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991.
This study estimated the net macro and micromineral requirement from the 48 male uncastrated lambs (24 growing male Santa Inês and 24 growing male Morada Nova hair sheep), with initial weights of 21.7 ± 1.2 kg and 20.8 ± 0.8 kg using the comparative slaughter method. The experimental diet consisted of 30% forage (Buffel—Cenchrus ciliaris (L) hay) and 70% concentrate (corn grain 43.5%, soybean meal 22.0%, vegetable oil 3.0% and mineral supplement 1.5%). The experimental design was a completely randomized with two breeds, four weights, and six replicate. Mineral requirements sufficient to promote weight gain in Santa Inês sheep ranged from 1.75 to 1.03 g Ca, 1.01 to 0.61 g of P, 0.38 to 0.21 g of K, 0.38 to 0.16 of Na, 0.10 to 0.06 Mg, 28.5 to 16.0 mg of Fe, 6.14 to 3.22 mg of Cu, and Zn 23.0 to 14.0 mg/kg per unit of empty body weight (EBW) gain. In the Morada Nova breed, the requirements ranged from 1.96 to 0.84 g of Ca, 1.15 to 0.46 of P, 0.39 to 0.19 of K, 0.28 to 0.13 of Na, 0.10 to 0.05 Mg, 26.2 to 12.9 mg of Fe, 5.59 to 2.46 Cu, and Zn 23.6 to 10.3 mg/kg of EBW gain. Mineral requirements varied mainly in accordance with the proportion of bone mass and fat concentration in the carcass, which were influenced by the slaughter weight of the animals, and therefore should be used in the formulation of dietary mineral supplements.  相似文献   
992.
Trichinellosis is a zoonotic disease due to the ingestion of raw or undercooked meat from animals infected with the larvae of nematodes belonging to the genus Trichinella. In January–February 2015, an outbreak of trichinellosis occurred in Genoa, Northern Italy. The epidemiological link was traced back to a dinner served at an agritourism farm on 31 December 2014, where a majority of the 52 guests had consumed the ‘beef’ steak tartare. The source of infection was not traced; however, it was noted that the amount of beef purchased officially for providing at the dinner did not correspond with that served, suggesting that meat of a different origin had been added to the beef to prepare the steak tartare. Clinical and laboratory data of 30 individuals out of the 52 (57.7%), of which four were hospitalized, were consistent with that of the case definition of trichinellosis. Western blot patterns of the sera from patients with confirmed trichinellosis were similar to the diagnostic pattern identified for the reference sera of Trichinella pseudospiralis but different from those of the control sera tested for patients infected with Trichinella spiralis and Trichinella britovi. Identification of T. pseudospiralis as the aetiological agent responsible for the outbreak of trichinellosis using an indirect tool represents an advancement in the epidemiological investigation of this zoonotic disease.  相似文献   
993.
Decline phenomena of shrub species such as Quercus coccifera and Retama raetam have occurred throughout Tunisian forests since 2012. These evergreen shrubs have long been regarded for their medicinal and ecological interests. Therefore, their preservation as valuable forest resources is of great interest. However, information regarding aetiology of this disease is still scarce. Hence, the aim of this study was to identify and characterize the causal agents associated with disease symptoms in two Tunisian forests. Thirty-eight isolates were obtained from symptomatic Q. coccifera and R. raetam twigs. Morphological characterization and phylogenetic analysis of the internal transcribed spacer (ITS) region of the nuclear ribosomal RNA gene cluster and partial sequence of the translation elongation factor 1-alpha gene (tef1-α) allowed the identification of three Diplodia species namely Diplodia africana, D. seriata and D. pseudoseriata. Our findings revealed that the incidence of Diplodia species was significantly correlated to the altitude, the temperature and the rainfall. Pathogenicity test showed that all Diplodia isolates are pathogenic. However, D. africana revealed to be the most aggressive species toward R. raetam. These findings were the first record of D. seriata as fungal pathogen associated with Q. coccifera dieback and D. pseudoseriata and D. africana on R. raetam in Tunisia.  相似文献   
994.
Evaluating canopy temperature-based indices for irrigation scheduling   总被引:1,自引:0,他引:1  
Summary Since the development of commercial versions of infrared sensors, they have been increasingly used to determine canopy temperature and schedule irrigations. However, some shortcomings of the technique have been identified, among them the sensitivity of canopy temperature measurements to weather fluctuations. Based on field and computer simulated data, an analysis of the suitability of crop water stress indices (CWSI's) developed from canopy temperature under variable weather conditions was done. Important day to day fluctuations of CWSI values determined using an empirical baseline (empirical CWSI) appeared common for nonstressed crops, particularly under low vapor pressure deficit conditions. These fluctuations generate uncertainty in the use of this empirical index to determine needs for irrigation. The use of an improved index (theoretical CWSI) requiring measurements of net radiation, soil heat flux and wind speed, and estimates of aerodynamic and canopy resistances reduced but did not eliminate these fluctuations. Results using a simulation model showed that the empirical CWSI provided late indication of irrigation needs, after some water stress has developed, which may limit its application for crops sensitive to water stress. These simulations also indicated that the theoretical CWSI was able to track the development of water stress and provide reasonable indication of irrigation needs. However, this result may not be fully realized in field applications where the determination of CWSI may be affected by various sources of variability which are not accounted for by the model.  相似文献   
995.
The variability in grain and starch characteristics and their relationship with the accumulation of starch granule associated proteins were investigated in five maize landraces of Northwest Mexico (Blando de Sonora, Chapalote, Elotero de Sinaloa, Reventador, and Tabloncillo). Significant differences were observed in grain hardness related traits, starch physicochemical properties, and structural properties. Blando de Sonora showed very soft grains, whereas the hardest grains were observed for Chapalote and Reventador. Starch granules isolated from landraces with hard grains contained more amylose and showed polygonal shapes, lower crystallinity and enthalpy of gelatinization, and greater retrogradation and proportion of long amylopectin chains. Proteomic analysis identified the enzymes granule‐bound starch synthase I (GBSSI), starch synthase I and IIa, starch branching enzyme IIb, sucrose synthase 1, and pyruvate phosphate dikinase 2 as granule‐associated proteins. The abundance of GBSSI correlated significantly with amylose content, consistent with the positive correlation observed between amylose and grain hardness. These results showed that the variability in the characteristics evaluated was mainly related to changes in the proportion of amylose in the starch granules, which were associated with differences in the expression of GBSSI. This information may be useful to define strategies for the exploitation and conservation of the landraces.  相似文献   
996.
Intensive land use in the Rolling Pampa of Argentina have resulted in a mosaic of fields with different cultural histories creating different soil environments, which interact with crops and cropping activities producing a wide range of habitats for insects. Species and functions in canopy structure, food quality and essential oils of the crop–weed associations may vary depending on the field's cropping history and management (i.e. crops, soil degradation, weeding and fertilization). Species composition and functional structure of insect communities may respond to these changes. We studied insect communities in wheat and coriander crops that differed in their canopy structures, essential oil production, and the cropping histories of the fields on which they grew. For this purpose we planted wheat (Triticum aestivum L.), and two coriander (Coriandrum sativum L.) landraces in plots with two levels of weeding and fertilization. The crops were grown in two consecutive years at two locations differing in cropping history and related to this in level of soil degradation. Insects were sampled in all plots at crop full flowering, and were classified and related to agronomic variables and to essential oils using multivariate techniques. Among all the environmental factors tested in this study, year and soil degradation were the main factors explaining insect community structure; and also weed community structure in unweeded plots. The proportion of essential oil components varied with cropping history, suggesting an association among soil properties indicative of soil degradation, plant chemical signals and insect distribution. Although insect community composition varied widely, functional structure was very similar among crop–weed communities. Soil degradation appeared to have affected directly crop–weed communities and insects’ assemblages, since no consistent relationship was found between plant composition and insect community structure. It can be hypothesized that soil degradation might have affected the amount of volatiles produced especially by coriander, generating a “soil degradation scent” that determined the structure in the insect community, and/or the soil itself emitted different signals, in relation to changes in its physical, chemical and biological characteristics.  相似文献   
997.
Milling and baking quality traits in wheat (Triticum aestivum L.) were studied by QTL analysis in the ITMI population, a set of 114 recombinant inbred lines (RILs) generated from a synthetic-hexaploid (W7985) × bread-wheat (Opata 85) cross. Grain from RILs grown in U.S., French, and Mexican wheat-growing regions was assayed for kernel-texture traits, protein concentration and quality, and dough strength and mixing traits. Only kernel-texture traits showed similar genetic control in all environments, with Opata ha alleles at the hardness locus Ha on chromosome arm 5DS increasing grain hardness, alkaline water retention capacity, and flour yield. Dough strength was most strongly influenced by Opata alleles at 5DS loci near or identical to Ha. Grain protein concentration was associated not with high-molecular-weight glutenin loci but most consistently with the Gli-D2 gliadin locus on chromosome arm 6DS. In Mexican-grown material, a 2DS locus near photoperiod-sensitivity gene Ppd1 accounted for 25% of variation in protein, with the ppd1-coupled allele associated with higher (1.1%) protein concentration. Mixogram traits showed most influence from chromosomal regions containing gliadin or low-molecular-weight glutenin loci on chromosome arms 1AS, 1BS, and 6DS, with the synthetic hexaploid contributing favorable alleles.Some RI lines showed quality values consistently superior to those of the parental material, suggesting the potential of further evaluating new combinations of alleles from diploid and tetraploid relatives, especially alleles of known storage proteins, for improvement of quality traits in wheat cultivars.Contribution number 06-77J from the Kansas Agricultural Experimental Station.  相似文献   
998.
999.
1000.
The aim of the present study was to evaluate the effects of zearalenone (ZEA) on the reproductive system morphometry, oestrogen (E2) levels and oocyte quality of beef heifers. Twenty non-pregnant purebred Nellore (Bos indicus) heifers [age, ≥18 months; initial body weight, 348 ± 30 kg (mean ± standard deviation)] were used. The animals were randomly divided into experimental group and a control group of 10 animals each. Group experimental was administered 300 ppb ZEA per os for 98 days, and the control group was administered placebo per os for 98 days. The administration of ZEA was carried out daily by adding mycotoxin to the diet. All heifers were evaluated weekly via rectal ultrasound examinations (12 weeks). Diameters of the right and left uterine horns, right and left ovaries, largest antral follicle and corpus luteum were measured. Vulva size was also measured. Blood samples were collected to estimate E2 levels. At the end of 12 weeks, the heifers were slaughtered, and the ovaries were sent to the laboratory for in vitro embryo production. A completely randomized design was adopted, and repeated measures analysis of variance (p < .05) was performed (except for oocyte quality). Vulva size (p = .0985); diameters of uterine horns (p = .0522), ovaries (p = .6955), antral follicles (p = .6355) and corpus luteum (p = .3808); and E2 levels (p = .3379) were not affected by the treatments. ZEA-contaminated diet significantly reduced (p = .05) the proportion of viable oocytes (49.4%, n = 207) compared with the control diet (59.9%, n = 222); however, the blastocyst rate did not differ between the groups (p = .9418). The results indicate that contamination of beef heifer's diet with 300 ppb ZEA affected neither morphometric parameters nor plasma oestrogen levels; however, ZEA contamination was detrimental to oocyte quality.  相似文献   
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