首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 578 毫秒
1.
在从炼油至后续深加工的石化产品生产中,会使加工设备表面沉积各种类型的污垢,从而使生产过程中的能耗增加,设备寿命缩短,严重时还会使污垢堵塞设备,使生产无法正常进行;为此,必须进行除垢清洗。本文主要以聚氯乙烯(PVC)生产装置中聚合釜内的污垢为清洗研究对象,针对污垢成分,采用正交试验法来确定适合的清洗配方。试验结果表明,以柴油为清洗基液,以三氯甲烷、N-N 二甲基甲酰胺、OP-10和乙醇为清洗成分的清洗剂,能有效地溶解聚氯乙烯型污垢。高温有利于污垢的溶解,表面活性剂 OP-10可促进污垢的溶解,使溶解后的污垢呈糊状。  相似文献   

2.
This article presents an integrated approach for the authentication of five Russian icons through the study of their paint materials (elemental composition and stratigraphic mapping), state of conservation and artistic technique. The results of the applied analytical protocol, involving optical and scanning electron microscopy coupled with energy‐dispersive X‐ray spectrometry and Fourier transformed infrared spectroscopy/microspectroscopy, led to the conclusion that the five icons belong to the same group and iconographic school (from Northern Russia) and date from the end of the 16th century to the beginning of 17th century. Because of massive overpainting, the icons “suffered” a change in iconographic style and significance, and restoration treatment brought to light the original painting and its attribution. Identification of the composition of the original chromatic palette used by the iconographer, the stratigraphic mapping and the conservation state of the painting materials, along with the features of the original artistic technique, furnished key elements for the icons' authentication. Here, we present the first experimental data concerning the identification of the authentication characteristics, being part of a large project that has as its final aim the evaluation of the effectiveness and effects of the cleaning agent on the paint layers. Microsc. Res. Tech. 2009. © 2009 Wiley‐Liss, Inc.  相似文献   

3.
Engines can be damaged in many ways: the principal oil‐related problems are due to deposit formation and viscosity increase. A first step in minimising the consequences of oil degradation is to reduce the formation of sludge and deposits. This can be accomplished by the judicious use of metal‐free (ashless) anti‐oxidants. Detergent/dispersant additives play a critical role in extending lubricant life by cleaning up deposits and keeping them in solution, and by neutralising acids formed during the combustion process. Several different types of antioxidants that can successfully eliminate precursors that lead to deposit formation and viscosity increase in oils in both gasoline and diesel engines have been identified. A novel, ashless, multifunctional additive that confers thermo‐oxidative stability and friction modification to engine lubricants is described here.  相似文献   

4.
Combined microscopy techniques are used to establish the usability of phosphonic acid layers as promoters of hydroxyapatite (HAp) growth. Using spread coating, octadecylphosphonic acid (OPA) self‐assembled bilayers are delivered to the thin natural oxide layer of a titanium film surface with no prior treatment. These bilayers aggregate two major advantages of phosphonic moieties to titanium surfaces: nucleation of hydroxyapatite crystals from ionic solution and affinity for both titanium oxide surface and HAp crystals. The functionalized substrates and bare titanium (control) samples are immersed in an aqueous solution containing calcium and phosphorus ions. Over a 4‐week immersion time, OPA‐functionalized substrates present numerous large agglomerates of inorganic crystals, in contrast to control samples, with no significant amount of deposits. Initial sample characterization was performed with atomic force microscopy (AFM). Compositional and structural characterization of these agglomerates (using TEM, EDS, and electron diffraction), revealed that they are indeed HAp, the main component of the inorganic bone matrix. Microsc. Res. Tech. 76:1278–1283, 2013. © 2013 Wiley Periodicals, Inc.  相似文献   

5.
A novel approach for studying the adsorption and evaporation processes of molecularly thin methanol film by the modified surface forces apparatus (M‐SFA) is reported. This method can be used precisely to measure the thickness, morphology, and mechanical properties of the film confined between two mica surfaces in a real‐time manner at gas atmosphere. By observing the adsorption and evaporation processes of the methanol molecule, it is found that the first adsorbed layer of the methanol film on the mica surface behaves as a solid‐like structure. The thickness of this layer is measured to be about 3.2 Å, approximately equal to the diameter of a methanol molecule. Besides, this first adsorbed layer can carry normalized loads of more than 5.6 atm due to the carrying capacity conserved by the bond of mica‐OH. The outer layers of the methanol film are further adsorbed with the increase of the exposure time, which are liquid‐like and can be easily eliminated out from the substrate. The present study suggests that the interacting mode between hydroxy and mica is of great potential in material science and biomedical systems. Microsc. Res. Tech. 77:851–856, 2014. © 2014 Wiley Periodicals, Inc.  相似文献   

6.
介绍了电动拖地车的结构和工作原理,对地面的污染情况进行了分析,研究了对不同污染情况进行不同清洁的方法。并且说明了持续拖地的方法,进行了劳动强度和效率的分析。  相似文献   

7.
The sharpness of atomic force microscope (AFM) tips is essential for acquiring high quality AFM images. However, AFM tips would easily get contaminated during scanning and storage at ambient condition, which influences image resolution and causes image distortion. Replacing the probe frequently is a solution, but uneconomical. To solve this problem, several tip cleaning methods have been proposed but there is space for further improvement. Therefore, this article developed a method of tip cleaning by using a one‐dimensional grating (600 lines/mm) as a micro‐washboard to “wash” contaminated tips. We demonstrate that the contaminants can be scrubbed away by rapidly scanning such micro‐washboard against the tip in the aids of Z‐dithering (10–20 Hz) exerted on the washboard. This method is highly efficient and proved to be superior to traditional ones. Experiments show that AFM images acquired with “washed” tips have higher resolution and less distortion compared with images acquired using contaminated tips, even comparable to those scanned by new ones. Microsc. Res. Tech. 76:1131–1134, 2013. © 2013 Wiley Periodicals, Inc.  相似文献   

8.
介绍了反应堆压力容器紧固件及其表面污垢的特点,结合紧固件清洗条件及要求,分析了常用的紧固件清洗方式,确定了适合反应堆压力容器紧固件清洗的技术方案,研制出相应的清洗设备。该设备布置灵活、且便于运输和系统扩展,并应用于工程实践。  相似文献   

9.
The osmium maceration method with scanning electron microscopy (SEM) enabled to demonstrate directly the three‐dimensional (3D) structure of membranous cell organelles. However, the polarity of the Golgi apparatus (that is, the cistrans axis) can hardly be determined by SEM alone, because there is no appropriate immunocytochemical method for specific labelling of its cis‐ or trans‐faces. In the present study, we used the osmium impregnation method, which forms deposits of reduced osmium exclusively in the cis‐Golgi elements, for preparation of specimens for SEM. The newly developed procedure combining osmium impregnation with subsequent osmium maceration specifically visualised the cis‐elements of the Golgi apparatus, with osmium deposits that were clearly detected by backscattered electron‐mode SEM. Prolonged osmication by osmium impregnation (2% OsO4 solution at 40°C for 40 h) and osmium maceration (0.1% OsO4 solution at 20°C for 24 h) did not significantly impair the 3D ultrastructure of the membranous cell organelles, including the Golgi apparatus. This novel preparation method enabled us to determine the polarity of the Golgi apparatus with enough information about the surrounding 3D ultrastructure by SEM, and will contribute to our understanding of the global organisation of the entire Golgi apparatus in various differentiated cells.  相似文献   

10.
The extra‐cellular matrix of fertilized eggs in the bufonid toads Bufo bufo and Bufotes balearicus was studied to clear the relationships between structural and molecular diversity. Histochemical (PAS, AB pH 2.5 and pH 1.0, Beta‐elimination PAS) and lectin‐histochemical (Con A, WGA, Succinyl‐WGA, PNA, RCA‐1, DBA, SBA, AAA, UEA‐I, LTA) techniques were used and the observations were made under light and electron microscopy. Both species present a fertilization envelope (FE) and two jelly layers (J1 and J2). The fibers of J2 are shared among the eggs of a clutch in a jelly ribbon. The FE of both species presents neutral glycoproteins, mostly N‐linked. In B. bufo there are also residuals of mannose and/or glucose and N‐acetylglucosamine. In the FE fibers run parallel to egg's surface or are in bundles or looser hanks with no clear orientation. The J1 layer of both species presents sialosulfoglycoproteins, mostly O‐linked, with lactosaminylated, galactosaminylated, glycosaminylated, and fucosylated residuals. A lower amount of galactosaminylated residuals is observed in B. balearicus in respect to B. bufo, whereas the opposite is seen in the amount of fucosylated residuals. The J2 layer is similar in composition to J1 but in B. balearicus there are no glucosaminylated residuals. J layers present fibers and granules that reduce towards J2. Several microorganisms, in particular blue algae, are observed in the J2 layer of both species. In respect to other species, B. bufo and B. balearicus have a lower number of jelly layers, but a comparable number of glycan types. Microsc. Res. Tech. 77:910–917, 2014. © 2014 Wiley Periodicals, Inc.  相似文献   

11.
The purpose of this study was to evaluate and compare cleaning effectiveness of TwistedFile, GT series X, Revo‐S, RaCe, Mtwo, and ProTaper Universal rotary files in curved canals. Seventy mesiobuccal canals of extracted human first maxillary molars were divided into seven groups of 10 samples each. Canals were prepared with six nickel–titanium (NiTi) rotary systems and manual K‐Flexofile. Irrigation was performed with 2 mL 2.5% NaOCl solution after each file, and 5 mL 2.5% NaOCl was used for the final flush. After the roots were split longitudinally, the presence of debris and smear layer was visualized using scanning electron microscopic photomicrographs taken at coronal, middle, and apical third. Mean scores for debris and the smear layer were calculated and statistically analyzed for significance between groups using the Kruskal–Wallis nonparametric analysis of variance (P < 0.05) and Mann–Whitney U test (P < 0.001). There was no significant difference among the groups in terms of debris and smear layer scores (P > 0.05). Without considering the preparation method used, while no statistically significant difference was found between the coronal third and the middle third (P > 0.05), higher amount of debris and smear layer were found in apical third (P = 0.001). The new generation of NiTi rotary files including the Twisted File and GT Series X presented similar cleaning effectiveness compared with traditionally ground NiTi rotary files. Microsc. Res. Tech. 76:231–236, 2013. © 2012 Wiley Periodicals, Inc.  相似文献   

12.
Consolidation of frail, degraded wood is a key issue of wooden cultural heritage conservation. Paraloid B72 is one of the most often used consolidant in conservation practice. The present research aimed at formulating stable consolidation solutions of Paraloid B72 with ZnO nano‐additives and at determining the influence of these additives on the penetration pathways, retention of the consolidation material into wood and on the water behavior of the treated wood. The experiments were performed on sound samples of aspen (Populus tremula). The addition of nano‐ZnO slightly increased the uptake and retention of the consolidant within the wooden structure and led to hydrophobic surfaces. However, the influence of nano‐ZnO additives to the water absorption was not conclusive. Scanning Electron Microscope coupled with an EDX Detector investigation proved vessels, fibers, and interconnecting pits as main pathways of consolidant penetration into the wooden structure as well as the presence and distribution of nano‐ZnO. Microsc. Res. Tech., 2013. © 2012 Wiley Periodicals, Inc.  相似文献   

13.
Our article presents the results of the analyses we performed by corroborating the Optical Microscopy, Scanning Electron Microscopy, Energy Dispersive Xray Analysis and micro Fourier Transformed InfraRed Analysis techniques to identify the archaeo‐metallurgic casting and ornamentation procedure of a decorated disk‐butted axe, which was discovered recently east of the Carpathian mountains, in the Moldavian Plateau. There are few known axes of that type found (A1, according to the usual typologies), as they are specific to the Middle Bronze Age period west of the Carpathians—the Wietenberg, Suciu de Sus, and Otomani‐Füzesabony cultures. The experimental data on the item under study revealed the fact that after casting it in molds made from porous silicone‐based stone, the object was coated with a thin layer, by immersing it in a lightly fusible tin alloy, whose main alloy component was copper and arsenic and iron as secondary components. After refining the shiny white layer, they applied a beautiful decoration pattern made by incision and engraving. This battle axe was an indication of higher status, such items usually being owned by community leaders. This important fact proves that the ancient metallurgic craftsmen were able to elaborate and manufacture various alloys from which they made beautiful objects and it also offers a new insight into the social and symbolic function of certain antique bronze items. Microsc. Res. Tech. 77:918–927, 2014. © 2014 Wiley Periodicals, Inc.  相似文献   

14.
纵轴流风筛式清选装置多因素试验研究   总被引:1,自引:0,他引:1  
为了改善纵轴流水稻收获机清选装置的清选性能,在自行研制了纵轴流风筛式清选装置试验台的基础上进行正交旋转试验研究,分析了清选装置的曲柄转速、离心风机转速、离心风机倾角三个参数对功耗、含杂率、损失率的影响.利用各性能指标的回归方程,采用主目标函数法,用MATLAB进行优化求解,综合评定后得到优化参数为:曲柄转速为235r/min,离心风机转速为764r/min,风机倾角为28°,通过验证试验后,所得到的性能指标均满足要求.通过研究,可为清选装置的设计、制造和使用提供可借鉴的依据.  相似文献   

15.
Among the various corrosion protection strategies for structural steels, coating techniques provide the most cost‐effective protection and have been used as the primary mode of corrosion protection. Existing coating techniques however have been used mainly for their barrier capability and therefore all have a limited service life due to oxidation aging, electrolytic degradation, or various inadvertent defects and flaws occurred in and after coating applications. This work investigated the anti‐corrosion potential of a π‐conjugated polymer—polyaniline (PANi), which was doped into an intrinsically conducting polymer and then included in a two‐layer coating system as a primer layer. To achieve a long service life, the primer layer was made by mixing the conductive PANi in a waterborne poly‐vinyl butyral solution to provide strong adhesion to steel surface, and then topcoated with a layer of elastomer‐modified polyethylene to obtain extra mechanical and barrier protections. Two ASTM standard tests were conducted to evaluate the corrosion durability and tensile adhesion of the two‐layer system, in which the system demonstrated superior performance. The Scanning Kelvin Probe Force Microscopy (SKPFM) was used to provide the microscopic evidences for the outstanding performance. Microsc. Res. Tech. 76:1186–1195, 2013. © 2013 Wiley Periodicals, Inc.  相似文献   

16.
对于污物重的大型、复杂零部件的清洗,已有的清洗方法难以实现大功率,为了解决这个问题,提出了电液式大功率清洗装置。其核心零件是2D四通转阀,通过控制2D四通转阀阀芯旋转可实现激振频率的控制,改变待清洗零件振动的快慢;控制阀芯轴向滑动可实现激振幅值的控制,改变待清洗零件振动的幅值。该装置采用2D四通转阀带动液压缸中的液压杆前后移动,从而带动清洗盒前后快速振动,剥离被清洗物表面的污垢,从而达到洗净目的,实现大功率清洗。通过数据采集系统实现对液压系统的控制、可视化实时数据采集、显示和保存。基于电液式大功率清洗的工作与控制原理搭建实验平台并做实验。结果表明:该电液式大功率清洗装置可达到下限频率为2669 Hz,实现大功率清洗。  相似文献   

17.
The aim of this study was to evaluate three reciprocating systems and complementary cleaning methods on filling material removal during retreatment of flattened canals. Thirty‐six mandibular incisors were prepared using rotary instruments up to size 25.08 and filled using the single‐cone technique. Subsequently, the teeth were divided into three groups (n = 12) according to retreatment procedures: Reciproc Blue (RB): 25/0.08 and 40/0.06; ProDesign R (PDR): 25/0.06 and 35/0.05; and WaveOne Gold (WOG): 25/0.07 and 35/0.06. The remaining filling volume materials were assessed by means of micro‐CT imaging before and after retreatment. After this, the specimens were subdivided into three groups according to complementary cleaning methods: XP‐Endo Shaper (30/0.01); passive ultrasonic irrigation (PUI); 60° oscillatory instrumentation with #30 H‐file, and micro‐CT scan was taken. Then, the roots were cut in half and the samples were analyzed by scanning electron microscope (SEM). The data were analyzed statistically using Kruskal–Wallis and Dunn's Multiple Comparison test with significance level of 5%. None of the reciprocating files promoted complete removal of filling material and there was no statistical difference between the groups, regardless instrument size (p > 0.05). Complementary cleaning methods increased remnant filling removal (p < 0.05). XP‐endo Shaper significantly reduced the amount of filling material in the apical and middle thirds, compared with H‐files (p < 0.05), with no difference with PUI. In the SEM, there was no statistical difference among the instruments (p > 0.05). The reciprocating systems showed similar effectiveness in removing root filling material. Complementary cleaning method with the XP‐Shaper enhanced filling material removal.  相似文献   

18.
This article covers a methodology for evaluating the effectiveness of cleaning two Russian icons. The icons belong to a group of five from the same iconographic school, dating from the 16th to 17th centuries. An integrated and complementary approach to varnish and overpaint removal involved microscopic techniques (optical and scanning electron microscopy) and colorimetry (CIE L*a*b* system). The materials and techniques used in these icons have been characterized previously. Cleaning revealed extensive overpainting that had not only dramatically changed the original appearance, but also the meaning and attribution of one of the two icons. The analyses carried out were useful in determining the extent of the overpainting and led to a better assessment of the results and effectiveness of the restoration. Microsc. Res. Tech. 73:752–760, 2010. © 2009 Wiley‐Liss, Inc.  相似文献   

19.
陈知泰  顾委 《机械传动》2012,36(2):84-86,88
高层建筑外墙面施工包括包装、保暖层的粉刷装饰以及高层窗户的清洗工作等,大多采用手动式摩擦绳轮升降机械,升降吊篮使用的安全性显得更加重要。讨论并设计了几种新颖的简单齿轮传动机构,克服了使用者操作力度大、效率不高的缺点。现场试验验证了该方案的可靠性和实用性。  相似文献   

20.
The aim of this study was to assess the cleaning capacity of the octenidine hydrochloride (OCT) used as root canal irrigant by scanning electron microscopy (SEM) analysis. Sixty human unirradicular extracted teeth were randomly distributed in 6 groups (n = 10) according to irrigant solutions which were used during root canal preparation: G1, 0.1% OCT; G2, 2% chlorhexidine (CHX); G3, 2.5% sodium hypochlorite (NaOCl); G4, OCT + 17% ethylenediaminetetraacetic acid (EDTA); G5, 2.5% NaOCl + 17% EDTA and G6, distilled water. All specimens were instrumented with ProTaper system up to F4. Teeth were sectioned and prepared for SEM. The smear layer was evaluated using a 5‐score system and the data were analyzed by Kruskal–Wallis and Dunn (α = 0.05). In all root canal thirds there was no significant difference between OCT, CHX, NaOCl, and water groups (p > .05), and these groups showed higher smear layer values than NaOCl + EDTA and OCT + EDTA groups (p < .05). There was no significant difference between NaOCl + EDTA and OCT + EDTA groups (p > .05). It was concluded that OCT used as a single root canal irrigant presented poor cleaning capacity and could be used in association with a final irrigation with EDTA to obtain smear layer removal.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号