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51.
52.
Plant architecture is important for cotton cultivation and breeding. In this study, two mapping generations/populations F2 and F2:3 in Upland cotton (Gossypium hirsutum L.), derived from ‘Baimian1’ and TM‐1, were used to identify quantitative trait loci (QTLs) for 10 plant architecture traits. A total of 55 main‐effect QTLs (M‐QTLs) were detected. Four common M‐QTLs, qTFB‐10(F2/F2:3) for total fruit branches, qFBL‐26b(F2)/qFBL‐26(F2:3) for fruit branch length, qFBA‐5(F2/F2:3) for fruit branch angle and qFBN‐26b(F2)/qFBN‐26(F2:3) for fruit branch nodes, were found. The synergistic alleles and the negative alleles can be utilized in cotton plant architecture breeding programmes according to specific breeding objectives. Altogether 54 pairs of epistatic QTLs (E‐QTLs) exhibiting the interactions of additive‐by‐additive (AA), additive‐by‐dominant (AD), dominant‐by‐additive (DA) and dominant‐by‐dominant (DD) were detected. The epistasis appeared to be an important contributor to genetic variation in cotton plant architecture traits. Therefore, the identified markers associated with E‐QTLs as well as M‐QTLs will be of importance in future breeding programmes to develop cotton cultivars exhibiting desirable plant architecture. 相似文献
53.
For reproductive success, flowering time must synchronize with favourable environmental conditions. Vernalization genes play a major role in accelerating or delaying the time to flowering. We studied how different vernalization (VRN1) gene combinations alter days to flowering and maturity and consequently the effect on grain yield and other agronomic traits. The study focussed on the effect of the VRN1 gene series (Vrn‐A1, Vrn‐B1 and Vrn‐D1) and their combinations. The Vrn gene group Vrn‐A1a, Vrn‐B1, vrn‐D1 was the earliest to flower and mature, while Vrn‐A1b, Vrn‐B1, vrn‐D1 was the latest to flower. Spring wheat lines with vrn‐A1, Vrn‐B1, Vrn‐D1 were the highest yielding and matured at a similar time as those having vernalization genes Vrn‐A1a, Vrn‐B1 and Vrn‐D1. The findings of this study suggest that the presence of Vrn‐D1 has a direct or indirect role in producing higher grain yield. We therefore suggest the introduction of Vrn‐D1 allele into higher‐yielding classes within Canadian spring wheat germplasm. 相似文献
54.
In building Samoan academic researcher capacity in Samoa, we argue that there is a need to first establish the kind of researcher community advocated by Linda Tuhiwai Smith, and to do so through developing research tools, such as the talanoa and faafaletui, in partnership with researcher capacity‐building initiatives such as the applied postgraduate social and health research methods course (coded PUBX731‐HSA505) run by the Centre for International Health, University of Otago, in partnership with the National University of Samoa. This paper offers a commentary on the talanoa and faafaletui as Pacific research methodologies, and asks what its value might be for researchers in Samoa. It reflects on the learning experiences of staff and students of the applied social and health research methods course in relation to the talanoa and faafaletui as Pacific research methodologies or methods. It concludes that developing Pacific research and researcher capacity in Pacific Island countries, such as Samoa, must include opening up spaces within these communities to critically engage what is Pacific or Samoan or indigenous about these research tools, methods or methodologies, and how they might differ in form or substance from other methods or methodologies. 相似文献
55.
This study explores the impacts of providing dynamic information on travelers' behavior and the induced demand for terminal‐surrounding activities. A nested logit model was used to identify the important factors, and a questionnaire was designed to explore the preference of travelers regarding activities and travel choices. Adopting dynamic information was found to have a significant influence on travel decisions. The results show that an increased duration of activity participation may accompany an alteration of departure time or mode choice. The results also show that the use of dynamic information for travelers is related to induced activity participation and travelers' socioeconomic characteristics. The content of the dynamic information should be designed in accordance with the preference of travelers to encourage travelers participating in terminal‐surrounding activities. 相似文献
56.
Yu Ma Shi‐ying Bao Tao Yang Jin‐guo Hu Jian‐ping Guan Yu‐hua He Xue‐Jun Wang Yu‐ling Wan Xue‐lian Sun Jun‐ye Jiang Cui‐xiang Gong Xu‐xiao Zong 《Plant Breeding》2013,132(4):397-400
Simple sequence repeat (SSR) marker is a powerful tool for construction of genetic linkage map which can be applied for quantitative trait loci (QTL) and marker‐assisted selection (MAS). In this study, a genetic map of faba bean was constructed with SSR markers using a 129 F2 individuals population derived from the cross of Chinese native variety 91825 (large seed) and K1563 (small seed). By screening 11 551 SSR primers between two parents, 149 primer pairs were detected polymorphic and used for F2 population analysis. This SSR‐based genetic linkage map consisted of 15 linkage groups with 128 SSR. The map encompassed 1587 cM with an average genetic distance of 12.4 cM. The genetic map generated in this study will be beneficial for genetic studies of faba bean for identification of marker‐locus‐trait associations as well as comparative mapping among faba bean, pea and grasspea. 相似文献
57.
The purpose of this paper is to provide empirical evidence on the neighboring effects of Internet adoption as measured by the percentage of firms with their own website in the European regions. This is the first study that explicitly analyzes the role played by spatial effects to explain website adoption for the European case. A set of instruments and techniques commonly used in the spatial econometrics framework is employed to test the hypothesis that proximity matters when explaining Internet adoption by firms. Results show that firms in physically adjacent regions register a similar degree of Internet adoption, confirming the presence in this context of positive spatial dependence. Nevertheless, the spatial effects detected are mainly constrained by national borders. Gross domestic product (GDP) per capita, population density, sectoral composition, and education are positively related to geographic distribution of Internet adoption in the enlarged European Union. In addition, regional disparities in Internet adoption were found to be less important than territorial inequalities in GDP per capita. 相似文献
58.
Ljiljana Tamburic‐Ilincic 《Plant Breeding》2012,131(6):722-727
The objectives of this study were to investigate (i) the correlations between Fusarium head blight (FHB) index, deoxynivalenol (DON) accumulation and percentage of Fusarium‐damaged kernels (FDK) with agronomic and quality traits and (ii) the effect associated with the presence of single QTLs for FHB resistance on agronomic and quality traits in winter wheat. The population was derived from the cross between ‘RCATL33' (FHB resistance derived from ‘Sumai 3’ and ‘Frontana’) and ‘RC Strategy’. Parental lines and recombinant inbred lines (RILs) were genotyped with SSR markers associated with the 3B, 5A and 3A QTLs. The population was planted in FHB‐inoculated nurseries and in agronomy trials. Lines in the 3B QTL class had the lowest FHB index, DON content and FDK level and did not have a significantly lower yield, thousand kernel weight or protein content compared with the lines grouped in other QTL classes (including no QTL class). Marker‐assisted selection of the 3B QTL for FHB resistance into high‐yielding FHB‐susceptible winter wheat is the recommended approach for the development of lines with increased FHB resistance without significant yield and quality penalties. 相似文献
59.
Scott W.D. Pearse‐Smith 《Asia Pacific viewpoint》2012,53(2):147-162
The Mekong River system provides a crucial source of natural resources for riparian nations. However, the increasingly rapid pace of hydro‐development in the Mekong Basin is threatening the integrity of the river system, posing a real concern for Lower Basin states, which are particularly dependent on the basin. This scenario has led to warnings of armed conflict, or even ‘water war’, between riparian states. Certainly, the expanding scale of hydro‐development can be expected to continue increasing interstate tensions in the Mekong region; but are these tensions really likely to escalate to armed conflict? This paper explores this question by drawing on the water and conflict theory of Aaron Wolf. Ultimately, this paper concludes that interstate tensions over Mekong hydro‐development are unlikely to generate armed conflict. This is in part due to the strategic impracticality of such a conflict as well as the presence of a river basin management institution. Most compellingly, though, armed conflict is unlikely because the economic imperative shared by Mekong states is better served by cooperation – or at least non‐interference – than conflict, over regional hydro‐development. In closing, the paper urges that the study of water and conflict in the Mekong Basin be refocused at the intrastate level. 相似文献
60.
T. A. Coutinho J. Roux K‐H. Riedel J. Terblanche M. J. Wingfield 《Forest Pathology》2000,30(4):205-210
Ralstonia solanacearum, the causal agent of bacterial wilt, has one of the widest host ranges of all phytopathogenic bacteria. This pathogen was first reported on Eucalyptus spp. in the late 1980s in Brazil. Since then, there have been reports of its occurrence on this host in Australia, China and Venezuela. Early in 1997, an 18‐month‐old clonally propagated Eucalyptus grandis × Eucalyptus camaldulensis (GC) hybrid in Zululand, KwaZulu/Natal, showed signs of wilting. The vascular tissue of infected trees was dicoloured and bacterial exudation was produced from cut surfaces. The bacterium was consistently isolated from diseased tissue, purified and identified as R. solanacearum biovar 3 race 1, using the BioLog bacterial identification system. Inoculation trials were conducted on three E. grandis × E. camaldulensis clones (GC515, GC550 and GC505). Clone GC550 displayed wilting after 3 days and all cuttings subsequently died. Clones GC515 and GC505 appeared to be less susceptible with cuttings not showing signs of disease until 7 days after inoculation. After 14 days, 90 and 80%, respectively, of cuttings of these two clones had died. This is the first report of bacterial wilt on Eucalyptus in South Africa. 相似文献