Abstract: A storage system includes multiple storage nodes. Each storage node includes a first storage device of a first type and a second storage device of a second type, and a performance level of the first storage device is higher than the second storage device. The globe cache includes a first tier comprising the first storage device in each storage node, and a second tier comprising the second storage device in each storage node. The first tier is for storing data with a high access frequency, and the second tier is for storing data with a low access frequency. The management node monitors an access frequency of target data stored in the first tier. When the access frequency of the target data is lower than a threshold, the management node instructs the first storage node to migrate the target data from the first tier to the second tier.

Abstract: Disclosed is a method for preparing structured graphene on a SiC substrate on the basis of Cl2 reaction, the procedures are as follows: firstly, performing standard cleaning to a SiC sample chip; depositing a layer of SiO2 on the surface of the SiC sample chip and engraving a figure window on the SiO2 layer; then arranging the windowed sample chip in a quartz tube, introducing a mixed gas of Ar and Cl2 into the quartz tube, reacting the bare SiC with Cl2 for 3-8 min at 700-1100° C. to generate a carbon film; arranging the generated carbon film in Ar gas, annealing for 10-30 min at 1000-1200° C. to generate the structured graphene on the window on the carbon film. The method is simple and safe; the generated structured graphene has a smooth surface and low porosity and can be used for making microelectronic devices.

Abstract: A layer I vanadium-doped PIN-type nuclear battery, including from top to bottom a radioisotope source layer(1), a p-type ohm contact electrode(4), a SiO2 passivation layer(2), a SiO2 compact insulation layer(3), a p-type SiC epitaxial layer(5), an n-type SiC epitaxial layer(6), an n-type SiC substrate(7) and an n-type ohm contact electrode(8). The doping density of the p-type SiC epitaxial layer(5) is 1×1019 to 5×1019 cm?3, the doping density of the n-type SiC substrate(7) is 1×1018 to 7×1018 cm?3. The n-type SiC epitaxial layer(6) is a low-doped layer I formed by injecting vanadium ions, with the doping density thereof being 1×1013 to 5×1014 cm?3. Also provided is a preparation method for a layer I vanadium-doped PIN-type nuclear battery. The present invention solves the problem that the doping density of layer I of the exiting SiC PIN-type nuclear battery is high.

Abstract: Provided is a process for preparing graphene on a SiC substrate, based on metal film-assisted annealing, comprising the following steps: subjecting a SiC substrate to a standard cleaning process; placing the cleaned SiC substrate into a quartz tube and heating the quartz tube up to a temperature of 750 to 1150° C.; introducing CCl4vapor into the quartz tube to react with SiC for a period of 20 to 100 minutes so as to generate a double-layered carbon film, wherein the CCl4 vapor is carried by Ar gas; forming a metal film with a thickness of 350 to 600 nm on a Si substrate by electron beam deposition; placing the obtained double-layered carbon film sample onto the metal film; subsequently annealing them in an Ar atmosphere at a temperature of 900 to 1100° C. for 10-30 minutes so as to reconstitute the double-layered carbon film into double-layered graphene; and removing the metal film from the double-layered graphene, thereby obtaining double-layered graphene.

Abstract: A method for preparing graphene by reaction with Cl2 based on annealing with assistant metal film is provided, comprising the following steps: applying normal wash to a Si-substrate, then putting the Si-substrate into a reaction chamber of a CVD system and evacuating, rising the temperature to 950° C.-1150° C. gradually, supplying C3H8 and carbonizing the Si-substrate for 3-10 min; rising the temperature to 1150° C.-1350° C. rapidly, supplying C3H8 and SiH4, growing a 3C—SiC hetero-epitaxial film on the carbonized layer, and then reducing the temperature to ambient temperature under the protection of H2 gradually, introducing the grown sample wafer of 3C—SiC into a quartz tube, heating to 700-1100° C., supplying mixed gas of Ar and Cl2, and reacting Cl2 with 3C—SiC to generate a carbon film, applying the sample wafer of carbon film on a metal film, annealing at 900° C.-1100° C.

Abstract: Disclosed is a method for preparing structured graphene on a SiC substrate on the basis of Cl2 reaction, the procedures are as follows: firstly, performing standard cleaning to a SiC sample chip; depositing a layer of SiO2 on the surface of the SiC sample chip and engraving a figure window on the SiO2 layer; then arranging the windowed sample chip in a quartz tube, introducing a mixed gas of Ar and Cl2 into the quartz tube, reacting the bare SiC with Cl2 for 3-8 min at 700-1100° C. to generate a carbon film; arranging the generated carbon film in Ar gas, annealing for 10-30 min at 1000-1200° C. to generate the structured graphene on the window on the carbon film. The method is simple and safe; the generated structured graphene has a smooth surface and low porosity and can be used for making microelectronic devices.

Abstract: Provided is a process for preparing graphene on a SiC substrate, based on metal film-assisted annealing, comprising the following steps: subjecting a SiC substrate to a standard cleaning process; placing the cleaned SiC substrate into a quartz tube and heating the quartz tube up to a temperature of 750 to 1150° C.; introducing CCl4vapor into the quartz tube to react with SiC for a period of 20 to 100 minutes so as to generate a double-layered carbon film, wherein the CCl4 vapor is carried by Ar gas; forming a metal film with a thickness of 350 to 600 nm on a Si substrate by electron beam deposition; placing the obtained double-layered carbon film sample onto the metal film; subsequently annealing them in an Ar atmosphere at a temperature of 900 to 1100° C. for 10-30 minutes so as to reconstitute the double-layered carbon film into double-layered graphene; and removing the metal film from the double-layered graphene, thereby obtaining double-layered graphene.

Abstract: A method for preparing graphene by reaction with Cl2 based on annealing with assistant metal film is provided, comprising the following steps: applying normal wash to a Si-substrate, then putting the Si-substrate into a reaction chamber of a CVD system and evacuating, rising the temperature to 950° C. -1150° C. gradually, supplying C3H8 and carbonizing the Si-substrate for 3-10 min; rising the temperature to 1150° C.-1350° C. rapidly, supplying C3H8 and SiH4, growing a 3C—SiC hetero-epitaxial film on the carbonized layer, and then reducing the temperature to ambient temperature under the protection of H2 gradually, introducing the grown sample wafer of 3C—SiC into a quartz tube, heating to 700-1100° C., supplying mixed gas of Ar and Cl2, and reacting Cl2 with 3C—SiC to generate a carbon film, applying the sample wafer of carbon film on a metal film, annealing at 900° C.-1100° C.

Abstract: A layer I vanadium-doped PIN-type nuclear battery, including from top to bottom a radioisotope source layer(1), a p-type ohm contact electrode(4), a SiO2 passivation layer(2), a SiO2 compact insulation layer(3), a p-type SiC epitaxial layer(5), an n-type SiC epitaxial layer(6), an n-type SiC substrate(7) and an n-type ohm contact electrode(8). The doping density of the p-type SiC epitaxial layer(5) is 1×1019 to 5×1019 cm3, the doping density of the n-type SiC substrate(7) is 1×1018 to 7×1018 cm3. The n-type SiC epitaxial layer(6) is a low-doped layer I formed by injecting vanadium ions, with the doping density thereof being 1×1013 to 5×1014 cm3. Also provided is a preparation method for a layer I vanadium-doped PIN-type nuclear battery. The present invention solves the problem that the doping density of layer I of the exiting SiC PIN-type nuclear battery is high.