After John wrote the abstract "对茶叶天然染料的碱性提取及提取液对蚕丝织物的染色进行研究.用碳酸钠水溶液提取茶叶天然染料,探讨碳酸钠用量、提取温度、提取时间对茶叶天然染料提取效果的影响及染色pH值、染色温度、染色时间、硫酸钠用量等对蚕丝织物直接染色效果的影响.研究结果表明,茶叶碳酸钠水溶液提取物染色蚕丝织物比茶叶水提取物染色蚕丝织物的颜色更浓.茶叶天然染料提取的优化工艺为:碳酸钠8g/L,提取温度90℃,提取时间40min.茶叶提取液对蚕丝织物直接染色的优化工艺为:染液pH值4.00左右,硫酸钠40g/L,染色温度90℃,染色时间60min,浴比50:1.碳酸钠水溶液提取物染色蚕丝织物具有较好的牢度,媒染可适当提高染色蚕丝织物的耐洗色牢度.", he wrote these keywords "提取物, 时间, 提取". Do you think his choice of keywords was correct? Answer yes or no.
no