论高等数学中蕴涵的人文精神

针对我国教育现状,为解决“边缘人”和“空心人”的问题,探讨了“高等数学”中所蕴涵的人文精神,认为可以从七个方面来挖掘,使“高等数学”的教育功能更加完备。     

论高等数学中蕴涵的人文精神

针对我国教育现状,为解决“边缘人“和“空心人“的问题,探讨了“高等数学“中所蕴涵的人文精神,认为可以从七个方面来挖掘,使“高等数学“的教育功能更加完备。     

关于高等数学的素质教育思考

提出了在完成“高等数学”教学大纲的同时,要重视揭示知识后面的精神世界,并认为有7个方面的内容。提出教师要由低到高引导提升大学生的追求,即由追求知识到追求能力,最终追求隐藏在定义定理后面的精神世界。     

Composite-Collector InGaAs/InP Double Heterostructure Bipolar Transistors with Current-Gain Cutoff Frequency of 242 GHz

To eliminate the conduction band spike at the base-collector interface, an InP/InGaAs double heterostructure bipolar transistor （DHBT） with an InGaAsP composite collector is designed and fabricated using the conventional mesa structure. The DHBT with emitter area of 1.6×15μm^2 exhibits current-gain cutoff frequency ft = 242 OHz at the high collector current density Jc = 2.1 mA/μm^2, which is to our knowledge the highest ft reported for the mesa InP DHBT in China. The breakdown voltage in common-emitter configuration is more than 5 V. The high-speed InP/InGaAs DHBT with high current density digital circuits. is very suitable for the application in ultra high-speed     

可调马赫-泽德干涉仪型NRZ到PRZ全光码型转换器

研制了一种基于光纤型马赫-泽德干涉仪的全光码型转换器.通过对工作温度的控制,实现了NRZ码到PRZ码的转换.分析了实现NRZ到PRZ码型的转换原理,讨论了干涉仪的结构设计.在10 Gb/s和20 Gb/s的码型转换实验中,得到较好的PRZ信号眼图.光谱分析表明,转换后的PRZ码包含了丰富的时钟分量,达到了理想的转换结果.结果表明,这种简单的光纤型非对称马赫-泽德干涉仪可以实现NRZ到PRZ的转换,并可以保持输出结果的稳定性.     

Growth and Characterization of GaAs／A1GaAs Thue-Morse Quasicrystal Photonic Bandgap Structures

One-dimensional quasicrystal structures composed of Ⅲ-Ⅴ semiconductor GaAs/AlGaAs multilayers in deterministic Thue-Morse (TM) sequences have been grown by using gas-source molecular beam epitaxy to investigate both the structural and the photonic bandgap properties. The x-ray measurements show that this aperiodic system exhibits obvious periodic spatial correlations, from which the precise thickness of the constitutive layers could be determined. Transmission and reflection measurements experimentally demonstrated plenty of photonic bandgaps with traditional or fractal features existing in those quasicrystal structures, which are in good agreement with the transfer matrix simulations. The diversity of this TM system makes it a good candidate for photonic device applications.     

Characterization of low-resistance ohmic contacts to heavily carbon-doped n-type InGaAsBi films treated by rapid thermal annealing

Carbon-doped In Ga As Bi films on In P:Fe(100)substrates have been grown by gas source molecular beam epitaxy(GSMBE).The electrical properties and non-alloyed Ti/Pt/Au contact resistance of n-type carbon-doped In Ga As Bi films were characterized by Van der Pauw-Hall measurement and transmission line method(TLM)with and without rapid thermal annealing(RTA).It was found that the specific contact resistance decreases gradually with the increase of carrier concentration.The electron concentration exhibits a sharp increase,and the specific contact resistance shows a noticeable reduction after RTA.With RTA,the In Ga As Bi film grown under CBr4 supply pressure of 0.18 Torr exhibited a high electron concentration of 1.6×10²¹ cm^-3 and achieved an ultra-low specific contact resistance of 1×10^-8Ω·cm²,revealing that contact resistance depends greatly on the tunneling effect.     

Possibility of Targeting Treatment for Ischemic Heart Disease With Liposome(Ⅱ)

Studies on the isolated rat heart perfusion model have proved that perfusion with high Ca_(2+) (4.5 mmol/L), high K~+ (8.7 mmol/L) or tree radical generating system (FRGS) significantly increases myocardial uptake of liposomes. Intravenous injection of liposomes covalently combined with antibody of rat myocardial cells obviously elevates the target action of liposomes to myocardium. Liposome-carried SOD for treatment of rat myocardial ischemia-repertusion injury is much more effective than simple SOD. The results evidence that the liposome as drug carrier for treatment of ischemic heart diseases shows a broad prospect for its clinical use.     

3G通信网络的安全分析

本文介绍了3G系统的安全性要求,对3G系统的安全技术进行了系统的分析,为3G通信网络的全面实施提供了依据。     

光纤通信工程技术传输的最新发展动态

光纤通信工程技术传输在通信领域处于重要地位,该文以当前我国光纤通信技术传输的发展现状为基础,对光纤通信工程技术传输的未来发展做出了一定的分析和研究,探讨了未来光纤传输的发展态势.