By means of ultra-violet(UV)irradiation with photoini-tiator and multifunctional crosslinking agent,thecrosslinking modification of ultrahigh molecular weightpolyethylene(UHMWPE)fibers prepared by gel-spin-ning was ca...By means of ultra-violet(UV)irradiation with photoini-tiator and multifunctional crosslinking agent,thecrosslinking modification of ultrahigh molecular weightpolyethylene(UHMWPE)fibers prepared by gel-spin-ning was carried out.Thermal properties of fiber sampleswere examined using differential scanning calorimetry(DSC),thermomechanical analysis(TMA)apparatusand a manual device.The results indicated that the opti-mal irradiation energy is 250-400 mJ/cm^2,heat-andcreep-resistant behaviors of modified fibers have beenimproved.展开更多
Due to the low density and excellent mechanical proper-ties,high performance fiber reinforced materials have aconsiderable application in the area of high technologyand dally usage.In this paper,the Ultra-high Molecu-...Due to the low density and excellent mechanical proper-ties,high performance fiber reinforced materials have aconsiderable application in the area of high technologyand dally usage.In this paper,the Ultra-high Molecu-lar Weight Polyethylene(UHMWPE)fiber reinforcedPE tape prepared with the method of powder impregnat-ion was studied.The effect of impregnate length and thetensile force of the yarn on the fiber content as well as on the strength and modulus of the tape were discussed.Calculation shows that the strength and the modulus ofthe ULMWPE fiber can keep about 85％ after it undergothe process.展开更多
Synthesis of a m m oniu m alu min u m carbonate hydroxide ( A A C H) w as investigated usinga m m oniu m alu min u m sulfate and a m moniu m hydro carbonate as the starting m aterials . Itw as found that A A C Hca...Synthesis of a m m oniu m alu min u m carbonate hydroxide ( A A C H) w as investigated usinga m m oniu m alu min u m sulfate and a m moniu m hydro carbonate as the starting m aterials . Itw as found that A A C Hcan be synthesized by adding a m m oniu m alu m inu m sulfate solution torapidly stirred a m moniu m hydro - carbonate solution at a tem perature of 30 ℃. A A C Hcantransfor m to α Al2 O3 co m pletely by calcining at 1100 ℃ for 1 hour , and the obtained po w ders , with a particle size of 100 n m , can be sintered to 98 99 % relative density at 1500 ℃for 2 hours .展开更多
This work explored the way to improve hot modulus q/＇ rupture （HMOR） and refractoriness under load （RUL） by adding mild-calcined coal gangue （MCG） in Al2O3 -SiO2 ultra low cement （ULC） castables, making use o...This work explored the way to improve hot modulus q/＇ rupture （HMOR） and refractoriness under load （RUL） by adding mild-calcined coal gangue （MCG） in Al2O3 -SiO2 ultra low cement （ULC） castables, making use of the in-situ effect of the MCG during heating-up. The influence of respective additions of 5%, 10% and 1.5% of the MCG powders calcined at 700℃ was investigated on HMOR at 1400 ℃ and RUL of the castables. With increased addition of the MCG, HMOR and RUL become significantly enhanced. At 10% of the MCG addition, HMOR reaches 3 MPa, as compared to 0. 3 MPa in the case of no MCG addition. RUL of the specimens dried at 110 ℃for 24 h can be increased by some 270 ℃ with 10% of the MCG addition. RUL 0.11 the specimens preheated at 1 500℃ for 3 h maintains the growth trend with the MCG addition increasing. The microstructure of the heated castable samples was investigated by means of SEM. The in-situ formed needle-like and interlaced mullite in the matrix is contributive to the tmprovement.展开更多
Purpose:To compare the measurement of flap thickness using intraoperative ultrasound pachymetry and postoperative visante anterior segment optical coherence tomography (Visante-OCT) in eyes receiving laser in situ ker...Purpose:To compare the measurement of flap thickness using intraoperative ultrasound pachymetry and postoperative visante anterior segment optical coherence tomography (Visante-OCT) in eyes receiving laser in situ keratomileusis (LASIK). Methods: Seventeen patients (34 eyes) received LASIK using a Technolas-217Z100 laser and AMADEUSⅡ mechanical microkeratome(140 μm head). Flap thickness was assessed with an ultrasound pachymeter intraoperatively and a Visante-OCT postoperatively at 1 week and 1 month. Results: The intraoperative mean flap thickness by ultrasound pachymetry was (124±13.9) μm (range: 96.5 to 160 μm), and mean flap thickness by Visante-OCT was (145±7.13) μm (range: 130 to 158 μm) and (143±5.32) μm (range: 132 to 155 μm) postoperatively at 1 week and 1 month respectively (F=63.52,P<0.01). Intraoperative subtraction pachymetry underestimated flap thickness compared with postoperative Visante-OCT.(P<0.01)..There was no significant difference between postoperative Visante-OCT measurements at 1 week and 1 month after LASIK.(P=0.16). The 95% limit of agreement.(LoA).of flap thickness between ultrasound Visante-OCT and pachymetry was -5.40 to 42.10 μm. Conclusion: OCT overestimates flap thickness compared with intraoperative ultrasound pachymetry when using the AMADEUSⅡ mechanical microkeratome.展开更多
目的通过观察制作超薄角膜瓣的准分子激光角膜原位磨镶术与制作普通角膜瓣的准分子激光原位角膜磨镶术(laser in situ keratomlleusis,LASIK)对术后角膜像差的影响,并对结果进行对比分析,探讨超薄角膜瓣对LASIK手术效果的影响。方法对...目的通过观察制作超薄角膜瓣的准分子激光角膜原位磨镶术与制作普通角膜瓣的准分子激光原位角膜磨镶术(laser in situ keratomlleusis,LASIK)对术后角膜像差的影响,并对结果进行对比分析,探讨超薄角膜瓣对LASIK手术效果的影响。方法对笔者医院80例近视患者共计160眼,其中制作超薄角膜瓣后行LASIK手术的40例,设为超薄瓣组,制作普通角膜瓣后行LASIK手术的40例,设为普通瓣组。另外,在各组里面按照近视度数不同,分为超薄瓣A组(≤-6.00D)及超薄瓣B组(>-6.00D);普通瓣A组(≤-6.00D)及普通瓣B组(>-6.00D),术后1个月时进行检查,同时与各组中患者手术前的视力及球差、慧差、总体像差(RMS)、高阶像差(RMSH)及低阶像差(RMSL)进行比较。结果在手术前后的比较中,术后超薄瓣组和普通瓣组中球差、慧差、总体像差(RMS)、高阶像差(RMSH)及低阶像差(RMSL)均较术前有明显增加(P<0.01);在中低度近视范围内,超薄瓣组手术前后的球差、慧差、总体像差(RMS)的增加值与中低度近视普通瓣组相比,差异无统计学意义(P>0.05);在高度近视范围内,超薄瓣组与普通瓣组的球差、慧差、总体像差(RMS)、低阶像差(RMSL)及高阶像差(RMSH)的增加值比较,差异无统计学意义(P>0.05)。结论制作超薄瓣和制作普通角膜瓣的LASIK手术,术后视力及视觉效果并没有明显的区别,但制作超薄瓣对于中高度近视的安全性更高,所以其值得临床应用和推广。展开更多
基金oral prepared in the Second East Asian Polymer Conference held in Hongkong,China,January 12-16,1999
文摘By means of ultra-violet(UV)irradiation with photoini-tiator and multifunctional crosslinking agent,thecrosslinking modification of ultrahigh molecular weightpolyethylene(UHMWPE)fibers prepared by gel-spin-ning was carried out.Thermal properties of fiber sampleswere examined using differential scanning calorimetry(DSC),thermomechanical analysis(TMA)apparatusand a manual device.The results indicated that the opti-mal irradiation energy is 250-400 mJ/cm^2,heat-andcreep-resistant behaviors of modified fibers have beenimproved.
文摘Due to the low density and excellent mechanical proper-ties,high performance fiber reinforced materials have aconsiderable application in the area of high technologyand dally usage.In this paper,the Ultra-high Molecu-lar Weight Polyethylene(UHMWPE)fiber reinforcedPE tape prepared with the method of powder impregnat-ion was studied.The effect of impregnate length and thetensile force of the yarn on the fiber content as well as on the strength and modulus of the tape were discussed.Calculation shows that the strength and the modulus ofthe ULMWPE fiber can keep about 85％ after it undergothe process.
文摘Synthesis of a m m oniu m alu min u m carbonate hydroxide ( A A C H) w as investigated usinga m m oniu m alu min u m sulfate and a m moniu m hydro carbonate as the starting m aterials . Itw as found that A A C Hcan be synthesized by adding a m m oniu m alu m inu m sulfate solution torapidly stirred a m moniu m hydro - carbonate solution at a tem perature of 30 ℃. A A C Hcantransfor m to α Al2 O3 co m pletely by calcining at 1100 ℃ for 1 hour , and the obtained po w ders , with a particle size of 100 n m , can be sintered to 98 99 % relative density at 1500 ℃for 2 hours .
文摘This work explored the way to improve hot modulus q/＇ rupture （HMOR） and refractoriness under load （RUL） by adding mild-calcined coal gangue （MCG） in Al2O3 -SiO2 ultra low cement （ULC） castables, making use of the in-situ effect of the MCG during heating-up. The influence of respective additions of 5%, 10% and 1.5% of the MCG powders calcined at 700℃ was investigated on HMOR at 1400 ℃ and RUL of the castables. With increased addition of the MCG, HMOR and RUL become significantly enhanced. At 10% of the MCG addition, HMOR reaches 3 MPa, as compared to 0. 3 MPa in the case of no MCG addition. RUL of the specimens dried at 110 ℃for 24 h can be increased by some 270 ℃ with 10% of the MCG addition. RUL 0.11 the specimens preheated at 1 500℃ for 3 h maintains the growth trend with the MCG addition increasing. The microstructure of the heated castable samples was investigated by means of SEM. The in-situ formed needle-like and interlaced mullite in the matrix is contributive to the tmprovement.
文摘Purpose:To compare the measurement of flap thickness using intraoperative ultrasound pachymetry and postoperative visante anterior segment optical coherence tomography (Visante-OCT) in eyes receiving laser in situ keratomileusis (LASIK). Methods: Seventeen patients (34 eyes) received LASIK using a Technolas-217Z100 laser and AMADEUSⅡ mechanical microkeratome(140 μm head). Flap thickness was assessed with an ultrasound pachymeter intraoperatively and a Visante-OCT postoperatively at 1 week and 1 month. Results: The intraoperative mean flap thickness by ultrasound pachymetry was (124±13.9) μm (range: 96.5 to 160 μm), and mean flap thickness by Visante-OCT was (145±7.13) μm (range: 130 to 158 μm) and (143±5.32) μm (range: 132 to 155 μm) postoperatively at 1 week and 1 month respectively (F=63.52,P<0.01). Intraoperative subtraction pachymetry underestimated flap thickness compared with postoperative Visante-OCT.(P<0.01)..There was no significant difference between postoperative Visante-OCT measurements at 1 week and 1 month after LASIK.(P=0.16). The 95% limit of agreement.(LoA).of flap thickness between ultrasound Visante-OCT and pachymetry was -5.40 to 42.10 μm. Conclusion: OCT overestimates flap thickness compared with intraoperative ultrasound pachymetry when using the AMADEUSⅡ mechanical microkeratome.
文摘目的通过观察制作超薄角膜瓣的准分子激光角膜原位磨镶术与制作普通角膜瓣的准分子激光原位角膜磨镶术(laser in situ keratomlleusis,LASIK)对术后角膜像差的影响,并对结果进行对比分析,探讨超薄角膜瓣对LASIK手术效果的影响。方法对笔者医院80例近视患者共计160眼,其中制作超薄角膜瓣后行LASIK手术的40例,设为超薄瓣组,制作普通角膜瓣后行LASIK手术的40例,设为普通瓣组。另外,在各组里面按照近视度数不同,分为超薄瓣A组(≤-6.00D)及超薄瓣B组(>-6.00D);普通瓣A组(≤-6.00D)及普通瓣B组(>-6.00D),术后1个月时进行检查,同时与各组中患者手术前的视力及球差、慧差、总体像差(RMS)、高阶像差(RMSH)及低阶像差(RMSL)进行比较。结果在手术前后的比较中,术后超薄瓣组和普通瓣组中球差、慧差、总体像差(RMS)、高阶像差(RMSH)及低阶像差(RMSL)均较术前有明显增加(P<0.01);在中低度近视范围内,超薄瓣组手术前后的球差、慧差、总体像差(RMS)的增加值与中低度近视普通瓣组相比,差异无统计学意义(P>0.05);在高度近视范围内,超薄瓣组与普通瓣组的球差、慧差、总体像差(RMS)、低阶像差(RMSL)及高阶像差(RMSH)的增加值比较,差异无统计学意义(P>0.05)。结论制作超薄瓣和制作普通角膜瓣的LASIK手术,术后视力及视觉效果并没有明显的区别,但制作超薄瓣对于中高度近视的安全性更高,所以其值得临床应用和推广。
