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11.
Brucella abortus vaccines composed of native cell envelopes or outer membrane proteins of smooth strain 2308 were compared with a vaccine (PG) composed of the insoluble residue of strain 2308 cell envelopes which had been extracted with hot sodium dodecyl sulfate. Vaccines were given by injection in an oil base adjuvant containing trehalose dimycolate and muramyl dipeptide or without adjuvant. Mice vaccinated with 30 micrograms native cell envelopes or PG and challenged 4 weeks later with virulent B. abortus strain 2308 displayed equivalent levels of protective immunity at 1 and 4 weeks post-infection. Heifers were vaccinated with 5 mg of antigens in adjuvant; PG was also administered without adjuvant. Humoral and cell mediated immune (CMI) responses were tested at monthly intervals. PG without adjuvant induced negligible immune responses. Native cell envelope antigens induced significantly higher titers of whole cell agglutinins over a 3-month period than did PG, although revaccination with PG in adjuvant enhanced the production of agglutinins and both vaccines induced antibodies to the O polysaccharide. Lymphocyte blastogenesis responses and delayed hypersensitivity reactions to porin and group 3 proteins were stimulated by both native and PG vaccines, and the magnitude of the responses did not differ significantly between the treatment groups. These vaccines were therefore comparable in their capacity to induce protective immunity in mice and CMI responses in cattle, whereas antibody responses induced by PG in cattle were generally lower. These findings provide a basis for evaluation of nonliving B. abortus vaccines in cattle. 相似文献
12.
ABSTRACT Sclerotinia trifoliorum and Sclerotium rolfsii are pathogens for which similar mechanisms of parasitism have been proposed. This suggested that resistance to these pathogens may be related in a common host plant. This study was undertaken to determine whether selection for quantitative resistance to Sclerotinia trifoliorum in alfalfa also increases resistance to Sclerotium rolfsii as expressed in excised leaf tissues and whole plants. Resistance in excised leaf tissues was evaluated according to the rate of necrosis induced by Sclerotium rolfsii following inoculation with mycelium. Resistance to Sclerotium rolfsii in whole plants was evaluated according to their survival following crown inoculations. Three alfalfa populations previously selected from cv. Delta for quantitative resistance to Sclerotinia trifoliorum exhibited enhanced resistance to Sclerotium rolfsii, in comparison with Delta or with susceptible populations, in excised leaf tissues. When whole plants of Delta and two of these populations, Sclerotinia trifoliorum resistant (STR) and Mississippi Sclerotinia resistant (MSR), were inoculated with Sclerotium rolfsii at 3 to 8 weeks of age, significant (P = 0.01) differences in survival were attributed to plant age at inoculation and alfalfa populations. Survival of both MSR and STR was significantly (P = 0.05) greater than for Delta; the best differential results were obtained by inoculating plants 5 to 7 weeks old. To evaluate relationships of resistance to Sclerotinia trifoliorum and Sclerotium rolfsii over a broader genetic background, additional populations were selected for resistance to Sclerotinia trifoliorum from four other alfalfa cultivars by leaf-inoculation techniques, and this resistance was confirmed by whole-plant inoculations. In excised leaf tissues, all four of these populations also expressed enhanced resistance to Sclerotium rolfsii in comparison with either parent cultivars or populations of comparable size selected at random. These results establish that selection for quantitative resistance to Sclerotinia trifoliorum in alfalfa also confers enhanced resistance to Sclerotium rolfsii as expressed in excised leaf tissues and whole plants. Results suggest, therefore, that genes for quantitative resistance to Sclerotinia trifoliorum and Sclerotium rolfsii in alfalfa are likely to be synonymous, overlapping, or closely linked. 相似文献
13.
Shu Q Hillard MA Bindon BM Duan E Xu Y Bird SH Rowe JB Oddy VH Gill HS 《American journal of veterinary research》2000,61(7):839-843
OBJECTIVE: To determine efficacy of vaccines incorporating QuilA, alum, dextran combined with mineral oil, or Freund adjuvant for immunization of feedlot cattle against Streptococcus bovis and Lactobacillus spp. ANIMALS: 24 steers housed under feedlot conditions. PROCEDURE: Steers were randomly assigned to 4 experimental groups and a control group. Animals in experimental groups were inoculated on days 0 and 26 with vaccines containing Freund adjuvant (FCA), QuilA, dextran combined with mineral oil (Dex), or alum as adjuvant. Serum anti-S bovis and anti-Lactobacillus IgG concentrations were measured, along with fecal pH, ruminal fluid pH, and number of S bovis and Lactobacillus spp in ruminal fluid. RESULTS: Throughout the study, serum anti-S bovis and anti-Lactobacillus IgG concentrations for animals in the Dex, QuilA, and alum groups were similar to or significantly higher than concentrations for animals in the FCA group. Serum anti-S bovis and anti-Lactobacillus IgG concentrations were significantly increased on days 26 through 75 in all 4 experimental groups, and there was a linear relationship between anti-S bovis and anti-Lactobacillus IgG concentrations. For animals in the QuilA and Dex groups, mean pH of feces throughout the period of experiment were significantly higher and numbers of S bovis and Lactobacillus spp in ruminal fluid on day 47 were significantly lower than values for control cattle. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that immunization of feedlot steers against S bovis and Lactobacillus spp with vaccines incorporating Freund adjuvant, QuilA, dextran, or alum as an adjuvant effectively induced high, long-lasting serum anti-S bovis and anti-Lactobacillus IgG concentrations. Of the adjuvants tested, dextran may be the most effective. 相似文献
14.
Haney SAMIR Kazuaki SASAKI Eman AHMED Aly KAREN Kentaro NAGAOKA Mohamed EL SAYED Kazuyoshi TAYA Gen WATANABE 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(5):549-556
Although color Doppler ultrasonography has been used to evaluate testicular blood flow in
many species, very little has been done in goat. Eight male Shiba goats were exposed to a
single intramuscular injection of either gonadotropin-releasing hormone (GnRH group; 1
µg/kg BW) or human chorionic gonadotropin (hCG group; 25 IU/kg BW).
Plasma testosterone (T), estradiol (E2) and inhibin (INH) were measured just before (0 hr)
and at different intervals post injection by radioimmunoassay. Testis volume (TV) and
Doppler indices, such as resistive index (RI) and pulsatility index (PI) of the
supratesticular artery, were measured by B-mode and color Doppler ultrasonography,
respectively. The results indicated an increase in testicular blood flow in both groups,
as RI and PI decreased significantly (P<0.05), but this increase was
significant higher and earlier in hCG group (1 hr) than in the GnRH group (2 hr). A high
correlation was found for RI and PI with both T (RI, r= −0.862; PI, r= −0.707) and INH in
the GnRH group (RI, r=0.661; PI, r=0.701). However, a significant
(P<0.05) correlation was found between E2 and both RI (r= −0.610) and
PI (r= −0.763) in hCG group. In addition, TV significantly increased and was highly
correlated with RI in both groups (GnRH, r= −0.718; hCG, r= −0.779). In conclusion, hCG
and GnRH may improve testicular blood flow and TV in Shiba goats. 相似文献
15.
T L Martin L V Swanson L H Appell K E Rowe F Stormshak 《Domestic animal endocrinology》1990,7(1):27-34
Two experiments were conducted to investigate the response of the bovine corpus luteum to surges of luteinizing hormone (LH) induced by natural gonadotropin-releasing hormone (GnRH) administered twice during the same estrous cycle. In experiment 1, eight mature beef cows, each cow serving as her own control, were injected intravenously (iv) with saline on days 2 and 8 of the cycle (day of estrus = day 0 of the cycle), then with 100 micrograms GnRH on days 2 and 8 of the subsequent cycle. Jugular blood samples were taken immediately prior to an injection and at 15, 30, 45, 60, 120 and 240 min postinjection, to quantitate changes in serum luteinizing hormone. Blood was also collected on alternate days after an injection until day 16 of the cycle, to characterize changes in serum progesterone concentrations. Although exogenous GnRH caused release of LH on days 2 and 8 of the cycle, the quantity of LH released was greater on day 8 (P less than .025). Serum levels of progesterone after treatment with GnRH on day 8 of the cycle did not differ significantly from those observed during the control cycles of the heifers. Because exposure of the bovine corpus luteum to excess LH, induced by GnRH early during the estrous cycle, causes attenuated progesterone secretion during the same cycle, these data suggest that a second surge of endogenous LH may ameliorate the suppressive effect of the initial release of LH on luteal function. Duration of the estrous cycle was not altered by treatment (control, 20.4 +/- .5 vs. treated, 20.4 +/- .4 days).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
16.
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18.
Summary The formation of triploids in 4x×2x crosses was studied in primitive potato varieties from the Andes of Peru and Bolivia. Triploid frequencies were as high as 80–100% in some crosses, although the actual number of seeds was low. The triploid block varied according to the tetraploid parent, and was never entirely absent. The likelihood of triploid formation was studied in 4x×2x crosses where pollen from both tetraploids and diploids of known genotype was used. Even though the diploids were chosen for their non-production of 2n gametes, as detected in pollen grain size, 66% of the hybrids were tetraploid. The amount and probability of gene-flow between the tetraploid and diploid gene-pools, either directly through 2n gametes or through triploid bridges was examined. Most of the 20 cultivars of S. x chaucha produced seed in crosses with tetraploids and diploids, although the fertility of the latter crosses was four times higher. The female fertility of some of the triploids thus allows them to exchange genes with the tetraploids and diploids, although gene-flow occurs more rapidly through direct transfer from diploids to tetraploids via 2n gametes. 相似文献
19.
Summary The variation in Solanum × chaucha
Juz. et Buk. (2n=3x=36) was studied using 114 accessions from the Potato Collection maintained by the International Potato Center. These accession represented less than 5% of the collection originally screened for ploidy. Twenty morphological characters of the tubers, inflorescences and leaves were scored. The accessions were grouped into 20 morphotypes on the basis of the tuber characters. Two-qualitative characters, red-anther tip and sky-blue flowers were diagnostic of 4 morphotypes, but the variation of the quantitative characters overlapped among morphotypes, and were of limited value. Electrophoretic separation of tuber proteins in 7.5% polyacrylamide gels generally confirmed the morphotype groupings. It is concluded that each of the morphotypes represents a single genotype, and these are named according to the International Code of Nomenclature for Cultivated Plants. The variation within S. × chaucha apparently has been restricted by its hybrid origin. 相似文献
20.
Rowe JB Toni I Josephs O Frackowiak RS Passingham RE 《Science (New York, N.Y.)》2000,288(5471):1656-1660
It is controversial whether the dorsolateral prefrontal cortex is involved in the maintenance of items in working memory or in the selection of responses. We used event-related functional magnetic resonance imaging to study the performance of a spatial working memory task by humans. We distinguished the maintenance of spatial items from the selection of an item from memory to guide a response. Selection, but not maintenance, was associated with activation of prefrontal area 46 of the dorsal lateral prefrontal cortex. In contrast, maintenance was associated with activation of prefrontal area 8 and the intraparietal cortex. The results support a role for the dorsal prefrontal cortex in the selection of representations. This accounts for the fact that this area is activated both when subjects select between items on working memory tasks and when they freely select between movements on tasks of willed action. 相似文献