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1.
A Web‐based teaching device was constructed to deliver information on fundamentals of ultrasound imaging to approximately one‐half the students in an undergraduate medical imaging course, while the remaining students were taught the same material via traditional lectures and typed notes. The students participating in this study were separated randomly but in such a manner that prior achievement was statistically equivalent for the two groups. After approximately two weeks of instruction, an ultrasound imaging exam was administered. Results indicated no statistically significant difference in scores on homework assigned during the instructional period between the traditional and online groups. Similarly, there was no statistically significant difference in the average exam scores of students in the two groups. The traditional group required significantly more time on learning activities than did the online group. These results indicated that level of understanding was not affected by use of the online device, while efficiency of learning improved dramatically. Reasons reported by the students for the improved efficiency of the online method included flexibility in time usage and ability to cater to the individual, which came with the added responsibility of self‐discipline. The traditional teaching method, meanwhile, allowed interaction with and instant feedback from a professor and other students. In this study we have demonstrated that the nature of an online device yields a higher level of efficiency than traditional lectures, despite the inherent drawbacks of the approach. The effectiveness of this device could potentially be improved by implementing enhancements to increase the level of interaction for the user and to help with discipline and time management.  相似文献   
2.
This paper focuses on recent trends and issues in the EU-25 countries related to one key broadband application area: digital media ‘content’ applications. It draws upon recently completed research addressing current and future uses and applications of broadband in the EU-25 area.

The paper presents key findings from the BEACON project concerning the broadband content trends and issues in the EU-25 countries. First, the paper briefly considers recent literature on broadband and digital media innovations as well as the policy context in Europe, which has an important influence on framing supports for innovation in content and digital media. Next, it addresses a number of key issues that impact upon the creation of content services. These include the high cost of content production and the difficulty of forming attractive business cases given the uncertainties related to user demand, and the IPR and copyright regimes. It will also consider users’ patterns of engagement with broadband content and emerging user applications. Next, the paper discusses whether broadband is reaching a ‘tipping point’, whereby broadband access is becoming the norm and in the next five years we will see the emergence of innovative, dynamic content services. The paper considers whether recent moves by three sets of significant actors (media corporations, the advertising sector, and EC regulators) could be early signs of a tipping point in favour of the creation of and more focused support for broadband content services.  相似文献   

3.
This article evaluates an intervention based on P. A Gollwitzer's (1993) concept of implementation intentions. Women registered at a medical practice in rural England (N?=?114) completed measures of the theory of planned behavior variables before a manipulation that induced one half of the sample to form implementation intentions specifying when, where, and how they would make the appointment. Subsequent attendance was determined from medical records. Findings show that the theory of planned behavior variables and previous delay behavior provided good prediction of attendance. However, despite equivalent motivation to attend, participants who formed implementation intentions were much more likely to attend for screening compared with controls (92% vs. 69%). Evidence also suggests that implementation intentions attenuated the relationship between previous delay behavior and subsequent attendance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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5.
Injuries caused by unsafe manual handling of patients are a major source of ill health in health care workers. The present study evaluated the ability of 4 classes of variable to predict use of a hoist when moving a heavily dependent patient. Variables examined were occupational role characteristics, such as hours of work and type of shift worked; biographics, including age and height; aspects of occupational context, such as number of hoists available and number of patients; and motivational variables specified by the theory of planned behavior (Ajzen, 1985) and protection motivation theory (Rogers, 1983). Regression analyses showed that background and social-cognitive variables were able to account for 59% of variance in intention to use a hoist and 41% of variance in use of the hoist assessed 6 weeks later. Height, hoist availability, coworker injunctive norm, perceived behavioral control, response cost, response benefits, and social and physical costs of not using the hoist each explained independent variance in motivation to use a hoist at work. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
6.
The four isomers of 4-aminopyrrolidine-2,4-dicarboxylate (APDC) were prepared and evaluated for their effects at glutamate receptors in vitro. (2R,4R)-APDC (2a), an aza analog of the nonselective mGluR agonist (1S,3R)-1-aminocyclopentane-1,3-dicarboxylate (1S,3R)-ACPD, 1), was found to possess relatively high affinity for metabotropic glutamate receptors (mGluRs) (ACPD-sensitive [3H]glutamate binding IC50 = 6.49 +/- 1.21 microM) with no effects on radioligand binding to NMDA, AMPA, or kainate receptors up to 100 microM. None of the other APDC isomers showed significant mGluR binding affinity, indicating that this interaction is highly stereospecific. Both 1 and 2a were effective in decreasing forskolin-stimulated cAMP formation in the adult rat cerebral cortex (EC50 = 8.17 +/- 2.21 microM for 1; EC50 = 14.51 +/- 5.54 microM for 2a); however, while 1 was also effective in stimulating basal tritiated inositol monophosphate production in the neonatal rat cerebral cortex (EC50 = 27.7 +/- 5.2 microM), 2a (up to 100 microM) was ineffective in stimulating phosphoinositide hydrolysis in this tissue preparation, further supporting our previous observations that 2a is a highly selective agonist for mGluRs negatively coupled to adenylate cyclase. Microelectrophoretic application of either 1 or 2a to intact rat spinal neurons produced an augmentation of AMPA-induced excitation (95 +/- 10% increase for 1, 52 +/- 6% increase for 2a). Intracerebral injection of 1 (400 nmol) produced characteristic limbic seizures in mice which are not mimicked by 2a (200-1600 nmol, ic). However, the limbic seizures induced by 1 were blocked by systemically administered 2a in a dose-dependent manner (EC50 = 271 mg/kg, ip). It is concluded that (2R,4R)-APDC (2a) is a highly selective, systemically-active agonist of mGluRs negatively coupled to adenylate cyclase and that selective activation of these receptors in vivo can result in anticonvulsant effects.  相似文献   
7.
The effect of grafting mastoid cavities with small Davis cutaneous pinch grafts was assessed in 15 patients. Following revision of the cavity and Davis pinch grafting the resultant cavity was completely dry in 13 patients (87%) over a period ranging from 1 to 30 months with a mean of 7.3 months, with five becoming dry within 1 month. Patient satisfaction with respect to reduction in discharge and smell was excellent (87%). We believe that the Davis graft technique has a beneficial role in persistent post-mastoidectomy otorrhoea especially when previous standard revision techniques have failed.  相似文献   
8.
The leucine-rich nuclear export signal (NES) is used by a variety of proteins to facilitate their delivery from the nucleus to the cytoplasm. One of the best-studied examples, protein kinase inhibitor (PKI), binds to the catalytic subunit of protein kinase A in the nucleus and mediates its rapid export to the cytoplasm. We developed a permeabilized cell assay that reconstitutes nuclear export mediated by PKI, and we used it to characterize the cytosolic factors required for this process. The two-step assay involves an import phase and an export phase, and quantitation is achieved by digital fluorescence microscopy. During the import phase, a fluorescent derivative of streptavidin is imported into the nuclei of digitonin-permeabilized HeLa cells. During the export phase, biotinylated PKI diffuses into the nucleus, binds to fluorescent streptavidin, and mediates export of the complex to the cytoplasm. Nuclear export of the PKI complex is cytosol dependent and can be stimulated by addition of the purified NES receptor, Crm1. HeLa cell cytosol treated with N-ethylmaleimide (NEM) or phenyl-Sepharose to inactivate or deplete Crm1, respectively, is still fully active in the PKI export assay. Significantly, the export activity can be depleted from cytosol by preadsorption with a protein conjugate that contains a functional NES. These data indicate that cytosol contains an export activity that is distinct from Crm1 and is likely to correspond to an NES receptor.  相似文献   
9.
OBJECTIVE: Four methods of producing maximum intensity projection (MIP) images were studied and compared. MATERIALS AND METHODS: Three of the projection methods differ in the interpolation kernel used for ray tracing. The interpolation kernels include nearest neighbor interpolation, linear interpolation, and cubic convolution interpolation. The fourth projection method is a voxel projection method that is not explicitly a ray-tracing technique. The four algorithms' performance was evaluated using a computer-generated model of a vessel and using real MR angiography data. The evaluation centered around how well an algorithm transferred an object's width to the projection plane. RESULTS: The voxel projection algorithm does not suffer from artifacts associated with the nearest neighbor algorithm. Also, a speed-up in the calculation of the projection is seen with the voxel projection method. Linear interpolation dramatically improves the transfer of width information from the 3D MRA data set over both nearest neighbor and voxel projection methods. Even though the cubic convolution interpolation kernel is theoretically superior to the linear kernel, it did not project widths more accurately than linear interpolation. A possible advantage to the nearest neighbor interpolation is that the size of small vessels tends to be exaggerated in the projection plane, thereby increasing their visibility. CONCLUSION: The results confirm that the way in which an MIP image is constructed has a dramatic effect on information contained in the projection. The construction method must be chosen with the knowledge that the clinical information in the 2D projections in general will be different from that contained in the original 3D data volume.  相似文献   
10.
BACKGROUND AND PURPOSE: The purpose of this study was to determine the reliability and validity of measurements obtained with a seven-item modified version of the Gait Abnormality Rating Scale (GARS-M), an assessment of gait designed to predict risk of falling among community-dwelling, frail older persons. SUBJECTS: Fifty-two community-dwelling, frail older persons, with a mean age of 74.8 years (SD = 6.75), participated. METHODS: A history of falls was determined from self-report or by proxy report. The GARS-M was scored from videotapes of subjects walking at self-selected paces. Gait characteristics were recorded during a timed walk on a 6-m brown-paper walkway. RESULTS: Scores obtained by three raters for 23 subjects demonstrated moderate to substantial intrarater and interrater reliability. Concurrent validity, as assessed by Spearman rank-order correlation coefficients, was demonstrated for the relationship between GARS-M scores and stride length (r = -.754) and for the relationship between GARS-M scores and walking speed (r = -.679). Mean GARS-M scores distinguished between frail older persons with and without a history of recurrent falls (mean GARS-M scores of 9.0 and 3.8, respectively). CONCLUSION AND DISCUSSION: The GARS-M is a reliable and valid measure for documenting gait features associated with an increased risk of falling among community-dwelling, frail older persons and may provide a clinically useful alternative to established quantitative gait-assessment methods.  相似文献   
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