磁力研磨优化钛合金管内表面光整度试验

基于磁力研磨加工技术,采用自行设计的旋转永磁场磁力研磨装置,对钛合金管内表面进行了研磨加工光整度试验。利用正交试验研究了当磁感应强度和磁场旋转速度为定值时,研磨加工时间、磁性磨粒中磨粒相Si C和铁磁相Fe粉的质量比、Si C颗粒粒径、Fe粉颗粒粒径对内表面光整度加工效果的影响。结果表明:在磁力研磨加工时间为15 min,Si C和Fe粉质量比为1∶2、Si C颗粒粒径为180目、Fe粉为400目的最优条件下,钛合金管内表面的粗糙度值大幅降低、表面形貌细化,光整效果最好。

机械加工技术对金属零件光整度和加工精度的影响研究

在机械加工技术中,主要通过溶解、钻、车削、划线、铣削和磨削等方法进行加工,通过系统的方法将金属材料加工成零件,然后装配到各种机械设备上。在进行金属零件加工时,一般采用的工艺技术会影响工件的加工精度。在相同的工艺条件下,提高产品的加工精度,降低产品的失效概率,可以提高企业的生产效率及经济效益。文章首先介绍了机械制造的工艺流程,然后分析了机械加工技术对金属零件加工的影响和控制措施,最后以实例分析的形式提出提高加工精度的对策。

电火花线切割加工表面微织构技术研究

表面微织构加工是一个相当复杂的过程,涉及微织构的尺寸、质量及形貌等问题。为解决制备微织构存在的问题,利用数控电火花线切割加工技术,在45钢表面加工微槽织构,研究线切割制备微织构的尺寸、形貌。试验分别采用钼丝、铜丝作为电极丝,设计脉宽、脉停、电流等线切割正交试验,切割宽度小于400μm的微槽织构,分析不同线切割参数、电极丝材料对微槽尺寸精度和微槽切口处光整度的影响。通过采集、测量试验所得工件表面微槽织构,发现线切割参数对微槽尺寸精度和切口处光整度有较大的影响;在较小线切割参数下,钼丝切割的微槽尺寸大于铜丝,在较大的线切割参数下,铜丝切割的微槽尺寸大于钼丝;对比微槽切口处光整度,发现钼丝切割的微槽整体质量优于铜丝。试验列出不同线切割参数切割的微槽尺寸,为电火花线切割加工微织构提供了试验数据。

机械加工技术对金属零件加工的影响

以机械加工技术引入研究论点;从光整度与精度两个视角分析影响金属零件加工的因素,提出对应解决措施;列举实例,落根于零件光整度,分析金属零件加工流程,用金属加热的方式确定零件雏形,借助滑擦、耕犁、切削三要素,控制零件光整度。

Photonics-to-electronics integration for optical interconnects in the early 21^(st) century

We discuss the technical rationale,challenges,and potential for achieving “optics-to-the chip” via the intimate integration of photonics components such as lasers,detectors,and modulators with VLSI electronics.We review the progress made towards commercializing this technology for high-density optical transceivers and switching products.

Implementation of Efficient Burst Assembly Algorithm with Traffic Prediction

This paper reports on the implementation of efficient burst assembly algorithms and traffic prediction. The ultimate goal is to propose a new burst assembly algorithm which is based on time-burst length （hybrid） threshold with traffic prediction to reduce burst assembly delay in OBS （Optical Burst Switching） networks. Research has shown that traffic always change from time to time, hence, any measure that is put in place should be able to adapt to such changes. With our implemented burst assembly algorithm, the traffic rate is predicted and the predicted rate is used to dynamically adjust the burst assembly length. This work further investigates the impact of the proposed algorithm on traffic self similarity.

Effects of spin-coating speed on the morphology and photovoltaic performance of the diketopyrrolopyrrole-based terpolymer

Polymer solar cells(PSCs) were fabricated by combining a diketopyrrolopyrrole-based terpolymer(PTBT-HTID-DPP) as the electron donor, and [6,6]-phenyl C_(61) butyric acid methyl ester(PC_(61)BM) as the electron acceptor, and the power conversion efficiency(PCE) of 4.31% has been achieved under AM 1.5 G(100 m W cm^(-2)) illumination condition via optimizing the polymer/PC_(61)BM ratio, the variety of solvent and the spin-coating speed. The impact of the spin-coating speed on the photovoltaic performance of the PSCs has been investigated by revealing the effects of the spin-coating speed on the morphology and the absorption spectra of the polymer/PC_(61)BM blend films. When the thickness of the blend films are adjusted by spin-coating a fixed concentration with different spin-coating speeds, the blend film prepared at a lower spin-coating speed shows a stronger absorption per unit thickness, and the correspond device shows higher IPCE value in the longer-wavelength region. Under the conditions of similar thickness, the blend film prepared at a lower spin-coating speed forms a more uniform microphase separation and smaller domain size which leads to a higher absorption intensity per unit thickness of the blend film in long wavenumber band, a larger short-circuit current density(J_(sc)) and a higher power conversion efficiency(PCE) of the PSC device. Noteworthily, it was found that spin-coating speed is not only a way to control the thickness of active layer but also an influencing factor on morphology and photovoltaic performance for the diketopyrrolopyrrole-based terpolymer.

Metal-organic framework film for fluorescence turn-on H2S gas sensing and anti-counterfeiting patterns

Hydrogen sulphide(H2 S)is a common air pollutant,which is produced in various industry processes.Therefore,it is of crucial importance to detect H2 S in real time.Many fluorescent sensors were reported aiming at detecting H2 S in solution;however,the fluorescence sensing of gaseous H2 S has not yet been reported.In this work,we utilized the post-functionalized fluorescent film,MIL-100(In)@Eu3+/Cu2+film,realizing fluorescence turn-on sensing of gaseous H2 S at room temperature for the first time with the limit of detection as low as 0.535 ppm,which is comparable to some reported fluorescent probes for S2-ions and semiconductor based gaseous H2 S sensors.The sensor was designed due to the strong affinity of H2 S with Cu2+.With the formation of CuS,the"antenna effect"between the ligand and Eu3+recovered,resulting in the fluorescence turn-on of Eu3+emission.Additionally,we proposed a new method to realize multi-colour anti-counterfeiting patterns with lanthanide ions ink,taking advantage of the extraordinary smooth surface and uncoordinated carboxylate groups within the MIL-100(In)film.

Angular tuning of defect modes spectra for one dimensional photonic crystal filters with a liquid crystal layer

A tunable photonic crystal filter with a twisted nematic liquid crystal layer is proposed. The defect modes spectra with varying incident angles are discussed in detail by 4×4 matrix method. The results show that the defect modes are mainly decided by the applied voltage when the incident angle is smaller than 8°. As the incident angle further increases, the band gap and the defect modes shift toward the shorter wavelength side, and the changes of the two modes are different, In the lower voltage range, the defect modes can be tuned not only by the applied voltage but also by the incident angle. In the higher voltage range, the defect modes can be further tuned by varying incident angle and the different modes can be separated from each other by a bip incident anple.