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991.
Conducted a questionnaire survey of medical school psychologists to assess attitudes toward work, advantages and disadvantages of working in medical schools, organizational structure, job satisfaction, and salary, from which 794 usable responses were obtained. 90% of Ss preferred that psychology be represented as an independent department or as part of an autonomous department of behavioral science. (6 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
992.
993.
Andrzej Z. Ringwelski Nathan Presser Robert J. Gordon 《Israel journal of chemistry》1984,24(3):214-217
The multiphoton induced isomerization of cis-3,4-dichlorocyclobutene (DCCB) was studied as a function of pressure. Three experiments indicated the existence of a nonthermal mechanism at neat pressures below 60 mtorr. These were: (i) the leveling off of the fractional yield of isomerization products at low pressures; (ii) the absence of dissociation products from 2-iodo-2-methyl propane, which served as a chemical thermometer in the presence of a large excess of DCCB; and (iii) a break in the power-law dependence of the optoacoustic signal produced by neat DCCB. The increased yield at higher DCCB pressures is believed to be due partly to a thermal reaction and partly to increased absorption caused by rotational or vibrational hole filling. Optoacoustic measurements also showed that at constant fluence the absorbed energy was greater for long, low intensity pulses, as might be expected for inhomogeneous excitation. However, the present experiments did not reveal an intensity dependence of the reaction yield. Addition of argon as a buffer gas monotonically decreased the yield, indicating that vibrational quenching more than offsets any hole-filling effects. 相似文献
994.
Maner Jon K.; DeWall C. Nathan; Baumeister Roy F.; Schaller Mark 《Canadian Metallurgical Quarterly》2007,92(1):42
Evidence from 6 experiments supports the social reconnection hypothesis, which posits that the experience of social exclusion increases the motivation to forge social bonds with new sources of potential affiliation. Threat of social exclusion led participants to express greater interest in making new friends, to increase their desire to work with others, to form more positive impressions of novel social targets, and to assign greater rewards to new interaction partners. Findings also suggest potential boundary conditions to the social reconnection hypothesis. Excluded individuals did not seem to seek reconnection with the specific perpetrators of exclusion or with novel partners with whom no face-to-face interaction was anticipated. Furthermore, fear of negative evaluation moderated responses to exclusion such that participants low in fear of negative evaluation responded to new interaction partners in an affiliative fashion, whereas participants high in fear of negative evaluation did not. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
995.
The deposition processes and electronic properties of thin-film semiconductors and insulators based on silicon in relation to the fabrication of electronic devices on flexible plastic substrates are considered. The films of amorphous hydrogenated silicon (a-Si:H), nanocrystalline silicon (nc-Si), and amorphous silicon nitride (a-SiNx), and also thin-film transistors are fabricated at comparatively low temperatures (120°C, 75°C) using existing commercial plasma-chemical equipment. The parameters of thin-film transistors based on a-Si:H and fabricated at the aforementioned relatively low temperatures are compatible with those of high-temperature analogues. 相似文献
996.
Attar Rony Bernstein Philip A. Goodman Nathan 《IEEE transactions on pattern analysis and machine intelligence》1984,(6):645-650
Site initialization is the problem of integrating a new site into a running distributed database system (DDBS). Site recovery is the problem of integrating an old site into a DDBS when the site recovers from failure. Site backup is the problem of creating a static backup copy of a database for archival or query purposes. We present an algorithm that solves the site initialization problem. By modifying the algorithm slightly, we get solutions to the other two problems as well. Our algorithm exploits the fact that a correct DDBS must run a serializable concurrency control algorithm. Our algorithm relies on the concurrency control algorithm to handle all intersite synchronization. 相似文献
997.
After the nudibranchAeolidia papillosa eats the sea anemoneAnthopleura elegantissima, anthopleurine, an alarm pheromone from the sea anemone, persists in the tissues of the nudibranch. For at least five days following such a meal, nudibranchs are capable of evoking alarm responses in anemones without touching them, presumably by releasing anthopleurine into the water. The anemone's alarm response to anthopleurine is to withdraw the tentacles and oral disk, the preferred sites of attack forAeolidia. This leaves exposed to attack the anemone body regions with the highest anthopleurine concentrations. Specimens ofAeolidia collected near sources ofAnthopleura are more likely to contain detectable amounts of anthopleurine than those more distant; some nudibranchs collected 0.5 m fromAnthopleura contained enough anthopleurine to evoke alarm responses in anemones they approached. These findings suggest that the predator helps in the transmission of anthopleurine, which may reduce the severity of predation onAnthopleura. 相似文献
998.
Pogodina OA Pustogov VV de Melas F Haberhauer-Troyer C Rosenberg E Puxbaum H Inberg A Croitoru N Mizaikoff B 《Analytical chemistry》2004,76(2):464-468
The determination of organic trace gases in the ambient environment at the lower ppb level is demonstrated based on a novel technique combining sorption tube sampling on Molsieve and Carbosieve S-III, thermal desorption, and detection of the trace analyte by hollow waveguide Fourier transform infrared (HWG-FT-IR) spectroscopy. While ethene concentrations of approximately 5 ppm can be directly observed using HWG-FT-IR, enrichment factors of up to 5000 were achieved by sorption tube sampling and thermal desorption. Detection limits of approximately 1 ppb are reported. Efficient enrichment by the sampling tube is achieved due to the favorable internal volume ( approximately 0.4 cm(3) at a length of 470 mm) of the hollow waveguide serving as a miniaturized gas cell. This new method was validated for ethene by thermodesorption-cryofocusing-GC-FID as the reference method. Analytical performance has been compared for standard gas mixtures and for ethene measurements in urban air. Finally, ethene data from a sampling campaign at two alpine sites in Tyrol/Austria are presented. 相似文献
999.
Microfluidic field-effect flow control (FEFC) modifies the zeta potential of electroosmotic flow using a transverse electric field applied through the microchannel wall. Previously demonstrated in silicon-based and glass microsystems, FEFC is presented here as an elegant method for flow control in polymer-based microfluidics with a simple and low-cost fabrication process. In addition to direct FEFC flow modulation, independent transverse electric fields in connected microchannels are demonstrated to produce a differential pumping rate between the microchannels. The different electroosmotic pumping rates formed by local zeta potential control induce an internal pressure at the microchannel intersection, resulting in hydrodynamic pumping through an interconnecting field-free microchannel. Modulation of the voltages applied to the gate electrodes adjusts the magnitude and direction of the bidirectional pressure pumping, with fine resolution volume flow rates from -2 to 2 nL/min in the field-free microchannel demonstrated. 相似文献
1000.
The fabrication and evaluation of a palladium decoupler and working electrode for microchip capillary electrophoresis (CE) with electrochemical detection is described. The use of the Pd decoupler allows the working electrode to be placed directly in the separation channel and eliminates the band-broadening characteristic of the end-channel configuration. The method used for fabrication of the decoupler and working electrode was based on thin-layer deposition of titanium followed by palladium onto a glass substrate. When employed as the cathode in CE, palladium absorbs the hydrogen gas that is generated by the hydrolysis of water. The effect of the decoupler size on the ability to remove hydrogen was evaluated with regard to reproducibility and longevity. Using boric acid and TES buffer systems, 500 microm was determined to be the optimum decoupler size, with effective voltage isolation lasting for approximately 6 h at a constant field strength of 600 V/cm. The effect of distance between the decoupler and working electrode on noise and resolution for the separation of dopamine and epinephrine was also investigated. It was found that 250 microm was the optimum spacing between the decoupler and working electrode. At this spacing, laser-induced fluorescence detection at various points around the decoupler established that the band broadening due to pressure-induced flow that occurs after the decoupler did not significantly affect the separation efficiency of fluorescein. Limits of detection, sensitivity, and linearity for dopamine (500 nM, 3.5 pA/microM, r(2) = 0.9996) and epinephrine (2.1 microM, 2.6 pA/microM, r(2) = 0.9996) were obtained using the palladium decoupler in combination with a Pd working electrode. 相似文献