The past decade has witnessed the rapid increasement in power conversion efficiency of perovskite solar cells(PSCs).However,serious ion migration hampers their operational stability.Although dopants composed of varied...The past decade has witnessed the rapid increasement in power conversion efficiency of perovskite solar cells(PSCs).However,serious ion migration hampers their operational stability.Although dopants composed of varied cations and anions are introduced into perovskite to suppress ion migration,the impact of cations or anions is not individually explored,which hinders the evaluation of different cations and further application of doping strategy.Here we report that a special group of sulfonic anions(like CF_(3)SO_(3)^(-))successfully introduce alkaline earth ions(like Ca^(2+))into perovskite lattice compared to its halide counterparts.Furthermore,with effective crystallization regulation and defect passivation of sulfonic anions,perovskite with Ca(CF_(3)SO_(3))_(2)shows reduced PbI2 residue and metallic Pb0 defects;thereby,corresponding PSCs show an enhanced PCE of 24.95%.Finally by comparing the properties of perovskite with Ca(CF_(3)SO_(3))_(2)and FACF_(3)SO_(3),we found that doped Ca^(2+)significantly suppressed halide migration with an activation energy of 1.246 eV which accounts for the improved operational stability of Ca(CF_(3)SO_(3))_(2-)doped PSCs,while no obvious impact of Ca^(2+)on trap density is observed.Combining the benefits of cations and anions,this study presents an effective method to decouple the effects of cations and anions and fabricate efficient and stable PSCs.展开更多
Focused exploration of earth-abundant and cost-efficient non-noble metal electrocatalysts with superior hydrogen evolution reaction(HER)performance is very important for large-scale and efficient electrolysis of water...Focused exploration of earth-abundant and cost-efficient non-noble metal electrocatalysts with superior hydrogen evolution reaction(HER)performance is very important for large-scale and efficient electrolysis of water.Herein,a sandwich composite structure(designed as MS-Mo2C@NCNS)ofβ-Mo2C hollow nanotubes(HNT)and N-doped carbon nanosheets(NCNS)is designed and prepared using a binary NaCl–KCl molten salt(MS)strategy for HER.The temperature-dominant Kirkendall formation mechanism is tentatively proposed for such a three-dimensional hierarchical framework.Due to its attractive structure and componential synergism,MS-Mo2C@NCNS exposes more effective active sites,confers robust structural stability,and shows significant electrocatalytic activity/stability in HER,with a current density of 10 mA cm-2 and an overpotential of only 98 mV in 1 M KOH.Density functional theory calculations point to the synergistic effect of Mo2C HNT and NCNS,leading to enhanced electronic transport and suitable adsorption free energies of H*(ΔGH*)on the surface of electroactive Mo2C.More significantly,the MS-assisted synthetic methodology here provides an enormous perspective for the commercial development of highly active non-noble metal electrocatalysts toward efficient hydrogen evolution.展开更多
In the field of fault diagnosis for rolling bearings under variable working conditions,significant progress has been made using methods based on unsupervised domain adaptation(UDA).However,most existing UDA methods pr...In the field of fault diagnosis for rolling bearings under variable working conditions,significant progress has been made using methods based on unsupervised domain adaptation(UDA).However,most existing UDA methods primarily achieve identification by directly aligning the distributions of the source and target domains,often overlooking the relevance of samples between different domains,which may result in incomplete extraction of deep features and alignment of feature distributions.Therefore,this study proposes a novel domain adaptation network based on Gaussian prior distributions,aiming at solving the challenges of cross working conditions bearing fault diagnosis.The method consists of a feature mining module and an adversarial domain adaptation module.The former effectively extracts deep features by stacking multiple residual networks(Resnet),while the latter employs an indirect latent alignment strategy,using Gaussian prior distributions in the latent feature space to indirectly align the feature distributions of the source and target domains,achieving more precise feature alignment.In addition,an adaptive factor is introduced to dynamically assess the method’s transfer and discriminative capabilities.Experimental data from two bearing systems validate that the method can effectively transfer source domain knowledge to the target domain,confirming its effectiveness.展开更多
The proper transfer of genetic information from DNA to RNA to protein is essential for cell-fate control,development,and health.Methylation of DNA,RNAs,histones,and non-histone proteins is a reversible post-synthesis ...The proper transfer of genetic information from DNA to RNA to protein is essential for cell-fate control,development,and health.Methylation of DNA,RNAs,histones,and non-histone proteins is a reversible post-synthesis modification that finetunes gene expression and function in diverse physiological processes.Aberrant methylation caused by genetic mutations or environmental stimuli promotes various diseases and accelerates aging,necessitating the development of therapies to correct the disease-driver methylation imbalance.In this Review,we summarize the operating system of methylation across the central dogma,which includes writers,erasers,readers,and reader-independent outputs.We then discuss how dysregulation of the system contributes to neurological disorders,cancer,and aging.Current small-molecule compounds that target the modifiers show modest success in certain cancers.The methylome-wide action and lack of specificity lead to undesirable biological effects and cytotoxicity,limiting their therapeutic application,especially for diseases with a monogenic cause or different directions of methylation changes.Emerging tools capable of site-specific methylation manipulation hold great promise to solve this dilemma.With the refinement of delivery vehicles,these new tools are well positioned to advance the basic research and clinical translation of the methylation field.展开更多
The dissemination of cancer cells called metastasis accounts for the majority of deaths of cancer patients.Neutrophil extracellular traps(NETs)released by neutrophils to fight pathogens have been shown to promote meta...The dissemination of cancer cells called metastasis accounts for the majority of deaths of cancer patients.Neutrophil extracellular traps(NETs)released by neutrophils to fight pathogens have been shown to promote metastasis in mouse models.However,the mechanism behind how NETs boost metastasis remains elusive.In a recent study in Nature,1 Yang et al reported that NETs are abundant in the liver metastases of patients with breast and colon cancers,and that the risk of liver metastasis in patients with earlystage breast cancer can be predicted by monitoring the levels of serum NETs.Furthermore,Yang et al.1 elucidated that the DNA component of NETs(NET-DNA)acts as a chemotactic factor that is recognized by coiled-coil domain containing protein 25(CCDC25),a cytoplasmic membrane-localized extracellular DNA sensor of cancer cells,which in turn activates the integrin-linked kinase(ILK)–β-parvin–RAC1–CDC42 cascade to promote metastasis(Fig.1).The clinical importance of CCDC25 was confirmed by Yang et al.,1 and targeting CCDC25 inhibits NET-mediated metastasis in mouse models,suggesting a potential therapeutic strategy to halt the metastasis.展开更多
A few monolayers of organic semiconductors adjacent to the dielectric layer are of vital importance in organic field-effect transistors due to their dominant role in charge transport.In this report,the 2-nm-thick poly...A few monolayers of organic semiconductors adjacent to the dielectric layer are of vital importance in organic field-effect transistors due to their dominant role in charge transport.In this report,the 2-nm-thick polymer monolayers based on poly(3-hexylthiophene)with different molecular weights(M_(n))were fabricated using dip-coating technique.During the monolayer(solid state)formation from the solution,a disorder-to-order transition of polymer conformation is observed through UV-vis absorption measurement.Meanwhile,high Mn polymer monolayer generates higher crystalline fibrillar microstructure than the low Mn one due to the strongerπ–πintermolecular packing between polymers.More importantly,the solution aging procedure is utilized to further improve the morphology of polymer monolayers.It is obvious that after aging for 6 d,both fiber dimension and density as well as conjugation length are significantly increased under the same processing conditions in comparison to the fresh solution,and consequently the field-effect mobilities are remarkably enhanced by 2—4 times.Note that the maximum mobility of 0.027 cm2·V^(–1)·s^(–1)is among the highest reported values for poly(3-hexylthiophene)monolayer transistors.These results demonstrate a simple but powerful strategy for boosting the device performance of polymer monolayer transistors.展开更多
基金support from the National Key Research and Development Program of China(No.2022YFE0137400)the National Natural Science Foundation of China(Grant No.62274040).
文摘The past decade has witnessed the rapid increasement in power conversion efficiency of perovskite solar cells(PSCs).However,serious ion migration hampers their operational stability.Although dopants composed of varied cations and anions are introduced into perovskite to suppress ion migration,the impact of cations or anions is not individually explored,which hinders the evaluation of different cations and further application of doping strategy.Here we report that a special group of sulfonic anions(like CF_(3)SO_(3)^(-))successfully introduce alkaline earth ions(like Ca^(2+))into perovskite lattice compared to its halide counterparts.Furthermore,with effective crystallization regulation and defect passivation of sulfonic anions,perovskite with Ca(CF_(3)SO_(3))_(2)shows reduced PbI2 residue and metallic Pb0 defects;thereby,corresponding PSCs show an enhanced PCE of 24.95%.Finally by comparing the properties of perovskite with Ca(CF_(3)SO_(3))_(2)and FACF_(3)SO_(3),we found that doped Ca^(2+)significantly suppressed halide migration with an activation energy of 1.246 eV which accounts for the improved operational stability of Ca(CF_(3)SO_(3))_(2-)doped PSCs,while no obvious impact of Ca^(2+)on trap density is observed.Combining the benefits of cations and anions,this study presents an effective method to decouple the effects of cations and anions and fabricate efficient and stable PSCs.
基金the National Natural Science Foundation of China(Nos.52072151,52171211,52102253,52271218,U22A20145)the Jinan Independent Innovative Team(2020GXRC015)+1 种基金the Major Program of Shandong Province Natural Science Foundation(ZR2021ZD05)the Science and Technology Program of University of Jinan(XKY2119).
文摘Focused exploration of earth-abundant and cost-efficient non-noble metal electrocatalysts with superior hydrogen evolution reaction(HER)performance is very important for large-scale and efficient electrolysis of water.Herein,a sandwich composite structure(designed as MS-Mo2C@NCNS)ofβ-Mo2C hollow nanotubes(HNT)and N-doped carbon nanosheets(NCNS)is designed and prepared using a binary NaCl–KCl molten salt(MS)strategy for HER.The temperature-dominant Kirkendall formation mechanism is tentatively proposed for such a three-dimensional hierarchical framework.Due to its attractive structure and componential synergism,MS-Mo2C@NCNS exposes more effective active sites,confers robust structural stability,and shows significant electrocatalytic activity/stability in HER,with a current density of 10 mA cm-2 and an overpotential of only 98 mV in 1 M KOH.Density functional theory calculations point to the synergistic effect of Mo2C HNT and NCNS,leading to enhanced electronic transport and suitable adsorption free energies of H*(ΔGH*)on the surface of electroactive Mo2C.More significantly,the MS-assisted synthetic methodology here provides an enormous perspective for the commercial development of highly active non-noble metal electrocatalysts toward efficient hydrogen evolution.
文摘In the field of fault diagnosis for rolling bearings under variable working conditions,significant progress has been made using methods based on unsupervised domain adaptation(UDA).However,most existing UDA methods primarily achieve identification by directly aligning the distributions of the source and target domains,often overlooking the relevance of samples between different domains,which may result in incomplete extraction of deep features and alignment of feature distributions.Therefore,this study proposes a novel domain adaptation network based on Gaussian prior distributions,aiming at solving the challenges of cross working conditions bearing fault diagnosis.The method consists of a feature mining module and an adversarial domain adaptation module.The former effectively extracts deep features by stacking multiple residual networks(Resnet),while the latter employs an indirect latent alignment strategy,using Gaussian prior distributions in the latent feature space to indirectly align the feature distributions of the source and target domains,achieving more precise feature alignment.In addition,an adaptive factor is introduced to dynamically assess the method’s transfer and discriminative capabilities.Experimental data from two bearing systems validate that the method can effectively transfer source domain knowledge to the target domain,confirming its effectiveness.
基金This work was supported by the pilot program of Southwest University(SWU-XDZD22006)the Natural Science Foundation of Chongqing(cstc2022ycjh-bgzxm0145)the Chongqing Postdoctoral Science Foundation(cstc2021jcyj-bsh0128).
文摘The proper transfer of genetic information from DNA to RNA to protein is essential for cell-fate control,development,and health.Methylation of DNA,RNAs,histones,and non-histone proteins is a reversible post-synthesis modification that finetunes gene expression and function in diverse physiological processes.Aberrant methylation caused by genetic mutations or environmental stimuli promotes various diseases and accelerates aging,necessitating the development of therapies to correct the disease-driver methylation imbalance.In this Review,we summarize the operating system of methylation across the central dogma,which includes writers,erasers,readers,and reader-independent outputs.We then discuss how dysregulation of the system contributes to neurological disorders,cancer,and aging.Current small-molecule compounds that target the modifiers show modest success in certain cancers.The methylome-wide action and lack of specificity lead to undesirable biological effects and cytotoxicity,limiting their therapeutic application,especially for diseases with a monogenic cause or different directions of methylation changes.Emerging tools capable of site-specific methylation manipulation hold great promise to solve this dilemma.With the refinement of delivery vehicles,these new tools are well positioned to advance the basic research and clinical translation of the methylation field.
基金supported by the National Key Research and Development Program of China(Nos.2016YFC1302204 and 2017YFC1308601)the Natural Science Foundation of China(Nos.81872071 and 81972357)+1 种基金the Natural Science Foundation of Chongqing(cstc2019jcyj-zdxmX0033)Chongqing University Innovation Team Building Program funded projects(CXTDX201601010).
文摘The dissemination of cancer cells called metastasis accounts for the majority of deaths of cancer patients.Neutrophil extracellular traps(NETs)released by neutrophils to fight pathogens have been shown to promote metastasis in mouse models.However,the mechanism behind how NETs boost metastasis remains elusive.In a recent study in Nature,1 Yang et al reported that NETs are abundant in the liver metastases of patients with breast and colon cancers,and that the risk of liver metastasis in patients with earlystage breast cancer can be predicted by monitoring the levels of serum NETs.Furthermore,Yang et al.1 elucidated that the DNA component of NETs(NET-DNA)acts as a chemotactic factor that is recognized by coiled-coil domain containing protein 25(CCDC25),a cytoplasmic membrane-localized extracellular DNA sensor of cancer cells,which in turn activates the integrin-linked kinase(ILK)–β-parvin–RAC1–CDC42 cascade to promote metastasis(Fig.1).The clinical importance of CCDC25 was confirmed by Yang et al.,1 and targeting CCDC25 inhibits NET-mediated metastasis in mouse models,suggesting a potential therapeutic strategy to halt the metastasis.
基金This work is supported by the National Key R&D Program of China(No.2019YFA0706100)the National Natural Science Foundation of China(Nos.62074163,61890944,61720106013)the Strategic Priority Research Program of Chinese Academy of Sciences(Nos.XDB30030000,XDB30030300).
文摘A few monolayers of organic semiconductors adjacent to the dielectric layer are of vital importance in organic field-effect transistors due to their dominant role in charge transport.In this report,the 2-nm-thick polymer monolayers based on poly(3-hexylthiophene)with different molecular weights(M_(n))were fabricated using dip-coating technique.During the monolayer(solid state)formation from the solution,a disorder-to-order transition of polymer conformation is observed through UV-vis absorption measurement.Meanwhile,high Mn polymer monolayer generates higher crystalline fibrillar microstructure than the low Mn one due to the strongerπ–πintermolecular packing between polymers.More importantly,the solution aging procedure is utilized to further improve the morphology of polymer monolayers.It is obvious that after aging for 6 d,both fiber dimension and density as well as conjugation length are significantly increased under the same processing conditions in comparison to the fresh solution,and consequently the field-effect mobilities are remarkably enhanced by 2—4 times.Note that the maximum mobility of 0.027 cm2·V^(–1)·s^(–1)is among the highest reported values for poly(3-hexylthiophene)monolayer transistors.These results demonstrate a simple but powerful strategy for boosting the device performance of polymer monolayer transistors.
