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51.
Development of engineered cementitious composites with limestone powder and blast furnace slag 总被引:1,自引:1,他引:0
Jian Zhou Shunzhi Qian M. Guadalupe Sierra Beltran Guang Ye Klaas van Breugel Victor C. Li 《Materials and Structures》2010,43(6):803-814
Nowadays limestone powder and blast furnace slag (BFS) are widely used in concrete as blended materials in cement. The replacement
of Portland cement by limestone powder and BFS can lower the cost and enhance the greenness of concrete, since the production
of these two materials needs less energy and causes less CO2 emission than Portland cement. Moreover, the use of limestone powder and BFS improves the properties of fresh and hardened
concrete, such as workability and durability. Engineered cementitious composites (ECC) is a class of ultra ductile fiber reinforced
cementitious composites, characterized by high ductility, tight crack width control and relatively low fiber content. The
limestone powder and BFS are used to produce ECC in this research. The mix proportion is designed experimentally by adjusting
the amount of limestone powder and BFS, accompanied by four-point bending test and uniaxial tensile test. This study results
in an ECC mix proportion with the Portland cement content as low as 15% of powder by weight. This mixture, at 28 days, exhibits
a high tensile strain capacity of 3.3%, a tight crack width of 57 μm and a moderate compressive strength of 38 MPa. In order
to promote a wide use of ECC, it was tried to simplify the mixing of ECC with only two matrix materials, i.e. BFS cement and
limestone powder, instead of three matrix materials. By replacing Portland cement and BFS in the aforementioned ECC mixture
with BFS cement, the ECC with BFS cement and limestone powder exhibits a tensile strain capacity of 3.1%, a crack width of
76 μm and a compressive strength of 40 MPa after 28 days of curing. 相似文献
52.
Polysaccharides,oligosaccharides and nitrogenous compounds change during the ageing of Tempranillo and Verdejo sparkling wines 下载免费PDF全文
53.
54.
Physicochemical Changes of Connective Tissue Proteins in Jumbo Squid (Dosidicus gigas) Muscle During Ice Storage 下载免费PDF全文
55.
Combined Effect of Ultrasound and Mild Temperatures on the Inactivation of E. coli in Fresh Carrot Juice and Changes on its Physicochemical Characteristics 下载免费PDF全文
56.
Diago MP Ayestarán B Guadalupe Z Garrido Á Tardaguila J 《Journal of the science of food and agriculture》2012,92(4):925-934
BACKGROUND: Early defoliation is a viticultural practice aimed at crop control. So far, the impact of early leaf removal on the monomeric phenolic composition of wines has not been explored. This study examines the effects of early defoliation on the phenolic profile and content in Tempranillo wines. The influence of the defoliation method (manual vs mechanical) and the timing of leaf removal (pre‐bloom vs fruit set) was investigated. RESULTS: Over two consecutive seasons, 2007 and 2008, the monomeric phenolic composition in Tempranillo wines was studied by high‐performance liquid chromatography with photodiode array detection, and 22 compounds were identified and quantified. Overall, early defoliation led to wines more intensely coloured, of higher alcohol content and with larger concentrations of hydroxycinnamic acids, flavonols and anthocyanins (in 2008 only for mechanical treatments). In the absence of fungal infection, resveratrol was found to increase in wines corresponding to early defoliation treatments. The method of leaf removal seemed to be more critical than the timing of intervention, and larger effects on wine phenolic composition were observed for mechanical treatments. CONCLUSION: Early defoliation proved to be an effective technique for improving the phenolic composition of Tempranillo wines, by favouring the accumulation of hydroxycinnamics, flavonols and anthocyanins. This is an important achievement, as wine quality is often described by its colour and phenolic attributes. Copyright © 2011 Society of Chemical Industry 相似文献
57.
Jesus Guardiola Jose M. Aragón Guadalupe Ramos Rosario Elvira Daniel Martín 《American Institute of Chemical Engineers》2012,58(12):3645-3652
The fine tuning of a sensor designed to locate interfaces using a two‐dimensional gas–solid fluidized bed (FB) as reference is described. The sensor works through computer vision and consists of a charge coupled device camera that is placed alongside the bed and, as the human eye would do, first establishes a straight segment of the bed's top surface to define the phase boundary and then through pattern recognition continuously scans the interface in search of a similar pattern. The field of view is 582 × 752 pixels2. The experimentally measured Pixel size is 216 × 208 μm2. The device allows for experimentally obtaining the position of the probe with a resolution of ± 0.01 pixels at 25 Hz. We also describe its use to measure the height of the FB and observe a linear relationship with fluidization velocity. © 2012 American Institute of Chemical Engineers AIChE J, 2012 相似文献
58.
Guadalupe Bustos Ana Beln Moldes Jos Manuel Cruz Jos Manuel Domínguez 《Journal of the science of food and agriculture》2004,84(15):2105-2112
Trimmings of vineshoots, an agricultural waste with little use, were hydrolysed with dilute sulphuric acid (1–5%) in order to obtain sugar solutions suitable as fermentation media. The operational conditions for hydrolysis were selected on the basis of both the generation of hemicellulosic sugars (mainly xylose) and glucose and the concentrations of reaction byproducts affecting fermentation (furfural, hydroxymethylfurfural and acetic acid). Hemicellulosic hydrolysates were supplemented with nutrients and fermented with Lactobacillus pentosus, without any previous detoxification stage, to produce lactic acid. Under the best operational conditions assayed (3% H2SO4 and 15 min), 21.8 g lactic acid l?1 was produced (QP = 0.844 g l?1 h?1, YP/S = 0.77 g g?1), which represents a theoretical yield of 99.6%. Acetic acid was the primary byproduct formed from xylose, at about 25% of the lactic acid level. Copyright © 2004 Society of Chemical Industry 相似文献
59.
Alejandro Aparicio-Saguilán Andrés Aguirre-Cruz Guadalupe Méndez-Montealvo Sandra L. Rodriguez-Ambriz Francisco J. Garcia-Suarez Delia E. Páramo-Calderón Luis A. Bello-Pérez 《LWT》2014
Two banana starches were studied to analyze the effect of the acid hydrolysis on their molecular structure, and the impact in their physicochemical features. The native banana starches exhibit differences in the amylose content, molar mass, gelatinization parameters, X-ray diffraction pattern, and pasting profile. These results suggested that different acid hydrolysis mechanisms may be operative in these two starches. The kinetic hydrolysis is different in both banana starches that are related to the crystalline packing of the starch molecules. This was confirmed by the amylose content, the X-ray diffraction pattern, and the thermal study in the acid hydrolyzed starches at different times. The acid-treated Roatan starch showed higher retrogradation than Macho starch, a phenomenon that increases in the sample hydrolyzed for the longer time. This pattern is related to the amylose/amylopectin ratio, the reduction in the molar mass and the gyration radius. The acid hydrolysis of banana starches, although they have some similarities, they are different. 相似文献
60.
Biochemical and Visual Changes in Cactus Stems (Opuntia ficus‐indica Mill.) Stored at 4, 12 and 26C 下载免费PDF全文
Lizette Liliana Rodríguez‐Verástegui Juliana Osorio‐Córdoba Fernando Díaz de León‐Sánchez Clara Pelayo‐Zaldívar David Manuel Díaz‐Pontones Elsa Bosquez‐Molina Guadalupe Judith Márquez‐Guzmán Héctor Bernardo Escalona‐Buendía José Ramón Verde‐Calvo Laura Josefina Pérez‐Flores 《Journal of Food Biochemistry》2015,39(4):449-461