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71.
Buffalo is considered short-day breeder in tropical and subtropical part of the world and seasonality and photoperiodism impart major influence on its fertility. However, its impact on in vitro embryo production (IVEP) remains elusive. Therefore, this study investigated the effect of seasonal variations and photoperiodism on morphological and molecular parameters of IVEP in buffalo. For this purpose, we conducted two different experiments on the oocytes obtained by aspirating follicles from abattoir derived ovaries. In Exp. I, retrospective analysis was performed for oocyte recovery, blastocyst and hatching rate, during four consecutive seasonal periods (i.e. January–March, April–June, July–September and October–December). In Exp. II, oocytes from peak breeding and non-breeding seasons were subjected to 24 hr in vitro maturation and evaluated for polar body extrusion to assess maturation rate. Results showed that embryo development was markedly low during second quarter (April–June) and maximum during fourth quarter (October–December) of the year; referred as non-breeding and breeding seasons, respectively. Comparative data analysis demonstrated that poor oocyte quality is major reason for lesser efficiency of embryo production during non-breeding season than peak breeding season as suggested by poor oocyte recovery (2.31 ± 0.10 vs. 3.65 ± 0.27) and maturation rate (33.32 ± 2.1 vs. 63.15 ± 7.31). Subsequently, comparative gene expression analysis of blastocysts during peak breeding season significantly upregulated pluripotency gene (OCT-4) and downregulated heat shock protein 90, as compared to non-breeding season. Therefore, it could be divulged from the present study that seasonal variations and photoperiodism have profound effect on oocyte quality and subsequent embryo development. It is recommended to find suitable additives for in vitro maturation that could mitigate seasonal effects.  相似文献   
72.
Cation exchange capacity (CEC) is an important soil property that is used as an input data in soil and environmental models. Although CEC can be measured directly, its measurement is expensive and time-consuming, therefore pedotransfer functions can be used for estimating it from more readily available soil data. As CEC is highly dependent on soil texture, it may be successfully estimated from the soil textural data. In this study, 20 soils were selected from Fars province, in the south of Iran, and the values of CEC, soil organic matter content, and soil particle size distribution curve of each soil were measured and the geometric mean particle-size diameter (d g ), and the summation of the number of spherical particles for whole parts of the soil particle-size distribution (N) were determined for each soil. Then, five multiple linear regressions were derived between CEC and mentioned soil properties. The results showed that more applicable equation for the study area was based on the percentages of clay, sand and soil organic matter content.  相似文献   
73.
In this paper, we report on morphological diversity, ecology and flowering phenological records of an endangered and an endemic species of Morocco Pyrus mamorensis Trab. For this study, a survey was undertaken in North-Western Morocco (Mamora forest and Zaër region) whereby 67 accessions of P. mamorensis were sampled. A set of 33 genotypes of Pyrus spp. from the international collection INRA-Angers (France) of the genus Pyrus were also analyzed. The variability of the total of 100 accessions was assessed by twenty-six characters including fourteen qualitative and twelve quantitative traits. The results demonstrated high levels of morphological variation in the sampled accessions of P. mamorensis and established the relationships among the local germplasm using the UPGMA cluster analysis and the factorial discriminant analysis. Furthermore, we were able to distinguish three types of flowering in the Mamora forest: early, intermediate and late flowering type. Otherwise, the UPGMA classification comparing local accessions of P. mamorensis to the international collection led to the formation of four major groups showing the closest correspondence to their geographical origins: (1) The North African species represented by P. mamorensis, (2) The East Asian pea species, (3) The West Asian species and (4) The European species. These findings suggest the importance of implementing a conservation strategy preserving the genetic resources of wild pear in North-Western Morocco.  相似文献   
74.

The two-location field experiment was conducted to investigate the effect of Thiobacillus and different levels of sulfur fertilizer on growth and physiological indices in the replacement intercropping of sesame and mung bean. A factorial experiment was performed based on a randomized complete block design in 3 replications in 2018. The experimental factors consisted of cropping ratio at five levels: 1. sesame sole cropping, 2. mung bean sole cropping, 3. 75% sesame +25% mung bean (3:1), 4. 50% sesame +50% mung bean (1:1), 5. 25% sesame +75% mung bean (1:3). Sulfur fertilizer was used at three levels: control level (S0), 50% of recommended amount (S1), 100% of recommended amount (S2). Thiobacillus bacteria was used at two levels: T0 and T1. The results showed that growth indices chlorophyll a, chlorophyll b, total chlorophyll, biological yield, and grain yield of sesame and mung bean were significantly affected by the studied treatments. The highest growth indices, chlorophyll a, chlorophyll b, total chlorophyll, biological yield and grain yield of sesame were obtained by the 3:1 ratio. For the mung bean, the highest growth indices, chlorophyll a, biological yield, grain yield were obtained by mung bean sole cropping and the highest chlorophyll b and total chlorophyll were obtained by the 1:1 ratio. Also, sulfur fertilizer, 100% of the recommended amount, increased all studied indices in both plants except for chlorophyll a in sesame. Interaction effects of cropping ratio and location on growth indices, grain biological yield, chlorophyll a of sesame and mung bean were significant.

  相似文献   
75.
Endozoochory is known as an important mechanism for the spread of weeds. We carried out experiments to assess the fate of seeds of several weed species (Convolvulus arvensis, Cuscuta campestris, Rumex crispus, Hordeum spontaneum and Sorghum halepense) after passing through the gut of sheep and goat. Eighteen animals of both sheep and goat received diet mixed with seeds of the weed species or control with only wheat bran (five weed species + control × three replications). Results showed that a higher proportion of seeds were missing after passage through the sheep gut than in goats. In goats, a greater proportion of seeds were dead after passage, but the number of seeds collected from dung was also greater. Weed species differed, with the highest seed recovery and viability in Cuscuta campestris. Based on time of seed passages through the animal gut estimated for the different weed species, we recommend that sheep should be kept in a corral for 96 hr to minimise seed transportation via their faeces. For goats, if R. crispus and C. arvensis seeds could be excluded from the diet, then maintaining them for 96 hr in an animal stall would ensure little seed transportation via dung, but we found R. crispus and C. arvensis seeds to be present and viable in goat dung even 120 hr after feeding. Very large numbers of viable seeds can be found in goat and sheep dung, so the use of rotted manure is highly recommended to avoid transportation of viable seeds via manure fertilisers.  相似文献   
76.
The one dimensional (1D) Ni-ZnO nanoparticles have been synthesized by a simple hydrothermal method. A novel photocatalyst of nanostructured Ni-ZnO which immobilized on polyacrylonitrile nanofibers were successfully fabricated using electrospinnig technique. The structures of nanofibers were characterized by various techniques including Scanning Electron Microscope (SEM), X-ray powder Diffraction (XRD), Fourier transform infrared (FT-IR), UV-Vis diffuse reflectance (DR) and thermogravimetric analys (TGA). The Ni-ZnO/PAN nanofibers photodegradation efficiency was optimized with factorial design method in order to act highly effective in the photocatalytic degradation of Methyle orange (MO). The highest decolorizing efficiencies using introduced material were achieved by 0.8 g l -1 of catalyst and 10 mg l -1 of MO at natural pH under visible light irradiation. The obtained results exhibited that Ni-ZnO/PAN nanofibers have high visible light photocatalitic activities. Overall, the presented material can be used as an efficient, low cost and healthily secure photocatalyst in the field of water treatment.  相似文献   
77.
Recently, drought-induced damaging impact in reducing the crop growth and development is drastically ranked at the top under various abiotic stresses. And especially water stress at the reproductive growth stages termed as terminal drought has become a severe threat for mungbean productivity. To mitigate the drought stress condition, "bio-priming" has emerged as a newly agronomic and sustainable technique in improving the mungbean production. A 2-year field study during Kharif season 2017–2018 was conducted to investigate the efficacy of rhizobacteria seed priming in mungbean(AZRI mung-06), at Agronomic Research Area, Department of Agronomy, Bahauddin Zakariya University, Multan, Pakistan. The experiment comprised two factors containing F_A(seed treatments, control(dry seeds), hydro-priming, silicon(Si)-priming, and bio-priming(mixture strains of Pseudomonas fluorescens+Rhizobium phaseoli)) and F_B(irrigation water-regimes at various growth stages including leaf formation(L), stem elongation(S)+flowering(F)+pod formation(P) containing treatments are normal irrigation(I_(L+S+F+P)) and terminal drought stress(I_(F+P))). All the treatments were arranged in randomized complete block design under factorial design and were replicated thrice. Results indicated that the exposure of drought stress at flowering and pod formation stages hampered the morpho-physiological growth and yield of mungbean. Nevertheless, seed priming treatments particularly bio-priming were effective in alleviating the detrimental effects of drought stress. Bio-priming significantly increased the yield and yield components(seeds/plant, 1 000-grain weight and harvest index) of mungbean and regulated the activities/levels of antioxidants(superoxide dismutase, catalase, peroxidase, ascorbic acid, and total phenolics) under drought stress. Compared with the control, bio-priming increased the seed yield of mungbean by 8–12% under normal as well as drought stress conditions during both years of study. Bio-priming also improved the nutrient uptake behavior followed by Si-and hydro-priming treatments under terminal drought stress. The study emphasized the effectiveness of bio-priming as dual seed treatment method may be helpful for vigorous germination of mungbean production along with plant tolerance against terminal drought stress. Among the various treatments, plants treated with bio-priming technique compensated the grain yield due to having strong antioxidant defense system and better nutrient uptake behaviour under terminal drought stress. Economic analysis also concluded that bio-priming is the easiest, cost-effective, friendly, and sustainable approach for the maximization of the mungbean production.  相似文献   
78.
An aquaponic system was designed to investigate the effects of foliar applications of potassium (K) on mint, radish, parsley, and coriander growth and physiological characteristics. Plants were sprayed with 100 mL pot?1 of 0.5 g L?1 potassium sulfate (K2SO4) twice a week. Fresh and dry masses of shoot in all species were higher in K-treated plants. Potassium concentration increased with K spray in the shoots of all species. K-sprayed parsley accumulated a greater amount of Fe and chlorophyll in shoots. Values of SPAD index in all species decreased significantly in untreated plants. The highest Quantum Photosynthetic Yield (Fv/Fm) values were observed in coriander plants treated with K, which was attributed to higher SPAD value in these plants. Potassium application had a negative effect on sodium (Na) and positive effect on magnesium (Mg), manganese (Mn), and zinc (Zn) concentrations in plants. These results indicated that foliar spray of K can effectively alleviate nutrient deficiencies in leafy and root vegetables grown in aquaponics.  相似文献   
79.
The establishment of a symbiotic interaction involves a signal exchange between the host legume (flavonoids) and the nitrogen-fixing rhizobia (nodulation factors (NFs)). Likewise, abiotic stress conditions, such as salinity and drought, strongly reduce the nodulation process, possibly affecting also the signal exchange. In this work we characterized the structure and biological activity of NFs produced by Bradyrhizobium japonicum USDA 138 under control, salt, and osmotic stress conditions. This strain is the most widely used in Argentine soybean culture; under control conditions, it produces a mixture of four types of NFs (V(C16:0,MeFuc), V(C18:1,MeFuc), IV(C18:1), and V(C18:1,Ac,MeFuc)). Interestingly, under stress conditions, this strain produces new types of NFs, one common for both stress conditions (V(C16:1,MeFuc)) and another one only present under salt stress (IV(C18:1,MeFuc)). All mixtures of NFs, extracted from control, salt, and osmotic stress conditions, showed biological activity in soybean plants, such as root hair deformation, and the radical application of purified NFs induced systemic differences in dry matter accumulation. The inoculation of soybean with genistein-induced bacteria cultured under both control and stress conditions had a positive effect on the number of nodules formed and in some cases on dry matter accumulation. These responses are not related to changes in chlorophyll fluorescence or greenness index.  相似文献   
80.
A TWINSPAN classification of 60 sample plots from the Khanikan forest (North of Iran) is presented. Plant types were determined from field observations and sample plot data arranged and analyzed in association tables. The types were defined on the basis of species patterns of presence, absence and coverage values. Vegetation was sampled with randomized-systematic method. Vegetation data including density and cover percentage were estimated quantitatively within each quadrate and using the two-way indicator species analysis. The objectives of the study were to plant type's classification for Khanikan lowland forest in North of Iran, Identification of indicator species in plant types and increase our understanding in regarding to one of Multivariate analysis methods (TWINSPAN). Five plant types were produced for the study area by TWINSPAN, i.e., Menta aquatica, Oplismenus undulatifolius, Carex grioletia, Viola odarata and Rubus caesius. Therefore, at each step of the process, the program identifies indicator species that show strongly differential distributions between groups and so can severe to distinguish the groups. The final result, incorporating elements of classification can provide a compact and powerful summary of pattern in the data set.  相似文献   
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