大比例尺构造岩相学填图理论创新、技术研发与发展方向

国家社会需求是构造岩相学创新技术研发和理论创新的动力源泉,构造岩相学填图技术研发过程推动了理论创新实现,逐渐形成了"五步式"研发范式为:解剖建相与技术研发→应用试验和深度研发→示范应用和理论创新→推广示范和普适验证→集成创新和融合建模。经对盆山原镶嵌构造区重要金属成矿盆地进行基底构造层(前盆地期)、成盆期、盆地改造期、盆内岩浆叠加期、盆地表生变化期与成岩相系的构造岩相学和地球化学岩相学综合研究,取得主要进展为:建立了沉积盆地内成岩相系划分新方案,创建了盆地构造变形史研究新方法,揭示了构造-岩浆-热事件形成机制,创建了复杂叠加成矿系统的构造岩相学解析研究方法技术,提出了"还原性流体成矿与预测"新理论,将塔西盆山原镶嵌构造区砂砾岩型铜铅锌成矿系统划分为三个成矿亚系统,开拓了盆山原镶嵌构造区研究的新领域。在回顾前期大比例尺构造岩相学填图创新技术研发和理论创新研究基础上,认为聚焦于矿山和金属矿集区的生态环境资源等国家需求,探索构造岩相学与深部地球物理等多学科综合探测和融合预测建模、基于人工智能与大数据平台技术进行创新技术研发和理论创新研究等是今后主要发展方向。     

Multi-objective design of vehicle suspension systems via a local diffusion genetic algorithm for disjoint Pareto frontiers

This article presents a multi-objective design optimization study of a vehicle suspension system with passive variable stiffness and active damping. Design of suspension systems is particularly challenging when the effective mass of the vehicle is subject to considerable variation during service. Perfectly maintaining the suspension performance under the variable load typically requires a controlled actuator to emulate variable stiffness. This is typically done through a hydraulic or pneumatic system, which can be too costly for small/medium pick-up trucks. The system in this article employs two springs with an offset to the second spring so that it engages during large deformation only, thereby providing passive variable stiffness without expensive hydraulics. The system damping is assumed to be controlled via variable viscosity magnetizable fluid, which can be implemented in a compact, low-power set-up. Performance indices from the literature are evaluated at minimum and maximum weight, and regarded as objectives in a multi-objective problem. As the individual objectives are prone to having local optima, the multi-objective problem is prone to having a disjointed Pareto-space. To deal with this issue, a modification is proposed to a multi-objective genetic algorithm. The algorithm performance is investigated via analytical test functions as well as the design case of the suspension system.     

文献分析视角下我国城乡规划学科研究动态

以《城市规划学刊》《规划师》《国际城市规划》为文献来源,依托中国知网(CNKI)文献计量可视化平台,分析以上期刊文献的关键词、文献共被引、文献指数等,结合对近3年相关中央文件的解读,总结我国城乡规划研究动态:①整体研究趋势为经典问题始终延续、前沿问题不断涌现;②经典问题包括:法定规划、问题导向的城市设计、国情政策导向的城镇化研究;③涌现的前沿问题包括新型城镇化、生态城市、旅游规划、产城融合;④未来研究趋势一方面延续新型城镇化、生态城市等领域的研究,另一方面将展开对乡村的系统性研究、对本土规划理论的构建以及健康与安全城市研究。     

Applications of additive manufacturing (AM) in sustainable energy generation and battle against COVID-19 pandemic: The knowledge evolution of 3D printing

Sustainable and cleaner manufacturing systems have found broad applications in industrial processes, especially aerospace, automotive and power generation. Conventional manufacturing methods are highly unsustainable regarding carbon emissions, energy consumption, material wastage, costly shipment and complex supply management. Besides, during global COVID-19 pandemic, advanced fabrication and management strategies were extremely required to fulfill the shortfall of basic and medical emergency supplies. Three-dimensional printing (3DP) reduces global energy consumption and CO₂ emissions related to industrial manufacturing. Various renewable energy harvesting mechanisms utilizing solar, wind, tidal and human potential have been fabricated through additive manufacturing. 3D printing aided the manufacturing companies in combating the deficiencies of medical healthcare devices for patients and professionals globally. In this regard, 3D printed medical face shields, respiratory masks, personal protective equipment, PLA-based recyclable air filtration masks, additively manufactured ideal tissue models and new information technology (IT) based rapid manufacturing are some significant contributions of 3DP. Furthermore, a bibliometric study of 3D printing research was conducted in CiteSpace. The most influential keywords and latest research frontiers were found and the 3DP knowledge was categorized into 10 diverse research themes. The potential challenges incurred by AM industry during the pandemic were categorized in terms of design, safety, manufacturing, certification and legal issues. Significantly, this study highlights the versatile role of 3DP in battle against COVID-19 pandemic and provides up-to-date research frontiers, leading the readers to focus on the current hurdles encountered by AM industry, henceforth conduct further investigations to enhance 3DP technology.     

2017年国际人工智能领域研究前沿的分析与研究

文献共被引可以为目标领域研究前沿的分析研究提供一种更加客观、全面的研究视角。文中利用文献共被引分析对2017年国际上人工智能领域的131篇ESI高被引论文进行分析,探寻得到了2017年该领域中包含的12个研究前沿和2个重点研究前沿。通过对研究前沿中核心论文的进一步研究发现,在2017年国际人工智能领域的多个研究前沿中,我国的学者已经成长为中坚力量,发挥着重要的作用。相比而言,在深度学习的两个重点研究前沿中,我国还缺乏高质量核心论文的产出者,这也激励着我国学者不断为之努力。     

现代制造科学展望

制造科学在２１世纪将发生深刻的变革,制造对象、制造材料、制造手段和制造环境的不断变化,为制造科学带来新的挑战和课题。简要介绍制造科学的研究现状和发展趋势,制造科学在２１世纪的前沿研究领域,以及我国制造科学的发展战略。     

机械工程学科“十五”优先领域构想

指出了现代机械工程科学前沿的显著特征 :一方面 ,它与信息技术、材料科学、生命科学和管理科学相交叉 ;另一方面 ,它在创造性地解决机械工程关键科学问题的过程中得到发展。提出了国家自然科学基金委员会机械工程学科“十五”优先资助领域的遴选原则和学科“十五”优先领域的构想。     

西部探区典型储层特征分析及物探技术思考

通过对西部新区各区块成藏条件和富集规律的分析认为!岩溶’深层白云岩’准噶尔盆地岩性油气藏’山前带复杂构造等是本区典型的储集体#首先从靶区的地质条件出发!对典型地质体的储层特征!特别是形成的地质条件进行了分析!在此基础上进行了物探技术思考#针对岩溶地质体的研究指出!高品质的三维叠前时间偏移地震资料是其识别的基础"深层白云岩储层成像应关注目的层以上地质体各向异性的影响"准噶尔盆地岩性油气藏勘探要求有较高的地震资料分辨率!储层预测识别中应加强各种物探’地质方法技术的综合应用"针对山前带复杂构造!应从高陡构造出发!探讨开展大面元三维地震勘探的可行性和必要性!同时在地震资料的解释过 程中!要加强应力机制探讨和地质建模分析!结合物探与地质开展高陡复杂构造区的地震资料解释     

Assessing Panamanian hospitals' performance with alternative frontier methods

In the last decades, there has been a growing interest in measuring the efficiency of hospitals using different methodological approaches, mainly represented by data envelopment analysis (DEA) and stochastic frontier analysis (SFA). In this study, we estimate efficiency measures of performance for a sample of Panamanian public hospitals over an 11-year period (2005–2015) using both traditional methods (DEA and SFA) and compare them with efficiencies estimated with an alternative approach, the so-called StoNED (stochastic semi-nonparametric envelopment of data), which combines the virtues of those methods in a unified framework. One of the most interesting features of the public health system in Panama is that it is segmented, as hospitals are operating under two parallel management schemes (the Ministry of Health and the Social Security Fund), thus in our empirical analysis we will also focus on exploring the differences between hospitals operating under each regime. Our results show that there are certain divergences in the efficiency scores estimated with different methodologies, but for all of them it is possible to detect that Panamanian hospitals experienced a clear decrease in their efficiency levels throughout the period evaluated, being this much higher in the hospitals belonging to the Social Security Fund.     

基因工程的发展与研究前沿

本文介绍了基因工程的创立与发展,简要叙述了基因工程的理论基础和基本过程,并着重介绍了基因工程的最新研究成果和研究前沿．