Single-atom catalysts(SACs)are among the most cutting-edge catalysts in the multiphase catalysis track due to their unique geometrical and electronic properties,the highest atom utilization efficiency,and uniform acti...Single-atom catalysts(SACs)are among the most cutting-edge catalysts in the multiphase catalysis track due to their unique geometrical and electronic properties,the highest atom utilization efficiency,and uniform active sites.SACs have been facing an unresolved problem in practical applications:the opposing contradiction of activity-stability.The successful development of single-atom nano-islands(SANIs)cleverly combines the ultra-high atom utilization efficiency of SACs with the confinement effect and structural stability of nano-island structures,realizing the“moving but not aggregation”of SACs,which fundamentally solves this inherent contradiction.Although research on the precise loading of single atoms on nano-islands continues to advance,existing reviews have not yet established a closed-loop cognitive framework encompassing“models-synthesis-high stability mechanisms-high activity essence-applications.”This work fills this critical gap by systematically integrating the basic conceptual models and cutting-edge synthesis strategies of SANIs,focusing on revealing the underlying mechanisms by which SANIs overcome the stability bottleneck of SACs,elucidating the role of nano-islands and their synergistic mechanisms to clarify the high activity essence,and establishing the structure-activity relationship between atomic confinement effects and macroscopic performance,ultimately achieving breakthrough validation across catalytic systems.This review aims to open new perspectives,drive a paradigm shift in understanding the multi-dimensional advantages of SANIs,and thereby spur breakthrough progress in this frontier field.展开更多
Exactly 30 years ago,Nakata and coworkers published a paper analyzing the 1664-nucleotide sequence of a chromosomal DNA segment that contained the iap gene and its flanking regions in Escherichia coli（Ishino et al.,1...Exactly 30 years ago,Nakata and coworkers published a paper analyzing the 1664-nucleotide sequence of a chromosomal DNA segment that contained the iap gene and its flanking regions in Escherichia coli（Ishino et al.,1987）.展开更多
The present study attempted to test a novel hypothesis that Ca^2＋ sparks play an important role in arterial relaxation induced by tacrolimus. Recorded with confocal laser scanning microscopy, tacrolimus（10 μmol/L）...The present study attempted to test a novel hypothesis that Ca^2＋ sparks play an important role in arterial relaxation induced by tacrolimus. Recorded with confocal laser scanning microscopy, tacrolimus（10 μmol/L） increased the frequency of Ca^2＋ sparks, which could be reversed by ryanodine（10 μmol/L）. Electrophysiological experiments revealed that tacrolimus（10 μmol/L） increased the large-conductance Ca^2＋-activated K＋ currents（BKCa） in rat aortic vascular smooth muscle cells（AVSMCs）, which could be blocked by ryanodine（10 μmol/L）. Furthermore, tacrolimus（10 and 50 μmol/L） reduced the contractile force induced by norepinephrine（NE） or KCl in aortic vascular smooth muscle in a concentration-dependent manner, which could be also significantly attenuated by iberiotoxin（100 nmol/L） and ryanodine（10 μmol/L） respectively. In conclusion, tacrolimus could indirectly activate BKCa currents by increasing Ca^2＋ sparks released from ryanodine receptors, which inhibited the NE- or KCl-induced contraction in rat aorta.展开更多
正At 19 o'clock, October 11th, Beijing time, the Swedish Academy awarded the 2012 Nobel Prize for Literature to the Chinese writer Mo Yan. Within several hours, Mo Yan's works were struck by the "Nobel ef...正At 19 o'clock, October 11th, Beijing time, the Swedish Academy awarded the 2012 Nobel Prize for Literature to the Chinese writer Mo Yan. Within several hours, Mo Yan's works were struck by the "Nobel effect", sales shooting up in both bookstores and online marts. Some websites also jumped on the bandwagon and put up a reservation service for the new editions.展开更多
A controversial annual dog meat festival is celebrated on summer solstice, falling on June 21 or 22, in Yulin, a city in south China＇s Guangxi Zhuang Autonomous Region. However, the festival has drawn widespread crit...A controversial annual dog meat festival is celebrated on summer solstice, falling on June 21 or 22, in Yulin, a city in south China＇s Guangxi Zhuang Autonomous Region. However, the festival has drawn widespread criticism in recent years.展开更多
An experimental device was designed for studying methane explosion ignited by sparks of cable bolt breakage. With the methane concentration being in explosion range, a series of experiments were conducted to study the...An experimental device was designed for studying methane explosion ignited by sparks of cable bolt breakage. With the methane concentration being in explosion range, a series of experiments were conducted to study the law of spark generation during cable bolt breakage and the probability of methane explosion caused by the spark. The results show that the probability of generating sparks during cable bolt breakage is 50%. The spark generated by the breakage of steel cable bolt strand can't ignite a methane explosion. A detection was carried out using infrared-ray imaging apparatus (IRIA) to measure temperature of the spark generated by cable bolt breakage. It is indicated that the maximum temperature of the spark generated by cable bolt breakage is far less than the required ignition temperature for a methane explosion.展开更多
In this paper, two types of underwater discharges, spark discharge and corona discharge, are investigated by optical diagnosis using a high speed framing camera （HSFC） with the framing time within nanoseconds under ...In this paper, two types of underwater discharges, spark discharge and corona discharge, are investigated by optical diagnosis using a high speed framing camera （HSFC） with the framing time within nanoseconds under the same experimental conditions. In order to capture the photographs of streamer propagation, the influence of the randomicity of the prebreakdown duration is taken into consideration. By increasing the conductivity of water, the randomicity reduces effectively. Experimental results show that, for a spark discharge, the process can be separated into three stages： the generation and propagation of a streamer, the generation and expansion of the discharge channel, and the development and annihilation of the plasma. The streamers do not directly move to the opposite electrode, but form a bush-like figure. With the increase of the number of branches, the velocity of streamer propagation slows down. The trajectory of the initial channel between electrodes is not straight. However, with the channel expanding, its shape transforms into a straight column. For a corona discharge, there are two stages： the generation and propagation of a streamer, and the stagnation and annihilation of the streamer. The initial streamer in a corona discharge is generated later than in a spark discharge. The forms of streamers for both kinds of discharge are similar; however, streamers generated by a corona discharge propagate with a slower velocity and the number of branches is less compared with a spark discharge. When the energy injection stops, the luminescence of plasma inside the discharge channel （spark discharge） or streamers （corona discharge） becomes weaker and weaker, and finally disappears.展开更多
This is the twinned paper of the increased mass paper, “Gravity is acting at superluminous infinite speed, thus collapsing special theory of relativity of Einstein, an explanation for almost everything (according to ...This is the twinned paper of the increased mass paper, “Gravity is acting at superluminous infinite speed, thus collapsing special theory of relativity of Einstein, an explanation for almost everything (according to the authors’ rigorous mathematical proof and overwhelming experimental evidence)"?[1]. In the present paper, we describe the repeated spark or repeat current in terms of the hidden, Non-Relativistic Longitudinal Cardinal Ampere Force which is not found yet infallible for every case. The impressive finding is the fact that these repeated sparks as we shall see, have no back-emf, but forward-emf and forward-Ampere-motive-force. The only consumption is the resistive load with the very high currents needed. This means its total energy consumption is less than the released energy-output work plus heat, plus the energy recharging the batteries. All these are in excess of the consumed input energy. This means the Repeated sparking is “over-unity” efficiency and that, using super-conductive materials, we shall have constructed the first “perpetual mobile” plus producing extra electrical energy. Several previous journals that we did not mention here their names did not dare to publish our disliked papers of very important and revolutionary results but were not able to counter argue our arguments. They preferred the silence and have not answered us at all for many years now. Even some of them were involved previously with the repeated sparking which is the same topic of our present paper.展开更多
“One World,One Family”is a theme that conjures up images of harmony and the desire to bridge cultural divides,so it was a fitting backdrop for the 18th“Chinese Bridge”—Chinese Proficiency Competition for Foreign ...“One World,One Family”is a theme that conjures up images of harmony and the desire to bridge cultural divides,so it was a fitting backdrop for the 18th“Chinese Bridge”—Chinese Proficiency Competition for Foreign College Students held in Changsha,Hunan Province this year.展开更多
Ca2+ sparks are the elementary events of intracellular Ca2+ release from the sar-coplasmic reticulum in cardiac myocytes. In order to investigate whether spontaneous L-type Ca2+ channel activation contributes to the g...Ca2+ sparks are the elementary events of intracellular Ca2+ release from the sar-coplasmic reticulum in cardiac myocytes. In order to investigate whether spontaneous L-type Ca2+ channel activation contributes to the genesis of spontaneous Ca2+ sparks, we used confocal laser scanning microscopy and fluo-4 to visualize local Ca2+ sparks in intact rat ventricular myocytes. In the presence of 0.2 mmol/L CdCI2 which inhibits spontaneous L-type Ca2+ channel activation, the rate of occurrence of spontaneous Ca2+ sparks was halved from 4.20 to 2.04 events/(100 μm·s), with temporal and spatial properties of individual Ca2+ sparks unchanged. Analysis of the Cd2+-sensitive spark production revealed an open probability of-10-5 for L-type channels at the rest membrane potentials (-80 mV). Thus, infrequent and stochastic openings of sarcolemmal L-type Ca2+ channels in resting heart cells contribute significantly to the production of spontaneous Ca2+ sparks.展开更多
This study investigated enhancing the wear resistance of Ti6Al4V alloys for medical applications by incorporating Ti C nanoreinforcements using advanced spark plasma sintering(SPS). The addition of up to 2.5wt% Ti C s...This study investigated enhancing the wear resistance of Ti6Al4V alloys for medical applications by incorporating Ti C nanoreinforcements using advanced spark plasma sintering(SPS). The addition of up to 2.5wt% Ti C significantly improved the mechanical properties, including a notable 18.2% increase in hardness(HV 332). Fretting wear tests against 316L stainless steel(SS316L) balls demonstrated a 20wt%–22wt% reduction in wear volume in the Ti6Al4V/Ti C composites compared with the monolithic alloy. Microstructural analysis revealed that Ti C reinforcement controlled the grain orientation and reduced the β-phase content, which contributed to enhanced mechanical properties. The monolithic alloy exhibited a Widmanstätten lamellar microstructure, while increasing the Ti C content modified the wear mechanisms from ploughing and adhesion(0–0.5wt%) to pitting and abrasion(1wt%–2.5wt%). At higher reinforcement levels, the formation of a robust oxide layer through tribo-oxide treatment effectively reduced the wear volume by minimizing the abrasive effects and plastic deformation. This study highlights the potential of SPS-mediated Ti C reinforcement as a transformative approach for improving the performance of Ti6Al4V alloys, paving the way for advanced medical applications.展开更多
当前,高职“Spark技术”课程教学存在学生前置知识不扎实、能力分化、考核方式缺乏针对性、项目案例孤立等问题,导致学生的技能与企业的需求脱节。文章结合项目驱动与成果导向教育(Outcome Based Education,OBE)理念,将生成式人工智能(A...当前,高职“Spark技术”课程教学存在学生前置知识不扎实、能力分化、考核方式缺乏针对性、项目案例孤立等问题,导致学生的技能与企业的需求脱节。文章结合项目驱动与成果导向教育(Outcome Based Education,OBE)理念,将生成式人工智能(Artificial Intelligence Generated Content,AIGC)融入课程教学,引入领域专用大语言模型SQLCoder-7B-2构建智能查询流程。教学案例借助Selenium技术获取租房信息,渗透“数据采集—数据清洗—数据分析”的大数据思维,详细阐述“课前—课中—课后”三阶段教学路径。该模式能有效降低Spark SQL编程学习难度,助力学生专注数据分析思维与AI工具应用能力培养,为大数据专业培育人工智能素养复合型人才提供可行教学范式。展开更多
基金supported by the National Key Research and Development Program of China(No.2022YFD1700801-3)Key Laboratory of Jiangxi Province for Persistent Pollutants Prevention Control and Resource Reuse(No.2023SSY02061)support of the projects and research platform support provided by the laboratory.
文摘Single-atom catalysts(SACs)are among the most cutting-edge catalysts in the multiphase catalysis track due to their unique geometrical and electronic properties,the highest atom utilization efficiency,and uniform active sites.SACs have been facing an unresolved problem in practical applications:the opposing contradiction of activity-stability.The successful development of single-atom nano-islands(SANIs)cleverly combines the ultra-high atom utilization efficiency of SACs with the confinement effect and structural stability of nano-island structures,realizing the“moving but not aggregation”of SACs,which fundamentally solves this inherent contradiction.Although research on the precise loading of single atoms on nano-islands continues to advance,existing reviews have not yet established a closed-loop cognitive framework encompassing“models-synthesis-high stability mechanisms-high activity essence-applications.”This work fills this critical gap by systematically integrating the basic conceptual models and cutting-edge synthesis strategies of SANIs,focusing on revealing the underlying mechanisms by which SANIs overcome the stability bottleneck of SACs,elucidating the role of nano-islands and their synergistic mechanisms to clarify the high activity essence,and establishing the structure-activity relationship between atomic confinement effects and macroscopic performance,ultimately achieving breakthrough validation across catalytic systems.This review aims to open new perspectives,drive a paradigm shift in understanding the multi-dimensional advantages of SANIs,and thereby spur breakthrough progress in this frontier field.
文摘Exactly 30 years ago,Nakata and coworkers published a paper analyzing the 1664-nucleotide sequence of a chromosomal DNA segment that contained the iap gene and its flanking regions in Escherichia coli（Ishino et al.,1987）.
基金supported by the National Natural Science Foundation of China(No.81102439)
文摘The present study attempted to test a novel hypothesis that Ca^2＋ sparks play an important role in arterial relaxation induced by tacrolimus. Recorded with confocal laser scanning microscopy, tacrolimus（10 μmol/L） increased the frequency of Ca^2＋ sparks, which could be reversed by ryanodine（10 μmol/L）. Electrophysiological experiments revealed that tacrolimus（10 μmol/L） increased the large-conductance Ca^2＋-activated K＋ currents（BKCa） in rat aortic vascular smooth muscle cells（AVSMCs）, which could be blocked by ryanodine（10 μmol/L）. Furthermore, tacrolimus（10 and 50 μmol/L） reduced the contractile force induced by norepinephrine（NE） or KCl in aortic vascular smooth muscle in a concentration-dependent manner, which could be also significantly attenuated by iberiotoxin（100 nmol/L） and ryanodine（10 μmol/L） respectively. In conclusion, tacrolimus could indirectly activate BKCa currents by increasing Ca^2＋ sparks released from ryanodine receptors, which inhibited the NE- or KCl-induced contraction in rat aorta.
文摘正At 19 o'clock, October 11th, Beijing time, the Swedish Academy awarded the 2012 Nobel Prize for Literature to the Chinese writer Mo Yan. Within several hours, Mo Yan's works were struck by the "Nobel effect", sales shooting up in both bookstores and online marts. Some websites also jumped on the bandwagon and put up a reservation service for the new editions.
文摘A controversial annual dog meat festival is celebrated on summer solstice, falling on June 21 or 22, in Yulin, a city in south China＇s Guangxi Zhuang Autonomous Region. However, the festival has drawn widespread criticism in recent years.
文摘An experimental device was designed for studying methane explosion ignited by sparks of cable bolt breakage. With the methane concentration being in explosion range, a series of experiments were conducted to study the law of spark generation during cable bolt breakage and the probability of methane explosion caused by the spark. The results show that the probability of generating sparks during cable bolt breakage is 50%. The spark generated by the breakage of steel cable bolt strand can't ignite a methane explosion. A detection was carried out using infrared-ray imaging apparatus (IRIA) to measure temperature of the spark generated by cable bolt breakage. It is indicated that the maximum temperature of the spark generated by cable bolt breakage is far less than the required ignition temperature for a methane explosion.
文摘In this paper, two types of underwater discharges, spark discharge and corona discharge, are investigated by optical diagnosis using a high speed framing camera （HSFC） with the framing time within nanoseconds under the same experimental conditions. In order to capture the photographs of streamer propagation, the influence of the randomicity of the prebreakdown duration is taken into consideration. By increasing the conductivity of water, the randomicity reduces effectively. Experimental results show that, for a spark discharge, the process can be separated into three stages： the generation and propagation of a streamer, the generation and expansion of the discharge channel, and the development and annihilation of the plasma. The streamers do not directly move to the opposite electrode, but form a bush-like figure. With the increase of the number of branches, the velocity of streamer propagation slows down. The trajectory of the initial channel between electrodes is not straight. However, with the channel expanding, its shape transforms into a straight column. For a corona discharge, there are two stages： the generation and propagation of a streamer, and the stagnation and annihilation of the streamer. The initial streamer in a corona discharge is generated later than in a spark discharge. The forms of streamers for both kinds of discharge are similar; however, streamers generated by a corona discharge propagate with a slower velocity and the number of branches is less compared with a spark discharge. When the energy injection stops, the luminescence of plasma inside the discharge channel （spark discharge） or streamers （corona discharge） becomes weaker and weaker, and finally disappears.
文摘This is the twinned paper of the increased mass paper, “Gravity is acting at superluminous infinite speed, thus collapsing special theory of relativity of Einstein, an explanation for almost everything (according to the authors’ rigorous mathematical proof and overwhelming experimental evidence)"?[1]. In the present paper, we describe the repeated spark or repeat current in terms of the hidden, Non-Relativistic Longitudinal Cardinal Ampere Force which is not found yet infallible for every case. The impressive finding is the fact that these repeated sparks as we shall see, have no back-emf, but forward-emf and forward-Ampere-motive-force. The only consumption is the resistive load with the very high currents needed. This means its total energy consumption is less than the released energy-output work plus heat, plus the energy recharging the batteries. All these are in excess of the consumed input energy. This means the Repeated sparking is “over-unity” efficiency and that, using super-conductive materials, we shall have constructed the first “perpetual mobile” plus producing extra electrical energy. Several previous journals that we did not mention here their names did not dare to publish our disliked papers of very important and revolutionary results but were not able to counter argue our arguments. They preferred the silence and have not answered us at all for many years now. Even some of them were involved previously with the repeated sparking which is the same topic of our present paper.
文摘“One World,One Family”is a theme that conjures up images of harmony and the desire to bridge cultural divides,so it was a fitting backdrop for the 18th“Chinese Bridge”—Chinese Proficiency Competition for Foreign College Students held in Changsha,Hunan Province this year.
基金supported by the National Natural Science Foundation of China(Grant No.30200088 for A-type grant)Chinese Major State Basic Research Development Program(Grant No.G2000057002).
文摘Ca2+ sparks are the elementary events of intracellular Ca2+ release from the sar-coplasmic reticulum in cardiac myocytes. In order to investigate whether spontaneous L-type Ca2+ channel activation contributes to the genesis of spontaneous Ca2+ sparks, we used confocal laser scanning microscopy and fluo-4 to visualize local Ca2+ sparks in intact rat ventricular myocytes. In the presence of 0.2 mmol/L CdCI2 which inhibits spontaneous L-type Ca2+ channel activation, the rate of occurrence of spontaneous Ca2+ sparks was halved from 4.20 to 2.04 events/(100 μm·s), with temporal and spatial properties of individual Ca2+ sparks unchanged. Analysis of the Cd2+-sensitive spark production revealed an open probability of-10-5 for L-type channels at the rest membrane potentials (-80 mV). Thus, infrequent and stochastic openings of sarcolemmal L-type Ca2+ channels in resting heart cells contribute significantly to the production of spontaneous Ca2+ sparks.
文摘This study investigated enhancing the wear resistance of Ti6Al4V alloys for medical applications by incorporating Ti C nanoreinforcements using advanced spark plasma sintering(SPS). The addition of up to 2.5wt% Ti C significantly improved the mechanical properties, including a notable 18.2% increase in hardness(HV 332). Fretting wear tests against 316L stainless steel(SS316L) balls demonstrated a 20wt%–22wt% reduction in wear volume in the Ti6Al4V/Ti C composites compared with the monolithic alloy. Microstructural analysis revealed that Ti C reinforcement controlled the grain orientation and reduced the β-phase content, which contributed to enhanced mechanical properties. The monolithic alloy exhibited a Widmanstätten lamellar microstructure, while increasing the Ti C content modified the wear mechanisms from ploughing and adhesion(0–0.5wt%) to pitting and abrasion(1wt%–2.5wt%). At higher reinforcement levels, the formation of a robust oxide layer through tribo-oxide treatment effectively reduced the wear volume by minimizing the abrasive effects and plastic deformation. This study highlights the potential of SPS-mediated Ti C reinforcement as a transformative approach for improving the performance of Ti6Al4V alloys, paving the way for advanced medical applications.
