Effects of extended dislocations on charge distribution in GaN epilayer

We have investigated the effect of extended dislocations (0.5-3 μm) on charge distribution in GaN epilayer grown by metalorganic chemical vapor deposition on (0001) sapphire using atomic force microscopy (AFM) and scanning surface potential microscopy (SSPM). It has been observed for the surface at the extended dislocations present in undoped GaN film to be negatively charged showing 0.04-0.2 V higher potential relative to regions that contain no dislocations. In addition to the higher potential at the dislocation core, the surrounding surfaces, including the edge of the dislocations, are also negatively charged in a symmetric way around the dislocations revealing crater-shaped higher potential regions (∼0.04 V) relative to surrounding dislocation-free area. The experimental results show that the protrusion-type of dislocation is also negatively charged and its potential is dependent on the size of dislocation.     

MoSi2发热体在熔铝炉中的运用

以电阻熔铝炉技术改造实践为例，介绍一种高效、节能、不渗铁的新型熔铝炉——二硅化钼熔铝炉的设计。     

Impact of nonlinear phase noise on direct-detection DQPSK WDM systems

The performance degradation of differential quadrature phase-shift keying (DQPSK) wavelength-division-multiplexed (WDM) systems due to self-phase modulation (SPM)- and cross-phase modulation (XPM)-induced nonlinear phase noise is evaluated in this letter. The XPM-induced nonlinear phase noise is approximated as Gaussian distribution and summed together with the SPM-induced nonlinear phase noise. We demonstrate that 10-Gb/s systems, whose walkoff length is larger than 40-Gb/s systems', are more sensitive to XPM-induced nonlinear phase noise than 40-Gb/s systems. Furthermore, DQPSK WDM systems show lower tolerance to both SPM- and XPM-induced nonlinear phase noise than differential phase-shift keying WDM systems.     

A 0.9 V 92 dB Double-Sampled Switched-RC Delta-Sigma Audio ADC

A 0.9 V third-order double-sampled delta-sigma audio ADC is presented. A new method using a combination of a switched-RC technique and a floating switched-capacitor double-sampling configuration enabled low-voltage operation without clock boosting or bootstrapping. A three-level quantizer with simple dynamic element matching was used to improve linearity. The prototype IC implemented in a 0.13 CMOS process achieves 92 dB DR, 91 dB SNR and 89 dB SNDR in a 24 kHz audio signal bandwidth, while consuming 1.5 mW from a 0.9 V supply. The prototype operates from 0.65 V to 1.5 V supply with minimal performance degradation.     

住宅产品与住宅设计相链接“二次技术开发”是关键

各位领导、各位专家、各位代表：上午好!首先，我代表中国房地产及住宅研究会住宅设施委员会，衷心感谢大家参加委员会一年一度的年会。刚刚周部长对委员会的工作做了重要指示，刘秀晨同志也发表了精彩的讲话，充分肯定了委员会的工作，指出了方向，提出了希望，我们深受鼓舞。刘秀晨同志给我们委员会做出了重要贡献，他从国务院参事和全国政协委员的角度提出了“推广绿色厨卫，     

烯烃聚合单活性中心非茂催化剂的最新研究进展

综述了近几年来烯烃聚合用单活性中心非茂催化剂的研究进展。简要介绍了 2 3种由前、后过渡金属组成的配位化合物催化剂的结构与性能     

A study on charge reduction in HfO/sub 2/ gate stacks

Charge in metal-organic chemical vapor deposition-grown HfO/sub 2/ gate stacks has been systematically studied using nMOS capacitors. It is found that, for these films, the charge in the stack is mainly concentrated at the interfaces between the layers and is negative at the HfO/sub 2//interfacial layer (IL) interface and positive at the Si/IL interface. In general, the calculated charge densities at both interfaces are of order 10/sup 12/ cm/sup -2/. A forming gas anneal (FGA) reduces both interface charge greatly. The FGA can also significantly reduce the hysteresis and interface state density. The effects of post deposition anneal at various temperatures and under various ambients have also been studied. It is found that a high-temperature dilute oxidizing ambient anneal followed by an FGA reduces the charge at both interfaces.     

薄板坯连铸连轧流程Ti微合金化高强钢开发与应用

在薄板坯连铸连轧流程上，经过对Ti微合金化技术研究，有效解决了Ti微合金化强度性能波动大的问题，开发出屈服强度450～700MPa高强钢。对试制钢组织性能和工业应用分析研究，表明该产品通板性能良好，通板强度差30MPa左右；成形性能良好，d=0时冷弯测试全部合格；同时还具有良好焊接性能，焊接后，强度波动较小，均在母材部位断开；试制钢显微组织为珠光体和铁素体，晶粒均匀细小，平均尺寸为4～8／μm；实物质量满足集装箱和汽车制造行业要求，具有广阔市场前景。     

合理开发利用钨矿资源 促进钨矿业可持续发展

简述了我国钨矿业概况、现有采选技术水平及钨矿加工利用率 ;从资源配置出发 ,阐述了钨矿业发展存在的几个主要问题 ,并且针对性地提出了可持续发展的几点建议。     

蓝湿皮酶软化的特性研究

以自行研制的一种复合酶为软化剂 ,研究了 p H值、反应温度、反应时间、酶用量以及铬含量对猪蓝湿皮软化效果的影响 ,其软化效果以软化液中羟脯氨酸的浓度增量来表征。研究结果表明 :通过蓝湿皮软化来改善成品革的质量是可行的 ,而且有明显的效果 ;以软化液中羟脯氨酸的浓度来表征软化效果是一个有效的方法 ;当用该复合酶软化猪蓝湿皮时 ,最适 p H值范围为 6 .0 - 6 .5 ;反应温度在 4 0 - 6 5℃之间时 ,软化效果随温度的升高而增大 ;在 5 5℃条件下 ,该酶有很好的热稳定性 ,能长时间保持活力不衰减 ;最适酶用量为 30 0 U/ g试样 ;蓝湿皮的铬含量对软化效果有影响 ,用该方法处理的蓝湿皮 ,其铬离子质量含量一般应≤ 2 .5 %。