The structure and microwave characteristics of low-voltage SiGe power HBTs are given.With this structure,the device can operate in a low-voltage and high-current state.By using an interdigital emitter strip layout and...The structure and microwave characteristics of low-voltage SiGe power HBTs are given.With this structure,the device can operate in a low-voltage and high-current state.By using an interdigital emitter strip layout and the operating voltage ranging from 3 to 4V,the output power in Class C operation can reach 1 65W at 1GHz,with the gain of 8dB.The highest collector efficiency is 67 8% under 3V.展开更多
Objective: To evaluate tear film stability and tear secretion in patients with diabetes after phacoemulsification. Methods: Twenty-five diabetic cataract patients and 20 age-matched non-diabetic cataract patients as c...Objective: To evaluate tear film stability and tear secretion in patients with diabetes after phacoemulsification. Methods: Twenty-five diabetic cataract patients and 20 age-matched non-diabetic cataract patients as control underwent pha- coemulsification. Tear film break-up time (TFBUT), Schirmer I test (SIT), corneal fluorescein staining, and dry eye symptoms were measured pre- and postoperatively. Results: Diabetics had a decreased preoperative TFBUT and SIT. TFBUT was reduced on Day 1 and recovered on Day 180 postoperatively in both groups. SIT was increased after phacoemulsification, but returned to preoperative levels by Day 180 in non-diabetics, whereas it was lower than preoperative level in diabetics. Positive corneal fluo- rescein staining was elevated in both groups, and returned to preoperative levels only in controls. Dry eye symptoms were similar to fluorescein staining in both groups. Conclusion: Tear secretion was reduced in diabetic cataract patients after phacoe- mulsification, which worsened dry eye symptoms and predisposed those patients to ocular damage.展开更多
Objectives： To evaluate the technical feasibility, safety, outcome, and incidence of complications after combined clear corneal phacoemulsification （PEA） with intraocular lens （IOL） implantation and vitreoretinal...Objectives： To evaluate the technical feasibility, safety, outcome, and incidence of complications after combined clear corneal phacoemulsification （PEA） with intraocular lens （IOL） implantation and vitreoretinal surgery. Methods： Combined operations of PEA and PPV were performed on 52 eyes of follow-up time was （10.3±2.8） months. Postoperatively, 52 patients with cataract and vitreoretinal diseases. Results： The mean visual acuity improved in 46 eyes （88.5%）; was unchanged in 6 eyes （11.5%）. The best-corrected visual acuities （BCVAs） were the following： 20/40 or better （9 eyes）, 20/50 to 20/100 （24 eyes）, 20/200 （5 eyes）, 20/400 （10 eyes）, and fingers counting （FC） to light perception （LP） （4 eyes）. In 38 eyes BCVA was 20/200 or better, and in 9 eyes it was 20/40 or better postoperatively. Postoperative complications included posterior capsual opacification （7 eyes）; secondary glaucoma （1 eye）; and retinal detachment （2 eyes）. Conclusion： Although further studies are indicated, our study suggests that the combined operation of PPV, PEA and IOL implantation is safe and effective for patients. The visual outcome and complications depended primarily on underlying posterior segment pathology and were not related to the combined procedure technique.展开更多
The multisublattice Green＇s function technique is applied to study the magnetic properties of a mixed spin-2 and spin-5/2 Heisenberg ferrimagnetic system on a two-dimensional honeycomb lattice. The role of the differ...The multisublattice Green＇s function technique is applied to study the magnetic properties of a mixed spin-2 and spin-5/2 Heisenberg ferrimagnetic system on a two-dimensional honeycomb lattice. The role of the different interactions in the Hamiltonian is explored. When only the nearest-neighbor interaction and the single-ion anisotropy are included, our results indicate that there are compensation points at finite temperatures. When the next-nearest-neighbor interaction exceeds a minimum value that depends on the other parameters in the Hamiltonian, the compensation point disappears. The next-nearest-neighbor interaction has the effect of changing the compensation temperature.展开更多
文摘The structure and microwave characteristics of low-voltage SiGe power HBTs are given.With this structure,the device can operate in a low-voltage and high-current state.By using an interdigital emitter strip layout and the operating voltage ranging from 3 to 4V,the output power in Class C operation can reach 1 65W at 1GHz,with the gain of 8dB.The highest collector efficiency is 67 8% under 3V.
文摘Objective: To evaluate tear film stability and tear secretion in patients with diabetes after phacoemulsification. Methods: Twenty-five diabetic cataract patients and 20 age-matched non-diabetic cataract patients as control underwent pha- coemulsification. Tear film break-up time (TFBUT), Schirmer I test (SIT), corneal fluorescein staining, and dry eye symptoms were measured pre- and postoperatively. Results: Diabetics had a decreased preoperative TFBUT and SIT. TFBUT was reduced on Day 1 and recovered on Day 180 postoperatively in both groups. SIT was increased after phacoemulsification, but returned to preoperative levels by Day 180 in non-diabetics, whereas it was lower than preoperative level in diabetics. Positive corneal fluo- rescein staining was elevated in both groups, and returned to preoperative levels only in controls. Dry eye symptoms were similar to fluorescein staining in both groups. Conclusion: Tear secretion was reduced in diabetic cataract patients after phacoe- mulsification, which worsened dry eye symptoms and predisposed those patients to ocular damage.
文摘Objectives： To evaluate the technical feasibility, safety, outcome, and incidence of complications after combined clear corneal phacoemulsification （PEA） with intraocular lens （IOL） implantation and vitreoretinal surgery. Methods： Combined operations of PEA and PPV were performed on 52 eyes of follow-up time was （10.3±2.8） months. Postoperatively, 52 patients with cataract and vitreoretinal diseases. Results： The mean visual acuity improved in 46 eyes （88.5%）; was unchanged in 6 eyes （11.5%）. The best-corrected visual acuities （BCVAs） were the following： 20/40 or better （9 eyes）, 20/50 to 20/100 （24 eyes）, 20/200 （5 eyes）, 20/400 （10 eyes）, and fingers counting （FC） to light perception （LP） （4 eyes）. In 38 eyes BCVA was 20/200 or better, and in 9 eyes it was 20/40 or better postoperatively. Postoperative complications included posterior capsual opacification （7 eyes）; secondary glaucoma （1 eye）; and retinal detachment （2 eyes）. Conclusion： Although further studies are indicated, our study suggests that the combined operation of PPV, PEA and IOL implantation is safe and effective for patients. The visual outcome and complications depended primarily on underlying posterior segment pathology and were not related to the combined procedure technique.
基金The project supported by National Natural Science Foundation of China under Grant Nos. 10574048 and 20490210
文摘The multisublattice Green＇s function technique is applied to study the magnetic properties of a mixed spin-2 and spin-5/2 Heisenberg ferrimagnetic system on a two-dimensional honeycomb lattice. The role of the different interactions in the Hamiltonian is explored. When only the nearest-neighbor interaction and the single-ion anisotropy are included, our results indicate that there are compensation points at finite temperatures. When the next-nearest-neighbor interaction exceeds a minimum value that depends on the other parameters in the Hamiltonian, the compensation point disappears. The next-nearest-neighbor interaction has the effect of changing the compensation temperature.
