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81.
B N V S Ganesh Gupta K Mritunjay Maharudrayya Hiremath Rajesh Kumar Prusty Bankim Chandra Ray 《应用聚合物科学杂志》2020,137(43):49318
Polymer hybridization technique, consisting of an interlayer arrangement of different polymers, acts as the most economical and promising technique in augmenting the glass fiber-reinforced polymer composite's mechanical properties. This investigation focuses on the effect of cure kinetics on the flexural behavior of glass-polymer hybrid (GPH) composite, and also elucidates the comparative analysis on the mechanical behavior of glass-epoxy (GE) composite, glass-vinyl ester (GVE) composite, and GPH composite. The optimal postcuring temperature has been found to be 200°C for GPH composite among the other postcuring temperatures conducted at 140, 170, and 230°C. Among all these abovementioned composites, highest flexural strength and interlaminar shear strength properties have been recorded by the 200°C postcured GPH composite leading to 10.87 and 18.76% increment, respectively, compared with GE composite. Furthermore, thermomechanical characterization has been done to know the viscoelastic behavior of the GPH composite postcured at different temperatures using dynamic mechanical thermal analysis. The fracture morphology of flexural tested composite samples demonstrated a combination of failure modes. Relevant information on the chemical restructuring and fracture morphology of experimented composite material using Fourier-transform infrared (FTIR) spectroscopy and Scanning electron microscopy (SEM) has also been studied. 相似文献
82.
Rajesh Grover Satwinder S Marwaha John F Kennedy 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2001,76(3):251-256
The methanogenesis of black liquor from pulp and paper mill was achieved using immobilized cell technology in a laboratory‐scale two‐stage reactor system run continuously for 340 days. The optimum organic loading rate for the anaerobic treatment of black liquor was 8.0 kgm?3d?1 at which the % COD removal, biogas production and methane content were 55%, 11 dm3d?1 and 71%, respectively. Organic loading rates above 8.0 kgm?3d?1 were observed to be toxic to the methanogenic bacteria and resulted in decreased methane content, biogas and COD removal. The applicability of the system to the large‐scale processing and treatment of paper mill liquid waste is discussed. © 2001 Society of Chemical Industry 相似文献
83.
Dodecylbenzene sulfonate (DBS)‐doped polypyrrole (PPY) conducting polymer films were electrochemically deposited onto the indium‐tin‐oxide (ITO)‐coated glass plates in aqueous medium. The enzyme cholesterol oxidase (ChOx) was immobilized on these DBS–PPY films by a physical adsorption technique. These ChOx‐immobilized DBS–PPY films were characterized by ultraviolet–visible and Fourier transform infrared spectroscopy. The enzyme activity studies indicate that ~40% of ChOx leaches out from the ChOx/DBS–PPY film. The ChOx activity in the ChOx/DBS–PPY film was assayed as a function of cholesterol concentration. The results of amperometric measurements conducted on ChOx/DBS–PPY/ITO film show linearity over the range 2–8 mM of cholesterol solution. The ChOx/DBS–PPY/ITO electrodes exhibit a response time of 30 s and are stable for ~3 months at 4 °C. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3486–3491, 2001 相似文献
84.
Harishchandra D. Jirimali Bhushan C. Chaudhari Jitendra C. Khanderay Sachin A. Joshi Vijay Singh Amardip M. Patil 《Polymer-Plastics Technology and Engineering》2018,57(8):804-811
Waste eggshells were utilized to make calcium oxide (E-CaO) and hydroxyapatite (E-HAP). E-CaO obtained by heat treatment to eggshells was utilized for the synthesis of E-HAP. Melt compounding of E-CaO/E-HAP was performed with linear low-density polyethylene (LLDPE) on a Brabender Plastograph and ground the obtained formulation for injection molding. Addition of E-CaO/E-HAP in the LLDPE significantly enhanced the flame retardant ability and thermal stability of resultant composites. In the comparative study, E-HAP nanopowder-containing polymer composite showed increment in thermal and mechanical properties than the composite prepared using E-CaO. 相似文献
85.
A systematic study of the comparative performances of supported Pt, Pd, Ru and conventional CoMo/Al2O3, NiMo/Al2O3, NiW/Al2O3 catalysts as well as the effects of solvent, H2 pressure and temperature on the hydroprocessing activity of a representative model bio-oil compound (e.g., p-cresol) is presented. With water as solvent, Pt/C catalyst shows the highest activity and selectivity towards hydrocarbons (toluene and methylcyclohexane), followed by Pt/Al2O3, Pd and Ru catalysts. Calculations indicate that the reactions in aqueous phase are hindered by mass-transfer limitations at the investigated conditions. In contrast, with supercritical n-heptane as solvent at identical pressure and temperature, the reactant and H2 are completely miscible and calculations indicate that mass-transfer limitations are eliminated. All the noble metal catalysts (Pt, Pd and Ru) show nearly total conversion but low selectivity to toluene in supercritical n-heptane. Further, conventional CoMo/Al2O3, NiMo/Al2O3 and NiW/Al2O3 catalysts do not show any hydrodeoxygenation activity in water, but in supercritical n-heptane, CoMo/Al2O3 shows the highest activity among the tested conventional catalysts with 97?% selectivity to toluene. Systematic parametric investigations with Pt/C and Pt/Al2O3 catalysts indicate that with water as the solvent, the reaction occurs in a liquid phase with low H2 availability (i.e., low H2 surface coverage) and toluene formation is favored. In supercritical n-heptane with high H2 availability (i.e., high H2 surface coverage), the ring hydrogenation pathway is favored leading to the high selectivity to 4-methylcyclohexanol. In addition to differences in H2 surface coverage, the starkly different selectivities between the two solvents may also be due to the influence of solvent polarity on p-cresol adsorption characteristics. 相似文献
86.
Raghunath V. Chaudhari 《Topics in Catalysis》2012,55(7-10):439-445
This brief review reports recent developments in homogeneous catalysis for synthesis of chemicals with a focus on new synthetic routes, clean catalytic alternatives and challenges in their industrial applications. Particularly, examples of hydroformylation, carbonylation, oxidative carbonylation and tandem synthetic approaches have been discussed. Challenges for future work and difficulties in commercialization are highlighted. 相似文献
87.
Kiran S. Dalal Yogesh B. Wagh Yogesh A. Tayade Dipak S. Dalal Bhushan L. Chaudhari 《Catalysis Letters》2018,148(11):3335-3341
A green synthesis of 3-indolyl-3-hydroxy oxindoles was reported using hen egg white lysozyme (HEWL) in an aqueous ethanol. The HEWL promotes this reaction efficiently from various isatins and indoles under mild reaction conditions with yields up to 98% bearing good adaptability to varied substrates in the reaction. This conversion has provided a new strategy to synthesize 3-indolyl-3-hydroxy oxindole derivatives employing biocatalytic promiscuity of less explored lysozyme. Based on the experimental studies, the plausible reaction mechanism is proposed. 相似文献
Graphical Abstract
88.
Bhupendra Singh Nitika Devi Lakshya Mathur Rajesh K. Singh Aman Bhardwaj Sun-Ju Song Dirk Henkensmeier 《Ceramics International》2018,44(6):6170-6175
In the present work, we report a method of fabrication of dense 10 mol% Mg2+-doped cerium pyrophosphate-phosphate (Ce0.9Mg0.1P2O7-PmOn; CMP-P) composites by microwave heat-treatment of the preformed Ce0.9Mg0.1P2O7 substrates in the presence of phosphoric acid. The composite was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The microwave heating at 375 °C for 5 min resulted in the formation of dense CMP-P composites which retained most of the pyrophosphate phase. The electrical conductivity was extracted from the EIS data and for the CMP-P composite prepared by H3PO4 loading for 10 h and microwave heat-treatment for 5 min it was found to be >10?2 S m?1 in 100–250 °C range with a maximum of 0.062 S cm?1 at 190 °C, which was significant for its application as electrolyte in intermediate temperature fuel cells. 相似文献
89.
NiNdxFe2-xO4 nanoferrites with different compositions of x?=?0.01, 0.03, 0.05, 0.07 and 0.09 were prepared using the sonochemical method. The structural, optical and morphological properties of the prepared nanoferrites were characterized by X-ray diffraction, ultra violet-diffuse reflectance spectroscopy, scanning electron microscopy and X-ray fluorescence techniques. The X-ray diffraction analysis of the prepared nanoferrites confirmed the presence of a cubic spinel structure. The average crystallite sizes of the prepared nanoferrites were 52, 49, 46, 44 and 40?nm for x?=?0.01, 0.03, 0.05, 0.07 and 0.09, respectively. The particle size of the prepared NiNdxFe2-xO4 nanoferrites was in the range 60–40?nm. The dielectric parameters ranged from 2.9?GHz to 5.6?GHz. Decrease in the dielectric constant was observed with an increase in Nd3+ ions in the prepared NiNdxFe2-xO4 nanoferrites. However, a reverse trend was observed in the dielectric loss. An impedance analysis of the prepared nanoferrites was carried out to explore the pseudo-capacitance behavior. The saturation magnetization and remnant magnetization values of the prepared nanoferrites decreased with an increase in the concentration of Nd3+ ions in NiNdxFe2-xO4 nanoferrites. 相似文献
90.
M. Kamal Warshi Vikash Mishra Vinayak Mishra Rajesh Kumar P.R. Sagdeo 《Ceramics International》2018,44(12):13507-13512
Rare-earth orthoferrites (RFeO3) are well-known for the antiferromagnetic ground state. However, some of the recent experimental results suggest that the few members of RFeO3 family possess ferromagnetism. In the present investigation we report the possible origin of ferromagnetism in antiferromagnetic YFeO3 using density functional theory. For this purpose, we have considered pure as well as self-doping in YFeO3 i.e. by considering the point defect at Y, Fe and O sites. Our finding suggests that the point defects in YFeO3 results in the mixed-valence state of Fe, which may result in ferromagnetism through Zener double exchange mechanism. 相似文献