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排序方式: 共有266条查询结果,搜索用时 15 毫秒
1.
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
2.
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
3.
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
4.
5.
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
6.
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
7.
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
8.
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
Ohne Zusammenfassung 相似文献
9.
This study investigated how instructional practices influence what students learn in Pascal programming classes. The study contrasted 8 introductory and 8 Advanced Placement (AP) level courses because goals of teachers, classroom activities, and assigned tasks differ. Introductory students primarily learn syntax and AP students learn to plan and debug complex problems. These differing cognitive demands would seem to require different instructional practices. In order to establish instructional practices, students reported teaching strategies, course structure, and classroom resources. To demonstrate programming proficiency, students modified and analyzed a computer program. Programming proficiency varied as a function of instructional practices and class level. Introductory students benefited from direct instruction, and AP students performed better with less direct guidance and more opportunities for autonomy. Characteristics of effective programming instruction vary depending on the cognitive demands of courses. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
10.
目前对机械密封端面型槽多采用多段线拟合或者点拟合的方法来形成近似的螺旋线,模拟效率低且模拟结果准确性不高。提出准确性更高的、参数方程驱动的对数螺旋线型槽绘制方法,基于Visual Basic编程语言对SolidWorks软件进行二次开发,实现对扩压式自泵送机械密封动环端面及其流体计算域的参数化建模。研究表明:参数化所建模型,其密封端面结构及流体域参数可以便捷修改,型槽的绘制更加快速,绘制的槽线更加顺滑,更接近于真实型槽曲线;参数化建模结果能够导入ICEM等软件进行处理,为扩压式自泵送机械密封性能数值模拟效率的提升奠定了技术基础。 相似文献