Theory experiment comparison of the electron backscattering factor from solids at low electron energy (250-5,000 eV)

The electron backscattering factor was measured from 24 different elements at low primary beam energy (250-5,000 eV). The results were compared with Monte Carlo simulations from a variety of freely available programs and an in-house developed program. The results suggest that a thin film of oxide can modify the backscattering factor at low primary energy. In addition, a number of problems have been identified with the freely available programs.     

弯道零件的斜孔加工

对于零件弯道的两个3空间斜孔,原通过组合夹具定位后,采用划线加工,加工质量不能满足图纸要求。针对该问题,指出了划线加工的不足,并采用新的加工方法,即在立卧转换加工中心上,开发并运用其潜在的"循环19(即零点跟踪)"功能,从而显著提高了整机的性能。     

软岩溜煤立眼的施工

软岩溜煤立眼的施工。(1)此立眼全部在岩层中施工,(2)、溜煤立眼采用料石支护,(3)、立眼料石支护与混凝土相比,施工中减少了支模工序,(4)节省了投资,保证安全施工效果良好。     

Optical fiber distributed acoustic sensing based on the self-interference of Rayleigh backscattering

In order to detect the weak underwater acoustic signal, a Distributed Acoustic Sensing (DAS) scheme based on the self-interference of Rayleigh backscattering is presented. Rayleigh backscattered light which contains a phase change induced by acoustic signal along the sensing fiber which is a standard telecom single-mode fiber is split and fed into an imbalance Michelson interferometer. With the self-interference of two Rayleigh backscattered beams, the phase change is amplified theoretically compared with phase-sensitive OTDR. We designed an experiment to prove the scheme, and successfully restored the acoustic information, meanwhile, the DAS system has preliminary realized around the acoustic phase sensitivity of −151 dB (re rad/μPa) at 600 Hz, and the minimum detectable acoustic pressure of 6 Pa in the experiment.     

C-EPS系统中转向器异响问题分析与研究

针对C-EPS系统中转向器常见的故障模式——异响进行了分析,根据产生异响的部位不同,对引起异响的原因进行了详细分析,并针对产生的原因提出预防对策,这些对策已经过验证与实际应用,对分析与解决C-EPS转向器的异响问题具有指导意义。     

中线平移互交视线测设法在斜交桥梁定位的应用

以福建某高速公路尤溪段源湖中桥为例,阐述了中线平移互交视线测设法在斜交桥梁墩台定位的应用情况,实践证明该方法能很好地解决斜交桥梁墩台定位的问题。     

The effect of microstructure and texture evolution on mechanical properties of low carbon steel in a non-circular drawing sequence

In this study, a new process sequence of non-circular and circular drawing is designed using finite element simulations and is proposed to produce strengthened wires in a simple continuous way for industrial applications. The developed non-circular drawing (NCD) sequence was experimentally applied to low carbon steel at room temperature. Mechanical properties, microstructure and texture evolution of the specimen processed by the newly proposed process and conventional wire drawing (WD) were investigated by tension test, electron backscattering diffraction (EBSD), and X-ray diffraction (XRD) for comparison. According to the present investigation, the specimen processed by the NCD sequence achieved 10.7% higher ultimate tensile strength (UTS) with slightly higher reduction of area at fracture than the one processed by the WD for the two-pass with the same area reductions. Furthermore, the UTS value (612 MPa) of the drawn wire by the two-pass NCD sequence was equivalent to the level of 602 MPa processed by the three-pass WD. From the EBSD results, the areal fraction of the low angle grain boundaries (1.12 μm⁻¹) of the specimen processed by the NCD was higher than that (0.78 μm⁻¹) of the specimen processed by the WD for the two-pass. The pole figures and ODFs of the specimen processed by the NCD sequence showed typical drawing and rolling textures. It is demonstrated that the non-circular drawing sequence could be beneficial in producing high-strength wires with comparable ductility through grain refinement according to the observations made in the present work.     

Feature integration across space, time, and orientation.

The perception of a visual target can be strongly influenced by flanking stimuli. In static displays, performance on the target improves when the distance to the flanking elements increases—presumably because feature pooling and integration vanishes with distance. Here, we studied feature integration with dynamic stimuli. We show that features of single elements presented within a continuous motion stream are integrated largely independent of spatial distance (and orientation). Hence, space-based models of feature integration cannot be extended to dynamic stimuli. We suggest that feature integration is guided by perceptual grouping operations that maintain the identity of perceptual objects over space and time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

压铸模定模侧组合型芯反推式斜抽机构设计

为解决铸件气缩孔问题,在压铸模定模侧设计了一种组合型芯反推式斜抽机构。在铸件定模侧存在大量斜孔无法直接出镶针的情况下,采用该机构能够将这些孔位做成整体斜抽。该新型反推式斜抽机构设计精巧,运行平稳,故障率低,使用可靠,值得推广应用。     

电磁波斜入射分层介质问题FDTD分析

分层半空间二维斜入射问题一般转化为一维情况来处理,但该处理方法的有效性与入射角的大小紧密相关。对一维修正处理方法斜入射角度的适用范围进行了研究,同时,利用该方法研究了介质的介电常数、电导率和色散特性对反射波时域、频域特性的影响,结论对分层半空间问题FDTD分析、地物反演等应用有重要指导作用。