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81.
82.
This paper analyses the scientific output and impact of 731 Ph.D. holders who were awarded their doctorate at Spanish universities between 1990 and 2002. The aim was to identify any differences in the amount of scientific output and the impact of publications, in terms of citations, according to gender. The analysis revealed no significant differences in the amount of scientific output between males and females. However, the proportion of female Ph.D. holders with no postdoctoral output was significantly higher than that of their male counterparts, and the median number of papers published after Ph.D. completion was also lower among women. As regards pre- and postdoctoral research, the data showed that early scientific output may be a good predictor of subsequent productivity in both gender groups. The results also indicated that articles by female Ph.D. holders were cited significantly more often, even when self-citations were excluded. 相似文献
83.
Valdir Ribeiro Campos Rebeca de Souza e Silva Sérgio Duailibi José Florentino dos Santos Ronaldo Laranjeira Ilana Pinsky 《Accident; analysis and prevention》2013
Objective
To present data on drinking and driving in the city of São Paulo, Brazil, and the effects of the new traffic law (Law 11,705) introduced in 2008.Methods
A cross-sectional study was performed using a questionnaire and passive breath test data to study the prevalence of drinking and driving and the association of drinking and driving with background characteristics and drinking patterns on two separate occasions. The data were gathered from 2007 to 2009 through roadside surveys conducted on busy public roads. Four thousand two-hundred thirty-four (4234) drivers were approached, before and after prohibition, from the south, north, east, and west regions of the city of São Paulo, located in southeastern Brazil, including cars, motorcycles, and utility vehicles. A total of 3854 (91%) consented to participate in the survey and answered the questionnaire. Out of this group, 3229 (84%) agreed to take the passive breathalyzer test.Results
Logistic regression analyses controlling for gender and age was used to predict a positive breath test (above 0.2 g/l) and the impact of the new law. These analyses indicated that, after the passage of the new traffic law, there was a 45% decrease in driver behavior with positive breathalyzer results. Having a pattern of alcohol consumption of at least once a week and the habit of drinking and driving are risks for a positive breathalyzer.Conclusions
Despite the decline in the frequency of motorists driving under the influence of alcohol, traffic-related injuries and deaths, after the new law, other measures for a public policy related to alcohol should be considered based on scientific evidence, consistency of action, clear goals, community support, and greater reliability in the laws. 相似文献84.
F González-Cebrino J García-Parra R Contador R Tabla R Ramírez 《Journal of food science》2012,77(8):C866-C873
The application of hydrostatic high pressure on a "Songold" plum purée was assessed in comparison with heat pasteurization. To simulate industrial conditions, one-half of the total purée was manufactured with a pretreatment of thermal blanching (TB) and the other half without it (nonthermally blanched, NTB). Changes after thermal treatment and high-pressure processing (HPP: 400, 600 MPa) and after 20 d of refrigerated storage were evaluated. HPP maintained the microbial stability of the purées until the end of the storage period. Polyphenol oxidase activity was lower in TB purées than NTB purées. No treatment was completely effective to stop the enzyme activity, although a significant reduction was reached. Thermally treated purées showed more intense color changes after processing and storage than HP-treated purées. After processing, high-pressure (HP) purées treated at 600 MPa (TB and NTB) increased the extractability of carotenoids compared with initial untreated purée. Nevertheless, at the end of the storage, the highest carotenoid content was found in the TB purée treated at 400 MPa. After processing, total polyphenol levels were similar in all purées. TB and 600 MPa processing was more effective in the maintenance of the polyphenols than the other purées. TB increased the level of antioxidants after storage, compared to NTB purées. A previous TB step is necessary to inactivate browning enzymes before HPP to maintain the levels of bioactive compounds. HPP of plum purée could be a suitable alternative to traditional thermal processing, but more studies are necessary to ensure a major inactivation of polyphenol oxidase. Practical Application: High-pressure processing is one of the most successful technologies to obtain high-quality fruit purées without appreciable losses in taste, flavor, color, and nutritive value. However, for the introduction of a new technology, some advantages compared to the traditional thermal treatment need to be emphasized. The application of this technology could be reduced due to resistance of certain enzymes to pressurization. For this reason, in some cases the application of a previous thermal blanching can be necessary at industrial level. However, this can reduce the advantages of HPP application. This paper provides interesting information about the storage stability of plum purées after high-pressure treatments and assesses the need for applying heat pretreatments. 相似文献
85.
Rebeca Herrero Marta Victoria Csar Domínguez Stephen Askins Ignacio Antn Gabriel Sala 《Progress in Photovoltaics: Research and Applications》2012,20(4):423-430
This paper proposes an indoor procedure based on charge‐coupled device camera measurements to characterize the non‐uniform light patterns produced by optical systems used in concentration photovoltaic (CPV) systems. These irradiance patterns are reproduced on CPV solar cells for their characterization at concentrated irradiances by using a concentrator cell tester and placing high‐resolution masks over the cells. Measured losses based on the masks method are compared with losses in concentrator optical systems measured by using the Helios 3198 solar simulator for CPV modules. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
86.
Rebeca Fernandez-Orozco Mariusz K. Piskula Henryk Zielinski Halina Kozlowska Juana Frias Concepción Vidal-Valverde 《European Food Research and Technology》2006,223(4):495-502
Antioxidant capacity, measured by glutathione (GSH), superoxide dismutase-like activity (SOD-like activity), peroxyl radical-trapping capacity (PRTC), trolox equivalent antioxidant capacity (TEAC) and inhibition of lipid peroxidation in unilamellar liposomes of egg yolk phosphatidylcholine (PC) has been evaluated in raw and germinated lupin seeds (Lupinus angustifolius L. var. Zapaton) for 2, 3, 4, 5, 6 and 9 days. The content of antioxidant vitamins E and C has been also studied. The tripeptide GSH kept invariable for the first 5 days of germination and suffered a decrease of 20 and 78% after 6 and 9 days, respectively. During lupin germination, SOD-like activity increased slightly whilst PRTC doubled the amount after 9 days. TEAC values changed slightly up to 5 days of germination but after 6 and 9 days a significant increase (25 and 28%, respectively) was found. The oxidation of PC was inhibited by germinated lupin extracts and 9-day germination seeds provided the highest inhibition. Furthermore, germinated lupins provided more vitamin C, vitamin E activity and polyphenols than raw seeds, and the largest amounts of these bioactive compounds were found after 6 days of germination. Therefore, germination of lupin seeds (Lupinus angustifolius L. var. Zapaton) seems to be a good process to enhance their antioxidant capacity. 相似文献
87.
Graphene quantum dots derived from carbon fibers 总被引:2,自引:0,他引:2
Peng J Gao W Gupta BK Liu Z Romero-Aburto R Ge L Song L Alemany LB Zhan X Gao G Vithayathil SA Kaipparettu BA Marti AA Hayashi T Zhu JJ Ajayan PM 《Nano letters》2012,12(2):844-849
Graphene quantum dots (GQDs), which are edge-bound nanometer-size graphene pieces, have fascinating optical and electronic properties. These have been synthesized either by nanolithography or from starting materials such as graphene oxide (GO) by the chemical breakdown of their extended planar structure, both of which are multistep tedious processes. Here, we report that during the acid treatment and chemical exfoliation of traditional pitch-based carbon fibers, that are both cheap and commercially available, the stacked graphitic submicrometer domains of the fibers are easily broken down, leading to the creation of GQDs with different size distribution in scalable amounts. The as-produced GQDs, in the size range of 1-4 nm, show two-dimensional morphology, most of which present zigzag edge structure, and are 1-3 atomic layers thick. The photoluminescence of the GQDs can be tailored through varying the size of the GQDs by changing process parameters. Due to the luminescence stability, nanosecond lifetime, biocompatibility, low toxicity, and high water solubility, these GQDs are demonstrated to be excellent probes for high contrast bioimaging and biosensing applications. 相似文献
88.
Martín Lpez-Nores Jorge García-Duque Jos J. Pazos-Arias Yolanda Blanco-Fernndez Manuel Ramos-Cabrer Alberto Gil-Solla Rebeca P. Díaz-Redondo Ana Fernndez-Vilas 《Journal of Network and Computer Applications》2009,32(6):1194-1209
This paper explores the idea of managing mobile ad-hoc networks (MANETs) by the communication needs of their nodes, as a means to facilitate the operation of distributed applications. Specifically, we present a middleware layer that enables reasoning about the multiple possibilities there may exist to ensure satisfiability of certain communication needs. This middleware has been explicitly devised to handle partial and changeable knowledge about the networks, and to guide the search for missing information whenever it cannot conclude whether it will be possible to satisfy some needs. These features provide the basis to implement policies with which to coordinate activities in a MANET, in quest for the configuration that best satisfies the communication needs of its nodes. We provide simulation results to show the comparative advantages of our solution, plus a report of experiments to assess its practicality and usability. 相似文献
89.
Jos J. Pazos‐Arias Martín Lpez‐Nores Jorge García‐Duque Alberto Gil‐Solla Manuel Ramos‐Cabrer Yolanda Blanco‐Fernndez Rebeca P. Díaz‐Redondo Ana Fernndez‐Vilas 《Software》2006,36(8):845-869
The increasing need of the developed countries to carry out effective distance learning strategies has led to a great development of Internet‐based learning technologies (e‐learning). Despite its evident advantages, the expansion of e‐learning has been limited by the difficulty in reaching important social sectors, and also by the absence of mechanisms to fight the feeling of isolation of the users, which often leads them to abandoning the distance learning activities. This paper tackles these problems by introducing ATLAS, a framework for the development and deployment of multiuser t‐learning services (i.e. learning services over Interactive Digital TV). This framework is built around three major features: an architecture for the services that exploits the multimedia capabilities of the television, a communications infrastructure that promotes the establishment of virtual learning communities, and a development tool that allows services to be created with minimum programming knowledge. ATLAS has been designed by considering several features that make Interactive Digital TV quite different from the PC, advising against the direct translation of the models developed for the Internet. In particular, ATLAS adheres to the Multimedia Home Platform (MHP) standard, which is gaining worldwide acceptance as one of the technical solutions that will shape the future of Interactive Digital TV. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
90.
Rebeca Fernandez‐Orozco Henryk Zieliski Mariusz K. Piskua 《Molecular nutrition & food research》2003,47(5):291-299
In this study four cultivars of lentil originating from Spain were examined: cv Paula, cv Agueda, cv Almar and cv Alcor. Since consumption of these seeds after heat treatment and as sprouts has been popularised, the impact of cooking (up to 30 min) and germination process (in dark, at 25°C, for up to 4 days) on peroxyl radical‐trapping capacity (PRTC) and Trolox‐equivalent antioxidant capacity (TEAC) of the processed seeds was addressed. Also, changes in the content of low‐molecular‐weight antioxidants (LMWA) and soluble proteins in the course of cooking and germination were studied. The analyzed LMWA were: total phenolics, tocopherols (α‐T, β‐T, γ‐T, δ‐T( reduced glutathione, and L ‐ascorbic acid. On the basis of the results obtained, the contribution of LMWA and soluble proteins to the PRTC and TEAC of raw, cooked, and germinated lentil seeds was calculated by multiple mean values for the content of investigated compounds and their relative potential with respect to Trolox. The results showed a very high molar percentage contribution of phenolic compounds and low contribution of tocopherols, glutathione, soluble proteins, and ascorbate (only in germinated seeds) to the total TEAC and total PRTC calculated as a sum of data provided for phosphate‐buffered and 80% methanolic extracts of raw and processed lentil seeds. 相似文献