The effect of thermal exposure at 350 ℃ for 200 h on microstructure and mechanical properties was investigated for Al-Si-Cu-Ni-Mg alloy, which was produced by permanent mold casting(PMC) and high pressure die casting...The effect of thermal exposure at 350 ℃ for 200 h on microstructure and mechanical properties was investigated for Al-Si-Cu-Ni-Mg alloy, which was produced by permanent mold casting(PMC) and high pressure die casting(HPDC). The SEM and IPP software were used to characterize the morphology of Si phase in the studied alloys. The results show that the thermal exposure provokes spheroidization and coarsening of eutectic Si particles. The ultimate tensile strength of the HPDC alloy after thermal exposure is higher than that of the PMC alloy at room temperature. However, the TEPMC and TEHPDC alloys have similar tensile strength around 67 MPa at 350 ℃. Due to the coarsening of eutectic Si, the TEPMC alloy exhibits better creep resistance than the TEHPDC alloy under studied creep conditions. Therefore, the alloys with small size of eutectic Si are not suitably used at 350 ℃.展开更多
AIM: To conduct a systematic review and Meta-analysis of the published literature to evaluate the pooled prevalence rate of amblyopia in patients with congenital ptosis.METHODS: We searched the PubMed, Embase, the Coc...AIM: To conduct a systematic review and Meta-analysis of the published literature to evaluate the pooled prevalence rate of amblyopia in patients with congenital ptosis.METHODS: We searched the PubMed, Embase, the Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure, Wanfang Data, and Chongqing VIP databases for studies reporting the prevalence of amblyopia in patients with congenital ptosis. The reference lists of relevant studies were scanned. Heterogeneity of effect sizes across studies was tested. We calculated prevalence ratios to compare prevalence estimates for different causes of amblyopia in patients with congenital ptosis, as well as for different geographical regions, year of publication and sample size in subgroup analyses. A systematic review and Meta-analysis were performed.RESULTS: We identified 29 eligible surveys with a total population of 2436. Prevalence rates of amblyopia ranged from 13.8% to 69%. We noted substantial heterogeneity in prevalence estimates for amblyopia in congenital ptosis(Cochran’s χ2 significant at P<0.0001; I2=90%). The pooled prevalence using random-effects models of 29 studies was 32.8%(95%CI: 27.3%-38.4%) in the overall population. Compared to the overall pooled prevalence, amblyopia prevalence was higher in studies in which only subjects with blepharophimosis syndrome were included.CONCLUSION: We confirm that nearly one-third of congenital ptosis patients are suffering from or at risk for amblyopia. Patients with blepharophimosis syndrome are more likely to develop amblyopia. The identificationand management of amblyopia should be integral to the treatment of congenital ptosis.展开更多
Layered double hydroxide(LDH)with special layered structure has been proved to have excellent hole transport capacity and good stability.Herein,we report a high efficient composite photocatalyst of CoAlLDH and BiPO4pr...Layered double hydroxide(LDH)with special layered structure has been proved to have excellent hole transport capacity and good stability.Herein,we report a high efficient composite photocatalyst of CoAlLDH and BiPO4prepared by hydrothermal and che mical adsorption(denoted as CoAl-LDH/BiPO_(4)).Phenol can be entirely degraded by 1%CoAl-LDH/BiPO_(4)under 30 min ultraviolet(UV)light irradiation,and the degradation rate constants k are 3 times and 39 times higher than that of pure BiPO_(4)and CoAl-LDH,respectively.The enhanced photocatalytic activity can be attributed to effective holes transfer from BiPO4to CoAl-LDH,which hinders the recombination of photo genera ted charge carriers.In addition,the combination of BiPO4and CoAl-LDH avoids the agglomeration of BiPO4and improves the stability of BiPO_(4).Active species capture experiments indicate that superoxide radicals(·O-_(2))are the main active species responsible for the degradation of phenol.This work provides technical approaches and research ideas for solving the photogenerated charge carrier recombination problem of photocatalyst.展开更多
基金Projects(2016YFB0700502,2016YFB0301001)supported by the National Key Research and Development Program of China。
文摘The effect of thermal exposure at 350 ℃ for 200 h on microstructure and mechanical properties was investigated for Al-Si-Cu-Ni-Mg alloy, which was produced by permanent mold casting(PMC) and high pressure die casting(HPDC). The SEM and IPP software were used to characterize the morphology of Si phase in the studied alloys. The results show that the thermal exposure provokes spheroidization and coarsening of eutectic Si particles. The ultimate tensile strength of the HPDC alloy after thermal exposure is higher than that of the PMC alloy at room temperature. However, the TEPMC and TEHPDC alloys have similar tensile strength around 67 MPa at 350 ℃. Due to the coarsening of eutectic Si, the TEPMC alloy exhibits better creep resistance than the TEHPDC alloy under studied creep conditions. Therefore, the alloys with small size of eutectic Si are not suitably used at 350 ℃.
基金Supported by the National Natural Science Foundation of China(No.81870688)Shanghai Science and Technology Commission Natural Science Foundation(No.16ZR1419600)the Science and Technology Commission of Shanghai(No.17DZ2260100)
文摘AIM: To conduct a systematic review and Meta-analysis of the published literature to evaluate the pooled prevalence rate of amblyopia in patients with congenital ptosis.METHODS: We searched the PubMed, Embase, the Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure, Wanfang Data, and Chongqing VIP databases for studies reporting the prevalence of amblyopia in patients with congenital ptosis. The reference lists of relevant studies were scanned. Heterogeneity of effect sizes across studies was tested. We calculated prevalence ratios to compare prevalence estimates for different causes of amblyopia in patients with congenital ptosis, as well as for different geographical regions, year of publication and sample size in subgroup analyses. A systematic review and Meta-analysis were performed.RESULTS: We identified 29 eligible surveys with a total population of 2436. Prevalence rates of amblyopia ranged from 13.8% to 69%. We noted substantial heterogeneity in prevalence estimates for amblyopia in congenital ptosis(Cochran’s χ2 significant at P<0.0001; I2=90%). The pooled prevalence using random-effects models of 29 studies was 32.8%(95%CI: 27.3%-38.4%) in the overall population. Compared to the overall pooled prevalence, amblyopia prevalence was higher in studies in which only subjects with blepharophimosis syndrome were included.CONCLUSION: We confirm that nearly one-third of congenital ptosis patients are suffering from or at risk for amblyopia. Patients with blepharophimosis syndrome are more likely to develop amblyopia. The identificationand management of amblyopia should be integral to the treatment of congenital ptosis.
基金supported by the National Key Research and Development Program of China [2019YFC1904500]National Natural Science Foundation of China [52270115, 21878331, 21777080]Science Foundation of China University of Petroleum, Beijing [2462019QNXZ05, 2462020YXZZ018]
文摘Layered double hydroxide(LDH)with special layered structure has been proved to have excellent hole transport capacity and good stability.Herein,we report a high efficient composite photocatalyst of CoAlLDH and BiPO4prepared by hydrothermal and che mical adsorption(denoted as CoAl-LDH/BiPO_(4)).Phenol can be entirely degraded by 1%CoAl-LDH/BiPO_(4)under 30 min ultraviolet(UV)light irradiation,and the degradation rate constants k are 3 times and 39 times higher than that of pure BiPO_(4)and CoAl-LDH,respectively.The enhanced photocatalytic activity can be attributed to effective holes transfer from BiPO4to CoAl-LDH,which hinders the recombination of photo genera ted charge carriers.In addition,the combination of BiPO4and CoAl-LDH avoids the agglomeration of BiPO4and improves the stability of BiPO_(4).Active species capture experiments indicate that superoxide radicals(·O-_(2))are the main active species responsible for the degradation of phenol.This work provides technical approaches and research ideas for solving the photogenerated charge carrier recombination problem of photocatalyst.