Development and performance test of a miniature movable mixed-refrigerant liquid nitrogen generator

In order to cover long-term but small quantity liquid nitrogen requirements of laboratory or field users, a miniature movable mixed-refrigerant liquid nitrogen generator (MRLN) was developed and tested here, based on a precooled mixed-refrigerant J-T (MRJT) refrigerator. With the full air-cooled, skid-mounted structure, this MRLN was built utilizing off-the-shelf refrigeration components like commercial single-stage oil-lubricated compressors to reduce construction cost greatly. Bottled pure N₂, pressure swing adsorption (PSA) unit and mini cryogenic rectification column could be employed to supply N₂ in different operation modes respectively. In pure N₂ mode, N₂ was directly liquefied by the MRJT refrigerator. With feed N₂ at 0.8 MPa, the specific power consumption (SPC) was 1.79 kWh L⁻¹, and figure of merit (FOM) was 6.27%. The estimated SPC in PSA mode was 2.68 kWh L⁻¹. For column mode, the SPC was 4.59 kWh L⁻¹, with FOM of 3.38%. A closed N₂ cycle could convey cooling capacity between flammable refrigerant and air. This MRLN could be a convenient and low-costing choice for some liquid nitrogen users.     

An operational high temperature thermal energy storage system using magnesium iron hydride

Metal hydrides have been demonstrated as energy storage materials for thermal battery applications. This is due to the high energy density associated with the reversible thermochemical reaction between metals and hydrogen. Magnesium iron hydride (Mg₂FeH₆) is one such material that has been identified as a thermal energy storage material due to its reversible hydrogenation reaction at temperatures between 400 and 600 °C. This study demonstates an automated thermal battery prototype containing 900 g of Mg₂FeH₆ as the thermal energy storage material with pressurised water acting as the heat transfer fluid to charge and discharge the battery. The operating conditions of the system were optimised by assessing the ideal operating temperature, flow rate of the heat transfer fluid, and hydrogen pressures. Overall, excellent cyclic energy storage reversibility was demonstrated between 410 and 450 °C with a maximum energy capacity of 1650 kJ which is 87% of the theoretical value (1890 kJ).     

Highly durable,Pt free and large-area Ni–B film synthesized by SILAR as a bifunctional electrode for electrochemical water splitting

A search for efficient, durable, large-area, and economic catalyst material for low-cost production of hydrogen and oxygen is currently a high priority in the field of electrocatalysis (EC). In view of this, a cost-effective, earth abundant, highly stable, Pt free, and large-area (8 cm × 8 cm) bifunctional Ni–B electrocatalyst is reported via simple and economic SILAR method. A highly porous surface of Ni–B film with high surface wettability indicated better electrochemical water-splitting properties for the films and is obtained at 100 cycles. A Low over-potential value to obtain HER (49 mV) and OER (340 mV) at 10 mA/cm² current suggested that they are comparable to the well-known Pt and RuO electrodes in alkaline medium (1M KOH), respectively. In actual water-splitting setup having Ni–B film (as cathode) and stainless steel (as anode), the hydrogen production of 612 ml/h is obtained at constant potential, which was enhanced by 18% i.e., 726 ml/h when a Ni–B film as both cathode and anode electrode was used. Both the electrodes are highly stable for over 15 days and interestingly they showed 7% increment in the EC performance.     

论采矿CAD开发方法及环境与工具选择

文章简单回顾和总结了采矿CAD技术在我国发展的过程，现状及存在的问题。指出了进行采矿CAD开发方法及环境与工具选择研究的必要性和重要意义。在综合分析了我国具有代表性的采矿CAD软件的基础上，针对采矿工作的特点．建议采用原型化法进行开发。并注意选择与之相适应的环境与工具。AutoCAD为支持环境与工具进行二次开发是一种较为经济和理想的开发方法，值得推广提倡。     

船屋文化：海南黎族传统民居探源

从文化心理行为模式的角度对黎族民居空间及造型形成过程进行了探讨。认为人类在塑造自己生存立足的场所时一直伴随着对意义的追求，人赋予建筑的表征意义在很大程度上决定了建筑空间及造型的可识别性特性，构成了场所感，成为特定地域、特定场所的一种文化“原型”识别性标志。     

建筑生长的意义——三峡学院图书馆新馆的创作理念

将建筑视为一个有机体,从生长的理念出发,借助实例阐述了建筑生长的涵义,探讨了建筑生长原形确定、生长的方式和过程,并将"生长"作为建筑更新设计的一种方式.     

管状交通空间--一种建筑空间组织的原型

抓住建筑中人的运动流线，运用原型理论对建筑空间组织的规律进行研究，试图从错综复杂的空间组织形式中归纳出建筑空间组合的原型——“管状交通空间”，并探讨它在建筑设计中的作用。     

基于类型学方法的现代园林景观文脉传承研究

景观文脉的传承始终是当代风景园林师关注的一大课题.现阶段,我国的园林建设面临盲目西化和符号化倾向,造成传统景观文脉严重缺失.该文在梳理建筑类型学核心理论的基础上,通过适用性分析,论证类型学方法对于解决文脉传承问题的有效性,进而将类型学方法移植至园林景观领域,结合我国的具体历史和地域文化条件,对类型学设计模式中的类型选择和类型转换进行了详尽的阐释和分析,旨在为现代园林设计中的景观文脉传承研究提供一种全新的思路.     

A secure and quality-aware prototypical architecture for the Internet of Things

The increasing diffusion of services enabled by Internet of Things (IoT) technologies raises several risks associated to security and data quality. Together with the high number of heterogeneous interconnected devices, this creates scalability issues, thereby calling for a flexible middleware platform able to deal with both security threats and data quality issues in a dynamic IoT environment. In this paper a lightweight and cross-domain prototype of a distributed architecture for IoT is presented, providing minimum data caching functionality and in-memory data processing. A number of supporting algorithms for the assessment of data quality and security are presented and discussed. In the presented system, users can request services on the basis of a publish/subscribe mechanism, data from IoT devices being filtered according to users requirements in terms of security and quality. The prototype is validated in an experimental setting characterized by the usage of real-time open data feeds presenting different levels of reliability, quality and security.