Abstract: A method for preparing (S)-nicotine by reduction includes conducting a reduction process on an alkene compound as shown in Formula I and/or an iminium cation compound as shown in Formula II, thereby producing (S)-nicotine. The method is simple, safe, reliable, and yields both high purity and high quantities of (S)-nicotine production.

Abstract: A slurrying device includes a slurrying tank and a rotor stirrer. The rotor stirrer includes a stirring drum, a transmission gear arranged at an end face of the stirring drum configured to face the slurrying tank, and a rotor stirring rod configured to extend from the stirring drum and into the slurrying tank to stir a slurrying liquid in the slurrying tank. The rotor stirring rod is meshed with the transmission gear and configured to revolve along a planar trajectory of the transmission gear while simultaneously rotating. The rotor stirrer further includes a driving device provided at the stirring drum and configured to drive the rotor stirring rod to rotate via the transmission gear.

Abstract: An energy conversion device is provided. The energy conversion device includes a reversible pulse-width modulation (PWM) rectifier (102) and a motor coil (103). The motor coil (103) includes L sets of winding units, and each set of winding unit is connected with the reversible PWM rectifier (102), where L?2 and is a positive integer. At least two sets of heating circuits of a to-be-heated device are formed by an external power supply (100), the reversible PWM rectifier (102), and the winding units in the motor coil (103). The energy conversion device controls the reversible PWM rectifier (102) according to a control signal, so that a current outputted from the external power supply (100) flows through at least two sets of winding units in the motor coil (103) to generate heat.

Abstract: The invention relates to the field of radio applications, and in particular to a radio radar device capable of adapting to severe weather. The invention includes a fuselage and a turret that is rotatably disposed above the fuselage. A radio radar, a protective cover rotatably connected to the rotating frame is provided above the radio radar, and a radio radar device capable of adapting to severe weather provided by the present invention can conveniently realize the turning of the radio radar. The protective cover can effectively protect the wireless radar in severe weather, and at the same time can ensure the normal operation of the radio radar. The device can be used in conjunction with the mobile trolley to facilitate the shipment. In addition, the equipment can lock itself on the trolley during the shipment process.

Abstract: A compound teeth type gas compressor comprises a housing with an upper end cover and a lower end cover mounted on both sides of the housing for constituting a seal cavity, a pair of meshing gears rotatably accommodated in the cavity, each gear having two kinds of teeth which are of different size and have a common pitch circle, an inlet port and an outlet port, an intake chamber and a discharge chamber positioned respectively on the sides of the inlet port and the outlet port in the cavity, characterized in fact that the gears are unidirectionally rotated, one of them is a driving gear having larger teeth, the other is a driven gear having larger gullets engaged with the larger teeth, the larger teeth and the larger gullets are formed with asymmetric shapes, and, as viewed in the rotation directions of the gears, their front flank profile curves are designed to achieve a transmission of a constant angular velocity ratio while their rear flank profile curves are designed to be in conjugate contact with each ot