网状结构织物制备与应用研究进展

为深入拓展网状结构织物在实际工程中的应用,分别介绍了近年来机织网状结构织物、针织网状结构织物和编织网状结构织物的应用基础和制备方法。从纤维原材料、织物组织结构和织物后整理方面重点阐述了网状结构织物的力学性能和仿真模拟的研究进展。针对网状结构织物应用领域的不断扩大,进一步探索了网状结构织物的力学性能,增强网状结构织物的动态模拟,提高网类材料的使用寿命、减少能耗,以使网状结构织物的性能和使用效果逐渐提升。结合当前科技发展趋势,预测网状结构织物将会在海洋、建筑、航空航天等领域方向有更深入的发展,期望为网状结构织物产品的研发提供参考。     

Adaptive investigation of the optical properties of polymer fibers from mixing noisy phase shifting microinterferograms using deep learning algorithms

In this article, an adaptive denoising method is suggested to accurate investigate the optical and structural features of polymeric fibers from noisy phase shifting microinterferograms. The mixed class of noise that may produce in the phase-shifting interferometric techniques is established. To our knowledge, this is an early study considered the mixing noises that may occur in microinterferograms. The suggested method utilized the convolution neural networks to detect the noise class and then denoising, it according to its class. Four convolution neural networks (Googlenet, VGG-19, Alexnet, and Alexnet–SVM) are refined to perform the automatic classification process for the noise class in the established data set. The network with the highest validation and testing accuracy of these networks is considered to apply the suggested method on realistic noisy microinterferograms for polymeric fibers, polypropylene and antimicrobial polyethylene terephthalate)/titanium dioxide, recoded using interference microscope. Also, the suggested method is applied on noisy microinterferograms include crazing and nanocomposite material. The demodulated phase maps and the three-dimensional birefringence profiles are calculated for tested fibers according to the suggested method. The obtained results are compared with the published data for these fibers and found to be in good agreements.     

Decarbonized combustion performance of a radiant mesh burner operating on pipeline natural gas mixed with hydrogen

With the pressing need to reduce greenhouse gas emissions, blending lower or zero carbon fuels like renewable hydrogen into natural gas is a promising and practical way to achieve clean energy transition. From the perspective of end users and combustion device manufactures, one of the major concerns is the influence of the renewable contents on the combustion devices performance. The possible renewable gas content percentage in pipeline also interests policy makers and gas utility companies. The present study investigates on the influence of hydrogen contents on the operating performance of a surface burner, which is widely adopted in industrial, commercial and residential applications. The interactions among heating load, excess air level and fuel contents are studied by a 3-factor13-level experiment design. Evaluated combustion performance characteristics include flame characteristics, burner/exhaust temperature and emissions (NO, NO₂, N₂O, CO, UHC, NH₃). The results showed that hydrogen addition to natural gas slightly increased the burner surface temperature but did not have significant impact on other burner performance parameters. Up to 20% (by volume) natural gas was replaced by hydrogen, and no abnormal effect was observed. Furthermore, tests carried out in a prototype water heater showed similar performance. This study gives a positive sign relative to replacing pipeline natural gas with renewable hydrogen at a low percentage without modifying the burner geometry.     

以药物结构为核心的药物化学教学设计

药物化学知识体系的形成和发展与有机化学、生物化学、分子生物学等基础学科息息相关,综合性强,且存在药物种类繁多、药物理化性质复杂、构效关系与作用机制不易理解等问题。本文通过以药物结构为教学核心,构建药物化学知识网,旨在克服教学过程中上述问题,避免知识点罗列的灌输性教学,降低教学难度和学习难度,并引导学生进一步掌握药物的构效关系、药理作用,讲解新药研发的创新思路,培养学生设计新药的思维。     

基于WTD-AR谱和MEA-BPNN的轴承故障诊断方法

针对滚动轴承故障诊断模型在噪声干扰下鲁棒性能差的问题,提出一种基于小波阈值去噪（WTD）、AR谱和思维进化算法（MEA）优化反向传播神经网络（BPNN）的轴承故障诊断方法。以原始振动信号为输入,采用小波方法分解重构原始信号滤除高频噪声,然后采用Burg算法估计AR模型参数提取降噪信号功率谱特征,最后将特征向量与对应标签分别作为MEA-BPNN神经网络的输入、输出进行训练,最终实现诊断。将该方法与一些先进的人工神经网络诊断方法作比较,测试该诊断模型的性能。研究结果表明：WTD-AR谱-MEA-BPNN诊断模型能够有效降低轴承振动信号的噪声干扰,实现特征增强,分辨率更高;相较于传统神经网络训练速度更快,在更短时间内甄别故障类型且识别率高。     

变量齿轮泵的新机制研究与微圆槽的卸荷能力分析

为实现功率和排量的同步变化以节省资源,提出一款齿轮泵变量的新机构,该机构原理简单,由变量弹簧力和高压油压力的动态平衡驱动齿轮副有效啮合宽度的自动变化,从而实现泵功率和排量随有效啮合宽度的同步变化;并就其困油性能与困油卸荷进行深入研究和分析,提出具有微圆结构的卸荷槽;最后,进行实例运算和分析。结果表明:微圆卸荷槽具有更大的卸荷面积和卸荷能力;有效啮合宽度越小,困油压力峰值越小,困油性能越好;反之,困油性能越差,但影响不大。     

综放巷内充填原位沿空留巷技术

针对综放沿空留巷的技术难点,在分析综放沿空留巷围岩结构力学模型的基础上,提出了巷内充填原位沿空留巷的新技术。此项技术有两个关键方面:一是大断面全煤巷道顶煤完整性的维护;二是大体积长距离充填体的整体稳定性控制。对巷内基本支护为梯形金属支架的原有巷道,提出了实施此项新技术的具体方案。现场工业性试验表明,该项技术的应用是成功而有效的,可在类似条件的综放工作面推广应用。     

挂网锚喷在高边坡防护中的应用

结合工作实践经验，重点个绍了有关高边坡挂网锚喷防护的设计要点、施工方案的各工序，阐述了有关质量管理和检测方法，以提高边坡的整体稳定性。     

HRB400级钢筋钢丝网混凝土梁抗弯性能的试验研究

对 HRB400级钢筋钢丝网混凝土梁进行了正截面抗弯试验研究。试验包括6根在箍筋表面绑扎钢丝网的试件和2根未绑扎钢丝网的对比试件。试验的主要目的是研究采取该施工工艺后,钢丝网对裂缝间距和宽度的影响作用。试验中量测了受弯构件的开裂荷载、极限荷载、钢筋应变、混凝土应变以及跨中挠度。试验结果表明,箍筋表面的钢丝网可以明显地改善构件的抗裂性能,裂缝的间距和宽度明显减小。     

热轧带肋钢筋焊接网的应用

介绍了热轧带肋钢筋焊接网的特点、工程应用情况和布网设计的心得 ,并进行了经济性分析比较