全文获取类型
收费全文 | 300篇 |
免费 | 10篇 |
专业分类
林业 | 23篇 |
农学 | 1篇 |
基础科学 | 10篇 |
19篇 | |
综合类 | 19篇 |
农作物 | 10篇 |
水产渔业 | 24篇 |
畜牧兽医 | 168篇 |
园艺 | 1篇 |
植物保护 | 35篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 8篇 |
2020年 | 6篇 |
2019年 | 3篇 |
2018年 | 5篇 |
2017年 | 8篇 |
2016年 | 7篇 |
2015年 | 3篇 |
2014年 | 6篇 |
2013年 | 9篇 |
2012年 | 17篇 |
2011年 | 12篇 |
2010年 | 7篇 |
2009年 | 7篇 |
2008年 | 17篇 |
2007年 | 18篇 |
2006年 | 25篇 |
2005年 | 15篇 |
2004年 | 15篇 |
2003年 | 11篇 |
2002年 | 14篇 |
2001年 | 22篇 |
2000年 | 10篇 |
1999年 | 12篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1994年 | 2篇 |
1992年 | 5篇 |
1991年 | 2篇 |
1990年 | 6篇 |
1989年 | 2篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 8篇 |
1984年 | 5篇 |
1981年 | 1篇 |
1978年 | 1篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1958年 | 2篇 |
排序方式: 共有310条查询结果,搜索用时 625 毫秒
121.
Yoshiyuki Inagaki Kazuki Miyamoto Shiro Okuda Mahoko Noguchi Takeharu Itou Kyotaro Noguchi 《Soil Science and Plant Nutrition》2013,59(5):710-718
The stem productivity of the hinoki cypress (Chamaecyparis obtusa Endlicher) in relation to plant nitrogen status and water-use efficiency was investigated in the Okuono (OKU) and Karakawa (KRK) areas in Shikoku district, Japan, where abundant precipitation occurs. The nitrogen concentration and carbon isotopic composition (δ13C) in the leaves were used as indexes of plant nitrogen status and water-use efficiency, respectively. The leaf nitrogen concentration increased with decreasing soil carbon/nitrogen (C/N) ratio and with increasing soil pH. There was a marginally significant negative correlation between leaf δ13C and soil water content in the KRK area, but leaf δ13C in the OKU area did not correlate with the soil water condition, and increased on the upper slope. The results suggest that hinoki trees in the KRK area have higher water-use efficiency (high leaf δ13C) under lower soil water conditions. In the OKU area, meanwhile, leaf δ13C in the upper slope was higher due to adaptation to adverse conditions. When 12 plots in two areas were included, the mean height and stem increments increased with increasing leaf nitrogen concentration and with decreasing leaf δ13C. These findings suggest that nitrogen acquisition is a primary factor for stem productivity in the areas concerned but the productivity of some forests is restricted by the soil water condition or other conditions, as indicated by the high value of leaf δ13C. The measurement of nitrogen concentration and δ13C in leaves can provide us with valuable insights into the relative importance of nitrogen, water and other conditions on stem productivity in the two areas. 相似文献
122.
Sodium (Na) application has marked beneficial effects on plant growth when the potassium (K) supply is low. Under low K supply, three japonica rice (Oryza sativa L.) cultivars, Koshihikari, Nipponbare, and Sasanishiki, accumulated more Na than three indica cultivars, IR36, IR64, and Kasalath, and the effect of Na application on growth was greater in japonica Koshihikari plants than in indica IR64 plants. A quantitative trait locus (QTL) analysis using a population of backcross inbred lines derived from japonica Koshihikari and indica Kasalath identified two significant loci associated with shoot Na concentration on chromosomes 3 and 6. The quantitative trait locus for shoot Na accumulation on chromosome 6 was confirmed in a population of chromosome segment substitution lines. The major QTL detected in this study could be useful for increasing crop productivity under low K input. 相似文献
123.
124.
Urara Watanabe Koji Okamoto Akio Miyamoto Takeshige Otoi Osamu Yamato Chenga Tshering Mitsuhiro Takagi 《Animal Science Journal》2013,84(5):389-394
Ten reared cows of a Japanese Black cattle herd in Kagoshima prefecture, Japan, exhibited extremely low blood urea nitrogen (BUN) concentration (2.6 ± 0.6 mg/dL). Examination of dietary feed nutrition and relevant pastureland soil content suggested a correlation with crude protein (CP) deficiency or unbalanced nutritional dietary feeds. Thirteen months after the introduction of a dietary remedial measure (bean cake supplementation), BUN, total cholesterol and albumin concentration from five of the original 10 cows increased significantly compared with their values of before the dietary remedy. The postpartum day open period was significantly lower after the dietary remedial measure than that before it. The abnormally low BUN levels of the cattle herd may be due to inadequate dietary nutritional content, primarily from the imbalance of total digestible nutrient and CP of the feed and far lower han average CP value. In conclusion, routine examination of serum biochemical parameters in Japanese Black breeding cattle may be a useful strategy for determining subclinical metabolic failure of cattle herds, and consequently, its effect on reproductive performance of the herd. 相似文献
125.
Makoto Nagai Noboru Hori Michiko Miyamoto Masanobu Sakaguchi Yuji Hayakawa Megumi Kawai Mitsuo Kita Tetsuya Furuya Kei Imai 《Animal Science Journal》2013,84(6):461-465
To improve embryo development in bovine separated blastomeres, we evaluated applicability of co‐culture with intact embryos. The morphological quality of blastocysts derived from separated blastomeres and rate of blastocyst formation were only slightly increased when the cells were co‐cultured with intact embryos, which did not provide significant differences when statistically analyzed. However, the cell count of inner cell mass (ICM), trophectoderm (TE) and total number of cells in Day 8 blastocysts were significantly higher when the cells were co‐cultured with the intact embryos than those with the cells cultured individually (P < 0.05). Transfer of four monozygotic pairs of blastocysts derived from the cells co‐cultured with intact embryos led to three pregnancies even when the blastomeres were produced by in vitro maturation and in vitro fertilization of oocytes collected by ovum pick‐up from elite cows. These results suggest that co‐culturing with intact embryos may enhance development of bovine separated blastomere. 相似文献
126.
Yuichi Iwasaki Takashi Kagaya Ken-ichi Miyamoto Hiroyuki Matsuda 《Water, air, and soil pollution》2012,223(1):145-158
We conducted a field survey in Japanese streams and rivers to generate useful information about whether the Japanese water
quality standard for zinc (Zn) in the freshwater environment (30 μg/L) is over- or underprotective of the populations and
communities of lotic benthic macroinvertebrates. Many macroinvertebrate populations were reduced and community characteristics
were altered at two polluted sites with Zn concentrations above 1,000 μg/L as compared with control sites with Zn concentrations
below 30 μg/L. In contrast, at least one site among three polluted sites with Zn concentrations of 80–126 μg/L experienced
noncritical effects (i.e., no significant difference was observed between the sample mean at a polluted site and that at the
control sites, and the sample mean was within the minimum–maximum range of those at the control sites) for most of the ten
community metrics for diversity and abundance. In addition, the abundances of 95% of the dominant taxa were not always significantly
lower at more than one polluted site (Zn concentrations, ≥80 μg/L). Our results suggest that Zn concentrations below approximately
100 μg/L are likely to protect most aspects of richness and abundance of the riverine macroinvertebrate communities in the
study areas. This study shows a case that the Japanese Zn standard is likely overprotective of the macroinvertebrate populations
and communities. 相似文献
127.
Kazutaka Kido Tomofumi Mochizuki Kazutoshi Matsuo Chika Tanaka Kenji Kubota Takehiro Ohki Shinya Tsuda 《European journal of plant pathology / European Foundation for Plant Pathology》2008,121(2):189-194
The single recessive gene, nsv, which confers resistance against Melon necrotic spot virus (MNSV), has recently been used to develop virus-resistant melon cultivars in Japan. However, the Chiba isolate of MNSV, a
common isolate in Japan, infected resistant cultivars when inoculated melon plants were grown at 15°C. Viral RNAs accumulated
in protoplasts from resistant cultivars at both 15 and 20°C. Mechanical inoculation of the cotyledons caused MNSV to spread
throughout the leaves at 15°C, but not at 20°C. These results support our novel hypothesis that a temperature-sensitive inactivation
of disease resistance genes occurs at the nsv locus in melon cultivars with the resistance gene grown at temperatures below 20°C.
The first and second authors contributed equally to this research. 相似文献
128.
Jianfeng Tong Yoshinori Miyamoto Keiichi Uchida Toyoki Sasakura Jun Han 《Fisheries Science》2014,80(6):1159-1167
In order to monitor the fish volume entrapped over time in a set net in real time, a new remote fish finder system based on a mobile network was developed and tested. This system was designed with a client/server architecture including an echo sounder terminal, a web server, and some end user display terminals, which allowed fishermen to monitor the fishing state of a set net via any display device. In addition, in order to transfer the echo data smoothly via a mobile network, a fish echo extraction method based on image processing and a data organization structure were proposed, which can significantly reduce the data volume for transmission, supply sufficient information to reconstruct the high resolution echogram at the user terminals, and calculate the positional and morphometric parameters of fish echoes. Furthermore, a semiautomatic data recording method for use with a database was proposed to manage the extracted fish echo data and the fishing records. The functions and capabilities of the new system were demonstrated by a sea trial. 相似文献
129.
Feed‐derived volatile basic nitrogen increases reactive oxygen species production of blood leukocytes in lactating dairy cows
下载免费PDF全文
![点击此处可从《Animal Science Journal》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Ei Tsunoda Josef J. Gross Chiho Kawashima Rupert M. Bruckmaier Katsuya Kida Akio Miyamoto 《Animal Science Journal》2017,88(1):125-133
The present study investigated over 9 months the changes of fermentative quality of total mixed rations (TMR) containing grass silage (GS) as a major component, associated with changes in the volatile basic nitrogen (VBN) levels in an experimental dairy farm. Effects of VBN levels in TMR on metabolic parameters, reactive oxygen species (ROS) production by blood polymorphonuclear leukocytes (PMNs) and conception rates for dairy cows were analyzed. According to VBN levels in TMR during survey periods, three distinct phases were identified; phase A with low VBN; phase B with high VBN; and phase C with mid‐VBN. Metabolic parameters in blood were all within normal range. However, during phases B and C, nitrogen metabolic indices such as blood urea nitrogen and milk urea nitrogen showed higher levels compared to those in phase A, and a simultaneous increase in ROS production by blood PMNs and the load on hepatic function in metabolic parameters was observed in the cows with a lower conception rate. This suggests that feeding TMR with elevated VBN levels due to poor fermented GS results in stimulation of ROS production by PMNs by ammonia, and negatively affects metabolism and reproductive performance in lactating dairy cow. 相似文献
130.
This work aimed to compare radial growth–climate relationships among three coexisting coniferous tree species across a wide geographic and climate range from southern British Columbia (BC) to central Yukon, Canada. Tree-ring data were collected from 20 mature stands of white spruce (Picea glauca), lodgepole pine (Pinus contorta var. latifolia), and subalpine fir (Abies lasiocarpa). Linear relationships between annual growth variation and monthly and seasonal climate were quantified with correlation and regression analyses, and variation in climate–growth responses over a climatic gradient were quantified by regressing growth responses against local mean climatic conditions. Temperatures had more consistent and stronger correlations with growth for all three species than precipitation, but growth–climate responses varied among species and among sites. In particular, pine and fir populations showed different responses between BC and Yukon, whereas spruce showed a more consistent response across the study domain. Results indicate that (1) the response and sensitivity of trees to seasonal climate variables vary among species and sites and (2) winter temperatures prior to growth may have significant impacts on pine and fir growth at some sites. The capacity to adapt to climate change will likely vary among the study species and across climatic gradients, which will have implications for the future management of mixed-species forests in Yukon and BC. 相似文献