自升式钻井平台DCS集成配置的研究

自升式钻井平台DCS（集散系统）是平台自动化控制的核心,该系统可以实现对整个平台及其重要设备的状态监测、控制、报警、记录等功能。本文对现有部分自升式钻井平台的DCS配置情况进行分析,致力于形成一种功能相对完善,配置相对合理的集成配套形式,可为自升式钻井平台项目DCS的搭建提供一个有益参考。     

半钢子午胎硫化供汽系统改造

在原有供汽系统等压运行条件下，通过合理改造，加装减温减压装置，将原系统分类内胎锅炉房高压供汽系统和老锅炉房低压供汽系统，以满足半钢子午胎对高压蒸汽的需求，达到缩短硫化时间，提高生产能力的目的。     

火力发电厂仪用压缩空气带水带油探究

采用系统分析、数学及物理计算的方法,对火电厂仪用压缩空气带水带油的原因进行论证,找出最主要原因,并有针对性地采取了预防和改造措施,对改造效果进行了分析与总结。     

定制非周期极化LiNbO3中多频率THz波的产生

描述一种非周期极化结构晶体中多频率太赫兹辐射波的产生.在此非周期结构的LiNbO3,超晶格中,基于飞秒脉冲二阶非线性光学整流效应,模拟多频率模式的太赫兹波形.通过选择最佳畴宽度,得到转换效率基本相等的3个主要太赫兹频率模式.该方法对多频率模式的个数无限制,且有助于多频率激光器中超晶格晶体的设计.     

无线数据中心网络：进展、挑战和展望

随着动态数据流量的迅速增长,庞杂的有线数据中心网络架构给网络扩张、能耗管理和运营维护等方面均带来了巨大的挑战。高速无线技术具有高带宽、动态连接且灵活可控的特征优势,成为一种潜在的数据中心组网解决方案,可以缓解数据中心长期存在的流量拥塞热点问题,减少部署和维护光缆所花费的时间、精力和成本。首先介绍了当前数据中心网络架构的发展趋势,分析比较了毫米波、太赫兹和自由空间光作为无线数据中心网络候选高速无线技术的优缺点。然后深入讨论了当前典型的无线数据中心网络架构,阐述了无线数据中心网络设计和部署面临的挑战,并对其未来发展方向进行了展望。     

A synthetical development approach for rehabilitation assistive smart product–service systems: A case study

Digital transformation (DT), the combination of information, computing, communication and connectivity technologies, which has triggered an effective upgrade of different aspects of market strategy, customer experience etc. Nowadays, rehabilitation assistive devices (RADs) are evolving to be more digital, intelligent and personalized. Digitalization and servitization have fostered to an emerging business model—the smart product–service system (Smart PSS). Therefore, DT of the RADs’ industry advocates not only the design of products and functions, the more important is the management of service processes and resource integration. With the increase in the elderly and disabled population, the requirement for RADs is becoming more urgent. However, research on Smart PSS for RAD is still limited. The rehabilitation assistive smart product–service systems (RASPSS) was introduced into the development of RADs based on the “Design and Management of DT” strategy through the service design of assistive devices and user requirements analysis. Further, an integrated design of RAD and Smart PSS has been created, a development method of RASPSS proposed, the theoretical model of the Smart PSS based on RADs built. To specify the service framework, this case study discusses the development of a home rehabilitation assistive system for femoral stem fracture patients. This paper evaluates the usability of the system, the results of which prove usability and effectiveness of the RASPSS development method. The RASPSS development model is designed to meet needs of stakeholders, improve the user rehabilitation experience, promote the service innovation of Smart PSS, bring certain market benefits of rehabilitation aids and create social value.     

Broadband terahertz spectroscopy of amino acids

Broadband spectra of 20 L-amino acids were obtained at room temperature by terahertz time-domain and infrared spectroscopy. The intensity of terahertz absorption peaks varied with the concentrations of amino acids, and the optimum proportion for each amino acid was obtained. An absorption spectral database of 20 L-amino acids was established from 0 to 6 THz. The associations between terahertz absorption peaks and molecular structures of amino acids were analyzed. The terahertz spectra for L-alanine were compared with the calculated results based on density functional theory using two basis sets that were reliably consistent.     

Enhancing power transfer capability through flexible AC transmission system devices:a review

Global demand for power has significantly increased, but power generation and transmission capacities have not increased proportionally with this demand. As a result, power consumers suffer from variou...     

Cold gas dynamic manufacturing: A non-thermal approach to freeform fabrication

This paper reports on the development of a novel freeform fabrication technique using a cold spray (CS) system. In the CS process, metallic powder particles are accelerated in a supersonic gas jet and impacted with a substrate at speeds in excess of 600 m/s. The non-melting nature of its deposition mechanism ensures that the sprayed material is free from thermally induced tensile stresses, while the underlying substrate remains unchanged. The process is seen as a viable method for additive manufacturing because of its high deposition rates and controllable spray jet. A process was developed to investigate the potential of non-thermal freeform fabrication and was coined Cold Gas Dynamic Manufacturing (CGDM). Here, additive and subtractive techniques were combined to enable the production of complex geometries. Whereas most CS facilities concentrate on the application of wear or corrosion-resistant coatings, CGDM is dedicated to the production of freeform components, whilst still retaining an inherent coating ability. The process can produce functional forms using novel manufacturing strategies that are unique to CS. This paper presents information on the process, and details the various strategies employed during component fabrication. It was possible to construct components from many materials, including titanium, which exhibited freeform surfaces, internal channels and embedded devices. A breakdown of the process economics is also provided, with and without helium recycling.     

Er-doped SiO2–Al2O3 thin films prepared by the sol–gel route

The synthesis of homogeneous and pure silica–alumina binary glasses doped with rare-earth (RE) ions such as Er³⁺ is currently a key challenge for the development of integrated optics devices such as lasers, optical amplifiers or waveguides. In this study Er³⁺-doped SiO₂–Al₂O₃ films were prepared by the sol–gel route. Aluminium sec-butoxide, Al(O-sec-C₄H₉)₃ (ASB), and tetraethoxysilane, Si(OC₂H₅)₄ (TEOS), were used as glass oxide precursors, whereas erbium was introduced as Er(NO₃)₃. The alumina content in the silica matrix was 10 at.%, while erbium doping ranged between 200 and 5000 ppm. The preparation of the starting sol–gel solution and the layer deposition by a dip-coating procedure were performed in dry-box under nitrogen atmosphere. The obtained films were subsequently annealed in air between 300 and 1000 °C. After treatment at 500 °C, layers 200 nm thick were obtained. The composition, microstructure and surface morphology of the films were investigated by X-ray photoelectron spectroscopy (XPS), secondary-ion mass spectrometry (SIMS), glancing incidence X-ray diffraction (GIXRD) and atomic force microscopy (AFM). Crack-free, transparent, high purity films were obtained, characterised by compositional and microstructural homogeneity.