Objective： To investigate prospectively the effectiveness ofkyphoplasty with SKY bone expander system in treatment of compression fracture of thoracic/ lumbar vertebrae and correction of the deformity. Methods： Twe...Objective： To investigate prospectively the effectiveness ofkyphoplasty with SKY bone expander system in treatment of compression fracture of thoracic/ lumbar vertebrae and correction of the deformity. Methods： Twenty-five patients with thoracic/lumbar vertebral osteoporotic compression fracture were admitted to our hospital between March 2007 and March 2008, and treated by kyphoplasty with SKY bone expander system. Patient＇s pain status was rated with Visual Analogue Scale （VAS） score system 1 day before and 1 hour, 48 hours, 6 months, 12 months after surgery. In addition, Rolland-Mor- ris and Oswestry disability questionnaires （RDQ and ODI） were used for survey 1 day before and 1, 6, 12 months after surgery. Pre- and post-operative vertebral heights and Cobb＇s angles were measured based on the X-ray films and statistically analyzed. Results： There were 27 fractured vertebrae in these 25 patients. After SKY kyphoplasty, the Cobb＇s angles （9.8°±9.76°） were significantly reduced compared with preoperative angles （17.18°±9.35°, P〈0.05）, and the average improve- ment rate was 39%. Patients＇ pain VAS scores were also greatly improved after operation （P〈0.05）. Moreover, postoperative RDQ and ODI scores were significantly smaller than preoperative values （P〈0.05）. Conclusions： Kyphoplasty with SKY bone expander system provides an effective method for treating thoracic/ lumbar vertebral osteoporotic compression fracture, with the advantages of small surgical wound and short duration. It can effectively recover the anterior and medial heights of fractured vertebrae （33% and 50%, respectively）, reduce the Cobb＇s angle, quickly alleviate pain and improve patients＇ quality of life in a relatively short time period.展开更多
A model for topographic correction and land surface reflectance estimation for optical remote sensing data in rugged terrian is presented.Considering a directional-directional reflectance that is used for direct solar...A model for topographic correction and land surface reflectance estimation for optical remote sensing data in rugged terrian is presented.Considering a directional-directional reflectance that is used for direct solar irradiance correction and a hemispheric-directional reflectance that is used for atmospheric diffuse irradiance and terrain background reflected irradiance correction respectively,the directional reflectance-based model for topographic effects removing and land surface reflectance calculation is developed by deducing the directional reflectance with topographic effects and using a radiative transfer model.A canopy reflectance simulated by GOMS model and Landsat/TM raw data covering Jiangxi rugged area were taken to validate the performance of the model presented in the paper.The validation results show that the model presented here has a remarkable ability to correct topography and estimate land surface reflectance and also provides a technique method for sequently quantitative remote sensing application in terrain area.展开更多
Geohazard recognition and inventory mapping are absolutely the keys to the establishment of reliable susceptibility and hazard maps. However, it has been challenging to implement geohazards recognition and inventory m...Geohazard recognition and inventory mapping are absolutely the keys to the establishment of reliable susceptibility and hazard maps. However, it has been challenging to implement geohazards recognition and inventory mapping in mountainous areas with complex topography and vegetation cover. Progress in the light detection and ranging(Li DAR) technology provides a new possibility for geohazard recognition in such areas. Specifically, this study aims to evaluate the performances of the Li DAR technology in recognizing geohazard in the mountainous areas of Southwest China through visually analyzing airborne Li DAR DEM derivatives. Quasi-3 D relief image maps are generated based on the sky-view factor(SVF), which makes it feasible to interpret precisely the features of geohazard. A total of 146 geohazards are remotely mapped in the entire 135 km^(2) study area in Danba County, Southwest China, and classified as landslide, rock fall, debris flow based on morphologic characteristics interpreted from SVF visualization maps. Field validation indicate the success rate of Li DAR-derived DEM in recognition and mapping geohazard with higher precision and accuracy. These mapped geohazards lie along both sides of the river, and their spatial distributions are related highly to human engineering activities, such as road excavation and slope cutting. The minimum geohazard that can be recognized in the 0.5 m resolution DEM is about 900 m^(2). Meanwhile, the SVF visualization method is demonstrated to be a great alternative to the classical hillshaded DEM method when it comes to the determination of geomorphological properties of geohazard. Results of this study highlight the importance of Li DAR data for creating complete and accurate geohazard inventories, which can then be used for the production of reliable susceptibility and hazard maps and thus contribute to a better understanding of the movement processes and reducing related losses.展开更多
Spaceborne synthetic remote sensing of atmospheric aerosol optical depth and vegetation reflectance is very significant, but it remains to be a question unresolved yet. Based on the property of vegetation reflectance ...Spaceborne synthetic remote sensing of atmospheric aerosol optical depth and vegetation reflectance is very significant, but it remains to be a question unresolved yet. Based on the property of vegetation reflectance spectra from near ultra violet to near infrared and the sensitivity of outgoing radiance to vegetation reflectance and atmospheric aerosol optical depth, a new method for spaceborne synthetic remote sensing of the reflectance and the depth is proposed, and an iteration correlation inversion algorithm is developed in this paper. According to numerical experiment, effects of radiance error, error in aerosol imaginary index and vegetation medium inhomogeneity on retrieved result are analyzed. Inversion results show that the effect of error in aerosol imaginary index is very important. As the error of aerosol imaginary index is within 0.01, standard errors of aerosol optical depth and vegetation reflectance solutions for 14 spectral channels from 410 nm to 900 nm are respectively less than 0.063 and 0.023. And as the radiance error is within 2%, the standard errors are less than 0.023 and 0.0056.展开更多
With the rapid development of population and urbanization and the progress of lighting technology, the influence of artificial light sources has increased.In this context, the problem of light pollution has attracted ...With the rapid development of population and urbanization and the progress of lighting technology, the influence of artificial light sources has increased.In this context, the problem of light pollution has attracted wide attention.Previous studies have revealed that light pollution can affect biological living environments, human physical and mental health, astronomical observations and many other aspects.Therefore, organizations internationally have begun to advocate for measures to prevent light pollution, many of which are recognized by the International Dark-Sky Association(IDA).In addition to improving public awareness, legal protections, technical treatments and other means, the construction of Dark Sky Reserves(DSR) has proven to be an effective preventive measure.So far, as a pioneer practice in this field, the IDA has identified 11 DSRs worldwide.Based on the DA requirements for DSRs, this paper utilizes NPP-VIIRS nighttime light data and other multi-source spatial data to analyze possible DSR sites in China.The land of China was divided into more than ten thousand 30 km × 30 km fishnets, and constraint and suitable conditions were designated, respectively, as light and cloud conditions, and scale, traffic and attractiveness conditions.Using a multiple criteria evaluation, 1443 fishnets were finally selected as most suitable sites for the construction of DSRs.Results found that less than 25% of China is not subject to light pollution, and less than 13% is suitable for DSR construction, primarily in western and northern areas, including Tibet, Xinjiang, Qinghai, Gansu and Inner Mongolia.展开更多
天地有奇观WONDERS OF THE SKY AND EARTH太阳沿着直古不变的轨道运动,雪山永恒地矗立在高原之上。当阳光轻轻酒落,皑皑营山便闪耀着金光,宛如天地间最纯净的宝石,又仿佛是大自然赠予这片土地的一顶圣洁皇冠。此刻,营山仿佛被赋子了生命...天地有奇观WONDERS OF THE SKY AND EARTH太阳沿着直古不变的轨道运动,雪山永恒地矗立在高原之上。当阳光轻轻酒落,皑皑营山便闪耀着金光,宛如天地间最纯净的宝石,又仿佛是大自然赠予这片土地的一顶圣洁皇冠。此刻,营山仿佛被赋子了生命,静静地诉说着雪域高原的神奇与壮美。阳光与雪山交织,展现出一种宁静而深邃的美,让人心生敬畏,又满怀向往。这是世间的无价之宝,它不属于任何人,只属于天地。展开更多
Building fresh air supply needs to meet certain regulations and fit people’s ever-growing indoor air quality de-mand.However,fresh air handling requires huge energy consumption that goes against the goal of net-zero ...Building fresh air supply needs to meet certain regulations and fit people’s ever-growing indoor air quality de-mand.However,fresh air handling requires huge energy consumption that goes against the goal of net-zero energy buildings.Thus,in this work,an adaptive fresh air pre-handling system is designed to reduce the cool-ing and heating loads of HVAC system.The sky-facing surface of the system uses electrochromic mechanism to manipulate the optical properties and thus make full use of solar energy(solar heating)and deep space cold source(radiative cooling)by switching between heating and cooling modes.In the cooling mode,the sky-facing surface shows a transmittance of down to zero,while the reflectance is high at 0.89 on average.In the heating mode,the electrochromic glass is highly transparent,allowing the sunlight to reach the solar heat absorber.To obtain the energy-saving potential under different climates,six cities were selected from various climate regions in China.Results show that the adaptive fresh air pre-handling system can be effective in up to 55.4%time of a year.The maximum energy-saving ratios for medium office,warehouse,and single-family house can reach up to 11.52%,26.62%,and 18.29%,respectively.In addition,the system shows multi-climate adaptability and broad application scenarios,making it a potential solution to building energy saving.展开更多
文摘Objective： To investigate prospectively the effectiveness ofkyphoplasty with SKY bone expander system in treatment of compression fracture of thoracic/ lumbar vertebrae and correction of the deformity. Methods： Twenty-five patients with thoracic/lumbar vertebral osteoporotic compression fracture were admitted to our hospital between March 2007 and March 2008, and treated by kyphoplasty with SKY bone expander system. Patient＇s pain status was rated with Visual Analogue Scale （VAS） score system 1 day before and 1 hour, 48 hours, 6 months, 12 months after surgery. In addition, Rolland-Mor- ris and Oswestry disability questionnaires （RDQ and ODI） were used for survey 1 day before and 1, 6, 12 months after surgery. Pre- and post-operative vertebral heights and Cobb＇s angles were measured based on the X-ray films and statistically analyzed. Results： There were 27 fractured vertebrae in these 25 patients. After SKY kyphoplasty, the Cobb＇s angles （9.8°±9.76°） were significantly reduced compared with preoperative angles （17.18°±9.35°, P〈0.05）, and the average improve- ment rate was 39%. Patients＇ pain VAS scores were also greatly improved after operation （P〈0.05）. Moreover, postoperative RDQ and ODI scores were significantly smaller than preoperative values （P〈0.05）. Conclusions： Kyphoplasty with SKY bone expander system provides an effective method for treating thoracic/ lumbar vertebral osteoporotic compression fracture, with the advantages of small surgical wound and short duration. It can effectively recover the anterior and medial heights of fractured vertebrae （33% and 50%, respectively）, reduce the Cobb＇s angle, quickly alleviate pain and improve patients＇ quality of life in a relatively short time period.
基金the National Natural Science Foundation of China (Grant No.40730525)Knowledge Innovation Engineering Project of Chinese Academy of Sciences (Grant No.KZCX2-YW-313)China's Special Funds for Major State Basic Research Project (Grant No.2007CB714401)
文摘A model for topographic correction and land surface reflectance estimation for optical remote sensing data in rugged terrian is presented.Considering a directional-directional reflectance that is used for direct solar irradiance correction and a hemispheric-directional reflectance that is used for atmospheric diffuse irradiance and terrain background reflected irradiance correction respectively,the directional reflectance-based model for topographic effects removing and land surface reflectance calculation is developed by deducing the directional reflectance with topographic effects and using a radiative transfer model.A canopy reflectance simulated by GOMS model and Landsat/TM raw data covering Jiangxi rugged area were taken to validate the performance of the model presented in the paper.The validation results show that the model presented here has a remarkable ability to correct topography and estimate land surface reflectance and also provides a technique method for sequently quantitative remote sensing application in terrain area.
基金The research was supported by the National Innovation Research Group Science Fund(No.41521002)the National Key Research and Development Program of China(No.2018YFC1505202)。
文摘Geohazard recognition and inventory mapping are absolutely the keys to the establishment of reliable susceptibility and hazard maps. However, it has been challenging to implement geohazards recognition and inventory mapping in mountainous areas with complex topography and vegetation cover. Progress in the light detection and ranging(Li DAR) technology provides a new possibility for geohazard recognition in such areas. Specifically, this study aims to evaluate the performances of the Li DAR technology in recognizing geohazard in the mountainous areas of Southwest China through visually analyzing airborne Li DAR DEM derivatives. Quasi-3 D relief image maps are generated based on the sky-view factor(SVF), which makes it feasible to interpret precisely the features of geohazard. A total of 146 geohazards are remotely mapped in the entire 135 km^(2) study area in Danba County, Southwest China, and classified as landslide, rock fall, debris flow based on morphologic characteristics interpreted from SVF visualization maps. Field validation indicate the success rate of Li DAR-derived DEM in recognition and mapping geohazard with higher precision and accuracy. These mapped geohazards lie along both sides of the river, and their spatial distributions are related highly to human engineering activities, such as road excavation and slope cutting. The minimum geohazard that can be recognized in the 0.5 m resolution DEM is about 900 m^(2). Meanwhile, the SVF visualization method is demonstrated to be a great alternative to the classical hillshaded DEM method when it comes to the determination of geomorphological properties of geohazard. Results of this study highlight the importance of Li DAR data for creating complete and accurate geohazard inventories, which can then be used for the production of reliable susceptibility and hazard maps and thus contribute to a better understanding of the movement processes and reducing related losses.
文摘Spaceborne synthetic remote sensing of atmospheric aerosol optical depth and vegetation reflectance is very significant, but it remains to be a question unresolved yet. Based on the property of vegetation reflectance spectra from near ultra violet to near infrared and the sensitivity of outgoing radiance to vegetation reflectance and atmospheric aerosol optical depth, a new method for spaceborne synthetic remote sensing of the reflectance and the depth is proposed, and an iteration correlation inversion algorithm is developed in this paper. According to numerical experiment, effects of radiance error, error in aerosol imaginary index and vegetation medium inhomogeneity on retrieved result are analyzed. Inversion results show that the effect of error in aerosol imaginary index is very important. As the error of aerosol imaginary index is within 0.01, standard errors of aerosol optical depth and vegetation reflectance solutions for 14 spectral channels from 410 nm to 900 nm are respectively less than 0.063 and 0.023. And as the radiance error is within 2%, the standard errors are less than 0.023 and 0.0056.
基金Under the auspices of the National Natural Science Foundation of China(No.41871162)
文摘With the rapid development of population and urbanization and the progress of lighting technology, the influence of artificial light sources has increased.In this context, the problem of light pollution has attracted wide attention.Previous studies have revealed that light pollution can affect biological living environments, human physical and mental health, astronomical observations and many other aspects.Therefore, organizations internationally have begun to advocate for measures to prevent light pollution, many of which are recognized by the International Dark-Sky Association(IDA).In addition to improving public awareness, legal protections, technical treatments and other means, the construction of Dark Sky Reserves(DSR) has proven to be an effective preventive measure.So far, as a pioneer practice in this field, the IDA has identified 11 DSRs worldwide.Based on the DA requirements for DSRs, this paper utilizes NPP-VIIRS nighttime light data and other multi-source spatial data to analyze possible DSR sites in China.The land of China was divided into more than ten thousand 30 km × 30 km fishnets, and constraint and suitable conditions were designated, respectively, as light and cloud conditions, and scale, traffic and attractiveness conditions.Using a multiple criteria evaluation, 1443 fishnets were finally selected as most suitable sites for the construction of DSRs.Results found that less than 25% of China is not subject to light pollution, and less than 13% is suitable for DSR construction, primarily in western and northern areas, including Tibet, Xinjiang, Qinghai, Gansu and Inner Mongolia.
文摘天地有奇观WONDERS OF THE SKY AND EARTH太阳沿着直古不变的轨道运动,雪山永恒地矗立在高原之上。当阳光轻轻酒落,皑皑营山便闪耀着金光,宛如天地间最纯净的宝石,又仿佛是大自然赠予这片土地的一顶圣洁皇冠。此刻,营山仿佛被赋子了生命,静静地诉说着雪域高原的神奇与壮美。阳光与雪山交织,展现出一种宁静而深邃的美,让人心生敬畏,又满怀向往。这是世间的无价之宝,它不属于任何人,只属于天地。
基金the support from National Natural Sci-ence Foundation of China(52276178)Natural Science Foundation of Jiangsu Province,China(BK20200373).
文摘Building fresh air supply needs to meet certain regulations and fit people’s ever-growing indoor air quality de-mand.However,fresh air handling requires huge energy consumption that goes against the goal of net-zero energy buildings.Thus,in this work,an adaptive fresh air pre-handling system is designed to reduce the cool-ing and heating loads of HVAC system.The sky-facing surface of the system uses electrochromic mechanism to manipulate the optical properties and thus make full use of solar energy(solar heating)and deep space cold source(radiative cooling)by switching between heating and cooling modes.In the cooling mode,the sky-facing surface shows a transmittance of down to zero,while the reflectance is high at 0.89 on average.In the heating mode,the electrochromic glass is highly transparent,allowing the sunlight to reach the solar heat absorber.To obtain the energy-saving potential under different climates,six cities were selected from various climate regions in China.Results show that the adaptive fresh air pre-handling system can be effective in up to 55.4%time of a year.The maximum energy-saving ratios for medium office,warehouse,and single-family house can reach up to 11.52%,26.62%,and 18.29%,respectively.In addition,the system shows multi-climate adaptability and broad application scenarios,making it a potential solution to building energy saving.
