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941.
Thin-layer and gas-liquid chromatography, ultraviolet analysis and bioassay with Chlorella spp. have been used to investigate the pathway of degradation of diuron to phytotoxic derivatives when diuron was used as a soil-residual herbicide in irrigation canals. Observations suggest that 1-(3,4-dichlorophenyl)-3-methylurea and 1-(3,4-dichlorophenyl)urea make a contribution to total residues equivalent to a maximum of about 40 and 55%, respectively, of diuron concentrations. Application of a phyto-toxicity rating suggests that in this environment, measurement of diuron specifically would underestimate the total phytotoxicity of residues by a maximum of about 7%.  相似文献   
942.
Convolvulus arvensis is the most important species of bindweed in Britain. Established plants spread by means of lateral roots: establishment from seed and fragments of the underground growth is not important. The hormone weedkillers like 2,4-D and MCPA give good control in the year of treatment. With the correct dose and timing there is also good control in the year after treatment. Adding paraquat to 2,4-D reduces the effect in the year after treatment. Repeated annual treatment with high doses of chlorthiamid that prevent shoot growth for the entire season are no more effective against the underground growth than the standard dose of 2,4-D. Calystegia sepium spreads rapidly by rhizomes and stolons. It is more susceptible than C. arvensis to MCPB.  相似文献   
943.
Two wild oat herbicides, benzoylprop-ethyl and flamprop-methyl were administered to lactating cows at low dose levels (0.3–3.0 mg/kg in total diet) and the excretion of total metabolites in milk, urine and faeces was measured. Total residues in tissues were also determined. Similarly a third and related herbicide flamprop-isopropyl was fed to cows, pigs and hens (at 0.5 mg/kg in total diet) and the residues were determined in excreta and tissues, including eggs. The amounts of the compounds fed were equivalent to approximately 10–300 times the total residue found in cereal treated in the field. Residues in milk in most cases were well below 0.001 mg/kg; in muscle samples <0.003 mg/kg; and in eggs, 0.0008 mg/kg, decreasing by 50% in approximately 3 days to 0.0001 mg/kg 4 days after the termination of treatment. Elimination of the herbicides from the animals was rapid in every case and this, together with the low residue levels, was attributed to very efficient metabolic de-esterification to the parent carboxylic acid metabolites (benzoylprop and flamprop). These metabolites possess physical properties ideally suited for excretion via the kidneys and bile into urine and faeces and, conversely, unsuited for transport into milk and eggs.  相似文献   
944.
The decay rate of six strains of Influenza virus Type A of human origin and eight strains of avian origin were examined in aerosol form under fixed conditions of temperature and humidity. Strains of avian origin were demonstrated to have greater resistance to decay of viability.  相似文献   
945.
946.
Summary Organic compounds present in minute quantities are responsible for bread flavor profile. Organic acids, alcohols, esters and carbonyl compounds have been identified and estimated, quantitatively, by use of paper, column and vapor-phase chromatography. Because of the minute quantities of most organic flavor constituents, some system of extraction and concentration must be employed for successful analysis. Separation into classes and concentration is best accomplished by formation of derivatives. Developing solvents, carrier system, and techniques of chromatography must be carefully selected for each group of compounds. Success in the analysis of bread flavor constituents has been significant in recent years because of the development of chromatography techniques.
Zusammenfassung Die Geschmackseigenschaften von Brot werden durch in sehr geringen Mengen vorhandene organische Verbindungen bedingt. Mittels Papier-, Säulen- und Gaschromatographie wurden organische Säuren, Alkohole, Ester und Karbonylverbindungen ermittelt und mengenmäßig bestimmt. Die äußerst geringen Mengen der Mehrzahl der organischen Geschmackskomponenten können nur mit einer Methode, die Extraktion und Konzentration umfaßt, erfolgreich analysiert werden. Diese Trennung in Gruppen und Konzentration wird am besten über die Bildung von Sekundärverbindungen erreicht. Hierbei muß für jede Gruppe von Komponenten eine sehr sorgfältige Auswahl der Entwicklungslösungen, der Vektorsysteme und der chromatographischen Technik getroffen werden. Die bedeutenden Fortschritte der chromatographischen Techniken der letzten Jahre sind der Grund für die Erfolge auf dem Gebiete der Analyse der Geschmackskomponenten von Brot.

Résumé Des composés organiques, présents en très faible quantités, régissent le profil de saveur du pain. Des acides organiques, des alcools, des esters et des composés carbonyliques ont été identifiés, et évalués, quantitativement par chromatographie sur papier, sur colonne, et en phase vapeur. Du fait des faibles quantités de la plupart des composants organiques de saveur, un système d'extraction et de concentration doit être utilisé pour réussir les analyses. La séparation en classes et la concentration peut être obtenue de façon la meilleure par formation de dérivés. Les solvants de développement, les systèmes vecteurs, et les techniques de chromatographie, doivent être soigneusement selectionnés pour chaque groupe de composants. Les réussites dans le domaine de l'analyse des composants de la saveur du pain ont été significatives ces dernières années, du fait du développement des techniques chromatographiques,


with 4 figs.

Contribution no. 424, Department of Flour and Feed Milling Industries, Kansas State Agricultural Experiment Station, Manhattan, Kansas, U.S.A.  相似文献   
947.
HYPERTROPHIC OSTEOPATHY ASSOCIATED WITH PULMONARY BLASTOMYCOSIS IN A DOG   总被引:1,自引:0,他引:1  
Hypertrophic osteopathy (HO) associated with pulmonary blastomycosis was diagnosed in a 5–year-old male mixed-breed dog. One year prior to referral, increased pulmonary opacity had been identified on radiographs made during an examination for a chronic cough. Although serologic tests for blastomycosis were negative, the dog was treated with oral ketoconozole on the basis of suspicious lesions seen on radiographs and clinical signs. Ten months after completing the ketoconozole therapy, the dog was presented for a persistent cough and lameness. Intrapulmonary masses and periosteat proliferation were observed radiographically. A biopsy of the pulmonary masses was done, and Blastomyces dermatitidis was identified. Amphotericin B and ketoconozole administration resulted in clinical improvement and partial resolution of the HO lesions five months after initiation of therapy.  相似文献   
948.
949.
Experiments with Cyperus rotundus L. III. Seasonal variations in growth   总被引:1,自引:0,他引:1  
John L.  Hammeron 《Weed Research》1975,15(5):339-348
Nutgrass tubers were planted in pots on thirteen occasions at 4-weekly intervals, and growth and development followed by sampling at 5-day intervals from 10 to 45 days after planting. Growth rates, final shoot numbers, dry weights and rhizome lengths, and new tuber production were highest in plantings made 1 and 29 March and 26 April. Correlation coefficients suggested that mean daylength during growth was a major factor influencing growth and development, but mean temperature appeared to be important in determining new tuber size and the proportion of dry-matter as new tubers. Shoot number appears to be a reliable guide to rhizome and tuber production.  相似文献   
950.
The case records of 20 horses with tetanus referred to the Ontario Veterinary College-Veterinary Teaching Hospital between 1970 and 1990 were reviewed. The fatality rate was 75%. There was a strong association with previous vaccination and survival ( P = .03). Most of the animals had been injured an average of 9 days (range 2 to 21 days) prior to development of clinical signs. Hyperesthesia and prolapse of the third eyelid were the most common clinical signs. Treatment regimens varied during hospitalization; however, all horses received parenteral penicillin, tranquilizers, tetanus toxoid, and antitoxin. Five of the nonsurviving animals were given intrathecal tetanus antitoxin. One animal had seizures as a complication of intrathecal treatment. The prognosis was best for horses that (1) had been vaccinated prior to the injury, (2) responded to the phenothiazine tranquilizers, and (3) did not rapidly (over 24 to 48 hours) become recumbent. Considering the species susceptibility, potential for contaminated wounds, and the increased survival of vaccinated horses, yearly revaccination is recommended.  相似文献   
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