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Children (aged 5–6 and 9–10 yrs) and adults participated in an eventful laboratory session and provided memory reports of the session. In 3 experiments, college students and parents viewed videotapes of highly accurate and highly inaccurate reports. In 2 experiments, these "fact finders" rated adult witnesses more believable and accurate than younger child witnesses, even when both groups were equally accurate. Perceptions of confidence and consistency mediated credibility judgments. Accurate witnesses were judged more believable and accurate than inaccurate witnesses. Higher perceived confidence, longer free recall, and fewer memory failure admissions were associated with more accurate adult memory reports. Fact finders overused confidence and underused the other cues in achieving modest accuracy discernment. The results suggest how strong and weak memory reports differ and how fact finders may learn to differentiate them. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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The formation of acid soaps has been used successfully for the separation of a mixture of fatty acids into high and low iodine value fractions. The acid soaps of saturated acid can be made to crystallize from water leaving their unsaturated counter parts in solution. Acid soaps of saturated fatty acids are well characterized compounds with the formula R-COOM.R-COOH, where R is a straight alkyl chain, and M is sodium, potassium or ammonium. Optimum crystallization conditions involve a soap concentration of 2–5%, pH adjustment to between 7.0 and 8.0, an initial crystallization temperature not below 25C, and a crystallization period of at least 4 hr during which time cooling to a final temperature of 5–10C must be gradual, and agitation gentle.  相似文献   
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 We are fabricating sub-collimating X-ray grids that are to be used in an orbiting solar X-ray telescope. The telescope optics consist of twelve rotating pairs of high aspect ratio grids. The pitch for the grids ranges from 34 μm to 317 μm. The grid thickness-to-grid-slit ratio must be approximately 50:1, resulting in grid thicknesses of 1 to 10 millimeters. We are implementing a design in which a 34 μm pitch, free-standing PMMA grid is fabricated with 20 μm wide slits through a 800 μm thickness. After exposure and developing, metal is electrodeposited into the slits in the PMMA grid and the PMMA is left in place to hold the individual metal pieces. For optimum imaging performance, the root-mean-square pitch of the two grids of each pair must match to within 1 part in 10000 and simultaneous exposures of stacked sheets of PMMA have insured that this requirement is met. Received: 30 October 1995 / Accepted: 25 January 1996  相似文献   
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Approximately 14–25% of Canadian children and youth have a diagnosable mental disorder. Fewer than 25% of those with such disorders receive specialised services. Even for those receiving services, there is no guarantee that the interventions provided are effective or based on any credible evidence. It is time that child and youth mental health be recognised as the health priority that it truly is. The barriers to meaningful change in child and youth mental health are many and include historical, attitudinal, cultural, financial, and systemic considerations. True change will require creativity, innovation, collaboration, and leadership. Mindsets need to be shifted and the status quo needs to be challenged. Canadian psychologists have skillsets that should be critical in accelerating change in child and youth mental health. We should not shy away from taking on leadership roles to provoke such change. Examples of where this is occurring and opportunities for further action are profiled. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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Increasing evidence from field measurements, modeling studies, and laboratory experiments suggests that heterogeneous reactions on stratospheric sulfate aerosol particles can change the partitioning in the nitrogen and chlorine families and thereby affect global ozone levels. In this study, a Knudsen cell flow reactor was used to measure the uptake of ClONO2 and N2O5 by sulfuric acid solutions representative of background and volcanic stratospheric aerosol particles. The uptake coefficient (γ) of chlorine nitrate on 50–75 wt% H2SO4 at 223 K was found to be markedly dependent on the acid concentration, with γ ranging from about 1 × 10−2 to 1 × 10−4. These results are in good agreement with literature reports and the data fit the expression log γ= 1.87 – 0.074 × (wt% H2SO4). This reaction will thus have its largest impact when stratospheric temperatures are low and sulfuric acid aerosols are most dilute. Uptake of N2O5 was studied on solutions with compositions in the range 58–96 wt% H2SO4 at temperatures from 193 to 303 K. N2O5 reacted readily on sulfuric acid surfaces with uptake coefficients of about 0.06. The uptake coefficient was found to be independent of the sulfuric acid concentration and the solution temperature over the ranges studied. These results suggest that the reaction of N2O5 with H2O will occur readily on sulfuric acid aerosol particles for most stratospheric conditions.  相似文献   
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Associative thickeners represent an important class of rheology modifiers used in waterborne coatings. Understanding molecular level interactions between associative thickeners and surfactants has been the subject of a number of prior studies. Our recent studies focused on the behavior of a hydrophobically modified, aminoplast ether (HEAT) associative thickener and a highly hydrophobic ethoxylated octylphenol surfactant in aqueous solution. Aqueous blends of these two materials exhibit shear-thinning, as well as rarely reported, transient, shear-induced thickening behavior. In addition, the same compositions exhibit both thixotropy and antithixotropy. The shear-induced thickening is shown to be the result of transient aggregated structures formed under shear. Addition of a third component, β-cyclodextrin—a molecule known to disrupt hydrophobic associations—to the mixture helped us advance the understanding of the nature of associative thickener–surfactant interactions that cause the transient shear-thickening behavior. Results indicate that, while overall viscosity of the HEAT/surfactant mixtures is decreased by β-cyclodextrin, the shear-induced thickening is unaffected. An intermolecular interaction model to describe the transient thickening mechanism is presented.  相似文献   
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The development of unit-dose, inhalable, antibiotic microparticles for use in primary and combined therapy approaches to treating tuberculosis (TB), multi-drug-resistant (MDR-TB), and extensively drug-resistant TB is explored using the gentle drying process of Carbon-dioxide Assisted Nebulization with a Bubble Dryer (CAN-BD). The microparticles produced using this method contain capreomycin, kanamycin, and isoniazid, respectively, imbedded in L-leucine. Antibiotics were developed into inhalable antibiotic formulations for their utility in both first line and second line antibiotic treatment regimens. Capreomycin and kanamycin are typically administered by injection making them desirable candidates for the development of a needle-free delivery system that addresses the Grand Challenges in Global Health Initiative #3. In response to this challenge, unit-dose packaging that preserves powder properties by protecting them from moisture, oxidants, and UV exposure, and a low cost “active” dry powder inhaler, the PuffHaler, were developed and used as a prototype device, in addition to the Aerolizer, to disperse the microparticle antibiotic formulations. Antibiotic formulations show yields above 50% in small-scale powder production by CAN-BD. Capreomycin and kanamycin show improved powder yields in scale up experiments. The particle properties were characterized using scanning electron microscopy, Karl Fischer moisture analysis, Anderson Cascade Impaction studies, and X-ray diffraction. The inhalable antibiotic formulations are within a respirable size range (1–5 μm), and have less than 3% residual moisture. Unit-dose dry powder antibiotics have the potential to provide easy-to-use, stable products with improved safety profiles.  相似文献   
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