一个高大空间暖通空调系统集成服务商的自白

正河南省周口市沈丘县是我国钢制散热器的发源地,20世纪80年代,在这片土地上诞生了我国第一片钢制柱形散热器,随着时间推进,单一的品种,简单的结构,使很多散热器企业的销售陷入困境,国营企业面临改制兼并重组,小企业惨遭淘汰。有人说,中国企业的寿命也就3年,在同质化竞争洪流的冲击下,成为百年老店已是遥不可及的梦想,但倔强的河南乾丰暖通科技股份有限公司(以下简称乾丰)伴随整个行业的发展在时代的夹缝     

直写纳米金墨水制备纸基柔性金属图形

将A4打印纸洗净、烘干,用硅氧偶联剂改性,在改性后的纸上用中性笔书写纳米金墨水图形,然后将其放入化学镀溶液中化学镀铜,得到纸基柔性金属图形.X射线衍射分析图谱(XRD)证实了纸张有金属铜镀上.扫描电子显微镜照片(SEM)显示金属铜图形有清晰的界面.X射线光电子能谱分析(XPS)显示改性后的纸的N和Si元素的含量都大幅上升,傅利叶变换红外测试(FTIR)图谱显示硅氧偶联剂改性后,纸的官能团还都存在,说明改性工艺对纸基材未构成破坏.用Scotch胶带方法测试金属和纸张粘附性,发现纸张与金属结合牢固无法分开.还探讨了书写次数与金属图形导电性的关系,发现手写必须达到一定次数才能成功镀上导电性较好的金属图形.     

能源与化学

化学是一门历史悠久的学科，贯穿于数千年人类文明史。中国古代的许多工艺如陶瓷、酿造、染色和金属冶炼等技术都包含着各式各样的化学过程。近代化学更是化工、材料、能源、信息、生命和环境等多个学科的基础。目前全球几大热点论题中，能源问题备受关注．其中很多急需解决的关键课题都强烈依赖于化学的发展。本文将从化石能源、太阳能、水裂解制氢、电化学储存等四个方面，探讨其中与化学相关的问题。     

Intrinsic abnormal electromagnetic medium based on polar lattice vibration

A new class of media with abnormal electromagnetic parameters has been attracting increasing attention because of its exotic properties and potential application. Currently, typical metamaterials are mainly composed of artificially designed metallic periodic structures. However, due to the limitations of available fabrication technologies, physical size and material effects, it is difficult to realize these abnormal properties by these artificial structures in the high-frequency regime. Therefore, it is important to find materials with intrinsic abnormal electromagnetic responses. In this field, a new mechanism based on the interaction between polar lattice vibrations and electromagnetic waves has been proposed. In this paper, we review progress in this field.     

Atomic packing and short-to-medium range order evolution of Zr-Pd metallic glass

A larger-scale Zr₇₀Pd₃₀ alloy system has been simulated using molecular dynamics (MD) to investigate structure evolution in Zr₇₀Pd₃₀ metallic glass. The simulated pair distribution function of Zr₇₀Pd₃₀ metallic glass agrees well with the experimental results. Voronoi polyhedron analysis indicates that the icosahedra are not randomly distributed in space, but form characteristic intercrossed icosahedral clusters with medium-range order. Intercrossed icosahedral clusters are the dominant local configurations in Zr₇₀Pd₃₀ metallic glass and probably cause the quasicrystalline phase discovered in Zr₇₀Pd₃₀ metallic glass.     

专题:多酸化学研究

·编者按·多酸,学名为多金属氧酸盐(polyoxometalates,POMs)或金属-氧簇(metal-oxygen clusters),是指一些前过渡元素(Mo,W,V,Nb,Ta等),以MO6和MO4为单元通过共角、共边桥连缩聚而成的一     

处理金属逸出功实验数据的三种方法

金属逸出功实验数据处理比较麻烦,本文对常用的作图法、最小二乘法、origin软件作图法分别做一介绍。     

Effect of Ni addition on the glass-forming ability and soft-magnetic properties of FeNiBPNb metallic glasses

The effect of Ni addition on the glass-forming ability (GFA) and soft-magnetic properties of an (Fe1-xNix)75.5B14.5P7Nb3 (x=0-0.6) alloy system were investigated. We found that the addition of Ni was effective in allowing the alloy to approach a eutectic point as well as increasing the thermal stability of the supercooled liquid. By increasing the amount of Ni,the supercooled liquid region (ΔTx),the reduced glass transition temperature Trg (Tg/Tl) and the Y parameter [Tx/(Tg+Tl)] increased from 49 to 75 K,0...     

浅析金属屋面施工技术

金属屋面系统适用于大跨公共建筑。对工程实例铝镁锰合金板直立锁边屋面系统进行了详细介绍,阐述了屋面系统的构造、建筑技术要求的适应性、施工技术及质量控制等重点内容,为同类工程的设计提供了参考和借鉴。     

有无填充墙钢管混凝土框架抗震性能对比研究

为了钢管混凝土框架结构在不同荷载作用下抗震性能的分析。通过现场试验的方法,对有无填充墙的两种钢管混凝土框架结构进行了在承载能力、延性、耗能能力以及破坏机制的分析研究。研究结果表明:两种框架结构在进行水平低周反复加载试验,带填充墙矩形钢管混凝土框架结构较无填充墙的框架结构其滞回曲线更加饱满,耗能能力强等抗震性能。该成果对高层钢管混凝土结构具有一定的参考价值和指导意义。