一种低压低功耗共源共栅带隙基准电压源的实现

提出了一种低压低功耗的带隙基准电压源电路,设计基于0.5μm2P3M BiCMOS Process,并使用了低压共源共栅电流镜结构减少了对电源电压的依赖,消除了精度与余度之间的矛盾,并用HL50S-S3.1S.lib库文件用HSPICE进行了仿真,其电源抑制比PSRR大约为-78.9dB。     

动画动态定位在网页上的方法

网页上经常会显示一些动画,如重要信息或广告等。本文用JavaScript实现了使动画固定在网页画面的相对位置上,不会被移出画面。     

Polycrystalline diamond MESFETs by Au-mask technology for RF applications

Metal-semiconductor field effect transistors (MESFETs) were fabricated on H-terminated polycrystalline diamond.The DC characteristics of the p-channel MESFET showed a maximum drain current density of 204 mA/mm at a gate-source voltage of 6 V,and a maximum transconductance of 20 mS/mm at a gate-source voltage of 1.5 V.The small signal S-parameters of MESFET with 2 100 m gate width and 2 m gate length were measured.An extrinsic cut-off frequency (fT) of 1.7 GHz and the maximum oscillation frequency (fmax) of 2.5 GHz were obtained,which was the first report on diamond MESFETs with RF characteristics in China.     

太湖流域水灾害应急对策研究

太湖流域是我国经济社会高度发达的地区之一,发生水灾害时往往会造成重大经济损失。对发生各类水灾害时的应急对策展开研究总结,以减轻水灾害,避免人员伤亡,保障经济社会可持续健康稳定发展,并通过分析典型案例的实际应对过程,为今后开展类似工作提供参考。     

Repeated Price Search

Consumers check few sites in online purchases. Previous research and experiments we perform demonstrate that consumers can not calculate the optimal strategy for price search. They use heuristics whose performance is better than random and less than optimal. To investigate online price search performance we survey student online textbook purchases. Students achieve good performance because they start with a good strategy and online market organization of marketplace and meta-search sites. An important factor is that algorithms at sites searched perform calculations that reduce the computational complexity of the search.     

经管类专业应用型人才培养模式研究

民办高校应用型人才培养模式是民办高校为培养应用型人才而探索形成的一种可操作性的经验与理论架构。本文简单阐述了经管类专业应用型人才培养的意义,构建了经管类专业应用型人才培养方案,主要是构建以企业为依托的合作办学模式,构建＂两平台＋N模块＋一拓展＂课程体系,构建以学生为主体的教学方法和＂双师型＂师资队伍。     

The oxidation state of sulfur detected in Na2O-CaO-SiO2 float glass by X-ray absorption near edge structure spectra

The oxidation state of sulfur is detected in Na2O-CaO-SiO2 float glass by synchrotron radiation X-ray absorption near edge structure (XANES) spectra at the sulfur K edge. The measured spectra show the only presence of S6+ in the Na2O-CaO-SiO2 float glass and the oxidation state of sulfur do not change with the increase of glass depth. It is also found that, after the melt has gone through the molten tin bath, the S6+ is the dominant species, but S2- is also present on both surfaces. It is not certain whether cation bonds to S2- or not, because there are many cations dissolved in the melted tin which makes the spectrum complicated.     

C*-代数中Moore-Penrose逆及Bott-Duffin逆的扰动分析

设A为C*-代数,a,-a=a δa∈A并且a 存在,‖a ‖‖δa‖<1。定义-a是a的稳定扰动,当且仅当-aA∩(1-aa )A={0}。此时-a 存在,并且‖-a ‖的上界被给出。对于B-D广义逆a p,在给出一般表达式的前提下,对于一类具有“p-零”性质的B-D广义逆,得到了‖-a p‖的一个上界。     

SiO2(am)在FoCa粘土和MX-80粘土中扩散实验的模拟

不定形二氧化硅[Amorphous Silica，简称SiO2（am）]是高放废物玻璃固化体在处置后，发生降解的主要产物。对SiO2（am）在FbCa粘土和MX-80粘土柱中的扩散迁移进行了实验研究，结果显示：在粘土柱中有大量的SiO2（am）沉淀产生；土柱中总Si增加量与时间的关系基本为线性正相关关系。采用CRUNCH程序对上述扩散迁移实验进行了模拟，模拟内容包括：溶液和岩相中Si浓度变化、总的筋增加量与时间的关系以及实验期间孔隙率的变化；同时分析了有效扩散系数对结果的影响。结果说明，使用CRUNCH程序进行反应迁移模拟是可行的；但是实验中pH值测量时机不适当；另外由于土样本身Si含量较高，易对土柱总Si的分析结果产生影响，这些因素需进一步实验时改进。     

时间分解光谱技术在钢铁分析中的应用

研究了单火花光谱在不同采样时间段分析灵敏度与窗口的关系,P、S、Al、Ni、Ti、B、Mg、Sb、Pb、As、Bi、Ta、Sn应用TRS技术检出限明显降低,而C、Si、Mn、Cr、Mo、V、W、Co、Nb则不显著;合适的采样窗口能提高Sb的分析准确度,Mg则可减少背景波动带来的影响,Cu可扩大分析线性范围;采用TRS技术在诸有效元素中分析灵敏度可提高1.36～5.00倍,能更好地满足品种钢的研究开发与生产检验的需求.