與物體相連之彈簧的縱向振動

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MOCVD growth of high-reflectivity AlN/GaN distributed Bragg reflectors

利用金属有机物化学气相沉积(MOCVD)方法在蓝宝石c面衬底上制备出高反射率AlN/GaN分布布拉格反射镜(DBR)。利用分光光度计测量,在418 nm附近最大反射率达到99%。样品表面显微照片显示,有圆弧形缺陷和少量裂纹出现;在缺陷和裂纹以外的区域,DBR具有较为平坦的表面,其粗糙度在10μm×10μm面积上为3.3 nm左右。样品的截面扫描电镜(SEM)照片显示,DBR具有良好的周期性。对反射率和表面分析的结果表明,该样品达到了制备GaN基垂直腔面发射激光器(VCSEL)的要求。A high reflectivity AlN/GaN distributed Bragg reflector(DBR) is grown on c-plane sapphire substrate by metalorganic chemical vapor deposition(MOCVD).A peak reflectivity of 99% is observed around 418 nm by spectrophotometer.Compass-shape defects and a few cracks are observed on the surface.The surface root mean square(RMS) of roughness in the flat area is around 3.3 nm over a 10 μm×10 μm area.The cross-sectional scanning electron microscope(SEM) image reveals the good periodicity of DBR.Considering the peak reflectivity and surface morphology,the DBR can be used to fabricate GaN-based vertical cavity surface emitting laser(VCSEL).国家高技术研究“863”计划资助项目(2006AA03Z409

南海中深层动力格局与演变机制研究进展

南海是连接印度洋-太平洋的最大边缘海,在季风、海峡水交换以及复杂地形影响下,南海环流呈现出独特的三层结构以及远强于大洋的混合特征.理论与观测表明,南海内潮、内孤立波以及强风等过程是强混合的动力来源.在南海强混合作用下,南海发育了活跃的中深层动力系统,一方面促进了南海与大洋之间的水体交换,另一方面调控上层风生环流,使得南海环流显著区别于其他热带与副热带海盆.南海活跃的中深层环流所具有的物质搬运能力又显著影响着南海的地质沉积、生物地球化学循环等过程.中国对深海研究持续投入,在南海中深层环流动力学研究方面取得了显著的成果,文章就该方面进行总结,并对南海深海环流未来研究设想进行初步探讨

关于“经济发展方式转变进程中的财税政策”的探讨(笔谈)

转变经济发展方式是当前中国的热门话题,而上海在城市发展中又肩负着率先转变的重要任务,在这一意义和背景下,2010年4月24日由上海金融学院学院主办、上海金融学院公共经济管理学院承办的“《中国城市财政发展报告2009/2010:促进‘两个中心’建设的上海城市财政》首发式暨‘经济发展方式转变进程中的财税政策’论坛“在我校举行。与会专家围绕经济发展方式转变进程中的财税政策的“趋势与目标“、“机遇和挑战“、“实施方略“和“地方实践“等四个专题进行研讨,各抒己见,智慧交锋。现将其真知灼见整理摘要与读者分享,以期待更多学者共同关注当前经济发展方式转变进程中的财税政策

肛瘘切开术与切除术治疗低位单纯性肛瘘中的价值

目的分析比较肛瘘切开术与切除术治疗低位单纯性肛瘘的价值。方法方便选择2014年7月—2016年7月该院所收治的120例明确诊断为低位单纯性肛瘘患者进行研究。按照随机数字表法分为肛瘘切开组(n=60)和肛瘘切除术组(n=60),两组采用相同的术前准备、麻醉方式和术后管理。对比两组手术操作时间和术中出血量,研究分析两组术后切口愈合时间、切口并发症(疼痛、出血及感染)、复发率、早期排便次数、大便失禁和狭窄并发症发生率。结果肛瘘切开术组手术操作时间为(16.1±2.3)min,肛瘘切除术组手术操作时间为(13.8±3.2)min,两组数据差异有统计学意义(t=4.520 8,P=0.013 1);肛瘘切开术组手术切开愈合时间为(22.5±4.5)d,肛瘘切除术组手术愈合时间为(28.8±4.6)d,两组数据差异有统计学意义(t=8.91,P=0.010 1);肛瘘切开术组早期排便次数为(1.5±0.5)次,肛瘘切除术组早期排便次数为(2.5±1.5)次,两组数据差异有统计学意义(t=3.167,P=0.002)。而两组在术中出血量、术后因切口疼痛导致的镇痛药使用率、切开疼痛评分方面差异无统计学意义(P>0.05)。术后随访1年,肛瘘切开术组患者术后复发率高于肛瘘切除术组,差异有统计学意义(P0.05)。结论肛瘘切除术与切除术在治疗低位单纯性肛瘘方面,操作简单,伤口较小,手术操作时间短、恢复快,但远期复发率高于肛瘘切除术

2001年亞洲盃女子足球比賽得失分特徵之研究

[[abstract]]Abstract This study analyses the goals scored in the ten crucial matches at the 2001 Women’s Asian Soccer Tournament, correlating the results obtained to period of playing time, shooting position, player position, and method of scoring. The results obtained were put to a one-way ANOVA analysis with α=.05 level。 The results obtained were as follows: 1. No notable difference was observed for goals scored in relation to playing period. 2. No notable difference was observed for goals scored in relation to shooting position. Most goals were scored from area A (the six yard box). Least goals were scored from area C (left and right sides of the penalty area). 3. A notable difference was observed for goals scored in relation to playing position. Attackers scored more goals than defenders. 4. An analysis of scoring method returned the following results: (1) Most goals scored in open play occurred from crosses to the near and far posts and from through passes. Fewer goals occurred from crossovers, overlaps, wall passes and back passes. (2) No notable difference was observed for goals scored from set plays. (3) An analysis of the occurrence of scoring opportunities revealed that most scoring chances arose from passes by team-mates. Fewer chances occurred from defensive fouls, defensive mistakes and individual dribbles by the attacking team. (4) A notable difference was observed in method of shot. Tap-ins and strong instep shots showed a notable difference compared to other methods of shooting. 5. No notable difference was observed in an analysis of goals scored from defensive mistakes.