皮带输送机在基坑肥槽回填施工中的应用分析

以回填料使用传统且常见的素土或灰土为背景,以秦都高铁枢纽换乘中心项目为实际案例,从皮带输送机在深基坑肥槽回填工程应用的可行性、经济性及安全性等3个主要方面进行综合研究分析,对渣土车运输配合装载机铲土进行肥槽回填的传统施工方案进行优化,实现提高回填土质量、工作效率及施工安全性.     

BRX筏形基础大体积混凝土养护措施

结合广东太平岭核电厂施工实践,就核电站建设施工过程中核岛筏基大体积混凝土施工并结合以往施工经验进行分析,计算确定养护层厚度,同时采用温水养护,全自动测温系统对大体积混凝土温度计应力进行监测,实时监控动态调整混凝土养护措施.通过动态有差别的养护措施调整,实现对混凝土应力应变的总体控制,从而有力地保障混凝土的成型质量.     

铝合金模板在超高层建筑中的应用

铝合金模板作为新型绿色建筑材料,由于操作方便、污染小、安全性高、可回收等优势,可有效提升建筑抗震、防火、承重等方面的性能,能够替代原有的钢模板、木模板与胶合板等进行梁柱、剪力墙支撑,在高层、超高层建筑领域具有较大的应用前景.从建筑领域铝合金模板的应用原理与特点出发,对模板的具体安装、拆卸与维护等工艺流程进行探析.     

基于LCA的绿色混凝土碳排放量评价体系研究

温室气体(GHG)排放导致气候异常已成为全球关注焦点,混凝土行业作为使用最多的基础建筑材料碳排放尤为严重.通过分析绿色混凝土全产业链的碳排放,提出基于LCA的绿色混凝土碳排放计算模型,并推导出单位立方米混凝土的碳排放计算公式,重点探讨了大掺量工业固废节能减排的量化方法,以诠释"绿色"的涵义.基于全生命周期理论,建立了绿色混凝土碳排放定额模型,并提出碳排放星级评价标准和绿色混凝土全生命周期评价体系,对指导绿色混凝土低碳生产具有重要意义.     

车载火箭发射系统模态分析与试验研究

为提高火箭炮的寿命及射击精度,通过试验模态分析法进行火箭炮系统模态测试。获取结构固有频率、 模态振型和阻尼比等模态参数,分析在不同胎压、支撑高度下系统的振动特性,为火箭炮结构系统的振动特性分析、 振动故障诊断和预报以及结构动力特性的优化设计提供依据。简化模态测试试验过程,将测试获得的整车模态振动 参数与有限元仿真结果对比分析。仿真结果验证了有限元分析的精确度,提高了计算模态分析的应用价值。     

Simultaneous ultrasonication‐assisted internal mixing to prepare MWCNTs‐filled epoxy composites with increased strength and thermal conductivity

The uniform dispersion of carbon nanotubes in epoxy resin is one of the key factors to achieve the composites with desirable mechanical and physical property enforcement. However, the widely used dispersion methods have their own respective limitations in pursuing satisfactory nanotube dispersion. Herein, a new dispersion approach, based on the synergetic effect of combining high speed internal mixing with running simultaneously continuous ultrasonication treatment, has been proposed. The dispersion of nanotubes was carried out in a high speed internal mixer, consisting of twin kneading block structured rotors and an integrated ultrasonic horn, which was intercalated into the central position between the twin rotors. At first, the FEM simulation was conducted to optimize the kneading element assembly and illuminate the geometry influence of the ultrasonic horn intercalation on the mixing flow. Afterwards, to confirm the feasibility of the approach, pristine MWCNTs (P‐CNTs), oxidation modified MWCNTs (M‐CNTs) and M‐CNTs/multilayer graphene nanoplatelets (MGPs) hybrid are dispersed into epoxy resin. The dispersion of each sample in its liquid epoxy state is investigated under transparent optical microscopy. More characterizations, including SEM, TG/DTA, tensile test, and thermal conductivity measurements, were conducted on the cured composites. Competitive reinforcements on mechanical tensile property and thermal conductivity were observed. Especially, at a 1.5 wt% M‐CNTs/MGPs hybrid content, the composite mechanical tensile strength and thermal conductivity were 47% and 30% higher than those of neat epoxy. This preliminary study demonstrates the feasibility and practicability of the proposed approach to achieving good MWCNTs dispersion and distribution in epoxy resin. POLYM. COMPOS., 37:870–880, 2016. © 2014 Society of Plastics Engineers     

银膜换能元的喷墨打印及其性能表征

针对常用薄膜换能元的沉积和成型方法耗时长、成本高、材料利用率低等问题,采用喷墨打印制备了银膜换能元,并采用扫描电镜（SEM）和原子力学显微镜（AFM）对换能元形貌及厚度进行了表征,对银膜桥的发火性能进行了研究。结果表明,银膜换能元厚度为2.1μm,表面平整,在不同输入能量下存在电热、电爆两种情况。银膜桥更容易产生等离子体;蘸有斯蒂芬酸铅（LTNR）的银膜桥在47μF脉冲放电下50%发火电压为6.65 V,脚-脚间可以耐受25 kV静电放电（放电电容为500 pF,串联5 kΩ电阻）,可通过钝感电火工品1A1W5min测试。     

ISO 14031：2013《环境管理环境绩效评价指南》助力组织环境绩效评价

环境绩效评价是对组织是否实现其环境目标的评价,旨在以持续的方式向相关方提供相关和可验证的信息。它既是组织对内、对外沟通环境绩效的一项重要程序和手段,也是组织进行环境管理的一项重要工具。ISO14031：2013《环境管理环境绩效评价指南》提供了完整的环境绩效评价PDCA模式,以及一整套环境绩效指标库,各行业可据此选择和确定具有行业及学科特点的环境绩效评价参数,实施更加有效的环境绩效评价。     

Quantifying long-term evolution of intra-urban spatial interactions

Understanding the long-term impact that changes in a city''s transportation infrastructure have on its spatial interactions remains a challenge. The difficulty arises from the fact that the real impact may not be revealed in static or aggregated mobility measures, as these are remarkably robust to perturbations. More generally, the lack of longitudinal, cross-sectional data demonstrating the evolution of spatial interactions at a meaningful urban scale also hinders us from evaluating the sensitivity of movement indicators, limiting our capacity to understand the evolution of urban mobility in depth. Using very large mobility records distributed over 3 years, we quantify the impact of the completion of a metro line extension: the Circle Line (CCL) in Singapore. We find that the commonly used movement indicators are almost identical before and after the project was completed. However, in comparing the temporal community structure across years, we do observe significant differences in the spatial reorganization of the affected geographical areas. The completion of CCL enables travellers to re-identify their desired destinations collectively with lower transport cost, making the community structure more consistent. These changes in locality are dynamic and characterized over short timescales, offering us a different approach to identify and analyse the long-term impact of new infrastructures on cities and their evolution dynamics.     

WC-11Co硬质合金与不同岩石的摩擦磨损特性

在MMU-10型多功能摩擦磨损试验机上采用销盘湿式摩擦方式,研究WC-11Co硬质合金与两种花岗岩摩擦副的摩擦磨损性能,利用扫描电子显微镜观察硬质合金的磨损表面形貌。结果表明:在同一摩擦条件下,硬质合金/高硬度花岗岩摩擦副的摩擦因数较低;当载荷为700 N时,硬质合金/高硬度花岗岩摩擦副的硬质合金磨损质量损失较高,与硬质合金/低硬度花岗岩摩擦副的硬质合金磨损质量损失差约为4%;而在其他低载荷摩擦条件下,两摩擦副的硬质合金磨损质量损失差均在12%左右,这表明在较低载荷作用下,配副材料对硬质合金磨损的影响相对增大;硬质合金/高硬度花岗岩的磨损机理主要为Co粘结相塑性变形、WC晶粒脱落,硬质合金/低硬度花岗岩的磨损机理主要为硬质合金表面的刮擦。