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991.
The pattern synthesis techinque described allows the power pattern to be optimized in a very useful sense over the desired operating band of the antenna array. This is an improvement over previous techniques involving constraints on such artificial parameters as source norm and superdirectivity ratio, which do not, in fact, ensure a useful pattern bandwidth. The procedure described provides minimum mean square error over an arbitrary number of discrete frequencies 相似文献
992.
993.
994.
R Albrecht TC Awes C Baktash P Beckmann F Berger R Bock G Claesson G Clewing L Dragon A Eklund RL Ferguson A Franz S Garpman R Glasow HA Gustafsson HH Gutbrod J Idh P Jacobs K Kampert BW Kolb P Kristiansson IY Lee H Loehner I Lund FE Obenshain A Oskarsson I Otterlund T Peitzmann S Persson F Plasil AM Poskanzer M Purschke H Ritter S Saini R Santo HR Schmidt T Siemiarczuk SP Sorensen E Stenlund ML Tincknell GR Young 《Canadian Metallurgical Quarterly》1991,44(6):2736-2752
995.
Ideal-gas thermodynamic properties for natural-gas applications 总被引:2,自引:0,他引:2
Calculating caloric properties from a thermal equation of state requires information such as isobaric heat capacities in the ideal-gas state as a function of temperature. In this work, values for the parameters of thec
p
0
correlation proposed by Aly and Lee were newly determined for 21 pure gases which are compounds of natural gas mixtures. The values of the parameters were adjusted to selectedc
p
0
data calculated from spectroscopic data for temperatures ranging from 10 to 1000 K. The data sources used are discussed and compared with literature data deduced from theoretic models and caloric measurements. The parameters presented will be applied in a current GERG project for evaluating equations of state (e.g., the AGA 8 equation) for their suitability for calculating caloric properties. 相似文献
996.
997.
Allen Daniel N.; Strauss Gregory P.; Kemtes Karen A.; Goldstein Gerald 《Canadian Metallurgical Quarterly》2007,21(6):713
Hemispheric involvement in reasoning abilities has been debated for some time, and it remains unclear whether the right hemisphere's involvement in problem solving is modality specific or dependent on the type of spatial reasoning required. In the current study, 2 types of nonverbal reasoning abilities were examined, spatial reasoning and proportional reasoning, in 109 patients with cerebrovascular disease that was confined to either the right or the left hemisphere or was diffuse in nature. Results indicated that no lateralizing effects were present based on type of spatial reasoning. Findings are consistent with the suggestion that higher order cognitive processes involved in nonverbal abstraction and problem solving are not strongly lateralized to the right hemisphere but rather are more generally distributed throughout the cortex. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
998.
L. P. Podenok L. I. Sharakhovskii V. D. Shimanovich O. I. Yas’ko 《Journal of Engineering Physics and Thermophysics》1997,70(1):95-99
The influence of heat transfer processes in arc discharges on the development of thermal instability is considered. A substantial
dependence of the process of destabilization on the plasma properties is shown by the example of argon and helium arcs.
Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 70, No. 1, pp. 93–98, January–February, 1997. 相似文献
999.
P Lechner 《Canadian Metallurgical Quarterly》1997,24(2):68-72
Anti-CEA-scintigraphy turned out very reliable in detecting primary and recurrent colorectal cancer, its overall accuracy being more than 90 p.c. The intraoperative application of this technology should provide similar results when focussing at extrahepatic tumor deposits, for example in lymph nodes, thus allowing accurate staging of the underlying disease. To test this hypothesis we lauched the following feasibility-study the results of which are compared to those reported in the recent literature. We investigated 20 patients-six with rectum-, 14 with colon cancer, 24 hours before surgery they were intravenously given 1 ml of an fab-fragment-antibody to CEA, labeled with 25mCi of 99mTc (CEA-Scan). During surgery the radioactivity in lymph glands regionary for the tumors was measured and compared to the-much lower-activity in healthy nodes. For this we used a scintillation-probe (C-Trak). All lymph nodes of interest were-then excised and submitted to frozen section pathology. In 7/20 cases scintimetry led to an up-staging of the disease. In addition we found metastatic spread to lymph nodes that were basically not regionary for the primary tumor. Our results are confirmed by those of other investigators. Scintimetry can precisely identify even very small tumor deposits. So it leads to accurate staging when surgery is still on-going. In a next step the concept of sentinel-node-diagnosis, which is right now being clinically evaluated, may be applied is colorectal surgical oncology. 相似文献
1000.
The surgical management of intractable epistaxis by external carotid artery ligation may become complicated if there is a high bifurcation of the common carotid artery. Occlusion of the bleeding vessels by catheter embolization is described in a patient in whom exploration of the neck had failed to locate the external carotid artery. 相似文献