共查询到20条相似文献，搜索用时 859 毫秒
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介绍了旋挖钻进所用的各种钻具结构特点及适用地层，包括螺旋钻具、旋挖钻斗、筒式环状钻头、扩底钻头。并介绍了这些钻具在青藏铁路等工程施工中应用所取得的良好效果。 相似文献
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本文从理论和实践的结合上，针对机械扩底锚杆技术的研究、提高、推广和应用展开论述。其内容共分五大部分：１．前言；２．扩底锚杆的构造与工作原理；３．扩底锚杆的施工；４．扩底锚杆的设计；５．工程实例。论文通过典型事例的剖析，运用深入浅出的对比方法，论证了机械扩底锚杆技术与传统灌浆锚杆技术的差异。充分证实了机械扩底锚杆技术独有的受力机理明确、质量可靠、锚固力强、造价低、工期短的五大优点、充分的显示了现行机 相似文献
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:科研院所在市场开发中要以市场为导向 ,开发适销对路的科技新产品并注重质量和服务。几年来 ,开发了PZX型组合牙轮钻头、CG型滚刀及滚刀钻头、MRR和MRS型扩底钻头、水文水井及工程钻头与钻具等产品 ,还研制了适用不同工法的新一代钻头和钻具。 相似文献
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青藏铁路基础桩孔施工用旋挖钻具的研究 总被引：3，自引：0，他引：3
根据青藏铁路采用旋挖钻进施工的特点，研制出适应青藏铁路各种地层条件的旋挖钻具，并制定出一套科学的旋挖钻进工艺，从而解决了青藏铁路桥桩基础施工这一世界难题，也为实现旋挖设备和钻具国产化打下良好基础。 相似文献
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A. V. Belyaev 《GeoJournal》1995,35(1):17-21
Presented natural-climatological characteristics of water resources forming conditions of the Aral sea basin. Analised flow variability correlation of Amy Darya and Syr Darya from the point of their influence on the sea level fluctuation.Shows up the tendences of structural changes and efficiency of water resources usage of the region, presents their present-day spacial-geographical peculiarities.On the basis of temporal analysis of water balance structure of the Aral Sea, forming processes of river flow and its discharge a conclusion about quantative correlation of natural and anthropogenic components of sea level degradation is made. 相似文献
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I. V. Lygin A. A. Bulychev D. A. Gilod T. B. Sokolova A. A. Fadeev 《Moscow University Geology Bulletin》2014,69(2):61-67
The scientific educational practice on gravimetry for the second-year students of the geophysical specialty in 2012–2013 was executed in Central Russia (Kaluga region, the Village of Aleksandrovka). It allowed us to provide an educational process with modern high-precision gravimeters and to fully preserve the curricula and to add elements of topography and geodesic practice. Over these 2 years reliable facts and data were received, which illustrated the possibilities of high-precision gravity measurements in studying the sedimentary cover features of a geological structure. 相似文献
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分析了综合机械化放顶煤开采所适用的地质条件及其拓展范围,提出了进一步拓展综放开采适用条件的研究方向及内容。 相似文献
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通过地质调绘、钻探等地质勘查手段,查明了织纳高速公路龙井河特大桥桥位区堆积体滑坡的工程地质、水文地质条件,对滑坡进行了稳定性计算分析。通过静力平衡原理对埋置式抗滑桩进行了受力分析简化计算,确定了埋置式抗滑桩的埋置深度和悬臂段长度,为埋置式抗滑桩在实际工程中的运用提供了实用的设计方法,滑坡治理达到预期效果。 相似文献
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Systemic analysis of soil microbiome deciphers anthropogenic influence on soil ecology and ecosystem functioning 总被引：1，自引：0，他引：1
S. Gupta M. Kumar J. Kumar V. Ahmad R. Pandey N. S. Chauhan 《International Journal of Environmental Science and Technology》2017,14(10):2229-2238
Soil is a complex ecosystem with defined microbial community signatures, modulated by the interaction between biotic and abiotic factors. Amidst biotic factors, land usage have significant impact onto the soil microbial structure and ecosystem functioning. In the current study, metagenomic approach was used to decipher effect of hospital settings on soil microbiome structure and physiological functions. Physico-chemical properties analysis revealed that key elements for maintenance of soil microflora, such as organic carbon, nitrogen, phosphorus and sulfur were relatively diminished within hospital soil, compared to garden soil. Comparative microbial diversity analysis with 97,315 SSU rRNA gene sequences generated from both the soil samples highlight relatively low microbial diversity, with an enrichment for Acidobacteria and Bacteroidetes and decreased Proteobacteria/Acidobacteria ratio. Comparative shotgun metagenome sequence analysis further revealed a shift in the physiological role of soil microbiomes with change in soil usage. Genes for carbohydrate, sulfur, potassium and nitrogen metabolism were significantly (q value <0.05) higher in the garden soil; while the genes for phage, plasmid DNA, transposon and aromatic compound metabolism were significantly enriched within hospital soil. Thus, the current study highlights a correlation between soil biochemistry and microbial ecology based on land usage. 相似文献