服装裁剪机高速钢直刀片真空热处理技术研究

W6Mo5Cr4V2钢板经冲裁加工制成的刀片,用盐浴油淬、低温回火后,经磨削工艺去除盐渍油污,耗时又费材。然而,采用光亮真空热处理及抛光加工技术替代传统的用盐浴油淬和磨削技术生产服装裁剪机用刀片,研究其真空热处理工艺参数,分析其组织和性能,可以降低材料的消耗和生产成本,提高产品质量。     

A comprehensive sintering mechanism for thermal barrier coatings‐Part III: Substrate constraint effect on healing of 2D pores

During thermal exposure, the sintering of the plasma‐sprayed thermal barrier coatings (PS‐TBCs) is highly dependent on the healing of the two‐dimensional (2D) pores (including the inter‐splat pores and the intra‐splat cracks), as reported in the previous Part‐I and Part‐II based on free‐standing coatings. As a further study, this part aims to reveal the effect of substrate constraint on healing behavior of the 2D pores, since the coatings are actually bonded to superalloy substrate during real service. The healing of the 2D pores was quantitatively examined, and the multiscale mechanical properties were determined during the overall thermal exposure. In addition, a structure model was used to quantitatively correlate the evolution of 2D pores with mechanical property. The results of experiments and model prediction show that, different from the two‐stage evolutionary trends in free‐standing coatings, the overall evolution trends of microstructure and property can be divided into 3 stages affected by the substrate constraint. Moreover, the anisotropic healing of the 2D pores reported in free‐standing coatings was enhanced significantly due to the additional stress in coatings resulting from constraint of substrate. This means that the healing of inter‐splat pores became faster and severer. Given that, an outlook on structural tailoring to retard the performance degradation of TBCs was proposed.     

Crown Ether-Assisted Growth and Scaling Up of FACsPbI3 Films for Efficient and Stable Perovskite Solar Modules

FACs-based (FA⁺, formamidinium and Cs⁺, cesium) perovskite solar cells have gained great attention due to their remarkable light and thermal stabilities toward practical application of perovskite modules. However, the moisture instability and difficulty in scalable fabrication are still the main obstacles blocking their photovoltaic applications in current status. Here, the employment of novel interaction between crown ether with metal cations is introduced to tailor the uniform growth and inhibit moisture invasion during the crystallization of α-phase FACsPbI₃, yielding the successful synthesis of high-quality perovskite films in a large scale. Consequently, perovskite solar cells (PSC) modules in the total area of 4 × 4 and 10 × 10 cm² are readily fabricated with respective champion efficiencies of 16.69% and 13.84% and excellent stability over 1000 h. This facile scaling-up strategy assisted by crown ether has shown great promise for pursuing efficient and highly stable large-area PSC modules.     

中高空面阵CCD航空相机操作系统裁剪技术研究

针对面阵CCD航空相机操作系统的实际需求,结合相机中PC104总线结构的硬件资源,对所采用的Linux系统进行实用性裁剪。采用粗粒度和细粒度相结合的裁剪方法,来增强Linux内核的抢占性,改善Linux内核的实时调度器的调度策略,以构建具有较强实施处理能力的嵌入式系统。在不同环境下,对系统的启动和任务响应性能的试验测试表明,裁剪后的系统稳定、可靠,且可达到启动时间小于5s,任务响应时间小于20ms的性能指标。     

Effect of α phase on fatigue crack growth of Ti-6242 alloy

Fatigue crack growth as a function ofαphase volume fraction in Ti-6Al-2Sn-4Zr-2Mo(Ti-6242)alloy was investigated using fatigue testing,optical microscopy,scanning electron microscopy,and transmission electron microscopy.Theα+βannealing treatments with different solid solution temperatures and cooling rates were conducted in order to tailor microstructure with differentαphase features in the Ti-6242 alloy,and fatigue crack growth mechanism was discussed after detailed microstructure characterization.The results showed that fatigue crack growth rate of Ti-6242 alloy decreased with the decrease in volume fraction of the primaryαphase(αp).Samples with a large-sizedαgrain microstructure treated at high solid solution temperature and slow cooling rate have lower fatigue crack growth rate.The appearance of secondaryαphase(αs)with the increase of solid solution temperature led to crack deflection.Moreover,a fatigue crack growth transition phenomenon was observed in the Paris regime of Ti-6242 alloy with 29.8% αp(typical bi-modal microstructure)and large-sizedαgrain microstructure,owing to the change of fatigue crack growth mechanism.     

Inherent anisotropy in transition metal diborides and microstructure/property tailoring in ultra-high temperature ceramics—A review

This is the first comprehensive review on inherent anisotropic features of transition metal diboride (MB₂) and their implementation for tailoring the microstructure and properties of MB₂-based Ultra-high temperature Ceramics (UHTCs). The emphasis is on the processing approaches, microstructures, and properties of self-reinforced and/or textured MB₂-based composites with elongated MB₂ grains. The crystal structure characteristics and grain growth behaviour of MB₂ are also critically reviewed. Benefiting from the tailored microstructure, the MB₂-based ceramics exhibit some improved properties. Considering the success of Si₃N₄ ceramics in the field of structural ceramics, it is expected that the potential MB₂-based ceramic composites with abundant elongated MB₂ grains, textured structures, and controlled grain boundaries would possess improved fracture toughness, thermal shock resistance, and reliable high-temperature properties, which are desired for their practical applications. Accordingly, microstructure designing and tailoring provide an important perspective for the future development of UHTCs.     

Pore Structure Tailoring of Pillared Clays with Cation Doping Techniques

Techniques and mechanism of doping controlled amounts of various cations into pillared clays without causing precipitation or damages to the pillared layered structures are reviewed and discussed. Transition metals of great interest in catalysis can be doped in the micropores of pillared clay in ionic forms by a two-step process. The micropore structures and surface nature of pillared clays are altered by the introduced cations, and this results in a significant improvement in adsorption properties of the clays. Adsorption of water, air components and organic vapors on cation-doped pillared clays were studied. The effects of the amount and species of cations on the pore structure and adsorption behavior are discussed. It is demonstrated that the presence of doped Ca²⁺ ions can effectively aides the control of modification of the pillared clays of large pore openings. Controlled cation doping is a simple and powerful tool for improving the adsorption properties of pillared clay.     

Tailoring Groupware: The Cooperative Hypermedia Approach

Tailoring groupware has to deal with adapting properties of a shared information space as well as with adapting properties of the cooperation support to the group's needs. In this paper, an approach for tailoring both aspects of groupware in an integrated fashion is proposed. This approach uses cooperative hypermedia as a unifying representation of shared information structures, functionality, and the coordination medium of a shared application. It enables cooperative definition of shared information structures, shared process models and their access models not only before collaboration starts, but also on the fly, when emergent processes evolve. The proposed approach addresses tailoring at all stages of the development and use of a groupware application. A prototype system called CHIPS is presented and different possibilities of tailoring in CHIPS are discussed. Examples of CHIPS demonstrate that the cooperative hypermedia approach to tailoring groupware can support the adaptation to different evolving tasks and processes performed by changing teams.     

明胶复合-铁氧化物纳米微粒的制备和表征

用凝胶 -微乳液化学剪裁技术制备了明胶复合的氧化铁纳米量级超细微粒。XRD TEM、和IR测试表明 :微粒为明胶包裹型球形超细微粒 ;微料的粒径为 2 0～ 40nm。