橡胶颗粒再生混凝抗拉和抗折性能试验研究

通过在再生混凝土中加入一定掺量的废弃橡胶颗粒,研究橡胶颗粒的掺量对其抗拉和抗折强度的影响。研究发现:当再生混凝土中橡胶颗粒的掺量为3%时,混凝土的抗拉和抗折强度都有一定幅度的增长,分别增长2.58%和1.54%;出现这种情况的原因是由于橡胶颗粒具有较好的抗拉性能和延性,掺入到混凝土中可以起到连接骨料的作用,可以增加混凝土的抗拉和抗折性能,且再生混凝土中橡胶颗粒在本试验中的最佳掺量为3%。     

Induced modi fi cations in the properties of Sr doped BiFeO3 multiferr oics

Multiferroics exhibit unique combination of ferroic properties,simultaneously.For instance,in BiFeO3,magnetic and electric properties co-exist.In this work,BiFeO3 and Sr-doped BiFeO3 samples with general formula,Bi1-x Srx FeO3(x=0.00,0.05,0.10,0.20,and 0.30) were synthesized by sol-gel auto-combustion technique,in order to investigate these ferroic properties.The samples were confrmed to have perovskite type rhombohedral structure,characteristic of BiFeO3.A dilute phase of Bi2Fe4O9was also found in all the Sr-doped samples.The micrographs of the palletized samples revealed that minutely doped Sr might not have any effect on the morphology of the samples.Frequency dependent dielectric measurements were carried out at room temperature for all the samples from 100 Hz to 1 MHz.The dielectric constant of un-doped sample at low frequency was 52 which decreased with increasing Sr doping.An enhancement of magnetic properties was observed with increasing the Sr contents.Pure BiFeO3 material was observed to have the least value of remanent magnetization.As the Sr2+ tions were doped in BiFeO3,its magnetization and remanence were increased to 0.867 emu/g and 0.175 emu/g,respectively,at x=0.30.     

Preface from guest editors

<正>1.Nanomaterials and device It has been widely accepted that,when a material comes to low dimensions,for example,0D quantum dots and hetero-nanocrystals,1D nanowires and nanotubes,2D nanosheets,and 3D hierarchical or branched nanostructures,the associated physical properties will differ from their bulk counterparts,and subsequently will render enhanced or emergent functions.This has generated a fascinating field of"nanomaterials and devices".It is a     

目前我国纳米科技发展状况

从纳米科技的基本概念出发,介绍了纳米材料的特殊性能及其制备方法、表征技术,并综述了纳米科技在我国产业革命的应用发展前景.     

MnOx纳米材料的合成及其在染料废水处理中的应用

利用乙醇还原高锰酸钾制得纳米锰氧化物,借助能谱分析（EDS）和扫描电镜（SEM）对产物的晶相及形貌进行了表征.并以锰氧化物为吸附剂,研究了其对亚甲基蓝的动力学、吸附平衡的影响.结果表明：所制得的锰氧化物为无规则状纳米颗粒,吸附平衡更符合Langmuir等温模型,最大吸附量为228.31mg·g-1.     

Recent advances in functional nanomaterials for X-ray triggered cancer therapy

X-ray is a form of ionizing radiation with high energy and strong tissue-penetrability, which has been widely used for cancer therapy, including radiation therapy (RT) as one of the mainstream cancer treatments and radiodynamic therapy (RDT) as an emerging treatment modality. However, the nonspecific absorption of X-ray and peculiar tumor microenvironment would lead to the unsatisfied therapeutic effect and severe damage to normal tissues. The fast progress of nanotechnology has provided great opportunities for the development of functional nanoparticles and strategies to solve these problems. In this review, we will summarize the recent advances in functional nanomaterials and the related strategies, discuss how they solve the challenges in order to improve the therapeutic efficacy and safety of RT and RDT, and moreover comment on the challenges and prospects for efficient X-ray triggered cancer therapy based on nanomedicine.     

层状双氢氧化物纳米材料的研究进展

层状双氢氧化物(LDHs)的成分可以在较大范围内调控、特殊的结构和性质以及有着广泛的应用前景,层状双氢氧化物纳米材料的研究吸引了国内外众多学者的关注。本文首先介绍了LDHs的化学组成和结构特点,然后综述了LDHs纳米材料的制备、结构表征及性能等方面的国内外最新研究进展,并阐述了纳米晶植入LDHs主体的复合材料的相关研究,最后对其应用前景进行了展望。     

Nanomaterials for renewable hydrogen production, storage and utilization

An ever growing demand for energy coupled with increasing pollution is forcing us to seek environmentally clean alternative energy resources to substitute fossil fuels. The rapid development of nanomaterials has opened up new avenues for the conversion and utilization of renewable energy. This article reviews nanostructured materials designed for selected applications in renewable energy conversion and utilization. The review is based on the authors’ research, with particular focus on solar hydrogen production, hydrogen storage and hydrogen utilization. The topics include photoelectrochemical (PEC) water splitting and photocatalytic hydrogen production, solid-state hydrogen storage, and proton exchange membrane fuel cells (PEMFCs). It is expected that the rational design of nanomaterials could play an important role in achieving a renewable energy based economy in the coming decades.     

硫化镉纳米材料对罗丹明B溶液的光催化降解性能

以氯化镉和硫脲为原料,以乙二胺和水为混合溶剂,采用溶剂热合成方法,在120oC和12h条件下,制得了六方相硫化镉样品,对其进行了XRD和TEM表征。以罗丹明B的降解为模型反应,对硫化镉纳米材料的光催化性能进行了研究,讨论了硫化镉的用量、降解体系的酸度及光源类型等因素对降解效果的影响。随着降解体系酸度的增加,硫化镉对罗丹明B溶液的光催化降解效果呈增大的趋势;太阳光照射下,罗丹明B溶液的降解效果好于250 W汞灯照射时的降解效果。     

Gas-Solution Interface Technique as a simple method to produce inorganic microtubes with scroll morphology

Over the past decade, numerous studies have dealt with new properties of inorganic nanomaterials with improved characteristics due to a particular morphology, and new facile methods to produce such materials have been reported. Inorganic microtubes can be designed for multifunctional materials with highly specific surface area. These microtubes can act as individual on-chip components of miniature devices or off-chip micromachines. The paper first discusses the main regularities of the reactions at the gas-solution interface and then goes on to present the basic principles of the Gas-Solution Interface Technique(GSIT), thus demonstrating a new way of facile synthesis of inorganic rolled-up microtubes. A distinctive feature of the technique is the formation of a gradient solid layer on the surface of the aqueous solution as a result of the gaseous and liquid reagents interaction. When dried in the air, this thin layer is capable of self-folding into microtubes with specific morphology. The paper considers the specific features of microtubes obtained by GSIT from numerous classes of inorganic compounds, including oxides, hydroxides, sulfides, fluorides. Further areas of possible practical applications of GSIT microtubes are discussed. The prospects of future development of the GSIT are outlined.