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991.
Greenhouse gas emissions from international maritime transport are exempt from liabilities under the Kyoto Protocol. Research into quantifying these emissions is ongoing, and influences policy proposals to reduce emissions. This paper presents a cargo-based analysis of fuel consumption and greenhouse gas emissions from New Zealand's international maritime transport of goods. Maritime transport moves 99.5% (by mass) of New Zealand's internationally traded products. It is estimated that 73% of visiting vessels' activity can be directly attributed to the movement of goods in and out of New Zealand. A cargo-based methodology was used to estimate that the international maritime transport of New Zealand's imports and exports consumed 2.5 million tonnes (Mt; 2.6 billion litres) of fuel during the year 2007, which generated 7.7 Mt of carbon dioxide (CO2) emissions. Double-counting of emissions would occur if a similar method was applied to all New Zealand's trading partners. In contrast, since few large vessels refuel in New Zealand, the National Greenhouse Gas Inventory listed 2007 international maritime transportation emissions as 0.98 Mt of CO2, calculated from fuel bunkered for international transport. The results, therefore, show a significant difference between activity-based and bunker-fuel methodologies in quantifying New Zealand's emissions. International policy implications are discussed.  相似文献   
992.
This paper critically assesses the geopolitical and geo-economic impact of novel fuel resources on both resource exporters and importers. Presently, very strong political and economic forces drive the utilisation of domestic, unconventional oil and gas recovery in the West as these enhance energy security and ease balance of payment issues. The additional capacity generated by this trend has, supported by other effects such as Saudi Arabia’s decision to maintain current production, triggered a significant reduction of oil prices. Consequently, it is now oil exporters that struggle with the balance of payment issues and often these countries base their fiscal budget completely on fossil fuel revenues. In fact, these unconventional resources help turn the tide while oil exporters are now politically significantly weakened due to the increased energy sufficiency of the West. The catch is that the extraction of unconventional types of oil has many environmental implications. So, internalising the environmental externalities have to be considered. This paper, therefore, assesses, next to geopolitics and geo-economics, the environmental implications of this trend.  相似文献   
993.
Throughout the world, infrastructure to support cities is critical to support sustainable and responsible economic development. This can include new infrastructure projects in the case of growing areas. It can also include the renewal and upgrading of existing infrastructure in areas that have been inhabited and already developed. Infrastructure includes roads, bridges and transportation systems; power grids and energy service; internet and telecommunications; and water and sewer services. This development can be part of a system of systems, in which government, industries, and universities can contribute knowledge, skills, and abilities. This paper will investigate the strategic project management taken by one university to provide an academic experience that will prepare engineering students to address several of the Grand Engineering Challenges of the 21st Century, as identified by the US National Academy of Engineering. The challenges relating to energy, water, information, and urban infrastructure can be approached using the functions of teaching, research, and service. By approaching the challenges strategically, resources of faculty time, student effort and laboratory facilities can be leveraged to achieve greater results. This case study will describe the efforts and results to date and identify opportunities for future growth.  相似文献   
994.
ABSTRACT:  Four different catfish oil extraction processes were used to extract oil from catfish viscera: process CF1 involved a mixture of ground catfish viscera and water, no heat treatment, and centrifugation; process CF2 involved ground catfish viscera (no added water), heat treatment, and centrifugation; process CF3 involved a mixture of ground catfish viscera and water, heat treatment, and centrifugation; process CF4 involved ground catfish viscera, enzymatic hydrolysis, and centrifugation. Chemical and physical properties of the resulting of catfish oils were evaluated. The CF4 process recovered significantly higher amounts of crude oil from catfish viscera than the other 3 extraction methods. The CF4 oil contained a higher percent of free fatty acid and peroxide values than CF1, CF2, and CF3 oils. Oleic acid in catfish oil was the predominant fatty acid accounting for about 50% of total fatty acids. Weight loss of oils increased with increasing temperatures between 250 and 500 °C. All the catfish oil samples melted around −32 °C regardless of the extraction methods. The flow behavior index of all the oil samples was less than 1, which indicated that the catfish oils exhibited non-Newtonian fluid behavior. The apparent viscosity at −5 and 0 °C was significantly higher ( P  < 0.05) than those at 5, 10, 15, 20, 25, and 30 °C. The average magnitude of activation energy for apparent viscosity of the oil was higher for CF2 than CF1, CF3, and CF4.  相似文献   
995.
The quantum state of the photon pair generated from type-II spontaneous parametric downconversion pumped by an ultrafast laser pulse exhibits strong decoherence in its polarization entanglement, an effect which can be attributed to the clock effect of the pump pulse or, equivalently, to distinguishing spectral information in the two-photon state. Here, we propose novel temporal and spectral engineering techniques to eliminate these detrimental decoherence effects. The temporal engineering of the two-photon wavefunction results in a universal Bell-state synthesizer that is independent of the choice of pump source, crystal parameters, wavelengths of the interacting photons and the bandwidth of the spectral filter. In the spectral engineering technique, the distinguishing spectral features of the two-photon state are eliminated through modifications to the two-photon source. In addition, spectral engineering also provides a means for the generation of polarization-entangled states with novel spectral characteristics: the frequency-correlated state and the frequency-uncorrelated state.  相似文献   
996.
We present a modelling approach for quantifying the value of information in supply chains using Markov decision processes (MDP). The case where information sharing occurs is modelled using a completely observable MDP. A restricted observation MDP is used to model the case where no information sharing occurs. We illustrate the use of this framework on a two-stage capacity-constrained supply chain consisting of a supplier and a retailer. We quantify the value of information sharing in this setting and construct several performance measures to identify the benefits to both the retailer and supplier as a result of the information sharing partnership.  相似文献   
997.
Biodiversity information obtained during environmental impact assessments (EIAs) is rarely accessible for other uses following the completion of the EIA. Such data need to be made readily accessible; adding them to publicly accessible national datasets is important if biodiversity science, conservation and future decisions based on environmental assessment are to benefit from new biodiversity data and improved biodiversity data coverage. An ‘EIA Biodiversity Data Publishing Framework’, based on the Global Biodiversity Information Facility (GBIF) global standards, is thus proposed to meet this need. This paper outlines the GBIF-catalysed initiative to establish such an operational framework for uptake by the EIA community, as well as options that are available for data publishing in the absence of such a framework. It reviews the current state of accessibility and management of the primary biodiversity data associated with EIA studies, and highlights the urgent need for uptake of a range of data-publishing tools and best practices for making EIA biodiversity data exchangeable using globally accepted standards. Lessons learnt from pilot projects in India and South Africa underline the call for the rapid uptake of a national-to-global scale EIA Biodiversity Data Publishing Framework.  相似文献   
998.
A series of Rh catalysts on various supports (Al2O3, MgAl2O4, ZrO2, and ZrO2–CeO2) have been applied to H2 production from the ethanol steam reforming reaction. In terms of ethanol conversion at low temperatures (below 450 °C) with 1wt% Rh catalysts, the activity decreases in the order: Rh/ZrO2–CeO2 > Rh/Al2O3 > Rh/MgAl2O4 > Rh/ZrO2. Support plays a very important role on product selectivity at low temperatures (below 450 °C). Acidic or basic supports favor ethanol dehydration, while ethanol dehydrogenation is favored over neutral supports at low temperatures. The Rh/ZrO2–CeO2 catalyst exhibits the highest CO2 selectivity up to 550 °C, which is due to the highest water gas shift (WGS) activity at low temperatures. Among the catalysts evaluated in this study, the 2wt% Rh/ZrO2–CeO2 catalyst exhibited the highest H2 yield at 450 °C, which is possibly due to the high oxygen storage capacity of ZrO2–CeO2 resulting in efficient transfer of mobile oxygen species from the H2O molecule to the reaction intermediate.  相似文献   
999.
The thermal conductivity of insulating polymers can be increased by the addition of conductive fillers. One potential market for these thermally conductive resins is for fuel cell bipolar plates. In this study, various amounts of three different carbon fillers (carbon black, synthetic graphite particles, and carbon fiber) were added to Vectra A950RX liquid crystal polymer. Because the resulting composites were anisotropic, they were tested for both through‐plane and in‐plane thermal conductivities. The effects of single fillers and combinations of the different fillers were studied via a factorial design. Each single filler caused a statistically significant increase in composite through‐plane and in‐plane thermal conductivities at the 95% confidence level, with synthetic graphite causing the largest increase. All of the composites containing combinations of the different fillers caused statistically significant increases in the composite through‐plane and in‐plane thermal conductivities. It is possible that thermally conductive pathways were formed that linked these carbon fillers, which resulted in increased composite thermal conductivity. Composites containing 70, 75, and 80 wt % synthetic graphite and the composite containing all three fillers (2.5 wt % carbon black, 65 wt % synthetic graphite, and 5 wt % carbon fiber) had in‐plane thermal conductivities of 20 W m?1 K?1 or higher, which is desirable for bipolar plates. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008  相似文献   
1000.
Helicobacter pylori is a highly persistent and common pathogen in humans. It is the causative agent of chronic gastritis and its further stages. HP0826 is the beta-1,4-galactosyltransferase involved in the biosynthesis of the LPS O-chain backbone of H. pylori. Though it was first cloned nearly a decade ago, there are surprisingly limited data about the characteristics of HP0826, especially given its prominent role in H. pylori pathogenicity. We here demonstrate that HP0826 is a highly efficient and promiscuous biocatalyst. We have exploited two novel enzymatic activities for the quantitative synthesis of the thiodisaccharide Gal-beta-S-1,4-GlcNAc-pNP as well as Gal-beta-1,4-Man-pNP. We further show that Neisseria meningitidis beta-1,4-galactosyltransferases LgtB can be used as an equally efficient catalyst in the latter reaction. Thiodisaccharides have been extensively used in structural biology but can also have therapeutic uses. The Gal-beta-1,4-Man linkage is found in the Leishmania species LPG backbone disaccharide repeats and cap, which have been associated with vector binding in Leishmaniasis.  相似文献   
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