超低能耗建筑发展现状及关键技术

当前,超低能耗建筑已成为国内外行业建筑节能发展趋势。本文从技术原理、标准、政策、示范项目等方面介绍了超低能耗建筑的发展现状,并梳理了寒冷地区超低能耗建筑技术体系,为推广落地超低能耗建筑项目奠定了基础。     

超高层钢结构转换层施工技术

广州珠江新城J2-2地块项目超高层钢结构转换层施工技术,采取厂内实体卧拼和计算机模拟预拼互验规则;优化后,可直接采用计算机模拟验收。桁架层超重构件吊装、定位、焊接等关键施工工段,采取相应的施工措施,保证施工质量及精度。为超高层钢结构转换层施工积累了宝贵的经验。     

开拓国内市场前景广阔

中国是全球最大的玩具生产国和出口国。据有关机构提供的数据显示，中国现有玩具生产企业8000余家，其中规模以上的玩具制造企业也有上千家，玩具业从业人员350多万人，可谓相当庞大的产业。然而中国玩具业依旧停留在劳动密集型的产业现状，缺少自主设计研发，缺少品牌效应，因而产品的附加值也不会有很大的提高，出口到国际市场利润也相应很低。     

The effect of addition of flaxseed gum on the emulsion properties of soybean protein isolate (SPI)

The effect of addition of flaxseed gum on the emulsion properties of soybean protein isolate (SPI) were investigated in this study. Flaxseed gum with 0.05-0.5% (w/v) concentration was used together with 1% (w/v) SPI to emulsify 10% (v/v) soybean oil. The emulsion was analyzed for emulsion activity (turbidity), stability, particle size, surface charge, and rheological properties. The turbidity and absolute zeta-potential values decreased initially by the addition of flaxseed gum and subsequently increased with further increase in the gum concentration to reach their peak around 0.35% (w/v) gum. The particle size of the emulsion decreased and reached a minimum value at 0.1% (w/v) gum concentration. Any increase in gum concentration beyond this value resulted into increase in the particle size. This study would help to widen the application of SPI and flaxseed gum mixture, and also contribute to the understanding of protein-gum interaction in emulsion.     

孔口缝合补强对层间应力影响的数值模拟

使用空间杆单元模拟缝合线,对含孔复合材料层合板开口缝合补强结构进行有限元模拟计算。研究含孔复合材料层合板在轴向拉伸载荷作用下,圆孔附近各个铺层交界面处层间正应力和剪应力的分布情况,将缝合后的层间应力值与缝合前的相关数值进行比较,并研究不同缝合参数(针距、行距、边距、单缝合和双缝合)对孔边层间应力的影响。结果表明,缝合补强后孔边的层间应力明显减小。孔边附近层间应力的分布与相邻铺层的铺层角有很大关系,不同铺层之间的层间应力有显著差别。不同铺层之间的层间应力沿孔边区域存在应力转换点(即层间应力由正值变为负值)。     

Design method and machine learning application of acoustic holographic computational metamaterials

Science China Technological Sciences -     

Fabrication and performance evaluation of planar solid oxide fuel cell with large active reaction area

Anode-supported planar solid oxide fuel cells (SOFCs) with dimension from 5 × 5 cm² to 15 × 15 cm² have been successfully fabricated by tape casting, screen-printing and single-step co-firing technologies, which shows a potential way of cost-effective for mass production. The performance of the cells has been investigated at operating temperature between 650 °C and 750 °C. The typical cell with dimension of 10 × 10 cm² (active reaction area of 9 × 9 cm²) obtained open circuit voltage (OCV) of 1.15 V and power density of 770 mW/cm² at current density of 950 mA/cm² at 750 °C. The performance degradation of the cell is lower than 1.56%/1000 h. When external reformed methane gas was used as fuel, the cell showed no obvious performance decrease compared to that using pure hydrogen as fuel. The test results have demonstrated that the as-prepared large size cells have excellent performance and reliability, which is ready for SOFC stack assembly.     

基于混合GEP的配电低压台区综合评价算法*

配电低压台区的综合评价对于智能配电网的运行监控至关重要。针对现有的这些配电网综合评估方法存在主观性强、评价指标体系复杂多样等问题,提出了基于混合基因表达式编程的配电低压台区综合评价算法。首先利用粗糙集的思想,通过对综合评价决策表依赖度的计算快速求解最优约简。在此基础上,利用基因表达式编程挖掘配电低压台区综合评价函数,最后基于该函数模型达到评价和预测配电低压台区运行状态的目的。仿真实验表明,对于复杂高维的配电低压台区综合评价决策信息,所提出的算法具有较高的挖掘效率和预测准确率,同时具有较强的实用性。     

Exploring link generation in a temporal evolution network for human mobility

The prevalence of mobile devices has spurred human mobility to be applied in mobile networking and communications by using network science, in which the temporal evolution of a network topology is of great importance for protocol design and performance analysis. This paper focuses on link generation in a temporal evolution network. Based on observations revealing the strong correlation between the connection patterns of different time periods, a link generation potential based on historical connections is proposed in this paper, aiming to provide a method for making topological predictions with less randomness. Using MIT Reality dataset, an evaluation of the accuracy of the proposed method was conducted. The experimental results demonstrate the proposal’s adequacy in terms of its accuracy.     

微波加热在纱线烘干中的应用

介绍了微波加热的基本原理、特点以及影响微波加热的因素,与蒸汽烘干、射频烘干相比,微波加热比蒸汽烘干节能40％,比射频烘干节能20％,仅每年运营维护费用比射频烘干节省4．5万元。提出应重点加强微波与物料间相互作用理论、微波场中物料的传热、传质机制,微波加热工艺与设备、微波加热技术与其它技术的有机结合等方面的研究。