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941.
Arshad Noor Siddiquee Sunil Pandey 《The International Journal of Advanced Manufacturing Technology》2014,73(1-4):479-486
In this paper, the effect of friction stir welding (FSW) parameters on wear and deformation behavior of tungsten carbide (WC) tool employed in the welding of AISI 304 austenitic stainless steel (SS) is reported. In addition, the wear and deformation of the tool are also characterized. Three FSW parameters, namely shoulder diameter, tool rpm, and traverse speed each at three levels were considered. Experiments were performed as per Taguchi’s L9 orthogonal array to investigate the effect of these parameters on wear and plastic deformation of the tool. Wear at the pin root and bottom face of the pin attributed to diffusion and attrition mechanisms, respectively, were observed. Significant deformation of the tool was also observed during welding which caused bulging of the shoulder with an increased cone angle of the pin. 相似文献
942.
Pandey Vinay Kumar Tripathi Anjali Srivastava Shivangi Dar Aamir Hussain Singh Rahul Farooqui Alvina Pandey Sneha 《Food science and biotechnology》2023,32(7):885-902
Food Science and Biotechnology - Fruits are an abundant source of minerals and nutrients. High nutritional value and easy-to-consume property have increased its demand. In a way to fulfil this... 相似文献
943.
Pratibha Pandey Arup Ranjan Bhattacharyya Pranav Kumar Gutch Ram Singh Chauhan Satish Chandra Pant 《应用聚合物科学杂志》2010,115(5):3005-3012
Nano fuller's earth was prepared by milling and subsequent sonication of clay. The polyvinyl alcohol (PVA) and PVA ‐Nano clay composite films were prepared by solution casting method. The films were characterized for their structural, mechanical, and thermal properties using electron microscopes (SEM, TEM), Tensile Tester, dynamic mechanical analyzer (DMA), thermo gravimetric analyzer (TGA), and Raman spectroscopy. The nanocomposite films showed improvement in mechanical properties, viscoelastic behavior as well as resistance towards thermal degradation. Uniform distribution of clay due to intimate interaction between clay and polymer appears to be the cause for improved properties. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
944.
The diffusion couples of lanthanum based strontium borosilicate glass with two different (high and low temperature) electrolytes have been heat‐treated at 850 and 800 °C, respectively, for 5, 100, and 750 h to understand the mechanism of interface formation and growth. These prepared diffusion couples have been characterized using various techniques like X‐ray diffraction (XRD), scanning electron microscope (SEM), X‐ray dot mapping, and electron probe microanalysis (EPMA). XRD revealed no detrimental phase formation. Other thermodynamic parameters like frequency factor, crystallization constants, free volume, and bulk thermal expansion coefficients have been calculated to understand the behavior of glass under the influence of temperature. These theoretical parameters will enable to understand the interfacial growth observed in heat‐treated couple for its end application in SOFC. The observed results indicate that lanthanum containing glass exhibit stable and smooth interface with yttria‐stabilized zirconia (high‐temperature electrolyte) as compared to doped bismuth vanadate (low temperature electrolyte). 相似文献
945.
Kamal A Sultana F Ramaiah MJ Srikanth YV Viswanath A Kishor C Sharma P Pushpavalli SN Addlagatta A Pal-Bhadra M 《ChemMedChem》2012,7(2):292-300
A new series of 3‐substituted 2‐phenylimidazo[2,1‐b]benzothiazoles ( 3 a – h ) were synthesized by C‐arylation of 2‐arylimidazo[2,1‐b]benzothiazoles using palladium acetate as catalyst, and the resulting compounds were evaluated for their anticancer activity. Compounds 3 a , 3 e , and 3 h exhibited good antiproliferative activity, with GI50 values in the range of 0.19–83.1 μM . Compound 3 h showed potent anticancer efficacy against 60 human cancer cell lines, with a mean GI50 value of 0.88 μM . This compound also induced cell‐cycle arrest in the G2/M phase and inhibited tubulin polymerization followed by activation of caspase‐3 and apoptosis. A high‐throughput tubulin polymerization assay showed that the level of inhibition for compound 3 h is similar to that of combretastatin A‐4. Molecular modeling studies provided a molecular basis for the favorable binding of compounds 3 a , 3 e , and 3 h to the colchicine binding pocket of tubulin. 相似文献
946.
Niroj Kumar Mohalik Somu Mandal Santosh Kumar Ray Asfar Mobin Khan Debashish Mishra Jai Krishna Pandey 《矿业科学技术学报(英文版)》2022,32(1):75-88
Thermogravimetric analysis/differential scanning calorimeter (TGA/DSC) technique along with basic coal characteristics study is carried out for eighty coal samples of Indian coalfields, to determine spontaneous combustion propensity behaviour of coal. TGA study of coal samples indicates that there is an increase in the mass of coal samples in the temperature range 150–350 ℃, which may be due to oxygen adsorption and absorption. The correlation and principal component analysis states that the component of proximate analysis (Mad, VMd, FR, and VR) have an acceptable correlation with the TGA experiments results i.e., Tgsh and Tgign. Multiple fixed nonlinear regression analysis shows that thermogravimetry (TG) experiment results Tgign may be the best index to categorise/classify the coal as per their susceptibility towards spontaneous combustion. The authors proposed four groups of classification as per their propensity towards spontaneous combustion depending upon the moisture (Mad), volatile matter (VMd), and TG ignition temperature from differential thermogravimetric (DTG) curve (Tgign) using hierarchal clustering analysis. The coal samples of different seams from Indian coalfield may be classified into four different clusters, viz. very highly/extremely susceptible (Tgign < 260 ℃), highly susceptible (260 ℃ ≤ Tgign < 290 ℃), moderately susceptible (290 ℃ ≤ Tgign ≤ 320 ℃), and poorly susceptible (Tgign > 320 ℃). The field observations and TGA/DSC experiment results with the following statistical analysis substantiate a similar assessment. 相似文献
947.
The photostabilization of wood surfaces is desirable to enhance the life of wood under exterior use and to improve the performance of clear coatings on wood surfaces. Chemical modification of wood has been found effective in upgrading properties such as biological durability and dimensional stability and has been suggested as a potential way for inducing photostability on wood surfaces. In this study, the photostability of chemically modified wood was assessed under accelerated weathering conditions. Wood specimens of Pinus roxburghii (Chir pine) were esterified with benzoyl chloride to 19.5 wt % gain and exposed to a xenon arc light source in a Weather‐O‐Meter for different periods ranging from 0 to 500 h. The irradiated samples were analyzed for color changes and chemical changes. The analysis of color changes in wood surfaces by ultraviolet–visible irradiation was carried out with a color measuring (CIELAB) system, and chemical changes were characterized with fluorescence and Fourier transform infrared spectroscopy. The esterification of wood by benzoyl chloride suppressed the color changes (photodiscoloration) due to irradiation. Modification also reduced the lignin degradation and generation of carbonyl groups on the surface of the irradiated wood. The fluorescence emission spectra of irradiated unmodified wood showed a large reduction in intensity and a large redshift in the emission maximum, whereas modified wood showed only a small change in fluorescence intensity on irradiation. The results show that the esterification of wood with benzoyl chloride was effective for the photostabilization of the wood polymers. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006 相似文献
948.
Archana Pandey 《Carbon》2010,48(1):287-292
Self-assembled bundling and catalyst removal can enhance the field emission stability and density of vertically-aligned multiwalled carbon nanotubes (VA-MWCNTs). These catalyst-free, opened tip, VA-MWCNTs offered better emission stability than the as grown samples. Both the emission stability and density were further enhanced as the opened-tip MWCNTs self-assembled into arrays of conical bundles. Theoretical simulation suggests that higher emission density was due to the reduced screening effects. The simulated local fields at the tips of the bundles suggest for a two-order of magnitude lower electric field loading on MWCNTs and contribute to prolong emission stability needed for practical applications. 相似文献
949.
Preetam Singh Ashvani Kumar Ajay Kaushal Davinder Kaur Ashish Pandey R. N. Goyal 《Bulletin of Materials Science》2008,31(3):573-577
Ultrasonic mist chemical vapour deposition (UM-CVD) system has been developed to prepare ZnO nanopowder. This is a promising
method for large area deposition at low temperature inspite of being simple, inexpensive and safe. The particle size, lattice
parameters and crystal structure of ZnO nanopowder are characterized by in situ high temperature X-ray diffraction (XRD). Surface morphology of powder was studied using transmission electron microscopy
(TEM) and field emission electron microscope (FESEM). The optical properties are observed using UV-visible spectrophotometer.
The influence of high temperature vacuum annealing on XRD pattern is systematically studied. Results of high temperature XRD
showed prominent 100, 002 and 101 reflections among which 101 is of highest intensity. With increase in temperature, a systematic
shift in peak positions towards lower 2θ values has been observed, which may be due to change in lattice parameters. Temperature dependence of lattice constants under
vacuum shows linear increase in their values. Diffraction patterns obtained from TEM are also in agreement with the XRD data.
The synthesized powder exhibited the estimated direct bandgap (E
g) of 3.43 eV. The optical bandgap calculated from Tauc’s relation and the bandgap calculated from the particle size inferred
from XRD were in agreement with each other. 相似文献
950.
Lowering of thickness of boron-doped microcrystalline hydrogenated silicon film by seeding technique
By using a seeding technique it has been possible to reduce the thickness of p-μc-Si:H film to 230 Å, with an improved electrical conductivity (0.93 S cm−1) and lower optical absorption compared to those of conventional p-μc-Si:H layers without a seed layer, for use at the tunnel junction and as the top layer of a double junction n–i–p structured a-Si solar cell. Undoped-μc-Si:H has been used as the seed layer. The layers were prepared by the radio frequency plasma-enhanced chemical vapour deposition (RF-PECVD) method (13.56 MHz) at 40 mW/cm2 rf power density and low substrate temperature (200 °C). The ultrathin seed layer (30 Å) enhances the growth of microcrystallinity of the p-type μc-Si:H film as confirmed by the results of transmission electron microscopy (TEM) analysis and Raman spectroscopy. 相似文献