全文获取类型
收费全文 | 58篇 |
免费 | 2篇 |
专业分类
林业 | 2篇 |
农学 | 1篇 |
5篇 | |
综合类 | 7篇 |
水产渔业 | 2篇 |
畜牧兽医 | 38篇 |
植物保护 | 5篇 |
出版年
2020年 | 1篇 |
2018年 | 2篇 |
2016年 | 2篇 |
2014年 | 1篇 |
2013年 | 6篇 |
2012年 | 2篇 |
2011年 | 1篇 |
2010年 | 4篇 |
2009年 | 3篇 |
2008年 | 1篇 |
2007年 | 2篇 |
2005年 | 1篇 |
1999年 | 6篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
排序方式: 共有60条查询结果,搜索用时 31 毫秒
11.
Marcio Rocha Francelino Carlos Ernesto G.R. Schaefer Felipe Nogueira Bello Simas Elpídio Incio Fernandes Filho Jos Joo Lelis Leal de Souza Liovando Marciano da Costa 《CATENA》2011,85(3):194-204
The main pedological, geomorphological and cryogenic features of Keller Peninsula, part of Admiralty Bay, King George Island, Maritime Antarctica, were mapped and quantified with emphasis on the relationship between the ice retreat process, melt-out, landform development and soil distribution. Moraines, protalus, scree slopes, inactive glacial cirques, uplift marine terraces, biogenic landforms, arêtes and Felsenmeer were mapped. Scree slope is the main landform, covering approximately 25% of the peninsula, indicating prominent paraglacial features. Inherited, glacial landforms, such as lateral moraines, highland plateau and exhumed U shaped-valleys, are now being exposed in north Keller by ice shrinkage of former ice protecting cover. Landforms influenced soil formation and stability. Cryosols and Leptosols (WRB) roughly corresponding to Gelisols and Entisols (SSS), respectively, are the most common soil classes, with an overall tendency of absent permafrost in the coastal areas, changing to sporadic permafrost at mid-slope, and discontinuous permafrost with greater altitude and substrate stability. 相似文献
12.
Salvador Becerra-Rodríguez Víctor Manuel Medina-Urrutia Marciano Manuel Robles-González Timothy Williams 《Euphytica》2008,164(1):27-36
Grapefruit growers in the tropics require information about existing and new citrus cultivars with high productivity potential.
The objective of this study was to determine the growth, yield, and fruit quality performance of seven pigmented and four
white grapefruit cultivars under the dry tropic conditions of Colima, Mexico. The trees were budded on sour orange (Citrus aurantium L.) rootstock and planted at a distance of 8 × 4 m. ‘Oroblanco’ and ‘Marsh Gardner’ white-fleshed grapefruit cultivars and
‘Chandler’, a pink-fleshed pummelo, were the largest trees with the greatest height (5.0–5.6 m), canopy diameter (6.2–6.3 m),
trunk diameter (21.9–23.3 cm), and canopy volume (109–123 m3). Lower height (4.3–4.8 m) and canopy volume (73–96 m3), but with similar canopy diameter to the previously mentioned cultivars, were recorded for the remaining pigmented cultivars.
‘Chandler’ pummelo and four pigmented grapefruit cultivars (‘Shambar’, ‘Río Red’, ‘Ray Ruby’, and ‘Redblush #3’) had yearly
productions of 34.8, 34.9, 34.1, 32.7, and 30.6 ton ha−1, respectively. The most productive white grapefruit cultivar was ‘Marsh Gardner’ (30.5 ton ha−1). Grapefruit cultivars having the largest fruit size showed a higher inverse relationship between fruit weight and yield
than those with small fruit. Most genotypes had higher values of fruit weight, juice content, and maturity index than those
required by the local market. The most promising grapefruit cultivars based on their acceptable growth, yield superior to
30 ton ha−1, and acceptable fruit color were ‘Río Red’, ‘Shambar’, ‘Ray Ruby’, and ‘Redblush #3’. 相似文献
13.
14.
16.
17.
Kelly P O'Sullivan K Berry D More S Meaney W O'Callaghan E O'Brien B 《Irish veterinary journal》2009,62(1):36-42
Research has shown that total bacterial count (TBC), which is the bacterial growth per ml of milk over a fixed period of time, can be decreased by good hygiene and farm management practices. The objective of the current study was to quantify the associations between herd management factors and bulk tank TBC in Irish spring calving, grass-based dairy herds. The relationship between bulk tank TBC and farm management and infrastructure was examined using data from 400 randomly selected Irish dairy farms where the basal diet was grazed grass. Herd management factors associated with bulk tank TBC were identified using linear models with herd annual total bacterial score (i.e., arithmetic mean of the natural logarithm of bulk tank TBC) included as the dependent variable. All herd management factors were individually analysed in a separate regression model, that included an adjustment for geographical location of the farm. A multiple stepwise regression model was subsequently developed. Median bulk tank TBC for the sample herds was 18,483 cells/ml ranging from 10,441 to 130,458 cells/ml. Results from the multivariate analysis indicated that the following management practices were associated with low TBC; use of heated water in the milking parlour; participation in a milk recording scheme; and tail clipping of cows at a frequency greater than once per year. Increased level of hygiene of the parlour and cubicles were also associated with lower TBC. Herd management factors associated with bulk tank TBC in Irish grazing herds were generally in agreement with most previous studies from confinement systems of milk production. 相似文献
18.
P. Marciano 《Phytoparasitica》1994,22(2):101-108
The polygalacturonase (PG) activity in culture filtrates fromSclerotinia sclerotiorum is reduced when glyceollin I, the major soybean phytoalexin, is present in the culture medium. When the enzyme activities
in the culture filtrates are expressed per unit of fungal growth, PG activity decreases with increasing concentration of glyceollin
I in the culture medium. The phytoalexin does not influence the isoenzyme pattern. This suggests that glyceollin I may inhibit
quantitative but not qualitative enzyme production. Only the highest glyceollin I concentration tested inhibits oxalic acid
production. The inhibitory effect on mycelial growth is confirmed. The data suggest a further hypothesis about the role of
phytoalexin during pathogenesis. 相似文献
19.
20.
Tegenes Senna de Oliveira Liovando Marciano de Costa Carlos Ernesto Schaefer 《Soil & Tillage Research》2005,83(2):260-269
Widespread intensive land use in the seasonal tropics can damage the physical stability of aggregates. Similar damage can be expected from wetting and drying cycles causing aggregate fragmentation and, consequently, leading to an increase in their specific area and exposure of internal electric charges. Thus, we hypothetised that the influence of wetting and drying cycles is dependent on the mineralogical composition of oxisols (latosols) and it is higher in soils with low aggregate stability. A greenhouse experiment was carried out to test this hypothesis in highly weathered soils from Brazil, all with variable-charge clays and highly stable aggregates. Wetting and drying cycles were defined from the quantity of water available between field capacity and the permanent wilting point. Soil columns were submitted to 0, 2, 6, 9, 12, 15 and 18 wetting and drying cycles. After each number of wetting and drying defined physical and chemical properties were determined. Statistical analysis, such as simple and multiple linear regression and Pearson's correlation were performed, showing significantly correlated WDC contents with wetting and drying cycles. The obtained results led to the conclusion that there was a close interdependence among mineralogical composition, aggregate stability and WDC influenced by wetting and drying cycles. Soils of reduced aggregate stability like kaolinitcs made them more susceptible to the action of wetting and drying on the WDC. Changes in the WDC with wetting and drying cycles showed correlated with eletrochemical properties. 相似文献