RZ-DPSK传输系统相位噪声的比较分析

建立了单信道40Gbit／s归零-差分相移键控码（RZ-DPSK）传输系统模型，详细地分析并比较了线性相位噪声和非线性相位噪声对系统性能的影响。结果表明，由放大器自发辐射（ASE）噪声带来的线性相位噪声对传输系统的性能影响最大，ASE与自相位调制（SPM）相互作用引起的Gordon-Mollenauer（G-M）相移次之，带内四波混频（IFWM）的影响最小。在最优输入功率的条件下，由ASE带来的线性相位噪声引起的系统差分相位Q值代价大于204dB，由G-M相移引起的系统差分相位Q值代价小于7．5dB。仿真结果表明，对于采用掺铒光纤放大器（EDFA）级联放大的单信道40Gbit／s RZ-DPSK传输系统，ASE噪声是限制系统无中继传输距离的最主要因素。     

一种新型配料核子秤信号的处理方式

新型配料系统核子秤以脉冲信号直接输人PLC的I／O接口，将检测参数转入计算机控制系统计算出料量，省去原有的一机八秤之专用PC机，提高了检测系统的可靠性，减小了信号转换误差。     

反射波法检测深层水泥搅拌桩的完整性

根据某工程100多根深层水泥搅拌桩的反射波法检测资料,并结合20余根桩的静载试验结果,对反射波法检测深层水泥搅拌桩桩身完整性的可行性进行了探讨.     

Thermodynamic properties and mixing thermodynamic parameters of two-phase metallic melts

Based on the calculating model of metallic melts involving eutectic, the calculating equations of mixing thermodynamic parameters for two phase metallic melts have been formulated in the light of those equations of homogeneous solutions. Irrespective as to whether the activity deviation relative to Raoultian behavior is positive or negative, or the deviation is symmetrical or unsymmetrical, the evaluated results not only agree well with experimental values, but also strictly obey the mass action law. This testifies that these equations can authentically reflect the structural reality and mixing thermodynamic characteristics of two-phase metallic melts. The calculating equations of mixing thermodynamic parameters for the model of two phase metallic melts offer two practical criteria (activity and mixing thermodynamic parameters) and one theoretical criterion (the mass action law).     

工业炸药生产中的混合理论及其技术

粉状工业炸药的混合效果影响其爆炸性能,文章就与工业炸药生产相关的混合理论及技术进行研究.引入混合度概念衡量混合效果,对工业上常用的几种固相混合设备、液相混合设备的结构和混合特点进行了分析对比,建议在进行工业炸药的工艺与配方研究的同时,注重用于粉状工业炸药生产的混合的设备装置的应用开发,以促进工业炸药生产技术整体水平和产品质量的提高.     

离子束混合过程中Au/Fe磁性膜的巨磁电阻效应在线研究

在离子柬混合和强磁场条件下，在线研究了Au/Fe磁性膜的巨磁电阻效应，发现了不同磁场强度下的离子柬混合对巨磁电阻效应影响的规律，以及不同注入条件对样品饱和磁场的影响。讨论了样品由磁性多层膜逐渐向磁性纳米颗粒膜的转变，以及与此相关的纳米磁性颗粒在磁场作用下的非各向同性生长，并通过高分辨透射电镜(TEM)观察证实了磁性膜样品中磁性纳米Fe颗粒存在各向异性生长现象。通过对室温放置了一年以上的磁性纳米颗粒膜样品的电磁物性测量，证明利用离子柬混合技术制备的纳米颗粒膜在室温具有良好的热稳定性和时间稳定性。     

Thermophysical Properties of Porous Sandstones: Measurements and Comparative Study of Some Representative Thermal Conductivity Models

The thermal conductivity and thermal diffusivity of porous consolidated sandstones have been measured simultaneously by the transient-plane source (TPS) technique in the temperature range from 280 to 330 K at ambient pressure using air as the saturant. The porosity and density parameters are measured using standard American Society for Testing and Materials (ASTM) methods at 307 ± 1 K. Data are presented for five types of samples ranging in porosity from 8 to 17 vol. %, taken from various positions above the baseline. The thermal conductivity and constituents of the minerals vary with porosity as well as with the position of the sample from the baseline. The thermal conductivity data are discussed in the framework of simple mixing laws and empirical models. Simple correlations between the effective density and porosity, and between the effective thermal conductivity and porosity, are also established     

Isothermal and Dynamic Microcalorimetry for Quantifying the Crystallization of an Amorphous Drug during Interactive Powder Mixing

This study reports the crystallization of amorphous nifedipine during an interactive mixing process quantified by using isothermal and dynamic microcalorimetry. Interactive mixtures of amorphous nifedipine and uniform glass beads were prepared by mixing in a Turbula® mixer. The difference in the extent of crystallization of amorphous nifedipine during mixing was characterized by the time it took for the crystallization of a known amount of amorphous nifedipine in isothermal calorimetry and the change in the height of the crystallization peak at 65°C in dynamic calorimetry. It was found that both isothermal and dynamic microcalorimetry are useful techniques for quantifying the physical transition of amorphous nifedipine during interactive mixing. The rate and extent of crystallization of amorphous nifedipine depended on both mixing time and speed, but mixing time played a more dominant role because the transformation of amorphous to crystalline nifedipine was greater after 3180 revolutions (9.7%) than after 405 revolutions (0.9%) at 27 rpm. The same trend was observed at 109 rpm, but the percentage of crystalline nifedipine after 3180 revolutions was only 5.2%. This meant that an increase in mixing time rather than speed increased the rate of amorphous to crystalline transformation. The greatest cause for crystal transformation during interactive mixing was the presence of crystal seeds of the thermodynamically stable nifedipine Modification I because the amount of amorphous to crystalline transformation increased from 2.6% for a completely amorphous mixture to 6.6% for a 92:8 mixture of amorphous and crystalline nifedipine when mixed for 30 minutes at 106 rpm.     

配比加香时滞控制系统设计及其实现

本文将常规控制理论、配比加香控制系统的基本特点以及PLC编程的技巧进行有机结合，提出了一整套简单可行的控制算法，通过延时送数，累计量配比、实时补偿等控制策略，有效的实现了这类大滞后系统的高精度参配控制问题，末尾给出了该控制算法在制丝线的一些实际应用情况，应用情况验证了控制算法的有效性。     

用动态法研究气升式环流反应器中氧传递规律的平推流模型

假设气升管内气液以平推流向上流动，下降管液体环流时溶氧浓度按时间滞后，求出气升式环流反应器中溶氧动态传质模型的解析解，实验结果表明对粘度较高的ＣＭＣ水溶液／空气系统，当循环速度较快时，平推流模型与实验数据吻合较好。