Self assembled monolayers(SAMs) based on a novel dendron thiols system, which maintain the alkanethiols active site, but the —SH group connected with independently variable groups by a dendron linker, showed the co...Self assembled monolayers(SAMs) based on a novel dendron thiols system, which maintain the alkanethiols active site, but the —SH group connected with independently variable groups by a dendron linker, showed the controllable surface pattern and wetting property. The precisely tailored structure of dendron thiols with local controlled hydrophobic and hydrophilic peripheries allow the formation of designed surface structures on gold surface, e.g. nano stripes, honeycomb and homogeneous structure.展开更多
Photoluminescence intensity is a crucial parameter for evaluating the performance of optoelectronic devices.To date,efforts to optimize the emission properties of luminescent materials are continuously implemented,suc...Photoluminescence intensity is a crucial parameter for evaluating the performance of optoelectronic devices.To date,efforts to optimize the emission properties of luminescent materials are continuously implemented,such as surface passivation with ligands or electronic structure modulation using heterojunctions.展开更多
Flourishing rare earth superhydrides are a class of recently discovered materials that exhibit near-room-temperature superconductivity at high pressures,ushering in a new era of superconductivity research at high pres...Flourishing rare earth superhydrides are a class of recently discovered materials that exhibit near-room-temperature superconductivity at high pressures,ushering in a new era of superconductivity research at high pressures.Yttrium superhydrides drew the most attention among these superhydrides due to their abundance of stoichiometries and excellent superconductivities.Here,we carried out a comprehensive study of yttrium superhydrides in a wide pressure range of 140 GPa-300 GPa.We successfully synthesized a series of superhydrides with the compositions of YH_(4),YH_(6),YH_(7),and YH_(9),and reported superconducting transition temperatures of 82 K at 167 GPa,218 K at 165 GPa,29 K at 162 GPa,and230 K at 300 GPa,respectively,as evidenced by sharp drops in resistance.The structure and superconductivity of YH_(4) were taken as a representative example and were also examined using x-ray diffraction measurements and the superconductivity suppression under external magnetic fields,respectively.Clathrate YH_(10),a candidate for room-temperature superconductor,was not synthesized within the study pressure and temperature ranges of up to 300 GPa and 2000 K.The current study established a detailed foundation for future research into room-temperature superconductors in polynary yttrium-based superhydrides.展开更多
The crystalline solid europium germanate NaEuGeO4 was prepared under hydrothermal conditions. The in-situ photoluminescence spectroscopic measurement and the synchrotron X-ray diffraction analysis in a diamond anvil c...The crystalline solid europium germanate NaEuGeO4 was prepared under hydrothermal conditions. The in-situ photoluminescence spectroscopic measurement and the synchrotron X-ray diffraction analysis in a diamond anvil cell （DAC） under high pressure were performed to study the pressure-induced phase transition of NaEuGeO4 as well as changes of the luminescent properties of Eu3＋ ions. Photoluminescence spectroscopic studies revealed that a phase transition occurred at a pressure range of 6.5--10 GPa and the high-pressure phase of NaEuGeO4 （NaEu- GeO4-HP） was still stable when the pressure raised up to about 20 GPa. As the pressure was released, the spectra returned to the original state, revealing that the pressure-induced phase transition is a completely reversible process. The synchrotron X-ray diffraction analysis demonstrated that the structure of NaEuGeO4 transformed to an uniden- tified phase NaEuGeO4-HP at a pressure higher than 10 GPa, and the phase transition is reversible. This result is consisted with that obtained by photoluminescence spectra analysis.展开更多
文摘Self assembled monolayers(SAMs) based on a novel dendron thiols system, which maintain the alkanethiols active site, but the —SH group connected with independently variable groups by a dendron linker, showed the controllable surface pattern and wetting property. The precisely tailored structure of dendron thiols with local controlled hydrophobic and hydrophilic peripheries allow the formation of designed surface structures on gold surface, e.g. nano stripes, honeycomb and homogeneous structure.
基金supported by the National Key R&D Program of China(2019YFE0120300)the National Natural Science Foundation of China(12174144 and 21725304)Young Elite Scientists Sponsorship Program by CAST(2022QNRC001)。
文摘Photoluminescence intensity is a crucial parameter for evaluating the performance of optoelectronic devices.To date,efforts to optimize the emission properties of luminescent materials are continuously implemented,such as surface passivation with ligands or electronic structure modulation using heterojunctions.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2021YFA1400203 and 2018YFA0305900)the National Natural Science Foundation of China(Grant Nos.52090024,11874175,12074139,12074138,11874176,and 12034009)+1 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB33000000)Program for JLU Science and Technology Innovative Research Team(JLUSTIRT)。
文摘Flourishing rare earth superhydrides are a class of recently discovered materials that exhibit near-room-temperature superconductivity at high pressures,ushering in a new era of superconductivity research at high pressures.Yttrium superhydrides drew the most attention among these superhydrides due to their abundance of stoichiometries and excellent superconductivities.Here,we carried out a comprehensive study of yttrium superhydrides in a wide pressure range of 140 GPa-300 GPa.We successfully synthesized a series of superhydrides with the compositions of YH_(4),YH_(6),YH_(7),and YH_(9),and reported superconducting transition temperatures of 82 K at 167 GPa,218 K at 165 GPa,29 K at 162 GPa,and230 K at 300 GPa,respectively,as evidenced by sharp drops in resistance.The structure and superconductivity of YH_(4) were taken as a representative example and were also examined using x-ray diffraction measurements and the superconductivity suppression under external magnetic fields,respectively.Clathrate YH_(10),a candidate for room-temperature superconductor,was not synthesized within the study pressure and temperature ranges of up to 300 GPa and 2000 K.The current study established a detailed foundation for future research into room-temperature superconductors in polynary yttrium-based superhydrides.
文摘The crystalline solid europium germanate NaEuGeO4 was prepared under hydrothermal conditions. The in-situ photoluminescence spectroscopic measurement and the synchrotron X-ray diffraction analysis in a diamond anvil cell （DAC） under high pressure were performed to study the pressure-induced phase transition of NaEuGeO4 as well as changes of the luminescent properties of Eu3＋ ions. Photoluminescence spectroscopic studies revealed that a phase transition occurred at a pressure range of 6.5--10 GPa and the high-pressure phase of NaEuGeO4 （NaEu- GeO4-HP） was still stable when the pressure raised up to about 20 GPa. As the pressure was released, the spectra returned to the original state, revealing that the pressure-induced phase transition is a completely reversible process. The synchrotron X-ray diffraction analysis demonstrated that the structure of NaEuGeO4 transformed to an uniden- tified phase NaEuGeO4-HP at a pressure higher than 10 GPa, and the phase transition is reversible. This result is consisted with that obtained by photoluminescence spectra analysis.
