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1.
大直径深立井井筒基岩段快速施工技术 总被引:2,自引:0,他引:2
鸡西建设工程公司在望峰岗矿主井井筒施工中,采用短段掘砌混合作业,充分发挥机械化配套设备能力,推广应用伞钻凿眼深孔爆破,双中心回转抓岩机装岩等凿井新技术,2005年连续7个月月成井破百米,为大直径深立井井筒快速施工积累了经验。 相似文献
2.
İlhan Tekeli 《Architectural Design》2010,80(1):32-39
Since reform started under Ottoman rule in the early 19th century, Istanbul has undergone a substantial period of modernisation that has spanned more than 150 years. İlhan Tekeli outlines the metropolis' enduring development, characterising Istanbul's transformation into a modern city into four distinct periods. It is a story that bridges the collapse of the Ottoman Empire and the reconstruction of the Turkish Republic as a nation-state, with the initial demise of the city in favour of Ankara; and continues with Istanbul regaining its status as a world city; as it evolves from a monstrous industrial city to an urban region and global centre. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
3.
反应条件对正庚烷在Mo2C/Hβ上异构产物的影响 总被引:1,自引:0,他引:1
以正戊烷为碳源,采用程序升温法制备了Hβ沸石分子筛负载碳化钼催化剂,并进行X射线衍射(XRD)表征。在固定床微型反应器内进行正庚烷在该催化剂上的异构化反应,考察反应条件对正庚烷异构化产物分布的影响,并探讨正庚烷异构化的反应机理。结果表明,正庚烷的异构化是双分子聚合裂化和经由金属环丁烷中间体的键转移机理协同作用的结果,异构产物以甲基己烷为主,同时产生部分二甲基戊烷和环烷烃以及裂化产物;在533~553K内,反应温度对正庚烷异构生成甲基己烷的影响不明显,但提高温度能促进裂化反应;氢气压强提高同时抑制异构化和加氢裂化反应;降低空速有利于单甲基己烷向辛烷值更高的二甲基戊烷转化;氢烃体积比增加对异构化反应有抑制作用,对裂化反应没有影响。 相似文献
4.
Daniel I Onwude Rafia Abdulstter Chandima Gomes Norhashila Hashim 《Journal of the science of food and agriculture》2016,96(12):3969-3976
Mechanisation of large‐scale agricultural fields often requires the application of modern technologies such as mechanical power, automation, control and robotics. These technologies are generally associated with relatively well developed economies. The application of these technologies in some developing countries in Africa and Asia is limited by factors such as technology compatibility with the environment, availability of resources to facilitate the technology adoption, cost of technology purchase, government policies, adequacy of technology and appropriateness in addressing the needs of the population. As a result, many of the available resources have been used inadequately by farmers, who continue to rely mostly on conventional means of agricultural production, using traditional tools and equipment in most cases. This has led to low productivity and high cost of production among others. Therefore this paper attempts to evaluate the application of present day technology and its limitations to the advancement of large‐scale mechanisation in developing countries of Africa and Asia. Particular emphasis is given to a general understanding of the various levels of mechanisation, present day technology, its management and application to large‐scale agricultural fields. This review also focuses on/gives emphasis to future outlook that will enable a gradual, evolutionary and sustainable technological change. The study concludes that large‐scale‐agricultural farm mechanisation for sustainable food production in Africa and Asia must be anchored on a coherent strategy based on the actual needs and priorities of the large‐scale farmers. © 2016 Society of Chemical Industry 相似文献
5.
Benedict Kayambo Rattan Lal Geofrey C. Mrema 《Journal of the science of food and agriculture》1986,37(10):969-978
An experiment was conducted over three consecutive seasons during 1982 and 1983 with the objective of evaluating the effects of traffic-induced compaction on soil physical properties of an Alfisol for no-till and ploughed systems. Main treatments of the split plot design consisted of disc ploughing to a depth of 200 mm followed by harrowing compared with no-seedbed preparation. Compaction treatments of none, two and four passes of a 2-tonne roller were the sub-plots. The roller was 60 cm in diameter, 180 cm long, with a contact area of 0.1729 m2 and was pulled by a 33.6 kW tractor. Compaction treatments were applied 2 to 3 days before seeding. Four passes increased the penetrometer resistance of the soil surface, and bulk density; and as a result there were significant reductions in total porosity, saturated hydralic conductivity, infiltration rate and the amount of water released between 0.1 and 100 kPa suctions. Two passes of the roller had small and non-significant effects on soil properties. The effects of vehicular traffic in terms of increasing soil compaction became progressively severe with repeated compaction in subsequent seasons. Compaction affected soil properties in the 0–100 mm depth layer only, and was more evident following ploughing than following no-tillage systems. 相似文献
6.
针对ZCY120R侧卸式装岩机在煤矿岩巷掘进中跟机电缆安全性差、出矸行走时间长、不能连续出矸、拖移机尾困难等问题,改良应用了自动吊挂跟机电缆装置、配套应用WZ-180/55挖掘式装载机和机尾综合简化、强化技术,有效地提高了基于ZCY120R侧卸式装岩机的出矸系统的效率,提高了岩巷掘进单进水平。 相似文献
7.
Mechanical yield regulation in winegrapes: comparison of early defoliation and crop thinning 总被引:1,自引:0,他引:1
J. TARDAGUILA J.A. BLANCO S. PONI M.P. DIAGO 《Australian Journal of Grape and Wine Research》2012,18(3):344-352
Background and Aims: Winter pruning and manual bunch thinning are the primary methods for crop regulation in viticulture. Recently, innovative mechanical approaches have been proposed as cost‐effective for yield management. The aim of this work was to compare the effectiveness of mechanical early defoliation and mechanical crop thinning on yield regulation, and on grape and wine composition. Methods and Results: The impact of mechanical early defoliation and crop thinning, applied at different timings, was investigated in Vitis vinifera L. cv. Tempranillo vertically shoot‐positioned‐trained grapevines over two seasons. Effects on yield components, leaf area, botrytis incidence, grape and wine composition were determined. Yield per vine was drastically reduced by both techniques (35–40%). Bunch weight, number of berries per bunch, bunch compactness and botrytis were also reduced by most of the treatments. Total leaf area per vine was not affected, however, the total leaf area‐to‐yield ratio increased in most cases. Berry soluble solids, anthocyanins and total phenols increased in the grapes. Wines were higher in alcohol and more intensely coloured in mechanical early defoliation treatments in comparison with those of mechanical thinning. Conclusions: Mechanical early defoliation and crop thinning may be suitable and efficient for regulating grape yield and improving grape and wine composition. Early defoliation, however, appeared to be more consistent. Significance of the Study: Effective yield control in winegrapes may be accomplished by mechanical techniques implemented between pre‐flowering and veraison. The choice of mechanical technique for yield management may influence the grape and wine composition. 相似文献
8.
丁礼建 《河北建筑工程学院学报》2003,21(2):47-50
针对装卸机械联合作业过程中,型号不同多台辅助施工机械与主导施工机械配合施工完成单次土方作业循环时间参差不齐的情况,利用优化方法,建立了非同型号辅助施工机械完成单次土方作业循环时间控制模型. 相似文献
9.
简述了浙江玫瑰米醋传统生产工艺的特点、存在的问题以及实现机械化生产应解决的技术难题;介绍了建立机械化浙江玫瑰米醋生产线所采取的工艺措施、工艺流程和主要技术参数;并对两种方法生产的产品进行了质量对比,对整条生产线进行了综合评价。经过一年连续生产表明:机械化生产的玫瑰米醋产品质量达到或比较接近传统工艺玫瑰米醋产品。 相似文献
10.
对煤炭采样机偏倚试验中最大允许偏倚(B)进行了研究.通过实测和分析得出,最大允许偏倚对于精煤为0.50 %,其它洗煤为0.80 %;对于灰分Ad<15 %,15%~30%以及>30 %的筛选煤分别为0.80 %,1.10 %和1.50 %;对于灰分Ad<15 %,15%~30%以及>30 %的原煤分别为1.00 %,1.30 %和1.80 %.该B值不仅是采样机偏倚试验的性能判据,实为适合我国煤炭品质均匀性的机械化采样最大允许系统误差,同时也为手工采样的系统误差提供了参考. 相似文献