Objective： The aim of this study was to anesthesia analyse the factors of conversing video-assisted thoracic surgery to thoracectomy in pulmonary carcinoma. Methods： Double-lumen tube bronchial catheter intubation a...Objective： The aim of this study was to anesthesia analyse the factors of conversing video-assisted thoracic surgery to thoracectomy in pulmonary carcinoma. Methods： Double-lumen tube bronchial catheter intubation and interstitial positive pressure ventilation （IPPV） were used in all patients with video-assisted thoracic surgery after fast-speed venous induced anesthesia. IPPV, positive expiratory pressure （PEEP） and continuous positive airway pressure （CPAP） in collapse lobes of lung were used in one lung ventilation, and ventilation parameters were adjusted. Results： Two hundred and fifity- two patients double-lumen bronchial tube intubation used by fiberscope was located very well. The level of oxygen saturation of blood （Sp02）, end.tidal carbon dioxide pressure （PETCO2） could be maintained normal. 5 cases were forced to converse video-assisted thoracic surgery to thoracotomy because of 2 cases pulmonary adhesion, 2 cases severe pulmonary dysfunction and 1 case abnormal anatomy respectively. Conclusion： Long one lung ventilation such as pulmonary adhesion, severe pulmonary dysfunction and abnormal anatomy should be considered to be relative contraindication.展开更多
This paper reports the results of experimental research the longitudinal stiffeners in an orthotropic plated bridge deck on concerning the connection between the deck plate and the web of a microscopic scale. An impor...This paper reports the results of experimental research the longitudinal stiffeners in an orthotropic plated bridge deck on concerning the connection between the deck plate and the web of a microscopic scale. An important number of test specimens of a weld are studied with the help of a video microscope, to detect the efficiency of the root of the weld. The second part of the paper is concerned with parametric analysis of the lack of weld penetration by using accurate finite element modelling. The results demonstrate that the weld quality often required can not always be assured, which surely has important consequence on the stresses in the weld and the fatigue resistance.展开更多
Aiming at the correction of high-order aberrations of human eye with spectacles, a design method of aspheric spectacles is proposed based on the eye's wavefront aberrations data. Regarding the eyeball and the spec...Aiming at the correction of high-order aberrations of human eye with spectacles, a design method of aspheric spectacles is proposed based on the eye's wavefront aberrations data. Regarding the eyeball and the spectacles as a whole system-the lens-eye system-the surface profiles of the spectacles are achieved by optimization procedure of lens design. Different from the conventional optometry, in which the refraction prescription is acquired with a visual chart, the design takes into account the two aspects of actual human viewing, eyeball rolling and certain distinct viewing field. The rotation angle of eyeball is set to be ±20° as wearing spectacles, and the field of view is set to be ±7° which is especially important as watching screen display. The individual eye model is constructed as the main part of the lens-eye system. The Liou eye model is modified by sticking a thin meniscus lens to the crystalline lens. Then the defocus of the individual eye is transferred to the front surface of the meniscus lens, and the astigmatism and high-order aberrations are transferred to the front surface of the cornea. 50 eyes are involved in this research, among which 36 eyes have good enough visual performance already after sphero-cylindrical correction. 10 eyes have distinct improvement in vision and 4 eyes have no visual improvement by further aspheric correction. 6 typical subject eyes are selected for the aberrations analysis and the spectacles design in this paper. It is shown that the validity of visual correction of aspheric lens depends on the characteristics of the eye's wavefront aberrations, and it is effective for the eye with larger astigmatism or spherical aberration. Compared with sphero-cylindrical correction only, the superiority taken by the aspheric correction is mainly on the improvement of MTF at a larger field of view. For the best aspheric correction, the MTF values increase by 18.87%, 38.34%, 44.36%, 51.29% and 57.32% at the spatial frequencies of 40, 80, 100, 125 and 150 cycles/mm, respectively.展开更多
文摘Objective： The aim of this study was to anesthesia analyse the factors of conversing video-assisted thoracic surgery to thoracectomy in pulmonary carcinoma. Methods： Double-lumen tube bronchial catheter intubation and interstitial positive pressure ventilation （IPPV） were used in all patients with video-assisted thoracic surgery after fast-speed venous induced anesthesia. IPPV, positive expiratory pressure （PEEP） and continuous positive airway pressure （CPAP） in collapse lobes of lung were used in one lung ventilation, and ventilation parameters were adjusted. Results： Two hundred and fifity- two patients double-lumen bronchial tube intubation used by fiberscope was located very well. The level of oxygen saturation of blood （Sp02）, end.tidal carbon dioxide pressure （PETCO2） could be maintained normal. 5 cases were forced to converse video-assisted thoracic surgery to thoracotomy because of 2 cases pulmonary adhesion, 2 cases severe pulmonary dysfunction and 1 case abnormal anatomy respectively. Conclusion： Long one lung ventilation such as pulmonary adhesion, severe pulmonary dysfunction and abnormal anatomy should be considered to be relative contraindication.
文摘This paper reports the results of experimental research the longitudinal stiffeners in an orthotropic plated bridge deck on concerning the connection between the deck plate and the web of a microscopic scale. An important number of test specimens of a weld are studied with the help of a video microscope, to detect the efficiency of the root of the weld. The second part of the paper is concerned with parametric analysis of the lack of weld penetration by using accurate finite element modelling. The results demonstrate that the weld quality often required can not always be assured, which surely has important consequence on the stresses in the weld and the fatigue resistance.
基金supported by the National Nature Science Foundation of China (Grant Nos. 60978068, 11104149)the Science and Technology Project of Tianjin City (Grant No. 10ZCKFGX18800)
文摘Aiming at the correction of high-order aberrations of human eye with spectacles, a design method of aspheric spectacles is proposed based on the eye's wavefront aberrations data. Regarding the eyeball and the spectacles as a whole system-the lens-eye system-the surface profiles of the spectacles are achieved by optimization procedure of lens design. Different from the conventional optometry, in which the refraction prescription is acquired with a visual chart, the design takes into account the two aspects of actual human viewing, eyeball rolling and certain distinct viewing field. The rotation angle of eyeball is set to be ±20° as wearing spectacles, and the field of view is set to be ±7° which is especially important as watching screen display. The individual eye model is constructed as the main part of the lens-eye system. The Liou eye model is modified by sticking a thin meniscus lens to the crystalline lens. Then the defocus of the individual eye is transferred to the front surface of the meniscus lens, and the astigmatism and high-order aberrations are transferred to the front surface of the cornea. 50 eyes are involved in this research, among which 36 eyes have good enough visual performance already after sphero-cylindrical correction. 10 eyes have distinct improvement in vision and 4 eyes have no visual improvement by further aspheric correction. 6 typical subject eyes are selected for the aberrations analysis and the spectacles design in this paper. It is shown that the validity of visual correction of aspheric lens depends on the characteristics of the eye's wavefront aberrations, and it is effective for the eye with larger astigmatism or spherical aberration. Compared with sphero-cylindrical correction only, the superiority taken by the aspheric correction is mainly on the improvement of MTF at a larger field of view. For the best aspheric correction, the MTF values increase by 18.87%, 38.34%, 44.36%, 51.29% and 57.32% at the spatial frequencies of 40, 80, 100, 125 and 150 cycles/mm, respectively.
