Structure and spectroscopic properties of Er3+/Ce3+ co-doped TeO2-Bi2O3-TiO2 glasses modified with various WO3 contents for 1.53 μm emission

The Er^3＋/Ce^3＋ co-doped tellurite-based glasses （TeO2-Bi2O3-TiO2） modified with various WO3 contents are prepared using conventional melt-quenching technique. The X-ray diffraction （XRD） patterns and Raman spectra of glass sam- ples are measured to investigate the structures. The absorption spectra, the up-conversion emission spectra, the 1.53 /am band fluorescence spectra and the lifetime of Er3＋：4113/2 level are measured, and the amplification quality factors of Er3＋ are calculated to evaluate the effect of WO3 contents on the 1.53 μm band spectroscopic properties. With the in- troduction of WO3, it is found that the prepared tellurite-based glasses maintain the amorphous structure, while the 1.53 μm band fluorescence intensity of Er3＋ is improved evidently, and the fluorescence full width at half maximum （FWHM） is broadened accordingly. In addition, the prepared tellurite-based glass samples have larger bandwidth qual- ity factor than silicate and germanate glasses. The results indicate that the prepared Er3＋/Ce3＋ co-doped tellurite-based glass with a certain amount of WO3 is an excellent gain medium applied for the 1.53 μm band Er3＋-doped fiber ampli- fier （EDFA）.     

胀袋火锅调料中腐败微生物的分离和鉴定

从某品牌胀袋火锅调料中分离筛选出3株腐败微生物,分别命名为H-1,H-2,H-3,经形态学、生理生化特征鉴定、16SrDNA序列分子鉴定和系统发育树分析,确定3株菌株分别为枯草芽孢杆菌(Bacillus subtilis)、解淀粉芽孢杆菌(Bacillus amyloliquefaciens)和地衣芽孢杆菌(Bacillus licheniformis),它们可能是造成火锅调料腐败的主要原因。由此对胀袋火锅调料中腐败微生物进行初步分析,为食品的保藏提供参考依据。     

3种食源性致病菌的实时荧光PCR快速检测

DNA提取方法采用先钢珠机械破坏细菌细胞壁,再添加丙酮、蛋白酶K溶解去除杂质,大大提高了食源性致病菌基因组DNA的得率和纯度。继而针对金黄色葡萄球菌egc基因、沙门氏菌NA(not availabale)基因、志贺氏菌ipaH基因为靶基因设计特异性引物对样品建立实时荧光定量PCR检测方法。结果试验设计的引物对3种细菌具有很强特异性,除目标细菌外,对单核细胞增生李斯特氏菌、副溶血性弧菌、蜡样芽孢杆菌3种对照菌均未检测到荧光信号。对金黄色葡萄球菌、沙门氏菌和志贺氏菌的检测灵敏度分别达到10~(-6)、10~(-6)、10~(-7) ng/μL。     

电网工程设计管理分布式系统的设计与实现

在设计企业中,参与设计项目的生产及管理部门较多,设计专业分工细化,跨部门、跨专业协调花费很多的时间、空间成本,采用信息化系统进行工程项目管理成为一种重要手段。笔者以中国能源建设集团广西电力设计研究院有限公司电网工程设计管理为例,介绍通过对原有设计管理系统软硬件的统一规划,进行流程整合,从而达到利用信息化手段以更好地满足电网工程设计管理需要的目的。     

肉制品中毛皮动物源性成分掺假检测阳性质粒分子的构建与评价

目的 建立一种肉制品中毛皮动物源性成分掺假快速检测技术。方法 构建狐狸、貉、水貂三种检测用阳性质粒分子,利用实时荧光定量PCR方法对其特异性、灵敏度和方法适用性等关键指标进行分析。结果 构建好的狐狸、貉、水貂阳性质粒分子特异性强、灵敏度高,检验灵敏度均可达到10-4 ng/μL,标准曲线扩增效率分别为94.451%、117.461%、114.709%,且相关系数(R2)均在0.995以上。在混合肉样品和市售肉制品中均可检测,三种成分的检测限均低至1%,具有较好的可行性及适用性。结论 本方法构建的三种阳性质粒分子可以满足实际工作中肉类掺假检测的需求。     

二氧化硅对铒/铈共掺碲酸盐玻璃光谱性质的影响(英文)

为进一步提高Er3+1.53μm波段的光谱特性,在Er3+:4 I11/2→4 I13/2和Ce3+:2 F5/2→2 F7/2跃迁间存在能量失配(1 400cm-1附近)的Er3+/Ce3+共掺碲酸盐(TeO2-Bi2O3-TiO2)玻璃中引入了高声子能量SiO2组分。测试分析了不同SiO2组分含量下的Er3+吸收光谱、上转换发光谱、1.53μm波段荧光谱、荧光寿命、放大品质因子和玻璃样品的热性能。结果表明:由于增强的Er3+/Ce3+离子间能量传递,当玻璃样品中SiO2含量达到9%(摩尔分数)时,Er3+的1.53μm波段荧光强度得到显著提高。同时,荧光半高宽随SiO2组分含量相应展宽,而玻璃热稳定性随之提高。     

Effect of SiO2 on the thermal stability and spectroscopic properties of Er3+-doped tellurite glasses

Er3＋-doped tellurite glass （TeO2-ZnO-Na2O） prepared using the conventional melt-quenching method is modified by introducing the SiO2, and its effects on the thermal stability of glass host and the 1.53 μm band spectroscopic properties of Er3＋ are investigated by measuring the absorption spectra, 1.53 μm band fluorescence spectra, Raman spectra and differential scanning calorimeter （DSC） curves. It is found that for Er3＋-doped tellurite glass, besides improving its thermal stability, introducing SiO2 is helpful for the further improvement of the fluorescence full width at half maximum （FWHM） and bandwidth quality factor. The results indicate that the prepared Er3＋-doped tellurite glass containing an appropriate amount of SiO2 has good prospect as a candidate of gain medium applied for 1.53 μm broadband amplifier.     

一种基于勒让德拟合的SAR 后向投影自聚焦算法

对于合成孔径雷达(SAR)成像来说,后向投影(Back Projection, BP)算法是一种十分重要的时域成像方法。然而现有的自聚焦算法都是基于频域成像算法开发的,无法直接用于BP 聚焦图像的误差相位估计。针对这一问题,该文提出一种适用于BP 图像的自聚焦算法。该算法以图像锐度函数为目标函数,以待估计的相位校正值为自变量,通过坐标下降最优化算法循环迭代获得它们的最优估计。在问题求解中,该算法利用勒让德多项式来拟合目标函数,使得每次迭代的最优解可以解析地获得,避免了低效的线搜索过程。基于仿真数据和实测数据的实验验证了该算法的精确性和有效性。      

一种识别电力系统关键输电线路的方法

电网关键输电线路的辨别有利于预防电网灾难事故,提高电力系统的安全稳定性。通过评估支路开断后系统潮流所受冲击的强弱,给出一种识别电力系统关键输电线路的方法。首先,基于等相角线理论,定义相角分割区,依据相角分割区和电气距离对系统输电线路进行分区,基于广义熵指数理论,定义潮流增长率广义熵指数指标,评估支路开断后潮流冲击分布的均衡度;然后,从网络拓扑结构的角度,定义边的Katz-Bonacich中心性指标评估输电线路位置的重要性,并定义评估系统对潮流冲击抵抗能力的余度指标;最后,基于云模型原理,对各评估指标进行云模型转换,以云图的形式展现评估结果。通过对IEEE 30节点系统和新英格兰10机39节点系统进行仿真,验证了所提方法的正确性。     

Influence of Yb2O3 on the 1.53 μm spectroscopic properties in Er3+/Ce3+ co-doped TeO2-WO3-Na2O-Nb2O5 glasses

The Yb2O3 component was introduced into the Er3+/Ce3+ co-doped tellurite glasses with the composition of TeO2-WO3-Na2O-Nb2O5 to study the effect of Yb3+ on the 1.53 μm spectroscopic properties of Er3+. The X-ray diffraction (XRD) curve and Raman spectrum were measured to investigate the structure nature of synthesized tellurite glasses. The absorption spectrum, upconversion emission spectrum and fluorescence spectrum were measured to evaluate the improved effect of Yb3+ concentration on the 1.53 µm band fluorescence of Er3+. Results of the measured 1.53 µm band fluorescence intensity show a significant improvement with the increase of Yb3+ concentration, while the total quantum efficiency reveals a similar increasing trend. The results of the present work indicate that Er3+/Ce3+/Yb3+ tri-doped tellurite glass has good prospect as a promising gain medium applied for the 1.53 µm broadband amplifier.