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61.
62.
Galina P. Simeonova Svetozar Z. Krastev Radostin S. Simeonov 《Veterinary research communications》2016,40(3-4):107-115
Background
The pathogenic mechanism of equine recurrent uveitis (ERU) is still poorly defined and many variations between experimental animal models and spontaneous disease exist.Objectives
The aim of our study was to investigate if Th17 cell-mediated response plays role in the pathogenesis of the used experimental model in horses and to reveal its pathological findings.Methods
Experimental uveitis was induced in 6 healthy horses. The concentrations of retinal autoantigen CRALBP and IL-17 were measured using ELISA in aqueous humor and vitreous body of the 12 inflamed eyes as well as in 12 control non-inflamed eyes taken from 6 horses in slaughter house. After centrifugation of the two eye media, smears were prepared and cytological investigation was performed. Tissue specimens were taken from all eye globes and were submitted to histopathological investigation.Results
CRALBP and IL-17 concentrations were significantly elevated in eye media of horses with experimental uveitis in comparison with controls. Cytological and histopathological findings corresponded to the changes characteristic of chronic immune-mediated inflammation with mononuclear cell infiltration of uvea, choroid, retina, and eye media as well as severe retinal destruction.Conclusions
Our study demonstrated the involvement of the retinal autoantigen CRALBP as well as IL-17 in the pathogenesis of experimental uveitis in horses. These findings suggests that this experimental uveitis in horses may serve as a suitable animal model for investigation of IL-17- mediated immune response during spontaneous autoimmune uveitis in horses as well as in humans.63.
64.
Booker CW Abutarbush SM Schunicht OC Jim GK Perrett T Wildman BK Guichon PT Pittman TJ Jones C Pollock CM 《Veterinary therapeutics : research in applied veterinary medicine》2007,8(3):183-200
The purpose of this study was to determine the efficacy and cost-effectiveness of tulathromycin (DRAX) versus tilmicosin (MIC) or oxytetracycline (TET) as a metaphylactic antimicrobial in feedlot calves. Calves that received DRAX had significantly (P<.05) lower initial undifferentiated fever (UF) treatment and relapse rates; lower overall chronicity, overall mortality, and cause-specific mortality rates; higher average daily gains; and improved quality grades. However, calves that received DRAX also had poorer (P<.05) yield grades compared with calves that received MIC or TET and worse feed conversion compared with calves that received MIC. Net advantages in the DRAX group were 3.79CanDollars/animal and 16.96CanDollars/animal compared with the MIC and TET groups, respectively. Based on these results, DRAX is a more efficacious and cost-effective metaphylactic antimicrobial than MIC or TET in feedlot calves at ultra-high risk of developing UF. In addition, this study presents a comparison between two methods ("deads out" and "deads in") of calculating feedlot performance variables. 相似文献
65.
Since its detection in 2001 the human Metapneumovirus (HMPV), a member of the Paramyxoviridae family, was observed to be a serious pathogen in human respiratory infections during childhood. Meanwhile, several animal models have been established to study the virus-host interactions and pathogenic effects. Mainly, small laboratory animals like mice and cotton rats have been used, although the usage of these two species for HMPV research is controversially discussed and contradictious results were obtained by different groups. Further trials with ferrets, hamsters and non human primates were performed revealing different success in their individual usage. In this review we present the different animal models, summarize their advantages and disadvantages, and discuss the controversial results from different studies. 相似文献
66.
Sodium chlorate effectively reduces or eliminates gram-negative pathogenic bacteria in the gastrointestinal tracts of live cattle. Limitations to the in vivo efficacy of chlorate are its rapid absorption from the gastrointestinal tract and its presumed reduction to chloride within the gastrointestinal tract. We hypothesized that chlorate would be reduced via ruminal bacteria in a ruminal in vitro system and that the reduction of chlorate would be influenced by the dietary for-age:concentrate ratio; thus, 4 ruminally cannulated steers were fed 20 or 80% concentrate diets in a crossover design. Ruminal fluid was collected in 2 periods and dispensed into in vitro tubes containing sodium [36Cl]chlorate, which was sufficient for 100 or 300 mg/L final chlorate concentrations. The tubes were incubated for 0, 1, 4, 8, 16, or 24 h; autoclaved, control ruminal fluid, fortified with sodium [36Cl]chlorate, was incubated for 24 h. Chlorate remaining in each sample was measured by liquid scintillation counting after [36Cl]chloride was precipitated with silver nitrate. A preliminary study indicated that chlorite, a possible intermediate in the reduction of chlorate, had a half-life of approximately 4.5 min in freshly collected (live) ruminal fluid; chlorite was, therefore, not specifically measured in ruminal incubations. The chlorate dose did not affect in vitro DM digestion (P > or = 0.11), whereas in vitro DM digestibility was decreased (P < or = 0.05) by 80% forage content. By 24 h, 57.5 +/- 2.6% of the chlorate remained in 100-mg/L incubations, whereas 78.2 +/- 2.6% of the chlorate remained in the 300-mg/L incubations. When the data were expressed on a concentration basis (mg/L), diet had no effect (P > or = 0.18) on chlorate reduction; however, when chlorate reduction was expressed on a percentage basis, chlorate reduction tended to be greater (P > or = 0.09) at 8 and 16 h in the incubations containing the low-concentrate diet. Chlorate remaining in autoclaved controls at 24 h was intermediate (P < 0.01) between chlorate remaining in live ruminal fluid samples incubated for 0 or 24 h. Attempts to isolate chlorate-respiring bacteria from 2 sources of ruminal fluid were not successful. These data indicate that microbial-dependent or chemical-dependent, or both, reduction of chlorate occurs in bovine ruminal fluid and that dietary concentrate had a negligible effect on chlorate reduction. 相似文献
67.
68.
69.
José Manuel Mirás-Avalos Francisco Pérez-Sarmiento Rosalía Alcobendas Juan José Alarcón Oussama Mounzer Emilio Nicolás 《Irrigation Science》2016,34(2):161-173
Irrigation techniques that reduce water applications are increasingly applied in areas with scarce water resources. In this study, the effect of two regulated deficit irrigation (RDI) strategies on peach [Prunus persica (L.) Batsch cv. “Catherine”] performance was studied over three growing seasons. The experimental site was located in Murcia (SE Spain), a Mediterranean region. Two RDI strategies (restricting water applications at stage II of fruit development and postharvest) based on stem water potential (Ψs) thresholds (?1.5 and ?1.8 MPa during fruit growth and ?1.5 and ?2.0 MPa during postharvest) were compared to a fully irrigated control. Soil water content (θv), Ψs, gas exchange parameters, vegetative growth, crop load, yield and fruit quality were determined. RDI treatments showed significantly lower values of θv and Ψs than control trees when irrigation water was restricted, causing reductions in stomatal conductance and photosynthesis rates. Vegetative growth was reduced by RDI, as lower shoot lengths and pruning weights were observed under those treatments when compared to control. However, fruit size and yield were unaffected, and fruit quality was slightly improved by RDI. Water savings from 43 to 65 % were achieved depending on the year and the RDI strategy, and no negative carryover effect was detected during the study period. In conclusion, RDI strategies using Ψs thresholds for scheduling irrigation in mid–late maturing peach trees under Mediterranean conditions are viable options to save water without compromising yield and even improving fruit quality. 相似文献
70.
The use of overhead trellis systems for the production of dry-on-vine (DOV) raisins and table grapes in California is expanding. Studies were conducted from 2006 to 2009 using Thompson Seedless grapevines grown in a weighing lysimeter trained to an overhead arbor trellis and farmed as DOV raisins for the first two years and for use as table grapes thereafter. Maximum canopy coverage for the two lysimeter vines across years was in excess of 80 %. Seasonal (15 March–31 October) evapotranspiration for the lysimeter vines (ETLys) was 952 mm in 2007 (farmed as DOV raisins) and 943 and 952 mm (when farmed as table grapes). The maximum crop coefficient (K cLys) across all 4 years ranged from 1.3 to 1.4. These maximum values were similar to those estimated using the relationship where K c is a function of the amount of shaded area measured beneath the canopy at solar noon (K c = 0.017 × percent shaded area). Covering the lysimeter’s soil surface with plastic (and then removing it) numerous times during the 2009 growing season (1 June–14 September) reduced ETLys from an average of 6.4 to 5.6 mm day?1 and the K c from 1.07 to 0.93. A seasonal basal K c (K cb) was calculated for grapevines using an overhead trellis system with a 13 % reduction in the K cLys across the growing season. 相似文献