This paper delves into the application of artificial intelligence in daily life and the basic concepts of machine learning.Firstly,the concept and background of artificial intelligence were introduced,as well as machi...This paper delves into the application of artificial intelligence in daily life and the basic concepts of machine learning.Firstly,the concept and background of artificial intelligence were introduced,as well as machine learning as an important branch of artificial intelligence.Subsequently,the specific applications of artificial intelligence in daily life were elaborated,including intelligent voice assistants,recommendation systems,as well as image recognition and facial recognition technologies.Subsequently,a preliminary exploration was conducted on the basic concepts of machine learning,including paradigms such as supervised learning,unsupervised learning,and reinforcement learning,as well as common algorithms such as linear regression,logistic regression,decision trees,and support vector machines.Finally,the application of artificial intelligence in daily life and the basic concepts of machine learning were summarized,and the development trends and future prospects of artificial intelligence technology were discussed,as well as the possibility of guiding readers to continue in-depth learning and exploration in the field of artificial intelligence.展开更多
We propose a method to characterize the features of a cold strontium cloud in a magneto-optical trap(MOT)through the photoionization of cold Sr atoms in a custom-designed reaction microscope.Sr atoms in the dark state...We propose a method to characterize the features of a cold strontium cloud in a magneto-optical trap(MOT)through the photoionization of cold Sr atoms in a custom-designed reaction microscope.Sr atoms in the dark state of 5s5p3P2 populated via the cascade transition 5s5p^(1)P_(1)→5s4d^(1)D_(2)→5s5p^(3)P_(2)accumulate a significant fraction,giving a long lifetime of 520 s.These atoms in the dark state are subsequently trapped by the gradient magnetic field of the MOT.By scanning the Sr+momentum distributions ionized with an 800 nm infrared femtosecond laser,we are able to outline the size of~0.55 mm in radius and the temperature of~0.40 mK for the dark-state atoms,which is significantly cooler than the MOT temperature of 3.3 mK trapped in the 461 nm.The size of MOT exhibits an oblate spheroidal distribution with a radius of approximately 0.35 mm and 0.55 mm,extracted with momenta of photoion and absorption imaging,respectively.The results using the photoion momenta are consistent with the expected results from absorption imaging,which confirms the method's reliability.The advantage of this method is the ability to simultaneously characterize the distribution information of atoms in different initial states within the cold atomic cloud.展开更多
The ability to predict a grinding force is important to control,monitor,and optimize the grinding process.Few theoretical models were developed to predict grinding forces when a structured wheel was used in a grinding...The ability to predict a grinding force is important to control,monitor,and optimize the grinding process.Few theoretical models were developed to predict grinding forces when a structured wheel was used in a grinding process.This paper aimed to establish a single-grit cutting force model to predict the ploughing,friction and cutting forces in a grinding process.It took into the consideration of actual topography of the grinding wheel,and a theoretical grinding force model for grinding hardened AISI 52100 by the wheel with orderly-micro-grooves was proposed.The model was innovative in the sense that it represented the random thickness of undeformed chips by a probabilistic expression,and it reflected the microstructure characteristics of the structured wheel explicitly.Note that the microstructure depended on the randomness of the protruding heights and distribution density of the grits over the wheel.The proposed force prediction model was validated by surface grinding experiments,and the results showed(1)a good agreement of the predicted and measured forces and(2)a good agreement of the changes of the grinding forces along with the changes of grinding parameters in the prediction model and experiments.This research proposed a theoretical grinding force model of an electroplated grinding wheel with orderly-micro-grooves which is accurate,reliable and effective in predicting grinding forces.展开更多
Bichromatic circularly polarized fields provide a useful tool to probe the ionization dynamics.In this work, we compare the photoelectron momentum distribution in few-cycle bichromatic field of different helicities.Th...Bichromatic circularly polarized fields provide a useful tool to probe the ionization dynamics.In this work, we compare the photoelectron momentum distribution in few-cycle bichromatic field of different helicities.The spectral features are analyzed with semiclassical trajectories derived from the strong field approximation.In particular, the interference fringes in momentum distribution are investigated by tracking the ionization time and tunneling exits of released photoelectrons.Different types of trajectories that contribute to the interference fringes are elucidated.展开更多
Employing recently developed magneto-optical trap recoil ion momentum spectroscopy(MOTRIMS)combined with cold atoms,strong laser pulse,and ultrafast technologies,we study momentum distributions of the multiply ionized...Employing recently developed magneto-optical trap recoil ion momentum spectroscopy(MOTRIMS)combined with cold atoms,strong laser pulse,and ultrafast technologies,we study momentum distributions of the multiply ionized cold rubidium(Rb)induced by the elliptically polarized laser pulses(35 fs,1.3×10^15 W/cm^2).The complete vector momenta of Rb^n+ions up to charge state n=4 are recorded with extremely high resolution(0.12 a.u.for Rb^+).Variations of characteristic multi-bands are displayed in momentum distributions because the ellipticity varies from the linear to circular polarization,are interpreted qualitatively with the classical overbarrier ionization model.Present momentum spectroscopy of cold heavy alkali atoms presents novel strong-field phenomena beyond the noble gases.展开更多
Teachers in colleges and universities are the nurturers of the core talents of the country.Teachers’comprehensive quality levels in colleges and universities fundamentally determine the quality of talent cultivation ...Teachers in colleges and universities are the nurturers of the core talents of the country.Teachers’comprehensive quality levels in colleges and universities fundamentally determine the quality of talent cultivation in colleges and universities,the level of scientific research,and the contribution to society.Based on moral cultivation and teachers’professional moral cultivation,this paper discusses the problems in the professional moral cultivation of college teachers and the measures to improve the professional moral cultivation of college teachers.展开更多
Propeller cavity bursting,triggered by the sharp hull wake,can significantly increase broadband noise.However,its complex multiscale nature presents substantial challenges for numerical simulations,limiting the predic...Propeller cavity bursting,triggered by the sharp hull wake,can significantly increase broadband noise.However,its complex multiscale nature presents substantial challenges for numerical simulations,limiting the prediction accuracy for propeller cavitation noise to only the first few blade-passing frequencies.To overcome this limitation,this study explores the potential of a novel Euler-Lagrange hybrid model for simulating cavity bursting and the resulting broadband noise.Focused on a benchmark test case of the INSEAN E779A propeller,the numerical results effectively reproduce the measured cavity bursting and its associated broadband pressure fluctuations,providing valuable insights for realistic simulations of propeller cavitation noise.展开更多
Aqueous zinc-ion batteries(AZBs)are considered safer and potential substitutes for large-scale energy storage and conversion devices.The conventional vanadium pentoxide(V_(2)O_(5))cathode material has attracted widesp...Aqueous zinc-ion batteries(AZBs)are considered safer and potential substitutes for large-scale energy storage and conversion devices.The conventional vanadium pentoxide(V_(2)O_(5))cathode material has attracted widespread attention duo to its typical layered structure and high theoretical capacity.Unfortunately,it still suffers from severe structural collapse,sluggish diffusion dynamics,and fast capacity fading.Herein,we rationally designed and prepared trivalent Al^(3+)and H_(2)O co-intercalated V_(2)O_(5)(AlVO),in which Al^(3+)plays a“pillar”role and forms strong Al−O bonds,while H_(2)O acts as the“lubricant”,synergistically maintaining the structural stability and accelerating the diffusion of zinc ions.The Zn//AlVO battery is found to possess not only an impressive reversible capacity of 390.7 mAh·g^(−1) at 0.5 A·g^(−1),5.13 times that of Zn//c-V_(2)O_(5),but also excellent rate capability and long-term cycling performance(with the residual capacity of 138.2 mAh·g^(−1) over 10000 cycles at 10 A·g^(−1)).展开更多
The origin of terahertz(THz)generation in a gas-phase medium is still in controversy,although the THz sources have been applied across many disciplines.Herein,the THz generation in a dual color field is investigated e...The origin of terahertz(THz)generation in a gas-phase medium is still in controversy,although the THz sources have been applied across many disciplines.Herein,the THz generation in a dual color field is investigated experimentally by precisely controlling the relative phase and polarization of dual-color lasers,where the accompanying third-harmonic generation is employed for in situ determination of the relative phase up to sub-wavelength accuracy.Joint studies with the strong approximation(SFA)theory reveal that the continuum-continuum(CC)transition within an escaped electron wave packet in the single atom gives birth to THz emission,without the necessity of considering the plasma effect.Meanwhile,we develop the analytic form from SFA-based CC description,which is able to reproduce and decompose the classical photocurrent model from the viewpoint of microscopic quantum theory,establishing the quantum-lassical correspondence and bringing a novel insight into the mechanism of THz generation.Present studies leave open the possibility for probing the ultrafast dynamics of continuum electrons and a new dimension for the study of THz-related science and methodology.展开更多
Dear Editor, End-binding protein 1 （EB1）, a member of microtubule plus- end tracking proteins （＋TIPs）, plays an important role in the regulation of microtubule dynamics and has been implicated in cancer developme...Dear Editor, End-binding protein 1 （EB1）, a member of microtubule plus- end tracking proteins （＋TIPs）, plays an important role in the regulation of microtubule dynamics and has been implicated in cancer development （Dong et al., 2010; Gouveia and Ak- hmanova, 2010; Wang et al., 2005）. However, it remains poorly understood how EB1 functions are regulated by phosphorylation in mammalian cells. To map the phosphory- lation pattern of EB1, we overexpressed GST-EB1 in HeLa cells and enriched GST-EB1 from cell lysates by GST pull- down. The pulldown preparations showed strong serine, threonine, and tyrosine phosphorylation signals in the immu- noblots （Fig. SlA）. GST-EB1 purified from cells was clearly visualized on the gel prior to in-gel digestion （Fig. S 1B）.展开更多
Job hopping affects the development of industries in terms of efficiency and quality of work. It is a problem for the Chinese construction industry, where excessive job hopping is detrimental to meeting the current da...Job hopping affects the development of industries in terms of efficiency and quality of work. It is a problem for the Chinese construction industry, where excessive job hopping is detrimental to meeting the current daunting challenges involved in the industry's transformation and efficiency improvement. To provide an exhaustive analysis of this effect, game theory is combined with social relationship networks to create an agent-based simulation model. Simulation results indicate that the frequent job moves of Chinese construction workers have a negative effect on their skill development, employment, and worker relationships, as well as results in sharp increase in employer labor costs. The findings point to the need to act for the benefit of workers and employers and maintain the development of the industry.展开更多
文摘This paper delves into the application of artificial intelligence in daily life and the basic concepts of machine learning.Firstly,the concept and background of artificial intelligence were introduced,as well as machine learning as an important branch of artificial intelligence.Subsequently,the specific applications of artificial intelligence in daily life were elaborated,including intelligent voice assistants,recommendation systems,as well as image recognition and facial recognition technologies.Subsequently,a preliminary exploration was conducted on the basic concepts of machine learning,including paradigms such as supervised learning,unsupervised learning,and reinforcement learning,as well as common algorithms such as linear regression,logistic regression,decision trees,and support vector machines.Finally,the application of artificial intelligence in daily life and the basic concepts of machine learning were summarized,and the development trends and future prospects of artificial intelligence technology were discussed,as well as the possibility of guiding readers to continue in-depth learning and exploration in the field of artificial intelligence.
基金Project supported by the Natural Science Foundation of Henan(Grant No.252300421304)the National Natural Science Foundation of China(Grant Nos.12204498,12474259+1 种基金12334011)the National Key Research and Development Program of China(Grant No.2022YFA1604302)。
文摘We propose a method to characterize the features of a cold strontium cloud in a magneto-optical trap(MOT)through the photoionization of cold Sr atoms in a custom-designed reaction microscope.Sr atoms in the dark state of 5s5p3P2 populated via the cascade transition 5s5p^(1)P_(1)→5s4d^(1)D_(2)→5s5p^(3)P_(2)accumulate a significant fraction,giving a long lifetime of 520 s.These atoms in the dark state are subsequently trapped by the gradient magnetic field of the MOT.By scanning the Sr+momentum distributions ionized with an 800 nm infrared femtosecond laser,we are able to outline the size of~0.55 mm in radius and the temperature of~0.40 mK for the dark-state atoms,which is significantly cooler than the MOT temperature of 3.3 mK trapped in the 461 nm.The size of MOT exhibits an oblate spheroidal distribution with a radius of approximately 0.35 mm and 0.55 mm,extracted with momenta of photoion and absorption imaging,respectively.The results using the photoion momenta are consistent with the expected results from absorption imaging,which confirms the method's reliability.The advantage of this method is the ability to simultaneously characterize the distribution information of atoms in different initial states within the cold atomic cloud.
基金Supported by National Natural Science Foundation of China(Grant Nos.52275405,52275311,51875050)Hunan Provincial Key Research and Development Program(Grant No.2021GK2021).
文摘The ability to predict a grinding force is important to control,monitor,and optimize the grinding process.Few theoretical models were developed to predict grinding forces when a structured wheel was used in a grinding process.This paper aimed to establish a single-grit cutting force model to predict the ploughing,friction and cutting forces in a grinding process.It took into the consideration of actual topography of the grinding wheel,and a theoretical grinding force model for grinding hardened AISI 52100 by the wheel with orderly-micro-grooves was proposed.The model was innovative in the sense that it represented the random thickness of undeformed chips by a probabilistic expression,and it reflected the microstructure characteristics of the structured wheel explicitly.Note that the microstructure depended on the randomness of the protruding heights and distribution density of the grits over the wheel.The proposed force prediction model was validated by surface grinding experiments,and the results showed(1)a good agreement of the predicted and measured forces and(2)a good agreement of the changes of the grinding forces along with the changes of grinding parameters in the prediction model and experiments.This research proposed a theoretical grinding force model of an electroplated grinding wheel with orderly-micro-grooves which is accurate,reliable and effective in predicting grinding forces.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11420101003,11604347,11827806,11874368,61675213,and 91636105)
文摘Bichromatic circularly polarized fields provide a useful tool to probe the ionization dynamics.In this work, we compare the photoelectron momentum distribution in few-cycle bichromatic field of different helicities.The spectral features are analyzed with semiclassical trajectories derived from the strong field approximation.In particular, the interference fringes in momentum distribution are investigated by tracking the ionization time and tunneling exits of released photoelectrons.Different types of trajectories that contribute to the interference fringes are elucidated.
基金National Natural Science Foundation of China(Grant Nos.1182780611874368+2 种基金6167521311822401and11674034)。
文摘Employing recently developed magneto-optical trap recoil ion momentum spectroscopy(MOTRIMS)combined with cold atoms,strong laser pulse,and ultrafast technologies,we study momentum distributions of the multiply ionized cold rubidium(Rb)induced by the elliptically polarized laser pulses(35 fs,1.3×10^15 W/cm^2).The complete vector momenta of Rb^n+ions up to charge state n=4 are recorded with extremely high resolution(0.12 a.u.for Rb^+).Variations of characteristic multi-bands are displayed in momentum distributions because the ellipticity varies from the linear to circular polarization,are interpreted qualitatively with the classical overbarrier ionization model.Present momentum spectroscopy of cold heavy alkali atoms presents novel strong-field phenomena beyond the noble gases.
文摘Teachers in colleges and universities are the nurturers of the core talents of the country.Teachers’comprehensive quality levels in colleges and universities fundamentally determine the quality of talent cultivation in colleges and universities,the level of scientific research,and the contribution to society.Based on moral cultivation and teachers’professional moral cultivation,this paper discusses the problems in the professional moral cultivation of college teachers and the measures to improve the professional moral cultivation of college teachers.
基金supported by the National Natural Science Foundation of China(Project Nos.52479085 and 123B2032).
文摘Propeller cavity bursting,triggered by the sharp hull wake,can significantly increase broadband noise.However,its complex multiscale nature presents substantial challenges for numerical simulations,limiting the prediction accuracy for propeller cavitation noise to only the first few blade-passing frequencies.To overcome this limitation,this study explores the potential of a novel Euler-Lagrange hybrid model for simulating cavity bursting and the resulting broadband noise.Focused on a benchmark test case of the INSEAN E779A propeller,the numerical results effectively reproduce the measured cavity bursting and its associated broadband pressure fluctuations,providing valuable insights for realistic simulations of propeller cavitation noise.
基金supported by National Natural Science Foundation of China(Grant No.22369006)Key Talent Projects in Gansu Province(2025RCXM011)+2 种基金College Students’Innovation and Entrepreneurship Training Program Project(S202310740033)Science and Technology Innovation Project for College Students(Grant Nos.Z10 and 146)Open Research Fund of the State Key Laboratory of Molecular Engineering of Polymers(K2025-21,Fudan University).
文摘Aqueous zinc-ion batteries(AZBs)are considered safer and potential substitutes for large-scale energy storage and conversion devices.The conventional vanadium pentoxide(V_(2)O_(5))cathode material has attracted widespread attention duo to its typical layered structure and high theoretical capacity.Unfortunately,it still suffers from severe structural collapse,sluggish diffusion dynamics,and fast capacity fading.Herein,we rationally designed and prepared trivalent Al^(3+)and H_(2)O co-intercalated V_(2)O_(5)(AlVO),in which Al^(3+)plays a“pillar”role and forms strong Al−O bonds,while H_(2)O acts as the“lubricant”,synergistically maintaining the structural stability and accelerating the diffusion of zinc ions.The Zn//AlVO battery is found to possess not only an impressive reversible capacity of 390.7 mAh·g^(−1) at 0.5 A·g^(−1),5.13 times that of Zn//c-V_(2)O_(5),but also excellent rate capability and long-term cycling performance(with the residual capacity of 138.2 mAh·g^(−1) over 10000 cycles at 10 A·g^(−1)).
基金National Natural Science Foundation of China(11827806,11874368,61675213).
文摘The origin of terahertz(THz)generation in a gas-phase medium is still in controversy,although the THz sources have been applied across many disciplines.Herein,the THz generation in a dual color field is investigated experimentally by precisely controlling the relative phase and polarization of dual-color lasers,where the accompanying third-harmonic generation is employed for in situ determination of the relative phase up to sub-wavelength accuracy.Joint studies with the strong approximation(SFA)theory reveal that the continuum-continuum(CC)transition within an escaped electron wave packet in the single atom gives birth to THz emission,without the necessity of considering the plasma effect.Meanwhile,we develop the analytic form from SFA-based CC description,which is able to reproduce and decompose the classical photocurrent model from the viewpoint of microscopic quantum theory,establishing the quantum-lassical correspondence and bringing a novel insight into the mechanism of THz generation.Present studies leave open the possibility for probing the ultrafast dynamics of continuum electrons and a new dimension for the study of THz-related science and methodology.
文摘Dear Editor, End-binding protein 1 （EB1）, a member of microtubule plus- end tracking proteins （＋TIPs）, plays an important role in the regulation of microtubule dynamics and has been implicated in cancer development （Dong et al., 2010; Gouveia and Ak- hmanova, 2010; Wang et al., 2005）. However, it remains poorly understood how EB1 functions are regulated by phosphorylation in mammalian cells. To map the phosphory- lation pattern of EB1, we overexpressed GST-EB1 in HeLa cells and enriched GST-EB1 from cell lysates by GST pull- down. The pulldown preparations showed strong serine, threonine, and tyrosine phosphorylation signals in the immu- noblots （Fig. SlA）. GST-EB1 purified from cells was clearly visualized on the gel prior to in-gel digestion （Fig. S 1B）.
文摘Job hopping affects the development of industries in terms of efficiency and quality of work. It is a problem for the Chinese construction industry, where excessive job hopping is detrimental to meeting the current daunting challenges involved in the industry's transformation and efficiency improvement. To provide an exhaustive analysis of this effect, game theory is combined with social relationship networks to create an agent-based simulation model. Simulation results indicate that the frequent job moves of Chinese construction workers have a negative effect on their skill development, employment, and worker relationships, as well as results in sharp increase in employer labor costs. The findings point to the need to act for the benefit of workers and employers and maintain the development of the industry.
