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111.
Fink K Richling E Heckel F Schreier P 《Journal of agricultural and food chemistry》2004,52(10):3065-3068
For the authenticity assessment of (E)-methyl cinnamate from different origins, combustion/pyrolysis-isotope ratio mass spectrometry (C/P-IRMS) was used by an elemental analyzer (EA) and on-line capillary gas chromatography coupling (HRGC-C/P-IRMS). For that reason, (E)-methyl cinnamate self-prepared from synthetic, natural, and semisynthetic educts was analyzed in comparison to the commercial synthetic and natural ester. In addition, (E)-methyl cinnamate from basil extract and a number of commercial natural aromas was investigated. The data of self-synthesized synthetic (E)-methyl cinnamate, i.e., delta(13)C(V)(-)(PDB) = -33.8 per thousand and delta(2)H(V)(-)(SMOW) = +349 per thousand, corresponded with that found for the commercial synthetic samples (-29.5 to -31.4 per thousand and +328 to +360 per thousand for delta(13)C(V)(-)(PDB) and delta(2)H(V)(-)(SMOW), respectively). The ester produced from natural educts by acid as well as Candida antarctica catalysis revealed delta(13)C(V)(-)(PDB) = -25.6 and -30.1 per thousand as well as delta(2)H(V)(-)(SMOW) = -162 and -169 per thousand, respectively. Acid-catalyzed semisynthetic products differed in their delta(13)C(V)(-)(PDB) and delta(2)H(V)(-)(SMOW) values depending on the origin of their educts. For the ester from synthetic methanol and natural cinnamic acid, -27.3 and -126 per thousand were determined for delta(13)C(V)(-)(PDB) and delta(2)H(V)(-)(SMOW), respectively, whereas for the ester produced from natural methanol and synthetic acid delta(13)C(V)(-)(PDB) = -30.6 per thousand and delta(2)H(V)(-)(SMOW) = +287 per thousand were found. Basil extract showed -28.9 and -133 per thousand for delta(13)C(V)(-)(PDB) and delta(2)H(V)(-)(SMOW), respectively. Commercial aromas declared to be natural revealed delta(13)C(V)(-)(PDB) and delta(2)H(V)(-)(SMOW) data ranging from -25.7 to -28.5 per thousand as well as -85 to -191 per thousand, respectively, indicating, in part, incorrect declaration. 相似文献
112.
Gisela Rack 《Journal of pest science》1969,42(12):184-186
Summary In two samples taken by different collectors a wet new constructed office-building situated in meadowland the author has found
seven mostly mould-eating mite-species partly in masses, among themNeoseiulus barkeri, till now not known in new buildings. The mite-trouble vanished after the edifice had been dried up.
相似文献
113.
Jacobasch G Dongowski G Florian S Müller-Schmehl K Raab B Schmiedl D 《Journal of agricultural and food chemistry》2008,56(4):1501-1510
APC-germline mutation creates predisposition for intestinal tumorigenesis. APCMin/+ mice, developing tumors preferentially in the small intestine and only minimally in the colon, were fed pectin-enriched diets (10% galacturonan; degree of methoxylation=37.0 and 70.4%) or standard diet. Pectins used in the present study do not inhibit intestinal tumorigenesis and rather accelerate it in APCMin/+ mice. Both pectins exhibited prebiotic effects associated with high fermentative formation of acetate but producing low butyrate. The differences of the short-chain fatty acid concentrations between cecum and colon and those between colon and feces were larger than expected and increased with cancer progression, indicating an inhibition of butyrate absorption. Pectins transported more bile acids toward the colon than the standard diet and caused a higher generation of secondary bile acids despite lower pH values. Overexpression of COX-2 resulted in lower antioxidative capacity, thus promoting cancer. Apoptosis increased in hyperplasia but decreased in late adenomas. When biological modular design principles are taken into consideration, it can be expected that pectin also reinforces colorectal tumorigenesis of patients suffering from APC gene defects. 相似文献
114.
Genetic variability in duration of pre-heading phases and relationships with leaf appearance and tillering dynamics in a barley population 总被引:1,自引:0,他引:1
The stem elongation phase seems critical in yield potential determination in barley (Hordeum vulgare L.). Extending its duration, without modifying total time to anthesis, has been proposed as a promising breeding tool. A prerequisite for its use is that the duration of phases before and after jointing (that including leaf and spikelet initiation, LS, and that of stem elongation, SE) should be under different genetic control. In addition, little is known about the implications of changes in the duration of LS and SE upon other developmental traits which could affect other aspects of yield generation, such as phyllochron and tillering. Thus, the objectives of the present work were to study the genetic variability in LS and SE, in traits related to leaf appearance and tillering, as well as their relationships, in a double-haploid (DH) population derived from the cross Henni × Meltan. DH lines and both parents were studied in four field trials. Despite the similarity in development between parents, there was significant genetic variability in duration of both LS and SE (i.e. considerable transgressive segregation was observed), with no major genetic correlations found between them. Although some significant genetic correlations were found between duration of phases and leaf appearance and tillering traits, it has been shown that modifying the duration of LS does not necessarily imply concomitant changes in traits that could be important for an early expansion of the crop canopy (i.e. phyllochron, onset and rate of tillering). 相似文献
115.
116.
Screening for persistence in Lolium perenne L.
The assessment of persistence, as well as yield potential, is fundamentally important for cultivar evaluation of perennial grasses. But it is difficult to estimate the persistence because of limited time available for testing new varieties. The aim of this study was to find out conditions for effective and quick selection for persistence in Lolium perenne. Four strains of Lolium perenne were investigated for three years in the following split pot design with 3 replications: 180–220 kg N/ha or 360–440 kg N/ha and year, 3 or 6 cuts/year and 3–4 cm or 7–8 cm cutting height.
Yield, regrowth (score 0–9, 7 days after each cut) and persistence (number of non-surviving ramets) were determined for each ramet of all clones and for each plot of the strains. The dry matter yield was reduced to about 50 % between the first and the third year of the investigation. The differences in the dry matter yield between the four strains have been more evident in the six than in the three cutting treatment.
Already at the end of the first year of the investigation the strains differed significantly in the regeneration in the six cut treatment. The regrowth of strain III showed a significant reduction compared with the other three strains.
A significant reduction of the surviving ramets was first observed at the end of the second year of the investigation in the six cut treatment only, but between the strains were no significant differences.
These results demonstrate, that an investigation on single plants over a period of three years cannot give an exactly prediction about the persistence of Lolium perenne strains. 相似文献
The assessment of persistence, as well as yield potential, is fundamentally important for cultivar evaluation of perennial grasses. But it is difficult to estimate the persistence because of limited time available for testing new varieties. The aim of this study was to find out conditions for effective and quick selection for persistence in Lolium perenne. Four strains of Lolium perenne were investigated for three years in the following split pot design with 3 replications: 180–220 kg N/ha or 360–440 kg N/ha and year, 3 or 6 cuts/year and 3–4 cm or 7–8 cm cutting height.
Yield, regrowth (score 0–9, 7 days after each cut) and persistence (number of non-surviving ramets) were determined for each ramet of all clones and for each plot of the strains. The dry matter yield was reduced to about 50 % between the first and the third year of the investigation. The differences in the dry matter yield between the four strains have been more evident in the six than in the three cutting treatment.
Already at the end of the first year of the investigation the strains differed significantly in the regeneration in the six cut treatment. The regrowth of strain III showed a significant reduction compared with the other three strains.
A significant reduction of the surviving ramets was first observed at the end of the second year of the investigation in the six cut treatment only, but between the strains were no significant differences.
These results demonstrate, that an investigation on single plants over a period of three years cannot give an exactly prediction about the persistence of Lolium perenne strains. 相似文献
117.
Endophytic fungi have been isolated from buds and twigs of beech trees collected at four different sites in Switzerland. Discula umbrinella. was recovered at high frequencies from the bud scales and the twig pieces contiguous to the buds, but was virtually absent from the rolled up leaves enclosed by the scales. In addition to infection by air-borne inoculum, thalli of D. umbrinella may grow from the twigs into the leaf tissues. 相似文献
118.
119.
Summary Successive generations of open pollinated (OP) true potato seed (TPS) families represent a low-cost planting material. This
study was conducted to determine whether inbreeding occurred during two successive OP generations and, if so, whether it adversely
affected the performance of transplant families from true seed. Potato seedling transplants from 4x×2x hybrid, OP1, OP2, S1 and S2 families were compared for plant vigour, flowering, pollen stainability, OP fruit set, tuber yield and specific gravity.
Hybrids were consistently superior, while S2 families were inferior. The performance of OP1, OP2 and S1 families did not differ significantly for most traits. The accumulation of inbreeding in successive OP generations was limited
by reduced OP seed production on selfed plants; thus, a synthetic TPS variety propagated by open pollination may be feasible.
Paper no. 3162 from the Department of Genetics, University of Madison. 相似文献
120.
An increase in the proportion ofhybrid vs. selfed plants improves the performance ofopen pollinated (OP) true potato seed (TPS) families. Strategies to increase the proportion ofhybrid seeds were investigated. A marker gene for yellow tuber flesh in a diploid clone, interplanted as the male parent, permitted identification of 4x × 2x hybrids among the OP progeny. Only 5% of the OP progeny were 4x × 2x hybrids. The proportion of 4x × 2x hybrid plants among the OP progeny was increased when the female parent had low male fertility and when only the largest 25% of the seeds were planted. The hybrid 4x × 2x plants were superior for all traits evaluated on the OP seedling transplant families. Traits included vigor, flowering, pollen stainability, OP fruit set, and tuber yield. Effects of the female parent were significant only for vigor and flowering, while seed size did not affect values for any trait consistently: With the limited outcrossing observed, the low seed set obtained when using parents with low male fertility and the work involved in selecting the largest seeds within individual fruits were not justifiable. However, research with OP true seed families asa low cost planting material should be continued, since high yielding OP families have been identified. 相似文献