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101.
Anirban Chowdhury Samantha O'Callaghan Thomas A. Skidmore Craig James Steven J. Milne 《Journal of the American Ceramic Society》2009,92(3):758-761
A Pechini-based chemical synthesis route was used to produce powders of Na0.5 K0.5 NbO3 (NKN). The thermochemistry of the gel was investigated using thermogravimetric analysis-fourier transform infrared (TGA-FTIR) evolved gas analysis; in addition, powder FTIR was used to analyze the gel residues after different heat treatments. The final decomposition of the organic components occurred at ∼650°C. However, hydrated–carbonated secondary phase(s) were detected by FTIR in powders that had been heated at 700°C, indicating that the NKN nanopowders are susceptible to a reaction with atmospheric moisture and carbon dioxide. The NKN particle sizes were in the range 50–150 nm after decomposition at 700°C. 相似文献
102.
Rothbaum Barbara Olasov; Hodges Larry; Smith Samantha; Lee Jeong Hwan; Price Larry 《Canadian Metallurgical Quarterly》2000,68(6):1020
Fear of flying (FOF) affects an estimated 10–25% of the population. Patients with FOF (N?=?49) were randomly assigned to virtual reality exposure (VRE) therapy, standard exposure (SE) therapy, or a wait-list (WL) control. Treatment consisted of 8 sessions over 6 weeks, with 4 sessions of anxiety management training followed by either exposure to a virtual airplane (VRE) or exposure to an actual airplane at the airport (SE). A posttreatment flight on a commercial airline measured participants' willingness to fly and anxiety during flight immediately after treatment. The results indicated that VRE and SE were both superior to WL, with no differences between VRE and SE. The gains observed in treatment were maintained at a 6-month follow up. By 6 months posttreatment, 93% of VRE participants and 93% of SE participants had flown. VRE therapy and SE therapy for treatment of FOF were unequivocally supported in this controlled study. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
103.
104.
Samantha L. Walker Michail Fourgialakis Belen Cerezo Stephen Livens 《Journal of the Institute of Brewing》2007,113(1):61-66
Microbial biofilms can form in dispense outlets as a result of poor or inadequate cleaning and can be difficult to remove using conventional practices. Enzymatic cleaners might help to remove biofilms by degrading the exopolysaccharide layers in which the microbes are embedded. A multispecies biofilm comprising wild type dispense isolates of Flavimonas oryzihabitans, Lactobacillus brevis, Leuconostoc mesenteroides and Saccharomyces cerevisiae was generated on a section of tubing and fitted into a pilot dispense system, which was left uncleaned for 12 weeks. After cleaning approximately 104 viable aerobes and 103 viable anaerobes were still present. Stainless steel coupons and pieces of dispense line contaminated with biofilm were incubated in the laboratory with an enzyme mix containing varying proportions of α‐amylase, β‐glucuronidase, glucose oxidase, dextranase, protease and pectinase. Cultures grown on stainless steel had significantly (F pr. > 0.05) less viable cells than non‐enzyme treated biofilms, but this was dependent on the microbial species. Typically Lactobacillus brevis was most susceptible to the enzyme treatment. Cultures grown on dispense line were much more resistant to enzymatic digestion. Pre‐digestion with protease was most effective for removal of Lactobacillus brevis and Leuconostoc mesenteroides but not for Saccharomyces cerevisiae and Flavimonas oryzihabitans. In the simulated bar, pre‐digestion with protease reduced the viable cell count by 0.64 log units for the aerobes and 1.9 log units for the anaerobes. This study demonstrates that pre‐digestion with enzyme solutions before line cleaning is useful for treating heavily contaminated lines in trade. 相似文献
105.
Samantha A. Whiteside Mahi M. Mohiuddin Sargon Shlimon Jaspreet Chahal Chad W. MacPherson Jana Jass Thomas A. Tompkins Carole Creuzenet 《International journal of molecular sciences》2021,22(11)
Helicobacter pylori is a prevalent bacterium that can cause gastric ulcers and cancers. Lactic acid bacteria (LAB) ameliorate treatment outcomes against H. pylori, suggesting that they could be a source of bioactive molecules usable as alternatives to current antibiotics for which resistance is mounting. We developed an in vitro framework to compare the anti-H. pylori properties of 25 LAB and their secretions against H. pylori. All studies were done at acidic and neutralized pH, with or without urea to mimic various gastric compartments. Eighteen LAB strains secreted molecules that curtailed the growth of H. pylori and the activity was urea-resistant in five LAB. Several LAB supernatants also reduced the urease activity of H. pylori. Pre-treatment of H. pylori with acidic LAB supernatants abrogated its flagella-mediated motility and decreased its ability to elicit pro-inflammatory IL-8 cytokine from human gastric cells, without reverting the H. pylori-induced repression of other pro-inflammatory cytokines. This study identified the LAB that have the most anti-H. pylori effects, decreasing its viability, its production of virulence factors, its motility and/or its ability to elicit pro-inflammatory IL-8 from gastric cells. Once identified, these molecules can be used as alternatives or complements to current antibiotics to fight H. pylori infections. 相似文献
106.
Warker Jill A.; Dell Gary S.; Whalen Christine A.; Gereg Samantha 《Canadian Metallurgical Quarterly》2008,34(5):1289
Adults can learn new artificial phonotactic constraints by producing syllables that exhibit the constraints. The experiments presented here tested the limits of phonotactic learning in production using speech errors as an implicit measure of learning. Experiment 1 tested a constraint in which the placement of a consonant as an onset or coda depended on the identity of a nonadjacent consonant. Participant speech errors reflected knowledge of the constraint but not until the 2nd day of testing. Experiment 2 tested a constraint in which consonant placement depended on an extralinguistic factor, the speech rate. Participants were not able to learn this constraint. Together, these experiments suggest that phonotactic-like constraints are acquired when mutually constraining elements reside within the phonological system. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
107.
Maryjane Tremayne Samantha Y. Chong Duncan Bell 《Frontiers of Computer Science in China》2009,3(1):101-108
Evolutionary search and optimisation algorithms have been used successfully in many areas of materials science and chemistry.
In recent years, these techniques have been applied to, and revolutionised the study of crystal structures from powder diffraction
data. In this paper we present the application of a hybrid global optimisation technique, cultural differential evolution
(CDE), to crystal structure determination from powder diffraction data. The combination of the principles of social evolution
and biological evolution, through the pruning of the parameter search space shows significant improvement in the efficiency
of the calculations over traditional dictates of biological evolution alone. Results are presented in which a range of algorithm
control parameters, i.e., population size, mutation and recombination rates, extent of culture-based pruning are used to assess
the performance of this hybrid technique. The effects of these control parameters on the speed and efficiency of the optimisation
calculations are discussed, and the potential advantages of the CDE approach demonstrated through an average 40% improvement
in terms of speed of convergence of the calculations presented, and a maximum gain of 68% with larger population size. 相似文献
108.
109.
Potential applicability of CNT and CNT/composites to implement ASEC concept: A review article 总被引:3,自引:0,他引:3
Samantha Wijewardane 《Solar Energy》2009,83(8):1379-2756
It is believed that the successful implementation of the Antenna Solar Energy Conversion (ASEC) to the commercial level would revolutionize the solar energy utilization. Screening suitable materials and technologies by analyzing potential pros and cones all the way to commercial level would conserve much time and resources. Here carbon nanotube (CNT) known as the material of the 21st century is evaluated concerning many aspects to implement ASEC concept. Thermomechanical and electrical properties of CNT as regards to ASEC, interaction of CNT and CNT arrays with optical spectrum and existing and future CNT technologies that have the potential to overcome possible future obstacles are discussed. The economic aspects which govern the future of ASEC concept, with CNT as a basic material are also discussed. 相似文献
110.
Gillham Jane E.; Reivich Karen J.; Freres Derek R.; Chaplin Tara M.; Shatté Andrew J.; Samuels Barbra; Elkon Andrea G. L.; Litzinger Samantha; Lascher Marisa; Gallop Robert; Seligman Martin E. P. 《Canadian Metallurgical Quarterly》2007,75(1):9
The authors investigated the effectiveness and specificity of the Penn Resiliency Program (PRP; J. E. Gillham, L. H. Jaycox, K. J. Reivich, M. E. P. Seligman, & T. Silver, 1990), a cognitive-behavioral depression prevention program. Children (N = 697) from 3 middle schools were randomly assigned to PRP, Control (CON), or the Penn Enhancement Program (PEP; K. J. Reivich, 1996; A. J. Shatté, 1997), an alternate intervention that controls for nonspecific intervention ingredients. Children's depressive symptoms were assessed through 3 years of follow-up. There was no intervention effect on average levels of depressive symptoms in the full sample. Findings varied by school. In 2 schools, PRP significantly reduced depressive symptoms across the follow-up relative to both CON and PEP. In the 3rd school, PRP did not prevent depressive symptoms. The authors discuss the findings in relation to previous research on PRP and the dissemination of prevention programs. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献