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961.
Records of 60 patients with primary salivary gland tumors were retrospectively analyzed. Most were European Jews, 60% were males, and the average age was 57 years. The parotid gland was the most frequent site of origin (76%). The main presenting symptom was painless swelling. Pain or facial palsy were rare and associated with poor prognoses. The most common types were mucoepidermoid, adenocystic, adenocarcinoma and malignant, mixed carcinomas (in descending order of frequency). Squamous cell carcinoma was the most prevalent histologic type. Most patients presented at an advanced stage. Treatment was mainly surgical and postoperative radiotherapy was given to those with advanced disease. Most recurrences occurred within 3 years of initial treatment. Actuarial 10-year survival for all patients was 40%. Superior survival rates were achieved in women, probably due to less aggressive malignancies. Low grade mucoepidermoid carcinoma had a favorable prognosis, whereas anaplastic carcinoma had the worst. Other significant prognostic factors included stage and grade of disease. 相似文献
962.
We present some sufficient and necessary conditions for convergent splitting of a non-Hermitian indefinite matrix. Some sufficient
conditions to determinate a matrix with a (strongly) dominant symmetric part for a class of boundary value problem are also
obtained. These results are applicable to identify the convergence of iterative methods for solving large sparse systems of
linear equations. 相似文献
963.
This paper presents two independent dynamic models of a nuclear gas turbine power plant. Both the high temperature nuclear reactor (HTR) and its energy conversion system (ECS) based on a direct Brayton cycle have been modelled. One model utilises RELAP5 for the ECS, the other Aspen Custom Modeler (ACM). The reactor model used in both models is a point kinetic model derived from a detailed reactor model. The ECS model is described and compared componentwise, with an emphasis on the turbomachinery. The total plant models are compared with each other by calculating two representative transients: one load rejection transient and one transient with the system at part load. 相似文献
964.
A highly linear electrooptic modulator has been designed, fabricated, and evaluated. The design of this modulator consists of only a simple modification to the directional coupler. Two-tone testing has demonstrated that, for an optical modulation depth of 30% per channel, the third-order intermodulation distortion is more than 30 dB lower than that of the conventional directional coupler or Mach-Zehnder modulators. This improvement was not observed to be accompanied by any increase in second harmonic distortion. Also included are results of two-tone computer simulations which predict the improvement in linearity of this device for a range of modulation depths.<> 相似文献
965.
Previously unknown alkaline-earth metal uranogermanates of the general formula MII[HGeUO6]2·nH2O (MII = Mg, Ca) were prepared in the form of higher and intermediate hydrates and anhydrous compounds. The compounds were studied by X-ray diffraction, IR spectroscopy, and thermal analysis. 相似文献
966.
Shape memory properties of Ni-Ti based melt-spun ribbons 总被引:1,自引:0,他引:1
R. Santamarta E. Cesari J. Pons T. Goryczka 《Metallurgical and Materials Transactions A》2004,35(3):761-770
Shape-memory properties of equiatomic NiTi, Ni45Ti50Cu5, and Ni25Ti50Cu25 ribbons made by melt spinning have been studied by temperature inducing the martensitic transformation under constant tensile
loads. Recoverable strains above 4 pct can be obtained under ∼100 MPa loads for the NiTi and Ni45Ti50Cu5 ribbons, transforming to B19’ martensite. The B19 martensite is formed in the Ni25Ti50Cu25 ribbon after crystallization, and according to the lowering in transformation strain as Cu content increases, the recoverable
strain is close to 2.5 pct for ∼150 MPa load. The transformation temperatures exhibit a linear dependence on the applied stress,
which can be quantitatively described by means of a Clausius-Clapeyron type equation. The NiTi and Ni45Ti50Cu5 ribbons exhibited some degree of two-way shape-memory effect (TWSME) after thermomechanical cycling. Texture analyses performed
on the different ribbons allow us to better understand the transformation strains obtained in each ribbon. The amounts of
shape-memory effect (SME) and nonrecoverable strain shown by the studied ribbons are of the same order as those already observed
in bulk materials, which makes melt spinning an ideal substitute to complicated manufacturing processes if really thin samples
are needed. However, applicable stresses in melt-spun ribbons are limited by a relatively “premature” brittle fracture caused
by irregularities in ribbon thickness. 相似文献
967.
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
968.
Dianov E.M. Grudinin A.B. Gurjanov A.N. Gusovsky D.D. Harutjunian Z.E. Ignatev S.V. Smirnov O.B. 《Lightwave Technology, Journal of》1992,10(2):118-124
The reproducible technology for producing high-birefringence fibers with stress-induced elliptical cladding and circular core is described. The authors have obtained fibers that have a birefringence of about (1-3) 10-4, a mode coupling parameter of about (2-7) 10 -5 m-1, and loss of less than 0.5 dB/km at 1.6 μm. The authors have found effects restricting the capability of test fibers to maintain the state of linear polarization 相似文献
969.
970.
Izard Carroll E.; Fantauzzo Christina A.; Castle Janine M.; Haynes O. Maurice; Rayias Maria F.; Putnam Priscilla H. 《Canadian Metallurgical Quarterly》1995,31(6):997
Four studies examined aspects of the differential emotions theory (DET) hypothesis of expressive behavior development. In Study 1, facial-expressive movements of 108 2.5–9-mo-old infants were video recorded in positive and negative mother–infant interactions (conditions). As expected, Max-specified full-face and partial expressions of interest, joy, sadness, and anger were morphologically stable between the 2 ages. Studies 1 and 2 confirmed predicted differential responding to mother sadness and anger expressions and to composite positive and negative conditions. Discrete negative expressions exceeded negative blends, and the amount of both expression types remained stable across ages. Studies 3 and 4 provided varying degrees of support for the social validity of Max-specified infant negative affect expressions. Conclusions include revisions and clarifications of DET. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献