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431.
Vincentius A. Halim Astrid Hunger Violetta Macioszek Peter Landgraf Thorsten Nürnberger Dierk Scheel Sabine Rosahl 《Physiological and Molecular Plant Pathology》2004,64(6):311-318
The Phytophthora-derived oligopeptide elicitor, Pep-13, originally identified as an inducer of plant defense in the nonhost–pathogen interaction of parsley and Phytophthora sojae, triggers defense responses in potato. In cultured potato cells, Pep-13 treatment results in an oxidative burst and activation of defense genes. Infiltration of Pep-13 into leaves of potato plants induces the accumulation of hydrogen peroxide, defense gene expression and the accumulation of jasmonic and salicylic acids. Derivatives of Pep-13 show similar elicitor activity in parsley and potato, suggesting a receptor-mediated induction of defense response in potato similar to that observed in parsley. However, unlike in parsley, infiltration of Pep-13 into leaves leads to the development of hypersensitive response-like cell death in potato. Interestingly, Pep-13-induced necrosis formation, hydrogen peroxide formation and accumulation of jasmonic acid, but not activation of a subset of defense genes, is dependent on salicylic acid, as shown by infiltration of Pep-13 into leaves of potato plants unable to accumulate salicylic acid. Thus, in a host plant of Phytophthora infestans, Pep-13 is able to elicit salicylic acid-dependent and -independent defense responses. 相似文献
432.
433.
Pressures in the right side of the heart and esophagus (pleural) have not been determined in the exercising equine subjects. In the present study, 8 healthy ponies were examined to determine the changes in these variables caused by 2 degrees of exercise done on a treadmill (heart rate:183 +/- 5 beats/min [trot] and 220 +/- 6 beats/min [canter]). Measurements were also made during both degrees of exertion 10 minutes and 120 minutes after furosemide (1.0 mg/kg) administration. It was observed that both gaits resulted in significant increases in pulmonary artery, right ventricular, and right atrial pressures. The pulmonary artery systolic, mean, and diastolic pressures during strenuous exertion were 306%, 252%, and 242% of the respective resting values. At canter, when respiratory frequency (138 +/- 4 breaths/min) is synchronized with stride frequency, the delta esophageal pressure approached 30.4 +/- 2.86 cm of water. During exercise 10 minutes after furosemide administration, the increment in right atrial pressure was markedly attenuated. During strenuous exertion 120 minutes after furosemide administration, the right atrial and pulmonary arterial pressures increased, but to a significantly lower level than did the prefurosemide values. However, the mean pulmonary artery pressure was still 240% of the resting value. It is concluded that marked pulmonary hypertension is a consistent feature of moderate, as well as strenuous, exertion in the pony. Although furosemide administration attenuated the pulmonary hypertension somewhat, the significance remains unclear. 相似文献
434.
D. Goetz 《植物养料与土壤学杂志》1971,130(1):82-83
Experiences with a new automatic apparaturs for mechanical analysis of soils A commercial instrument for mechanical analysis of soil was improved technically. 相似文献
435.
436.
The aim of the study was to investigate antimicrobial susceptibilities of bovine Helcococcus ovis isolates and to detect genes encoding for H. ovis erythromycin and tetracycline resistance. Twenty-nine isolates were included and the minimal inhibitory concentrations (MICs) of seven antimicrobials were determined using test conditions as given in an approved CLSI guideline for the pyridoxal-dependent Abiotrophia spp. and Granulicatella spp. Furthermore, the macrolide resistance phenotype was examined by the erythromycin-clindamycin double-disk test (D-zone test). Erythromycin MICs of ≥ 8 μg/ml were found in three (10%) isolates which also presented the macrolide, lincosamide, and streptogramin B (MLS(B)) resistance phenotype, either constitutive or inducible. The erm(B) gene was detected in one of these isolates. Increased tetracycline MICs (≥ 8 μg/ml) were obtained for 24 (83%) isolates, mostly associated with the tet(M) gene alone (n=21) or both the tet(L) and tet(M) genes (n=2). The MICs determined for penicillin, ampicillin, amoxicillin-clavulanic acid, and cephalothin did not indicate resistance to these antimicrobials. The study suggests that resistance to MLS(B) antimicrobials and tetracycline is frequent in H. ovis. Moreover, this is the first report about occurrence of the resistance genes erm(B), tet(L), and tet(M) in the Helcococcus genus. 相似文献
437.
Anthropogenic pollutants affect ecosystem services of freshwater sediments: the need for a “triad plus x” approach 总被引:1,自引:0,他引:1
Gerbersdorf Sabine Ulrike Hollert Henner Brinkmann Markus Wieprecht Silke Schüttrumpf Holger Manz Werner 《Journal of Soils and Sediments》2011,11(6):1099-1114
Purpose
Freshwater sediments and their attached microbial communities (biofilms) are essential features of rivers and lakes, providing valuable ecosystem services such as nutrient recycling or self-purification which extend beyond the aquatic environment. Anthropogenic pollutants, whether from the industrial era or as a result of our contemporary lifestyles, can negatively affect these functions with hitherto unknown consequences on ecology, the economy and human health. Thus far, the singular view of the involved disciplines such as ecotoxicology, environmental microbiology, hydrology and geomorphology has prevented a deeper understanding of this emerging issue. 相似文献438.
439.
Lydie Huché-Thélier Rachid Boumaza Sabine Demotes-Mainard Angélique Canet Ronan Symoneaux Odile Douillet Vincent Guérin 《Scientia Horticulturae》2011
Rosebush architecture resulting from the spatial organisation of the plant axes induces plant shape and consequently within ornamental horticulture context, its visual quality and commercial value. This architecture can be modulated by environmental conditions, particularly in the horticulture context in which the possibilities to control growing conditions are numerous. The objectives of the study were to determine, in young rose bushes, (1) whether short periods of nitrogen deficiency affect branching and (2) whether this effect is sufficient to modify the visual quality of the plant in a sustainable manner. Between vegetative bud burst and the petal colour visible stage of the generated primary branch, young rooted cuttings of bush rose (cv Radrazz) were subjected to one of three nitrogen regimes: (1) no nitrogen deficiency, (2) continuous nitrogen deficiency, i.e. 35 days of N deficiency, and (3) nitrogen deficiency restricted to the flowering stages, i.e. 18 days of N deficiency. After the petal colour visible stage, all three groups of plants were supplied continuously with nitrogen. We observed the morphology of the axes and the kinetics of axillary bud burst. Twelve weeks after the petal colour visible stage, the visual quality of the rose bushes was evaluated by an expert jury. We found that nitrogen deficiencies (1) increased bud burst ratios in the medial and basal zones of the primary branch, (2) delayed the bud burst in the apical zone of the primary branch and (3) had long-term effects on plant visual quality. The continuous nitrogen deficiency regime produced flatter, more asymmetric and less vigorous rose bushes than the no nitrogen deficiency regime. By contrast, nitrogen deficiency during the flowering stages only resulted in more symmetric, taller and more vigorous rose bushes than the no nitrogen deficiency regime. Based on these results, the role of nitrogen on bud burst was discussed and candidate processes at the origin of the visual quality modification were suggested. This new approach combining ecophysiology and sensory assessment of ornamental plants enabled the identification of some early architecture components to be correlated with later visual quality characteristics and then to better target the physiological processes of interest. 相似文献
440.
A potent nonpeptide cholecystokinin antagonist selective for peripheral tissues isolated from Aspergillus alliaceus 总被引:7,自引:0,他引:7
R S Chang V J Lotti R L Monaghan J Birnbaum E O Stapley M A Goetz G Albers-Sch?nberg A A Patchett J M Liesch O D Hensens 《Science (New York, N.Y.)》1985,230(4722):177-179
A new, competitive, nonpeptide cholecystokinin (CCK) antagonist, asperlicin, was isolated from the fungus Aspergillus alliaceus. The compound has 300 to 400 times the affinity for pancreatic, ileal, and gallbladder CCK receptors than proglumide, a standard agent of this class. Moreover, asperlicin is highly selective for peripheral CCK receptors relative to brain CCK and gastrin receptors. Since asperlicin also exhibits long-lasting CCK antagonist activity in vivo, it should provide a valuable tool for investigating the physiological and pharmacological actions of CCK. 相似文献