全文获取类型
收费全文 | 449篇 |
免费 | 6篇 |
国内免费 | 1篇 |
专业分类
林业 | 41篇 |
农学 | 8篇 |
基础科学 | 2篇 |
48篇 | |
综合类 | 12篇 |
农作物 | 20篇 |
水产渔业 | 83篇 |
畜牧兽医 | 180篇 |
园艺 | 5篇 |
植物保护 | 57篇 |
出版年
2022年 | 10篇 |
2021年 | 22篇 |
2020年 | 8篇 |
2019年 | 9篇 |
2018年 | 8篇 |
2017年 | 6篇 |
2016年 | 10篇 |
2015年 | 21篇 |
2014年 | 33篇 |
2013年 | 40篇 |
2012年 | 22篇 |
2011年 | 35篇 |
2010年 | 19篇 |
2009年 | 16篇 |
2008年 | 22篇 |
2007年 | 27篇 |
2006年 | 35篇 |
2005年 | 22篇 |
2004年 | 29篇 |
2003年 | 25篇 |
2002年 | 17篇 |
2001年 | 6篇 |
2000年 | 8篇 |
1999年 | 2篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1984年 | 1篇 |
排序方式: 共有456条查询结果,搜索用时 0 毫秒
101.
We surveyed the distribution of red sea bream eggs between 2006 and 2010 in the east Seto Inland Sea to determine the location of the spawning grounds and the characteristics of preferred spawning habitats. We identified early-development stage red sea bream eggs using a monoclonal antibody assay. The early-development stage eggs were present in waters around Awaji Island (AW area) and around Ieshima Island, Shodo Island, and Bisan Seto (collectively the ISB area). The mean red sea bream egg density in the AW area was not significantly different from that in the ISB area. Based on the locations where we observed early-development stage eggs and the density of eggs, the ISB and AW areas appeared to be the primary spawning grounds in the east Seto Inland Sea during the survey period. A quotient analysis suggested that spawning fish had clear preferences for physical conditions. The areas suitable for spawning appear to be those with sandy substrate at a depth of 30–70 m. The temperature range suitable for spawning was between 16.5 and 21.5 °C. 相似文献
102.
Yukio?AgatsumaEmail author Yasuhiro?Kuwahara Kazuya?Taniguchi 《Fisheries Science》2005,71(5):1107-1114
ABSTRACT: The life cycle of Dilophus okamurae and the associated benthic invertebrate fauna were studied monthly or bimonthly from June 1998 to September 1999 at a depth of 4–7 m in Onagawa Bay along the Pacific coast of north-eastern Honshu, Japan (38°28'N, 149°29'E). Dry biomass ranged from 230 g/m2 in June to 10 g/m2 in October. Sporophytes with tetrasporangia appeared during July to September 1998. Gametophytes with oogonia or antheridia were observed for the first time in May 1999 during observation. The absence of mature sporophytes in 1999 suggests that the life cycle is completed over two years. The sympatric gastropods Lirularia iridescens , Homalopoma sangrarense, Conotalopia minima and Cantharidus callichroa synchronized with seasonal changes in biomass of this algae. In contrast, Barleeia angustata and B. trifasciata fluctuated independently. The juvenile sea urchin Strongylocentrotus nudus appeared in the algal population starting in October at 0.7 mm mean test diameter at high density, and disappeared after March. 相似文献
103.
Validation of otolith daily increments for larval and juvenile Japanese halfbeak Hyporhamphus sajori
Mitsuhiro Nakaya Taizo Morioka Kyohei Fukunaga Sachio Sekiya Tadao Jinbo Hiroshi Nagashima Yasuhiro Ueno 《Fisheries Research》2008,93(1-2):186-189
Daily ring formation was verified by examining the growth of the marginal increment on sagittal otoliths of larval and juvenile Japanese halfbeak Hyporhamphus sajori. The relationship between age (x) and number of increments (y) is y = 1.0x + 2.0. The first daily increment was formed during the 2 days before hatching. The relationship between the number of rings deposited after the alizarin complexone (ALC) mark (x) and the number of increments (y) is given by: y = 1.0x − 0.2. The index of completion of the marginal increment was 99 ± 4.1% (mean ± S.D.) at 04:00, and from 24 ± 4.4% at 08:00 it increased with time of day and reached 98 ± 3.6% until the next day at 04:00. Growth of the incremental zone started a few hours after sunrise prior to which the discontinuous zone seemed to be formed. Light rhythms tend to be one of the most important factors for the formation of the marginal increment on otoliths. Based on the relationships between time of day and the marginal increment on otoliths, it would be possible to estimate the predation time for specimens retrieved from stomach contents, and also clearer analysis of the growth history immediately prior to the sampling time. 相似文献
104.
Methane uptake and nitrous oxide emission in Japanese forest soils and their relationship to soil and vegetation types 总被引:1,自引:1,他引:1
Tomoaki MORISHITA Tadashi SAKATA Masamichi TAKAHASHI Shigehiro ISHIZUKA Takeo MIZOGUCHI Yoshiyuki INAGAKI Kazuhiko TERAZAWA Satoshi SAWATA Masanori IGARASHI Hiroshi YASUDA Yasuhiro KOYAMA Yoshihito SUZUKI Nobuyuki TOYOTA Masamichi MURO Masaru KINJO Hirokazu YAMAMOTO Daitaro ASHIYA Yoichi KANAZAWA Tetsu HASHIMOTO Hidetaka UMATA 《Soil Science and Plant Nutrition》2007,53(5):678-691
105.
Masaharu Kubota Osamu Tamura Yasuhiro Nomura Noriko Orihara Norihito Yamauchi Kengo Yonemoto Kenichiro Chiba Nobutaka Someya 《Journal of General Plant Pathology》2017,83(2):117-120
Isolates of spinach downy mildew fungus, Peronospora farinosa f. sp. spinaciae, collected at seven sites in Japan from December 2013 to March 2016, were identified as belonging to races 8, 10, 12 and 13, and one was unauthorized. Races 10, 12, 13 and the unauthorized were first found in Japan. 相似文献
106.
Kazuhiro UMEYAMA Kasumi HONDA Hitomi MATSUNARI Kazuaki NAKANO Tatsuro HIDAKA Keito SEKIGUCHI Hironori MOCHIZUKI Yasuhiro TAKEUCHI Tsukasa FUJIWARA Masahito WATANABE Masaki NAGAYA Hiroshi NAGASHIMA 《The Journal of reproduction and development》2013,59(6):599-603
Somatic cell nuclear transfer (SCNT) is a useful technique for creating pig strains
that model human diseases. However, production of numerous cloned disease model pigs
by SCNT for large-scale experiments is impractical due to its complexity and
inefficiency. In the present study, we aimed to establish an efficient procedure for
proliferating the diabetes model pig carrying the mutant human hepatocyte nuclear
factor-1α gene. A founder diabetes transgenic cloned pig was generated by SCNT and
treated with insulin to allow for normal growth to maturity, at which point
epididymal sperm could be collected for cryopreservation. In vitro
fertilization and intrafallopian insemination using the cryopreserved epididymal
sperm resulted in diabetes model transgenic offspring. These results suggest that
artificial reproductive technology using cryopreserved epididymal sperm could be a
practical option for proliferation of genetically modified disease model pigs. 相似文献
107.
刘璨 Maxim Lobovikov Daniel Murdiyarso Hiroyasu Oka Yeo-Chang Youn Keith Barney Makoto Inoue Hariadi Kartodihardjo Pia Katila Tetsuya Saito Bintang Simangunsong Yasuhiro Yokota 吕金芝 林海燕 《绿色中国(A版)》2005,52(22):33-36
在过去的20年里,亚洲林业经历了引人注目的转型,包括从计划经济到市场经济的转变,从天然林供给木材到人工林供给木材的转变,木材替代品与非木质林产品的增加,地方分权与当地群众的参与,生态时代的发展与生态系统管理。在促进亚洲可持续森林资源管理中,市场工具、社区参与和环境服务都得到了应用。亚洲林业的转型表现出多样化,其森林、社会与环境之间的联系是丰富多彩的。 相似文献
108.
Hiroshi Matsunaga Rika Shiotari Junji Matsumura Kazuyuki Oda Yasuhiro Utsumi Koichi Yamamoto 《Journal of Wood Science》2006,52(2):95-100
This is the first report to ascertain potassium location in black heartwood of sugi (Cryptomeria japonica). The objective of this study was to understand the distribution of potassium in sugi black heartwood in connection with
anatomical morphology. Scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDXA) was used to investigate
the distribution of inorganic elements, especially potassium. In black heartwood, potassium was detected in all tissues (tracheids,
ray parenchyma, and axial parenchyma), but its concentrations were different in each xylem tissue. Potassium was particularly
accumulated in the droplets in axial parenchyma cells. In addition, calcium was also detected in all tissues. Phosphorus sometimes
existed in the granules in ray parenchyma cells. From optical microscopy, the axial parenchyma cells were observed to be arranged
in a tangential direction on transverse section and the droplets in these cells were distributed in areas of high ash and
green moisture content. For red heartwood, potassium detected by SEM-EDXA was far lower in all tissues than in the black heartwood,
while the trend for calcium was the converse. Potassium in axial parenchyma cells was more abundant in black heartwood than
in typical pale red heartwood. 相似文献
109.
Cell behavior in the cambium and developing xylem of 3-year-old Japanese cedar (Cryptomeria japonica D. Don.) trees, during and after an 11-day suspension of irrigation, was analyzed. Leaf xylem pressure potential and tangential strain of the stem surface were monitored throughout the experiment. Anatomical features and numbers of developing tracheids and cambial cells were observed in four trees, sampled on Days 0, 4, 8 and 11 after irrigation was suspended. Daytime xylem pressure potential decreased to -1.9 MPa on Day 7 and remained the same until irrigation was resumed on Day 11. The transverse dimensions of the tracheids, which began to form secondary walls, began to decrease on Day 4. The number of cells in the cambial zone and cell expansion zone decreased abruptly on Day 8. Tangentially aligned developing tracheids with collapsed cell walls were observed in samples harvested on Days 8 and 11. Secondary wall formation was recognized in these tracheids. After the resumption of irrigation, xylem pressure potential recovered rapidly to the same value as before the suspension of irrigation. Tangential strain increased within 30 min after the resumption of irrigation, and continued to increase until the onset of light the next day. Eighteen days after the resumption of irrigation, anatomical features of cells in the cambium and cell-expansion zone were similar to those observed before suspension of irrigation. 相似文献
110.
Ageyama N Hanazono Y Shibata H Ono F Nagashima T Ueda Y Yoshikawa Y Hasegawa M Ozawa K Terao K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(5):507-510
Genes and proteins of human origin are often administered to monkeys for research purposes, however, it can be difficult to obtain sufficient levels of the products in vivo due to immunological clearance. In this study, we showed that human erythropoietin (hEPO) induces generation of anti-hEPO antibody in cynomolgus macaques (n=2), although 92% of amino acid residues are common between the human and macaque EPO. The administered hEPO was thus eliminated from the animals. On the other hand, when an immunosuppressant, cyclosporin A (CyA), was administered (6 mg/kg) intramuscularly every other day in combination with hEPO (n=2), no anti-hEPO antibody was generated and high serum levels of hEPO were obtained during administration of hEPO, resulting in an increase in serum hemoglobin levels. No adverse effects associated with CyA were observed. Thus, CyA treatment is useful for prevention of immune responses associated with the administration of human proteins in monkeys. 相似文献