全文获取类型
收费全文 | 351篇 |
免费 | 14篇 |
国内免费 | 1篇 |
专业分类
林业 | 22篇 |
农学 | 10篇 |
基础科学 | 4篇 |
74篇 | |
综合类 | 25篇 |
农作物 | 30篇 |
水产渔业 | 62篇 |
畜牧兽医 | 96篇 |
园艺 | 17篇 |
植物保护 | 26篇 |
出版年
2024年 | 2篇 |
2023年 | 3篇 |
2022年 | 4篇 |
2021年 | 12篇 |
2020年 | 12篇 |
2019年 | 21篇 |
2018年 | 20篇 |
2017年 | 18篇 |
2016年 | 17篇 |
2015年 | 13篇 |
2014年 | 12篇 |
2013年 | 24篇 |
2012年 | 21篇 |
2011年 | 20篇 |
2010年 | 20篇 |
2009年 | 15篇 |
2008年 | 25篇 |
2007年 | 12篇 |
2006年 | 6篇 |
2005年 | 14篇 |
2004年 | 12篇 |
2003年 | 8篇 |
2002年 | 5篇 |
2001年 | 6篇 |
2000年 | 5篇 |
1999年 | 7篇 |
1998年 | 3篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1975年 | 1篇 |
1972年 | 1篇 |
1954年 | 1篇 |
1953年 | 1篇 |
1951年 | 1篇 |
1950年 | 1篇 |
1949年 | 1篇 |
排序方式: 共有366条查询结果,搜索用时 46 毫秒
101.
In the Mediterranean zone, efforts to optimize combinations of supplemental irrigation (SI), improved varieties, nitrogen (N) and sowing dates aim to improve and stabilize cereal yields and maintain quality, especially for durum wheat. Thus, a 4 year field study (1992/1993 to 1995/1996) on a deep clay soil in northern Syria assessed the impact of SI (rain-fed, 1/3, 2/3 and full SI) combined with variable N application rates (0, 50, 100, 150 kg ha−1) and sowing date (early, normal, late) for four improved durum wheat varieties adapted to rain-fed and irrigated conditions. As rainfall and evapotranspiration varied over the 4 years, the amount of SI water required also varied. Yields varied with the season, and the main factors, except variety, were significant. Delaying sowing from November to January reduced yields and response to both SI and N. With irrigation, crop responses were generally significant up to 100 N ha−1, whereas the optimum response for rain-fed conditions occurred with 50 kg N ha−1. Limited SI (1/3) significantly increased yields, but almost maximum yields were obtained by 2/3 of full SI. Water- and N-use efficiencies were greatly increased by SI, with little variation among varieties. However, irrigation and delayed sowing decreased grain protein levels, which were partially compensated for by added N. A similar effect was observed for kernel vitreousness. Models developed from the response data can facilitate the potential transfer of these findings. Thus, in most growing seasons, minimum irrigation during the winter growing season, combined with appropriate fertilization, can enhance wheat output and yet maintain grain quality. 相似文献
102.
Mustafa Erkan
zgür 《Aquaculture Research》2019,50(10):2838-2845
This study investigated the protective effects of 1 mM Vitamin C and 1 mM Trolox on kinematic and oxidative stresses in rainbow trout (Oncorhynchus mykiss) sperm cells against flower‐like zinc oxide nanoparticles (ZnO‐NP, 1 mg/L) in vitro, during 2 hr. Trolox showed protective effects on all kinematic parameters measured for sperm cells against ZnO‐NPs, whereas Vitamin C only affected angular path velocity (VAP), linearity (LIN) and amplitude of lateral displacement of the sperm cell head (ALH). Although ZnO‐NPs reduced total glutathione (TGSH) and catalase (CAT) compared with the control, there were positive treatment effects for both Trolox and Vitamin C on antioxidant capacity. Conversely, while ZnO‐NP increased the rate of malondialdehyde (MDA) lipid peroxidation, it decreased following antioxidant therapy. This research suggests that Trolox and Vitamin C play a protective role for rainbow trout sperm exposed to ZnO‐NP. 相似文献
103.
104.
Gülsün Özyurt Esmeray Kuley Boga A. Serhat Özkütük Mustafa Durmuş Yılmaz Uçar 《Journal Of Aquatic Food Product Technology》2019,28(3):314-328
The impacts of fermentation process with acid and lactic acid bacteria strains (Lactobacillus plantarum, Lactobacillus brevis, Pediococcus acidilactici, Enterococcus gallinarum, and Streptococcus spp.) on the biogenic amine formation of wet and spray-dried fish silage obtained from whole gibel carp (Carassius gibelio, freshwater discard), whole ponyfish (Equulites klunzingeri, seawater discard), and processing by-products of seabass (Dicentrarchus labrax) were investigated. The results showed that among biogenic amines, cadaverine, putrescine, spermidine, spermine, serotonin, dopamine, and agmatine were predominant in all groups. Significant differences (p < 0.05) in biogenic amine concentrations of wet and spray-dried fish silage were observed. Raw fish and wet silages contained histamine level lower than the allowable limit of 50mg/kg, indicating the use of raw fish material with low microbial counts. In addition, no histamine was detected in spray-dried fish silage, except for seabass by-products with a trace quantity of histamine (<0.04mg/100g). The starter culture used for silage preparation did not effectively retard formation of biogenic amines compared to acid silage. It can be concluded that there is potential use of fermented fish silage as a protein source and possibly as a probiotic ingredient for animal feed in both wet and dry form. 相似文献
105.
Mickky Bardees Aldesuquy Heshmat Elnajar Mustafa 《Journal of Crop Science and Biotechnology》2019,22(1):21-29
Journal of Crop Science and Biotechnology - Wheat (Triticum aestivum L.) is a major cereal with its productivity being highly affected by drought. In the current study, 10 wheat cultivars were... 相似文献
106.
107.
Small-scale Forestry - Both the reducing emissions from deforestation and forest degradation program (REDD+) and community-based forest management (CBFM) aim to combat forest degradation and... 相似文献
108.
Rainbow trout Oncorhynchus mykiss and mirror carp Cyprinus carpio were slaughtered by either percussion or asphyxiation. For determination of the physical (texture value) and biochemical
quality attributes [pH, lactic acid, total volatile basic nitrogen (TVB-N), and malondialdehyde (MDA) values] of trout and
carp, the fish were filleted immediately (within 2 h), 12 h after harvest (pre-rigor), 24 and 36 h after harvest (in-rigor),
and finally 48 and 60 h after harvest (post-rigor). For microbiological quality attribute (mesophilic and psychrophilic bacteria
count) analyses, the fish were filleted immediately (within 2 h) after harvest (pre-rigor), 24 h after harvest (in-rigor)
and 48 and 72 h after harvest (post-rigor). By percussion slaughtering followed by pre-rigor filleting, it was possible to
process rainbow trout and mirror carp without inflicting excessive handling stress. Percussion slaughter delayed onset of
rigor and the percussion-slaughtered fish exhibited a long pre-rigor period (≈24 h), giving plenty time for pre-rigor processing.
Percussion slaughtering and pre-rigor filleting of fish was considered to be superior to the traditional asphyxiation slaughtering
with respect to texture, TVB-N and MDA attributes. 相似文献
109.
Shearing male lambs in the cold season improves the carcass yield without affecting fattening performance 总被引:1,自引:0,他引:1
This research was carried out to determine the effects of shearing of different genotypes of male lambs (one from pure Karayaka stock and two from its crossbreed) in winter on bodyweight gain, feed consumtion, feed conversion efficiency, rectal temperature and carcass yield. A total of 21 lambs aged 8 months were allocated randomly to experimental groups according to a 2 × 3 factorial arrangement for shorn and unshorn animals. The lambs were fed grass hay (100 g/lamb/day) and commercial concentrate feed ad libitum during a 54‐day of fattening period. The lambs were shorn in the middle of the experiment (27 days after beginning the trial). The interaction between the shearing treatment × genotype of the studied parameters was found to be insignificant. The shearing process increased the rectal temperature (P < 0.01), hot carcass yield (P < 0.05) and dressing percentage (P < 0.05) and decreased the weight of the edible inner organs (P < 0.01). Some of these parameters were affected by the genotypes. It was concluded that shearing male lambs in the winter can have a beneficial effect on the hot carcass weight and dressing percentage without affecting fattening performance, and the performance of Karayaka lambs and its crossbred male lambs were similar under the conditions of the present study. 相似文献
110.
Mustafa A Rankaduwa W Campbell P 《The Canadian veterinary journal. La revue veterinaire canadienne》2001,42(1):54-56
Parasitic sea lice are serious problems in aquaculture. The true cost of these parasites is unknown. We demonstrate the economic burden imposed by sea lice, so that researchers, aquatic specialists, and policy makers can approximate the economic cost of this problem and work towards developing alternative control methods. 相似文献