数据驱动的冷却水塔建模与节能优化操作

针对冷却水塔的节能操作给出了一种数据驱动的建模与优化方法。首先,基于冷却水塔实际运行数据,应用非负绞杀变量选择方法给出一个自适应模型用于描述冷却水塔过程,该模型对于冷却水塔出口水温具有良好的预测精度。根据变量选择结果,分析了外界空气温度与湿度对冷却能力的影响。然后,提出了基于模型的冷却水塔风机的优化操作策略,并进行实验将之应用于冷却水塔的操作。研究结果显示,基于模型的优化操作具有较大的节能空间。     

β-甘露聚糖酶理化性质与其最适pH的相关性

为了探究影响GH5家族β-甘露聚糖酶最适pH的各种因素,利用该酶的序列信息,构建了基于氨基酸组成的β-甘露聚糖酶理化性质与其最适pH的相关性模型。结果表明:该酶N端氨基酸序列是影响其最适pH的重要因素,在243个理化性质中有17个呈极显著相关,其中7个呈正相关。优化的转移能量参数相关性最高,为0.78:7个正相关的理化性质中,与螺旋相关的理化性质占3个。优化的转移能量参数和螺旋是影响pH稳定性的最重要的因素。所建立的模型为研究该酶酸碱适应性机理提供了一种简单有效的方法。     

Solar barometric distillation for seawater desalting part I: Basic layout and operational/technical features

The report presents an innovative solar barometric distillation technology for seawater desalting (SW-SBD) which has several attractive features such as: (1) efficient vacuum solar collectors of simple construction; (2) a barometric layout for quasi-steady operation at subatmospheric pressure; (3) a demister system of simple mechanical construction; and (4) an electronic control system regulating plant productivity parameters on available solar radiation flux. The proposed seawater desalting technology consists of single-effect distillation with water vapor produced and heated at subatmospheric pressure in a solar collector loop; the basic layout, operational features, and energy efficiency are presented and analysed in detail. Subsequent reports will provide technico-economical data from prototype desalting plants in view of industrial implementation. A promising specific electric energy consumption,∼2 kWm³ offresh water produced, was found by estimating pumping power requirements of major SW-SBD plant pumps. A sizable reduction in produced water cost with respect to an existing solar seawater desalting plant in Abu Dhabi is expected on the basis of a preliminary economic evaluation for a ∼100 m³/d plant prototype.     

环境能量驱动的无线传感器节点数据传输优化机制

将环境能量收集模块引入无线传感器网络,可以有效改善网络的使用寿命,但是能量的随时补充也给原有的能量管理策略带来了巨大挑战.针对单个环境能量驱动节点在数据序列已经到达的情况下,研究了优化的数据传输策略,采用内罚函数法优化传输过程,使得固定时间内节点传输的数据量最大.理论分析及仿真结果表明,当各个时刻节点的传输功率比较接近时会获得最大的数据传输量;当实际节点获得最大数据传输时节点的传输功率随时间呈增大趋势.     

一种基于优先级表的实时调度方法

针对单处理器实时系统动态调度问题进行了研究,分析任务的到达时间、执行时间、截止时间和空闲时间等任务属性的敏感度和影响度,提出了一种基于优先级表的调度算法PTBM,使相对截止期越小、空闲时间越大的任务优先级越高。对关于实时任务属性敏感度和影响度的结论验证和与传统的EDF、LLF和PTD算法的对比进行仿真实验,仿真结果表明基于优先级表设计的实时调度算法PTBM具有较高的调度成功率。该方法可应用于实时系统的实时任务的动态调度中。     

注塑车间布局的设计及优化

注塑车间布局设计应以工艺流程为基础,根据生产物流的特点建立合理的车间物理布局。本文还进一步阐述了注塑车间布局优化的方法,以及节能和环境保护的措施。     

基于细胞膜优化算法的WSN分簇协议研究

针对无线传感器网络能量受约束的问题,为实现节点均衡能耗,平衡网络簇头分布,并最大限度地延长网络寿命,提出一种基于细胞膜优化算法的无线传感器网络能量均衡分簇协议。细胞膜优化算法具有良好的全局寻优和快速收敛能力,通过浓度与能量因素对节点进行划分,并结合距离因素完成全局均衡分簇,能够解决传感器网络中簇头分布不均匀、全局能耗不均衡等问题。实验结果表明,该协议具有对无线传感器网络进行快速全局均衡分簇的能力,且与LEACH算法和LEAH-C算法相比,在均衡节点能耗和延长网络生存周期等方面具有更好的性能。     

多标准视频编码器下的运动估计评估

运动估计是视频编码过程中最为复杂和耗时的阶段。为分析和优化其性能,从多个流行的开源视频编码器中提取出单独的运动估计算法模块,根据视频分辨率和视频内容的不同建立程序输入集,从而构成一套完整的测试程序集合。利用性能分析工具对算法性能和微体系结构性能进行量化分析,给出这些算法在当今主流处理器体系结构上的性能差异。实验结果表明,复杂视频和高分辨率视频下的运动估计算法耗时最长,且大部分算法的指令级并行性没有太大差异。算法最后一级高速缓存的缺失率和分支误预测率都较低,分别在0.01%和7%以下。     

Corrosion inhibition of carbon steel in acid chloride solution using ethoxylated fatty alkyl amine surfactants

Four novel non-ionic ethoxylated fatty alkyl amine surfactants (I–IV) were synthesised and investigated as corrosion inhibitors of carbon steel in 1 M hydrochloric acid solution using gravimetric, open circuit potential and potentiostatic polarisation techniques. The percentage inhibition efficiency (η%) for each inhibitor increased with increasing concentration until the critical micelle concentration (cmc) was reached. The maximum inhibition efficiency approached 95.1% in the presence of 400 ppm of the inhibitor (IV). It was found that the adsorption of the surfactants on carbon steel followed the Langmuir adsorption isotherm. Potentiostatic polarisation data indicated that these surfactants act as mixed type inhibitors. The values of activation energy (E _a*) of carbon steel dissolution in 1 M HCl were calculated in the absence and presence of 400 ppm of each inhibitor. Finally, scanning electron microscopy (SEM) was used to examine the surface morphology of polished carbon steel surfaces and those immersed in 1 M HCl in the absence and presence of 400 ppm of inhibitor (IV).     

Upgrading of gas oils: the HDS kinetics of dibenzothiophene and its derivatives in real gas oil

The hydrodesulphurization (HDS) of dibenzothiophene (DBT), 4-methyl dibenzothiophene (4 M-DBT), 4,6-dimethyl dibenzothiophene (4,6 DM-DBT) and 4,6-diethyl dibenzothiophene (4,6 DE-DBT) as real gas oil components on NiMo/Al₂O₃ catalyst was investigated. On the basis of the first order rate constants of HDS of the individual sulphur compounds reactivities of the investigated compounds decreased in the order DBT ≫ 4 M-DBT > 4,6 DE-DBT ≈ 4,6 DM-DBT. Apparent activation energies of HDS of above sulphur compounds increased from 80.0 to 120.5 kJ/mol.