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排序方式: 共有221条查询结果,搜索用时 125 毫秒
91.
Katsumasa Yamada Masakazu Hori Susumu Matsuno Tatsuo Hamano Masami Hamaguchi 《Fisheries Science》2009,75(3):601-610
It has been suggested that the Japanese sea cucumber, Apostichopus japonicus, has three color types (red, green, and black), although the qualitative difference between the color types, particularly
between the green and black types, is unclear because of continuous color variation among color types. This study elucidated
the color variation between green and black types using image processing (RGB, red–green–blue system) and multivariate analysis to demonstrate whether or not the black and green types can be quantitatively classified.
Moreover, spatial variation of the RGB value among various local sites was clarified to estimate potential environmental factors
that may affect the color variation. The series of analyses revealed that a quantitative boundary between green and black
types could be provisionally established, and also that spatial variability in the intermediate (continuous) color trait between
green and black types was significant. Potential environmental factors (depth and industrial activity index) were correlated
with the color traits in both color types. These results suggest that the green and black types cannot be regarded as independent
color traits and that the color variation between green and black types may be influenced by local environmental factors. 相似文献
92.
Offshore currents explain the discontinuity of a fish community in the seagrass bed along the Japanese archipelago 下载免费PDF全文
Atsushi Fukuta Yasuhiro Kamimura Masakazu Hori Masahiro Nakaoka Tsutomu Noda Yoh Yamashita Tsuguo Otake Jun Shoji 《Fisheries Oceanography》2017,26(1):65-68
Oceanographic conditions can affect spatial variability in fish community structures by influencing the temperature‐dependent latitudinal distribution of adult fishes and transport during their young stages. In order to examine latitudinal variability in the fish community structure within a single coastal ecosystem, quantitative sampling was conducted in the sub‐tidal zone of seagrass Zostera marina beds over a broad latitudinal scale (31.31–43.0°N: from subtropical to sub‐boreal zones, covering 80% of the latitudinal range of seagrass distribution in Japan) in the western North Pacific based on a uniform methodology. Cluster analysis with the similarity of fish communities showed that 13 sampling sites were divided into two clusters. The border between the two clusters corresponded with the area of mixing of two dominant currents, Oyashio and Kuroshio, which form a border between the warm temperate zone and the cool temperate zone off the Pacific coast of Japan. Oceanographic properties, such as major currents off the coast, are suggested to affect the latitudinal variability in the fish communities in the coastal ecosystem in the western North Pacific. 相似文献
93.
S. Schiff C. Tani A. Cimmino G. Mandalà T. Cinelli A. Evidente M. Fiori G. Surico G. Marchi 《Plant pathology》2019,68(6):1109-1119
The ability to produce indole-3-acetic acid (IAA) through the indole-3-acetamide (IAM) pathway as well as cytokinins is a common trait of Pseudomonas savastanoi populations causing disease on oleander and olive. These phytohormones are required for the induction and development of an outgrowth of plant cell tissue termed a knot. However, in myrtle orchards of Sardinia (Italy), strains of P. savastanoi unable to produce cytokinins were found coexisting with cytokinin-producing strains. Data presented here show that the ability to produce IAA through the IAM pathway is also a variable trait within this population, raising questions on the exact role of these plant growth substances in the disease process on myrtle. Three P. savastanoi strains were selected based on their differential ability to produce phytohormones in vitro, and their interaction with the host was investigated over a period of 8 months using histological methods. All strains successfully invaded the infected twigs, moving systemically (unhalted by host defences) upward and downward from the inoculation point, both by completely degrading the cell walls and by taking advantage of the xylem vessels and intercellular spaces. Moreover, all strains induced the development of cankers, which slowly evolved into typical knots only on the twigs inoculated with the phytohormone-producing strains. This study further demonstrates that cytokinins and IAA are essential for knot development; moreover, it ascertains that bacterial production of cytokinins is not necessary for host colonization and for the expression of pathogenicity (i.e. the ability to cause disease) of P. savastanoi on myrtle. 相似文献
94.
Sakai K Yada K Sakabe G Tani O Miyaji K Nakamura M Takehara K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(5):491-494
Serum samples from 191 ostriches (Struthio camelus) in Japan were tested for antibodies to Newcastle disease virus (NDV) and avian influenza virus (AIV). Twenty-two (12%) contained NDV-specific neutralizing antibodies by a virus-neutralization (VN) test without vaccination. Antibodies to AIV were not detected in the any sera by an agar gel precipitation test. Seven serum samples that had vaccinated with live NDV by eye drop were all positive by the VN test at 1 month post vaccination. A haemagglutination inhibition (HI) test for NDV seemed not to be suitable for ostriches because of non-specific agglutination of chicken red blood cells. No haemagglutinating viruses were isolated. This is the first report on detection of antibodies against NDV in ostriches in Japan. 相似文献
95.
96.
Kunihiko Komatsu Tae-Young Hwang Masakazu Takahashi Takashi Sayama Hideyuki Funatsuki Nobuhiko Oki Masao Ishimoto 《Breeding Science》2012,61(5):646-652
The length of the reproductive period affects the grain yield of soybean (Glycine max [L.] Merr), and genetic control of the period might contribute to yield improvement. To detect genetic factor(s) controlling the reproductive period, a population of recombinant inbred lines (RILs) was developed from a cross between Japanese landrace ‘Ippon-Sangoh’ and, Japanese cultivar ‘Fukuyutaka’ which differ in their duration from flowering to maturation (DFM) relative to the difference in the duration from sowing to flowering (DSF). In the RIL population, the DFM correlated poorly (r = −0.16 to 0.34) with the DSF in all field trials over 3 years. Two stable QTLs for the DFM on chromosomes (Chr-) 10 and 11 as well as two stable QTLs for the DSF on Chr-10 and -16 were identified. The QTL on Chr-11 for the reproductive period (designated as qDfm1; quantitative trait locus for duration from flowering to maturation 1) affected all three trials, and the difference in the DFM between the Fukuyutaka and Ippon-Sangoh was mainly accounted for qDfm1, in which the Fukuyutaka allele promoted a longer period. qDfm1 affected predominantly the reproductive period, and thus it might be possible to alter the period with little influence on the vegetative period. 相似文献
97.
Nobuhiko Oki Kunihiko Komatsu Takashi Sayama Masao Ishimoto Masakazu Takahashi Motoki Takahashi 《Breeding Science》2012,61(5):608-617
The common cutworm (CCW, Spodoptera litura Fabricius) is one of the most serious pests of soybean (Glycine max (L.) Merr.). Previously, two quantitative trait loci (QTLs) for antibiosis resistance to CCW, CCW-1 and CCW-2, were detected in the resistant cultivar Himeshirazu. In this study, we conducted an anti-xenosis bioassay using a recombinant inbred population derived from a cross between a susceptible cultivar Fukuyutaka and Himeshirazu to perform QTL analysis. Two QTLs for antixenosis resistance, qRslx1 and qRslx2, were identified on Chrs 7 and 12, and the resistant alleles of qRslx1 and qRslx2 were derived from Himeshirazu and Fukuyutaka, respectively. The position of qRslx1 is similar to that of CCW-1. We also analyzed pubescence characteristics because they have been reported to be associated with soybean insect resistance. Two QTLs for pubescence length (on Chrs 7 and 12) and two QTLs for pubescence density (on Chrs 1 and 12) were identified. The pubescence QTLs on Chrs 7 and 12 were located near qRslx1 and qRslx2, respectively. These results suggest that the antixenosis resistance could be controlled genetically by the identified QTLs and that the pubescence characteristics might contribute to the soybean antixenosis resistance to CCW. 相似文献
98.
A new analytical procedure has been developed to analyze 2-alkylcyclobutanones to detect gamma-ray-irradiated fat-containing foodstuffs. Samples were extracted with an accelerated solvent extraction system via hot and pressurized ethyl acetate in cells. A large amount of fat in the extract was precipitated and removed with filtration by standing at -20 degrees C after the addition of acetonitrile. The extract was further cleaned with a 1 g silica gel mini column, and the radiolytic compounds of 2-docecylcyclobutanone (2-DCB) and 2-tetradecylcyclobutanone (2-TCB) were determined with gas chromatography with mass spectrometry (GC/MS). Sample preparation time before GC/MS was 7-8 h. At first, the procedure was evaluated with a recovery test in eight samples spiked with 2-DCB and 2-TCB at 20 ng/g, resulting in 70-105% recoveries with mostly less than 10% relative standard deviations. The procedure was further evaluated with beef, pork, chicken, and salmon samples irradiated with gamma-rays from 0.7 to 7.0 kGy at -19 degrees C. Both 2-DCB and 2-TCB in most samples were detected with good dose-response relations at all doses, while salmon was detected more than 2 kGy irradiation. The amounts of 2-alkylcyclobutanones produced reflected precursor fatty acids levels in samples, especially for the combination of 2-TCB and stearic acid. The results indicated that the production rate of 2-TCB to stearic acid was more obvious than that of 2-DCB to palmitic acid in frozen samples with gamma-ray irradiation. 相似文献
99.
100.
In contrast to the relatively stable climate of the past 10,000 years, during glacial times the North Atlantic region experienced large-amplitude transitions between cold (stadial) and warm (interstadial) states. In this modeling study, we demonstrate that hydrological interactions between the Atlantic thermohaline circulation (THC) and adjacent continental ice sheets can trigger abrupt warming events and also limit the lifetime of the interstadial circulation mode. These interactions have the potential to destabilize the THC, which is already more sensitive for glacial conditions than for the present-day climate, thus providing an explanation for the increased variability of glacial climate. 相似文献