The monosized macroporous-polymer beads based on cross-linked poly(glycidylmethacrylate) have been synthesized by a new improving method-combining dispersionpolymerization with swelling polymerization and polymeric so...The monosized macroporous-polymer beads based on cross-linked poly(glycidylmethacrylate) have been synthesized by a new improving method-combining dispersionpolymerization with swelling polymerization and polymeric solution porogens. The structure and gel chromatographic properties of the resins have been studied. The resins as matrix materials of various types of high performance liquid chromatography (HPLC) packings possess excellent separation展开更多
Monosize, 1.6 μm, magnetic beads of poly（glycidyl methacrylate） [M-poly（GMA）], were prepared by dispersion polymerization in the presence of Fe3O4 nano-powder. Monosize M-poly（GMA） beads were characterized by s...Monosize, 1.6 μm, magnetic beads of poly（glycidyl methacrylate） [M-poly（GMA）], were prepared by dispersion polymerization in the presence of Fe3O4 nano-powder. Monosize M-poly（GMA） beads were characterized by swelling tests, density measurements, electron spin resonance （ESR）, vibrating sample magnetometer （VSM） and scanning electron microscopy （SEM）. The characteristic functional groups of M-poly（GMA） beads were analyzed by Fourier transform infrared spectrometer （FTIR）. The M-poly（GMA） beads are highly uniform in size and have a spherical shape and non-porous structure. Polydispersity index （PDI） of M-poly（GMA） beads was calculated to be around 1.008. The hydrated density of the M-poly（GMA） beads measured at 25 ℃ was 1.14 g/cm^3. The content of oxirane groups on the surface of the M-poly（GMA） sample was found to be 3.46 mmol/g by using perchloric acid titration. The specific surface area of the M-poly（GMA） beads was determined to be 3.2 m^2/g. The equilibrium swelling ratio was 52%. The volume fraction of magnetite nanopowder in the M-poly（GMA） beads was found to be 4.5%. The g factor, that can be considered as a quantity characteristic of the molecules in which the unpaired electrons are located, was found to be 2.28 for M-poly（GMA）. The external magnetic field at resonance was calculated to be 2055 Gs which was found sufficient to excite all of the dipole moments present in 1.0 g of M-poly（GMA） sample.展开更多
A novel reactive resin as active support was synthesized by an improved method based on seed swelling and surface coating polymerization. The resin is monosized beads with inner nucleus of cross-linked polymer and sur...A novel reactive resin as active support was synthesized by an improved method based on seed swelling and surface coating polymerization. The resin is monosized beads with inner nucleus of cross-linked polymer and surface layer of copolymer containing epoxy groups. The physico-chemical structures of beads were characterized.展开更多
We propose and investigate a novel metal/SiO_2/Si_3N_4/SiO_2/SiGe charge trapping flash memory structure（named as MONOS）, utilizing Si Ge as the buried channel. The fabricated memory device demonstrates excellent pr...We propose and investigate a novel metal/SiO_2/Si_3N_4/SiO_2/SiGe charge trapping flash memory structure（named as MONOS）, utilizing Si Ge as the buried channel. The fabricated memory device demonstrates excellent programerasable characteristics attributed to the fact that more carriers are generated by the smaller bandgap of Si Ge during program/erase operations. A flat-band voltage shift 2.8 V can be obtained by programming at ＋11 V for 100 us. Meanwhile, the memory device exhibits a large memory window of ~7.17 V under ±12 V sweeping voltage, and a negligible charge loss of 18% after 104 s＇ retention. In addition, the leakage current density is lower than 2.52 × 10^（-7） A·cm^（-2） below a gate breakdown voltage of 12.5 V. Investigation of leakage current-voltage indicates that the Schottky emission is the predominant conduction mechanisms for leakage current. These desirable characteristics are ascribed to the higher trap density of the Si_3N_4 charge trapping layer and the better quality of the interface between the SiO_2 tunneling layer and the Si Ge buried channel. Therefore, the application of the Si Ge buried channel is very promising to construct 3 D charge trapping NAND flash devices with improved operation characteristics.展开更多
In guinea-pigs, cats and dogs, 4-R-2,2,5,5-tetracis （trifluoromethyl）-imidazoline （R =NHCH2OCOCH3, throughout this paper the term 'SIS-Ⅱ' refers to this derivate） has been shown to induce stepping movemen...In guinea-pigs, cats and dogs, 4-R-2,2,5,5-tetracis （trifluoromethyl）-imidazoline （R =NHCH2OCOCH3, throughout this paper the term 'SIS-Ⅱ' refers to this derivate） has been shown to induce stepping movements together with an anaesthesia-like state. Stepping movements after SIS-Ⅱ were observed in intact and in decerebrate but not展开更多
： Metal-oxide-nitride-oxide-silicon （MONOS） capacitors with thermally grown SiO2 as the tunnel layer are fabricated, and the effects of different ambient nitridation （NH3, NO and N20） on the characteristics of th...： Metal-oxide-nitride-oxide-silicon （MONOS） capacitors with thermally grown SiO2 as the tunnel layer are fabricated, and the effects of different ambient nitridation （NH3, NO and N20） on the characteristics of the memory capacitors are investigated. The experimental results indicate that the device with tunnel oxide annealed in NO ambient exhibits excellent memory characteristics, i.e. a large memory window, high program/erase speed, and good endurance and retention performance （the charge loss rate is 14.5% after l0 years）. The mechanism involved is that much more nitrogen is incorporated into the tunnel oxide during NO annealing, resulting in a lower tunneling barrier height and smaller interface state density. Thus, there is a higher tunneling rate under a high electric field and a lower probability of trap-assisted tunneling during retention, as compared to N20 annealing. Furthermore, compared with the NH3-annealed device, no weak Si-H bonds and electron traps related to the hydrogen are introduced for the NO-annealed devices, giving a high-quality and high-reliability SiON tunneling layer and SiON/Si interface due to the suitable nitridation and oxidation roles of NO. Key words： MONOS memory; memory characteristics; annealing; nitridation展开更多
文摘The monosized macroporous-polymer beads based on cross-linked poly(glycidylmethacrylate) have been synthesized by a new improving method-combining dispersionpolymerization with swelling polymerization and polymeric solution porogens. The structure and gel chromatographic properties of the resins have been studied. The resins as matrix materials of various types of high performance liquid chromatography (HPLC) packings possess excellent separation
文摘Monosize, 1.6 μm, magnetic beads of poly（glycidyl methacrylate） [M-poly（GMA）], were prepared by dispersion polymerization in the presence of Fe3O4 nano-powder. Monosize M-poly（GMA） beads were characterized by swelling tests, density measurements, electron spin resonance （ESR）, vibrating sample magnetometer （VSM） and scanning electron microscopy （SEM）. The characteristic functional groups of M-poly（GMA） beads were analyzed by Fourier transform infrared spectrometer （FTIR）. The M-poly（GMA） beads are highly uniform in size and have a spherical shape and non-porous structure. Polydispersity index （PDI） of M-poly（GMA） beads was calculated to be around 1.008. The hydrated density of the M-poly（GMA） beads measured at 25 ℃ was 1.14 g/cm^3. The content of oxirane groups on the surface of the M-poly（GMA） sample was found to be 3.46 mmol/g by using perchloric acid titration. The specific surface area of the M-poly（GMA） beads was determined to be 3.2 m^2/g. The equilibrium swelling ratio was 52%. The volume fraction of magnetite nanopowder in the M-poly（GMA） beads was found to be 4.5%. The g factor, that can be considered as a quantity characteristic of the molecules in which the unpaired electrons are located, was found to be 2.28 for M-poly（GMA）. The external magnetic field at resonance was calculated to be 2055 Gs which was found sufficient to excite all of the dipole moments present in 1.0 g of M-poly（GMA） sample.
基金supported by the National Natural Science Foundation of China(Grant No.29635010).
文摘A novel reactive resin as active support was synthesized by an improved method based on seed swelling and surface coating polymerization. The resin is monosized beads with inner nucleus of cross-linked polymer and surface layer of copolymer containing epoxy groups. The physico-chemical structures of beads were characterized.
基金Supported by the National Science and Technology Major Project of China under Grant No 2013ZX02303007the National Key Research and Development Program of China under Grant No 2016YFA0301701the Youth Innovation Promotion Association of the Chinese Academy of Sciences under Grant No 2016112
文摘We propose and investigate a novel metal/SiO_2/Si_3N_4/SiO_2/SiGe charge trapping flash memory structure（named as MONOS）, utilizing Si Ge as the buried channel. The fabricated memory device demonstrates excellent programerasable characteristics attributed to the fact that more carriers are generated by the smaller bandgap of Si Ge during program/erase operations. A flat-band voltage shift 2.8 V can be obtained by programming at ＋11 V for 100 us. Meanwhile, the memory device exhibits a large memory window of ~7.17 V under ±12 V sweeping voltage, and a negligible charge loss of 18% after 104 s＇ retention. In addition, the leakage current density is lower than 2.52 × 10^（-7） A·cm^（-2） below a gate breakdown voltage of 12.5 V. Investigation of leakage current-voltage indicates that the Schottky emission is the predominant conduction mechanisms for leakage current. These desirable characteristics are ascribed to the higher trap density of the Si_3N_4 charge trapping layer and the better quality of the interface between the SiO_2 tunneling layer and the Si Ge buried channel. Therefore, the application of the Si Ge buried channel is very promising to construct 3 D charge trapping NAND flash devices with improved operation characteristics.
文摘In guinea-pigs, cats and dogs, 4-R-2,2,5,5-tetracis （trifluoromethyl）-imidazoline （R =NHCH2OCOCH3, throughout this paper the term 'SIS-Ⅱ' refers to this derivate） has been shown to induce stepping movements together with an anaesthesia-like state. Stepping movements after SIS-Ⅱ were observed in intact and in decerebrate but not
基金supported by the National Natural Science Foundation of China(No.60976091)
文摘： Metal-oxide-nitride-oxide-silicon （MONOS） capacitors with thermally grown SiO2 as the tunnel layer are fabricated, and the effects of different ambient nitridation （NH3, NO and N20） on the characteristics of the memory capacitors are investigated. The experimental results indicate that the device with tunnel oxide annealed in NO ambient exhibits excellent memory characteristics, i.e. a large memory window, high program/erase speed, and good endurance and retention performance （the charge loss rate is 14.5% after l0 years）. The mechanism involved is that much more nitrogen is incorporated into the tunnel oxide during NO annealing, resulting in a lower tunneling barrier height and smaller interface state density. Thus, there is a higher tunneling rate under a high electric field and a lower probability of trap-assisted tunneling during retention, as compared to N20 annealing. Furthermore, compared with the NH3-annealed device, no weak Si-H bonds and electron traps related to the hydrogen are introduced for the NO-annealed devices, giving a high-quality and high-reliability SiON tunneling layer and SiON/Si interface due to the suitable nitridation and oxidation roles of NO. Key words： MONOS memory; memory characteristics; annealing; nitridation
