环保型CuInSe_(2)量子点具有高消光系数和宽光谱吸收范围,在光电化学催化应用中展现了良好的发展前景.然而,CuInSe_(2)量子点较低的载流子分离能力和严重的界面电荷复合降低了其光电化学性能,制约了其应用.因此,我们设计并合成了具有Ⅱ...环保型CuInSe_(2)量子点具有高消光系数和宽光谱吸收范围,在光电化学催化应用中展现了良好的发展前景.然而,CuInSe_(2)量子点较低的载流子分离能力和严重的界面电荷复合降低了其光电化学性能,制约了其应用.因此,我们设计并合成了具有Ⅱ型能带排列的CuInSe_(2)/CuInS_(2)核/壳结构量子点,以促进载流子分离、减少界面缺陷;进一步通过调节In/Cu前驱体的摩尔比,产生铜空位.光物理性质研究表明,导带电子-铜空位捕获的空穴之间的辐射复合成为主要的复合方式,有效延长了载流子寿命,促进了载流子分离.因此,基于富铜空位的CuInSe_(2)/CuInS_(2)核壳量子点的光阳极获得了~8.0 mA cm^(-2)的最大饱和光电流密度,该性能是当前报道的CISe基量子点光电化学电池中的最高值之一.本工作提供了一种通过表面或内在缺陷的调控来促进光电化学应用中的电荷载流子分离和传输的有效方法.展开更多
Transition metal and rare earth intermetallics have been a fertile playground for research of various quantum states.We report detailed magnetic studies on Sm Mn_(2)Ge_(2),an anisotropic itinerant magnet with multiple...Transition metal and rare earth intermetallics have been a fertile playground for research of various quantum states.We report detailed magnetic studies on Sm Mn_(2)Ge_(2),an anisotropic itinerant magnet with multiple magnetic phases.The critical behavior of the ferromagnetic phase transition is investigated by employing the modified Arrott plot with the Kouvel-Fisher method.The critical temperature TCis determined to be around 342.7 K with critical exponents ofβ=0.417 andγ=1.122,and the interaction function is found to be J(r)~r^(-4.68),suggesting the coexistence of long-range and shortrange magnetic interactions.Our results contribute to the understanding of complex magnetism in Sm Mn_(2)Ge_(2),which may provide fundamental guidance in future spintronic applications.展开更多
We report polarization reversal periodically controlled by the electric field in multiferroic MnWO_(4) with a pulsed field up to 52 T.The electric polarization cannot be reversed by successive opposite electric fields...We report polarization reversal periodically controlled by the electric field in multiferroic MnWO_(4) with a pulsed field up to 52 T.The electric polarization cannot be reversed by successive opposite electric fields in low magnetic fields(<14 T)at 4.2 K,whereas polarization reversal is directly achieved by two opposite electric fields under high magnetic fields(<45 T).Interestingly,the polarization curve of rising and falling fields for H∥u(magnetic easy axis)is irreversible when the magnetic field is close to 52 T.In this case,the rising and falling polarization curves can be individually reversed by the electric field,and thus require five cycles to recover to the initial condition by the order of the applied electric fields(+E,-E,-E,+E,+E).In addition,we find that ferroelectric phaseⅣcan be tuned from parallel to antiparallel in relation to ferroelectric phase AF2 by applying a magnetic field approximated to the c axis.展开更多
核磁共振(nuclear magnetic resonance, NMR)技术是研究生物大分子结构、动力学和相互作用最理想的工具之一.近年来,高场NMR波谱仪的使用和NMR实验方法的不断创新,在很大程度上提高了NMR技术检测的灵敏度和分辨率,使NMR技术得到快速发...核磁共振(nuclear magnetic resonance, NMR)技术是研究生物大分子结构、动力学和相互作用最理想的工具之一.近年来,高场NMR波谱仪的使用和NMR实验方法的不断创新,在很大程度上提高了NMR技术检测的灵敏度和分辨率,使NMR技术得到快速发展和广泛应用.目前,生命科学与物质科学的交叉融合使生命科学研究从观察、描述性科学转向定量、可预测性科学,多种学科交叉渗透发展已成为科学研究领域十分普遍的现象.在这种趋势下,生物复杂环境下的磁共振谱学研究体系日趋成熟,本文重点回顾和讨论了多学科交叉研究趋势下NMR技术在生物复杂体系中的应用和发展,主要包括复杂膜环境下的膜蛋白研究、复杂细胞环境下的细胞内NMR(in-cell NMR)研究以及骨组织的固体NMR研究等.展开更多
The health and productivity of mining operations are negatively impacted by coal mine fires, making them dangerous. It happened everywhere, in both working and abandoned coal mines. This study seeks to review and prov...The health and productivity of mining operations are negatively impacted by coal mine fires, making them dangerous. It happened everywhere, in both working and abandoned coal mines. This study seeks to review and provide technical analytics of potential mine fires and fire detection in a Dual-Cab suppression system. Analysis was done on potential mine fires like spontaneous combustion, flammable gas explosions, and cab vehicle fires. Additionally, a review of the NIOSH experiment was conducted to assess the performance of smoke and flame detectors in a dual-cab suppression system. This study guides both open-pit and underground mining operations. Additionally, a few ideas and suggestions are presented to assist with on-the-job safety analysis, ensuing creative alterations, and technology advancement for the mining industry’s overall safety.展开更多
基金supported by the National Natural Science Foundation of China (52011530123,52272134,and 51902019)Beijing Natural Science Foundation (2222061 and 2232082)+4 种基金the IndustryUniversity-Research Cooperative Education of Ministry of Education (2205064205258 and 220606429170400)Shandong Weiqiao Pioneering Group Company Limited (BINTECH-KJZX-20220831-09 and BINTECHKJZX-20220831-29)the support from Swedish Research Council (2021-05319)Danish Villum Foundation Experiment Grant (50350)Swedish Foundation for International Cooperation in Research and Higher Education (F2020/1618)。
文摘环保型CuInSe_(2)量子点具有高消光系数和宽光谱吸收范围,在光电化学催化应用中展现了良好的发展前景.然而,CuInSe_(2)量子点较低的载流子分离能力和严重的界面电荷复合降低了其光电化学性能,制约了其应用.因此,我们设计并合成了具有Ⅱ型能带排列的CuInSe_(2)/CuInS_(2)核/壳结构量子点,以促进载流子分离、减少界面缺陷;进一步通过调节In/Cu前驱体的摩尔比,产生铜空位.光物理性质研究表明,导带电子-铜空位捕获的空穴之间的辐射复合成为主要的复合方式,有效延长了载流子寿命,促进了载流子分离.因此,基于富铜空位的CuInSe_(2)/CuInS_(2)核壳量子点的光阳极获得了~8.0 mA cm^(-2)的最大饱和光电流密度,该性能是当前报道的CISe基量子点光电化学电池中的最高值之一.本工作提供了一种通过表面或内在缺陷的调控来促进光电化学应用中的电荷载流子分离和传输的有效方法.
基金supported by the National Key Research and Development Program of China(Grant No.2021YFA1600204)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302802)+2 种基金the National Natural Science Foundation of China(Grant Nos.U1832214,U2032213,12104461,and 12074135)the High Magnetic Field Laboratory of Anhuisupported by the Start-up Project of Anhui University(Grant No.S020318001/020)。
文摘Transition metal and rare earth intermetallics have been a fertile playground for research of various quantum states.We report detailed magnetic studies on Sm Mn_(2)Ge_(2),an anisotropic itinerant magnet with multiple magnetic phases.The critical behavior of the ferromagnetic phase transition is investigated by employing the modified Arrott plot with the Kouvel-Fisher method.The critical temperature TCis determined to be around 342.7 K with critical exponents ofβ=0.417 andγ=1.122,and the interaction function is found to be J(r)~r^(-4.68),suggesting the coexistence of long-range and shortrange magnetic interactions.Our results contribute to the understanding of complex magnetism in Sm Mn_(2)Ge_(2),which may provide fundamental guidance in future spintronic applications.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.12074135,12104388,and 52272219)Nanyang Normal University,the Natural Science Foundation of Henan Province (Grant Nos.222300420255 and 232300421220)the Key Scientific and Technological Projiect of Technology Depeartment of Henan Province of China (Grant Nos.222102230105 and 212102210448)。
文摘We report polarization reversal periodically controlled by the electric field in multiferroic MnWO_(4) with a pulsed field up to 52 T.The electric polarization cannot be reversed by successive opposite electric fields in low magnetic fields(<14 T)at 4.2 K,whereas polarization reversal is directly achieved by two opposite electric fields under high magnetic fields(<45 T).Interestingly,the polarization curve of rising and falling fields for H∥u(magnetic easy axis)is irreversible when the magnetic field is close to 52 T.In this case,the rising and falling polarization curves can be individually reversed by the electric field,and thus require five cycles to recover to the initial condition by the order of the applied electric fields(+E,-E,-E,+E,+E).In addition,we find that ferroelectric phaseⅣcan be tuned from parallel to antiparallel in relation to ferroelectric phase AF2 by applying a magnetic field approximated to the c axis.
文摘核磁共振(nuclear magnetic resonance, NMR)技术是研究生物大分子结构、动力学和相互作用最理想的工具之一.近年来,高场NMR波谱仪的使用和NMR实验方法的不断创新,在很大程度上提高了NMR技术检测的灵敏度和分辨率,使NMR技术得到快速发展和广泛应用.目前,生命科学与物质科学的交叉融合使生命科学研究从观察、描述性科学转向定量、可预测性科学,多种学科交叉渗透发展已成为科学研究领域十分普遍的现象.在这种趋势下,生物复杂环境下的磁共振谱学研究体系日趋成熟,本文重点回顾和讨论了多学科交叉研究趋势下NMR技术在生物复杂体系中的应用和发展,主要包括复杂膜环境下的膜蛋白研究、复杂细胞环境下的细胞内NMR(in-cell NMR)研究以及骨组织的固体NMR研究等.
文摘The health and productivity of mining operations are negatively impacted by coal mine fires, making them dangerous. It happened everywhere, in both working and abandoned coal mines. This study seeks to review and provide technical analytics of potential mine fires and fire detection in a Dual-Cab suppression system. Analysis was done on potential mine fires like spontaneous combustion, flammable gas explosions, and cab vehicle fires. Additionally, a review of the NIOSH experiment was conducted to assess the performance of smoke and flame detectors in a dual-cab suppression system. This study guides both open-pit and underground mining operations. Additionally, a few ideas and suggestions are presented to assist with on-the-job safety analysis, ensuing creative alterations, and technology advancement for the mining industry’s overall safety.
