某8V150型柴油机平衡轴优化设计

文章以某8V150柴油机为例,对其平衡轴进行了优化设计,使得双轴平衡机构不但能够100％的平衡二级往复惯性力,而且所设计的平衡轴尺寸小,质量轻,能够有效地消减机体的倾覆力矩,改善了发动机的振动特性,满足了设计要求.     

秸杆栽培食用菌拮抗菌株的鉴定及混菌发酵条件的优化

从海洋泥样和食用菌发酵料中分离出了32个菌株,从中筛选出了既具有较高的纤维素酶活性又具有对青霉(Penicillium spp)、木霉(Trichoderma spp.)、根霉(Rhizopus)、曲霉(Aspergillus spp)、毛霉(Mucro)较强拮抗能力的W-4、W-10、N-14三个菌株。经鉴定W-4、W-10分别属于放线菌中黄色节杆菌(Arthrobacter flavescens)和石灰壤诺卡氏菌(Nocardia calcarea),N-14属于细菌中的乳酸乳杆菌(Lactobacillus lactis)。通过正交试验对上述3个菌株混合发酵条件进行优化,确定在温度35℃、时间36h、pH7.5、装液量60ml/250ml时为最适发酵条件。在此条件下3个菌株混合发酵液纤维素酶活力仍然很高。同时混合发酵液对青霉、曲霉、毛霉、木霉、根霉的拮抗能力分别为单菌株发酵液的1.79倍、1.36倍、1.29倍、1.04倍、1.07倍。     

对同步发电机励磁控制优化设计仿真研究

提出基于现代内点非线性规划方法的非线性最优控制设计思想。将控制系统的二次性能指标选取为非线性规划的目标函数;运用隐式积分方法,将控制系统的状态方程差分为等式约束;控制量的上下限幅选取为不等式约束;从而将最优控制问题转化为非线性规划问题,形成以规划方法处理控制问题的设计思路和算法。这种设计方法可按实际需要选择目标函数,并能够找到在选定的目标函数下,使非线性控制系统达到最优的控制规律,且设计灵活。以发电机励磁控制系统为例,提出了基于内点非线性规划的发电机励磁控制设计方法。为了考查该设计方法的灵活性,选择不同的控制目标进行设计。仿真结果表明：该设计方法使发电机具有良好的输出特性,具有广泛的应用前景。     

梯级引水工程水位优化调度模型研究

大型引水工程整个系统在进入稳态运行后,在各站的抽水流量或首级站进口水位发生变化的情况下及时做出运行决策,调整各梯级站间的水位,达到整个系统总能耗最小的目的。针对这一问题提出了大型引水工程各梯级站水位优化调度的数学模型,并对其解法进行探讨。     

多目标系统模糊决策法在导流标准

施工导流工程是施工组织设计中关键环节，而施工导流标准的选择是施工导流工程的核心，选择合适的施工导流标准可使水电工程施工达到安全可靠和经济可行相统一的目的。利用多目标系统模糊决策法进行导流标准的比选，综合考虑工程的导流投资、经济损失、施工强度等决策指标，建立导流标准的多目标系统模糊决策模型，计算各指标的相对隶属度，根据隶属度最大为最优的原则，选择最优的导流标准方案。实例分析说明，导流标准的多目标系统模糊决策分析模型是可靠的、合适的。     

东深供水改造工程全线供水调度与管理自动化

结合东深供水改造工程全线供水系统的水力特性、供水系统的分散性及优化调度的经济性，提出供水系统的调度和管理模式确保实现全线自动调度方式，力争实现全线优化调度方式；并对主要技术措施、技术手段作了详细介绍：全线供水自动化主要有站间安全闭锁、站间流量平衡、全线供水自动控制、全线供水优化调度等功能。     

基于粒子群优化算法与混合罚函数

粒子群算法(PSO)具有简单易实现，可调参数少的优点。将其用于最优潮流的求解，结合混合罚函数来限制最优潮流的约束条件，使粒子群算法的寻优速度加快，迭代次数减少。通过在IEEE9节点和IEEE30节点上的仿真计算表明，该算法在优迭代速度和收敛精度上都取得了较好的效果。     

人工湿地优化设计方法研究

在总结国内外人工湿地传统设计方法的基础上,引入了Monod反应动力学模型和离散型水流流动模型.通过对人工湿地系统特别是对垂直复合流人工湿地系统重要水力学问题的分析研究,改进传统的根据一级反应动力学模型的设计方法,提出了复合垂直流人工湿地的优化设计方法.笔者提出的新的人工湿地结构参数推算方法,在设计的准确性和经济性等方面较传统设计方法有了较大的提高,将对人工湿地工程的构建有一定的指导意义.     

The rehabilitation of an irrigation system along the Yellow River

The People's Victory Irrigation System which diverts water from the Yellow River of China covers a total irrigable area of 59 000 ha. The system encountered some serious problems in the first decade of its operation — salinity and waterlogging of irrigated land, siltation of irrigation and drainage channels, as well as a low efficiency of water use. This paper describes a series of structural and functional measures which have been adopted in the past 24 years for the rehabilitation of the system, including: improvement of the existing drainage system and construction of new drainage system on agricultural land, conjunctive use of surface and groundwater supplies, a comprehensive programme to reduce the levels of siltation as well as the implementation of improved water management practices. A model for the optimal operation of the system by using system analysis theory as an aid in reducing the operation and maintenance (O & M) costs has been developed in recent years. The results are that the soil salinity has been controlled and the agricultural production has increased whilst the efficiency of water use has improved and the siltation levels reduced. Experience gained on this system has been successfully used in developing and managing other irrigation projects along the lower reaches of the Yellow River. The proposed procedure of solving the said optimal model has also embodied some benefits from reducing O & M costs in operation.     

Object‐Based Mapping of Karst Rocky Desertification using a Support Vector Machine

Accurate and cost‐effective mapping of karst rocky desertification (KRD) is still a challenge at the regional and national scale. Visual interpretation has been utilised in the majority of studies, while an automated method based on pixel data has been investigated repeatedly. An object‐based method coupling with support vector machine (SVM) was developed and tested using Enhanced Thematic Mapper Plus (ETM+) images from three selected counties (Liujiang, Changshun and Zhenyuan) with different karst landscapes in SW China. The method supports a strategy of defining a mapping unit. It combined ETM+ images and ancillary data including elevation, slope and Normalized Difference Vegetation Index images. A sequence of scale parameters estimation, image segmentation, training data sampling, SVM parameters tuning and object classification was performed to achieve the mapping. A quantitative and semi‐automated approach was used to estimate scale parameters for segmenting an object at an optimal scale. We calculated the sum of area‐weighted standard deviation (WS), rate of change for WS, local variance (LV) and rate of change for LV at each scale level, and the threshold of the aforementioned index that indicated the optimal segment level and merge level. The KRD classification results had overall accuracies of 85·50, 84·00 and 84·86 per cent for Liujiang, Changshun and Zhenyuan, respectively, and kappa coefficients are up to 0·8062, 0·7917 and 0·8083, respectively. This approach mapped six classes of KRD and offered a visually appealing presentation. Moreover, it proposed a conceptual and size‐variable object from the classification standard of KRD. The results demonstrate that the application of our method provides an efficient approach for the mapping of KRD. Copyright © 2012 John Wiley & Sons, Ltd.