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71.
Ring Opening of Epoxidized Soybean Oil with Compounds Containing Two Different Functional Groups 下载免费PDF全文
Kemal Karadeniz Hatice Akı Mustafa Yasin Sen Yakup Çalıkoğlu 《Journal of the American Oil Chemists' Society》2015,92(5):725-731
Epoxidized vegetable oils are desirable chemicals due to their eco‐friendly characteristics and their being a major source of many green products. Ring opening is one of the ways to convert these epoxidized oils to some new intermediates. The use of mono‐functional amines, alcohols, acid anhydrides and thioethers for epoxy ring opening has been reported in the literature. In this study, thioglycolic acid (TGA) bearing thiol and carboxylic acid as two different functional groups and methyl ester of thioglycolic acid (TGAME) were used. Currently, there is no reported literature describing epoxy ring opening using chemicals bearing two different functional groups simultaneously. In this way, two new polyols were synthesized, one with TGA (polyol 1) and one with TGAME (polyol 2). FTIR and 1H‐ and 13C‐NMR spectroscopy confirmed that the ring was opened by the carboxylic acid group of TGA, and the thiol group was not involved in the ring opening whereas the ring was opened by the thiol group in the case of TGAME. 相似文献
72.
Changes in Volatile Compounds of Black Cumin Oil and Hazelnut Oil by Microwave Heating Process 下载免费PDF全文
Mustafa Kiralan S. Sezer Kiralan 《Journal of the American Oil Chemists' Society》2015,92(10):1445-1450
Black cumin and hazelnut oils were subjected to a heating process in a microwave oven for a duration of 2, 4, 6 and 8 min at a constant frequency of 2450 MHz and a power of 0.45 kW. The ultraviolet absorption and volatile products of the oils were investigated in detail during the processes. The experimental evidences obtained show that K232 and K270 parameters reach values of 4.69 and 1.30 for black cumin oil, 3.22 and 1.75 for hazelnut oil, respectively with the increment of heating time. The headspace SPME method was used to analyze volatile compounds extracted from black cumin and hazelnut oils being exposed to the microwave heating process. The SPME–GC/MS method allowed the detection of 17 identified volatile compounds (hexanal, α‐thujene, α‐pinene, sabinene, β‐pinene, 2‐heptenal, α‐terpinene, limonene, p‐cymene, γ‐terpinene, E‐2‐octenal, nonanal, 4‐terpineol, thymoquinone, E,E‐2,4‐decadienal, α‐longipinene and isolongifolene) in black cumin oils. Of the products, hexanal, 2‐heptenal, E‐2‐octenal, nonanal and E,E‐2,4‐decadienal were determined to be the predominant volatile oxidation products. In fact, the hexanal was found as a major volatile oxidation compound and reached a local maximum point of 7.41 × 106 AU at the end of heating. On the other hand, only 8 volatile oxidation products (hexanal, heptanal, 2‐heptenal, nonanal, E‐2‐decenal, E,Z‐2,4‐decadienal, E,E‐2,4‐decadienal and E‐2‐tridecenal) were identified in hazelnut oils as a consequence of the heating process. Based on the experimental evidence observed, it is reasonable to conclude that the nonanal content dramatically increased at the end of heating and reached a value of 9.22 × 106 AU. 相似文献
73.
The aims of this study were to prepare organogels from pomegranate seed oil (PO) with carnauba wax (CW) and monoglyceride (MG), compare the organogels with a commercial margarine (CM) and evaluate 3 months storage stability. At 3% organogelator addition, no gels were formed, while at 7 and 10% additions, the oil binding capacities increased and were always higher in CW organogels, with crystal formation times of 8.0 to 14.0 min. Solid fat content (SFC) of the CW organogels varied between 2.96 and 8.71% at 20°C, while MG gels had 2.89–9.43%, and CM had 29.73% SFC. The peak melting temperatures of the CW organogels ranged from 74.73 to 75.74°C and MG organogels ranged from 11.09 to 50.63°C, whereas CM product exhibited 45.92°C peak melting temperature. The hardness of CW organogels was higher than that of MG organogels. The organogels showed potential as spreadable products. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41343. 相似文献
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75.
Mustafa Yıldırım Murat Tonaroğlu Murat E. Selçuk Cem Akgüner 《Bulletin of Engineering Geology and the Environment》2013,72(3-4):413-420
For over 50 years, the Upper Oligocene–Upper Miocene sedimentary sequence in Istanbul has been considered to be formed of two distinct sequences separated by an unconformity. However, recent field observations and an analysis of numerous borehole data indicate the Gürp?nar, Çukurçe?me and Güngören Formations are in fact a single sequence of alternating clay–sand/sandstone beds/lenses, here named the Avc?lar Formation. The Bak?rköy Formation, which is typically composed of carbonate rocks, conformably overlies the Avc?lar Formation. The paper provides the geotechnical parameters of the units within the Avc?lar Formation which it is hoped will facilitate selecting suitable geotechnical and engineering geological parameters to represent the deposits and minimize errors in the interpretation/evaluation of in-situ conditions. 相似文献
76.
Mustafa Esen Marti 《分离科学与技术》2016,51(11):1806-1816
Combined use of inert diluents with polar modifiers enables former to be utilized for the recovery of polar value-added chemicals. The results show that polarities of both solvent and modifier are critical for efficient separations. Thus, KD values with 1-octanol were higher than those with 1-decanol; however, those with xylene were superior to those with hexane and toluene. Increasing the amine concentrations increased the KD values, in contrast to the trends with pH and temperature. About 33%, 79% and 67% of acetic acid was recovered using 25% (v/v) Alamine 336 in xylene, 1-octanol and 30% 1-octanol-modified xylene, respectively. Therefore, solvent modification positively affects the extraction power of inert diluents for acetic acid recovery. 相似文献
77.
Membranes are located in a membrane module that physically seals and isolates the feed stream from the permeate flux in membrane bioreactors (MBRs). Therefore, module type, structure, and geometrical configuration are critical design considerations affecting membrane performance in MBRs. In this study, impact of membrane module design on treatment and filtration performance of MBRs was investigated. For this purpose, two flat sheet membrane modules with different outlet structures and module geometries, including rectangular- and D-shaped, were tested. In addition to the differences in outlet structure and module geometry, size of circular structures which supported membranes in rectangular- and D-shaped modules differed from each other. Considering the results, permeate quality was not affected from the change in the module design. However, the most remarkable impact of the module design was observed on the transmembrane pressure (TMP) evolution and fouling potential. D-shaped membrane module including smaller circular structures resulted in a decrease in fouling potential and thus, this module could be operated longer time in comparison to rectangular-shaped membrane module without a severe TMP increase. The observed differences in TMP increase and fouling potential lead to the hypothesis that module design is a critical factor affecting filtration performance in MBRs. 相似文献
78.
H. Esra Ülker Ali Ihsan Erkan Nuray Günaydın Firdevs Kahvecioğlu Mustafa Ülker 《Journal of Adhesion Science and Technology》2016,30(10):1119-1130
Purpose: The purpose of the present study was to compare the Vickers hardness numbers (VHNs), roughness numbers (RNs) and biological compatibility of glass carbomer (Glass Fill), resin-modified glass ionomer (Fuji II LC) and self-adhering flowable composite (Vertise Flow) materials. Materials and methods: Disc-shaped specimens of test materials (n = 15/group) were prepared, and VHNs and RNs were determined after 24 h. A direct contact test was used for cytotoxicity evaluation. Cell viability was measured for 24 h post-exposition with a photometric test (MTT assay; n = 16). Data were analysed using one-way analysis of variance with a post hoc Tukey’s test, the Kruskal–Wallis test and the Mann–Whitney U-test (p < 0.05). Results: Fuji II LC had the highest VHN. The VHN of Fuji II LC differed significantly from those of the other materials (p < 0.05). The RNs of Fuji II and Glass Fill were higher than that of Vertise Flow (p < 0.05). The self-adhering materials were not significantly cytotoxic compared with the control group (p > 0.05). Conclusions: The materials tested in this study showed a similar lack of cytotoxicity. The VHN of Fuji II LC was the highest, and the RN of Vertise Flow was the lowest. 相似文献
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