对若尔盖盆地进行实地考察,选取盆地西端黄河出口段典型的一级阶地沉积序列为研究对象。通过沉积物粒度和端元特征分析及OSL测年断代,对若尔盖盆地出口段的环境变化进行研究。研究结果表明:阶地底部的河床相砂卵石与河漫滩沙层构成了二...对若尔盖盆地进行实地考察,选取盆地西端黄河出口段典型的一级阶地沉积序列为研究对象。通过沉积物粒度和端元特征分析及OSL测年断代,对若尔盖盆地出口段的环境变化进行研究。研究结果表明:阶地底部的河床相砂卵石与河漫滩沙层构成了二元结构沉积层,其中河漫滩沙层夹有5.0—4.2 ka B.P.期间堆积形成的浅洼地泥沼土透镜状层,表明该河段黄河一级阶地从5.0 ka B.P.开始形成。河漫滩上为高原强劲风力改造成的风沙层,夹有古洪水滞流沉积层组,表明4.2—4.0 ka B.P.期间气候恶化,黄河源曾发生多期特大洪水事件。4.0—2.8 ka B.P.期间气候湿润,阶地面浅洼地有淤泥质沼泽形成。其后沙尘暴搬运堆积的粗粉沙覆盖阶地面,形成了风成黄土,其上部经生物风化成壤改造,发育成为具有团粒构造的现代亚高山草甸黑土土壤层。展开更多
Order-oriented production is the main production method of some small and mediumsized enterprises(SMEs),which not only indicates that customer demand becomes the vane of enterprise production,but also puts high demand...Order-oriented production is the main production method of some small and mediumsized enterprises(SMEs),which not only indicates that customer demand becomes the vane of enterprise production,but also puts high demands on the flexibility of production.Material requirements planning(MRP)is a modern enterprise management method based on basic databill of materials(BOM).For order-driven SMEs,MRP not only helps enterprises to complete material delivery in a timely manner,but also provides flexibility to meet customer needs.Standardization and MRP complement each other in enterprise operation,and they are effective in solving problems such as untimely material supply,undetermined procurement timing,and supply chain system jams.By studying the standardization application of MRP in enterprises,the article not only optimizes the standardization management system of enterprises,but also contributes to the high-quality development of SMEs.展开更多
文摘对若尔盖盆地进行实地考察,选取盆地西端黄河出口段典型的一级阶地沉积序列为研究对象。通过沉积物粒度和端元特征分析及OSL测年断代,对若尔盖盆地出口段的环境变化进行研究。研究结果表明:阶地底部的河床相砂卵石与河漫滩沙层构成了二元结构沉积层,其中河漫滩沙层夹有5.0—4.2 ka B.P.期间堆积形成的浅洼地泥沼土透镜状层,表明该河段黄河一级阶地从5.0 ka B.P.开始形成。河漫滩上为高原强劲风力改造成的风沙层,夹有古洪水滞流沉积层组,表明4.2—4.0 ka B.P.期间气候恶化,黄河源曾发生多期特大洪水事件。4.0—2.8 ka B.P.期间气候湿润,阶地面浅洼地有淤泥质沼泽形成。其后沙尘暴搬运堆积的粗粉沙覆盖阶地面,形成了风成黄土,其上部经生物风化成壤改造,发育成为具有团粒构造的现代亚高山草甸黑土土壤层。
文摘Order-oriented production is the main production method of some small and mediumsized enterprises(SMEs),which not only indicates that customer demand becomes the vane of enterprise production,but also puts high demands on the flexibility of production.Material requirements planning(MRP)is a modern enterprise management method based on basic databill of materials(BOM).For order-driven SMEs,MRP not only helps enterprises to complete material delivery in a timely manner,but also provides flexibility to meet customer needs.Standardization and MRP complement each other in enterprise operation,and they are effective in solving problems such as untimely material supply,undetermined procurement timing,and supply chain system jams.By studying the standardization application of MRP in enterprises,the article not only optimizes the standardization management system of enterprises,but also contributes to the high-quality development of SMEs.
