model specifically designed for this task,which adaptively fuses spatial context to accurately classify the scene samples.CAT adaptively fuses spatial context to accurately classify the scene samples by learning attentional features that capture the relationships between the center and auxiliary scenes.Based on MEET,we establish a comprehensive benchmark for fine-grained geospatial scene classification,evaluating CAT against 11 competitive baselines.The results demonstrate that CAT significantly outperforms these baselines,achieving a 1.88%higher balanced accuracy(BA)with the Swin-Large backbone,and a notable 7.87%improvement with the Swin-Huge backbone.Further experiments validate the effectiveness of each module in CAT and show the practical applicability of CAT in the urban functional zone mapping.The source code and dataset will be publicly available at https://jerrywyn.github.io/project/MEET.html.
基金Project supported by the National Key Research and Development Program of China(2022YFB3503403)the Inner Mongolia Major Technology Project(2021ZD0035)+1 种基金the Ningbo Natural Science Foundation(2023J343)the Science and Technology Innovation 2025 Major Project of Ningbo(2022Z106)。
文摘In this study,to enhance the coercivity and high-temperature stability of hot-deformed PrNd-Fe-B magnets,the NdHoAlGa alloy was utilized as a diffusion source and a dual-alloy diffusion process was employed to enhance the room temperature coercivity from 1.72 to 2.28 T.For the magnet doped with7 wt%Nd_(72.3)Ho_(13).8Al_(2.3)Ga_(11.7),within the temperature range from 20 to 200℃,the remanence temperature coefficient a increases from-0.16%/℃to-0.14%/℃,and the coercivity temperature coefficientβincreases from-0.49%/℃to-0.43%/℃.By controlling grain boundary(GB)phases and optimizing the main phase simultaneously,Ga was induced to motivate the formation of non-ferromagnetic GB phases,reducing the size of grains and intergranular exchange coupling.Additionally,Ho was diffused into the main phase,forming(Pr,Nd,Ho)-Fe-B phase,which enhances the magnetic crystalline anisotropy field of the main phase grains at high temperatures.
基金supported by the Guangxi Science and Technology Major Program of China(Nos.AA23073019 and AA24263074)the National Natural Science Foundation of China(No.52265004)+7 种基金the Guangxi Natural Science Fund for Distinguished Young Scholars of China(No.2024JJG160014)the Innovation Project of Guangxi Graduate Education of China(No.YCSW2024119)the Open Fund of State Key Laboratory of Intelligent Manufacturing Equipment and Technology of China(No.IMETKF2025021)the Open Research Fund of State Key Laboratory of Precision Manufacturing for Extreme Service Performance-Central South University of China(No.Kfkt2023-06)the Open Fund of High-end Basic Component Innovation Station of China(No.KY01080030124001)the Open Fund for Academician Mao Ming's Workstation of China(No.XSJSFW-QNKXJ-202404-007)the Technology Innovation Platform Project of China Aviation Engine Group Corporation(No.CXPT-2023-044)the Open Fund for Innovation Workstation in the National Defense Science and Technology Innovation Special Zone(Xi'an Jiaotong University).
文摘The metamaterial based on external meshing gears(MEG)is designed based on the principle of external meshing gear transmission.Based on the meshing transmission principle of external meshing gears and planetary gear trains,the internal and external gear rings are designed.Based on the internal and external gear rings,the metamaterial based on inner and outer planetary gear trains(MIP)is designed to study the shear modulus,Young's modulus,and amplitude-frequency characteristics of the metamaterial based on gears at different angles.The effects of the number of planetary gears on the physical characteristics of the MIP are studied.The results show that the MEG can be continuously adjusted by adjusting the shear modulus and Young's modulus due to its meshing characteristics.With the same number of gears,the adjustment range of the MIP is larger than the adjustment range of the MEG.When the number of planetary gears increases,the adjustment range of the MIP decreases.Moreover,when the metamaterial based on gears rotates,the harmonic response changes with the change of the angle.
基金financial support from the National Natural Science Foundation of China(No.32072445)the Science and Technology Plan Project of Guizhou Province(Qiankehezhicheng[2024]the general 083)+7 种基金the Program of Introducing Talents to Chinese Universities(No.D20023)the Central Government Guides Local Science and Technology Development Fund Projects(Qiankehezhongyindi(2023)001)the Technology Achievement Transformation(general project)of Guizhou Province(Qiankehechengguo[2022]the general 063)Key Agricultural Technology R&D Projects of the Xinjiang Production and Construction Corps(NYHXGG,No.2023AA602)the Frontiers Science Centre for Asymmetric Synthesis and Medicinal MoleculesDepartment of EducationGuizhou Province[Qianjiaohe KY(2020)004]the specific research fund of TheInnovation Platform for Academicians of Hainan Province(No.SQ2020PTZ0009)。
文摘Piperidine is a crucial pharmacophore and a special scaffold in the realm of drug discovery.Its flexibility increases the molecule’s capability to bind to the receptor.The piperidine-containing compounds are distinguished by their remarkable activity,and are increasingly becoming a vital category of pesticides.In this review,the research progress of piperidines in the discovery of pesticides was updated according to their active characteristics.The structure-activity relationships(SARs),and mechanisms of action of piperidine-containing compounds were also discussed.This article is meant to enable readers to quickly understand piperidines,while providing ideas for creating piperidines with novel structures and unique mechanisms of action.
基金supported by the National Social Science Funds of China“A Study of the Psychosocial Mechanisms of Youth Online Trolling”(23BSH143).
文摘This study explored the connection between childhood psychological maltreatment and online trolling,as well as the influence of moral disengagement and mindfulness in that relationship.A total of 984 college students(54%females,Mean age=20.9 years,SD=1.57 years)took part in the current research.The students responded to standardized measures of childhood psychological maltreatment,online trolling,moral disengagement,mindfulness.Results following the regression and the mediation analyses showed that childhood psychological maltreatment was associated with higher online trolling among college students.Moral disengagement played a mediating role in the link between childhood psychological maltreatment and online trolling,predicting to increased trolling behavior.Furthermore,mindfulness moderated the direct connection between moral disengagement and online trolling.Specifically,compared to those with high mindfulness,individuals with high moral disengagement were more inclined to engage in online trolling when they had low mindfulness.These findings add to our understanding of how and when childhood psychological maltreatment relates to online trolling of which moral engagement and mindfulness would be protective.
基金supported by the National Natural Science Foundation of China(Nos.U21A2043,and U22A20129)the Youth Innovation Promotion Association,CAS(No.2022191).
文摘Additive manufacturing provides an opportunity to efficiently produce the structure-performance integrated forming of aluminum alloy components,which has long been a primary objective in the aerospace and automobile industries.However,achieving nearly fully dense additive manufacturing of high-strength aluminum alloys remains a major challenge because of their high cracking sensitivity.In this study,an Al-Fe-V-Si-Sc alloy was designed and prepared by laser powder bed fusion(LPBF).The extremely high cooling rate and thermal gradient during the LPBF process facilitate the formation of a unique hierarchical heterostructure.The amorphous/crystal composite structure,located at the molten pool center,along with various nanoscale precipitates present at the molten pool boundary,can provide strengthening effects to this alloy,thereby conferring ultrahigh strength on the alloy at both room temperature and elevated temperatures.These findings offer valuable insights into the design of additively manufactured aluminum alloys,holding great promise for the advancement of aerospace components.
基金Project supported by the Pioneer and Leading Goose R&D Program of Zhejiang(2020C01190)the Science and Technology Innovation 2025Major Project of Ningbo(2020Z064)+1 种基金the Zhejiang Province Postdoctoral Science Foundation(ZJ2021080)the Inner Mongolia Major Technology Project(2021ZD0035)。
文摘Grain boundary diffusion process(GBDP)was first proposed for sintered Nd-Fe-B magnets to achieve the high utilization efficiency of heavy rare earth elements.Recent success of fabricating high performance nanocomposite magnets by GBDP indicates that this method also exerts huge applicable potential on hot-deformed Nd-Fe-B magnets.In this review,the development and magnetic property enhancement mechanisms of different diffusion methods proposed on hot-deformed magnets were thoroughly elucidated.Moreover,the improve room for further property enhancement and the accompanying problems of GBDP on hot-deformed magnets are also discussed in this article.
基金the National Key R&D Program of China(2018YFA0702600)the Key Research program of Chinese Academy of Sciences(ZDBS-SSW-JSC007-13)+1 种基金the institute of Geology and Geophysics,Chinese Academy of Sciences(IGGCAS-202101)the National Natural Science Foundation of China(grants no.41890843,41920104009)。
文摘New samples returned by China Chang’e-5(CE-5)mission offer an opportunity for studying the lunar geologic longevity,space weathering,and regolith evolution.The age determination of the CE-5 samples was among the first scientific questions to be answered.However,the precious samples,most in the micrometer size range,challenge many traditional analyses on large single crystals of zircon developed for massive bulk samples.Here,we developed a non-destructive rapid screening of individual zirconium-containing particle for isotope geochronology based on a Micro X-ray fluorescence analysis(μXRF).The selected particles were verified via scanning electron microscopy(SEM),3D X-ray microscopy(XRM),and focused ion beam scanning electron microscopy(FIB-SEM)techniques,which showed that zirconium-bearing minerals with several microns were precisely positioned and readily suitable for site-specific isotopic dating by second ion mass spectrometry(SIMS).Such protocol could be also appli-cable in non-destructively screening other types of particles for different scientific purposes.We there-fore proposed a correlative workflow for comprehensively studying the CE-5 lunar samples from single particles on nanometer to atomic scales.Linking various microscopic and spectromicroscopic instru-ments together,this workflow consists of six steps:(1)single-particle selection with non-destructive μXRF technique,(2)2D/3D morphological and structural characterization with a correlative submicron 3D XRM and nanoscale resolution FIB-SEM imaging methods,(3)SEM analysis of the surface morphology and chemistry of the selected particle,(4)a series of microscopic and microbeam analyses(e.g.,SEM,electron probe microanalysis,and SIMS)on the cross-section of the selected particle to obtain structural,mineralogical,chemical,and isotopic features from the micron to nanometer scale,(5)advanced 2D/3D characterization and site-specific sample preparation of thin foil/tip specimens on a microregion of inter-est in the selected particle with FIB-SEM technique,and(6)comprehensive analyses on the FIB-milled specimens at nanometer to atomic scale with synchrotron-based scanning transmission X-ray micro-scopy,analytic transmission electron microscopy,and atom probe tomography.Following this technical roadmap,one can integrate multiple modalities into a uniform frame of multimodal and multiscale cor-related datasets to acquire high-throughput information on the limited or precious terrestrial and extraterrestrial samples.
基金support from the Key Project of National Social Science Foundation of China (NO. 13&ZD159)
文摘With the frequent fluctuations of international crude oil prices and China＇s increasing dependence on foreign oil in recent years, the volatility of international oil prices has significantly influenced China domestic refined oil price. This paper aims to investigate the transmission and feedback mechanism between international crude oil prices and China＇s refined oil prices for the time span from January 2011 to November 2015 by using the Granger causality test, vector autoregression model, impulse response function and variance decomposition methods. It is demonstrated that variation of international crude oil prices can cause China domestic refined oil price to change with a weak feedback effect. Moreover, international crude oil prices and China domestic refined oil prices are affected by their lag terms in positive and negative directions in different degrees. Besides, an international crude oil price shock has a signif- icant positive impact on domestic refined oil prices while the impulse response of the international crude oil price variable to the domestic refined oil price shock is negatively insignificant. Furthermore, international crude oil prices and domestic refined oil prices have strong historical inheri- tance. According to the variance decomposition analysis, the international crude oil price is significantly affected by its own disturbance influence, and a domestic refined oil price shock has a slight impact on international crude oil price changes. The domestic refined oil price variance is mainly caused by international crude oil price disturbance, while the domestic refined oil price is slightly affected by its own disturbance. Generally, domestic refined oil prices do not immediately respond to an international crude oil price change, that is, there is a time lag.
基金supported by the National Natural Science Foundation of China (Grant No.U21A2043)the Youth Innovation Promotion Association,CAS (No.2022191)the Bintech-IMR R&D Program (No.GYY-JSBU-2022-010).
文摘Eutectic high entropy alloy(EHEA)possesses promising prospects for industrial application due to its controllable and near-equilibrium dual-phase structure.Due to the advantages of high material utiliza-tion,efficient production,and design freedom,the laser powder bed fusion(LPBF)technique provides a new path to prepare EHEA components with complex structure and excellent performance.In this study,near fully dense AlCoCrFeNi_(2.1) samples were obtained by adjusting the process parameters of LPBF.Con-sidering the balling phenomenon and powder splashing during the LPBF process,laser remelting was selected as an optimized scanning strategy to further improve the forming quality of AlCoCrFeNi21.The microstructure of remelted AlCoCrFeNi_(2.1) sample exhibited regular eutectic lamellae consisting of nano-scale face-centered-cubic(FCC)and B2 phases,in which the FCC phase accounted for a higher proportion.By investigating the tensile behavior and deformation mechanism,it was revealed that the ultrafine eu-tectic lamellae could induce a strong dual-phase synergistic strengthening,thereby significantly improv-ing the strength of the sample.Compared with the vacuum induction melted(VIM)sample,the remelted sample showed a 54%increase in ultimate tensile strength(UTS-1518 MPa)and a 130%increase in yield strength(YS-1235 MPa)with reasonable plasticity.This study indicates that by combining the design and manufacturing freedom of LPBF with the EHEA,it is expected to fabricate high-property 3D EHEA parts,expanding the application field of EHEA.
基金supported by the Major Project of“Science and Technology Innovation 2025 in Ningbo City(Nos.2020Z064,2019B10093)the Basic research expenses for provincial universities of Zhejiang Ocean University(No.2019J00036)the Talent introduction research fund of Zhejiang Ocean University(Nos.xjrcyj201801,11045091021)。
文摘To restrict grain growth in coarse grain regions caused by the diffusion of Nd-Cu eutectic alloys,the Nb element was introduced into the precursor alloy to regulate the microstructure of melt-spun powder and die-upset magnets.The magnetic properties and thermal stability of die-upset magnets were appreciably improved through the addition of Nb.For the Nb-doped diffusion die-upset magnet,the grains inside the ribbons were refined and the coarse non-oriented surface crystallite got suppressed on the interface of ribbons during the hot-deformation process to form the anisotropic magnet.Moreover,Nd gathers at the intergranular phases,which is considered to enforce domain wall pinning force.The Nb-modified microstructure is advantageous to thermal stability and coercivity enhancement.High-resolution transmission electron microscopy images revealed that the Nb element gathered on the grain boundary and triple grain boundary to form c-Nb and h-Nb Fe B to hinder the grain growth during the hot-deformation process,which led to direct enhancement in the coercivity.Furthermore,the c-Nb and h-Nb Fe B are nonmagnetic phases that strengthened the magnetic isolation.However,the h-Nb Fe B precipitated from the hard magnetic phase and formed crystal defects which led to remanence deterioration.
