新型无杆水力采油装置研制与应用

针对中原油田中后期开发存在的液面降低、泵挂加深使得抽油机载荷增加、冲程损失增大、杆管偏磨严重等问题,研制了新型无杆水力采油装置。该装置采用球阀换向,冲程长、冲次低。现场试验时SC38—74—4.8型无杆水力采油装置与常规管式抽油泵联用,下泵深度1650m,冲程4.8m,冲次2.7min-1,日注水量72m3,产出液60m3。结果表明,新型无杆水力采油装置延长了抽油泵的使用寿命,彻底根除了杆管偏磨,采用球阀换向,对动力液要求较低,日常维护简单。     

波形刃铣刀片铣削温度试验分析

进行了铣削温度试验 ,采用改进的人工热电偶法 ,利用动态数据采集系统 ,对波形刃铣刀片的铣削温度进行了采集。利用C语言和MATLAB软件对试验数据进行了分析 ,拟合出温度—时间 (T t)曲线 ,初步得到了受热密度函数 ,为温度场的可视化打下有力的基础     

Creation of Ultra-precision Microstructures with High Aspect Ratios

In recent years, ultra-precision micromachining technology has been used in a variety of fields such as optical instruments, electronic devices, medical equipments, etc. At present, it is essential to meet the requirement of producing various shapes, one of which is a structure with a high aspect ratio. Such structures are applied, for example, to a shaft of micro robot, a long part of microactuator and micromachine, a microneedle for syringe, etc. However, due to its fragile nature, it is extremely difficult to fabricate the structure with a high aspect ratio since it is easily damaged during cutting. It is intended to produce micro towers with high aspect ratios by applying the ultra-precision milling technology using a single crystal diamond cutting tool. The method enables accurate creation of a variety of microstructures with high aspect ratios. In addition, the study also proposes a new machining method to create microneedle arrays, avoiding the contact of cutting edge with already machined parts again. As a result, it is concluded that the proposed method has the potential of producing a variety of microstructures with high aspect ratios.     

Transformations in machining. Part 1. enhancement of wavelet transformation neural network (WT-NN) combination with a preprocessor

Properly selected transformation methods obtain the most significant characteristics of metal cutting data efficiently and simplify the classification. Wavelet Transformation (WT) and Neural Networks (NN) combination was used to classify the experimental cutting force data of milling operations previously. Preprocessing (PreP) of the approximation coefficients of the WT is proposed just before the classification by using the Adaptive Resonance Theory (ART2) type NNs. Genetic Algorithm (GA) was used to estimate the weights of each coefficient of the PreP. The WT-PreP-NN (ART2) combination worked at lower vigilances by creating only a few meaningful categories without any errors. The WT-NN (ART2) combination could obtain the same error rate only if very high vigilances are used and many categories are allowed.     

变频器在龙门铣床上的应用

介绍龙门铣床的直流调速控制系统的改造方案，根据龙门铣床工作台运动过程及原直流电机的容量来选择交流电机和变频器并对变频器的功能进行设定。     

提高干压各向异性SrM磁体磁性能的方法

以Y30H-1的SrM预烧料为原料,通过对二次添加剂、二次球磨及烧结曲线的调整,做出了Br≥380mT,Hcb≥240kA穖-1,Hcj≥250kA穖-1,(BH)max≥27.0kJm-3的干压各向异性锶铁氧体产品。     

制粉系统的经济运行

分析了广州发电厂员村热电厂制粉系统电耗偏高的原因，通过对制粉系统的一系列改进，使得制粉电耗由原来的27～30kwh／t降低至22～24kwh／t。降低了制粉电耗，提高了制粉系统运行的经济性。     

An intelligent sensor for detection of milling chatter

In this paper, a new real-time sensor system has been developed to detect chatter in milling operations. In the developed sensor system, a pattern recognition technique based on an unsupervised neural network using the adaptive resonance theory (ART) is adopted for detection of milling chatter. The features on the cutting force spectrum are fed into the sensor system to classify the milling process with or without chatter. The experimental results indicate that the proposed sensor system can accurately detect milling chatter regardless of the variation in cutting conditions.     

Dependence of Silicon Carbide Product Morphology on the Degree of Mechanical Activation

Mechanical activation before carbothermic reduction can substantially enhance the formation of SiC from SiO₂and carbon mixtures. However, the morphology (e.g., particles or whiskers) of SiC formed from mechanically activated SiO₂and carbon mixtures is dependent of the degree of mechanical activation and the condition of the subsequent carbothermic reduction. These phenomena are investigated and rationalized based on the increased reactivity of the reactants and SiC formation mechanisms.     

在高速气流粉碎作用下PVC的力化学降解及形态变化的研究

通过ＧＰＴ、ＦＴ－ＩＲ、ＳＥＭ和力学性能测试，研究了在高速气流作用下聚氯乙烯（ＰＶＣ）的力化学降解反应、颗粒形态和微晶结构变化及其对ＰＶＣ物理、力学性能的影响。实验结果表明，经过高速气流处理ＰＶＣ，分子量将有所降低，晶体结构发生变化，颗粒尺寸和表观密度降低，比表面积增大，加工性能和力学性能得到明显改善。