多孔SiO2分子巢制备多功能涤纶纤维试验研究

针对传统PET材料不具备抗菌、不耐洗等问题,以煎煮法为基础,以草珊瑚、艾叶和薄荷为原料,制备含植物活性成分的溶液,其具有抗菌、杀菌的作用;以溶胶-凝胶法为多孔材料制备方法,用十六烷基三甲基溴化铵、十二烷基苯磺酸钠表面活性剂为模板剂,正硅酸乙酯为有机硅源,氨水为催化剂,乙醇和乙醚为助溶剂,在水-乙醇-乙醚体系中合成多孔二氧化硅微球;然后,多孔二氧化硅微球与提取液混合制备含植物活性成分的多孔二氧化硅分子巢;最后以制备的多孔二氧化硅分子巢与普通的聚酯切片用熔融纺丝工艺进行造粒、纺丝,得到具有抗菌、杀菌和耐洗的多功能涤纶纤维.通过SEM微观观察和力学性能测试、抗菌试验、耐洗性测试,对上述制备的多功能涤纶纤维性能进行验证.结果表明:在模板剂总浓度为0.029 mol·L-1、V醇:V醚=20:20、两种表面活性剂比为4:1时,得到的多孔SiO2微球排列规整;当多孔二氧化硅分子巢掺量(质量分数)在0.5％～1％时,通过熔融共混纺丝得到的新型多功能涤纶纤维力学性能表现最优;当多孔二氧化硅分子巢掺量(质量分数)在1％时,得到的新型多功能涤纶纤维的抗菌性能达到87.9％.而二氧化硅分子巢掺量越高,纤维材料越耐洗.以上结果说明本试验制备涤纶纤维的方案可行.     

Precipitating spinel into precursor glass and its assistance in crystallization

The crystallization phenomena of spinel in CaO-MgO-Al₂O₃-SiO₂-Fe₂O₃ glass have received much attention due to the particular role in preparation of glass-ceramic materials, which represent an effective option to manage hazardous waste. In this study, both preliminary spinel and secondary spinel were precipitated in the precursor glass. The formation of these spinel was meticulously assessed by a combination of X-ray diffractometry and scanning electron microscopy. The structure of the microenvironment in the precursor glass was characterized by Raman spectrums. These advanced techniques highlight the potential for one-step crystallization of the glass. The investigation, which focused on one-step crystallization, demonstrated the growth of pyroxene on spinel accompanying a migration of chromium. The results also show the microstructure of the obtained glass-ceramic was very dependent on the heat-treat temperature. This study not only unambiguously reveals the precipitation mechanisms of spinel but also provides more documentation for one-step crystallization in the glass-ceramics field.     

Microwave drying performance of lignite with the assistance of biomass-derived char

Microwave lignite drying with assistance of biomass-derived char was addressed and effect of bio-char on drying rate and energy consumption was investigated in this work. Effective diffusion coefficient and activation energy for the drying process were also analyzed. The results indicated the drying process was largely dependent on the variation of sample temperature. Bio-char originated from pine wood was most favorable for lignite drying, considering its better promoting effect and advanced security. There existed an optimal bio-char addition ratio for drying process at different power. The corresponding optimal ratio was 10% at 231?W and 15% at 385?W, at which the biggest drying rate and the least energy consumption were reached. It was compared lignite drying initiated at 385?W was better for energy conservation. Effective diffusivity was improved and activation energy was simultaneously reduced, with the addition of bio-char. The minimum activation energy was 15.54?W?·?g^?1, which was gained at bio-char addition ratio of 10%. The results revealed the effect of bio-char on depressing activation energy could rival that of metal-based additives. The drying process with assistance of microwave and bio-char could present technical and economical benefits on lignite upgrading.     

土耳其盐穴地下储气库大井眼钻井技术

土耳其Tuz G?lü盐矿区拟建造地下天然气储气库,存在2个可能性风险:矿床实际深度与原计划钻探深度的偏离;钻井与建腔过程中侵出CO2气体,因此该气库建造存在一定的地质及工程风险。为加快该项目进展,满足盐穴储气库钻井要求,通过优化方案采用国内没有应用过的生产套管大尺寸井眼井身结构,采用液压扩孔器扩眼,并形成钻井配套技术。文中从井身结构、钻头优选及螺杆钻具应用、钻井液体系优选、固井以及钻探效果等方面,阐述Tuz G?lü天然气地下储气库钻井技术。通过实施,有效降低了钻井事故复杂时率、缩短钻井周期,机械钻速得到提高,取得了显著的经济效益。     

深度学习识别光网络单元故障的设计与应用

为解决依赖装维上门鉴别光网络单元故障带来的不便,可以从机器视觉入手实现自动化故障识别。近年,ImageNet挑战赛的成功推动了物体识别技术的跨越式发展,特别是基于卷积的深度学习技术在视觉识别方面已经达到人类水平,为光网络单元故障的自动识别提供了技术基础。文章对识别光网络单元的工作状态进行了研究,将设备工作状态分为7个场景,提出了利用手机APP采集图片识别故障的解决方案并投入了实际生产;重点阐述了深度学习模块的设计与实现,提出一种通过算法整合的方式综合运用物体检测和图像分类算法,分3阶段逐步求精,解决了图片过滤,光网络单元型号和状态识别等问题,实现了基于计算机视觉自动识别光网络单元故障。从数据上看产品的端到端准确率超过84%,识别速度达到10 FPS,月均提供服务超过1万人次,在减少用户等待的同时节约了人力资源。     

Structural,morphological, dielectric and magnetic properties of Zn-Zr co-doping yttrium iron garnet

In this study, yttrium iron garnet co-doped with Zn and Zr atoms with a chemical formula Y₃Zn_xZr_xFe_(5−2x)O₁₂ (x = 0.0-0.3) has been successfully prepared by the solid-state reaction method. The effects of doping concentration on the microstructure, crystal structure, magnetic properties, and dielectric properties of Y₃Zn_xZr_xFe_(5−2x)O₁₂ were investigated. The microstructure analysis indicates that co-doping of YIG with Zn and Zr can effectively reduce the grain size of the ceramic. The crystal structure results reveal that the doping concentration of Zn–Zr has substantial influence on the lattice parameters of YIG, such as, increases the lattice constant, crystal cell size, and interplanar spacing. However, the second phase of ZrO₂ appears once x ≥ 0.15. Additionally, the dielectric properties of YIG ferrite can be regulated using this Zn–Zr co-doping method. Zn–Zr co-doping can improve the dielectric stability and reduce the dielectric loss at high temperature. The magnetization measurement shows that the saturation magnetization is stabilized at x < 0.15, and the magnetic loss is decreased with the increase in the doping concentration. Overall, the findings show that the ceramic with x = 0.1 exhibits better properties included high saturation magnetization (24.607 emu/g), low magnetic loss (0.0025 @ 1 MHz), and relatively low dielectric loss (496 @ 400°C).     

Corrosion resistance of Al–Cr-slag containing chromium–corundum refractories to slags with different basicity

Al–Cr slag is the solid waste generated by the smelting of Cr metal. It presents a range of environmental hazards. This study addressed the corrosion resistance of Al–Cr slag containing chromium–corundum refractories to slags with different basicity. Herein, we provide suggestions for the use of Cr–corundum of different basicity in kilns. Al–Cr slag, brown fused Al₂O₃, and chrome green were used as the raw materials, with pure calcium aluminate cement being used as a binder. The brick samples, prepared using different blends of chrome green and corundum, were fired at 1600?°C, and subsequently subjected to a slag corrosion test. After corrosion by slag of different basicity, the phase composition and microstructure of the sample were analyzed by X-ray diffraction, energy dispersive spectrometer and scanning electron microscopy. There were two major findings. First, Cr–corundum brick made from Al–Cr slag has a better slag corrosion resistance than that made from Cr₂O₃ and brown fused Al₂O₃. Second, Cr–corundum brick made from Al–Cr slag has superior corrosion resistance to slag with a CaO:SiO₂ ratio of 2:1.     

Zinc doped Fe2O3 for boosting Electrocatalytic Nitrogen Fixation to ammonia under mild conditions

Artificial nitrogen fixation is emerging as a promising approach for synthesis of ammonia at mild conditions. Inspired by biological nitrogen fixation based on bacteria containing iron, zinc doped Fe₂O₃ nanoparticles are proposed as an efficient and earth abundant electrocatalyst for converting N₂ to NH₃. In neutral media, it achieves a maximum Faradaic efficiency (FE) of 10.4% and a large NH₃ yield rate of 15.1 μg h^?1 mg^?1_cat. at ?0.5 V vs. reversible hydrogen electrode. This catalyst also exhibits excellent selectivity and stability. Theoretical calculations suggest the reaction follows the associative enzymatic mechanism and it has a barrier of as low as 0.68 eV.     

起升中四腿落地式K型井架及底座的应力分析

针对在用四腿落地式K型井架在起升中井架与底座存在的问题,文章以JJ162/42-K型井架为例,采用I-DEAS有限元软件对起升过程中处于各角度时的井架及底座做了应力分析,并将其结果与两腿落地式K型井架进行了比较。分析表明,四腿落地式K型井架及底座在井架刚起升时,应力值较大,存在安全隐患。为了增强在井架起升过程中底座的安全性,建议在底座上井架2个铰支座之间加焊加强钢板,并加大井架前立柱铰支座的尺寸。