Abstract: A battery pack includes a battery pack box with an internal space including a first region to an n-th region, each provided with a battery cell. A positive electrode active substance in a positive electrode of each k-th battery cell includes lithium iron phosphate and/or lithium nickel cobalt manganate having a first discharge voltage plateau and one or more types of supplementary active substances having a second discharge voltage plateau. For the first battery cell to the n-th battery cell, in any case where a sum of a discharge capacity corresponding to the first discharge voltage plateau and a discharge capacity corresponding to the second discharge voltage plateau is 100%, a discharge capacity proportion corresponding to the second discharge voltage plateau of the k-th battery cell is greater than a discharge capacity proportion corresponding to the second discharge voltage plateau of the (k?1)-th battery cell.

Abstract: A battery pack includes a first battery cell, a second battery cell, and a third battery cell. A positive electrode active substance of each battery cell is composed of lithium iron phosphate and a low-temperature additive. The low-temperature additive is selected from compounds containing at least two carbonyl groups, which are conjugated with an unsaturated structure or an atom having lone-pair electrons connected with the carbonyl groups, and a discharging cut-off voltage of the battery pack at a low temperature has the following rules: discharging cut-off voltages V1, V2, and V3 of the first battery cell, second battery cell, and third battery cell range from 1.95V to 2.1V, from 1.8 V to 2.0V, from 1.6V to 1.9V, respectively, and V1, V2, and V3 satisfy a relationship of V1>V2>V3.

Abstract: The present invention relates to a method of preparing n-butyric acid by using poly-3-hydroxybutyrate. The method comprises following steps: placing poly-3-hydroxybutyrate in a closure means, passing hydrogen into the closure means to eliminate air after making an initial hydrogen pressure be 2 to 6 MPa, carrying out an agitation at 190 to 240° C. for reaction for 6 to 36 hours to obtain n-butyric acid. The preparation method provided by the present invention does not require a catalyst or a reaction solvent, and converts poly-3-hydroxybutyrate into n-butyric acid by a one-step reaction under a hydrogen atmosphere. The conversion rate of poly-3-hydroxybutyrate is 100%, the yield of n-butyric acid reaches up to 97%, the purity of n-butyric acid in all obtained liquid products reaches up to 98%, and no additional subsequent separation process is needed to the target product n-butyric acid.

Abstract: The present invention relates to data application technologies in the field of video surveillance, and discloses an intelligent playback method for video records based on a motion information and an apparatus thereof. The method comprises the following steps: searching for all motion detection additional information conforming to a time period of a playback request in a hard disc, and storing the motion detection additional information as a motion information in a motion information linked list in terms of a time sequence; obtaining a current playback mode and a current playback time, and looking up a nearest motion information under the current playback mode and the current playback time from the motion information linked list; matching the found nearest motion information with the current playback time; controlling a playback speed according to a matching result, so as to implement an automatic control of an intelligent playback speed.

Abstract: A first digital video recorder (DVR) obtains a firmware version identity of at least one second DVR within a local area network (LAN) where the first DVR belongs, compares the obtained firmware version identity with a firmware version identity of the first DVR, determines a firmware version identity of the latest firmware version, obtains files of the latest firmware version from a third DVR that provides the firmware version identity of the latest firmware version, and performs version update using the files obtained.

Abstract: The present invention relates to data application technologies in the field of video surveillance, and discloses an intelligent playback method for video records based on a motion information and an apparatus thereof. The method comprises the following steps: searching for all motion detection additional information conforming to a time period of a playback request in a hard disc, and storing the motion detection additional information as a motion information in a motion information linked list in terms of a time sequence; obtaining a current playback mode and a current playback time, and looking up a nearest motion information under the current playback mode and the current playback time from the motion information linked list; matching the found nearest motion information with the current playback time; controlling a playback speed according to a matching result, so as to implement an automatic control of an intelligent playback speed.