Genetic synthesis of a fuzzy pulse discriminator in electrical discharge machining

In this paper, a sensor system, called a fuzzy pulse discriminator, is developed to classify various discharge pulses in electrical discharge machining (EDM). The fuzzy rules of the pulse discriminator are obtained based on the features of the gap voltage and gap current between the tool workpiece. The membership functions of the fuzzy pulse discriminator are automatically synthesized by using genetic algorithms. The effectiveness of this approach is verified under different cutting parameters.     

Generalization of the Gram-Charlier/Edgeworth Series and Application to Time-Frequency Analysis

We derive a general equation relating probability densities and as special cases we the obtain Gram-Charlier and Edgeworth series. This allows us to generalize these methods and clarify a number of issues pertaining to both probability theory and time-frequency analysis. In particular we show how the Gram-Charlier and Edgeworth series are related to the kernel method of time-frequency analysis. The approach allows us to construct densities that satisfy given constraints such as joint moments or conditional moments. Also, we show that the kernel has to be signal dependent and that to obtain a proper distribution it should be the ratio of two characteristic functions.     

注聚采出水分离用动态水力旋流器特性研究

原有的地面工艺和设备已不能满足聚合物驱采出水分离的要求。采用自行研制的动态水力旋流器，在增压与不增压两种工艺流程下，分别进行了流量和转数对分离效率的影响、转数与压力降的关系，以及入口压力与处理量的关系等项试验研究。试验结果表明，与静态水力旋流器相比，动态水力旋流器的分离效率明显提高，一般可提高10％左右；压力损失显著降低，约可减少0．1MPa，足见可在低压下工作，易于实现无泵运行；无泵运行明显比有泵增压运行的分离效率高，但处理量会有所降低。将动态水力旋流器应用于聚合物驱产出水的油－水分离处理是完全可行的。     

发动机扭矩与转速关系经验公式试验研究

在对发动机外特性曲线扭矩与转速实验数据分析的基础上，对原有的经验公式进行了分析、改进，提出了新的经验公式．由这一经验公式所计算的数值，在最大扭矩与最大功率点之间，可与实验数据拟合得很好．与原经验曲线相比，新经验曲线与实验曲线的离差可下降50％以上．     

对洪水分级的浅见

洪水的等级划分应考虑流量、水位、防洪能力及灾害等因素,综合这些因素把洪水分成5个等级。1、2级洪水,洪水流量小,水位低,基本无灾;3级洪水,洪水流量较大或水位较高,有一定灾害;4级洪水,为大洪水或高水位,有较大灾害;5级洪水,为特大洪水或高水位,灾情严重。     

铝电解槽料箱排气管结构的优化改造

简要介绍了铝电解槽料箱排气管在原设计上存在的缺陷和不足，针对缺陷产生的原因进行了结构优化改造。     

The Role of Metastable Atoms in a Homogeneous Atmospheric Pressure Barrier Discharge in Helium

A one-dimensional fluid model for homogeneous atmospheric pressure barrier discharges in helium is presented by considering elementary processes of excitation and ionization including a metastable atom effect. Using this model we investigate the behaviours of the helium metastable atoms in discharges as well as their influence on the discharge characteristics. It is shown that the metastable atoms with a relatively high concentration during the discharge are mainly produced in the active phase of the discharge and dissolved in the off phase. It is also found that the metastable atom collisions can not only provide seed electrons for discharges but also influence the concentration of ions. A reduction of matestable atom density results in a drop in the charged particle densities and causes a qualitative change in the discharge patterns.     

大朝山水电站碾压混凝土重力坝台阶式溢流面设计

大朝山水电站碾压混凝土重力坝的最大坝高为111m,设计洪水位为899m(500年一遇),此时,表孔下泄的设计流量为9992m3/s,堰顶设计单宽流量为132.7m3(/s·m)。通过多次表孔水工模型试验研究和近三年表孔泄水运行,验证了大朝山水电站碾压混凝土重力坝的表孔采用宽尾墩、台阶式溢流面和戽式消力池联合消能的设计方案是合理可行的,为全段面碾压混凝土重力坝和表孔溢流面的设计开拓了新的思路。     

海洋石油开发工业污染物产生系数和排放系数研究

污染物产生系数和排放系数是工程环境影响评价的重要指标,但对于海洋石油开发工程环境影响评价来说,迄今尚无具权威性的系数可资使用。在我国近海石油开发工程污染源系统调查的基础上,对海洋石油开发行业污染物产生系数和排放系数的定义、计算方法、应用范围及应用方式进行了探讨,研究结果可为海洋石油开发工程项目环境影响评价及环境保护管理,以及行业或企业有关标准的制定提供参考。     

致密低渗透气田的试井特征分析--以新场气田为例

经对新场气田的试井资料处理,建立了不同类型储层典型井试井解释范例,得出低渗透试井判别式和判别图版,对该区具有低渗透特征的试井曲线进行了讨论。根据试井结果,可识别气藏(气层)储集类型,确定产层物性参数,为气藏动态分析提供基础资料。为开发致密低渗砂岩气藏、保持稳产高产奠定基础。