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11.
Young, middle-aged, and older adult participants evaluated conversation scenarios that presented a middle-aged woman confronting either her young adult daughter or her older adult mother about a problem behavior. In all scenarios, the competence of the younger or older adult was salient, and the middle-aged woman used 1 of 3 control strategies: indirect, direct, or no control. As predicted, participants evaluated the direct control strategy more negatively than the other 2 strategies, and rated the indirect control strategy as more nurturing than the other 2 strategies. In addition, participants who were considering mothers in their 70s viewed the direct control strategy as more appropriate and the no control strategy as less appropriate than did those considering daughters in their 20s. Contrary to expectations, however, participant and target age did not interact to affect perceptions of the strategies, nor did a clear preference for the no control strategy over indirect control emerge. Results are interpreted within the framework of politeness theory (Brown & Levinson, 1987), notions of autonomy and paternalism (Cicirelli, 1992), and the communication predicament of aging model (Ryan, Giles, Bartolucci, & Henwood, 1986).  相似文献   
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An example system is studied to discuss precision of the multipoleexpansion, applied to determine forces exerted on particlesby a viscous low-Reynolds-number fluid flow. A single spherein an ambient flow (pure shear, quadratic, and modulated shear)parallel to a close plane wall is considered. Forces and torquesexerted by the ambient flow on a motionless sphere are evaluated.Their precision is determined and related to a multipole orderof the truncation. Similar analysis is performed for a movingsphere with no ambient flow and for a freely moving sphere.Relative motion of the sphere with respect to the wall givesrise to strong lubrication interactions. It is analysed howthese interactions affect accuracy of the pure multipole expansion,and what are the smallest distances where it becomes insufficient.An alternative precise method is applied, in which lubricationexpressions are subtracted from the hydrodynamic forces andtorques, and the residue is evaluated as a fast-convergent seriesof inverse powers of the distance between the sphere centreand the wall. The accuracy of this procedure is carefully analysed.  相似文献   
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A significant proportion of MRI units are being installed in MRI Centers that are free standing enterprises offering outpatient diagnoses separate from hospitals. The development of such Centers represents a challenge to more traditional arrangements and may have serious implications for physician responsibility that depend on their management and administration. In this review several legal and ethical issues arising from the proliferation of such Centers are analyzed and it is argued that regulatory attitudes may need to be altered to avoid major shifts of emphasis in the pattern of use of high cost imaging equipment.  相似文献   
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Automatic tumor segmentation using knowledge-based techniques   总被引:11,自引:0,他引:11  
A system that automatically segments and labels glioblastoma-multiforme tumors in magnetic resonance images (MRIs) of the human brain is presented. The MRIs consist of T1-weighted, proton density, and T2-weighted feature images and are processed by a system which integrates knowledge-based (KB) techniques with multispectral analysis. Initial segmentation is performed by an unsupervised clustering algorithm. The segmented image, along with cluster centers for each class are provided to a rule-based expert system which extracts the intracranial region. Multispectral histogram analysis separates suspected tumor from the rest of the intracranial region, with region analysis used in performing the final tumor labeling. This system has been trained on three volume data sets and tested on thirteen unseen volume data sets acquired from a single MRI system. The KB tumor segmentation was compared with supervised, radiologist-labeled “ground truth” tumor volumes and supervised K-nearest neighbors tumor segmentations. The results of this system generally correspond well to ground truth, both on a per slice basis and more importantly in tracking total tumor volume during treatment over time  相似文献   
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The formation of lithiophobic inorganic solid electrolyte interphase (SEI) on Li anode and cathode electrolyte interphase (CEI) on the cathode is beneficial for high-voltage Li metal batteries. However, in most liquid electrolytes, the decomposition of organic solvents inevitably forms organic components in the SEI and CEI. In addition, organic solvents often pose substantial safety risks due to their high volatility and flammability. Herein, an organic-solvent-free eutectic electrolyte based on low-melting alkali perfluorinated-sulfonimide salts is reported. The exclusive anion reduction on Li anode surface results in an inorganic, LiF-rich SEI with high capability to suppress Li dendrite, as evidenced by the high Li plating/stripping CE of 99.4% at 0.5  mA cm−2 and 1.0 mAh cm−2, and 200-cycle lifespan of full LiNi0.8Co0.15Al0.05O2 (2.0 mAh cm−2) || Li (20 µm) cells at 80 °C. The proposed eutectic electrolyte is promising for ultrasafe and high-energy Li metal batteries.  相似文献   
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Time of flight and energy of fission fragments were measured using pulsed beam. Fission fragment mass and energy integrated angular distributions were extracted. Fission fragment anisotropy was explained in the framework of saddle point model.  相似文献   
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