Three japonica rice varieties were soaked in 110 mg/L paclobutrazol solution for 48 h and then directly seeded, and seeds soaked with clean water were used as a control group. The analysis of dry weights of various or...Three japonica rice varieties were soaked in 110 mg/L paclobutrazol solution for 48 h and then directly seeded, and seeds soaked with clean water were used as a control group. The analysis of dry weights of various organs and agronomic traits showed that soaking of japonica seeds with paclobutrazol had little impact on the correlation between dry weights of various organs, but there were still significant differences between cultivars. The correlation coefficients between lengths of the first and second nodes with filled grain weight changed from 0.024 and 0.056 in the CK to -0.116 and -0.042 correspondingly after presoaking with paclobutrazol. Therefore, paclobutrezol reduces the effect of stem-sheath weight on filled grain weight, and as a result, photosynthetic product could not be effectively transported in maturation stage of rice.展开更多
Topological materials and topological phases have recently become a hot topic in condensed matter physics.In this work,we report an In-intercalated transition-metal dichalcogenide In_(x)TaSe_(2)(named 112 system),a to...Topological materials and topological phases have recently become a hot topic in condensed matter physics.In this work,we report an In-intercalated transition-metal dichalcogenide In_(x)TaSe_(2)(named 112 system),a topological nodal-line semimetal in the prep seffiffinffi ce of both charge density wave(CDW)and superconductivity.In the x=0.58 sample,the 2×√3 commensurate CDW(CCDW)and the 2×2 CCDW are observed below 116 and 77 K,respectively.Consistent with theoretical calculations,the spin–orbital coupling gives rise to two twofold-degenerate nodal rings(Weyl rings)connected by drumhead surface states,confirmed by angle-resolved photoemission spectroscopy.Our results suggest that the 2×2 CCDW ordering gaps out one Weyl ring in accordance with the CDW band folding,while the other Weyl ring remains gapless with intact surface states.In addition,superconductivity emerges at 0.91 K,with the upper critical field deviating from the s-wave behavior at low temperature,implying possibly unconventional superconductivity.Therefore,we think this type of the 112 system may possess abundant physical states and offer a platform to investigate the interplay between CDW,nontrivial band topology and superconductivity.展开更多
We investigated the coexistence of superconductivity and antiferromagnetic order in the compound Er_(2)O_(2)Bi with anti-ThCr_(2)Si_(2)-type structure through resistivity,magnetization,specific heat measurements and f...We investigated the coexistence of superconductivity and antiferromagnetic order in the compound Er_(2)O_(2)Bi with anti-ThCr_(2)Si_(2)-type structure through resistivity,magnetization,specific heat measurements and first-principle calculations.The superconducting transition temperature Tc of 1.23 K and antiferromagnetic transition temperature TN of 3 K are observed in the sample with the best nominal composition.The superconducting upper critical field H_(c2)(0)and electron-phonon coupling constantλe−ph in Er_(2)O_(2)Bi are similar to those in the previously reported non-magnetic superconductor Y_(2)O_(2)Bi with the same structure,indicating that the superconductivity in Er_(2)O_(2)Bi may have the same origin as in Y_(2)O_(2)Bi.The first-principle calculations of Er_(2)O_(2)Bi show that the Fermi surface is mainly composed of the Bi 6p orbitals both in the paramagnetic and antiferromagnetic state,implying minor effect of the 4f electrons on the Fermi surface.Besides,upon increasing the oxygen incorporation in Er_(2)O_(x)Bi,Tc increases from 1 to 1.23 K and TN decreases slightly from 3 K to 2.96 K,revealing that superconductivity and antiferromagnetic order may compete with each other.The Hall effect measurements indicate that hole-type carrier density indeed increases with increasing oxygen content,which may account for the variations of Tc and TN with different oxygen content.展开更多
Superconductivity in crystals without inversion symmetry has received extensive attention due to its unconventional pairing and possible nontrivial topological properties.Using first-principles calculations,we systemi...Superconductivity in crystals without inversion symmetry has received extensive attention due to its unconventional pairing and possible nontrivial topological properties.Using first-principles calculations,we systemically study the electronic structure of noncentrosymmetric superconductors A_(2)Cr_(3)As_(3)(A=Na,K,Rb,and Cs).展开更多
文摘Three japonica rice varieties were soaked in 110 mg/L paclobutrazol solution for 48 h and then directly seeded, and seeds soaked with clean water were used as a control group. The analysis of dry weights of various organs and agronomic traits showed that soaking of japonica seeds with paclobutrazol had little impact on the correlation between dry weights of various organs, but there were still significant differences between cultivars. The correlation coefficients between lengths of the first and second nodes with filled grain weight changed from 0.024 and 0.056 in the CK to -0.116 and -0.042 correspondingly after presoaking with paclobutrazol. Therefore, paclobutrezol reduces the effect of stem-sheath weight on filled grain weight, and as a result, photosynthetic product could not be effectively transported in maturation stage of rice.
基金the National Key R&D Program of the China(2016YFA0300402,2014CB648400,and 2016YFA0300203)the National Natural Science Foundation of China(11774305 and 11274006)the Fundamental Research Funds for the Central Universities of China。
文摘Topological materials and topological phases have recently become a hot topic in condensed matter physics.In this work,we report an In-intercalated transition-metal dichalcogenide In_(x)TaSe_(2)(named 112 system),a topological nodal-line semimetal in the prep seffiffinffi ce of both charge density wave(CDW)and superconductivity.In the x=0.58 sample,the 2×√3 commensurate CDW(CCDW)and the 2×2 CCDW are observed below 116 and 77 K,respectively.Consistent with theoretical calculations,the spin–orbital coupling gives rise to two twofold-degenerate nodal rings(Weyl rings)connected by drumhead surface states,confirmed by angle-resolved photoemission spectroscopy.Our results suggest that the 2×2 CCDW ordering gaps out one Weyl ring in accordance with the CDW band folding,while the other Weyl ring remains gapless with intact surface states.In addition,superconductivity emerges at 0.91 K,with the upper critical field deviating from the s-wave behavior at low temperature,implying possibly unconventional superconductivity.Therefore,we think this type of the 112 system may possess abundant physical states and offer a platform to investigate the interplay between CDW,nontrivial band topology and superconductivity.
基金This work was supported by the National Key R&D Projects of China(Grant Nos.2019YFA0308602 and 2016YFA0300402)the National Natural Science Foundation of China(Grant No.11774305)the Fundamental Research Funds for the Central Universities of China.
文摘We investigated the coexistence of superconductivity and antiferromagnetic order in the compound Er_(2)O_(2)Bi with anti-ThCr_(2)Si_(2)-type structure through resistivity,magnetization,specific heat measurements and first-principle calculations.The superconducting transition temperature Tc of 1.23 K and antiferromagnetic transition temperature TN of 3 K are observed in the sample with the best nominal composition.The superconducting upper critical field H_(c2)(0)and electron-phonon coupling constantλe−ph in Er_(2)O_(2)Bi are similar to those in the previously reported non-magnetic superconductor Y_(2)O_(2)Bi with the same structure,indicating that the superconductivity in Er_(2)O_(2)Bi may have the same origin as in Y_(2)O_(2)Bi.The first-principle calculations of Er_(2)O_(2)Bi show that the Fermi surface is mainly composed of the Bi 6p orbitals both in the paramagnetic and antiferromagnetic state,implying minor effect of the 4f electrons on the Fermi surface.Besides,upon increasing the oxygen incorporation in Er_(2)O_(x)Bi,Tc increases from 1 to 1.23 K and TN decreases slightly from 3 K to 2.96 K,revealing that superconductivity and antiferromagnetic order may compete with each other.The Hall effect measurements indicate that hole-type carrier density indeed increases with increasing oxygen content,which may account for the variations of Tc and TN with different oxygen content.
基金This work has been supported by the NSFC(Nos.11874137,11574265,and 11774309)the 973 project(Nos.2014CB648400 and 2016YFA0300402).
文摘Superconductivity in crystals without inversion symmetry has received extensive attention due to its unconventional pairing and possible nontrivial topological properties.Using first-principles calculations,we systemically study the electronic structure of noncentrosymmetric superconductors A_(2)Cr_(3)As_(3)(A=Na,K,Rb,and Cs).