全文获取类型
收费全文 | 325篇 |
免费 | 13篇 |
专业分类
林业 | 39篇 |
农学 | 21篇 |
基础科学 | 1篇 |
53篇 | |
综合类 | 29篇 |
农作物 | 12篇 |
水产渔业 | 22篇 |
畜牧兽医 | 146篇 |
园艺 | 6篇 |
植物保护 | 9篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 6篇 |
2020年 | 4篇 |
2019年 | 5篇 |
2018年 | 9篇 |
2017年 | 8篇 |
2016年 | 6篇 |
2015年 | 11篇 |
2014年 | 7篇 |
2013年 | 26篇 |
2012年 | 15篇 |
2011年 | 27篇 |
2010年 | 8篇 |
2009年 | 14篇 |
2008年 | 14篇 |
2007年 | 10篇 |
2006年 | 14篇 |
2005年 | 22篇 |
2004年 | 9篇 |
2003年 | 7篇 |
2002年 | 11篇 |
2001年 | 11篇 |
2000年 | 8篇 |
1999年 | 8篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1994年 | 1篇 |
1992年 | 3篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 6篇 |
1987年 | 8篇 |
1986年 | 11篇 |
1985年 | 11篇 |
1984年 | 5篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1969年 | 2篇 |
1967年 | 1篇 |
排序方式: 共有338条查询结果,搜索用时 375 毫秒
1.
Natsumi ENDO Larasati Puji RAHAYU Toshiya ARAKAWA Tomomi TANAKA 《The Journal of reproduction and development》2016,62(1):115-119
Here, we report a new method for measuring behavioral patterns during estrus in goats based on video
tracking analysis. Data were collected from cycling goats, which were in estrus (n = 8) or not in estrus (n =
8). An observation pen (2.5 m × 2.5 m) was set up in the corner of the female paddock with one side adjacent
to a male paddock. The positions and movements of goats were tracked every 0.5 sec for 10 min by using a video
tracking software, and the trajectory data were used for the analysis. There were no significant differences
in the durations of standing and walking or the total length of movement. However, the number of approaches to
a male and the duration of staying near the male were higher in goats in estrus than in goats not in estrus.
The proposed evaluation method may be suitable for detailed monitoring of behavioral changes during estrus in
goats. 相似文献
2.
Tomoki Hashimoto Katsuya Hyodoh Takuma Hirose Satoshi Nishikawa Toshiya Katano Shin-ichi Nakano 《Aquaculture International》2008,16(4):309-318
In the pearl cultivation farms of the Ehime Prefecture, Japan, mass mortalities of the pearl oyster Pinctada fucata have occurred since 1994. The occurrences of mass mortality roughly coincided with a shift of the dominant phytoplankton
from Skeletonema and Chaetoceros to Chaetoceros and Nitzschia all of which belong to Bacillariophyceae. Hence, we evaluated Nitzschia, together with Chaetoceros and Isocrysis, as food for the oyster. Wet weights, lengths, widths, glycogen contents, and growth rates in terms of wet weight of the
oysters in all the feeding treatments were significantly higher than those in the non-feeding treatment. The highest glycogen
content (2.34%) and growth rate (2.21 g month−1) were found in the Chaetoceros treatment. Growth rate in the Isocrysis treatment (1.63 g month−1) was also high, although glycogen content in this treatment (0.41%) was low. In the Nitzschia treatment, growth rate of the oyster (0.94 g month−1) was the lowest and glycogen content (0.83%) was also low relative to that in the Chaetoceros treatment. Chlorophyll a concentration in fecal pellets was lowest in the Nitzschia treatment (<2.7 μg mg−1), suggesting more complete digestion of Nitzschia by the oyster. Thus, Nitzschia was edible and digestible but not assimilated by P. fucata. We propose the following scenario for the relationship between Nitzschia dominance and mass mortality. When Nitzschia dominates in a culture area, the physiological condition of P. fucata deteriorates due to low assimilation of Nitzschia by the oyster, followed by susceptibility of the oyster to infection by agents lethal to the oyster. 相似文献
3.
Shiori Fujiwara Yuko Yamaguchi Tsubasa Saito Tomomi Nakazawa Kazutoshi Tamura 《Journal of toxicologic pathology》2022,35(1):99
This case report describes a case of spontaneous pancreatic islet cell carcinoma with vascular invasion in a 110-week-old male F344 rat. Histologically, a pancreatic nodule consisting of tumor cells and many blood-rich vessels, and covered with a fibrous capsule showed local invasion in the capsule and adjacent acinar tissues, encircling a large duct-like structure (DS). The tumor was composed of well-differentiated tumor cells resembling normal pancreatic islet cells, which had small round nuclei and eosinophilic cytoplasm. Mitotic figures were rare. Immunohistochemistry revealed that the tumor cells were positive for insulin. Although endothelial cells were not detected, the DS wall showed cells positive for α-smooth muscle actin and elastic fibers, suggesting that the DS is the pancreatic artery. This is a rare case of islet cell carcinoma consisting of well-differentiated tumor cells with invasion of the pancreatic artery in a rat. 相似文献
4.
Cadmium transport and tolerance in rice: perspectives for reducing grain cadmium accumulation 总被引:10,自引:0,他引:10
In recent decades, numerous studies have attempted to project the impact of hypothesised anthropogenic climate change on rice production. In this study, we offer a comprehensive review of our current understanding related to temperature, CO2, and water-demand parameters in rice growth models. As to future rice yield, night time temperature should be focused in the models as well as day time temperature owing to the contribution of temperature on the night time respiration. Furthermore, although CO2-enhanced photosynthesis is critical for the accurate prediction of rice production in a higher CO2 atmosphere, we found that recent well-developed photosynthesis-stomatal model cannot realize the variation of CO2 stomatal sensitivity with humidity conditions. To estimate water stress under projected climate-change conditions, rice growth model should be required to link with water resource model, which includes natural processes and anthropogenic regulations. The understanding of abilities and limitations in the models is important not only to improve the schemes that models employ, but to also critically review the simulated results. 相似文献
5.
Yasuo Tomida Toshiya Suzuki Tsutomu Yamada Ryuji Asami Hirofumi Yaegashi Yasufumi Iryu Tsuguo Otake 《Fisheries Science》2014,80(2):273-280
We examined differences in otolith oxygen (δ18Ootolith) and carbon (δ13Cotolith) stable isotope ratios between hatchery and wild pink salmon fry. The δ18Ootolith values of hatchery and wild fry were ?7.7 ± 0.2 ‰ and ?8.3 ± 0.3 ‰ (1σ), respectively. This difference reflected differences in temperature conditions experienced by each fry. The δ13Cotolith values of hatchery and wild fry were ?19.2 ± 0.3 ‰ and ?11.1 ± 1.8 ‰ (1σ), respectively. The lower δ13Cotolith values of hatchery fry were probably related to their intake of artificial diets. Discriminant analysis of δ18Ootolith and δ13Cotolith values demonstrated a highly significant difference between hatchery and wild fry with 95.8 % classification accuracy. Therefore, analysis of δ18Ootolith and δ13Cotolith precipitated in the fry stage may be useful for discriminating the origin of returning adult pink salmon. The discrimination method for returning adult fish would provide important information for evaluating the effect of hatchery release and their impact on the wild population. 相似文献
6.
7.
Pathological observations of feline mast cell tumor 总被引:1,自引:0,他引:1
8.
9.
Yutaka Kataoka Makoto Kiguchi Takeshi Fujiwara Philip D. Evans 《Journal of Wood Science》2005,51(5):531-536
Low density wood is more rapidly eroded than denser wood when exposed to the weather, possibly because it is more susceptible
to photodegradation. Fourier transform infrared microscopy was used to examine: (1) the depth of photodegradation in earlywood
and latewood of sugi (Japanese cedar) and earlywood of hinoki (Japanese cypress) exposed for up to 1500 h to artificial sunlight
emitted by a xenon lamp (375 W/m2 within the 300 to 700 nm spectral range); and (2) the relationship between the density of wood tissues and depth of photodegradation.
The depth of photodegradation varied between species (sugi and hinoki) as well as within a growth ring (sugi earlywood and
latewood), and there was an inversely proportional relationship between depth of photodegradation and wood density. These
findings may explain why low density earlywood is more rapidly eroded than latewood during weathering, and more generally,
why there is an inverse relationship between the density of wood species and their rate of erosion during artificial and natural
weathering.
Part of this work was presented at the 54th Annual Meeting of the Japan Wood Research Society, Sapporo, August 2004 相似文献
10.
Tsutomu Suzuki Kyoko Suzuki Yukio Takahashi Mitsuhiro Okimoto Tetsuo Yamada Noriyasu Okazaki Yuichi Shimizu Masashi Fujiwara 《Journal of Wood Science》2007,53(1):54-60
Japanese larch wood loaded with nickel (1%–4%) alone or with nickel and calcium (0.25%–1.5%) was carbonized at 800°–900°C
for 0–120min with a heating rate of 5°–20°C min−1 in a helium flow of 5.8−46.4 ml STP cm−2 min−1 to examine the influence of these variables on the crystallization of carbon (the formation of T component) and the development
of mesoporosity. From the obtained results, reaction conditions suitable for effective production of carbon with the dual
functions of adequate electroconductivity and adsorption capacity in liquid phase were established, thereby explaining the
factors that govern the process. It was also confirmed that mesopore having a diameter of about 4 nm was selectively produced
at the cost of specific (BET) surface area in parallel with the formation of T component. This result provided good insight
into how the simultaneous dual function could be realized. 相似文献