Abstract: A circuit for controlling power supply startup includes a switch-controlling module and a switch module; a signal-detecting terminal is electrically connected to a negative electrode of a battery lead clamp and a negative electrode of a startup power supply respectively; a signal-detecting terminal and a voltage output terminal are electrically connected to a positive electrode of the battery lead clamp; a controlling terminal of the switch-controlling module is electrically connected to a controlled terminal; a voltage-detecting terminal is electrically connected to a positive terminal of the startup power supply; the switch-controlling module automatically detects the polarity connection status between the battery lead clamp and the startup power supply; the switch module is automatically connected when the connection is correct, so that the voltage of the startup power supply is output to the battery, thereby finishing the startup of the battery.

Abstract: A method for preparing large size beta-type ammonium tetramolybdate monocrystal particle includes industrial ammonium molybdate, ammonia, de-ionized water are used to prepare ammonium molybdate solution with concentration of 0.2˜0.6 g/ml; pH is adjusted to 5˜7, temperature is adjusted to the first temperature of 70˜90° C. to obtain the first ammonium molybdate solution; beta-type ammonium tetramolybdate crystal seed is put into crystallization container, and the first ammonium molybdate solution is poured in the crystallization container, to form crystallization system; the crystallization system stands still at room temperature, naturally cooling, the beta-type ammonium tetramolybdate crystal seed grows into large size beta-type ammonium tetramolybdate monocrystal particle. A beta-type ammonium tetramolybdate crystal seed is obtained by constant-temperature crystallization at 70˜90° C.

Abstract: A method for preparing large size beta-type ammonium tetramolybdate monocrystal particle includes industrial ammonium molybdate, ammonia, de-ionized water are used to prepare ammonium molybdate solution with concentration of 0.2˜0.6 g/ml; pH is adjusted to 5˜7, temperature is adjusted to the first temperature of 70˜90° C. to obtain the first ammonium molybdate solution; beta-type ammonium tetramolybdate crystal seed is put into crystallization container, and the first ammonium molybdate solution is poured in the crystallization container, to form crystallization system; the crystallization system stands still at room temperature, naturally cooling, the beta-type ammonium tetramolybdate crystal seed grows into large size beta-type ammonium tetramolybdate monocrystal particle. A beta-type ammonium tetramolybdate crystal seed is obtained by constant-temperature crystallization at 70˜90° C.