Mechanosynthesis of nanocomposites in TiO2–B2O3–Mg–Al quaternary system

The mechanochemical behavior of TiO₂–B₂O₃–Mg–Al quaternary system to synthesize various composite nanopowders was studied. A mixture of boron oxide and titanium dioxide powders along with different amounts of magnesium and aluminum was milled using a high-energy planetary ball mill to persuade necessary conditions for the occurrence of a mechanically induced self-sustaining reaction (MSR). Results showed that the formation of composite nanopowders was influenced strongly by the reducing agents content. In the absence of Al (100 wt% Mg), TiB₂ nanopowder was formed after 34 min of milling. In the presence of x wt% Mg–y wt% Al (x=40 and 70; y=100−x), mechanical activation was completed after 37–40 min which caused the formation of TiB₂–MgFe_0.6Al_1.4O₄ composite nanopowders. In the case of 10 wt% Mg–90 wt% Al, a ternary nanocomposite (TiB₂–MgAl₂O₄–Al₂O₃) was produced after 43 min of milling. Besides, Al₂O₃–TiB₂ nanocomposite was formed after 90 min of milling in the absence of Mg (100 wt% Al). From the SEM images, mechanochemical process reached a steady state after short milling times where the particles have become homogenized in size and shape. The reaction mechanism steps were proposed to clarify the reactions occurring during mechanochemical process.     

焦炉煤气正、负压HPF脱硫工艺比较

对正、负压HPF脱硫工艺进行工艺特点和经济比较,并对2种工艺的设备、产品、原材料及消耗指标进行了对比,分析可知,操作运行费用2种工艺相当,而建设费用HPF正压脱硫工艺具有优势,因此,正压脱硫在焦化行业中应用广泛。     

Surface modifications of activated carbon by gamma irradiation

Four commercial activated carbons with different chemical and textural characteristics were modified by gamma irradiation under five different conditions: irradiated in absence of water, in presence of ultrapure water, in ultrapure water at pH = 1.0 and 1000 mg L⁻¹ Cl⁻, in ultrapure water at pH = 7.5 and 1000 mg L⁻¹ Br⁻, and in ultrapure water at pH = 12.5 and 1000 mg L⁻¹ NO₃⁻. Changes in surface chemistry were studied by X-ray photoelectron spectroscopy; pH of point of zero charge, total acidic groups and total basic groups, which were determined by assessment with HCl and NaOH; and textural changes were determined by obtaining the corresponding adsorption isotherms of N₂ and CO₂. Outcomes show that the activated carbon surface chemistry can be modified by gamma irradiation and that the changes depend on the irradiation conditions. Modifications in the sp² hybridization of the surface carbons suggest that the irradiated carbons undergo graphitization. Measurements of structural parameters indicate that the irradiation treatment does not modify the textural properties of the carbons. Finally, studies of pristine and irradiated activated carbons using diffuse reflectance spectroscopy with the Kubelka–Munk function revealed a reduction in band gap energy in the irradiated carbons associated with an increase in sp² hybridization of the carbon atoms.     

The interpretation of the English landscape garden between 1815 and 1840 through Xavier Kurten’s work in Piedmont (north-west Italy)

Xavier Kurten (?–1840) was a Prussian landscape gardener who worked for the Savoy family in the Piedmont region of Italy in the first half of the nineteenth century. He designed or redesigned all royal parks, creating a specific style based on the English naturalistic garden approach. This research was performed with the aim of investigating the development of the English landscape garden in Italy. Historical documents relating to Kurten’s biography and his work in Piedmont, including plans, were collected and analysed. We analyse and discuss the features that characterised his work: the relationship between the landscape—garden—house, the path system, the use of water, the vegetation, and the garden as a productive landscape. Kurten’s style is compared with the projects of William Kent and Lancelot ‘Capability’ Brown.     

Nanoinformatics: Emerging Databases and Available Tools

Nanotechnology has arisen as a key player in the field of nanomedicine. Although the use of engineered nanoparticles is rapidly increasing, safety assessment is also important for the beneficial use of new nanomaterials. Considering that the experimental assessment of new nanomaterials is costly and laborious, in silico approaches hold promise. Several major challenges in nanotechnology indicate a need for nanoinformatics. New database initiatives such as ISA-TAB-Nano, caNanoLab, and Nanomaterial Registry will help in data sharing and developing data standards, and, as the amount of nanomaterials data grows, will provide a way to develop methods and tools specific to the nanolevel. In this review, we describe emerging databases and tools that should aid in the progress of nanotechnology research.     

广州市公园对比评价研究——基于社交媒体数据的文本分析

传统公园评价的研究大多集中在单个公园使用满意度方面,存在问卷样本量小、采集时间较集中等缺陷。大数据相关研究的快速发展为公园系统评价提供了新的契机。基于对社交媒体数据的文本分析,研究对比广州市 50 个公园的评价结果,同时探究公园评价与人口统计学特征、地理区位、评价时间以及公园属性之间的关系。研究发现, 1）公园正面评价主要集中在免费设施、环境和特色等方面,而负面评价多集中于公园卫生、交通成本、停车等管理服务方面,广州公园的管理服务水平亟待提升。 2）女性较男性更关注公园能否满足其对社交场所的需求,本地游客较外地游客更关注公园本身的服务质量而非公园的外部属性。 3）基干公园应更侧重其可达性和基本的服务功能,承担大众日常活动;特色公园应更注重满足特定人群的需求及特色打造;自然公园应更关注公园生态质量并能够承担需要较大场地的活动。 4） 2010—2018 年,人们越来越关注公园特色的打造,在公园中的活动类型也越来越多样,现代公园建设更应着力于文化服务质量的提升。研究突破传统公园研究方法的局限,将大数据的手段运用到多个公园的整体评价当中,有助于建立更普适、更有针对性的公园评价指标体系,具有较高的实践价值。     

再生骨料混凝土的开发利用

本文阐述了再生骨料混凝土开发利用的必要性及开发利用情况 ,并且指出了扩大再生骨料混凝土的应用范围 ,必须对再生骨料进行改性以及对再生骨料进行工业化生产 ,并且具体提出了再生骨料改性的参考方案和再生骨料的生产工艺流程     

浅析热拌冷铺沥青混合料的强度形成机理

介绍了热拌冷铺沥青混合料技术的应用及优越性，通过试验分析了冷铺沥青混合料的组成特点与强度形成机理，论证了冷铺沥青混合料的强度与矿粉用量、粘聚力、骨料的摩擦角的关系。     

台州古塔的建筑特色与人文价值

在对台州现存的22座古塔作初步调查的基础上，就古塔的外观造型、内部结构、建筑思想及其文化内涵、艺术价值等方面作出分析，并对保护和利用提出建议。