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141.
Copro-diagnostic methods for Toxoplasma gondii infected cats have been traditionally based on the identification of oocysts by light microscopy or by bioassays. The first method is not sensitive and also unable to differentiate between Toxoplasma oocysts from other coccidian parasites in cats, and the second is cumbersome, time consuming and expensive. We have adapted a polymerase chain reaction (PCR) method to detect T. gondii oocyst DNA in fecal samples. Oocysts were successfully disrupted by freeze thawing coupled with mechanical means, and DNA extraction was subsequently accomplished. The test, based on amplifying a 529 bp repeated sequence, proved sensitive for detecting 1-2 oocysts in 200 microg of stool sample. The test specificity was established by showing that DNA from other cat coccidia tested negative. Specificity was reconfirmed by Southern hybridization of the PCR products with a specific probe. Of 122 stool samples from Jerusalem cats surveyed for the presence of Toxoplasma oocysts, 11 were found positive by PCR while none was detected by microscopy. 相似文献
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Mojave desert tortoise (Gopherus agassizii) thermal ecology and reproductive success along a rainfall cline 下载免费PDF全文
Annette E. SIEG Megan M. GAMBONE Bryan P. WALLACE Susana CLUSELLA‐TRULLAS James R. SPOTILA Harold W. AVERY 《Integrative zoology》2015,10(3):282-294
Desert resource environments (e.g. microclimates, food) are tied to limited, highly localized rainfall regimes which generate microgeographic variation in the life histories of inhabitants. Typically, enhanced growth rates, reproduction and survivorship are observed in response to increased resource availability in a variety of desert plants and short‐lived animals. We examined the thermal ecology and reproduction of US federally threatened Mojave desert tortoises (Gopherus agassizii), long‐lived and large‐bodied ectotherms, at opposite ends of a 250‐m elevation‐related rainfall cline within Ivanpah Valley in the eastern Mojave Desert, California, USA. Biophysical operative environments in both the upper‐elevation, “Cima,” and the lower‐elevation, “Pumphouse,” plots corresponded with daily and seasonal patterns of incident solar radiation. Cima received 22% more rainfall and contained greater perennial vegetative cover, which conferred 5°C‐cooler daytime shaded temperatures. In a monitored average rainfall year, Cima tortoises had longer potential activity periods by up to several hours and greater ephemeral forage. Enhanced resource availability in Cima was associated with larger‐bodied females producing larger eggs, while still producing the same number of eggs as Pumphouse females. However, reproductive success was lower in Cima because 90% of eggs were depredated versus 11% in Pumphouse, indicating that predatory interactions produced counter‐gradient variation in reproductive success across the rainfall cline. Land‐use impacts on deserts (e.g. solar energy generation) are increasing rapidly, and conservation strategies designed to protect and recover threatened desert inhabitants, such as desert tortoises, should incorporate these strong ecosystem‐level responses to regional resource variation in assessments of habitat for prospective development and mitigation efforts. 相似文献
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H. Harold Toba John E. Turnet Donnie M. Powell 《American Journal of Potato Research》1981,58(8):423-428
A relationship between injury (any penetration of a tuber) and damage (in accordance with the U.S. Standards for Grades of Potatoes) caused by the sugarbeet wireworm,Limonius californicus (Mannerheim), the Pacific Coast wireworm,L. canus LeConte, and the Great Basin wireworm,Ctenicera priunina (Horn), to potatoes was determined. Based on tuber weights, the percentage of damage (D) increased curvilinearly with increased percentage of injury (I). Percentages of injured and damaged tubers based on tuber weights were significantly different from those based on tuber count. Difference in the relationship of injury vs. damage between untreated and fonofos-treated tubers was not significant. The regression D = -0.012 + 0.1 111 + 0.003I2 can be used to estimate the amount of damage from the amount of injury without the necessity of cutting and measuring feeding holes. 相似文献
148.
Copper (II) salts are used as metallizing agents in the synthesis of new non-genotoxic direct dyes for cotton. Specifically,
cotton fabric is dyed with non-genotoxic disazo direct dyes and then treated with copper salts. The complexes are characterized
by neutron activation analysis, absorption spectrometry and standard Salmonella mammalian mutagenicity assay, and the after-treated
fabrics are evaluated for lightfastness and washfastness. Direct dyes possessingortho-propoxy andortho’-hydroxy substituted systems formed the corresponding nonmutagenic 1:2 dye:metal complex and undergo significant improvement
in lightfastness following metallization. 相似文献
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Lee Fox K. Duane Biever H. Harold Toba James E. Duffus Peter E. Thomas 《American Journal of Potato Research》1993,70(7):505-515
A potato leafroll virus (PLRV) isolate has been successfully transmitted to and recovered from two wild crucifers,Sisymbrium altissimum L. (Jim Hill or tumble mustard) andCapsella. bursa-pastoris (L.) Medic. (shepherd’s purse) by the green peach aphid (GPA),Myzus persicae (Sulzer). Virus antigen in both plant species was found to be higher in root tissue than in foliar tissue, based on enzyme-linked immunosorbent assay (ELISA) determinations.C. bursa-pastoris was apparently a relatively poorer source of inoculum for the GPA thanS. altissimum. Using two geographically-separated biotypes ofC. bursa-pastoris, a Washington biotype was found to contain higher antigen titer in both leaf and root tissue than a California biotype, as determined by ELISA. Field studies demonstrated that both weed species can serve as overwintering sources of PLRV 相似文献
150.
A series of new direct dyes based on benzidine congeners, 2,2′-dimethyl-5,5′-dipropoxybenzidine and 5,5′-dipropoxybenzidine,
were evaluated for mutagenicity in Salmonella typhimurium strains TA98 and TA100. All of the dyes examined were judged to
be non-mutagenic with and without metabolic activation while toxicity was seen in some dyes at high doses. The study also
suggested that the standard Salmonella mutagenicity plate-incorporated assay was an excellent method for evaluation of direct
dyes for mutagenicity. 相似文献