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为解决工作面回采过断层期间顶板破碎易片帮冒顶等问题,对11100工作面地质条件进行分析,对注浆加固机理进行研究,提出工作面注浆加固快速过断层技术。该技术采用调斜旋转回采和割顶留底回采方案,合理选取注浆材料,设计注浆参数,并对注浆效果进行检验。实践证明,通过断层区域的注浆加固,改善了煤岩体物理力学性质,提高了顶板稳定性和煤岩承载能力,结合对回采方案的优化,保证了工作面快速安全通过断层。 相似文献
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Quantifying change after large habitat restoration efforts is critical to assessing the effort's success. After river restoration activities, fish abundance is expected to increase and also fluctuates naturally by season and with environmental conditions. A side‐looking hydroacoustic system was used to estimate fish abundance in the Penobscot River, ME, from 2010 to 2016 during predam (2010–2013) and postdam (2014–2016) removal years during nonice periods. Automated data processing enabled continuous abundance estimates from fish tracks. A threefold increase in mean fish abundance was recorded after dam removal. A fourfold increase in median fish abundance occurred in the fall relative to spring and summer of the same year, regardless of dam presence. Interannual fish abundance in every season monitored increased at least twofold after dam removal. We related variability in fish abundance to tide, discharge, temperature, diurnal cycle, daylength, moon phase, and restoration activities (focusing on dam presence). Daylength corresponding to the fall and summer was the most important indicator for higher fish abundance. Fish abundance was generally greatest in the fall during outgoing tides at night, with lesser peaks occurring during the month of June at night. Before dam removal, fish abundance peaked when water temperature was less than 9.25°C, at night, during outgoing tides. After dam removal, fish abundance peaked when daylength was less than 11.3 hr, at night, during outgoing tides, when water temperature was above 4.56°C and no full moon was present. Peak fish abundance occurred during only 0.02–2.3% of the total time sampled. The threefold increase in fish abundance recorded after dam removal was observed despite yearly stocking efforts of adult alewife increasing 24% in postdam removal years. Finally, parallel studies of fish presence in the Penobscot River were used to compare the utility of this method as an indicator of fish abundance in response to dam removal. 相似文献
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Ronaldo C. Gurgel‐Loureno Leonardo M. Pinto Luis A. V. Bezerra Jorge I. Snchez‐Botero 《河流研究与利用》2020,36(7):1353-1359
Several fish species from Central America and other regions have been introduced into Brazil. In this study, we evaluated the bioecological aspects of a non‐native cichlid of the genus Amatitlania (convict cichlid) and its possible establishment in high‐altitude forest enclaves of semi‐arid Northeastern Brazil. Specimens of Amatitlania nigrofasciata (Günther, 1867) were captured in a local stream displaying abiotic conditions like those of its natural range of distribution. The individuals collected were predominantly adult, insectivorous and displayed normal length–weight relationships, although we observed some phenotypical plasticity (variation in body depth, and a morphologically abnormal dorsal fin in three cases). Our results indicate that A. nigrofasciata has successfully colonized an Atlantic forest enclave in the Brazilian semi‐arid region, making it necessary to adopt measures to prevent the species from spreading to other water bodies in the surroundings. 相似文献
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目的 系统地研究景区解说设施评价体系,建立合理完善的评价方法,为景区解说设施的优化升级提供科学的理论支撑.方法 选取泉州市崇武古城的解说设施为研究对象,以SERVQUAL(服务质量)模型为基础建立解说设施满意度评价体系,借助主成分分析、模糊综合评价以及IPA分析法3种方法,探索景区解说设施满意度及其影响因素.结论 研究表明,构成景区解说设施满意度评价体系的一级指标主要为有形性(UA)、保证性(UB)、移情性(UC)、可靠性(UD),四者的权重由大到小依次为UB>UA>UD>UC;泉州崇武古城景区解说设施满意度评价结果为良好,基本达到旅游解说要求.但是解说设施的有形性方面亟待提升,在视觉效果上的满意度相对较低,影响游客对古城景区的满意度. 相似文献
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Yu Liu Yizhen Huang Zheming Wang Shihai Cai Beiwei Zhu Xiuping Dong 《International Journal of Food Science & Technology》2021,56(10):4959-4969
Aquatic products are one of the most important foods with plenty of high-quality protein, unsaturated fatty acids (EPA, DHA), a variety of minerals and other essential nutrients. However, the bad smell of fish, such as fishy smell and earthy smell, restricts its production and consumption. The main fishy odour substances from freshwater fish and marine fish are different. The geosmin and 2-methylisobomeol are the main compounds in freshwater fish, and aldehydes, alcohols and ketones are found in most marine fish. The odour compounds can come from environment like water, feed and alga, enzymolysis and oxidative reactions of protein and lipid. Thus, it is necessary to remove or inhibit odour by managing farming environment like improving water quality, using physical method like adding some substance to cover the bad smell and using some chemical or biological method to prevent enzymolysis or oxidation. Therefore, knowing the composition of fishy substances and understanding their production pathways will play an important role in suppressing fishy substances and improving the competitiveness of consumer production. Besides, it could provide new ideas for innovative deodorising methods. 相似文献
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