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排序方式: 共有590条查询结果,搜索用时 15 毫秒
191.
Rashid Masood Khan Waseem Iqbal Muhammad Faisal Amjad Haider Abbas Hammad Afzal Abdul Rauf Maruf Pasha 《The Journal of supercomputing》2018,74(10):5060-5081
Recent years have seen tremendous increase in crime and terrorism all over the world which has necessitated continuous surveillance of public spaces, commercial entities and residential areas. CCTV cameras are an integral part of any modern surveillance system and have evolved significantly. They are a vital part of any investigation that follows a criminal or terrorism incident by providing invaluable evidence. In this paper, we show that the Advance Systems Format (ASF) file used in most IP cameras, which is also the main file containing metadata about the streaming packets, is vulnerable to forgery. This file is stored in plain text and any technically savvy person can forge it; therefore, a mechanism is needed to prevent it. To that end, we have gathered critical artifacts from an ASF file of IP cameras and carried out their forensic analysis. The analysis performed during this study demonstrates successful detection of forgery/tampering of evidence in IP cameras. 相似文献
192.
193.
Carry-over of Fusarium toxins (deoxynivalenol and zearalenone) from naturally contaminated wheat to pigs. 总被引:1,自引:0,他引:1
Tanja Goyarts Sven D?nicke Hana Valenta Karl-Heinz Uebersch?r 《Food Additives & Contaminants》2007,24(4):369-380
The frequent contamination of grain with the Fusarium toxins, deoxynivalenol (DON) and zearalenone (ZON), is an important issue in animal and human nutrition. However, data on the exposure of humans to these toxins through consumption of animal tissues exposed to Fusarium toxins (carry-over) are fragmentary. Therefore, residues of DON, ZON and their metabolites were determined in tissues and body fluids of pigs (female and castrated male) from a fattening trial. Pigs were fed a control (n = 6, 0.24 mg DON and 0.009 mg ZON per kg diet as fed) or a Fusarium toxin-contaminated diet (n = 12, 6.68 mg DON and 0.056 mg ZON per kg diet as fed) either ad libitum or for restrictive consumption for 12 weeks. After slaughter (96.3 +/- 11.6 kg live weight), the concentrations of DON and its metabolite, de-epoxy-DON, were measured in serum, bile, liver, kidney, musculus longissimus and back fat, while ZON and its metabolites, alpha- and beta-zearalenol (alpha-/beta-ZOL), were determined in serum, bile and liver. The mean carry-over factor of DON + de-epoxy-DON, defined as the concentration of both substances in the tissue/fluid divided by the DON concentration in the diet, for all pigs decreased from bile (0.1046 +/- 0.0653) > kidney (0.0151 +/- 0.0070) > liver (0.0057 +/- 0.0043) > serum (0.0023 +/- 0.0018) > muscle (0.0016 +/- 0.0016) > back fat (0.0002 +/- 0.0004). The time interval between the end of feeding and slaughter had no consistent effect on DON + de-epoxy-DON concentrations in the analysed specimen of Fusarium toxin-exposed pigs fed restrictively. No transfer of ZON and its metabolites could be observed into serum of pigs, while the mean carry-over factors of ZON + alpha-ZOL + beta-ZOL were 0.0094 +/- 0.0123 and 4.0 +/- 2.2 for liver and bile, respectively. Therefore, it can be concluded that serum is a reliable indicator for DON exposure, but an inappropriate parameter to deduce ZON exposure, which is better represented by bile concentration of ZON + alpha-ZOL + beta-ZOL. However, the exposure risk to humans by consumption of edible tissues of animals exposed to Fusarium toxins is negligible compared to the direct consumption of grain-based food. 相似文献
194.
195.
Hyunnho Cho Eunae Cho Hana Jung Hae Chang Yi Bomee Lee Keum Taek Hwang 《Food science and biotechnology》2014,23(4):1295-1303
The polyphenol, flavonoid, and ascorbic acid contents of sea buckthorn leaf tea extracts, along with antioxidant activities, were compared with green tea extracts under different extraction conditions. Sea buckthorn leaf tea and green tea were extracted using water (SW, GW) and ethanol at room temperature (SE, GE), respectively, and at 80°C (SWH, GWH, SEH, and GEH, respectively). GEH, GWH, SE, and SEH contained more antioxidant compounds and higher activities, and SWH, SEH, GWH, and GEH had elevated antioxidant enzyme activity levels in H2O2-treated RAW264.7 cells. Cells treated with SWH and SEH showed elevated expression of nuclear factor (erythroid-derived 2)-like 2 and maintained the cell glutathione (GSH)/glutathione disulfide (GSSG) ratio at levels similar to H2O2-untreated controls. 相似文献
196.
Hana Scepankova Carlos A. Pinto Vanessa Paula Letícia M. Estevinho Jorge A. Saraiva 《Comprehensive Reviews in Food Science and Food Safety》2021,20(6):5393-5420
Honey is a natural food of worldwide economic importance. Over the last decades, its potential for food, medical, cosmetical, and biotechnological applications has been widely explored. One of the major safety issues regarding such applications is its susceptibility to being contaminated with bacterial and fungi spores, including pathogenic ones, which may impose a hurdle to its consumption in a raw state. Another factor that makes this product particularly challenging relies on its high sugar content, which will lead to the formation of hydroxymethylfurfural (HMF) when heated (due to Maillard reactions). Moreover, honey's bioactivity is known to be affected when it goes through thermal processing due to its unstable and thermolabile components. Therefore, proper food processing methodologies are of utmost importance not only to ensure honey safety but also to provide a high-quality product with low content of HMF and preserved biological properties. As so, emerging food processing technologies have been employed to improve the safety and quality of raw honey, allowing, for example, to reduce/avoid the exposure time to high processing temperatures, with consequent impact on the formation of HMF. This review aims to gather the literature available regarding the use of conventional and emergent food processing technologies (both thermal and nonthermal food processing technologies) for honey decontamination, preservation/enhancement of honey biological activity, as well as the sensorial attributes. 相似文献
197.
This paper describes the performance of a nonstorage, continuous, solar operated absorption refrigeration cycle. The solar collectors and the refrigeration experimental unit are manufactured locally. The results presented in this paper are based on the operation of the unit when there was enough solar energy to power its generator. This amounted to 4–5 h per day during the months of August and September in Amman, Jordan. These results include the variation of both the generator and evaporator temperatures during the test periods, the performance of the unit as a function of these temperatures and available solar intensity, and the ideal performance of the unit based on the measured temperatures. The maximum ideal coefficient of performance was determined as being equal to 1.6, while the peak actual coefficient of performance was determined to be equal to 0.55. These values are very close to published values. 相似文献
198.
This paper presents the work carried out to predict the behavior of a 0.6 m Impulse turbine with fixed guide vanes with 0.6 hub-to-tip (H/T) ratio under real sea conditions. In order to predict the true performance of the actual Oscillating Water Column (OWC), the numerical technique has been fine tuned by incorporating the compressibility effect. Water surface elevation verses time history based on Pierson Moskowitz Spectra was used as the input data. Standard numerical techniques were employed to solve the non-linear behavior of the sea waves. The effect due to compressibility inside the air chamber and turbine performance under unsteady and irregular flow condition has been analyzed numerically. Considering the quasi-steady assumptions, unidirectional steady flow experimental data was used to simulate the turbine characteristics under irregular unsteady flow conditions. The results show that the performance of this type of turbine is quite stable and efficiency of air chamber and the mean conversion 相似文献
199.
Cold forming of high strength materials is accompanied by an undesirable spring-back effect and therefore the automotive industry prefers to produce components from high strength steels by hot stamping.Hot deformation and cooling in a die are applied to obtain shaped components with martensitic microstructure and high yield strength and ultimate tensile strength.This article presents new applications of this forming technology by incorporating another innovative heat treatment by the Q-P process,which improves both strength and ductility of obtained structures at the same time.Ultimate strengths over 2000 MPa with ductility above 10% can be achieved by this processing.To test microstructure development,thin sheet was hot formed and a corresponding FEM simulation was created.This processing was applied to low alloyed AHS steel with 0.42% of carbon and with an alloying strategy based on Mn,Si and Cr.Martensitic microstructure with retained austenite was obtained by this processing with a strength of around 2000 MPa and ductility of 10%. 相似文献
200.
Ahmad Abu Hammad 《Water and Environment Journal》2011,25(2):149-162
The generation of an easily adaptable method for erosion risk assessment is important for management and conservation of the available resources in developing countries. The study aims to assess the risk of soil erosion by using an integrated, easy to apply, time‐ and money‐conserving revised universal soil loss equation‐geographic information systems (RUSLE‐GIS)‐based model in the Eastern part of the Mediterranean. Although the model showed a good efficiency in predicting the annual soil loss (R2=0.68), the limited runoff–erosion data warrant the need for long‐term data to test and calibrate the model. The model showed that 24% of the watershed area has an annual soil loss exceeding the soil loss tolerance (SLT) of the area (5 Mg/ha). When all the RUSLE factors were kept constant, except the C factor, the model showed the highest soil loss potential under olive groves (20–30 Mg/ha), and the lowest under wheat and barley (5 Mg/ha). The application of proper conservation practices to these areas is thus important, i.e. reducing the number of tillage and/or time of tillage practices. 相似文献