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Xingguang Chen Beibei Chu Huiting Xi Junjun Xu Lizhi Lai Huifeng Peng Danwen Deng Ganhui Huang 《Journal of dairy science》2018,101(11):9647-9658
Chloride ion concentration in milk was determined by pulsed amperometric detection in a flow injection system. Results showed that the Au electrode lost 3 electrons at 1.10 V and formed chloroaurate ions (AuCl4?) by combining with chloride ions, after which AuCl4? was partly reduced to Au at 0.6 V. Based on the electrochemical process, a triple waveform with detection potential of 1.15 V, detection time of 150 ms, oxidation potential of 1.4 V, oxidation time of 550 ms, reduction potential of 0 V, and reduction time of 400 ms was applied to the Au electrode for detecting chloride ion concentration in milk. The approach is rapid and automatic and features a detection limit of 0.005 g/L. The relative standard deviation obtained by 60 repetitive injections reached 1.48% at 2 g/L of NaCl. The method developed using the Au electrode without modification was used to analyze the chloride ion concentration in raw milk without preprocessing. The method showed good agreement with potentiometric titration. 相似文献
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《Journal of dairy science》2021,104(12):12365-12374
Cronobacter sakazakii is a foodborne, emerging opportunistic pathogen that causes severe bacteremia, necrotizing enterocolitis, and sepsis with a mortality rate of up to 80%. In this study, we developed a simple and sensitive fluorescent turn-off aptasensor with rolling circle amplification assay for viable C. sakazakii detection in powdered infant formula. The results showed that the proposed aptasensor has good performance and specificity for detecting viable C. sakazakii in pure culture and powdered infant formula samples within 3 h. Under the optimal reaction conditions, there is a linear relationship between fluorescent intensity at 490 nm and logarithmic concentration of C. sakazakii in the range of 2.7 × 105 to 2.7 × 102 cfu/mL, with a limit of detection of 2.7 × 102 cfu/mL in pure culture. The proposed aptasensor achieved a recovery of 104 to 111% in pure culture, and 96 to 107% in spiked powdered infant formula samples. The proposed aptasensor does not require complicated DNA extraction steps or antibodies, and can be performed at 37°C, making it a convenient and sensitive strategy for C. sakazakii detection. 相似文献
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某高层建筑地上38层,结构总高度139.2 m,采用框架-核心筒结构。本文针对其外框架部分进行结构选型研究,对外框架采用钢筋混凝土柱-钢筋混凝土梁、型钢混凝土柱-钢筋混凝土梁、钢管混凝土柱-型钢混凝土梁三种方案进行比选,根据JGJ3—2010《高规》关于高层建筑结构的设计要求,对结构在风荷载和地震作用下结构抗侧性能进行比较,并且结合三种方案的经济性,最终确定外框架采用型钢混凝土柱-钢筋混凝土梁的方案。 相似文献
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《Food and Bioproducts Processing》2014,92(1):30-37
Effects of ultrasonic treatment on emulsifying properties and structure of peanut protein isolate (PPI) were evaluated by analysis of particle size distribution, protein surface hydrophobicity, SDS-PAGE, circular dichroism spectra and environmental scanning electron microscopy. The emulsifying properties of the PPI were found to be improved by ultrasonic treatment. The mean particle size decreased from 474.7 nm to 255.8 nm while the molecular weight remained unaffected. The results of intrinsic fluorescence spectroscopy and surface hydrophobicity indicated that ultrasonic treatment induced tertiary structural changes of the proteins in PPI. Emulsifying activity index and emulsion stability index were found to be correlated fairly well with surface hydrophobicity (H0) (r = 0.712 and r = 0.668, respectively). 相似文献
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《Carbon》2014
Proper disposal of waste frying oil (WFO) is an important waste-management concern. In this paper, we develop a facile method to reuse WFO for one-step synthesis of sulfur-doped carbon dots (S-C-dots) with the assistance of concentrated sulfuric acid. The as-synthesized S-C-dots are uniform in size and show partial disordered graphite-like structure. Different from the doping-free or nitrogen-doped carbon dots, the S-C-dots perform a strong ultraviolet emission at 378 nm due to successful sulfur-doping. Noticeably, the S-C-dots exhibit a distinct pH-sensitive feature and the intensity of photoluminescence increases linearly in the pH range from 3 to 9. Furthermore, possessing fascinating optical properties, high photostability, and low cytotoxicity, the S-C-dots have served as fluorescent probes for cell imaging. 相似文献
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Man‐Li Zhao Jiang‐Ning Hu Xue‐Mei Zhu Hong‐Yan Li Jing Li Ya‐Wei Fan Ze‐Yuan Deng 《International Journal of Food Science & Technology》2014,49(2):453-459
Medium‐ and long‐chain triacylglycerols (MLCTs)–enriched structured lipid (SL) was synthesised through enzymatic interesterification from Cinnamomum camphora seed oil (CCSO) and camellia oil (CO) using Lipozyme RM IM from Rhizomucor miehei as a biocatalyst. Effects of different reaction conditions including substrate molar ratio, reaction time and reaction temperature were investigated. Results showed that 55.81% of total MLCT species (CCO/LaCL, LaCO/LCL, COO/OCO and LaOO/OLaO) was obtained in the interesterified product under the optimal conditions of substrate molar ratio of 1:1.5 (CCSO/CO) at 60 °C for 3 h. Thereafter, fatty acid profiles, tocopherol contents and physiochemical characteristics of the interesterified product and physical blend were comparatively investigated. The fatty acid composition of the interesterified product consisted of capric acid (26.33%), lauric acid (21.29%) and oleic acid (42.33%). It should be mentioned that the interesterified product contained predominantly oleic acid (88.69%) at Sn‐2 position, while MCFAs (68.05%) at Sn‐1,3 positions. Compared with physical blend, the reduction in tocopherol contents and changes of physiochemical characteristics occurred in SL. The smoke point of the interesterified product was much higher than that of the physical blend, which meant that such MLCTs‐enriched SL could be better for cooking purpose. 相似文献
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Hua Xiong Shen‐qi Wang Chun‐qing Bai Qiang Zhao 《International Journal of Food Science & Technology》2014,49(1):91-97
Zero‐trans interesterified fats were produced from camellia seed oil (CSO), palm stearin (PS) and coconut oil (CO) with three weight ratios (CSO/PS/CO, 50:50:10, 40:60:10 and 30:70:10) using Lipozyme TL IM. Results showed that the interesterified products contained palmitic acid (34.28–42.96%), stearic acid (3.96–4.72%), oleic acid (38.73–47.95%), linoleic acid (5.92–6.36%) and total medium‐chain fatty acids (MCFA)s (∑MCFAs, 5.03–5.50%). Compared with physical blends, triacylglycerols of OOO and PPP were decreased and formed new peaks of equivalent carbon number (ECN) 44 in the interesterified products. The product CPC3′ showed a slip melting point of 36.8 °C and a wide plastic range of solid fat content (SFC) (45.8–0.4%) at 20–40 °C. Also, the major β′ form was determined. These data indicated that the zero‐trans interesterified fats would have a potential functionality for margarine fats. Subsequently, the antioxidative stabilities of interesterified products with the addition of α‐tocopherol (α‐TOH) and ascorbyl palmitate (AP) were investigated. The results indicated that AP had a dose‐dependent effect at concentrations of 100, 200 and 400 ppm. 相似文献