全文获取类型
收费全文 | 1149篇 |
免费 | 88篇 |
国内免费 | 1篇 |
专业分类
林业 | 99篇 |
农学 | 47篇 |
基础科学 | 8篇 |
304篇 | |
综合类 | 88篇 |
农作物 | 63篇 |
水产渔业 | 101篇 |
畜牧兽医 | 368篇 |
园艺 | 24篇 |
植物保护 | 136篇 |
出版年
2023年 | 7篇 |
2022年 | 19篇 |
2021年 | 44篇 |
2020年 | 42篇 |
2019年 | 43篇 |
2018年 | 51篇 |
2017年 | 43篇 |
2016年 | 49篇 |
2015年 | 53篇 |
2014年 | 45篇 |
2013年 | 67篇 |
2012年 | 77篇 |
2011年 | 86篇 |
2010年 | 49篇 |
2009年 | 39篇 |
2008年 | 77篇 |
2007年 | 56篇 |
2006年 | 59篇 |
2005年 | 51篇 |
2004年 | 52篇 |
2003年 | 37篇 |
2002年 | 41篇 |
2001年 | 24篇 |
2000年 | 11篇 |
1999年 | 13篇 |
1998年 | 5篇 |
1997年 | 7篇 |
1996年 | 6篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 8篇 |
1991年 | 4篇 |
1989年 | 6篇 |
1988年 | 6篇 |
1987年 | 9篇 |
1986年 | 4篇 |
1985年 | 5篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1973年 | 4篇 |
1971年 | 2篇 |
1965年 | 1篇 |
1958年 | 1篇 |
1945年 | 1篇 |
1937年 | 1篇 |
排序方式: 共有1238条查询结果,搜索用时 15 毫秒
41.
Desneux Nicolas Han Peng Mansour Ramzi Arn Judit Brvault Thierry Campos Mateus R. Chailleux Anais Guedes Raul N. C. Karimi Javad Konan Kouassi Arthur J. Lavoir Anne-violette Luna Mara G. Perez-Hedo Meritxell Urbaneja Alberto Verheggen Franois J. Zappal Lucia Abbes Khaled Ali Abid Bayram Yunus Cantor Fernando Cuthbertson Andrew G. S. De Vis Raf Erler Fedai Firake Dnyaneshwar M. Haddi Khalid Hajjar M. Jamal Ismoilov Khasan Jaworski Coline C. Kenis Marc Liu Hao-tian Madadi Hossein Martin Thibaud Mazih Ahmed J. Messelink Gerben Mohamed Samira A. Nofemela Robert S. Oke Abiola Ramos Csar Ricupero Michele Roditakis Emmanouil Shashank Pathour R. Wan Fang-Hao Wang Ming-hui Wang Su Zhang Yi-Bo Biondi Antonio 《Journal of pest science》2022,95(1):17-39
Journal of Pest Science - The South American tomato pinworm, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), has invaded most Afro-Eurasian countries and is threatening worldwide tomato... 相似文献
42.
Effects of road transportation or droving on the weight and metabolism of young bulls 总被引:1,自引:0,他引:1
Marcella Cândia D’Oliveira Maria Inês Lenz Souza Ruy Alberto Caetano Corrêa Filho Maria da Graça Morais Camila Celeste Brandão Ferreira Ítavo Gumercindo Loriano Franco 《Tropical animal health and production》2014,46(8):1447-1453
This study evaluated the effects of the mode of transportation on weight and metabolism of young bulls, which are generally transported by two systems: droving and truck. This experiment consisted of two phases: transportation and refeeding and involved transportation by droving and truck. Fifty young Nellore bulls were separated in equal numbers in both groups, droving group and truck group. In the transportation phase, animals were moved, in a 640-km journey. The refeeding phase consisted of 84 days and commenced after the animals arrived at the fattening farm. The effect of the transportation system on animals’ weight, metabolic hormones, and serum biochemistry was assessed after 28, 56, and 84 days. During the transportation phase, animals in the droving group lost 10.11 kg and animals in the truck group gained 13.1 kg. The truck group showed 20.5 kg of weight gain at the end of the refeeding phase. The highest triiodothyronine (T3) and thyroxine (T4) concentrations were observed on days 0 and 60 in the transportation phase in both droving and truck groups. The serum cortisol concentration was higher in the droving group than in the truck group on day 56 of the refeeding phase. The IGF-I concentrations were higher during the refeeding phase in the droving group than in the truck group. Our results showed that transportation by droving leads to increased weight loss and reduced further weight gain compared to transportation by truck and that serum concentrations of T4, cortisol, and insulin-like growth factor (IGF-I) hormones are altered by the transportation system. 相似文献
43.
Elisa Crisci Lorenzo Fraile Sonia Valentino Laura Martínez-Guinó Barbara Bottazzi Alberto Mantovani Maria Montoya 《Veterinary microbiology》2014
Long pentraxin 3 (PTX3) is a conserved pattern-recognition secreted protein and a host-defence-related component of the humoral innate immune system. The aim of the present study was to characterize swine PTX3 (SwPTX3) protein expression in influenza virus infected pigs. First, we performed in silico studies to evaluate the cross-reactivity of PTX3 human antibodies against SwPTX3. Secondly, we used in vitro analysis to detect SwPTX3 presence in swine bone marrow dendritic cells (SwBMDC) upon stimulation with different agents by Western blot and immunofluorescence. Finally, the levels of SwPTX3 were assessed in experimental infection of pigs with different strains of influenza virus. This is a novel study where the expression of SwPTX3 was evaluated in the context of a pathogen infection. The initial characterization of SwPTX3 in influenza virus infected pigs contributes to understand the role of PTX proteins in the immune response. 相似文献
44.
Alberto J.P. Nunes Marcelo V.C. S Francisco Felipe Andriola-Neto Daniel Lemos 《Aquaculture (Amsterdam, Netherlands)》2006,260(1-4):244-254
Nine commercial feeding attractants and stimulants for Litopenaeus vannamei were evaluated by observation of behavioral responses in animals allotted in one Y-maze aquarium apparatus. In the validation phase, fishmeal–Brazilian origin (FMBO); fishmeal–Peruvian origin (FMPO); blood meal (BM), meat and bone meal (MBM), squid meal (SM), fish oil (FO) and fish solubles (FS) were evaluated. There was also a control without stimulatory raw material. The tested materials were included at 3% in neutral gelatin pellets (wet basis). In each behavioral observation, two different ingredients were offered at the same time in equal quantities, being allotted in the end of each chamber's arm. In Phase II after system validation, the following commercial attractants were tested: 80% crude protein (CP) vegetable dried biomass (VDB80), 68% CP vegetable dried biomass + glutamate + betaine (VDB68), complex of amino acids (alanine, valine, glycine, proline, serine, histidine, glutamic acid, tyrosine and betaine) with enzymatically digested bivalve mollusk (CAA), condensed fish soluble protein (CFSP), squid liver meal (SLM), betaine (Bet), dried fish solubles–low biogenic amines (DFSLB), dried fish solubles–high biogenic amines (DFSHB) and whole squid protein hydrolysate (WSPH). Attractants were used at a 3% level wet basis with neutral gelatin, without any additional ingredient source available. The best four commercial attractants from this phase (CAA, CFSP, SLM and WSPH) were compared under 0.5% and 1.0% levels. In Phase I of the study, a higher percentage of choices were observed for FMPO and FMBO. BM and FO were the least chosen ingredients. In Phase II, the worst results were observed for Bet, DFSHB and, mainly, for VDB80 and VDB68. When two-by-two comparisons were performed, results suggested that CFSP and CAA were the best commercial attractants tested. In the last phase, both CFSP and CAA at 1.0% level were significantly more chosen by shrimp than CFSP (0.5%), SLM (0.5 or 1.0%) or WSPH (0.5 or 1.0%). At both 0.5% and 1.0% levels, shrimp spent a similar amount of time feeding on CFSP and CAA. However, only CAA was statistically better than SLM and WSPH together. Further work is required to better elucidate the chemical drivers of chemostimulation for L. vannamei for each one of the attractants tested. 相似文献
45.
Dal-Sang Jeong Enrique Blanco Gonzalez Kagayaki Morishima Katsutoshi Arai Tetsuya Umino 《Fisheries Science》2007,73(4):823-830
The genetic contribution of 51 broodstock, comprising 29 females and 22 males, reared at Hiroshima City Marine Products Promotion
Center for the production of stocked black sea bream was monitored during two consecutive years using seven microsatellite
DNA loci. The high discrimination ability of these markers was reflected in the polymorphic identification content (PIC=0.831), the exclusion probability (Q≈1), and the low probability of identity index (I=3.635−10). The total number of breeders contributing to the mating process was estimated at 32 (62.7%) in 2000 and 30 (58.8%) in 2001.
On pedigree reconstruction, 69.3% of the offspring were successfully assigned to a single broodstock pair. Loss of alleles
accounted for 16.9% during seed production; nevertheless, 90.9% of males and 69.0% of females participated in the mating process.
Based on microsatellite genetic tagging, 58.9% of the fish sampled during the two months after release were identified as
hatchery stock, presenting no significant differences from wild conspecifics in either fork length or body weight. 相似文献
46.
Maria Rosaria Vadrucci Fabio Vignes Annita Fiocca Alberto Basset Immacolata Santarpia Gian Carlo Carrada Marina Cabrini Serena Fonda Umani 《水产资源保护:海洋与淡水生态系统》2003,13(6):489-506
- 1. The relevance of biodiversity to ecosystem processes is a major topic in ecology. Here, we analyse the relationship between biodiversity and productivity of the nano‐ and micro‐phytoplankton guilds in coastal marine ecosystems.
- 2. The patterns of variation of species richness, diversity and primary productivity (as 14C assimilation) were studied in two marine areas: a eutrophic–mesotrophic area beside the River Po delta (northern Adriatic) and an oligotrophic area around the Salento peninsula (southern Adriatic–Ionian). The study was carried out at 23 sites in the northern area and at 45 sites in the southern area. Sites were arranged on expected spatial and temporal gradients of primary productivity variation, according to distance from the coast, optical depths and seasonal period.
- 3. 167 taxa were identified in the northern area and 153 taxa in the southern area. In both areas, the taxonomic composition of the nano‐ and micro‐phytoplankton guilds exhibited greater temporal than spatial variation. The latter was much higher in the southern area than in the northern area (average dissimilarity between stations being 70.7±0.8% and 44.7±4.2% respectively).
- 4. Primary productivity varied in space and time on the gradients considered. Phytoplankton species richness and diversity exhibited significant patterns of variation in space and time; overall, these were inversely related to the primary productivity patterns in the northern area, whereas they were directly related in the southern area.
- 5. The small individual size and the high turnover rate of phytoplankton are likely to underlie the observed relationships, which emphasized a threshold response to nutrient enrichment in agreement with the ‘paradox of enrichment’. Under resource enrichment conditions, the high turnover of producers leads to hierarchical partitioning of the available resources with an increasing dominance of a few species. Therefore, the relationship observed here seems likely to be explained by the complementarity hypothesis.
47.
Enrique Maldonado-Cervantes José A. Huerta-Ocampo Gabriela M. Montero-Morán Alberto Barrera-Pacheco Eduardo Espitia-Rangel Ana P. Barba de la Rosa 《Journal of Cereal Science》2014
Amaranth is taking great attention as an important cereal crop that could fulfill food requirements for the growing population, especially in developing countries. However, the protein composition of these seeds is not well known yet. We have used the proteomics tools to characterize amaranth seed proteome. About 400 proteins spots were resolved on two-dimensional gel electrophoresis (2-DE) and protein spots were analyzed by LC-MS/MS (liquid chromatography tandem mass spectrometry). Identified proteins were related to stress and defense responses, metabolic, respiratory, and oxide-reduction processes. One abundant spot was identified as a Late Embryogenesis Abundant (LEA) protein and the gene was cloned and characterized. The AcLEA cDNA contains a 418 bp open reading frame (ORF) encoding a polypeptide of 139 amino acids. Bioinformatics analysis showed that AcLEA belongs to LEAs Group 5. Proteomics is a powerful technique that could be used even in non-sequenced organisms such as amaranth. The obtained information reveals that amaranth seed, beyond the classical seed storage proteins, contains proteins related to protection against stress. The identification of these proteins opens the door to the application of new strategies to improve the quality of amaranth production. 相似文献
48.
49.
Rodríguez Marianela Desireé León Alberto Edel Bustos Mariela Cecilia 《Plant foods for human nutrition (Dordrecht, Netherlands)》2022,77(3):345-352
Plant Foods for Human Nutrition - Complementary feeding starts at around six months of age because neither breast milk nor formula assure the proper nutrition of infants. Therefore, along... 相似文献
50.
Oliana Carnevali Maria Claudia Zamponi Roberto Sulpizio Arianna Rollo Miria Nardi Carla Orpianesi Stefania Silvi Massimo Caggiano Alberta Maria Polzonetti Alberto Cresci 《Aquaculture International》2004,12(4-5):377-386
Two bacterial strains Lactobacillus fructivorans (AS17B), isolated from adult sea bream (Sparus aurata) gut, and Lactobacillus plantarum (906), isolated from human faeces, were administered contemporaneously, during sea bream development using Brachionus plicatilis and/or Artemia salina and dry feed as vectors. The probiotic treatment influenced gut colonization: at 35 days post-hatching (p.h.) L. fructivorans was not present in the gut, but the treatment induced colonization by L. plantarum. At 66 days p.h., L. fructivorans was evident also in the control; moreover, when suitable environmental conditions appeared in the post-metamorphosis gastro-intestinal tract, competition between L. plantarum and L. fructivorans occurred. At 90 days p.h., L. plantarum was displaced by L. fructivorans that became significantly higher with respect to the control. In treated groups, probiotic administration significantly decreased larvae and fry mortality. 相似文献