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21.
To match the reflectance profile of desert colors including dark brown, light brown and olive green in the visible‐near IR (Vis‐NIR) bands, five selected colored pigments were utilized to print woven cotton/nylon fabrics. Multi‐walled carbon nanotube particles (MWCNT's) were also added to some of the printing pastes. The reflectance of printed fabrics was evaluated by using spectrophotometric technique. The effect of adding MWCNT's, on washing; light and crocking fastness alongside with colorimetric values of printed samples was evaluated. Furthermore, the water absorption time was measured in order to determine wettability of each printed sample. The results demonstrated that the presence of MWCNT's in concentration range of 0.04–0.12 g kg?1 in printing formulations was found to cause considerable decline in Near Infrared (NIR) reflectance while a surprising increase in visible reflectance of samples was observed. Color characteristics of printed fabrics were noticeably changed even at concentrations as low as 0.12 g kg?1 MWCNTs in printing formulations. Presence of MWCNTs in printing formulations was found to cause a significant increase in wetting time of samples. Also, the results indicated that air permeability of printed samples containing MWCNT's were higher than samples printed with no MWCNTs. Phenomena imposed by MWCNT's presence on pigment printed samples showed very good fastness levels in crocking, washing and light fastness tests. In dark brown sample, adding MWCNTs to the pigment printing pastes could tune the overall reflectance in order to match the standard reflectance profile accepted for use in concealment color of desert areas. © 2013 Wiley Periodicals, Inc. Col Res Appl, 40, 93–98, 2015 相似文献
22.
Shobhana Dey 《Fuel Processing Technology》2012,94(1):151-158
The flotation of fine (− 0.5 mm) low rank or oxidized coal is difficult to achieve with the common coal flotation collectors like kerosene, fuel oil or diesel oil (oily collector). The presence of small amounts of oxygen is enough to cause oxidation. The oxidation of coals starts with the physical adsorption of oxygen on the surface to form an oxycomplex followed by chemical adsorption of oxygen to form polar phenolic-OH, carbonyls, phenols and peroxide type oxygenated moieties by the rupture of cyclic rings. The addition of promoter, surfactant or oxygenated functional groups to the collector molecule markedly enhances the flotation of lower rank and oxidized coals due to the hydrogen bonding with the polar part of the coal surface and the reagent. The performance of these reagents is compared with that of oily collectors, namely kerosene, dodecane, nonylbenzene and polar part of the surfactant having an oxygen atom. The mode of addition of non-ionic surfactant with oily collector also has a major role in the flotation response. The addition of non-ionic surfactant after the oily collector has shown a positive effect on yield and grade. 相似文献
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24.
Neslihan Arhun Derya Merve Halacoglu Zümrüt Ceren Ozduman Duygu Tuncer 《Journal of Adhesion Science and Technology》2018,32(21):2405-2418
Purpose: To evaluate the wetting ability and the microtensile bond strength of adhesive systems in various depths of dentin. Materials and Method: 48 extracted human molars cut in half in buccolingual direction. Buccal and lingual surfaces were used to obtain deep (n = 48) and superficial (n = 48) dentin. Groups were divided into 4 subgroups: Self-etch (CSE), etch&rinse (SB), multi-mode self-etch (SAU) and multimode etch&rinse (EAU) adhesive systems. 3 consecutive contact-angle measurements were obtained: T0- 3 μl drop of distilled water on dentin; T1-Droplet of the adhesive; T2- Distilled water after polymerization of the adhesive. After composite build-ups, microtensile measurements were performed. Contact angle data were analysed with analysis of variance for repeated measures. Bond strength data were analyzed by repeated measures analysis of variance, comparisons were made according to the logarithmic values (p < 0.05). Results: The difference between groups was not significant regardless of dentin depth for all measurements (p < 0.05). All groups except CSE enhanced the wetting ability of the adhesive but reduced the wetting ability of distilled water after application of the adhesive (p < 0.05). Regarding adhesive systems, the groups showed no significant difference between bond strengths to various depths of dentin except SAU (p > 0.05); in SAU, bond strength to deep dentine were significantly higher than superficial dentin (p < 0.05). Regarding adhesives’ bond strength, CSE showed significantly greater values than the other groups (p < 0.05). Conclusion: The cavity depth does not affect the bonding ability for all adhesive systems; self-etch adhesive systems might be a better choice since different adhesives may influence the wetting ability and microtensile bond strength of the dentin substrates. 相似文献
25.
Yong Wang Xiaochen Liu Tiliu Jiao Jinping Niu 《Journal of surfactants and detergents》2017,20(1):183-191
Comparison of surface and interfacial properties of internal olefin sulfonates (IOS) and alpha olefin sulfonates (AOS) shows that hydrocarbon chain branching has a significant influence on interfacial properties at the air–water, pentadecane–water and parafilm–water interfaces. The isomeric branched IOS shows a higher critical micelle concentration and are more effective in reducing the surface tension at the air–water interface by occupying a larger area per molecule. IOS exhibits better dynamic air–water interfacial properties due to a lower meso-equilibrium surface tension. The equilibrium interfacial tensions for AOS and IOS have no remarkable difference at the pentadecane–water interface. The water wettability and electrolyte tolerance are enhanced with branched hydrocarbon chain olefin sulfonates. 相似文献
26.
《Ceramics International》2017,43(6):5302-5310
Sn-0.7Cu is among the least expensive types of lead-free solders available. However, its poor mechanical properties have limited its application. In this study, Sn-Cu lead-free solder reinforced with amorphous silica (SiO2) nanoparticles was synthesized through powder metallurgy route. Desired mixtures of raw materials was mechanically milled, compressed, sintered and extruded to prepare bulk solder samples. The samples were characterized by optical and electron microscopy as well as mechanical tests. The results showed that mechanical properties were increased by addition of SiO2 nanoparticles to the solder matrix. Addition of 1.5 wt% ceramic reinforcement to the composite increased tensile, yield and compressive strengths up to 27%, 23% and 41%, respectively, compared to those of the monolithic sample. In addition, the ceramic nanoparticles caused an up to 50% decrease in the wetting angle between the substrate and the nanocomposite solder. 相似文献
27.
《Ceramics International》2017,43(10):7674-7681
In the current study, the wettability between Fe-Al alloy and sintered MgO substrate was investigated. The stable contact angle between the sintered MgO substrate and the liquid iron was approximately 134° at 1550 °C, hardly influenced by Al concentrations of 18 ppm and 370 ppm in the liquid iron. By changing hydrogen partial pressure from 0 vol% to 1 vol%, the oxygen partial pressure decreased. Meanwhile, the contact angle between the MgO substrate and the liquid iron with 370 ppm Al increased with the decrease of oxygen partial pressure. The oxygen partial pressure and contact angle were scarcely affected by increasing hydrogen partial pressure from 1 vol% to 5 vol%. In all cases with 370 ppm Al in the liquid iron, oxide layers were detected on the surface of iron samples. The oxidation of iron could be effectively prevented by increasing the hydrogen partial pressure. The MgO substrate was reduced to Mg vapor in the reducing atmosphere at a high temperature. Then the Mg vapor was dissolved into the iron even before iron melting. Under thermodynamic equilibrium condition, an oxide layer containing two components, i.e. MgO·Al2O3 phase and CaO-SiO2-MgO-Al2O3 phase, was generated on the surface of the iron sample. Due to the different wettability between the iron and the two phases, MgO·Al2O3 phase was repelled, while the CaO-SiO2-MgO-Al2O3 phase adhered to the inside area. 相似文献
28.
The purpose of this study was to determine the influence of the photoinitiator system and moisture condition on the degree of C=C conversion (DC), the water sorption (Wsp), and the solubility (Wsl) of experimental two-step etch-and-rinse dental adhesives. Different photoinitiator systems were added at 0.5 mol% to an experimental adhesive blend (55:45 wt% Bis-GMA:HEMA), defining the experimental groups: camphorquinone (CQ)+ethyl-4-dimethylaminobenzoate (EDMAB), 9,10-phenanthrenequinone (PQ), PQ+EDMAB, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO), and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO). The adhesives were tested in two moisture conditions: neat and wet (with the addition of 10 wt% D2O). The DC (n=6) was evaluated by Fourier-transformed infrared spectroscopy (FTIR). Wsp and Wsl were determined (n=10) after successive weighting procedures. Data were submitted to two-way ANOVA and Tukey׳s post hoc test (α=0.05). Pearson׳s correlation tests were used to analyze the correlation between DC and Wsp or Wsl. TPO and BAPO presented the highest DC in the neat condition while CQ+EDMAB presented the highest in the wet condition. Wsp and Wsl were both dependent on the photoinitiator system and moisture condition. PQ–based materials presented the highest Wsp and Wsl in both neat and wet conditions. Pearson׳s tests were not able to detect any significant correlation between DC and Wsp or DC and Wsl. Within the limitations of the present study, it can be concluded that the photoinitiator system and moisture condition influenced the DC, Wsp, and Wsl of experimental two-step etch-and-rinse adhesives. 相似文献
29.
30.
Ping Shen Lifeng Zhang Jianxun Fu Hao Zhou Yi Wang Limei Cheng 《Ceramics International》2019,45(9):11287-11295
In the present study, the wettability between liquid iron with two different Al contents and MgOAl2O3 binary substrates was studied in reducing atmosphere. The contact angles between liquid iron with 18?ppm Al and MgO, MgO·Al2O3, Al2O3 were 133.5°, 113.7°, 126.9° respectively. With the variation of the substrate composition, the contact angles for the intermediate binary phases of the three components (MgO, MgO·Al2O3, Al2O3) obeyed the Cassie theory. In the experiment using iron with 370?ppm Al, all the contact angles were higher than that using low Al-containing iron. The surface of the iron drop was covered with an oxide layer, which mainly consisted of many small particles. With the variation of the substrate gradually from MgO to Al2O3, the composition of the oxide layer changed from MgO·Al2O3 to CaOAl2O3. The formation of the oxide layer prevented the spreading of liquid iron, leading to the increase of the contact angle. 相似文献