Three types of material as platen in contact drying process were tested in Composition Board Laboratory of Northeast Forestry University in 1998. Poplar veneers were dried under’0.3 MPa at 160℃ or 180℃. Through com...Three types of material as platen in contact drying process were tested in Composition Board Laboratory of Northeast Forestry University in 1998. Poplar veneers were dried under’0.3 MPa at 160℃ or 180℃. Through comparison a non-metal flexible material was chosen as screen for designing contact dryer and replacing curved metal plate. The new type contact dryer solved the problem of long auxiliary time by loading wet veneers into press and unloading dried veneers out of press at the same time. This increased productivity. Veneer’s moisture content(MC) varied with drying time in index law. The process of contact drying with non-metal flexible screen was analyzed by stages of preheating, high-speed drying, retarded drying and extremely slow drying.展开更多
The moisture contents (MC) of popular veneers were tested in Composition Board Laboratory of Northeast Forestry University by contact drying with flexible screen. The influence factors considered included temperature,...The moisture contents (MC) of popular veneers were tested in Composition Board Laboratory of Northeast Forestry University by contact drying with flexible screen. The influence factors considered included temperature, initial moisture contents (IMC), and veneer thickness. Veneer-drying laws under different hot press conditions were analyzed. The results showed that the drying rate increased with temperature rising. 160°C was considered to be more efficient than 140°C and 180°C because excessive high temperature has no significant contribution to drying rate. IMC had significant effect on drying rate. The veneer with high IMC had a higher drying rate at above fiber saturation point (FSP) and a lower drying rate at below FSP, compared to the veneer with low IMC. Average drying rate also varied with thickness in power law.展开更多
AIM：To compare the results of non-mydriatic ultra-wide field imaging system,mydriatic slit-lamp lens（Volk＋90 D） and mydriatic Goldmann three-mirror contact lens examinations in screening fundus lesions among patie...AIM：To compare the results of non-mydriatic ultra-wide field imaging system,mydriatic slit-lamp lens（Volk＋90 D） and mydriatic Goldmann three-mirror contact lens examinations in screening fundus lesions among patients after cataract surgery.METHODS：Non-mydriatic images were obtained with an Optomap panoramic 200Tx（Optomap 200Tx） 3d after surgery and graded by a blinded ophthalmologist.A mydriatic slit-lamp lens examination was performed by another blinded retinal specialist on the same day.A third blinded retinal specialist examined patients two weeks after surgery using a Goldmann three-mirror contact lens.RESULTS：In total,160 patients（184 eyes） were examined,and 66,69,and 75 cases of retinal lesion（s）were identified using the Optomap 200 Tx,slit-lamp lens,and Goldmann three-mirror contact lens,respectively.In13 cases,fundus changes were sight-threatening.The results obtained by Optomap 200 Tx examination and by mydriatic slit-lamp lens examination have good consistency（P =0.375,Kappa =0.942）.The mydriatic Goldmann three-mirror lens examination revealed more fundus lesions but are consistent with Optomap 200Tx（P=0.004,Kappa =0.897） and mydriatic slit-lamp lens examination（P=0.031,Kappa=0.932）.CONCLUSION：Early post-operative fundus screening in cataract patients is extremely important and necessary to prevent further vision loss.Wide-field imaging is a feasible and convenient tool for fundus examination that can be used as a primary screening method among patients after cataract surgery.展开更多
The velocity of warhead fragment is key criteria to determine its mutilation efficiency.We have designed an optoelectronic system to accurately measure the average velocity of warhead fragments.The apparatus including...The velocity of warhead fragment is key criteria to determine its mutilation efficiency.We have designed an optoelectronic system to accurately measure the average velocity of warhead fragments.The apparatus including two parallel laser screens spaced apart at a known fixed distance for providing time measurement start and stop signals.The large effective screen area is formed by laser source,retro-reflector and large area photo-diode with a central hole.Whenever a moving fragment interrupts two optical screen,the corresponding photometers senses the event,due to partial obscuration of the incident energy.Experiments have been performed to measure velocity of the different kinds of projectiles and fragments within various size and velocity ranges,including 7.62 mm bullet shooting experiments,prefabricated steel-ball exploding experiments.They were proved that the system is adequate to measure the velocity of larger than 5 mm,less than 1 000 m/s in the range,when fixed trajectory,test the velocity of the projectile average relative deviation is less than 4.21%.The system can perform satisfactorily with a lot of advantages such as larger effective light screen area,quick response speed,low uncertainty,strong repetition and reliability,etc.展开更多
文摘Three types of material as platen in contact drying process were tested in Composition Board Laboratory of Northeast Forestry University in 1998. Poplar veneers were dried under’0.3 MPa at 160℃ or 180℃. Through comparison a non-metal flexible material was chosen as screen for designing contact dryer and replacing curved metal plate. The new type contact dryer solved the problem of long auxiliary time by loading wet veneers into press and unloading dried veneers out of press at the same time. This increased productivity. Veneer’s moisture content(MC) varied with drying time in index law. The process of contact drying with non-metal flexible screen was analyzed by stages of preheating, high-speed drying, retarded drying and extremely slow drying.
文摘The moisture contents (MC) of popular veneers were tested in Composition Board Laboratory of Northeast Forestry University by contact drying with flexible screen. The influence factors considered included temperature, initial moisture contents (IMC), and veneer thickness. Veneer-drying laws under different hot press conditions were analyzed. The results showed that the drying rate increased with temperature rising. 160°C was considered to be more efficient than 140°C and 180°C because excessive high temperature has no significant contribution to drying rate. IMC had significant effect on drying rate. The veneer with high IMC had a higher drying rate at above fiber saturation point (FSP) and a lower drying rate at below FSP, compared to the veneer with low IMC. Average drying rate also varied with thickness in power law.
基金Supported by the National Natural Science Foundation of China(No.81271045No.81470642)Shanghai Science and Technology Committee(No.15XD1502800)
文摘AIM：To compare the results of non-mydriatic ultra-wide field imaging system,mydriatic slit-lamp lens（Volk＋90 D） and mydriatic Goldmann three-mirror contact lens examinations in screening fundus lesions among patients after cataract surgery.METHODS：Non-mydriatic images were obtained with an Optomap panoramic 200Tx（Optomap 200Tx） 3d after surgery and graded by a blinded ophthalmologist.A mydriatic slit-lamp lens examination was performed by another blinded retinal specialist on the same day.A third blinded retinal specialist examined patients two weeks after surgery using a Goldmann three-mirror contact lens.RESULTS：In total,160 patients（184 eyes） were examined,and 66,69,and 75 cases of retinal lesion（s）were identified using the Optomap 200 Tx,slit-lamp lens,and Goldmann three-mirror contact lens,respectively.In13 cases,fundus changes were sight-threatening.The results obtained by Optomap 200 Tx examination and by mydriatic slit-lamp lens examination have good consistency（P =0.375,Kappa =0.942）.The mydriatic Goldmann three-mirror lens examination revealed more fundus lesions but are consistent with Optomap 200Tx（P=0.004,Kappa =0.897） and mydriatic slit-lamp lens examination（P=0.031,Kappa=0.932）.CONCLUSION：Early post-operative fundus screening in cataract patients is extremely important and necessary to prevent further vision loss.Wide-field imaging is a feasible and convenient tool for fundus examination that can be used as a primary screening method among patients after cataract surgery.
基金supported by the Science and Technology on Electronic Test & Measurement Laboratory,China(No.9140C1204041009)Science and Technology on Electronic Test & Measurement Laboratory Fund for Young Scholars,China
文摘The velocity of warhead fragment is key criteria to determine its mutilation efficiency.We have designed an optoelectronic system to accurately measure the average velocity of warhead fragments.The apparatus including two parallel laser screens spaced apart at a known fixed distance for providing time measurement start and stop signals.The large effective screen area is formed by laser source,retro-reflector and large area photo-diode with a central hole.Whenever a moving fragment interrupts two optical screen,the corresponding photometers senses the event,due to partial obscuration of the incident energy.Experiments have been performed to measure velocity of the different kinds of projectiles and fragments within various size and velocity ranges,including 7.62 mm bullet shooting experiments,prefabricated steel-ball exploding experiments.They were proved that the system is adequate to measure the velocity of larger than 5 mm,less than 1 000 m/s in the range,when fixed trajectory,test the velocity of the projectile average relative deviation is less than 4.21%.The system can perform satisfactorily with a lot of advantages such as larger effective light screen area,quick response speed,low uncertainty,strong repetition and reliability,etc.
