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111.
ABSTRACT. The respiration of metamorphosing gyne Lasiusflavus Fab. has been measured in field and laboratory populations. Twelve morphological stages are identified and their respiratory rate investigated. Only five physiological phases are distinguished. The specific respiratory rate varies between these phases, to produce the U-shape characteristic of insects. There is good agreement between the data from English field and Danish laboratory populations. The minimum rate is only 40% of the maximum. Except at the beginning and end of metamorphosis, the Q10 is significantly different in the two temperature intervals 10–20 and 20–30C. Metamorphosis was completed in approximately 33 days at 20 C. The total oxygen consumption by the gynes during metamorphosis was 2.4 ml. Their weight loss amounted to 2.2 mg, or 36% of the dry weight and, of this, 0.67mg was accounted for by fat. Assuming the rest was carbohydrate, consumption of these reserves would release 62.9 J, which, for this combination of fat and carbohydrate, can be calculated to be equivalent to 3.1 ml oxygen which is in reasonable agreement with the figure calculated from the measurement of oxygen consumption. The specific respiratory rate in English field populations of male pupae varies in the same way as the gyne-pupae, but it is about 50% higher. 相似文献
112.
Morphological Approaches to Phylogeny 总被引:1,自引:0,他引:1
SYNOPSIS. Traditional views on the interrelationships of themajor animal groups are based on morphological characters, butmolecular data of various types have in the last decade givenindications of new and sometimes quite puzzling phylogenies.This should be an incentive not only to reevaluation of theavailable morphological characters but also to new studies tofill the voids in our knowledge. Modern morphology is not concernedonly with traditional studies of structure and ontogeny of organsystems, but also with newer methods, such as SEM, TEM, immunocytochemistry,and cell marking. This has given morphology new dimensions,but it also has shown that vast areas of the animal kingdomremain very poorly known even through traditional studies. Phylogenetictrees built on morphology (and molecular trees with morphologicalcharacters added) demonstrate morphological characters thatare in conflict with the phylogeny, and therefore should bereinvestigated; they also indicate areas where new researchcan contribute significantly to our understanding of the pathwaysof the evolution. Morphological phylogeny has the distinct advantagethat characters of ancestors can be inferred and the evolutionarychanges checked in terms of functional continuity and hypothesesof adaptation. 相似文献
113.
Abstract The preference in seed selection by Messor capitatus (Latreille) was studied with artificial seeds (weighted styropore spheres) in the laboratory and with natural seeds in the field. The laboratory experiments showed no strong preference for size of the artificial seeds in the range 3–8 mm (diameter). A mass of about 400 mg was selected when artificial seeds of 5-5.5 mm were offered at different distances from the nest.
In the field experiments, crushed seeds were placed 2 m from the nest and ants showed a clear preference for the size class 2.0–3.0 mm in diameter, which is much smaller and lighter than the preference for the artificial seeds. The preference of seeds from different plants showed very big variability. There was no correlation between the preference and any of the following variables of the seeds: fresh mass, dry mass, water content, energy content, and nitrogen content. No evidence for energy optimizing in food selection in Messor capitatus was found.
The energetic reward of bringing any seed back to the nest will, under all normal conditions, be much higher than the energetic expenditure. For example, the energetic content in a wheat seed is about 650 Joule, which is sufficient energy for a worker ant of Messor capitatus to carry the seed for a distance of 6.5 km at a temperature of 30o C. 相似文献
In the field experiments, crushed seeds were placed 2 m from the nest and ants showed a clear preference for the size class 2.0–3.0 mm in diameter, which is much smaller and lighter than the preference for the artificial seeds. The preference of seeds from different plants showed very big variability. There was no correlation between the preference and any of the following variables of the seeds: fresh mass, dry mass, water content, energy content, and nitrogen content. No evidence for energy optimizing in food selection in Messor capitatus was found.
The energetic reward of bringing any seed back to the nest will, under all normal conditions, be much higher than the energetic expenditure. For example, the energetic content in a wheat seed is about 650 Joule, which is sufficient energy for a worker ant of Messor capitatus to carry the seed for a distance of 6.5 km at a temperature of 30
114.
CHARLOTTE L. ROY NIELSEN ROBERT J. GATES EDWARD H. ZWICKER 《The Journal of wildlife management》2007,71(3):875-883
Abstract: Wood ducks (Aix sponsa) and other species use tree cavities in forested wetlands and adjacent upland forests for nest sites and cover. The availability of tree cavities suitable for nesting is important to the population dynamics of hole-nesting species, but there is little quantitative information on how forest succession and maturation affect densities of suitable nest sites in eastern deciduous forests. Several studies have measured availability of tree cavities for nesting wood ducks, but data on cavity formation and persistence rates are needed to model changes in cavity abundance. We measured abundance and persistence of tree cavities suitable for nesting wood ducks in southern Illinois, USA, during 1993-2002. We simulated changes in abundance of nest cavities in the Mississippi River floodplain and adjacent upland forests using estimates of tree cavity densities by tree-diameter size classes and 10-year cavity persistence rates by tree species. Cavities were disproportionately common in the largest size classes, but tree species varied in their propensity to form cavities. Beech (Fagus grandifolia; 0.41 cavities/tree) and sycamore (Plantanus occidentalis; 0.50 cavities/tree) were prolific cavity producers, whereas a small proportion (0.05 cavities/tree) of cottonwoods (Populus deltoides) contained cavities. Kaplan-Meier estimates of annual and 10-year cavity persistence averaged 0.95 and 0.64, respectively. Cavity persistence also differed among species (P = 0.02): cottonwoods had the lowest (0.54) and sycamores had the highest (0.89) 10-year tree cavity persistence rates. Tree fall (50.0%), cavity floor deterioration (37.5%), and narrowing of the cavity entrance (12.5%) were the most prevalent causes of tree cavity loss. Forest stand projections indicated that cavity abundance will increase up to 34% over recent levels during the first 10 years and by 44% after 50 years. Most of this increase will be contributed by tree species that are not commonly used by wood ducks, but cavities will increase in oaks (Quercus spp.) and beeches as the forest matures into cavity-bearing size classes. Sycamores will steadily contribute cavities, but cottonwood is predicted to provide fewer cavities due to low survival of cavity-bearing size classes. Our results suggest that availability of nest and den sites for cavity-dependent wildlife will increase as eastern deciduous forests mature over the next half century. Cost-effectiveness of artificial nest box programs should be reevaluated in light of projected changes in tree cavity availability as deciduous forests mature in the eastern United States. 相似文献
115.
CLAUS NIELSEN 《Zoologica scripta》1996,25(1):61-75
Three new species of Loxosoma are described, L. nung and L. song , on the polychaete Pectinaria brevispinis from the reef flat in front of Phuket Marine Biological Center, and L. sum on the polychaete Axiothella obockiensis from a sand flat at Nai Yang Beach, Phuket Island. The genus Loxosoma is briefly reviewed. Species originally referred to Loxosoma but now transferred to Loxosomella are listed; insufficiently characterized species probably belonging to Loxosomella are listed as well. The monospecific genus Loxostemma is synonymized with Loxosoma . The subgenus name Loxosomina is proposed to replace the junior homonym Loxomorpha . 相似文献
116.
P. BRAuUNER NIELSEN 《Animal genetics》1991,22(2):183-185
By means of a new antiserum, Mm, the Mae phenotype can be shown to be controlled by the Maem allele, the Mef phenotype by either the original Mef or a new Mefm allele, and the Mbe(f) phenotype by the Mbe(f)m allele. The complexity of the porcine M system is now extended to 13 internationally recognized blood group factors controlled by at least 19 alleles. 相似文献
117.
Abstract The identities of the Microlepidoptera described by Linnaeus and Clerck have been critically reviewed. Evidence used to reassess usage of Linnaeus and Clerck names comes in part from the surviving material of these two authors, from their publications and those of subsequent revisers, and from contemporary collections. Results are presented in the form of an alphabetic catalogue of the species-group names used by Linnaeus and Clerck for Microlepidoptera, with a complete listing of material in the Linnaeus and Clerck collections. Lectotypes are designated for most of the species and new synonymies are proposed. 相似文献
118.
119.
VESICULAR-ARBUSCULAR MYCORRHIZA IN FIELD-GROWN CROPS 总被引:10,自引:6,他引:4
120.
The Influence of Cu on Photosynthesis and Growth in Diatoms 总被引:1,自引:0,他引:1
Cu in ionic form in a balanced medium affects the rate of photosynthesis and growth in the diatom Nitzschia palea in about the same way as in the green alga Chlorella pyrenoidosa. Remarkable differences are found, however. Small concentrations of Cu influence the rate of photosynthesis considerably more in the diatom than in the green alga whereas the opposite is the case concerning growth. The latter is most likely a consequence of excretion of organic matter by the diatom in presence of Cu whereas this does not take place in Chlorella. Some of the excreted organic matter may bind Cu and thus make the medium suitable for growth. Although pre-treatment with Cu in the dark has no influence on the subsequent rate of photosynthesis in the light, organic matter is excreted in the dark immediately after the addition of Cu. The influence of Cu on the rate of photosynthesis varies by a factor of about 30 according to the stage of growth in a synchronized culture. 相似文献