Ambient Pressure Preparation,Surface Structure and Adsorption Properties of Silica Aerogels

The data on this sheet represent typical values. Since application variables are a major factor in product performance, this information should serve only as a general guide. Axalta assumes no obligation or liability for use of this information . UNLESS AXALTA AGREES OTHERWISE IN WRITING, AXALTA MAKES NO WARRANTIES, EXPRESS ORIMPLIED, AND DISCLAIMS ALL IMPLIED WARRANTIES INCLUDING WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE OR FREEDOM FROM PATENT INFRINGEMENT. AXALTA WILL NOT BE LIABLE FOR ANY SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES. Your only remedy for any defect in thisproduct is the replacement of the defective product, or a refund of its purchase price, at our option. The information in this sheet, as well as the products referenced herein, shall beGENERAL INFORMATIONAxalta ’s Amarium Production Self-Seal Pre-Catalyzed Lacquers are an excellent product formulated to offer good durability and value. They are fast drying and easy to apply with excellent sanding properties. They offer good mar, solvent, chemical andmoisture resistance. When properly applied as a self-seal system or with the companion sealers, the film properties of this system provide a tough, durable finish that passes KCMA performance standards. This product is designed for professional application only. For Wood Substrates Only.1. PRODUCTS• NUF2401 – Matte● NUF2402 – Satin• NUF2404 – Soft-Gloss ● NUF2406 -Semi-Gloss• NUC2409 – Gloss2. MIXING RATIO• All products should be stirred well before use and, for bestresults, continuously agitated while in use.3. SHELF LIFE @ 77°F (25°C)• 12 months4. CLEAN UP• Dispose of dirty solvent and cleaning rags in a safe andcompliant manner. Solvent or lacquer soaked rags should be stored in water-filled, closed containers prior to disposal.5. SURFACE PREPARATION• Surface must be clean and dust free with a moisturecontent of 6-8% prior to finishing. Remove all dust, dirt, wax and wood marks. Proper sanding and preparation of the wood is critical to achieving consistent results.• On new wood, finish sand surface with 150-180 grit sandpaper• On previously finished wood, remove all old paint or varnish and follow new wood procedure.6. COMPANION PRODUCTS• NUS4010 ●NUS4020 • Graintone Plus ™ Stain system7. SUBSTRATES• Commonly used furniture and cabinetry woods • MDF/HDFNOTE: Not to be used on exterior applications10. APPLICATION• Apply at a rate of 3-4 wet mils per coat. Sand betweencoats with 240-320 grit, no fill sandpaper. This finish mustbe sanded between coats for proper adhesion. Whether using this product as a self-seal system or using inconjunction with one of the companion sealers, a total of three coats will be necessary to pass KCMA performance standards. DO NOT APPLY more than four coats at 3-4 wet mils per coat. Maximum film thickness of the total coating system MUST NOT EXCEED 4 dry mils.11. FLASH / DRY TIMESAIR DRY @ 77°F (25°C)12. FORCE DRYFlash 8 – 10 Minutes Bake 15 Minutes @ 125°F Cool Down 10 Minutes ambient Stack2 hours after cool down13. GUN SET UPGravity Feed 1.4 mm - 1.8 mm Siphon Feed 1.4 mm – 1.8 mm Airless10 – 15 thousandths Air-Assisted Airless11 – 15 thousandthsAIR PRESSURESGravity Feed 30-35 psi (2.0-2.4 bar) Siphon Feed 35-40 psi (2.4-2.8 bar) Air-Assisted Airless5-10 psi (0.3-0.7 bar)See spray gun manufacturer data for more information14. PHYSICAL DATAViscosity 23-27 EZ Zahn 2 @77FWeight Solids % 26.8 – 27.1% Volume Solids % 19.7 – 19.9%Actual VOC5.08 -5.11lbs/gal of ProductVOC Ratio (lb.voc/lb.solids) 2.49–2.54 lb VOC/lb solidRegulatory VOC(less water and exempt solvents)650 - 651 g/lWeight Per Gallon 7.52-7.54 1bs/gal Flash Point1ºF Closed CupTheoretical Coverage 316-318 ft/gal @ 1 mil dryVHAP (lb.HAP/lb.solids) 0.1 – 0.11 lb VHAP/lb solidPhotochemically Reactive No Coating CategoryClearDry to touch15-20 Minutes Flash between coats 30-45 Minutes To Stack16 - 24 HoursThe data on this sheet represent typical values. Since application variables are a major factor in product performance, this information should serve only as a general guide. Axalta assumes no obligation or liability for use of this information . UNLESS AXALTA AGREES OTHERWISE IN WRITING, AXALTA MAKES NO WARRANTIES, EXPRESS ORIMPLIED, AND DISCLAIMS ALL IMPLIED WARRANTIES INCLUDING WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE OR FREEDOM FROM PATENT INFRINGEMENT. AXALTA WILL NOT BE LIABLE FOR ANY SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES. Your only remedy for any defect in thisproduct is the replacement of the defective product, or a refund of its purchase price, at our option. The information in this sheet, as well as the products referenced herein, shall beApplication Notes:General:Always pre-test the system on your substrate to verify suitability of the application.Apply by spray only, using Conventional Air, HVLP,Airless, or Air Assisted Airless equipment. Apply at a rate of 3-4 wet mils per coat. Sand between coats with 240-320 grit, no fill sandpaper. Remove sanding dust before applying the next coat. This finish must be sandedbetween coats for proper adhesion. Whether using this product as a self seal system or using in conjunctionwith one of the companion sealers, a total of three coats will be necessary to pass KCMA performance standards. DO NOT APPLY more than four coats at 3-4 wet mils per coat. Maximum film thickness of the total coating system MUST NOT EXCEED 4 dry mils.Drying Times:Dry to touch: 15-20 minutesDry to sand and recoat: 30-45 minutes (depending on ambient conditions).Do not apply if the material or substrate temperature is below 55ºF.This product is best applied when surface and airtemperatures are between 55º-90º F (~12-32°C) and when relative humidity is below 50% during application and drying time.Clean Up:Refer to your local regulations for compliancerequirements for cleaning solvents. Dispose of dirty solvent and cleaning rags in a safe and compliantmanner. Solvent or lacquer soaked rags should be stored in water-filled, closed containers prior to disposal.Precautions:These products are recommended for professionalapplication and are designed for interior use only. Always pre-test the system on your substrate and under your line conditions to verify suitability to the application and toavoid potential need for costly refinishing. Axalta Industrial Wood Coatings products are designed to protect andenhance the natural beauty of wood, but cannot eliminate natural discoloration or deterioration of wood as it ages.Additional notes:Do not mix with other finishing systems or deviate from these finishing recommendations. Axalta will not be heldliable for finish failures resulting from the mixing of products or deviations from finishing recommendations.Storage:Store in a cool, dry place. Close all containers after use. Do not store near heat or sparks. Spills should be cleaned up with non-sparking tools. See the product MSDS for complete safety information.Warning:Always pre-test the system on your substrate and underyour line conditions to verify suitability to the application and avoid potential need for costly refinishing. All dry times listed are as tested under ideal indoor environmental conditions of 78°F (26°C) with relative humidity notexceeding 50%. These products are recommended for use under temperature conditions of 60-100°F (16-38°C) and when relative humidity is below 50% during application and drying time. Low temperatures, poor air circulation or high humidity will extend dry times. Axalta strongly recommends against use of these products iftemperatures of air, material, or surface to be coated are below 60°F (16°C) or below the dew point.Abnormal conditions of temperature or humidity may adversely affect product performance. Please contact your authorized Axalta Industrial Wood Coatings distributor for additional product use recommendations and finishing guidance.。

碳气凝胶的制备及结构郭志军;朱红;张新卫【摘要】以甲醛和间苯二酚溶胶凝胶制备有机气凝胶(OA),将有机气凝胶在半密封的情况下干燥,再在高温下碳化,制备得到碳气凝胶(CA),并分析了有机气凝胶的形成机理.通过红外(IR)、透射电镜(TEM)、X射线衍射(XRD)等考察了有机气凝胶到碳气凝胶的结构变化,从具有丰富的官能团结构的有机物,最后碳化得到具有纳米尺度、无序的、连续三维网络结构的碳材料.【期刊名称】《北京交通大学学报》【年(卷),期】2010(034)006【总页数】4页(P103-106)【关键词】溶胶-凝胶;有机气凝胶;碳气凝胶;碳化【作者】郭志军;朱红;张新卫【作者单位】北京交通大学理学院,北京,100044;北京化工大学理学院,北京,100029;北京交通大学理学院,北京,100044【正文语种】中文【中图分类】TQ127.1碳气凝胶是一种由纳米球状粒子构成,一般是由酚类和醛类在碱性条件下聚合成有机气凝胶,再经过溶剂置换、干燥、碳化而得到的碳素材料.1989年,美国罗伦斯国家实验室R.W.Pekala等[1]首次以间苯二酚与甲醛为前躯体,通过溶胶凝胶法制得有三维结构的纳米气凝胶.碳气凝胶具有孔隙率高、比表面积大、密度变化广且有很好的电化学性能等优越的性质[2-4]而广泛应用于超级电容器、燃料电池、吸附分离、催化剂载体等[5-6]领域,成为一种应用前景广阔的新型碳素材料.碳气凝胶的研究涉及到多个学科的研究,这也为碳气凝胶的研究、开发和应用提供了诸多机遇. 然而通过溶胶-凝胶法制备的湿有机气凝胶,在干燥时由于溶剂表面张力的存在,使得结构塌陷,这大大影响碳气凝胶的性质.一般通过超临界干燥来解决这个问题,但这样却增加了实验室成本和风险,限制了碳气凝胶的研究应用.本文作者利用溶胶-凝胶法,以甲醛和间苯二酚为原料,以无水碳酸钠为催化剂,经陈化、酸化、溶剂置换、半密封式干燥,最后高温碳化得到碳气凝胶,并利用红外(IR)、透射电镜(TEM)和X射线衍射仪(XRD)对其进行了结构表征.1 实验部分1.1 有机气凝胶的制备将甲醛和间苯二酚以1∶2比例混合,以无水碳酸钠为催化剂,再加入三次去离子水,在惰性气体保护下搅拌混合均匀,放入密封容器.在85℃环境中存放7 d(陈化),得到有机气凝胶.1.2 酸化和溶剂置换将陈化后得到的有机气凝胶在3%的乙酸溶液中浸泡1 d(酸化),以丙酮为溶剂进行溶剂置换(将酸化后的有机气凝胶浸泡在丙酮中,浸泡3 d,每天换1次丙酮).1.3 半密封式干燥和高温碳化将溶剂置换后得到有机气凝胶进行半密封式干燥,直至有机气凝胶恒重.将得到干燥的有机气凝胶研磨成粉末,在惰性气体保护下管式炉中碳化.用2 h升温到250℃维持2 h,用1 h升温到400℃,用2 h升温到1 050℃保持4 h,然后自然冷却降温,得到黑色的碳气凝胶粉末.图1为制备碳气凝胶的流程图.图1 碳气凝胶制备示意图Fig.1 Flow chart of p reparing carbon aerogels1.4 表征与测试用红外(IR Prestige-2 1 FTIR-8400S High Temperature/Vacuum Chainber,P/N 700-0042型,日本岛津公司,采用KBr压片)对气凝胶的组成结构测试;用透射电镜(H-800型,日本日立公司)观测气凝胶的微结构和变化;用X射线衍射仪(D/MAX 2400型,日本理学公司)观测气凝胶的晶体结构.图3 有机气凝胶的形成示意图Fig.3 Schematic p rocess of form ing organic aerogels2 结果与讨论2.1 IR测试图2是干燥后的有机气凝胶的红外谱图.从有机气凝胶的红外谱图上可以看出,在2 928、2 856、1 474 cm-1处有明显的CH2伸缩、弯曲振动峰;在1 616 cm-1处有苯环的伸缩振动峰;在1 221 cm-1和1 094 cm-1处有明显的C-O-C伸缩振动峰,这是甲醛和间苯二酚缩合而成的峰;在3 400 cm-1处有着-OH的伸缩振动特征峰.图2 有机气凝胶(OA)的红外谱图Fig.2 IR spectrum of organic aerogels(OA) 这些有机特征峰的出现主要是因为有机气凝胶的形成分为两步:第1步是通过甲醛和间苯二酚在碱性条件下加成生成多元羟甲基间苯二酚中间体;第2步是中间体之间缩聚反应生成以亚甲基键(-CH2-)或亚甲基醚键(-CH2OCH 2-)连接的基元胶体颗粒,基元胶体颗粒再进一步生长形成团簇,团簇进一步缩合成网络状的聚合物,见图3.干燥后的有机气凝胶仍保持有机官能团结构,因此有机气凝胶的红外谱图显示出如图2所示的结果.从高温碳化有机气凝胶而得到的碳气凝胶的红外谱图来看,没有了明显的有机官能团的特征峰.图 4为碳气凝胶的红外谱图.碳气凝胶在1 570 cm-1处和1 250 cm-1处有两个比较微弱的吸收峰,这两个峰应为碳气凝胶骨架中碳的吸收峰,这两个峰对应着骨架中不同晶型的碳.这表明经过高温碳化碳气凝胶内部出现了微晶化结构.从碳气凝胶的红外谱图来看和一般碳的红外谱图差别不大.图4 碳气凝胶(CA)的红外谱图Fig.4 IR spectrum of carbon aerogels(CA)高温碳化过程中,有机气凝胶的骨架遭到破坏,生成大量的小分子CO、CO2、H2、CH4等气体的形式逸出,气凝胶的C含量增加,随着温度的升高和最终温度碳化时间的延长,气凝胶最终全部碳化甚至出现部分的石墨化.2.2 TEM测试图5是有机气凝胶和碳气凝胶的TEM图.图5 有机气凝胶和碳气凝胶的TEM图Fig.5 TEMimages oforganic aerogels and carbon aerogels从图中可以看出不管是有机气凝胶还是碳气凝胶都是由大量的纳米三维网络的结构构成.从图5 (a)可以看出有机气凝胶团簇大小不一,孔洞大小不一,是较为典型的无序多孔结构,粒径大约在30 nm左右.从图5(b)看出碳气凝胶与有机气凝胶相比更加紧密.直径约40 nm左右的球状颗粒构成网络,网络间的孔洞丰富,且孔洞间具有很好的连通性.有机气凝胶通过煅烧,不可避免的导致纳米网络塌陷收缩使气凝胶变的基干变粗,但始终保持这纳米无序多孔的网络结构.2.3 XRD测试图6是碳气凝胶的小角X射线衍射图.从图中可以看出只有一个衍射峰,说明碳气凝胶的有序程度非常低,即为一个无序的结构这与透射电镜得到的结果相吻合.图6 碳气凝胶的小角XRD图Fig.6 XRD pattern of carbon aerogels图7 碳气凝胶的XRD图Fig.7 XRD pattern of carbon aerogels图7为碳气凝胶的广角X射线衍射图谱.从图中可以清晰地看出在2θ为24.5°左右和43°左右有两个宽化的衍射峰,这说明碳气凝胶是一种非晶态结构.碳气凝胶骨架内碳原子主要以sp3杂化为主,价键的四面体指性形成无规则的刚性结构.而除了这两个较缓和的宽峰外,尚有少量代表晶体的衍射峰,但其强度均极小.说明经高温碳化的碳气凝胶中仍有少量石墨化的微晶结构.这与红外得到的结果碳气凝胶内部出现微晶变化相吻合.3 结论采用间苯二酚、甲醛为初始原料,无水碳酸钠为催化剂,通过溶胶凝胶法制备了有机气凝胶.经陈化、酸化、溶剂置换、半密封式干燥及高温碳化制备得到了碳气凝胶.用IR、XRD、TEM对样品进行了结构和性能表征.根据红外检测结果推断了有机气凝胶的形成过程;XRD、TEM表征结果表明半密封式常压干燥制备的碳气凝胶微观结构是由直径为40 nm左右的粒子组成,粒子间相互融合,形成互相贯通无序的三维网络,粒子与粒子之间形成连通性极好的纳米孔洞,孔洞以中孔为主.碳气凝胶晶态为无定形结构,由于高温处理内部有微晶化结构.参考文献:[1]Pekala RW.Low Density Resorcinol-Formaldehyde Aerogels:USA Patent,4873218[P].1989.[2]Maldonado-hodar F j,Ferro-GarciaMA,Rivera-U trilla J, et al.Synthesis and Textural Characteristics of Organic Aerogels,Transition-Metal-Containing Organic Aerogels and Their CarbonizedDerivatives[J].Carbon,1999,37: 1199-1205.[3]Liang C,Sha G,Guo S.Resorcinol-Formaldehyde Aerogels Prepared by Supercritical A cetone Drying[J].Journal of Non-CrystallineSolids,2000,271:167-170.[4]Wu D,Fu R,Zhang S,et al.Preparation of Low-Density Carbon Aerogels by Ambient Pressure D rying[J].Carbon, 2004,42:2033-2093.[5]Saliger R,Fischer U,Herta C,et al.H igh Surface Area Carbon Aerogels forSupercapacitors[J].Journal of Non-Crystalline So lids,1998,225:81-85. [6]Moreno-Castilla C,Maldonado-hodar F J.Carbon Aerogels for Catalysis Application:An Overview[J].Carbon,2005, 43:455-465.。

大气科学系微机应用基础Primer of microcomputer applicationFORTRAN77程序设计FORTRAN77 Program Design大气科学概论An Introduction to Atmospheric Science大气探测学基础Atmospheric Sounding流体力学Fluid Dynamics天气学Synoptic Meteorology天气分析预报实验Forecast and Synoptic analysis生产实习Daily weather forecasting现代气候学基础An introduction to modern climatology卫星气象学Satellite meteorologyC语言程序设计 C Programming大气探测实验Experiment on Atmospheric Detective Technique云雾物理学Physics of Clouds and fogs动力气象学Dynamic Meteorology计算方法Calculation Method诊断分析Diagnostic Analysis中尺度气象学Meso-Microscale Synoptic Meteorology边界层气象学Boundary Layer Meteorology雷达气象学Radar Meteorology数值天气预报Numerical Weather Prediction气象统计预报Meteorological Statical Prediction大气科学中的数学方法Mathematical Methods in Atmospheric Sciences专题讲座Seminar专业英语English for Meteorological Field of Study计算机图形基础Basic of computer graphics气象业务自动化Automatic Weather Service空气污染预测与防治Prediction and Control for Air Pollution现代大气探测Advanced Atmospheric Sounding数字电子技术基础Basic of Digital Electronic Techniqul大气遥感Remote Sensing of Atmosphere模拟电子技术基础Analog Electron Technical Base大气化学Atmospheric Chemistry航空气象学Areameteorology计算机程序设计Computer Program Design数值预报模式与数值模拟Numerical Model and Numerical Simulation接口技术在大气科学中的应用Technology of Interface in Atmosphere Sciences Application海洋气象学Oceanic Meteorology现代实时天气预报技术（MICAPS系统）Advanced Short-range Weather Forecasting Technique(MICAPS system)1) atmospheric precipitation大气降水2) atmosphere science大气科学3) atmosphere大气1.The monitoring and study of atmosphere characteristics in near space as an environment forspace weapon equipments and system have been regarded more important for battle support.随着临近空间飞行器的不断发展和运用,作为武器装备和系统环境的临近空间大气特性成为作战保障的重要条件。

19215 Redwood Road • Cleveland, OH 44110800-321-7628 t • 216-531-9596 f CEMENTITIOUS GROUT APPLICATION GUIDECEMENTITIOUS GROUTThe following instructions detail the general installation procedures for grouts manufactured by The Euclid ChemicalCompany. The contractor and engineer are encouraged to consult the individual product’s technical data sheetregarding possible additional suggestions for successful installations.Note: If the contractor is not familiar with standard grout placement techniques, a pre-job meeting is suggested toreview the project details unique to the particular job. Contact your local Euclid Chemical Company representativefor additional information.This guideline is written specifically for DRY PACK GROUT , EUCO PRE-CAST GROUT , HI-FLOW GROUT , NC GROUT ,and NS GROUT .General GuidelinesCareful preparation is a must for a successful grouting operation. Grouts generally work best at 50°F to 80°F (10°C to27°C). Cold weather retards strength gain and set time. Hot weather accelerates setting time and causes prematuredrying of the grout. Provide heating or cooling, as necessary, to compensate for extremes in ambient temperaturesand resulting variations in cure time.Surface Preparation: Surfaces to be grouted and the underside of the baseplate should be clean and free from rust,grease, oil, laitance, and other contaminants. Concrete should be mechanically roughened to a Concrete SurfaceProfile (CSP) of 5-9 in accordance with ICRI 310.2R. Determine work schedule and plan for grout placement, thenprepare strong, properly braced forms to retain the grout and provide relief holes, if needed. The concrete surfaceshould be saturated with water and maintained in a saturated condition for a minimum of 24 hours before grouting.Remove all excess surface water immediately before grouting.Forming: Forms should be rigid and sealed with caulk or sealant to prevent grout leakage. Forms should be coatedwith release agent but do not allow release agent to contact underside of the baseplate or the concrete surface.Forms should extend at least 1” (2.5 cm) above the bottom of the baseplate on all sides. A headbox must beconstructed on one side of the baseplate so that a pressure head can be developed. The headbox should begin 2”(5 cm) from the baseplate and slope away from the plate at approximately 45 degrees and provide a minimum grouthead of 6” (15 cm). The headbox should be caulked/sealed to the form to generate the head pressure required toensure proper grout flow. The form on the side opposite the headbox and forms parallel to grout flow should all be atleast 1” (2.5 cm) from the plate edge. This allows air to vent during grout placement. Closer-fitting forms may causeair entrapment under the baseplate.FIGURE 1 FORMING REQUIREMENTS1" (25 mm)minimum 6" (150 mm)minimum SHIMS CAULK ATFOUNDATIONBRACE FORMS 2" (50 mm)Application GuideMixing: Consult the technical data sheet for the correct amount of mixing water. Never exceed the maximum watercontent, as this will cause bleeding, segregation, and poor performance. Small quantities of grout may be mixedwith a drill and paddle mixer. For large jobs, a mortar mixer can be used only if it provides high-shear mixing.All materials should be in the proper temperature range of 50°F to 80°F (10°C to 27°C). Add the correct amount ofclean, potable water to the mixing vessel and then add the dry grout. Mix for a minimum of 3 minutes. The flow ofthe grout should be measured with a flow cone and care taken to ensure the grout will not bleed with the amount ofwater that has been added. The mixed grout should be quickly transported to the headbox and placed immediately.(DRY PACK GROUT does not use a head box.) The amount of time the contractor has to place the grout varies fromproduct to product. Consult the technical data sheet for typical setting times.Do not add sand or cement to the grout since this may significantly change the grout’s performance characteristics.Grout Placement: Grouts should be placed quickly and continuously. Place grout from one side only, using theheadbox, to assure complete filling of the space being grouted. Use a rod or strapping to assist in placement onlarge or difficult grouting configurations. Place grout only to the bottom edge of the baseplate.Finishing and Curing: As soon as the sheen of water disappears and the grout has begun to stiffen, pond with wateror cover with wet rags, burlap or plastic to prevent premature drying. The forms may be removed as soon as thegrout has stiffened or set sufficiently to prevent sagging away from the bottom of the baseplate.Cut back the shoulders of the grout to a 45 degree angle, sloping downward from the bottom of the baseplate to thefoundation. Do not allow any excess grout to remain above the bottom edge of the baseplate or in an unchamferedshoulder. Finish the grout surface to the desired texture where required. Following cut back and finishing operations,apply two coats of a high solids curing compound to the grout. If a curing compound is not desired, keep allsurfaces wet by sprinkling the surface with water then covering with wet burlap or polyethylene sheeting for aminimum of 72 hours.Treatment of Shrinkage Cracks: Cracks in exposed grout (shoulders) typically do not propagate under thebaseplate, and do not affect the vertical load-carrying capacity of the grout. However, if repair is desired, the surfaceof hairline cracks can be treated with a low-viscosity epoxy crack healer/sealer. Another acceptable option is to routout and fill cracks by hand with a compatible grout.• Keep grout from freezing until it reaches a minimum strength of 4,000 psi (28 MPa).• Proper curing is required.• Do not add admixtures or fluidifiers, cement, or sand to the grout.• Store bagged grout in a dry place.• Do not use materials at temperatures that may cause premature freezing.• W hen using in extreme conditions, follow the recommendations in ACI 305R “Guide to Hot Weather Concreting”or ACI 306R “Guide to Cold Weather Concreting”.• Employ cold weather or hot weather grout practices as the temperatures dictate.• Do not use grouts as a topping or repair material.• In all cases, consult the Safety Data Sheet before use.Rev. 01.19 WARRANTY: The Euclid Chemical Company (“Euclid”) solely and expressly warrants that its products shall be free from defects in materials and workmanship for one (1) year from the date of purchase. Unless authorized in writing by an officer of Euclid, no other representations or statements made by Euclid or its representatives, in writing or orally, shall alter this warranty. EUCLID MAKES NO WARRANTIES, IMPLIED OR OTHERWISE, AS TO THE MERCHANTABILITY OR FITNESS FOR ORDINARY OR PARTICULAR PURPOSES OF ITS PRODUCTS AND EXCLUDES THE SAME. If any Euclid product fails to conform with this warranty, Euclid will replace the product at no cost to Buyer. Replacement of any product shall be the sole and exclusive remedy available and buyer shall have no claim for incidental or consequential damages. Any warranty claim must be made within one (1) year from the date of the claimed breach. Euclid does not authorize anyone on its behalf to make any written or oral statements which in any way alter Euclid’s installation information or instructions in its product literature or on its packaging labels. Any installation of Euclid products which fails to conform with such installation information or instructions shall void this warranty. Product demonstrations, if any, are done for illustrative purposes only and do not constitute a warranty or warranty alteration of any kind. Buyer shall be solely responsible for determining the suitability of Euclid’s products for the Buyer’s intended purposes.。

Respiratory protective Devices-- Compressed air for breathing apparatus呼吸防护装置-呼吸装置压缩空气National foreword国家前言This British Standard is the English language version of EN 12021:1998.这是英国标准的EN 12021:1998英文版本。

Clause 6.2.1 of this European Standard requires that, in any event all contaminants shall be kept to as low a level as possible and shall be below the national exposure limit. National Occupational Exposure Limits (OEL) for substances hazardous to health are published yearly by the Health and Safety Executive and can be found in Guidance Note, Occupational exposure limits (EH40). In the context of this European Standard below the national limit will mean that the concentration level should not be greater than 10 % of the relevant time (8 h) weighted average OEL.第6.2.1本欧洲标准规定，在任何情况下污染物都应保持在尽可能低的水平，并应低于国家的暴露极限。

SiO 2气凝胶疏水改性方法研究进展1刘明龙，杨德安天津大学材料学院先进陶瓷与加工技术教育部重点实验室，天津 (300072)E-mail ：m.dragonliu@摘 要：文章综述了对SiO2气凝胶进行疏水改性的技术的最新研究进展，介绍了溶剂置换-表面改性法，直接表面改性法和联合前驱体法三种改性方法的改性机制及各种常用的表面改性剂，并从所制得的最终样品的性能、成本、实用性等方面进行了比较，从而总结出一种较经济实用的制备方法。

关键词：SiO2气凝胶；纳米多孔材料；溶胶-凝胶；疏水型；绝热材料1本课题得到国家自然基金委重点基金项目(10232030)，天津大学先进陶瓷与加工技术教育部重点实验室 (x06050)的资助。

SiO 2气凝胶是一种具有独特的纳米多孔网络结构的轻质材料，因其极低的折射率、热导率和介电常数，高的比表面积和对气体的选择透过等特性，而在绝热材料、隔音材料、过滤材料以及催化剂载体等众多领域有着广泛的应用前景，尤其在作为高性能绝热材料方面受到了普遍关注。

由于通常方法制备出的SiO 2气凝胶内表面有大量的硅羟基存在，它们不仅会因缩聚而引起凝胶块体产生额外收缩，还能吸附空气中的水分而使气凝胶开裂破碎，严重影响了气凝胶的声、光、电、热、力学等性能，限制了它的应用场合。

因此，只有设法对制备的气凝胶进行疏水改性，增加它在空气中的稳定性和使用寿命，另外，再配合一系列增强、增韧措施，以制成纳米多孔绝热复合材料，才能在保温工程中发挥出它的真正作用。

1. SiO 2气凝胶的疏水改性及原理SiO 2气凝胶通常是由溶胶-凝胶法制备的，开始制得的醇凝胶固态骨架周围存在着大量溶剂（包括醇类、少量水和催化剂），要得到气凝胶，必须通过干燥以去掉其中的溶剂。

然而，在溶剂干燥过程中，由于凝胶纳米孔内气-液界面间产生表面张力，导致邻近的Si-OH 基团发生缩聚反应，形成Si-O-Si 键，从而产生了不可恢复的收缩；另外，这些Si-OH 基团还可以吸附空气中的水分，使表面张力增大，从而使气凝胶块体开裂破碎。

大气科学系微机应用基础Primer of microcomputer applicationFORTRAN77程序设计FORTRAN77 Program Design大气科学概论An Introduction to Atmospheric Science大气探测学基础Atmospheric Sounding流体力学Fluid Dynamics天气学Synoptic Meteorology天气分析预报实验Forecast and Synoptic analysis生产实习Daily weather forecasting现代气候学基础An introduction to modern climatology卫星气象学Satellite meteorologyC语言程序设计 C Programming大气探测实验Experiment on Atmospheric Detective Technique云雾物理学Physics of Clouds and fogs动力气象学Dynamic Meteorology计算方法Calculation Method诊断分析Diagnostic Analysis中尺度气象学Meso-Microscale Synoptic Meteorology边界层气象学Boundary Layer Meteorology雷达气象学Radar Meteorology数值天气预报Numerical Weather Prediction气象统计预报Meteorological Statical Prediction大气科学中的数学方法Mathematical Methods in Atmospheric Sciences专题讲座Seminar专业英语English for Meteorological Field of Study计算机图形基础Basic of computer graphics气象业务自动化Automatic Weather Service空气污染预测与防治Prediction and Control for Air Pollution现代大气探测Advanced Atmospheric Sounding数字电子技术基础Basic of Digital Electronic Techniqul大气遥感Remote Sensing of Atmosphere模拟电子技术基础Analog Electron Technical Base大气化学Atmospheric Chemistry航空气象学Areameteorology计算机程序设计Computer Program Design数值预报模式与数值模拟Numerical Model and Numerical Simulation接口技术在大气科学中的应用Technology of Interface in Atmosphere Sciences Application海洋气象学Oceanic Meteorology现代实时天气预报技术（MICAPS系统）Advanced Short-range Weather Forecasting Technique(MICAPS system)1) atmospheric precipitation大气降水2) atmosphere science大气科学3) atmosphere大气1.The monitoring and study of atmosphere characteristics in near space as an environment for space weapon equipments and system have been regarded more important for battle support.随着临近空间飞行器的不断发展和运用,作为武器装备和系统环境的临近空间大气特性成为作战保障的重要条件。