SiNx：H films with different N/Si ratios are synthesized by plasma-enhanced chemical vapor deposition （PECVD）. Composition and structure characteristics are detected by Fourier transform infrared spectroscopy （FTIR...SiNx：H films with different N/Si ratios are synthesized by plasma-enhanced chemical vapor deposition （PECVD）. Composition and structure characteristics are detected by Fourier transform infrared spectroscopy （FTIR） and X-ray photoelectron spectroscopy （XPS）. It indicates that Si-N bonds increase with increased NH3/SiH4 ratio. Electrical property investigations by I-V measurements show that the prepared films offer higher resistivity and less leakage current with increased N/Si ratio and exhibit entirely insulating properties when N/Si ratio reaches 0.9, which is ascribed to increased Si-N bonds achieved.展开更多
Dear Sir,Eye drops(single use)commonly used in clinics do have varying pH values.The use of such drops in the initial management of chemical eye injury may influence the accuracy of pH measurement of the eye,and subse...Dear Sir,Eye drops(single use)commonly used in clinics do have varying pH values.The use of such drops in the initial management of chemical eye injury may influence the accuracy of pH measurement of the eye,and subsequently influence its management.Chemical eye injury is an ophthalmic emergency,which may be caused by exposure to an acidic(pH【4)or an alkali(pH】10)solution to the eye.Rinsing the eye decreases the concentration of these solutions on ocular surface.The initial management would be copious irrigation with clean or sterile water or Ringer’s solution(pH 7.3-7.4)or its equivalent,of a展开更多
A problem in chemical analysis in connection with measurements of a substance normally occurring in a sample, or identification of a substance which should not exist in a sample, is insufficient selectivity. In this a...A problem in chemical analysis in connection with measurements of a substance normally occurring in a sample, or identification of a substance which should not exist in a sample, is insufficient selectivity. In this article, we analyze this problem and propose remedies. We use a real doping case to illustrate how chemical noise causes a serious selectivity problem, probably causing a false positive outcome.展开更多
A three-dimensional finite element model for phase change random access memory （PCRAM） is established for comprehensive electrical and thermal analysis during SET operation. The SET behaviours of the heater additio...A three-dimensional finite element model for phase change random access memory （PCRAM） is established for comprehensive electrical and thermal analysis during SET operation. The SET behaviours of the heater addition structure （HS） and the ring-type contact in bottom electrode （RIB） structure are compared with each other. There are two ways to reduce the RESET current, applying a high resistivity interracial layer and building a new device structure. The simulation resuIts indicate that the variation of SET current with different power reduction ways is little. This study takes the RESET and SET operation current into consideration, showing that the RIB structure PCRAM cell is suitable for future devices with high heat efficiency and high-density, due to its high heat efficiency in RESET operation.展开更多
文摘SiNx：H films with different N/Si ratios are synthesized by plasma-enhanced chemical vapor deposition （PECVD）. Composition and structure characteristics are detected by Fourier transform infrared spectroscopy （FTIR） and X-ray photoelectron spectroscopy （XPS）. It indicates that Si-N bonds increase with increased NH3/SiH4 ratio. Electrical property investigations by I-V measurements show that the prepared films offer higher resistivity and less leakage current with increased N/Si ratio and exhibit entirely insulating properties when N/Si ratio reaches 0.9, which is ascribed to increased Si-N bonds achieved.
文摘Dear Sir,Eye drops(single use)commonly used in clinics do have varying pH values.The use of such drops in the initial management of chemical eye injury may influence the accuracy of pH measurement of the eye,and subsequently influence its management.Chemical eye injury is an ophthalmic emergency,which may be caused by exposure to an acidic(pH【4)or an alkali(pH】10)solution to the eye.Rinsing the eye decreases the concentration of these solutions on ocular surface.The initial management would be copious irrigation with clean or sterile water or Ringer’s solution(pH 7.3-7.4)or its equivalent,of a
文摘A problem in chemical analysis in connection with measurements of a substance normally occurring in a sample, or identification of a substance which should not exist in a sample, is insufficient selectivity. In this article, we analyze this problem and propose remedies. We use a real doping case to illustrate how chemical noise causes a serious selectivity problem, probably causing a false positive outcome.
文摘A three-dimensional finite element model for phase change random access memory （PCRAM） is established for comprehensive electrical and thermal analysis during SET operation. The SET behaviours of the heater addition structure （HS） and the ring-type contact in bottom electrode （RIB） structure are compared with each other. There are two ways to reduce the RESET current, applying a high resistivity interracial layer and building a new device structure. The simulation resuIts indicate that the variation of SET current with different power reduction ways is little. This study takes the RESET and SET operation current into consideration, showing that the RIB structure PCRAM cell is suitable for future devices with high heat efficiency and high-density, due to its high heat efficiency in RESET operation.
