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排序方式: 共有263条查询结果,搜索用时 15 毫秒
1.
Rubber Tired Gantry Cranes (RTGCs) are the most widely used pieces of equipment in the Hong Kong sea-freight container yards. Workload distribution in the yard changes continuously over time. The dynamic deployment of RTGCs is an important issue in yard operation management. This paper investigates the dynamic crane deployment problem with the objective of determining the crane deployment frequency and routes over a planning horizon to minimize the total workload overflow. The problem is formulated as a mixed integer programming model. A heuristic algorithm is then developed to solve problems of practical sizes. The heuristic quickly finds a near optimal solution for crane deployment operation. 相似文献
2.
Allen Karen; Linn Richard T.; Gutierrez Horacio; Willer Barry S. 《Canadian Metallurgical Quarterly》1994,39(1):29
Investigated burden experienced by 60 spouses and 71 parents who served as primary caregivers to individuals with traumatic brain injury (BI). Burden levels, as assessed by the Questionnaire on Resources and Stress (QRS-SF), were compared for spouses and parents. Both parents and spouses exhibited high levels of burden. Relative to spouses, parents reported significantly greater burden related to lifespan care. Spouses reported significantly less personal reward than did parents. The presence of social aggression and cognitive disability in the individual with BI was found to have a greater association with subjective burden of caregivers than was the presence of physical disability or injury severity. Results of previous studies with QRS-SF scores show that the responsibility assumed by spouses and parents of persons with BI was as great as that experienced by families of people with severe chronic physical disabilities. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
3.
Noei Maziar Luckner Paul Linn Tobias Jungemann Christoph 《Journal of Computational Electronics》2022,21(1):153-168
Journal of Computational Electronics - We discuss the numerical aspects of the Boltzmann transport equation (BE) for electrons in semiconductor devices, which is stabilized by Godunov’s... 相似文献
4.
Zhang A Robbins PS Averill AL Weber DC Linn CE Roelofs WL Villani MG 《Journal of chemical ecology》2003,29(7):1635-1642
Hoplia equina LeConte (Coleoptera: Scarabaeidae: Melolonthinae) is a beetle pest of cranberry beds in Massachusetts. Larvae feed on the roots of the cranberry plant, reducing yield as well as vine density. The female sex pheromone was identified as 2-tetradecanone. There were eight compounds found in the airborne volatiles collected from females that elicited antennal responses from males. Of the eight compounds tested (nonanal, decanal, dodecanal, 2-dodecanone, 2-tridecanone, 2-tetradecanone, 2-pentadecanone, and 2-hexadecanone), 2-tetradecanone was the only one that attracted male beetles in the field. Combining any of the other seven antennally active compounds with 2-tetradecanone did not increase male capture. 相似文献
5.
6.
目的 制备并评价产肠毒素大肠埃希氏菌(ETEC)标准物质。方法 分别用基质辅助激光解吸电离(MALDI-TOF MS)、生化、16 s RNA基因序列测定三种方法确认菌株种属。采用冷冻干燥技术制备600个ETEC标准样品(103CFU/样品);从中随机抽取20个进行均匀性检验;模拟25℃和37℃的运输温度测试样品的运输稳定性,同时在4℃和-20℃的条件下进行保藏稳定性检验。组织3家实验室对样品进行协同验证。最后选择20件食品基质来验证样品的使用效果。结果 生化、MALDI-TOF MS、16 s RNA基因序列鉴定CMCC(B)43208为大肠埃希氏菌,lt、stp、sth基因确认其为ETEC。均匀性检验中,单因素方差分析得F=1.48,小于FINV(0.05,19,20)。稳定性检验中,在25℃和37℃保藏7 d后结果为103CFU/样品,在-20℃保藏60 d和4℃保存28 d后结果为103CFU/样品。协同标定实验中,3家实验室检测样品中菌株均为ETEC(103CFU/标准样品)。使用效果评价中,ETEC标准样品加入20种食品基质后均可检出,而本底对照均未检出。结论 本实验制备的... 相似文献
7.
8.
The clay catalyzed dimer of linoleic acid has been examined by mass spectrometry of the unhydrogenated, the partially hydrogenated
and completely hydrogenated dimer. The results show that monocyclic, bicyclic and tricyclic structures are present. Monocyclic
structures predominate, bicyclic structures are also prominent, and tricyclic structures are relatively minor. The monocyclic
structure is believed to arise from a Diels-Alder type addition reaction. The bicyclic structure may result from a free radical
coupling followed by intramolecular ring closure. The monocyclic structure in the unhydrogenated dimer appears to be mostly
a benzene ring with saturated and unsaturated side-chains. It probably is formed by hydrogen transfer from the Diels-Alder
cyclohexene structure first formed. Little, if any, of the Diels-Alder dimer structure as such is present. The catalytic linoleate
dimer has a higher ratio of monocyclic to bicyclic dimer than does the noncatalytic (thermal) dimer made from normal (nonconjugated)
linoleate, while the thermal dimer of a conjugatedtrans-trans linoleate is exclusively monocyclic. It is suggested that the clay catalyzes conjugation and hence favors the Diels-Alder
reaction, and then catalyzes hydrogen transfer to aromatize the cyclohexene ring. 相似文献
9.
Effects of moisture content of complete diets on feed intake and milk production by cows 总被引:1,自引:0,他引:1
D A Lahr D E Otterby D G Johnson J G Linn R G Lundquist 《Journal of dairy science》1983,66(9):1891-1900
In two trials, 47 and 54 Holstein cows were fed diets containing ensiled forages, ensiled and dry forages, or diets of different moisture contents. In trial 1, diets were fed during a preliminary dry period, early lactation, late lactation, a second dry period, and a second early lactation. In trial 2, four diets identical except for moisture content (78, 64, 52, and 40% dry matter) were fed for the first 200 days of lactation. Substitution of dry hay for alfalfa silage increased dry matter intake during the first early lactation, whereas partial substitution of corn silage with straw did not affect intake during dry periods. Dry matter intake increased linearly as dry matter content of diet increased in trial 2. Neither milk production nor body weight were affected by treatment in either trial. Percentage total solids increased linearly as dry matter content of diet decreased in trial 2. Volatile fatty acids differed slightly, but no trends were consistent. No differences of daily chewing time were observed. From these trials, diets of less than 60 to 65% dry matter may reduce intake by lactating dairy cows. 相似文献
10.
G. Altrogge L. Streitferdt W. Dinkelbach G. Feichtinger J. -H. Wieken U. Ammermann N. Linn Günter Fandel K. W. Gaede J. -H. Wieken H. -J. Zimmermann K. -H. Strauß 《OR Spectrum》1986,8(4):196-254
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