The concept of“STEM+”integrates art,humanistic literacy,and social values in the traditional STEM education concept,advocates cross-disciplinary integration,and aims to cultivate compound talents equipped to tackle ...The concept of“STEM+”integrates art,humanistic literacy,and social values in the traditional STEM education concept,advocates cross-disciplinary integration,and aims to cultivate compound talents equipped to tackle future challenges.In 2022,the Ministry of Education issued the“Compulsory Education Information Technology Curriculum(2022 Edition),”emphasizing the core literacy of information science and technology and the integration of interdisciplinary disciplines,and encouraging the teaching mode suitable for discipline characteristics.The 6E teaching mode is a student-centered teaching strategy characterized by active exploration and cross-disciplinary integration.This article innovatively designed the“STEM+”6E teaching mode,which is applied to junior high school information technology teaching,which can better achieve core literacy teaching goals.展开更多
SF_(6)电气设备内部的分解组分可以通过可调谐吸收光谱技术进行检测,其中CO_(2)浓度反映了设备内部的绝缘缺陷情况。因此,通过准确测量CO_(2)浓度可以及时发现设备潜在的绝缘故障。为克服传统最小二乘法浓度反演模型稳定性较差的问题,...SF_(6)电气设备内部的分解组分可以通过可调谐吸收光谱技术进行检测,其中CO_(2)浓度反映了设备内部的绝缘缺陷情况。因此,通过准确测量CO_(2)浓度可以及时发现设备潜在的绝缘故障。为克服传统最小二乘法浓度反演模型稳定性较差的问题,文中基于改进的旗鱼优化算法(Improved Sailed Fish Optimizer,ISFO)与核极限学习机(Kernel Based Extreme Learning Machine,KELM)建立了ISFO-KELM气体浓度反演模型。利用多策略初始化方法、Levy随机步长、柯西变异和自适应t分布变异等技术提升了旗鱼优化算法寻优能力和跳出局部最优解能力。实验结果表明,该模型具有高精度和鲁棒性,并且在稳定性和泛化能力方面优于最小二乘法、极限学习机、反向传播(Back Propagation,BP)神经网络等传统方法,对评估SF_(6)电气设备运行状态具有重要意义。展开更多
The non-chain chemical HF(DF)laser is one of the most powerful electrically-driven lasers operating in mid-infrared,in which SF6-C2H6 mixtures are often used as lasering media.Due to the electronegativity of SF6,the d...The non-chain chemical HF(DF)laser is one of the most powerful electrically-driven lasers operating in mid-infrared,in which SF6-C2H6 mixtures are often used as lasering media.Due to the electronegativity of SF6,the discharge in SF6-C2H6 presents a complicated discharge mode.To achieve reproducible pulsed laser output,pulsed discharge in SF6-C2H6 mixtures is investigated for discharge mode using plane electrodes assisted by array pre-ionization spark pins in cathode surface.Firstly,two modes can be distinguished.One mode is called the selfsustained volume discharge(SSVD),which is characterized by spatial uniformity in the discharge gap and pulse to pulse repeatability.On the contrary,another mode includes random arc passages in the discharge gap and therefore cannot conduct lasering.By varying discharge conditions(gap voltage,gas pressure,etc)two discharge modes are observed.Secondly,the holding scope of the SSVD mode is analyzed for the optimal mixture ratio of 20:1,and the boundary tend of the holding scope of SSVD indicates there exists maximum gas pressure and maximum charging voltage for SSVD.Finally,the peak current of SSVD relates positively to charging voltage,while negatively to gas pressure,from which it is drawn that synchronous electron avalanches initiated by the sliding array overlap spatially into SSVD and thus SSVD is essentially an α ionization avalanche.展开更多
A temperature-dependent Raman spectroscopic study on Bi2 Zn OB2O6crystal was carried out to investigate the structure change of the crystal with the increase of temperature. Raman spectra of crystal Bi2 Zn OB2O6were r...A temperature-dependent Raman spectroscopic study on Bi2 Zn OB2O6crystal was carried out to investigate the structure change of the crystal with the increase of temperature. Raman spectra of crystal Bi2 Zn OB2O6were recorded in the spectral range 10–1600 cm-1at room temperature first. Compared with the vibrational spectra of the referred compounds,satisfactory assignment of most of the high-energy modes to vibrations of Bi–O, B–O, and Zn–O bonds was achieved. In particular, the Raman high-frequency peak located at 1344 cm-1was attributed to the B–O vibration in the BO3 triangle.This temperature-dependent Raman spectroscopic study was carried out up to 600°C. It was found that all the Raman lines exhibit decreases in frequency and the widths of the Raman peaks increase with increasing temperature. No phase transition was observed under 600°C.展开更多
Raman spectra of a vanadoborate （Na3VO2B6Oll） crystal from room temperature up to the melting point have been recorded. The main internal vibrational modes of the crystal have been assigned. It was found that all th...Raman spectra of a vanadoborate （Na3VO2B6Oll） crystal from room temperature up to the melting point have been recorded. The main internal vibrational modes of the crystal have been assigned. It was found that all the Raman bands exhibit decreases in frequency and the widths of the Raman bands increase with the increase of temperature. However, no phase transition was observed under 525 ℃. The micro-structure of its melt was studied by quantum chemistry ab initio calculation. The continuous three-dimensional network of the crystal collapsed and transformed into VO4 and VBO6 clusters during the melting process with an isomerization reaction from four-coordinated boron to a three-coordinated species.展开更多
基金2024 Chongqing Normal University Graduate Research Innovation Project“Construction and Application of Information Technology Knowledge Map based on the Three-Layer Architecture”(CYS240395)。
文摘The concept of“STEM+”integrates art,humanistic literacy,and social values in the traditional STEM education concept,advocates cross-disciplinary integration,and aims to cultivate compound talents equipped to tackle future challenges.In 2022,the Ministry of Education issued the“Compulsory Education Information Technology Curriculum(2022 Edition),”emphasizing the core literacy of information science and technology and the integration of interdisciplinary disciplines,and encouraging the teaching mode suitable for discipline characteristics.The 6E teaching mode is a student-centered teaching strategy characterized by active exploration and cross-disciplinary integration.This article innovatively designed the“STEM+”6E teaching mode,which is applied to junior high school information technology teaching,which can better achieve core literacy teaching goals.
文摘SF_(6)电气设备内部的分解组分可以通过可调谐吸收光谱技术进行检测,其中CO_(2)浓度反映了设备内部的绝缘缺陷情况。因此,通过准确测量CO_(2)浓度可以及时发现设备潜在的绝缘故障。为克服传统最小二乘法浓度反演模型稳定性较差的问题,文中基于改进的旗鱼优化算法(Improved Sailed Fish Optimizer,ISFO)与核极限学习机(Kernel Based Extreme Learning Machine,KELM)建立了ISFO-KELM气体浓度反演模型。利用多策略初始化方法、Levy随机步长、柯西变异和自适应t分布变异等技术提升了旗鱼优化算法寻优能力和跳出局部最优解能力。实验结果表明,该模型具有高精度和鲁棒性,并且在稳定性和泛化能力方面优于最小二乘法、极限学习机、反向传播(Back Propagation,BP)神经网络等传统方法,对评估SF_(6)电气设备运行状态具有重要意义。
基金National Natural Science Foundation of China(No.11375041).
文摘The non-chain chemical HF(DF)laser is one of the most powerful electrically-driven lasers operating in mid-infrared,in which SF6-C2H6 mixtures are often used as lasering media.Due to the electronegativity of SF6,the discharge in SF6-C2H6 presents a complicated discharge mode.To achieve reproducible pulsed laser output,pulsed discharge in SF6-C2H6 mixtures is investigated for discharge mode using plane electrodes assisted by array pre-ionization spark pins in cathode surface.Firstly,two modes can be distinguished.One mode is called the selfsustained volume discharge(SSVD),which is characterized by spatial uniformity in the discharge gap and pulse to pulse repeatability.On the contrary,another mode includes random arc passages in the discharge gap and therefore cannot conduct lasering.By varying discharge conditions(gap voltage,gas pressure,etc)two discharge modes are observed.Secondly,the holding scope of the SSVD mode is analyzed for the optimal mixture ratio of 20:1,and the boundary tend of the holding scope of SSVD indicates there exists maximum gas pressure and maximum charging voltage for SSVD.Finally,the peak current of SSVD relates positively to charging voltage,while negatively to gas pressure,from which it is drawn that synchronous electron avalanches initiated by the sliding array overlap spatially into SSVD and thus SSVD is essentially an α ionization avalanche.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.50932005 and 51102239)
文摘A temperature-dependent Raman spectroscopic study on Bi2 Zn OB2O6crystal was carried out to investigate the structure change of the crystal with the increase of temperature. Raman spectra of crystal Bi2 Zn OB2O6were recorded in the spectral range 10–1600 cm-1at room temperature first. Compared with the vibrational spectra of the referred compounds,satisfactory assignment of most of the high-energy modes to vibrations of Bi–O, B–O, and Zn–O bonds was achieved. In particular, the Raman high-frequency peak located at 1344 cm-1was attributed to the B–O vibration in the BO3 triangle.This temperature-dependent Raman spectroscopic study was carried out up to 600°C. It was found that all the Raman lines exhibit decreases in frequency and the widths of the Raman peaks increase with increasing temperature. No phase transition was observed under 600°C.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51302268 and 51102239)the Natural Science Foundation of Anhui Province,China(Grant No.KJ2015A339)
文摘Raman spectra of a vanadoborate （Na3VO2B6Oll） crystal from room temperature up to the melting point have been recorded. The main internal vibrational modes of the crystal have been assigned. It was found that all the Raman bands exhibit decreases in frequency and the widths of the Raman bands increase with the increase of temperature. However, no phase transition was observed under 525 ℃. The micro-structure of its melt was studied by quantum chemistry ab initio calculation. The continuous three-dimensional network of the crystal collapsed and transformed into VO4 and VBO6 clusters during the melting process with an isomerization reaction from four-coordinated boron to a three-coordinated species.
