Bacillus cereus SZ-4产蛋白酶脱毛蓝湿革机械性能研究

将蜡状芽孢杆菌(Bacillus cereus)SZ-4摇瓶发酵后所产脱毛蛋白酶粗酶液应用于猪皮、牛皮和绵羊皮的脱毛后,对经软化工序与未经软化工序制备成的蓝湿革进行比较。绵羊皮二者之间,在抗张强度、撕裂强度检测结果上未表现出明显的差别;而对于猪皮、牛皮而言,因为其皮张较羊皮厚且脱毛作用时间比较短,导致脱毛酶只能作用至毛囊附近而未能进一步对皮胶原纤维间质等进行水解,未能完全达到软化皮张的作用。     

添加Si3N4纳米粒子的镍磷复合锻工艺及镀层性能研究

通过正交试验法确定了镍-磷-Si3N4纳米粒子复合镀最佳施镀工艺,研究了热处理温度对镀层硬度的影响,对镀层的微观结构进行了分析.     

“化学与材料科学”专题复习

一、知识要点金属材料包括纯金属和合金．纯金属有良好的导电性、导热性、延展性,硬度较大,熔点较高．合金用途最广泛的是生铁和钢,生铁是含碳量为2%～4.3%的铁合金,钢是含碳量为0．03%～2%的铁合金．合金因具有比纯金属强度高、硬度大、耐腐蚀、机械性能好和熔点低等特点,因此在     

Anti-seismic behavior of HRB400 reinforced steel bars

1 Introduction Steel bar is one of the most important constructional materials ensuring the safety of buildings, and sufficient anti-seismic strength is required when it is applied to buildings in the region where an earthquake might occur. HRB335 steel bars are being used in China while 400 MPa steel bars are wildly used in Europe [1]. To ensure the security of buildings, 400 MPa steel bars have been developed in China. Before these steel bars being wildly used, a full-scale survey of the…