全文获取类型
收费全文 | 120篇 |
免费 | 14篇 |
专业分类
林业 | 4篇 |
农学 | 1篇 |
18篇 | |
综合类 | 13篇 |
农作物 | 4篇 |
水产渔业 | 46篇 |
畜牧兽医 | 40篇 |
园艺 | 3篇 |
植物保护 | 5篇 |
出版年
2021年 | 3篇 |
2019年 | 1篇 |
2018年 | 3篇 |
2017年 | 4篇 |
2016年 | 6篇 |
2015年 | 9篇 |
2014年 | 13篇 |
2013年 | 5篇 |
2012年 | 7篇 |
2011年 | 11篇 |
2010年 | 6篇 |
2009年 | 6篇 |
2008年 | 10篇 |
2007年 | 10篇 |
2006年 | 6篇 |
2005年 | 4篇 |
2004年 | 8篇 |
2003年 | 9篇 |
2002年 | 1篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1995年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1960年 | 1篇 |
排序方式: 共有134条查询结果,搜索用时 31 毫秒
111.
Ryuichi Matsukura Hiroki Yasuma Hiroto Murase Shiroh Yonezaki Tetsuichiro Funamoto Satoshi Honda Kazushi Miyashita 《Fisheries Science》2009,75(6):1377-1387
The mass density and sound-speed contrasts against surrounding seawater (g and h, respectively) of Neocalanus copepods (N. cristatus and N. plumchrus) were measured in 2006 and 2007 to compute the theoretical target strength (TS). The values of g ranged from 0.997 to 1.009 in N. cristatus and from 0.995 to 1.009 in N. plumchrus. There were no correlations between prosome length (PL) and g. The values of h ranged from 1.006 to 1.021 in N. cristatus and from 1.013 to 1.025 in N. plumchrus and varied with changes in temperature. TS was estimated with the theoretical sound scattering model using the values of
g and h based on the temperature, salinity, and depth of the location where the specimens were collected. Regressions of the tilt-averaged
TS versus PL were obtained at 38, 120, and 200 kHz. The averaged TS of N. cristatus and N. plumchrus at 120 kHz, which is widely used as a high frequency, ranged from −110.0 to −103.1 dB and from −121.4 to −109.7 dB, respectively.
There was a positive correlation between frequency and averaged TS: the higher the frequency, the higher the value of averaged
TS. The TS at 120 and 38 kHz varied from 14.8 to 16.4 dB in N. cristatus and from 17.9 to 18.7 dB in N. plumchrus, respectively; that at 200 and 120 kHz varied from 2.9 to 5.5 dB in N. cristatus and from 5.3 to 6.5 dB in N. plumchrus, respectively. 相似文献
112.
113.
Lonicera caerulea L. var. emphyllocalyx (Maxim.) Nakai is a berry crop cultivated in cold regions. So far, commercial cultivars have been mainly introduced from selection of wild plants. Therefore, fruit traits and other agricultural characteristics have been limited. In this study, interspecific crosses between L. caerulea var. emphyllocalyx and Lonicera gracilipes var. glabra Miquel were examined to increase genetic variability of L. caerulea var. emphyllocalyx. Seedlings were obtained from reciprocal crosses between L. caerulea var. emphyllocalyx and L. gracilipes var. glabra. The hybrid nature of seedlings was confirmed with random amplified polymorphic DNA analysis. Viable green plants were obtained efficiently from L. gracilipes var. glabra × L. caerulea var. emphyllocalyx. In contrast, all plants produced from L. caerulea var. emphyllocalyx × L. gracilipes var. glabra were albino. These albino plants were very weak and only survived in culture condition. The chlorophyll deficiency was unilaterally observed, suggesting the occurrence of nuclear–cytoplasmic incompatibility. Viable F1 hybrids obtained from L. gracilipes var. glabra × L. caerulea var. emphyllocalyx are amphidiploid (2n = 4x = 36) as showing same to both parents. The hybrid plants are expected to increase the variability of fruit traits, and may have heat tolerance from L. gracilipes var. glabra. 相似文献
114.
Yasuzumi?FujimoriEmail author Kenji?Chiba Tatsuki?Oshima Kazushi?Miyashita Satoshi?Honda 《Fisheries Science》2005,71(4):738-747
ABSTRACT: Variations in trawl dimension, bottom contact, and catch with differing warp lengths during walleye pollock surveys conducted by the Fisheries Research Agency were examined. The ratio of warp length to fishing depth (scope ratio) was set at 2.5, 3.0 and 3.5 at depths of 110 m. At a 2.5 scope ratio, the net mouth shape and footgear contact fluctuated, as the trawl door did not contact the bottom. Footgear contact was complete when the scope ratio was 3.0 or more. Walleye pollock, sculpins and flatfishes were the main catch in all tows, and the catch increased with scope ratio. There was no difference in the length frequency of walleye pollock ( n = 300) captured at 2.5 and 3.0 scope ratio. However, the length frequency at 3.5 was significantly different from that of other scope ratios. These results suggest that at a scope ratio of 3.0 or more, the trawl door will not leave the bottom at any depths. To compliment echo surveys for walleye pollock, a 3.0 scope ratio would be optimal, since the catch data for a 3.5 scope ratio was dissimilar from that of scope ratios. 相似文献
115.
116.
117.
Yuji IWATA Yoshihiro NAKASHIMA Sayaka TSUCHIDA Pierre Philippe Mbehang NGUEMA Chieko ANDO Kazunari USHIDA Juichi YAMAGIWA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(10):1247-1252
African rainforest harbors herbivores at high density. However, because plants and soils
typically lack in some essential minerals, rainforest is not always a suitable habitat for
herbivores. How they fulfill the mineral requirements is therefore an important question
to animal ecology and conservation. Although large marshes, called ‘bais’, are often
mentioned as efficient mineral-resource, little information on other sodium resources has
still been available. Our laboratory works and field surveys found that a peculiar item,
decaying wood stumps of Anthostema aubryanum, played as a major sodium
resource for herbivores in Moukalaba-Doudou National Park, Gabon. When A.
aubryanum is alive, the sodium content of its bark is low and its latex is
toxic. Sodium is accumulated in decaying stumps (mean=1,343 mg/kg dry matter). Eight
herbivores visited stumps to ingest the dead wood. Fecal sample analysis revealed that
western lowland gorillas, a species most-frequently using the stumps, consumed large
amount of the dead wood as regular food. Our findings suggest that decaying A.
aubryanum is critical sodium-resources and is a key species for herbivores in
our study area. Importance of the A. aubryanum may be particularly large
there, because it is a limited sodium-rich material that is available year round. Our
study site is known as the site where the densities of several herbivores are among the
highest at Central Africa. The relatively high herbivores density in our study site may
partly depend on decaying A. aubryanum as sodium resources. 相似文献
118.
Airanthi MK Sasaki N Iwasaki S Baba N Abe M Hosokawa M Miyashita K 《Journal of agricultural and food chemistry》2011,59(8):4156-4163
Brown seaweed lipids from Undaria pinnatifida (Wakame), Sargassum horneri (Akamoku), and Cystoseira hakodatensis (Uganomoku) contained several bioactive compounds, namely, fucoxanthin, polyphenols, and omega-3 polyunsaturated fatty acids (PUFA). Fucoxanthin and polyphenol contents of Akamoku and Uganomoku lipids were higher than those of Wakame lipids, while Wakame lipids showed higher total omega-3 PUFA content than Akamoku and Uganomoku lipids. The levels of docosahexaenoic acid (DHA) and arachidonic acid (AA) in liver lipids of KK-A(y) mouse significantly increased by Akamoku and Uganomoku lipid feeding as compared with the control, but not by Wakame lipid feeding. Fucoxanthin has been reported to accelerate the bioconversion of omega-3 PUFA and omega-6 PUFA to DHA and AA, respectively. The higher hepatic DHA and AA level of mice fed Akamoku and Uganomoku lipids would be attributed to the higher content of fucoxanthin of Akamoku and Uganomoku lipids. The lipid hydroperoxide levels of the liver of mice fed brown seaweed lipids were significantly lower than those of control mice, even though total PUFA content was higher in the liver of mice fed brown seaweed lipids. This would be, at least in part, due to the antioxidant activity of fucoxanthin metabolites in the liver. 相似文献
119.
Miyashita N Kubo Y Yonai M Kaneyama K Saito N Sawai K Minamihashi A Suzuki T Kojima T Nagai T 《The Journal of reproduction and development》2011,57(5):636-642
Dolly, the first mammal cloned from a somatic cell, had shorter telomeres than age-matched controls and died at an early age because of disease. To investigate longevity and lifetime performance in cloned animals, we produced cloned cows with short telomeres using oviductal epithelial cells as donor cells. At 5 years of age, despite the presence of short telomeres, all cloned cows delivered multiple healthy offspring following artificial insemination with conventionally processed spermatozoa from noncloned bulls, and their milk production was comparable to that of donor cows. Moreover, this study revealed that the offspring had normal-length telomeres in their leukocytes and major organs. Thus, cloned animals have normal functional germ lines, and therefore germ line function can completely restore telomere lengths in clone gametes by telomerase activity, resulting in healthy offspring with normal-length telomeres. 相似文献
120.
Chitinase and N-acetylglucosaminidase activities in forest soils were examined by a highly sensitive method using 4-methylumbelliferyl (4MU) derivatives of N-acetyl-D-glucosamine oligomers as substrates. The method involves the fluorometric estimation of the 4-MU released through the activity of the soil enzymes when a soil sample and the substrate are incubated in a buffer. The activities of both enzymes decreased markedly with depth in the 4 forest soil profiles studied (i.e. Andosol, Podzol, 2 Cambisols). The activities of these soil enzymes were highly correlated with the carbon and nitrogen content of the soils. 相似文献