Improved data analysis method of single-molecule experiments based on probability optimization

To extract the dynamic parameters from single molecule manipulation experiments, usually lots of data at different forces need to be recorded. But the measuring time of a single molecule is limited due to breakage of the tether or degradation of the molecule. Here we propose a data analysis method based on probability maximization of the recorded time trace to extract the dynamic parameters from a single measurement. The feasibility of this method was verified by dealing with the simulation data of a two-state system. We also applied this method to estimate the parameters of DNA hairpin folding and unfolding dynamics measured by a magnetic tweezers experiment.     

LaNi5-xAlx合金吸放氢过程的滞后现象

测定了LaNi5-xAlx(x=0, 0.1, 0.2, 0.3)合金在吸放氢过程中P-C等温线的坪台压力及热力学参数.结果表明,坪台压力与热力学参数焓变ΔH,熵变ΔS随合金中Al含量的增加而降低,吸氢及放氢过程中的坪台压力存在一定的差异,即滞后现象(用滞后系数Hf表示).Hf随温度的升高而减弱,随合金中Al含量的增加而降低.滞后现象与合金在吸放氢过程中的应力释放有关.     

卢瑟福散射实验装置的研制

研制了一种鼎瑟福散的实验装置,并介绍了其实验结果,由于要用了步进电机和半导体探测器,该装置具有结构紧凑,操作简便等优点。     

一种微带反射阵列天线单元特性研究

带开路短截线的贴片是微带反射阵列天线设计中最常用的单元形式之一。结合应用于民用航天领域的薄膜反射阵列天线设计,比较和分析不同物理参数、阵列环境下单元电讯性能变化特点,并优化设计单层薄膜反射阵列天线试验阵面,给出分析结果,供不同应用背景下的反射阵列天线设计参考。     

Chord双向查找算法研究

Chord算法是一种典型的结构化P2P搜索算法,该算法简洁而且拓扑结构清晰,但该算法还存在着路由表信息冗余,查找效率不高的问题。在分析经典Chord算法的基础上,通过扩展Chord路由表,提出一种新的查找算法,该算法能够消除路由表的一些冗余信息,减少查找次数。通过理论分析,该算法提高了Chord的查找效率。     

一种超宽带CMOS除二电路及其优化方法

本文提出了一种新型的基于轮换触发的除二电路及其基于大信号分析的优化方法。通过减小跟随相输出节点的RC常数,增大锁存相输出节点的RC常数,减小内部信号摆幅和补偿锁存相输出节点漏电流的损失等电路技术,大大拓宽了其工作频带。本论文在SMIC 0.13μm RF CMOS工艺条件下设计了一款原型电路,其后仿工作频率可以达到320MHz到29.6GHz。此外,这款除二电路还应用于两款整数分频锁相环芯片中,分别对频率为4224MHz和10GHz的信号进行分频。测试结果表明,这款除二电路可以对其进行正确分频,而且整体锁相环的带内相噪分别为-94dBC/Hz@10kHz和-84dBc/Hz@10kHz.     

A low jitter, low spur multiphase phase-locked loop for an IR-UWB receiver

A low jitter,low spur multiphase phase-locked loop(PLL) for an impulse radio ultra-wideband(IR-UWB) receiver is presented.The PLL is based on a ring oscillator in order to simultaneously meet the jitter requirement, low power consumption and multiphase clock output.In this design,a noise and matching improved voltage-controlled oscillator(VCO) is devised to enhance the timing accuracy and phase noise performance of multiphase clocks.By good matching achieved in the charge pump and careful choice of the l...     

Design and optimization of an ultra-wide frequency range CMOS divide-by-two circuit

A novel toggled flip-flop(TFF) divide-by-two circuit(DTC) and its optimization method based on a large-signal analysis approach are proposed.By reducing the output RC constant in tracking mode and making it large in latching mode,compressing the internal signal swing as well as compensating the current leaked in the latching mode, the operating frequency range is greatly expanded.Implemented in a SMIC 0.13μm RF CMOS process with a 1.2 V power supply,it can work under an ultra-wide frequency band ranging ...     

小灵通3S技术

一个基站的信号覆盖是有一定范围的，为了能让无线电话在一个很大区域内(如一个市)都能打电话，就需要很多基站，使信号能覆盖这片区域。这样，当用户在移动过程中通话，就会发生切换。这种切换在常规情况下会有1～2秒，有时有短暂停顿的感觉。越区切换是所有无线电话都会发生的现象，只不过由于小灵通网络采用的是微蜂窝技术，基站辐射半径小，覆盖相同区域需要更多的基站，切换的频次可能会高一些。如何使切换不停顿，保证通话流畅，成了小灵通业研究的重要课题。