全文获取类型
收费全文 | 183篇 |
免费 | 7篇 |
国内免费 | 4篇 |
出版年
2023年 | 1篇 |
2022年 | 3篇 |
2021年 | 2篇 |
2020年 | 1篇 |
2019年 | 4篇 |
2018年 | 8篇 |
2017年 | 5篇 |
2016年 | 11篇 |
2015年 | 8篇 |
2014年 | 14篇 |
2013年 | 6篇 |
2012年 | 11篇 |
2011年 | 13篇 |
2010年 | 11篇 |
2009年 | 12篇 |
2008年 | 7篇 |
2007年 | 5篇 |
2006年 | 7篇 |
2005年 | 11篇 |
2004年 | 9篇 |
2003年 | 4篇 |
2002年 | 4篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1999年 | 1篇 |
1998年 | 6篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1988年 | 1篇 |
1985年 | 2篇 |
1983年 | 4篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有194条查询结果,搜索用时 15 毫秒
61.
Kozlovskiĭ AG Zhelifonova VP Adanin VM Antipova TV Ozerskaia SM Kochkina GA Grafe U 《Mikrobiologiia》2003,72(6):816-821
The study of the secondary metabolites of the relict strain Penicillium citrinum VKM FW-800 isolated from ancient Arctic permafrost sediments showed that this fungus produces agroclavine-1 and epoxyagroclavine-1, which are rare ergot alkaloids with the 5R,10S configuration of the tetracyclic ergoline ring system. The production of the alkaloids by the fungus showed a biphasic behavior, being intense in the phase of active growth and slowing down in the adaptive lag phase and in the stationary growth phase. The addition of zinc ions to the incubation medium led to a fivefold increase in the yield of the alkaloids. The alkaloids-producing Penicillium fungi isolated from different regions exhibited the same tendencies of growth and alkaloid production. 相似文献
62.
Kirichuk VF Antipova ON Ivanov AN Krenitskiĭ AP Maĭborodin AV Tupikin VD Betskiĭ OV 《Rossi?skii fiziologicheski? zhurnal imeni I.M. Sechenova / Rossi?skaia akademiia nauk》2004,90(9):1121-1128
We have investigated impact of electromagnetic SWF-oscillations at nitric oxide molecular spectrum of radiation and absorption (MSRA) on rheological blood properties of albino rats under the immobilizing stress. The SWF-irradiation was demonstrated to foster restoration of disordered rheological blood properties, its efficiency depending on the period of irradiation. 相似文献
63.
64.
Phosphoglucomutase (EC 2.7.5.1, PGM) was purified to homogeneity from maize (Zea mays L.) leaves. The enzyme had specific activity 11. 7 U/mg protein and molecular mass (determined by gel-chromatography) of 133 +/- 4 kD. The molecular mass of PGM subunits determined by SDS-electrophoresis was 66 +/- 3 kD. The enzyme had Km for glucose-1-phosphate and glucose-1,6-diphosphate of 20.0 +/- 0.9 and 16.0 +/- 0.8 &mgr;M, respectively. Concentrations of glucose-1-phosphate and glucose-1,6-diphosphate above 3 and 0.4 mM, respectively, cause substrate inhibition. The enzyme activity was maximal at pH 8.0 and temperature 35 degreesC. Magnesium ions activate the enzyme and manganese ions inhibit it. 3-Phosphoglycerate is an uncompetitive inhibitor of the enzyme (Ki = 1.22 +/- 0.05 mM). Fructose-6-phosphate, 6-phosphogluconate, and ADP activate PGM, whereas ATP, UTP, and AMP inhibit the enzyme. Citrate was also a potent inhibitor, inhibitory effects of isocitrate and cis-aconitate being less pronounced. 相似文献
65.
66.
Jan Willem Erisman Nelleke Domburg Wim de Vries Hans Kros Bronno de Haan Kaj Sanders 《中国科学:生命科学英文版》2005,48(Z2)
The Netherlands is "well known" for its nitrogen problems; it has one of the highest reactive nitrogen (Nr) emission densities in the world. It is a small country at the delta of several large European rivers. Ever since the industrial revolution, there has been a growing excess of nutrients and related emissions into the atmosphere (ammonia, nitrogen oxides and nitrous oxide) and into groundwater and surface water (nitrate), leading to a large range of cascading environmental impacts. Vehicular traffic, sewage and animal husbandry are the main sources of oxidized and reduced forms of Nr. This paper provides an overview of the origin and fate of nitrogen in the Netherlands, the various reported impacts of nitrogen, the Dutch and European policies to reduce nitrogen emissions and related impacts. In addition, ways are presented to go forward to potentially solve the problems in a European perspective. Solutions include the improvement of nitrogen efficiencies in different systems, technological options and education. 相似文献
67.
Kirichuk VF Tsymbal AA Antipova ON Krenitskiĭ AP Maĭborodin AV Tupikin VD Betskiĭ OV 《Rossi?skii fiziologicheski? zhurnal imeni I.M. Sechenova / Rossi?skaia akademiia nauk》2005,91(6):678-685
The effects of EMR MHF of molecular spectrum of radiation and absorption of nitrogen oxide on blood coagulation properties in white rats subjected to immobilization stress, have been studied. It has been revealed that MHF irradiation of the animals results in restoration of hemostasis mechanism indices. 相似文献
68.
Phylogenetic relationships of typical antbirds (Thamnophilidae) and test of incongruence based on Bayes factors 总被引:1,自引:0,他引:1
Martin?IrestedtEmail author Jon?Fjelds? Johan?AA?Nylander Per?GP?Ericson 《BMC evolutionary biology》2004,4(1):23
Background
The typical antbirds (Thamnophilidae) form a monophyletic and diverse family of suboscine passerines that inhabit neotropical forests. However, the phylogenetic relationships within this assemblage are poorly understood. Herein, we present a hypothesis of the generic relationships of this group based on Bayesian inference analyses of two nuclear introns and the mitochondrial cytochrome b gene. The level of phylogenetic congruence between the individual genes has been investigated utilizing Bayes factors. We also explore how changes in the substitution models affected the observed incongruence between partitions of our data set. 相似文献69.
Kozlovskii A. G. Zhelifonova V. P. Adanin V. M. Antipova T. V. Shnyreva A. V. Viktorov A. N. 《Microbiology》2002,71(6):666-669
The analysis of the absorption spectra of the low-molecular-weight nitrogen-containing secondary metabolites—alkaloids—of four Penicillium chrysogenum strains and six P. expansum strains isolated on board the Mir space station showed that all these strains synthesize metabolites of alkaloid origin (roquefortine, 3,12-dihydroroquefortine, meleagrin, viridicatin, viridicatol, isorugulosuvin, rugulosuvin B, N acetyltryptamine, and a yellow metabolite containing the benzoquinone chromophore). 相似文献