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排序方式: 共有188条查询结果,搜索用时 718 毫秒
141.
142.
Gyrgyi Horvth Eszter Csiks Eichertn Violetta Andres Tímea Bencsik Anik Taktsy Gergely Gulys-Fekete Erika Turcsi Jzsef Deli va Szke gnes Kemny Maja Payrits Lajos Szente Marianna Kocsis Pter Molnr Zsuzsanna Helyes 《Molecules (Basel, Switzerland)》2021,26(2)
Melilotus officinalis is known to contain several types of secondary metabolites. In contrast, the carotenoid composition of this medicinal plant has not been investigated, although it may also contribute to the biological activities of the drug, such as anti-inflammatory effects. Therefore, this study focuses on the isolation and identification of carotenoids from Meliloti herba and on the effect of isolated (all-E)-lutein 5,6-epoxide on primary sensory neurons and macrophages involved in nociception, as well as neurogenic and non-neurogenic inflammatory processes. The composition of the plant extracts was analyzed by high performance liquid chromatography (HPLC). The main carotenoid was isolated by column liquid chromatography (CLC) and identified by MS and NMR. The effect of water-soluble lutein 5,6-epoxide-RAMEB (randomly methylated-β-cyclodextrin) was investigated on Ca2+-influx in rat primary sensory neurons induced by the activation of the transient receptor potential ankyrin 1 receptor agonist to mustard-oil and on endotoxin-induced IL-1β release from isolated mouse peritoneal macrophages. (all-E)-Lutein 5,6-epoxide significantly decreased the percent of responsive primary sensory neurons compared to the vehicle-treated stimulated control. Furthermore, endotoxin-evoked IL-1β release from macrophages was significantly decreased by 100 µM lutein 5,6-epoxide compared to the vehicle-treated control. The water-soluble form of lutein 5,6-epoxide-RAMEB decreases the activation of primary sensory neurons and macrophages, which opens perspectives for its analgesic and anti-inflammatory applications. 相似文献
143.
Focsan AL Bowman MK Konovalova TA Molnár P Deli J Dixon DA Kispert LD 《The journal of physical chemistry. B》2008,112(6):1806-1819
Pulsed electron nuclear double resonance (ENDOR) and two-dimensional (2D)-hyperfine sublevel correlation spectroscopy (HYSCORE) studies in combination with density functional theory (DFT) calculations revealed that photo-oxidation of natural zeaxanthin (ex Lycium halimifolium) and violaxanthin (ex Viola tricolor) on silica-alumina produces the carotenoid radical cations (Car*+) and also the neutral carotenoid radicals (#Car*) as a result of proton loss (indicated by #) from the C4(4') methylene position or one of the methyl groups at position C5(5'), C9(9'), or C13(13'), except for violaxanthin where the epoxide at positions C5(5')-C6(6') raises the energy barrier for proton loss, and the neutral radicals #Car*(4) and #Car*(5) are not observed. DFT calculations predict the largest isotropic beta-methyl proton hyperfine couplings to be 8 to 10 MHz for Car*+, in agreement with previously reported hyperfine couplings for carotenoid pi-conjugated radicals with unpaired spin density delocalized over the whole molecule. Anisotropic alpha-proton hyperfine coupling tensors determined from the HYSCORE analysis were assigned on the basis of DFT calculations with the B3LYP exchange-correlation functional and found to arise not only from the carotenoid radical cation but also from carotenoid neutral radicals, in agreement with the analysis of the pulsed ENDOR data. The formation of the neutral radical of zeaxanthin should provide another effective nonphotochemical quencher of the excited state of chlorophyll for photoprotection in the presence of excess light. 相似文献
144.
Jzsef Deli Erzsbet sz Pter Molnr Ferenc Zsila Mikls Simonyi Gyula Tth 《Helvetica chimica acta》2001,84(12):3810-3817
(6′S)‐ and (6′R)‐‘Capsorubol‐6‐one' (=(3S,3′S,5R,5′R,6′S)‐ and (3S,3′S,5R,5′R,6′R)‐3,3′,6′‐trihydroxy‐κ,κ‐caroten‐6‐one; 8 and 9 , resp.), (6S,6′R)‐ and (6R,6′R)‐capsorubol (=3S,3′S,5R,5′R,6S,6′R)‐ and (3S,3′S,5R,5′R,6R,6′R)‐κ,κ‐carotene‐3,3′,6,6′‐tetrol; 11 and 12 , resp.) and (6′S)‐ and (6′R)‐cryptocapsol (=(3′S,5′R,6′S)‐ and (3′S,5′R,6′R)‐β,κ‐carotene‐3′,6′‐diol; 5 and 6 , resp.) were prepared in crystalline from by the reduction of capsorubin (=(3S,3′S,5R,5′R)‐3,3′‐dihydroxy‐κ,κ‐carotene‐6,6′‐dione; 7 ) and cryptocapsin (=(3′S,5′R)‐3′‐hydroxy‐β,κ‐caroten‐6′‐one; 4 ) and characterized by their UV/VIS, CD, 1H‐NMR, and mass spectra. 相似文献
145.
146.
生物及化学反硝化过程中N2O的产生与控制 总被引:4,自引:0,他引:4
长期以来,人们都将N2O视为一种温室气体,然而事实上N2O在航天领域是一种宝贵的能源物质,西方发达国家对N2O的制备技术相当重视。生物及化学反硝化过程都能产生大量的N2O,但将N2O作为能源气体收集利用在我国还未受到重视。本文介绍了国内外关于污水脱氮过程中N2O生成情况的研究,分析了生物脱氮过程中N2O的产生机理和影响因素,同时探讨了化学反硝化作用,尤其是Fe(Ⅱ)的还原作用对N2O生成和控制的影响,提出了对N2O进行资源化利用的途径。最后指出,可以大量积累N2O的化学反硝化过程应是今后水体脱氮的重要研究方向,尤其是化学反硝化过程中N2O的产生机理和影响因素值得进一步研究。 相似文献
147.
Physical Simulation of Small bore Copper vapor Laser 总被引:2,自引:0,他引:2
YU Deli TAO Yongxiang YIN Xianhua WANG Runwen CHEN Lin YANG Yan LI Hailan 《Chinese Journal of Lasers》1999,8(1):21-28
1IntroductionInrecentyearsthecoppervaporlaser(CVL)hasbeendevelopedrapidly,amarkedachievementhasbeenobtainedonitstheoriesandd... 相似文献
148.
Comparative study on the carotenoid composition in the buds and flowers of differentAesculus species
Summary The HPLC analysis of the buds, pollens and petals of two species ofAesculus is reported. Violaxanthin, neoxanthin, aesculaxanthin, lutein, β-carotene, β-cryptoxanthin β-citraurin and theircis-isomers could be detected with a diodearray detector utilising authentic samples.
Presented at Balaton Symposium on High Performance Separation Methods, Siófok, Hungary, September 1–3, 1999 相似文献
149.
Some natural and semisynthetic carotenoids were examined by means of FT‐IR spectroscopy. The IR bands of the characteristic functional groups (CH3, CH2, CC, CO, OH, etc.) were assigned when possible. Some special functional groups – without H‐atoms – such as CCC, ‘cross epoxides', etc., which cannot be easily identified by 1H‐NMR methods, were also detected in the FT‐IR spectra. 相似文献
150.
Donny W.H. Merkx Faruk Delić Peter A. Wierenga Marie Hennebelle John P.M. van Duynhoven 《Magnetic resonance in chemistry : MRC》2019,57(9):540-547
Lipid oxidation is the main reason for the limited shelf life of mayonnaise. One of the main catalysts of this process is iron, which is introduced in its ferric (Fe(III)) form via phosvitin, an egg yolk phosphoprotein rich in phosphoserines. The binding of Fe(III) to phosvitin and its ability to establish a redox couple with Fe(II) is believed to determine the oxidation rate of unsaturated lipids. In this work, a 31P NMR based method was developed to quantify loading of phosvitin with Fe(III) and its reductive release. Both features could be quantified in model phosvitin solutions by exploiting the paramagnetic broadening of 31P NMR signal of phosphoserine residues by Fe(III). This method was then successfully applied to quantify the phosvitin-Fe(III) loading in mayonnaise water phase by liquid NMR, whereas 31P NMR MAS could only provide a qualitative measure. The 31P NMR method showed a direct relation between loading of the Fe(III)-phosvitin complex and lipid oxidation. 相似文献