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861.
J. F. Gonalvks E. Gomes L. Amaral J. Coimbra 《International Review of Hydrobiology》1990,75(6):875-881
Three isoproteic and isoenergetic diets containing fish meal as a protein source (control diet) or incorporating 10 and 20% of protein from mycelia Penicilium sp. as a fish meal substitute were tested during three months for eel fingerlings growth. Some preliminary “in vitro” experiments on the L-Lysin intestinal absorption in the presence and in the absence of Penicilin (500 mg/l) after 17 h of contact show a positive effect of this antibiotic. No residues of Penicilin were detected in carcass of eels fed 7 days with 100 mg/kg Penicilin in the food. The present results show that the use of Penicilin mycelia in eels diets will have the advantage of increasing growth without any appreciable change in the quality of the carcass and also, eventually, reductions of nitrogen excretion with a positive effect in effluent quality. 相似文献
862.
<Emphasis Type="Italic">Xenopus laevis</Emphasis> (Daudin, 1802), a new exotic amphibian in Portugal
Rui Rebelo Patrícia Amaral Marta Bernardes João Oliveira Paulo Pinheiro Domingos Leitão 《Biological invasions》2010,12(10):3383-3387
The African clawed frog Xenopus laevis has been introduced at several locations, including Mediterranean climate-type regions. In 2006, several individuals of this
species were found inhabiting a stream at Oeiras, about 20 km W of Lisbon, Portugal. Although the place and time of introduction
are not clearly identified, there are reasons to believe that this population may be the result of an almost 30-year-old introduction
proceeding from research laboratories located nearby. Field surveys were conducted in 2007 and 2008 on the distribution and
abundance of this species in the region. The species was found in two streams, about 5 km from each other. While being locally
abundant, the adults of X. laevis are smaller than those from South Africa and California. In spite of an abundant production of eggs and tadpoles at one of
the streams, no tadpoles were found in advanced developmental stages. Until now, most individuals were found in heavily urbanized
areas that should constrain their ability to cross overland to other water bodies. An eradication program may be feasible,
but the presence of adults on two streams indicates that the species may be expanding, in spite of the urban landscape. 相似文献
863.
Dany S.S.L. Amaral Madelaine Venzon Marcus V.A. Duarte Fernanda F. Sousa Angelo Pallini James D. Harwood 《Biological Control》2013,64(3):338-346
Habitat manipulation has long been used as strategy to enhance beneficial insects in agroecosystems. Non-crop weed strips have the potential of supplying food resources to natural enemies, even when pest densities are low. However, in tropical agroecosystems there is a paucity of information pertaining to the resources provided by non-crop weeds and their interactions with natural enemies. In this study we evaluated (a) whether weeds within chili pepper fields affect the diversity and abundance of aphidophagous species; (b) whether there are direct interactions between weeds and aphidophagous arthropods; and (c) the importance of weed floral resources for survival of a native and exotic coccinellid in chili pepper agroecosystems. In the field, aphidophagous arthropods were dominated by Coccinellidae, Syrphidae, Anthocoridae, Neuroptera and Araneae, and these natural enemies were readily observed preying on aphids, feeding on flowers or extrafloral nectaries, and using plant structures for oviposition and/or protection. Survival of native Cycloneda sanguinea (Coleoptera: Coccinellidae) differed between plant species, with significantly greater survival on Ageratum conyzoides and Bidens pilosa. However, no evidence was gathered to suggest that weed floral resources provided any nutritional benefit to the exotic Harmonia axyridis (Coleoptera: Coccinellidae). This research has provided evidence that naturally growing weeds in chili pepper agroecosystems can affect aphid natural enemy abundance and survival, highlighting the need for further research to fully characterize the structure and function of plant resources in these and other tropical agroecosystems. 相似文献
864.
865.
In this study, autometallography and immunohistochemistry were used to localize and quantify cadmium and metallothionein (MT) levels, respectively, in cellular compartments of turbot liver on exposure to cadmium for 7 days and further depuration treatment for 14 days. Metals weakly bound to proteins (i.e. MTs) in hepatocyte lysosomes were visualized as black silver deposits (BSDs) using a light microscope. With the aid of a newly developed immunohistochemical procedure, MTs were localized and semi-quantified in both the cytosolic and the lysosomal compartments of hepatocytes. The BSD extent in the lysosomes of hepatocytes increased significantly as a result of cadmium exposure. This response was evidenced after 1h. Further, a progressive increase in the volume density of BSDs occurred up to the seventh day. Total MT immunohistochemical levels increased at a lower rate, starting after 1 day of cadmium exposure. BSD extent values recovered after depuration, whilst MT levels remain unchanged. It is possible that the detoxification rate of metals via lysosomes was diminished, whilst MT levels remained unchanged, at least after 14 days of depuration. It can be concluded that autometallography and MT immunohistochemistry are good tools for clarifying metal and metal-MT trafficking routes in hepatocytes, and also that BSD extent and MT immunohistochemical levels in the lysosomes and cytosol of fish hepatocytes can be considered to be useful biomarkers of metal exposure. 相似文献
866.
867.
Luciano A Rigano María R Marano Atilio P Castagnaro Alexandre Morais Do Amaral Adrian A Vojnov 《BMC microbiology》2010,10(1):176
Background
Citrus Bacterial Canker (CBC) is a major, highly contagious disease of citrus plants present in many countries in Asia, Africa and America, but not in the Mediterranean area. There are three types of Citrus Bacterial Canker, named A, B, and C that have different genotypes and posses variation in host range within citrus species. The causative agent for type A CBC is Xanthomonas citri subsp. citri, while Xanthomonas fuscans subsp. aurantifolii, strain B causes type B CBC and Xanthomonas fuscans subsp. aurantifolii strain C causes CBC type C. The early and accurate identification of those bacteria is essential for the protection of the citrus industry. Detection methods based on bacterial isolation, antibodies or polymerase chain reaction (PCR) have been developed previously; however, these approaches may be time consuming, laborious and, in the case of PCR, it requires expensive laboratory equipment. Loop-mediated isothermal amplification (LAMP), which is a novel isothermal DNA amplification technique, is sensitive, specific, fast and requires no specialized laboratory equipment. 相似文献868.
The prejuvenile development of Echinocardium cordatum (Echinoidea) was investigated by means of scanning electron, confocal and light microscopes, aiming to illustrate the early
life history of a spatangoid representative and to compare it with the other major echinoid groups. During the larval development
of E. cordatum, two periods follow one another. The first one takes 12 days; it ends with the formation of a complete echinopluteus with
twelve elongated larval arms. The second lasts from 3 to 12 days; it is entirely devoted to the building of the echinid rudiment
and ends with the acquisition of larval competence. No appendage other than arms develops at the larva’s outer surface. Competent
larvae are demersal. They settle onto the substratum and test it for suitability using the five rudiment podia that protrude
through the vestibule opening. Metamorphosis is a rapid event that lasts less than an hour. The rudiment does not everse and
its spines and podia actively tear up the larval epidermis which is progressively covered by the growing vestibular epidermis.
The resulting postlarva is short-lived and morphologically similar to both the late rudiment and the early juvenile, which,
however, is exotrophic. Late rudiments in E. cordatum show basic spatangoid features being bilaterally symmetric and having clavulae and sphaeridia. More importantly, they already
have the convex shape and the appendage cover of early juveniles. Metamorphosis in E. cordatum appears to be less complex, i.e. no rudiment is everted, and more complete, since, in contrast to “regular” echinoids, no
transitory appendages are seen. Metamorphosis/development of E. cordatum, thus, is closer to that of clypeasteroids, since the rudiment of the latter already bears juvenile definitive appendages,
when everted during metamorphsis. 相似文献
869.
870.
Anapaula Sommer Vinagre Ana Paula Nunes do Amaral Fabiana Pinto Ribarcki Eliane Fraga da Silveira Eduardo Prico 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2007,146(4):514
The aim of this study was to analyze the seasonal variations of carbohydrate and lipid metabolism of the ghost crab Ocypode quadrata (Fabricius, 1787) on a sandy beach in the southern region of Brazil. Crabs and hemolymph samples were collected monthly in the field. Hepatopancreas, gills, gonads and claw muscles were used for glycogen determination. In males, blood glucose levels increased in the summer and in the winter. The glycogen values increased significantly in the hepatopancreas in the winter, but remained constant in the muscle, gonads and gills. In females, hemolymph glucose levels, glycogen values in the hepatopancreas and in the gills remained constant throughout the year; however, muscular glycogen increased in the spring and gonad glycogen decreased in the summer. Hemolymph triglyceride levels of males and females and total cholesterol of males decreased significantly in the spring. In females, a significant increase of total cholesterol levels was found in the winter. The findings suggest that in O. quadrata lipids seem to be an important reserve of energy used during reproduction, both in males and females, while glycogen may be used during periods of intense activity or fasting. 相似文献