全文获取类型
收费全文 | 433篇 |
免费 | 34篇 |
专业分类
林业 | 21篇 |
农学 | 13篇 |
基础科学 | 2篇 |
76篇 | |
综合类 | 5篇 |
农作物 | 17篇 |
水产渔业 | 78篇 |
畜牧兽医 | 199篇 |
园艺 | 7篇 |
植物保护 | 49篇 |
出版年
2023年 | 9篇 |
2022年 | 13篇 |
2021年 | 21篇 |
2020年 | 31篇 |
2019年 | 27篇 |
2018年 | 29篇 |
2017年 | 24篇 |
2016年 | 29篇 |
2015年 | 15篇 |
2014年 | 29篇 |
2013年 | 21篇 |
2012年 | 25篇 |
2011年 | 35篇 |
2010年 | 19篇 |
2009年 | 15篇 |
2008年 | 24篇 |
2007年 | 24篇 |
2006年 | 17篇 |
2005年 | 7篇 |
2004年 | 8篇 |
2003年 | 8篇 |
2002年 | 9篇 |
2001年 | 6篇 |
2000年 | 4篇 |
1999年 | 5篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有467条查询结果,搜索用时 0 毫秒
91.
Electro-acupuncture and Chinese herbs for treatment of cervical intervertebral disk disease in a dog
Ayne Murata Hayashi Júlia Maria Matera Tatiana Soares da Silva Ana Carolina Brand?o de Campos Fonseca Pinto Sílvia Renata Gaido Cortopassi 《Journal of veterinary science (Suw?n-si, Korea)》2007,8(1):95-98
A non-ambulatory dog with tetraparesis following a pain episode that had evolved over 2 months was submitted for medical treatment and diagnosed with intervertebral disk disease at C3-C4 and dorsal extradural compression at C1-C2 and C3-C4 using myelography and computed tomography. The dog experienced ambulation recovery after 15 days of treatment with only electroacupuncture and Chinese herbal medicine, with marked improvement occurring after only 10 treatments. Six months of follow-up demonstrated that the dog was stable and had no recurrence of symptoms. Therefore, it was concluded that the combination of electroacupuncture and Chinese herbal medicine was responsible for motor rehabilitation. 相似文献
92.
Nogueira EO J Piantino Ferreira A Martins Soares R Luiz Durigon E Lazzarin S Brentano L 《Comparative immunology, microbiology and infectious diseases》2007,30(2):81-96
Specific amino acid (aa) substitutions in VP1, VP2 and VP3 genes were reported as a distinctive feature of the American CIA-1 strain, characterized as having a variable rate of growth and tropism for different MSB-1 cell sublines [Renshaw RW, Soiné C, Weinkle T, O'Connell PH, Ohashi K, Watson S, et al. A hypervariable region in VP1 of chicken anemia virus mediates rate of spread and cell tropism in tissue culture. J Virol 1996;70(12):8872-8]. DNA sequencing of 878 nucleotides from twelve Brazilian CAV, eight of which tested for in vitro isolation in three different sources of MDCC-MSB1 cell line and identified as lacking capacity to propagate in any of these cells, were compared to sequence data available for CAV strains propagated or not in cell culture. Alignment of the deduced aa resulted in a lack of singled out amino acid substitutions in the partial genomic sequences of Brazilian isolates that would entirely contrast them to viruses propagated in MSB-1 cells, indicating that the combined VP1, VP2 and VP3 substitutions observed may not entirely account as sole determinants of CAV isolation and propagation in MDCC-MSB-1 cells. 相似文献
93.
Felipe Richter Reis Aline Caroline de Oliveira Gabriella Giani Pieretti Gadelha Marcela Breves de Abreu Hillary Isabelle Soares 《Plant foods for human nutrition (Dordrecht, Netherlands)》2017,72(2):120-125
In an attempt to obtain shelf-stable litchi fruit with preserved nutritional quality and good sensory features, quarters of peeled and pitted fruits were vacuum dried at 50, 60 and 70 °C at a constant pressure of 8.0 kPa. The product was assessed for its vitamin C, total phenolics and texture (hardness). In addition, the product with the best texture was assessed for its shelf-life by means of accelerated testing. Results suggest that vacuum dried litchi retained almost 70% of the vitamin C and total phenolics when compared to frozen fruits (control). Vitamin C and phenolic compounds content significantly decreased with drying, while no difference was found between different drying temperatures. Hardness increased with drying temperature. The sample dried at 70 °C presented crispness, which is a desired quality feature in dried fruit products. This sample was subjected to shelf-life evaluation, whose result suggests a shelf-life of eight months at 23 °C. Total color change (CIE ΔE00) was the expiry criterion. Vacuum drying was a suitable technique for producing shelf-stable litchi fruit with good texture while preserving its desirable original nutrients. Consumption of vacuum dried litchi may be beneficial to health due to its remarkable content of phenolic compounds and vitamin C. 相似文献
94.
Charlotte Whatmough Andrew P Moores Ricardo Soares Magalhaes Christopher R Lamb 《Veterinary radiology & ultrasound》2008,49(2):129-134
Caudocranial stifle radiographs with variations in positioning were made in two greyhound cadavers. Radiographs were repeated after each of three interventions: cranial cruciate desmotomy; release of the caudal horn of the medial meniscus; complete medial meniscectomy. The joint space on medial and lateral aspects of the joint was measured by a observer who was unaware of positioning or intervention. One dog had significantly wider joint space than the other (1.0 vs. 1.5mm). The lateral aspect of the joint space was wider than the medial aspect (1.7 vs. 0.7 mm). Medial rotation of the stifle resulted in an increase of 0.4 mm in width of the lateral joint space, whereas lateral rotation of the stifle reduced the lateral joint space by an average of 0.4 mm. Decentering the X-ray beam had no significant effect on joint space width. Tension increased the width of the medial joint space by an average of 1.2 mm and the lateral aspect by an average of 1.3 mm. Cranial cruciate desmotomy resulted in an average 0.3 mm increase in width of the joint space, and medial meniscectomy with an average 0.2 mm reduction of the joint space. Although the femorotibial joint space was affected by iatrogenic stifle injuries and by medial or lateral rotation, these changes were less than the differences between the two dogs. Hence it seems unlikely that the small changes in joint space width associated with cruciate ligament desmotomy and medial meniscectomy will be detectable in clinical practice. 相似文献
95.
Pedro Vieira de Azevedo Jose Monteiro Soares Bernardo Barbosa da Silva 《Agricultural Water Management》2008,95(3):301-308
This study deals with the effects of intermittent irrigation on actual evapotranspiration (ET) and leaf area index (LAI) of “Superior” grapevines grown in a semiarid environment in northeastern Brazil. The field experiments were carried out during two consecutive fruiting cycles (dry season and rainy season) of grapevines (Vitis vinifera, L) irrigated by drip at a rate of 2.3 L h−1. Four irrigation time intervals were used as follow: one turn irrigation-time (I-1), two turn irrigation-time (I-2), three turn irrigation-time (I-3), and four turn irrigation-time (I-4). The growing cycles received different amounts of water by irrigation, which for dry and rainy seasons were 470.5 and 243.5 mm, respectively. The ET increased from 5.7 to 7.5 mm day−1 when the irrigation time interval changed from I-1 to I-4 and resulted in a higher value of LAI. The values of ET during the rainy-season growing cycle were much lower throughout the phenological stages, reaching a maximum of 6.4 mm day−1 for I-4 in the maturation stage. For both growing cycles, an increase in the cumulated vineyard evapotranspiration was observed when changing the irrigation time interval from I-1 to I-4, except I-2, which was slightly greater than I-3. Soil water drainage had a very gradual exponential decrease from I-1 to I-4 in both fruiting cycles. The grapevine coefficient under intermittent irrigation can be described as function of days after pruning by polynomial models. 相似文献
96.
Henrique M. V. S. Azevedo-Pereira Marco F. L. Lemos Amadeu M. V. M. Soares 《Water, air, and soil pollution》2011,219(1-4):215-224
Imidacloprid is a new insecticide that mimics nicotine, combining its insecticidal activity with a reduced persistence in the environment. The toxicity of imidacloprid to Chironomus riparius Meigen using the formulated product Confidor® from Bayer®, in pulse and continuous exposure, was evaluated in this study. The behavioural response of the midge after toxicant exposure using an online biomonitor was also investigated. Early second-instar C. riparius larvae were exposed in either constant (10 days) or pulse (4 days, followed by 6 days post exposure in clean medium) conditions. Imidacloprid constant exposure resulted in a decrease in growth and impairment of the behavioural pattern of the midge larvae. Pulsed exposure followed by a recovery period revealed a recovery of midge physiological conditions, by reaching a stabilisation of normal behavioural activities and growth among treatments. Moreover, ventilation showed to be a more sensitive parameter by revealing a faster recovery than locomotion. Behaviour alterations may weaken the ability to escape from predators, and reduce food acquisition with consequent growth impairment. These effects may have an impact at the population and community level. 相似文献
97.
Several hypotheses have been put forward to explain the causes of damage to plants by atmospheric pollution. None however, fully explain why some species are more prone to damage than others. In the literature, certain higher plants are more commonly reported as suffering damage from atmospheric pollution. These include climax species such as conifers, some broadleaf species such as oak and beech, and ericaceous species. Pioneer species such as highly nitrophillous woody species and ruderal herbaceous species are seldom reported in connection with damage from atmospheric pollutants. A screening of 18 species (woody and herbaceous) for 5 physiological and metabolic parameters and subsequent regression analysis of the data, showed that plants could be grouped according to their tolerance to acidity. There was a marked positive correlation between leaf nitrate reductase (NR) activity and the buffering capacity index (BCI) of the leaf. Foliar mistings and soil applications of 3 mol m?3 KNO3 to 6 assorted plant species also revealed that pioneer species, can induce NR activity when NO3 ? is applied directly to the foliage or soil. However, climax species have a much lower ability to increase NR activity in response to foliar and soil NO3 ? inputs. Leaf NO3 ? assimilation carries with it the direct generation of OH?, involves greater uptake of base cations and confers greater physiological buffering capability through the close interaction of carbon and nitrogen acquisition in the leaf. The hypothesis states that leaf nitrate assimilators are physiologically more competent at buffering acidic inputs whether directly as H+, or indirectly through uptake of acidic pollutants. 相似文献
98.
Vitor Klein Schmidt Aurora Carneiro Zen Bernardo Fernandes Soares Bruno Anicet Bittencourt 《Growth and change》2023,54(2):596-624
The recent economic, technological, and social shocks have led to a period of high economic uncertainty. The term “economic resilience” has been used to describe how regional clusters deal with and adapt to various shocks. This paper aims to analyze the elements that influence the resilience trajectory of a cluster. We conduct qualitative and exploratory research on the centennial Wine Cluster in Serra Gaúcha, Brazil, using data sources, interviews, and documents. To this end, we first identify seven elements that influence cluster resilience from the literature review. Subsequently, through an empirical case study, we verify whether these elements could represent the resilience of clusters. The results show that these seven elements are integrable and represent dimensions that explain the resilience of the cluster analyzed. Moreover, the findings highlight that resilience and resistance to crises are the historical results of improvements and the development of new routines for clustered companies. This study contributes to the cluster resilience literature and presents elements explaining how regions can adapt to and deal with shocks. 相似文献
99.
Michael S. Switzenbaum Chris Holden Hugo Soares Geoffrey A. Kuter 《Compost science & utilization》2013,21(2):35-43
? A study was conducted on a full scale in-vessel agitated bed process to determine the influence of two common amendments on nitrogen management. Sawdust and mulch were tested for their ability as amendments to conserve nitrogen and thus lower the amount of ammonia volatilization. Neither of the amendments showed a major advantage in conserving nitrogen, although the mulch amended mix had a slight advantage, most likely due to the more readily available nature of the carbon which would lead to greater nitrogen assimilation. 相似文献
100.
Kieran A. Monaghan Carlos S. Agostinho Fernando M. Pelicice Amadeu M. V. M. Soares 《Ecology of Freshwater Fish》2020,29(2):384-397
We employed the trophic upsurge hypothesis as an analytical framework to describe the response of Neotropical fish communities to terrestrial inundation associated with river damming. Data were collected for the impact assessment of the Peixe Angical Dam, Tocantins River, Brazil. Monthly surveys were conducted at nine sites (seven upstream, two downstream) from 15 months before to 20 months after dam closure and a follow-up survey 60–83 months after closure. Fish responses differed in timing and magnitude across sites. In the new reservoir, populations peaked 8–13 months after flooding, demonstrating increases in richness (84 ± 52%), biomass (329 ± 266%) and abundance (681 ± 348%) with the maxima for richness and abundance tending to precede biomass maxima. Populations of all families increased but were greatest for Engraulidae, Hemiodontidae, Serrasalmidae and Characidae, and lower for the benthic catfish: Sciaenidae, Dorididae, Pimelodidae. Downstream populations peaked 5–12 months after closure or showed consistent decline. Five years after dam-closure richness and abundance were lower compared to predam levels, with populations at all sites demonstrating an ongoing decline. Reservoir creation triggers reproductive recruitment and otherwise pools spatially disparate populations from across the flooded valley. If the rise in richness is largely explained by the increased catchability of species otherwise present prior to flooding, it may be more appropriate to estimate species loss with reference to upsurge data. As peak biomass coincides with declining richness, modelling fisheries production from annually aggregated data may risk overestimating the potential for sustainable harvests. Upsurge–response curves can help identify the timing of critical ecological thresholds for flood-managed fisheries. 相似文献