全文获取类型
收费全文 | 95篇 |
免费 | 5篇 |
专业分类
林业 | 7篇 |
农学 | 2篇 |
43篇 | |
综合类 | 12篇 |
农作物 | 2篇 |
水产渔业 | 3篇 |
畜牧兽医 | 23篇 |
园艺 | 1篇 |
植物保护 | 7篇 |
出版年
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 4篇 |
2019年 | 4篇 |
2018年 | 1篇 |
2017年 | 3篇 |
2016年 | 3篇 |
2015年 | 4篇 |
2014年 | 5篇 |
2013年 | 2篇 |
2012年 | 8篇 |
2011年 | 9篇 |
2010年 | 3篇 |
2009年 | 6篇 |
2008年 | 9篇 |
2007年 | 3篇 |
2006年 | 4篇 |
2005年 | 7篇 |
2004年 | 4篇 |
2003年 | 6篇 |
2002年 | 1篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1994年 | 2篇 |
1987年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有100条查询结果,搜索用时 15 毫秒
1.
Cruciferous oilseeds are important sources of oil, proteins, and glucosinolates (GLs), potentially available when biorefinery processes are used. The proposed extraction technology is based on the use of reverse micelles (RMs) made with cetyltrimethylammonium bromide (CTAB) dispersed in organic solvent. The physicochemical properties of this extraction system and the good water solubility of many high value compounds, such as GLs and some proteins, permit the simultaneous extraction of oil, and these products from cruciferous oilseed meals. This procedure is based on three main steps: (i) seed conditioning; (ii) solid-liquid extraction by RM solution; and (iii) back-transfer of the RM solution for recovery of the extracted compounds. The method makes it possible to simultaneously extract almost the same amount of oil as with pure organic solvents used in the current extraction plants and more than 90% of soluble proteins and GLs. It is a promising biorefinery technology alternative to traditional oil extraction processes. 相似文献
2.
Sandro Froehner Daniele Botelho Souza Karina Scurupa Machado Edson Cordova da Rosa 《Water, air, and soil pollution》2010,210(1-4):33-41
The Barigüi River watershed is located in the metropolitan region of Curitiba, Southern Brazil, passing through several neighboring counties. In recent years, due to growth and disorderly occupation along the river, in addition to lack of sanitation, the Barigüi River suffered a very large inflow of untreated domestic wastewater. Current programs to monitor the watershed use traditional physical–chemical parameters. Here, the presence of some molecular tracers found in domestic effluents was investigated, such as caffeine and coprostanol at some selected sites in Barigüi River. Caffeine is highly soluble in water and its presence in water bodies is due to the disposal of untreated sewage. Caffeine is eliminated in the urine (approximately 0.5% to 10% of the consumption). The samples were collected in three campaigns, two in dry weather and another during a week in the rainy season. The results showed that caffeine concentration ranged between zero and 753.5 μg g?1. Higher values were found on rainy days. Caffeine showed a positive correlation between BOD and nitrate; it also showed a positive correlation with coprostanol, a fecal biomarker. Finally, caffeine has been shown to be a good parameter to determine the contamination by domestic wastewater. 相似文献
3.
The complex geological history of Italy is responsible for the remarkable number of different landscapes and ecosystems present today. The immigration of animals and plants from neighbouring lands, when natural bridges were available, the survival of warm species along the coast during the Quaternary glaciations, and the relict populations which remained in the Apennines after the withdrawal of the ice, have all contributed to the richness of wildlife. In order to preserve adequately this biotic variety it is necessary to protect a large number of separate areas as National or Regional Parks or as nature reserves. In addition, the existence of important bird migration routes along or across the Italian peninsula and islands makes it necessary to provide safe areas where these birds can rest and feed. In spite of these needs, the State and the Regional Governments are not sufficiently concerned with wildlife and environmental conservation and so far have done very little to improve the protection of nature in Italy. In this paper 56 main areas are discussed which are in urgent need of protection from commercial speculation and the threat of irreparable damage. The authors hope that national and international public opinion will encourage the Italian Government to establish many more protected territories and to provide the resources for realistic management. 相似文献
4.
Helge Sierotzki Sandro Parisi Ute Steinfeld Isabel Tenzer Sylvie Poirey Ulrich Gisi 《Pest management science》2000,56(10):833-841
Field isolates of Mycosphaerella fijiensis, causing black Sigatoka of banana, were characterised for their sensitivity to different inhibitors of the cytochrome bc1 enzyme complex (Qo respiration inhibitors, strobilurin fungicides), using physiological, biochemical and molecular genetic methods. Strobilurin‐resistant isolates exhibited very high resistance factors both in mycelial growth inhibition and NADH consumption assays. Cross‐resistance was observed among all Qo inhibitors, including trifloxystrobin, azoxystrobin, famoxadone, strobilurin B and myxothiazol. However, the Qi and the cytochrome aa3 inhibitors, antimycin A and potassium cyanide, respectively, were not cross‐resistant to Qo inhibitors. In sensitive but not in resistant isolates, mixtures of Qo inhibitors and SHAM, an inhibitor of the alternative oxidase (AOX), were more active than the components alone, indicating that the alternative pathway is essential in metabolism, but not causal for resistance. In the cell‐free NADH‐consumption assay, the Qo inhibitors affected the sensitive but not the resistant isolates, suggesting that AOX was not active in sub‐mitochondrial particles. In whole cells, however, the AOX has a basic expression level and is probably not inducible by trifloxystrobin. Sequencing of the cytochrome b gene of sensitive and resistant M fijiensis isolates revealed a difference in the nucleotide sequence leading to a single amino acid change from glycine to alanine at position 143 in the resistant isolate. This change is known to occur also in the naturally tolerant basidiomycete Mycena galopoda. It is suggested that the field isolates of M fijiensis can acquire resistance to Qo inhibitors due to a target site alteration with a single base pair change. Resistant isolates do not seem to contain a mixture of mutated and non‐mutated DNA, indicating a complete selection of resistant mitochondria and a maternally donated mode of resistance. © 2000 Society of Chemical Industry 相似文献
5.
Angioni A Barra A Russo MT Coroneo V Dessi S Cabras P 《Journal of agricultural and food chemistry》2003,51(10):3073-3078
The composition of the essential oil from ripe and unripe berries and leaves of Juniperus oxycedrus L. ssp. oxycedrus, Juniperus phoenicea ssp. turbinata and Juniperus communis ssp. communis was analyzed by GC-MS, and microbiological assays were carried out. Samples were collected in different localities (Sardinia, Italy) and hydro distilled. The yields ranged between 2.54% +/- 0.21 (v\w dried weight) and 0.04% +/- 0.00. A total of 36 components were identified. The major compounds in the essential oils were alpha-pinene, beta-pinene, delta-3-carene, sabinene, myrcene, beta-phellandrene, limonene, and D-germacrene. Both qualitative and quantitative differences between species and between different parts of the plant were observed. The essential oils and their major compounds were tested against Candida albicans, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, and the minimum inhibitory concentration and minimum bactericidal concentration were determined. The results obtained led to a nonsignificant inhibitory effect, although all the essential oils from Juniperus phoenicea ssp. turbinata and the essential oil from leaves of Juniperus oxycedrus ssp. oxycedrus exhibited rather good or weak activity against Candida albicans and Staphylococcus aureus. 相似文献
6.
7.
Claudio Chiesa Alma Dal Prà Giancarlo Guarneri Sandro Penso Leonardo Rodella Laura Volterra Adriano Zugno 《Water, air, and soil pollution》1987,34(3):241-244
Results from examining shellfish collected from ‘safe’ (2–34Escherichia coli/100 mL) and ‘unsafe’ (> 34E. coli/100 mL) waters for the presence ofYersinia enterocolitica and related bacteria are reported. The recovery of these microorganisms was low in bivalve mollusks destined for food consumption, high in those derived from prohibited areas. No human pathogenic bio-serogroup f Yersinia was found during the entire survey. 相似文献
8.
Ataide SF Schmitz N Shen K Ke A Shan SO Doudna JA Ban N 《Science (New York, N.Y.)》2011,331(6019):881-886
Cotranslational targeting of membrane and secretory proteins is mediated by the universally conserved signal recognition particle (SRP). Together with its receptor (SR), SRP mediates the guanine triphosphate (GTP)-dependent delivery of translating ribosomes bearing signal sequences to translocons on the target membrane. Here, we present the crystal structure of the SRP:SR complex at 3.9 angstrom resolution and biochemical data revealing that the activated SRP:SR guanine triphosphatase (GTPase) complex binds the distal end of the SRP hairpin RNA where GTP hydrolysis is stimulated. Combined with previous findings, these results suggest that the SRP:SR GTPase complex initially assembles at the tetraloop end of the SRP RNA and then relocalizes to the opposite end of the RNA. This rearrangement provides a mechanism for coupling GTP hydrolysis to the handover of cargo to the translocon. 相似文献
9.
Eukaryotic ribosomes are substantially larger and more complex than their bacterial counterparts. Although their core function is conserved, bacterial and eukaryotic protein synthesis differ considerably at the level of initiation. The eukaryotic small ribosomal subunit (40S) plays a central role in this process; it binds initiation factors that facilitate scanning of messenger RNAs and initiation of protein synthesis. We have determined the crystal structure of the Tetrahymena thermophila 40S ribosomal subunit in complex with eukaryotic initiation factor 1 (eIF1) at a resolution of 3.9 angstroms. The structure reveals the fold of the entire 18S ribosomal RNA and of all ribosomal proteins of the 40S subunit, and defines the interactions with eIF1. It provides insights into the eukaryotic-specific aspects of protein synthesis, including the function of eIF1 as well as signaling and regulation mediated by the ribosomal proteins RACK1 and rpS6e. 相似文献
10.
Renato Gerdol Sandro Degetto Dionisio Mazzotta Giorgio Vecchiati 《Water, air, and soil pollution》1994,75(1-2):93-106
The patterns of concentration of the Cs-137 derived from the Chernobyl accident were analysed in a series of vertical profiles ofSphagnum collected at two peatlands in the southern Alps. The peak concentrations of the Chernobyl radiocesium were found in segments ofSphagnum located at different distances from the growing apex, probably corresponding to the plant tissues produced in the 1986 vegetation season. This indicated that the growth rates ofSphagnum are subject to considerable variations not only between species, but also between years and even between individuals of the same species when growing in different microhabitats at the same site. However, the concentrations of the Chernobyl-derived radiocesium are high also in theSphagnum segments produced after 1986. This was due to a continuous translocation of Cs-137 towards the capitulum, probably determined by the chemical similarity between cesium and potassium. Although the two sites investigated received nearly the same amounts of rainfall in the two-week period following the arrival of the Chernobyl plume, the average concentrations of radiocesium in allSphagnum species were significantly higher at one of them, presumably because the fall-out deposition was conditioned by a number of meteorological factors besides precipitation. 相似文献