气流诱发调节阀杆振动的研究

应用调节阀模型试验台和微小型高频动态压力传感器及其采集测量系统，对汽轮机常用的型线阀和球型阀的内部流场进行测试，着重于阀门不稳定工况和振动工况，并且采用谱分析方法对测试数据进行了分析研究。结果表明：型线阀比球型阀的流场脉动强度小，阀门稳定工况范围更大；从安全角度讲，球型阀用于较小升程不太合适。图5表1参5     

晶态 Ni 粉与非晶 Fe_(78)Si_(12)B_(10)球磨时的固态反应

研究了晶态 Ni 粉与非晶 Fe_(78)Si_(12)B_(10)球磨时的固态反应。结果表明,当以(?)17at.-%Ni 和30at.-%Ni 与相应的非晶粉混合球磨后,产物为新的含 Ni 的完全非晶粉末。当以50at.-%Ni 与相应的非晶粉末混合球磨后,除了生成新的非晶相外,还有γ(Fe,Ni)相生成。     

Mechanochemically initiated polymerisations. 12. Spectral and thermal characterisation of some products obtained by vibratory milling of benzene and pyridine

Vibratory milling is used to open the aromatic ring of compounds such as benzene and pyridine and this is followed by concatenation of the structural units. The products obtained form both the soluble fractions in methanol, i.e. dimethylformamide and the insoluble fraction, the latter being found in the prevalent amount. Analysis of the soluble fractions by infrared spectroscopy (i.r.) and pyrolysis-gas chromatography (p.-g.c.) conforms their linear structure of the polyenic type with some short crosslinkings and a great sensitivity to the action of atmospheric oxygen.     

微晶CuCr50真空断路器触头材料的研制

采用高能球磨法制取ＣｕＣｒ５０合金粉。在真空炉内热压成致密块体，利用扫描电镜、Ｘ－ｒａｙ衍射仪，能谱仪等考察了球磨过程粉末粒度，形貌的变化，热压块体的显微组织以及其密度随温度时间的变化。     

Five-axis NC cylindrical milling of sculptured surfaces

In theory, the five-axis numerical control (NC) machining of sculptured surfaces can be classified into facing milling and cylindrical milling (or side milling). In general, the first one, using flat-end cutter, is suitable for the machining of large sculptured surfaces, e.g. the blade of hydraulic turbine, whose binding relations with drive surface (DS) and check surface (CS) are simple, and the second one, using cylindrical cutter, has wide applications for the milling of small and middle dimensional surfaces whose binding relations with DS and CS are more complex, such as the milling of integral turbine wheels. In practice, the second one suffers more difficulties than the first one, which are mostly related to gouge avoidance, interference avoidance and tool strength. This paper, on the basis of the theories of differential geometry and analytical geometry, describes research on algorithms for the toolpath generation of five-axis cylindrical milling of sculptured surfaces with cylindrical cutter. The approach includes (a) single point offset (SPO) algorithm, and (b) double point offset (DPO) algorithm for the cutter location data (CLDATA) calculation of five-axis cylindrical milling.     

Ni50Ti50非晶粉末在球磨时的稳定性

将Ｎｉ５０Ｔｉ５０单质混合粉末经机械合金化形成非晶态合，再进一步球磨使其产生晶化。结果表明，晶化产物为Ｎｉ３Ｔｉ金属间化合物。当Ｎｉ５０Ｔｉ５０非晶体加热时，产生的晶化产物有ＮｉＴｉ，ＮｉＴｉ２和Ｎｉ３Ｔｉ三种金属间化合物。本文通过ＤＳＣ差热分析，测定了Ｎｉ５０Ｔｉ５０非晶合金的晶化热及晶化激活能，并讨论了过度球磨时非晶晶化机制。     

Calculations of chip thickness and cutting forces in flexible end milling

In the end milling process of a flexible workpiece, it is well recognized that the precise determination of the instantaneous uncut chip thickness (IUCT) is essential for the cutting force calculation. This paper will present a general method that incorporates simultaneously the cutter/workpiece deflections and the immersion angle variation into the calculation of the IUCT and cutting forces. Contributions are twofold. Firstly, considering the regeneration model, a new scheme for the IUCT calculation is determined based on the relative positions between two adjacent tooth path centers. Secondly, a general approach is established to perform numerical validations. On one hand, the engagement/separation of the cutter from the workpiece is instantaneously identified. On the other hand, the calculation of the IUCT is iteratively performed. To demonstrate the validity of the method, several examples are used to show the convergence history of the cutting force and the IUCT during the flexible end milling process. Both theoretical analyses and numerical results show that the regeneration mechanism is short lived and will disappear after several tooth periods in flexible static end milling process .     

球形触点阵列与四边扁平封装的比较

球形触点阵列（ＢＧＡ）封装技术作为一种新的封装技术越来越受到人们的重视。从安装率和成本、表面安装印制板设计以及焊点可靠性三个方面对球形触点阵列与四边扁平封装（ＱＦＰ）进行了比较。分析认为，ＢＧＡ和ＱＦＰ各有其优势和劣势，各有其应用重点。     

Fabrication of fine apertures in metal foils by photoelectrochemical milling

The potential of a photofabrication process involving photolithography and electrochemical milling has been established for the production of accurate holes in a range of sheet materials (10–500 μm thick), including molybdenum, platinum, Pt-10Rh, sterling silver, carat gold and silver- and palladium-based alloys. Based on scanning electron microscopy, the new technique shows its unique capability of producing high quality components in materials which were hitherto considered to be difficult or impossible to fabricate. Furthermore, the technique does not involve the use of any highly toxic or aggressive chemicals; a non-passivating neutral solution of sodium chloride is used as the electrolyte. Details of the type, concentration and application of the electrolyte are discussed. The technique appears to be potentially attractive to the manufacturers of fine apertures and similar intricate shapes of industrial components and jewellery items.