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The effects of early initiation of first service for dairy heifers on their fertility and productivity up to the third lactation were examined under constant raising and management conditions. Eight Holstein heifers in their early breeding regimens and eight Holstein heifers in their late breeding regimens were initiated to be bred at 12 and 15 months of age, respectively, and were first calved at 21.5 and 25.1 months of age, respectively, with bodyweights of 563 and 638 kg after calving, respectively. Early first breeding resulted in a lower bodyweight and a lower body condition score, but it did not affect the fertility or milk production during the first lactation of heifers as cows. The calving intervals of cows to the second and third calving were similar in early and late bred heifers. Although the early bred heifers had a significantly lower fat‐corrected milk yield at the second lactation than that of the late bred heifers, early breeding did not impair the productivity indicated by the mean milk yield per day from birth to the end of the third lactation with a shorter production period.  相似文献   
74.
Metabolic hormones affect ovarian function in the cow. However, the relationship between metabolic factors and ovarian function is not clear in the postpartum primiparous cow because they are still growing. The aim of the present study was to investigate in detail the time-dependent profile of the metabolic hormones, metabolites, and milk yields of ovulatory and anovulatory primiparous cows during the first follicular wave postpartum. We used 16 primiparous Holstein cows and obtained blood samples for the profiles of metabolites (glucose; non-esterified fatty acid, NEFA; ketone body; total cholesterol; and aspartate aminotransferase), metabolic hormones (growth hormone, GH; insulin-like growth factor-I, IGF-1; and insulin), and progesterone every other day from 1 to 21 days postpartum. In addition, all ovaries were observed using ultrasound. Dairy milk yield was recorded during the experimental period. In all cows, the first follicular wave postpartum was observed and 6 of the cows ovulated. The plasma glucose (P<0.0001) and IGF-1 (P<0.001) concentrations were lower and the plasma NEFA (P<0.0001) and ketone bodies (P<0.0001) concentrations and daily milk yield (P<0.0001) were higher in the anovulatory cows compared to the ovulatory cows. However, the GH levels, which enhance lipolysis for milk production, insulin and other metabolites did not differ between the two groups. In conclusion, the present study suggests that anovulation of the dominant follicle during the first follicular wave postpartum in primiparous cows is induced by low IGF-1 levels that are similar to those of multiparous cows. In addition, anovulatory cows are likely to mobilize body fat stores for milk production more easily than ovulatory cows.  相似文献   
75.
An 11-day-old Holstein calf presented with a high rectal temperature and tachypnea. Treatment with antibiotics and non-steroidal anti-inflammatory drugs did not improve the clinical signs. Bleeding tendency, with several hemorrhage spots on the body surface, appeared five days after admission. Severe pancytopenia was observed in the blood examination. The calf died on the 11th day after admission with severe bleeding from an injection site. Necropsy findings revealed that the pancytopenia had resulted from severe bone marrow aplasia. A congenital disorder was suspected to be the cause of pancytopenia associated with bone marrow aplasia.  相似文献   
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Matings of male-sterileC. japonica and fertile eliteC. japonica, as well as backcross seedlings of male-sterile trees, were carried out to clarify the genetic trait of male sterility of theC. japonica. The seeds from male-sterileC. japonica were germinated in an incubator and grown them in the greenhouse between 1994 and 1997. The seedlings were treated with 100 ppm gibberellin at early July 1994 and early July 1995 to promote the formation of male flowers. In the middle of January 1995, the male flowers of all seedlings were examined under the microscope to confirm the production of pollen. In January 1996, pollen did not developed in to the male flowers from the seedlings between the fertiled elite and backcrossC. japonica. In January 1997, all seedlings of eliteC. japonica produced pollen in their male flowers; however, pollen did not developed in 55 out of 120 backcrossed seedlings. This evidence suggests that the heredity pattern of male sterility inC. japonica is nuclear male sterility controlled by a pair of recessive genes.  相似文献   
78.
The relationship between the fate of clomeprop in soil and its phytotoxic activity on the growth of radish (Raphanus sativus) seedlings was investigated in the laboratory. The phytotoxic activity of clomeprop in sea sand was much higher than in non-autoclaved soil, and the phytotoxic activity in non-autoclaved soil was higher than in autoclaved soil. The phytotoxic activity of 2-(2,4-dichloro-3-methylphenoxy)propionic acid (DMPA), a hydrolysed metabolite of clomeprop, was higher than that of the latter under both soil conditions. Clomeprop was adsorbed on soil to a greater extent than DMPA. The concentration of clomeprop in soil water of non-autoclaved soil decreased with increase of the DMPA concentration in the soil water in a time-dependent manner. It is suggested that the phytotoxic activity of clomeprop applied to soil is induced mostly by the DMPA concentration in soil water after hydrolytic degradation by soil microbes. © 1999 Society of Chemical Industry  相似文献   
79.
Inhibitory effects on degranulation of rat basophilic leukemia (RBL-2H3) cells and mouse eosinophils by marine algae extracts were examined. More than 50% of the degranulation of RBL-2H3 cells was inhibited by water extracts of Ecklonia cava and Chrysymenia wrightii at a concentration of 100 μg/mL. More than 50% of the degranulation of RBL-2H3 cells was inhibited by methanol extracts of Petalonia binghamiae, Scytosiphon lomentaria, Undaria pinnatifida, Porphyra dentata, Codium fragile and Ulva japonica at a concentration of 200 μg/mL. Most inhibitory substances in the methanol extracts were partitioned into ethyl acetate and hexane layers. The ethyl acetate-partitioned layer of methanol extract of Petalonia binghamiae had higher inhibitory effects than the hexane-partitioned layer on the degranulation of RBL-2H3 cells. By contrast, the hexanepartitioned layer of the same extract had a higher inhibitory effect than the ethyl acetate-partitioned layer on the degranulation of mouse eosinophils. The ethyl acetate-partitioned layer of methanol extract of Petalonia binghamiae was further separated into eight fractions by silica gel column chromatography. Most inhibited the degranulation of RBL-2H3 cells, but not that of mouse eosinophils significantly. These results suggest methanol extract of Petalonia binghamiae contains materials that inhibit the degranulation of basophils and eosinophils differentially.  相似文献   
80.
  • ? Awareness of the shortage of fossil resources leads to an increasing demand for woody biomass. We investigated the feasibility of using fast-growing Gmelina arborea wood for material production. Gmelina arborea wood samples were collected from trees of varying cambium ages in Indonesia, from 3.5-, 7- and 12-year-old plantations.
  • ? The lateral growth rate and the cambium age did not significantly affect the longitudinal released strain of the growth stress, xylem density, or microfibril angle at the outermost surface of the secondary xylem at any sampling site. However, fiber length in the 3.5-year-old plantation tended to be shorter in smaller diameter trees, whereas in larger diameter trees it was almost the same as that in trees from the 7- and 12-year-old plantations. This suggests that smaller diameter trees in the 3.5-year-old plantation had not yet produced mature wood.
  • ? Xylem qualities had already reached values appropriate for harvesting, except in the smaller diameter trees from the 3.5-year-old plantation. This indicates that the larger diameter trees had already matured, regardless of their cambium age. These results suggest that the next step is to develop silvicultural treatments to increase the lateral growth rate during the early growing stage, in order to produce as much mature wood as possible, as quickly as possible.
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