Rare-earth metal oxide CeO_(2) with a unique electronic structure has always been one of the popular research materials in the field of catalysis.However,due to its inherent band structure limitations and the recombin...Rare-earth metal oxide CeO_(2) with a unique electronic structure has always been one of the popular research materials in the field of catalysis.However,due to its inherent band structure limitations and the recombination of photo-generated carriers,its photocatalytic performance still needs to be rationally optimized and improved.Here,an in situ assembly method was employed to construct 3 D/2D CeO_(2)/Bi_(2)MoO_(6)(Ce/BMO) S-scheme heterojunctions for enhanced tandem reaction of photocatalytic secondary amines synthesis.Experimental results and density functional theory calculations reveal that the transfer of photo-generated carriers between CeO_(2) and Bi_(2)MoO_(6)(BMO) conforms to the S-scheme heterojunction mechanism which regulates the band structure and greatly promotes the separation and effective utilization of photogenerated carriers.In situ Fourier-transform infrared(in situ FTIR) spectra and adsorption energy calculations demonstrate that the unique Ce^(3+)/Ce^(4+)component in CeO_(2) promotes the nitrobenzene adsorption and the unsaturated Mo sites on Bi_(2)MoO_(6) are responsible for benzyl alcohol adsorption,which is highly favorable for surface oxidation and reduction reactions.Thus,the optimal 0.7-CeO_(2)/Bi_(2)MoO_(6)(0.7Ce/BMO) exhibited a 93%conversion rate of nitrobenzene and a 91% selectivity for secondary amines.This work emphasizes the crucial role of S-scheme heterojunctions for constructing efficient rareearth metal oxide-based composite photocatalysts.展开更多
[Significance]In alignment with the national germplasm security strategy,current research efforts are accelerating the adoption of precision breeding in sheep.Within the whole-genome selection,accurate phenotyping of ...[Significance]In alignment with the national germplasm security strategy,current research efforts are accelerating the adoption of precision breeding in sheep.Within the whole-genome selection,accurate phenotyping of body morphometrics is critical for assessing growth performance and breeding value.Traditional manual measurements are inefficient,prone to human error,and may cause stress to sheep,limiting their suitability for precision sheep management.By summarizing the applications of sheep body size measurement technologies and analyzing their development directions,this paper provides theoretical references and practical guidance for the research and application of non contact sheep body size measurement.[Progress]This review synthesizes progress across three principal methodological paradigms:two-dimensional(2D)image-based techniques,three-dimensional(3D)point cloud-based approaches,and integrated 2D-3D fusion systems.2D methods,employing either handcrafted geometric features or deep learning-based keypoint detector algorithms,are cost-effective and operationally simple but sensitive to variation in imaging conditions and unable to capture critical circumference metrics.3D point-cloud approaches enable precise reconstruction of full animal morphology,supporting comprehensive body-size acquisition with higher accuracy,yet face challenges including high hardware costs,complex data workflows,and sensitivity to posture variability.Hybrid 2D-3D fusion systems combine semantic richness from RGB imagery with geometric completeness from point clouds.Having been effectively validated in other livestock specise,e.g.,cattle and pigs,these fusion systems have demonstrated excellent performance,providing important technical references and practical insights for sheep body size measurement.[Conclusions and Prospects]Firstly,future research should focus on constructing large-scale,high-quality datasets for sheep body size measurement that encompass diverse breeds,growth stages,and environmental conditions,thereby enhancing model robustness and generalization.Secondly,the development of lightweight artificial intelligence models is essential.Techniques such as model compression,quantization,and algorithmic optimization can substantially reduce computational complexity and storage requirements,facilitating deployment in resource-constrained environments.Thirdly,the 3D point cloud processing pipeline should be streamlined to improve the efficiency of data acquisition,filtering,registration,and segmentation,while promoting the integration of low-cost,high-resilience vision systems into practical farming scenarios.Fourthly,specific emphasis should be placed on improving the accuracy of curved-dimensional measurements,such as chest circumference,abdominal circumference,and shank circumference,through advances in pose standardization,refined 3D segmentation strategies,and multimodal data fusion.Finally,the cross-fertilization of sheep body size measurement technologies with analogous methods for other livestock species offers a promising pathway for mutual learning and collaborative innovation,accelerating the industrialization of automated sheep morphometric systems and supporting the development of intelligent,data-driven pasture management practices.展开更多
The introduction of two-dimensional(2D)perovskite layers on top of three-dimensional(3D)perovskite films enhances the performance and stability of perovskite solar cells(PSCs).However,the electronic effect of the spac...The introduction of two-dimensional(2D)perovskite layers on top of three-dimensional(3D)perovskite films enhances the performance and stability of perovskite solar cells(PSCs).However,the electronic effect of the spacer cation and the quality of the 2D capping layer are critical factors in achieving the required results.In this study,we compared two fluorinated salts:4-(trifluoromethyl)benzamidine hydrochloride(4TF-BA·HCl)and 4-fluorobenzamidine hydrochloride(4F-BA·HCl)to engineer the 3D/2D perovskite films.Surprisingly,4F-BA formed a high-performance 3D/2D heterojunction,while4TF-BA produced an amorphous layer on the perovskite films.Our findings indicate that the balanced intramolecular charge polarization,which leads to effective hydrogen bonding,is more favorable in 4F-BA than in 4TF-BA,promoting the formation of a crystalline 2D perovskite.Nevertheless,4TF-BA managed to improve efficiency to 24%,surpassing the control device,primarily due to the natural passivation capabilities of benzamidine.Interestingly,the devices based on 4F-BA demonstrated an efficiency exceeding 25%with greater longevity under various storage conditions compared to 4TF-BA-based and the control devices.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.22402042,22362012,and 22408074)Hainan Provincial Natural Science Foundation of China(No.224QN188)+1 种基金the Innovational Fund for Scientific and Technological Personnel of Hainan Province(No.NHXXRCXM202301)the Collaborative Innovation Center of Ecological Civilization,Hainan University(No.XTCX2022STC11)
文摘Rare-earth metal oxide CeO_(2) with a unique electronic structure has always been one of the popular research materials in the field of catalysis.However,due to its inherent band structure limitations and the recombination of photo-generated carriers,its photocatalytic performance still needs to be rationally optimized and improved.Here,an in situ assembly method was employed to construct 3 D/2D CeO_(2)/Bi_(2)MoO_(6)(Ce/BMO) S-scheme heterojunctions for enhanced tandem reaction of photocatalytic secondary amines synthesis.Experimental results and density functional theory calculations reveal that the transfer of photo-generated carriers between CeO_(2) and Bi_(2)MoO_(6)(BMO) conforms to the S-scheme heterojunction mechanism which regulates the band structure and greatly promotes the separation and effective utilization of photogenerated carriers.In situ Fourier-transform infrared(in situ FTIR) spectra and adsorption energy calculations demonstrate that the unique Ce^(3+)/Ce^(4+)component in CeO_(2) promotes the nitrobenzene adsorption and the unsaturated Mo sites on Bi_(2)MoO_(6) are responsible for benzyl alcohol adsorption,which is highly favorable for surface oxidation and reduction reactions.Thus,the optimal 0.7-CeO_(2)/Bi_(2)MoO_(6)(0.7Ce/BMO) exhibited a 93%conversion rate of nitrobenzene and a 91% selectivity for secondary amines.This work emphasizes the crucial role of S-scheme heterojunctions for constructing efficient rareearth metal oxide-based composite photocatalysts.
文摘[Significance]In alignment with the national germplasm security strategy,current research efforts are accelerating the adoption of precision breeding in sheep.Within the whole-genome selection,accurate phenotyping of body morphometrics is critical for assessing growth performance and breeding value.Traditional manual measurements are inefficient,prone to human error,and may cause stress to sheep,limiting their suitability for precision sheep management.By summarizing the applications of sheep body size measurement technologies and analyzing their development directions,this paper provides theoretical references and practical guidance for the research and application of non contact sheep body size measurement.[Progress]This review synthesizes progress across three principal methodological paradigms:two-dimensional(2D)image-based techniques,three-dimensional(3D)point cloud-based approaches,and integrated 2D-3D fusion systems.2D methods,employing either handcrafted geometric features or deep learning-based keypoint detector algorithms,are cost-effective and operationally simple but sensitive to variation in imaging conditions and unable to capture critical circumference metrics.3D point-cloud approaches enable precise reconstruction of full animal morphology,supporting comprehensive body-size acquisition with higher accuracy,yet face challenges including high hardware costs,complex data workflows,and sensitivity to posture variability.Hybrid 2D-3D fusion systems combine semantic richness from RGB imagery with geometric completeness from point clouds.Having been effectively validated in other livestock specise,e.g.,cattle and pigs,these fusion systems have demonstrated excellent performance,providing important technical references and practical insights for sheep body size measurement.[Conclusions and Prospects]Firstly,future research should focus on constructing large-scale,high-quality datasets for sheep body size measurement that encompass diverse breeds,growth stages,and environmental conditions,thereby enhancing model robustness and generalization.Secondly,the development of lightweight artificial intelligence models is essential.Techniques such as model compression,quantization,and algorithmic optimization can substantially reduce computational complexity and storage requirements,facilitating deployment in resource-constrained environments.Thirdly,the 3D point cloud processing pipeline should be streamlined to improve the efficiency of data acquisition,filtering,registration,and segmentation,while promoting the integration of low-cost,high-resilience vision systems into practical farming scenarios.Fourthly,specific emphasis should be placed on improving the accuracy of curved-dimensional measurements,such as chest circumference,abdominal circumference,and shank circumference,through advances in pose standardization,refined 3D segmentation strategies,and multimodal data fusion.Finally,the cross-fertilization of sheep body size measurement technologies with analogous methods for other livestock species offers a promising pathway for mutual learning and collaborative innovation,accelerating the industrialization of automated sheep morphometric systems and supporting the development of intelligent,data-driven pasture management practices.
基金supported by the National Key Research and Development Programs-Intergovernmental International Cooperation in Science and Technology Innovation Project(Grant No.2022YFE0118400)the Natural Science Foundation of Hunan Province(2023JJ50132)+1 种基金Shenzhen Science and Technology Innovation Committee(Grants Nos.JCYJ20220818100211025,and KCXST20221021111616039)Shenzhen Science and Technology Program(No.20231128110928003)。
文摘The introduction of two-dimensional(2D)perovskite layers on top of three-dimensional(3D)perovskite films enhances the performance and stability of perovskite solar cells(PSCs).However,the electronic effect of the spacer cation and the quality of the 2D capping layer are critical factors in achieving the required results.In this study,we compared two fluorinated salts:4-(trifluoromethyl)benzamidine hydrochloride(4TF-BA·HCl)and 4-fluorobenzamidine hydrochloride(4F-BA·HCl)to engineer the 3D/2D perovskite films.Surprisingly,4F-BA formed a high-performance 3D/2D heterojunction,while4TF-BA produced an amorphous layer on the perovskite films.Our findings indicate that the balanced intramolecular charge polarization,which leads to effective hydrogen bonding,is more favorable in 4F-BA than in 4TF-BA,promoting the formation of a crystalline 2D perovskite.Nevertheless,4TF-BA managed to improve efficiency to 24%,surpassing the control device,primarily due to the natural passivation capabilities of benzamidine.Interestingly,the devices based on 4F-BA demonstrated an efficiency exceeding 25%with greater longevity under various storage conditions compared to 4TF-BA-based and the control devices.
