A multi-physics approach was used to quantify the effect of process parameters (laser power, scanning speed, hatch spacing, and scanning strategy) on the thermal history and corresponding microstructure evolution of T...A multi-physics approach was used to quantify the effect of process parameters (laser power, scanning speed, hatch spacing, and scanning strategy) on the thermal history and corresponding microstructure evolution of Ti-25Nb (at%) alloy during the dual-track selective laser melting (SLM) process. Simulation results reveal that during the dual-track SLM process, increasing laser power results in greater thermal accumulation, leading to a molten pool of larger volume and coarser grains. Reducing scanning speed enhances remelting and promotes cellular growth at the top of molten pool, whereas faster scanning speed leads to rougher melt tracks and finer grains. Notably, hatch spacing significantly influences the molten pool dimensions and microstructures, and smaller hatch spacing promotes remelting. Furthermore, the orientations of grains in the second track during zigzag scanning differ markedly from those in the first track. More importantly, compared with those after the first track, both the temperature gradient and cooling rate at the boundaries of remelting molten pool are reduced after the second track scanning, resulting in slower interface velocity and significant change in solidification microstructure. This research provides a theoretical foundation for controlling non-equilibrium microstructure and offering novel insights into the optimization of SLM process parameters of titanium alloys.展开更多
Background:Infectious disease control has historically functioned as a critical intersection of biological survival and social organization.For centuries,humanity relied on empirical defenses such as quarantine and en...Background:Infectious disease control has historically functioned as a critical intersection of biological survival and social organization.For centuries,humanity relied on empirical defenses such as quarantine and environmental sanitation.However,the theoretical foundation of prevention has shifted significantly toward biomedical sciences,including microbiology,immunology,and molecular biology.Methods:Using a public health history framework,this review synthesizes data from academic archives,monographs,and policy documents.We examined key case studies-Plague,Cholera,Influenza,HIV/AIDS,and COVID-19-to map the technological and institutional evolution of disease management.Results:We locate the primary historical turning point in the 19th century.It was here that control strategies evolved from crude population mandates into precise biomedical interventions.The synthesis of sanitary reform and germ theory catalyzed this era of scientific progress.Following the standardization of vaccines and antibiotics,the focus shifted to chronic management during the HIV/AIDS crisis.Contemporary tools like mRNA platforms and genomic surveillance continue this lineage,yet their practical application remains uneven globally.Conclusion:We conclude that biomedical breakthroughs are necessary but insufficient for security.Effective defense requires coupling scientific tools with resilient infrastructure and global health coordination to resolve systemic inequities.展开更多
Quantifying the timing and amplitude of multiple subsidence or uplift stages in sedimentary basins is crucial for understanding their tectonic evolution.In this study,18 samples from 10 drilling wells in the Pearl Riv...Quantifying the timing and amplitude of multiple subsidence or uplift stages in sedimentary basins is crucial for understanding their tectonic evolution.In this study,18 samples from 10 drilling wells in the Pearl River Mouth Basin(PRMB)were subjected to apatite and zircon fission track analyses,and suitable samples were selected for thermal history simulation using Hefty.The thermal history simulation results,combined with balanced cross-section analysis,constrain the Cenozoic tectonothermal history of the PRMB.The results indicate that the PRMB underwent differential uplift in the early Paleogene,followed by regional thermal subsidence in the late Paleogene.Subsequently,the PRMB began tectonic activation in the late Miocene due to the Dongsha movement,marked by two rapid cooling events of ca.11–6.5 and 6.5 Myr to the present.These cooling events are characterized by a gradual migration from east to west.The first rapid cooling event can be attributed to the NW-SE compressive stress field in the northeastern South China Sea,driven by the clockwise rotation of the Philippine Sea Plate during the late Miocene.The second rapid cooling event is linked to intensive arc-continental collision and the Taiwan Orogeny triggered by the rapid WNW-ward migration of the Philippine Sea Plate.展开更多
Background:With the rapid development of modern emerging technologies,the ethical dilemmas and social controversies triggered by scientific and technological activities have become increasingly prominent.How to guide ...Background:With the rapid development of modern emerging technologies,the ethical dilemmas and social controversies triggered by scientific and technological activities have become increasingly prominent.How to guide technology for good and prevent and control technological risks has become an important issue of global concern.Research on science and technology ethics is dedicated to integrating ethical theories into governance practices and constructing ethical models that adapt to the development of the times.Methods:This article systematically reviews the six core approaches of scientific and technological ethics thought,including technological autonomy and political philosophy criticism,responsibility ethics and intergenerational obligations,technological intermediation and the integration of life and the world,ethical principles and normative frameworks,participatory governance and ethical practice innovation,as well as domain-specific ethical norms,thereby constructing an ethical analysis framework applicable to medical technology risks.And cross-analysis was conducted by taking medical events such as gene editing and xenotransplantation as examples.Results:Research shows that a single ethical approach has limitations in addressing complex medical ethical challenges,while the six approaches are complementary and synergistic.By criticizing technological autonomy,establishing a responsibility ethics orientation,setting the bottom line of ethical principles,promoting participatory governance,formulating domain norms,and continuously reflecting on the intermediary nature of technology,a multi-level and dynamically adaptive governance system for scientific and technological ethics can be constructed.Conclusion:The key to addressing contemporary medical ethics challenges lies in the comprehensive application of science and technology ethics theories and the integration of ethical considerations throughout the entire process of scientific and technological research and development.In the future,a governance framework that adapts to the development of new technologies should be established to promote cross-cultural and cross-disciplinary ethical dialogue and public participation,ensuring that scientific and technological innovation always serves the dignity of human life and overall well-being.展开更多
The influence of oscillation amplitude on molten pool thermal history,weld morphology characteristics,microstructural evolution,and mechanical properties during laser oscillating welding of QP980 steel was systematica...The influence of oscillation amplitude on molten pool thermal history,weld morphology characteristics,microstructural evolution,and mechanical properties during laser oscillating welding of QP980 steel was systematically investigated.Results show that laser beam oscillation significantly regulates molten pool thermomechanical behavior through optimized spatial energy distribution,thereby enabling microstructural reconstruction and joint performance enhancement.As the oscillation amplitude increases from 0 to 0.8 mm,the molten pool duration extends to 1.7 times the original value,while peak temperature and average cooling rate decrease by 19%and 39%,respectively.This thermal regulation promotes weld surface width expansion from 0.72 to 1.07 mm.The welding mode undergoes a progressive transition from keyhole mode→transitional mode→conduction mode.This transformation effectively suppresses porosity defects,substantially reducing porosity from 1.8%to 0.15%.Microstructural analysis indicates that oscillation modifies the maximum temperature gradient direction within the molten pool,facilitating preferential growth of coarse columnar grains along the welding centerline to establish load-transfer-favorable crystallographic orientations.The synergistic effects of these factors substantially improve joint mechanical properties:lap joint shear load increases by 81.5%(7.6→13.8 kN),and fracture elongation is enhanced by 135%(0.98→2.3 mm).The operational principles of laser oscillation parameters on the welding quality of QP980 steel were elucidated,providing theoretical foundations for joining process optimization.展开更多
Knowing about the far away past is something teenagers are not interested in.They prefer to deal with the present time,their present interactions,and their present life.When they study history of the past,they most of...Knowing about the far away past is something teenagers are not interested in.They prefer to deal with the present time,their present interactions,and their present life.When they study history of the past,they most often do it just to have good grades,not for a personal interest.But this condition can be changed,their interests can be enlarged,so as to include what happened centuries ago,and this can be done with educational proposals that appear to them fun,involving and different from the usual school routines.Over the years,the author has proposed several educational activities that captured the interest and motivated teenagers to put themselves in another time period and understand what happened.The following projects show not only how to make them curious about what happened in the far away past,but through that understanding,know more about themselves,to see themselves as individuals who are able to make a difference also in the present and future times.展开更多
Background:The advent of the self-media age,digital humanities,and artificial intelligence(AI)technologies is gradually reshaping the narrative frameworks of the history of science and technology in general and the hi...Background:The advent of the self-media age,digital humanities,and artificial intelligence(AI)technologies is gradually reshaping the narrative frameworks of the history of science and technology in general and the history of medicine in particular,as it transforms the specific shape of contemporary medical science and health communication practice with the help of interactive,scenario-based communication ecosystems.Methods:This paper focuses on the interactive relationship between the history of science and science communication,employing historical tracing and case study comparison as research methods to explore the pathways and innovative models for reintegrating the history of science and technology including the history of medicine into contemporary scientific discourse.Results:The study finds that in the Chinese context,three key pathways facilitate the engagement of the history of science and technology including the history of medicine in science communication:administrative intervention,value reconstruction,and personalized adaptation.Specifically,administrative intervention promotes the integration of the history of science education into talent development through policy design;value reconstruction,centered on the scientific spirit,enhances societal cultural recognition of technological progress;and personalized adaptation leverages big data and social media technologies to enable precise and tailored knowledge dissemination.Conclusion:The rise of the“web-based knowledge brokering model”in the era of social media has introduced professional knowledge brokers,ensuring the accuracy and accessibility of science communication.These innovations not only serve as decision-making simulation tools for medical science and health communication,linking historical insights with contemporary practice,but also provide theoretical foundations and practical paradigms for realizing the value of the history of science and technology in the digital era.展开更多
0 INTRODUTION The Kuqa Depression,situated along the northern margin of the Tarim Basin,holds substantial geological significance due to its intricate sedimentary burial history,tectonic history,and the evolution of h...0 INTRODUTION The Kuqa Depression,situated along the northern margin of the Tarim Basin,holds substantial geological significance due to its intricate sedimentary burial history,tectonic history,and the evolution of hydrocarbon source rocks(Jiang et al.,2024;Zhang et al.,2023;Huang et al.,2019;Yang et al.,2017;Jia et al.,2003;Hendrix,2000).展开更多
There is a close intertextual and symbiotic relationship between music and history in cultural inheritance.Aiming at the deficiencies of existing research in the combination of theory and practice and from a cultural ...There is a close intertextual and symbiotic relationship between music and history in cultural inheritance.Aiming at the deficiencies of existing research in the combination of theory and practice and from a cultural perspective,this paper deeply analyzes the relationship between the two from a multidisciplinary perspective.The historical context influences musical expression at the material,institutional,and spiritual levels.Musical expression reflects the historical context through the encoding of formal structures and symbolic meanings.Cultural significance is generated in the educational field through historical decoding,contemporary interpretation,and meaning reconstruction.These three elements form a dynamic mutual construction and an educational and cultural cycle,providing a theoretical basis for the cultivation of cultural understanding ability in interdisciplinary teaching.In the future,it can be expanded in the directions such as neuro-experiments,the application of digital humanities technologies,and the comparison of different cultural contexts,so as to promote the development of humanistic education.展开更多
It is one of the must-visit history museums,known for its vast collection of historical artifacts,attracting around three million domestic and international visitors each year.THE Shaanxi History Museum(SHM),in the re...It is one of the must-visit history museums,known for its vast collection of historical artifacts,attracting around three million domestic and international visitors each year.THE Shaanxi History Museum(SHM),in the renowned historic city of Xi’an in Shaanxi Province,is often regarded as one of the museums most difficult to get a ticket to in China.Each day,approximately 12,000 free online tickets are made available and are fully booked within just a couple of minutes.Its vast collection of treasured relics and numerous national treasures leave visitors in awe.展开更多
Grapevine is unique among crops because its domestication resulted not only in new morphological characteristics,but also in altered reproductive mechanisms.Viticulture involves a change from a dioecious to a hermaphr...Grapevine is unique among crops because its domestication resulted not only in new morphological characteristics,but also in altered reproductive mechanisms.Viticulture involves a change from a dioecious to a hermaphroditic mating system,which makes the reproductive system more efficient.In consequence and the fact that it is one of the oldest and most economically important cultivated plants,Vitis vinifera could be defined as an over-domesticated species.Here we review some key aspects in viticulture.The main areas of interest have remained consistent throughout history,including the origin and characterisation of cultivars,resistance to environmental con-ditions,pests and pathogens,and berry quality.Advances in genomic analysis and epigenetics shed new light on these aspects.Although the vine has a long and complex life cycle,recent haplotype sequencing techniques allow genomic characteristics related to different reproduction processes to be identified.Recent work on haplotype sequencing reveals genomic changes accompanying each reproductive type,providing improved detail about the sex-determining region(SDR).Meanwhile,the application of epigenetic analysis offers new tools for defining varietal characteristics and their responses to changing environmental conditions.However,critical issues,such as differentiating between sylvestris and feral cultivars,remain unclear.Understanding the molecular basis of morphological differences and investigating the epigenetic regulation of gene expression and genome dynamics in response to breeding and environmental factors in this species will be crucial.Seed morphology could help to resolve how to differentiate between wild and feral plants.展开更多
On September 3,2025,heads turned to Beijing for a grand military parade marking the 80th anniversary of the victory in the Chinese People’s War of Resistance Against Japanese Aggression and the World Anti-Fascist War...On September 3,2025,heads turned to Beijing for a grand military parade marking the 80th anniversary of the victory in the Chinese People’s War of Resistance Against Japanese Aggression and the World Anti-Fascist War.Such events often highlight military strength,but this commemoration sought to project a deeper message:remembrance of sacrifice,recognition of the immense costs of conflict,and a renewed commitment to peace.展开更多
Gas chromatography-mass spectrometry(GC-MS)was used to analyze the pentacyclic triterpenoid distributions,specifically hopane and oleanane fingerprints,in 24 crude oil samples from the Niger Delta depobelts,with the a...Gas chromatography-mass spectrometry(GC-MS)was used to analyze the pentacyclic triterpenoid distributions,specifically hopane and oleanane fingerprints,in 24 crude oil samples from the Niger Delta depobelts,with the aim of defining the petroleum system,filling history,and the age of source rock producing these oils.The results indicate that the Niger Delta oils belong to a single fluvio-deltaic petroleum system,reflecting similar source organic facies and depositional environments.Geochemical parameters,including C29/C30hopane ratios,oleanane index,Ts/Tm,(Ts/(Ts+Tm)),moretane/C30hopane ratios,and C3222S/(22S+22R)ratios,suggest oxic conditions during source rock deposition and thermal maturity of the oils.The presence of terrigenous organic matter and complex filling history are also evident and influenced by multiple phases of sedimentation,and petroleum generation.A comparative plot of geologic time(Paleogene-Neogene age)and oleanane percentage composition show that the crude oils are constrained to the chronostratigraphic ages of their respective depobelts,demonstrating the potential of oleanane-derived parameters for relative dating of hydrocarbon sources,complementing traditional index fossil methods.展开更多
On May 7,2025,Chinese President Xi Jinping published a signed article titled"Learning from History to Build Together a Brighter Future"in Russian newspaper Gazette ahead of his arrival in Moscow for a state ...On May 7,2025,Chinese President Xi Jinping published a signed article titled"Learning from History to Build Together a Brighter Future"in Russian newspaper Gazette ahead of his arrival in Moscow for a state visit to Russia and attendance at the celebration marking the 80th anniversary of the Victory in the Soviet Union's Great Patriotic War.展开更多
Yunnan in southwest China is a geographically and ethnically complex region at the intersection of southern China and Southeast Asia,and a focal point for human migrations.To clarify its maternal genetic history,we ge...Yunnan in southwest China is a geographically and ethnically complex region at the intersection of southern China and Southeast Asia,and a focal point for human migrations.To clarify its maternal genetic history,we generated 152 complete mitogenomes from 17 Yunnan archaeological sites.Our results reveal distinct genetic histories segregated by geographical regions.Maternal lineages of ancient populations from northwestern and northern Yunnan exhibit closer affinities with past and present-day populations from northern East Asia and Xizang,providing important genetic evidence for the migration and interaction of populations along the Tibetan-Yi corridor since the Neolithic.Between 5500 and 1800 years ago,central Yunnan populations maintained their internal genetic relationships,including a 7000-year-old basal lineage of the rare and widely dispersed haplogroup M61.At the Xingyi site,changes in mitochondrial DNA haplogroups occurred between the Late Neolithic and Bronze Age,with haplogroups shifting from those predominant in the Yellow River region to those predominant in coastal southern China.These results highlight the high diversity of Yunnan populations during the Neolithic to Bronze Age.展开更多
From a very early period,the Chinese already vaguely sensed that the cultivation of crops required an intricate system.The third century BCE work Master Lü’s Spring and Autumn Annals(Lüshi chunqiu吕氏春秋)s...From a very early period,the Chinese already vaguely sensed that the cultivation of crops required an intricate system.The third century BCE work Master Lü’s Spring and Autumn Annals(Lüshi chunqiu吕氏春秋)states that crops were fed by heaven and raised by earth,and that harvests depended on the farmers who worked the land.Therefore,these three elements,that is,heaven,earth,and farmers,together with crops,jointly constituted a complex community.According to the ancient Chinese,moving a crop away from its native place could bring huge benefits to the new area to which the crop was moved.When writing and compiling Fundamentals of Agriculture and Sericulture(Nongsang jiyao农桑辑要),the officials of the Agricultural Extension Bureau司农司in the Yuan dynasty(1271–1368)excitedly noted the changes brought about by non-native crops to the agriculture of the Central Plains of China中原:“Ramie(Boehmeria nivea)is a crop native to southern China,while cotton(Gossypium herbaceum)comes from the Western Regions西域.In recent years,nevertheless,ramie has been introduced to Henan,while cotton has started to be planted in Shaanxi.The two crops thrive and show no difference from local crops.Farmers in the two regions benefit a lot therefrom”(Agricultural Extension Bureau 1888,juan 2:21).展开更多
Chic Beijing:An Insider’s Guide to Unique New Places Compiled by Beijing Radio and Television Station Price:RMB 138 Paperback,307 pages Published by Foreign Languages Press&Beijing Publishing Group If you’re pla...Chic Beijing:An Insider’s Guide to Unique New Places Compiled by Beijing Radio and Television Station Price:RMB 138 Paperback,307 pages Published by Foreign Languages Press&Beijing Publishing Group If you’re planning a trip to Beijing,prepare to be swept up in a living mosaic–more than 3,000 years of history,vibrant contemporary culture,and skyline-defining architecture all fusing and flowing across a vast canvas.This book,Chic Beijing:An Insider’s Guide to Unique New Places,allows readers to take a breathtaking journey through Beijing,the majestic metropolitan capital of China.It also unlocks doors that usually stay closed:rooftop gardens overlooking palace rooftops,micro-galleries tucked into 300-year-old courtyards,and cocktail labs where baijiu meets coffee.展开更多
This concise paper,delivered at a conference,addresses a broad topic with the goal of providing a condensed and inevitably subjective perspective.Initially,it outlines the primary characteristics that distinguish coin...This concise paper,delivered at a conference,addresses a broad topic with the goal of providing a condensed and inevitably subjective perspective.Initially,it outlines the primary characteristics that distinguish coins from other historical sources.Subsequently,it provides a succinct overview of numismatics,categorized into seven phases:1.Pre-1550(coins as reflections of vice and virtue);2.From circa 1550 to circa 1620(coins as testimony of authentic history);3.From circa 1650 to circa 1730(the heyday of the“Republic of Medals”);4.From circa 1730 to circa 1840(the decline of the“Republic of Medals”and the emergence of scientific practices by Viennese Jesuits);5.From circa 1840 to circa 1940(die-studies and art history);6.From circa 1940 to circa 2000(coins as instruments of exchange);7.Since 2000(cultural shift and digital humanities).展开更多
基金Guangdong Basic and Applied Basic Research Foundation (2024A1515011873)Shenzhen Basic Research Project (JCYJ20241202123504007)Shenzhen Science and Technology Innovation Commission (KJZD20240903101400001, KJZD20240903102006009)。
文摘A multi-physics approach was used to quantify the effect of process parameters (laser power, scanning speed, hatch spacing, and scanning strategy) on the thermal history and corresponding microstructure evolution of Ti-25Nb (at%) alloy during the dual-track selective laser melting (SLM) process. Simulation results reveal that during the dual-track SLM process, increasing laser power results in greater thermal accumulation, leading to a molten pool of larger volume and coarser grains. Reducing scanning speed enhances remelting and promotes cellular growth at the top of molten pool, whereas faster scanning speed leads to rougher melt tracks and finer grains. Notably, hatch spacing significantly influences the molten pool dimensions and microstructures, and smaller hatch spacing promotes remelting. Furthermore, the orientations of grains in the second track during zigzag scanning differ markedly from those in the first track. More importantly, compared with those after the first track, both the temperature gradient and cooling rate at the boundaries of remelting molten pool are reduced after the second track scanning, resulting in slower interface velocity and significant change in solidification microstructure. This research provides a theoretical foundation for controlling non-equilibrium microstructure and offering novel insights into the optimization of SLM process parameters of titanium alloys.
基金supported by the National Key Research and Development Program(Grant No.2024YFA0917200)the Projects of the Chinese Center for Disease Control and Prevention(Grant No.BB2110240090)World Medical History under the Education Innovation Plan of the University of Science and Technology of China(Grant No.2024YCHX07).
文摘Background:Infectious disease control has historically functioned as a critical intersection of biological survival and social organization.For centuries,humanity relied on empirical defenses such as quarantine and environmental sanitation.However,the theoretical foundation of prevention has shifted significantly toward biomedical sciences,including microbiology,immunology,and molecular biology.Methods:Using a public health history framework,this review synthesizes data from academic archives,monographs,and policy documents.We examined key case studies-Plague,Cholera,Influenza,HIV/AIDS,and COVID-19-to map the technological and institutional evolution of disease management.Results:We locate the primary historical turning point in the 19th century.It was here that control strategies evolved from crude population mandates into precise biomedical interventions.The synthesis of sanitary reform and germ theory catalyzed this era of scientific progress.Following the standardization of vaccines and antibiotics,the focus shifted to chronic management during the HIV/AIDS crisis.Contemporary tools like mRNA platforms and genomic surveillance continue this lineage,yet their practical application remains uneven globally.Conclusion:We conclude that biomedical breakthroughs are necessary but insufficient for security.Effective defense requires coupling scientific tools with resilient infrastructure and global health coordination to resolve systemic inequities.
基金funded by the National Natural Science Foundation of China(Nos.42121005,92358302,42302233)the Science and Technology Innovation Project of Laoshan Laboratory(No.LSKJ202204400)the Fundamental Research Funds for the Central Universities(No.202172003)。
文摘Quantifying the timing and amplitude of multiple subsidence or uplift stages in sedimentary basins is crucial for understanding their tectonic evolution.In this study,18 samples from 10 drilling wells in the Pearl River Mouth Basin(PRMB)were subjected to apatite and zircon fission track analyses,and suitable samples were selected for thermal history simulation using Hefty.The thermal history simulation results,combined with balanced cross-section analysis,constrain the Cenozoic tectonothermal history of the PRMB.The results indicate that the PRMB underwent differential uplift in the early Paleogene,followed by regional thermal subsidence in the late Paleogene.Subsequently,the PRMB began tectonic activation in the late Miocene due to the Dongsha movement,marked by two rapid cooling events of ca.11–6.5 and 6.5 Myr to the present.These cooling events are characterized by a gradual migration from east to west.The first rapid cooling event can be attributed to the NW-SE compressive stress field in the northeastern South China Sea,driven by the clockwise rotation of the Philippine Sea Plate during the late Miocene.The second rapid cooling event is linked to intensive arc-continental collision and the Taiwan Orogeny triggered by the rapid WNW-ward migration of the Philippine Sea Plate.
基金supported by the National Key Research and Development Program(Grant No.2024YFA0917200)the Projects of the Chinese Center for Disease Control and Prevention(Grant No.BB2110240093)World Medical History under the Education Innovation Plan of the University of Science and Technology of China(Grant No.2024YCHX07).
文摘Background:With the rapid development of modern emerging technologies,the ethical dilemmas and social controversies triggered by scientific and technological activities have become increasingly prominent.How to guide technology for good and prevent and control technological risks has become an important issue of global concern.Research on science and technology ethics is dedicated to integrating ethical theories into governance practices and constructing ethical models that adapt to the development of the times.Methods:This article systematically reviews the six core approaches of scientific and technological ethics thought,including technological autonomy and political philosophy criticism,responsibility ethics and intergenerational obligations,technological intermediation and the integration of life and the world,ethical principles and normative frameworks,participatory governance and ethical practice innovation,as well as domain-specific ethical norms,thereby constructing an ethical analysis framework applicable to medical technology risks.And cross-analysis was conducted by taking medical events such as gene editing and xenotransplantation as examples.Results:Research shows that a single ethical approach has limitations in addressing complex medical ethical challenges,while the six approaches are complementary and synergistic.By criticizing technological autonomy,establishing a responsibility ethics orientation,setting the bottom line of ethical principles,promoting participatory governance,formulating domain norms,and continuously reflecting on the intermediary nature of technology,a multi-level and dynamically adaptive governance system for scientific and technological ethics can be constructed.Conclusion:The key to addressing contemporary medical ethics challenges lies in the comprehensive application of science and technology ethics theories and the integration of ethical considerations throughout the entire process of scientific and technological research and development.In the future,a governance framework that adapts to the development of new technologies should be established to promote cross-cultural and cross-disciplinary ethical dialogue and public participation,ensuring that scientific and technological innovation always serves the dignity of human life and overall well-being.
基金supported by the National Natural Science Foundation of China(Grant Nos.51805084 and 52474401)Guangdong Basic and Applied Basic Research Foundation(Grant Nos.2023B1515120086 and 2025A1515012873).
文摘The influence of oscillation amplitude on molten pool thermal history,weld morphology characteristics,microstructural evolution,and mechanical properties during laser oscillating welding of QP980 steel was systematically investigated.Results show that laser beam oscillation significantly regulates molten pool thermomechanical behavior through optimized spatial energy distribution,thereby enabling microstructural reconstruction and joint performance enhancement.As the oscillation amplitude increases from 0 to 0.8 mm,the molten pool duration extends to 1.7 times the original value,while peak temperature and average cooling rate decrease by 19%and 39%,respectively.This thermal regulation promotes weld surface width expansion from 0.72 to 1.07 mm.The welding mode undergoes a progressive transition from keyhole mode→transitional mode→conduction mode.This transformation effectively suppresses porosity defects,substantially reducing porosity from 1.8%to 0.15%.Microstructural analysis indicates that oscillation modifies the maximum temperature gradient direction within the molten pool,facilitating preferential growth of coarse columnar grains along the welding centerline to establish load-transfer-favorable crystallographic orientations.The synergistic effects of these factors substantially improve joint mechanical properties:lap joint shear load increases by 81.5%(7.6→13.8 kN),and fracture elongation is enhanced by 135%(0.98→2.3 mm).The operational principles of laser oscillation parameters on the welding quality of QP980 steel were elucidated,providing theoretical foundations for joining process optimization.
文摘Knowing about the far away past is something teenagers are not interested in.They prefer to deal with the present time,their present interactions,and their present life.When they study history of the past,they most often do it just to have good grades,not for a personal interest.But this condition can be changed,their interests can be enlarged,so as to include what happened centuries ago,and this can be done with educational proposals that appear to them fun,involving and different from the usual school routines.Over the years,the author has proposed several educational activities that captured the interest and motivated teenagers to put themselves in another time period and understand what happened.The following projects show not only how to make them curious about what happened in the far away past,but through that understanding,know more about themselves,to see themselves as individuals who are able to make a difference also in the present and future times.
基金The National Key R&D project granted by the Ministry of Science and Technology(2024YFA0917200)Digital Museum Construction Project of Chinese Centre for Disease Control and Prevention(BB2110240080)Science Communication Project of Chinese Academy of Sciences(CX2090000008).
文摘Background:The advent of the self-media age,digital humanities,and artificial intelligence(AI)technologies is gradually reshaping the narrative frameworks of the history of science and technology in general and the history of medicine in particular,as it transforms the specific shape of contemporary medical science and health communication practice with the help of interactive,scenario-based communication ecosystems.Methods:This paper focuses on the interactive relationship between the history of science and science communication,employing historical tracing and case study comparison as research methods to explore the pathways and innovative models for reintegrating the history of science and technology including the history of medicine into contemporary scientific discourse.Results:The study finds that in the Chinese context,three key pathways facilitate the engagement of the history of science and technology including the history of medicine in science communication:administrative intervention,value reconstruction,and personalized adaptation.Specifically,administrative intervention promotes the integration of the history of science education into talent development through policy design;value reconstruction,centered on the scientific spirit,enhances societal cultural recognition of technological progress;and personalized adaptation leverages big data and social media technologies to enable precise and tailored knowledge dissemination.Conclusion:The rise of the“web-based knowledge brokering model”in the era of social media has introduced professional knowledge brokers,ensuring the accuracy and accessibility of science communication.These innovations not only serve as decision-making simulation tools for medical science and health communication,linking historical insights with contemporary practice,but also provide theoretical foundations and practical paradigms for realizing the value of the history of science and technology in the digital era.
基金supported by the National Key Research and Development Project(No.2019YFA0708601)the National Natural Science Foundation of China(No.4231101056)the Chinese Academy of Geological Sciences Basic Research Fund(No.JKYZD202402)。
文摘0 INTRODUTION The Kuqa Depression,situated along the northern margin of the Tarim Basin,holds substantial geological significance due to its intricate sedimentary burial history,tectonic history,and the evolution of hydrocarbon source rocks(Jiang et al.,2024;Zhang et al.,2023;Huang et al.,2019;Yang et al.,2017;Jia et al.,2003;Hendrix,2000).
文摘There is a close intertextual and symbiotic relationship between music and history in cultural inheritance.Aiming at the deficiencies of existing research in the combination of theory and practice and from a cultural perspective,this paper deeply analyzes the relationship between the two from a multidisciplinary perspective.The historical context influences musical expression at the material,institutional,and spiritual levels.Musical expression reflects the historical context through the encoding of formal structures and symbolic meanings.Cultural significance is generated in the educational field through historical decoding,contemporary interpretation,and meaning reconstruction.These three elements form a dynamic mutual construction and an educational and cultural cycle,providing a theoretical basis for the cultivation of cultural understanding ability in interdisciplinary teaching.In the future,it can be expanded in the directions such as neuro-experiments,the application of digital humanities technologies,and the comparison of different cultural contexts,so as to promote the development of humanistic education.
文摘It is one of the must-visit history museums,known for its vast collection of historical artifacts,attracting around three million domestic and international visitors each year.THE Shaanxi History Museum(SHM),in the renowned historic city of Xi’an in Shaanxi Province,is often regarded as one of the museums most difficult to get a ticket to in China.Each day,approximately 12,000 free online tickets are made available and are fully booked within just a couple of minutes.Its vast collection of treasured relics and numerous national treasures leave visitors in awe.
文摘Grapevine is unique among crops because its domestication resulted not only in new morphological characteristics,but also in altered reproductive mechanisms.Viticulture involves a change from a dioecious to a hermaphroditic mating system,which makes the reproductive system more efficient.In consequence and the fact that it is one of the oldest and most economically important cultivated plants,Vitis vinifera could be defined as an over-domesticated species.Here we review some key aspects in viticulture.The main areas of interest have remained consistent throughout history,including the origin and characterisation of cultivars,resistance to environmental con-ditions,pests and pathogens,and berry quality.Advances in genomic analysis and epigenetics shed new light on these aspects.Although the vine has a long and complex life cycle,recent haplotype sequencing techniques allow genomic characteristics related to different reproduction processes to be identified.Recent work on haplotype sequencing reveals genomic changes accompanying each reproductive type,providing improved detail about the sex-determining region(SDR).Meanwhile,the application of epigenetic analysis offers new tools for defining varietal characteristics and their responses to changing environmental conditions.However,critical issues,such as differentiating between sylvestris and feral cultivars,remain unclear.Understanding the molecular basis of morphological differences and investigating the epigenetic regulation of gene expression and genome dynamics in response to breeding and environmental factors in this species will be crucial.Seed morphology could help to resolve how to differentiate between wild and feral plants.
文摘On September 3,2025,heads turned to Beijing for a grand military parade marking the 80th anniversary of the victory in the Chinese People’s War of Resistance Against Japanese Aggression and the World Anti-Fascist War.Such events often highlight military strength,but this commemoration sought to project a deeper message:remembrance of sacrifice,recognition of the immense costs of conflict,and a renewed commitment to peace.
文摘Gas chromatography-mass spectrometry(GC-MS)was used to analyze the pentacyclic triterpenoid distributions,specifically hopane and oleanane fingerprints,in 24 crude oil samples from the Niger Delta depobelts,with the aim of defining the petroleum system,filling history,and the age of source rock producing these oils.The results indicate that the Niger Delta oils belong to a single fluvio-deltaic petroleum system,reflecting similar source organic facies and depositional environments.Geochemical parameters,including C29/C30hopane ratios,oleanane index,Ts/Tm,(Ts/(Ts+Tm)),moretane/C30hopane ratios,and C3222S/(22S+22R)ratios,suggest oxic conditions during source rock deposition and thermal maturity of the oils.The presence of terrigenous organic matter and complex filling history are also evident and influenced by multiple phases of sedimentation,and petroleum generation.A comparative plot of geologic time(Paleogene-Neogene age)and oleanane percentage composition show that the crude oils are constrained to the chronostratigraphic ages of their respective depobelts,demonstrating the potential of oleanane-derived parameters for relative dating of hydrocarbon sources,complementing traditional index fossil methods.
文摘On May 7,2025,Chinese President Xi Jinping published a signed article titled"Learning from History to Build Together a Brighter Future"in Russian newspaper Gazette ahead of his arrival in Moscow for a state visit to Russia and attendance at the celebration marking the 80th anniversary of the Victory in the Soviet Union's Great Patriotic War.
基金supported by the National Natural Science Foundation of China(41925009)National Key R&D Program of China(2022YFE0203800)+2 种基金the Ministry of Finance of the People’s Republic of China(YSBR-019)Science and Technology Innovation Team of Shaanxi Province(2024RS-CXTD-74)Xiaohong Wu was supported by the Key National Social Science Foundation of China(No.16ZDA144).
文摘Yunnan in southwest China is a geographically and ethnically complex region at the intersection of southern China and Southeast Asia,and a focal point for human migrations.To clarify its maternal genetic history,we generated 152 complete mitogenomes from 17 Yunnan archaeological sites.Our results reveal distinct genetic histories segregated by geographical regions.Maternal lineages of ancient populations from northwestern and northern Yunnan exhibit closer affinities with past and present-day populations from northern East Asia and Xizang,providing important genetic evidence for the migration and interaction of populations along the Tibetan-Yi corridor since the Neolithic.Between 5500 and 1800 years ago,central Yunnan populations maintained their internal genetic relationships,including a 7000-year-old basal lineage of the rare and widely dispersed haplogroup M61.At the Xingyi site,changes in mitochondrial DNA haplogroups occurred between the Late Neolithic and Bronze Age,with haplogroups shifting from those predominant in the Yellow River region to those predominant in coastal southern China.These results highlight the high diversity of Yunnan populations during the Neolithic to Bronze Age.
文摘From a very early period,the Chinese already vaguely sensed that the cultivation of crops required an intricate system.The third century BCE work Master Lü’s Spring and Autumn Annals(Lüshi chunqiu吕氏春秋)states that crops were fed by heaven and raised by earth,and that harvests depended on the farmers who worked the land.Therefore,these three elements,that is,heaven,earth,and farmers,together with crops,jointly constituted a complex community.According to the ancient Chinese,moving a crop away from its native place could bring huge benefits to the new area to which the crop was moved.When writing and compiling Fundamentals of Agriculture and Sericulture(Nongsang jiyao农桑辑要),the officials of the Agricultural Extension Bureau司农司in the Yuan dynasty(1271–1368)excitedly noted the changes brought about by non-native crops to the agriculture of the Central Plains of China中原:“Ramie(Boehmeria nivea)is a crop native to southern China,while cotton(Gossypium herbaceum)comes from the Western Regions西域.In recent years,nevertheless,ramie has been introduced to Henan,while cotton has started to be planted in Shaanxi.The two crops thrive and show no difference from local crops.Farmers in the two regions benefit a lot therefrom”(Agricultural Extension Bureau 1888,juan 2:21).
文摘Chic Beijing:An Insider’s Guide to Unique New Places Compiled by Beijing Radio and Television Station Price:RMB 138 Paperback,307 pages Published by Foreign Languages Press&Beijing Publishing Group If you’re planning a trip to Beijing,prepare to be swept up in a living mosaic–more than 3,000 years of history,vibrant contemporary culture,and skyline-defining architecture all fusing and flowing across a vast canvas.This book,Chic Beijing:An Insider’s Guide to Unique New Places,allows readers to take a breathtaking journey through Beijing,the majestic metropolitan capital of China.It also unlocks doors that usually stay closed:rooftop gardens overlooking palace rooftops,micro-galleries tucked into 300-year-old courtyards,and cocktail labs where baijiu meets coffee.
文摘This concise paper,delivered at a conference,addresses a broad topic with the goal of providing a condensed and inevitably subjective perspective.Initially,it outlines the primary characteristics that distinguish coins from other historical sources.Subsequently,it provides a succinct overview of numismatics,categorized into seven phases:1.Pre-1550(coins as reflections of vice and virtue);2.From circa 1550 to circa 1620(coins as testimony of authentic history);3.From circa 1650 to circa 1730(the heyday of the“Republic of Medals”);4.From circa 1730 to circa 1840(the decline of the“Republic of Medals”and the emergence of scientific practices by Viennese Jesuits);5.From circa 1840 to circa 1940(die-studies and art history);6.From circa 1940 to circa 2000(coins as instruments of exchange);7.Since 2000(cultural shift and digital humanities).
