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161.
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163.
In spite of their importance in fundamental and applied studies, the preparation of endohedral fullerenes has relied on difficult-to-control physical methods. We report a four-step organic reaction that completely closes a 13-membered ring orifice of an open-cage fullerene. This process can be used to synthesize a fullerene C60 encapsulating molecular hydrogen, which can be isolated as a pure product. This molecular surgical method should make possible the preparation of a series of C60 fullerenes, encapsulating either small atoms or molecules, that are not accessible by conventional physical methods. 相似文献
164.
Development of a multiplex polymerase chain reaction method for simultaneous detection of eight events of genetically modified maize 总被引:2,自引:0,他引:2
Onishi M Matsuoka T Kodama T Kashiwaba K Futo S Akiyama H Maitani T Furui S Oguchi T Hino A 《Journal of agricultural and food chemistry》2005,53(25):9713-9721
In this study, we developed a novel multiplex polymerase chain reaction (PCR) method for simultaneous detection of up to eight events of genetically modified (GM) maize within a single reaction. The eight detection primer pairs designed to be construct specific for eight respective GM events (i.e., Bt11, Event176, GA21, MON810, MON863, NK603, T25, and TC1507) and a primer pair for an endogenous reference gene, ssIIb, were included in the nonaplex(9plex) PCR system, and its amplified products could be distinguished by agarose gel and capillary electrophoreses based on their different lengths. The optimal condition enabled us to reliably amplify two fragments corresponding to a construct specific sequence and a taxon specific ssIIb in each of the eight events of GM maize and all of nine fragments in a simulated GM mixture containing as little as 0.25% (w/w) each of eight events of GM maize. These results indicate that this multiplex PCR method could be an effective qualitative detection method for screening GM maize. 相似文献
165.
Hiroshi Tago Hirokazu Kimura Kunihisa Kozawa Koichi Fujie 《Water, air, and soil pollution》2005,163(1-4):269-280
We measured formaldehyde concentrations in ambient air at urban (Isesaki) and rural (Annaka) sites in Gunma Prefecture, Japan from June 1998 to March 2003. Measurements were carried out once in a month to obtain daily mean formaldehyde concentrations. At both the sites, mean concentrations of formaldehyde were significantly higher from April to September (summer) than from October to March (winter). Formaldehyde concentrations in Annaka were essentially as high as those in Isesaki in summer, but were significantly lower in winter. At both the sites, concentrations of formaldehyde and oxidants correlated significantly with one another in the summer; correlation coefficients in Annaka and Isesaki were 0.82 and 0.64, respectively. The fraction of formaldehyde formed photochemically based on concentrations of benzene was calculated to be as high as 80% in both the sites in summer. The results suggested that formaldehyde concentrations were high even in rural air, reflecting photochemical reactions rather than automobile exhaust. 相似文献
166.
Yuuto KAWASHIMA Ayako FUJIMOTO Morihiro SAITO Osamu MIKAMI Yoshiharu ISHIKAWA Koichi KADOTA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(6):968
The histology and immunohistochemistry of pleomorphic and conventional epithelioid mesotheliomas were examined. The former was detected in two young calves aged 2 and 4 months and was characterized by pleomorphic and atypical cells with decreased expression of cytokeratin 7 (CK7). In contrast, the latter was found in a 31-month-old heifer, consisting of tumor cells uniform in size and shape with CK7 expression in nearly all cells. Production of collagen by tumor cells was demonstrated in both histological types, and was considered to be characteristic of bovine epithelioid mesothelioma. Pleomorphic mesothelioma is far more pleomorphic and mitotically active than conventional mesothelioma, and its normal counterpart may be immature mesothelial cells with high proliferation potential, which exist in fetal life and early calfhood. 相似文献
167.
Flood mitigation in irrigation tanks and paddy fields is their favorable aspect though its practical effect is not known very
well. A dynamic and systematic approach is presented to assess flood mitigation in a tank irrigated paddy fields area in the
worst case where no static buffer function is expected. Based on the linear control theory, transfer function models for runoff
process in catchments are identified. Hydraulic models are developed to represent flood dynamics in irrigation tanks, paddy
fields, and drainage channels. These models are integrated as an ordinary differential equations system. Then, using the perturbed
linear system, flood mitigation in each component of the system is examined in terms of frequency response. An application
example demonstrates that a tank irrigated paddy fields area has a significant flood mitigation effect as a low-pass filter.
This method has the advantage of assessing flood mitigation even in the case of an increase in the total runoff ratio. 相似文献
168.
Koichi Fujie Hong-Ying Hu Hajime Tanaka Kohei Urano Katsuaki Saitou Arata Katayama 《Soil Science and Plant Nutrition》2013,59(3):467-470
Recently, the analysis of the microbial community structure in soil has received a great deal of attention. Various analytical methods based on biomarkers have been developed: 16S-rDNA, total DNA, phospholipid fatty acids, ergosterols, muramic acids, etc. (Tunlid and White 1992; Carter and Lynch 1993). In a previous paper, we reported that respiratory quinones are useful biomarkers to characterize the microbial community structure in soil (Fujie et al. 1998). In these analyses, only fresh moist soils or frozen soils had been used as samples. However, the soil samples are generally stored in the dark after air drying in many research institutes and experimental stations. It was considered that the analysis of microbial communities in dried soil samples was not possible. In this paper, we observed that the drying of soils did not affect the proportions of quinone species in soil although the treatment decreased the amount of extracted quinones. These findings suggest that the analysis of the respiratory quinone profile of dried soils reflects the micro biota present in fresh moist soils before drying. 相似文献
169.
Arata Katayama Hong-Ying Hu Mamie Nozawa Haruyoshi Yamakawa Koichi Fujie 《Soil Science and Plant Nutrition》2013,59(4):559-569
Quinone profile analysis of stored air-dried soils gave an approximation of the long-term changes in the microbial community structure in four soils subjected to different types of fertilizer application from 1987 to 1997: unfertilized soil (NF-soil), soil amended with chemical fertilizers (CF-soil), soil amended with chemical fertilizers and 40 t ha-1 y-1 of farmyard manure (CF+ FYM-soil), and soil amended with 400 t ha-1 y-1 of farmyard manure (FYM-soil). The carbon content increased, and the soil pH remained higher in the soils receiving farmyard manure. Principal component analysis of the quinone profiles of the soils indicated that the microbial community structure showed a high similarity among the four soils before the onset of cultivation and changed to a different community structure specific to the respective fertilizing practices except for the NF-soil. The specific quinone profile became stable after two cropping seasons in the FYM-soil, after 10 cropping seasons in the CF+ FYM-soil and after 15 cropping seasons in the CF-soil, respectively. The quinone profile of the NF-soil did not become stable, and no specific profile was developed. The specific quinone profiles in the FYM- and CF+ FYM-soils were both characterized by large mole fractions of menaquinone with seven isoprenoid units (MK-7). Farmyard manure itself contained a large mole fraction of MK-7. It was suggested that the amount of MK-7 increased due to the application of farmyard manure. MK-7 indicates the presence of Gram-positive bacteria with low guanine plus cytosine contents such as Bacillus and Gram-negative bacteria of the Cytophaga-Flavobacterium complex. The specific quinone profile in the CF-soil was characterized by the presence of menaquinone with seven isoprenoid units dihydrated (MK-7(H2)and MK-7(H4). Although Brevibacterium and Kocuria contain MK-7(H2), no microorganisms are known to have MK- 7(H.) as major quinone. The common major quinones were MK-8, MK-10(H4) and a mixture of MK-8(H4) and MK-9, suggesting the predominance of Grampositive bacteria in all the soils. Mole fractions of Ubiquinone with 8 isoprenoid units (Q-8) and Q-10 increased at various times in all the soils, indicating the sporadic growth of Gram-negative bacteria. 相似文献
170.
Koichi Hayano 《Soil Science and Plant Nutrition》2013,59(2):103-108
A method is described for the rapid and simple assay of soil β-glucosidase activity. It involves colorimetric estimation of ρ-nitrophenol released by β-glucosidase activity when soil is incubated in McIlvaine buffer (pH 4.8) with ρnitrophenyl βd-glucoside and toluene at 30°C for 1 hr. The method has been applied to three different soils. The range of β-glucosidase activity in cultivated soils was from 10.1 to 15.2 mµ mole per min per gram of dried soil. Km value for ρ-nitrophenyl β-d-glucoside was 3.3 × 10-4 M. Optimum pH was 4.8. 相似文献