This work presents a brief introduction on three kinds of newly developed Nd^(3+)-doped laser glasses in Shanghai Institute of Optics and Fine Mechanics(SIOM), China. Two Nd^(3+)-doped phosphate glasses with lower the...This work presents a brief introduction on three kinds of newly developed Nd^(3+)-doped laser glasses in Shanghai Institute of Optics and Fine Mechanics(SIOM), China. Two Nd^(3+)-doped phosphate glasses with lower thermal expansion coefficient and thermal shock resistance 4 times higher than that of N31 glass are developed for laser processing.Nd:Silicate and Nd:Aluminate glasses with peak emission wavelength at 1061 and 1065 nm, effective emission bandwidth of 34 and 50 nm, respectively, are developed for Exawatt-class laser system application. Fluorophosphate glasses with low nonlinear refractive index(n_2=0.6–0.86) and long fluorescence lifetime(430–510 μs) are investigated for the purpose of decreasing B integral in high-power laser system. The properties of all these glasses are presented and compared with those of commercial neodymium laser glasses.展开更多
Transparent polycrystaUine neodymiumdoped yttrium aluminum garnet ceramics （Nd：YAG） with better chemical stability, excellent optical and high temperature mechanical property is becoming a new laser host material. ...Transparent polycrystaUine neodymiumdoped yttrium aluminum garnet ceramics （Nd：YAG） with better chemical stability, excellent optical and high temperature mechanical property is becoming a new laser host material. The Nd：YAG precursor powders with loosely dispersed, slightly agglomerated and YAG cubic crystal phase were synthesized at 1100 ℃ by the co-precipitation method combined with the reverse strike,展开更多
The homogeneously dispersed, less agglomerated (Nd0.01Y0.99)3Al5O12 nano-sized powders were synthesized by the low temperature combustion (LCS), using Nd2O3, Y2O3, Al(NO3)3·9H2O, ammonia water and citric acid as ...The homogeneously dispersed, less agglomerated (Nd0.01Y0.99)3Al5O12 nano-sized powders were synthesized by the low temperature combustion (LCS), using Nd2O3, Y2O3, Al(NO3)3·9H2O, ammonia water and citric acid as starting materials. This method effectively solves the problems caused by solid-state reaction at high temperature and hard agglomerates brought by the chemical precipitation method. The powders were characterized by TG-DTA, XRD, FT-IR, TEM respectively and the photoluminescence (PL) spectra of (Nd0.01Y0.99)3Al5O12 green and sintered ceramic disks were measured. The results show that the forming temperature of YAG crystal phase is 850 ℃ and YAP crystal phase appearing during the calcinations transforms to pure YAG at 1050 ℃. The particle size of the powders synthesized by the LCS is in a range of 20～50 nm depending on the thermal treatment temperatures. The effectively induced cross section (σin) with the value 4.03×10-19 cm2 of (Nd0.01Y0.99)3Al5O12 ceramics is about 44% higher than that of single crystal.展开更多
We investigate the total intensity fluctuation spectrum of the two-longitudinal- mode Nd：YVO4microchip laser（ML）.We find that low-frequency relaxation oscillation（RO） peaks still appear in the total intensity flu...We investigate the total intensity fluctuation spectrum of the two-longitudinal- mode Nd：YVO4microchip laser（ML）.We find that low-frequency relaxation oscillation（RO） peaks still appear in the total intensity fluctuation spectrum, which is different from a previous research result that the low-frequency RO peaks exist in the spectrum of the individual mode but compensate for each other totally in the total intensity fluctuation spectrum. Taking the spatial hole-burning effect into account, one and two-mode rate equations for Nd：YVO4ML laser are established and studied. Based on the theoretical model, we find that when the gains and losses for two longitudinal models are different, a low-frequency RO peak will appear in the total intensity fluctuation spectrum, while when they share the same gain and loss, the total spectrum will behave like that of a single mode laser. Theoretical simulation results coincide with experimental results very well.展开更多
To research the solidification behavior and microstructures of a laser remelting/solidification layer on anisotropic Nd_(15)Fe_(77)B_(8 )sintered magnets with their magnetization direction parallel to X, Y, Z-axis res...To research the solidification behavior and microstructures of a laser remelting/solidification layer on anisotropic Nd_(15)Fe_(77)B_(8 )sintered magnets with their magnetization direction parallel to X, Y, Z-axis respectively, their surfaces (parallel to XOY plane) were scanned by 5 kW Roffin-Sinar 850 type of CO_(2) laser along Y axis. The rapid solidification of the molten alloy in the layer results in three distinct zones. The transition zone close to the unmolten portion of a magnet (substrate), consists of the columnar Nd_(2)Fe_(14)B phase (matrix), the 10.0%~15.1% dendrite primary iron phase dispersing in the matrix, and the Nd-rich phase along Nd_(2)Fe_(14)B grain boundaries. The columnar crystal zone in the middle of the layer consists of the long columnar Nd_(2)Fe_(14)B grains and their grain boundary Nd-rich phase. And the dendrite crystal zone near the free surface of the layer consists of dendrite Nd_(2)Fe_(14)B grains and their grain boundary Nd-rich phase. When the laser scanning velocity is lower, the growing direction of the microstructures in the layer tends to the laser scanning direction step by step. When the velocity is not lower than 25 mm·s^(-1), the laser remelting/solidification layer thins and the columnar crystal zone comprises almost the whole layer. Under this condition, on the substrate with its magnetization direction along X or Y-axis respectively, the columnar Nd_(2)Fe_(14)B grains in the layer grow in the direction of Z-axis (that is their long-axis along Z-axis), their alignment of the easy magnetization axis [001] is parallel to the magnetization direction of the substrate correspondingly; but on the substrate with its magnetization direction along Z-axis, the columnar Nd_(2)Fe_(14)B grains in the transition zone grow at an angle of 30°~50° between Z-axis and their long-axis. And the columnar Nd_(2)Fe_(14)B grains in the columnar crystal zone gradually tend to the Z-axis,and their easy magnetization axis [001] arrange in the range of 0°~360° of the plane perpendicular to their long-axis.展开更多
The canal walls of extracted human teeth, following Nd∶YAG Laser irradiation, were examined with a scanning electron microscope and compared with those prepared with conventional methods or pretreated with citric aci...The canal walls of extracted human teeth, following Nd∶YAG Laser irradiation, were examined with a scanning electron microscope and compared with those prepared with conventional methods or pretreated with citric acid as control. The results showed that all the dentinal tubules were closed and smeared layer disrupted following laser irradiation, It was suggested that Nd∶YAG Laser irradiation would be expectablly applied to endodontics, especially in root canal therapy (RCT).展开更多
substitutes tion, high loosely dis Neodymium doped-yttrium aluminum garnet （Nd ： YAG） transparent polycrystalline ceramics already become of single crystals because they are provided with easy fabrication, low cost...substitutes tion, high loosely dis Neodymium doped-yttrium aluminum garnet （Nd ： YAG） transparent polycrystalline ceramics already become of single crystals because they are provided with easy fabrication, low cost, large size, highly doped concentraheat conductivity, mass fabrication, multi-layers and multi-filnctions. The Nd：YAG precursor powders with persed , slightly agglomerated, super fine and YAG cubic crystal phase were synthesized at 1100 ℃ by the homogeneous precipitation method, using Nd2O3, Y2O3, Al（NO3）3·9H2O and urea as raw materials, （NH4）2SO4 as electrical stabilizer, TEOS as sintering additive. The Nd：YAG transparent ceramics were prepared after being vacuum sintered at 1700 ℃ for 5 h. The Nd：YAG ceramic materials were characterized by the TG-DTA, XRD, FT-IR, TEM, FEG-ESEM and FT-PL. The results show that the crystallization temperature of YAG is 850 ℃ and the intermediate crystal phase YAP forming during the heat treatment transforms to YAG cubic crystal phase at 1050 ℃. The lasing wavelength of （Nd0.01 Y0.99）3Al5O12 transparent ceramics is 1.065 μm and there exists a slight red-shift compared to the single crystal with the same chemical composition. The optical transmittance is 45 % in the visible light and 58 % in the near infrared light and the optical transmittance descends with the decreasing the wavelength.展开更多
BACKGROUND Bouveret syndrome,also known as gallstone ileus,is a rare form of gastric outlet obstruction accounting for 1%-3%of cases.This condition is most often reported in females.The diagnosis can be challenging an...BACKGROUND Bouveret syndrome,also known as gallstone ileus,is a rare form of gastric outlet obstruction accounting for 1%-3%of cases.This condition is most often reported in females.The diagnosis can be challenging and is often missed due to atypical presentations,which occasionally mimic gastric outlet obstruction symptoms such as nausea,vomiting,loss of appetite and hematemesis.The symptoms vary with stone size.Larger stones are managed with a surgical approach,but this carries increased morbidity and mortality.Over the past decade,the endoscopic approach has emerged as an alternative mode of treatment,but it is generally unsuccessful in the management of larger-sized stones.A literature review revealed cases of successful endoscopic treatment requiring multiple sessions for stone sizes measuring up to about 4.5 cm.Here we present a unique case of an elderly patient with Bouveret syndrome with a 5 cm stone mimicking a gastric mass and causing gastric outlet obstruction,who was successfully managed in a single session using a complete endoscopic approach with laser lithotripsy.CASE SUMMARY An 85-year-old female patient presented with 1-month history of intermittent abdominal pain,vomiting,decreased appetite and weight loss.An abdominal computed tomography showed a 4.5 cm×4.7 cm partially calcified mass at the gastric pylorus causing gastric outlet obstruction.Endoscopy showed an ulcerated fistulous opening and a large 5 cm impacted gallstone in the duodenal bulb.Endoscopic nets and baskets were used in an attempt to remove the stone,but this approach was unsuccessful.Given her advanced age,poor physical condition and underlying comorbidities,she was deemed to be high-risk for surgery.Thus,a minimally invasive approach using endoscopic laser lithotripsy was attempted and successfully treated the stone.Post-procedure,the patient experienced complete resolution of her symptoms with no complications and was able to tolerate her diet.She was subsequently discharged home at 48 h,with an uneventful recovery.CONCLUSION In our paper we describe Bouveret syndrome and highlight its management with a novel endoscopic approach of laser lithotripsy in addition to various other endoscopic approaches available to date and its success rates.展开更多
The Raman spectrum of rhombohedral NdAl 3 (BO 3) 4 (NAB) is recorded and interpreted. A factor group analysis of the NAB space group shows that there are 21A 1 and 59E Raman active modes. A discussion of ...The Raman spectrum of rhombohedral NdAl 3 (BO 3) 4 (NAB) is recorded and interpreted. A factor group analysis of the NAB space group shows that there are 21A 1 and 59E Raman active modes. A discussion of the assignment of the individual Raman lines is given. The splitting predicted by factor group for the internal modes of (BO 3) 3+ anion are observed and interpreted.展开更多
A 50-year-old man had noticed the gradual appearance of asymptomatic skin lesions on the dorsal aspects of the hands during the last 3 years. Physical examination revealed clusters of multiple purplish dome-shaped inf...A 50-year-old man had noticed the gradual appearance of asymptomatic skin lesions on the dorsal aspects of the hands during the last 3 years. Physical examination revealed clusters of multiple purplish dome-shaped infiltrated papules. Histopathological examination was compatible mutinucleate cell angiohistiocytoma. We treated him with 10,464 nm Nd:YAG laser, after the second session, some of the lesions had disappeared completely while the rest has gained substantial improvement. There were no adverse reactions and no recurrence after two years of follow-up. MCAH is a rare vascular fibrohistiocytic proliferation. No standard of care exists. We believe that Nd:YAG laser should be considered the treatment of choice.展开更多
文摘This work presents a brief introduction on three kinds of newly developed Nd^(3+)-doped laser glasses in Shanghai Institute of Optics and Fine Mechanics(SIOM), China. Two Nd^(3+)-doped phosphate glasses with lower thermal expansion coefficient and thermal shock resistance 4 times higher than that of N31 glass are developed for laser processing.Nd:Silicate and Nd:Aluminate glasses with peak emission wavelength at 1061 and 1065 nm, effective emission bandwidth of 34 and 50 nm, respectively, are developed for Exawatt-class laser system application. Fluorophosphate glasses with low nonlinear refractive index(n_2=0.6–0.86) and long fluorescence lifetime(430–510 μs) are investigated for the purpose of decreasing B integral in high-power laser system. The properties of all these glasses are presented and compared with those of commercial neodymium laser glasses.
文摘Transparent polycrystaUine neodymiumdoped yttrium aluminum garnet ceramics （Nd：YAG） with better chemical stability, excellent optical and high temperature mechanical property is becoming a new laser host material. The Nd：YAG precursor powders with loosely dispersed, slightly agglomerated and YAG cubic crystal phase were synthesized at 1100 ℃ by the co-precipitation method combined with the reverse strike,
文摘The homogeneously dispersed, less agglomerated (Nd0.01Y0.99)3Al5O12 nano-sized powders were synthesized by the low temperature combustion (LCS), using Nd2O3, Y2O3, Al(NO3)3·9H2O, ammonia water and citric acid as starting materials. This method effectively solves the problems caused by solid-state reaction at high temperature and hard agglomerates brought by the chemical precipitation method. The powders were characterized by TG-DTA, XRD, FT-IR, TEM respectively and the photoluminescence (PL) spectra of (Nd0.01Y0.99)3Al5O12 green and sintered ceramic disks were measured. The results show that the forming temperature of YAG crystal phase is 850 ℃ and YAP crystal phase appearing during the calcinations transforms to pure YAG at 1050 ℃. The particle size of the powders synthesized by the LCS is in a range of 20～50 nm depending on the thermal treatment temperatures. The effectively induced cross section (σin) with the value 4.03×10-19 cm2 of (Nd0.01Y0.99)3Al5O12 ceramics is about 44% higher than that of single crystal.
基金Project supported by the Beijing Higher Education Young Elite Teacher ProjectChina(Grant No.YETP0086)+2 种基金the Tsinghua University Initiative Scientific Research ProgrammeChina(Grant No.2012Z02166)the Special-funded Programme on National Key Scientific Instruments and Equipment Development of China(Grant No.2011YQ04013603)
文摘We investigate the total intensity fluctuation spectrum of the two-longitudinal- mode Nd：YVO4microchip laser（ML）.We find that low-frequency relaxation oscillation（RO） peaks still appear in the total intensity fluctuation spectrum, which is different from a previous research result that the low-frequency RO peaks exist in the spectrum of the individual mode but compensate for each other totally in the total intensity fluctuation spectrum. Taking the spatial hole-burning effect into account, one and two-mode rate equations for Nd：YVO4ML laser are established and studied. Based on the theoretical model, we find that when the gains and losses for two longitudinal models are different, a low-frequency RO peak will appear in the total intensity fluctuation spectrum, while when they share the same gain and loss, the total spectrum will behave like that of a single mode laser. Theoretical simulation results coincide with experimental results very well.
基金ProjectsupportedbytheNaturalScienceFundationofJiangxi(CA99110901)andZhejiang(M503096andM502166) Province
文摘To research the solidification behavior and microstructures of a laser remelting/solidification layer on anisotropic Nd_(15)Fe_(77)B_(8 )sintered magnets with their magnetization direction parallel to X, Y, Z-axis respectively, their surfaces (parallel to XOY plane) were scanned by 5 kW Roffin-Sinar 850 type of CO_(2) laser along Y axis. The rapid solidification of the molten alloy in the layer results in three distinct zones. The transition zone close to the unmolten portion of a magnet (substrate), consists of the columnar Nd_(2)Fe_(14)B phase (matrix), the 10.0%~15.1% dendrite primary iron phase dispersing in the matrix, and the Nd-rich phase along Nd_(2)Fe_(14)B grain boundaries. The columnar crystal zone in the middle of the layer consists of the long columnar Nd_(2)Fe_(14)B grains and their grain boundary Nd-rich phase. And the dendrite crystal zone near the free surface of the layer consists of dendrite Nd_(2)Fe_(14)B grains and their grain boundary Nd-rich phase. When the laser scanning velocity is lower, the growing direction of the microstructures in the layer tends to the laser scanning direction step by step. When the velocity is not lower than 25 mm·s^(-1), the laser remelting/solidification layer thins and the columnar crystal zone comprises almost the whole layer. Under this condition, on the substrate with its magnetization direction along X or Y-axis respectively, the columnar Nd_(2)Fe_(14)B grains in the layer grow in the direction of Z-axis (that is their long-axis along Z-axis), their alignment of the easy magnetization axis [001] is parallel to the magnetization direction of the substrate correspondingly; but on the substrate with its magnetization direction along Z-axis, the columnar Nd_(2)Fe_(14)B grains in the transition zone grow at an angle of 30°~50° between Z-axis and their long-axis. And the columnar Nd_(2)Fe_(14)B grains in the columnar crystal zone gradually tend to the Z-axis,and their easy magnetization axis [001] arrange in the range of 0°~360° of the plane perpendicular to their long-axis.
文摘The canal walls of extracted human teeth, following Nd∶YAG Laser irradiation, were examined with a scanning electron microscope and compared with those prepared with conventional methods or pretreated with citric acid as control. The results showed that all the dentinal tubules were closed and smeared layer disrupted following laser irradiation, It was suggested that Nd∶YAG Laser irradiation would be expectablly applied to endodontics, especially in root canal therapy (RCT).
文摘substitutes tion, high loosely dis Neodymium doped-yttrium aluminum garnet （Nd ： YAG） transparent polycrystalline ceramics already become of single crystals because they are provided with easy fabrication, low cost, large size, highly doped concentraheat conductivity, mass fabrication, multi-layers and multi-filnctions. The Nd：YAG precursor powders with persed , slightly agglomerated, super fine and YAG cubic crystal phase were synthesized at 1100 ℃ by the homogeneous precipitation method, using Nd2O3, Y2O3, Al（NO3）3·9H2O and urea as raw materials, （NH4）2SO4 as electrical stabilizer, TEOS as sintering additive. The Nd：YAG transparent ceramics were prepared after being vacuum sintered at 1700 ℃ for 5 h. The Nd：YAG ceramic materials were characterized by the TG-DTA, XRD, FT-IR, TEM, FEG-ESEM and FT-PL. The results show that the crystallization temperature of YAG is 850 ℃ and the intermediate crystal phase YAP forming during the heat treatment transforms to YAG cubic crystal phase at 1050 ℃. The lasing wavelength of （Nd0.01 Y0.99）3Al5O12 transparent ceramics is 1.065 μm and there exists a slight red-shift compared to the single crystal with the same chemical composition. The optical transmittance is 45 % in the visible light and 58 % in the near infrared light and the optical transmittance descends with the decreasing the wavelength.
文摘BACKGROUND Bouveret syndrome,also known as gallstone ileus,is a rare form of gastric outlet obstruction accounting for 1%-3%of cases.This condition is most often reported in females.The diagnosis can be challenging and is often missed due to atypical presentations,which occasionally mimic gastric outlet obstruction symptoms such as nausea,vomiting,loss of appetite and hematemesis.The symptoms vary with stone size.Larger stones are managed with a surgical approach,but this carries increased morbidity and mortality.Over the past decade,the endoscopic approach has emerged as an alternative mode of treatment,but it is generally unsuccessful in the management of larger-sized stones.A literature review revealed cases of successful endoscopic treatment requiring multiple sessions for stone sizes measuring up to about 4.5 cm.Here we present a unique case of an elderly patient with Bouveret syndrome with a 5 cm stone mimicking a gastric mass and causing gastric outlet obstruction,who was successfully managed in a single session using a complete endoscopic approach with laser lithotripsy.CASE SUMMARY An 85-year-old female patient presented with 1-month history of intermittent abdominal pain,vomiting,decreased appetite and weight loss.An abdominal computed tomography showed a 4.5 cm×4.7 cm partially calcified mass at the gastric pylorus causing gastric outlet obstruction.Endoscopy showed an ulcerated fistulous opening and a large 5 cm impacted gallstone in the duodenal bulb.Endoscopic nets and baskets were used in an attempt to remove the stone,but this approach was unsuccessful.Given her advanced age,poor physical condition and underlying comorbidities,she was deemed to be high-risk for surgery.Thus,a minimally invasive approach using endoscopic laser lithotripsy was attempted and successfully treated the stone.Post-procedure,the patient experienced complete resolution of her symptoms with no complications and was able to tolerate her diet.She was subsequently discharged home at 48 h,with an uneventful recovery.CONCLUSION In our paper we describe Bouveret syndrome and highlight its management with a novel endoscopic approach of laser lithotripsy in addition to various other endoscopic approaches available to date and its success rates.
文摘The Raman spectrum of rhombohedral NdAl 3 (BO 3) 4 (NAB) is recorded and interpreted. A factor group analysis of the NAB space group shows that there are 21A 1 and 59E Raman active modes. A discussion of the assignment of the individual Raman lines is given. The splitting predicted by factor group for the internal modes of (BO 3) 3+ anion are observed and interpreted.
文摘A 50-year-old man had noticed the gradual appearance of asymptomatic skin lesions on the dorsal aspects of the hands during the last 3 years. Physical examination revealed clusters of multiple purplish dome-shaped infiltrated papules. Histopathological examination was compatible mutinucleate cell angiohistiocytoma. We treated him with 10,464 nm Nd:YAG laser, after the second session, some of the lesions had disappeared completely while the rest has gained substantial improvement. There were no adverse reactions and no recurrence after two years of follow-up. MCAH is a rare vascular fibrohistiocytic proliferation. No standard of care exists. We believe that Nd:YAG laser should be considered the treatment of choice.
