全文获取类型
收费全文 | 3343篇 |
免费 | 238篇 |
专业分类
林业 | 279篇 |
农学 | 159篇 |
基础科学 | 29篇 |
988篇 | |
综合类 | 128篇 |
农作物 | 166篇 |
水产渔业 | 310篇 |
畜牧兽医 | 1150篇 |
园艺 | 60篇 |
植物保护 | 312篇 |
出版年
2024年 | 4篇 |
2023年 | 34篇 |
2022年 | 48篇 |
2021年 | 82篇 |
2020年 | 95篇 |
2019年 | 95篇 |
2018年 | 138篇 |
2017年 | 138篇 |
2016年 | 160篇 |
2015年 | 131篇 |
2014年 | 148篇 |
2013年 | 263篇 |
2012年 | 270篇 |
2011年 | 300篇 |
2010年 | 138篇 |
2009年 | 149篇 |
2008年 | 218篇 |
2007年 | 193篇 |
2006年 | 178篇 |
2005年 | 162篇 |
2004年 | 136篇 |
2003年 | 119篇 |
2002年 | 104篇 |
2001年 | 51篇 |
2000年 | 62篇 |
1999年 | 52篇 |
1998年 | 12篇 |
1997年 | 16篇 |
1996年 | 10篇 |
1995年 | 6篇 |
1994年 | 6篇 |
1993年 | 6篇 |
1992年 | 7篇 |
1991年 | 5篇 |
1990年 | 8篇 |
1989年 | 4篇 |
1988年 | 7篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1971年 | 1篇 |
1966年 | 1篇 |
1955年 | 2篇 |
1947年 | 1篇 |
排序方式: 共有3581条查询结果,搜索用时 15 毫秒
31.
Ana E. González-Santiago Belinda Vargas-Guerrero Pedro M. García-López Alma L. Martínez-Ayala José A. Domínguez-Rosales Carmen M. Gurrola-Díaz 《Plant foods for human nutrition (Dordrecht, Netherlands)》2017,72(2):134-140
Lupinus albus seeds contain conglutin gamma (Cγ) protein, which exerts a hypoglycemic effect and positively modifies proteins involved in glucose homeostasis. Cγ could potentially be used to manage patients with impaired glucose metabolism, but there remains a need to evaluate its effects on hepatic glucose production. The present study aimed to analyze G6pc, Fbp1, and Pck1 gene expressions in two experimental animal models of impaired glucose metabolism. We also evaluated hepatic and renal tissue integrity following Cγ treatment. To generate an insulin resistance model, male Wistar rats were provided 30% sucrose solution ad libitum for 20 weeks. To generate a type 2 diabetes model (STZ), five-day-old rats were intraperitoneally injected with streptozotocin (150 mg/kg). Each animal model was randomized into three subgroups that received the following oral treatments daily for one week: 0.9% w/v NaCl (vehicle; IR-Ctrl and STZ-Ctrl); metformin 300 mg/kg (IR-Met and STZ-Met); and Cγ 150 mg/kg (IR-Cγ and STZ-Cγ). Biochemical parameters were assessed pre- and post-treatment using colorimetric or enzymatic methods. We also performed histological analysis of hepatic and renal tissue. G6pc, Fbp1, and Pck1 gene expressions were quantified using real-time PCR. No histological changes were observed in any group. Post-treatment G6pc gene expression was decreased in the IR-Cγ and STZ-Cγ groups. Post-treatment Fbp1 and Pck1 gene expressions were reduced in the IR-Cγ group but increased in STZ-Cγ animals. Overall, these findings suggest that Cγ is involved in reducing hepatic glucose production, mainly through G6pc inhibition in impaired glucose metabolism disorders. 相似文献
32.
Henrique de Souza Luche José Antonio Gonzalez da Silva Rafael Nornberg Emilio Ghisleni Arenhardt Vanderlei da Rosa Caetano Luciano Carlos da Maia Antonio Costa de Oliveira 《Journal of Crop Science and Biotechnology》2017,20(2):73-80
In wheat, the increase of yield and stability associated traits can be achieved by combining parents containing the stay-green trait and favorable alleles for grain yield. The aim of this work was to analyze the genetic dissimilarity between wheat lines from stay-green and synchronized maturation groups and elite cultivars. Moreover, to propose promising combinations seeking the selection of high-grain yield and high bread-making quality genotypes containing stay-green trait. The experiment was conducted in a randomized block design with three replications in 2003, 2004, and 2005, using sister-lines with the presence and absence of stay-green trait and elite cultivars. Genetic variability exists among wheat strains from the synchronized stay-green maturation group and elite cultivars. Genotypes of maturation group stay-green obtained an average performance superior to the synchronized group. Crosses between stay-green lines and the CEP 29 and BRS 177 cultivars are promising in the selection of genotypes carrying the stay-green trait with high yield and bread-making quality. 相似文献
33.
34.
Gueribis Faiza Zermane Nadjia Khalfi-Habess Ouassila Siafa Abderrahmane Cimmino Alessio Boari Angela Evidente Antonio 《植物病害和植物保护杂志》2019,126(5):437-446
Journal of Plant Diseases and Protection - The efficacy of four bi- and tri-cyclic sesquiterpenes, namely inuloxins A, B and C and α-costic acid, extracted from aerial parts of Dittrichia... 相似文献
35.
San-José Miriam Arroyo-Rodríguez Víctor Jordano Pedro Meave Jorge A. Martínez-Ramos Miguel 《Landscape Ecology》2019,34(5):1069-1080
Landscape Ecology - Landscape structure can affect seed dispersal, but the spatial scale at which such effect is maximized (scale of effect, SoE) is unknown. We assessed patterns and predictors of... 相似文献
36.
Supercritical fluid extraction of pesticides from a table-ready food composite of plant origin (gazpacho) 总被引:1,自引:0,他引:1
Aguilera A Brotons M Rodríguez M Valverde A 《Journal of agricultural and food chemistry》2003,51(19):5616-5621
Supercritical fluid carbon dioxide extraction (SFE) has been evaluated for the extraction of 17 organohalogen and organophosphate pesticides in gazpacho (a table-ready food composite containing crude vegetables, white bread, vegetable oil, water, and other minor components) using anhydrous magnesium sulfate as drying agent. The effects of different parameters, such as fat content in gazpacho composites, magnesium sulfate/gazpacho ratio, supercritical fluid volume, pressure, temperature, and static modifier additions, on SFE recoveries from spiked gazpacho samples have been studied. Analyses were performed by gas chromatography (GC) with flame photometric (FPD), electron capture (ECD), and mass spectrometry (MSD) detectors. In most experiments, recoveries obtained for the nonpolar organohalogen pesticides were lower than those obtained for the most polar organophosphate pesticides, but overall pesticide recoveries determined by using the optimal SFE conditions indicate that SFE could be used to determine pesticide residue levels in gazpacho. 相似文献
37.
1-methylcyclopropene increases storability and shelf life in climacteric and nonclimacteric plums 总被引:2,自引:0,他引:2
Martínez-Romero D Dupille E Guillén F Valverde JM Serrano M Valero D 《Journal of agricultural and food chemistry》2003,51(16):4680-4686
The effect of 1-methylcyclopropene (1-MCP) at three different doses (0.25, 0.50, and 0.75 microL L(-1)) on the ripening processes of a climacteric, cv. Santa Rosa, and a suppressed climacteric type, cv. Golden Japan, plum was studied. For both cultivars, positive effects were observed in terms of inhibition of ethylene production and delays of the physical, chemical, and biochemical changes associated with ripening. 1-MCP-treated plums were firmer with lower weight loss, reduced degrees Brix/titratable acidity ratios, and lower color changes during cold storage and subsequent shelf life at 20 degrees C than controls. For most factors, the effectiveness of 1-MCP was dose-dependent in Santa Rosa but dose-independent for Golden Japan. 相似文献
38.
Remo Bucci Andrea D Magrí Antonio L Magrí Domenico Marini Federico Marini 《Journal of agricultural and food chemistry》2002,50(3):413-418
This work has focused on discriminating extra virgin olive oils from Sabina (Lazio, Italy) by olive fruit variety (cultivar). A set of oils from five of the most widespread cultivars (Carboncella, Frantoio, Leccino, Moraiolo, and Pendolino) in this geographical area was analyzed for chemical composition using only the Official Analytical Methods, recognized for the quality control and commercial classification of this product. The obtained data set was converted into a computer-compatible format, and principal component analysis (PCA) and a method based on the Fisher F ratio were used to reduce the number of variables without a significant loss of chemical information. Then, to differentiate these samples, two supervised chemometric procedures were applied to process the experimental data: linear discriminant analysis (LDA) and artificial neural network (ANN) using the back-propagation algorithm. It was found that both of these techniques were able to generalize and correctly predict all of the samples in the test set. However, these results were obtained using 10 variables for LDA and 6 (the major fatty acid percentages, determined by a single gas chromatogram) for ANN, which, in this case, appears to provide a better prediction ability and a simpler chemical analysis. Finally, it is pointed out that, to achieve the correct authentication of all samples, the selected training set must be representative of the whole data set. 相似文献
39.
Fernández PL Pablos F Martín MJ González AG 《Journal of agricultural and food chemistry》2002,50(7):1833-1839
40.
The influence of a fire retardant (Firesorb, an acrylic–acrylamide copolymer) on the microbial community structure determined by phospholipid fatty acid (PLFA) analysis was examined under laboratory conditions using two different textured soils under pine forest. Firesorb was added to unheated and heated soil samples (350°C for 10 min followed by reinoculation, to mimic a forest fire) at three levels of application (none, usual and three times the usual levels), and measurements were made after 12 weeks of incubation. The relative importance of the three factors considered on the PLFA profiles was as follows: soil heating ≫ soil texture ≈ Firesorb treatment. In the unheated soils, Firesorb had a larger effect than soil texture, while the opposite was found in the heated soils. Soil heating reduced the total PLFAs, while Firesorb tended to increase them in both the unheated and heated soils. Soil heating decreased the PLFAs indicative of gram-positive (G+) bacteria and tended to increase the fatty acids associated with gram-negative (G−) bacteria and, to a lesser extent, the PLFA 18:2ω6, considered to be predominantly of fungal origin. Firesorb treatment decreased the G−/G+ bacteria ratio in the heated soils but tended to increase it in the unheated soils, the effect being dose dependent. 相似文献