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41.
This paper reports findings of surveys into small-scale sawmilling and timber processing in Phu Tho Province and the Tam Dao
National Park buffer zone in northern Vietnam. The objective of these surveys was to examine the extent to which small sawmills
and timber processors utilise farm-grown timber, so as to explore the prospects for expansion of farm-grown timber markets.
The operational scope, supply chain and value chain of the industry are reported. Resource availability and current and future
perspectives are discussed. Timber prices were found to vary greatly between species and study areas. Species most in demand
by enterprises are Artocarpus heterophyllus, Melia azedarach, Manglietia conifera, Acacia spp., Chukrasia tabularis and Erythrophloeum fordii. Small-scale sawmilling and timber processing activities fit well with rural communities in Vietnam and have potential for
further development if current constraints can be overcome. Further tree planting is needed to meet the presently unsatisfied
timber demand and to create income and employment. Information from sawmillers and timber processors suggests the types of
species that farmers should be considering for their plantings. 相似文献
42.
White spot syndrome virus (WSSV) is the most important pathogen in shrimp farming systems worldwide including the Mekong Delta, Vietnam. The genome of WSSV is characterized by the presence of two major ‘indel regions’ found at ORF14/15 and ORF23/24 (WSSV‐Thailand) and three regions with variable number tandem repeats (VNTR) located in ORF75, ORF94 and ORF125. In the current study, we investigated whether or not the number of repeat units in the VNTRs correlates with virus outbreak status and/or shrimp farming practice. We analysed 662 WSSV samples from individual WSSV‐infected Penaeus monodon shrimp from 104 ponds collected from two important shrimp farming regions of the Mekong Delta: Ca Mau and Bac Lieu. Using this large data set and statistical analysis, we found that for ORF94 and ORF125, the mean number of repeat units (RUs) in VNTRs was significantly lower in disease outbreak ponds than in non‐outbreak ponds. Although a higher mean RU number was observed in the improved‐extensive system than in the rice‐shrimp or semi‐intensive systems, these differences were not significant. VNTR sequences are thus not only useful markers for studying WSSV genotypes and populations, but specific VNTR variants also correlate with disease outbreaks in shrimp farming systems. 相似文献
43.
44.
TRAN DANG XUAN EIJI TSUZUKI HIROYUKI TERAO MITSUHIRO MATSUO TRAN DANG KHANH SEIICHI MURAYAMA NGUYEN HUU HONG 《Weed Biology and Management》2003,3(2):137-144
Two alfalfa varieties, namely Rasen and Yuba , and rice by-products of Koshihikari ( Oryza sativa L. cv. Japonica ), including hull and bran were used for weed control in rice. Rasen and Yuba were sequentially evaluated to have the strongest allelopathic potential among eight common alfalfa varieties in Japan. Rasen , Yuba and rice by-products in a laboratory experiment exhibited suppression of emergence of lettuce ( Lactuca sativa L.), barnyardgrass ( Echinochloa oryzicola Vasing.), and monochoria ( Monochoria vaginalis Presl var. plantaginea Solms-Laub.). In a paddy field experiment, at 15 days after application, a dose of 1 ton ha−1 of alfalfa, rice by-products and the incorporated alfalfa-rice by-products significantly inhibited weed growth and reduced weed species, except for rice bran. However, at 40 days after application, the greatest weed control was sequentially recorded with Yuba (95.2%), Rasen (90.5%) and the incorporated Rasen -hull (88.3%). Rice hull exhibited stronger (51.7%) weed control than the negligible weed control of rice bran (25.1%). Inhibition of both Rasen and Yuba on weed emergence after application became more vigorous, whereas those of rice by-products were gradually devitalized. Rasen had a maximum increase of rice yield (80.6%) compared to the control and it was slightly higher (9.6%) than the herbicide treatment. Findings showed that Rasen was the most promising material for weed control among those studied. Results denoted that weed control capability of allelopathic materials had an impetuous effect on rice growth and yield. 相似文献
45.
Cameron RG Savary BJ Hotchkiss AT Fishman ML Chau HK Baker RA Grohmann K 《Journal of agricultural and food chemistry》2003,51(7):2070-2075
A pectin methylesterase (PME) from sweet orange fruit rag tissue, which does not destabilize citrus juice cloud, has been characterized. It is a salt-dependent PME (type II) and exhibits optimal activity between 0.1 and 0.2 M NaCl at pH 7.5. The pH optimum shifted to a more alkaline range as the salt molarity decreased (pH 8.5-9.5 at 50 mM NaCl). It has an apparent molecular mass of 32.4 kDa as determined by gel filtration chromatography, an apparent molecular mass of 33.5 kDa as determined by denaturing electrophoresis, and a pI of 10.1 and exhibits a single activity band after isoelectric focusing (IEF). It has a K(m) of 0.0487 mg/mL and a V(max) of 4.2378 nkat/mg of protein on 59% DE citrus pectin. Deblocking the N-terminus revealed a partial peptide composed of SVTPNV. De-esterification of non-calcium-sensitive pectin by 6.5% increased the calcium-sensitive pectin ratio (CSPR) from 0.045 +/- 0.011 to 0.829 +/- 0.033 but had little, if any, effect on pectin molecular weight. These properties indicate this enzyme will be useful for studying the PME mode of action as it relates to juice cloud destabilization. 相似文献
46.
Immunity-related genes and gene families in Anopheles gambiae 总被引:2,自引:0,他引:2
Christophides GK Zdobnov E Barillas-Mury C Birney E Blandin S Blass C Brey PT Collins FH Danielli A Dimopoulos G Hetru C Hoa NT Hoffmann JA Kanzok SM Letunic I Levashina EA Loukeris TG Lycett G Meister S Michel K Moita LF Müller HM Osta MA Paskewitz SM Reichhart JM Rzhetsky A Troxler L Vernick KD Vlachou D Volz J von Mering C Xu J Zheng L Bork P Kafatos FC 《Science (New York, N.Y.)》2002,298(5591):159-165
We have identified 242 Anopheles gambiae genes from 18 gene families implicated in innate immunity and have detected marked diversification relative to Drosophila melanogaster. Immune-related gene families involved in recognition, signal modulation, and effector systems show a marked deficit of orthologs and excessive gene expansions, possibly reflecting selection pressures from different pathogens encountered in these insects' very different life-styles. In contrast, the multifunctional Toll signal transduction pathway is substantially conserved, presumably because of counterselection for developmental stability. Representative expression profiles confirm that sequence diversification is accompanied by specific responses to different immune challenges. Alternative RNA splicing may also contribute to expansion of the immune repertoire. 相似文献
48.
Ngo T.B. TRAN Hiroshi SHIMODA Junko MIZUNO Keita ISHIJIMA Kenzo YONEMITSU Shohei MINAMI Supriyono Yudai KURODA Kango TATEMOTO Milagros V. MENDOZA Ai TAKANO Masahiko MUTO Haruhiko ISAWA Kyoko SAWABE Daisuke HAYASAKA Ken MAEDA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2022,84(1):82
Kabuto Mountain virus (KAMV), the new member of the genus Uukuvirus, was isolated from the tick Haemaphysalis flava in 2018 in Japan. To date, there is no information on KAMV infection in human and animals. Therefore, serological surveillance of the infection among humans and wild mammals was conducted by virus-neutralization (VN) test and indirect immunofluorescence assay (IFA). Sera of 24 humans, 59 monkeys, 171 wild boars, 233 Sika deer, 7 bears, and 27 nutria in Yamaguchi Prefecture were analyzed by VN test. The positive ratio of humans, monkeys, wild boars, and Sika deer were 20.8%, 3.4%, 33.9% and 4.7%, respectively. No positive samples were detected in bears and nutria. The correlation coefficients between VN test and IFA in human, monkey, wild boar, and Sika deer sera were 0.5745, 0.7198, 0.9967 and 0.9525, respectively. In addition, KAMV was detected in one pool of Haemaphysalis formosensis ticks in Wakayama Prefecture. These results indicated that KAMV or KAMV-like virus is circulating among many wildlife and ticks, and that this virus incidentally infects humans. 相似文献
49.
Several mixed hydroxides obtained by co-precipitation of FeCl2 or FeCl2 with Na2SiO2 followed by ageing and purification were studied by X-ray diffraction, infra-red spectroscopy, and surface-area measurements. The compounds with molecular ratios SiO2/Fe2O3 ranging from 0·1 to 1·17 are essentially amorphous. Silica, which is not to be considered as an integral part of the gel, is chemi-sorbed on the ferric or‘ferrosic’ phase. The good agreement between IR, DTA, and surface-area measurements with increasing molecular ratios permits the distinction between two ranges of silica contents. In the first range, MR <·1, silica is directly chemisorbed on the adsorbant. In the MR >0·1 range, silica polymerizes as a separate phase growing upon the‘ferrosic’ or‘ferric’ phase. 相似文献
50.
Weed control with alfalfa pellets in transplanting rice 总被引:1,自引:1,他引:1
TRAN DANG XUAN EIJI TSUZUKI HIDEO UEMATSU HIROYUKI TERAO 《Weed Biology and Management》2001,1(4):231-235
Alfalfa [ Medicago sativa L. ( M. media , M. falcate )] plants contain allelochemicals that have detrimental effects on their own growth and that of surrounding plants. Alfalfa pellets, used as a food for livestock, were used as the material for the control of weeds in this study. In a greenhouse experiment, alfalfa pellets applied at 1–3 tons ha−1 completely inhibited the emergence of abunome ( Doparium junceum Hamilt.), false pimpernel ( Lindernia pyxidaria L.), and long stemmed water wort ( Elatine trianda Schk. var. pedicellata Krylov) The number and the dry weight of emerged Echinochloa oryzicola plants were significantly reduced. Application of 3 tons ha−1 alfalfa pellets completely inhibited the emergences of Eleocharis acicularis and Rotala indica. Results demonstrated that the inhibitory effect of alfalfa pellets became greater as the dose increased, and it also varied among weed species. Furthermore, the paddy field experiment suggested that the dose of 1–2 tons ha−1 of alfalfa pellets could control more weed species without any rice plant injury. 相似文献