Objective] The alm was to provide scientific references for determination of optimal N and P quantities of malze. [Method] The research conducted a test in field to expIore the effects of N and P fertiIizers on malze ...Objective] The alm was to provide scientific references for determination of optimal N and P quantities of malze. [Method] The research conducted a test in field to expIore the effects of N and P fertiIizers on malze yield. [Result] Both of N and P fertiIizers have significant effects on malze yield. When malze yield reached the highest, the quantities of N fertiIizers and P fertiIizers were 530.56 and 105.44 kg/hm2, respectiveIy. [Conclusion] Malze yield keeps growing upon N or P fertiIizers to certaln extent, and excessive quantities of N and P fertiIizer wouId reduce malze yield.展开更多
[Objective] This study aimed to investigate the effects of different land use patterns on soil ecological environment. [Method] Total three representative land use patterns （corn field, cherry tree land, wood land） ...[Objective] This study aimed to investigate the effects of different land use patterns on soil ecological environment. [Method] Total three representative land use patterns （corn field, cherry tree land, wood land） were selected from Hongta District, Yuxi City, and under these three patterns, soil microbial quantity and activity were studied. [Result] Under the three land use patterns, soil microorganisms were domi- nated by bacteria; soil microbial quantity ranked as wood land＇s〉cheery tree land＇s〉 corn field＇s; and total microbial activity, catalase activity and urease activity all ranked as cherry tree land＇s〉wood land＇s〉corn field＇s. [Conclusion] Soil microbial activity and functions are related to farmland management measures, as well as land use pattern and soil nutrients.展开更多
In this paper, the optimal policy is considered when the buyer faces two supply sources： one is the contract supplier from which the buyer orders over a specific contract period （say, a year） at a pre-agreed price,...In this paper, the optimal policy is considered when the buyer faces two supply sources： one is the contract supplier from which the buyer orders over a specific contract period （say, a year） at a pre-agreed price, and the other is the spot market. However, when ordering from the contract supplier, the buyer must fulfill a pre-determined total order quantity, or the so-called definite total order quantity commitment, over the whole contract period. In other words, the commitment secures the buyer a fixed price but obliges him/her a total order quantity over the contract period. Although the spot market gives the buyer more flexibility in terms of order quantities, its prices are volatile. Such a combination of contract and spot procurements is often observed in practice. Within the contract period, there are multiple sub-periods, during each of which the buyer reviews the inventory, issues an individual order, and uses the on-hand inventory to meet the random demand. Thus, in each （ordering） period, the buyer will weigh between the current known spot price （by procuring from the spot market） and a lower future price （by waiting while consuming the remaining commitment）. An optimal dual ordering policy is characterized for each period, depending on the on-hand inventory level, the spot price, and the remaining commitment quantity. The optimal policy in each period is also shown to be independent of the contract price. Through a numerical study, the inventory cost is demonstrated to be （1） insensitive to the contract price when the total commitment quantity is lower than the total expected demand over the contract period and （2） non-increasing in the variability of spot prices.展开更多
基金Supported by Yantai Science and Technology Development Program(2007155)~~
文摘Objective] The alm was to provide scientific references for determination of optimal N and P quantities of malze. [Method] The research conducted a test in field to expIore the effects of N and P fertiIizers on malze yield. [Result] Both of N and P fertiIizers have significant effects on malze yield. When malze yield reached the highest, the quantities of N fertiIizers and P fertiIizers were 530.56 and 105.44 kg/hm2, respectiveIy. [Conclusion] Malze yield keeps growing upon N or P fertiIizers to certaln extent, and excessive quantities of N and P fertiIizer wouId reduce malze yield.
文摘[Objective] This study aimed to investigate the effects of different land use patterns on soil ecological environment. [Method] Total three representative land use patterns （corn field, cherry tree land, wood land） were selected from Hongta District, Yuxi City, and under these three patterns, soil microbial quantity and activity were studied. [Result] Under the three land use patterns, soil microorganisms were domi- nated by bacteria; soil microbial quantity ranked as wood land＇s〉cheery tree land＇s〉 corn field＇s; and total microbial activity, catalase activity and urease activity all ranked as cherry tree land＇s〉wood land＇s〉corn field＇s. [Conclusion] Soil microbial activity and functions are related to farmland management measures, as well as land use pattern and soil nutrients.
基金support from Hong Kong RGC Grant No: 2150518/410907support from NSFC projects under Grant Nos. 70725001,70821001 and 71090401/71090400
文摘In this paper, the optimal policy is considered when the buyer faces two supply sources： one is the contract supplier from which the buyer orders over a specific contract period （say, a year） at a pre-agreed price, and the other is the spot market. However, when ordering from the contract supplier, the buyer must fulfill a pre-determined total order quantity, or the so-called definite total order quantity commitment, over the whole contract period. In other words, the commitment secures the buyer a fixed price but obliges him/her a total order quantity over the contract period. Although the spot market gives the buyer more flexibility in terms of order quantities, its prices are volatile. Such a combination of contract and spot procurements is often observed in practice. Within the contract period, there are multiple sub-periods, during each of which the buyer reviews the inventory, issues an individual order, and uses the on-hand inventory to meet the random demand. Thus, in each （ordering） period, the buyer will weigh between the current known spot price （by procuring from the spot market） and a lower future price （by waiting while consuming the remaining commitment）. An optimal dual ordering policy is characterized for each period, depending on the on-hand inventory level, the spot price, and the remaining commitment quantity. The optimal policy in each period is also shown to be independent of the contract price. Through a numerical study, the inventory cost is demonstrated to be （1） insensitive to the contract price when the total commitment quantity is lower than the total expected demand over the contract period and （2） non-increasing in the variability of spot prices.
