实现Ethernet over SDH的嵌入式系统研究

简要介绍了Ethemetover SDH(EoS)系统的结构原理，阐述和分析了EoS的LAPS协议核心技术，给出了使用FPGA完成SDH网络和以太网的连接，从而实现EOS的嵌入式系统设计方案。     

High pressure phase behavior of carbon dioxide + nitrobenzene binary system at 298.15, 310.45 and 322.75 K

The phase behavior of the carbon dioxide + nitrobenzene binary system has been studied in a high-pressure variable-volume view cell using an analytical method. The phase boundaries were measured at temperatures of 298.15, 310.45 and 322.75 K under pressures between 2.76 and 12.83 MPa, and it was found that three-phase equilibria existed over a temperature range from 303.60 to 313.65 K. The experimental data could be correlated with the Peng-Robinson equation of state (PR EoS) and two binary parameters. The phase behavior of the carbon dioxide + nitrobenzene system appears to belong to Type-V according to the classification of van Konynenburg and Scott.     

氟利昂体系汽液平衡二元相互作用参数的普遍化关联

用ＭＨ（８１）方程关联了十一个氟利昂体系的等温汽液平衡数据，得出其二元相互作用参数，关联结果同实验符合良好。根据分子热力学的基本原理，加上一些经验的关联，提出了一个四常数的关联式来关联氟利昂混合物的ＭＨ（８１）方程二元相互作用参数，利用关联结果推算了ＤＭＥ／Ｒ１５２ａ体系在２８３．３１Ｋ、２９３．８４Ｋ、Ｒ２３／Ｒ２２在２５８．１５Ｋ和Ｒ３２、Ｒ１５２ａ在２７３．１５Ｋ的等温汽液平衡，与实验数据进行对照吻合良好，表明此式有相当程度的预测性，在氟利昂替代物的预选和工程计算中有重要的实际应用价值。     

GFP和LAPS协议在EoS应用中的传输性能比较

论述了衡量EoS传输性能的重要参数,并据此分析了LAPS与GFP在网络应用中对数据传送效率和性能的不同影响。基于多业务传送硬件平台对GFP和LAPS在传输过程中的丢包率指标进行测试,实验结果表明帧长是影响协议传输性能的主要因素,在短帧情况下GFP和LAPS具有相似的传输性能,在长帧情况下GFP的传输特性明显优于LAPS。     

Thermodynamic modeling of vapor-liquid equilibrium of binary systems ionic liquid + supercritical {CO2 or CHF3} and ionic liquid + hydrocarbons using Peng-Robinson equation of state

Vapor-liquid equilibrium (VLE) data from literature for binary systems involving several ionic liquids were correlated. The Peng-Robinson equation of state, coupled with the van der Waals and Wong-Sandler mixing rules, was used as the thermodynamic model to evaluate the fugacity coefficients. The UNIQUAC and NRTL models were used to calculate the excess Gibbs free energy in the Wong-Sandler mixing rule. A molecular modeling strategy using the software ChemOffice was used to calculate the volume and surface area parameters of ionic liquids for UNIQUAC, while the binary interaction energy parameters for UNIQUAC and NRTL models, as well as the binary interaction parameter of the van der Waals and Wong-Sandler mixing rules were estimated through a method based on the genetic algorithm. The results show that, as expected, the Wong-Sandler mixing rules represented better the data, with both activity coefficient models showing high accuracy. However, in one case, NRTL predicted an erroneous azeotropic condition, while UNIQUAC was able to correlate the data without this error.     

Artificial neural network for the second virial coefficient of organic and inorganic compounds: An ANN for B of organic and inorganic compounds

An artificial neural network (ANN) to estimate the second virial coefficient, valid for organic and inorganic compounds, is presented. First, we statistically analyzed 6,531 experimental points, belonging to 234 fluids, collected from literature. The data were investigated with a factor analysis approach to identify the most significant parameters that influence the second virial coefficient. The factor analysis, combined with physical considerations, allowed to find four (T_r, T_c, P_c, ω) or five (μ_r) parameters as input variables for the ANN, according to the specific chemical family. The architecture of the proposed multi-layers perceptron (MLP) neural network consists of one input layer with five input variables (T_r, T_c, P_c, ω, μ_r), one output layer with one neuron (B) and two-hidden-layers with 19 neurons each. We trained, validated and tested several configurations of the neural network to obtain this network topology that minimizes the deviations between experimental and calculated points. Results show that the ANN is able to calculate the second virial coefficient with greater accuracy (RMSE?=?29.38?cm³/mol) than that of correlations available in literature. To identify the outliers and applicability domain of the proposed MLP neural network, an outlier diagnosis based on the Leverage approach was performed. This analysis shows that the model is statistically valid.     

Measurements and predictive models of high-pressure H2 solubility in brine (H2O+NaCl) for underground hydrogen storage application

In the context of Underground Hydrogen Storage (UHS), the stored gas is in direct contact with brine (residual brine from the cavern or formation water of deep aquifers). Therefore, knowledge of the phase equilibria (solubility of hydrogen in brine and water content in the hydrogen-rich phase) in the geological reservoir is necessary for the study of hydrogen mobility and reactivity, as well as the control, monitoring and optimization of the storage. The absence of measured data of high-pressure H₂ solubility in brine has recently led scientists to develop predictive models or to generate pseudo-data using molecular simulation. However, experimental measurements are needed for model evaluation and validation. In this work, an experimental apparatus based on the “static-analytic” method developed and used in our previous work for the measurement of gas solubility in brine was used. New solubility data of H₂ in H₂O+NaCl were measured more or less under the geological conditions of the storage, at temperatures between 323 and 373 K, NaCl molalities between 0 and 5m, and pressures up to 230 bar. These data were used to parameterize and evaluate three models (Geochemical, SW, and e-PR-CPA models) tested in this work. Solubility and water content tables were generated by the e-PR-CPA model, as well as a simple formulation (Setschenow-type relationship) for quick and accurate calculations (in the fitting range) of H₂ solubility in water and brine was proposed. Finally, the developed models estimate very well the water content in hydrogen-rich phase and capture and calculate precisely the salting-out effect on H₂ solubility.     

MSTP以太传输网性能测量与分析

MSTP作为一种可以同时对数据业务和语音业务传输进行优化的技术,正越来越多地受到电信运营商的青睐.在MSTP的实际应用中,网络传输性能是用户和运营商所共同关注的问题.本文结合实例介绍了一种测量和分析方法,通过这种方法可以有效地分析MSTP以太网通道端到端的业务质量,评测以太网通道的实际带宽,实现符合RFC2544标准的性能测试与分析.     

Prediction of near and supercritical fatty acid ester + alcohol systems with the CPA EoS

The use of supercritical alcohols has been proposed as a non-catalytical method to produce biodiesel, overcoming some of the shortcomings related to conventional catalytic methods.In this work, the Cubic-Plus-Association equation of state is used to predict the vapor-liquid equilibria of several alcohol + fatty acid ester and alcohol + glycerol systems, in the temperature range 493-573 K and pressure range 2-12 MPa. The resulting predictions reproduce accurately the experimental data, within their experimental uncertainty.The ability to predict these phase equilibria is of primary importance for designing, operating and optimizing biodiesel production at near or supercritical conditions. The CPA EoS is shown to be a powerful prediction tool for an adequate design of the operations involved in the biodiesel production with near or supercritical alcohols.     

EoS中高阶虚级联的设计与实现

虚级联技术解决了EoS中SDH带宽与以太网带宽不匹配的问题.首先介绍了虚级联技术的基本原理.然后以千兆以太网为例,介绍了高阶虚级联技术在接收端和发送端的设计.最后使用Modelsim和ISE对整个设计进行了仿真、综合和FPGA实现.