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排序方式: 共有234条查询结果,搜索用时 15 毫秒
11.
Darran R. Cairns Matthew S. Shafran Konstantinos A. Sierros Wade W. Huebsch Aaron J. Kessman 《Materials Letters》2010,64(10):1133-1136
Electrically responsive liquid crystal polymer nanorods were fabricated by template synthesis. Liquid crystal monomers are templated by alumina membranes. Molecular ordering of the liquid crystal molecules resulted from the confinement in the sub-micron channels and this ordering can be captured permanently through photo-polymerization. Template removal and sonication result in individual rods that can be reoriented by applied electrical and magnetic fields. Such anisotropic particles have significant potential applications in electro-rheological fluids and in active mixing in microfluidic channels. 相似文献
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Summary 1. Dilatometric curves have been determined over the complete melting range for samples of prime steam lard, oleo oil, all-hydrogenated
vegetable shortening, and partially hydrogenated cottonseed oil. From the dilatometric data estimates have been made of the
percentages of solids and liquid in the fats at different temperatures.
2. Estimates of the percentages of solids and liquid in the hydrogenated cottonseed oil agreed with those previously reported
on the same oil from calorimetric data when allowance was made for a lack of equilibrium conditions in the calorimetric experiment.
Since a condition of equilibrium between solids and liquid is attained in the dilatometer, this instrument is to be preferred
to the calorimeter for determining the composition of fats in terms of the two phases.
3. The consistency of the fats, as measured by micropenetrations, was different for different fats which contained equal percentages
of solids. The consistency, therefore, is not determined solely by the amount of solids present, but also by the character
of the solid particles.
One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration, U. S.
Department of Agriculture. 相似文献
14.
S. Dorr Brian Ashley Moerke Michael Bur Chuck Bassett Tony Aderman Dan Traynor Russell D. Singleton Peter H. Butchko Jimmy D. Taylor II 《Journal of Great Lakes research》2010
Diverse management techniques have been used to mitigate conflicts between humans and double-crested cormorants (Phalacrocorax auritus) including harassment methods supplemented by lethal take. In this study we evaluated impacts of programs to harass spring migrating cormorants on the walleye (Sander vitreus) fishery in Brevoort Lake and the yellow perch (Perca flavescens) and walleye fisheries at Drummond Island. Cormorant foraging declined significantly (p < 0.05) at both locations subsequent to initiation of harassment programs. Overall harassment deterred 90% of cormorant foraging attempts while taking less than 6% lethally on average at each site. Yellow perch were a predominate prey item in number and biomass at both locations. Walleye made up a small proportion of the diet at both locations. However, both walleye and yellow perch abundance increased significantly (p < 0.05) at Drummond Island. Walleye abundance at age 3 increased to record levels in 2008 following 3 years of cormorant management at Brevoort Lake. The estimated cormorant consumption of age-1 walleye in the absence of management at Brevoort Lake during 2005 would account for 55% of the record 2006 age-1 walleye population. These results support the hypothesis that cormorant predation on spawning aggregations of sportfish was a significant mortality factor and cormorant management reduced sportfish mortality and increased abundance at both locations. Continuation of harassment programs and fishery assessments will determine whether improvement of targeted sport fisheries through control of spring migrating cormorants is sustainable. 相似文献
15.
Summary 1. A hydrogenated cottonseed oil has been molecularly distilled, and the distilled fractions examined.
2. Fractionation of a molecularly distilled oil occurs, as is to be expected, on the basis of variations in molecular weight
of the glycerides. The composition of cottonseed oil is such that there is a considerable separation of the glycerides according
to their degree of unsaturation. The composition of peanut oil is such that similar separation can only be slight. Soybean
oil is in this respect intermediate between cottonseed oil and peanut oil.
3. Molecular distillation of hydrogenated cottonseed oil causes a segregation of tocopherols and related compounds similar
to that observed in peanut oil. However, the fractions first distilled from the oil are relatively weak in antioxygenic properties.
It appears probable that their lack of effectiveness is due to the presence of unknown substances capable of inhibiting or
counteracting the action of tocopherols. However, the presence of substances other than tocopherols, which respond to or interfere
with the Emmerie-Engel test is not to be excluded. The tocopherols in the potent fractions are more effective thana-tocopherol, but less effective than γ-tocopherol.
This is one of four regional research laboratories operated by the Bureau of Agricultural and Industrial Chemistry, Agricultural
Research Administration, U. S. Department of Agriculture. 相似文献
16.
RH Cleveland M Schluchter BP Wood WE Berdon MI Boechat KA Easley M Meziane RB Mellins KI Norton E Singleton L Trautwein 《Canadian Metallurgical Quarterly》1997,27(11):880-887
Dorsal fusion with the internal fixator has become the standard treatment of instabilities and deformities of the thoracolumbar spine. With our new device, the modular spine fixator (MSF), which has been specially designed for short-distance instrumentations, we have increasingly been treating unstable injuries of the thoracolumbar spine by one-level stabilization. Prerequisite is an accurate evaluation of the indication, including CT and MRI to assess the involvement of the intervertebral disc and the ligamental structures. The operative technique differs in some details from the procedure in more-multi-level instrumentations, especially concerning the application of the pedicle screws. The instrumentation is always combined with posterior allogenic bone grafting. Since the beginning of 1993 we also perform anterior autogenic transpedicular bone grafting. Between January 1991 and July 1995, 57 one-level stabilizations with the MSF were performed. Of the 57 patients operated on 39, 27 men and 12 women, with an average age of 41 years, have had a clinical and radiographic follow-up examination so far, on average, 27 months after the accident. Seventeen patients were completely free of pain and 17 patients (were only) sensitive to weather changes or had minor pain during great physical stress. Five patients had pain even during slight physical stress or at rest. The preoperatively measured Cobb angle was 15.1 degrees on average, after the operation 5.2 degrees, and at the time of the follow-up examination amounted to 8.1 degrees. The patients' range of motion was normal. Only five minor complications have been seen. No implant fatigue failure has been noted in this series. We derive from these results that, for correct indications, one-level stabilization can be performed successfully and should be firmly established in the operative treatment of unstable fractures of the thoracolumbar spine. 相似文献
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18.
Embossing of 3D ceramic microstructures 总被引:4,自引:0,他引:4
B. Su T. W. Button A. Schneider L. Singleton P. Prewett 《Microsystem Technologies》2002,8(4-5):359-362
An embossing method based on the viscous polymer processed (VPP) ceramic tape has been used to fabricate 3D ceramic microstructures
with high aspect ratios. Examples of lead zirconate titanate (PZT) microrod arrays with feature sizes of 10–150 μm and aspect
ratios of 3–10 have been demonstrated. Advantages of the embossing technique over conventional casting and moulding methods
are discussed.
Received: 10 August 2001/Accepted: 24 September 2001 相似文献
19.
Joaquín Prada Jiménez de Cisneros Michael J. Stear Colette Mair Darran Singleton Thorsten Stefan Abigail Stear Glenn Marion Louise Matthews 《Journal of the Royal Society Interface》2014,11(99)
Gastrointestinal nematodes are a global cause of disease and death in humans, wildlife and livestock. Livestock infection has historically been controlled with anthelmintic drugs, but the development of resistance means that alternative controls are needed. The most promising alternatives are vaccination, nutritional supplementation and selective breeding, all of which act by enhancing the immune response. Currently, control planning is hampered by reliance on the faecal egg count (FEC), which suffers from low accuracy and a nonlinear and indirect relationship with infection intensity and host immune responses. We address this gap by using extensive parasitological, immunological and genetic data on the sheep–Teladorsagia circumcincta interaction to create an immunologically explicit model of infection dynamics in a sheep flock that links host genetic variation with variation in the two key immune responses to predict the observed parasitological measures. Using our model, we show that the immune responses are highly heritable and by comparing selective breeding based on low FECs versus high plasma IgA responses, we show that the immune markers are a much improved measure of host resistance. In summary, we have created a model of host–parasite infections that explicitly captures the development of the adaptive immune response and show that by integrating genetic, immunological and parasitological understanding we can identify new immune-based markers for diagnosis and control. 相似文献
20.