The magnetic behavior of a two-electron quantum dot/ring system is analytically studied with electron-electron(e-e)interaction taking into account the Rashba spin-orbit interaction(SOI)and magnetic field.The Jacobi tr...The magnetic behavior of a two-electron quantum dot/ring system is analytically studied with electron-electron(e-e)interaction taking into account the Rashba spin-orbit interaction(SOI)and magnetic field.The Jacobi transformation has been employed to separate the Hamiltonian of the system to the center of mass and relative terms.The Schrödinger equation is analytically solved,and energy spectra are obtained.Then,the magnetization and susceptibility are calculated.The magnetization decreases by raising the magnetic field without and with SOI,and also without e-e interaction.Also,the SOI slightly modifies the magnetization of the system without e-e interaction.The susceptibility displays a peak structure as the magnetic field changes from low values to high values.The susceptibility by considering e-e interaction and without the SOI is always negative and its value decreases by rising the magnetic field.The susceptibility displays a transition from diamagnetic to paramagnetic with e-e interaction and SOI.展开更多
Carbon dot(CD)is an edge-bound,nanometer-sized carbon material possessing unique optical and electronic properties,making it promising metal-free,environmentally benign.In this study,we identified a highly hydrophilic...Carbon dot(CD)is an edge-bound,nanometer-sized carbon material possessing unique optical and electronic properties,making it promising metal-free,environmentally benign.In this study,we identified a highly hydrophilic CD complexed with Fe(Ⅲ)via carboxyl groups to form CD-COOFeⅢ,which exhibited remarkably enhanced Fenton-like reaction performance boosted by visible light irradiation.CD-COOFeⅢenabled high activity in the visible region beyondλ>420 nm,and maintained stable oxidation efficiency in the presence of H_(2)O_(2)over at least ten cycles.The capacity of electrons transferred from photo-excited CD to reduce Fe(Ⅲ)was calculated to be 1.1 mmol/g of CD.Furthermore,the quantum yield(QY)of solarto-Fe(Ⅱ)conversion reached an impressive 87.7%.These findings not only suggest a viable strategy for efficient conversion of solar-to-chemical using a CD-COOFeⅢcomplex in visible light boosted Fenton-like oxidation reaction,but also provide insight for understanding the effect of nanosized artificial and/or natural carbon materials in iron recycling in a natural surface environment.展开更多
With the rapid development of modern information technology,the Internet of Things(IoT)has been integrated into various fields such as social life,industrial production,education,and medical care.Through the connectio...With the rapid development of modern information technology,the Internet of Things(IoT)has been integrated into various fields such as social life,industrial production,education,and medical care.Through the connection of various physical devices,sensors,and machines,it realizes information intercommunication and remote control among devices,significantly enhancing the convenience and efficiency of work and life.However,the rapid development of the IoT has also brought serious security problems.IoT devices have limited resources and a complex network environment,making them one of the important targets of network intrusion attacks.Therefore,from the perspective of deep learning,this paper deeply analyzes the characteristics and key points of IoT intrusion detection,summarizes the application advantages of deep learning in IoT intrusion detection,and proposes application strategies of typical deep learning models in IoT intrusion detection so as to improve the security of the IoT architecture and guarantee people’s convenient lives.展开更多
In recent years,the network public opinion reversal governance events have occurred frequently.Over time,the repeated truth of the matter will not only weaken the rational judgment of the public to a certain extent,so...In recent years,the network public opinion reversal governance events have occurred frequently.Over time,the repeated truth of the matter will not only weaken the rational judgment of the public to a certain extent,so that its negative emotions accumulate,but also have a serious impact on the credibility of the media and the government,and may even further intensify social contradictions.Therefore,in the face of such a complex online public opinion space,accurately identifying the truth behind the incident and how to carry out the reversal of online public opinion governance is particularly critical.And blockchain technology,with its advantages of decentralization and immutable information,provides new technical support for the network public opinion reversal governance.Based on this,this paper gives an overview and analysis of blockchain technology and network public opinion reversal,and on this basis introduces the network public opinion reversal governance mechanism based on blockchain technology,aiming to further optimize the network public opinion reversal governance process,for reference only.展开更多
The Internet of Things technology provides a comprehensive solution for the real-time monitoring of cold chain logistics by integrating sensors,wireless communication,cloud computing,and big data analysis.Based on thi...The Internet of Things technology provides a comprehensive solution for the real-time monitoring of cold chain logistics by integrating sensors,wireless communication,cloud computing,and big data analysis.Based on this,this paper deeply explores the overview and characteristics of the Internet of Things technology,the feasibility analysis of the Internet of Things technology in the cold chain logistics monitoring,the application analysis of the Internet of Things technology in the cold chain logistics real-time monitoring to better improve the management level and operational efficiency of the cold chain logistics,to provide consumers with safer and fresh products.展开更多
Objective:To study the effect of transcranial magnetic stimulation(TMS)on improving motor symptoms in patients with Parkinson’s disease(PD).Methods:60 PD patients who visited the hospital from September 2023 to Augus...Objective:To study the effect of transcranial magnetic stimulation(TMS)on improving motor symptoms in patients with Parkinson’s disease(PD).Methods:60 PD patients who visited the hospital from September 2023 to August 2024 were selected as samples and randomly divided into two groups.Group A received conventional medication plus TMS treatment,while Group B received medication only.The efficacy of motor function improvement,neurological symptoms,mental state,sleep quality,quality of life,and adverse reactions was compared between the two groups.Results:The efficacy of Group A was higher than that of Group B(P<0.05).The scores of the Scales for Outcomes in Parkinson’s Disease-Autonomic(SCOPA-AUT),Mini-Mental State Examination(MMSE),and Pittsburgh Sleep Quality Index(PSQI)in Group A were lower than those in Group B(P<0.05).The quality of life scale(SF-36)score in Group A was higher than that in Group B(P<0.05).The adverse reaction rate in Group A was lower than that in Group B(P<0.05).Conclusion:TMS used in the treatment of PD patients can improve patients’mental state and motor function,optimize sleep quality and quality of life,and is safe and efficient.展开更多
The 2024 MRE HP Special Volume selects papers on new theoretical and experimental developments in the use of static largevolume presses(LVPs)1–3 and dynamic compression4,5 for studies under extreme high-pressure and ...The 2024 MRE HP Special Volume selects papers on new theoretical and experimental developments in the use of static largevolume presses(LVPs)1–3 and dynamic compression4,5 for studies under extreme high-pressure and high-temperature(HPHT)conditions.It also continues the previous year’s6 contemporary focus on superhydrides7–11 with extremely high superconducting temperatures Tc and addresses some controversial issues.12–14 In addition,it explores unconventional pressure-induced chemistry,particularly novel chemical stoichiometry and its impact on geochemistry and cosmochemistry in the deep interiors of Earth and other planets.18–21.展开更多
The moment a media delegation from the Republic of the Congo arrived at the Othello Kitchenware Museum on 18 November 2025,they were greeted with a vivid show of Guangdong’s industrial strength.Standing before them w...The moment a media delegation from the Republic of the Congo arrived at the Othello Kitchenware Museum on 18 November 2025,they were greeted with a vivid show of Guangdong’s industrial strength.Standing before them was not a typical exhibition hall,but a building shaped like a gleaming stainless-steel cooking pot.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
[Objective] To analyze the key factor in agricultural technology diffusion- technology support, and to explore the method to quicken the diffusion of agricultural technology. [Method] The technology acquisition advant...[Objective] To analyze the key factor in agricultural technology diffusion- technology support, and to explore the method to quicken the diffusion of agricultural technology. [Method] The technology acquisition advantage of social network was il- lustrated by summarizing the status and characteristics of agricultural technology and technology supporting types in the process of agriculture technology diffusion. [Result] The multi-layer, complex, persistence, systematization features of agricultural technol- ogy require support and help of technology from surrounding social network to ulti- mately internalize the technology. [Conclusion] Using social networks for the technol- ogy support will be a powerful supplement to the system of agricultural technology diffusion.展开更多
By using variational method of Pekar type, we have studied the energy levels of strong coupling magnetopolaron in disk shape quantum dot(QD) and quantum well(QW). Our results show that, with the increasing magnetic f...By using variational method of Pekar type, we have studied the energy levels of strong coupling magnetopolaron in disk shape quantum dot(QD) and quantum well(QW). Our results show that, with the increasing magnetic field and confinement strength, the magnetopolaron binding energy of QD and QW in the ground state and in the excited state is enhanced. The limiting results of bulk type and strict two dimensional type are obtained.展开更多
Over the past decade, carbon dots have ignited a burst of interest in many different fields, including nanomedicine, solar energy, optoelectronics, energy storage,and sensing applications, owing to their excellent pho...Over the past decade, carbon dots have ignited a burst of interest in many different fields, including nanomedicine, solar energy, optoelectronics, energy storage,and sensing applications, owing to their excellent photoluminescence properties and the easiness to modify their optical properties through doping and functionalization. In this review, the synthesis, structural and optical properties,as well as photoluminescence mechanisms of carbon dots are first reviewed and summarized. Then, we describe a series of designs for carbon dot-based sensors and the different sensing mechanisms associated with them.Thereafter, we elaborate on recent research advances on carbon dot-based sensors for the selective and sensitive detection of a wide range of analytes, including heavy metals, cations, anions, biomolecules, biomarkers,nitroaromatic explosives, pollutants, vitamins, and drugs.Lastly, we provide a concluding perspective on the overall status, challenges, and future directions for the use of carbon dots in real-life sensing.展开更多
By using the variational method of Pekar type, the ground state and the first excited state of the strong coupling magnetopolaron in cylinder shape quantum dot are considered. The results show that, with the increasi...By using the variational method of Pekar type, the ground state and the first excited state of the strong coupling magnetopolaron in cylinder shape quantum dot are considered. The results show that, with the increasing cyclotron frequency and the confinement strength, the magnetopolaron binding energies in both the ground state and the excited state, and the resonance frequency of magnetopolaron are enhanced. The limiting case of the bulk and strict one dimensional type is also discussed.展开更多
Real-time ultrasound has been, and will continue to be, one of the most important tools in enhancing genetic improvement in the U.S. Recent advancements in the technology have allowed ultrasound to be used in evaluati...Real-time ultrasound has been, and will continue to be, one of the most important tools in enhancing genetic improvement in the U.S. Recent advancements in the technology have allowed ultrasound to be used in evaluating intramuscular fat in live animals. Together with other genetic improvement tools, ultrasound technology will offer seedstock producers the opportunity to select for improved IMF in potential breeding stock replacements and hence speed genetic progress for the improvement of this trait. After three generations of selection for IMF using real-time ultrasound in an Iowa State University study, the average EBV for select line pigs is 0.83% greater than for control line pigs. Selection for IMF has, however, resulted in slightly more backfat and less loin muscle area, and a trend toward more days to 114 kg in the select line compared to the control line. Carcass evaluation of a sample of pigs from each litter indicated a similar increase in IMF, increase in backfat, and reduction in loin muscle area for select line pigs. No differences were found for Hunter L* color, Minolta reflectance, and ultimate pH.展开更多
In the present work, we have studied electronic and optical properties of a lens-shaped quantum dot under an external magnetic field. For this goal, we have calculated the energy levels and wave functions using the fi...In the present work, we have studied electronic and optical properties of a lens-shaped quantum dot under an external magnetic field. For this goal, we have calculated the energy levels and wave functions using the finite element method(FEM) for different values of magnetic field. We have also studied effect of magnetic field on second harmonic generation(SHG) and third-harmonic generation(THG) in the lens-shaped quantum dot. In this regard, we have obtained an analytic expression for the SHG and THG by a compact density matrix approach and an iterative procedure. According to the obtained results, it is found that the presence of the magnetic field affects the symmetry of the system. The SHG and THG are decreased with increasing the magnetic field. The magnetic field has a great influence on the energy levels, wave functions, the SHG and THG in a lens shaped quantum dot.展开更多
Bilayer graphene quantum dots with rotational stacking faults(RSFs) having different rotational angles were studied.Using the first-principles calculation, we determined that these stacking faults could quantitatively...Bilayer graphene quantum dots with rotational stacking faults(RSFs) having different rotational angles were studied.Using the first-principles calculation, we determined that these stacking faults could quantitatively modulate the magnetism and the distribution of spin and energy levels in the electronic structures of the dots.In addition, by examining the spatial distribution of unpaired spins and Bader charge analysis, we found that the main source of magnetic moment originated from the edge atoms of the quantum dots.Our research results can potentially provide a new path for producing all-carbon nanodevices with different electrical and magnetic properties.展开更多
文摘The magnetic behavior of a two-electron quantum dot/ring system is analytically studied with electron-electron(e-e)interaction taking into account the Rashba spin-orbit interaction(SOI)and magnetic field.The Jacobi transformation has been employed to separate the Hamiltonian of the system to the center of mass and relative terms.The Schrödinger equation is analytically solved,and energy spectra are obtained.Then,the magnetization and susceptibility are calculated.The magnetization decreases by raising the magnetic field without and with SOI,and also without e-e interaction.Also,the SOI slightly modifies the magnetization of the system without e-e interaction.The susceptibility displays a peak structure as the magnetic field changes from low values to high values.The susceptibility by considering e-e interaction and without the SOI is always negative and its value decreases by rising the magnetic field.The susceptibility displays a transition from diamagnetic to paramagnetic with e-e interaction and SOI.
基金the support of Natural Science Foundation of China(No.22276123)the Shanghai Engineering Research Center of Water Environment Simulation and Ecological Restoration(No.WESER-202201)the Postdoctoral Fellowship Program of CPSF(No.GZB20240456)。
文摘Carbon dot(CD)is an edge-bound,nanometer-sized carbon material possessing unique optical and electronic properties,making it promising metal-free,environmentally benign.In this study,we identified a highly hydrophilic CD complexed with Fe(Ⅲ)via carboxyl groups to form CD-COOFeⅢ,which exhibited remarkably enhanced Fenton-like reaction performance boosted by visible light irradiation.CD-COOFeⅢenabled high activity in the visible region beyondλ>420 nm,and maintained stable oxidation efficiency in the presence of H_(2)O_(2)over at least ten cycles.The capacity of electrons transferred from photo-excited CD to reduce Fe(Ⅲ)was calculated to be 1.1 mmol/g of CD.Furthermore,the quantum yield(QY)of solarto-Fe(Ⅱ)conversion reached an impressive 87.7%.These findings not only suggest a viable strategy for efficient conversion of solar-to-chemical using a CD-COOFeⅢcomplex in visible light boosted Fenton-like oxidation reaction,but also provide insight for understanding the effect of nanosized artificial and/or natural carbon materials in iron recycling in a natural surface environment.
基金the research result of the 2022 Municipal Education Commission Science and Technology Research Plan Project“Research on the Technology of Detecting Double-Surface Cracks in Concrete Lining of Highway Tunnels Based on Image Blast”(KJQN02202403)the first batch of school-level classroom teaching reform projects“Principles Applications of Embedded Systems”(23JG2166)the school-level reform research project“Continuous Results-Oriented Practice Research Based on BOPPPS Teaching Model-Taking the‘Programming Fundamentals’Course as an Example”(22JG332).
文摘With the rapid development of modern information technology,the Internet of Things(IoT)has been integrated into various fields such as social life,industrial production,education,and medical care.Through the connection of various physical devices,sensors,and machines,it realizes information intercommunication and remote control among devices,significantly enhancing the convenience and efficiency of work and life.However,the rapid development of the IoT has also brought serious security problems.IoT devices have limited resources and a complex network environment,making them one of the important targets of network intrusion attacks.Therefore,from the perspective of deep learning,this paper deeply analyzes the characteristics and key points of IoT intrusion detection,summarizes the application advantages of deep learning in IoT intrusion detection,and proposes application strategies of typical deep learning models in IoT intrusion detection so as to improve the security of the IoT architecture and guarantee people’s convenient lives.
基金Gansu Provincial Department of Education:Innovation Fund Project for College Teachers:Research on the Governance of Network Public Opinion Reversal Based on Blockchain Technology(NO.2025A-137)Teaching Reform Research at the School Level of Gansu University of Political Science and Law in 2024:Research and Implementation of CSCW Cloud Storage Collective Lesson Preparation System Based on Blockchain Technology(NO.GZJG2024-A04)+1 种基金2024 Gansu University of Political Science and Law“Three in One Education”Research:Project Research and Implementation of CSCW Network Teaching Platform Based on Web in the Direction of Network Education(NO.GZSQYR-37)2024 Lanzhou Philosophy and Social Sciences Planning Project:Research on Cloud Governance of Network Public Opinion for Major Public Events in Lanzhou City(NO.24-B45)。
文摘In recent years,the network public opinion reversal governance events have occurred frequently.Over time,the repeated truth of the matter will not only weaken the rational judgment of the public to a certain extent,so that its negative emotions accumulate,but also have a serious impact on the credibility of the media and the government,and may even further intensify social contradictions.Therefore,in the face of such a complex online public opinion space,accurately identifying the truth behind the incident and how to carry out the reversal of online public opinion governance is particularly critical.And blockchain technology,with its advantages of decentralization and immutable information,provides new technical support for the network public opinion reversal governance.Based on this,this paper gives an overview and analysis of blockchain technology and network public opinion reversal,and on this basis introduces the network public opinion reversal governance mechanism based on blockchain technology,aiming to further optimize the network public opinion reversal governance process,for reference only.
文摘The Internet of Things technology provides a comprehensive solution for the real-time monitoring of cold chain logistics by integrating sensors,wireless communication,cloud computing,and big data analysis.Based on this,this paper deeply explores the overview and characteristics of the Internet of Things technology,the feasibility analysis of the Internet of Things technology in the cold chain logistics monitoring,the application analysis of the Internet of Things technology in the cold chain logistics real-time monitoring to better improve the management level and operational efficiency of the cold chain logistics,to provide consumers with safer and fresh products.
文摘Objective:To study the effect of transcranial magnetic stimulation(TMS)on improving motor symptoms in patients with Parkinson’s disease(PD).Methods:60 PD patients who visited the hospital from September 2023 to August 2024 were selected as samples and randomly divided into two groups.Group A received conventional medication plus TMS treatment,while Group B received medication only.The efficacy of motor function improvement,neurological symptoms,mental state,sleep quality,quality of life,and adverse reactions was compared between the two groups.Results:The efficacy of Group A was higher than that of Group B(P<0.05).The scores of the Scales for Outcomes in Parkinson’s Disease-Autonomic(SCOPA-AUT),Mini-Mental State Examination(MMSE),and Pittsburgh Sleep Quality Index(PSQI)in Group A were lower than those in Group B(P<0.05).The quality of life scale(SF-36)score in Group A was higher than that in Group B(P<0.05).The adverse reaction rate in Group A was lower than that in Group B(P<0.05).Conclusion:TMS used in the treatment of PD patients can improve patients’mental state and motor function,optimize sleep quality and quality of life,and is safe and efficient.
基金financial support from the Shanghai Key Laboratory of MFree,China(Grant No.22dz2260800)the Shanghai Science and Technology Committee,China(Grant No.22JC1410300).
文摘The 2024 MRE HP Special Volume selects papers on new theoretical and experimental developments in the use of static largevolume presses(LVPs)1–3 and dynamic compression4,5 for studies under extreme high-pressure and high-temperature(HPHT)conditions.It also continues the previous year’s6 contemporary focus on superhydrides7–11 with extremely high superconducting temperatures Tc and addresses some controversial issues.12–14 In addition,it explores unconventional pressure-induced chemistry,particularly novel chemical stoichiometry and its impact on geochemistry and cosmochemistry in the deep interiors of Earth and other planets.18–21.
文摘The moment a media delegation from the Republic of the Congo arrived at the Othello Kitchenware Museum on 18 November 2025,they were greeted with a vivid show of Guangdong’s industrial strength.Standing before them was not a typical exhibition hall,but a building shaped like a gleaming stainless-steel cooking pot.
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 Social Science Foundation of China:the Sociological Study on the Technology Adoption Behaviors of Farmers(08BSH049)~~
文摘[Objective] To analyze the key factor in agricultural technology diffusion- technology support, and to explore the method to quicken the diffusion of agricultural technology. [Method] The technology acquisition advantage of social network was il- lustrated by summarizing the status and characteristics of agricultural technology and technology supporting types in the process of agriculture technology diffusion. [Result] The multi-layer, complex, persistence, systematization features of agricultural technol- ogy require support and help of technology from surrounding social network to ulti- mately internalize the technology. [Conclusion] Using social networks for the technol- ogy support will be a powerful supplement to the system of agricultural technology diffusion.
文摘By using variational method of Pekar type, we have studied the energy levels of strong coupling magnetopolaron in disk shape quantum dot(QD) and quantum well(QW). Our results show that, with the increasing magnetic field and confinement strength, the magnetopolaron binding energy of QD and QW in the ground state and in the excited state is enhanced. The limiting results of bulk type and strict two dimensional type are obtained.
基金supported by NTUA*STAR Silicon Technologies Centre of Excellence under the program Grant (No.11235100003)Grants Tier 2 MOE2017-T2-2-002 (No.M402110000) from Ministry of Educationthe NRF-ANR Joint Call 2017 Research Grant (No. M419640000) from the National Research Foundation,Singapore
文摘Over the past decade, carbon dots have ignited a burst of interest in many different fields, including nanomedicine, solar energy, optoelectronics, energy storage,and sensing applications, owing to their excellent photoluminescence properties and the easiness to modify their optical properties through doping and functionalization. In this review, the synthesis, structural and optical properties,as well as photoluminescence mechanisms of carbon dots are first reviewed and summarized. Then, we describe a series of designs for carbon dot-based sensors and the different sensing mechanisms associated with them.Thereafter, we elaborate on recent research advances on carbon dot-based sensors for the selective and sensitive detection of a wide range of analytes, including heavy metals, cations, anions, biomolecules, biomarkers,nitroaromatic explosives, pollutants, vitamins, and drugs.Lastly, we provide a concluding perspective on the overall status, challenges, and future directions for the use of carbon dots in real-life sensing.
文摘By using the variational method of Pekar type, the ground state and the first excited state of the strong coupling magnetopolaron in cylinder shape quantum dot are considered. The results show that, with the increasing cyclotron frequency and the confinement strength, the magnetopolaron binding energies in both the ground state and the excited state, and the resonance frequency of magnetopolaron are enhanced. The limiting case of the bulk and strict one dimensional type is also discussed.
文摘Real-time ultrasound has been, and will continue to be, one of the most important tools in enhancing genetic improvement in the U.S. Recent advancements in the technology have allowed ultrasound to be used in evaluating intramuscular fat in live animals. Together with other genetic improvement tools, ultrasound technology will offer seedstock producers the opportunity to select for improved IMF in potential breeding stock replacements and hence speed genetic progress for the improvement of this trait. After three generations of selection for IMF using real-time ultrasound in an Iowa State University study, the average EBV for select line pigs is 0.83% greater than for control line pigs. Selection for IMF has, however, resulted in slightly more backfat and less loin muscle area, and a trend toward more days to 114 kg in the select line compared to the control line. Carcass evaluation of a sample of pigs from each litter indicated a similar increase in IMF, increase in backfat, and reduction in loin muscle area for select line pigs. No differences were found for Hunter L* color, Minolta reflectance, and ultimate pH.
文摘In the present work, we have studied electronic and optical properties of a lens-shaped quantum dot under an external magnetic field. For this goal, we have calculated the energy levels and wave functions using the finite element method(FEM) for different values of magnetic field. We have also studied effect of magnetic field on second harmonic generation(SHG) and third-harmonic generation(THG) in the lens-shaped quantum dot. In this regard, we have obtained an analytic expression for the SHG and THG by a compact density matrix approach and an iterative procedure. According to the obtained results, it is found that the presence of the magnetic field affects the symmetry of the system. The SHG and THG are decreased with increasing the magnetic field. The magnetic field has a great influence on the energy levels, wave functions, the SHG and THG in a lens shaped quantum dot.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11374174,51390471,51527803,and 51701143)the National Basic Research Program of China(Grant No.2015CB654902)+4 种基金the National Key Research and Development Program of China(Grant No.2016YFB0700402)the Foundation for the Author of National Excellent Doctoral Dissertation,China(Grant No.201141)the Tianjin Municipal Education Commission,Chinathe Tianjin Municipal Science and Technology Commission,Chinathe Fundamental Research Fund of Tianjin University of Technology
文摘Bilayer graphene quantum dots with rotational stacking faults(RSFs) having different rotational angles were studied.Using the first-principles calculation, we determined that these stacking faults could quantitatively modulate the magnetism and the distribution of spin and energy levels in the electronic structures of the dots.In addition, by examining the spatial distribution of unpaired spins and Bader charge analysis, we found that the main source of magnetic moment originated from the edge atoms of the quantum dots.Our research results can potentially provide a new path for producing all-carbon nanodevices with different electrical and magnetic properties.
