Reinventing Memory System Design for Many-Accelerator Architecture

The many-accelerator architecture, mostly composed of general-purpose cores and accelerator-like function units （FUs）, becomes a great alternative to homogeneous chip multiprocessors （CMPs） for its superior power-efficiency. However, the emerging many-accelerator processor shows a much more complicated memory accessing pattern than general purpose processors （GPPs） because the abundant on-chip FUs tend to generate highly-concurrent memory streams with distinct locality and bandwidth demand. The disordered memory streams issued by diverse accelerators exhibit a mutual- interference behavior and cannot be efficiently handled by the orthodox main memory interface that provides an inflexible data fetching mode. Unlike the traditional DRAM memory, our proposed Aggregation Memory System （AMS） can function adaptively to the characterized memory streams from different FUs, because it provides the FUs with different data fetching sizes and protects their locality in memory access by intelligently interleaving their data to memory devices through sub-rank binding. Moreover, AMS can batch the requests without sub-rank conflict into a read burst with our optimized memory scheduling policy. Experimental results from trace-based simulation show both conspicuous performance boost and energy saving brought by AMS.     

大型圆柱滚子轴承振动检测机

介绍了一种大型圆柱滚子轴承振动检测机,包括它的结构组成、工作原理及主要结构部件的设计。本检测机作为圆柱滚子轴承出厂检测仪器,操作简便,测值准确,有效降低了操作者的劳动强度,提高了工作效率。     

RKE解锁报警问题解析

随着现代社会的发展,汽车的相关功能也由传统的机械控制向自动控制发展,电子电气在汽车中比重也越来越大,由此就会带来决策层与执行层之间的配合问题,换言之就是电子化控制与机械执行之间的相互作用关系.     

均相铑膦催化体系下1-癸烯氢甲酰化反应研究

氢甲酰化反应是目前生产醛醇化合物最重要的反应之一,高碳烯烃氢甲酰化工艺改进是研究的难点和热点之一。探索了一种C10烯烃氢甲酰化反应的工艺,以三苯基膦（Ph₃P）和亚磷酸三（2-叔丁基-4-甲氧基苯基）酯（L_A）混合物为配体,与乙酰丙酮二羰基铑原位合成的催化体系催化1-癸烯氢甲酰化反应。系统考察了反应温度、反应压力、铑浓度、膦铑比、无机盐添加剂对反应的影响。结果表明,在n（Ph₃P）/n（L_A）=10、铑质量分数为280 mg/kg,1-癸烯用量（相对于甲苯）为0.3 g/mL,n（膦）/n（铑）=45、反应温度为90 ℃、反应压力为2.0 MPa、n（一氧化碳）/n（氢气）=1条件下反应4 h,1-癸烯转化率为98.1%、醛收率为93.2%、正异比为7.5。研究还发现,在减压蒸馏产物与催化剂分离时,加入无机盐添加剂能够提高催化剂的稳定性,减少铑损失。     

Performance evaluation of a Scheimpflug stereocamera for particle image velocimetry

We describe a novel stereocamera for particle image velocimetry (PIV) applications that incorporates the Scheimpflug condition that the object plane, lens plane, and image plane must be collinear. We examined the governing equations for this system using a computer-based sensitivity analysis to predict the accuracy of the in-plane and out-of-plane measurement. We evaluated the performance of the Scheimpflug PIV system with a three-dimensional uniform translation test. Results indicate that the Scheimpflug PIV stereocamera performs as expected. The larger off-axis angles possible with the Scheimpflug system can provide a higher accuracy in the out-of-plane component when compared with a translation PIV stereocamera.     

Investigation of Ti coatings on cubic boron nitride (cBN) grits by discharge treatment in spark plasma sintering system

The Ti coatings on cubic boron nitride (cBN) grits were prepared by discharge treatment on a mixture of Ti powders and cBN grits in spark plasma sintering system. The uniform and full coatings with a thickness of ～1.2 μm were prepared at 850 °C for 60 min, which were constituted with TiB₂, TiN, and Ti phases. The compressive fracture strength and toughness impact of the Ti-coated cBN grits were 11.6% and 7.4% higher than the cases of the pristine ones, respectively. With the aid of Ti coatings, the interface bonding strength between cBN grits and Fe-based matrix was improved by 335 MPa in the Fe-based matrix/cBN composites.     

Equivalent Tensile Properties Analysis of the Dimpled Sheet

A dimpled sheet is a novel cold-roll structure made from a plain sheet. The yield strength and elastic modulus of the sheet are altered significantly during the dimpling process. In this study, the equivalent tensile properties of a dimpled sheet are examined. First, tensile testing of a dimpled sheet with typical structural parameters is conducted. Then, finite element analysis based on a unit cell is used to analyze the tensile properties; the results are found to be in good agreement with the experimental findings. Finally, the effects of different structural parameters on the equivalent tensile properties of the dimpled sheet are investigated. The results show that the tensile properties can be obtained using the unit-cell finite element method. Further, the changes in the tensile properties are caused by geometric variations and work hardening occurring during the dimpling process. The yield strength of the dimpled sheet first increases and then decreases as the relative thickness increases. However, the yield strength decreases with increasing relative period distance. The equivalent elastic modulus decreases as the relative thickness increases, but increases with the relative period distance. This study and its findings provide theoretical support for optimal design of a dimpled sheet under tensile loading.     

Liquid Exfoliation of Few-layer 1T-TaS<Subscript>2−<Emphasis Type="Italic">x</Emphasis></Subscript>Se<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> Superconductors

Atomic layer superconductors (ALSCs) have been applied in studying many quantum phenomena over the past ten years. However, self-standing ALSCs beyond the conventional substrates have not been developed yet except from mechanical exfoliation. We here report the successful synthesis of the freestanding unadulterated TaS_2?x Se _x ALSCs via a simple liquid exfoliation method.     

Polarization Encoded Color Image Embedded in a Dielectric Metasurface

Optical metasurfaces have shown unprecedented capabilities in the local manipulation of the light's phase, intensity, and polarization profiles, and represent a new viable technology for applications such as high‐density optical storage, holography and display. Here, a novel metasurface platform is demonstrated for simultaneously encoding color and intensity information into the wavelength‐dependent polarization profile of a light beam. Unlike typical metasurface devices in which images are encoded by phase or amplitude modulation, the color image here is multiplexed into several sets of polarization profiles, each corresponding to a distinct color, which further allows polarization modulation‐induced additive color mixing. This unique approach features the combination of wavelength selectivity and arbitrary polarization control down to a single subwavelength pixel level. The encoding approach for polarization and color may open a new avenue for novel, effective color display elements with fine control over both brightness and contrast, and may have significant impact for high‐density data storage, information security, and anticounterfeiting.