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煤矿安全生产的重要作用 煤矿安全生产是煤矿企业生存与发展的基础,而煤矿生产安全问题一直是煤矿企业管理工作的重点。煤矿生产过程客观上存在着水、火、瓦斯、粉尘、顶板等危险因素,而煤矿生产程序又包括采、掘、机、运、通等工序和环节,一定程度上决定了煤矿生产工作具有危险性和复杂性的特点,一旦发生安全事故直接会造成人员伤亡以及经济财产损失。 相似文献
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我国正处在城市化快速发展时期,城乡统筹,城规划法的发布,灾后重建等,社会对高职城市规划专业学生素质提出了越来越高的要求.文章就此进行了探讨. 相似文献
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当今城市化建设已步入快速发展的时期,然而国内许多城市的城中村仍呈现自由化发展的趋势,由此滋生出一系列严峻的社会问题,严重阻碍了城市的可持续发展。文章围绕城市建设可持续发展的大目标。建筑师在建筑设计中应精雕细琢。力争得居者、城市与建筑的共赢,结合某工程设计实例对这一问题进行了探讨。 相似文献
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当今城市化建设已步入快速发展的时期,然而国内许多城市的城中村仍呈现自由化发展的趋势,由此滋生出一系列严峻的社会问题,严重阻碍了城市的可持续发展.文章围绕城市建设可持续发展的大目标,建筑师在建筑设计中应精雕细琢,力争得居者、城市与建筑的共赢,结合某工程设计实例对这一问题进行了探讨. 相似文献
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户外广告是一种街头宣传方式，是一种贴近城市生活，可以起到广泛传播效果的宣传形式。为做好这次活动的宣传工作，在圣保罗，我们选择了保利斯塔大街的灯杆吊旗作为这次活动的广告摆故处。这条五里长街是圣保罗的金融街，号称该市的“经济和金融大动脉”。在这条街上有百座以上高楼大厦，集中了巴西和世界的数十家银行。据说巴西每生产4元钱， 相似文献
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Olivier Schalm Ine De Raedt Joost Caen Koen Janssens 《Journal of Cultural Heritage》2010,11(4):81-492
The chemical composition of 11 glass panes originating from two 13th century non-figurative windows were analyzed by means of Scanning Electron Microscopy–Energy Dispersive X-ray system (SEM-EDX). The windows were discovered in the back-wall of the triforium during the restoration of the choir of the cathedral St. Michael and St. Gudule in Brussels (Belgium). In order to determine if these windows were fabricated with glass of different origin or not, the compositional difference between the panes were compared with the variation in composition as a result of the following causes: (1) compositional fluctuation between panes cut from the same sheet of glass, (2) compositional fluctuation caused when panes are cut from different sheets that were made with the same batch, (3) compositional fluctuation caused when the glass is made from different batches at the same production center, and (4) compositional fluctuation as a result of glass produced at different fabrication centers. 相似文献
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《Journal of Cultural Heritage》2001,2(3):199-207
Lava columns from the cathedral St Maria of Randazzo (Catania, Italy), were studied in order to establish the classification of these rocks and to investigate their origin. At the beginning of the XIX century, some columns of the old frame of the nave were removed to build the dome and stored in a fornix beneath the cathedral. Samples were taken directly from these columns. The specimens underwent petrographic investigation through optical microscopy, X-ray diffraction analysis (XRD) and Fourier transform infrared spectroscopy (FTIR) and chemical analyses of major and trace elements through X-ray fluorescence (XRF). Some trace element (Sr, Rb, Y, Zr and Nb) concentrations were assessed through non-destructive analyses, performed with a portable X-ray device which can detect homogeneous concentrations of such elements on the columns of the cathedral. According to chemical data, these rocks can be classified as mugeariites whose mineral assemblage is given by plagioclase (mostly andesinic), augitic pyroxene, olivine, magnetite and, occasionally, apatite. In order to investigate the origin of the material used for the columns, a comparative examination was conducted between the column samples and specimens collected from quarries in the surrounding area of the town of Randazzo (Randazzo and Maniace quarries and the 1536 lava flow). The correlation with the Randazzo quarry proved to be excellent. 相似文献
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The hewn sandstone and ornamental figures of the Albertino Chancel, built around the mid-14th century, are covered with black encrustations of plaster and carbon deposits, often several millimetres thick. Their removal constitutes one of the main objectives in the conservation of the precious materials of the cathedral. The Nd:YAG laser method cleans the original surface of hardened encrustations without damaging or affecting the old coloured plasters and without affecting the centuries-old patina. Laser-Tech GmbH, founded by two expert restorers from Austria and Italy, is specialised in large-scale projects and, regarding the present project for the chancel, has managed to combine the sensitivity of the preserver with the laser technology applied to large surfaces. The present project concerning St. Stephen's Church comprises over 2000 m2 of stone surface treated only with laser systems, by groups of qualified restorers trained at Altech to use such instrumentation on artistic historic surfaces. 相似文献
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Domenico Calcaterra Piergiulio Cappelletti Alessio Langella Vincenzo Morra Abner Colella Roberto de Gennaro 《Journal of Cultural Heritage》2000,1(4)
Piperno, a Late Quaternary magmatic rock cropping out on the eastern side of the Campi Flegrei (Italy), is probably the most important building stone of Naples, used over a time-span from at least the Roman age until the beginning of the 20th century. Despite its wide diffusion in the monumental architecture of Naples, very little is known about this rock, as regards its technical features, as well as the geological aspects. This paper aims at providing a first overall contribution towards a rediscovery of this long-time-used material, in view of careful restoration works, which nowadays at Naples only take into account the proper geological features of the stone in a few peculiar cases. Thus, it seems of extreme importance to understand the basic parameters of Piperno and, above all, its response to weathering agents. Main mineralogical, petrographical and engineering–geological properties are presented here for the first time, with specific reference to two sampling areas, located at Pianura and Soccavo, in the western sector of the Neapolitan urban area. As far as many of its physico–mechanical features are concerned, Piperno extends over a wide range of values, which allow different varieties of the rock to be identified. This preliminary result is seemingly in accordance with data from old historical literature, which stated the existence of six horizons in the Piperno formation. 相似文献
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Renzo Salimbeni Roberto Pini Salvatore Siano Giancarlo Calcagno 《Journal of Cultural Heritage》2000,1(4):2215
The utilization of laser light to produce fine and selective cleaning of superficial deposits and encrustation from stones was originally proposed more than 20 years ago by John Asmus who performed pioneering trials of laser cleaning on stone façades in Venice, Cremona and Padua. The opportunity to collect stone samples from these sites allowed us to carry out an original study aimed at evaluating the conservation state of stone surfaces cleaned 10–20 years ago by means of three different techniques: Nd:YAG laser radiation, micron sandblasting and chemical pads. Samples of various stone types, as Istria limestone, Botticino limestone and Nanto sandstone were collected and examined by means of optical and SEM microscopy, FT/IR, and EDAX analyses. The results provided preliminary indications that the state of conservation of stone surfaces previously subjected to laser cleaning is generally better in comparison with those which concurrently underwent mechanical and chemical cleaning. 相似文献
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An investigation has been undertaken at St Andrew’s church, Walpole St Andrew, Norfolk, to establish the underlying causes of the observed stone decay to the upper parts of the six stone piers. The stone decay was first recorded in the early 1930s. The salt-contaminated masonry within the church has been shown to undergo severe salt decay during the summer, with little damage occurring over the winter months. The south aisle piers have been shown to decay 2.5 times faster than the north aisle piers. Although crystallization–hydration cycles have been identified, the rate of decay is at its greatest when the cycling is relatively infrequent. This was not the expected trend. Furthermore, it has been shown that during extended periods where the ambient relative humidity is less than 75%, the rate of decay reaches a maximum. It is the length of this ‘drying’ period that apparently has the greatest influence on the rate of decay and could explain the significant difference in the rate of decay between the south and north aisle piers. The results have serious implications for passive conservation, where it is often recommended to lower the ambient relative humidity to well below the equilibrium relative humidity of the salt contaminant, to avoid crystallization–hydration cycles. Since, at the time of building, the church was situated on the coast, it is possible that the sodium chloride contamination occurred during the building process (1440–1520), particularly since the area was prone to sea-flooding at this time. Alternatively, the salt could have been applied as a treatment during the general restoration of 1897. Whatever the source of the salt, it seems likely that the ambient environment was changed by the insertion of a sealed floor in 1897, which could account for the onset of the salt decay. 相似文献
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《Journal of Cultural Heritage》2001,2(2):117-132
The preservation of historical monuments requires both a detailed understanding of water circulation inside construction materials, and a deep comprehension of the associated physical and chemical effects on building structure. Combining mass and temperature measurements may be a new powerful tool to achieve this purpose, as first results obtained on a wall of the Saint-Gatien cathedral in Tours, France, indicate. The proposed method has been evaluated with dedicated experiments in a climatic chamber, regulated in both temperature and humidity, using three types of stones: Tours tuffeau, Baumberg limy sandstone, and Rüthen sandstone. Climatic chamber data indicate that temperature gradients between rock surface and atmosphere provide a meaningful and practical estimate of the water flow, which controls the heat exchange between rock and atmosphere because of the high enthalpy of vaporisation of water. Continuous measurements of the mass of a sample confirm this assumption and allow the calibration of temperature data with respect to water flow estimations. Temperature gradients between points on the stone surface are also dominated by changes in the water flux, and they provide a sensitive estimate of local variations in the heat and water transport properties of non-saturated stones. Combined mass and temperature measurements therefore appear as a promising method to estimate in situ the global and local water flow between the rock and the atmosphere and thus to diagnose the state of stone degradation, or to estimate quantitatively the efficiency of treatment processes, both in the field and in the laboratory. 相似文献
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The genesis and characterisation of ‘Marmor Misium’ from Kozak (Turkey), a granite used in antiquity
《Journal of Cultural Heritage》2000,1(2):145-153
‘Marmor Misium’ was one of the most used granites of antiquity, especially for the manufacture of columns and slabs. It was quarried in the area of Kozak (Turkey) and used locally from the Late Hellenistic period and later, probably at the end of the 1st century AD, exported to Rome and other important Roman towns of the Mediterranean sea. It seems that ‘Marmor Misium’ continued to be quarried until the Early Byzantine time; it is now still quarried for local use (road paving, etc.). In spite of its historical importance and geological interest, this granite has never been the subject of detailed petrological studies. That is why in this work it has been sampled from various outcrops of the plutonite and in abandoned ancient quarries and characterised petrographically and geochemically. From the petrographic point of view, the plutonites of Kozak are medium-grained biotite-hornblende granite and granodiorite composed of 34.2–53 % (modal) zoned plagioclase, 23.7–35.4 % K-feldspar, 21.4–29 % anhedral quartz, 4.9–10 % brown biotite and 7.7 % green hornblende. These rocks are I-type metaluminous granitoids of high-k calc-alkaline orogenic series forming a crystallised body at a depth of about 10 km. The positive distinction between ‘Marmor Misium’ and two other granites used in antiquity and macroscopically very similar to it, those from the Elba and Giglio islands (Italy), is easily made by considering the absence of hornblende, the peraluminous character and the lower Sr and Ba and higher Rb contents for the latter. 相似文献