气相色谱法与高效液相色谱法测定琥珀酸索利那新原料药中的残留溶剂北大核心CSCD

建立了测定琥珀酸索利那新原料药中残留溶剂甲醇、乙醇、丙酮、叔丁醇、乙酸乙酯、正庚烷、石油醚、甲苯的气相色谱法和测定吡啶的高效液相色谱法。气相色谱法中以N,N-二甲基甲酰胺为溶剂,以TR-5毛细管柱为分离柱,采用氢火焰离子化检测器。高效液相色谱法中以AQC18色谱柱为分离柱,以50mmol·L-1磷酸氢二钠水溶液(含0.1%三乙胺,pH为7.6)-乙腈(1+1)为流动相,检测波长为254nm。9种溶剂的质量浓度在一定范围内呈线性,吡啶的检出限为0.01mg·L-1,其余8种溶剂的检出限在1.17~5.00 mg·L-1之间,加标回收率在86.3%~101%之间,相对标准偏差(n=6)在2.4%~6.3%之间。     

Dynamical signatures of the one-dimensional deconfined quantum critical point

We study the critical scaling and dynamical signatures of fractionalized excitations at two different deconfined quantum critical points (DQCPs) in an S = 1/2 spin chain using the time evolution of infinite matrix product states. The scaling of the correlation functions and the dispersion of the conserved current correlations explicitly show the emergence of enhanced continuous symmetries at these DQCPs. The dynamical structure factors in several different channels reveal the development of deconfined fractionalized excitations at the DQCPs. Furthermore, we find an effective spin-charge separation at the DQCP between the ferromagnetic (FM) and valence bond solid (VBS) phases, and identify two continua associated with different types of fractionalized excitations at the DQCP between the X-direction and Z-direction FM phases. Our findings not only provide direct evidence for the DQCP in one dimension but also shed light on exploring the DQCP in higher dimensions.     

Gaussian solitons in nonlocal media: variational analysis

Exact solutions of Gaussian solitons in nonlinear media with a Gaussian nonlocal response are obtained. Using the variational approach, we obtain the approximate solutions of such solitons when the degree of the nonlocality is arbitrary. Specifically, we study the conditions for Gaussian solitons that propagate in weakly and highly nonlocal media. We also compare the variational result with the known exact solutions for weakly and highly nonlocal media.     

具有无穷时滞的It\^{o}型随机模糊微分方程[英文]

在非Lipschitz条件和弱线性增长条件下, 我们证明了具有无穷时滞的It\^{o}型随机模糊微分方程强解的存在唯一性.