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61.
Ashit Rao Subhash C. Ayirala Mohammed B. Alotaibi Michel H. G. Duits A. A. Yousef Frieder Mugele 《Advanced functional materials》2021,31(51):2106396
Dissolution is inherent to fluid-mineral systems. Yet its impact on minerals reacting with electrolytes is overlooked. Here, a novel nonmonotonic behavior for the surface interactions of carbonates (calcite and Mg-calcite) with organic acids is reported. Applying a bioinspired approach, Mg-calcite sensors via amorphous precursors, avoiding any preconditioning with functional groups are synthesized. A quartz crystal microbalance is used to study the mass changes of the mineral on contact with organic acids under varying ionic conditions, temperatures, and flow velocities. Supported by confocal Raman microscopy and potentiometric titrations, nonmonotonous mass developments are found as a function of Ca2+ concentration and flowrate, and attributed to three coupled chemical reactions: i) carbonate dissolution via Ca2+ ion complexation with organic molecules, and the formation of organo-calcium compounds as ii) a surface phase at the mineral–water interface, and iii) particles in the bulk fluid. These processes depend on local ion contents and the precipitation onset (i.e., saturation index) of organo-calcium salts, both of which substantially differ in the bulk fluid and in the fluid boundary layer at mineral interfaces. This continuum between dissolution and precipitation provides a conceptual framework to address reactions at mineral interfacial across disciplines including biomineralization, ocean acidification and reservoir geochemistry. 相似文献
62.
Berkhouch Mohammed Müller Fernanda Maria Lakhnati Ghizlane Righi Marcelo Brutti 《Computational Economics》2022,59(2):527-547
Computational Economics - In practice, risk forecasts are obtained by risk measures based on a given probability measure on a measurable space. In our study, we consider the probability measures as... 相似文献
63.
64.
Geoffrey Lawrence Arun V Baskar Mohammed H El-Newehy Wang Soo Cha Salem S Al-Deyab Ajayan Vinu 《Science and Technology of Advanced Materials》2015,16(2)
Three-dimensional cage-like mesoporous FDU-12 materials with large tuneable pore sizes ranging from 9.9 to 15.6 nm were prepared by varying the synthesis temperature from 100 to 200 °C for the aging time of just 2 h using a tri-block copolymer F-127(EO106PO70EO106) as the surfactant and 1,3,5-trimethyl benzene as the swelling agent in an acidic condition. The mesoporous structure and textural features of FDU-12-HX (where H denotes the hydrothermal method and X denotes the synthesis temperature) samples were elucidated and probed using x-ray diffraction, N2 adsorption, 29Si magic angle spinning nuclear magnetic resonance, scanning electron microscopy and transmission electron microscopy. It has been demonstrated that the aging time can be significantly reduced from 72 to 2 h without affecting the structural order of the FDU-12 materials with a simple adjustment of the synthesis temperature from 100 to 200 °C. Among the materials prepared, the samples prepared at 200 °C had the highest pore volume and the largest pore diameter. Lysozyme adsorption experiments were conducted over FDU-12 samples prepared at different temperatures in order to understand their biomolecule adsorption capacity, where the FDU-12-HX samples displayed high adsorption performance of 29 μmol g−1 in spite of shortening the actual synthesis time from 72 to 2 h. Further, the influence of surface area, pore volume and pore diameter on the adsorption capacity of FDU-12-HX samples has been investigated and results are discussed in correlation with the textural parameters of the FDU-12-HX and other mesoporous adsorbents including SBA-15, MCM-41, KIT-5, KIT-6 and CMK-3. 相似文献
65.
Amna Youssef Ramzy Ahmed Mohammed Moneeb El‐Sabbagh Leif Steuernagel Gerhard Ziegmann Dieter Meiners 《应用聚合物科学杂志》2014,131(3)
The presented study investigates the flow length and the corresponding fiber content distribution in the injection‐moulded natural fiber reinforced thermoplastics and its relation to fiber type and processing parameters such as injection pressure, temperature, injection rate and mould tempering by increasing die temperature. In this research, polypropylene compounds with nominally 30 wt % hemp and sisal fibers are investigated. The influence of the injection pressure (500 and 1000 bar), melt temperature (180°C, 200°C, and 220°C), and die temperature (23°C and 80°C) on the fiber content distribution all over the sample is investigated. An increasing linear trend of fiber content along the spiral length is observed as an evidence of a fiber/polymer multiflow system. A pattern for fiber content distribution with respect to the fiber length along the injected spiral can be distinguished, where the longer fibers are usually found at the end of the injected part and the shorter fibers remain near mould entrance point. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39861. 相似文献
66.
Rui Feng Hamid A. Al-Megren Zhanquan Zhang Mohammed C. Al-Kinany Zifeng Yan Zhongdong Zhang Xionghou Gao 《Journal of Porous Materials》2014,21(6):947-956
Interest in reducing SO2 emission from the fluid catalytic cracking (FCC) crude oil has been encouraging the development of new materials to achieve such goal. The nanostructured Mg–Al spinel (MgAl2O4) was prepared by co-precipitation and post hydrothermal treatment in the presence of glucose and followed by elimination of the organic components by calcination at 700 °C for 3 h. Physical and chemical properties were characterized by XRD, N2 sorption, TG, FTIR, SEM, and TEM methods. Mesoporous nanostructured MgAl2O4 with a high surface area of 324 m2 g?1 were obtained. The organic components contributed to the development of mesoporosity, functioning as a soft template. SO2 adsorption tests showed that the nanostructured MgAl2O4 had a 51.58 % increase of SO2 sorption capacity than MgAl2O4 prepared without glucose. These results showed that the nanostructured MgAl2O4 is a promising candidate as catalyst for flue gas desulfurization in FCC process. Three kinetic models were also applied to analyze the SO2 adsorption kinetics; the pseudo-second order kinetic model fit well with a correlation coefficient (R2) of 0.991 for nanostructured MgAl2O4. 相似文献
67.
Yassine Ennaciri Mohammed Bettach Hanan El Alaoui-Belghiti 《The International journal of environmental studies》2020,77(2):297-306
ABSTRACTThe production of phosphoric acid generates an enormous amount of phosphogypsum with emission of toxic fluorine acid gas. To remedy these environmental problems, a novel and a simple procedure permits converting phosphogypsum waste by recycled fluorine acid into valuable products. The obtained results confirm the efficiency of this procedure, which synthesises at room temperature the calcium fluoride in the form of nano-crystalline powder and the ammonium bisulphate salt from the exact stoichiometric proportions of phosphogypsum, hydrofluoric acid and ammonia. The total conversion of phosphogypsum is achieved after reaction time equal to one hour and a half. Generally, this novel procedure offers not only a solution for reducing phosphogypsum waste and fluorine gas emission, but also gives rise to valuable products, useful to industry and agriculture. 相似文献
68.
Archibald N. Sherbourne Mohammed R. Bahaari 《Journal of Constructional Steel Research》1996,40(3):169-187
The paper presents a finite element methodology in a three-dimensional (3D) framework to study numerically the stiffness and strength of the T-stub to unstiffened column flange bolted connection as part of a comprehensive research program to investigate the behavior of endplate bolted connections. In such connections, the axes of rotation of the T-stem and column flange are at right angles; the planes containing the tensile forces are also perpendicular to each other. Therefore, they are highly interactive spatially. The main objective here is to study the applicability of the model to such a connection, so that most of the important features which are not accessible to routine experiments, like prying action and gradual plasticity of components, can be monitored. ANSYS, version 4.4, a large-scale general purpose finite element code is selected for this analysis. Initially, the simplest connection with the bolt groups in tension, which is a symmetric T-stub hanger with a single line of bolts parallel on each side of the web, is considered. Then the T-stub connection to an unstiffened column flange is discussed. Analytical results of a full-scale extended endplate connected to unstiffened column flange will be presented in Part II, a companion paper (Journal of Constructional Steel Research, 1996, 40, 189–223) in which the structural properties of such connections will be discussed. 相似文献
69.
This study describes a process for water treatment by continuous adsorption and electrochemical regeneration using an air-lift reactor. The process is based on the adsorption of dissolved organic pollutants onto an adsorbent material (a graphite intercalation compound, Nyex®1000) and subsequent electrochemical regeneration of the adsorbent leading to oxidation of the adsorbed pollutant. Batch experiments were carried out to determine the adsorption kinetics and equilibrium isotherm for adsorption of a sample contaminant, the organic dye Acid Violet 17. The adsorbent circulation rate, the residence time distribution (RTD) of the reactor, and treatment by continuous adsorption and electrochemical regeneration were studied to investigate the process performance. The RTD behaviour could be approximated as a continuously stirred tank. It was found that greater than 98% removal could be achieved for continuous treatment by adsorption and electrochemical regeneration for feed concentrations of up to 300 mg L−1. A steady state model has been developed for the process performance, assuming full regeneration of the adsorbent in the electrochemical cell. Experimental data and modelled predictions (using parameters for the adsorbent circulation rate, adsorption kinetics and isotherm obtained experimentally) of the dye removal achieved were found to be in good agreement. 相似文献
70.
El Guerraf Abdelqader Ben Jadi Sana Aouzal Zaynab Bouabdallaoui Mimouna Bakirhan Nurgul K. Ozkan Sibel A. Bazzaoui Mohammed Bazzaoui El Arbi 《Journal of Applied Electrochemistry》2022,52(9):1383-1407
Journal of Applied Electrochemistry - Modern technologies continuously need special materials with specific properties to adopt the desired application. Recently, numerous researches have been... 相似文献