高分子材料导热性能影响因素研究进展

介绍了高分子材料导热性能影响因素研究进展，重点阐释了聚合物基体的结构特性（链结构、分子间相互作用、取向、结晶度等）、导热填料（种类、含量、形态、尺寸等）以及制备方法等对高分子材料导热性能的影响。     

生物质基喷气燃料的生产及应用进展

生物质基喷气燃料是指全部或大部分来源于生物资源的喷气燃料，符合清洁低碳、安全高效的现代能源体系的要求。以生物质基喷气燃料替代传统石油基喷气燃料有助于我国早日实现“碳达峰、碳中和”的远大目标。在阐述生物质基喷气燃料生产工艺的发展历程及生物质基喷气燃料应用现状的基础上，提出高密度的生物质基喷气燃料是未来喷气燃料的发展方向，具有多环结构的生物质是合成高密度生物质基喷气燃料组分的优质原料；同时，总结了高密度生物质基喷气燃料组分生产工艺的研究进展，展望了生物质基喷气燃料未来的发展及挑战。     

基于立体定向靶标的探针式多视场三维视觉测量系统

针对含有遮挡区域、深孔及凹槽等特征的多面体或回转体物体，设计了一套基于立体定向靶标的探针式多视场三维视觉测量系统，并阐述该套测量系统的结构组成和基本工作原理。首先，基于近景摄影测量技术建立立体定向靶标的6个单元模型，计算靶标各侧面角点在各自单元模型内的坐标，再通过单元模型的链接和光束平差，获取全部角点的精确全局坐标，并将其作为立体定向靶标的全局控制点。然后，设计了利用共面角点辅助定位的探针，仍基于近景摄影测量技术解算出角点和测头在探针坐标系中的精确坐标。最后，利用共面的棋盘格角点与其像平面之间的单应性矩阵，推导全局坐标系、探针坐标系各自与相机坐标系的位姿关系，进而求得探针测头的全局坐标。以量块（量棒）的标准长度作为评价指标，在2m×1.5m的视场范围内测量精度优于0.1mm。测量实验表明，多视场三维视觉测量系统用于具有回转体结构特征的水壶测量，能够获取水壶表面全部区域的点云数据。     

Competitive growth of Al2O3/YAG/ZrO2 eutectic ceramics during directional solidification: Effect of interfacial energy

The microstructure evolution and growth behavior of the Al₂O₃/Y₃Al₅O₁₂(YAG)/ZrO₂ ternary eutectic ceramics during directional solidification were well investigated. During directional solidification of the Al₂O₃/YAG/ZrO₂ ternary eutectic ceramics, {} Al₂O₃ paralleled with {001}ZrO₂ while they did not parallel with {001}YAG at the same time in the competitive growth stage. All of the interfaces parallel to each other finally. The area percentage of the Al₂O₃/ZrO₂ and YAG/ZrO₂ interfaces are 40.4 ± 0.2% and 30.8 ± 0.1%, respectively, higher than that of the Al₂O₃/YAG (28.8 ± 0.2%). The content of Al₂O₃ and YAG phases are 39.9% and 41.1%, respectively, almost double of that of ZrO₂. The interfaces of Al₂O₃/ZrO₂ and YAG/ZrO₂ are shorter and more dispersed than that of the Al₂O₃/YAG. It was found that the interfacial energy of Al₂O₃/ZrO₂ and YAG/ZrO₂ interfaces are lower than that of Al₂O₃/YAG. It can be concluded that interfacial energy plays a decisive role in affecting the crystallographic orientation and interfaces distribution in the Al₂O₃/YAG/ZrO₂ eutectic since the interfaces of Al₂O₃/ZrO₂ and YAG/ZrO₂ with lower interfacial energy can be formed more easily during directional solidification. Therefore, the contents of Al₂O₃/ZrO₂ and YAG/ZrO₂ interfaces are higher. This study can provide theoretical guidance for interface design of multi-phase materials.     

新发展阶段中国水资源安全保障战略对策

进入新发展阶段，中国水资源安全保障需要以“节水优先、空间均衡、系统治理、两手发力”治水思路为指导，厘清问题、研判趋势、优化对策，支撑新阶段水利高质量发展。本文在全面分析我国水资源安全保障存在的突出问题与面临形势基础上，阐述了新发展阶段中国水资源安全保障的基本思路与战略路径，从保证资源安全、构建国家水网、强化供水保障、建设美丽河湖、改善水环境质量等方面提出了战略对策和需要进一步回答的重大问题，以期为完善新发展阶段中国水资源安全保障战略，全面提高国家水资源安全保障能力提供有力支撑。     

热定形对并列复合再生聚酯短纤维性能的影响

以再生聚酯瓶片料和泡料混合料为原料进行并列复合纺丝,并经后纺工艺处理得到并列复合再生聚酯短纤维。通过对纤维进行干热定形,研究热定形温度、时间对并列复合再生聚酯短纤的强伸性能、卷曲性能和热收缩性能的影响。结果表明:聚酯短纤维的断裂强度和断裂伸长率随着热定形温度升高而增大;断裂强度随热定形时间的延长逐渐下降,断裂伸长率先增大后减小,在20 min时达到最大值,为17.4%,声速取向因子则随着热定形时间的延长呈现下降趋势。纤维的卷曲性能随着热定形温度的升高而改善,较短的时间内,纤维的卷曲性能已经达到最佳;热定形温度的升高使纤维的热收缩率增大;并列复合再生聚酯短纤维的最佳热定形温度是140～160℃,最佳定形时间为10 min。     

Rayleigh-Type Wave in A Rotated Piezoelectric Crystal Imperfectly Bonded on a Dielectric Substrate

Propagation characteristics of Rayleigh-type wave in a piezoelectric layered system are theoretically investigated. The piezoelectric layer is considered as a cubic crystal with finite thickness rotated about Y-axis and is imperfectly bonded onto a semi-infinite dielectric substrate. The imperfect interface between the two constituents is assumed to be mechanically compliant and dielectrically weakly conducting. The exact dispersion relations for electrically open or shorted boundary conditions are obtained. The numerical results show that the phase velocity of Rayleigh-type wave is symmetric with respect to the cut orientation of 45。 and can achieve the maximum propagation speed in this orientation. The mechanical imperfection plays an important role in the dispersion relations, further the normal imperfection can produce a significant reduction of phase velocity comparing with the tangential imperfection. Comparing with the mechanical imperfection the electrical imperfection makes a relatively small reduction of phase velocity of Rayleigh-type wave. The obtained results can provide some fundamentals for understanding of piezoelectric semiconductor and for design and application of piezoelectric surface acoustic wave devices.     

Misconceptions of human factors concepts

Abstract

Like many scientific topics, Human Factors, and Ergonomics concepts are susceptible to being misunderstood by people unfamiliar with the subject matter. Most of the time these misunderstandings are harmless, like when a safety poster within a work setting encourages employees to 'overcome complacency'. This misunderstanding of complacency suggests it is a motivational aspect of human behaviour correctable with encouragement, whereas the human factors approach to overcoming complacency would be to evaluate how task design could diminish the destructive consequences of unexpected changes within a routine setting. No harm comes from the message within the safety poster, other than some wasted ink and paper, but misconceptions among particular audiences can eventually result in dire consequences for the human operator. This paper presents recent evidence that the concepts are being misapplied by casual consumers of human factors, particularly in the aftermath of accidents within complex systems, in ways detrimental to the core mission of improving the well-being of the human operator. Later, because this special issue presents new ways to demonstrate value via return on investment, practical efforts we can take to overcome such misconceptions are suggested.     

分子生物技术在果汁鉴伪中应用的研究现状

为探究传统发酵牦牛酸奶及奶酪中细菌群落结构的多样性，采用Illumina Miseq高通量测序对西藏林芝传统自然发酵牦牛酸奶（sn）和酪乳（nl）样品进行细菌群落结构分析。结果表明，酪乳和酸奶样品总计测得有效序列条数分别为（58 455±1 145）条和（57 068±1 263）条，共产生（63±2）个和（25±3）个操作分类单元（OTUs）。酪乳样品的α多样性指较高，具有较高的细菌群落多样性；酸奶和酪乳样品细菌的优势细菌门均为厚壁菌门（Firmicutes），其相对丰度分别为（99.80±3.47）%和（50.76±2.13）%；酸奶样品的优势菌属为乳杆菌属（Lactobacillus）（相对丰度为（74.32±1.23）%），酪乳样品的优势属为乳球菌属（Lactococcus）（相对丰度为（48.44±2.13）%）；酸奶和酪乳样品在属水平的热图分析表明两个样品的细菌群落结构具有差异性和相似性。     

无轨辅助运输现状及发展前景

随着现代化矿井的高产高效,井下无轨辅助运输以载重大、速度快、运输灵活等优势替代了有轨辅助运输。经过多年的发展,无轨辅助设备种类多,功能全,适应于井下各种运输需要。但在发展的同时,无轨辅助运输也存在很多不足之处。针对此现状,从设备智能化、自动化和市场规模扩大化的角度阐述了无轨辅助运输的远大发展前景,对无轨辅助运输行业的发展具有一定的借鉴作用。