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1.
Four experiments examined 10-mo-old infants' causal event perception. Exp 1 replicated previous studies except that the specific objects used as agent and recipient varied from trial to trial. Under these conditions infants did not process the causality. Instead they keyed on specific temporal and spatial differences among the events. Exp 2 showed that infants notice a change in the particular agent performing either a causal or noncausal action. Exp 3 showed that infants do not notice a change in the type of action done to a particular recipient. Exp 4 demonstrated that infants do not pay attention to the object used as a recipient. As a whole, the results indicate that 10-mo-old infants perceive the causality of simple events by associating a specific agent with the causal action. These results provide more support for an information-processing view than for the view that infants have a causal module. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
2.
Primary cultures of neonatal rat aortic smooth muscle cells inoculated at high densities (1 X 10(6) cells/25 cm2 Falcon flask) with adequate nutrient media and pH control grow rapidly and form multilayers of cells with typical "hill and valley" organization. After 10 days growth insoluble elastin formation could be visualized by phase contrast microscopy as small particles which grew rapidly to become larger irregular refractile aggregates and later coalesced to form larger aggregates and small fibres. With light and electronmicroscopy, elastin was the predominant matrix protein formed, with the "hill regions" of cultures containing abundant elastin aggregates and some collagen. In 2-week-old cultures differentiation could be observed within the cell multilayer. The older deeper cells contained more protein synthesis organelles and myofilaments and were in close association with large often coalescing elastin aggregates; compared to younger more superficial cells which contained more free polyribosomes less myofilaments, and were associated with fewer and small elastin aggregates. In older cultures this differentiation was not apparent; the cells contained many myofilaments, dense bodies, and lysosomes. Elastin aggregates and newly formed elastic fibres were abundant in the matrix. Quantitative analysis of insoluble elastin formation in the cell layer during the 4-week culture period indicated continuous biosynthesis and deposition which paralleled that of desmosine formation. Amino-acid analysis of a hot alkali insoluble residue (regarded as elastin) from 30-day-old cultures gave a profile identical with neonatal rat aortic elastin in vivo. Insoluble collagen formation in the cell layer tended to plateau after the log phase of growth was completed (10 days). Proteoglycans were found predominantly in the supernatant media. Glycosaminoglycan analysis revealed a profile of dermatan sulphate (32%), chondroitin 4-sulphate (43%), keratan and heparan sulphate (30%), with only a trace of hyaluronic acid. This study indicates that primary cultures of neonatal rat aortic smooth muscle cells remain differentiated in culture and have the unique capacity to continue to synthesize and deposit large amounts (mg) of insoluble elastin which aggregate and from elastic fibres in vitro. 相似文献
3.
Bates Elizabeth; Thal Donna; Whitesell Kimberly; Fenson Larry; Oakes Lisa 《Canadian Metallurgical Quarterly》1989,25(6):1004
Whether language/gesture correlations in early language development can be explained by parallelism or comprehension mediation was examined. Study 1, parental report data for 95 1-year olds, suggested that word comprehension and production are dissociated in this age range and that the comprehension and production factors map onto distinct aspects of gesture. Study 2 tested 41 13–15-month-olds in a task in which the modeled gesture was accompanied by supportive, contradictory, or neutral narratives. Results showed that infants can use adult speech as an aid in reproduction of modeled gestures (comprehension mediation). However, there is still additional variance in gestural production that correlates with expressive vocabulary when comprehension-related variance is moved. Thus, comprehension mediation and parallelism both appear to be operating. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
4.
Chen CW Suchanek WL Shuk P Byrappa K Oakes C Riman RE Brown K Tenhuisen KS Janas VF 《Journal of materials science. Materials in medicine》2007,18(7):1413-1421
The role of citrate washing on the physical and chemical characteristics of magnesium-substituted apatites (HAMgs) was performed.
HAMgs were synthesized by a mechanochemical–hydrothermal route at room temperature in as little as 1 h, which is five times
faster than our previous work. Magnesium-substituted apatites had concentrations as high as 17.6 wt% Mg with a corresponding
specific surface area (SSA) of 216 m2/g. A systematic study was performed to examine the influence of increasing magnesium content on the physical and chemical
characteristics of the reaction products. As the magnesium content increased from 0 to 17.6 wt%, magnesium-doped apatite crystallite
size decreased from 12 to 8.8 nm. The Mg/(Mg + Ca) ratio in the product was enriched relative to that used for the reacting
precursor solution. During mechanochemical–hydrothermal reaction, magnesium doped apatites co-crystallize with magnesium hydroxide.
Citrate washing serves to remove the magnesium hydroxide phase. The concomitant increase in surface area results because of
the removal of this phase. Possible mechanisms for magnesium hydroxide leaching are discussed to explain the measured trends. 相似文献
5.
Use of Stable Isotopes to Trace Municipal Wastewater Effluents into Food Webs within a Highly Developed River System 下载免费PDF全文
Many anthropogenic inputs, such as municipal wastewater effluents (MWWEs), affect stable isotope signatures (δ13C and δ15N) at the base of exposed food webs creating spatial patterns reflecting their incorporation into aquatic food webs. The Grand River in southern Ontario, Canada, is a heavily modified, rapidly urbanizing river that assimilates wastewater from 30 municipal wastewater treatment plants. Stable isotope analysis was applied to resident aquatic invertebrates and fish influenced by three different wastewater outfalls in early, middle, and late summer to determine how values shifted seasonally and with differing effluent quality. There was a slight increase in δ13C in both invertebrates and fish in late summer downstream from the three outfalls, but it is difficult to separate effects of the effluents from downstream gradients. Downstream of two of the three outfalls, the δ15N tended to increase relative to upstream, while the remaining effluent, of the poorest quality, decreased δ15N values of both invertebrates and fish. Spatial trends in stable isotopes became more pronounced as the summer progressed with the greatest between‐site differences occurring in late summer. This study reflects the complex nutrient dynamics associated with MWWE inputs to rivers and contributes to our understanding and application of stable isotope analysis in impacted lotic ecosystems. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
6.
Student success and persistence within the major and university were examined through hierarchical linear and logistic regression analyses for two cohorts of engineering students. Indicators of success and persistence were based on theoretical and empirical evidence and included both cognitive and noncognitive variables. Cognitive variables included high school rank, SAT scores, and university cumulative grade point average. Noncognitive factors included academic motivation and institutional integration. Outcome variables included grade point average, enrollment at the university, and status as an engineering major. Gender differences also were evaluated. Several significant relationships among the variables were found. For instance, increased levels of motivation were significantly related to continuing in the major. Implications and directions for future research are discussed. 相似文献
7.
Judy L Oakes Kenneth L Bost Kenneth J Piller 《Journal of the science of food and agriculture》2009,89(13):2191-2199
BACKGROUND: Soybean seeds are rich in natural protein and are favorable environments for targeted protein expression. Soybeans represent an ideal platform for the production of novel vaccines that, in theory, do not require a cold chain. This study investigated the stability of a soybean‐derived antigen following long‐term storage, formulation, and shipment overseas in the absence of refrigeration. RESULTS: Transgenic seeds can be stored for more than 4 years at ambient temperature with no detectable loss of FanC antigen stability. Conventional processing methods utilizing heat, mechanical extraction and solvent extraction resulted in practical formulations that could be lyophilized, stored as dried milk powder and rehydrated in water without loss of FanC antigen stability. Overseas shipment of transgenic seed powder and soymilk formulations in the absence of a cold chain had no adverse effects on formulations or the FanC antigen. CONCLUSION: The feasibility of long‐term storage, processing and shipment of transgenic soy products in the absence of a cold chain was demonstrated. Soybeans represent a practical platform for development of novel vaccines to potentially address the worldwide need for vaccines that are cost‐effective, easy to formulate and can be manufactured, stored and transported without refrigeration. Copyright © 2009 Society of Chemical Industry 相似文献
8.
A case of a mature posterior cervical teratoma resembling two fingers and a case of a lumbosacral limb are presented. These are at least the seventh and eighth reported paraspinous or occipital teratomas with recognizable extremity development. Both anomalies had intradural extension and required exploration to decrease the likelihood of future spinal cord tethering. Preoperative evaluation, surgical technique, postoperative follow-up, and review of the literature are presented. 相似文献
9.
G. M. Ludtka R. E. Oakes R. L. Bridges J. L. Griffith 《Metallurgical and Materials Transactions A》1993,24(2):369-377
A uranium-2 molybdenum (U-2Mo) alloy was shown to exhibit superplastic behavior over the β + γ two-phase field temperature
regime and over a limited temperature span in the α + γ field. At Oak Ridge, two distinct processes were developed that evolved
microstructures conducive to superplasticity. These microstructures were shown to exhibit superplasticity (elongations >500
pct) over a broad range of strain rates, from 2.5 × 10-4 to 1 × 10-2 s-1. A maximum value of 700 pct elongation was reached at 695 °C and a true constant strain rate of 2.5 × 10-3 s-1. This study details the processing sequences, microstructures, strain-rate sensitivity, and maximum elongation data generated
to characterize the superplastic U-2Mo alloy. In addition, the fracture and cavitation analyses conducted on constant strain-rate
tensile test specimens are discussed. 相似文献
10.
SM Jackson H Nakato M Sugiura A Jannuzi R Oakes V Kaluza C Golden SB Selleck 《Canadian Metallurgical Quarterly》1997,124(20):4113-4120
Decapentaplegic (Dpp) is a Drosophila member of the Transforming Growth Factor-beta (TGF-beta)/Bone Morphogenetic Protein (BMP) superfamily of growth factors. Dpp serves as a classical morphogen, where concentration gradients of this secreted factor control patterning over many cell dimensions. Regulating the level of Dpp signaling is therefore critical to its function during development. One type of molecule proposed to modulate growth factor signaling at the cell surface are integral membrane proteoglycans. We show here that division abnormally delayed (dally), a Drosophila member of the glypican family of integral membrane proteoglycans is required for normal Dpp signaling during development, affecting cellular responses to this morphogen. Ectopic expression of dally+ can alter the patterning activity of Dpp, suggesting a role for dally+ in modulating Dpp signaling strength. These findings support a role for members of the glypican family in controlling TGF-beta/BMP activity in vivo by affecting signaling at the cell surface. 相似文献