Hunan Yushen New Energy Technology Co., Ltd.: Manufactory for stainless steel pipe and forgings,nickel based alloy pipe and forgings in China. We also provide beveling, polishing, welding, hemming,
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Hunan Yushen New Energy Technology Co., Ltd.: Manufactory for stainless steel pipe and forgings,nickel based alloy pipe and forgings in China. We also provide beveling, polishing, welding, hemming,
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YASSIAN is one of the most professional bucket teeth pins manufacturers and suppliers in China. Please rest assured to buy or wholesale customized bucket teeth pins at competitive price from our
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Zhejiang Wanna Industry&Trade Co.,Ltd: Find professional cutting disc, grinding disc, flap disc, velcro disc, metal cutting disc manufacturers and suppliers in China here! With over 25 years'
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In the presence of phosphoric acid thiophene and acetic anhydride reaction, put the acetic anhydride, 85% phosphoric acid and thiophene into the reaction pot, stir, gradually heated to reflux temperature (96-97℃) to maintain reflux for 2.5h, cooling, washing, separation of water layer.