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71.
In order to establish the migration route of Pacific saury Cololabis saira, we measured the radius of otolith annual rings (ROA) in fish collected from areas off the Japanese coast up to 165°W in June and July (pre-fishing season) and from fishing grounds in August?CNovember (fishing season). The average ROA for six sea areas that each spanned 10° of longitude sampled during the pre-fishing season were compared with data obtained during each month of the fishing season. The average ROA decreased from west to east and also decreased monthly from August to November. The average ROA of fish caught after October at the peak of the fishing season was equivalent to that of the fish caught in the areas east of 160°E or 170°E. We conclude that Pacific saury caught by Japanese fishing vessels during the peak of the fishing season migrate from an area east of 160°E. 相似文献
72.
73.
Chen-Wei Chiu Tomonori Kume Hikaru Komatsu Han Tseng Tsong-Huei Wey Kyoichi Otsuki 《Journal of Forest Research》2016,21(4):151-160
Stand transpiration (E) estimated using the sap flux methods is affected by the azimuthal, radial, and tree-to-tree variations of sap flux. Although several studies have examined the relative importance of the three variations in estimating E, the seasonality of the three variations remains unknown. In the current study, we attempted to clarify whether the relative importance of these three variations could show seasonal changes. Using sap flux data measured in a subtropical cloud forest from August 2010 to July 2011, we calculated the differences resulting from omitting the three variations in estimating E. The effects of the three variations in estimating E showed seasonality. The azimuthal and tree-to-tree variations were more pronounced during winter, whereas the radial variation was more pronounced during summer. However, the effect of tree-to-tree variation was consistently much larger than the other two variations throughout the study period. The tree-to-tree variation is more important in estimating E monthly, seasonally and annually than both the azimuthal and radial variations, although all three variations have shown seasonality. In addition, the sensor allocation for summer would be acceptable for the practical estimation of E if aiming at the long time scale. 相似文献
74.
Wood Science and Technology - The effects of wet–dry and moist–dry cycling on the mechanical properties of reed (Arundo donax L.) were investigated. Because water-soluble extractives... 相似文献
75.
Yuka Onozawa Masaaki Chiwa Hikaru Komatsu Kyoichi Otsuki 《Journal of Forest Research》2009,14(2):111-116
In recent years, moso bamboo (Phyllostachys pubescens) forest areas in Japan have rapidly expanded, and bamboo is now invading nearby natural or plantation forests. To date, only
one study has examined the rainfall interception of a moso bamboo forest. In that study, it was reported that the interception
ratio (interception/rainfall) of the bamboo forest did not exceed the interception ratios of other natural and plantation
forests (n = 4) in Japan. To expand the current state of knowledge about rainfall interception of bamboo forests, we measured throughfall
and stemflow at another bamboo forest site. Annual rainfall (Rf), throughfall (Tf), and stemflow (Sf) during the measurement period were 2,105, 1,556, and 322 mm, respectively. Annual rainfall interception at the plot (I) was 228 mm. Tf/Rf, Sf/Rf, and I/Rf were 73.9, 15.3, 10.8%, respectively. I/Rf was less than 20% throughout the year except in October, the month with lowest rainfall. We also summarized rainfall interception
data from 19 other natural and plantation forests. The I/Rf value of our site did not exceed the I/Rf values of these natural and plantation forests (n = 19). Our data will be useful for assessing changes in water resources that result from replacement of natural or plantation
forests by bamboo forests. 相似文献
76.
In several autogamous and vegetatively propagated crops, DNA markers have been used for cultivar identification. However,
allogamous crops such as bunching onion (Allium fistulosum L.) are recalcitrant to marker-aided cultivar identification, as well as hybrid seed purity tests, due to the high degree
of genetic heterogeneity within each cultivar. To aid cultivar identification and ensure its accuracy in bunching onion, we
proposed the “SSR-tagged breeding” scheme in our previous study. The feasibility of this scheme was investigated here using
a landrace of bunching onion with two populations tagged with two or four selected SSR markers. Compared with a control population,
no significant differences were detected in the agronomic traits of the SSR-tagged populations. The targeted SSR loci were
genetically uniform within each population whereas other loci maintained high heterogeneity. These results demonstrate that
the SSR-tagged breeding scheme, even with a very small number of markers, is efficient for the identification of newly bred
cultivars, and consequently for F1 purity tests, in allogamous crops in which inbreeding depression is as severe as in bunching onion. 相似文献
77.
Tatsuki Yoshinaga Michael J. Miller Kazuki Yokouchi Tsuguo Otake Shingo Kimura Jun Aoyama Shun Watanabe Akira Shinoda Machiko Oya Sachie Miyazaki Kei Zenimoto Ryusuke Sudo Tetsuya Takahashi Hyojin Ahn Ryotaro Manabe Seishi Hagihara Hiroshi Morioka Hikaru Itakura Masamichi Machida Kazuyuki Ban Mayu Shiozaki Bunpei Ai Katsumi Tsukamoto 《Fisheries Science》2011,77(6):983-992
Eggs of the Japanese eel Anguilla japonica collected in the western North Pacific were identified by onboard species-specific polymerase chain reaction (PCR) and DNA nucleotide sequencing after the cruise. Fish eggs of various species were collected by large plankton net tows at 12 stations along the southern part of the West Mariana Ridge on 19–25 May 2009. A total of 43 fish eggs were distinguished morphologically as possibly being of A. japonica. Thirty-one of those were analyzed by PCR, which included 15 eggs collected at 12°50–55′N, 141°15–20′E (in 5 tows) that showed positive results. The 16S ribosomal RNA (rRNA) gene sequences of eggs determined after the cruise indicated that 31 A. japonica eggs had been collected. The remaining eggs were of mesopelagic eel species (Serrivomeridae and Derichthyidae), or unidentified species. The morphological characteristics of the A. japonica eggs were consistent with those of artificially spawned eggs, except they had a slightly larger diameter. The egg diameter range did not overlap with those of mesopelagic eels of the Serrivomeridae, which often spawn in the same area as A. japonica. These results suggest that egg diameter and embryo shape can be used to morphologically identify naturally spawned A. japonica eggs. 相似文献
78.
Satoshi Suyama Kazuhiro Oshima Masayasu Nakagami Yasuhiro Ueno 《Fisheries Science》2009,75(2):325-333
We examined seasonal changes in the relationship between otolith radius and body length in age-zero Pacific saury Cololabis saira collected from June to December 2002–2004, based on 12,164 specimens. Results of the analysis using a generalized linear
model indicated that there were differences in the intercepts among months, but no difference was seen in the slopes. In addition,
post hoc analysis showed that the intercepts got larger as the month progressed from June to December. These results suggested
that although the body length growth rate decreased, the growth of the otolith does not decrease to the same degree as the
body after September, so the ratio of otolith radius to body length becomes larger as the months pass. Consequently, we consider
that the seasonal change in relation between otolith radius and body length affects the back-calculation of body length based
on otolith radius. 相似文献
79.
Masaki Okuda Isao Aramaki Takuya Koseki Hikaru Satoh Katsumi Hashizume 《Cereal Chemistry》2005,82(4):361-368
Using rice samples derived from normal rice cultivars and endosperm starch mutant, we investigated key factors contributing to the enzyme digestibility of steamed rice grains. The chemical composition of polished rice grains, structural features of endosperm starch, and enzyme digestibility of steamed rice grains were examined. The protein content of polished rice grains was 4.6–9.1%, amylose content was 4–27%, the DPn of purified amylose was 900–1,600, the amylopectin short/long chain ratio was 1.2–5.9, and the enzyme digestibilities of steamed polished rice grains were 0.9–12.6 °Brix. Amylose content and RVA parameters (viscosity, breakdown, and setback) correlated significantly with enzyme digestibility of steamed rice grains. Multiple regression formulas were constructed to predict digestibility of steamed rice grain as a function of the molecular characteristics of the starch. When both amylose content and the short/long chain amylopectin ratio were used as predictor variables, they accounted for >80% of the observed variance in digestibility of steamed rice grains. Multiple regression revealed that the more digestible rice samples had starch with a lower amylose content and more short‐chain amylopectin. Reassociation of amylose‐lipid complex and recrystallization of amylopectin in the stored steamed rice grains was monitored by differential scanning calorimetry (DSC), and the observed retrogradation properties were related to the structural characteristics of starch and to the enzyme digestibility of steamed rice grains. 相似文献
80.
Hikaru Watanabe Makoto Okazaki Tsutomu Tamura Kenji Konishi Denzo Inagake Takeharu Bando Hiroshi Kiwada Tomio Miyashita 《Fisheries Science》2012,78(3):557-567
This study represents the first quantitative analysis of the characteristics of the distribution areas and stomach contents
of common minke whale Balaenoptera acutorostrata, sei whale B. borealis, and Bryde’s whale B. edeni in relation to oceanographic and prey environments in mid summer in the western North Pacific. Common minke whales were distributed
within subarctic regions and the northernmost region of the transitional domain, coinciding with the main habitat of their
preferred prey, Pacific saury Cololabis saira. Sei whales were mainly found in the northernmost part of the transition zone and showed prey preference for Japanese anchovy
Engraulis japonica, which was significantly more abundant in the main distribution area of the whale than in its adjacent areas. “Hot spots”
of Bryde’s whales were found in several regions of the transition zone between the subarctic boundary and the Kuroshio front.
This whale species preferred Japanese anchovy as prey, for which the distribution density was significantly higher in the
main distribution area of the whale than in the adjacent areas. These results indicate that the summer distributions of Pacific
saury and Japanese anchovy greatly influence the distributions of these whale species, suggesting that the whales’ habitat
selection is closely related to their prey selection. 相似文献