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991.
One of the most important applications of chelating and functional polymers is their capability to recover metal ions from their solutions. This study concerns the synthesis of a hydrophilic glycidyl methacrylate (GMA) monomer‐bearing diethanol amine (DEA) chelating group from the reaction of GMA and DEA. The formed adduct (A) was characterized via FTIR and mass spectra and subjected to homopolymerization and binary copolymerization with ethyl methacrylate and butyl methacrylate. The copolymerization process was carried out via a semi‐batch emulsion polymerization technique by using potassium persulphate/sodium bisulphite as a redox pair initiation system and sodium dodecyl benzene sulphonate as an emulsifier at 65°C. The obtained polymers were characterized via FTIR, thermal gravimetric analysis, and UV–VIS. Volume‐average diameters (Dv) in nanoscale range for the prepared polymers were confirmed by transmission electron microscope investigation. It was shown that the obtained nano‐size chelating polymers have a powerful adsorption character toward transition metal ions (Cu+2, Cr+3, Ni+2, and Co+2) and efficient selectivity for Cu+2 and Ni+2 ions at normal pH. The effects of pH, time, and different comonomer feed compositions on the uptake of metal ions were studied. The reaction between the obtained chelating resins and different metal ions was confirmed to be a second‐order reaction. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
992.
The stable polyurethane‐epoxy composite emulsion with the epoxy‐amine oligomer (DEA‐EP) and the epoxy resin oligomer has been prepared by step‐growth polymerization and controlled crosslinking technique. The emulsion forming transparent films can be cured at room temperature with trimethylolpropane tris (1‐ethyleneimine) propionate (TMPTA‐AZ). The DEA‐EP structure and its reaction with urethane prepolymers were proved by Fourier transform infrared spectra (FTIR). The studies on particle size, the particle size distribution, viscosity, and the films' transmittance (Tr) indicated that both trimethylol propane (TMP) and DEA‐EP contributed to improving the resin blends' compatibility and reducing the viscosity. The epoxy resin content can increase up to 20.0 wt % (based on the total content of the polyurethane and epoxy resin) and the emulsion was still stable. The data from the tensile test experiments showed that with the epoxy content increasing, the tensile strength (σb) and Young's modulus were proportionately raised, but the elongation at break (εb) decreased. Tensile tests also revealed that introducing TMPTA‐AZ as an outside‐crosslinker can increase the tensile strength. By adding 0.3 wt % of TMPTA‐AZ, the εb reduced from 429% to 371% and the σb increased from 4.4 to 13.73 MPa; by adding 1.8 wt % of TMPTA‐AZ, εb of the film was 67% of εb of the film with 0.3 wt % of TMPTA‐AZ, but its σb was 24.77 MPa and 180% of σb of the film with 0.3 wt % of TMPTA‐AZ. The cured films possessed excellent water and toluene resistance: water uptake (48 h, 3.1%; degree of curing: 70%), toluene uptake (210 h, 8%. degree of curing: 70%). Better properties of the composite emulsion will confer it as a potential application in low volatile industrial coatings. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
993.
In this study, a series of (anionic and nonionic) emulsifiers were investigated to prepare acrylic pressure sensitive adhesives (PSA) with core‐shell structure by semicontinuous emulsion polymerization. The cloud point of different emulsifiers was characterized to explain the emulsifier effects on the emulsification ability. It was interestingly found that the hybrid emulsifiers (anionic coupling with nonionic) with optimized compositions could enhance the stability of emulsion system and improve the properties of PSA compared with the mono‐emulsifier. The stability of emulsion polymerization, the appearance of the emulsion system and the properties of PSA were studied in details by changing the proportion and the content of hybrid emulsifiers. When the ratio of sodium dodecyl sulfate (SDS: anionic emulsifier) to polyoxyethylene alkyl phenyl ether (OP‐10: nonionic emulsifier) reached 2 : 1, the content of hybrid emulsifiers reached 3 wt % and the reaction temperature was around 80°C, a better emulsion system was obtained in terms of comprehensive properties. At this condition, the synthesized PSA demonstrated the good holding power and 180° peel strength properties with fair tacky property, which was promising for industrial applications. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
994.
Polyaniline salt was synthesized through the chemical oxidation of aniline with sodium persulfate as the oxidant and didecyl ester of 4‐sulfophthalic acid via three different polymerization pathways (aqueous, emulsion, and interfacial). In these polymerization processes, the ester acted as a novel plast dopant and as an emulsifier. The yield, conductivity, and number of ester units present in the polyaniline salts were determined. A polyaniline salt prepared by emulsion polymerization was soluble in chloroform and showed excellent solution‐processing properties. Polyaniline samples prepared by aqueous or interfacial polymerization were not soluble in chloroform. A soluble polyaniline salt was successfully synthesized through the washing of an organic layer containing the polyaniline salt with water in emulsion polymerization. X‐ray diffraction spectra of polyaniline salts prepared by the three different methods showed an ordered, layer‐type supramolecular structure. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
995.
The butyl acrylate (BA)/methyl methacrylate (MMA), and glycidyl methacrylate (GMA) composite copolymer latex was synthesized by seeded emulsion polymerization technique taking poly(methyl methacrylate) (PMMA) latex as the seed. Four series of experiments were carried out by varying the ratio of BA : MMA (w/w) (i.e. 3.1 : 1, 2.3 : 1, 1.8 : 1, and 1.5 : 1) and in each series GMA content was varied from 1 to 5% (w/w). The structural properties of the copolymer were analyzed by FTIR, 1H‐, and 13C‐NMR. Morphological characterization was carried out using transmission electron microscopy (TEM). In all the experiments, monomer conversion was ~99% and final copolymer composition was similar to that of feed composition. The incorporation of GMA into the copolymer chain was confirmed by 13C‐NMR. The glass transition temperature (Tg) of the copolymer latex obtained from the differential scanning calorimetry (DSC) curve was comparable to the values calculated theoretically. With increase in GMA content, particles having core‐shell morphology were obtained, and there was a decrease in the particle size as we go from 2–5% (w/w) of GMA. The adhesive strength of the latexes was found to be dependent on the monomer composition. With increase in BA : MMA ratio, the tackiness of the film increased while with its decrease the hardness of the film increased. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
996.
997.
有机硅改性环氧-聚氨酯乳液的合成与性能研究 总被引:4,自引:1,他引:3
以异佛尔酮二异氰酸酯(IPDI)、聚氧化丙烯二醇(PPG)、二羟甲基丙酸(DMPA)为主要原料,用4%的环氧树脂和3%的氨基硅烷复合改性合成了有机硅改性环氧-聚氨酯乳液,乳液外观呈黄白色且具有较好的稳定性。用红外光谱仪、接触角测定仪、热重分析仪对涂膜的结构和性能进行了检测,结果表明:聚合物中因环氧树脂的交联作用和Si—O键的存在,涂膜表面憎水性增强、耐水性和耐热性得到提高。 相似文献
998.
999.
Christopher G. Dobie Kamelia V.K. Boodhoo 《Chemical Engineering and Processing: Process Intensification》2010
The feasibility of enhancing the latex yield and colloid characteristics in the surfactant-free emulsion polymerisation (SFEP) of methyl methacrylate (MMA) and methyl acrylate (MA) through the use of intensified processing technologies is reported in this paper. The effects of high power ultrasonic energy as a well-established technique for mixing and mass transfer enhancements were compared with thermal initiation in a conventional mechanically agitated reactor. Although increases in ultrasonic power input resulted in higher rates of reaction and larger particles in the MMA polymerisation, reaction yields were nevertheless found to be low compared with the thermally initiated stirred tank reactor experiments. This was attributed to the low frequency ultrasound used (24 kHz) that was observed to provide excellent emulsification but was ineffective in terms of radical generation. The results for a thermally initiated SFEP of MA in a narrow channel reactor as an example of a continuous flow reactor technology showed that reaction rates were comparable with those achieved in the stirred tank reactor but at only a fraction of the specific power input whilst smaller particles with a tighter distribution are generated. These effects highlight the process intensification characteristics of the narrow channel reactor for the SFEP of MA. 相似文献
1000.
Preparation and characterization of flame retardant solvent base and emulsion paints 总被引:1,自引:0,他引:1
In this research solvent base alkyd and emulsion paint formula were made flame retardant (FR) by incorporation of hexachlorodiphosh (V) azane of types (I–III). Elemental analysis was used to characterize the structure of these compounds. These additives are physically incorporated into the paint formula through grinding in a pebble mill until all particulates have a size below 38 μm. Experimental coatings were manufactured on a laboratory scale, applied by brush on wood and steel panels. Results of an oxygen index value indicated that coating with these compounds containing chlorine, nitrogen and phosphorus exhibit very good flame retardant effect when mixed with solvent base alkyd and emulsion paint. The physical, mechanical and corrosion resistance were studied to evaluate the additives drawbacks. The additives did not affect the flexibility and pinholes of paint formula. The gloss and the impact strength were decreased by the additives, the hardness and adhesion resistance increased by the additives. However, corrosion resistance was not significantly changed by these additives. 相似文献