全文获取类型
收费全文 | 1076篇 |
免费 | 56篇 |
国内免费 | 1篇 |
专业分类
林业 | 29篇 |
农学 | 45篇 |
基础科学 | 3篇 |
100篇 | |
综合类 | 264篇 |
农作物 | 125篇 |
水产渔业 | 87篇 |
畜牧兽医 | 422篇 |
园艺 | 11篇 |
植物保护 | 47篇 |
出版年
2023年 | 4篇 |
2022年 | 15篇 |
2021年 | 31篇 |
2020年 | 11篇 |
2019年 | 14篇 |
2018年 | 21篇 |
2017年 | 14篇 |
2016年 | 27篇 |
2015年 | 17篇 |
2014年 | 29篇 |
2013年 | 51篇 |
2012年 | 69篇 |
2011年 | 73篇 |
2010年 | 40篇 |
2009年 | 41篇 |
2008年 | 83篇 |
2007年 | 86篇 |
2006年 | 88篇 |
2005年 | 70篇 |
2004年 | 49篇 |
2003年 | 47篇 |
2002年 | 49篇 |
2001年 | 38篇 |
2000年 | 27篇 |
1999年 | 14篇 |
1998年 | 8篇 |
1997年 | 11篇 |
1996年 | 3篇 |
1995年 | 5篇 |
1994年 | 5篇 |
1993年 | 7篇 |
1992年 | 7篇 |
1990年 | 9篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 4篇 |
1986年 | 6篇 |
1985年 | 8篇 |
1984年 | 5篇 |
1983年 | 6篇 |
1980年 | 3篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1973年 | 4篇 |
1971年 | 2篇 |
1970年 | 3篇 |
1969年 | 2篇 |
排序方式: 共有1133条查询结果,搜索用时 15 毫秒
31.
Flow cytometric assessment of ethylene glycol monoethyl ether on spermatogenesis in rats 总被引:1,自引:0,他引:1
Yoon CY Hong CM Cho YY Chung YH Min HK Yun YW Lee BJ Yang KH Lee YS Kim CK 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(2):207-212
The effects of ethylene glycol monoethyl ether (EGEE) on testicular cell populations in rats were investigated by a flow cytometric method. Rats were administered by gavage with EGEE at the various doses of 0 (saline alone), 100, 200, 400, and 800 mg/kg body weight/day for 4 weeks. The treatment of EGEE caused decreases in the weight of testis and epididymis and in the number of testicular cells. Histopathologically, exfoliation of germ cells into the tubular lumen was observed at the doses of above 200 mg/kg. The treatment of EGEE at the dose of 400 mg/kg caused moderate testicular degeneration. A significant depletion of haploid cells and a disproportionate ratio of diploid and tetraploid cells were observed as determined by flow cytometric analysis. These results indicate that the toxic effect of EGEE on the male reproductive system may be strongly associated with the disproportion of testicular germ cells. 相似文献
32.
Shin DH Lee KS Lee E Chang YP Kim JW Choi YS Kwon BS Lee HW Cho SS 《Anatomia, histologia, embryologia》2003,32(6):378-383
In this immunocytochemical study on the constitutive expression of Pax-7 protein in the postnatal chicken brain, Pax-7 showed region and cell type specific expression. In the optic tectum, only cells in grey matter showed positive immunoreactivities (IRs), whereas those in the white matters did not show any IRs. In thalamic nuclei and several pontine nuclei, we also localized Pax-7 positive IRs. On the contrary, in the cerebellum, Pax-7 was mainly localized within the Bergmann glia, whereas Purkinje cells did not show any IRs. In double immunolabelling studies, most of the Pax-7 IRs did not originate from neuroglial cells such as oligodendrocytes, microglia or astrocytes, but from neurons, with the exception of Bergmann glia in the cerebellum. The presence of Pax-7 IRs in the adult chicken brain could suggest that Pax-7 might play a role in maintaining normal physiological function in some postnatal chicken brain cells. 相似文献
33.
34.
Kim J Choi C Cho WS Chae C 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2000,62(7):771-773
Detection method of Lawsonia intracellularis was studied in formalin-fixed paraffin-embedded intestinal tissues from 5 naturally infected pigs by immunohistochemistry with a monoclonal antibody against outer membrane protein of L. intracellularis. Warthin-Starry silver stain revealed clusters of argyrophilic, slightly curved rod-shaped organisms in the apical cytoplasm of enterocytes. Immunohistochemical staining with a L. intracellularis-specific monoclonal antibody confirmed the presence of the organism in the apical cytoplasm of hyperplastic enterocytes. The presence of L. intracellularis in the ileum of pig with proliferative enteropathy was confirmed by polymerase chain reaction (PCR) further on the basis of amplification of 319 base pair products specific for porcine L. intracellularis chromosomal DNA. Immunohistochemistry and PCR may be a complementary method to confirm the diagnosis of L. intracellularis infection in pigs. 相似文献
35.
The present study was to construct a parentage testing system for Thoroughbred (TB) horse. A total number of 1,285 TB horse samples including 962 foals for parentage testing, 9 sires and 314 dams for individual identification were genotyped. Genomic DNA was extracted from 5 hair roots and genotyped by using 14 microsatellite markers (AHT4, AHT5, ASB2, ASB17, ASB23, CA425, HMS1, HMS3, HMS6, HMS7, HTG4, HTG10, LEX3 and VHL20). This method consisted of multiplexing PCR procedure and showed reasonable amplification of all PCR products. Genotypes were determined by genetic analyzer. The number of alleles per locus varied from 3 to 9 with a mean value of 6.36 in TB horse. The expected heterozygosity was ranged from 0.548 to 0.831 (mean 0.699), and the total exclusion probability of 14 microstellite loci was 0.9998. Of the 14 markers, ASB2, ASB17, ASB23, HMS7 and HTG10 loci have relatively high PIC value (> 0.7). Of the 962 foals, 960 foals were qualified by compatibility according to the Mendelism. These results suggest that the DNA typing method has high potential for parentage verification and individual identification of TB horses. 相似文献
36.
D. U. Han C. Choi J. Kim W.‐S. Cho H.‐K. Chung S.‐K. Ha K. Jung C. Chae 《Zoonoses and public health》2002,49(7):346-348
The in vitro susceptibilities of 128 isolates of east1+Escherichia coli from pre‐weaned and post‐weaned pigs with diarrhoea were tested with nine commonly used anti‐microbial agents by an agar dilution minimal inhibitory concentration (MIC) procedure according to National Committee for Clinical Laboratory Standards guidelines. For the isolates from pre‐weaned and post‐weaned pigs, most of them were susceptible to low concentrations (MIC90) of tetracycline (4 and 2 μg/ml), ceftiofur (2 and 2 μg/ml), and colistin (4 and 2 μg/ml). Marked resistance was found in others. 相似文献
37.
38.
Stuart P. Hardegree Corey A. Moffet Gerald N. Flerchinger Jaepil Cho Bruce A. Roundy Thomas A. Jones Jeremy J. James Patrick E. Clark Frederick B. Pierson 《Strength and Conditioning Journal》2013,66(2):127-135
The microclimatic requirements for successful seedling establishment are much more restrictive than those required for adult plant survival. The purpose of the current study was to use hydrothermal germination models and a soil energy and water flux model to evaluate intra- and interannual variability in seedbed microclimate relative to potential germination response of six perennial grasses and cheatgrass. We used a 44-yr weather record to parameterize a seedbed microclimate model for estimation of hourly temperature and moisture at seeding depth for a sandy loam soil type at the Orchard Field Test Site in southwestern Ada County, Idaho. Hydrothermal germination response was measured in the laboratory for two seed lots of cheatgrass (Bromus tectorum L.), four seed lots of bluebunch wheatgrass (Pseudoroegneria spicata [Pursh] Löve), three seed lots of bottlebrush squirreltail (Elymus elymoides [Raf] Swezey), and one seed lot each of Sandberg bluegrass (Poa secunda J. Presl.), big squirreltail (Elymus multisetus [J.G. Smith] M.E. Jones), thickspike wheatgrass (Elymus lanceolatus [Scribn. And J.G. Smith] Gould) and Idaho fescue (Festuca idahoensis Elmer). Germination response models were developed to estimate potential germination rate for 13 subpopulations of each seed lot for every hour of the 44-yr simulation. Seedbed microclimate was assessed seasonally and for each day, month, and year, and germination rate-sum estimates integrated for a numerical index of relative site favorability for germination for each time period. The rate-sum favorability index showed a consistent pattern among seed lots for different years, and provides a relatively sensitive indicator of annual and seasonal variability in seedbed microclimate. This index could be used with field data to define minimum weather thresholds for successful establishment of alternative plant materials, in conjunction with weather forecast models for making restoration and fire-rehabilitation management decisions in the fall season, for evaluation of potential climate-change impacts on plant community trajectories, and in optimization schemes for selecting among alternative restoration/rehabilitation management scenarios. 相似文献
39.
Zamoto A Tsuji M Wei Q Cho SH Shin EH Kim TS Leonova GN Hagiwara K Asakawa M Kariwa H Takashima I Ishihara C 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(7):785-792
We previously reported that small wild rodents in Japan harbor two types of novel Babesia microti-like parasites (designated as Hobetsu and Kobe types), but not the type commonly found in the northeastern United States (U.S. type) where human babesiosis is endemic. To determine whether these new types of parasites are distributed in places surrounding Japan, an epizootiologic survey was undertaken in three geographically distant areas in northeastern Eurasia; South Korea, Vladivostok in Russia, and Xinjiang in China. Blood samples were collected from a total of 387 animals comprising 24 species. DNAs extracted from the samples were tested by nested PCR targeting babesial nuclear small-subunit rRNA gene (rDNA), which revealed that small rodents harboring B. microti exist in all three survey areas. Sequence analysis showed that all PCR-positive samples had rDNA sequences virtually identical to that of U.S.-type B. microti. However, when beta-tubulin gene sequences were compared, evident geographic variations were seen. By use of primers specific for each of the beta-tubulin genes of Kobe-, Hobetsu-, and U.S.-type parasites, a type-specific PCR was developed. Parasite with Hobetsu- or Kobe-type sequence was not detected from any of the three survey areas. These findings suggest that U.S.-type B. microti is widely distributed among small wild mammals in temperate zones of not only North America, but also Eurasia, whereas that Hobetsu- and Kobe-type parasites may be uniquely distributed in Japan. 相似文献
40.