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Waste Management 25 (2005) 733736 /locate/wasman Composite materials based on wastes of at glass processing A.V. Gorokhovsky a,*, J.I. Escalante-Garcia a, G.Yu. Gashnikova b, L.P. Nikulina b, S.E. Artemenko b a Department of Engineering Ceramics, CINVESTAV Unidad Saltillo, Carr. Saltillo-Monterrey km13, AP 663, Saltillo, CP25000 Coahuila, Mexico b Department of Chemical Technology, Technological Institute of Saratov State Technical University, Pl. Svobody 17, Engels 413100, Russian Federation Accepted 3 November 2004 Available online 25 December 2004 Abstract Glass mirrors scrap and poly (vinyl) butiral waste (PVB) obtained from at glass processing plants were investigated as raw mate- rials to produce composites. The emphasis was on studying the inuence of milled glass mirror waste contents on properties of com- posites produced with PVB. The characterization involved: elongation under rupture, water absorption, tensile strength and elastic modulus tests. The results showed that the composite containing 10 wt% of ller powder had the best properties among the com- positions studied. The inuence of the time of exposure in humid atmosphere on the composite properties was investigated. It was found that the admixture of PVB iso-propanol solution to the scrap of glass mirrors during milling provided stabilization of the properties of the composites produced. 2004 Elsevier Ltd. All rights reserved. 1. Introduction The use of industrial wastes to produce composite materials is one of the current problems of industry; this provides a means to decrease environmental contamina- tion. Flat glass processing involves the generation of wastes, like scrap of glass mirrors as well as strips of poly (vinyl) butiral lm (PVB), from the manufacture of automobile windscreens (Garner, 1996) and safety architectural glass (Lievens, 1995). Clean PVB waste can be recycled on the basis of well-known technological processes; however, about 520% of this waste contains contamination, which precludes its recycling. Moreover, in developing countries there is little eorts or possibility for the recycling of this type of waste. Additionally, waste from glass mirror production (scrap or mirrors not meeting standards) has to be disposed because of the lack of technological processes oriented towards its * Corresponding author. Tel.: +52 844 438 9600; fax: +52 844 438 9610. E-mail address: alexandesaltillo.cinvestav.mx (A.V. Gorokhovsky). utilization (Foss, 1997). The amounts of such waste can reach 1015% of commercial production in dierent plants. Taking into account that the plants oriented to at glass processing, usually produce both types of the aforementioned wastes or are located close by, it was of interest to investigate the possibility of producing glass-polymer composites based on the complex utiliza- tion of such wastes that are inapplicable for recycling. The production of composites based on PVB wastes is especially attractive in developing countries, where their collection as well as transportation into the plants spe- cialized in PVB recycling is economically unprotable. The high adhesion properties of the PBV to the soda- lime-silicate glass surface (Garner, 1996; Gopal et al., 1997) make the composite, based on PVB waste and milled glass, a promising material useful for dierent applications. The best scheme is that for plants produc- ing both wastes, for example in the manufacturing of dierent proled rods, characterized with high mechan- ical properties stable in conditions of humid atmosphere and temperature changes. However, the presence of 0956-053X/$ - see front matter 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.wasman.2004.11.007 nts734 A.V. Gorokhovsky et al. / Waste Management 25 (2005) 733736 metal particles on the glass surface of milled glass mirror scrap as well as the use of PVB waste could negatively inuence the exploitation properties and thus must be investigated. 2. Methodology Wastes of Saratovsteklo Inc. (Russia) were used for the experiments. The glass used to produce mirrors had the following chemical composition (wt%): 73.1 SiO2; 1.1 Al2O3; 8.6 CaO; 3.6 MgO; 13.6 Na2O. The mirror coating was formed by vacuum sputtering of stainless steel. PVB waste was obtained from the poly- mer lm B-17 produced by Monsanto. In Series 1 of the experiments, the ller was produced by dry ball milling of glass mirror scrap, in jars of alu- mina with balls of alumina, to reach a surface area of 4000 100 cm2/g (controlled by LHM-8MD Russian equipment). The ground glass was then added to PVB waste molten at 115 C, the latter was previously ad- mixed with 0.5 wt% of poly (ethyl) silane (PES-5, Volzh- skii, Russia) to promote the blending of components and increase homogeneity of composition. The ratio of glass powder and molten PVB was varied in the range of 130 wt%. The mixtures obtained were used to pro- duce lms by quenching, as well as rods by extrusion. It is well known that water vapor adsorption onto the surface of soda-lime-silicate glasses inuences their adhesion to polymers (Kawaguchi and Pearson, 2003; Gu et al., 2000; Radhakrishnan and Unde, 1999). It has been shown (Soshko et al., 1989) that the admixtures of some organic polymers into the glass scrap during milling promoted the modication of the glass surface by the products of their thermo-mechanical destruction (Dhaliwal and Hay, 2000). For this reason, an addi- tional batch of Series 2 was prepared using composites made from the resulting material obtained after joint ball milling of glass mirrors scrap admixed with PVB waste dissolved at room temperature in iso-propanol (15% solution); the weight ratio of glass scrap and PVBalcohol solution was 0.05. It was expected that the glass powder thus obtained would have enhanced hydrophobic properties and improved adhesion to PVB. To characterize such surface modication, the ob- tained llers were investigated by TGA/DTGA (Perkin Elmer/Seiko Instruments, Japan) for the following types of glass powder: (a) fresh dry milled, (b) dry milled and exposed to a humid atmosphere for a month, (c) milled with PVB alcohol solution and exposed to a hu- mid atmosphere for a month. The average tensile mechanical strength of the com- posite articles was measured by testing 18 specimens of each system using the ER-5046-5 Russian equipment. The Young modulus was measured following the E1875-00e1 ASTM standard using UZIS equipment (LETI, Russia). Taking into account the inuence of environmental factors on the properties of materials produced, speci- mens of the two composites, prepared with the llers of Series 1 and 2, were exposed for three months at 25 C in air (40% humidity); and the same mechanical tests, as previously described, were repeated to determine the range of variation in the main characteristics during exploitation. 3. Results and discussion The main characteristics of composites with dierent contents of glass powder for Series 1, measured immedi- ately after their production, are presented in Table 1. The introduction of 110 wt% of glass powder into the matrix of PVB waste increased the mechanical strength of the composite (by 1.6 times) and decreased its relative elongation under the rupture (by 1.3 times). Further in- crease of glass powder contents decreased the exploita- tion properties. The inuence of exposure to a humid atmosphere on the exploitation properties of the composite, made from Series 1 with 10 wt% of glass powder (highest mechani- cal properties), is presented in Figs. 1 and 2. All the tested properties decreased only during the rst two months of exposure and then stabilized. The same eect was displayed by the results presented in Table 2, show- ing the properties of composites obtained with the fresh and old (exposed in air for a month) glass powder. Such reduction in the exploitation properties observed, in agreement with published results (Keller and Mortelmans, 1999), can be attributed to the pro- cesses taking place on the surface of glass ller before the production of composites: adsorption (condensa- tion) of water vapor from the atmosphere, leaching of sodium ions, and crystallization of Na2CO3 and NaH- Table 1 The properties of composites obtained by extrusion of samples made of separate dry milling of glass Properties Contents of glass powder (wt%) 0 1 3 5 10 15 20 2530 Young module (MPa) 2.3 2.5 2.7 2.9 4.3 3.8 2.7 2.5 2.3 Tensile strength (MPa) 6.8 5.2 7.4 7.9 11.2 8.4 8.5 7.0 5.4 Relative elongation under rupture (%) 318 345 288 271 237 328 295 286 142 ntsA.V. Gorokhovsky et al. / Waste Management 25 (2005) 733736 735 35 30 25 Relative elongation 60 50 40 1 4 5 6 C 20 15 10 under a rupture Tensile strength 30 20 10 1 1 2 2 3 B 5 Young A 0 modulus 0 50 100 150 Exposure, days 0 50 100 150 200 250 300 350 400 450 500 Temperature,C Fig. 1. Inuence of exposure to humid atmosphere on properties of composites produced with powder obtained from Series 1 (continuous lines) and Series 2 (dashed lines): relative elongation under a rupture (%10 1), tensile strength (MPa), Young modulus (MPa). CO3 as a result of the sodium ions interaction with dis- solved CO2. The presence of these crystals and adsorbed water onto the surface of glass ller decreased adhesion with PVB. At the same time, modication of the glass powder surface during the milling of glass mirrors scrap with PVB alcohol solution (Series 2) can increase the hydrophobic properties of the glass powder and stabilize the structure of the composite. A comparison of proper- ties for composites from Series 1 and 2 is shown in Figs. 1 and 2; an improvement and increased stability of prop- erties of the composite produced in Series 2 can be noted. 3 2.5 2 1.5 1 0.5 0 0 50 100 150 Exposure, days Fig. 2. Inuence of exposure in humid atmosphere (dashed lines) and water (continuous lines) on weight of composite rods produced from Series 1 (d) and Series 2 (s). Fig. 3. DTGA data obtained for dierent types of ller: A fresh dry milled, B old dry milled, C old milled with PVB alcohol solution. 1, 2 desorption of condensed water, 3 desorption of chemically adsorbed water, 4 melting of PVB; 5, 6 thermal decomposition of PVB and its derivatives formed by milling. The obtained data of DTGA (Fig. 3) indicates that the old glass ller, in comparison with the fresh l- ler obtained by dry ball milling, is characterized by the additional intensive peak at 350420 C, related to the desorption of chemically adsorbed water (Hench, 1978; Gorokhovsky, 1988). At the same time, this peak is ab- sent for the ller milled jointly with the PVB solution in iso-propanol; moreover, the quantity of condensed water is much less. The additional peaks in the thermo- gram of this ller are related to the melting and thermal decomposition of PVB (Dhaliwal and Hay, 2000). Thus, it is possible to propose that the eect of stabilization of the mechanical properties, obtained for the composite produced on the base of glass powder with modied sur- face (Series 2), was achieved due to a decreased adsorp- tion of water vapor. The composite rods of dierent proles, produced by extrusion of the batch based on the PVB wastes and glassy ller (10 wt%), obtained by joint ball milling of glass mirrors scrap with PVB waste, dissolved at room temperature in iso-propanol (15% solution), were ap- plied in Salavatsteklo Co. (Salavat, Russia) to manufac- ture the double glazing blocks, as well as bases for the storage and transportation of glass sheets of high thick- ness (weight). Table 2 Properties of composites, made from Series 1 and with 10 wt% of glass powder, produced immediately after the milling and after one month of glass powder storage in air Property Type of glass powder applied 4. Conclusions Composite materials with attractive exploitation properties can be produced on the basis of typical wastes of at glass processing: poly (vinyl) butiral ribbons and One month after milling Fresh powder glass mirror scrap. The contents about of 10 wt% of glass powder results in composites with high and stable Young modulus (MPa) 3.8 4.3 Tensile strength (MPa) 8.2 11.2 mechanical properties. The introduction of PVB alco- hol solution resulted in the stabilization of properties Relative elongation before the rupture (%) 281 237 of the composites in the case of exposure to humid atmospheres. nts736 A.V. Gorokhovsky et al. / Waste Management 25 (2005) 733736 References Dhaliwal, A.K., Hay, J.N., 2000. The characterization of polyvinyl butyral by thermal analysis. Thermochimica Acta 391 (12), 245 255. Foss, R.V., 1997. Recycling of architectural and automotive glass in Europe. With emphasis on Germany. In: Proc. of 6th International Conference on Architectural and Automotive Glass, Tampere, pp. 4448. Garner, J., 1996. Automotive glass windscreen design and shaping. Glass Technology 37 (5), 151152. Gopal, S., Ramchandran, R., Agnihotry, R.S.A., 1997. Polyvinyl butyral based solid polymeric electrolytes: preliminary studies. Solar Energy Materials and Solar Cell 45 (1), 1725. Gorokhovsky, A.V., 1988. About the nature of surface acidity of multi-component silicate glass. Fizika I Khimiya Stekla (Glass Physics and Chemistry) 14 (5), 739743. Gu, W., Wu, H.F., Kampe, S.L., Lu, G.-Q., 2000. Volume fraction eects on interfacial adhesion strength of glass-ber-reinforced polymer composite. Materials Science and Engineering A 277 (1 2), 237243. Hench, L., 1978. Physical chemistry of glass surfaces. Journal of Non- Crystalline Solids 28 (1), 83105. Kawaguchi, T., Pearson, R.A., 2003. The eect of particlematrix adhesion on the mechanical behavior of glass lled epoxies. Part 2. A study on fracture toughness. Polymer 44 (15), 42394247. Keller, U., Mortelmans, H., 1999. Adhesion in laminated safety glass what makes it work. In: Proc. of 6th International Conference on Architectural and Automotive Glass, Tampere, pp. 353356. Lievens, H., 1995. Wide web coating of complex materials. Surface and Coatings Technology 7677 (Part 2), 744753. Radhakrishnan, S., Unde, S., 1999. Eect of substrate preconditioning on charge transport at the phthalocyanineconducting polymer lm interface. Thin Solid Films 347 (12), 229232. Soshko, A.I., Shkarapata, Ya.E., Bolyuk, I.M., 1989. Inuence of polymer containing compositions on the eectiveness of the mechanical treatment of glass. Glass Ceramics 65 (2), 1516. ntswastesS.E.SaratovFederationNovember25 Decembeinfluenceposites produced with PVB. The characterization involved: elongation under rupture, water absorption, tensile strength and elasticprovides a means to decrease environmental contamina-tion. Flat glass processing involves the generation ofthe lack of technological processes oriented towards itsglass processing, usually produce both types of theaforementioned wastes or are located close by, it wasapplications. The best scheme is that for plants produc-ing both wastes, for example in the manufacturing ofdierent profiled rods, characterized with high mechan-ical properties stable in conditions of humid atmosphereand temperature changes. However, the presence of*Corresponding author. Tel.: +52 844 438 9600; fax: +52 844 4389610.E-mail address: alexandesaltillo.cinvestav.mx (A.V. Gorokhovsky).Waste Management 250956-053X/$ - see front matter C211 2004 Elsevier Ltd. All rights reserved.wastes, like scrap of glass mirrors as well as strips ofpoly (vinyl) butiral film (PVB), from the manufactureof automobile windscreens (Garner, 1996) and safetyarchitectural glass (Lievens, 1995). Clean PVB wastecan be recycled on the basis of well-known technologicalprocesses; however, about 520% of this waste containscontamination, which precludes its recycling. Moreover,in developing countries there is little eorts or possibilityfor the recycling of this type of waste. Additionally,waste from glass mirror production (scrap or mirrorsnot meeting standards) has to be disposed because ofof interest to investigate the possibility of producingglass-polymer composites based on the complex utiliza-tion of such wastes that are inapplicable for recycling.The production of composites based on PVB wastes isespecially attractive in developing countries, where theircollection as well as transportation into the plants spe-cialized in PVB recycling is economically unprofitable.The high adhesion properties of the PBV to the soda-lime-silicate glass surface (Garner, 1996; Gopal et al.,1997) make the composite, based on PVB waste andmilled glass, a promising material useful for dierentmodulus tests. The results showed that the composite containing 10 wt% of filler powder had the best properties among the com-positions studied. The influence of the time of exposure in humid atmosphere on the composite properties was investigated. It wasfound that the admixture of PVB iso-propanol solution to the scrap of glass mirrors during milling provided stabilization of theproperties of the composites produced.C211 2004 Elsevier Ltd. All rights reserved.1. IntroductionThe use of industrial wastes to produce compositematerials is one of the current problems of industry; thisutilization (Foss, 1997). The amounts of such wastecan reach 1015% of commercial production in dierentplants.Taking into account that the plants oriented to flatComposite materials based onA.V. Gorokhovskya,*, J.I. Escalante-GarciaL.P. Nikulinab,aDepartment of Engineering Ceramics, CINVESTAV Unidad Saltillo, Carr.bDepartment of Chemical Technology, Technological Institute ofRussianAccepted 3Available onlineAbstractGlass mirrors scrap and poly (vinyl) butiral waste (PVB) obtainedrials to produce composites. The emphasis was on studying thedoi:10.1016/j.wasman.2004.11.007of flat glass processinga, G.Yu. Gashnikovab,ArtemenkobSaltillo-Monterrey km13, AP 663, Saltillo, CP25000 Coahuila, MexicoState Technical University, Pl. Svobody 17, Engels 413100,2004r 2004from flat glass processing plants were investigated as raw mate-of milled glass mirror waste contents on properties of /locate/wasman(2005) 733736ntsmetal particles on the glass surface of milled glass mirrorscrap as well as the use of PVB waste could negativelyinfluence the exploitation properties and thus must beinvestigated.2. Methodologyof glass powder: (a) fresh dry milled, (b) dry milledand exposed to a humid atmosphere for a month, (c)milled with PVB alcohol solution and exposed to a hu-mid atmosphere for a month.The average tensile mechanical strength of the com-posite articles was measured by testing 18 specimens ofeach system using the ER-5046-5 Russian equipment.The Young modulus was measured following thetested properties decreased only during the first twomonths of exposure and then stabilized. The same eectTable 1The properties of composites obtained by extrusion of samples made of separa(wt%)2.77.4734 A.V. Gorokhovsky et al. / Waste Management 25 (2005) 733736Properties Contents of glass powder013Young module (MPa) 2.3 2.5Tensile strength (MPa) 6.8 5.2Wastes of Saratovsteklo Inc. (Russia) were used forthe experiments. The glass used to produce mirrorshad the following chemical composition (wt%): 73.1SiO2; 1.1 Al2O3; 8.6 CaO; 3.6 MgO; 13.6 Na2O. Themirror coating was formed by vacuum sputtering ofstainless steel. PVB waste was obtained from the poly-mer film B-17 produced by Monsanto.In Series 1 of the experiments, the filler was producedby dry ball milling of glass mirror scrap, in jars of alu-mina with balls of alumina, to reach a surface area of4000 100 cm2/g (controlled by LHM-8MD Russianequipment). The ground glass was then added to PVBwaste molten at 115 C176C, the latter was previously ad-mixed with 0.5 wt% of poly (ethyl) silane (PES-5, Volzh-skii, Russia) to promote the blending of componentsand increase homogeneity of composition. The ratio ofglass powder and molten PVB was varied in the rangeof 130 wt%. The mixtures obtained were used to pro-duce films by quenching, as well as rods by extrusion.It is well known that water vapor adsorption onto thesurface of soda-lime-silicate glasses influences theiradhesion to polymers (Kawaguchi and Pearson, 2003;Gu et al., 2000; Radhakrishnan and Unde, 1999). Ithas been shown (Soshko et al., 1989) that the admixturesof some organic polymers into the glass scrap duringmilling promoted the modification of the glass surfaceby the products of their thermo-mechanical destruction(Dhaliwal and Hay, 2000). For this reason, an addi-tional batch of Series 2 was prepared using compositesmade from the resulting material obtained after jointball milling of glass mirrors scrap admixed with PVBwaste dissolved at room temperature in iso-propanol(15% solution); the weight ratio of glass scrap andPVBalcohol solution was 0.05. It was expected thatthe glass powder thus obtained would have enhancedhydrophobic properties and improved adhesion toPVB. To characterize such surface modification, the ob-tained fillers were investigated by TGA/DTGA (PerkinElmer/Seiko Instruments, Japan) for the following typesRelative elongation under rupture (%) 318 345 288was displayed by the results presented in Table 2, show-ing the properties of composites obtained with thefresh and old (exposed in air for a month) glasspowder. Such reduction in the exploitation propertiesobserved, in agreement with published results (Kellerand Mortelmans, 1999), can be attributed to the pro-cesses taking place on the surface of glass filler beforethe production of composites: adsorption (condensa-tion) of water vapor from the atmosphere, leaching ofsodium ions, and crystallization of Na2CO3and NaH-te dry milling of glass510152025302.9 4.3 3.8 2.7 2.5 2.37.9 11.2 8.4 8.5 7.0 5.4E1875-00e1 ASTM standard using UZIS equipment(LETI, Russia).Taking into account the influence of environmentalfactors on the properties of materials produced, speci-mens of the two composites, prepared with the fillersof Series 1 and 2, were exposed for three months at 25C176C in air (40% humidity); and the same mechanical tests,as previously described, were repeated to determine therange of variation in the main characteristics duringexploitation.3. Results and discussionThe main characteristics of composites with dierentcontents of glass powder for Series 1, measured immedi-ately after their production, are presented in Table 1.The introduction of 110 wt% of glass powder into thematrix of PVB waste increased the mechanical strengthof the composite (by 1.6 times) and decreased its relativeelongation under the rupture (by 1.3 times). Further in-crease of glass powder contents decreased the exploita-tion properties.The influence of exposure to a humid atmosphere onthe exploitation properties of the composite, made fromSeries 1 with 10 wt% of glass powder (highest mechani-cal properties), is presented in Figs. 1 and 2. All the271 237 328 295 286 142ntsCO3as a result of the sodium ions interaction with dis-solved CO2. The presence of these crystals and adsorbedwater onto the surface of glass filler decreased adhesionwith PVB. At the same time, modification of the glasspowder surface during the milling of glass mirrors scrapwith PVB alcohol solution (Series 2) can increase thehydrophobic properties of the glass powder and stabilizethe structure of the composite. A comparison of proper-ties for composites from Series 1 and 2 is shown in Figs.1 and 2; an improvement and increased stability of prop-glass mirrors scrap with PVB waste, dissolved at roomtemperature in iso-propanol (15% solution), were ap-Temperature,C3530Characteristics25Relative elongation under a rupture 2015Tensile strength105Youngmodulus00 50 100 150Exposure, daysFig. 1. Influence of exposure to humid atmosphere on properties ofcomposites produced with powder obtained from Series 1 (continuouslines) and Series 2 (dashed lines): relative elongation under a rupture(%10C01), tensile strength (MPa), Young modulus (MPa).A.V. Gorokhovsky et al. / Waste Managementerties of the composite produced in Series 2 can benoted.32.5Sweling, wt.%21.510.50Table 2Properties of composites, made from Series 1 and with 10 wt% of glasspowder, produced immediately after the milling and after one monthof glass powder storage in airProperty Type of glass powder appliedOne monthafter millingFresh powderYoung modulus (MPa) 3.8 4.3Tensile strength (MPa) 8.2 11.2Relative elongation beforethe rupture (%)281 2370 50 100 150Exposure, daysFig. 2. Influence of exposure in humid atmosphere (dashed lines) andwater (continuous lines) on weight of composite rods produced fromSeries 1 (d) and Series 2 (s).The obtained data of DTGA (Fig. 3) indicates thatthe old glass filler, in comparison with the fresh fil-ler obtained by dry ball milling, is characterized by theadditional intensive peak at 350420 C176C, related to thedesorption of chemically adsorbed water (Hench, 1978;Gorokhovsky, 1988). At the same time, this peak is ab-sent for the filler milled jointly with the PVB solution iniso-propanol; moreover, the quantity of condensedwater is much less. The additional peaks in the thermo-gram of this filler are related to the melting and thermaldecomposition of PVB (Dhaliwal and Hay, 2000). Thus,it is possible to propose that the eect of stabilization ofthe mechanical properties, obtained for the compositeproduced on the base of glass powder with modified sur-face (Series 2), was achieved due to a decreased adsorp-tion of water vapor.The composite rods of dierent profiles, produced byextrusion of the batch based on the PVB wastes andglassy filler (10 wt%), obtained by joint ball milling ofFig. 3. DTGA data obtained for dierent types of filler: A freshdry milled, B old dry milled, C old milled with PVB alcoholsolution. 1, 2 desorption of condensed water, 3 desor
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