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71.
72.
Antim K. Maurya Gaurav Aggarwal Sachin Vashisath Vikas Kumar Prof. Dr. Vijai K. Agnihotri 《化学与生物多样性》2023,20(8):e202300223
The aim of current work was to determine essential oils (EOs) composition from three Eucalyptus species, including E. citriodora, E. camaldulensis and E. globulus and assess their α-glucosidase inhibitory activity. The EOs were collected using the hydrodistillation technique and characterized by GC/MS, GC-FID and NMR. The isolated EOs from leaves parts of Eucalyptus species varied from 0.56 to 1.0 % on fresh weight basis. The content of the EOs was distinct according to the species. The most abundant metabolites were identified as citronellal (0–83.0 %), 1,8-cineole (0.2–44.8 %), spathulenol (0.4–16.1 %) α-pinene (0.4–15.9 %), p-cymene (3.7–11.9 %), citronellol (0–8.6 %), β-eudesmol (5.3–8.6 %) and β-pinene (0–7.1 %). The EOs obtained from targeted samples exhibited strong α-glucosidase inhibitory activity. These results are encouraging and underline that the EOs of Eucalyptus species may be a promising alternative source of natural antidiabetic. 相似文献
73.
Souad El Hafidi Khadija Bakhy Mohammed Ouhssine Abderrahim Benzakour Hamid Khamar Joseph Casanova Mathieu Paoli Félix Tomi 《化学与生物多样性》2023,20(1):e202201022
Cladanthus scariosus (Ball) Oberpr. & Vogt is endemic to Moroccan High Atlas. It is known under the vernacular names Irezghi or Irezgui. Three essential oil samples have been isolated from aerial parts and analyzed by combination of chromatographic and spectroscopic techniques [gas chromatography (GC) in combination with retention indices (RI), gas chromatography-mass spectrometry (GC/MS) and 13C-NMR spectroscopy]. The compositions of oil samples were dominated by monoterpenes: α-pinene sabinene, and terpinen-4-ol. Chamazulene and dihydrochamazulene isomers as well as various hemiterpene esters and analogs have been identified. To evidence a chemical variability, statistical analysis performed on 13 oil sample compositions allowed partitioning into three groups, mainly differentiated by their contents of sabinene, camphor, borneol, terpinen-4-ol, and germacrene D. 相似文献
74.
Eya Khemis Mayssa Ben Mustapha Ikbel Chaieb Roberta Ascrizzi Guido Flamini Abdel Halim Harrath Hichem Ben Jannet Afifa Zardi-Bergaoui 《化学与生物多样性》2023,20(2):e202200646
Due to the several side effects of synthetic pesticides, including environmental pollution, threats to human health, and the development of pest resistance to insecticides, the use of alternative healthy, available and efficient agents in pest management strategies is necessary. Recently, the use of essential oil obtained from aromatic plants has shown significant potential for insect pest management. For this reason, the essential oil isolated from seeds of Thapsia garganica L. was investigated for the first time for its chemical profile, and its toxicity and repellency effects against Tribolium castaneum adults. Qualitative and quantitative analyses of the chemical composition by gas chromatography coupled to mass spectrometry (GC/MS) revealed the presence of 18 organic volatiles representing 96.8 % of the total constituents. The main compounds were 1,4-dimethylazulene (51.3 %) followed by methyl palmitate (8.2 %), methyl linoleate (6.2 %) and costol (5.1 %). Concerning the repellent effect, results revealed that SEO (Seed Essential Oil) was very repellent towards T. castaneum adults, with 100 % repellency after 2 h of exposure. Furthermore, the essential oil exhibited remarkable contact toxicity against T. castaneum (93.3 % of mortality) at the concentration of 10 % (v/v). The median lethal dose (LD50) of the topical application of the seed essential oil was 4.4 %. These encouraging outcomes suggested that the essential oil from T. garganica seeds could be considered a potent natural alternative to residual persistent and toxic insecticides. 相似文献
75.
CHANGES IN CELL CHEMICAL COMPOSITION DURING THE LIFE CYCLE OF SCRIPPSIELLA TROCHOIDEA (DINOPHYCEAE)1
Thaithaworn Lirdwitayaprasit Tomotoshi Okaichi Shigeru Montani Tadashi Ochi Donald M. Anderson 《Journal of phycology》1990,26(2):299-306
The cellular content of carbon, nitrogen, amino acids, polysaccharides, phosphorus and adenosine trtphosphate (ATP) was determined at several stages during the life cycle of the dinoflagellate Scrippsiella trochoidea (Stein) Loeblich. Carbon per cell decreased slightly between exponential and stationary phase growth in vegetative cells whereas nitrogen per cell did not change. Both of these cellular components increased markedly on encystment and then decreased to vegetative cell levels during dormancy and germination. C/N ratios increased gradually during cyst dormancy and activation, reflecting a more rapid decrease in N than in C pools, even though both decreased through time. Amino acid composition was relatively constant during the vegetative cell stages; glutamic acid was the dominant component. Arginine was notably higher in cysts than in vegetative cells but decreased significantly during germination, suggesting a role in nitrogen storage. The ratio of neutral ammo acids to total ammo acids (NAA/TAA) decreased as cysts were formed and then gradually increased during storage and germination. The ratio of basic ammo acids to total ammo acids (BAA/TAA) changed in the opposite direction of NAA/TAA, whereas the ratio of acidic acids to total amino adds (AAA/TAA) was generally invariant. Ammo acid pools were not static during the resting slate in the cysts: there was degradation or biosynthesis of certain, but not all, classes of these compounds. The monosacchande composition of cold and hot water extracted polysaccharides was quite different between cells and cysts. A high percentage of glucose in cysts suggests that the storage carbohydrate is probably in the form of glucan. Total cellular phosphorus was higher in all cyst stages than in vegetative cells. However, ATP-cell?1 decreased as vegetative cells entered stationary phase and encysted, and continued to decrease in cysts during dark cold storage. ATP increased only as the cysts were activated at warm temperatures in the light and began to germinate. The above data demonstrate that dormancy and quiescence are not periods of inactive metabolism but instead are times when numerous biochemical transformations are occurring that permit prolonged survival in a resting state. 相似文献
76.
Mark A. Tahmindjis Damien P. Higgins Michael J. Lynch Julie A. Barnes Colin J. Southwell 《Marine Mammal Science》2003,19(3):581-589
Between October and December of 1996–1999, off eastern Antarctica (60°-150°E), we darted 31 crabeater seals with midazolam and pethidine at estimated dose rates of 0.15–0.4 mg/kg and 1–3 mg/kg, respectively. Maximum sedation was reached at 23 ± 9 min (n = 18) and first signs of recovery were noted at 54 ± 24 min (n = 4). Seals greater than 250 kg body-mass were sedated by administration of approximately 90–100 mg midazolam and 600 mg pethidine, but the degree of sedation was unpredictable and did not permit invasive procedures in some cases. Behavior of the seal and adjacent conspecifics affected the success of procedures and our ability to monitor vital signs. Naloxone and flumazenil reversed sedation, making this combination attractive for use in animals adjacent to water. Additional ketamine was administered to two seals, resulting in improved restraint. 相似文献
77.
In this paper the NMR secondary chemical shifts, that are estimated from a set of 3D-structures, are compared with the observed ones to appraise the behaviour of a known x-ray diffraction structure (of the bovine pancreatic trypsin inhibitor protein) when various molecular dynamics are applied. The results of a 200 ps molecular dynamics under various conditions are analysed and different ways to modify the molecular dynamics are considered. With the purpose of avoiding the time-consuming explicit representation of the solvent (water) molecules, an attempt was made to understand the role of the solvent and to develop an implicit representation, which may be refined. A simulation of hydrophobic effects in an aqueous environment is also proposed which seems to provide a better approximation of the observed solution structure of the protein. 相似文献
78.
铜锌超氧化物歧化酶(Cu, Zn-SOD)表面的赖氨酸经化学修饰后, 酶的稳定性显著提高. 赖氨酸被修饰后, 酶的电荷结构遂发生变化, 从而影响到酶分子电场. 使用FDPB方法(有限差分法求解Poission-Boltzman方程)计算了酶修饰前后的静电场变化, 以及对维持酶的结构稳定起重要作用的Cu, Zn配位结构的影响.结果表明, Cu, Zn配位体的两级离解常数在酶修饰后分别约下降103, 106. 相似文献
79.
中药金樱子的研究应用概况 总被引:20,自引:2,他引:18
本文就国内外对中药金樱子的化学成分及其提取分离方法、药理学研究和临麻应用作了综述,为金樱子的综合开发提供依据。 相似文献
80.
Shigeko Ishimatsu Toshihiro Kawamoto Koji Matsuno Yasushi Kodama 《Biological trace element research》1995,49(1):43-52
In this study, eight kinds of nickel (Ni) compounds were orally administered to Wistar male rats and the distribution of each
compound was investigated 24 h after the administration. The Ni compounds used in this experiment were nickel metal [Ni−M],
nickel oxide (green) [NiO(G)], nickel oxide (black) [NiO(B)], nickel subsulfide [Ni3S2], nickel sulfide [NiS], nickel sulfate [NiSO4], nickel chloride [NiCl2], and nickel nitrate [Ni(NO3)2]. The solubilities of the nickel compounds in saline solution were in the following order; [Ni(NO3)2>NiCl2>NiSO4]≫[NiS>Ni3S2]>[NiO(B)>Ni−M>NiO(G)]. The Ni level in the visceral organs was higher in the rats given soluble Ni compounds; Ni(NO3)2, NiCl2, NiSO4, than that in the rats receiving other compounds. In the rats to which soluble Ni compounds were administered, 80–90% of
the recovered Ni amounts in the examined organs was detected in the kidneys. On the other hand, the Ni concentration in organs
administered scarcely soluble Ni compounds; NiO(B), NiO(G), and Ni−M were very low. The estimated absorbed fraction of each
Ni compounds was increased with the increase of the solubility. These results suggest that the kinetic behavior of Ni compounds
administered orally is closely related with the solubility of Ni compounds, and that the solubility of Ni compounds is one
of the important factors for determining the health effect of Ni compounds. 相似文献