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151.
This paper approaches the measurement of energy efficiency from a production theoretic framework and uses Data Envelopment Analysis to measure energy efficiency in the Indian manufacturing sector. Using data from the Annual Survey of Industries for the years 1998–99 through 2003–04, the study compares the energy efficiency in manufacturing across states, based on several models. The results show considerable variation in energy efficiency across states. Comparing the results across our models, we find that the relative pricing of energy does not provide the appropriate incentives for energy conservation. A second-stage regression analysis reveals that states with a larger share of manufacturing output in energy-intensive industries have lower energy efficiency. Also, higher quality labor force associates with higher energy efficiency. Finally, the power sector reforms have not yet had any significant impact on achieving energy efficiency.  相似文献   
152.
Applications of the boundary element method (BEM) and the finite element method (FEM), to the analysis of two-dimensional problems of moving cracks in creeping bodies, is the subject of this paper. In the absence of an acceptable crack growth law valid under small scale transient as well as extended steady state creep conditions, the computer simulations are carried out here for crack extension at prescribed constant speeds. It is shown here that the BEM is most effective for the analysis of transient crack growth under small scale creep conditions while the FEM appears to be best suited for the study of crack growth under conditions of extensive creep throughout most of the structure. These two methods, therefore, tend to complement each other for this class of problems. It is felt that the numerical methods presented here can, in conjunction with experiments, be very useful for the evaluation of existing crack growth laws as well as for the development of new ones.
Résumé Le sujet du mémoire est l'application de la méthode par valeurs aux limites (BEM) et de la méthode par éléments finis (FEM) à l'analyse de problèmes bidimensionnels de fissures en extension dans des composants soumis à fluage.En l'absence d'une loi d'extension de fissure qui soit applicable tant sous des conditions de fluage transitoire à petite échelle que de fluage stable généralisé, on procède aux simulations per calcul on considérant le développement d'une fissure à des vitesses constantes fixées.On montre que la méthode BEM est plus efficace pour analyser la croissance d'une fissure de fluage en régime transitoire à une petite échelle, tandis que la méthode FEM convient le mieux pour étudier la croissance d'une fissure dans des conditions de fluage s'étendant à l'ensemble du composant.Dès lors, les deux méthodes tendent à se compléter pour cette classe de problèmes. On estime que les méthodes numériques qui sont présentées ici, peuvent être très utiles, en association avec des essais, pour évaluer les lois existantes en matière de propagation de fissures, ainsi que pour en développer de nouvelles.
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153.
154.
Inhibition of the angiotensin-converting enzyme (ACE) in the setting of chronic left ventricular (LV) dysfunction has been demonstrated to have beneficial effects on survival and symptoms. However, whether ACE inhibition has direct effects on myocyte contractile processes and if these effects are mediated primarily through the AT1 angiotensin-II receptor subtype remains unclear. The present project examined the relationship between changes in LV and myocyte function and beta adrenergic receptor transduction in four groups of six dogs each: (1) Rapid Pace: LV failure induced by chronic rapid pacing (4 weeks; 216 +/- 2 bpm); (2) Rapid Pace/ACEI: concomitant ACE inhibition (ACEI: fosinopril 30 mg/kg b.i.d.) with chronic pacing; (3) Rapid Pace/AT1 Block: concomitant AT1 Ang-II receptor blockade [Irbesartan: SR 47436(BMS-186295) 30 mg/kg b.i.d.] with chronic pacing; and (4) Control: sham controls. With Rapid Pace, the LV end-diastolic volume increased by 62% and the ejection fraction decreased by 53% from control. With Rapid Pace/ACEI, the LV end-diastolic volume was reduced by 24% and the ejection fraction increased by 26% from Rapid Pace only values. Rapid Pace/AT1 Block did not improve LV geometry or function from Rapid Pace values. Myocyte contractile function decreased by 40% with Rapid Pace and increased from this value by 32% with Rapid Pace/ACEI. Rapid Pace/AT1 Block had no effect on myocyte function when compared with Rapid Pace values. With Rapid Pace/ACEI, beta receptor density and cyclic AMP production were normalized and associated with an improvement in myocyte beta adrenergic response compared with Rapid Pace only. Although Rapid Pace/AT1 also normalized beta receptor density, cyclic AMP production was unchanged and myocyte beta adrenergic response was reduced by 15% compared with Rapid Pace only. ACE inhibition with chronic rapid pacing improved LV and myocyte geometry and function, and normalized beta receptor density and cyclic AMP production. However, AT1 Ang-II receptor blockade with chronic rapid pacing failed to provide similar protective effects on LV and myocyte geometry and function. These unique findings suggest that the effects of ACE inhibition on LV geometry and myocyte contractile processes in the setting of developing LV failure are not primarily caused by modulation of AT1 Ang-II receptor activation.  相似文献   
155.
The production of different size and shape silver nanoparticles (AgNPs) has increased considerably in recent years due to several commercial and biological applications. Here, rod‐shaped AgNPs (SNRs) were prepared using the microwave‐assisted method and characterised by ultraviolet–visible spectroscopy, and transmission electron microscopy analysis. The present study aims to investigate the cyto–genotoxic effect of various concentrations (5, 10, and 15 µM) of SNRs using Allium cepa model. As a result, concentration‐dependent cyto–genotoxic effect of SNRs was observed through a decrease in the mitotic index, and an increase in the chromosomal aberrations such as chromosome break, disturbed metaphase, and anaphase bridge. To check the impact of Ag+ ions, 15 µM silver nitrate (AgNO3) was prepared and tested in all the assays. Furthermore, cell viability and different reactive oxygen species assays were performed to test the cytotoxicity evaluation of SNRs. The authors found that in all the tested assays, SNRs at high concentrations (15 µM) and AgNO3 (15 µM) were observed to cause maximal damage to the roots. Therefore, the current study implies that the cytotoxicity and genotoxicity of SNRs were dependent on the concentration of SNRs.Inspec keywords: ultraviolet spectra, biomedical materials, silver, cellular biophysics, nanorods, toxicology, visible spectra, nanoparticles, nanofabrication, transmission electron microscopy, nanomedicine, aberrations, microwave materials processingOther keywords: biological applications, rod‐shaped AgNPs, microwave‐assisted method, ultraviolet‐visible spectroscopy, transmission electron microscopy, chromosomal aberrations, chromosome break, silver nitrate, reactive oxygen species assays, cytotoxicity, genotoxicity, silver nanorods, oxidative stress, shape silver nanoparticles, concentration‐dependent cyto‐genotoxic effect, Allium cepa model, mitotic index, disturbed metaphase, anaphase bridge, cell viability, cytotoxicity evaluation, Ag  相似文献   
156.
The effect of post-deposition annealing on the structural and optical properties of barium strontium titanate, Ba0.8Sr0.2TiO3 film has been investigated. The films have been deposited on oxidized p-silicon substrates by r.f. magnetron sputtering followed by annealing in O2 atmosphere at different temperatures. In situ deposition has also been carried out at 550 °C for comparison. The nature of the variation of refractive index and extinction coefficient with annealing temperature and wavelength has been studied. Absorption band edges shift towards lower photon energy values as the temperature is increased causing a reduction in the optical band gap energy. Infrared absorption bands show a cubic symmetry at lower frequency and are found to be broadened and even split at higher frequency.  相似文献   
157.
A study was conducted to evaluate the nutritional potential of four commonly available, unexplored aquatic weeds namely, Salvinia cuculata, Trapa natans, Lemna minor and Ipomoea reptans from northeast India for ascertaining their suitability for utilization as supplementary fish feed with the aim to reduce the cost of commercial feeds. Results of proximate analysis showed that the crude protein content of the aquatic weeds ranged between 11.0% and 32.2% (w/w), whereas crude fibre and ash contents varied between 4.2% and 20% (w/w), and 13.3% and 31.2% (w/w), respectively. Protein to energy ratio (P/E) of these weeds ranged between 30.7 mg/kcal and 95.3 mg/kcal and the highest value was displayed by I. reptans. All these aquatic weeds contained high amounts of vitamins E and C and mineral elements required for the normal growth and development of fish.  相似文献   
158.
Material removal rate (MRR) of aluminium work piece has been obtained by electrochemical machining using NaCl electrolyte at different current densities and compared with the theoretical values. It has been observed that resistance of the electrolyte solution decrease sharply with increasing current densities. The over-voltage of the system initially increases and then attains a saturation value with increasing current densities. The material removal rate, determined experimentally, almost corresponds to theoretical value with Al3+ state. On the other hand, taking into account over-voltage, MRR comes out be 72%. It appears that removal of a fraction of aluminium occurs in Al+ which subsequently gets converted into Al3+ through a series chemical reactions. A mechanism of such chemical reactions is proposed.  相似文献   
159.
Magnesium reinforced in situ TiC particulates was successfully synthesized by utilizing the self-propagating high temperature synthesis (SHS) process. The result showed that preform temperature and compact density have effects on the SHS reaction. It is observed that when the compact density was below 68% of the theoretical density, no SHS reaction occurred. However, with an increase in density from 68 to 72%, the successful thermal explosion reaction was observed in the Mg melt. Besides this, the effect of preheat temperature on the fabrication of Mg/TiC composite was extensively studied and found that the preheat temperature below 300 °C failed to give rise to SHS reaction. However, the preheat temperature of 450, 500, and 550 °C favors the reaction inside the liquid melt, but the temperature of 600 °C leads to the ignition reaction in the preheating furnace itself. SEM and EDX study confirms fine distribution of TiC in the matrix.  相似文献   
160.
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