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61.
Yi-Jen Fang Chih-Hsien Chiu Yuan-Yen Chang Chung-Hsi Chou Hui-Wen Lin Ming-Feng Chen Yi-Chen Chen 《Food research international (Ottawa, Ont.)》2011,44(9):3105-3110
Chronic alcohol consumption or alcohol abuse is the main cause of alcoholic steatohepatitis or further cirrhosis. This study was to exam if the antioxidant capacity and alcohol metabolism in livers of chronic alcohol-fed rats were improved by supplementing taurine (Tau). Rats were randomly divided into four groups with five times per week of treatment: 1) isocaloric solution; 2) 3 g alcohol/kg BW/day; 3) 3 g alcohol/kg BW/day + 1 g taurine (Tau)/kg BW/day; and 4) 3 g alcohol/kg BW/day + 2 g Tau/kg BW/day. A 6-week alcohol consumption resulted in lower (p < 0.05) body weight gain and self-antioxidant capacities, as well as increased (p < 0.05) liver size, serum/hepatic lipids, and AST and ALT values. However, alcohol-fed rats co-treated with Tau have decreased (p < 0.05) liver lipid levels via increasing fecal lipid output and cholesterol metabolism. Besides, co-treatment of Tau also enhanced (p < 0.05) self-antioxidant capacities and alcohol metabolism in livers via enhancing GSH contents, CAT, GSH-Px, ADH, and ALDH activities, but decreasing MDA contents. In a histological examination of rat liver, microvesicular steatosis and necrotic cells were observed in alcohol-fed rats without Tau while largely suppressed microvesicular steatosis and no necrotic cells were observed in alcohol-fed rat supplemented with Tau. Therefore, Tau could be an effective hepatoprotective agent against alcohol-induced damage via enhancing self-antioxidant capacity and alcohol metabolism. 相似文献
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63.
ω-Formyl-functionalized polystyrenes can be synthesized in quantitative yield by reacting poly(styryl)lithium (M n = 2 × 103?8 × 103 g/mol) in benzene with a 0.1?0.4 molar excess of 4-morpholinecarboxaldehyde followed by methanol termination and precipitation into methanol. Narrow molecular weight distribution ω-formyl-functionalized polystyrenes were characterized by hydroxylamine end-group titration, thin layer chromatography and both 1H and 13C NMR spectroscopy. The mechanism of the functionalization was studied by trapping the tetrahedral α-amino alkoxide intermediate with diphenylphosphinic chloride. 相似文献
64.
lvaro Beltrn Eleuterio lvarez M. Mar Díaz‐Requejo Pedro J. Prez 《Advanced Synthesis \u0026amp; Catalysis》2015,357(13):2821-2826
The reaction of aldehydes, amines and alcohols usually leads to a series of equilibria from which isolation of one product is difficult to achieve. We have found that this three‐component reaction can be controlled and directed in an exclusive manner toward the formation of the hemiaminal ether. A series of 33 hemiaminal ethers has been obtained in high yields, from different aldehydes, amines and alcohols, under very mild conditions just with molecular sieves as promoter.
65.
在非均相条件下,利用漆酶催化氧化原儿茶酸使其接枝到壳聚糖进行改性,初步探究改性过程中,反应体系各组分相对浓度的变化、改性壳聚糖上原儿茶酸的接枝反应历程以及改性壳聚糖抗氧化性能的提升效果。通过React IR(反应红外)分析表明壳聚糖先将原儿茶酸吸附到固相之后才发生进一步反应,通过Py-GC/MS(裂解气相色谱质谱联用)分析表明接枝反应后原儿茶酸是通过化学键连接到了壳聚糖,利用Solid-state 13C NMR(固体核磁共振)和FT-IR(红外光谱)检测到接枝前后新的化学键生成,进一步表明原儿茶酸通过化学键接枝到了壳聚糖,通过ABTS法测定接枝反应前后壳聚糖的抗氧化性能,发现接枝后壳聚糖抗氧化性能的提高显著。 相似文献
66.
Alcohol dehydrogenases catalyse the reversible oxidation of alcohols to aldehydes or ketones, with concomitant reduction of NAD(+) or NADP(+) . Adh1p is responsible for the reduction of acetaldehyde to ethanol, while Adh2p catalyses the reverse reaction, the oxidation of ethanol to acetaldehyde. Lack of Adh1p shifts the cellular redox balance towards excess NADH/NADPH and acetaldehyde, while absence of Adh2p does the opposite. Yeast mutant adh1Δ had a slow growth rate, whereas adh2Δ grew like the isogenic wild-type (WT) during prediauxic shift fermentative metabolism. After 48 h WT and mutants reached the same number of viable cells. When exponentially growing (LOG) cells were exposed to calcofluor white, only mutant adh1Δ displayed an irregular deposition of chitin. Quantitative analyses of both LOG and stationary-phase cells showed that adh1Δ mutant contained significantly less ergosterol than cells of WT and adh2Δ mutant, whereas the erg3Δ mutant contained extremely low ergosterol pools. Both adh1Δ and adh2Δ mutants showed higher-than-WT resistance to heat shock and to H(2) O(2) but had WT resistance when exposed to ultraviolet (UV) light and the DNA cross-linking agent diepoxyoctane, indicating normal DNA repair capacity. Mutant adh1Δ was specifically sensitive to acetaldehyde and to membrane peroxidizing paraquat. Our results link the pleiotropic phenotype of adh1Δ mutants to low pools of ergosterol and to reductive stress, and introduce the two new phenotypes, resistance to heat shock and to H(2) O(2) , for the adh2Δ mutant, most probably related to increased ROS production in mitochondria, which leads to the induction of oxidative stress protection. 相似文献
67.
一种新型电流变体材料——酮醛树脂盐类电流变体 总被引:1,自引:0,他引:1
决定电流变体材料性能的主要因素是其分散相的选择。文中首次提出了以酮醛树脂盐类作为电流变体的分散相,研究了反应温度、反应时间及催化剂用量等各种因素对其分子量的影响,测试了以酮醛树脂盐与硅油组成的电流变体材料的稳定特性、温度特性、流变特性、介电特性,结果表明该流体具有良好的抗高剪切速率的特性。 相似文献
68.
Joo Pissarra Sandra Loureno Jos Maria Machado Nuno Mateus David Guimaraens Victor de Freitas 《Journal of the science of food and agriculture》2005,85(7):1091-1097
The commercial wine spirit used for this study revealed that the aldehyde content mainly comprises acetaldehyde but other aldehydes such as propionaldehyde, 2‐methylbutyraldehyde, isovaleraldehyde, methylglyoxal, benzaldehyde and others are also present in significant amounts. A typical grape must was used to assess the influence of wine spirit in the analytical and sensorial characteristics of fortified wines. Decreasing levels of anthocyanins, as well the increase in the red colour and tanning capacity, were observed, and seem to be positively correlated with the increase of the aldehyde content present in the wine spirits used to fortify the must. Using the CIE L*a*b* system, this aldehyde content present in the spirit used seemed to be correlated with the decrease of the wines' lightness (darkening effect), the displacement of the hue angle to higher values (yellowing effect) and the increase of the chromaticity (colour saturation) of the wines. Copyright © 2005 Society of Chemical Industry 相似文献
69.
Melinda L Perkins Bruce R D'Arcy Allan T Lisle Hilton C Deeth 《Journal of the science of food and agriculture》2005,85(14):2421-2428
Solid phase microextraction (SPME) offers a solvent‐free and less labour‐intensive alternative to traditional flavour isolation techniques. In this instance, SPME was optimised for the extraction of 17 stale flavour volatiles (C3–11,13 methyl ketones and C4–10 saturated aldehydes) from the headspace of full‐cream ultrahigh‐temperature (UHT)‐processed milk. A comparison of relative extraction efficiencies was made using three fibre coatings, three extraction times and three extraction temperatures. Linearity of calibration curves, limits of detection and repeatability (coefficients of variation) were also used in determining the optimum extraction conditions. A 2 cm fibre coating of 50/30 µm divinylbenzene/Carboxen/polydimethylsiloxane in conjunction with a 15 min extraction at 40 °C were chosen as the final optimum conditions. This method can be used as an objective tool for monitoring the flavour quality of UHT milk during storage. Copyright © 2005 Society of Chemical Industry 相似文献
70.