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随着采深的增大,晋华宫矿开采过程产生严重的地表沉降问题,对该矿地面建构及设施造成了安全隐患。该矿选择采用虚拟参考站技术(VRS技术)来对地表沉降进行测量监测。监测结果表明,VRS技术具有更好的准确性和科学性,在监测过程中表现出测量范围广、工作效率高、工作量小的特点,可以对该矿地表沉降问题进行有效监测。 相似文献
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Hua-Shan Tai 《中国工程学刊》2018,41(1):69-75
This study has analyzed the properties of blended polypropylene (PP) specimens and employed statistical analysis to develop a method for determining the virgin–recycled mixing ratio of a specimen. Morphological observations and analyses of thermal and mechanical properties were conducted to examine specimen properties. The results were incorporated into regression analysis to create relationship equations. The results revealed that the melt temperature ranged between 167 and 169 °C, melt index (MI) ranged between 7.59 and 18.36 g/10 min, viscosity decreased when the amount of recycled PP and the rotation speed increased, the maximum decomposition temperature decreased with an increase in recycled PP content and increased with the heating rate, activation energy (Ea) ranged between 39.91 and 12.07 kcal/mol, Young’s modulus ranged between 1121.1 and 1910.2 MPa, and impact strength ranged between 37.94and 49.41 J/m (no significant trends). Scanning electron microscopy showed unbroken fibrils distributed on the fracture surface of Specimens 1–3. Additionally, the tensile strain of these specimens was comparatively high. The fracture surfaces of the specimens showed favorable compatibility after undergoing impact tests. The results of regression analysis indicated that the mixing ratio achieved significant correlations with Ea, MI, and Young’s modulus. Thus, regression and multiple regression analysis were performed to create relationship equations. 相似文献
56.
Owing to lack of proper recycling methods, plastic flexible film wastes are usually directly discarded or incinerated, which brings about severe environmental pollution. Therefore, converting plastic wastes into value‐added products has received more and more attention in recent years. In this work, paper‐like composites derived from plastic flexible film wastes were prepared via the thermally induced phase separation method by adding polyethylene‐graft‐maleic anhydride (PE‐g‐MAH) as a compatibilizer and fumed silica as an additive. The resulting paper‐like composites were characterized by SEM and infrared spectroscopy. Other properties such as mechanical properties, thermal properties, whiteness, printability and adsorption performance were also tested in detail. It was found that remarkable enhancements in mechanical, thermal and printable properties of the paper‐like composites were obtained when nano‐SiO2 loading was 2.5–3 wt%. Uniformly distributed holes that can endow good printability by providing space for ink or other functional molecules were observed by using SEM. Furthermore, the CIE whiteness value of the resulting composites can reach 91.6%–96.7% on adding nano‐SiO2. Additionally, the paper‐like composites integrating nano‐SiO2 and PE‐g‐MAH exhibited good solid ink affinity and high water or oil adsorption capacity. Thus, according to this research, high‐performance printable paper‐like composites used as major components of multifunctional papers can be prepared based on plastic flexible film wastes. © 2019 Society of Chemical Industry 相似文献
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《Ceramics International》2020,46(3):2836-2844
This research investigates the alterations in microstructure, mechanical properties, and corrosion behavior of binary magnesium-hydroxyapatite bionanocomposites with 2, 5, and 10 wt%HA. By mixing Mg and HA powders with different percentages of HA contents, a combined method of cyclic extrusion compression (CEC), equal channel angular pressing (ECAP) and conventional extrusion were employed to consolidate the mixture of powders. All composites were examined. The results indicate that the addition of hydroxyapatite to magnesium improves the mechanical properties, but these properties are deteriorated with the hydroxyapatite content of over 5 wt%. The corrosion behavior of the composites was examined by immersion test, mass loss and polarization tests in Hank’s solution. The results indicate that Mg-5HA exhibits the best corrosion resistance and the corrosion rate increases when the HA content rises to more than 5 wt%. In addition, the specimen produced through the proposed method in this work indicates better corrosion resistance in comparison with cast and extruded pure Mg. 相似文献
59.
建立了检测塑胶跑道面层中6种有害物质(环己基异氰酸酯(CHI)、2,4-甲苯二异氰酸酯(2,4-TDI)、2,6-甲苯二异氰酸酯(2,6-TDI)、六亚甲基二异氰酸酯(HDI)、萘-1,5-二异氰酸酯(NDI)和4,4'-二苯基甲烷二异氰酸酯(4,4'-MDI))含量的GC-MS检测方法,分别讨论了定量方式和萃取时间对6种有害物质回收率的影响。将样品剪碎至10~20目(0.85~2.00 mm)的颗粒,用10 mL乙酸乙酯萃取,室温下超声20 min,提取液用DB-17MS石英毛细管色谱柱(30 m×0.25 mm×0.25μm)分离,采用GC-MS法并选择离子检测,内标法定量。结果表明,在0.5~100.0 mg/L(4,4'-MDI在1.0~100.0 mg/L)浓度范围内,线性良好,相关系数均大于0.998,方法检出限范围为2.0~10.0 mg/kg,定量限范围为6.0~20.0 mg/kg;加标平均回收率在80.1%~100.8%之间,相对标准偏差(n=6)小于5.2%。该方法快速、准确,适用于塑胶跑道面层中有害物质的测定。 相似文献
60.
Size-dependent separation of graphene oxide by deformation of packed-gel in a chromatographic column
Yuji Takaoka Shohei Esaki Koichi Sakaguchi Tomotsumi Fujisawa Masashi Unno Shintaro Morisada 《分离科学与技术》2020,55(7):1356-1363
ABSTRACTA deformable gel-packed chromatographic column was used to separate as-synthesized graphite oxide with different sizes. The synthesized gel (56 µm) was deformed by pressure of the fluid flow and the gaps in the gels showed a range of sizes. A suspension of graphene oxide (0.1 g/L, 10 mL) was injected, and graphene oxide in the elution had a size at 0.56 μm and 0.14 μm, whereas in half upper and bottom domain of the gel layer graphene oxide had a size at 33 µm and 2.9 µm, respectively, demonstrating that graphene oxide suspension was separated by size through gel layer. 相似文献