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排序方式: 共有550条查询结果,搜索用时 15 毫秒
541.
Ryuya Takanashi Wataru Ishihara Kei Sawata Yuzou Sano Tomonori Azuma Mitsunori Mori Akio Koizumi Yoshihisa Sasaki Takuro Hirai 《Journal of Wood Science》2014,60(3):186-193
In order to investigate shear failure surface of decayed wood, wood pieces of ezomatsu (Picea jezoensis) were exposed to brown-rot fungus (Fomitopsis palustris), and standard shear test in radial plane was conducted. The failure surfaces were examined by scanning electron microscopy and surface roughness measurements were also conducted. Transwall failure that the crack elongated parallel to the tracheid axis was observed in the earlywood region through all phases of decay. Intrawall failure principally occurred in the latewood region on the early phase of decay. When decay progressed considerably, transwall failure that the crack elongated perpendicularly to the tracheid axis occurred. And transwall failure was also dominant failure morphology in the latewood region. Fragments of tracheids which were partly peeled out from S2 layers were observed in some specimens. Size and appearance frequency of fragments of tracheid were smaller and lower when decay progressed. Arithmetic average roughness, which was the index of fragment size and appearance frequency, had positive correlation to shear strength ratio. Especially, line surface roughness of radial direction, which was measured across the radial files of tracheid, had the highest correlation to the shear strength ratio. The surface roughness would be a good indicator to evaluate the decay degree. 相似文献
542.
Newly released rice varieties are mostly progenies of common commercial cultivars and so most gene sources for rice breeding have closely related genotypes. Protoplast fusion technique is a method that can produce hybrid plants in one‐step within a desired cultivar. To introduce new genetic diversity into rice‐breeding materials, hybrids between Oryza sativa L. (AA) and Oryza punctata Kotschy ex Steud. (BBCC) were generated by symmetric protoplast fusion. The genomic distribution in interspecific somatic hybrids was investigated by multi‐colour genomic in situ hybridization. Differences in chromosome numbers were observed not only between different somatic hybrid plants but also within individual hybrid plants. Chromosomal reduction of the A genome was found in two somatic hybrids. These results suggest that it is possible to reconstruct new interspecific rice genomes. Chromosomal reduction in interspecific somatic hybrids may be used to generate breeding lines with novel chromosomal constitutions. 相似文献
543.
Kazuyuki Mori Kenji Asano Seiji Tamiya Takashi Nakao Motoyuki Mori 《Breeding Science》2015,65(1):3-16
The potato (Solanum tuberosum L.) is cultivated all year round in Japan by using four types of cropping: summer and winter croppings, and double cropping in spring and fall. In each cropping season, growth conditions such as temperature, day length, and growing period, differ drastically; thus, different cultivars adapted to each environment are required. Breeding stations are located in both summer cropping areas and double cropping areas, and cultivars suitable for each cropping system are developed. The required cultivars differ according to cropping type and according to use such as table use, food processing, and starch production. The qualities necessary for each purpose differ and are therefore evaluated accordingly. Improvements in pest and disease resistance and in yield abilities are important as common breeding targets for all purposes. To develop potato cultivars that meet different needs, breeders have continued efforts to improve these traits. In this review, we introduce our approaches to developing new potato cultivars. We also discuss problems predicted in the future and introduce our efforts on broadening genetic diversity. 相似文献
544.
The sulfur-induced embrittlement of nickel has long been wrapped in mystery as to why and how sulfur weakens the grain boundaries of nickel and why a critical intergranular sulfur concentration is required. From first-principles calculations, we found that a large grain-boundary expansion is caused by a short-range overlap repulsion among densely segregated and neighboring sulfur atoms. This expansion results in a drastic grain-boundary decohesion that reduces the grain-boundary tensile strength by one order of magnitude. This decohesion may directly cause the embrittlement, because the critical sulfur concentration of this decohesion agrees well with experimental data on the embrittlement. 相似文献
545.
546.
Assistance of microbial glycolipid antigen processing by CD1e 总被引:1,自引:0,他引:1
de la Salle H Mariotti S Angenieux C Gilleron M Garcia-Alles LF Malm D Berg T Paoletti S Maître B Mourey L Salamero J Cazenave JP Hanau D Mori L Puzo G De Libero G 《Science (New York, N.Y.)》2005,310(5752):1321-1324
Complexes between CD1 molecules and self or microbial glycolipids represent important immunogenic ligands for specific subsets of T cells. However, the function of one of the CD1 family members, CD1e, has yet to be determined. Here, we show that the mycobacterial antigens hexamannosylated phosphatidyl-myo-inositols (PIM6) stimulate CD1b-restricted T cells only after partial digestion of the oligomannose moiety by lysosomal alpha-mannosidase and that soluble CD1e is required for this processing. Furthermore, recombinant CD1e was able to bind glycolipids and assist in the digestion of PIM6. We propose that, through this form of glycolipid editing, CD1e helps expand the repertoire of glycolipidic T cell antigens to optimize antimicrobial immune responses. 相似文献
547.
Diabetes mellitus (DM) is a common endocrine disease in cats and dogs with increasing prevalence. Type 1 DM appears to be
the most common form of diabetes in dogs whereas Type 2 DM prevails for cats. Since insulin resistance is more frequently
encountered in cats than dogs, our laboratory was interested in determining whether differences at the insulin signaling pathway
level and differences in glucose and lipid metabolism could be observed between cats and dogs. Insulin resistance has been
positively correlated to insulin signaling pathway abnormalities. As such, this study measured insulin receptor substrate-1
(IRS-1), insulin receptor substrate-2 (IRS-2), and phosphatidylinositol 3-kinase (PI3-K) P-85α mRNA expression levels in classical
insulin-responsive sensitive tissues (liver, skeletal muscle, and abdominal fat) and peripheral leukocytes between cats and
dogs by qRT-PCR. Different tissues were sampled because it is currently unknown where insulin-resistance arises from. In addition,
enzymes involved in glucose and lipid metabolism, malate dehydrogenase (MDH), glucose-6-phosphate dehydrogenase (G6PDH) and
fatty acid synthase (FAS) were also assessed since glucose and lipid metabolism differs between cats and dogs. Overall, IRS-1,
IRS-2, PI3-K, MDH, G6DPH, and FAS mRNA tissue expression profiles demonstrated different levels of expression, in various
tissues for both canines and felines, which was expected. No distinct expression pattern emerged; however, differences were
noted between canines and felines. In addition, IRS-1, IRS-2, PI3-K, MDH, G6DPH, and FAS mRNA expression was significantly
higher in canine versus feline tissues, including peripheral leukocytes. Remarkable differences in insulin signaling gene
expression between felines and canines indicate that cats may have an underlying low insulin sensitivity level due to low
IRS-1, IRS-2, and PI3-K P-85α mRNA expression levels which would predispose cats to develop insulin resistance. Moreover,
differences in glucose and lipid metabolism related gene expression (MDH, G6DPH, and FAS) demonstrate that felines have an
overall lower metabolic rate in various tissues which may be attributed to overall lower insulin signaling gene expression
and a lack of physical activity as compared to canines. Therefore, a combination of genetic and environmental factors appears
to make felines more prone to suffer from insulin resistance and type 2 DM than canines. 相似文献
548.
T. Sako A. Mori P. Lee T. Sato H. Mizutani T. Takahashi Y. Kiyosawa H. Tazaki T. Arai 《Veterinary research communications》2009,33(5):473-479
Measurements of serum fructosamine, glycated hemoglobin, and glycated albumin (GA) complement serum glucose concentration
for better management of diabetes mellitus (DM). Especially, the serum fructosamine test has long been used for diagnosing
and monitoring the effect of treatment of DM in dogs. However, fructosamine tests are currently not performed in veterinary
medicine in Japan. GA and fructoasmine levels have been shown to strongly correlate. However, the clinical implications of
using GA remain to be elucidated. Therefore, the purpose of the current study was threefold: 1) Determine whether GA% is altered
by acute hyperglycemia in normal dogs, simulating stress induced hyperglycemia; 2) Demonstrate that GA% does not dynamically
change with diurnal variation of blood glucose concentration in diabetic dogs; and 3) Investigate whether GA% is capable of
providing an index of glycemic control for 1–3 weeks in diabetic dogs as is the case with diabetic human patients. Our study
demonstrated that serum GA% remains very stable and unaltered under acute hyperglycemic conditions (intravenous glucose injection)
and in spite of diurnal variation of blood glucose concentration. Furthermore, serum GA% can reflect long-term changes (almost
1–3 weeks) in blood glucose concentration and the effect of injected insulin in diabetic dogs. 相似文献
549.
Tetsuichiro Funamoto Orio Yamamura Osamu Shida Kazuhiko Itaya Ken Mori Yoshiaki Hiyama Yasunori Sakurai 《Fisheries Science》2014,80(2):117-126
The Japanese Pacific stock (JPS) and the northern Japan Sea stock (JSS) of walleye pollock Theragra chalcogramma are mainly distributed in the Pacific Ocean and the Sea of Japan off northern Japan, respectively. This paper summarizes and compares the factors affecting the recruitment variability of these two stocks. Spawning season is from December to March for both stocks. JPS recruitment has a positive relationship with the water temperature in January and February, whereas that of JSS has a negative relationship with the water temperature in January, February, and April. One possible reason for this is that pollock larvae have an optimum growth temperature of approximately 5 °C in the field. Drift of early life stages also appears to be an important influence on the recruitment of both stocks. Because the current generated by the northwest wind carries eggs of JPS into the main larval nursery ground, JPS recruitment is enhanced in years when the northwest wind is predominant in February. On the other hand, early life stages of JSS are transported into the nursery ground by the Tsushima Warm Current. However, this current also carries early life stages into the Sea of Okhotsk and offshore, resulting in poor JSS recruitment in years when this current is strong in March. In contrast to JPS, the recruitment of which is significantly impacted by cannibalism, young pollock have not been found in the stomachs of adult JSS. Warm temperatures in the Sea of Japan seem to induce the separation of young and adult pollock, and the shape of the stock–recruitment relationship also suggests that cannibalism is not important for JSS. Based on this knowledge, and on the hatch date distributions of larvae and juveniles, we propose mechanisms that can explain the recruitment fluctuations for JPS and JSS pollock. 相似文献
550.
Warita K Sugawara T Yue ZP Tsukahara S Mutoh K Hasegawa Y Kitagawa H Mori C Hoshi N 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(12):1257-1267
For the purpose of investigation of working mechanisms in endocrine disruptors, we evaluated the dose-related effects of fetal and/or neonatal exposure to an estrogenic compound on the male reproductive organs in adult mice, particularly with respect to gene expression of steroidogenic acute regulatory protein (StAR). The pregnant ICR mice were given subcutaneous injections of 10 micro g/day/animal of diethylstilbestrol (DES) to subject the fetal mice to in utero exposure (IUE). Subsequently, the newborn male mice were subjected to neonatal exposure (NE) by treatment with vehicle or 0.1-10 micro g/day/animal of DES. Fertility rates of each group were as follows: control, 100%; IUE only, 60%; IUE+NE 0.1 micro g, 25%; IUE+NE 1 micro g, 0%; IUE+NE 10 micro g, 0%. In general histology, germ cell layers in the seminiferous tubules were thinned in the group of IUE+NE 10 micro g. Hypoplasia of the Leydig cells, in which the staining intensity of eosin was diminished, was also observed in the groups of IUE+NE 0.1-10 micro g. The androgen receptor (AR) and estrogen receptor alpha (ERalpha) immunoexpression in the Leydig cells of IUE+NE 1-10 micro g was slightly lower than that in the controls. Long-term dysfunction of the hypothalamo-pituitary-testicular axis, including sustained hypoproduction of gonadotropin and testosterone, and altered expressions of steroid hormone receptors and StAR genes were observed. The hypothalamo-pituitary control of gonadotropin secretion may be affected by the smaller doses of estrogenic agents than the reproductive organs. Furthermore, the fertility rate in the male mice exposed to this estrogenic agent was closely correlated with the testosterone levels, and even more so with the rate-limiting factor of steroidogenesis, StAR. This finding suggests that endocrine disruptors have an important pronounced effect on StAR gene expression. 相似文献