全文获取类型
收费全文 | 76篇 |
免费 | 4篇 |
国内免费 | 3篇 |
专业分类
林业 | 9篇 |
农学 | 3篇 |
基础科学 | 1篇 |
15篇 | |
综合类 | 6篇 |
农作物 | 6篇 |
水产渔业 | 10篇 |
畜牧兽医 | 19篇 |
园艺 | 3篇 |
植物保护 | 11篇 |
出版年
2022年 | 1篇 |
2021年 | 4篇 |
2020年 | 5篇 |
2019年 | 6篇 |
2018年 | 4篇 |
2017年 | 5篇 |
2016年 | 6篇 |
2015年 | 5篇 |
2014年 | 4篇 |
2013年 | 4篇 |
2012年 | 8篇 |
2011年 | 2篇 |
2010年 | 6篇 |
2009年 | 2篇 |
2008年 | 1篇 |
2007年 | 1篇 |
2006年 | 1篇 |
2005年 | 1篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2001年 | 1篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1989年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1971年 | 1篇 |
1969年 | 2篇 |
1968年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有83条查询结果,搜索用时 17 毫秒
1.
AbstractThe effect of different rice-based crop rotation sequences on the population densities of Meloidogyne graminicola and on the yield of rice was evaluated in a microplot experiment under lowland rice field conditions. Ten treatments of cropping sequences were grown in four successive growing seasons: continuous growing of the susceptible rice cultivar Thihtatyin (rice-rice-rice-rice), four treatments of 1- season crop rotation sequences (rice-rice-chickpea-rice, rice-rice-black gram-rice, rice-rice-soybean-rice, rice-rice-cowpea-rice), and five treatments of 2-season crop rotation sequences (groundnut-rice-chickpea-rice, green gram-rice-black gram-rice, cowpea-rice-soybean-rice, sesame-rice-cowpea-rice, sunflower-rice-sesame-rice). Population densities of M. graminicola recovered from the rice plants and the nematode multiplication factors (Mf) in the soil in the continuous rice cropping sequence (rice-rice-rice-rice) was the highest among the ten cropping sequences. Lowest nematode Mf in the soil was observed in the 2-season crop rotation sequence sunflower-rice-sesame-rice and the highest was observed in the 1-season crop rotation sequence rice-rice-cowpea-rice among the nine crop rotation sequences. Highest rice yield was obtained in the 2-season crop rotation sequences green gram-rice-black gram-rice, sesame-rice-cowpea-rice and sunflower-rice-sesame-rice, which were about 2 times higher compared with the 1-season crop rotation sequences and about 3 times higher compared with the continuous rice cropping sequence. 相似文献
2.
3.
以7份高粱自交系幼胚为外植体,研究了不同基因型对组织培养的反应和植株再生的差异。结果表明:不同高粱基因型间愈伤组织诱导率没有明显差异,但胚性愈伤组织百分率、不定芽分化率以及再生频率有明显差异。其中YN336A、YN267R、YN510R和YN338A的再生效果较好,其不定芽发生率、不定根发生率及移栽成活率分别为64.4%-72.8%,76.2%-100.0%和36.3%-80.0%。对只生根不生芽的基因型,加入1-2 mg/L KT有明显抑制生根、促进生芽的效应。 相似文献
4.
实时定量PCR(qRT-PCR)是分析功能基因表达水平的常用方法之一,qRT-PCR数据统计分析离不开合适内参基因的选择。为了选择中国小麦花叶病毒(Chinese wheat mosaic virus, CWMV)侵染条件下的小麦内参基因,本实验通过PCR扩增效率和扩增特异性分析,从10个持家基因中选择8个候选基因,然后以接种CWMV的小麦样品为材料,利用qRT-PCR技术进一步检测上述8个基因在CWMV侵染条件下小麦样品中的时空表达特性。基于这些数据,通过geNorm、NormFinder程序分析,结果表明,2个小麦基因(即26S和CDC)在CWMV侵染前后以及不同组织中表达最为稳定,26S和CDC组合可选作CWMV与小麦互作过程中功能基因表达分析的内参基因。 相似文献
5.
Işcan G Kirimer N Kürkcüoğlu M Başer KH Demirci F 《Journal of agricultural and food chemistry》2002,50(14):3943-3946
Essential oils of peppermint Mentha piperita L. (Lamiaceae), which are used in flavors, fragrances, and pharmaceuticals, were investigated for their antimicrobial properties against 21 human and plant pathogenic microorganisms. The bioactivity of the oils menthol and menthone was compared using the combination of in vitro techniques such as microdilution, agar diffusion, and bioautography. It was shown that all of the peppermint oils screened strongly inhibited plant pathogenic microorganisms, whereas human pathogens were only moderately inhibited. Chemical compositions of the oils were analyzed by GC and GC/MS. Using the bioautography assay, menthol was found to be responsible for the antimicrobial activity of these oils. 相似文献
6.
Vladimir Ćirić Milivoj Belić Ljiljana Nešić Srđan Šeremešić Borivoj Pejić Atila Bezdan 《Archives of Agronomy and Soil Science》2016,62(12):1654-1664
Soil organic carbon (SOC) has a high impact on the sustainability of ecosystems, global environmental processes, soil quality and agriculture. Long-term tillage usually leads to SOC depletion. The purpose of this study was to determine the impact of different land uses on water extractable organic carbon (WEOC) fractions and to evaluate the interaction between the WEOC fractions and other soil properties. Using an extraction procedure at 20°C and 80°C, two fractions were obtained: a cold water extractable organic carbon (CWEOC) and a hot water extractable organic carbon (HWEOC). The results suggest that there is a significant impact from different land uses on WEOC. A lower relative contribution of WEOC in SOC and a lower concentration of labile WEOC fractions are contained in arable soil compared to forestlands. Chernozem soil was characterized by a lower relative contribution of WEOC to the SOC and thus higher SOC stability in contrast to Solonetz and Vertisol soils. Both CWEOC and HWEOC are highly associated with SOC in the silt and clay fraction (<53 µm) and were slightly associated with SOC in the macroaggregate classes. The WEOC fractions were highly and positively correlated with the SOC and mean weight diameter. 相似文献
7.
In 19 wheat-milling fractions total pentosan content, calculated as 0.88 x (% L-arabinose + % D-xylose), varied between 1.44 and 30.66% on dry matter (dm). It increased with ash content once the latter exceeded 0.6% (dm basis). Water-extractable arabinoxylans were recovered by saturating water extracts to 65% ethanol. Their contents in the milling fractions varied between 0.35 and 1.38%, and above 0.6% ash content also increased with this parameter. Their L-arabinose-to-D-xylose ratios ranged between 0.65 and 0.39, with the lowest values found for the fractions with highest ash content, indicating that the ash-rich tissues contain more arabinoxylans that are less branched. (1)H NMR spectroscopy revealed that the decrease in L-arabinose-to-D-xylose ratio was accompanied by an increase in unsubstituted xylose residues and a decrease in disubstituted xylose residues, while the contents of monosubstituted xyloses were virtually constant. 相似文献
8.
9.
Selection logging is a principal management scheme in natural teak-bearing forests in Myanmar. Monitoring the spatial extent
and intensity of selection logging is important for sustainable forest management. This study applied the normalized difference
vegetation index (NDVI) image differencing method using two SPOT-5 pan-sharpened images (2.5 m spatial resolution) taken in
October 2007 and January 2009 to analyze canopy changes associated with damage from forest harvesting. According to the pixel-based
analysis, NDVI changes were larger in most logging road/log landing points whereas smaller NDVI changes were seen in most
unlogged points. NDVI changes in teak stump areas were related to distance from a logging road and the number of stumps within
the estimated crown area (a circular area with a 10 m radius from the center of each stump). A Fisher’s exact test showed that one of the main factors
causing the high NDVI change in teak stump areas was the effect of road construction. The distribution pattern of teak stumps
indicated that teak stumps with estimated crown areas that contained more than one stump had high mean change in NDVI. The spectral difference between before and after logging
revealed that logging roads had a greater effect on canopy changes than teak stumps. 相似文献
10.
Khin Thawda Win Ryoko Nonaka Koki Toyota Takashi Motobayashi Masaaki Hosomi 《Biology and Fertility of Soils》2010,46(6):589-595
A lysimeter experiment was carried out to evaluate the effects of the NH3 volatilization mitigation by adding anaerobically digested cattle slurry (ADCS) alone, with wood vinegar (WV) or with a higher
level of floodwater (HFW), on emissions of CH4 and N2O from a paddy soil planted with fodder rice. We have carried out the following treatments: (1) chemical fertilizer, (2) ADCS,
(3) ADCS + WV, and (4) ADCS + HFW; the height of floodwater was 10 cm in the latter treatment, and it was 3 to 4 cm in the
other treatments just before fertilizer applications. Nitrogen fertilizer rate added to soil in each treatment was 30 g NH4+–N m−2 (split in one basal and two top-dressing additions). Ammonia volatilization in the ADCS treatment was 2.7 g NH3–N m−2 throughout the growing season, and it was significantly reduced by 79% and 55% in the ADCS + WV and ADCS + HFW treatments,
respectively. The total amount of CH4 emitted in the ADCS treatment in the growing season was not significantly enhanced by the mitigation of NH3 volatilization either by adding wood vinegar or by increasing the height of the floodwater. Negligible N2O emissions were observed in all treatments during the growing period. 相似文献