Abstract: A method for the reaction of an isatin and cyclopropenone compound at low catalytic amount. In the presence of an amine compound and phosphite, the isatin and cyclopropenone are reacted in an organic solvent using a silicon amino rare earth compound as a catalyst to synthesize pyrano[2,3-b]indol-2-one compounds. In the reaction above, the amount of catalyst is few, and noble metal is not needed for catalysis. The present method can achieve preparation of the pyrano[2,3]indol-2-one compound efficiently and simply.

Abstract: The present disclosure relates to a heat dissipation system, a wind generating set, and a heat dissipation supporting platform. The heat dissipation system includes: a supporting platform, the supporting platform including a body portion, the body portion including an inlet, an outlet, a flow channel communicating the inlet with the outlet, and a mounting position for mounting a functional device, the inlet, the outlet and the flow channel together form a medium circulation passage; and a heat exchange apparatus which communicates with the medium circulation passage and delivers the cooling medium into the medium circulation passage, the cooling medium flowing through the inlet and the flow channel and flowing out from the outlet to exchange heat with the functional device.

Abstract: The present invention discloses a cyclopenta[c]chromene compound and a preparation method thereof. A chalcone compound as a reactant, A cationic rare earth metal compound Ln(CH3CN)9]3+[(AlCl4)3]3?.CH3CN as a catalyst, and 2-naphthalenethiol as an accelerator, react in an organic solvent to prepare the cyclopenta[c]-chromene compound. Ln represents a positive trivalent rare earth metal ion, which is selected from the group consisting of La, Nd, Sm, Gd, and Yb. The starting materials are easy obtained, the reaction process is simple, and the yield of the target product is high, up to 85%.

Abstract: The present invention discloses a method for preparing a cyclopenta[c]chromene compound. A cationic rare earth compound [Ln(CH)3CN)9]3+[(AlCl4)3]3?.CH3CN is used as a catalyst, and p-methyl thiophenol is used as an accelerator for a catalytic reaction of a chalcone compound so as to prepare a product; and Ln, contained in the catalyst, represents a positive trivalent rare earth metal ion and is selected from one of La, Nd, Sm, Gd and Yb. According to the method, the starting materials are easy to obtain, the reaction process is simple, the catalyst usage is low, the catalyst is universally applicable to various substituted 2-hydroxy chalcones, and the obtained cyclopenta[c]chromene compound has not been reported. The catalyst synthesis method is simple and easy to obtain, and the yield of the target product is high.

Abstract: The present invention discloses a cyclopenta[c]chromene compound and a preparation method thereof. A chalcone compound as a reactant, A cationic rare earth metal compound Ln(CH3CN)9]3+[(AlCl4)3]3?.CH3CN as a catalyst, and 2-naphthalenethiol as an accelerator, react in an organic solvent to prepare the cyclopenta[c]-chromene compound. Ln represents a positive trivalent rare earth metal ion, which is selected from the group consisting of La, Nd, Sm, Gd, and Yb. The starting materials are easy obtained, the reaction process is simple, and the yield of the target product is high, up to 85%.

Abstract: The present invention discloses a method for preparing a cyclopenta[c]chromene compound. A cationic rare earth compound [Ln(CH)3CN)9]3+[(AlCl4)3]3?.CH3CN is used as a catalyst, and p-methyl thiophenol is used as an accelerator for a catalytic reaction of a chalcone compound so as to prepare a product; and Ln, contained in the catalyst, represents a positive trivalent rare earth metal ion and is selected from one of La, Nd, Sm, Gd and Yb. According to the method, the starting materials are easy to obtain, the reaction process is simple, the catalyst usage is low, the catalyst is universally applicable to various substituted 2-hydroxy chalcones, and the obtained cyclopenta[c]chromene compound has not been reported. The catalyst synthesis method is simple and easy to obtain, and the yield of the target product is high.

Abstract: The present disclosure relates to a heat dissipation system, a wind generating set, and a heat dissipation supporting platform. The heat dissipation system includes: a supporting platform, the supporting platform including a body portion, the body portion including an inlet, an outlet, a flow channel communicating the inlet with the outlet, and a mounting position for mounting a functional device, the inlet, the outlet and the flow channel together form a medium circulation passage; and a heat exchange apparatus which communicates with the medium circulation passage and delivers the cooling medium into the medium circulation passage, the cooling medium flowing through the inlet and the flow channel and flowing out from the outlet to exchange heat with the functional device.

Abstract: A video frame fade-in/fade-out detection method is provided, the detection method includes: before motion search, performing inter-frame comparison on block direct current components in some rows of a picture or performing inter-frame comparison on block direct current components in a partial area of a picture; collecting statistics on an inter-frame comparison result; determining whether fade-in/fade-out exists, to choose whether prediction is in a weighted mode; and if it is detected, by means of inter-frame comparison on block direct current components on some rows, that no global fade-in/fade-out exists, selecting a partial area within a range of some detected rows to perform inter-frame comparison on block direct current components again, and detecting local fade-in/fade-out.

Abstract: A method and an apparatus for determining a small-object region in a video frame. The method includes dividing a current video frame into at least two regions, and determining a global motion vector corresponding to each region; determining an interframe motion vector of each group of adjacent frames in multiple video frames that include the current video frame and a reference frame of the current video frame; determining a candidate small-object region in the current video frame according to the interframe motion vector of the each group of adjacent frames and the determined global motion vector corresponding to each region; and performing filtering on the candidate small-object region in the current video frame, and determining a region obtained after the filtering as a small-object region in the current video frame.

Abstract: A method and an apparatus for determining a small-object region in a video frame. The method includes dividing a current video frame into at least two regions, and determining a global motion vector corresponding to each region; determining an interframe motion vector of each group of adjacent frames in multiple video frames that include the current video frame and a reference frame of the current video frame; determining a candidate small-object region in the current video frame according to the interframe motion vector of the each group of adjacent frames and the determined global motion vector corresponding to each region; and performing filtering on the candidate small-object region in the current video frame, and determining a region obtained after the filtering as a small-object region in the current video frame.

Abstract: A video frame fade-in/fade-out detection method is provided, the detection method includes: before motion search, performing inter-frame comparison on block direct current components in some rows of a picture or performing inter-frame comparison on block direct current components in a partial area of a picture; collecting statistics on an inter-frame comparison result; determining whether fade-in/fade-out exists, to choose whether prediction is in a weighted mode; and if it is detected, by means of inter-frame comparison on block direct current components on some rows, that no global fade-in/fade-out exists, selecting a partial area within a range of some detected rows to perform inter-frame comparison on block direct current components again, and detecting local fade-in/fade-out.