全文获取类型
收费全文 | 129篇 |
免费 | 7篇 |
国内免费 | 3篇 |
专业分类
林业 | 3篇 |
农学 | 5篇 |
基础科学 | 1篇 |
3篇 | |
综合类 | 38篇 |
农作物 | 1篇 |
水产渔业 | 28篇 |
畜牧兽医 | 47篇 |
园艺 | 4篇 |
植物保护 | 9篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 4篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 1篇 |
2017年 | 10篇 |
2016年 | 4篇 |
2015年 | 7篇 |
2014年 | 5篇 |
2013年 | 7篇 |
2012年 | 5篇 |
2011年 | 10篇 |
2010年 | 9篇 |
2009年 | 4篇 |
2008年 | 5篇 |
2007年 | 9篇 |
2006年 | 3篇 |
2005年 | 10篇 |
2004年 | 3篇 |
2003年 | 2篇 |
2002年 | 1篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 4篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 4篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1979年 | 1篇 |
1893年 | 1篇 |
排序方式: 共有139条查询结果,搜索用时 15 毫秒
11.
From mid-2004 to mid-2005, several grass carp, Ctenophayngodon idella (Valenciennes), showing evidence of spinal deformity were presented to the Aquatic Animal Health Program, Cornell University. The carp were from three separate locations in New York State. The first case involved several fish from a natural body of water in the Catskill Mountain region of south-eastern New York State. The second was a single affected individual from a private pond in the Fingerlakes region of Central New York State. The third was a single individual from the Cold Springs Harbor Fish Hatchery, Cold Springs Harbor, Long Island. All fish were at least 7 years of age. Radiographs and computed tomography (CT) scans revealed the deformities to be of bony origin. The spinal deformities were characterized by variable amounts of kyphosis, scoliosis and rotation. While it is not possible to determine the specific cause(s) of the lesions, we consider a genetic component as a likely contributor to the observed pathology. 相似文献
12.
Emily R. Cornwell Eileen A. Penner Rodman G. Getchell Geoffrey H. Groocock Paul R. Bowser 《Journal of the World Aquaculture Society》2013,44(5):669-681
The emergence of a new sublineage of viral hemorrhagic septicemia virus (VHSV) within the Laurentian Great Lakes has caused concern for aquaculture in the United States. Because of the occurrence of VHSV in a new geographic location, new host species have been identified and the complete host range has not been determined. This study confirmed the high resistance of rainbow trout, Oncorhynchus mykiss, to VHSV type IVb infection. In addition, the experimental susceptibility of hybrid striped bass, Morone chrysops ♂ × Morone saxatilis ♀, to VHSV type IVb infection was examined but determined to be highly dependent on age of fish and exposure temperature. No mortality was observed in adult fish infected via intraperitoneal (IP) injection at 15 C, whereas yearling fish infected via IP injection under the same conditions experienced 20.8% mortality. Among yearling fish infected via IP injection, mortality increased to 100% when exposure to VHSV occurred at 10 C. An LD50 for yearling hybrid striped bass exposed to VHSV at 10 C by IP injection was determined to be 1.4 × 104 pfu (SE = 2.1). Thus, at 10 C, yearling hybrid striped bass experience a high mortality when exposed to VHSV IVb by IP injection. 相似文献
13.
KENG‐HSIANG CHENG YU‐CHING CHIAO HSIN‐YU SHIH TAI‐YU LEE TA‐SHUN CHO 《Growth and change》2011,42(4):517-548
The purpose of this study was to investigate how Taiwanese high‐tech firms' foreign direct investment (FDI) leads to agglomeration and competition among cities in China. By using social network analysis to analyze 1,111 subsidiaries affiliated with 270 multinational corporations (MNCs) during the years between 1988 and 2006 in 30 major Chinese cities, this study finds that: 1) agglomeration in Chinese cities falls into three primary categories: the hub cluster, the communication‐extended cluster, and the computer‐extended cluster. Among the aforementioned clusters, the hub cluster is the most critical in terms of firm location, and therefore is often a high‐priority investment site for Taiwanese high‐tech firms. 2) Chinese cities fall into four primary groups, or “blocks”: the core block, the coast block, the inland block, and the periphery block; these groups were determined by applying a structural equivalence analysis of which members of each type are in competition with one another. By linking the findings of the urban network characteristics to Chinese regional economic policies, this study provides guidance to aid executives in determining the optimal location for future FDI. Implications and suggestions for host country governments in terms of firms' investment strategies are also discussed. 相似文献
14.
Galibert F Finan TM Long SR Puhler A Abola P Ampe F Barloy-Hubler F Barnett MJ Becker A Boistard P Bothe G Boutry M Bowser L Buhrmester J Cadieu E Capela D Chain P Cowie A Davis RW Dreano S Federspiel NA Fisher RF Gloux S Godrie T Goffeau A Golding B Gouzy J Gurjal M Hernandez-Lucas I Hong A Huizar L Hyman RW Jones T Kahn D Kahn ML Kalman S Keating DH Kiss E Komp C Lelaure V Masuy D Palm C Peck MC Pohl TM Portetelle D Purnelle B Ramsperger U Surzycki R Thebault P Vandenbol M Vorholter FJ 《Science (New York, N.Y.)》2001,293(5530):668-672
The scarcity of usable nitrogen frequently limits plant growth. A tight metabolic association with rhizobial bacteria allows legumes to obtain nitrogen compounds by bacterial reduction of dinitrogen (N2) to ammonium (NH4+). We present here the annotated DNA sequence of the alpha-proteobacterium Sinorhizobium meliloti, the symbiont of alfalfa. The tripartite 6.7-megabase (Mb) genome comprises a 3.65-Mb chromosome, and 1.35-Mb pSymA and 1.68-Mb pSymB megaplasmids. Genome sequence analysis indicates that all three elements contribute, in varying degrees, to symbiosis and reveals how this genome may have emerged during evolution. The genome sequence will be useful in understanding the dynamics of interkingdom associations and of life in soil environments. 相似文献
15.
Hui-Min Hsu Gregory A. Wooster Paul R. Bowser 《Journal of the World Aquaculture Society》1994,25(4):535-540
Rainbow trout Oncorhynchus mykiss were fed a ration medicated to provide enrofloxacin (Baytrilo®, Bayer) at 2.5, 5.0, or 10.0 mg drug per kg fish per d either 5 or 10 d. Tissue Concentrations of enrofloxacin were measured in liver, kidney, muscle, skin, and serum during the medication period, and thereafter for a total of 30 d. Highest tissue concentrations were observed in fish medicated with 5 mg enrofloxacin per kg fish per d for 10 d. Tissue concentrations of anitmicrobial activity were found to exceed minimum inhibitory concentrations of enrofloxacin for several isolates of Aeromonas salmonicida and Renibacterium salmoninarum . Lower than expected tissue concentrations were observed for the 10 mg per kg fish per d doses, perhaps due to a lack of acceptance of the medicated ration. The results support evaluation of a 5 mg per kg fish dose to treat bacterial infections of salmonids under field conditions. 相似文献
16.
Groocock GH Grimmett SG Getchell RG Wooster GA Bowser PR 《Journal of aquatic animal health》2008,20(3):158-164
During 2004 and 2005 a survey was conducted to investigate the presence and geographic distribution of largemouth bass virus (LMBV) in New York State. This iridovirus is widely distributed across the eastern United States; however, it had not previously been reported in New York State. Two hundred and eighty-three wild largemouth bass Micropterus salmoides and 8 smallmouth bass M. dolomieu were collected from 37 locations across the state. No clinical signs of LMBV or mortalities attributable to the virus were observed in the fish collected. Using a quantitative polymerase chain reaction (QPCR) method, we detected LMBV in 28 fish from 13 locations. Viral cytopathic effect in cell culture was observed in 5 fish from 3 locations. The virus isolated from cell culture was confirmed to be LMBV by an independent PCR method. Statistical analysis of the largemouth bass samples collected during 2005 revealed a wide difference in prevalence between the QPCR results and the cell culture results. Analysis of possible predictors, including age, sex, and month collected, showed no significant associations with the QPCR results. This survey confirms the presence and wide distribution of a potentially pathogenic form of LMBV in multiple water systems across New York State. 相似文献
17.
JE Lupton ET Baker N Garfield GJ Massoth RA Feely JP Cowen RR Greene TA Rago 《Science (New York, N.Y.)》1998,280(5366):1052-1055
The migration and evolution of a deep ocean hydrothermal event plume were tracked with a neutrally buoyant RAFOS float. The float remained entrained in the plume for 60 days, and the plume vorticity was calculated directly from the anticyclonic motion of the float. Concentrations of suspended particles, particulate iron, and dissolved manganese in the plume did not decay significantly during the 60 days, which indicates that event plumes would be easily detectable a year after formation. 相似文献
18.
MC Stiner ND Munro TA Surovell E Tchernov O Bar-Yosef 《Science (New York, N.Y.)》1999,283(5399):190-194
Variations in small game hunting along the northern and eastern rims of the Mediterranean Sea and results from predator-prey simulation modeling indicate that human population densities increased abruptly during the late Middle Paleolithic and again during the Upper and Epi-Paleolithic periods. The demographic pulses are evidenced by increasing reliance on agile, fast-reproducing partridges, hares, and rabbits at the expense of slow-reproducing but easily caught tortoises and marine shellfish and, concurrently, climate-independent size diminution in tortoises and shellfish. The results indicate that human populations of the early Middle Paleolithic were exceptionally small and highly dispersed. 相似文献
19.
20.
Lorelei Ford Kuttichantran Subramaniam Thomas B. Waltzek Paul R. Bowser Larry Hanson 《Journal of fish diseases》2021,44(1):119-122
The channel catfish (Ictalurus punctatus, Rafinesque) ovary (CCO) cell line is the standard cell line used for channel catfish diagnostics. Next‐gen sequencing studies of a virus cultured in the CCO cells revealed mitochondrial sequences matching those of brown bullhead (Ameiurus nebulosus, Lesueur). Therefore, we systematically performed partial cytochrome oxidase 1 gene sequencing of several sources of the CCO cell line and all matched the brown bullhead and not the channel catfish. 相似文献