Synthesis of functional nanostructures with the least number of tests is paramount towards the propelling materials development. However, the synthesis method containing multivariable leads to high uncertainty, exhaus...Synthesis of functional nanostructures with the least number of tests is paramount towards the propelling materials development. However, the synthesis method containing multivariable leads to high uncertainty, exhaustive attempts, and exorbitant manpower costs. Machine learning (ML) burgeons and provokes an interest in rationally designing and synthesizing materials. Here, we collect the dataset of nano-functional materials carbon dots (CDs) on synthetic parameters and optical properties. ML is applied to assist the synthesis process to enhance photoluminescence quantum yield (QY) by building the methodology named active adaptive method (AAM), including the model selection, max points screen, and experimental verification. An interactive iteration strategy is the first time considered in AAM with the constant acquisition of the furnished data by itself to perfect the model. CDs exhibit a strong red emission with QY up to 23.3% and enhancement of around 200% compared with the pristine value obtained through the AAM guidance. Furthermore, the guided CDs are applied as metal ions probes for Co^(2+) and Fe^(3+), with a concentration range of 0–120 and 0–150 µM, and their detection limits are 1.17 and 0.06 µM. Moreover, we also apply CDs for dental diagnosis and treatment using excellent optical ability. It can effectively detect early caries and treat mineralization combined with gel. The study shows that the error of experiment verification gradually decreases and QY improves double with the effective feedback loops by AAM, suggesting the great potential of utilizing ML to guide the synthesis of novel materials. Finally, the code is open-source and provided to be referenced for further investigation on the novel inorganic material prediction.展开更多
In this work,p⁃phenylenediamine and L⁃cysteine were used as raw materials,and water⁃soluble N,S co⁃doped carbon dots(N,S⁃CDs)with excellent performance were prepared through a one⁃step solvothermal method.The morpholo...In this work,p⁃phenylenediamine and L⁃cysteine were used as raw materials,and water⁃soluble N,S co⁃doped carbon dots(N,S⁃CDs)with excellent performance were prepared through a one⁃step solvothermal method.The morphology and structure of N,S⁃CDs were characterized by transmission electron microscope,X⁃ray diffrac⁃tion,Fourier transform infrared spectroscopy,and X⁃ray photoelectron spectroscopy,and the basic photophysical properties were investigated via UV⁃Vis absorption spectra and fluorescence spectra.Meanwhile,the N,S⁃CDs have excellent luminescence stability with pH,ionic strength,radiation time,and storage time.Experimental results illus⁃trated the present sensor platform exhibited high sensitivity and selectivity in response to baicalein with a detection limit of 85 nmol·L-1.The quenching mechanism is proved to be the inner filter effect.In addition,this sensor can also detect baicalein in biofluids(serum and urine)with good accuracy and reproducibility.展开更多
We show that the recently proposed invariant eigenoperator method can be successfully applied to solving the energy levels of an electron in a saddle-potential quantum dot under a uniform magnetic field. The Landau di...We show that the recently proposed invariant eigenoperator method can be successfully applied to solving the energy levels of an electron in a saddle-potential quantum dot under a uniform magnetic field. The Landau diamagnetism decreases with the value wy2 - wx2 due to the existence of the saddle potential.展开更多
The magnetization of two interacting electrons confined in a quantum dot presented in a magnetic field had been calculated by solving the relative Hamiltonian using variational method. We had investigated the dependen...The magnetization of two interacting electrons confined in a quantum dot presented in a magnetic field had been calculated by solving the relative Hamiltonian using variational method. We had investigated the dependence of the magnetization on temperature, magnetic field strength and confining frequency. The singlet-triplet transitions in the ground state of the quantum dot spectra and the corresponding jumps in the magnetization curves had been shown. The comparisons show that our results are in very good agreement with reported works.展开更多
We investigate the nonlinear optical rectification(NOR) of spherical quantum dots(QDs) under Hulthén plus Hellmann confining potential with the external tuning elements. Energy and wavefunction are determined by ...We investigate the nonlinear optical rectification(NOR) of spherical quantum dots(QDs) under Hulthén plus Hellmann confining potential with the external tuning elements. Energy and wavefunction are determined by using the Nikiforov–Uvarov method. Expression for the NOR coefficient is derived by the density matrix theory. The results show that the applied external elements and internal parameters of this system have a strong influence on intraband nonlinear optical properties. It is hopeful that this tuning of the nonlinear optical properties of GaAs/Ga_(1-x)Al_(x)As QDs can make a greater contribution to preparation of new functional optical devices.展开更多
以尼龙66(PA66)和植酸(IP6)为前驱体、乙酸为溶剂,采用溶剂热法制备了PA66基碳点(66CDs)。利用TEM、FTIR、XPS、荧光光谱对其进行了表征,对其光学性能、离子稳定性和时间稳定性进行了测试,探究了其指纹识别、荧光防伪、光线阻挡的应用...以尼龙66(PA66)和植酸(IP6)为前驱体、乙酸为溶剂,采用溶剂热法制备了PA66基碳点(66CDs)。利用TEM、FTIR、XPS、荧光光谱对其进行了表征,对其光学性能、离子稳定性和时间稳定性进行了测试,探究了其指纹识别、荧光防伪、光线阻挡的应用。结果表明,将1.6 g PA66、1.1 g IP6加入20 mL乙酸中,于260℃下反应36h,制备的66CDs具有最大荧光强度。66CDs为球形结构,平均粒径4.00nm,表面含有羧基、羟基、氨基等官能团;66CDs的荧光为非激发波长依赖型,最佳激发波长和发射波长分别为360和490 nm,荧光量子产率可达11.69%,其荧光强度不受常见金属阳离子影响,30 d内具有稳定性。由66CDs与水溶性淀粉制备的荧光粉末可用于指纹识别,不仅可将66CDs制成油墨用于荧光防伪,还可将其制成防蓝光膜,用于蓝光防护。展开更多
混凝土是由砂浆和骨料构成的非均质材料。在细观层面上评估混凝土的断裂过程有助于阐明混凝土的材料特性。采用C++编制的梁-粒子模型求解器(Beam Particle Model Solver,简称BPMS)对砂浆和混凝土进行二维数值分析。为了模拟混凝土的断裂...混凝土是由砂浆和骨料构成的非均质材料。在细观层面上评估混凝土的断裂过程有助于阐明混凝土的材料特性。采用C++编制的梁-粒子模型求解器(Beam Particle Model Solver,简称BPMS)对砂浆和混凝土进行二维数值分析。为了模拟混凝土的断裂,采用点阵法高效快速地建立细观尺度的颗粒模型。数值研究较好地呈现了砂浆和混凝土在单轴压缩条件下的破坏行为以及混凝土三点弯在冲击条件下的断裂过程,从而证实了BPMS的强健性及稳定性。展开更多
基金the support from Beijing National Science Foundation(No.L222109)the Military Health Care Project(No.22BJZ22)+1 种基金Q.X.acknowledges the support from the National Natural Science Foundation of China(No.52211530034)the Beijing National Science Foundation(No.3222018).
文摘Synthesis of functional nanostructures with the least number of tests is paramount towards the propelling materials development. However, the synthesis method containing multivariable leads to high uncertainty, exhaustive attempts, and exorbitant manpower costs. Machine learning (ML) burgeons and provokes an interest in rationally designing and synthesizing materials. Here, we collect the dataset of nano-functional materials carbon dots (CDs) on synthetic parameters and optical properties. ML is applied to assist the synthesis process to enhance photoluminescence quantum yield (QY) by building the methodology named active adaptive method (AAM), including the model selection, max points screen, and experimental verification. An interactive iteration strategy is the first time considered in AAM with the constant acquisition of the furnished data by itself to perfect the model. CDs exhibit a strong red emission with QY up to 23.3% and enhancement of around 200% compared with the pristine value obtained through the AAM guidance. Furthermore, the guided CDs are applied as metal ions probes for Co^(2+) and Fe^(3+), with a concentration range of 0–120 and 0–150 µM, and their detection limits are 1.17 and 0.06 µM. Moreover, we also apply CDs for dental diagnosis and treatment using excellent optical ability. It can effectively detect early caries and treat mineralization combined with gel. The study shows that the error of experiment verification gradually decreases and QY improves double with the effective feedback loops by AAM, suggesting the great potential of utilizing ML to guide the synthesis of novel materials. Finally, the code is open-source and provided to be referenced for further investigation on the novel inorganic material prediction.
文摘In this work,p⁃phenylenediamine and L⁃cysteine were used as raw materials,and water⁃soluble N,S co⁃doped carbon dots(N,S⁃CDs)with excellent performance were prepared through a one⁃step solvothermal method.The morphology and structure of N,S⁃CDs were characterized by transmission electron microscope,X⁃ray diffrac⁃tion,Fourier transform infrared spectroscopy,and X⁃ray photoelectron spectroscopy,and the basic photophysical properties were investigated via UV⁃Vis absorption spectra and fluorescence spectra.Meanwhile,the N,S⁃CDs have excellent luminescence stability with pH,ionic strength,radiation time,and storage time.Experimental results illus⁃trated the present sensor platform exhibited high sensitivity and selectivity in response to baicalein with a detection limit of 85 nmol·L-1.The quenching mechanism is proved to be the inner filter effect.In addition,this sensor can also detect baicalein in biofluids(serum and urine)with good accuracy and reproducibility.
基金supported by the Doctoral Scientific Research Startup Fund of Anhui University,China (Grant No. 33190059)the National Natural Science Foundation of China (Grant No. 10874174)+1 种基金the President Foundation of the Chinese Academy of Sciencesthe Open Fund of the State Key Laboratory for Infrared Physics
文摘We show that the recently proposed invariant eigenoperator method can be successfully applied to solving the energy levels of an electron in a saddle-potential quantum dot under a uniform magnetic field. The Landau diamagnetism decreases with the value wy2 - wx2 due to the existence of the saddle potential.
文摘The magnetization of two interacting electrons confined in a quantum dot presented in a magnetic field had been calculated by solving the relative Hamiltonian using variational method. We had investigated the dependence of the magnetization on temperature, magnetic field strength and confining frequency. The singlet-triplet transitions in the ground state of the quantum dot spectra and the corresponding jumps in the magnetization curves had been shown. The comparisons show that our results are in very good agreement with reported works.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.51702003,61775087,11674312,52174161,and 12174161)。
文摘We investigate the nonlinear optical rectification(NOR) of spherical quantum dots(QDs) under Hulthén plus Hellmann confining potential with the external tuning elements. Energy and wavefunction are determined by using the Nikiforov–Uvarov method. Expression for the NOR coefficient is derived by the density matrix theory. The results show that the applied external elements and internal parameters of this system have a strong influence on intraband nonlinear optical properties. It is hopeful that this tuning of the nonlinear optical properties of GaAs/Ga_(1-x)Al_(x)As QDs can make a greater contribution to preparation of new functional optical devices.
文摘以尼龙66(PA66)和植酸(IP6)为前驱体、乙酸为溶剂,采用溶剂热法制备了PA66基碳点(66CDs)。利用TEM、FTIR、XPS、荧光光谱对其进行了表征,对其光学性能、离子稳定性和时间稳定性进行了测试,探究了其指纹识别、荧光防伪、光线阻挡的应用。结果表明,将1.6 g PA66、1.1 g IP6加入20 mL乙酸中,于260℃下反应36h,制备的66CDs具有最大荧光强度。66CDs为球形结构,平均粒径4.00nm,表面含有羧基、羟基、氨基等官能团;66CDs的荧光为非激发波长依赖型,最佳激发波长和发射波长分别为360和490 nm,荧光量子产率可达11.69%,其荧光强度不受常见金属阳离子影响,30 d内具有稳定性。由66CDs与水溶性淀粉制备的荧光粉末可用于指纹识别,不仅可将66CDs制成油墨用于荧光防伪,还可将其制成防蓝光膜,用于蓝光防护。
文摘混凝土是由砂浆和骨料构成的非均质材料。在细观层面上评估混凝土的断裂过程有助于阐明混凝土的材料特性。采用C++编制的梁-粒子模型求解器(Beam Particle Model Solver,简称BPMS)对砂浆和混凝土进行二维数值分析。为了模拟混凝土的断裂,采用点阵法高效快速地建立细观尺度的颗粒模型。数值研究较好地呈现了砂浆和混凝土在单轴压缩条件下的破坏行为以及混凝土三点弯在冲击条件下的断裂过程,从而证实了BPMS的强健性及稳定性。
