上海光源150 MeV直线加速器次谐波腔耦合器的设计与调试

通过将次谐波腔体等效为RLC并联回路,求得了射频功率馈入腔体的耦合度公式,分析了上海光源直线加速器次谐波腔输入耦合器的设计要点,通过3维电磁计算软件CST的数值模拟方法对耦合器结构尺寸、耦合环的深度与方位、耦合度进行了模拟计算。介绍了对次谐波腔耦合器进行小信号测试的过程、腔体安装及在线调试的方法。     

超导腔的热击穿和超导铌材料RRR值的无损测量

介绍超导腔热击穿原理 ;讨论了超导体热击穿磁场与超导材料 RRR值之间的定量关系 ;同时介绍一种非常实用的超导腔体 RRR值的测量方法涡流法无损测量原理及其实现方法 ;最后给出了国内外两种典型超导铌材料 RRR值的比较测量结果     

一类波动方程有限元投影格式的误差分析

1.引 言 本文考虑如下不含阻尼项的波动方程的有限元逼近: 其中区域Ω Rd（d=2,3）是足够光滑的有界多边形区域,其边界为Γ=　Ω.初始条件为:当t=0时,u=u0,ut=u1.     

Inverted colloidal crystals as three-dimensional cell scaffolds

A new type of three-dimensional scaffold with inverted colloidal crystal geometry for the investigation of topological effects in cell cultures is introduced in this publication. The scaffolds are made by infiltration of the hexagonal crystal lattice of polystyrene spheres with sol-gel formulation and subsequent annealing. It possesses a relatively high degree of order among existing cell scaffolds and affords tight control over the scaffold porosity and tissue organization. The prepared scaffolds can be a convenient system for the investigation of cell-cell and cell-matrix interactions. Their biocompatibility is demonstrated for human hepatocellular carcinoma HEP G2 and human bone marrow HS-5 cell cultures. A preliminary effect of the scaffold topology on cell proliferation is observed. HEP G2 hepatocytes form a large number of 10-15 cell colonies on scaffolds made from 75-microm spheres, while their number diminishes for scaffolds from 10- and 160-microm spheres. Under similar conditions, HS-5 forms smaller colonies consisting of three to four cells in 90-microm cavities.     

3D inverted opal hydrogel scaffolds with oxygen sensing capability

The measurement of local oxygen level in 3D cell culture is desired but remains as a challenge problem. We developed a 3D cell scaffold with luminescence-based oxygen sensing capability that opens the possibility of 3D mapping of oxygen level during cell growth. Hydrogel inverted opal scaffold was prepared by photo-polymerization of poly(2-hydroxyethyl methacrylate (pHEMA) and poly(methacryloyloxy)ethyl-trimethylammonium chloride (pMEATAC) monomer using close-packed bead assembly as template. Tris(4,7-diphenyl-1,10-phenanthroline)ruthenium chloride (Ru(dpp)(3)), was coated on the pHEMA-pMEATAC 3D scaffolds by layer-by-layer (LBL) assembly. pHEMA-pMEATAC copolymer was coated on top of the Ru(dpp)(3) layer as a protection layer. The fluorescence emission of Ru(dpp)(3) can be dynamically quenched by oxygen. By measuring the emission intensity of the scaffold, the local oxygen level can be monitored. The hydrogel scaffolds are transparent, and thus 3D fluorescence intensity can be mapped by confocal microscopy. Human bone marrow stromal cells HS-5 were successfully cultured on the oxygen sensing scaffold, and the observed Ru(dpp)(3) emission intensity from the scaffold was stronger in cell rich area, which indicates a lower oxygen level due to the consumption of the cells.     

Development of the energy flow in light-harvesting dendrimers

Modeling the multistep flow of energy in light-harvesting dendrimers presents a considerable challenge. Recent studies have introduced an operator approach based on a matrix representation of the connectivity between constituent chromophores. Following a review of the theory, detailed applications are now shown to exhibit the time development of the core excitation following pulsed laser irradiation and the steady-state behavior that can be expected under conditions of constant illumination. It is also shown how energy capture by whole dendrimers can be analytically related to chromophore pair-transfer properties and, in particular, the spectroscopic gradient toward the core. Indicative calculations also illustrate the consequences of tertiary folding. In each respect, the model affords opportunities to derive new, physically meaningful information on the photophysical and structural features of dendrimeric systems.     

克尔效应对高斯光束质量M2因子的影响及抑制

用分步傅里叶方法计算了高斯光束在克尔介质中的传输过程,采用最小均方根办法对光场进行二项式曲线拟合得到光束质量因子,计算结果表明：当B积分在2rad以内,克尔效应越强则它对因子影响越大;同时,它的这种影响能力也受到光束宽度和光束腰平面到克尔介质的距离的两个因素的影响,即光束越宽,影响越小,距离越大,影响反而较小;最后,基于B积分的可叠加性,提出用具有负非线性折射率系数的非线性介质来补偿正克尔效应、降低光束因子,并指出两端补偿是最优的方式之一.     

求解间断系数椭圆型问题的一种改进的DG方法

本文考虑对间断系数椭圆型问题的普通DG方法进行改进,提出了一种综合了DG方法及区域分解方法的优点的新方法.对此法进行了先验误差分析并给出其残量型后验误差估计,且通过数值实验验证了该方法及其自适应方法的有效性.     

Nutrition,Bioactive Components,and Hepatoprotective Activity of Fruit Vinegar Produced from Ningxia Wolfberry

Wolfberry (Lycium barbarum L.) is a nutritious and medicinal fruit, and deeply processed products of wolfberry needs to be improved. In this study, nutrition, bioactive compounds, and hepaprotective activity were explored in wolfberry vinegar (WFV). The contents of nutrients including total sugar and protein in WFV samples were 2.46 and 0.27 g/100 mL, respectively. Total phenolic and flavonoid contents in WFV were 2.42 mg GAE/mL and 1.67 mg RE/mL, respectively. p-Hydroxybenzoic acid and m-hydroxycinnamic acid were the main polyphenols in WFV. The antioxidant activity of WFV were 20.176 mM Trolox/L (ABTS), 8.614 mM Trolox/L (FRAP), and 26.736 mM Trolox/L (DPPH), respectively. In addition, WFV treatment effectively alleviated liver injury by improving histopathological changes and reducing liver biochemical indexes in CCl4-treated mice. WFV alleviated oxidative damage by inhibiting oxidative levels and increasing antioxidant levels. These results suggest that WFV can be utilized as a functional food to prevent oxidative liver injury.     

X射线自由电子激光试验装置

X射线自由电子激光试验装置(以下简称"SXFEL试验装置")是中国第一台X射线相干光源,其输出波长小于9 nm.这台基于0.84 GeV直线加速器、以掌握装置相关技术和实验演示种子型自由电子激光(FEL)级联与短波长回声型FEL为主要目标的自由电子激光装置,于2020年11月通过国家验收.本文将介绍SXFEL试验装置的...