全文获取类型
收费全文 | 441篇 |
免费 | 28篇 |
国内免费 | 2篇 |
专业分类
林业 | 62篇 |
农学 | 32篇 |
基础科学 | 3篇 |
49篇 | |
综合类 | 17篇 |
农作物 | 20篇 |
水产渔业 | 83篇 |
畜牧兽医 | 183篇 |
园艺 | 6篇 |
植物保护 | 16篇 |
出版年
2022年 | 3篇 |
2021年 | 21篇 |
2020年 | 11篇 |
2019年 | 15篇 |
2018年 | 13篇 |
2017年 | 12篇 |
2016年 | 15篇 |
2015年 | 9篇 |
2014年 | 21篇 |
2013年 | 26篇 |
2012年 | 23篇 |
2011年 | 17篇 |
2010年 | 8篇 |
2009年 | 18篇 |
2008年 | 29篇 |
2007年 | 29篇 |
2006年 | 29篇 |
2005年 | 35篇 |
2004年 | 36篇 |
2003年 | 23篇 |
2002年 | 20篇 |
2001年 | 18篇 |
2000年 | 11篇 |
1999年 | 4篇 |
1998年 | 4篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1981年 | 1篇 |
1976年 | 1篇 |
1966年 | 1篇 |
1965年 | 2篇 |
1964年 | 1篇 |
排序方式: 共有471条查询结果,搜索用时 558 毫秒
61.
This study aimed to characterize the relationship between the growth of rumen papillae in calves and the mRNA expression of insulin‐like growth factor‐binding proteins (IGFBPs) in the rumen papillae. The length of rumen papillae, the mRNA expression of IGFBPs in rumen papillae by quantitative real‐time PCR, and the presence of insulin‐like growth factors I and II (IGF‐I and II) by immunohistochemistry (IHC) were analyzed in nine Holstein calves divided into three groups: suckling (2 weeks, n = 3), milk‐continued (8 weeks, n = 3), and weaned (8 weeks, n = 3). The length of rumen papillae was greater (p < 0.01) in weaned calves than in suckling and milk‐continued calves, whereas the expressions of IGFBP2, IGFBP3, and IGFBP6 genes were lower (p < 0.05) in the rumen papillae of weaned calves than in milk‐continued calves. Thus, rumen papillae length and IGFBP2, 3, and 6 expressions were negatively correlated. The IHC analysis showed that IGF‐I and IGF‐II were present in the rumen epithelium of calves. These results suggested that the growth of rumen papillae after weaning is associated with the induction of IGFs by the low levels of IGFBP2, IGFBP3, and IGFBP6. 相似文献
62.
Plant height, a vigor trait, in 1-year-old seedlings made from Japanese pear (Pyrus pyrifolia) cultivars/selections was measured using 994 individuals from 29 families. The family mean of plant height was negatively correlated (r = −0.72**) to the inbreeding coefficients (F). The regression of the family mean (Fm) on the F value (Fm = 130 − 104F) showed that inbreeding depressions were 8%, 20%, and 40% for F = 0.1, 0.25, and 0.5, respectively. According to the regression, the family mean at F = 0 was estimated at 130 cm. These results showed that the vigor was greatly influenced by inbreeding in Japanese pear. Within-family variances, the genetic segregation of offspring in a family, differed according to family. The proportions of offspring with plant height above 130 cm (estimated Fm for F = 0) were extremely low, i.e., 0–17% for 0.5 ≤ F < 0.60 and 0–8% for F = 0.75. 相似文献
63.
Cortical microtubules (MTs) in differentiating compression wood tracheids of Taxus cuspidata stems were visualized by confocal laser microscopy. They were oriented obliquely at an angle of about 45° to the tracheid axis during formation of the secondary wall. Artificial inclination altered the pattern of alignment of MTs. Banding MTs were helically oriented late during the formation of the secondary walls. These results indicate that MTs might control the orientation and localized deposition of cellulose microfibrils in the secondary walls of compression wood tracheids.Part of this report was presented at the 46th annual meeting of the Japan Wood Research Society, Kumamoto, April 1996 相似文献
64.
Satoshi Hashimoto Kenichi Ueno Kenichi Takahashi Toshiyuki Suzuki Yutaka Itabashi 《Fisheries Science》2010,76(3):529-536
Photosensitivity was observed in the mice used in bioassays of diarrhetic shellfish poisoning. The mice were intraperitoneally
injected with the extracts from the midgut glands of cultured scallops Patinopecten yessoensis gathered in early spring in Funka Bay, Hokkaido, Japan. The injections induced atypical symptoms in the mice within 24 h.
The symptoms included piloerection, substantial eye discharge, swelling of the ears and head, and ear scratching. They were
similar to those reported in studies of photosensitivity caused by pyropheophorbide in the midgut glands of abalones, which
are herbivorous gastropods. The problematic scallops also accumulated a large amount of pyropheophorbide-a. The amount determined with high-performance liquid chromatography was 300–530 μg per 1 g of the homogenate of the midgut
glands. The dose of pyropheophorbide sufficient to cause photosensitivity in a mouse is estimated to be 0.99–2.3 mg per mouse
with 20-g body weight. Moreover, comparative tests in mice showed that the onset of the symptoms required light and a substantial
amount of pyropheophorbide. Therefore, we determined that the observed symptoms were photosensitivity caused by pyropheophorbide.
Scallops, which are suspension-feeding bivalves, can accumulate a large amount of pyropheophorbide in the midgut glands depending
on the habitat environment. 相似文献
65.
Asep Ridwanudin Yutaka Haga Takayuki Katagiri Shuichi Satoh 《Aquaculture Research》2019,50(8):2218-2230
A feeding trial was conducted to evaluate the effect of nucleotides supplementation to low‐fish meal feed on growth and fatty acid composition of rainbow trout. Six isonitrogenous (42% crude protein) and isolipidic (18% crude lipid) diets were formulated containing fish meal and plant ingredients as main protein sources. The control diet was a basal diet without supplementation of nucleotides, and five experimental diets were prepared by supplementing one of the five different nucleotides in the form of 5′‐monophosphate (0.15%), that is inosine (IMP), adenosine (AMP), guanosine (GMP), uridine (UMP) and cytidine (CMP) onto basal diet. Two hundred forty juvenile rainbow trout with an initial average body weight 9.8 g were randomly distributed into twelve aquaria. After 15 weeks of feeding period, growth performance and feed utilization of rainbow trout were not significantly different among dietary treatments. Dietary GMP, UMP and CMP tended to accumulate crude lipid in the muscle and whole fish body. Moreover, dietary GMP, UMP and CMP significantly increased hepatic 18:3n‐3 and long‐chain homologue 18:4n‐3 and 20:4n‐3 contents. Hepatic 18:2n‐6 content showed also increase in fish fed GMP, UMP and CMP diets, but decreased in long‐chain homologue 20:3n‐6 and 20:4n‐6 contents. Decrease in 20:4n‐6, 20:5n‐3 and 22:6n‐3 contents was also found in the muscle of fish fed IMP, GMP and CMP diets. The present study clearly showed that there was no positive effect of dietary nucleotides on growth of fish, but dietary nucleotides particularly GMP, UMP and CMP altered polyunsaturated fatty acid composition of rainbow trout. 相似文献
66.
Thermal-softening properties and cooling set of water-saturated bamboo were investigated using stressrelaxation measurements
in heating and cooling processes, followed by residual deflection measurement. In the heating process, an obvious decrease
in relative relaxation modulus due to thermal-softening of lignin was found at around 60°C. On the other hand, no clear change
in the relative relaxation modulus was recognized in the cooling process. After the cooling process, about 65% and 75% of
residual set was measured when the specimen was loaded on the epidermis and endodermis side, respectively. Also, residual
set depended on the maximum temperature reached in the heating process and the unloaded temperature in the cooling process.
From these results, it was deduced that the glass transition of lignin from the rubbery to glassy state is important to fix
the deformation. Comparing thermal-softening behavior between bamboo and wood, the relative relaxation modulus of wood decreased
steeply at higher temperatures than for bamboo. On the other hand, while about 75% of residual set was also found for wood,
almost the same as for bamboo, the recovery of deformation with time was larger for wood than for bamboo.
Part of this article was presented at the 53rd Annual Meeting of the Japan Zairyou Society, Okayama, May 2004 相似文献
67.
Suzuki Toshiyuki Kamiyama Takashi Okumura Yutaka Ishihara Kenji Matsushima Ryoji Kaneniwa Masaki 《Fisheries Science》2009,75(4):1039-1048
Fatty-acid esters of dinophysistoxin-1 (DTX1) in scallops Patinopecten yessoensis, mussels Mytilus coruscus, and toxic dinoflagellate Dinophysis species, collected from Japanese seawater, were analyzed by liquid-chromatography mass spectrometry (LC–MS). Precursor ion
monitoring, multiple reaction monitoring for 18 fatty-acid esters of DTX1, and full-scan MS/MS spectra obtained with a hybrid
triple–quadrupole linear-ion-trap mass spectrometer showed that 14:0, 16:0, and 16:1 esters were the most abundant 7-O-acyl-DTX1 analogues in bivalves. Fatty-acids esters formed by conjugations at hydroxyl positions other than the 7-position
of DTX1 were not detected in the bivalves. DTX1 and okadaic acid-16:0 fatty-acid esters have been reported as the most abundant
ester in bivalves in several previous studies; however, we found that 7-O-16:1-DTX1 was the most abundant ester in some mussels in which 16:1 was more dominant than 16:0 in the free fatty-acid profile.
Comparison between 7-O-acyl-DTX1 and free fatty-acid profiles in the same bivalve samples suggests that polyunsaturated fatty acids are selectively
excluded in enzymatic acylation of DTX1. No 7-O-acyl-DTX1 was detected in any single-cell isolates of D. fortii, D. acuminata, D. mitra, D. norvegica, D. tripos, D. infundibulus, and D. rotundata. 相似文献
68.
Sirusa Kritsanapuntu Nilnaj Chaitanawisuti Yutaka Natsukari 《Aquaculture International》2009,17(1):77-84
Growth and water quality for growing-out of juvenile spotted Babylon, Babylonia areolata, were determined at three water-exchange regimes of 7-, 15- and 30-day intervals in large-scale operation of earthen ponds
over a 5-month period. Results showed that growth was significantly different among the water-exchange treatments (P < 0.05). The higher body weight gains and shell length increments were observed in snails held at water exchange of 7- and
15-day intervals when compared with those held at water exchange of 30-day intervals. At the end of the experiment, average
body weight gains were 4.22, 3.73 and 2.77 g for snails held in water-exchange treatments of 7-, 15- and 30-day intervals,
respectively, and 16.63, 15.04 and 13.78 mm for those of shell length increments, respectively, The average final survivals
were 83.60, 80.90 and 74.20% for snails held in water-exchange treatments of 7-, 15- and 30-day intervals, respectively. Seawater
temperature, salinity, pH, dissolved oxygen, nitrite–nitrogen and ammonia–nitrogen had gradually changed throughout the culture
period for all water-exchange treatments. With one exception, the total alkalinity showed the greatest changes during the
culture period for all water-exchange treatments ranging from 58.67–97.50 mg/l. 相似文献
69.
Megumi Matsumoto Mahumoud Tanekey Amer Kyosuke Araki Atsushi Nishitani Kazuma Hayashi Yutaka Takeuchi Kazuhiro Shiozaki Atsushi Yamamoto 《Fisheries Science》2018,84(5):857-867
Interleukin-10 (IL-10) is an anti-inflammatory cytokine and negatively regulates cell-mediated immunity (CMI) induction by inhibiting cytokine production in type 1 T helper cells. IL-10 genes have been isolated from several fish, and inflammatory cytokine inhibition by IL-10 has been well examined. However, a CMI regulator of IL-10 in fish has not yet been identified. In this study, we cloned the IL-10 gene in amberjack Seriola dumerili and analyzed its function using its recombinant protein (rIL-10). In an in vitro culture experiment, gene expression of inflammatory cytokines was suppressed in leukocytes incubated with rIL-10 compared with cells that only received Nocardia seriolae stimulation. This result suggests amberjack IL-10 has conserved function as an inflammatory cytokine inhibitor. Bactericidal activity of amberjack cells against intracellular pathogen stimulation was decreased in a rIL-10 dose-dependent manner. Furthermore, a significant reduction in the T-bet/GATA-3 ratio was observed in N. seriolae living cell (LC)?+?rIL-10-injected fish. Taken together, these results suggest amberjack rIL-10 suppresses CMI induction both in vitro and in vivo. In addition, the number of IgM+ cells among spleen leukocytes in N. seriolae?+?rIL-10-injected fish was higher than in only N. seriolae LC, suggesting that Th2-dominant immunity was induced by adding rIL-10. 相似文献
70.
Masanori KOYAGO Ken NAKADA Nobuo TSUNODA Masaharu MORIYOSHI Yutaka SAWAMUKAI 《Journal of Equine Science》2009,20(1):1-5
To clarify the physiological changes of sperm morphology in active Thoroughbred stallions
during the breeding season, we examined the dismount semen collected from the penile
urethra immediately after service. The spermatozoa were analyzed for relationships between
the morphology and the stallion’s age or the number of services. Seasonal variation was
apparent in the rate of the sperm tail abnormalities, spermatozoa with cytoplasmic
droplets, appearance of medusa cells, and sperm head length. Area and width of the sperm
head correlated negatively with age (P<0.05). The rate of appearance of medusa cells
and the length of the sperm head were positively related to the number of services
(P<0.05), and the aspect ratio was negatively related (P<0.01). 相似文献