全文获取类型
收费全文 | 628篇 |
免费 | 15篇 |
国内免费 | 1篇 |
专业分类
林业 | 41篇 |
农学 | 15篇 |
94篇 | |
综合类 | 35篇 |
农作物 | 14篇 |
水产渔业 | 115篇 |
畜牧兽医 | 299篇 |
植物保护 | 31篇 |
出版年
2023年 | 3篇 |
2022年 | 4篇 |
2021年 | 19篇 |
2020年 | 8篇 |
2019年 | 7篇 |
2018年 | 13篇 |
2017年 | 9篇 |
2016年 | 11篇 |
2015年 | 15篇 |
2014年 | 27篇 |
2013年 | 60篇 |
2012年 | 40篇 |
2011年 | 46篇 |
2010年 | 25篇 |
2009年 | 15篇 |
2008年 | 31篇 |
2007年 | 49篇 |
2006年 | 40篇 |
2005年 | 38篇 |
2004年 | 29篇 |
2003年 | 32篇 |
2002年 | 20篇 |
2001年 | 21篇 |
2000年 | 12篇 |
1999年 | 8篇 |
1998年 | 5篇 |
1997年 | 5篇 |
1996年 | 4篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1986年 | 6篇 |
1985年 | 3篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1974年 | 1篇 |
1968年 | 3篇 |
1967年 | 5篇 |
1966年 | 1篇 |
1965年 | 1篇 |
1960年 | 1篇 |
1956年 | 1篇 |
排序方式: 共有644条查询结果,搜索用时 468 毫秒
81.
Comparison and phylogenetic analysis of the heat shock protein 70 gene of Babesia parasites from dogs 总被引:1,自引:0,他引:1
Yamasaki M Inokuma H Sugimoto C Shaw SE Aktas M Yabsley MJ Yamato O Maede Y 《Veterinary parasitology》2007,145(3-4):217-227
The heat shock protein 70 (hsp70) genes of Babesia gibsoni, B. canis canis, B. canis vogeli, and B. canis rossi isolated from infected dogs were cloned by polymerase chain reaction (PCR) and sequenced. In the nucleotide sequence and the predicted amino acid sequence of the gene, the parasites were very similar to each other. The nucleotide sequences of the hsp70 gene had more variety than those of 18S nuclear subunit ribosomal DNA (18S rDNA). A phylogenetic analysis of these sequences and comparisons with sequences from other Babesia and Theileria species revealed that all canine babesial isolates analyzed in the present study were closely related to each other and formed one cluster. Additionally, a phylogenetic analysis of Babesia and Theileria species showed that these parasites could be divided into three groups: group A including canine babesial isolates, B. divergens, B. odocoilei, B. bovis, B. caballi, and B. ovis; group B including Theileria annulata, T. orientalis, and T. cervi; and group C including B. microti and B. rodhaini. These results suggested that a phylogenetic analysis of the hsp70 gene sequence might be helpful in classifying Babesia and Theileria species, and that canine babesial isolates might be closely related to each other, indicating their evolution from the same ancestry. 相似文献
82.
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
83.
Toru Kobayashi Ryo Ishibashi Shinji Yamamoto Satoshi Otani Koichi Ueno Osamu Murata 《Aquaculture Research》2011,42(2):230-239
The timing of primordial germ‐cell (PGC) migration with regard to the gonadal anlagen, gonad formation and sex differentiation was examined histologically in the chub mackerel (Scomber japonicus) at 5–190 days post hatching (dph). At 5 dph, PGCs appeared on the peritoneal epithelium surface or in the mesentery, on the dorsal side of the abdominal cavity. By 10 dph, stromal cells around the PGCs proliferated. The gonadal primordium was formed by 15 dph. The gonadosomatic index was 0.01% at 30 dph and increased thereafter (0.32% in females and 0.04% in males at 160 dph). Ovarian differentiation occurred at 30–40 dph, indicated by ovarian cavity formation (elongation and fusion of the upper and lower ovarian edges). Meiosis was subsequently initiated. A few meiotic oocytes surrounded the cavity at 50 dph; most were in the perinucleolus stage at 60 dph and attained a diameter of 60–70 μm at 190 dph. Testicular differentiation occurred at 30 dph, indicated by the formation of the sperm duct primordium. Spermatogonia gradually proliferated, developing into spermatocytes at the chromatin–nucleolus stage (after 90 dph) and subsequently into spermatids and spermatozoa (160 dph). These data could aid the development of seeding and cell‐engineering technologies for scombrid fish. 相似文献
84.
Amal Biswas Biswajit K. Biswas Junichi Ito Osamu Takaoka Norishige Yagi Syunsuke Itoh Kenji Takii 《Fisheries Science》2011,77(4):615-621
This study was carried out to investigate whether expensive enzyme-treated fish meal (EFM) can be partially replaced by soybean
meal (SM) or enzyme-treated SM (ESM) without compromising the growth of captive-raised Pacific bluefin tuna (PBT) juveniles.
Five fish diets were tested: EFM (control) and EFM in which 10 or 20% of the EFM was replaced with either ESM or SM (ESM10, ESM20, SM10 and SM20, respectively). The respective diets were provided to 28-day-old PBT juveniles (mean body weight approx. 0.38 g) stocked
randomly in 15-m3 tanks (276 juveniles per tank; two tanks per treatment) for 12 days. The final mean body weight of PBT juveniles on diets
EFM, SM10, and SM20 was significantly higher than that of juveniles on diet ESM20. Although daily feeding rate was significantly higher in the ESM and SM groups, feed efficiency (FE) was significantly higher
in the EFM group; there was no significant difference between juveniles fed diets EFM and SM10. Protein and phosphorus retention efficiency were significantly lower in the ESM20, and ESM20 and EFM groups, respectively. Phosphorus discharge was significantly lower in the SM groups. The results demonstrate that
10% SM (11% EFM replacement) can be included in EFM without compromising the growth performance of PBT juveniles. 相似文献
85.
Hideaki Endo Eiji Takahashi Masataka Murata Hitoshi Ohnuki Huifeng Ren Wakako Tsugawa Koji Sode 《Fisheries Science》2010,76(4):687-694
A wireless biosensor system was developed for the continuous measurement of blood glucose levels in flatfish. The biosensor
was implanted in the interstitial fluid under the scleral surface of the eyeball (EISF) to investigate the relationship between
EISF and blood glucose levels. EISF glucose levels were found to be correlated with those in the blood and to be approximately
the same as blood glucose levels in the range of 7–25 mg dl−1. A needle-type biosensor was prepared for the continuous EISF glucose monitoring in flatfish. A working electrode was constructed
using platinum iridium wire, and glucose oxidase was immobilized to the electrode. The biosensor was inserted into the EISF
of flatfish for sensor implantation. A 650-mV potential (vs. Ag/AgCl) was applied by a wireless potentiostat to the working
electrode for the amperometric glucose measurement. We investigated whether glucose in the EISF can be determined in vivo.
The estimated glucose levels using a one-point calibration method were correlated with actual blood glucose levels. In conclusion,
using a wireless biosensor system, we were able to monitor blood glucose levels in flatfish under free-swimming conditions
for 16 h. 相似文献
86.
Kenji Nohara Hiroyuki Takeuchi Tatsuo Tsuzaki Nobuaki Suzuki Osamu Tominaga Tadahisa Seikai 《Fisheries Science》2010,76(1):75-81
Sequence analysis based on the anterior part of the mitochondrial DNA control region was carried out to reveal the genetic diversity, stock structure, and historical demography of the red tilefish. Nucleotide sequences of 388 bp in length were determined for 280 individuals taken from eight localities. The molecular diversity, haplotype diversity, and nucleotide diversity were relatively high (average h = 0.929 ± 0.011; average π = 0.008 ± 0.005). The mismatch distribution was not significantly different from the expected distribution for a rapidly expanding population (P = 0.453). The minimum spanning network connecting with full-sequence haplotypes contained star-like topologies derived from multiple ancient lineages, supporting the mismatch distribution analysis. No significant genetic differentiation was observed among eight localities (maximum pairwise F ST = 0.023, reduced-sequence data set). Our results suggest a large panmictic population of the red tilefish along the coast of Honshu to the East China Sea. 相似文献
87.
88.
Osamu SAKAI Shoji OGINO Toshihiro TSUKUI Masaya IGASE Takuya MIZUNO 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(10):1495
Chimeric antigen receptor (CAR) CAR-T cell therapy targeting CD20 can be a novel adoptive cell therapy for canine patients with B-cell malignancy. After injection of the CAR-T cells in vivo, monitoring circulating CAR-T cells is essential to prove in vivo persistence of CAR-T cells. In this study, we developed a novel monoclonal antibody against canine CD20 CAR, whose single-chain variable fragment was derived from the our previously reported anti-canine CD20 therapeutic antibody. Furthermore, we proved that this monoclonal antibody can detect therapeutic anti-canine CD20 chimeric antibody in the serum from healthy beagle dogs injected with the therapeutic antibody for safety study. This monoclonal antibody is a useful tool for monitoring both canine CD20-CAR-T cells and anti-canine CD20 therapeutic antibody for canine lymphoma. 相似文献
89.
Tran Van Do Phung Dinh Trung Mamoru Yamamoto Osamu Kozan Nguyen Toan Thang Dang Van Thuyet 《Journal of Sustainable Forestry》2018,37(1):1-14
Forest ecosystems can modify the atmospheric CO2 through biomass accumulation mostly in tree stems with diameter at breast height (DBH) ≥ 10 cm. Aboveground biomass increment (ΔAGB), and changes in stand AGB, no. stems and basal area (BA) were calculated from mortality, recruitment, and growth data of tree stems in tropical evergreen broadleaved forest, Central Highland Vietnam. Data were derived from ten 1-ha permanent plots established in 2004, where all stems with DBH ≥ 10 cm were tagged, identified to species, and measured for DBH in 2004 and 2012. In an 8-year duration, the increment was 53 ± 10 stems ha–1, 7.8 ± 0.3 m2 ha–1 for BA and 86.0 ± 4.6 Mg ha–1 for AGB. The stem mortality rate was 0.9% year–1 and the stem recruitment rate was 2.2% year–1. Annual ΔAGB was 10.8 Mg ha–1 year–1, equaling to 5.4 Mg C ha–1 year–1. Of which, tree stems of 35–80 cm DBH classes accounted for 65%. The results indicated that the forest is in stage of carbon sequestration. Any disturbances causing death of 35–80 cm DBH tree stems will much reduce carbon sequestration capacity and it will take a long time for AGB to return to pre-disturbance stage. 相似文献
90.
Long‐term changes in recruitment of age‐0 Pacific bluefin tuna (Thunnus orientalis) and environmental conditions around Japan 下载免费PDF全文
Yukimasa Ishida Hiromu Fukuda Ko Fujioka Osamu Sakai Yuko Hiraoka Kazuhiro Oshima Shuya Nakatsuka Nobuaki Suzuki Hiroyuki Shimada 《Fisheries Oceanography》2018,27(1):41-48
Recruitment of age‐0 Pacific bluefin tuna (Thunnus orientalis) from 1952 to 2014 was examined by a sequential regime shift detection method. The regime shifts in recruitment were detected in 1957, 1972, 1980, 1994 and 2009. The durations of regime shift ranged from 8–15 years and averaged 13.0 years. In both the total (1952–2014) and data rich (1980–2014) periods, negative relationships were found between recruitment and the Pacific Decadal Oscillation in autumn, and positive relationships were found between recruitment and sea surface temperature (SST) anomalies in the northern part of the East China Sea, in the southwestern part of the Sea of Japan, and in the waters off Shikoku and Tokai in summer and autumn. The 1994 and 2009 regime shifts in recruitment occurred in the same years as shifts in SST anomalies in the northern part of the East China Sea in summer. These results suggest that the ocean conditions in the northern part of the East China Sea are closely related to recruitment of Pacific bluefin tuna, and that the warmer conditions result in higher recruitment of the species. 相似文献