设置碟形弹簧的框架-摇摆墙结构抗震性能试验研究

受控摇摆墙通常采用预应力筋的形式实现，预应力筋基础锚固施工困难，墙体摇摆幅度很小且易与基础发生碰撞。为解决上述问题，研发了一种受控摇摆墙，主要通过基于碟形弹簧的装置实现墙体的受控约束，墙体与主体框架、基础分别采用耗能连接件和V形支撑连接。设计制作了缩尺比为1∶2的对比框架与框架-摇摆墙试件，通过低周往复加载试验研究其抗震性能、破坏模式和自复位特性。结果表明，设置碟形弹簧的框架-摇摆墙较对比框架承载力提高了107.1%，且具有更好的刚度退化性能与耗能性能，框架结构的变形模式得到改善，使得各层的层间位移趋于均匀。连接件是影响框架-摇摆墙结构耗能及协调层间变形的关键，应进一步研究其改进措施及优化设计。     

Preparation and toughening mechanism of Mo2NiB2-based cermets with SiC whiskers

Mo₂NiB₂ is a kind of cermet with excellent mechanical properties, stable chemical properties, and excellent corrosion resistance and is often used in wear-resistant application fields, such as injection molding machine parts, can making tools and hot copper extruding dies. The brittleness of Mo₂NiB₂-based cermets limits their wide application. Mo₂NiB₂-based cermets were prepared by the vacuum sintering method, the effect of SiC whiskers (SiCw) on the microstructure and mechanical properties of cermets was investigated, and the toughening mechanism of SiCw on cermets was further discussed. The results indicate that with increasing SiCw content, the indentation fracture toughness (K_IC), transverse fracture strength (TRS), and Vickers hardness (HV) of the cermets first increase and then decrease. The HV, TRS, and indentation fracture toughness of Mo₂NiB₂-based cermets with 0.5 wt% SiCw are 1 113 HV, 1 620 MPa, and 27.97 MPa·m^1/2, respectively, which are 16.8%, 22.7%, and 25% higher than those without SiCw. In the sliding friction tests, Mo₂NiB₂-based cermets with 0.5 wt% SiCw have the smallest friction coefficient, low wear rate, and high wear resistance. SEM observation and analysis of the crack path and fracture surface showed that the toughening mechanism is whisker bridging, crack deflection, microcrack toughening, and whisker pull-out. The results indicate that the addition of 0.5 wt% SiCw can effectively improve the mechanical properties of Mo₂NiB₂-based cermets and further expand the application space of Mo₂NiB₂-based cermets.     

生态产品价值实现视域下矿山废弃地生态修复与重建

开展矿山废弃地生态修复与重建、提高矿山废弃地生态产品输出能力是生态文明建设的一项重要内容。针对历史遗留和修复责任主体灭失的矿山废弃地，本文探讨其所输出的生态产品概念和内涵。基于投入主体和修复方向角度，总结矿山废弃地修复治理的主要方式。在对矿山废弃地分类基础上，分析矿山废弃地输出的生态产品价值实现困境：生态产品价值依附于土地再利用产生的经济收益中，无法单独体现。根据矿山废弃地输出的生态产品价值实现的阶段特性，提出生态产品价值实现途径：提高矿山废弃地输出的生态产品数量和品质，夯实生态产品价值实现基础；完善生态产品价值实现机制，激励多方主体修复治理。     

城市隧道照明设计探讨

根据近些年的城市隧道工程设计经验,介绍了隧道照明的设计依据、标准及基本要求,分析了城市隧道照明设计的照明标准值、灯具布置、应急照明、照明控制、配线、节能措施等方面内容,并对隧道照明工程设计实例进行了探讨。     

The smallest target size for a comfortable pointing in freehand space: human pointing precision of freehand interaction

Universal Access in the Information Society - Designing interfaces that suit human pointing precision in freehand space can improve the smoothness and naturalness of gestural interaction. However,...     

石灰膏抹面木梁受火后受力性能静力试验研究

木梁受火后由于炭化作用将使其有效截面减少、承载能力降低.通过2组11根木梁三面受火后力学性能的对比试验研究,分析了石灰膏抹面对木梁火灾性能影响.研究结果表明:对比木梁、三面受火无石灰膏抹面木梁和三面受火有石灰膏抹面木梁的破坏形态基本相似;三面受火30min的石灰膏抹面木梁由于含水率降低且木材未遭受炭化损伤,其承载力反而...     

影响针入度分析准确度的因素探讨

就水浴温度精度、不同厂家标准针、沥青放置时间长短及重复加热对针入度及针入度比的影响进行探讨,试验表明这些因素对针入度结果影响较明显,而对针入度比结果影响并不大。     

P403B屏蔽泵的腐蚀分析及防护

屏蔽泵被介质腐蚀而穿孔,介质进入屏蔽套内,又腐蚀定子线圈,造成线圈烧毁。通过水质成分分析和能谱分析,认为P-403B屏蔽套发生腐蚀开裂的主要原因是由于氯化物应力腐蚀开裂造成的,并提出了消除应力的五项具体措施。     

Profibus在棒材生产线中的应用及故障分析与处理

介绍了在棒材连轧机组中应用西门子公司产品组成的西门子工业通信网络系统.同时,涉及到Profibus-DP协议及以太网络的应用及故障处理.