Abstract: The disclosure relates to the technical field of solar seawater desalination, in particular to an all-weather solar seawater desalination device and a method. Through a prepared composite hydrogel evaporator, the water in seawater is evaporated into steam and condensed into fresh water. By combining solar energy with a long afterglow luminous device, the composite hydrogel evaporator is irradiated by solar energy to evaporate during the day, while at night, the light energy released by the long afterglow luminous device continues to maintain the evaporation process.

Abstract: A method for preparing a carbon nano tube/polyacrylic acid hydrogel, a product and an application thereof are provided. The method includes: oxidizing a carbon nanotube into a carboxylated carbon nanotube, thereafter performing in-situ polymerization with acrylic acid, sodium hydroxide, ammonium persulfate, triethanolamine and N, N-methylenebisacrylamide to obtain a carbon nanotube/polyacrylic acid hydrogel. The hydrogel has a uniform porous structure, facilitating a rapid transmission and supply of water. The carbon nanotubes in the hydrogel are of an array structure, achieving a full absorption of solar energy to realize a high-efficiency photothermal conversion. The gel is attached to a sponge base to obtain a solar-powered carbon nano tube/polyacrylic acid hydrogel steam generator for the photothermal conversion. The steam generator is used for solar seawater desalination, but can improve evaporation rate and evaporation efficiency.

Abstract: A composite hydrogel sponge and its preparation method and application, and a solar desalination device are provided. The composite hydrogel sponge includes a water supply layer and an evaporation layer disposed on the water supply layer. A material of the water supply layer is polyacrylamide hydrogel, and a material of the evaporation layer is polyacrylamide/graphene composite hydrogel. The polyacrylamide/graphene composite hydrogel includes the polyacrylamide hydrogel and the graphene dispersed in the polyacrylamide hydrogel. The composite hydrogel sponge has a special porous structure of the sponge, which is beneficial to the rapid transmission and supply of water; meanwhile, the graphene on the surface of the evaporation layer can fully receive solar energy to achieve higher photo-thermal conversion efficiency.

Abstract: A method for preparing a carbon nano tube/polyacrylic acid hydrogel, a product and an application thereof are provided. The method includes: oxidizing a carbon nanotube into a carboxylated carbon nanotube, thereafter performing in-situ polymerization with acrylic acid, sodium hydroxide, ammonium persulfate, triethanolamine and N, N-methylenebisacrylamide to obtain a carbon nanotube/polyacrylic acid hydrogel. The hydrogel has a uniform porous structure, facilitating a rapid transmission and supply of water. The carbon nanotubes in the hydrogel are of an array structure, achieving a full absorption of solar energy to realize a high-efficiency photothermal conversion. The gel is attached to a sponge base to obtain a solar-powered carbon nano tube/polyacrylic acid hydrogel steam generator for the photothermal conversion. The steam generator is used for solar seawater desalination, but can improve evaporation rate and evaporation efficiency.

Abstract: Data migration is facilitated. An example method comprises initiating data migration from a first storage system to a second storage system, wherein the data migration is divided into stages, and the stages comprise a first stage and a second stage after the first stage. The method comprises executing tasks in a first group of tasks in the first stage in parallel, wherein the tasks comprise a first task and a second task. The method further comprises generating a third task corresponding to the first task and a fourth task corresponding to the second task in the second stage in response to determining that the first task and the second task are completed respectively. For instance, in the staged data migration process, multiple execution tasks in different stages can be executed in parallel, and thus the speed of data migration is increased and fault tolerance performance of the system is improved.

Abstract: Metadata of a storage object is managed. For instance, in response to metadata of a storage object being updated, a first index structure for indexing the metadata of the storage object and a page table corresponding to the first index structure in a memory are updated, wherein the first index structure and the page table have been stored in a persistent storage device. Updates of the page table are recorded in at least one page table journal and the updated first index structure and the at least one page table journal are stored in the persistent storage device. Embodiments can significantly increase the speed of failover and persistence of metadata in a distributed object storage system.

Abstract: Data migration is facilitated. An example method comprises initiating data migration from a first storage system to a second storage system, wherein the data migration is divided into stages, and the stages comprise a first stage and a second stage after the first stage. The method comprises executing tasks in a first group of tasks in the first stage in parallel, wherein the tasks comprise a first task and a second task. The method further comprises generating a third task corresponding to the first task and a fourth task corresponding to the second task in the second stage in response to determining that the first task and the second task are completed respectively. For instance, in the staged data migration process, multiple execution tasks in different stages can be executed in parallel, and thus the speed of data migration is increased and fault tolerance performance of the system is improved.