全文获取类型
收费全文 | 711篇 |
免费 | 18篇 |
专业分类
林业 | 110篇 |
农学 | 87篇 |
基础科学 | 5篇 |
92篇 | |
综合类 | 36篇 |
农作物 | 30篇 |
水产渔业 | 36篇 |
畜牧兽医 | 234篇 |
园艺 | 8篇 |
植物保护 | 91篇 |
出版年
2018年 | 7篇 |
2017年 | 10篇 |
2016年 | 9篇 |
2015年 | 7篇 |
2014年 | 11篇 |
2013年 | 36篇 |
2012年 | 24篇 |
2011年 | 18篇 |
2010年 | 19篇 |
2009年 | 6篇 |
2008年 | 24篇 |
2007年 | 22篇 |
2006年 | 21篇 |
2005年 | 28篇 |
2004年 | 19篇 |
2003年 | 30篇 |
2002年 | 31篇 |
2000年 | 15篇 |
1999年 | 16篇 |
1998年 | 9篇 |
1997年 | 14篇 |
1996年 | 13篇 |
1995年 | 18篇 |
1994年 | 7篇 |
1993年 | 14篇 |
1992年 | 9篇 |
1991年 | 6篇 |
1990年 | 9篇 |
1989年 | 10篇 |
1988年 | 8篇 |
1987年 | 6篇 |
1986年 | 10篇 |
1985年 | 10篇 |
1982年 | 11篇 |
1980年 | 8篇 |
1979年 | 6篇 |
1978年 | 9篇 |
1977年 | 12篇 |
1976年 | 8篇 |
1975年 | 7篇 |
1974年 | 7篇 |
1973年 | 13篇 |
1972年 | 6篇 |
1971年 | 13篇 |
1970年 | 10篇 |
1969年 | 7篇 |
1968年 | 8篇 |
1967年 | 7篇 |
1966年 | 7篇 |
1959年 | 6篇 |
排序方式: 共有729条查询结果,搜索用时 15 毫秒
31.
Nickolas?G.?KavallieratosEmail author George?J.?Stathas Christos?G.?Athanassiou George?Th.?Papadoulis 《Phytoparasitica》2002,30(3):231-242
The role of the self-sown shrubsDittrichia viscosa (L.) W. Greuter andRubus ulmifolius Schott as reservoirs of aphid parasitoids was investigated. In the field studies conducted,D. viscosa grew adjacent to crops of durum wheat and barley andR. ulmifolius grew adjacent to cotton. The relative abundance of the parasitoids of(a) Capitophorus inulae (Passerini) onD. viscosa, (b) Rhopalosiphum padi (Linnaeus) on durum wheat and barley,(c) Aphis ruborum (Börner) onR. ulmifolius, and(d) Aphis gossypii Glover on cotton in various parts of Greece, was assessed during the years 1996–2000. In 2000, the fluctuation of parasitization of the above four aphid species was recorded and the action of the aphidophagous predators of the family Coccinellidae was studied. It was observed thatAphidius matricariae Haliday predominated onC. inulae andR. padi in all sampling cases. In contrast,Lysiphlebus fabarum (Marshall) was the dominant species parasitizingA. ruborum onR. ulmifolius andA. gossypii on cotton in Thessaly (central Greece) and Macedonia (northern Greece), whereasLysiphlebus confusus Tremblay et Eady andBinodoxys acalephae (Marshall) were the dominant parasitoid species in Thrace (northern Greece).Coccinella septempunctata Linnaeus was the most abundant coccinellid species on durum wheat, whereasAdonia variegata (Goeze) predominated on cotton. However, coccinellid individuals were scarce on bothD. viscosa andR. ulmifolius. The present study indicated that these two shrubs can be regarded as useful reservoirs of aphid parasitoids. 相似文献
32.
O. Schmidt D. Dujesiefken H. Stobbe U. Moreth R. Kehr Th. Schröder 《Forest Pathology》2008,38(2):124-128
Bacteria were isolated from necrotic lesions on a horse chestnut tree (Aesculus hippocastanum) with bleeding canker in Hamburg, Germany. Sequencing of the rDNA-ITS region revealed great similarity to pathovars of Pseudomonas syringae. Pseudomonas syringae pv. aesculi was identified by sequence homology of the gyrase B gene. This is the first report of P. syringae pv. aesculi in Germany. Phytophthora was not detected. 相似文献
33.
34.
U.Th. WEBER DrMedVet Diplomate ECVS S. ARNOLD DrMedVet M. HUBLER DMV J.R. KUPPER DrMedVet 《Veterinary surgery : VS》1997,26(1):51-56
A modified technique for fixation of the deferent ducts to the abdominal wall as a therapy for urinary incontinence caused by urethral sphincter mechanism incompetence (USMI) in male dogs is described, and the results in seven dogs are reported. The goal of this treatment was to achieve an effect similar to colposuspension in female dogs with USMI. An increase in urethral length of an average of 28 mm was obtained (range, 5 to 50 mm, measured radiographically). Preoperatively, the neck of the bladder was located intrapelvically in five of seven dogs. Postoperatively, the neck of the bladder was located intra-abdominally, near the caudo-ventral abdominal wall, in all dogs. After a follow-up period of 12 to 49 months, the response to surgery, based on lack of or decrease of incontinence, was excellent in three dogs, good in another three, and poor in one dog. 相似文献
35.
The capillarization of the M. pectoralis was examined in the turkey as it changed with age. Examined was the density of the muscles fibers (per mm2), the density of the capillaries (per mm2) and the quotient muscle fibers/capillaries. In accordance with the sequence of the original data four functions of organismic growth (slightly altered) were utilized for the approximation of the data for descending amounts: Pütter/Bertalanffy (1920, 1934); Richards (1959); Janoschek enlarged after Sager (1980) and Richards enlarged after Sager (1980). The approximations were made via nonlinear regressions, whereby the sum of the error amounts and the sums of the error squares served as criteria of quality. The results including the deduced initial and end amounts are combined in tables which also contain the parameter of the way the computations were conducted. 相似文献
36.
Th. Wolff-Fridenau 《Forstwissenschaftliches Centralblatt》1918,40(4):138-145
Ohne Zusammenfassung 相似文献
37.
38.
Th. Wolff-Friedenou 《Forstwissenschaftliches Centralblatt》1918,40(10):372-387
Ohne Zusammenfassung 相似文献
39.
Ohne Zusammenfassung 相似文献
40.