一种低噪声高PSRR的LDO线性稳压器

介绍了 LDO线性稳压器的系统组成原理,分析了系统的电源电压抑制比(PSRR)以及噪声与电路结构的关系,在此基础上,对LDO的核心电路模块进行了设计,并基于0.5μm标准CMOS工艺,运用Cadence平台进行了模拟仿真和验证.测试结果表明:该LDO的PSRR最低约为-45 dB@1 MHz,最高约为-75 dB@217 Hz;输出电压噪声在10 Hz频率以下约为0.78 μV(P-P),在10 Hz至l00 kHz频率范围内约为0.1 μV(RMS),能满足低噪声和高PSRR应用的要求.     

Single atoms in the ring lattice for quantum information processing and quantum simulation

We have demonstrated preparing and rotating single neutral rubidium atoms in an optical ring lattice generated by a spatial light modulator, inserting two atoms into a single microscopic optical potential efficiently by dynamically reshaping the optical dipole trap, trapping single atoms in a blue detuned optical bottle beam trap, and confining single atoms into the Lamb-Dicke regime by combining red and blue detuned optical potentials. In combination with the manipulation of internal states of single atoms, the study is opening a way for research in the field of quantum information processing and quantum simulation. In this paper we review the past works and discuss the prospects.     

Degradation of the antibiotic sulfamonomethoxine sodium in aqueous solution by photo-Fenton oxidation

In this study, photo-Fenton oxidation was applied to degradation of sulfamonomethoxine sodium (SMMS) in aqueous solution. The operation parameters of pH, temperature, and concentrations of H2O2, Fe2+ and SMMS were investigated. The optimum conditions for the photo-Fenton process were determined as follows: [SMMS]=4.53 mg/L, pH 4.0, [H2O2]=0.49 mmol/L, [Fe2+]= 19.51 μmol/L and T=25°C. Under these conditions 98.5% of the SMMS degraded. The kinetics were also studied, and degradation of SMMS by the photo-Fenton process could be described by first-order kinetics. The apparent activation energy was calculated as 23.95 kJ/mol. Mineralization of the process was investigated by measuring the chemical oxygen demand (COD), and the COD decreased by 99% after 120 min. This process could be used as a pretreatment method for wastewater containing sulfamonomethoxine sodium.     

La2O3-Al2O3-SiO2 glass-infiltrated 3Y-TZP all-ceramic composite for the dental restorative application

The 3 mol％ yttria stabilized tetragonal zirconia polycrystals (3Y-TZP) powder had three particle size distributions,while the fine one was lower than 100 nm.The 3Y-TZP compact was prepared by dry-press...     

二阶双曲方程新非协调混合元格式分析

将非协调旋转1rot元应用到二阶双曲方程,建立了一个新的混合元格式.直接利用单元插值的性质,平均值及导数转移技巧,在正方形网格上,分别得到了原始变量及通量的H1-模及L2-模最优误差估计.     

多级光杠杆测量微小形变量研究

光通过镜面发生反射,在入射光线方向不变的情况下,如果镜面旋转的角度为0,则反射光线偏转20．利用该原理对传统使用的光杠杆进行改进,提出多级光杠杆的概念．多级光杠杆对微小测量值的放大倍数远远超过传统光杠杆,灵敏度得到提高．同时在数据处理上采用线性拟合的方法得出结果,避免了传统光杠杆中的直接测量标尺和反射镜之间距离而引入的误差,使微小目标测量结果更加可靠．     

4个群体西太公鱼mtDNAD—loop区段的限制性片段长度多态性分析

应用PCR技术对天津市于桥水库、北京市密云水库、日本北海道和日本青森县4个群体共151尾西太公鱼（Hypomesusnipponensis）的mtDNAD-loop区段进行扩增,得到长度约为1．8kbp的扩增片段．扩增出的DNA片段使用13种核酸内切限制酶进行酶切,其中8种核酸内切限制酶（AluI、DraI、HaeⅢ、Hindm、HinfI、MboI、TaqI和XspI）有酶切位点,5种核酸内切限制酶（AluI、HinfI、MboI、TaqI和XspI）个体间存在变异．不同酶切结果组合后,共得到28种单倍型,于桥水库、密云水库、北海道和青森西太公鱼均以单倍型6为主,分别为36．36％、38．30％、43．33％和26．67％;于桥水库、密云水库、北海道及青森西太公鱼单倍型多样性指数（危）分别为0．8171、0．8141、0．7793和0．8828;核苷酸多样性指数Or）分别为0．007918、0．007326、0．007255和0．009710．于桥水库西太公鱼与密云水库西太公鱼之间的Rogers遗传距离最小,为0．1499;于桥水库西太公鱼与日本青森西太公鱼之间的Rogers遗传距离最大,为0．2215;日本北海道西太公鱼与密云水库西太公鱼之间的遗传距离为0．1511,大于于桥水库西太公鱼与密云西太公鱼之间的遗传距离,但小于日本境内北海道西太公鱼与青森西太公鱼之间的遗传距离．     

无限维随机车辆跟随系统的稳定性分析

为了提高自动高速公路车辆纵向跟随控制系统的稳定性,基于随机因素建立了无限维随机关联系统模型．运用向量李雅普诺夫函数法研究了无限维随机车辆跟随系统的指数群稳定性,分别得到了一类无限维“顾前”型和一类“顾前顾后”型随机车辆纵向跟随系统指数群稳定性的充分性判据,为随机车辆纵向跟随系统的控制器设计提供了理论基础．     

环境噪声抑制的红外接近传感器设计

分析红外接近传感器的工作原理,针对红外接近传感器容易受到环境噪声影响而发生检测错误的问题,提出一种高效的环境噪声抑制方法．该方法通过光学镀膜滤波和基于时序控制的数字模拟混合减法电路,分步滤除环境噪声,达到准确接近检测目标的目的．设计了相关传感器电路,可以在太阳光或灯光光照度低于4000lx,温度低于85℃的环境下,实现25cm范围内的物体接近程度的准确测定．在相同工艺下,通过Spec-tre进行仿真,结果表明：该传感器在给定的噪声环境中工作与无环境噪声的理想情况相比,最大误差不超过1％．所设计电路已在0．35μm3VCMOS工艺下投片验证,结果满足设计指标．