Mutagenesis,cultivation and ultrastructural observation of Synechococcus sp.PCC7942 and two Amp-tolerant mutants

利用化学诱变剂,对野生型蓝藻Synechococcussp.PCC7942进行诱变筛选,获得2株抗氨苄的聚球藻突变株.对抗氨苄株1、抗氨苄株2及野生藻PCC7942的生长情况、优化培养条件和超微结构等方面进行了比较分析,结果表明,野生型PCC7942的基础抗性为100 mg.L-1,而抗氨苄株1、抗氨苄株2分别为240和250 mg.L-1.经培养,3种藻的生长都表现出全天光照优于半天光照.在加入氨苄青霉素的BG-11培养基中,抗氨苄株1、2的长势明显好于野生型PCC7942,但都不如它们各自在正常BG-11培养基中的长势.用透射电镜对3种藻不同生理时期的超微结构进行观察,发现在一般情况下3种藻之间以及它们在不同生长时期的外观基本相同,但出现了螺旋结构和出芽生殖的特殊情况.Two Amp-tolerant mutants of PCC7942 were acquired after ethylmethyl sulphonate (EMS) mutagenesis and ampicillin enrichment.Through comparing among PCC7942 and two mutants on their growing responses,cultivating conditions and ultrastructures,it was discovered that the basic tolerance of PCC7942 to Amp was 100 mg·L~(-1) while the values of mutant 1 and 2 were 240 mg·L~(-1) and 250 mg·L~(-1).It was also observed that PCC7942 and the two mutants all grew better when receiving all-day illumination than half-day one.In BG-11 containing antibiotic Amp,the growing responses of mutant 1 and 2 were obviously better than wild type PCC7942.In the ultrastructural level,the structure of the wild-type and two mutants was similar in the different growing phases,but some special phenomenons such as the spiral structure and budding were also discovered.国家科学技术部国家转基因研究与产业化专项基金资助项目(J00-B-014

The Factuality Status of Chinese Necessity Modals. Exploring the Distribution Via Corpus-Based Approach

This paper is intended to test the deontic vs anankastic hypothesis outlined by Sparvoli 2012. The stipulation is that, in past contexts, deontic modals trigger a counterfactual inference, while anankastic modals (here called ‘goal-oriented modals’) either trigger an actuality entailment effects (‘only possibility’ modals) or a generic non-factual reading (‘mere necessity’ modals). The result of this corpus-based study conducted in a Chinese-English parallel corpus confirms the crucial role played by the deontic vs goal oriented contrast in the marking of factuality in Chinese and shows that the factuality value decreases across a cline from goal-oriented to deontic modals

基于gm/Id方法的跨阻放大器设计

针对短沟道晶体管数学模型高复杂度问题，文章提出了一种适用于刻画短沟道晶体管模型的gm/Id方法。该方法主要通过建立电路指标与晶体管尺寸的关系来优化电路性能。采用gm/Id方法设计了一种低功耗、低噪声和宽带宽的2.5 Gbit/s跨阻放大器，并进行了版图后仿真，仿真结果表明，当光电二极管电容为250 fF、跨阻放大器的低频增益为59.72 dBΩ、-3 dB带宽为3.445 GHz、输入的等效噪声电流密度为6.209×10-3 nA/sqrt/Hz、等效输入积分噪声电流为876.0 nA且采用1.2 V的电压供电时，该电路整体功耗为7.5 mW。测试结果表明，输入100μA电流时，电路的峰值数据抖动约为64.92 ps，输出摆幅为81.1 mV

带有电流监控的1.25Gbit/s CMOS跨阻放大器

文章提出一种速率为1.25 Gbit/s、具有可控电流监控的光纤通信用跨阻放大器（TIA）电路,该放大器可以通过拉电流和灌电流两种方式来检测电流监控的电流流向。设计使用的是0.18μm的标准互补型金属氧化物半导体（CMOS）工艺。仿真结果表明,光电流在1μA1 mA范围内时,各种工艺条件下检测到的光电流误差均小于5%

Data Acquisition System for AC-drive Test Based on LabVIEW

This paper introduced the hardware structure and the software design of data acquisition system for AC-drive test based on LabVIEW and proposed a method to realize high-speed continuous data storage and data preprocess in LabVIEW. The system has strong function, easy operation, friendly interface and so on, which provides a strong support for the AC-drive test

带AGC的CMOS光接收机前置放大器的设计

设计了一种带有自动增益控制电路（AGC）的动态范围较宽的互补型金属氧化物半导体（CMOS）光接收机跨阻前置放大器（TIA）。该放大器的工作电压为3.3 V。采用0.25μm CMOS工艺库仿真,结果表明:小信号输入时,跨阻增益可达76 kΩ,单端输出信号在输入信号为0 dBm时为281 mV

622Mbit/s光接收模块CMOS限幅放大器前端设计

文章采用0.25μm互补型金属氧化物半导体（CMOS）工艺设计了一种622 Mbit/s速率光接收模块的限幅放大器,整个系统包括偏置电路、输入缓冲、三级放大、输出缓冲和直流反馈,采用全差分结构。利用3.3 V电源供电,功耗约为109 mW,电路增益可达97 dB,在46 dB的输入动态范围内可以保持790 mV的恒定输出摆幅

DPMZ调制器自动偏压控制算法的研究

针对双平行马赫-曾德尔调制器工作点漂移的问题,提出一种适用于16进制正交幅度调制的双平行马赫-曾德尔调制器自动偏压控制算法。算法分为两个部分,初始化部分和跟踪锁定部分。初始化部分的目的是找到一个接近偏置电压的工作点,以减少跟踪锁定部分算法锁定工作点需要花费的时间;跟踪锁定部分使用抖动信号检测法找到精确工作偏置点,并且能实时地跟踪随环境变化的偏置点,使得偏置电压在尽量长时间内处于最佳偏置点附近,且在最佳偏置点附近游走的范围尽量小。通过实验分析了影响算法结果的因素。实测数据表明,此算法能在较短时间内找到双平行马赫-曾德尔调制器最佳工作偏置点,并能实时进行跟踪调整