成人做爰免费视频免费看_成人a级高清视频在线观看,成人a大片在线观看,成人a大片高清在线观看,成人av在线播放,一a一级片,一级黄 中国色 片,一级黄 色蝶 片,一级黄色 片生活片

產品推薦:氣相|液相|光譜|質譜|電化學|元素分析|水分測定儀|樣品前處理|試驗機|培養箱


化工儀器網>技術中心>其他文章>正文

歡迎聯系我

有什么可以幫您? 在線咨詢

高硼硅玻璃介紹(Borosilicate Glass Introduction)

來源:開封市宏興科教儀器廠   2010年02月02日 14:20  

Borosilicate glass is a type of glass with the main glass-forming constituents silica and boron oxide. Borosilicate glasses are most well known for having very low coefficient of thermal expansion, making them resistant to thermal shock, more so than any other common glass. Borosilicate glass was first developed by German glassmaker Otto Schott in the late 19th century and sold under the brand name "Duran" in 1893. After Corning Glass Works introduced Pyrex in 1915, it became a synonym for borosilicate glass in the English-speaking world (however, since 1998 Pyrex kitchen brand is no longer made of borosilicate but of soda-lime glass).

Most borosilicate glass is clear. Colored borosilicate, for the art glass trade, was first widely brought onto the market in 1986 when Paul Trautman founded Northstar Glassworks. There are now a number of small companies in the U.S. and abroad that manufacture and sell colored borosilicate glass for the art glass market.

In addition to the quartz, sodium carbonate, and calcium carbonate traditionally used in glassmaking, boron is used in the manufacture of borosilicate glass. Typically, the resulting glass composition is about 70% silica, 10% boron oxide, 8% sodium oxide, 8% potassium oxide, and 1% calcium oxide (lime). Though somewhat more difficult to make than traditional glass (Corning conducted a major revamp of their operations to make it), it is economical to produce because its superior durability, chemical and heat resistance finds excellent use in chemical laboratory equipment, cookware, lighting, and in certain cases, windows.

Manufacturing process

Borosilicate glass is created by adding boron to the traditional glassmaker's "frit" of silicate sand, soda, and ground lime. Since borosilicate glass melts at a higher temperature than ordinary silicate glass, some new techniques were required to bring it into industrial production. Borrowing from the welding trade, new burners combining oxygen with natural gas were required.

Composition and physical characteristics

Borosilicate glass has a very low thermal expansion coefficient, about one-third that of ordinary glass. This reduces material stresses caused by temperature gradients, thus making it more resistant to breaking. This makes it a popular material for objects like escope mirrors, where it is essential to have very little deviation in shape. It is also used in the processing of high-level nuclear waste, where the waste is immobilised in the glass through a process known as vitrification (contrast with Synroc).

Borosilicate glass begins to soften around 821°C (1510°F); at this temperature, the viscosity of type 7740 Pyrex is 107.6 poise.

Borosilicate glass is less dense than ordinary glass.

While more resistant to thermal shock than other types of glass, borosilicate glass can still crack or shatter when subject to rapid or uneven temperature variations. When broken, borosilicate glass tends to crack into large pieces rather than shattering (it will snap rather than splinter).

Optically, borosilicate glasses are crown glasses with low dispersion (Abbe numbers around 65) and relatively low refractive indices (1.51–1.54 across the visible range).

Usage

Borosilicate glass's refractory properties and physical strength make it ideal for use in laboratories, where it is used to make high-durability glass lab equipment, such as beakers and test tubes. In addition, borosilicate glass warps minimally when exposed to heat allowing a borosilicate container to provide accurate measurements of volume over time.

During the mid-twentieth century borosilicate glass tubing was used to pipe coolants (often distilled water) through high power vacuum tube–based electronic equipment, such as commercial broadcast transmitters.

Glass cookware is another common usage; a borosilicate glass pie plate is almost the American standard pie dish. Borosilicate glass measuring cups, featuring painted-on markings illustrating graduated measurements, are also widely used in American kitchens.

Aquarium heaters are sometimes made out of borosilicate glass. Due to its high heat resistance, it can tolerate the great temperature differences between water and the nichrome heating element.

Many high quality flashlights use borosilicate glass for the lens. This allows for a higher percentage of light transmittance through the lens than compared to plastics and lower-quality glass.

Specialty marijuana and tobacco pipes are made from borosilicate glass. The high heat resistance allows the pipe to tolerate a longer period of use, and these pipes are also more durable.

Most premanufactured glass guitar slides are also made of borosilicate glass.

New lampworking techniques led to artistic applications such as contemporary glass marbles. The modern glass art movement, spurred largely by the rapid development of a borosilicate color palette at Northstar Glass in the 1980s and 1990s, has provided vast economic growth for borosilicate glass suppliers. Borosilicate is commonly used in the glassblowing form of lampworking and the artists create a range of products ranging from jewelry, kitchenware, to sculpture as well as for artistic glass tobacco pipes.

Borosilicate glass is sometimes used for high-quality beverage glassware. Borosilicate glass lends the kitchenware and glassware increased durability along with microwave and dishwasher compatibility.

Most astronomical reflecting escope glass mirror components are made of borosilicate glass because of its low coefficient of expansion with heat. This makes very precise optical surfaces possible that change very little with temperature, and matched glass mirror components that "track" across temperature changes and retain the optical system's characteristics.

The optical glass most often used for making instrument lenses is Schott BK-7 (or the equivalent from other makers), a very finely made borosilicate crown glass. It is also designated as 517642 glass after its 1.517 refractive index and 64.2 Abbe number. Other less costly borosilicate glasses, such as Schott B270 or the equivalent, are used to make "crown glass" eyeglasses lenses. Ordinary lower-cost borosilicate glass, like that used to make kitchenware and even reflecting escope mirrors, cannot be used for high quality lenses because of the striations and inclusions common to lower grades of this type of glass.

Borosilicate is also a material of choice for evacuated tube solar thermal technology, because of its high strength and heat resistance.

Borosilicate glasses also find application in the semiconductor industry in the development of micromechanical devices, known as MEMS, as part of stacks of etched silica wafers bonded to the etched borosilicate glass.

The thermal insulation tiles on the Space Shuttle are coated with Borosilicate glass. Lighting manufacturers use borosilicate glass in their refractors.
 

玻璃反應釜工藝參數如下:
 
G3.3高硼硅玻璃的線膨脹系數是3.3*10-6 K-1,以氧化鈉(Na2O)、氧化硼(B2O2)、二氧化硅(SIO2)為基本成份的一種玻璃。該玻璃成分中硼硅含量較高,分別為硼:12.5~13.5%,硅:78~80%,故稱此類玻璃為高硼硅玻璃。屬于硼硅酸鹽玻璃中的PYREX玻璃。耐酸耐堿耐水,抗腐蝕性能*,擁有良好的熱穩定性、化學穩定性和電學性能,故具有抗化學侵蝕性、抗熱沖擊性、機械性能好、承受溫度高等特性。
 
G3.3高硼硅玻璃具體物理化學性能如下:
 

含硅量
80%以上
應變溫度
520℃
退火溫度
560℃
軟化溫度
820℃
折射率
1.47
透光率(2MM)
92%
彈性模量
76KNmm-2
抗張強度
40-120Nmm-2
玻璃應力光學常數
3.8*10-6 mm2/N
加工溫度(104dpas)
1220℃
線膨脹系數(20-300℃)
3.3*10-6 K-1
密度(20℃)
2.23gcm-1
比熱
0.9jg-1K-1
導熱率
1.2Wm-1K-1
耐水性能(ISO 719)
1級
耐酸性能(ISO 195)
1級
耐堿性能(ISO 695)
2級

免責聲明

  • 凡本網注明“來源:化工儀器網”的所有作品,均為浙江興旺寶明通網絡有限公司-化工儀器網合法擁有版權或有權使用的作品,未經本網授權不得轉載、摘編或利用其它方式使用上述作品。已經本網授權使用作品的,應在授權范圍內使用,并注明“來源:化工儀器網”。違反上述聲明者,本網將追究其相關法律責任。
  • 本網轉載并注明自其他來源(非化工儀器網)的作品,目的在于傳遞更多信息,并不代表本網贊同其觀點和對其真實性負責,不承擔此類作品侵權行為的直接責任及連帶責任。其他媒體、網站或個人從本網轉載時,必須保留本網注明的作品第一來源,并自負版權等法律責任。
  • 如涉及作品內容、版權等問題,請在作品發表之日起一周內與本網聯系,否則視為放棄相關權利。
企業未開通此功能
詳詢客服 : 0571-87858618
主站蜘蛛池模板: 国产亚洲av在线| 丰满少妇乱A片无码| 精品动漫国产亚洲AV在线观看| 巨爆乳中文字幕爆乳区| 欧美激情日韩综合一区久久| 99久久这里只精品国产免费| 亚洲精品区无码欧美日韩| 久久久久久久久四区三区| 艳妇荡乳1-8| 国产人成精品综合欧美成人| 韩日三级成年人的电影| 欧美日韩一区二区三区三州| 大学生久久香蕉国产线看观看| 免费国产黄网站在线观看动图| 亚洲VA中文字幕无码毛片| 亚洲v欧美v日韩v国产v| 久久91精品国产91久久户| 久久ZYZ资源站无码中文动漫| 久久久91久久| 亚洲中文精品久久久久久| 少妇啪啪AV一区二区三区| 婷婷激情五月AV在线观看| 色情无码永久免费网站WWW| 波多野结衣无码中字| 羽月希被黑人吃奶dasd585| 亚洲成AV人片一区二区三区| 人妻欧美精品片在线91| 男人天堂av电影| 玖欧美性生交XXXXX无码| 步步高三级影院| 在线视频日韩中文字幕| 欧美日韩国产中文高清视频| 日韩欧美字幕在线| 欧美三级韩国三级日本三斤| 亚洲精品嫩草AV在线观看| 日韩中文字幕在线第一页| 久久精品亚洲熟女| 浴室里的娇喘H| 国产精品综合亚洲AV久久久小说| 欧美牲交视频免费观看K8经典| 亚洲春色综合另类网蜜桃|