全文获取类型
收费全文 | 116篇 |
免费 | 6篇 |
专业分类
化学工业 | 33篇 |
金属工艺 | 3篇 |
建筑科学 | 11篇 |
能源动力 | 4篇 |
轻工业 | 30篇 |
一般工业技术 | 17篇 |
冶金工业 | 7篇 |
自动化技术 | 17篇 |
出版年
2022年 | 3篇 |
2021年 | 2篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 4篇 |
2017年 | 3篇 |
2016年 | 3篇 |
2015年 | 5篇 |
2014年 | 3篇 |
2013年 | 9篇 |
2012年 | 7篇 |
2011年 | 9篇 |
2010年 | 6篇 |
2009年 | 5篇 |
2008年 | 7篇 |
2007年 | 3篇 |
2006年 | 6篇 |
2005年 | 2篇 |
2004年 | 1篇 |
2003年 | 9篇 |
2002年 | 7篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1982年 | 1篇 |
1977年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有122条查询结果,搜索用时 15 毫秒
31.
Monica H Carlsen Inger TL Lillegaard Anette Karlsen Rune Blomhoff Christian A Drevon Lene F Andersen 《Nutrition journal》2010,9(1):37
Background
We have developed a food frequency questionnaire (FFQ) for the assessment of habitual diet, with special focus on the intake of fruit, vegetables and other antioxidant-rich foods and beverages. The aim of the present study was to evaluate the relative validity of the intakes of energy, food and nutrients from the FFQ. 相似文献32.
Pille Mänd Lea Hallik Josep Peñuelas Pierpaolo Duce Claus Beier János Garadnai Inger Kappel Schmidt Patricia Prieto Joke W. Westerveld 《Remote sensing of environment》2010,114(3):626-297
The aim of this study was to evaluate the use of ground-based canopy reflectance measurements to detect changes in physiology and structure of vegetation in response to experimental warming and drought treatment at six European shrublands located along a North-South climatic gradient. We measured canopy reflectance, effective green leaf area index (green LAIe) and chlorophyll fluorescence of dominant species. The treatment effects on green LAIe varied among sites. We calculated three reflectance indices: photochemical reflectance index PRI [531 nm; 570 nm], normalized difference vegetation index NDVI680 [780 nm; 680 nm] using red spectral region, and NDVI570 [780 nm; 570 nm] using the same green spectral region as PRI. All three reflectance indices were significantly related to green LAIe and were able to detect changes in shrubland vegetation among treatments. In general warming treatment increased PRI and drought treatment reduced NDVI values. The significant treatment effect on photochemical efficiency of plants detected with PRI could not be detected by fluorescence measurements. However, we found canopy level measured PRI to be very sensitive to soil reflectance properties especially in vegetation areas with low green LAIe. As both soil reflectance and LAI varied between northern and southern sites it is problematic to draw universal conclusions of climate-derived changes in all vegetation types based merely on PRI measurements. We propose that canopy level PRI measurements can be more useful in areas of dense vegetation and dark soils. 相似文献
33.
Marthe Jordbrekk Blikra Sigrun Henjum Inger Aakre 《Comprehensive Reviews in Food Science and Food Safety》2022,21(2):1517-1536
Brown algae are becoming increasingly popular as a food source and dietary supplement in Europe and other Western countries. As they are highly rich in iodine, they represent a potential new dietary iodine source. Iodine deficiency has been re-emerging in Europe, and it is important to ensure adequate intake through one's diet. However, macroalgae, and especially brown algae, may contain very high amounts of iodine, and both iodine deficiency and excessive iodine may increase the risk of negative health effects. The iodine content of algae or foods containing algae is currently not regulated in the European Union. The aim of this paper is to review the literature to determine the chemical species of iodine in brown algae, the loss of iodine during processing, and the bioavailability and bioaccessibility of iodine. A systematic search of the literature was performed in April 2021, via the databases Web of Science and PubMed. The review includes studies of iodine in brown macroalgae in relation to bioavailability, bioaccessibility, processing and speciation. A meta-analysis was conducted in relation to the following topics: (i) the correlation between total iodine and iodide (I–) content in brown algae; (ii) the correlation between the loss of iodine during processing and the I– content; and (iii) the correlation between bioavailability and the I– content. The bioavailability of iodine from brown algae was generally high, with in vivo bioavailability ranging from 31% to 90%. The in vitro bioavailability of iodine (2%–28%) was systematically lower than in vivo bioavailability (31%–90%), indicating an inadequate in vitro methodology. Processing may reduce the iodine content of brown algae, and a higher I– content was positively correlated with increased iodine loss during processing. Although processing strategies may reduce the iodine content of brown algae significantly, the iodine content may still be high after processing. These findings may be used in food safety evaluations of brown algae as well as in the development of macroalgae-containing foods with iodine contents suitable for human consumption. Further research on processing techniques to reduce the iodine content in brown macroalgae are warranted. 相似文献
34.
Revilija Mozuraityte Inger Beate Standal Janna Cropotova Emilia Budźko Turid Rustad 《International Journal of Food Science & Technology》2021,56(4):1918-1928
Quality changes in Atlantic mackerel fillets during superchilled, chilled and frozen storage focusing on lipid quality, colour and changes in low molecular weight metabolites relevant for quality and safety were studied. Low formation of oxidation products was observed in chilled (up to 7 days), superchilled (up to 14 days) and frozen storage (up to one year). Only slight formation of TBARS was measured in the samples which correlated with the increasing fillet yellowness. The profile of low molecular weight compounds, analysed by high-resolution NMR, showed clear grouping of the different samples according to both treatment and storage time. The increase in K-value was highest in the chilled samples, reaching a K-value of 93 ± 3% on day 5, exceeding the proposed limit of human consumption (80%) while superchilling reached a K-value of ca 90 % after 14 days. Frozen samples showed acceptable quality in the whole storage period. 相似文献
35.
Inger Elfman-Börjesson Sander van den Hark Magnus Härröd 《Journal of the American Oil Chemists' Society》1997,74(9):1177-1180
Cis and trans isomers of fatty acid methyl esters, fatty alcohols, and triacylglycerols were analyzed with a silverion high-performance
liquid chromatography system. Gradients of n-heptane and acetonitrile were used to elute molecules with up to nine cis double bonds. The analyses were as fast and reliable and had a resolution similar to that of the best published analyses.
However, published analyses were performed with chlorinated solvents, and these solvents are carcinogenic and mutagenic. The
solvents we used, heptane and acetonitrile, are less dangerous to the analyst. 相似文献
36.
Kristina Sjödin Monika Persson Jenny Fäldt Inger Ekberg Anna-Karin Borg-Karlson 《Journal of chemical ecology》2000,26(7):1701-1720
The relative amounts and enantiomeric compositions of monoterpene hydrocarbons in branch and trunk xylem, in needles, and in resin from apical buds in 18 Pinus sylvestris trees have been determined and compared with the terpene content in branch xylem and needles of Picea abies. Besides the high amount of (+)-3-carene, an excess of (+)--pinene has been found in P. sylvestris, whereas in P. abies (–)--pinene dominates over (+)--pinene. In P. sylvestris, clear positive correlations were found between (+)--pinene and (+)-camphene in the four tissues analyzed. Good positive correlations were also observed between (–)--pinene and (–)-camphene in the two types of xylem, between (+)--pinene and (+)--pinene in the resin, and between tricyclene and (–)-camphene in resin and needles. In P. abies, positive correlations were found between (+)--pinene and (+)-camphene in the branch xylem and between tricyclene and (–)-camphene as well as between (–)--pinene and (–)-camphene in the needles. Complex relationships between (–)--pinene and (–)--pinene were found both in the P. abies and in the P. sylvestris tissues. The importance of the enantiomeric composition of -pinene for the host selection of Ips typographus, Tomicus piniperda, and Hylobius abietis is discussed. 相似文献
37.
Inger Vikholm-LundinAuthor Vitae Sanna AuerAuthor VitaeAnn-Charlotte HellgrenAuthor Vitae 《Sensors and actuators. B, Chemical》2011,156(1):28-34
A molecular layer with low non-specific binding enabling determination of low concentrations of 3,4-methylenedioxymethamphetamine (MDMA) by the displacement of antibodies has been developed. Antibody Fab′-fragments at various concentrations have been site-directly immobilised on gold and intercalated with a hydrophilic non-ionic polymer that reduces non-specific binding. Bovine serum albumin conjugated with MDMA and various concentrations of anti-MDMA antibodies were bound to the layer. The amount of conjugates and antibodies bound was dependent on the amount of Fab′-fragments in the layer. Antibodies were also bound to the conjugates physisorbed directly onto the gold surface and in mixtures with the polymer or with a lipoamide. A high displacement of antibodies was observed by surface plasmon resonance (SPR) on interaction of MDMA with the different layers in buffer solution. No displacement could, however, be observed in saliva with the pure conjugate layer because of a high non-specific binding of proteins. When the conjugates were coupled to the surface through the antibody Fab-fragment/polymer layer, MDMA concentrations as low as 0.02 ng mL−1 (0.14 nM) could easily be detected in buffer. In diluted saliva the lowest limit of detection was 0.4 ng mL−1 enabling determination of drugs from saliva with a cut-off concentration of 2 ng mL−1. The molecular layer of antibody Fab′-fragments and polymer thus shows great potential for binding conjugates and antibodies that can be displaced on the interaction with very low concentrations of small-sized molecules. A low non-specific binding is guaranteed by the presence of the hydrophilic polymer. 相似文献
38.
Monika Ruszak Marek Inger Stefan Witkowski Marcin Wilk Andrzej Kotarba Zbigniew Sojka 《Catalysis Letters》2008,126(1-2):72-77
Catalytic high temperature decomposition (secondary abatement) of nitrous oxide over calcium aluminate 12CaO · 7Al2O3 (mayenite) was studied in the model laboratory tests (TPSR) and pilot units (steady-state) using the real feed. X-ray diffraction (XRD), scanning electron microscopy (SEM), N2-sorption (BET), electron paramagnetic resonance (EPR) and Raman spectroscopies were used to characterize the synthesized material. The catalyst exhibited high efficiency and selectivity in N2O removal, reaching practically 100% conversion at 1150 K without appreciable total losses of NO x . Owing to its high thermal stability and resistivity to sintering and low cost of production raw materials, mayenite was found to be a promising catalyst for economically appealing secondary abatement of nitrous oxide in nitric acid plants. 相似文献
39.
Direct aerobic oxidation of primary alcohols to methyl esters catalyzed by a heterogeneous gold catalyst 总被引:2,自引:0,他引:2
Inger S. Nielsen Esben Taarning Kresten Egeblad Robert Madsen Claus H. Christensen 《Catalysis Letters》2007,116(1-2):35-40
Methyl esters can be produced in high yields by oxiding methanolic solutions of primary alcohols with dioxygen over a heterogeneous
gold catalyst. The versatility of this new methodology is demonstrated by the fact that alkylic, benzylic and allylic alcohols,
as well as alcohols containing an amine functionality are oxidized in good to excellent yields. 相似文献
40.
Silja Skogstad Tuv Marianne Skov-Skov Bergh Jannike Mrch Andersen Synne Steinsland Vigdis Vindenes Michael H. Baumann Marilyn A. Huestis Inger Lise Bogen 《International journal of molecular sciences》2021,22(21)
Methiopropamine is a novel psychoactive substance (NPS) that is associated with several cases of clinical toxicity, yet little information is available regarding its neuropharmacological properties. Here, we employed in vitro and in vivo methods to compare the pharmacokinetics and neurobiological effects of methiopropamine and its structural analog methamphetamine. Methiopropamine was rapidly distributed to the blood and brain after injection in C57BL/6 mice, with a pharmacokinetic profile similar to that of methamphetamine. Methiopropamine induced psychomotor activity, but higher doses were needed (Emax 12.5 mg/kg; i.p.) compared to methamphetamine (Emax 3.75 mg/kg; i.p.). A steep increase in locomotor activity was seen after a modest increase in the methiopropamine dose from 10 to 12.5 mg/kg, suggesting that a small increase in dosage may engender unexpectedly strong effects and heighten the risk of unintended overdose in NPS users. In vitro studies revealed that methiopropamine mediates its effects through inhibition of norepinephrine and dopamine uptake into presynaptic nerve terminals (IC50 = 0.47 and 0.74 µM, respectively), while the plasmalemmal serotonin uptake and vesicular uptake are affected only at high concentrations (IC50 > 25 µM). In summary, methiopropamine closely resembles methamphetamine with regard to its pharmacokinetics, pharmacodynamic effects and mechanism of action, with a potency that is approximately five times lower than that of methamphetamine. 相似文献