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181.
本文根据岩石支护相互作用原理,分析了竖井稳定性,推导出竖井围岩与支护的应力、位移计算式,并可根据围岩泊松比值大小,判断围岩周边最大主应力方向。文中的分析方法已被编制成程序,并用于凡口铅锌矿新副井稳定性的分析。 相似文献
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183.
Jicai Liang Chen Ding Zhiyong Wei Lin Sang Ping Song Guangyi Chen Ying Chang Jinting Xu Wanxi Zhang 《Polymer Composites》2015,36(7):1335-1345
Biodegradable poly(butylene succinate) (PBS)/carbon fiber (CF) composites were prepared by melt blending method using twin‐screw extruder followed by injection molding. Mechanical properties, crystallization behavior, morphology, crystal structure, and thermal stability of PBS/CF composites were investigated with different CF contents (0, 5, 10, 15, and 20 wt%). It was found that the tensile and impact properties of the composites were improved markedly with the addition of CF; while too much CF would lead to agglomeration and thus weaken the improvement. Scanning electron microscopic photographs on the fracture surfaces showed superior interfacial adhesion between fibers and PBS matrix. Crystallization peak temperature of PBS in its composites was increased due to the heterogeneous effect of CF. The spherulite size of PBS/CF composites decreased and the nucleation density increased drastically. The crystal structure was not affected by the incorporation of CF, as confirmed from the wide‐angle X‐ray diffraction analysis. thermogravimetric analysis showed that the thermal stability of PBS/CF composites was also enhanced. POLYM. COMPOS., 36:1335–1345, 2015. © 2014 Society of Plastics Engineers 相似文献
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Dae Gyu Kwon Myung Ku Kim Yoon Sang Jeon Yoon Cheol Nam Jin Seong Park Dong Jin Ryu 《International journal of molecular sciences》2022,23(3)
Osteoarthritis (OA) has generally been introduced as a degenerative disease; however, it has recently been understood as a low-grade chronic inflammatory process that could promote symptoms and accelerate the progression of OA. Current treatment strategies, including corticosteroid injections, have no impact on the OA disease progression. Mesenchymal stem cells (MSCs) based therapy seem to be in the spotlight as a disease-modifying treatment because this strategy provides enlarged anti-inflammatory and chondroprotective effects. Currently, bone marrow, adipose derived, synovium-derived, and Wharton’s jelly-derived MSCs are the most widely used types of MSCs in the cartilage engineering. MSCs exert immunomodulatory, immunosuppressive, antiapoptotic, and chondrogenic effects mainly by paracrine effect. Because MSCs disappear from the tissue quickly after administration, recently, MSCs-derived exosomes received the focus for the next-generation treatment strategy for OA. MSCs-derived exosomes contain a variety of miRNAs. Exosomal miRNAs have a critical role in cartilage regeneration by immunomodulatory function such as promoting chondrocyte proliferation, matrix secretion, and subsiding inflammation. In the future, a personalized exosome can be packaged with ideal miRNA and proteins for chondrogenesis by enriching techniques. In addition, the target specific exosomes could be a gamechanger for OA. However, we should consider the off-target side effects due to multiple gene targets of miRNA. 相似文献
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Myeong Seong Sim Hye Jeong Kim Sang Hee Jo Chun Kim Il Yup Chung 《International journal of molecular sciences》2022,23(7)
Lysophosphatidylserine (LysoPS) is an amphipathic lysophospholipid that mediates a broad spectrum of inflammatory responses through a poorly characterized mechanism. Because LysoPS levels can rise in a variety of pathological conditions, we sought to investigate LysoPS’s potential role in airway epithelial cells that actively participate in lung homeostasis. Here, we report a previously unappreciated function of LysoPS in production of a mucin component, MUC5AC, in the airway epithelial cells. LysoPS stimulated lung epithelial cells to produce MUC5AC via signaling pathways involving TACE, EGFR, and ERK. Specifically, LysoPS- dependent biphasic activation of ERK resulted in TGF-α secretion and strong EGFR phosphorylation leading to MUC5AC production. Collectively, LysoPS induces the expression of MUC5AC via a feedback loop composed of proligand synthesis and its proteolysis by TACE and following autocrine EGFR activation. To our surprise, we were not able to find a role of GPCRs and TLR2, known LyoPS receptors in LysoPS-induced MUC5AC production in airway epithelial cells, suggesting a potential receptor-independent action of LysoPS during inflammation. This study provides new insight into the potential function and mechanism of LysoPS as an emerging lipid mediator in airway inflammation. 相似文献
188.
Landfill bioreactors (LBRs) with management of leachate and biogas have presented numerous advantages such as accelerated stabilization of solid wastes, reduced amount of leachate, and in situ leachate treatment. Such advantages have minimized environmental risks, have allowed extension of the useful life of the landfill site, and have fostered cost reduction. LBRs of three types have been developed using both anaerobic and aerobic modes: anaerobic, aerobic, and hybrid. Microorganisms in landfills cause various reactions related with organic fractions and heavy metals. Such functions have been stimulated in LBRs by recirculation of leachate with or without aeration. To date, most studies of microorganisms in LBRs have analyzed bacteria and archaea based on 16S rRNA genes and have analyzed fungi based on 18S rRNA genes from a taxonomical viewpoint. Indicator genes for specific functions in LBRs such as nitrification, denitrification, and methane production have also been monitored. The population dynamics of microorganisms in LBRs have been partially clarified, but the obtained data remain limited because of highly heterogeneous features of solid wastes inside LBRs. Systematic monitoring of microorganisms should be established to improve LBR performance. 相似文献
189.
Ruofei Xiang Yuanbing Li Shujing Li Yawei Li Shaobai Sang 《International Journal of Applied Ceramic Technology》2016,13(3):603-608
Waste foundry sand collected from lost foam casting industry is a solid waste that contains ZrSiO4. For the purpose of re‐utilization, it is adopted to synthesize cordierite with the addition of MgO powders and fused silica by direct sintering, meanwhile the effect of various MgO mole ratios on the sintering behaviors is investigated using XRD, SEM, and mercury porosimetry. The lowest temperature corresponding to the formation of cordierite is 1150°C, and the increase of MgO mole ratio does not reduce the temperature for cordierite crystallization but increase the microhardness and thermal expansion coefficients. 相似文献
190.
The effect of coal size (0.73–1.03 mm), excess air ratio (1.0–1.4), operating bed temperature (750–900‡C), coal feeding rate
(1–3 kg/h), and coal recycle rate (20–40 kg/h) on combustion efficiency, temperature profiles along the bed height and flue
gas composition have been determined in a bubbling and circulating fluidized bed combustor (7.8 cm-ID x 2.6 m-high).
Combustion efficiency increases with increasing excess air ratio and operating bed temperature and it decreases with increasing
particle size in the bubbling and circulating fluidzing beds. In general, temperature profiles and combustion efficiency are
more uniform and higher in a circulating bed than those in bubbling bed. Combustion efficiency also increases with increasing
recycle rate of unburned coal in the circulating bed.
The ratio of CO/CO2 of flue gas decreases with increasing bed temperature and excess air ratio, whereas the ratio of O2(CO + CO2) decreases with bed temperature in both bubbling and circulating fluidized beds. 相似文献