合成的人γ-干扰素cDNA在大肠杆菌的高效表达

合成了人γ-干扰素(IFN-γ)cDNA,其特点是选用了大肠杆菌偏爱密码子。将合成基因克隆到含P_L启动子的不同表达载体中,共获得9种不同的表达质粒,它们的SD与起始密码子ATG间的距离(D)不同,在起始翻译区(TIR)的最小自由生成能△G_(f298)~°不同,故其表达量的差异也很大。其中pLY_4-γ_5表达的IFN_γ的量占菌体总蛋白的60％—80％,为国际上所罕见。表达高的原因是由于选择(D)距离适当,△G_(f298)~°较高,以及选用的密码子较好。采用十分简便迅速纯化IFN-γ的方法分离包涵体可达90％以上纯度,再经一步分子筛柱层析,IFN-γ纯度即可达95％以上,比活约2.0×10~7IU/mg。     

燃烧太平洋N-Gage QD专用游戏《荣誉之路2:战争岛》评测篇

介绍 “Pathway to Glory：lkusa lslands”，lkusa为日语“ぃくさ”（汉字为“戦”）的音译，“lkusa lslands”翻译成汉语便是“战争岛屿”之意。从游戏名就可以知道游戏的故事发生在群岛之中，敌人则为日本人。     

兼顾个别化学习的网络教学模式—也评“高等数学”教学设计

随着计算机网络技术的发展，网络教学在我国各种层次的学校中已蓬勃展开，它为现代教育带来了新观念，新方法和新技术，本结合“高等数学”课件设计，对课件的制作，内容选取，表现方式等方面逐一分析，希望人们能在此基础上对网络教学的内涵有进一步的理解和认识。     

固定化血红蛋白氧载体的研究（Ⅱ）：氧化纤维素共价键联 …

以纤维素为载体，经高碘酸钠氧化后共价键联血红蛋白，制备氧载体。研究了氧化条件对血红蛋白固定量的影响。纤维素只有经过预氧化，碱处理和再氧化三步活化反应，才能使血红蛋白大量化，每克纤维素固定血红蛋白量达１．０ｇ。氧载体稳定性好，血红蛋白不脱落。经铁氰化钾氧化，氧载体放氧效率为３３．１％。     

Erratum to “Designing thermal demultiplexer: Splitting phonons by negative mass and genetic algorithm optimization”

Equations (8) and (9) in the original paper [Chin. Phys. B 30 036301 (2021)] are corrected.     

Designing thermal demultiplexer: Splitting phonons by negative mass and genetic algorithm optimization

We propose the concept of thermal demultiplexer, which can split the heat flux in different frequency ranges intodifferent directions. We demonstrate this device concept in a honeycomb lattice with dangling atoms. From the view ofeffective negative mass, we give a qualitative explanation of how the dangling atoms change the original transport property.We first design a two-mass configuration thermal demultiplexer, and find that the heat flux can flow into different ports incorresponding frequency ranges roughly. Then, to improve the performance, we choose the suitable masses of danglingatoms and optimize the four-mass configuration with genetic algorithm. Finally, we give out the optimal configuration witha remarkable effect. Our study finds a way to selectively split spectrum-resolved heat to different ports as phonon splitter,which would provide a new means to manipulate phonons and heat, and to guide the design of phononic thermal devices inthe future.     

新型通用异步收发器在MAX3100单片机系统中的应用

摘要：介绍了公司的新型通用异步收发芯片的功能特点、引脚含义、控制指令及工作原理, 给出了 一系列单片机系统中, 在串行数据通讯应用中的设计实例。对和另一种常用的可编程串 行通讯接口芯片进行比较, 提出几点在使用时的注意事项, 最后给出几点实验结论。     

一种高速高能效时域温度传感器

高能效温度传感器在物联网(Internet of thing,IoT)系统中有着极为广泛的应用.提出了一种基于流水线型时间-数字转换器(Time-to-digital converter,TDC)的时域温度传感器,该温度传感器中的TDC电路采用了一种具有高线性度的可编程时间放大器(Programmable-gain t...     

Synthesis of ZnO films with a special texture and enhanced field emission properties

ZnO films with special textures are fabricated on Mo-coated Al₂O₃ ceramic substrates by the catalyst-free electron beam evaporation method, and the as-deposited films are treated by hydrogen plasma. It is found that the surface morphologies of the films are changed significantly after hydrogen plasma treatment and that the films consist of vertically standing and intersecting nanosheets. A lower turn-on field of 1.2 V/μm and an enhanced current density ～0.11 mA/cm² at 2.47 V/μm are achieved. The low threshold field and the high emission current density are attributed primarily to the unique shape and smaller resistivity of the ZnO nanosheet films.