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151.
This study examined the basic literacy skills and related processes of 1st- through 4th-grade children speaking English as a 1st language (L1) and English as a 2nd language (ESL). The performances of the L1 and ESL children on phonological awareness, word and pseudoword reading, and word and pseudoword spelling tasks were highly similar. The ESL children were at an advantage with regard to lexical access but performed more poorly on verbal working memory and syntactic awareness tasks. The results suggest that the main processes underlying L1 children's basic reading ability in Grades 1 and 2, namely phonological awareness and lexical access, are of equal importance for ESL children. Phonological awareness remained the strongest predictor of word reading ability for L1 and ESL children in Grades 3 and 4. However, the processes involved in L1 and ESL word reading and spelling appeared to vary at other points. Verbal working memory and syntactic awareness were found to be of importance for the word reading and spelling abilities of L1 children but not for ESL children. Lexical access was found to be of more importance for ESL children. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
152.
□ Small milling tools for dental application were diamond coated by means of Hot Filament CVD (HFCVD). Different thicknesses were obtained by using different diamond deposition times (3 and 12 h) and seeding conditions. The surface roughness was measured for coated and uncoated mills and milling tests were performed to measure the cutting forces. A ceramic material and a polymeric matrix composite (PMC) were used as workpiece materials. The highest cutting forces were measured for the coated tool with the highest thickness of the diamond coating. Probably, roughness increase and non-optimal edge profiles affect the tool behavior during cutting. As a consequence, tool failure was observed in the case of milling of ceramic by means of the coated tool with the highest coating thickness. The coated tool with a lower thickness of the diamond coating showed an optimal behavior under cutting, above all in the case of PMC milling. 相似文献
153.
W. Polini S. Turchetta 《The International Journal of Advanced Manufacturing Technology》2007,35(5-6):454-467
The application of sensor systems is becoming more commonplace in improving productivity, automation, and reliability. The
sensors employed in such systems possess signal and information ability for enhancing the monitoring and control of machining
processes. Although measuring force and acceleration signals have been commonly used for the monitoring of metal machining
processes, their application to stone cutting has not been well developed, which is perhaps due to the complexity of the interaction
between the stone and the diamond disk. In order to enhance knowledge in this area of applications, a multi-sensor system
was developed and installed for the monitoring of stone cutting by diamond mill. The signals acquired and analysed by the
system include force and acceleration under different machining conditions. The measured signal data was used to perform time-domain
analysis. The results indicate the feasibility of using the RMS features of force or acceleration signals along z-axis for the monitoring of disk wear. 相似文献
154.
Claudio Gennaro Rita Lenzi Federica Mandreoli Riccardo Martoglia Matteo Mordacchini Wilma Penzo Simona Sassatelli 《Information Systems》2011
In recent years, the emerging diffusion of peer-to-peer networks is going beyond the single-domain paradigm like, for instance, the mono-thematic file sharing one (e.g. Napster for music). Peers are more and more heterogeneous data sources which need to share data with commercial, educational, and/or collaboration purposes, just to mention a few. Moreover, in current information processing applications data cannot be meaningfully searched by precise database queries that would return exact matches (e.g. when dealing with multimedia, proteomic, statistical data). 相似文献
155.
156.
Influence of nanoclay‐carbon black hybrid fillers on cure and properties of natural rubber compounds
Janak Sapkota Minna Poikelispää Amit Das Wilma Dierkes Jyrki Vuorinen 《Polymer Engineering and Science》2013,53(3):615-622
The influence of organically modified nanoclay‐carbon black (CB) hybrid filler on the curing behavior of natural rubber (NR) was explored in this investigation. Here an effort was paid to understand the curing kinetics of organomodified nanoclay filled rubber compounds. On the basis of two different types of modified clay, NR nanocomposites were prepared and cured by a conventional vulcanization system. A faster curing rate and lower torque values were found when the modification was done by quaternary ammonium compounds. The activation energy of the rubber curing process decreased with the incorporation of nanoclay. In addition, it was revealed that the quaternary ammonium compounds used as modifier in the clay show a plasticization effect. Additionally, X‐ray diffraction studies indicated, that the basal spacing of the clay minerals was increased in both cases after incorporation in the rubber matrix. The dynamic mechanical analysis using a strain sweep mode showed that the Payne effect decreases because of an improved dispersion of CB induced by the presence of nanoclay. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers 相似文献
157.
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159.
Era Tuladhar Wilma C. Hazeleger Marion Koopmans Marcel H. Zwietering Erwin Duizer Rijkelt R. Beumer 《International journal of food microbiology》2013
Human norovirus (NoV) contaminated hands are important routes for transmission. Quantitative data on transfer during contact with surfaces and food are scarce but necessary for a quantitative risk assessment. Therefore, transfer of MNV1 and human NoVs GI.4 and GII.4 was studied by artificially contaminating human finger pads, followed by pressing on stainless steel and Trespa® surfaces and also on whole tomatoes and cucumber slices. In addition, clean finger pads were pressed on artificially contaminated stainless steel and Trespa® surfaces. The transfers were performed at a pressure of 0.8–1.9 kg/cm2 for approximately 2 s up to 7 sequential transfers either to carriers or to food products. MNV1 infectivity transfer from finger pads to stainless steel ranged from 13 ± 16% on the first to 0.003 ± 0.009% on the sixth transfer on immediate transfer. After 10 min of drying, transfer was reduced to 0.1 ± 0.2% on the first transfer to 0.013 ± 0.023% on the fifth transfer. MNV1 infectivity transfer from stainless steel and Trespa® to finger pads after 40 min of drying was 2.0 ± 2.0% and 4.0 ± 5.0% respectively. MNV1 infectivity was transferred 7 ± 8% to cucumber slices and 0.3 ± 0.5% to tomatoes after 10 min of drying, where the higher transfer to cucumber was probably due to the higher moisture content of the cucumber slices. Similar results were found for NoVs GI.4 and GII.4 transfers measured in PCR units. The results indicate that transfer of the virus is possible even after the virus is dried on the surface of hands or carriers. Furthermore, the role of fingers in transmission of NoVs was quantified and these data can be useful in risk assessment models and to establish target levels for efficacy of transmission intervention methods. 相似文献
160.
Giancarlo Fortino Carlo Mastroianni Wilma Russo 《Journal of Network and Computer Applications》2009,32(1):135-157
Content distribution networks have recently been introduced as a more efficient alternative to centralized servers for the delivery of static content as well as media streaming services ranging from TV broadcasts to video on-demand. Content Distribution Networks can also efficiently provide collaborative playback service, which allows a synchronous group of users to select, simultaneously watch altogether and share the control of a multimedia session. This paper presents the definition and analysis of the Hierarchical Cooperative Control Protocol (HCOCOP), which allows a synchronous group of users to share the control of the media streaming session provided by a Content Distribution Network. The analysis phase, which was supported by discrete-event simulation, was carried out to characterize the efficiency of the protocol on the basis of the following defined performance indices: blocking probability, denial probability, server load and network load. The performances obtained for architectures based on Content Distribution Networks are compared with those obtained for centralized architectures providing collaborative playbacks. The comparison shows that HCOCOP significantly improves performance of media streaming control. 相似文献