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131.
Panagiota Diamantopoulou Seraphim Papanikolaou Eleni Katsarou Michael Komaitis George Aggelis Antonios Philippoussis 《Applied biochemistry and biotechnology》2012,167(7):1890-1906
Volvariella volvacea strains were studied in relation with their ability to produce biomass, lipids and polysaccharides. Firstly, screening of four strains (AMLR 188, 190, 191 and 192) was performed in agar cultures, where the mycelial growth rate of the strains was measured, and in static liquid cultures, where the production of biomass, the biosynthesis of total cellular lipids and the consumption of glucose were monitored. For all strains, biomass production was significant (13?C15?g?l?1) and total lipid in dry weight (%, w/w) ranged from 3 to 12?%. Afterwards, a detailed kinetic analysis of mycelial biomass, extra- and intra- cellular polysaccharides (EPS, IPS, respectively) as well as lipid production by a V. volvacea selected strain was conducted in submerged static and agitated cultures. Maximum values of 15?g?l?1 biomass, ??1.0?g?l?1 EPS and 5.5?g?l?1 IPS were recorded. Agitation did not have severe impact on biomass, EPS and IPS production, but it increased total lipid in dry weight quantities. EPS, IPS and lipid in dry weight values decreased with time. Glucose was the major cellular carbohydrate detected. Total fatty acid analysis of cellular lipids was performed for all V. volvacea strains and linoleic acid ??9,12C18:2 was predominant. Neutral lipids constituted the major fraction of cellular lipids, but their quantity decreased as fermentation proceeded. Phospholipids were the most saturated lipid fraction. 相似文献
132.
Kyriakou E Primikyri A Charisiadis P Katsoura M Gerothanassis IP Stamatis H Tzakos AG 《Organic & biomolecular chemistry》2012,10(9):1739-1742
Unprecedented regioselective acylation of flavonoid aglycones was achieved using Candida antarctica lipase B (CALB). The rapid screening of product formation was performed by the use of the high resolution phenol-type OH (1)H NMR spectral region recorded after the addition of picric acid. 相似文献
133.
Charalambous M Moushi EE Papatriantafyllopoulou C Wernsdorfer W Nastopoulos V Christou G Tasiopoulos AJ 《Chemical communications (Cambridge, England)》2012,48(44):5410-5412
The initial use of 1,3-propanediol in mixed Mn/3d cluster chemistry has led to a Mn(III)(28)Mn(II)(8)Ni(II)(4) molecular aggregate which consists of two Mn(III)(8)Ni(2) loops and two Mn(III)(6)Mn(II)(4) supertetrahedral units and displays a high ground spin state value S(T) = 26 ± 1. 相似文献
134.
Riala M Markoulides MS Moushi EE Chronakis N 《Chemical communications (Cambridge, England)》2011,47(43):11948-11950
The Bingel functionalisation of C(60) with a structurally novel tether equipped with three reactive malonate groups afforded a C(2v)-symmetrical e(edge),e(face),trans-1 trisadduct in a complete regioselective manner and in an excellent yield of 65%. The [60]fullerene trisadduct showed pronounced ability to crystallise and gave X-ray quality single crystals for analysis. 相似文献
135.
136.
Maria Rikkou‐Kalourkoti Eleni Kassi Costas S. Patrickios 《Journal of polymer science. Part A, Polymer chemistry》2012,50(4):665-674
Seven cyclolinear polymers bearing the tertiary‐butyl α‐(hydroxymethyl)acrylate (TBHMA) ether dimer were prepared using reversible addition–fragmentation chain transfer (RAFT) polymerization. Of the seven polymers, five were cyclolinear homopolymers of the TBHMA ether dimer with different degrees of polymerization, one was an “arm‐first” star homopolymer, and the other was an amphiphilic linear copolymer based on the positively ionizable hydrophilic 2‐(dimethylamino)ethyl methacrylate (DMAEMA) and the TBHMA ether dimer. For comparison, two more polymers were prepared using RAFT polymerization where the TBHMA ether dimer was replaced by tertiary‐butyl methacrylate (tBuMA). In particular, an amphiphilic linear DMAEMA–tBuMA diblock copolymer and a tBuMA arm‐first star homopolymer were also synthesized. All polymers were characterized in terms of their molecular weights and composition using gel permeation chromatography and 1H NMR spectroscopy, respectively. Subsequently, the tertiary‐butyl groups of the TBHMA ether dimer units and those of the tBuMA units were cleaved by hydrolysis to yield carboxylic acid groups. The successful removal of the tertiary‐butyl groups was confirmed using 1H and 13C NMR and attenuated total reflectance‐Fourier transform infrared spectroscopies. The hydrolyzed (co)polymers exhibited pK values of the carboxylic acid groups of around 4.5, and glass transition temperatures, Tg, of around 200 °C, which were 50 °C higher than those of their nonhydrolyzed precursors. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
137.
Μichailia Angelopoulou Athanasios Botsialas Alexandros Salapatas Panagiota S. Petrou Willem Haasnoot Eleni Makarona Gerhard Jobst Dimitrios Goustouridis Athanasia Siafaka-Kapadai Ioannis Raptis Konstantinos Misiakos Sotirios E. Kakabakos 《Analytical and bioanalytical chemistry》2015,407(14):3995-4004
138.
Panagiota N. Eleni Magdalini K. KrokidaGregory L. Polyzois Constantinos A. CharitidisElias P. Koumoulos Vasiliki P. TsikourkitoudiIoannis Ziomas 《Polymer Degradation and Stability》2011,96(4):470-476
The degradation of maxillofacial prosthetic elastomers that occur during physical weathering is usually responsible for the replacement of the prosthesis. In this study the mechanical behaviour of a polydimethylsiloxane (PDMS) elastomer was investigated, after 1 year outdoor weathering in two different weathering locations in Greece (Thessaloniki, Athens). The hypothesis investigated was that irradiation time did not affect the measured properties. Specimens (Elastomer 42) were prepared according to manufacturer’s instructions and exposed to solar radiation for 1 year. Compression, tensile and nanoindentation tests were performed before and after the exposure. Compression and tensile data were also subjected to analysis of variance (ANOVA) and Tukey Post hoc tests at a level of α = .05. These properties were selected due to their clinical significance for fabrication and maintenance of a facial prosthesis. According to statistical analysis all the measured properties changed significantly after outdoor weathering. More specifically, most of the properties presented significant changes after six months of weathering. The observed changes also depended on the weathering locations. The hypothesis investigated was rejected. Material A became harder and the observed differences in the mechanical behaviour resulted from photo-degradation and hydrolysis that might occur due to weathering. The study also provides new information about maxillofacial prosthetics serviceability obtained from nanoindentation tests. 相似文献
139.
Fabiana Carina Pavezzi Andréia A. Jacomassi Carneiro Daniela Alonso Bocchini-Martins Heloiza Ferreira Alves-Prado Henrique Ferreira Paula M. Martins Eleni Gomes Roberto da Silva 《Applied biochemistry and biotechnology》2011,163(1):14-24
Three mutations, Ser54→Pro, Thr314→Ala, and His415→Tyr, were identified in Aspergillus awamori glucoamylase gene expressed by Saccharomyces cerevisiae. The mutant glucoamylase (GA) was substantially more thermostable than a wild-type GA at 70 °C, with a 3.0 KJ mol−1 increase in the free energy of thermo-inactivation. The effect of starch from different botanical sources on the production
of this GA was measured in liquid fermentation using commercial soluble starch, cassava, potato, and corn as the carbon source.
The best substrate for GA production was the potato starch showing an enzymatic activity of 6.6 U/mL. The commercial soluble
starch was also a good substrate for the enzyme production with 6.3 U/mL, followed by cassava starch and corn starch with
5.9 and 3.0 U/mL, respectively. These results showed a significant difference on GA production related to the carbon source
employed. The mutant GA was purified by acarbose–Sepharose affinity chromatography; the estimated molecular mass was 100 kDa.
The mutant GA exhibited optimum activity at pH 4.5 and an optimum temperature of 65 °C. 相似文献
140.
The wood-based activated carbon, either as received or oxidized with nitric acid, was exposed to dimethylamine vapors. This modification was expected to introduce nitrogen groups. Then, the modified samples were used as adsorbents of NO(2) under dynamic conditions. Both NO(2) breakthrough curves and the NO concentration curves were recorded. The samples before and after exposure to NO(2) were characterized using adsorption of nitrogen, elemental analysis, potentiometric titration, FTIR, and thermal analysis. Modifications with amines resulted in an increase in NO(2) adsorption and in a decrease in NO emission. The effects were more visible when oxidation was used as a pretreatment of the carbon surface. This process increased the incorporation of nitrogen to the carbon matrix via acid-based reactions resulting in the formation of amides and amine carboxylic salts. Besides this, dimethylamine was strongly adsorbed on the carbon surface via hydrogen bonding with oxygen-containing groups. When the samples were exposed to nitrogen dioxide, there was an indication that nitramine and nitrosoamine were formed in the reactions of NO(2) with either amides or amines. In the reactions of amines with NO, nitrosoamines are the likely products. As a next step, the surface of the carbon matrix is reoxidized by NO(2), which is accompanied by the release of NO. 相似文献