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排序方式: 共有622条查询结果,搜索用时 315 毫秒
81.
Ribeiro VL dos Santos JC Martins JR Schripsema J Siqueira IR von Poser GL Apel MA 《Veterinary parasitology》2011,179(1-3):195-198
Calea serrata Less. (Asteraceae), an endemic species of south Brazil known as "quebra-tudo", is used in Afro-Brazilian religious rituals and in folk medicine for treating liver disorders. Phytochemical studies of the n-hexane extract of this plant demonstrated the presence of precocene II, a benzopyran derivative known for its insecticidal activity. The aim of this work was to isolate this benzopyran and determine the chemical composition of the essential oil of C. serrata and further to evaluate the acaricidal activity of the essential oil and precocene II against the larvae of Rhipicephalus (Boophilus) microplus. The LC(99.9) and LC(50) values obtained with the oil, which presents precocene II and sesquiterpenes, were 3.94 μL/mL and 0.28 μL/mL, respectively. For precocene II this values were 4.25mg/mL and 1.78 mg/mL, respectively. The results indicate a synergistic interaction between the components of the oil and precocene II. 相似文献
82.
Abias Santos Silva Luiz Gustavo Ribeiro Pereira Márcio dos Santos Pedreira Fernanda Samarini Machado Mariana Magalhães Campos Cristina Simões Cortinhas Tiago Sabella Acedo Rafael Dantas dos Santos João Paulo Pacheco Rodrigues Rogério Martins Maurício Thierry Ribeiro Tomich 《Journal of animal physiology and animal nutrition》2020,104(1):76-87
The effect of exogenous amylase on the in vitro rumen digestion kinetics of whole-crop maize silage made from dent (RB9004) or flint grain type (RB9308) was evaluated at different phenological stages: soft dough (SOD), early dent (EAD), ½ milkline (½M) and ¾ milkline (¾M). Forage was harvested from 70 to 110 days after sowing. Two rumen-cannulated cows receiving or not exogenous amylase (0.7 g/kg dry matter—DM, provided to achieve 396 kilo Novo units of amylase activity/kg of TMR DM) were used as donor of ruminal fluid. The in vitro gas production kinetics was evaluated according to a dual-pool logistic model. The chemical composition and gas production kinetics were affected by the hybrid and phenological stages. The flint hybrid had lower range for chemical analysis among physiological stages. Harvesting at ½M and ¾M improved DM content, bromatological composition and silage quality parameters compared to dent or flint types. Amylase (i) increased methane (CH4) production and in vitro dry matter digestibility (IVDMD) in ½M stage, (ii) improved digestion kinetics by reducing lag time and increasing total gas production and fermentation rates of non-fibrous carbohydrates (NFC) and fibrous carbohydrates (FC), and (iii) increased extent and fermentation rate of NFC and increased fermentation rate of FC fraction in whole-crop maize silages produced from dent or flint types in all phenological stages. Harvesting between ½M and ¾M is the best phenological stage to improve chemical composition and silage quality parameters. Exogenous amylase showed improvements on fibre digestion of silages at ½M and ¾M phenological stages in both grain types of corn. 相似文献
83.
Ruiz Maria Luiza Owatari Marco Shizuo Yamashita Marcela Maya Ferrarezi José Victor Saffadi Garcia Patricia Cardoso Lucas Martins Maurício Laterça Mouriño José Luiz Pedreira 《Tropical animal health and production》2020,52(1):167-176
Tropical Animal Health and Production - The aims of this study were to evaluate the inclusion of different concentrations of Lactobacillus plantarum in Nile tilapia diet and to verify histological... 相似文献
84.
85.
Antonio Carlos Martins dos Santos Kleycianne Ribeiro Marques Larissa Urzêdo Rodrigues Álvaro José Gomes de Faria Vitor L. Nascimento 《Journal of plant nutrition》2013,36(19):2522-2531
AbstractBiofortification of soybean grains with lithium (Li) is a strategy to improve a food with high social acceptance, in order to promote health benefits. The aim of this work was to evaluate the development of plants and the production of biofortified soybeans with two Li sources. The experiment was conducted in a completely randomized design with five replicates. Ten treatments were obtained in a 2x5 factorial scheme, comprising two sources of Li (LiOH - Li hydroxide and Li2SO4 - Li sulfate) and five doses (0, 30, 60, 90 and 120?mg kg?1) in stages V4 and R1. The supply of Li promoted significant effects (p?≤?0.05) on the morphology, yield components and nutritional status of soybean plants. The highest grain yield was obtained with the use of Li2SO4 at the estimated dose of 45.7?mg kg?1. The plants accumulated Li between 8.00 and 11.20?mg kg ?1, respectively, with the use of Li2SO4 and LiOH. In the grains, the highest concentrations of Li were obtained with the application of 120?mg kg?1. Li2SO4 and LiOH are good sources for biofortification of soybean grains. 相似文献
86.
Cristina Cruz S. Herman Lips Maria Amelia Martins‐Loucao 《Journal of plant nutrition》2013,36(8):1517-1530
The response of carob (Ceratonia siliqua L.) seedlings grown at different root zone temperatures affected by nitrate and ammonium nutrition was studied. When root temperatures ranged from 10 to 35°C, ammonium‐fed plants were significantly larger than nitrate‐fed plants. Ammonium‐fed plants displayed toxicity symptoms and were much smaller at 40°C root temperature in comparison with the nitrate‐fed plants grown at the same root temperature. Root/shoot ratio slightly increase with root temperature in ammonium‐ and nitrate‐fed plants in a similar way, and shoot demand per root unit decreased with root temperature between 15 and 25°C. There was a general increase in net photosynthesis with root temperature, though nitrate‐fed plants were more sensitive to low and ammonium‐fed plants to high temperatures. Increasing the root temperature of ammonium fed plants from 10 to 40°C leads to a 30% increase in the amount of photosynthates sent to the roots. The presence of ammonium resulted in the distribution of newly fixed carbon away from carbohydrates and into nitrogen compounds. Potassium, calcium, and nitrogen content of the plants also increased with increasing root temperature. 相似文献
87.
We analyzed the effect of different copper (Cu) concentrations (0.10, 0.15, 0.20 and 0.35 mM) and time (1 day to 9 days) on several growth and biochemical parameters of roots and shoots of white lupin plants (Lupinus albus cv Estoril) grown in nutrient solution. A significant decrease in leaf fresh weight and leaf area was detected. Copper accumulated in the roots, and an impairment of nutrient translocation was only observed after six days at the highest Cu concentrations applied. A transient increase in the activity of polyphenoloxidase (EC 1.10.3.1) enforces a role for lignification as a defense strategy under enhanced Cu levels. The activities of several antioxidative enzymes were enhanced after Cu application. Our results indicate that Lupinus albus cv ‘Estoril’ is a rather resistant plant that can cope with moderate concentrations of copper, mostly by controlling up to a certain point, the uptake of excessive amounts of this metal. 相似文献
88.
de Oliveira Cristiana Maia do Carmo Margarida Gorete Ferreira Ferreira Leandro Martins Höfte Monica do Amaral Sobrinho Nelson Moura Brasil 《European journal of plant pathology / European Foundation for Plant Pathology》2021,161(2):273-287
European Journal of Plant Pathology - Fusarium wilt caused by Fusarium oxysporum f. sp. lycopersici (FOL) is one of the main diseases affecting tomato plants. Three races (races 1, 2 and 3) of the... 相似文献
89.
Aeration strategy for controlling grain storage based on simulation and on real data acquisition 总被引:1,自引:0,他引:1
Daniela de Carvalho Lopes Jos Helvecio Martins Adílio Flauzino Lacerda Filho Evandro de Castro Melo Paulo Marcos de Barros Monteiro Daniel Maral de Queiroz 《Computers and Electronics in Agriculture》2008,63(2):140-146
In this work a new control strategy for grain aeration systems was proposed. This strategy was implemented in a software package called AERO and relates four conditions which depend on real time data acquisition and on the process simulation. The main advantage of AERO controller is that it can be used in different geographic regions, during different seasons and with different aeration systems, automatically adjusting its set points. The objectives of AERO controller are to equalize the temperatures inside the bin, to cool the grain mass whenever is possible and to maintain the moisture content under safe conditions. The results showed that the proposed strategy is efficient to achieve these objectives. Moreover, significant energy saving has been achieved with the AERO controller. 相似文献
90.
G. R. Xavier L. M. V. Martins M. C. P. Neves N. G. Rumjanek 《Biology and Fertility of Soils》1998,27(4):386-392
A large collection of cowpea rhizobia strains was obtained from soil samples collected from either a semi-arid or a tropical
rain forest area located at about the same latitude in the north-eastern region of Brazil and evaluated for their intrinsic
antibiotic resistance to eight commercial antibiotics. The aim of this study was to correlate antibiotic resistance of native
rhizobia strains to edaphic-climatic factors as a way to establish suitable inoculants for specific areas. A large diversity
regarding intrinsic antibiotic resistance was found, and 17 clusters were identified as varying from sensitive to gradually
resistant up to 500 μg·ml–1 of the antibiotics tested. Clustering analysis did not show any pattern related to the geographic region where isolates have
been obtained. On the other hand, an increase in the antibiotic-resistant rhizobia population was associated with an increase
in soil P and Al contents. lsolates which were sensitive to spectinomycin, ampicillin, streptomycin, chloramphenicol and tetracycline
were present at higher rates in soils devoid of Al. Rhizobia bacteria producing mucus type I (fluid and capable of spreading
over the solid media) were found preferentially in soil with Al concentrations up to 36 mg·kg–1, diminishing quickly at higher levels.
Received: 2 May 1997 相似文献