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41.
Keller HU Jorda L Küppers M Gutierrez PJ Hviid SF Knollenberg J Lara LM Sierks H Barbieri C Lamy P Rickman H Rodrigo R 《Science (New York, N.Y.)》2005,310(5746):281-283
The OSIRIS cameras (optical, spectroscopic, and infrared remote imaging system) onboard the European Space Agency's Rosetta spacecraft observed comet 9P/Tempel 1 for 17 days continuously around the time of NASA's Deep Impact mission. The cyanide-to-water production ratio was slightly enhanced in the impact cloud, compared with that of normal comet activity. Dust particles were flowing outward in the coma at >160 meters per second, accelerated by the gas. The slope of the brightness increase showed a dip about 200 seconds after the impact. Dust Afrho values before and long after the impact confirm the slight decrease of cometary activity. The dust-to-water mass ratio was much larger than 1. 相似文献
42.
Stover J Bertozzi S Gutierrez JP Walker N Stanecki KA Greener R Gouws E Hankins C Garnett GP Salomon JA Boerma JT De Lay P Ghys PD 《Science (New York, N.Y.)》2006,311(5766):1474-1476
A strong, global commitment to expanded prevention programs targeted at sexual transmission and transmission among injecting drug users, started now, could avert 28 million new HIV infections between 2005 and 2015. This figure is more than half of the new infections that might otherwise occur during that period in 125 low- and middle-income countries. Although preventing these new infections would require investing about U.S.$122 billion over this period, it would reduce future needs for treatment and care. Our analysis suggests that it will cost about U.S.$3900 to prevent each new infection, but that this will produce a savings of U.S.$4700 in forgone treatment and care costs. Thus, greater spending on prevention now would not only prevent more than half the new infections that would occur from 2005 to 2015 but would actually produce a net financial saving as future costs for treatment and care are averted. 相似文献
43.
Two populations of common bean, Phaseolus vulgaris L., were used to make three independent location-specific selections at Palmira, Quilichao, and Popayán, Colombia. Also, three across-location selections were made by alternating generations between Palmira and Popayan, between Quilichao and Popayán, and among Palmira, Quilichao, and Popayán. The seven highest yielding lines selected from each environment and population along with 14 parents and two checks were evaluated for seed yield, seed weight, maturity, and reaction to an-thracnose, angular leaf spot, and common bacterial blight. Mean squares due to evaluation and selection environments, selected lines, and their interactions were significant for all traits. Mean yields of selected lines were higher than the mean of parents in both populations. Among location-specific selections, lines yielded higher at their respective selection site. Moreover, selections made at Popayán were higher yielding than those made at Quilichao or Palmira when tested across locations and years. Use of Popayán, a relatively wetter and cooler site, either alone or in combination with other locations resulted in higher yield, higher seed weight, and higher resistance to anthracnose. On the average, location-specific selections were lower yielding than the across-location selections. Among across-location selections, those selected between Palmira and Popayán were the highest yielding in both populations. Selections at Palmira and across all three locations resulted in greater stability. 相似文献
44.
C. Hernández Y. Sanchez‐Gutierrez R. W. Hardy A. Benitez‐Hernández P. Domínguez‐Jimenez B. González‐Rodríguez L. Osuna‐Osuna O. Tortoledo 《Aquaculture Nutrition》2014,20(6):623-631
A 12‐week feeding trial was conducted to examine the replacement of fish meal with pet‐grade poultry by‐product meal (PBM‐PG) in the spotted rose snapper Lutjanus guttatus diet. Five experimental diets were formulated to contain graded levels of PBM‐PG at proportion of 250, 500, 75 or 900 g kg?1. The control diet contained sardine fish meal as the main protein source. Four groups of 15 randomly assigned L. guttatus juveniles were fed to satiation 3 times day?1. Except for the fish fed the PBM‐PG90 diet, the growth performance, survival and feed utilization efficiency of the experimental fish were not significantly lower than those of the control fish. The dietary level of PBM‐PG did significantly affect the haematological characteristics (P < 0.05). The dietary dry matter and protein apparent digestibility coefficients (ADCs) decreased with increasing dietary PBM‐PG. High values for lipid ADCs were observed in all diets, with significant differences among the dietary treatments. The fish whole‐body protein, moisture, lipid and ash contents were not affected by the inclusion of dietary PBM. These results indicate that high‐quality terrestrial PBM can successfully replace more than half of the marine fish meal protein in the L. guttatus diet. 相似文献
45.
Patricio Arce Mauricio Moreno Mónica Gutierrez Marlene Gebauer Paola Dell’Orto Hebert Torres Ivette Acuña Pauline Oliger Alejandro Venegas Xavier Jordana Julio Kalazich Loreto Holuigue 《American Journal of Potato Research》1999,76(3):169-177
Blackleg and soft rot diseases, caused by the bacteriumErwinia carotovora, are among the diseases that cause important losses in culture and storage of potato. In this paper, we introduced bacterial resistance into potato, via genes encoding for proteins with antibacterial activity. For this purpose, potato clones were transformed either with the gene encoding the acidic attacin protein fromHyalophora cecropia, or with the gene encoding the cecropin analog peptide SB37. These clones were evaluated for soft rot and blackleg resistance, after inoculation with the bacterial strainErwinia carotovora subsp.atroseptica T7. Results reported in this paper indicate that a considerable percentage of the potato clones (15–22%) showed increased resistance to bacterial infection, revealed by reduced severity of blackleg or soft rot symptoms. Expression of the transgenes was demonstrated in some of the clones by Northern blot analysis. This is the first report indicating that expression of the gene encoding for an attacin protein and for the cecropin SB-37 peptide in transgenic potato confers increased resistance to bacterial infection. 相似文献
46.
LJ Lanzerotti K Rinnert G Dehmel FO Gliem EP Krider MA Uman J Bach 《Science (New York, N.Y.)》1996,272(5263):858-860
During the Galileo probe's descent through Jupiter's atmosphere, under the ionosphere, the lightning and radio emission detector measured radio frequency signals at levels significantly above the probe's electromagnetic noise. The signal strengths at 3 and 15 kilohertz were relatively large at the beginning of the descent, decreased with depth to a pressure level of about 5 bars, and then increased slowly until the end of the mission. The 15-kilohertz signals show arrival direction anisotropies. Measurements of radio frequency wave forms show that the probe passed through an atmospheric region that did not support lightning within at least 100 kilometers and more likely a few thousand kilometers of the descent trajectory. The apparent opacity of the jovian atmosphere increases sharply at pressures greater than about 4 bars. 相似文献
47.
During mating male and female Breviceps become ‘glued’ together. The distribution of multicellular dermal glands varies between the sexes. The mate has a large number of holocrine glands on the ventrum, while the female has similar glands on the dorsum of the back. II thus appears that both sexes contribute to the ‘glueing’ mechanism. New hypotheses to explain the adhesion between the sexes are proposed, viz., that the shift to terrestrial habils and subterranean laying in Breviceps have secondarily resulted in male si2e diminution. In other microhylids which adhere during aquatic oviposition, yet demonstrate a terrestrial morphology and habits, bouyancy is suggested to be of primary functional value. 相似文献
48.
OBJECTIVE: To determine and analyse the immunophenotype and histological appearance of naturally occurring cases of lymphosarcoma in Australian cats. DESIGN: A prospective multi-institutional study of naturally occurring feline lymphosarcoma. METHODS: One hundred and eighteen cats were referred for diagnosis and/or management of suspected lymphosarcoma. Tissue samples for histopathological analysis and immunophenotyping were collected as biopsies or at necropsy from 109 cases. Histological classification of the neoplasms followed the Working Formulation Classification System. Four multi-species cross-reactive antibodies were used to classify tumours as having a B or T cell phenotype. RESULTS: Seventy-six (70%) cases were B cell tumours and 28 (26%) were T cell tumours. The remaining 5 (4%) specimens failed to stain with the four antibodies. Histologically, 11 (10%) cases were classified as low-grade, 72 (66%) were medium-grade and 26 (24%) were high-grade tumours. There were no significant associations between age and either histological grade or immunophenotype. Mediastinal and leukaemic cases were significantly more likely to be T cell tumours (P < 0.001 and P < 0.001, respectively). CONCLUSIONS: In contrast to previously documented studies in the cat, the majority of cases of lymphosarcoma were of B cell phenotype and intermediate histological grade. Based on our data, the histological phenotype of lymphosarcoma is unlikely to predict immunotype, nor are cases of certain immunotypes likely to be of specific histological subtype. Considered in relation to previous reports, the findings suggest that epidemiological factors operating in these cats to produce lymphosarcoma may be different to those operating in North American and UK cat populations. 相似文献
49.
M. C. Fernández H. Belinque F. H. Gutierrez Boem G. Rubio 《Journal of plant nutrition》2013,36(12):2027-2043
ABSTRACT A more comprehensive understanding of the mechanisms of phosphorus (P) efficiency is agronomically significant to advance in the design of crop management schemes that increase P efficiency and reduce the need of fertilizers. Phosphorus efficiency is defined as the ability of a plant to acquire P from the soil and/or to utilize it in the production of biomass or the harvestable organ. Because most parameters related to P efficiency vary according to the growth conditions and isolation of the individual effect of P efficiency is not straightforward; plants must be grown in uniform experimental conditions to obtain a fair comparison of their nutrient acquisition and utilization. In this work, we compare the ability of soybean, sunflower, and maize to utilize and acquire soil P. Field and greenhouse experiments including different P levels were conducted. The general observation was that the three species ranked differently according to the specific parameter of P efficiency considered. Maize clearly showed higher P utilization efficiency than soybean and sunflower, either expressed as biomass or as grain produced per unit of absorbed P. In turn, soybean and sunflower exhibited higher acquisition efficiency than maize. Soybean showed the shallowest root system: 69% of the total root length was concentrated in the top 20 cm of the soil. Phosphorus uptake per unit root length was rather similar among the three species, but soybean and sunflower had higher P uptake per unit of root weight. This can be explained by the higher specific root length (SRL) and specific root area (SRA) of both dicots. For example, SRL averaged 59, 94, and 34 m g?1 in field grown soybean, sunflower, and maize, respectively. The more favorable root morphology determined that soybean and sunflower can explore more soil with the same belowground biomass and absorb more P per unit of carbon invested belowground. Since the three species exhibited similar values of P uptake per unit root length, we hypothesize that the capacity of each segment of root to deplete soil P fractions is similar. 相似文献
50.
Dinorah Vargas Lilia Gutierrez Ivan Juárez Francisco Gonzalez Héctor Sumano 《American journal of veterinary research》2008,69(8):1085-1090
OBJECTIVE: To determine the pharmacokinetics after SC administration of an experimental, long-acting parenteral formulation of doxycycline hyclate in a poloxamer-based matrix and after IV and IM administration of an aqueous formulation of doxycycline hyclate in goats. ANIMALS: 30 clinically normal adult goats. PROCEDURES: Goats were allocated to 3 groups (10 goats/group). One group of goats received doxycycline hyclate (10 mg/kg) IM, a second group received the same dosage of doxycycline hyclate IV, and the third group received the long-acting parenteral formulation of doxycycline hyclate SC. Serum concentrations of doxycycline were determined before and at various intervals after administration. RESULTS: The long-acting parenteral formulation of doxycycline hyclate had the greatest bioavailability (545%); mean +/- SD maximum serum concentration was 2.4 +/- 0.95 microg/mL, peak time to maximum concentration was 19.23 +/- 2.03 hours, and elimination half-life was 40.92 +/- 4.25 hours. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that the long-acting parenteral formulation of doxycycline hyclate distributed quickly and widely throughout the body after a single dose administered SC, and there was a prolonged half-life. Bioavailability of the longacting parenteral formulation of doxycycline hyclate after SC administration was excellent, compared with bioavailability after IV and IM administration of an aqueous formulation of doxycycline hyclate. Although no local tissue irritation and adverse effects were detected, clinical assessment of drug-residues and toxicologic evaluations are warranted before this long-acting parenteral formulation of doxycycline hyclate can be considered for use in goats with bacterial infections. 相似文献