准确度更高的高含硫天然气压缩因子计算方法

目的 考查国内外不同状态方程计算结果的准确性。方法 通过python3.6编写了GERG-2008状态方程的软件模块,与AGA8-92DC、PR、SRK、CPA、BWRS等状态方程的计算结果进行对比分析,评估了不同状态方程对不同组成高含硫天然气压缩因子计算的准确性。结果 (1)对标准中规定的组成较简单的管输天然气,GERG-2008方程与AGA8-92DC方程的计算准确度基本相当,在天然气管输温度、压力范围内,两个方程的计算准确度均在0.10%以内;(2)基于331组高含硫天然气压缩因子实验数据的计算结果,GERG-2008方程准确度最高,偏差范围为0.31%～1.14%,平均偏差为0.67%,相比于AGA8-92DC提升了14.9%;(3)H₂S摩尔分数在0%～27%范围内,对于研究的几种状态方程的压缩因子计算方法,其准确度排序依次为：GERG-2008、AGA8-92DC、CPA、BWRS、SRK、PR。由于实验数据有限,现有研究大多是针对某种工况下的计算分析,其在更广的范围内计算准确性需要进一步验证;(4)ISO 20765-2:2015 Natural g...     

IC芯片视觉检测中快速图像匹配定位

利用IC芯片定位图像特征,提出一种用其投影特征的基于优势遗传自适应遗传算法(AGA)的快速匹配算法(P-AGA)。设计基于图像灰度投影特征的匹配规则,使算法适应于一定的噪声、缩放、旋转和变形图形,而且运算量小。对图像采用2×2重采样,使运算量降低3/4。匹配过程是在二维图像空间的随机寻优,提出优势遗传的AGA,用匹配距离作为适应度函数,并自适应改变交叉变异概率进行匹配寻优,快速准确求出全局最优匹配点。实验表明,该算法比标准遗传算法(SGA)快约1.9倍,准确度提高约22.5%,有效提高匹配速度和准确度,有很强的抗噪声能力,鲁棒性好。     

Complex polymer architectures via RAFT polymerization: From fundamental process to extending the scope using click chemistry and nature's building blocks

Reversible addition fragmentation chain transfer (RAFT) polymerization has made a huge impact in macromolecular design. The first block copolymers were described early on, followed by star polymers and then graft polymers. In the last five years, the types of architectures available have become more and more complex. Star and graft polymers now have block structures within their branches, or a range of different branches can be found growing from one core or backbone. Even the synthesis of hyperbranched polymers can be positively influenced by RAFT polymerization, allowing end group control or control over the branching density. The creative combination of RAFT polymerization with other polymerization techniques, such as ATRP or ring-opening polymerization, has extended the array of available architectures. In addition, dendrimers were incorporated either as star core or endfunctionalities. A range of synthetic chemistry pathways have been utilized and combined with polymer chemistry, pathways such as ‘click chemistry’. These combinations have allowed the creation of novel structures. RAFT processes have been combined with natural polymers and other naturally occurring building blocks, including carbohydrates, polysaccharides, cyclodextrins, proteins and peptides. The result from the intertwining of natural and synthetic materials has resulted in the formation of hybrid biopolymers. Following these developments over the last few years, it is remarkable to see that RAFT polymerization has grown from a lab curiosity to a polymerization tool that is now been used with confidence in material design. Most of the described synthetic procedures in the literature in recent years, which incorporate RAFT polymerization, have been undertaken in order to design advanced materials.     

MVI56-AFC流量计算模块在天然气计量系统中的应用

详细地介绍了MVI56-AFC流量计算模块的性能特点和工作原理,以及利用MVI56-AFC流量计算模块计算天然气压缩因子,并由上位组态软件读取MVI56-AFC计算的压缩因子,生成天然气流量计检定计算表,从而完成天然气流量计的实流检定.     

复合左右手传输线结构漏波天线优化设计

针对目前复合左右手(Composite Right/Left Handed,CRLH)结构漏波天线设计上的难题,提出了一种共面波导(Coplanar Waveguide,CPW) CRLH结构漏波天线的优化设计方法.为了妥善处理元件尺寸带来的寄生效应,基于Matlab软件,开发了一款天线结构参数优化计算机辅助设计(Computer Aided Design,CAD)软件,减少了CRLH结构设计过程中反复调试的次数,加快了开发速率.利用该软件和快速遗传算法(Accelerated Genetic Algorithm,AGA),设计了一个小型化CPW-CRLH结构宽带漏波天线,通过仿真计算、制作加工和实验测量,验证了该文设计方法的正确性,为CRLH结构的广泛应用提供了技术支持.     

Kinetic analysis on gaseous and aqueous product formation by mixed anaerobic hydrogen-producing cultures

Anaerobic hydrogen production by mixed cultures is a complex process, and information about its kinetic analysis is sparse. In this study, an integrated approach with the weighted nonlinear least-squares analysis and accelerating genetic algorithm is proposed to evaluate the kinetic parameters of biohydrogen production from a sucrose by mixed anaerobic cultures. The weighted nonlinear least-squares analysis is used to calculate the differences in gaseous and aqueous product concentrations between the predicted and the measured results, while the accelerating genetic algorithm is utilized to optimize the objective function by minimizing the total sum of the squared weighted errors. The kinetic parameters for specific maximum substrate uptake rate, substrate uptake affinity constant, yield coefficient are calculated with this approach, and are validated by the results of the independent experimental results reported in literature. This integrated approach is effective and rapid to estimate the anaerobic hydrogen production kinetics by mixed cultures.     

风-光-沼可再生能源分布式发电系统电源规划

为了有效提高风–光–沼混合可再生能源分布式发电系统的可靠性和经济性,首先研究分析了风、光、沼各发电电源特点以及该分布式发电系统结构特征,并以此为基础建立了其系统电源规划的优化目标函数和约束条件函数等数学模型。由于改进的自适应遗传算法使用最优保存策略进化模型的选择算子、改进的自适应交叉算子和变异算子,来获得较优的全局搜索能力和较强的鲁棒性,所以采用该遗传算法对此分布式发电系统电源规划进行优化运算处理。最后选取某负荷中心的300 kW负荷总量为对象进行风–光–沼混合可再生能源分布式发电系统的电源规划模拟优化求解,算例结果验证了该方法的可行性和有效性,而且对其它类型可再生能源分布式发电系统电源规划有一定的指导意义。     

自发脑电信号的支持向量机分类算法

针对自发脑电信号的特征分类,将基于支持向量机(SVM)的算法应用于脑机接口(BCI)系统,提出一种基于自适应遗传算法优化SVM模型参数的脑电信号分类算法,获得最佳的分类性能。以基于小波包分解得到的系数均值和子空间能量作为特征向量,利用BCI 2005data setⅢb标准数据分析了该方法的实验背景和理论依据,并与基于经验SVM的分类结果、基于普通遗传算法优化SVM参数的分类结果、基于概率神经网络的分类结果以及竞赛的最好精度进行了比较,表明所提出方法运用在实际系统中的有效性和优越性。     

改进的实数编码加速遗传算法在暴雨强度公式参数优化中的应用

针对城市暴雨强度公式参数识别时,传统求解方法(如牛顿迭代法、高斯-牛顿法等)存在间接拟合,而优化算法(如实数编码加速遗传算法、蚁群算法等)存在随机性,盲目地在一个区间内寻优拟合精度不高等问题,本文将两种方法结合,提出一种改进的实数编码加速遗传算法(RAGA),为暴雨强度公式参数识别提供一种新途径。该方法将传统求解方法所求的可行解作为改进遗传算法的初始参数,通过在每次代际寻优时设置各参数廊道约束来改进RAGA以提高算法搜索效率,直至公式拟合精度无法提高为止。将该方法应用于国内多地暴雨强度公式参数识别中以评估算法的有效性,结果表明此方法实用可行、搜索效率较高,可以快速收敛到最优解。实例表明该方法在暴雨强度公式参数识别中是实用有效的。     

一种新的图象分割自适应算法的研究

首先对自适应遗传算法的变异算子进行了改进,对单点变异算子与双点变异算子的结合能有效地改善局部收敛进行了验证,然后提出了一种新的用自适应遗传算法分割图象的方法,并与传统的Ｏｔｓｕ方法、灰度差直方图法和基于熵的方法作了比较。