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541.
Ultrasonography (US) has been applied to the ovary and the uterus of domestic animals from the late 1980s, and established in 1990s as a practical tool for animal production. US made it possible to detect pregnancy at a very early stage and, most importantly, to observe the real-time dynamics of follicular development and hence the discovery of follicular waves. This has greatly contributed to our understanding of ovarian physiology and helped us to develop several "pin-point" protocols for hormonal treatment. While US may not seem to fit preconceived ideas of a "green" technology, it does not contravene environmental priorities, and it is non-invasive ("ethical") and non-hormonal ("clean"). Using the US technology that is now commercially available at a reasonable price, we are able to estimate the best timing for AI and this allows us to plan either the use of precisely-timed nutritional supplements for fetal development or an immediate 2nd AI service to achieve a better economic efficiency. During the last few years, we have also begun to be able to observe in detail the local blood flow in individual ovarian follicles and CL using color Doppler ultrasonography in the cow. From the series of observations, we have found that: 1) the change of blood supply to an individual follicle closely relates to the dynamics of follicular growth and atresia; 2) the local blood flow detected in the theca externa of mature follicles rapidly increases around the onset of LH surge and is most active before ovulation; 3) the blood supply to the developing CL increases in parallel with CL volume and plasma progesterone concentrations; and 4) the local blood flow surrounding the mature CL acutely increases prior to the onset of luteolysis in response to uterine as well as exogenous PGF(2alpha). It is now clear that color Doppler ultrasound is very useful for observing echogenicity with local blood flow thereby providing an easily obtained estimation of the physiological status of follicles, CLs and early conceptus. Widespread commercial application of color US will depend on further technological developments that reduce the cost and improve performance and ease-of-use. Overall, US is now a most effective non-invasive tool for managing reproduction, at the level of both the individual animal and the herd system. In particular, US can help us to clarify potential problems in high-producing dairy cattle during the postpartum period.  相似文献   
542.
Blood flow to the gravid and nongravid uterine horns of four multiparous Holstein cows (mean +/- SD, BW=641.8 +/- 95.4 kg; age=4.8 +/- 1.2 years; parity=3.0 +/- 1.2) was measured on days 225, 248, and 266 of gestation. Surgery was conducted on day 214.5 +/- 4.0 of gestation through the flank of the standing cows. Transit-time ultrasonic flow probes (diameter 12 or 14 mm) were fitted surgically around the uterine arteries of each cow. Surgery was completed within two hours of anesthesia, and the animals recovered rapidly following surgery. Uterine blood flow (UBF, l/min) was recorded at 10 sec intervals for approximately 23.5 hours; these values were averaged to determine UBF. The mean gravid UBF was significantly (P<0.05) greater than the nongravid UBF in this study. The range of the gravid and nongravid UBFs varied from 3.61 to 14.05 and 0.72 to 6.54 l/min, respectively. There were no changes (P>0.1) in the mean gravid and nongravid UBFs from day 225 to 266 of gestation.  相似文献   
543.

Accurately predicting the price of exported fishery products is an important task for fisheries because it will enable market trends to be determined, leading to the development of high-quality fishery products. In this study, we predicted prices in selected base periods (2, 3, 6, and 12 months) to investigate how historical data influenced the Vietnamese export price. A dataset (from May 1995 to May 2019) was collected from the US Department of Agriculture (USDA). We initially hypothesized that the dependent variable, Vietnamese export price, was affected by 33 independent variables, but ultimately used 15 key variables, which were chosen on the basis of Akaike information criterion (AIC) to train the models. A tree-based machine learning technique, including the random forest and gradient boosting tree algorithms, was applied for predictions. It was found that the random forest algorithm performed well for historical data for periods of more than 6 months, while the gradient boosting tree algorithm was better over short durations of less than 6 months.

  相似文献   
544.
Gallbladder adenocarcinomas in two captive African lions (Panthera leo), an 18-yr-old male and a 17-yr-old female, are described in this report. Grossly, both lions had hemoperitoneum with thickened and sclerotic gallbladder walls. Histopathologically, the male's tumor was well differentiated and the female's was poorly differentiated with multinucleate giant cells. Both tumors were highly invasive and involved the gallbladder serosa. The male also had a tumor in the liver, and the female's tumor had disseminated to the serosal surfaces of abdominal organs. In both cases, neoplastic cell cytoplasm stained diffusely for cytokeratin AE-1/AE-3 and cytokeratin 7 and granularly for lysozyme on immunohistochemical staining.  相似文献   
545.
546.
547.
A twig canker disease of Japanese persimmon with characteristic coral spots was found in Tottori Prefecture, Japan. The causal fungus was identified as Nectria cinnabarina, which causes coral spot disease on many host plants. This is the first report of the disease caused by N. cinnabarina on Japanese persimmon in Japan.  相似文献   
548.
 In June 1996, a leaf spot disease widely occurred in Japanese persimmon (Diospyros kaki) orchards in Tottori Prefecture, Japan. The main diagnostic symptom was ring spot on the leaves and calyxes of young fruits; in severe cases, lesions developed on more than half of the area of the leaf, resulting in early defoliation. Based on morphological and pathological studies of the isolated fungi, it was shown that Pestalotiopsis longiseta, P. glandicola, P. acaciae, and P. crassiuscula were responsible for the diseases. These fungi, except P. longiseta, were found to be new pathogens of the disease. Received: May 20, 2002 / Accepted: July 25, 2002  相似文献   
549.
As an analysis of the cashmere proteins by Type IV 2‐DE, ten kinds of components, including three components with molecular mass 42–50 kDa whose expression level increased in the winter, were separated. In analyzing nine components of these ten using a mass spectrometer, the three components of molecular mass 70–120 kDa and pI 5.3 were identified as keratin type II microfibrillar (accession no. KRSHL2 ), keratin 48 k type I microfibrillar component 8c‐1 (accession no. KRSHL1 ) and cytosolic phospholipase A2 (accession no. O77793 ), respectively. The three components whose expression level increased in the winter, were identified as keratin type I microfibrillar 48 kDa component 8C‐1 (accession no. P02534 ) and keratin type I microfibrillar 47.6 kDa (accession no. P25690 ) (pI 5.2/42 kDa), keratin type II microfibrillar component 7C (accession no. P15241 ) and keratin typeII‐sheep (accession no. S34165 ) (pI 5.5/45 kDa), and the keratin type II microfibrillar component 5 (accession no. P25691 ) (pI 5.8–6.0/45 kDa), respectively. The three components of less than 17 kDa were identified as hair keratin type II intermediate filament (accession no. CAA51836 ) (pI 5.2) and keratin high‐sulfur matrix protein IIIB2 (accession no. P02447 ) with a different isoelectric point (pI 5.4 and 5.9), respectively.  相似文献   
550.
To detect the magnitude of indirect positive effects of deer and mice on seedling survival of some woody species in a Japanese temperate forest, we analyzed the data from an earlier field experiment using a hierarchical Bayesian approach. The forest studied was inhabited by sika deer (Cervus nippon) and mice (Apodemus spp.), and the floor was covered with dwarf bamboo, Sasa nipponica, which negatively affected tree seedlings and was in turn negatively affected by deer and mice. The field experiment was designed as the combination of exclusion or removal of these factors: deer, mice and dwarf bamboo. A hierarchical Bayesian model was constructed and the parameters were estimated by the Markov chain Monte Carlo method. The model successfully showed the indirect positive effects of deer and mice, which improved the survival rate of five cohorts of the seedlings of three tree species by ameliorating the direct negative effect of dwarf bamboo. The cohorts studied were formed by the seedlings of Abies homolepis that emerged in 1997 and 2002, those of Fraxinus lanuginosa f. serrata that emerged in 1998 and 2002, and those of Fagus crenata that emerged in 1999. The positive indirect effect was especially large in F. crenata, which is known to be severely affected by dwarf bamboo. The total effect of deer was shown to be positive for all cohorts except the A. homolepis cohort that emerged in 1997, at which time the dwarf bamboo had not yet fully recovered from the browsing pressure of deer. The total effect of mice was shown to be positive for all of the cohorts. We conclude that these positive effects were due to the large negative effect of dwarf bamboo on the seedlings.  相似文献   
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