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941.
942.
Johannes Jansen Martin P. Boer Marco C. A. M. Bink W. Eric van de Weg 《Euphytica》2009,166(1):131-144
Many important crop species are outbreeding. In outbreeding species the search for genes affecting traits is complicated by
the fact that in a single cross up to four alleles may be present at each locus. This paper is concerned with the search for
interacting quantitative trait loci (QTL) in populations which have been obtained by crossing a number of parents. It will
be assumed that the parents are unrelated, but the methods can be extended easily to allow a pedigree structure. The approach
has two goals: (1) finding QTL that are interacting with other loci and also loci which behave additively; (2) finding parents
which segregate at two or more interacting QTL. Large populations obtained by crossing these parents can be used to study
interactions in detail. QTL analysis is carried out by means of regression on predictions of QTL genotypes. 相似文献
943.
Marco Erni Pay Drechsel Hans-Peter Bader Ruth Scheidegger Christian Zurbruegg Rolf Kipfer 《Irrigation and Drainage Systems》2010,24(1-2):113-125
Due to poor urban sanitation farmers in and around most cities in developing countries face highly polluted surface water. While the sanitation challenge has obvious implications for environmental pollution and food safety it can also provide ‘free’ nutrients for irrigating farmers. To understand the related dimensions, a box-flow model was used to identify the most important water and nutrient flows for the Ghanaian city of Kumasi, a rapidly growing African city with significant irrigation in its direct vicinity. The analysis focused on nitrogen and phosphorus and was supplemented by a farm based nutrient balance assessment. Results show that the city constitutes a vast nutrient sink that releases considerable nutrients loads in its passing streams, contributing to the eutrophication of downstream waters. However, farmers have for various practical reasons little means and motivation in using this resource of nutrients. This might change under increasing fertilizer prices as the nutrient load will continue to increase by 40% till 2015 assuming a widening gap between population growth and investments in water supply on one side and investments in sanitation on the other. However, even a strong investment into flushing toilets would not reduce environmental pollution due to the dominance of on-site sanitation systems, but instead strongly increase water competition. Key options to reduce the nutrient load would be via optimized waste collection and investment in dry or low-flush toilets. The latter seems also appropriate for the city to meet the water and sanitation Millennium Development Goals (MDGs) without increasing water shortages in toilet connected households. 相似文献
944.
Lucia Aidos Mauro Vasconi Francesco Abbate Luisa M. P. Valente Marco Lanfranchi Alessia Di Giancamillo 《Aquaculture Research》2019,50(2):588-598
This study evaluated the effects of rearing density on muscle growth and development in Siberian sturgeon (Acipenser baerii) larvae. Three different stocking densities were tested: low (LD, 30 larvae/l), mid (MD, 80 larvae/l) and high (HD, 150 larvae/l) in a recirculating aquaculture system. Larvae were sampled at hatching (T0), schooling (T1) and complete yolk‐sac absorption (T2) stage and were weighed and processed for muscle tissue histometrical analyses and for qualitative morphological study analyses; fatty acid profile was also determined by Gas Chromatography—Flame Ionization Detector analysis. Low‐density larvae presented a higher weight than MD or HD at T2 (p < 0.05). Histometrical analysis revealed that total muscle area was similar at T1 and T2, but higher than T0, while it was lower at HD at schooling (p < 0.05). The fatty acid profile revealed no differences between densities while, during development, there was a selective consumption: sparing or increasing of essential fatty acids to the detriment of their precursors. Our study suggests that lower densities appear to be more suitable to rear Siberian sturgeon in this particular stage of development. Indeed, larvae reared at the lower density were heavier and longer while larvae reared at the higher density showed lower muscle proliferation rate. As a consequence, LD larvae may exert an increase of potential growth at a mid‐long term. 相似文献
945.
Emilie Laurin Ian A. Gardner Andrea Peña Marco Rozas-Serri Jorge Gayosa Joaquin Neumann Heise Fernando O. Mardones 《Journal of fish diseases》2020,43(10):1167-1175
Early detection of piscirickettsiosis is an important purpose of government- and industry-based surveillance for the disease in Atlantic salmon farms in Chile. Real-time qPCRs are currently used for surveillance because bacterial isolation is inadequately sensitive or rapid enough for routine use. Since no perfect tests exist, we used Bayesian latent class models to estimate diagnostic sensitivity (DSe) and specificity (DSp) of qPCR and culture using separate two-test, single-population models for three farms (n = 148, 151, 44). Informative priors were used for DSp (culture (beta(999,1); qPCR (beta(98,2)), and flat priors (beta 1,1) for DSe and prevalence. Models were run for liver and kidney tissues combined and separately, based on the presence of selected gross-pathological signs. Across all models, qPCR DSe was 5- to 30-fold greater than for culture. Combined-tissue qPCR median DSe was highest in Farm 3 (sampled during P. salmonis outbreak (DSe = 97.6%)) versus Farm 1 (DSe = 85.6%) or Farm 2 (DSe = 83.5%), both sampled before clinical disease. Median DSe of qPCR was similar for liver and kidney, but higher when gross-pathological signs were evident at necropsy. High DSe and DSp and rapid turnaround-time indicate that the qPCR is fit for surveillance programmes and diagnosis during an outbreak. Targeted testing of salmon with gross-pathological signs can enhance DSe. 相似文献
946.
Benedetto Sicuro Paola Badino Franco Daprà Francesco Gai Marco Galloni Rosangela Odore Giovanni Battista Palmegiano Elisabetta Macchi 《Aquaculture International》2010,18(3):415-431
Olive mill vegetation water (VW) is an olive oil by-product rich in polyphenols has powerful antioxidant effects. In light
of the interest on the research of novel natural antioxidants to use in fish feed, the aim of this research was to use VW
as a potential substitute for artificial antioxidants in rainbow trout diet as well as checking its effects on the blood chemistry
and digestive organ physiology of the fish. The experimental plan was monofactorial, balanced (4 × 3) and the experimental
factor considered was the fish diet. Diets were isoproteic (CP 40%) and isoenergetic (18 MJ kg−1 DM) with two inclusion levels of VW (1 and 5%: VW1 and VW5) tested against a control diet. A feeding trial was performed
on quadruplicate groups of 200 fish (mean body weight: 44.2 g) fed experimental diets for 94 days. At the end of the trial,
the growth performance traits were determined and sampling of blood and different tissues (brain, ovary, stomach, liver, and
intestine) were carried out for haematology, endocrinology, histology, and digestive enzyme analysis. The main results of
the present experimentation are that VW inclusion in rainbow trout feed slightly affects the productive traits and blood chemistry,
while the histological structure of digestive organs and digestive enzyme physiology were not affected. 相似文献
947.
Marina Pozzolini Eleonora Tassara Andrea Dodero Maila Castellano Silvia Vicini Sara Ferrando Stefano Aicardi Dario Cavallo Marco Bertolino Iaroslav Petrenko Hermann Ehrlich Marco Giovine 《Marine drugs》2021,19(10)
Collagen filaments derived from the two marine demosponges Ircinia oros and Sarcotragus foetidus were for the first time isolated, biochemically characterised and tested for their potential use in regenerative medicine. SDS-PAGE of isolated filaments revealed a main collagen subunit band of 130 kDa in both of the samples under study. DSC analysis on 2D membranes produced with collagenous sponge filaments showed higher thermal stability than commercial mammalian-derived collagen membranes. Dynamic mechanical and thermal analysis attested that the membranes obtained from filaments of S. foetidus were more resistant and stable at the rising temperature, compared to the ones derived from filaments of I. oros. Moreover, the former has higher stability in saline and in collagenase solutions and evident antioxidant activity. Conversely, their water binding capacity results were lower than that of membranes obtained from I. oros. Adhesion and proliferation tests using L929 fibroblasts and HaCaT keratinocytes resulted in a remarkable biocompatibility of both developed membrane models, and gene expression analysis showed an evident up-regulation of ECM-related genes. Finally, membranes from I. oros significantly increased type I collagen gene expression and its release in the culture medium. The findings here reported strongly suggest the biotechnological potential of these collagenous structures of poriferan origin as scaffolds for wound healing. 相似文献
948.
Circe E. Badillo-Salas Enrique Valenzuela-Espinoza Marco A. González-Gómez Griselda Pares-Sierra Francisco Ley-Lou Zaul Garcia-Esquivel 《Aquaculture International》2009,17(2):173-186
Two trials were carried out in the laboratory in order to assess the effect of microparticulated feed (F) and live (Thalassiosira pseudonana, M) diets on the growth of recently set (396 ± 13 μm shell height) and 2 mm Crassostrea gigas postlarvae. Different proportions of M and F (100:0, 75:25, 50:50; 25:75, 0:100) were delivered in a single dose of 3 h d−1 in trial 1. Dietary M:F proportions of 100:0, 50:50, and 0:100 were delivered as a single pulse of 8 h d−1 (P1) or two pulses of 4 h−1 (P2) in trial 2. Maximal daily M ration was 296 cells μl−1 d−1 (trial 1), 150 M cells μl−1 d−1 (trial 2), or their equivalent F dry weight. Shell height (SH), dry (DW), and organic weight (AFDW) were evaluated weekly.
Oysters from trial 1 significantly increased their size after 28 days, and exhibited no significant dietary differences in
terms of DW (1.21 ± 0.15 to 2.01 ± 0.28 mg) or AFDW (0.091 ± 0.022 to 0.166 ± 0.029 mg). Newly set postlarvae (trial 2) also
exhibited significant growth after 25 days. No dietary differences were observed in trial 2, yet P2 oysters attained significantly
higher shell heights (825–912 μm) than P1 oysters (730–766 μm) after 25 d. Pulse effects were marginally not significant in
terms of AFDW and growth rate. Together, these findings showed that balanced microfeeds have a practical potential for the
culture of early C. gigas postlarvae, when they are delivered in pulse-feeding schemes 相似文献
949.
950.