全文获取类型
收费全文 | 984篇 |
免费 | 29篇 |
国内免费 | 3篇 |
专业分类
林业 | 134篇 |
农学 | 41篇 |
基础科学 | 1篇 |
120篇 | |
综合类 | 45篇 |
农作物 | 57篇 |
水产渔业 | 179篇 |
畜牧兽医 | 356篇 |
园艺 | 12篇 |
植物保护 | 71篇 |
出版年
2023年 | 2篇 |
2022年 | 20篇 |
2021年 | 54篇 |
2020年 | 21篇 |
2019年 | 18篇 |
2018年 | 17篇 |
2017年 | 25篇 |
2016年 | 30篇 |
2015年 | 30篇 |
2014年 | 52篇 |
2013年 | 61篇 |
2012年 | 52篇 |
2011年 | 67篇 |
2010年 | 32篇 |
2009年 | 39篇 |
2008年 | 61篇 |
2007年 | 57篇 |
2006年 | 61篇 |
2005年 | 52篇 |
2004年 | 51篇 |
2003年 | 64篇 |
2002年 | 45篇 |
2001年 | 39篇 |
2000年 | 21篇 |
1999年 | 11篇 |
1998年 | 14篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1984年 | 2篇 |
1980年 | 2篇 |
排序方式: 共有1016条查询结果,搜索用时 796 毫秒
141.
Taisei Nagata Mamoru Sameshima Taku Uchikawa Natsumi Osafune Takeshi Kitano 《Fisheries Science》2017,83(2):273-281
Episodes of summer mortality of the Kumamoto oyster Crassostrea sikamea are a major problem for its cultivation. Expression of the heat shock protein 70 (HSP70) is induced by various environmental stresses, including heat. We cloned and sequenced hsp70 complementary DNA from C. sikamea to investigate the relationship between hsp70 expression and heat tolerance in this oyster. Quantitative real-time polymerase chain reaction was performed using gill tissue dissected from oysters before and after heat shock for 1 h. The results showed hsp70 expression was faster and greater in oysters cultured at 20–22 °C than at 10–12 °C, and survival was lower among oysters cultured at 20–22 °C than at 10–12 °C. Moreover, heat tolerance was investigated by a 1-h pre-heat treatment, followed by exposure to heat shock conditions 5 days later. Survival was higher and hsp70 expression was notably lower in oysters that received the pre-heat treatment compared with those that did not. We conclude that a pre-heat treatment of only 1 h may be useful for inducing heat tolerance in C. sikamea, and that a low level of hsp70 expression after heat shock is an important index in selecting for high heat tolerance in these oysters. 相似文献
142.
Hirofumi Furuita Tatsuya Unuma Kazuharu Nomura Hideki Tanaka Tsuyoshi Sugita & Takeshi Yamamoto 《Aquaculture Research》2009,40(11):1270-1278
This paper describes the relationship between the egg vitamin concentrations and the egg quality in the Japanese eel Anguilla japonica . No notable relation was found between any vitamin and the fertilization rate. Hatching and survival rates of larvae, however, significantly increased with an elevated level of egg vitamin C (VC). In contrast to VC, the relation between vitamins E (VE) and A (VA) concentrations and survival rate showed a clear peak, with a reduced survival rate at both higher and lower vitamin concentrations. The ratio of VE to lipid or highly unsaturated fatty acid (HUFA) in eggs positively correlated with hatching and survival rates of larvae. High-quality (HQ) eggs were determined as eggs that produced larvae having a survival rate higher than 80% at 8 days post hatch, and low-quality (LQ) eggs were determined as eggs that did not hatch. The level of VC of HQ was significantly higher than LQ. The results of this study suggest that HQ eggs, which produce larvae having a high survival rate, must have high levels of VC and VE/HUFA ratio and contain optimum levels of VA and VE in Japanese eel. 相似文献
143.
We studied the effect of amylose content on the gelatinization, retrogradation, and pasting properties of starch using wheat starches differing in amylose content. Starches were isolated from waxy and nonwaxy wheat and reciprocal F1 seeds by crossing waxy and nonwaxy wheat. Mixing waxy and nonwaxy wheat starch produced a mixed starch with the same amylose content as F1 seeds for comparison. The amylose content of F1 seeds ranged between waxy and nonwaxy wheat. Nonwaxy‐waxy wheat had a higher amylose content than waxy‐nonwaxy wheat. Endothermic enthalpy and final gelatinization temperature measured by differential scanning calorimetry correlated negatively with amylose content. Gelatinization onset and peak temperature clearly differed between F1 and mixed starches with the same amylose content as F1 starches. Enthalpy for melting recrystallized starches correlated negatively with amylose content. Rapid Visco Analyser measurement showed that F1 starches had a higher peak viscosity than waxy and nonwaxy wheat starches. Mixed starches showed characteristic profiles with two low peaks. Setback and final viscosity correlated highly with amylose content. Some of gelatinization and pasting properties differed between F1 starches and mixed starches. 相似文献
144.
Fisheries Science - The present study established an age determination technique and analyzed growth patterns in three sculpins, Myoxocephalus jaok, Enophrys diceraus, and Gymnocanthus... 相似文献
145.
Saitoh Kanae Yoshimura Tomohiro Sun Luchuanyang Yang Min Wang Yao Taniyama Shigeto Hara Kenji Murayama Fumihito Nikawa Takeshi Tachibana Katsuyasu Hirasaka Katsuya 《Fisheries Science》2020,86(1):187-196
Fisheries Science - Fish oil containing omega-3 polyunsaturated fatty acids (PUFA) attenuates chronic inflammation found in obesity, leading to a reduction in insulin resistance. The effect of fish... 相似文献
146.
Takeshi Yamamoto Kazuhisa Teruya Takashi Hara Hiroto Hokazono Isao Kai Hiroshi Hashimoto Hirofumi Furuita Hiroyuki Matsunari Keiichi Mushiake 《Fisheries Science》2009,75(3):697-705
We evaluated the nutrient contents of rotifers sampled from larval-rearing tanks (tank rotifers) without water exchange during
the seed production of amberjack Seriola dumerili at three facilities (Kamiura, Kagoshima, and Miyazaki) and compared them with the nutrient contents of freshly enriched rotifers.
Compared to the enriched rotifers, the lipid contents, especially neutral lipids and proportion of 22:6n-3, tended to decrease
in the tank rotifers. These trends were clearer at Miyazaki where the tank rotifers were sampled before daily supplementation
of microalgae (Nannochloropsis). Crude protein content of the tank rotifers did not decrease markedly although the proportion of lysine tended to decrease.
Vitamin C and E contents of the tank rotifers decreased significantly only at Miyazaki. Calcium content of the tank rotifers
increased at Kamiura and Miyazaki, and the increases in iron and manganese contents of the tank rotifers at Miyazaki and zinc
content at Kagoshima were pronounced. These results suggest that the nutritional value of rotifers in larval-rearing tanks
without water exchange can be maintained by appropriate supplementation of microalgae. The effect of certain minerals that
became high in tank rotifers on subsequent larval development requires further investigation. 相似文献
147.
Yasuro Iwashita Nobuhiro Suzuki Hiroyuki Matsunari Tsuyoshi Sugita Takeshi Yamamoto 《Fisheries Science》2009,75(5):1307-1315
To investigate the cause of the changes in intestinal morphology and biliary bile status of rainbow trout Oncorhynchus mykiss fed defatted soybean meal (SBM)-based diets, casein-based semipurified diets supplemented with soya saponin, soya lectin,
and cholyltaurine were fed to rainbow trout for 6 weeks. An unsupplemented control diet and a SBM-based diet were also tested
as references. Poor development of microvilli and pinocytotic vacuoles, and accumulation of large vacuoles in the epithelial
cells were observed in the distal intestine of fish fed diets containing saponin but not cholyltaurine. Hyperplastic connective
tissue in the mucosal folds of the distal intestine was observed in fish fed a diet containing both saponin and lectin but
not cholyltaurine. However, intestinal histological features in fish fed diet supplemented with cholyltaurine and lectin and/or
saponin were similar to those in the control diet group. Liver morphology and biliary bile status were not affected by saponin
and lectin. These results suggest that the abnormal features of the distal intestine of rainbow trout fed SBM-based diets
are caused by the combination of soya saponin and soya lectin, and that supplemental cholyltaurine plays certain roles in
normalizing the intestinal abnormalities caused by the saponin and lectin. 相似文献
148.
Go Suzuki Wataru Okada Youko Yasutake Sayaka Kai Yuji Fujikura Iwao Tanita Hiroshi Yamashita Takeshi Hayashibara Wataru Ando Koichi Nogami Masayuki Fudo 《Fisheries Science》2018,84(5):849-856
Extremely low post-settlement survival is one of the largest barriers for artificial rehabilitation of Acropora corals. However, little data have been found for interspecific difference of the post-settlement survival probably because the observation of coral juvenile is difficult in the field. Here, we analyzed the survival of three dominant species of Acropora corals (A. digitifera, A. tenuis, A. yongei), with different colony morphologies and habitat preferences, for 2 years after settlement under the same environmental conditions. The post-settlement survival was significantly higher for A. tenuis than for A. digitifera 3 months after settlement. Two years later, the survival rate of A. tenuis was approximately 15 times higher than A. digitifera. In a separate analysis of three bottle-brush species (A. awi, A. echinata, A. subglabra) and A. tenuis, post-settlement survival was always higher for A. awi than for other two bottle-brush species, suggesting that the initial survival was different among morphologically sister species. Low survival was possibly associated with slow growth rates during the first 7 months. Thus, species selection is important for successful artificial coral rehabilitation, with A. tenuis being the most viable option. Alternatively, new techniques are required to improve post-settlement survival of slow growing coral species. 相似文献
149.
First feeding of diploid and triploid yellowtail tetra Astyanax altiparanae: An initial stage for application in laboratory studies
下载免费PDF全文
![点击此处可从《Aquaculture Research》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Rafaela Manchin Bertolini José Augusto Senhorini Nivaldo Ferreira do Nascimento Matheus Pereira‐Santos Laura Satiko Okada Nakaghi Wellington Adriano Moreira Peres Regiane Cristina da Silva George Shigueki Yasui 《Aquaculture Research》2018,49(1):68-74
In this study, the aim was to establish a protocol for first feeding of diploid and triploid yellowtail tetra Astyanax altiparanae in laboratory conditions. The fry were fed with five different diets: (i) Artemia franciscana nauplii, (ii) plankton, (iii) dry food, (iv) Artemia franciscana nauplii + plankton, and (v) Artemia nauplii + plankton + dry food. Additionally, the growth and survival rates of diploid and triploid individuals were also evaluated. On day 10, the length of the fish between the treatments differed significantly (p = .0001) and ranged from 4.07 ± 0.06 mm (dry food) to 8.50 ± 0.64 mm (plankton + Artemia). The sizes of the fish increased with time, except for the fish fed with dry food. The survival rates were similar for the fish fed with the four diets and ranged from 80.7 ± 5.4% (dry food + plankton + Artemia to 92.0 ± 1.6% (plankton + Artemia), but differed from the fish fed with dry food (17.7 ± 5.8%, p = .0017). Diploids and triploids did not present differences on day 0 (p = .2252) and on day 10 (p = .4844) when the fish presented 6.77 ± 0.25 mm and 6.54 ± 0.15 mm respectively. Survival of diploids (87.3 ± 5.13%) and triploids (74.67 ± 2.30%) were also similar (p = .0285). These data are innovative and useful for establishing protocols for this species in both academic and applied sciences. 相似文献
150.
Pseurotins A1 (1) and A2 (2) were isolated from a culture broth of the fungal strain Aspergillus fumigatus WFZ-25 as stereoisomers of pseurotin A (3) in 2011. We also isolated 1 and 2 together with 3 from A. fumigatus OUPS-T106B-5 separated from the marine fish Mugil cephalus. In this study, we re-examined the stereochemistry of 1 and 2 using chemical transformation and the CD spectra, and found the relationship between the CD Cotton effect and the absolute configurations of 1 and 2, which led us to revise the stereostructure of pseurotin A2. 相似文献