Junior English for China’ is based on the ’Five-Step’ teachingmethod: Revision, Presentation, Drilling, Practice, Consolidation. Each step has itsown particular methodology and requires the teacher to adopt a certa...Junior English for China’ is based on the ’Five-Step’ teachingmethod: Revision, Presentation, Drilling, Practice, Consolidation. Each step has itsown particular methodology and requires the teacher to adopt a certain role. Thispaper is a discussion of the "Five-Step Method".展开更多
The construction of the double-lane five-step ship lock of the Three Gorges Project （TGP） wascommenced in 1994, the excavation of the ship lock was completed by the end of 1999, and the ship lockwas put in operation...The construction of the double-lane five-step ship lock of the Three Gorges Project （TGP） wascommenced in 1994, the excavation of the ship lock was completed by the end of 1999, and the ship lockwas put in operation in June 2003. The side slopes of the ship lock are characterized by great height（170 m）, steepness （70 m in height of upright slope）, and great length （over 7000 m in total length）. Inassociation with the ship lock, the surrounding rocks in slope have a high potential to deform, withwhich the magnitude of deformation is restricted. Monitoring results show that the deformation of thefive-step ship lock high slopes of the TGP primarily occurred in excavation period, and deformationtended to be stable and convergent during operation period, suggesting the allowable ranges of deformation.At present, the slopes and lock chambers are stable, and the ship lock works well under normaloperation condition, enabling the social and economic benefits of the TGP. 2015 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved.展开更多
A flow-based iodometric extraction method for the determination of selenium sulfide was developed and applied to cosmeceutical products. Iodine which was generated from the reduction of selenium（IV） ions by iodide i...A flow-based iodometric extraction method for the determination of selenium sulfide was developed and applied to cosmeceutical products. Iodine which was generated from the reduction of selenium（IV） ions by iodide ion was on-line extracted using a polypropylene HFM （hollow fiber membrane） liquid extraction technique. The HFM extraction unit was constructed and used to support an organic solvent （hexane） and separate between the organic phase and aqueous phase. The resulting purple extract was carried to a fiber optic spectrophotometric detector for the measurement at 521 nm. Parameters which affected the extraction efficiency, sensitivity and sample throughput such as iodide （selenium molar ratio, extraction time and washing time between the cycles） were investigated and optimized. A linear dynamic range of 80-373 mg.Lt selenium solution was obtained with an extraction time of 60 sec. The total analysis time including washing was about 180 sec which provided a sample throughput of approximately 20 samples＇hr1 and excluded the sample pre-treatment. The recoveries for the determination of selenium in the forms of selenium dioxide and selenium sulfide were in the range of 103%-104% with 1%-3% RSD （relative standard deviation）. The relative errors of this method which was applied for determination of selenium sulfide levels in an anti-dandruff shampoo and a cosmeceutical bead sample were both less than 2.5%.展开更多
文摘Junior English for China’ is based on the ’Five-Step’ teachingmethod: Revision, Presentation, Drilling, Practice, Consolidation. Each step has itsown particular methodology and requires the teacher to adopt a certain role. Thispaper is a discussion of the "Five-Step Method".
文摘The construction of the double-lane five-step ship lock of the Three Gorges Project （TGP） wascommenced in 1994, the excavation of the ship lock was completed by the end of 1999, and the ship lockwas put in operation in June 2003. The side slopes of the ship lock are characterized by great height（170 m）, steepness （70 m in height of upright slope）, and great length （over 7000 m in total length）. Inassociation with the ship lock, the surrounding rocks in slope have a high potential to deform, withwhich the magnitude of deformation is restricted. Monitoring results show that the deformation of thefive-step ship lock high slopes of the TGP primarily occurred in excavation period, and deformationtended to be stable and convergent during operation period, suggesting the allowable ranges of deformation.At present, the slopes and lock chambers are stable, and the ship lock works well under normaloperation condition, enabling the social and economic benefits of the TGP. 2015 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved.
文摘A flow-based iodometric extraction method for the determination of selenium sulfide was developed and applied to cosmeceutical products. Iodine which was generated from the reduction of selenium（IV） ions by iodide ion was on-line extracted using a polypropylene HFM （hollow fiber membrane） liquid extraction technique. The HFM extraction unit was constructed and used to support an organic solvent （hexane） and separate between the organic phase and aqueous phase. The resulting purple extract was carried to a fiber optic spectrophotometric detector for the measurement at 521 nm. Parameters which affected the extraction efficiency, sensitivity and sample throughput such as iodide （selenium molar ratio, extraction time and washing time between the cycles） were investigated and optimized. A linear dynamic range of 80-373 mg.Lt selenium solution was obtained with an extraction time of 60 sec. The total analysis time including washing was about 180 sec which provided a sample throughput of approximately 20 samples＇hr1 and excluded the sample pre-treatment. The recoveries for the determination of selenium in the forms of selenium dioxide and selenium sulfide were in the range of 103%-104% with 1%-3% RSD （relative standard deviation）. The relative errors of this method which was applied for determination of selenium sulfide levels in an anti-dandruff shampoo and a cosmeceutical bead sample were both less than 2.5%.
