CTF增效剂在高强混凝土中的应用研究

本文介绍了掺入CTF增效剂与未掺入CTF增效剂的混凝土在拌合物性能、力学性能、耐久性能和成本控制四个方面进行对比试验。由试验得出结论：在混凝土中掺用CTF增效剂后,可以明显的改善高强度等级混凝土和易性等工作性能,对抗压强度、混凝土脱模强度和耐久性能也有积极作用,同时能够降低成本,具有十分可观的经济效益和环保效益。     

A criterion for the assessment of the reliability of ASHRAE conduction transfer function coefficients

This paper presents a new mathematical approach, which, when applied to conduction transfer functions (CTFs) of a multi-layered wall, is able to predict the reliability of building simulations. This new procedure can be used to identify the best set of CTF coefficients, which are a critical point at the core of the ASHRAE calculation methodology founded on the transfer function method. To evaluate the performance of different CTF coefficient sets, the authors performed a large number of thermal simulations on the multi-layered walls included in the ASHRAE Handbook, volume fundamentals, and on other walls typical of Mediterranean building heritage. Those data were employed to test an algorithm able to assess the reliability of the simulations. The numerical results show that it is possible to select the optimal number of coefficients on the basis of the size of the poles of a CTF. The proposed criterion, which employs a pole threshold value, is highly accurate, fast and easy to integrate in the most diffuse building simulation tools.     

基于嵌入式处理器EP9312的多串口扩展

在嵌入式产品中,大多需要与多个外设进行通信,一般的嵌入式处理器往往没有足够的串口接口,需要对CPU的串口模块进行扩展;文中详细介绍了利用SUPPERI/O控制芯片W83977EF/CTF对ARM9嵌入式处理器EP9312进行串口、PS/2接口和并口的扩展;描述了详细的连接方式,并给出了串口模块硬件设计电路图和初始化编程;串口模块在系统整合后运行稳定,经过实际测试表明,电路的设计符合了嵌入式系统的要求,满足了设计需要,目前该串口模块设计已在银税类终端产品上得到应用.     

基于CTcP和CTF工艺的网点复制特性研究(英文)

CTcP技术采用普通预涂感光版,在国内印刷市场中的应用正逐渐增加。为了更好地控制网点的复制过程,提高印刷质量,通过实验和对比方法,采用6套不同方案,对测试版进行了输出,探讨了印版网点的复制特性,分析了印版网点的微观结构。结果表明:制版工艺、加网线数、成像分辨率均对网点复制有一定的影响。与传统的CTF工艺相比,CTcP制版工艺的网点复制性能更佳,表现为成像更精确,均匀性更好,阶调复制曲线更平滑,制版过程的可控性更佳。     

光锥CCD耦合器件对提高CCD成像分辨率的探讨

成像分辨率是评价CCD成像系统的主要技术指标.提高成像分辨率可以改变CCD的成像性能.本论文以实验的方法验证了倒置光锥CCD耦合器件可提高CCD成像分辨率,同时与正置光锥CCD耦合器件实验结果对比,分别绘制了与非耦合器件的对比传递函数(CTF)曲线,直观地表示出了二者关系,与理论分析结果相吻合.     

TDI-CCD总剂量辐射效应及测试

为评估空间辐射效应对应用于某空间相机的TDI-CCD的成像性能的影响,从器件的电路结构入手,分析了总剂量辐射效应对器件主要性能指标的影响.针对此器件的总剂量辐照测试方法研制了测试装置.用~(60)Co 对器件进行了γ射线总剂量辐照实验,定量测试了受辐照前后器件的光电响应性能及对比度传递函数的变化情况.实验结果表明,总辐照剂量达到20 krad(Si)时,定制TDI-CCD的相对响应度、暗电流、动态范围、最大信噪比相对于该器件没受辐照的初始值变化量均小于5%,对比度传递函数(CTF)没有明显变化,说明定制TDI-CCD器件能够满足某空间相机的使用要求.     

CTP会取代CTF吗

阐述了印前系统的CTF和CTP技术,比较了二者的投资成本、工艺流程及操作维护,同时对国内近期CTP 是否会取代CTF进行了系统的分析.得出,CTP是印前的发展必然,但目前CTF和CTP各有千秋,并存发展.     

增效剂与减缩增韧剂复掺优化高标号海工大体积混凝土

依托港珠澳大桥重点工程,针对该工程预制承台高标号大体积混凝土水化温升和海洋服役环境的性能要求,通过复掺CTF增效剂和减缩增韧剂,有效降低了水泥用量和混凝土绝热温升,提高了抗裂性能,开发出高耐久低温升抗裂C45海工大体积混凝土。设计出的混凝土成功应用于港珠澳大桥预制承台,应用效果良好,没有出现温度裂缝。     

Fitting conduction transfer function method to low Fourier numbers: application to ground-coupled floors

This paper proposes a practical solution to the problems arising when the conduction transfer function (CTF) method is applied to solve the 1D transient component of heat transfer in the internal zone of ground-coupled floors. The lower boundary condition for these problems must be imposed at a depth of several metres. The proposed method is based on the division of the ground domain into a number of layers that allows calculation of transfer function coefficients while keeping the first cross coefficient negligible. A mathematical expression is proposed for the proper layer thickness that assures the applicability of the CTF method to thick ground domains. A numerical validation for a slab-on-grade configuration has been carried out showing maximum errors of 0.09°C (0.42%) and 0.73?W/m² (2.24%) for temperature and heat flow rates on the floor surface, respectively.     

A novel approximation method of CTF amplitude correction for 3D single particle reconstruction

The typical resolution of three-dimensional reconstruction by cryo-EM single particle analysis is now being pushed up to and beyond the nanometer scale. Correction of the contrast transfer function (CTF) of electron microscopic images is essential for achieving such a high resolution. Various correction methods exist and are employed in popular reconstruction software packages. Here, we present a novel approximation method that corrects the amplitude modulation introduced by the contrast transfer function by convoluting the images with a piecewise continuous function. Our new approach can easily be implemented and incorporated into other packages. The implemented method yielded higher resolution reconstructions with data sets from both highly symmetric and asymmetric structures. It is an efficient alternative correction method that allows quick convergence of the 3D reconstruction and has a high tolerance for noisy images, thus easing a bottleneck in practical reconstruction of macromolecules.