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21.
A field experiment was conducted to study the effects of coated urea with urease inhibitor [copper (Cu) and zinc (Zn)], nitrification inhibitor (DMPP), biochar and geopolymer on ammonium, nitrate, Cu, Zn content and crop yield of maize. The treatments were composed of urea alone (control), urea coated Cu and Zn (UCuZn), urea coated with Cu, Zn, and DMPP (UCuZnDMPP), urea impregnated with biochar (Ubio) and urea coated with geopolymer (Ug2). Data showed that treatments with Cu, Zn, and DMPP produced lower ammonium (NH4) and nitrate (NO3) in UCuZn and UCuZnDMPP while they had the highest concentration of Cu and Zn in soil and plant tissues. Plots treated with UCuZn and UCuZnDMPP produced maximum N concentrations in grains and yield, with increases by 79.5% and 74.1%, respectively, as compared with urea (control). This finding demonstrates that by slow down the hydrolysis and nitrification process using urease and nitrification inhibitor were beneficial to increased N uptake, ultimately produced higher yield.  相似文献   
22.
The polyphagous obligate parasites Meloidogyne spp. devastate a wide range of crop plants including bananas and plantains. Their infestations impact agriculture worldwide. Therefore, an effective combating regime against this nematode species and an in-depth understanding of plant-nematode interaction are essential. Early detection of infection by visual inspection is not possible. This hampers early control strategy efforts and makes in-depth research of the early infection and plant defence unfeasible. A simple and robust in planta PCR-based nematode detection method is described here as the first crucial step. This PCR-based detection assay exploits the existence of the Internal Transcribed Spacer 1 (ITS 1) region of the ribosomal DNA (rDNA) gene family in the nematodes for early detection of nematode penetration into the roots. The results demonstrate that this detection assay is suitable to serve as a molecular screening tool for plant root diagnostic purposes.  相似文献   
23.
A 312 bp segment of the mitochondrial cytochrome b gene was sequenced from 132 sea bass Lates calcarifer individuals from nine populations across Peninsular Malaysia. Phylogenetic analysis and analysis of molecular variance within and among populations showed no significant geographical structuring. Several populations formed discrete units while others were of mixed populations. The former group suggests a low gene flow among some populations while the latter suggests that widespread translocations have impacted the other wild and cultured local populations. The data from this study have important implications for fishery management, conservation of sea bass stocks and translocation policy for aquaculture and stock enhancement in Peninsular Malaysia.  相似文献   
24.
SUMMARY: To identify the river buffalo chromosome carrying the genes coding for GAPD, TPI1, and LDHB, karyotypic examination was carried out on 14 buffalo-hamster hybrid clones previously tested for presence of this syntenic group. In cattle, this group (U3) has been assigned to chromosome 5, which is assumed to be homologous to the long arm of buffalo chromosome 4. Chromosome 4 was present in all five clones expressing the three enzymes, and absent in all seven negative clones, indicating that in the buffalo GAPD, TPI1, and LDHB are located on chromosome 4. One clone, expressing GAPD and TPI1, but not LDHB, was found to carry a translocation between hamster marker chromosome M(2) and buffalo 4q1 → 4qter. In another clone, expressing LDHB, but not GAPD and TPI1, chromosome 4 was absent, while a very small, unidentifiable acrocentric was present. These observations suggest that LDHB is located in the proximal part of 4q1, and that GAPD and TPI1 are located more distally, in 4q1 → 4q2. ZUSAMMENFASSUNG: Lokalisierung von Genen auf Chromosom 4 des Flu?büffels durch Büffel-Hamster-Hybridzellen Zur Identifikation von Flu?büffelchromosomen mit Genen für GAPD, TPI1 und LDHB wurden Karyotypenbestimmungen an 14 Büffel-Hamster-Hybridklonen durchgeführt, die vorher auf Anwesenheit der betreffenden synthenischen Gruppen geprüft worden waren. Bei Rindern wird diese Gruppe (U3) dem Chromosom 5 zugeordnet, welches als homolog mit dem langen Arm des Büffelchromosoms 4 betrachtet wird. Chromosom 4 war in allen fünf Klonen, die die drei Enzyme exprimiert haben, vorhanden und fehlte in allen sieben negativen klonen, so da? angenommen werden kann, da? sich bei Büffeln GAPD, TPI1 und LDHB auf Chromosom 4 befinden. Bei einem Klon, der GAPD und TPI1, aber nicht LDHB zeigte, wurde eine Translokation zwischen dem Hamstermarkerchromosom M2 und Büffel 4q1 → 4qter gefunden. Im einem anderen Klon, der LDHB, nicht aber GAPD und TPI1 zeigte, war Chromosom 4 nicht vorhanden, wohl aber ein sehr kleines, nicht identifizierbares akrozen-trisches Chromosom. Diese Beobachtungen weisen darauf hin, da? sich LDHB im proximalen Teil von 4q1 befindet und GAPD und TPI1 vertu distal in 4q1 → 4q2 lokalisiert sind.  相似文献   
25.
A study on the preparation of activated carbon from Acacia mangium wood was conducted, and the operating factors, such as activating agent concentration, activation temperature and activation time, were optimized using response surface methodology. In order to determine the effects of the operating factors namely H3PO4 concentration (6.48–48.5 %), activation temperature (364–1,036 °C) and activation time (19–146 min) on the characteristics of activated carbon, a three-level rotatable central composite design was used. The second-order mathematical model was proposed by regression analysis of the experimental data gathered from 20 batch runs. The optimum H3PO4 concentration, activation temperature and activation time were found to be 40 %, 900 °C and 45 min, respectively. At optimum conditions of the operating factors, the percent yield and surface area were 20.3 % and 1,767 m2/g, respectively. The activated carbon was found to be largely composed of mesopores. About 95 % of the total surface area was attributed to mesopores.  相似文献   
26.
The Beyond Compliance project, which began in July 2011 with funding from the Standards and Trade Development Facility for 2 years, aims to enhance competency and confidence in the South East Asian sub‐region by applying a Systems Approach for pest risk management. The Systems Approach involves the use of integrated measures, at least two of which are independent, that cumulatively reduce the risk of introducing exotic pests through trade. Although useful in circumstances where single measures are inappropriate or unavailable, the Systems Approach is inherently more complicated than single‐measure approaches, which may inhibit its uptake. The project methodology is to take prototype decision‐support tools, such as Control Point‐Bayesian Networks (CP‐BN), developed in recent plant health initiatives in other regions, including the European PRATIQUE project, and to refine them within this sub‐regional context. Case studies of high‐priority potential agricultural trade will be conducted by National Plant Protection Organizations of participating South East Asian countries in trials of the tools, before further modifications. Longer term outcomes may include: more robust pest risk management in the region (for exports and imports); greater inclusion of stakeholders in development of pest risk management plans; increased confidence in trade negotiations; and new opportunities for trade.  相似文献   
27.
28.
Detachment of soil particles by the processes of splash from rainfall and shallow flow from surface runoff is influenced by soil cohesion, soil aggregate properties, and characteristics of this flow. We have evaluated relationships between rates of detachment, aggregate size, and tensile strength of the soil. Soil and water losses were determined in the laboratory from sieved air‐dry samples on three aggregate size ranges of two clay loam soils differing in particle‐size distribution and organic matter. Tensile strength was measured for each aggregate size range. The results showed that as clod size increased, detachment rates increased and interaggregate tensile strength decreased. Wash erosion increased as initial clod size increased despite a decrease in runoff. Final rates of loss by splash were greater from the largest clods than from the smaller clods. Finally, splashed material was larger in size than material washed off. The fact that the size of the splashed material was larger than washed‐off material shows that material in the wash suffered more impact by raindrops and thus was more likely to be fragmented.  相似文献   
29.
This preliminary trial investigated the effect of transportation and lairage periods on physiological parameters of goats subjected to slaughter. Nine male Boer cross goats aged 8–12 months were transported for 6 h and kept at lairage for 3, 6, or 16 h (n = 3). Blood samples were collected at pre- (pre-T) and post-transportation (post-T), and post-slaughter (post-S) for determination of hematological parameters, serum enzyme, protein, and cortisol concentrations. Electroencephalogram readings were taken at pre-T, post-T, pre-slaughter (pre-S), and post-S to determine the median frequency (F50) and total power (Ptot) values. At post-T, there were manifestations of stress leukogram; increase in hematocrit, total protein, and muscle enzyme concentrations; and decrease in Ptot (p < 0.05). The high pre-T cortisol concentration suggests that the goats were already under stress before transportation. Stress leukogram became less evident after lairage, indicating that the goats had recovered from the stress of transportation. Although the Ptot increased at post-S especially following 3 h of lairage, F50 values at post-S did not differ from pre-L, suggesting that the pre-slaughter stress may have affected the pain threshold. It is suggested that after 6 h of transportation, goats should ideally be placed in lairage for a minimum period of 3 h before slaughter.  相似文献   
30.
Abstract

Leaf-level physiology, yield, and fruit quality of two strawberry (Fragaria?×?ananassa Duch.) cultivars, “BG4.370” and “Splendor” grown in five growing substrates were assessed. Substrate ratios were T1: tuff (0–4?mm), T2: cocopeat?+?perlite 4:1, T3: peatmoss?+?perlite 4:1, T4: tuff?+?cocopeat 4:1, and T5: tuff?+?peatmoss 4:1. Strawberry parameters were greatly affected by substrate composition but not cultivars. Plants grown in cocopeat?+?perlite 4:1 had the highest photosynthesis, transpiration, radical scavenging activity, and fruit firmness while those grown in peatmoss?+?perlite 4:1 had the highest yield, total phenolics and nitrate concentration compared to other substrates. Given that peat-based growing substrate has raised concerns over the environmental impacts such as, a reduction of wet-lands and loss of soil organic carbon, the lower environmental impact and higher fruit quality grown on cocopeat justifies the use of cocopeat as an alternative substrate to peatmoss.  相似文献   
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