Abstract: A 3D printer extrusion structure, comprising: a housing; a motor provided on the housing; an active extrusion gear provided in the housing and connected to the motor; an adjusting support rotatably connected inside the housing; a driven extrusion gear provided at one end of the adjusting support and rotatably connected to the adjusting support; and an elastic member, the elastic member being connected to an other end of the adjusting support to enable the end of the adjusting support provided with the driven extrusion gear to approach the active extrusion gear, so that the driven extrusion gear works in conjunction with the active extrusion gear to extrude material, wherein the end of the adjusting support provided with the driven extrusion gear extends to the outside of the housing.

Abstract: The invention provides new methods for the direct umpolung self-condensation of 5-hydroxymethylfurfural (HMF) by organocatalysis, thereby upgrading the readily available substrate into 5,5?-di(hydroxymethyl) furoin (DHMF). While many efficient catalyst systems have been developed for conversion of plant biomass resources into HMF, the invention now provides methods to convert such nonfood biomass directly into DHMF by a simple process as described herein. The invention also provides highly effective new methods for upgrading other biomass furaldehydes and related compound to liquid fuels. The methods include the organocatalytic self-condensation (umpolung) of biomass furaldehydes into (C8-C12)furoin intermediates, followed by hydrogenation, etherification or esterification into oxygenated biodiesel, or hydrodeoxygenation by metal-acid tandem catalysis into premium hydrocarbon fuels.

Abstract: The invention provides new methods for the direct umpolung self-condensation of 5-hydroxymethylfurfural (HMF) by organocatalysis, thereby upgrading the readily available substrate into 5,5?-di(hydroxymethyl) furoin (DHMF). While many efficient catalyst systems have been developed for conversion of plant biomass resources into HMF, the invention now provides methods to convert such nonfood biomass directly into DHMF by a simple process as described herein. The invention also provides highly effective new methods for upgrading other biomass furaldehydes and related compound to liquid fuels. The methods include the organocatalytic self-condensation (umpolung) of biomass furaldehydes into (C8-C12)furoin intermediates, followed by hydrogenation, etherification or esterification into oxygenated biodiesel, or hydrodeoxygenation by metal-acid tandem catalysis into premium hydrocarbon fuels.

Abstract: The invention provides new methods for the direct umpolung self-condensation of 5-hydroxymethylfurfural (HMF) by organocatalysis, thereby upgrading the readily available substrate into 5,5?-di(hydroxymethyl)furoin (DHMF). While many efficient catalyst systems have been developed for conversion of plant biomass resources into HMF, the invention now provides methods to convert such nonfood biomass directly into DHMF by a simple process as described herein. The invention also provides highly effective new methods for upgrading other biomass furaldehydes and related compound to liquid fuels. The methods include the organocatalytic self-condensation (umpolung) of biomass furaldehydes into (C8-C12)furoin intermediates, followed by hydrogenation, etherification or esterification into oxygenated biodiesel, or hydrodeoxygenation by metal-acid tandem catalysis into premium hydrocarbon fuels.

Abstract: The invention provides new methods for the direct umpolung self-condensation of 5-hydroxymethylfurfural (HMF) by organocatalysis, thereby upgrading the readily available substrate into 5,5?-di(hydroxymethyl)furoin (DHMF). While many efficient catalyst systems have been developed for conversion of plant biomass resources into HMF, the invention now provides methods to convert such nonfood biomass directly into DHMF by a simple process as described herein. The invention also provides highly effective new methods for upgrading other biomass furaldehydes and related compound to liquid fuels. The methods include the organocatalytic self-condensation (umpolung) of biomass furaldehydes into (C8-C12)furoin intermediates, followed by hydrogenation, etherification or esterification into oxygenated biodiesel, or hydrodeoxygenation by metal-acid tandem catalysis into premium hydrocarbon fuels.