Peakon Soliton Solutions Of K(2,-2,4) Equation

In this paper, the qualitative analysis methods of a dynamical system are used to investigate the peakon soliton solutions of K(2;-2; 4) equation: ut + a(u2)x + b[u-2(u4)xx]x = 0. The phase portrait bifurcation of the traveling wave system corresponding to the equation is given. The explicit expressions of the peakon soliton solutions are obtained by using the portraits. The graph of the solutions are given with the numerical simulation. This supplements the results obtained in [4].     

Improved Synthesis of a Novel Biodegradable Tunable Micellar Polymer Based on Partially Hydrogenated Poly(β-malic Acid-co-benzyl Malate)

Poly(benzyl malate) (PBM), together with its derivatives, have been studied as nanocarriers for biomedical applications due to their superior biocompatibility and biodegradability. The acquisition of PBM is primarily from chemical routes, which could offer polymer-controlled molecular weight and a unique controllable morphology. Nowadays, the frequently used synthesis from L-aspartic acid gives an overall yield of 4.5%. In this work, a novel synthesis route with malic acid as the initiator was successfully designed and optimized, increasing the reaction yield up to 31.2%. Furthermore, a crystalline form of PBM (PBM-2) that polymerized from high optical purity benzyl-β-malolactonate (MLABn) was discovered during the optimization process. X-ray diffraction (XRD) patterns revealed that the crystalline PBM-2 had obvious diffraction peaks, demonstrating that its internal atoms were arranged in a more orderly manner and were different from the amorphous PBM-1 prepared from the racemic MLABn. The differential scanning calorimetry (DSC) curves and thermogravimetric curves elucidated the diverse thermal behaviors between PBM-1 and PBM-2. The degradation curves and scanning electron microscopy (SEM) images further demonstrated the biodegradability of PBM, which have different crystal structures. The hardness of PBM-2 implied the potential application in bone regeneration, while it resulted in the reduction of solubility when compared with PBM-1, which made it difficult to be dissolved and hydrogenated. The solution was therefore heated up to 75 °C to achieve benzyl deprotection, and a series of partially hydrogenated PBM was sequent prepared. Their optimal hydrogenation rates were screened to determine the optimal conditions for the formation of micelles suitable for drug-carrier applications. In summary, the synthesis route from malic acid facilitated the production of PBM for a shorter time and with a higher yield. The biodegradability, biosafety, mechanical properties, and adjustable hydrogenation widen the application of PBM with tunable properties as drug carriers.     

表面增强拉曼光谱法对水中残留绿麦隆的检测

利用银镜反应原理在玻璃片上镀一层具有表面增强拉曼散射(SERS)效应的表面粗糙的银膜,通过测定农药绿麦隆在银镜表面上的表面增强拉曼光谱,探讨了绿麦隆在银镜表面的吸附取向。结果表明,在银镜表面,当绿麦隆浓度小到10-10mol L时,仍然能得到明确的光谱信息,且吸附饱和时间仅为2h,这为探索水体中微量污染物的检测方法提供了一个很好的途径。     

八-羟基喹啉铝薄膜光致发光的厚度依赖性质

In situ thickness dependent photoluminescence (PL) measurements of tris(8-hydroxyquinoline) aluminum(Alq3) film were performed. At the beginning of Alq3 deposition on the glass substrate, the Alq3 emission showed a sharp red-shift. Further deposition of Alq3 resulted slight red-shift, and finally tended to saturated value. The total red-shift of about 12 nm was observed for the Alq3 film thickness range from 2 to 500 nm.This red-shift was attributed to the change from the 2D to 3D exciton state with increasing Alq3 film thickness. Meanwhile, the PL intensity of Alq3 emission increased continuously, and showed a rate change at the initial deposition of Alq3 due to non-rediative decay of excitons arised from the interaction between excitons and the substrate, and finally tended to saturation with the Alq3 thickness.     

气相色谱法测定喷雾杀虫剂中的胺菊酯和氯菊酯

用SE-30毛细管柱、160~300℃程序升温、以邻苯二甲酸二环己酯为内标物,气相色谱法同时测定家用气雾杀虫剂中有效成分胺菊酯、氯菊酯的含量。胺菊酯、氯菊酯的平均回收率分别为94.0%、95.4%,相对标准偏差分别为2.23%、6.73%。     

Investigation of Nonlinear Optical Modulation Characteristics of MXene VCrC for Pulsed Lasers

We report the surface morphology and the nonlinear absorption characteristics of MXene VCrC nanosheets prepared by the liquid-phase exfoliation method. The self-made MXene VCrC was applied as a saturable absorber in the Tm:YAP laser experiments, performing excellent Q-switching optical modulation characteristics in infrared range. With this absorber, a stable passively Q-switched 2 μm laser was achieved. Under an incident pump power of 3.52 W, a maximum output power of 280 mW was obtained with a T = 3% output coupler at a repetition frequency of 49 kHz. The corresponding pulse energy and peak power were 5.7 μJ and 6.6 W, respectively. The shortest pulse duration was 658 ns at the repetition rate of 63 kHz with a T = 1% output coupler.     

19F-核磁共振法测定甲磺酸帕珠沙星样品中的氟含量

1引言 甲磺酸帕珠沙星又名帕物沙星,是由日本富山化学公司和绿十字公司联合开发的文谱氟喹诺酮抗菌剂,是第三代喹诺酮类产品中的优秀品种.     

2020年先进能源材料与器件国际大会学术会议综述

来自国内外150多所高校和企业的近400名专家学者和研究生代表出席了本次会议. 会议围绕新能源的先进电化学储能材料与器件展开研讨, 所涉及的储能体系包括了锂离子电池、锂硫电池、超级电容器及新型二次电池等. 本次会议为推动先进能源材料与器件领域的发展提供了一个良好的学术交流平台, 大大提升了研发人员对新能源行业的发展动态、市场需求以及前沿工艺技术的深层次了解, 对于推动基础研究成果和产业化应用的紧密结合起到了积极的作用.     

Isogeometric analysis of multi-patch solid-shells in large deformation

Acta Mechanica Sinica - In the context of isogeometric analysis (IGA) of shell structures, the popularity of the solid-shell elements benefit from formulation simplicity and full 3D stress state....     

截断光束的广义M2因子测量的实验研究

提出了一种可广泛适用于截断光束和非截断光束的广义M2因子测量的实验方法和相应的数据处理方法。在利用广义强度二阶矩计算光束束宽时,以积分角谱范围能够包含光束总能量的75%以上作为积分范围的选取标准,并遵循现有的国际标准化组织(ISO)规定的测量步骤和方法对截断高斯光束的广义M2因子进行了测量,并将不同截断参量时的实验结果与理论计算结果进行了比较,证明了该方法的正确性。研究结果表明,根据该方法测量截断光束M2因子时,只须将非截断光束M2因子测量的数据处理部分进行适当修正,而无需增加其他硬件开销,该方法简便易行且测量步骤仍可遵循国际标准化组织规定。