全文获取类型
收费全文 | 369篇 |
免费 | 25篇 |
国内免费 | 2篇 |
专业分类
林业 | 21篇 |
农学 | 28篇 |
基础科学 | 6篇 |
88篇 | |
综合类 | 55篇 |
农作物 | 36篇 |
水产渔业 | 26篇 |
畜牧兽医 | 91篇 |
园艺 | 6篇 |
植物保护 | 39篇 |
出版年
2023年 | 3篇 |
2022年 | 16篇 |
2021年 | 18篇 |
2020年 | 15篇 |
2019年 | 19篇 |
2018年 | 16篇 |
2017年 | 13篇 |
2016年 | 14篇 |
2015年 | 15篇 |
2014年 | 13篇 |
2013年 | 29篇 |
2012年 | 11篇 |
2011年 | 29篇 |
2010年 | 7篇 |
2009年 | 12篇 |
2008年 | 14篇 |
2007年 | 22篇 |
2006年 | 8篇 |
2005年 | 16篇 |
2004年 | 13篇 |
2002年 | 4篇 |
2001年 | 9篇 |
2000年 | 5篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 6篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 6篇 |
1986年 | 4篇 |
1985年 | 6篇 |
1984年 | 7篇 |
1983年 | 3篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1976年 | 2篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1963年 | 1篇 |
1962年 | 1篇 |
排序方式: 共有396条查询结果,搜索用时 0 毫秒
31.
32.
目前已明确番茄抗晚疫病R基因表现明显的株龄相关抗性(Age-related Resistance,ARR),但抗晚疫病QTL的抗性规律尚不明确。以携带抗晚疫病基因Ph-3的栽培种番茄(Solanum lycopersicum)‘CLN2037B’和野生种醋栗番茄(S.pimpinellifolium)‘L3708’以及易感病材料栽培种番茄(S.lycopersicum)‘LA2818’为对照,对含有抗晚疫病QTL的多毛番茄(S.habrochaites)‘LA2099’、‘LA1033’和‘LA1777’是否也存在株龄相关抗性进行了分析。结果表明,携带抗晚疫病QTL的3个材料的6叶期和9叶期植株病情级数均比3叶期明显降低,表明QTL抗性与株龄相关。利用乙烯、水杨酸和茉莉酸素合成或缺失的突变体和病毒诱导基因沉默(Virus Induced Gene Silencing,VIGS)技术,初步明确了乙烯和水杨酸参与6叶期Ph-3基因介导的对晚疫病的抗性,而茉莉酸不参与。 相似文献
33.
34.
Cheel J Theoduloz C Rodríguez J Saud G Caligari PD Schmeda-Hirschmann G 《Journal of agricultural and food chemistry》2005,53(22):8512-8518
Three E-cinnamic acid glycosides, tryptophan, and cyanidin-3-O-beta-D-glucopyranoside were isolated from ripe fruits of the Chilean strawberry Fragaria chiloensis ssp. chiloensis. 1-O-E-Cinnamoyl-beta-D-xylopyranoside, 1-O-E-cinnamoyl-beta-D-rhamnopyranoside, and 1-O-E-cinnamoyl-alpha-xylofuranosyl-(1-->6)-beta-D-glucopyranose are reported for the first time. The cinnamic acid glycosides and aromatic compound patterns in F. chiloensis fruits were determined by high-performance liquid chromatography (HPLC). HPLC analyses of extracts showed that cyanidin-3-O-beta-D-glucopyranoside and free ellagic acid are present in achenes while the E-cinnamoyl derivatives and tryptophan were identified only in the thalamus. The free radical scavenging effect of the fruit extract can be associated with the anthocyanin content. 相似文献
35.
Hafiz Mohkum Hammad Abdul Khaliq Farhat Abbas Wajid Farhad Shah Fahad Muhammad Aslam 《Communications in Soil Science and Plant Analysis》2020,51(10):1406-1422
ABSTRACT Organic amendments in the soil perform better than synthetic fertilizers in regards to soil fertility and sustainable crop productivity. Experiments were conducted to compare the effects of organic and synthetic fertilizers on soil fertility and wheat (Triticum aestivum L.) productivity. Soil fertility and protein contents of wheat grains (13.2% and 13.3% during 2005–06 and 2006–07, respectively) were improved by organic amendments. However, synthetic fertilizer (at the rate of 150, 100, and 60 kg ha?1 N, P2O5, and K2O, respectively) applications resulted in the maximum grain yield (4.05 and 4.46 t ha?1 during 2005–06 and 2006–07, respectively). The observed and simulated soil organic carbon (SOC) reasonably agreed during RothC model validation (R 2 = 0.99). Economic analysis showed the maximum net profit and relative increase in income ($729 US ha?1 and 309%, respectively) from inorganic treatment. Application of synthetic fertilizers increased grain yield and farm profit while organic manure enhanced grain quality. The RothC model had potential for determining the SOC in organic farming under arid environment. 相似文献
36.
Khan I Nisar M Ahmad M Shah H Iqbal Z Saeed M Halimi SM Kaleem WA Qayum M Aman A Abdullah SM 《Fitoterapia》2011,82(2):276-281
A new taxoid Taxawallin I (1) along with two known taxoids (2-3) were isolated from methanolic bark extract of Taxus wallichiana Zucc. Structural characterization was confirmed by mass and NMR spectral techniques. Taxawallin I exhibited significant in-vitro anticancer activity against HepG2, A498, NCI-H226 and MDR 2780AD cancer lines. Tubulin binding assay was performed to assess its tubulin binding activity. Molecular docking analysis was performed to study the potential binding mode inside the taxol binding site of β-tubulin. 相似文献
37.
38.
试验采用含钙0.88%和1.78%的玉米—豆饼型基础饲粮(含锌29ppm,添加0.10和40ppm锌(ZnSO_4·7H_2O)。结果表明,随着饲粮锌水平的提高,雏鸡增重显著提高(P<0.01),这种效应随着雏鸡周龄的增长愈趋明显。饲粮高钙使雏鸡前期增重显著降低(P<0.01),后期效应愈趋缓解。血清碱性磷酸酶的活性随着饲粮锌水平的提高而显著提高(P<0.01),饲粮高钙使之显著降低(P<0.01)。饲粮加锌使血清白蛋白含量显著高于未加锌组(P<0.05),饲粮高钙使血清白蛋白含量显著降低(P<0.01),使血清球蛋白含量显著提高(P<0.01),而血清总蛋白含量不受饲粮钙水平显著影响(P>0.05)。肝脏(P<0.05)、肾脏(P<0.01)、胰脏(P<0.01)、胫骨(P<0.01)以及粪便排泄物(P<0.01)中锌含量随饲粮锌水平的提高而显著提高,肺脏锌含量没有明显变化(P>0.05)。饲粮高钙使肾脏(P<0.05)、肺脏(P<0.01)、胫骨(P<0.05)锌含量显著降低,使粪便排泄物中锌含量显著提高(P<0.05)。饲粮中含锌29ppm,不能满足雏鸡维持正常代谢和生长发育的营养需要,饲粮高钙时,饲粮总锌69ppm为宜。 相似文献
39.
40.
U3 sequences from HTLV-I and -II LTRs confer pX protein response to a murine leukemia virus LTR 总被引:8,自引:0,他引:8
H Kitado I S Chen N P Shah A J Cann K Shimotohno H Fan 《Science (New York, N.Y.)》1987,235(4791):901-904