The Ga_(2)O_(3) films are deposited on the Si and quartz substrates by magnetron sputtering, and annealing. The effects of preparation parameters(such as argon–oxygen flow ratio, sputtering power, sputtering time and...The Ga_(2)O_(3) films are deposited on the Si and quartz substrates by magnetron sputtering, and annealing. The effects of preparation parameters(such as argon–oxygen flow ratio, sputtering power, sputtering time and annealing temperature)on the growth and properties(e.g., surface morphology, crystal structure, optical and electrical properties of the films) are studied by x-ray diffractometer(XRD), scanning electron microscope(SEM), and ultraviolet-visible spectrophotometer(UV-Vis). The results show that the thickness, crystallization quality and surface roughness of the β-Ga_(2)O_(3) film are influenced by those parameters. All β-Ga_(2)O_(3) films show good optical properties. Moreover, the value of bandgap increases with the enlarge of the percentage of oxygen increasing, and decreases with the increase of sputtering power and annealing temperature, indicating that the bandgap is related to the quality of the film and affected by the number of oxygen vacancy defects. The I–V curves show that the Ohmic behavior between metal and β-Ga_(2)O_(3) films is obtained at 900℃. Those results will be helpful for the further research of β-Ga_(2)O_(3) photoelectric semiconductor.展开更多
Rational carbonate electrolyte chemistry is critical for the development of high-voltage lithium metal batteries(LMBs).However,the implementation of traditional carbonate electrolyte is greatly hindered by the generat...Rational carbonate electrolyte chemistry is critical for the development of high-voltage lithium metal batteries(LMBs).However,the implementation of traditional carbonate electrolyte is greatly hindered by the generation of an unstable electrode interphase and corrosive by-product(HF).Herein,we propose a triple-function eutectic solvent additive of N-methylacetamide(NmAc)with LiNO_(3) to enhance the stability and compatibility of carbonate electrolyte.Firstly,the addition of NmAc significantly improves the solubility of LiNO_(3) in carbonate electrolyte by forming an eutectic pair,which regulates the Li~+solvation structure and leads to dense and homogenous Li plating.Secondly,the hydrolysis of acidic PF_5 is effectively alleviated due to the strong complexation of NmAc with PF_5,thus reducing the generation of corrosive HF.In addition,the optimized cathode electrolyte interphase layer decreases the structural degradation and transition metal dissolution.Consequently,Li||LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622)cells with the designed electrolyte deliver superior long-term cycle reversibility and excellent rate capability.This study unveils the rationale for incorporating eutectic solvent additives within carbonate electrolytes,which significantly contribute to the advancement of their practical application for high-voltage LMBs.展开更多
This review summarizes the clinical efficacy and experimental research of traditional Chinese medicine(TCM)moxibustion in the intervention of ovarian injury.Clinical and experimental research results have shown that a...This review summarizes the clinical efficacy and experimental research of traditional Chinese medicine(TCM)moxibustion in the intervention of ovarian injury.Clinical and experimental research results have shown that as a nonpharmacological treatment method,Chinese medical moxibustion therapy is of great significance in the treatment of ovarian injuries such as diminished ovarian reserve,polycystic ovarian syndrome,premature ovarian failure,and premature ovarian insufficiency.Moxibustion,heat-sensitive moxibustion,and electroacupuncture have significant effects in improving ovarian func-tion,overall treatment efficacy,pregnancy rate,ovulation rate,and sex hormone levels and have higher safety.Their therapeutic mechanisms have also been demonstrated.In conclusion,TCM moxibustion therapy has a significant effect in the treatment of ovarian injury,providing a new option for the treatment of the ovarian injury.展开更多
In this paper,we report on a wide wavelength tuning optical vortex carrying orbital angular momentum(OAM)of±?,from a thulium-doped yttrium aluminum perovskite(YAP)laser employing a birefringent filter.The OAM is ...In this paper,we report on a wide wavelength tuning optical vortex carrying orbital angular momentum(OAM)of±?,from a thulium-doped yttrium aluminum perovskite(YAP)laser employing a birefringent filter.The OAM is experimentally found to be well maintained during the whole wavelength tuning process.The Laguerre-Gaussian(LG_(0,+1))mode with a tuning range of 58 nm from 1934.8 to 1993.0 nm and LG0,-1mode with a range of 76 nm from 1920.4 to 1996.6 nm,are,respectively,obtained.This is,to the best of our knowledge,the first experimental implementation of wavelength tuning for a scalar vortex laser in the 2μm spectral range,as well as the broadest tuning range ever reported from the vortex laser cavity.Such a vortex laser with robust structure and straightforward wavelength tuning capability will be an ideal light source for potential applications in the field of optical communication with one additional degree of freedom.展开更多
氢能作为一种潜在的能源载体,有望取代化石燃料,解决当今社会的能源需求和环境问题.质子交换膜电解水(PEMWE)技术因其工作电流密度大、氢气纯度高和系统响应迅速等优点,能够有效地弥补可再生能源波动性等缺点,被认为是一种利用可再生能...氢能作为一种潜在的能源载体,有望取代化石燃料,解决当今社会的能源需求和环境问题.质子交换膜电解水(PEMWE)技术因其工作电流密度大、氢气纯度高和系统响应迅速等优点,能够有效地弥补可再生能源波动性等缺点,被认为是一种利用可再生能源制氢的可持续手段.但其阳极氧析出反应(OER)为四电子/质子转移过程,反应动力学缓慢,同时强氧化性和强酸性环境会对阳极催化剂的产生腐蚀,导致稳定性差,因此亟需开发高效且稳定的催化剂.研究发现,无定型氧化铱材料中的特殊缺陷结构可显著提升其催化酸性OER的活性,但该结构也会加速反应过程中铱的溶解,导致催化剂稳定性降低,严重限制了其实际应用.本文采用高价金属掺杂的策略,利用高价金属元素与氧的强成键作用,对无定型氧化铱的整体结构及活性位点起到优化且稳定的作用.首先,采用改性的亚当斯熔融法制备了金属钽掺杂的无定型氧化铱:350-Ta@IrO_(x),400-Ta@IrO_(x),450-Ta@IrO_(x)(350,400和450代表样品分别在350,400和450℃烧结),并用于催化酸性OER;作为对比,制备了无掺杂的无定型氧化铱:350-IrO_(x),400-IrO_(x)和450-IrO_(x).然后,通过扫描电子显微镜、透射电子显微镜(TEM)和X射线衍射等表征技术考察了材料的宏观形貌及微观结构.结果表明,掺杂后的350-Ta@IrO_(x)材料表面具有丰富的氧空位贡献的活性位点,且表现出多晶的超小纳米颗粒形貌.电化学测试结果表明,350-Ta@IrO_(x)具有较好的酸性OER活性,在10 mA cm-2的电流密度下,过电势仅为223 mV,在1.55 V vs.RHE的电位下质量活性为1207.4 A gIr-1,是商业二氧化铱的147.7倍.且该催化剂的稳定性比未掺杂Ta样品及商业二氧化铱有明显提升,在0.5 mol L^(-1)硫酸溶液中反应500 h后电位未发生明显变化.密度泛函理论计算结果表明,Ta掺杂与构建缺陷有利于OER决速步中水分子的亲核进攻,从而提升催�展开更多
钠离子电池作为新型的储能电池体系因钠资源储量丰富、成本低廉等优势有望填补锂离子电池在某些应用领域的空缺,非常适用于大规模储能领域.然而,高容量储钠负极材料仍然需要进一步研究.本文以废旧铅酸电池的回收铅和商业化硒粉为原料,...钠离子电池作为新型的储能电池体系因钠资源储量丰富、成本低廉等优势有望填补锂离子电池在某些应用领域的空缺,非常适用于大规模储能领域.然而,高容量储钠负极材料仍然需要进一步研究.本文以废旧铅酸电池的回收铅和商业化硒粉为原料,采用机械球磨法制备了纳米硒化铅与碳纳米管(PbSe@CNTs)的复合材料.碳纳米管网络缠绕在PbSe纳米粒子上,可有效抑制纳米粒子的团聚,同时提高了电子导电性.纳米级的PbSe和拓扑结构的CNTs有利于电解液的渗透,缩短了Na+和电子的传输路径,缓解了脱嵌钠过程中的机械应变,提高了倍率和长循环稳定性能.PbSe@CNTs电极在20 mA g^(-1)电流密度下具有597 mA h g^(-1)的可逆比容量,在100 m A g^(-1)循环100圈仍保持458.9 mA h g^(-1)的可逆比容量,容量保持率为88%.通过X射线衍射和拉曼光谱分析,证实了PbSe的储钠机理为两步转化-合金化过程,反应方程式为PbSe+5.75Na++5.75e-?0.25Na15Pb4+Na2Se.展开更多
基金Project supported by the Science and Technology Major Project of Shanxi Province,China (Grant No.20181102013)the “1331 Project” Engineering Research Center of Shanxi Province,China (Grant No.PT201801)the Natural Science Foundation of Shanxi Province,China (Grant No.201801D221131)。
文摘The Ga_(2)O_(3) films are deposited on the Si and quartz substrates by magnetron sputtering, and annealing. The effects of preparation parameters(such as argon–oxygen flow ratio, sputtering power, sputtering time and annealing temperature)on the growth and properties(e.g., surface morphology, crystal structure, optical and electrical properties of the films) are studied by x-ray diffractometer(XRD), scanning electron microscope(SEM), and ultraviolet-visible spectrophotometer(UV-Vis). The results show that the thickness, crystallization quality and surface roughness of the β-Ga_(2)O_(3) film are influenced by those parameters. All β-Ga_(2)O_(3) films show good optical properties. Moreover, the value of bandgap increases with the enlarge of the percentage of oxygen increasing, and decreases with the increase of sputtering power and annealing temperature, indicating that the bandgap is related to the quality of the film and affected by the number of oxygen vacancy defects. The I–V curves show that the Ohmic behavior between metal and β-Ga_(2)O_(3) films is obtained at 900℃. Those results will be helpful for the further research of β-Ga_(2)O_(3) photoelectric semiconductor.
基金supported by the National Natural Science Foundation of China(22379166)Natural Science Foundation for Distinguished Young Scholars of Hunan Province(2022JJ10089)+1 种基金Central South University Innovation-Driven Research Program(2023CXQD034)supported in part by the High-Performance Computing Center of Central South University。
文摘Rational carbonate electrolyte chemistry is critical for the development of high-voltage lithium metal batteries(LMBs).However,the implementation of traditional carbonate electrolyte is greatly hindered by the generation of an unstable electrode interphase and corrosive by-product(HF).Herein,we propose a triple-function eutectic solvent additive of N-methylacetamide(NmAc)with LiNO_(3) to enhance the stability and compatibility of carbonate electrolyte.Firstly,the addition of NmAc significantly improves the solubility of LiNO_(3) in carbonate electrolyte by forming an eutectic pair,which regulates the Li~+solvation structure and leads to dense and homogenous Li plating.Secondly,the hydrolysis of acidic PF_5 is effectively alleviated due to the strong complexation of NmAc with PF_5,thus reducing the generation of corrosive HF.In addition,the optimized cathode electrolyte interphase layer decreases the structural degradation and transition metal dissolution.Consequently,Li||LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622)cells with the designed electrolyte deliver superior long-term cycle reversibility and excellent rate capability.This study unveils the rationale for incorporating eutectic solvent additives within carbonate electrolytes,which significantly contribute to the advancement of their practical application for high-voltage LMBs.
文摘This review summarizes the clinical efficacy and experimental research of traditional Chinese medicine(TCM)moxibustion in the intervention of ovarian injury.Clinical and experimental research results have shown that as a nonpharmacological treatment method,Chinese medical moxibustion therapy is of great significance in the treatment of ovarian injuries such as diminished ovarian reserve,polycystic ovarian syndrome,premature ovarian failure,and premature ovarian insufficiency.Moxibustion,heat-sensitive moxibustion,and electroacupuncture have significant effects in improving ovarian func-tion,overall treatment efficacy,pregnancy rate,ovulation rate,and sex hormone levels and have higher safety.Their therapeutic mechanisms have also been demonstrated.In conclusion,TCM moxibustion therapy has a significant effect in the treatment of ovarian injury,providing a new option for the treatment of the ovarian injury.
基金financially supported by the National Natural Science Foundation of China(Nos.52032009 and 62075090)Natural Science Foundation of Jiangsu Province(Nos.SBK2019030177 and SBX2021020083)Postgraduates Innovation Program of Jiangsu Province(No.KYCX21_2619)。
文摘In this paper,we report on a wide wavelength tuning optical vortex carrying orbital angular momentum(OAM)of±?,from a thulium-doped yttrium aluminum perovskite(YAP)laser employing a birefringent filter.The OAM is experimentally found to be well maintained during the whole wavelength tuning process.The Laguerre-Gaussian(LG_(0,+1))mode with a tuning range of 58 nm from 1934.8 to 1993.0 nm and LG0,-1mode with a range of 76 nm from 1920.4 to 1996.6 nm,are,respectively,obtained.This is,to the best of our knowledge,the first experimental implementation of wavelength tuning for a scalar vortex laser in the 2μm spectral range,as well as the broadest tuning range ever reported from the vortex laser cavity.Such a vortex laser with robust structure and straightforward wavelength tuning capability will be an ideal light source for potential applications in the field of optical communication with one additional degree of freedom.
基金financially supported in part by the National Key R&D Program of China (2020YFA0406103)the National Natural Science Foundation of China (21725102, 22122506, 91961106, 22075267, 22109148)+4 种基金Strategic Priority Research Program of the Chinese Academy of Sciences (XDPB14)the Youth Innovation Promotion Association of the Chinese Academy of Sciences (2019444)the Hundred Talents Program of the Chinese Academy of SciencesFundamental Research Funds for the Central Universities (WK2060000039)support from the USTC Center for Micro- and Nanoscale Research and Fabrication。
文摘氢能作为一种潜在的能源载体,有望取代化石燃料,解决当今社会的能源需求和环境问题.质子交换膜电解水(PEMWE)技术因其工作电流密度大、氢气纯度高和系统响应迅速等优点,能够有效地弥补可再生能源波动性等缺点,被认为是一种利用可再生能源制氢的可持续手段.但其阳极氧析出反应(OER)为四电子/质子转移过程,反应动力学缓慢,同时强氧化性和强酸性环境会对阳极催化剂的产生腐蚀,导致稳定性差,因此亟需开发高效且稳定的催化剂.研究发现,无定型氧化铱材料中的特殊缺陷结构可显著提升其催化酸性OER的活性,但该结构也会加速反应过程中铱的溶解,导致催化剂稳定性降低,严重限制了其实际应用.本文采用高价金属掺杂的策略,利用高价金属元素与氧的强成键作用,对无定型氧化铱的整体结构及活性位点起到优化且稳定的作用.首先,采用改性的亚当斯熔融法制备了金属钽掺杂的无定型氧化铱:350-Ta@IrO_(x),400-Ta@IrO_(x),450-Ta@IrO_(x)(350,400和450代表样品分别在350,400和450℃烧结),并用于催化酸性OER;作为对比,制备了无掺杂的无定型氧化铱:350-IrO_(x),400-IrO_(x)和450-IrO_(x).然后,通过扫描电子显微镜、透射电子显微镜(TEM)和X射线衍射等表征技术考察了材料的宏观形貌及微观结构.结果表明,掺杂后的350-Ta@IrO_(x)材料表面具有丰富的氧空位贡献的活性位点,且表现出多晶的超小纳米颗粒形貌.电化学测试结果表明,350-Ta@IrO_(x)具有较好的酸性OER活性,在10 mA cm-2的电流密度下,过电势仅为223 mV,在1.55 V vs.RHE的电位下质量活性为1207.4 A gIr-1,是商业二氧化铱的147.7倍.且该催化剂的稳定性比未掺杂Ta样品及商业二氧化铱有明显提升,在0.5 mol L^(-1)硫酸溶液中反应500 h后电位未发生明显变化.密度泛函理论计算结果表明,Ta掺杂与构建缺陷有利于OER决速步中水分子的亲核进攻,从而提升催�
基金supported by the National Natural Science Foundation of China (22109037)the Natural Science Foundation of Hebei Province (B2020201001)+2 种基金the Advanced Talents Incubation Program of Hebei University (521000981408)the Young Elite Scientists Sponsorship Program by CAST (2021QNRC001)the Research Innovation Team of the College of Chemistry and Environmental Science of Hebei University (hxkytd2102)。
文摘钠离子电池作为新型的储能电池体系因钠资源储量丰富、成本低廉等优势有望填补锂离子电池在某些应用领域的空缺,非常适用于大规模储能领域.然而,高容量储钠负极材料仍然需要进一步研究.本文以废旧铅酸电池的回收铅和商业化硒粉为原料,采用机械球磨法制备了纳米硒化铅与碳纳米管(PbSe@CNTs)的复合材料.碳纳米管网络缠绕在PbSe纳米粒子上,可有效抑制纳米粒子的团聚,同时提高了电子导电性.纳米级的PbSe和拓扑结构的CNTs有利于电解液的渗透,缩短了Na+和电子的传输路径,缓解了脱嵌钠过程中的机械应变,提高了倍率和长循环稳定性能.PbSe@CNTs电极在20 mA g^(-1)电流密度下具有597 mA h g^(-1)的可逆比容量,在100 m A g^(-1)循环100圈仍保持458.9 mA h g^(-1)的可逆比容量,容量保持率为88%.通过X射线衍射和拉曼光谱分析,证实了PbSe的储钠机理为两步转化-合金化过程,反应方程式为PbSe+5.75Na++5.75e-?0.25Na15Pb4+Na2Se.
