全文获取类型
收费全文 | 420篇 |
免费 | 19篇 |
国内免费 | 2篇 |
专业分类
林业 | 40篇 |
农学 | 36篇 |
基础科学 | 1篇 |
52篇 | |
综合类 | 38篇 |
农作物 | 12篇 |
水产渔业 | 57篇 |
畜牧兽医 | 181篇 |
园艺 | 8篇 |
植物保护 | 16篇 |
出版年
2023年 | 1篇 |
2022年 | 6篇 |
2021年 | 9篇 |
2020年 | 4篇 |
2019年 | 13篇 |
2018年 | 10篇 |
2017年 | 7篇 |
2016年 | 12篇 |
2015年 | 9篇 |
2014年 | 12篇 |
2013年 | 30篇 |
2012年 | 18篇 |
2011年 | 22篇 |
2010年 | 15篇 |
2009年 | 15篇 |
2008年 | 23篇 |
2007年 | 20篇 |
2006年 | 24篇 |
2005年 | 19篇 |
2004年 | 16篇 |
2003年 | 18篇 |
2002年 | 17篇 |
2001年 | 11篇 |
2000年 | 11篇 |
1999年 | 20篇 |
1998年 | 6篇 |
1997年 | 4篇 |
1996年 | 7篇 |
1995年 | 2篇 |
1993年 | 1篇 |
1992年 | 8篇 |
1991年 | 3篇 |
1990年 | 6篇 |
1989年 | 7篇 |
1988年 | 4篇 |
1987年 | 6篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1979年 | 5篇 |
1978年 | 2篇 |
1976年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1966年 | 1篇 |
1933年 | 1篇 |
排序方式: 共有441条查询结果,搜索用时 328 毫秒
51.
Full-length canine HSP70 cDNA was sequenced and the expression of HSP70 mRNA was investigated. The full-length cDNA sequence of the HSP70 gene (2322 bp) contained a single long open reading frame (1920 bp) coding a protein of 640 amino acids. The amino acid sequence of the canine HSP70 gene shared about 90-95% sequence similarity with bovine, human and mouse HSP70 proteins. Southern blot analysis with HSP70 probe gave three distinct bands of 9.4 kb, 5 kb and 4.4 kb in BamHI digests and two distinct bands of 19 kb and 4 kb in EcoRI digests. Canine HSP70 mRNA was detectable in canine peripheral blood mononuclear cells and stomach but not in liver, kidney, spleen, small intestine, large intestine and skin of dogs. 相似文献
52.
Abe S Mukai T Hirata N Barnouin-Jha OS Cheng AF Demura H Gaskell RW Hashimoto T Hiraoka K Honda T Kubota T Matsuoka M Mizuno T Nakamura R Scheeres DJ Yoshikawa M 《Science (New York, N.Y.)》2006,312(5778):1344-1347
The ranging instrument aboard the Hayabusa spacecraft measured the surface topography of asteroid 25143 Itokawa and its mass. A typical rough area is similar in roughness to debris located on the interior wall of a large crater on asteroid 433 Eros, which suggests a surface structure on Itokawa similar to crater ejecta on Eros. The mass of Itokawa was estimated as (3.58 +/- 0.18) x 10(10) kilograms, implying a bulk density of (1.95 +/- 0.14) grams per cubic centimeter for a volume of (1.84 +/- 0.09) x 10(7) cubic meters and a bulk porosity of approximately 40%, which is similar to that of angular sands, when assuming an LL (low iron chondritic) meteorite composition. Combined with surface observations, these data indicate that Itokawa is the first subkilometer-sized small asteroid showing a rubble-pile body rather than a solid monolithic asteroid. 相似文献
53.
Ohtsuka H Watanabe C Kohiruimaki M Ando T Watanabe D Masui M Hayashi T Abe R Koiwa M Sato S Kawamura S 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(11):1161-1166
To clarify the relationship between cellular immune status and nutritive condition in periparturient dairy cows, feeding content, blood profiles, and immune condition were observed in cows from two dairy herds with different types of feed content. Immunological analyses such as leukocyte population and peripheral blood mononuclear cell (PBMC) mRNA of IFN-gamma, TNF-alpha, IL-4, and IL-10, quantified by real-time RT-PCR were performed. With regard to feed content during dry periods, there were six cows in the herd with insufficient non-structural carbohydrate (NFC) intake (group I) and six cows in the herd with sufficient NFC intake (group II). Significantly lower levels of blood glucose were observed in group I between weeks -12 and 16 compared with group II. Serum cholesterol level was significantly lower in group I between weeks 2 and 10 than in group II. The numbers of CD3+ and CD4+ T cells in group I were significantly lower than those in group II in weeks 6 and 14. The numbers of CD21+ B cells were significantly lower in group I than in group II in weeks -16, -12, 2, and 10. On the other hand, the CD4+/CD8+ ratio in group II was significantly higher than group I between weeks 2 and 14. The IFNgamma/IL-4 mRNA rate in group I was significantly lower than group II in week 6. We concluded that cellular immune depression occurrs after calving in dairy cows with low nutritional status in the periparturient period. 相似文献
54.
55.
Diversity in starch, protein and mineral composition of sorghum landrace accessions from Ethiopia 总被引:1,自引:1,他引:0
Abe Shegro Nemera Geleta Shargie Angeline van Biljon Maryke Tine Labuschagne 《Journal of Crop Science and Biotechnology》2012,15(4):275-280
Sorghum (Sorghum bicolor (L.) Moench) is an important food crop in arid and semi-arid tropics where it is grown mainly due to its drought tolerance. In Ethiopia, sorghum is grown in different agro-ecological zones primarily for food. Landraces are widely cultivated in the region due to their adaptation to the growing conditions and other characteristics such as food quality, quantity, and quality of by-products. The objective of this research was to determine the genetic variation in protein, mineral composition, total starch and its components in sorghum landraces collected from the western regions of Ethiopia. Sorghum whole grains were analyzed for crude protein, total starch and its components, and mineral profile (calcium, magnesium, potassium, phosphorus, iron, manganese, zinc, and sodium). The analysis of variance showed significant differences among the sorghum landraces in nutritional composition. There was highly significant correlation between phosphorus and magnesium, and between zinc and phosphorus and protein which indicated that some interaction existed in absorption and translocation between minerals and protein content. The genetic variation found among the sorghum landrace accessions in chemical composition can be exploited in the breeding program. 相似文献
56.
57.
Abe Shegro Gerrano Willem S. Jansen van Rensburg Funso R. Kutu 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2019,69(4):295-303
Cultivar development of cowpea with increased grain yield depends on evaluation and selection of genetically unique and complementary breeding lines. The objective of this study was to evaluate cowpea collections using agronomic traits to select promising parents to develop breeding population. Twenty-two cowpea genotypes were field evaluated using a randomised complete block design with three replications in two locations in South Africa. Analysis of variance revealed significant genotypic (G) and locations (L) differences for all agronomic traits evaluated. Significant differences were also observed for most of the traits due to G X L, G X Year (Y), L X Y and G X L X Y interactions effects. The genotypes tested at two locations showed considerable genetic variation for the following agronomic traits that varied for number of leaves (NL) (20.08–179.78), leaf length (LL) (12.36–67.72 cm), leaf width (LW) (4.78–22.02 cm), number of branches (NB) (6.81–13.85), number of pods per plant (NPPP) (14.33–54.04), number of seeds per pod (NSPP) (11.7286.28), pod diameter (PD) (5.75–22.73 mm), plant height (PH) (6.57–233.71 cm), pod length (PL) (3.94–100.92 mm), hundred seed weight (HSWt) (8.11–49.52 g) and grain yield (GY) (0.10-1.48 t ha?1). Grain yield was significant and positively correlated with all of the traits except leaf length. The principal component analysis (PCA) identified four principal components (PCs) contributing to 73.62% of the total explained variation amongst the tested genotypes. The selected cowpea genotypes for most of agronomic characteristics are useful and candidate genetic resources for the development of breeding population in cowpea breeding and enhanced production and productivity for food and nutrition in the country. 相似文献
58.
59.
Preimplantation development of embryos in labrador retrievers 总被引:1,自引:0,他引:1
Abe Y Suwa Y Yanagimoto-Ueta Y Suzuki H 《The Journal of reproduction and development》2008,54(2):135-137
Preimplantation development of canine embryos is not well understood. To understand the timing of preattachment embryogenesis relative to the luteinizing hormone (LH) surge, early embryonic development was examined in Labrador Retrievers after artificial insemination. The embryos migrated from the oviduct to the uterus beginning on day 11 after the LH surge. This transport must be completed within 24 h. By day 13 after the LH surge, all of the embryos had moved and were localized in the uterus. The embryos developed to the morula stage within 11-13 days and to the blastocyst stage within 14 days after the LH surge, respectively. These findings add to the current understanding concerning the physiology of preimplantation development and should help further develop assisted reproductive techniques in canine species, such as cryopreservation and subsequent embryo transfer. 相似文献
60.
Takeshi Hayashi Kazuki Kansaku Takahito Abe Shuji Ueda Hisataka Iwata 《Animal Science Journal》2019,90(7):849-856
This study evaluated the effects of cryopreservation by slow freezing on the mitochondrial function, DNA integrity, and developmental ability of bovine embryos and examined whether resveratrol treatment of the frozen‐thawed blastocysts improved embryonic viability. In vitro produced bovine embryos were subjected to slow freezing. After thawing, the ATP content and mitochondrial DNA integrity (mtDNA), determined by real‐time PCR targeting short and long mitochondrial sequences, was found to be lower in frozen‐thawed embryos than in fresh embryos, and mtDNA copy number was significantly reduced during the 24‐hr incubation post warming. Furthermore, immunostaining against double‐strand DNA revealed DNA damage in frozen‐thawed embryos. When frozen‐thawed embryos were incubated in the medium containing 0.5 µM resveratrol, SIRT1 expression, and survival rate of the embryos significantly improved compared with the vehicle‐treated embryos. In addition, cell‐free mtDNA content in medium was higher in case of resveratrol‐treated embryos than of vehicle‐treated embryos. In conclusion, slow freezing affects mitochondrial integrity and function in the blastocysts. In the frozen‐thawed embryos, mitochondria were removed during post‐thawing incubation and resveratrol enhanced the process, resulting in improved survivability of the embryos. 相似文献