Three-dimensional(3D)printing technology is increasingly used in experimental research of geotechnical engineering.Compared to other materials,3D layer-by-layer printing specimens are extremely similar to the inherent...Three-dimensional(3D)printing technology is increasingly used in experimental research of geotechnical engineering.Compared to other materials,3D layer-by-layer printing specimens are extremely similar to the inherent properties of natural layered rock masses.In this paper,soft-hard interbedded rock masses with different dip angles were prepared based on 3D printing(3DP)sand core technology.Uniaxial compression creep tests were conducted to investigate its anisotropic creep behavior based on digital imaging correlation(DIC)technology.The results show that the anisotropic creep behavior of the 3DP soft-hard interbedded rock mass is mainly affected by the dip angles of the weak interlayer when the stress is at low levels.As the stress level increases,the effect of creep stress on its creep anisotropy increases significantly,and the dip angle is no longer the main factor.The minimum value of the long-term strength and creep failure strength always appears in the weak interlayer within 30°–60°,which explains why the failure of the layered rock mass is controlled by the weak interlayer and generally emerges at 45°.The tests results are verified by comparing with theoretical and other published studies.The feasibility of the 3DP soft-hard interbedded rock mass provides broad prospects and application values for 3DP technology in future experimental research.展开更多
In order to store and manage a large amount of ground and indoor image data with high resolution, an integrated data management system needs to be developed. Possible strategies for this purpose were discussed togethe...In order to store and manage a large amount of ground and indoor image data with high resolution, an integrated data management system needs to be developed. Possible strategies for this purpose were discussed together with initial test on the newly defined 3D maps. The features of such 3D maps, data organization, key techniques used for the map storage, such as image compression based on wavelet transformation, quadtree index, update and retrieval, were analyzed, with the goals of bringing some profits to the storage and management of the digital data in the visual construction of digital mine, digital city and digital community.展开更多
Neurosurgeons who perform intracere-bral hemorrhage(ICH)evacuation procedures have lim-ited options for monitoring hematoma evacuation and intraoperatively assessing residual-hematoma burden.In recent years,neuroendos...Neurosurgeons who perform intracere-bral hemorrhage(ICH)evacuation procedures have lim-ited options for monitoring hematoma evacuation and intraoperatively assessing residual-hematoma burden.In recent years,neuroendoscope-assisted,minimally inva-sive surgery for spontaneous ICH is simple and effective and becoming increasingly common.Many methods are applied in neuronavigation-assisted surgery for ICH evac-uation,such as neuroendoscopy,three-dimensional(3D)reconstruction,intraoperative ultrasound,and stereotac-tic craniotomy.Compared with a traditional craniotomy operation,hematoma removal(using methods of accurate localization)can reduce iatrogenic damage,protect white matter,and shorten patients’recovery time.This paper mainly outlines the treatment of basal ganglia-cerebral hemorrhage with neuroendoscopy assistance using local-ization techniques.展开更多
Background Brain tumor surgery has been using operative microscope for years.Recently,thanks to developments in surgical technology with procedures performed on head-up displays,exoscopes have been introduced as an al...Background Brain tumor surgery has been using operative microscope for years.Recently,thanks to developments in surgical technology with procedures performed on head-up displays,exoscopes have been introduced as an alternative to microscopic vision.Case presentation We present a case of a 46-year-old patient with a low-grade glioma recurrence of the right gyrus cinguli removed with a contralateral transfalcine approach using an exoscope(ORBEYE 4K-three-dimensional(3D)exoscope,Sony Olympus Medical Solutions Inc.,Tokyo,Japan).The operating room setup for this approach is illustrated.During the procedure,the surgeon was seated with head and back in an upright position,while the camera was aligned with the surgical corridor.The exoscope provided detailed,high-quality 4K-3D images of the anatomical structures and optimal depth perception,making surgery accurate and precise.At the end of the resection,an intraoperative MRI scan showed complete removal of the lesion.The patient was discharged on postoperative day 4 with an excellent performance on neuropsychological examination.Conclusions In this clinical case the contralateral approach was favorable because the glioma was located close to the midline and because it offered a straight path to the tumor,minimizing retraction on the brain.The exoscope provided the surgeon with important advantages in terms of anatomical visualization and ergonomics during the entire procedure.展开更多
In this study, Fengyun-3 D(FY-3 D) Micro Wave Radiation Imager(MWRI) radiance data were directly assimilated into the Global/Regional Assimilation and Pr Ediction System(GRAPES) four-dimensional variational(4 DVar) sy...In this study, Fengyun-3 D(FY-3 D) Micro Wave Radiation Imager(MWRI) radiance data were directly assimilated into the Global/Regional Assimilation and Pr Ediction System(GRAPES) four-dimensional variational(4 DVar) system. Quality control procedures were developed for MWRI applications by using algorithms from similar microwave instruments. Compared with the FY-3 C MWRI, the bias of FY-3 D MWRI observations did not show a clear node-dependent difference from the numerical weather prediction background simulation. A conventional bias correction approach can therefore be used to remove systematic biases before the assimilation of data. After assimilating the MWRI radiance data into GRAPES, the geopotential height and humidity analysis fields were improved relative to the control experiment. There was a positive impact on the location of the subtropical high, which led to improvements in forecasts of the track of Typhoon Shanshan.展开更多
基金the support of the National Natural Science Foundation of China(Grant Nos.42207199,52179113,42272333)Zhejiang Postdoctoral Scientific Research Project(Grant Nos.ZJ2022155,ZJ2022156)。
文摘Three-dimensional(3D)printing technology is increasingly used in experimental research of geotechnical engineering.Compared to other materials,3D layer-by-layer printing specimens are extremely similar to the inherent properties of natural layered rock masses.In this paper,soft-hard interbedded rock masses with different dip angles were prepared based on 3D printing(3DP)sand core technology.Uniaxial compression creep tests were conducted to investigate its anisotropic creep behavior based on digital imaging correlation(DIC)technology.The results show that the anisotropic creep behavior of the 3DP soft-hard interbedded rock mass is mainly affected by the dip angles of the weak interlayer when the stress is at low levels.As the stress level increases,the effect of creep stress on its creep anisotropy increases significantly,and the dip angle is no longer the main factor.The minimum value of the long-term strength and creep failure strength always appears in the weak interlayer within 30°–60°,which explains why the failure of the layered rock mass is controlled by the weak interlayer and generally emerges at 45°.The tests results are verified by comparing with theoretical and other published studies.The feasibility of the 3DP soft-hard interbedded rock mass provides broad prospects and application values for 3DP technology in future experimental research.
文摘In order to store and manage a large amount of ground and indoor image data with high resolution, an integrated data management system needs to be developed. Possible strategies for this purpose were discussed together with initial test on the newly defined 3D maps. The features of such 3D maps, data organization, key techniques used for the map storage, such as image compression based on wavelet transformation, quadtree index, update and retrieval, were analyzed, with the goals of bringing some profits to the storage and management of the digital data in the visual construction of digital mine, digital city and digital community.
文摘Neurosurgeons who perform intracere-bral hemorrhage(ICH)evacuation procedures have lim-ited options for monitoring hematoma evacuation and intraoperatively assessing residual-hematoma burden.In recent years,neuroendoscope-assisted,minimally inva-sive surgery for spontaneous ICH is simple and effective and becoming increasingly common.Many methods are applied in neuronavigation-assisted surgery for ICH evac-uation,such as neuroendoscopy,three-dimensional(3D)reconstruction,intraoperative ultrasound,and stereotac-tic craniotomy.Compared with a traditional craniotomy operation,hematoma removal(using methods of accurate localization)can reduce iatrogenic damage,protect white matter,and shorten patients’recovery time.This paper mainly outlines the treatment of basal ganglia-cerebral hemorrhage with neuroendoscopy assistance using local-ization techniques.
文摘Background Brain tumor surgery has been using operative microscope for years.Recently,thanks to developments in surgical technology with procedures performed on head-up displays,exoscopes have been introduced as an alternative to microscopic vision.Case presentation We present a case of a 46-year-old patient with a low-grade glioma recurrence of the right gyrus cinguli removed with a contralateral transfalcine approach using an exoscope(ORBEYE 4K-three-dimensional(3D)exoscope,Sony Olympus Medical Solutions Inc.,Tokyo,Japan).The operating room setup for this approach is illustrated.During the procedure,the surgeon was seated with head and back in an upright position,while the camera was aligned with the surgical corridor.The exoscope provided detailed,high-quality 4K-3D images of the anatomical structures and optimal depth perception,making surgery accurate and precise.At the end of the resection,an intraoperative MRI scan showed complete removal of the lesion.The patient was discharged on postoperative day 4 with an excellent performance on neuropsychological examination.Conclusions In this clinical case the contralateral approach was favorable because the glioma was located close to the midline and because it offered a straight path to the tumor,minimizing retraction on the brain.The exoscope provided the surgeon with important advantages in terms of anatomical visualization and ergonomics during the entire procedure.
基金Supported by the National Natural Science Foundation of China(41675108)National Key Research and Development Program(2018YFC1506700)Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0105)。
文摘In this study, Fengyun-3 D(FY-3 D) Micro Wave Radiation Imager(MWRI) radiance data were directly assimilated into the Global/Regional Assimilation and Pr Ediction System(GRAPES) four-dimensional variational(4 DVar) system. Quality control procedures were developed for MWRI applications by using algorithms from similar microwave instruments. Compared with the FY-3 C MWRI, the bias of FY-3 D MWRI observations did not show a clear node-dependent difference from the numerical weather prediction background simulation. A conventional bias correction approach can therefore be used to remove systematic biases before the assimilation of data. After assimilating the MWRI radiance data into GRAPES, the geopotential height and humidity analysis fields were improved relative to the control experiment. There was a positive impact on the location of the subtropical high, which led to improvements in forecasts of the track of Typhoon Shanshan.
