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关键词： TiNi合金   冷轧形变   微观结构   力学性能   Ti_3Ni_4析出相  

摘要： TiNi形状记忆合金具有优异的功能特性和结构特性,在多种领域有着明确的目标需求。本文聚焦B_(2)结构奥氏体富镍TiNi合金,拟通过冷轧退火循环调控TiNi合金微观结构,以期提升合金较低的力学强度和塑性形变能力。系统考察了Ti_(48.9)Ni_(50.9)Zr_(0.2)和Ti_(47.9)Ni_(51.9)Zr_(0.2)合金力学性能和微观结构与冷轧形变以及再结晶退火之间的依赖关系。拉伸力学性能测试表明,冷轧退火循环可显著提升合金综合力学性能,其中Ti_(48.9)Ni_(50.9)Zr_(0.2)合金6道次冷轧退火后抗拉强度从未轧制样品的550 MPa提升至1070 MPa,断后伸长率从4.9%增加至10.0%。通过EBSD、SEM和TEM微观结构观察可以发现,合金多道次冷轧退火后,形变组织和再结晶组织交替变化,合金晶粒显著细化,发生了明显的择优取向,合金织构进一步增强。析出相Ti_(2)Ni和Ti_(3)Ni_(4)破碎细化,纳米级Ti_(3)Ni_(4)与基体间有着良好的晶格匹配性。此外,合金中出现了应力诱发的马氏体以及析出相附近大量高密度位错。合金力学性能与材料微观结构密切相关,强度和塑性提升机制可通过细晶强化、位错强化、沉淀强化和织构强化来理解。

摘要： We report the serendipitous discovery of a bow-shock nebula around the cataclysmic variable (CV) SY Cancri. In addition, SY Cnc lies near the edge of a faint H alpha-emitting nebula with a diameter of about 15 ' . The orientation of the bow shock is consistent with the direction of SY Cnc's proper motion. Nebulae are extremely rare around CVs, apart from those known to have undergone classical-nova (CN) outbursts;bow shocks and off-center nebulae are even more unusual. Nevertheless, the properties of SY Cnc and its nebulosity are strikingly similar to those of V341 Ara, another CV that is also associated with a bow shock and is likewise off-center with respect to its faint H alpha nebula. Both stars are binaries with optically thick accretion disks, belonging to the classes of Z Cam CVs or nova-like variables. We discuss three scenarios to explain their properties. They may have resulted from chance encounters with interstellar gas clouds, with the stars leaving in their wakes material that is recombining after being photoionized by ultraviolet radiation from the CVs. Alternatively, the large nebulae could be ejecta from unobserved CN outbursts in the recent past, which have been decelerated through collisions with the interstellar medium (ISM), while the stars continue to snowplow through the gas. Or the faint H alpha nebulae may be ambient ISM that was flash-ionized by a CN outburst in the past and is now recombining.

关键词： 互联网+政务服务   政策评估   S-CAD方法  

摘要： 推进“互联网+政务服务”改革进程是提升国家治理体系和治理能力现代化的重要举措,也是“放管服”改革和政府简政放权的有机结合。基于此,以贵州省贵安新区为例,运用S-CAD政策方法,在明确方法各要素的基础上对“互联网+政务服务”相关政策进行一致性分析、充要性分性和可行性分析。结果表明,“互联网+政务服务”政策逻辑严谨,政策要素间一致性程度较高,政策手段是其他政策要素的必要不充分条件,政策可行性较强,整体实施效果较好,但政策在实施过程中仍然存在不少问题。下一步应从法律法规、平台体系、监督机制和工作手段等方面进行优化完善。

关键词： Computer-aided design   Artificial intelligence   Intelligent CAD   3D generative modeling   3D multimodal modeling  

摘要： Integrating modern artificial intelligence(AI)techniques,particularly generative AI,holds the promise of revolutionizing computer-aided design(CAD)tools and the engineering design ***,the direction of"AI+CAD"remains unclear:how will the current generation of intelligent CAD(ICAD)differ from its predecessor in the 1980s and 1990s,what strategic pathways should researchers and engineers pursue for its implementation,and what potential technical challenges might arise?As an attempt to address these questions,this paper investigates the transformative role of modern AI techniques in advancing CAD towards *** first analyzes the design process and reconsiders the roles AI techniques can assume in this process,highlighting how they can restructure the path humans,computers,and designs interact with each *** primary conclusion is that ICAD systems should assume an intensional rather than an extensional role in the design *** offers insights into the evaluation of the previous generation of ICAD(ICAD 1.0)and outlines a prospective framework and trajectory for the next generation of ICAD(ICAD 2.0).

关键词： Engineering machinery   Hydraulic motor   Pulsation   Oil distributor port   Speed stability   Optimization design  

摘要： High-end equipment always operate in low-speed and heavy-load working environments,highlighting the need for cam-lobe hydraulic motors with excellent speed stability(<1 r/min)and ultrahigh-power rotary output(>1 MW).The successful operation of cam-lobe hydraulic motors relies on the circulation supply of high-and low-pressure ***,the switching between high-/low-pressure oil controlled by the oil distributor inevitably causes an obvious pressure impact and speed pulsation,which directly reduces the speed stability of hydraulic ***,an optimization design approach for the oil distributor port is proposed to minimize the speed pulsation of cam-lobe hydraulic *** the proposed approach,a simulation model that links the oil distributor port structural parameters with the hydraulic motor speed pulsation was developed to clarify the e ect of the oil distributor structural parameters on speed ***,an orthogonal analysis method was used to identify the optimized oil distributor port structural parameters while minimizing the hydraulic motor's speed pulsation as much as ***,several experiments were conducted to validate the e ectiveness and accuracy of the proposed optimization design *** experimental results indicate that the pulsation rate of the hydraulic motor equipped with the optimized oil distributor was 62.5%lower than that of the original motor at a working pressure of 25 MPa,which is consistent with the simulation results using the proposed optimization design *** findings of this study o er a feasible and e ective approach to guide the design optimization of the oil distributor port for low-pulsation hydraulic motors.

关键词： 纺织品   绿色   染整工艺  

摘要： 传统纺织品染整生产存在诸多弊端,使用不良染整剂不仅会给周围环境带来一定影响,而且还会对人体带来危害,不利于纺织行业的稳健发展。在此情况下,纺织行业很有必要对绿色染整技术进行研究,并且进行大力推广。现简单介绍绿色染整工艺的定义、特点,以及优势等,然后阐述纺织品绿色染整工艺要点,最后利用案例验证纺织品绿色染整工艺的可靠性,以避免给周围环境以及人体带来损伤,实现良好经济效益,促使纺织行业可以稳健发展。

关键词： 玉米醇溶蛋白   纳米微粒   超疏水   蜂蜡  

摘要： 基于玉米醇溶蛋白本身具有的自组装特性,通过反溶剂法制备玉米醇溶蛋白纳米颗粒(ZNPs),并将其作为底层整理到棉织物表面构建粗糙表面;并利用蜂蜡低表面能的特性,采用双涂层法制备超疏水棉织物。结果表明:通过反溶剂法制备得到的ZNPs的粒径为178.37±2.24 nm;采用浸渍法分别将ZNPs和蜂蜡整理至织物表面,织物获得了长久的超疏水性质,接触角达到155.63±4.02°,水滴吸收时间大于600 s;电子显微镜(SEM)可观察到ZNPs在织物上形成了微纳米级粗糙表面,红外光谱(FT-IR)显示玉米醇溶蛋白和蜂蜡均在织物表面沉积。该织物表面具有优异的防水抗污性能,同时具有较好的耐摩擦性和耐水洗性,且织物仍保留了较好的物理机械性能和透湿透气性。

关键词： 校园街道空间   街道步行性   视觉感知体验   深度学习   类激活图   可解释性  

摘要： 相较于城市街道,校园中更为简单的人群结构和低差异性的空间,提供了相对严格的控制变量条件和可重复性更高的实验环境,有助于更专注地分析特定的校园街景要素对视觉感知的影响。文章采用类激活可视化解释技术(Grad-CAM),对南方某大学的校园街道步行空间视觉感知体验进行研究。通过对比Grad-CAM类激活图与眼动追踪数据,并结合SHAP模型和核密度估计模型分析,归纳了影响校园街道空间步行感知的主要街道特征,揭示了街景要素对视觉感知的差异化影响。研究可为街道步行空间的精细化设计和更复杂的城市街道研究提供参考和借鉴。

关键词： 西周   礼器   画缋  

摘要： 从设计伦理学角度研究西周时期的画缋纺织品,探讨其在社会、实用和美学价值之间的驱动关系。研究包括画缋纺织品的历史沿革及其在祭服、祭器和明器中的应用,解析其设计伦理学意义。作为礼器的画缋纺织品在礼仪活动中扮演着重要角色,其上的纹饰反映了工匠在礼法制度和伦理思考下对自然的观察和对社会的归纳,其设计也为后世纺织品纹饰设计及设色奠定了基调。