全文获取类型
收费全文 | 186篇 |
免费 | 4篇 |
专业分类
林业 | 12篇 |
农学 | 8篇 |
20篇 | |
综合类 | 9篇 |
农作物 | 3篇 |
水产渔业 | 15篇 |
畜牧兽医 | 104篇 |
园艺 | 3篇 |
植物保护 | 16篇 |
出版年
2022年 | 4篇 |
2021年 | 7篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 2篇 |
2015年 | 11篇 |
2014年 | 10篇 |
2013年 | 12篇 |
2012年 | 12篇 |
2011年 | 17篇 |
2010年 | 5篇 |
2009年 | 8篇 |
2008年 | 15篇 |
2007年 | 10篇 |
2006年 | 8篇 |
2005年 | 11篇 |
2004年 | 17篇 |
2003年 | 5篇 |
2002年 | 9篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 1篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1988年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有190条查询结果,搜索用时 203 毫秒
171.
For truncation selection on a proportion‐defined trait, an approximate expression for the true truncation point is currently available, which has been derived assuming that the component traits follow a curtailed normal distribution. This note deterministically examines the validity of the approximate expression in some details. We show that the value defined by the approximate expression is equivalent to that derived from an approximation to the true probability density function for the proportion trait of concern. We also show that the validity of the approximate expression is definitely dependent on the magnitude of the lower limit in the definite integral involved in the true probability density function for the proportion trait. We reveal some properties of the lower limit concerning its maximum and minimum. We indirectly assess the adequacy of the approximate expression under the settings of the altered coefficients of variation for the component traits and the changed correlation between them. The results indicate that the true value of the truncation point can be numerically represented quite sufficiently by the approximate expression, when the coefficients of variation are approximately below 25% and the positive correlation is not extremely high. 相似文献
172.
Sumiyama D Kitamura S Terasawa F Hori Y Murata K Kulski JK Inoko H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2008,70(7):711-713
We applied previously published PCR primer pairs to amplify alleles at three polymorphic microsatellite loci to determine the genetic relationship of 6 bottlenose dolphins (Tursiops truncatus) that were living together in a Japanese aquarium. The three microsatellite loci were sufficient to determine the haplotype relationships of the six dolphins, which represented three different generations. It was confirmed that this genotyping method is simple and economical for assessing, establishing and maintaining genetic diversity in captive populations and will become a very effective technique for ex situ conservation in aquariums and zoos. 相似文献
173.
Hori Y Kanai K Nakao R Hoshi F Higuchi S 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2008,70(4):359-366
We developed a novel index to assess left ventricular (LV) relaxation as the ratio of transmitral early diastolic velocity to pulmonary diastolic velocity (E/D ratio). Mixed breed dogs (n=7) were anesthetized and their respiration was controlled. A 3.5-Fr micromanometer-tipped catheter was placed into the left ventricle. Dobutamine (5.0 or 10 microg/kg/min) or esmolol (100 or 500 microg/kg/min) was administered via the cephalic vein. The transmitral flow (TMF) and pulmonary venous flow (PVF) were recorded using transthoracic echocardiography from the apical long-axis view. The heart rate, systolic LV pressure, +dP/dt, and -dP/dt were significantly elevated by dobutamine, but significantly reduced by esmolol. Dobutamine significantly decreased tau, whereas esmolol significantly increased tau. The TMF-derived E and PVF-derived D wave velocities increased significantly with dobutamine, but decreased significantly with esmolol. A significant correlation was detected between the E and D wave velocities (r=0.92). Consequently, the E/D ratio was decreased significantly with dobutamine, and increased significantly with esmolol. Furthermore, the E/D ratio was significantly correlated with -dP/dt (r= -0.64) and tau (r=0.84). Our results suggest that the E/D ratio reflects LV relaxation, and may potentially provide further information on LV relaxation. 相似文献
174.
The effects of chlordimeform [N-(2-methyl-4-chlorophenyl)-N′,N′-dimethylformamidine] on amine regulatory mechanisms in insects were studied. Chlordimeform inhibits monoamine oxidase (MAO) from cockroach heads in vitro, and the MAO substrates serotonin and norepinephrine accumulate in poisoned insects in vivo. Chlordimeform synergizes the toxicity of tryptamine, another MAO substrate. The significance of these findings in relation to the mode of action of chlordimeform is discussed. 相似文献
175.
Vitamin B12 is synthesized by only certain bacteria and archaea but not by animals or plants. In marine environments, bacterial vitamin B12 is transferred and concentrated into fish and shellfish bodies by plankton in the marine food chain. Moreover, marine macrophytic red algae, Porphyra spp. specifically contain substantial amounts of vitamin B12, due to microbial interaction. Although some meats or viscera of edible fish and shellfish are excellent sources of biologically active vitamin B12, an inactive corrinoid, pseudovitamin B12, was found in some edible shellfish using liquid chromatography/electrospray ionization–tandem mass spectrometry. To prevent elderly people from developing vitamin B12 deficiency due to food protein-bound vitamin B12 malabsorption, we present a survey of marine foods containing free vitamin B12. The results of our study suggest that bonito and clam extracts (or soup stocks), which contain considerable amounts of free vitamin B12 are useful not only as seasonings and flavorings but also as excellent sources of free vitamin B12. 相似文献
176.
Yukio Ishihara Kazumi Ueta Tomohiro Bito Shigeo Takenaka Yukinori Yabuta Fumio Watanabe 《Fisheries Science》2013,79(2):321-326
In Lake Togo (Tottori prefecture, Japan), the vitamin B12 content of the brackish-water bivalve Corbicula japonica remained high (17.3–22.5 μg/100 g wet weight of the edible portion) throughout the year, except during August and September. We evaluated whether the bivalve contained true vitamin B12 or other corrinoid compounds that are inactive in humans by purifying the compounds and identifying them using LC/ESI–MS/MS chromatograms. The results indicated that “true” vitamin B12 predominated in the bivalve, although small amounts of inactive corrinoid compounds (pseudovitamin B12 and three unidentified compounds) were also found. 相似文献
177.
Rice Metabolomics 总被引:1,自引:0,他引:1
Metabolomics is a recently developed technology for comprehensive analysis of metabolites in organisms. Plant metabolites that are produced for the growth, development, and chemical defense of plants against climatic alterations or natural predators are also useful to us as nutrients or medicines; hence, it is important to comprehend the amounts and varieties of plant metabolites. Besides providing an understanding of the metabolic state in plants under various circumstances, metabolomic techniques are applicable to the clarification of the functions of unknown genes by using natural variants or mutants of the target plants. Furthermore, a metabolomic approach might be useful in the breeding of crops, since valuable plant traits such as taste and yield are closely related to metabolic conditions. Here, we describe the methodology of metabolomics including sample extraction and preparation, metabolite detection, and data processing and analysis, and introduce the application of metabolomic studies to rice. 相似文献
178.
Hideyuki Mannen Riku Yonesaka Aoi Noda Takeshi Shimogiri Ichiro Oshima Kiyomi Katahira Misao Kanemaki Tetsuo Kunieda Yousuke Inayoshi Fumio Mukai Shinji Sasazaki 《Animal Science Journal》2017,88(5):739-744
This study aims to estimate the mitochondrial genetic diversity and structure of Japanese Polled and Kuchinoshima feral cattle, which are maintained in small populations. We determined the mitochondrial DMA (mtDNA) displacement loop (D‐loop) sequences for both cattle populations and analyzed these in conjunction with previously published data from Northeast Asian cattle populations. Our findings showed that Japanese native cattle have a predominant, Asian‐specific mtDNA haplogroup T4 with high frequencies (0.43–0.81). This excluded Kuchinoshima cattle (32 animals), which had only one mtDNA haplotype belonging to the haplogroup T3. Japanese Polled showed relatively lower mtDNA diversity in the average sequence divergence (0.0020) than other Wagyu breeds (0.0036–0.0047). Japanese Polled have been maintained in a limited area of Yamaguchi, and the population size is now less than 200. Therefore, low mtDNA diversity in the Japanese Polled could be explained by the decreasing population size in the last three decades. We found low mtDNA diversity in both Japanese Polled and Kuchinoshima cattle. The genetic information obtained in this study will be useful for maintaining these populations and for understanding the origin of Japanese native cattle. 相似文献
179.
Zeen Huang Koh Hashida Rei Makino Fumio Kawamura Kuniyoshi Shimizu Ryuichiro Kondo Seiji Ohara 《Journal of Wood Science》2009,55(3):225-229
Heartwoods of 22 African tropical wood species were extracted with methanol and the contents of total phenolic compounds in
these extracts were measured. Three bioassays were conducted to evaluate the antioxidant activity, tyrosinase inhibitory activity,
and antifungal activity of the methanol extracts. The results indicated that the extracts from 13 species exhibited high antioxidant
potential, and their inhibitory concentrations that caused 50% scavenging of the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical
(IC50) were less than 10 μg/ml. The crude extract from Cylicodiscus gabunensis showed the highest antioxidant activity, and was even higher than that of (+)-catechin, which is known as a potent antioxidant.
There was a good correlation between the antioxidant activity and the content of total phenolic compounds, indicating that
phenolic compounds played a predominant role in the antioxidant property of the wood extracts. Among all 22 species, only
1 species, Milicia excelsa, contained extractives that showed very high tyrosinase inhibitory activity. The extracts from 9 species showed high antifungal
activity. No consistent relationship was observed between the tyrosinase inhibitory activity or antifungal activity and the
content of total phenolics in the extracts.
Part of this article was presented at the 56th Annual Meeting of the Japan Wood Research Society, Akita, August 2006 相似文献
180.
Ohtsuka H Koiwa M Fukuda S Satoh Y Hayashi T Hoshi F Yoshino TO Kawamura S 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(8):905-909
To clarify the cellular immune system in dairy cows with inflammatory diseases after calving, the leukocyte subsets were examined in Holstein dairy cows. Twenty Holstein cows reared in one herd, were used in this study. Nine cows (Group 1) experienced onset of mastitis or puerperal fever within 2 weeks after calving, and the other eleven cows remained healthy (Group 2) after calving. The numbers of CD3(+), CD4(+) and CD8(+) cells tended to be lower in Group 1 than in Group 2 from the day of calving through week 1. These results suggested that the cows with inflammatory diseases might have experienced a decline in T cells by the day of calving, before the onset of disease. 相似文献