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91.
Seeds of 49 accessions of corn (Zea mays ssp. mays), 9 accessions of teosinte (Zea species that are thought to be ancestors and probable progenitors to corn), and 3 accessions of Job's tears (Coix lacryma), obtained from a germplasm repository, were ground and extracted with hexane. Whole kernel oil yields and levels of four phytonutrients (free phytosterols, fatty acyl phytosterol esters, ferulate phytosterol esters, and gamma-tocopherol) in the oils were measured. Among the seeds tested, oil yields ranged from 2.19 to 4.83 wt %, the levels of ferulate phytosterol esters in the oil ranged from 0.047 to 0.839 wt %, the levels of free phytosterols in the oil ranged from 0.54 to 1.28 wt %, the levels of phytosterol fatty acyl esters in the oil ranged from 0.76 to 3.09 wt %, the levels of total phytosterols in the oil ranged from 1.40 to 4.38 wt %, and the levels of gamma-tocopherol in the oil ranged from 0.023 to 0.127 wt %. In general, higher levels of all three phytosterol classes were observed in seed oils from accessions of Zea mays ssp. mays than in seed oils from accessions of the other taxonomic groups. The highest levels of gamma-tocopherol were observed in teosinte accessions.  相似文献   
92.
Most of the crop salt tolerance studies are often conducted in a glasshouse and are limited under field conditions. Therefore, the present research study was conducted under field conditions to evaluate the performance of six wheat cultivars at five salinity levels (EC 0, 3, 6, 9, and 12 dS m?1) in split plot design with three replications. Increasing salinity significantly increased soil pH, electrical conductivity (EC), and sodium adsorption ratio (SAR). Yield parameters of different cultivars were affected more at higher salinity levels than lower in two years. Data over two years revealed that up to EC 9 dS m?1 cultivars PBW 658 and HD 2967 performed ???better on the absolute yield basis but PBW 621 produced ?higher relative yield. At EC 12 dS m?1, PBW 658 produced significantly higher grain yield (4.23 t ha?1) than cultivars HD 2967 (4.11 t ha?1) and PBW 621 (3.99 t ha?1); therefore, should be preferred at salinity more than 9 dS m?1.  相似文献   
93.
Comparative studies of two cultivated and sixteen wild species of the genus Oryza were carried out using one- and two-dimensional gel electrophoresis for variation in their seed proteins for interrelationships of these species. A number of polypeptides in the range of molecular weight 13–110 kDa were seen to vary. Under reducing conditions, polypeptides spread over the regions of mol. wt. 33–40.5, 25–27 and 19–21.5 kDa exhibited maximum variation in their patterns. Two-dimensional gel electrophoresis revealed the occurrence of disulphide-linked glutelin polypeptide pairs of mol. wt. 60, 58, 52 and 25 kDa breaking into a large and a small subunit each in the range of mol. wt. 18–40.5 and 16–25 kDa respectively in Oryza sativa. The number of such polypeptide pairs varied from 2 to 6 in different species and also in O. sativa showed variation in mol. wts. of their constituent subunits. The UPGMA dendrogram revealed that most of the Oryza species occurred in different clusters and subclusters and thus did not share very close relationships. The undisputed and closest relationship observed was that of cultivated rice O. sativa with the O. rufipogon followed by that with O. nivara. The African cultivated O. glaberrima occurring on the nearest branch of the same subcluster, thereby, supporting the phylogenetic of these species suggested in earlier studies. Eight diploid species and seven tetraploid species were included in one part of the dendrogram while the remaining two species with AA genome i.e. O. glumaepatula and O. meridionalis and one with FF i.e. O. brachyantha stood separately from these as scattered in the group of seven tetraploid species with BBCC, CCDD and HHJJ genomes. The tetraploids O. alta, O. latifolia and O. grandiglumis with CCDD genomes which occurred on the farthest part were distantly related with O. sativa. The cyanogen bromide peptide maps and two dimensional gel electrophoresis also supported the closest relationship between O. sativa and O. rufipogon.  相似文献   
94.
Cultivated tetraploid Gossypium hirsutum L. (Malvaceae) cotton has been characterized as having one flower at a primordia. In a strain (CSH-13) of Gossypium hirsutum cotton, four plants out of 103 had two to three double bolls or twin bolls/plant during 2003–2004 crop season at CICR regional station, Sirsa, Haryana, India. Progeny evaluation in 2004 and 2005 crop seasons indicated that plants raised from seeds harvested from double bolls/twin bolls produced plants bearing double bolls only and plant progeny raised from the seed of single bolls from these mutant plants produced two to three double bolls per plant similar to the parent. Progeny testing revealed that double boll formation is the result of spontaneous mutation and environment does not influence its expression. The mutant is early in maturity by 10–15 days, naked seeded and possesses comparable agronomic characters with normal plants. Another spontaneous mutant of Gossypium hirsutum having more than three appendages originating from primordia.: four bolls one leaf, three bolls one leaf, two bolls two leaves, one boll three leaves were obtained from the population of CISV-13 strain in crop season 2003. These appendage groups have been described as bicolor unit by Clemens Bayer, [Zur Infloreszenzmorphologie der Malvales. Dissertations Botany 212 (1994)] and cluster mutant by Russell and Luther [J Cott Sci 6 (2002) 115]. One to three bolls in a cluster or bicolor unit were observed without formation of seeds and lint. About one-third of the total bolls on the mutant plant were of this type. In progeny testing during 2004 and 2005 crop seasons, this mutant produced plants exclusively with more than three appendages revealing that plants identified in 2003 were due to spontaneous mutation. This mutant was also early and naked seeded. Many of the other characters of the mutant plants were comparable with the wild type plants of the strain. Both the mutants were observed having economic impact due to their better yielding ability as compare to respective parents.  相似文献   
95.
Interactions of the model flavor compound 2-nonanone with individual milk proteins, whey protein isolate (WPI), and sodium caseinate in aqueous solutions were investigated. A method to quantify the free 2-nonanone was developed using headspace solid-phase microextraction followed by gas chromatography with flame ionization detection. Binding constants (K) and numbers of binding sites (n) for 2-nonanone on the individual proteins were calculated. The 2-nonanone binding capacities decreased in the order bovine serum albumin > beta-lactoglobulin > alpha-lactalbumin > alpha s1-casein > beta-casein, and the binding to WPI was stronger than the binding to sodium caseinate. All proteins appeared to have one binding site for 2-nonanone per molecule of protein at the flavor concentrations investigated, except for bovine serum albumin, which possessed two classes of binding sites. The binding mechanism is believed to involve predominantly hydrophobic interactions.  相似文献   
96.
An experiment was conducted to evaluate the effects of tillage and residue incorporation on soil properties and yields of rice (Oryza sativa L.) and wheat (Triticum aestivum L.) in rotation for 4 years on a silty clay loam of an Aquic Hapludoll with natural water table fluctuating between 0.05 and 0.97 m depth The rice experiment was laid out in split plot design with four levels of tillage, viz. conventional puddling (CP), puddling by four passes of rotavator (PR), reduced puddling by two passes of rotavator (ReP), and direct seeding without puddling (DSWP) and two levels of residue, viz. residue incorporation (RI) and residue removal (RR) in four replications. The treatments for wheat were zero tillage (ZT) and conventional tillage (CT) with RI and RR superimposed over the plots of rice. Tillage for rice increased puddling index and bulk density (BD) over the years. The increase was significantly higher in CP and PR than in ReP. In wheat season, BD was higher under ZT than under CT but the differences were not significant. Puddling decreased saturated hydraulic conductivity with time, which became significantly lower in CP and PR in the fourth year than in ReP in the first year. Infiltration rate (IR) also decreased with time and was lowest in CP and PR. In wheat season, IR was at par under ZT and CT. Rice yield in PR was maximum and at par with that in ReP. But wheat yield was lowest in PR and highest in DSWP, and was at par in DSWP and ReP. Thus, rice yields were optimum under ReP, in which changes in soil properties were least, and wheat yields were optimum both under ZT and CT in the DSWP and ReP plots of rice under shallow water table conditions of the silty clay loam.  相似文献   
97.
Sixteen germplasm accessions of Prosopis cineraria with suitable horticultural traits were identified from north-western Rajasthan, India, propagated clonally by budding on seedling rootstock and maintained in the field gene bank. Morphological characterization of seven-year-old trees of these accessions by 21 traits indicated a lot of variation among the accessions tested. Higher number of flowers per raceme was found in accession CIAH/K2, higher width of ripened pod in CIAH/K5, higher number of seeds per pod in CIAH/K12 and a higher weight of seed per pod in CIAH/K6. Overall, CIAH/K16 was found to be a superior genotype for most of the useful traits. High significant positive correlation was obtained with traits useful for horticultural values. Out of 62 random decamer primers for random amplification (RAPD) reaction, and four minisatellite core sequence for direct amplification of minisatellite DNA (DAMD) screened with these accessions, 12 RAPD and 2 DAMD primers were found polymorphic. Average polymorphism resolved by these markers among the accessions was 93.2%. Genetic diversity revealed by Jaccard’s co-efficient was between 0.11 and 0.77, and four major clusters were identified among these accessions by phylogenetic analysis using NTSYSpc-2.02e software. This study shows the existence of high genetic diversity within these accessions.  相似文献   
98.
The study was undertaken to quantify the distribution of soil in different size fractions of water-stable aggregates, and organic C, total N, and total P associated with these aggregates, along a gradient of forest-savanna-cropland in the Indian dry tropics. The effect of residue (wheat straw) amendment under dryland cultivation was also investigated. Proportions of macroaggregates (>0.3 mm) were highest in the forest and lowest in the cropland soil and ranged from 58–66% in forest, to 55% in savanna and 25–36% in cropland. In contrast, microaggregates (<0.3 mm) were highest in cropland (64–75%), followed by savanna (45%), and lowest in forest soil (34–42%). Organic C, total N, and total P associated with the macroaggregates ranged from 6.52–29.56, to 0.62–2.44 and 0.06–0.15 g kg-1 soil, respectively, while the respective values in microaggregates were 4.99–22.11, 0.42–2.01, and 0.07–0.19 g kg-1 soil. This study indicates that land-use changes (conversion of forest into savanna and cropland) reduce the organic matter input to the soil and the proportion of macroaggregates. The application of wheat straw did not significantly influence the organic C and total N levels (P>0.05) in the short term, although the proportion of macroaggregates increased, indicating an improvement in soil structure. Thus soil degradation after conversion of natural systems to cropland can be arrested up to some extent by residue input to the soil.  相似文献   
99.
Measurements were made in 1980 over a fully-developed soybean (Glycine max (L.) Merrill) canopy at Mead, Nebraska to determine how crop water status influences photosynthesis, evapotranspiration and water use efficiency. Water use efficiency was calculated in terms of the CO2—water flux ratio (CWFR). Micrometeorological techniques were used to measure the exchange rates of CO2 and water vapor above the crop canopy. Crop water status was evaluated by reference to volumetric soil moisture (θv), stomatal resistance (rs), and leaf water potential (ψ) measurements.Stomatal resistance (rs) was independent of ψ when the latter was greater than ?1.1 MPa. rs increased sharply as ψ dropped below this threshold. Canopy CO2 exchange (Fc) decreased logarithmically with increasing rs under strong irradiance. Although Fc was found to be strongly correlated with rs, the influence of low values of ψ and of high air temperature cannot be discounted since these factors affect the enzymatic reactions associated with photosynthesis. Stomatal closure also reduced evapotranspiration and influenced the partitioning of net radiation.Under strong irradiance the CO2 water flux ratio (CWFR) decreased with increasing stomatal resistance. This observation is at variance with predictions of certain early ‘resistance’ models, but substantiates predictions of some recent models in which leaf energy balance considerations are incorporated.  相似文献   
100.
The scarcity of non-renewable fertilizers resources and the consequences of climate change can dramatically influence the food security of future generation. Introduction of high yielding varieties, intensive cropping sequence and increasing demand of food grains day-by-day, application of recommended dose of fertilizers could not fulfill our targets due to outdated fertilizers recommendations are yet in practice. It not only alters soil quality, nutrient balance, microbial and enzymatic ecology but also affected productivity and sustainability of rice in Gangetic alluvial soils of India. The effect of fertilizers application based on “fertilizing the soil versus fertilizing the crop” which insure real balance between the applied and available soil nutrient is urgently needed. Hence, the present study was conducted during three consecutive crop seasons (2010, 2011, and 2012) to assess the effect of imbalance and balance fertilization based on initial soil test values and targeted yields, and to determine the effect of farmyard manure (FYM) when superimposed with balanced fertilizers on identification of minimum data set for the development soil quality, nutrient acquisition, and grain yield of rice. The six fertilizer treatments were laid out in a randomized block design with three replications. The treatments were: T1-control (no fertilization), T2-farmyard manure @ 5 t ha?1, T3-farmers practice (60:30:30 kg N:P2O5:K2O ha?1), T4-precise application of mineral fertilizers based on initial soil test values (77:24:46 kg N:P2O5:K2O ha?1) for targeted grain yield of 4.0 t ha?1, T5-precise application of mineral fertilizers based on initial soil test values (74:23:43 kg N:P2O5:K2O ha?1) plus FYM (5 t ha?1) for targeted grain yield of 4.0 t ha?1 and T6-precise application of mineral fertilizers based on initial soil test values (135:34:65 kg N:P2O5:K2O ha?1) for targeted rice grain yield of 5.0 t ha?1. Result revealed that the targeted rice grain yield of 4.0 and 5.0 t ha?1 was achieved in T4 and T6 treatments with 1.59% (4.06 t ha?1) and –3.40% (4.83 t ha?1) deviations, respectively. T4, T5, and T6 significantly increased crop growth, nutrient uptake, available P (Pa) and K (Ka) and augmented rice grain yield by 10.6, 20.2 and 31.6%, respectively, over T3. Microbial biomass carbon, soil respiration and enzymatic activity were enhanced significantly in T5 as compared to T6. Highest soil quality index was found in T5 (0.95) followed by T6 (0.90) and, lowest was in T1 (0.63). The contribution of minimum data set (MDS) toward the SQI was in the descending order of ALP (30.6%) > SOC (21.5%) > Ka (11.3%) > PSM (9.68%) > Na (8.51%). Overall, rice yield and soil quality was improved by using balance fertilization based on fertilizing the crop Vs fertilizing the soil in alluvial soils of India.  相似文献   
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