7 results about "Short lifetime" patented technology

The invention provides an organic electroluminescent device, and particularly relates to the technical field of organic electroluminescence. In order to solve the problems of low luminous efficiency and short service life of the device in the prior art, the invention provides the organic light-emitting device with excellent performance. The hole transmission region comprises a triarylamine compound represented by a formula 1, the electron transmission region comprises a fluorene compound represented by a formula 2, and the triarylamine compound and the fluorene compound can effectively block electrons transmitted to the light-emitting layer and diffusion of holes to the hole / electron transmission layer, so that the probability that the holes and the electrons are compounded into excitons in the light-emitting layer is increased, and the light-emitting efficiency of the device is improved; and device aging caused by leakage of electrons and holes into the hole transport layer and the electron transport layer is avoided, so that the service life of the device is prolonged. The preparation method of the compound is simple, raw materials are easy to obtain, and the compound can be widely applied to the fields of lighting sources, organic thin film transistors and the like and has good industrialization prospects.

Electron sources that emit electrons by tunneling through a solid have the problem of having a short lifetime. This invention provides a new planar electron source with a long lifetime and a method for manufacturing the same. [Solution] The electron source comprises a graphene layer 130 having a planar electron emission area 150 on one side, and a p-type semiconductor layer in direct contact with the other side of the graphene layer 130. As a result, electrons are accelerated in the depletion layer within the p-type semiconductor layer. Preferably, the p-type semiconductor layer has a depletion layer with a width of 2.91 nm to 30 nm. [Effects] Unlike MIS-type electron sources, electrons are not accelerated within the insulating layer, so dielectric breakdown, which occurs when a large number of electrons travel through the valence band of the insulator, does not occur, resulting in a long-life electron source.

The utility model provides a spiral opening and closing type plastic shut-off stop valve, and belongs to the technical field of valve manufacturing. The problem that an existing stop valve is short in service life is solved. The spiral opening and closing type plastic shut-off stop valve comprises a valve body and a valve cover, a valve rod is in threaded connection with the interior of the valve cover, filler is arranged between the valve cover and the valve rod, a pressing cover penetrates through the top of the valve cover, a first screw penetrates through and is fixedly connected to the bottom end of the valve rod, and a sealing plate fixedly sleeves the surface of the first screw; a rubber pad is fixedly connected to the bottom of the sealing plate, threaded holes are formed in the two sides of the valve deck, inner cavities of the threaded holes are in threaded connection with limiting mechanisms, the limiting mechanisms comprise limiting bolts, and limiting grooves are formed in the top of the surface of the valve deck. According to the utility model, the pressing cover can be limited and fixed, so that the pressing cover does not fall off when being subjected to water pressure impact and frequent opening and closing actions, and the sealing performance is further improved.

This invention relates to a self-balancing multistage pump with axial force, solving the problems of high energy consumption, short lifespan, and poor operational stability caused by the large axial force generated by the equal outer diameter of the front and rear cover plates and a specific speed (ns>300) in existing technologies. The technical solution includes a pump body, an impeller string housed within the pump body, and several sets of impeller units within the impeller string. The key feature is that each impeller unit includes a guide shroud, an impeller housed in the guide cavity of the guide shroud, and the impeller comprising a front cover plate, a rear cover plate, and blades disposed between the front and rear cover plates. The outer diameter of the front cover plate is larger than that of the rear cover plate. The front cover plate mates with the bottom of the guide cavity and with the open portion of the guide cavity. Its effects are: by using an impeller with a front cover plate area larger than the rear cover plate area, and in conjunction with the guide shroud, self-balancing of the impeller axial force is achieved, making the pump operation more stable and reliable, significantly reducing power consumption, greatly improving social and economic benefits, and achieving the goal of energy conservation and emission reduction.

The invention discloses a blue light laminated organic light-emitting device and a preparation method thereof. The blue light laminated organic light-emitting device comprises at least two blue light-emitting units which are connected in series through a charge generation layer, and each electroluminescent unit internally comprises a sandwich type core constraint structure of an electron blocking layer / blue light emitting layer / hole blocking layer. The unique double-side constraint structure can efficiently limit carriers and excitons in emission layers of respective light-emitting units, so that non-radiation quenching of the excitons on a functional layer interface and a charge generation layer interface is greatly inhibited. In addition, rare earth metal is preferably adopted as an n-type doping agent in the charge generation layer, so that the operation stability of the charge generation layer is improved. The laminated device structure cooperatively solves the technical problems that an existing blue light OLED is low in efficiency and short in service life, and an extra attenuation path exists in a laminated device, and excellent luminous efficiency, extremely low efficiency roll-off and excellent working stability are achieved.

The invention discloses a working method and device of storage equipment, equipment and a storage medium, and the method comprises the steps: monitoring the PECS frequency of the storage equipment in real time, and obtaining a first monitoring parameter; wherein different storage devices carry storage media of different transmission types, and the storage media of different transmission types correspond to different PECS frequency thresholds; comparing the first monitoring parameter with a PECS frequency threshold corresponding to a storage medium of the storage device; if the first monitoring parameter reaches the PECS frequency threshold, switching the current working mode of the storage device to a target working mode; wherein the data transmission density of the target working mode is lower than that of the current working mode. Therefore, the loss is reduced before the storage medium reaches the life threshold, the problem of short life of a high-density storage medium in the prior art is solved, and the method has the advantages of prolonging the service life of the storage device and keeping reasonable storage capacity at the same time.

The application belongs to the technical field of crystal preparation, and particularly relates to a kind of alpha-Al2Mo3O 12 Nanometer sheet, its preparation method and application. The application adopts chemical vapor deposition method to epitaxially grow high directional monocrystal nanometer sheet on c face sapphire substrate, improves crystal quality, reduces production cost, and can be mass produced. The application also provides nanometer sheet obtained by the preparation method. The nanometer sheet provided by the application is two-dimensional crystal composed of multiple layers of atoms, has extremely low thermal conductivity coefficient, and excellent chemical, optical and electronic properties. Systematic variable-temperature Raman spectrum research finds that characteristic phonon has extremely short lifetime, indicating that the nanometer sheet has extremely low thermal conductivity coefficient.