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Achieving high‐quality, frequency‐upconversion single‐mode lasing output is an important requirement for developing new nonlinear optoelectronic devices, such as on‐chip optical communication, nonlinear optical switches, and optical parametric amplifiers. Here, an individual CsPbBr3 microwire prepared by the anti‐solvent method is served as both gain media and microresonator to achieve two‐photon pumped frequency upconversion single‐mode lasing with the side‐mode suppression ratio of 18 dB. Meanwhile, the refractive index of orthorhombic perovskite is theoretically calculated based on first principles, and determining its square whispering‐gallery oscillation type by combining with the plane wave model and the steady‐state oscillation conditions of laser. The extracted exciton binding energy of 33.15 meV higher than the thermal ionization energy of room temperature (≈26 meV) suggests that the as‐grown CsPbBr3 microwires possess the capacity to achieve two‐photon pumped lasing output, as well further gaining deeper insights into the role of exciton‐phonon coupling in light emission. [ABSTRACT FROM AUTHOR]

Circularly and elliptically polarized high-order harmonics have unique advantages when used in studying the chiral and magnetic features of matter. Here, we studied the polarization properties of high-order harmonics generated from alignment nitrogen molecules driven by cross-linearly polarized two-color laser fields. Through adjusting various laser parameters and targets, such as the relative phase, the crossing angle, the intensity ratio of the driving fields, and the molecular alignment angle, we obtained highly elliptically polarized high-order harmonics with the same helicity in a wide spectral range. This provides a possible effective way to generate elliptically polarized attosecond pulses. Finally, we showed the probability of controlling the spectral range of elliptically polarized harmonics. [ABSTRACT FROM AUTHOR]

We investigated the nonsequential double ionization (NSDI) of by linearly polarized (LP) and elliptically polarized (EP) laser pulses using the classical ensemble model. For the two cases, the ensemble from NSDI was separated into two kinds of subensemble according to the relative momentum along the y-axis , respectively. The results show only for the case of relatively small , the momentum distribution along the x-axis can show a V-like shape obviously, which is according with the experiment [ Phys. Rev. Lett. 99, 263003 (2007)]. What is important is that we firstly examine the role of the repulsion interaction between two electrons for the two kinds of subensemble, and find that the process of NSDI for the case of relatively small exits a strong repulsion interaction which contributes significantly to the V-like shape. However, for the case of relatively big , the repulsion interaction between two electrons is relatively weak, and both the nuclear Coulomb attraction and electric field force dominate the process of NSDI. [ABSTRACT FROM AUTHOR]

Systematic ac susceptibility measurements have been carried out to study the vortex dynamics in CaKFe 4 As 4 and Ba 0.6 K 0.4 Fe 2 As 2 single crystals under various temperatures, dc magnetic fields, ac field frequencies and amplitudes. The field-temperature phase diagrams were shown, and the characteristics of irreversibility line were also derived. The specific expressions of activation energy on the parameters of temperature ( T ), current density ( J ), and dc magnetic field ( H ) are obtained according to these data. The results indicate that both superconductors have similar functional expressions of activation energy and flux pinning behaviors. Though both CaKFe 4 As 4 and Ba 0.6 K 0.4 Fe 2 As 2 superconductors exhibit very strong flux pinning ability, the vortex pinning potential in CaKFe 4 As 4 is slightly smaller than that in Ba 0.6 K 0.4 Fe 2 As 2, which may result from its distorted FeAs 4 -tetrahedron in CaKFe 4 As 4 . The depinning critical current densities at the limit of low temperature and low field were also extrapolated, yielding the corresponding values of J c0 (0) ∼ 1.0 × 10 8 and 2.2 × 10 8 A cm -2 for CaKFe 4 As 4 and Ba 0.6 K 0.4 Fe 2 As 2 superconductors, respectively, which suggest potential applications., (© 2020 IOP Publishing Ltd.)

Objective: To investigate the different effect of three methods of blood purification for paraquat poisoning patients:hemoperfusion (HP), hemoperfusion combined with hemodialysis (HP + HD), hemoperfusion combined with continuous veno-venous hemofiltration (HP + CVVH)., Methods: 72 cases of paraquat poisoning patients were divided into three groups after giving conventional therapy HP group, HP + HD group, HP + CVVH group. Compared the rate of decline concentrations of paraquat in blood, the liver and the kidney damage between before and after blood purification and contrast the mortality in three groups after different method of blood purification., Results: The rate of decline concentrations of paraquat in blood of the HP + HD group and HP + CVVH group were both significantly greater than the HP group, but this result of HP + HD group has no significant difference compared with HP + CVVH group; Among the three groups of patients after 72 hours, the degree of dysfunction of liver of the HP + HD group and HP + CVVH group were both significantly lower than the HP group, whilely the degree of dysfunction of kidney of the HP + HD group was significantly lower than the HP group and the HP + CVVH group. The survival time of the HP + HD group and the HP + CVVH group were significant linger than the HP group, but the comparison among the three groups had no significant difference in mortality., Conclusion: Three blood purification methods can effectively remove paraquat absorbed into the blood, and the hemoperfusion combined with hemodialysis or continuous veno-venous hemofiltration can effectively reduce the degree of damage of liver and kidney and also can prolong survival time, but did not significantly improve the survival rate of patients.