正交试验优化转杯纺织物浆纱工艺的实践

为解决高紧度转杯纺织物织造断经多、打纬阻力大、易出波纹疵点等问题,分析了该类品种的生产难点,并以十万纬断经数和波纹疵点为指标通过正交试验对浆液黏度、压浆力、浆纱车速、浆纱回潮率、浆纱伸长和卷曲张力进行了优化,最终织机效率达87％以上,波纹疵点得到明显减少.认为:优选浆纱工艺是解决该类产品生产质量问题的关键.     

Numerical investigation of the mechanical component design of a hexacopter drone for real-time fine dust monitoring

Journal of Mechanical Science and Technology - Multi-rotor unmanned aerial vehicles (UAVs) are being widely used in various military and civilian fields because they can replace manned systems in...     

A study on the fracture characteristics of tapered double cantilever beams made of heterogeneous composites with adhesive interfaces

Journal of Mechanical Science and Technology - In this study, CFRP and aluminum properties were investigated by carrying the static experiment on the shape-dependent bonding structure, and designed...     

基于 LeNet5like 的迁移学习风电机组叶片覆冰故障诊断研究

针对海上风电场和高海拔地区风机机组的叶片覆冰故障模型精度低、建模速度慢等问题,提出一种基于 LeNet5like 的 迁移学习风电机组叶片覆冰故障诊断方法。 首先,整合监控和数据采集系统的记录数据与风机覆冰情况进行预处理,建立训练 数据集;其次,基于改进后的 LeNet5like 网络构建覆冰故障诊断模型,提取数据集中多变量间的相关性特征信息;然后,经网络 参数微调迁移学习对模型进行训练,实现对其他风机覆冰故障诊断模型的快速建立;最后,经实验验证,该模型覆冰故障诊断准 确率为 98. 90% ,较无迁移模块网络训练时间缩短 28 s,提升约 15. 91% ,验证了基于 LeNet5like 的迁移学习风电机组叶片覆冰 故障诊断方法的精确性和快速性。     

Expression Patterns of Sugar Transporter Genes in the Allocation of Assimilates and Abiotic Stress in Lily

During the growth cycle of lilies, assimilates undergo a process of accumulation, consumption and reaccumulation in bulbs and are transported and allocated between aboveground and underground organs and tissues. The sink–source relationship changes with the allocation of assimilates, affecting the vegetative growth and morphological establishment of lilies. In this study, the carbohydrate contents in different tissues of five critical stages during lily development were measured to observe the assimilates allocation. The results showed bulbs acted as the main source to provide energy before the budding stage (S3); after the flowering stage (S4), bulbs began to accumulate assimilates as a sink organ again. During the period when the plant height was 30cm with leaf-spread (S2), leaves mainly accumulated assimilates from bulbs through the symplastic pathway, while when leaves were fully expanded, it transformed to export carbohydrates. At the S4 stage, flowers became a new active sink with assimilates influx. To further understand the allocation of assimilates, 16 genes related to sugar transport and metabolism (ST genes) were identified and categorized into different subfamilies based on the phylogenetic analysis, and their protein physicochemical properties were also predicted. Tissue-specific analysis showed that most of the genes were highly expressed in stems and petals, and it was mainly the MST (monosaccharide transporter) genes that were obviously expressed in petals during the S4 stage, suggesting that they may be associated with the accumulation of carbohydrates in flowers and thus affect flower development process. LoSWEET14 (the Sugar will eventually be exported transporters) was significantly correlated with starch in scales and with soluble sugar in leaves. Sugar transporters LoHXT6 and LoSUT1 were significantly correlated with soluble sugar and sucrose in leaves, suggesting that these genes may play key roles in the accumulation and transportation of assimilates in lilies. In addition, we analyzed the expression patterns of ST genes under different abiotic stresses, and the results showed that all genes were significantly upregulated. This study lays a solid foundation for further research on molecular mechanism of sink–source change and response to abiotic stresses in lilies.     

2014年我国热固性工程塑料进展

根据2014年国内公开发表的文献,综述了我国热固性树脂及其塑料的开发研究状况。2014年我国热固性工程塑料的研究开发集中在环氧树脂、聚氨酯和酚醛树脂等大品种树脂的增强增韧及功能化上。利用各种新型树脂或固化剂、无机纳米粒子或功能型助剂等对传统热固性工程塑料的改性取得了较多的成果。     

Synthesis of boron-doped double-walled carbon nanotubes by the catalytic decomposition of tetrahydrofuran and triisopropyl borate

Boron-doped double-walled carbon nanotubes (DWCNTs) were produced by the catalytic decomposition of tetrahydrofuran and triisopropyl borate over a Fe–Mo/MgO catalyst at 900 °C. The synthesized B-doped DWCNTs had average outer and inner diameters in the range of 1.6–2.4 nm and 0.8–1.6 nm within the bundle, respectively. They had a larger interlayer spacing in the range of 0.36–0.39 nm, than did undoped DWCNTs. The B-C bonding evident from the B 1s signals in the X-ray photoelectron spectroscopy results indicated that highly coordinated boron atoms replaced the carbon atoms within the graphene sheet. As the triisopropyl borate concentration was increased from 0 to 2.5 M, the substituted boron concentration increased from 0.8 to 3.1 at.%. The results demonstrate that the substituted boron concentration in the hexagonal carbon lattices can be easily controlled by regulating the triisopropyl borate concentration.     

分布式离散事件系统的模式故障预测研究

针对分布式离散事件系统,提出了一种模式故障预测方法.首先对分布式离散事件系统的模式故障可预测性进行形式化.通过构造一个模式故障识别器,从系统所有行为中识别出所发生的模式故障,并针对分布式系统的不同观测点构造不可观测闭包.在此基础上,联合各站点观测到的事件序列构造出模式故障预测验证器,解决了分布式离散事件系统的模式故障预...