We demonstrate the first commercial production–ready white light-emitting diodes(LEDs)for the general illumination market with red colloidal quantum dots(QDs)applied in an on–chip configuration.We show the red QDs w...We demonstrate the first commercial production–ready white light-emitting diodes(LEDs)for the general illumination market with red colloidal quantum dots(QDs)applied in an on–chip configuration.We show the red QDs with tunable peak emission and narrow full width at half-maximum in combination with a conventional phosphor material can lead to LED conversion efficiency improvements of 5% to 15% over commercial phosphor based LEDs at correlated color temperatures(CCTs)ranging from 5000 to 2700 K.Furthermore,the challenges associated with reliability under high temperature,high blue flux intensity,and high humidity operation have been overcome to meet consumer market requirements.Finally,a demonstrator lamp at 3000 K color temperature and 90 color rendering index(CRI)with QD based LEDs show a larger efficiency gain up to 17%,attributed to the reduced blue LED droop from the lower drive current and the lower heat sink temperature when compared to a standard phosphor based LED lamp output.展开更多
Objective.To describe the clinical features that distinguish accidental from abusive head injury in hospitalized children < 24 months of age.Methods.Prospective study of children < 24 months of age hospitalized ...Objective.To describe the clinical features that distinguish accidental from abusive head injury in hospitalized children < 24 months of age.Methods.Prospective study of children < 24 months of age hospitalized for head injury between August 1, 2000, and October 31, 2002.During hospitalization, children had computed tomographic scans of the brain, serial neurologic examinations, dilated ophthalmoscopic eye examinations, evaluation by a social worker, and, in some cases, a child abuse specialist.Outcome Measures.The main outcome measure was the proportion of children in each group with retinal hemorrhages (RHs).Secondary outcome measures were the proportion of children in each group who had vitreous hemorrhage; abnormal mental status on presentation; seizures; scalp hematomas; need for anticonvulsants; and operative pro-cedures such as subdural tap, craniotomy, ventriculostomy, tracheostomy, and gastrostomy.Results.Eighty-seven children were prospectively enrolled.Fifteen children were classified as having abusive head injury, and 72 were classified as having accidental head injury.Five children, all in the accidental head injury group, were excluded from statistical analysis, because they did not have a dilated ophthalmoscopic examination during their hospitalization.Thus 82 children were included in the statistical analysis.There were no significant differences between the 2 groups with respect to mean age, gender, or ethnicity.RHs were more likely to be seen in children with abusive head injury (60%vs 10%) and were more likely to be bilateral (40%vs 1.5%).Pre-RHs were more likely to be seen in children with abusive head injury (30%vs 0%).Premacular RHs and RHs that extended to the periphery of the retina were alsomore likely to be seen in children with abusive head injury (20%vs 0%and 27%vs 0%, respectively).Of the 7 children with accidental head injury who had RHs, 6 had unilateral RHs.Children with abusive head injury were more likely to have seizures (53%vs 6%) and an abnormal mental status on initial presen展开更多
Diamonds form in a variety of environments between subducted crust,lithospheric and deep mantle.Recently,deep source diamonds with inclusions of the high-pressure H2O-phase ice-VII were discovered.By correlating the p...Diamonds form in a variety of environments between subducted crust,lithospheric and deep mantle.Recently,deep source diamonds with inclusions of the high-pressure H2O-phase ice-VII were discovered.By correlating the pressures of ice-VII inclusions with those of other high-pressure inclusions,we assess quantitatively the pressures and temperatures of their entrapment.We show that the iceVII-bearing diamonds formed at depths down to 800±60 km but at temperatures 200–500 K below average mantle temperature that match the pressure-temperature conditions of decomposing dense hydrous mantle silicates.Our work presents strong evidence for coupled recycling of water and carbon in the deep mantle based on natural samples.展开更多
文摘We demonstrate the first commercial production–ready white light-emitting diodes(LEDs)for the general illumination market with red colloidal quantum dots(QDs)applied in an on–chip configuration.We show the red QDs with tunable peak emission and narrow full width at half-maximum in combination with a conventional phosphor material can lead to LED conversion efficiency improvements of 5% to 15% over commercial phosphor based LEDs at correlated color temperatures(CCTs)ranging from 5000 to 2700 K.Furthermore,the challenges associated with reliability under high temperature,high blue flux intensity,and high humidity operation have been overcome to meet consumer market requirements.Finally,a demonstrator lamp at 3000 K color temperature and 90 color rendering index(CRI)with QD based LEDs show a larger efficiency gain up to 17%,attributed to the reduced blue LED droop from the lower drive current and the lower heat sink temperature when compared to a standard phosphor based LED lamp output.
文摘Objective.To describe the clinical features that distinguish accidental from abusive head injury in hospitalized children < 24 months of age.Methods.Prospective study of children < 24 months of age hospitalized for head injury between August 1, 2000, and October 31, 2002.During hospitalization, children had computed tomographic scans of the brain, serial neurologic examinations, dilated ophthalmoscopic eye examinations, evaluation by a social worker, and, in some cases, a child abuse specialist.Outcome Measures.The main outcome measure was the proportion of children in each group with retinal hemorrhages (RHs).Secondary outcome measures were the proportion of children in each group who had vitreous hemorrhage; abnormal mental status on presentation; seizures; scalp hematomas; need for anticonvulsants; and operative pro-cedures such as subdural tap, craniotomy, ventriculostomy, tracheostomy, and gastrostomy.Results.Eighty-seven children were prospectively enrolled.Fifteen children were classified as having abusive head injury, and 72 were classified as having accidental head injury.Five children, all in the accidental head injury group, were excluded from statistical analysis, because they did not have a dilated ophthalmoscopic examination during their hospitalization.Thus 82 children were included in the statistical analysis.There were no significant differences between the 2 groups with respect to mean age, gender, or ethnicity.RHs were more likely to be seen in children with abusive head injury (60%vs 10%) and were more likely to be bilateral (40%vs 1.5%).Pre-RHs were more likely to be seen in children with abusive head injury (30%vs 0%).Premacular RHs and RHs that extended to the periphery of the retina were alsomore likely to be seen in children with abusive head injury (20%vs 0%and 27%vs 0%, respectively).Of the 7 children with accidental head injury who had RHs, 6 had unilateral RHs.Children with abusive head injury were more likely to have seizures (53%vs 6%) and an abnormal mental status on initial presen
基金This work was supported through NSF EAR-1838330,EAR-1942042,Natural Science Foundation of China(41925017,41721002)and the Fundamental Research Funds for the Central Universities(WK2080000144)The Advanced Light Source is supported through contract no.DE-AC02-05CH11231.W.Wang acknowledges support from the UCL-Carnegie Postdoctoral Scholarship.We thank two anonymous referees for their thorough and constructive reviews,and Dr.Gaojun Li for his editorial handling.
文摘Diamonds form in a variety of environments between subducted crust,lithospheric and deep mantle.Recently,deep source diamonds with inclusions of the high-pressure H2O-phase ice-VII were discovered.By correlating the pressures of ice-VII inclusions with those of other high-pressure inclusions,we assess quantitatively the pressures and temperatures of their entrapment.We show that the iceVII-bearing diamonds formed at depths down to 800±60 km but at temperatures 200–500 K below average mantle temperature that match the pressure-temperature conditions of decomposing dense hydrous mantle silicates.Our work presents strong evidence for coupled recycling of water and carbon in the deep mantle based on natural samples.
