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971.
Overexpression of the Barley Nicotianamine Synthase Gene HvNAS1 Increases Iron and Zinc Concentrations in Rice Grains 总被引:1,自引:0,他引:1
Hiroshi Masuda Kanako Usuda Takanori Kobayashi Yasuhiro Ishimaru Yusuke Kakei Michiko Takahashi Kyoko Higuchi Hiromi Nakanishi Satoshi Mori Naoko K. Nishizawa 《Rice》2009,2(4):155-166
In humans, iron (Fe) and zinc (Zn) deficiencies result in major worldwide health problems. Transgenic technologies to produce Fe- and Zn-biofortified rice varieties offer a promising potential solution. Nicotianamine, the precursor of phytosiderophores, chelates Fe2+ and Zn2+ and plays an important role in transporting these metals to both vegetative and reproductive organs within the plant. Our objective was to increase Fe and Zn contents in rice grains by overexpressing the barley nicotianamine synthase gene HvNAS1. HvNAS1-overexpressing transgenic rice showed increased HvNAS1 expression and subsequent increases in endogenous nicotianamine and phytosiderophore content in shoots, roots, and seeds. Fe and Zn concentrations in polished T1 seeds from transgenic plants increased more than three and twofold, respectively; Fe and Zn concentrations also increased in both polished and brown T2 seeds. These results suggest that the overproduction of nicotianamine enhances the translocation of Fe and Zn into rice grains. 相似文献
972.
We examined the effects of cultivar (Taporuri, Mohretsu, Tachiaoba, and Hinohikari) on estimated total digestible nutrient (TDN) yield of forage rice in double harvesting. The total estimated whole-plant TDN yield (i.e., of the first crop plus second crop) of Taporuri was the highest in double harvesting. In the first crop, the estimated whole-plant TDN yield of Taporuri was the highest. In the second crop, the estimated whole-plant TDN yield of Taporuri was almost the same as those of Mohretsu and Tachiaoba but higher than that of Hinohikari. We also examined the effects of cultivation method (double harvesting or single harvesting) on estimated TDN yield of forage rice. In Taporuri and Mohretsu, the total estimated whole-plant TDN yield was similar in double harvesting and single harvesting. However, in Tachiaoba and Hinohikari, it was lower in double harvesting than in single harvesting. It is important to maximize the amount of nutrition in leaf and stem rather than panicle because the grain is not digested well by cattle. In the double harvesting, the total estimated leaf blade (leaf) TDN yield of Taporuri was higher than that of Hinohikari and almost the same as those of Tachiaoba and Mohretsu. The total estimated leaf sheath plus stem (stem) TDN yield of Taporuri was the highest. In comparison of the total TDN yield of double harvesting with that of single harvesting, the total estimated leaf and stem TDN yields were higher in double harvesting than in single harvesting in all cultivars except for Hinohikari. Thus, double harvesting of Taporuri is an effective way of reducing the overall loss of nutrition from the crop. 相似文献
973.
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
974.
Takashi Kitagawa Takashi Nakagawa Ryuji Kimura Hiroshi Niino Shingo Kimura 《Fisheries Science》2011,77(2):217-222
Arabesque greenling Pleurogrammus azonus form schools of 30,000–60,000 individuals to feed on mesozooplankton near the sea surface. The fish need to be close to the
surface where mesozooplankton production occurs, but the food is not sufficiently dense there for the fish to grow optimally
while avoiding predation by sea birds. Arabesque greenling use a unique method to optimize their feeding conditions while
avoiding staying on the sea surface. When the school swims upward, water is pushed downward. Upward swimming of a school of
30,000 individuals generates a downward stream of about 0.8–1.1 m/s, resulting in a convergent flow near the surface. This
convergence concentrates the mesozooplankton on the sea surface and transports them into deeper layers with a strong vortex
about 3.0 m in diameter and 10–20 m long. Thus, schooling of this fish induces vortex flows that provide a rich feeding environment. 相似文献
975.
976.
Tomonari Kotani Yoshiyuki Wakiyama Tatsuhiro Imoto Hisahide Suzuki Hiroshi Fushimi 《Journal of the World Aquaculture Society》2009,40(3):383-393
Depending on the initial stocking density, ocellate puffer larvae exhibit the cannibalism that resulted in high mortality. We aimed to clarify the relationship between stocking density of larvae, mortality, and the effect of density on cannibalism. Ocellate puffer larvae were reared at five different stocking densities between 5 and 25 larvae/L with duplicate 1‐m3 tank for each treatment. Larvae were stocked at 0 d after hatch (d.a.h.), and the experimental cultures lasted for 55 d. In larvae stocked initially at more than 10 larvae/L, cannibalism was evident from 11 to 17 d.a.h., and the survival rate at 55 d.a.h. was less than 15%. The survival rate was 25.5% at 5 larvae/L, and cannibalism was observed from 31 to 32 d.a.h. Consequently, an initial density of 5 larvae/L was the most efficient in terms of survival and the prevention of cannibalism. On the other hand, when cannibalism is still observed at 5 larvae/L, it is necessary to lower the stocking density before the onset of cannibalism. 相似文献
977.
Larval metamorphosis inducers of the sea cucumber Apostichopus japonicus were screened from physiologically active compounds. Doliolaria larvae completed their metamorphosis to juveniles in 120 h
when treated with 5–10 μM of dopamine and l-DOPA, and 50 μM of l-adrenaline and l-noradrenaline. Doliolaria larvae had to be exposed to dopamine or l-DOPA for at least 24 h. D1-like dopamine receptor antagonists SKF87566 and LE300 (10 μM) inhibited metamorphosis by dopamine.
However, the D2-like dopamine receptor antagonists sulpiride and nemonapride (10 μM) did not inhibit the effect of dopamine.
The results suggest that D1-like dopamine receptors are involved in larval metamorphosis of the sea cucumber A. japonicus. 相似文献
978.
The morphological development of larval and juvenile blacktip grouper, Epinephelus fasciatus, was examined using a hatchery-reared series. By about 5 mm body length (BL), the larvae developed characteristic pigmentation
patterns of groupers, such as melanophores on the dorsal part of the gut, on the tips of the second-dorsal and pelvic fin
spines, and on the midpoint of the tail to form a cluster. In addition, characteristic spines of groupers, such as spinelets
on the second-dorsal and pelvic fin spines, and the preopercular angle spine developed by about 6 mm BL. The notochord end
was in the process of flexion in larvae of 6–7 mm BL, by when major melanophores, spines, and jaw teeth started to appear.
After the fin ray counts attained the adult complement at about 14 mm BL, somewhat densely pigmented bands started to appear
on the body. The fish had the five distinct transverse bands and attained adult-like attire at about 40 mm BL when the major
head spines disappeared and body parts in relation to BL became stable. 相似文献
979.
Hiroshi Aiki Katsuhiko Takayama Takashi Tamaru Nobuhiro Mano Masafumi Shimada Hiroshi Komaki Hitomi Hirose 《Fisheries Science》2009,75(4):903-908
The Japanese eight-barbel loach Lefua echigonia, which is a freshwater fish native to Japan, is distributed from the Tohoku to Kinki districts and is divided into six regional
populations according to mtDNA analysis. In this study, we investigated L. echigonia collected from several locations in Yamagata Prefecture and neighboring prefectures using mtDNA control region sequences
and confirmed the spatial distribution pattern among the new regional population (Yamagata population). The new population
was limited to the Mogami river system in the inland area of Yamagata Prefecture and is distinguished from other regional
populations by high sequence divergences. 相似文献
980.
Tetsuya Umino Teruyuki Kajihara Hiroshi Shiozaki Toshiyuki Ohkawa Dal-Sang Jeong Kenichi Ohara 《Fisheries Science》2009,75(4):909-919
Twelve populations of Girella punctata, from widespread locations of the species’ range in Japan and Korea, were screened for sequence variability within the mitochondrial
DNA (mtDNA) control region (n = 128) and at five polymorphic microsatellite loci (n = 547) to determine the genetic structure maintaining population integrity. mtDNA variability of 132 variable sites within
a 334-bp region reveals shallow genetic differentiation across populations. The weak differentiation of G. punctata was partly supported by the screening of five polymorphic microsatellite loci. However, hierarchical analysis of molecular
variance and principal component analysis on the basis of allele frequencies in microsatellite loci extracted a subtle substructure
in a subsidiary population and in near-subsidiary populations in the semi-enclosed Seto Inland Sea. 相似文献