Abstract: The present invention provides for a genetically modified yeast host cell comprising a heterologous citramalate synthase, or multiple copies of a citramalate synthase, and knocked out or reduced in expression, or under conditional expression, for an endogenous or native pyruvate decarboxylase (PDC) gene; a method for constructing the genetically modified yeast host cell, and a method for producing citramalate using the genetically modified yeast host cell.

Abstract: A fluid-induced vibration energy harvesting apparatus with a non-rotating bluff body is provided. The apparatus does not use a common design method of rigidly securing a bluff body to an elastic beam in a design of the bluff body, but adopts a manner of connecting the bluff body and the elastic beam through a rotating shaft and a connecting shaft. Because a kinematic pair at a connection position is a rotating pair, the bluff body will only vibrate transversely and will not rotate, thereby achieving an effect of increasing an amplitude at the same frequency, and finally realizing an increase of converted electric energy and improving the conversion efficiency.

Abstract: A fluid-induced vibration energy harvesting apparatus with a non-rotating bluff body is provided. The apparatus does not use a common design method of rigidly securing a bluff body to an elastic beam in a design of the bluff body, but adopts a manner of connecting the bluff body and the elastic beam through a rotating shaft and a connecting shaft. Because a kinematic pair at a connection position is a rotating pair, the bluff body will only vibrate transversely and will not rotate, thereby achieving an effect of increasing an amplitude at the same frequency, and finally realizing an increase of converted electric energy and improving the conversion efficiency.

Abstract: Disclosed is an active energy harvesting device. The device includes a rigid body configured to vibrate corresponding to vibration of an external vibration body and including a first end at which an energy harvesting structure is provided to convert mechanical energy into electric energy, a magneto-rheological material provided at a second end of the rigid body to be bound to the rigid body and including a material which is changed in elastic force according to the surrounding magnetic field strength, a fixing unit for binding the second end of the rigid body and the magneto-rheological material and connecting the rigid body to the external vibration body, and a first permanent magnet arranged symmetrically apart from the magneto-rheological material while interposing the magneto-rheological material therebetween and provided so as to adjust a gap from the magneto-rheological material and change an elastic coefficient of the magneto-rheological material according to the gap.

Abstract: Disclosed is an active energy harvesting device. The device includes a rigid body configured to vibrate corresponding to vibration of an external vibration body and including a first end at which an energy harvesting structure is provided to convert mechanical energy into electric energy, a magneto-rheological material provided at a second end of the rigid body to be bound to the rigid body and including a material which is changed in elastic force according to the surrounding magnetic field strength, a fixing unit for binding the second end of the rigid body and the magneto-rheological material and connecting the rigid body to the external vibration body, and a first permanent magnet arranged symmetrically apart from the magneto-rheological material while interposing the magneto-rheological material therebetween and provided so as to adjust a gap from the magneto-rheological material and change an elastic coefficient of the magneto-rheological material according to the gap.