In this paper, we consider a production inventory system with service time and production vacations. Customers arrive in the system according to a Poisson process requiring service from a single server. The single pro...In this paper, we consider a production inventory system with service time and production vacations. Customers arrive in the system according to a Poisson process requiring service from a single server. The single production facility produces items according to an (s, S) policy, and 让 takes a vacation of random duration once the inventory level becomes S. It is assumed that all arriving customers are lost during the stock out period. We first derive the stationary joint distribution of the queue length and the on-hand inventory level in product form. Then, we compute explicitly some performance measures, and develop a cost function based on these performance measures. Finally;some numerical results are presented.展开更多
In view of the inadequate cementing quality in the cementation for long isolation intervals ofoil and gas wells, and considering the field practice in Tarim Oilfield, a nanometer material LC-212 was introduced as the ...In view of the inadequate cementing quality in the cementation for long isolation intervals ofoil and gas wells, and considering the field practice in Tarim Oilfield, a nanometer material LC-212 was introduced as the base stock to experimentally develop a new spacer system NMS-I, in combination with other materials, including a chemical gel plugging agent, carboxymethyl cellulose and barite. Experimental results indicated that the system had a wide adjustable range of density, good rheological property, static stability and compatibility with cement slurry. It also showed no flocculating or thickening effect on the water-base drilling fluid and low-density cement system. Meanwhile, the capacity of lost circulation control and the influence of the spacer on the second interfacial cementing strength were evaluated by a self-made lost circulation simulator and shearing test facility. The results showed that the spacer had favorable plugging and flushing effect, and the second interfacial cementing strength can be greatly improved. Moreover, based on the experiments, the mechanisms of spacer function were analyzed. The results obtained from the investigation offer a novel approach to resolving some practical problems in cementing jobs.展开更多
文章从影片Lost in Translation的片名翻译入手,探究了"lost in translation"的出处,通过分析英语电影片名的特点及主要功能,总结翻译电影片名的终极目的,试图回答这个问题:影片Lost in Translation缘何译成《迷失东京》?对...文章从影片Lost in Translation的片名翻译入手,探究了"lost in translation"的出处,通过分析英语电影片名的特点及主要功能,总结翻译电影片名的终极目的,试图回答这个问题:影片Lost in Translation缘何译成《迷失东京》?对该问题的回答也为解决英语电影片名的翻译提供理论指导。展开更多
基金the Natural Science Foundation of Hebei Province, China (No.A2017203078).
文摘In this paper, we consider a production inventory system with service time and production vacations. Customers arrive in the system according to a Poisson process requiring service from a single server. The single production facility produces items according to an (s, S) policy, and 让 takes a vacation of random duration once the inventory level becomes S. It is assumed that all arriving customers are lost during the stock out period. We first derive the stationary joint distribution of the queue length and the on-hand inventory level in product form. Then, we compute explicitly some performance measures, and develop a cost function based on these performance measures. Finally;some numerical results are presented.
文摘In view of the inadequate cementing quality in the cementation for long isolation intervals ofoil and gas wells, and considering the field practice in Tarim Oilfield, a nanometer material LC-212 was introduced as the base stock to experimentally develop a new spacer system NMS-I, in combination with other materials, including a chemical gel plugging agent, carboxymethyl cellulose and barite. Experimental results indicated that the system had a wide adjustable range of density, good rheological property, static stability and compatibility with cement slurry. It also showed no flocculating or thickening effect on the water-base drilling fluid and low-density cement system. Meanwhile, the capacity of lost circulation control and the influence of the spacer on the second interfacial cementing strength were evaluated by a self-made lost circulation simulator and shearing test facility. The results showed that the spacer had favorable plugging and flushing effect, and the second interfacial cementing strength can be greatly improved. Moreover, based on the experiments, the mechanisms of spacer function were analyzed. The results obtained from the investigation offer a novel approach to resolving some practical problems in cementing jobs.
文摘文章从影片Lost in Translation的片名翻译入手,探究了"lost in translation"的出处,通过分析英语电影片名的特点及主要功能,总结翻译电影片名的终极目的,试图回答这个问题:影片Lost in Translation缘何译成《迷失东京》?对该问题的回答也为解决英语电影片名的翻译提供理论指导。
