Abstract: The method includes: determining required virtual inertia based on a frequency change rate monitored at a grid connection point of a photovoltaic grid-connected system; obtaining values of indexes that affect virtual inertia provided by each virtual synchronous generator (VSG) control unit in a photovoltaic cluster of the photovoltaic grid-connected system; determining, by using a predetermined function equation, a function value corresponding to each index; and determining an allocation proportion of the required virtual inertia in each VSG control unit based on the function value corresponding to each index. A problem of difficult conversion between a plurality of kinds of performance during operation of a power system is resolved, the frequency change rate is suppressed to a certain extent, and a stable state is recovered quickly.

Abstract: Adjustable handles that are uniquely designed and mounted to a self-propelled lawn mower to improve and accommodate the different operating requirements by the operator standing on a sulky device or in a walking position behind the lawn mower. The adjustable handles comprise a front handle, a left control handle lever, a right control handle lever, and a back handle, each individually adjustable and releaseably fixed to the same opposed supports or plates fixedly secured to the lawn mower.

Abstract: A display panel, a display device and a method of manufacturing the display panel. The display panel includes a display region, and the display region includes a first region and a second region. The display panel includes a base body and a first electrode layer. At least a portion of the first electrode layer is located on a side of the base body, the first electrode layer includes a plurality of first electrodes and a plurality of openings, the first electrodes are located within the first region, and the openings are located within the second region. The display panel is provided with a blocking structure which is configured to block the first electrodes from extending to the second region.

Abstract: A blockchain sharding method combining spectral clustering and a reputation value mechanism includes: obtaining, every other account grouping cycle Ta, account transaction data recorded during operation of a blockchain to generate an account transaction graph; obtaining an adjacency similarity matrix W and a degree matrix D based on the account transaction graph; generating a Normalized Laplace matrix L based on the adjacency similarity matrix W and the degree matrix D, performing dimension reduction on L to obtain a feature matrix F, and then clustering the feature matrix F with a clustering dimension of k by row through a K-means clustering method; and dividing blockchain accounts into k groups based on an obtained clustering result, and allocating accounts in the k groups to k blockchain shards.

Abstract: An offshore floating platform for operating in ice-infested waters and harsh environment for oil/gas drilling and exploration in Arctic area comprises four (4) sections, i.e., an upper cone, a transition section, a lower cone and a bottom frame. The upper cone, the transition section, the lower cone and the bottom frame are coincident with a centerline, and a through center well is designed around the centerline from top to bottom. The diameter at the bottom frame is smaller than that of the main body of the center well. The upper cone, the transition section and the lower cone are internally connected and divided into plural compartments. Through ballast compartments are designed outside the sidewall of the upper cone, the transition section and the lower cone vertically connected with a consistent cross-sectional area from top to bottom. Plural ballast compartments and void compartments are arranged within the bottom frame.

Abstract: Methods, systems, and devices are disclosed for controlling the magnetic and electrical properties of materials. In one aspect, a multi-layer structure includes a first layer comprising a ferromagnetic or ferrimagnetic material, and a second layer positioned within the multi-layer structure such that a first surface of the first layer is in direct physical contact with a second surface of the second layer. The second layer includes a material that undergoes structural phase transitions and metal-insulator transitions upon experiencing a change in temperature. One or both of the first and second layers are structured to allow a structural phase change associated with the second layer cause a change magnetic properties of the first layer.

Abstract: Methods, systems, and devices are disclosed for controlling the magnetic and electrical properties of materials. In one aspect, a multi-layer structure includes a first layer comprising a ferromagnetic or ferrimagnetic material, and a second layer positioned within the multi-layer structure such that a first surface of the first layer is in direct physical contact with a second surface of the second layer. The second layer includes a material that undergoes structural phase transitions and metal-insulator transitions upon experiencing a change in temperature. One or both of the first and second layers are structured to allow a structural phase change associated with the second layer cause a change magnetic properties of the first layer.