A new blasting approach of combined blastholes with different diameters is proposed to solve the problems of oversize boulders and rock toes in open-pit mine. A non-ideal detonation model and a statistical damage cons...A new blasting approach of combined blastholes with different diameters is proposed to solve the problems of oversize boulders and rock toes in open-pit mine. A non-ideal detonation model and a statistical damage constitutive model are implemented in dynamic finite element analysis to investigate the formation mechanism of oversize boulders and toes. The damage distribution and evolution process of rock blasting fragmentation is simulated, and the scheme is further optimized. Numerical analysis results showed that pocket charges and satellite blastholes can only improve bench top fragmentation, but they cannot reduce the oversize in the middle and bottom of bench as well as the toe problem. The new blasting approach of combined blastholes with different diameters can effectively reduce the oversize boulders and toes as well as the production costs.展开更多
BACKGROUND Cholesterol crystal embolization(CCE)is a multisystemic and fatal disease with multiple clinical manifestations;however,there are few cases of idiopathic CCE.Here we report a patient with idiopathic CCE acc...BACKGROUND Cholesterol crystal embolization(CCE)is a multisystemic and fatal disease with multiple clinical manifestations;however,there are few cases of idiopathic CCE.Here we report a patient with idiopathic CCE accompanied by atheroembolic renal disease and blue toes who had a relatively good prognosis in the short-term due to early treatment with corticosteroids and statins.CASE SUMMARY A 76-year-old man complained of coldness,numbness and purple color change in his left foot for 7 d.He had a feeling of fatigue,constipation,foamy urine,poor appetite and sleep.He had a lacunar infarction for 5 years and hypertension for 9 mo.Laboratory results showed elevated eosinophils,cholesterol,uric acid,serum creatinine,urea and 24 h urine analysis revealed proteinuria.A renal biopsy revealed atheroembolic renal disease.Taken together,these findings strongly supported the diagnosis of idiopathic CCE and atheroembolic renal disease.CONCLUSION Atheroembolic renal disease and blue toes syndrome can be caused by idiopathic CCE,and early treatment with corticosteroids is effective but requires further investigation.展开更多
Located on eastern slope of Mingsha Mountain and the west bank of Dangquan River,which is 25 km to the southeast of Dunhuang city,Mogao Grottoes were first constructed in366 A.D.and continuously built for around1,000 ...Located on eastern slope of Mingsha Mountain and the west bank of Dangquan River,which is 25 km to the southeast of Dunhuang city,Mogao Grottoes were first constructed in366 A.D.and continuously built for around1,000 years across 11 dynasties or periods.展开更多
The Binyang North Grotto in the Longmen Grottoes,located in Luoyang,an ancient dynastie capital in cen tral China's Henan Province,has become especially popular among young people due to its iconic“peace sign”Bu...The Binyang North Grotto in the Longmen Grottoes,located in Luoyang,an ancient dynastie capital in cen tral China's Henan Province,has become especially popular among young people due to its iconic“peace sign”Buddha statue.Visitors flock to the site,eager to snap the perfect shot for their social media feeds.展开更多
The 3-dimensional interactions between toes of a gecko and substrates (ceilings or walls) were measured when it moves on ceilings or walls by using a 3-dimensional force measuring array,and the correspondent morpholog...The 3-dimensional interactions between toes of a gecko and substrates (ceilings or walls) were measured when it moves on ceilings or walls by using a 3-dimensional force measuring array,and the correspondent morphology of the gecko toes was recorded by a high speed camera.The study aims to understand the relationship between adhesive and shear forces generated by the toes of the gecko and the locomotion behavior when it walks on walls and ceilings.Results showed that shear force is along the toe-only 12.6° and 3.1° away from the toe for wall-climbing and ceiling-crawling,respectively while the adhesion is big enough to balance the body weight and moment.The shear forces generated by the first and the fifth toes are in opposite directions;this redundant force increases the reliability of adhesion and stability of locomotion.The support angles of toes are equal approximately for ceiling-crawling and wall-climbing.The study greatly inspires the design of a gecko-like robot.展开更多
基金supported by Chinese National Natural Science Foundation (No. 51809016 and No. 51979152)Chongqing Municipal Natural Science Foundation (No. cstc2019jcyjmsxmX0645)
文摘A new blasting approach of combined blastholes with different diameters is proposed to solve the problems of oversize boulders and rock toes in open-pit mine. A non-ideal detonation model and a statistical damage constitutive model are implemented in dynamic finite element analysis to investigate the formation mechanism of oversize boulders and toes. The damage distribution and evolution process of rock blasting fragmentation is simulated, and the scheme is further optimized. Numerical analysis results showed that pocket charges and satellite blastholes can only improve bench top fragmentation, but they cannot reduce the oversize in the middle and bottom of bench as well as the toe problem. The new blasting approach of combined blastholes with different diameters can effectively reduce the oversize boulders and toes as well as the production costs.
文摘BACKGROUND Cholesterol crystal embolization(CCE)is a multisystemic and fatal disease with multiple clinical manifestations;however,there are few cases of idiopathic CCE.Here we report a patient with idiopathic CCE accompanied by atheroembolic renal disease and blue toes who had a relatively good prognosis in the short-term due to early treatment with corticosteroids and statins.CASE SUMMARY A 76-year-old man complained of coldness,numbness and purple color change in his left foot for 7 d.He had a feeling of fatigue,constipation,foamy urine,poor appetite and sleep.He had a lacunar infarction for 5 years and hypertension for 9 mo.Laboratory results showed elevated eosinophils,cholesterol,uric acid,serum creatinine,urea and 24 h urine analysis revealed proteinuria.A renal biopsy revealed atheroembolic renal disease.Taken together,these findings strongly supported the diagnosis of idiopathic CCE and atheroembolic renal disease.CONCLUSION Atheroembolic renal disease and blue toes syndrome can be caused by idiopathic CCE,and early treatment with corticosteroids is effective but requires further investigation.
文摘Located on eastern slope of Mingsha Mountain and the west bank of Dangquan River,which is 25 km to the southeast of Dunhuang city,Mogao Grottoes were first constructed in366 A.D.and continuously built for around1,000 years across 11 dynasties or periods.
文摘The Binyang North Grotto in the Longmen Grottoes,located in Luoyang,an ancient dynastie capital in cen tral China's Henan Province,has become especially popular among young people due to its iconic“peace sign”Buddha statue.Visitors flock to the site,eager to snap the perfect shot for their social media feeds.
基金supported by the National High Technology Research and Development Program of China ("863" Program)(Grant No. 2007AA04Z201)National Natural Science Foundation of China (Grant Nos. 60535020,60910007,30770285,30700068)
文摘The 3-dimensional interactions between toes of a gecko and substrates (ceilings or walls) were measured when it moves on ceilings or walls by using a 3-dimensional force measuring array,and the correspondent morphology of the gecko toes was recorded by a high speed camera.The study aims to understand the relationship between adhesive and shear forces generated by the toes of the gecko and the locomotion behavior when it walks on walls and ceilings.Results showed that shear force is along the toe-only 12.6° and 3.1° away from the toe for wall-climbing and ceiling-crawling,respectively while the adhesion is big enough to balance the body weight and moment.The shear forces generated by the first and the fifth toes are in opposite directions;this redundant force increases the reliability of adhesion and stability of locomotion.The support angles of toes are equal approximately for ceiling-crawling and wall-climbing.The study greatly inspires the design of a gecko-like robot.
