全文获取类型
收费全文 | 583篇 |
免费 | 46篇 |
专业分类
林业 | 63篇 |
农学 | 32篇 |
基础科学 | 1篇 |
135篇 | |
综合类 | 28篇 |
农作物 | 35篇 |
水产渔业 | 56篇 |
畜牧兽医 | 205篇 |
园艺 | 9篇 |
植物保护 | 65篇 |
出版年
2024年 | 2篇 |
2023年 | 17篇 |
2022年 | 12篇 |
2021年 | 25篇 |
2020年 | 30篇 |
2019年 | 39篇 |
2018年 | 33篇 |
2017年 | 41篇 |
2016年 | 44篇 |
2015年 | 22篇 |
2014年 | 28篇 |
2013年 | 43篇 |
2012年 | 36篇 |
2011年 | 57篇 |
2010年 | 22篇 |
2009年 | 19篇 |
2008年 | 27篇 |
2007年 | 30篇 |
2006年 | 17篇 |
2005年 | 15篇 |
2004年 | 15篇 |
2003年 | 16篇 |
2002年 | 11篇 |
2001年 | 3篇 |
2000年 | 7篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1990年 | 1篇 |
1985年 | 1篇 |
1978年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1972年 | 1篇 |
1970年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有629条查询结果,搜索用时 0 毫秒
91.
Márcio Fléquisson Alves Miranda Maria Betânia Galvão dos Santos Freire Brivaldo Gomes Almeida Fernando José Freire Luiz Guilherme Medeiros Pessoa 《Archives of Agronomy and Soil Science》2018,64(9):1207-1221
This study aimed to evaluate the use of phytoremediation and soil conditioners in the recovery of physical attributes of a saline-sodic Fluvic Neossol in Brazil Northeast. The applied treatments were: Atriplex nummularia L., as phytoremediation plant, due to its ability to extract salts from the soil; organic conditioners, such as bovine and sheep manure; gypsum and polymer, as chemical conditioners. Samples with preserved structure were collected at the time of the experiment installation and 18 months after in the layers 0–10 cm and 10–30 cm. The analyzed attributes were: water dispersed clay, dispersion index, bulk density, penetration resistance, soil porosity, and saturated hydraulic conductivity. The use of sheep manure, gypsum and polymer promoted an increase in saturated hydraulic conductivity in the 0–10 cm layer from 4.51 to 16.37 cm day?1, 11.26 to 23.95 cm day?1 and 7.24 to 22.77 cm day?1, respectively. Gypsum increased the macroporosity in the superficial layer by 42.6%. Atriplex and polymer were more efficient at reducing soil penetration resistance. The polymer was more efficient at improving the physical properties. However, it is necessary to consider phytoremediation with Atriplex as a more sustainable alternative that can still be used as complementary fodder in animal feed. 相似文献
92.
Vinicius de Abreu D’Ávila Elen de Lima Aguiar-Menezes Renato Nunes Pereira Vânia Gonçalves-Esteves Cláudia Barbieri Ferreira Mendonça Saulo José de Melo Tamires Medeiros dos Santos 《Phytoparasitica》2017,45(4):471-484
Coleomegilla maculata DeGeer is an omnivorous lady beetle that feeds on natural or alternative prey and artificial foods, which allows its laboratory rearing for use on augmentative biocontrol. In addition, C. maculata may supplement its diet with pollen and nectar, which helps in its conservation in agroecosystems. This study aimed to evaluate if Apiaceous flowers (Anethum graveolens L. and Coriadrum sativum L.), with and without alternative prey [eggs of Ephestia kuehniella (Zeller) or larvae of Drosophila melanogaster Meigen] or an artificial food (aqueous solution of honey), may guarantee the survival and complete development of the immature and adult stages of C. maculata in the laboratory. The immature stages developed only when Apiaceous flowers were offered with E. kuehniella eggs. The food with only one of the alternative prey (moth eggs or fly larvae) or moth eggs + honey solution resulted in fertile adults; however, the number of eggs/cluster was greater for the foods with E. kuehniella eggs + honey solution, A. graveolens flowers, or only D. melanogaster. Foods comprising only the two Apiaceous species, only the honey solution, or only water resulted in larval development up to a specific instar. Adults of C. maculata also survived on these foods, but there was no oviposition. The foods of the two Apiaceous species produced heavier adults only when associated with E. kuehniella eggs. The results indicate that the zoophytophagous habit of C. maculata should be considered in conservation biocontrol programs aimed at using this lady beetle to control crop pests. 相似文献
93.
Biofilms of Candida spp. from the ocular conjunctiva of horses with reduced azole susceptibility: a complicating factor for the treatment of keratomycosis? 下载免费PDF全文
Raimunda Sâmia Nogueira Brilhante Paula Vago Bittencourt Débora de Souza Collares Castelo‐Branco Glaucia Morgana de Melo Guedes Jonathas Sales de Oliveira Lucas Pereira Alencar Rossana de Aguiar Cordeiro Mariana Pinheiro Evilázio Fernandes Nogueira‐Filho Waldemiro de Aquino Pereira‐Neto José Júlio Costa Sidrim Marcos Fábio Gadelha Rocha 《Veterinary ophthalmology》2017,20(6):539-546
94.
The influence of Ringer's lactate or HES 130/0.4 administration on the integrity of the small intestinal mucosa in a pig hemorrhagic shock model under general anesthesia 下载免费PDF全文
95.
Luciano Fernandes Sousa Rogério Martins Maurício Guilherme Rocha Moreira Lúcio Carlos Gonçalves Iran Borges Luiz Gustavo Ribeiro Pereira 《Agroforestry Systems》2010,79(2):189-199
This study aimed at evaluating the influence of a silvopastoral system (SPS) composed of “Aroeira” trees (Myracrodruon urundeuva) on the nutritional value of Brachiaria brizantha cv. Marandu forage grass over the rainy season. The experiment was conducted in the SPS located in the “Cerrado” biome in
Lagoa Santa County, Minas Gerais state, Brazil, in the agricultural year of 2004–2005. It was evaluated the influence of “Aroeira”,
whose density in the area was 140 trees/ha, on the following parameters of the B. brizantha cv. Marandu forage grass: forage mass harvest above stubble height, morphogenic attributes, bromatological composition and
nutritional value. The effects of “Aroeira” trees on the micro-climatic conditions were also evaluated. The experiment adopted
a randomized block design with five blocks (cutting seasons), two treatments (a shaded pasture—B. brizantha cv. Marandu shaded by M. urundeuva—and a pasture in full sun—B. brizantha cv. Marandu in full sun), and three replicates. The tree component, composed of the tree species M. urundeuva in the experimental density adopted, increased dry matter and crude protein of the forage mass harvest above stubble height,
without affecting the concentration of neutral detergent fibre or acid detergent fibre, thus causing dry matter and organic
matter in vitro degradability as well as effective degradability of the forage grass to remain the same as those obtained
in full sun. Therefore, the results of this study show the possibility of using trees and grass to increase both animal production
and environmental services. 相似文献
96.
Suely Ruiz Giolo Enrico Antonio Colosimo Clarice Garcia Borges Demétrio 《Journal of Agricultural, Biological & Environmental Statistics》2009,14(2):154-169
Interval-censored survival data, in which the event of interest is not observed exactly but is only known to occur within
some time interval, occur very frequently. In some situations, event times might be censored into different, possibly overlapping
intervals of variable widths; however, in other situations, information is available for all units at the same observed visit
time. In the latter cases, interval-censored data are termed grouped survival data. Here we present alternative approaches
for analyzing intervalcensored data. We illustrate these techniques using a survival data set involving mango tree lifetimes.
This study is an example of grouped survival data. 相似文献
97.
Dirk Jungmann Cornelia Bandow Thomas Gildemeister Roland Nagel Thomas G. Preuss Hans T. Ratte Cândida Shinn Lennart Weltje Hanna M. Maes 《Journal of Soils and Sediments》2009,9(2):94-102
Background, aim, and scope
Fenoxycarb is an insect growth regulator widely used to control a variety of pests. As a juvenile hormone analogue, it interacts with the natural hormones involved in insect development, inhibiting metamorphosis to the adult stage. Adverse effects of fenoxycarb on non-target organisms have been repeatedly observed and its rapid dissipation from water to the organic fraction of the sediment is known. The aim of this work was to investigate the impact of fenoxycarb on the development of sediment-dwelling larvae of the midge Chironomus riparius after exposure to spiked sediment. 相似文献98.
Tognolini M Giorgio C Hassan Mohamed I Barocelli E Calani L Reynaud E Dangles O Borges G Crozier A Brighenti F Del Rio D 《Journal of agricultural and food chemistry》2012,60(36):8877-8884
The Eph tyrosine kinase receptors and their ephrin ligands play a central role in human cancer as their deregulated expression induces tumorigenesis with aggressive phenotypes. To evaluate their potential contribution to EphA2-ephrinA1 modulation, several colonic catabolites of dietary (poly)phenolics, known to be generated in vivo, were screened using an ELISA-based binding assay. Some of the catabolites inhibited the binding in a dose-dependent manner (IC(50) values from 0.26 to 43 μM). Functional studies on prostate adenocarcinoma cells revealed that pyrogallol and protocatechuic acid specifically antagonized ephrinA1-Fc-induced EphA2 phosphorylation at concentrations that were not cytotoxic. The active concentrations of pyrogallol appear to be close to what can be reached in vivo under physiological conditions. Finally, because of the roles played by the Eph-ephrin system not only in cancer development but also in neurodegeneration and diabetes, pyrogallol and protocatechuic acid are candidates for more detailed functional studies to elucidate their role in these pathophysiological processes. 相似文献
99.
Mitter Eduardo Kovalski dos Santos Graziely Cristina de Almeida Érica Janaína Rodrigues Morão Luana Galvão Rodrigues Heide Dayane Prates Corso Carlos Renato 《Water, air, and soil pollution》2012,223(2):765-770
With the development of the textile industry, there has been a demand for dye removal from contaminated effluents. In recent
years, attention has been directed toward various natural solid materials that are capable of removing pollutants from contaminated
water at low cost. One such material is sugarcane bagasse. The aim of the present study was to evaluate adsorption of the
dye Acid Violet Alizarin N with different concentrations of sugarcane bagasse and granulometry in agitated systems at different
pH. The most promising data (achieved with pH 2.5) was analyzed with both Freundlich and Langmuir isotherms equations. The
model that better fits dye adsorption interaction into sugarcane bagasse is Freundlich equation, and thus the multilayer model.
Moreover, a smaller bagasse granulometry led to greater dye adsorption. The best treatment was achieved with a granulometry
value lower than 0.21 mm at pH 2.50, in which the total removal was estimated at a concentration of 16.25 mg mL−1. Hence, sugarcane bagasse proves to be very attractive for dye removal from textile effluents. 相似文献
100.
Olfa Baâtour Jun Huang Nawel Nasri Imen Ben Salah Imen Tarchoun Maha Zaghdoudi Margaret Y. Gruber Mokhtar Lachaâl Zeineb Ouerghi Abdelali Hannoufa 《植物养料与土壤学杂志》2012,175(4):641-648
In this study, we report on the relationship between individual antioxidant carotenoids, phenolic fractions, and flavonoids and attenuating NaCl toxicity in two contrasting varieties of lettuce (Lactuca sativa L., var. Verte and Romaine), as a means of developing more precise targets for lettuce breeding. In seedling leaves, carotenoid levels increased under NaCl stress in Verte, but remained unchanged in Romaine. Chlorogenic acid (CGA), a soluble polyphenol abundantly present in leaves, was the only phenolic acid that accumulated significantly in both varieties and was predominant under salinity. Remarkably, CGA was more prominent in Verte than Romaine at moderate salinity levels (100 mM). Foliar flavonoid levels were also differentially increased in both seedling types grown under 100 mM NaCl, but dropped significantly in both varieties under 200 mM NaCl. Germination, which was overall more salt‐resistant in Romaine, was significantly increased under salt stress by application of low dosage (10–6 to10–5 M) of CGA to Verte, but not to Romaine. These results suggest that CGA is involved in modulating NaCl‐induced oxidative‐stress responses during seed germination in Verte. 相似文献