Elimination of phosphorus vaporizing from silicon was investigated. Si-P alloy made from electronic grade silicon was used. All the samples were analyzed by GD-MS. Theory calculation determines that phosphorus evapora...Elimination of phosphorus vaporizing from silicon was investigated. Si-P alloy made from electronic grade silicon was used. All the samples were analyzed by GD-MS. Theory calculation determines that phosphorus evaporates from molten silicon as gas species P and P2 at a finite reduced pressure. The experimental results show that phosphorus mass fraction can be decreased from 0.046% （460ppmw） to around 0.001% （10ppmw） under the condition of temperature 1 873 K, chamber pressure 0.6-0.8 Pa, holding time 1 h. Both experimental data and calculation results agree that at high phosphorus concentration, phosphorus removal is quite dependent on high chamber pressure while it becomes independent on low chamber pressure. The reason is that phosphorus evaporates from molten silicon as gas species P2 at a relatively high phosphorus concentration, while gas species P will be dominated in its vapour at low phosphorus content.展开更多
The objective of the present study was to determine the proper sources and concentrations of soybean lecithin （phosphatidylcholine, PC） to be used as substitute for hen egg yolk in extender for preserving goat semen...The objective of the present study was to determine the proper sources and concentrations of soybean lecithin （phosphatidylcholine, PC） to be used as substitute for hen egg yolk in extender for preserving goat semen. Two sources of soybean lecithin （20% and 95% soybean phosphatidylcholine; PC20 and PC95） and three concentrations （1%, 2% and 3% v/v） of PC20 and PC95 supplemented in Tris-citric acid-fructose （TCF） extender were tested. The TCF extender supplemented with 20% hen egg yolk was used as a control. Fresh semen samples were collected from 3 goats by artificial vagina. Seminal plasma was removed by centrifugation and sperm pellets were pooled together and divided into 7 groups according to types of extender. The diluted semen samples were kept at 4 ℃ （equilibration）. The semen qualities including progressive motility, sperm viability, sperm plasma membrane integrity and tail abnormalities were evaluated before dilution and after 4 hrs equilibration. It was found that the progressive motility of equilibrated semen in egg yolk and PC20 extenders were higher than those in PC95 extender （P 〈 0.05）. Sperm viability was lower in 1% and 2% PC95 extender compared to other extenders （P 〈 0.05）. PC20 extender maintained the sperm membrane integrity and normal tail morphology at low temperature better than egg yolk and PC95 （P 〈 0.05）. It can be concluded that 20% soybean phosphatidylcholine supplemented in TCF extender at 1%-3% （v/v） is as effective as hen egg yolk to preserve goat semen during equilibration at 4 ℃ for 4 hrs .展开更多
基金Project (2007J0012) supported by the Natural Science Foundation of Fujian Province, ChinaProject (2007HZ0005-2) supported by the Key Technological Program of Fujian Province, ChinaProject (BASIC-10341702) supported by Norwegian Research Council
文摘Elimination of phosphorus vaporizing from silicon was investigated. Si-P alloy made from electronic grade silicon was used. All the samples were analyzed by GD-MS. Theory calculation determines that phosphorus evaporates from molten silicon as gas species P and P2 at a finite reduced pressure. The experimental results show that phosphorus mass fraction can be decreased from 0.046% （460ppmw） to around 0.001% （10ppmw） under the condition of temperature 1 873 K, chamber pressure 0.6-0.8 Pa, holding time 1 h. Both experimental data and calculation results agree that at high phosphorus concentration, phosphorus removal is quite dependent on high chamber pressure while it becomes independent on low chamber pressure. The reason is that phosphorus evaporates from molten silicon as gas species P2 at a relatively high phosphorus concentration, while gas species P will be dominated in its vapour at low phosphorus content.
文摘The objective of the present study was to determine the proper sources and concentrations of soybean lecithin （phosphatidylcholine, PC） to be used as substitute for hen egg yolk in extender for preserving goat semen. Two sources of soybean lecithin （20% and 95% soybean phosphatidylcholine; PC20 and PC95） and three concentrations （1%, 2% and 3% v/v） of PC20 and PC95 supplemented in Tris-citric acid-fructose （TCF） extender were tested. The TCF extender supplemented with 20% hen egg yolk was used as a control. Fresh semen samples were collected from 3 goats by artificial vagina. Seminal plasma was removed by centrifugation and sperm pellets were pooled together and divided into 7 groups according to types of extender. The diluted semen samples were kept at 4 ℃ （equilibration）. The semen qualities including progressive motility, sperm viability, sperm plasma membrane integrity and tail abnormalities were evaluated before dilution and after 4 hrs equilibration. It was found that the progressive motility of equilibrated semen in egg yolk and PC20 extenders were higher than those in PC95 extender （P 〈 0.05）. Sperm viability was lower in 1% and 2% PC95 extender compared to other extenders （P 〈 0.05）. PC20 extender maintained the sperm membrane integrity and normal tail morphology at low temperature better than egg yolk and PC95 （P 〈 0.05）. It can be concluded that 20% soybean phosphatidylcholine supplemented in TCF extender at 1%-3% （v/v） is as effective as hen egg yolk to preserve goat semen during equilibration at 4 ℃ for 4 hrs .
