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101.
Osamu Hirayama Hideyuki Matsuda Kanae Senzaki Tsuneko Masuda 《Bioscience, biotechnology, and biochemistry》2013,77(6):1205-1210
Lyophilized photosystem I subchloroplast fragments prepared from spinach chloroplasts were extracted and reconstituted. Hexane extraction eliminated 26 % of the photosystem I activity without removing chlorophylls, and the reconstitution with β-carotene, an unkown lipid or chlorophyll a restored almost all the activity. Extraction with hexane–acetone (2:1, v/v) eliminated 81% of the activity with removal of 78% of the chlorophylls. In this case, reconstitution with chlorophyll a showed complete restoration of the activity, but β-carotene, the unknown lipid, and plastoquinone A caused a rather inhibitory effect. A possible explanation is that photosystem I reaction centers are closely surrounded by chlorophyll a; and β-carotene, the unknown lipid, and plastoquinone A function only through chlorophyll a. 相似文献
102.
Diversity and composition of tropical butterflies along an Afromontane agricultural gradient in the Jimma Highlands,Ethiopia 下载免费PDF全文
《Biotropica》2017,49(3):346-354
Afromontane landscapes are typically characterized by a mosaic of smallholder farms and the biodiversity impacts of these practices will vary in accordance to local management and landscape context. Here, we assess how tropical butterfly diversity is maintained across an agricultural landscape in the Jimma Highlands of Ethiopia. We used transect surveys to sample understory butterfly communities within degraded natural forest, semi‐managed coffee forest (SMCF), exotic timber plantations, open woodland, croplands and pasture. Surveys were conducted in 29 one‐hectare plots and repeated five times between January and June 2013. We found that natural forest supports higher butterfly diversity than all agricultural plots (measured with Hill's numbers). SMCF and timber plantations retain relatively high abundance and diversity, but these metrics drop off sharply in open woodland, cropland and pasture. SMCF and timber plantations share the majority of their species with natural forest and support an equivalent abundance of forest‐dependent species, with no increase in widespread species. There was some incongruence in the responses of families and sub‐families, notably that Lycaenidae are strongly associated with open woodland and pasture. Adult butterflies clearly utilize forested agricultural practices such as SMCF and timber plantations, but species diversity declines steeply with distance from natural forest suggesting that earlier life‐stages may depend on host plants and/or microclimatic conditions that are lost under agricultural management. From a management perspective, the protection of natural forest remains a priority for tropical butterfly conservation, but understanding functioning of the wider landscape mosaic is important as SMCF and timber plantations may act as habitat corridors that facilitate movement between forest fragments. 相似文献
103.
The European spruce bark beetle Ips typographus is the most important insect pest in Central European forests. Under climate change, its phenology is presumed to be changing and mass infestations becoming more likely. While several studies have investigated climate effects across a latitudinal gradient, it remains an open question how phenology will change depending on elevation and topology. Knowing how an altered climate is likely to affect bark beetle populations, particularly across diverse topographies and elevations, is essential for adaptive management. We developed a time‐varying distributed delay model to predict the phenology of I. typographus. This approach has the particular advantage of capturing the variability within populations and thus representing its stage structure at any time. The model is applied for three regional climate change scenarios, A1B, A2 and RCP3PD, to the diverse topography of Switzerland, covering a large range of elevations, aspects and slopes. We found a strong negative relationship between voltinism and elevation. Under climate change, the model predicts an increasing number of generations over the whole elevational gradient, which will be more pronounced at low elevations. In contrast, the pre‐shift in spring swarming is expected to be greater at higher elevations. In comparison, the general trend of faster beetle development on steep southern slopes is only of minor importance. Overall, the maximum elevation allowing a complete yearly generation will move upwards. Generally, the predicted increase in number of generations, earlier spring swarming, more aggregated swarming, together with a projected increase in drought and storm events, will result in a higher risk of mass infestations. This will increase the pressure on spruce stands particularly in the lowlands and require intensified management efforts. It calls for adapted long‐term silvicultural strategies to mitigate the loss of ecosystem services such as timber production protection against rockfall and avalanches and carbon storage. 相似文献
104.
G. T. McQuate 《Journal of Applied Entomology》2009,133(6):444-448
Bactrocera latifrons (Hendel) is a tephritid fruit fly of primarily Asian distribution that has invaded Hawaii and, more recently, the continent of Africa (Tanzania and Kenya). It primarily infests solanaceous fruits, so has the potential to impact production of crops such as peppers (Capsicum annuum L. and Capsicum frutescens L.), eggplant (Solanum melongena L.), African eggplant (Solanum aethiopicum L.) and tomatoes (Solanum lycopersicum L.). Because little work has been done to develop suppression techniques for this fruit fly species, field cage tests of the effectiveness of a commercially available bait spray, GF‐120NF Fruit Fly Bait, against wild B. latifrons were conducted. Sexually mature B. latifrons adults (75 male and 75 female) were introduced to both a control cage and a treatment cage, each of which held six fruiting Anaheim chili pepper (C. annuum L.) plants. Fruits were harvested, and assessed for infestation, both before and after the application of the bait spray in the treatment cage. There was no difference in infestation rate between control and treatment cages before the application of the bait spray, whereas there was a significantly lower infestation rate in treatment cages following the application of the bait spray. Post‐spray infestation rate in the treatment cages (in two separate, replicated bioassays) was always zero and no live flies were detected in the treatment cages at the end of the trials. The results of this study provide evidence that GF‐120NF Fruit Fly Bait should be effective in suppressing B. latifrons populations in the field. 相似文献
105.
Dancea Z. Baba A. Morar M. V. Catoi C. Macri A. Drochner W. Schollenberger M. 《Mycotoxin Research》2004,20(1):19-23
Investigations on the mycological quality of feeds from Transylvanian farms are presented. The investigations had two objectives:
More than 50% of the samples showed water contents exceeding 16%, due to inadequate harvesting and storage conditions. This
correlated with high my-cological contamination, with dominant species of the genusFusarium, Aspergillus, Alternaria,Penicillium andRhizopus. Feeding trials with broilers showed that live weight gain and digestibility coefficients of protein and fat in animals givenFusarium infested grain were depressed. As well N-retention and feed conversion rate (kg feeding stuff/ kg weight gain) were impaired. 相似文献
1. | survey for mycological contamination and related chemical composition; |
2. | the evaluation of effects ofFusarium graminearum Schw. infested wheat (8% in the diet) on productivity and digestibility of nutrients in broilers. |
106.
Ha YC Heo JM Kim HJ Go GM Lee SJ Jeong SH Ahn SI Kim MC Kim JE Song HY Park JW Kim BS Sohn WM 《The Korean journal of parasitology》2000,38(1):41-43
The infestation status of head louse among children attending primary schools and kindergartens in Chinju-shi, Kyongsangnam-do, Korea, was investigated between June and July 1999. Out of 2,288 children examined, 3.9% of boys (48/1,242) and 23.5% of girls (246/1,046) were infested with nits or adult/nymphs of lice. The effectiveness of lindane shampoo (1% gamma benzene hexachloride solution) was evaluated after one or two time applications to all the children infested. The negative conversion rate of pediculosis was 93.5%. Effective control measures are needed to control and prevent such ectoparasite infestation amongst children. 相似文献
107.
A study was carried out to assess the resistance of pure and cross-bred groups of cattle to the horn fly Haematobia irritans (Linnaeus) (Diptera: Muscidae) in northern Argentina. Pure-bred cattle were Criolla, Iberian Bos taurus Linnaeus (Artiodactyla: Bovidae) and Nellore, Bos indicus Linnaeus (Artiodactyla: Bovidae). Cross-bred cattle were Hereford, British B. taurus (34%) X Nellore (66%) and Hereford (66%) X Nellore (34%). All were heifers and animals were maintained in two groups, each containing a mixture of pure and cross-breeds. The lowest fly numbers were found on Criolla heifers and the highest on Hereford X Nellore cross-breeds. However, it could not be determined from this study whether this was a consequence of breed and/or size, as Criolla heifers were lighter than the corresponding Hereford X Nellore heifers. Fly numbers on the heifers followed an approximately negative binomial distribution. However, the ranking of individual animals in their level of infestation within subgroups was not consistent. Hence, culling the most infested heifers on any given date would at best give only a small improvement in H. irritans control. 相似文献
108.
B Alexander L. A. Agudelo F. Navarro F. Ruiz J. Molina G. Aguilera M. L. Quiñones 《Medical and veterinary entomology》2001,15(4):364-373
The phlebotomine sandfly fauna of traditional (shaded) and intensified (unshaded) coffee plantations in Colombia was sampled by a variety of methods and the species composition and density under the two systems compared. Twenty species of Lutzomyia sandflies (Diptera: Psychodidae: Phlebotominae) were collected, of which eight were found only in the 'Coffee Axis' ('Eje Cafetero') of the departments of Caldas, Risaralda and Quindio, six were exclusive to the department of Norte de Santander and six occurred in both regions. Four species were collected only in traditional plantations and two exclusively in intensified ones. At least 13 species occurred in both plantation types. Fifteen species are opportunistic man-biters and eight are suspected vectors of leishmaniasis caused by Le. braziliensis, Le. panamensis or Le. mexicana. Seven species were collected inside houses and may be involved in intradomiciliary transmission of Leishmania. The dominant species in Norte de Santander was Lu. spinicrassa, which made up 93.8% of all the sandflies collected in this department. This species was absent from the Eje Cafetero and a number of others among the 15 recorded there might be responsible for Leishmania transmission in this region, including Lu. trapidoi, Lu. yuilli, Lu. gomezi, L. hartmanni and Lu. ovallesi. Sandfly population densities were significantly higher in traditional plantations than in intensified ones. Residents of traditional plantations were able to describe sandflies in significantly more detail than those of intensified plantations, based on seven basic characteristics related to the appearance and biting behaviour of the insects. 相似文献
109.
Abstract: Field studies were conducted in Harran Plain, Turkey, to investigate the infestation of spiny bollworm (SBW) and pink bollworm (PBW) in cotton blind bolls during the period 1999–2001. Blind bolls left on the cotton plants after the harvest were collected, and the PBW and SBW larvae, which are the causes of infection were counted in the laboratory by splitting the bolls. The statistical methods reveal that the infestation ratio variable plays an important role in reducing cotton yield. The infestation ratio variable was found to be statistically significant in all models used. Different soil types may have little effects on yield. We also estimate elasticity of yield with respect to infestation ratio variable. A 1% increase in infestation ratio would reduce about 2.5–6% of cotton yield. Although the infestation ratio of cotton yield is inelastic, which means that the yield is less responsive to the infestation ratio, the elasticity is however an economically important indication because additional cost spent on pests will increase total cost thereby increasing the level where marginal revenue equals the marginal cost. 相似文献
110.
Guilherme Loss-Morais Daniela C.R. Ferreira Rogério Margis Márcio Alves-Ferreira Régis L. Corrêa 《Genetics and molecular biology》2014,37(4):671-682
As microRNAs (miRNAs) are important regulators of many biological processes, a series of small RNAomes from plants have been produced in the last decade. However, miRNA data from several groups of plants are still lacking, including some economically important crops. Here microRNAs from Coffea canephora leaves were profiled and 58 unique sequences belonging to 33 families were found, including two novel microRNAs that have never been described before in plants. Some of the microRNA sequences were also identified in Coffea arabica that, together with C. canephora, correspond to the two major sources of coffee production in the world. The targets of almost all miRNAs were also predicted on coffee expressed sequences. This is the first report of novel miRNAs in the genus Coffea, and also the first in the plant order Gentianales. The data obtained establishes the basis for the understanding of the complex miRNA-target network on those two important crops. 相似文献