掩埋隧道结在长波长VCSEL结构中的应用

采用气态源分子束外延技术在InP(100)衬底上分别生长了δ掺杂的p -AlIn-As-n -InP和p -InP-n -InP两种隧道结结构,用电化学C-V和I-V特性曲线表征了载流子浓度和电学特性,发现p -AlInAs-n -InP隧道结性能优于p -InP-n -InP隧道结.在InP(100)衬底上生长了包含p -AlInAs-n -InP掩埋隧道结和多量子阱有源层的1.3μm垂直腔面发射激光器(VCSEL)结构,测试得出其开启电压比普通的pin结VCSEL小,室温下其电致发光谱波长为1.29μm.     

宽带隙ZnMgO的电学特性及其透明薄膜场效应晶体管

首次提出了用六方相晶体结构的宽带隙ZnMgO作为薄膜场效应晶体管（TFT）的沟道层，用立方相ZnMgO纳米晶体薄膜作为栅绝缘层，在实验中用透明的ITO导电玻璃作为衬底，通过连续沉积六方和立方相结构的纳米ZnMgO晶体薄膜，并通过光刻、电极工艺等，研制了透明的ZnO基TFT, TFT的电流开关比达到1E4，场效应迁移率为0.6cm2/(V·s).在偏压2.5MV/cm下漏电流为1E-8A.     

α－Pb（N_3）_2热分解和热爆炸机理的实验与论证

本文利用飞行时间质谱和电子能谱检测了α－Ｐｂ（Ｎ＿３）＿２热分解和热爆炸过程的产物，提出了两种不同的反应机理；在热分解过程中，α－Ｐｂ（Ｎ＿３）＿２热分解步骤是Ｎ＿３中π电子受激发生成Ｎ＿３自由基，Ｎ＿３自由基进一步相互碰撞生成Ｎ＿２．在热爆炸过程中，系统中能量足够高，致使Ｎ＿３中的π锻和σ键同时发生断裂，生成Ｎ原子和Ｎ＿２分子。根据实测的数据，讨论了α－Ｐｂ（Ｎ＿３）＿２热分解和热爆炸化学反应机理的差别。     

Evaluation of the carcinogenic effect of ceramic fibers in experiments on rats and mice

The metabolism of toborinone, (+/-)-6-[3-(3,4-dimethoxybenzylamino)-2-hydroxypropoxy]-2(1H)-quin - olinone, a novel inotropic agent, was studied in rats and dogs after intravenous administration. Chemical structures of the 13 metabolites were characterized by direct-probe FAB/MS and field desorption/MS, LC/FAB/MS, and various NMR measurements. After intravenous dosing of 10 mg/kg [14C]toborinone, fecal and urinary recoveries of the 14C dose were approximately 70% and 26-30%, respectively, in both rats and dogs. The predominant component of radioactivity was the unchanged toborinone in every biological specimen in rats and dogs. Although unchanged toborinone was predominantly observed, toborinone underwent extensive conjugations with glucuronic acid, sulfate, and glutathione, either directly or following phase I reaction. Metabolites resulting from oxidative N-C cleavage were minor both in number and in quantity in every biological specimen in rats and dogs. In rats, toborinone underwent O-demethylation to form M-7 and successive phase it reaction to yield the glucuronide M-1 and the sulfoconjugate M-2, and deconjugation to yield M-7, which was a primary metabolite accounted for 35.67% of the radioactivity excreted in the feces by 48 hr. Conjugates M-1 and M-2 were the major metabolites in rat plasma. In dogs, toborinone was metabolized via mercapturic acid pathway to yield the primary metabolites, cysteine conjugates M-10 and M-11 that accounted for 19.10% and 6.70% of the radioactivity excreted in the feces by 48 hr and that were detected species specifically in dogs. The glutathione conjugate M-13, which was isolated from in vitro incubations using dog liver, led us to consider a possible mercapturic acid pathway from the parent compound to M-10. Metabolites in dog plasma and those in urine in both rats and dogs were minor in quantity. The metabolic pathways of toborinone in rats and dogs are proposed herein.     

坚持自主创新 推进上海RFID应用与产业的发展

紧跟国际RFID发展步伐,上海RFID的应用及其产业的发展开始全面启动,在政府的大力支持下,上海RFID产业坚持科技创新,初步形成了政府资助、企业为主体、产学研联盟的RFID科技创新机制。     

Construction Control and Pile Body Tensile Stresses Distribution Pattern during Driving

In this paper, the pile body tensile stresses distribution pattern during driving is discussed, based on dynamic piling testing results of 13 driven piles attained by the laboratory and in situ tests. These tests indicate that the maximum driving tensile stresses occur in the upper portion of the pile, especially at the initial stages of driving the pile tip seated on soft soils or if the pile foundation is built on a soft foundation. After serious study, it can be concluded that the maximum driving tensile stress often occurs at (1/4)l (l stands for the length of pile) from pile top with its value accounts for 50% of the driving compressive stresses at the same cross section. This high driving tensile stress would lead to the occurrence of transverse cracks and even the breakage of the pile, which should claim the attention of the engineer. The tests also demonstrate that high driving tensile stresses often occur due to the usage of a conventional pile cap in the driving of a prestressed concrete (tubular) pile. To the contrary, the tensile stresses tend to diminish within the control tensile stresses (5?MPa) due to the usage of a new type of disk spring pile cap during driving. Moreover, this new pile cap can prevent driving deviation from alignment, ensure an even distribution of the hammer blow on pile top, and protect the integrity of the pile body.     

Effect of Bi2O3 and Sb2O3 on the grain size distribution of ZnO

In the present study, the effect of Bi₂O₃ and Bi₂O₃+Sb₂O₃ additions on the size distribution of ZnO grains is investigated. Without the usage of a powder bed, the addition of Bi₂O₃ provides a transient liquid phase that enhances the densification. The residual Bi segregates alters the surface/grain boundary energy ratio, which encourages the ZnO grains to grow. The size variation is also increased. The addition of both Bi₂O₃ and Sb₂O₃ induces the formation of pyrochlore, spinel and inversion boundary. Their presence reduces not only the average grain size, but also the size variation.     

干法刻蚀对InAsP/InGaAsP应变多量子阱发光特性的影响

采用气态源分子束外延(GSMBE)生长了具有不同阱宽的InAsP/InGaAsP应变多量子阱,并对干法刻蚀前、干法刻蚀及湿法腐蚀不同厚度覆盖层后的多量子阱光致发光(PL)谱进行了表征.测量发现干法刻蚀量子阱覆盖层一定厚度后量子阱光致发光强度得到了明显的增强.这与干法刻蚀后量子阱覆盖层表面粗糙度变化及量子阱内部微结构变化有关.     

浅谈任务驱动法在职中计算机课中的应用

任务驱动法是指在整个教学过程中,老师不直接讲解教学内容,而是把教学内容分解到精心设计的一系列任务中,让学生通过自己完成一个个任务来学习知识、掌握技能,整个过程老师起辅助作用,学生是学习的主体.由于计算机的专业课很多又是以操作为主,面对新软件的操作,很多老师往往只是简单地使用填鸭式教学,忽略了对任务驱动法的使用,更加忽略对课堂任务的设计,而学生在老师这种枯燥的教学方法教育下,学习兴趣跟学习积极性下降.笔者联系自己的教学体会,浅谈任务驱动法在计算机课中的必要性和应用.