全文获取类型
收费全文 | 578篇 |
免费 | 61篇 |
专业分类
林业 | 66篇 |
农学 | 12篇 |
124篇 | |
综合类 | 20篇 |
农作物 | 30篇 |
水产渔业 | 86篇 |
畜牧兽医 | 233篇 |
园艺 | 11篇 |
植物保护 | 57篇 |
出版年
2024年 | 1篇 |
2023年 | 5篇 |
2022年 | 10篇 |
2021年 | 25篇 |
2020年 | 28篇 |
2019年 | 32篇 |
2018年 | 37篇 |
2017年 | 39篇 |
2016年 | 35篇 |
2015年 | 24篇 |
2014年 | 27篇 |
2013年 | 44篇 |
2012年 | 38篇 |
2011年 | 49篇 |
2010年 | 21篇 |
2009年 | 32篇 |
2008年 | 25篇 |
2007年 | 28篇 |
2006年 | 21篇 |
2005年 | 12篇 |
2004年 | 21篇 |
2003年 | 18篇 |
2002年 | 18篇 |
2001年 | 10篇 |
2000年 | 5篇 |
1999年 | 4篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1992年 | 2篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1985年 | 4篇 |
1983年 | 1篇 |
1974年 | 2篇 |
1968年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有639条查询结果,搜索用时 125 毫秒
91.
Ricardo Marcos Marta Santos Fernanda Malhão Rui Pereira Ana Cristina Fernandes Luís Montenegro Paola Roccabianca 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2009,38(2):201-205
Abstract: A 4‐year‐old, domestic shorthair, female spayed cat was presented for decreased appetite and depression. Severe pancytopenia with erythrocyte autoagglutination was found. The cat was seronegative for feline immunodeficiency and leukemia viruses. Immune‐mediated hemolytic anemia was suspected but no response to treatment with a blood transfusion, enrofloxacin, and prednisone was observed. Blood and bone marrow smears obtained 11 days later contained Leishmania amastigotes in the cytoplasm of neutrophils and macrophages, respectively. Serologic and PCR testing of peripheral blood confirmed infection with Leishmania infantum. Despite treatment, the cat worsened clinically and was euthanized. At necropsy, visceral dissemination of the parasite was confirmed. The findings in this case indicate that visceral leishmaniasis should be considered as a differential diagnoses in cats with pancytopenia in areas endemic for Leishmania. In addition, amastigotes may be observed in peripheral blood neutrophils. 相似文献
92.
María Sol Arias Jos Luis Surez G.V. Hillyer Ivn Francisco Enrique Calvo Rita Snchez-Andrade Pablo Díaz Rubn Francisco Pablo Díez-Baos Patrocinio Morrondo Adolfo Paz-Silva 《Veterinary journal (London, England : 1997)》2009,182(1):73-78
The therapeutic efficacy of albendazole and netobimin in ruminants with naturally occurring fascioliasis was investigated using a recombinant-based ELISA. The variation in the IgG response against a 2.9-kDa recombinant protein (FhrAPS), termed efficacy index (EI) 1, and the egg-output changes, termed EI 2, were used to evaluate drug efficacy.The values of EI 1 ranged between 0% and 50% in sheep, and between 0% and 30% in cattle after treatment with albendazole and netobimin. Similar EI 2 values were observed in sheep receiving albendazole or netobimin, but the highest values were found in cattle treated with netobimin. The significant reduction in the IgG response to FhrAPS found in this study shows promise in terms of developing alternative methods for evaluating the efficacy of chemotherapy against Fasciola hepatica in grazing ruminants. 相似文献
93.
B.A.N. Silva R.F.M. Oliveira J.L. Donzele H.C. Fernandes A.L. Lima D. Renaudeau J. Noblet 《Livestock Science》2009,120(1-2):25-34
Fifty nine primiparous sows PIC Camborough 23 were distributed in a completely randomized 2 × 2 (with and without floor cooling × two dietary treatments) factorial design with 16 sows/treatment, each sow being considered as an experimental unit. Four replicates of sixteen sows each were used during the trial with the objective of evaluating the effects of floor cooling and the use of dietary amino acid contents on their performance and behaviour during summer. The sows were distributed among the treatments according to body weight and backfat thickness after farrowing. The sows were maintained in the experiment until weaning at 21 days of lactation. The two experimental diets supplied the same levels of crude protein (22%), metabolizable energy (ME; 14.65 MJ/kg) and levels of essential digestible AA relative to digestive lysine and differed according to the digestible lysine to ME ratio (0.75 vs. 0.82 g/MJ of ME). The temperature of the water circulating in the cooled floor was maintained at about 17 °C. Based on the average minimum and maximum temperatures (21.5 and 29.5 °C) obtained during the experimental trial, it can be assumed that the sows were exposed to periods of heat stress. The replicate and the interaction between replicate and treatment effects on all the measurements were not significant. Similarly, no effect of diet or interaction between diet and floor cooling system was found for all criteria measured. An effect (P < 0.05) of floor cooling on average daily feed intake was observed and floor cooling sows showed a higher average (P < 0.05) digestible lysine (61.5 vs. 51.8 g/d) and ME (78.2 vs. 65.9 MJ/d) intakes. The sows submitted to floor cooling showed, consistently, higher absolute values for average weight (+ 8.5 kg) and backfat (+ 0.75 mm) at weaning, compared with the control sows. The sows submitted to the cooled floor showed a shorter (P < 0.01) weaning-to-oestrus interval. The piglet and litter's daily weight gain (DWG), average weight at weaning (AWW) and total weight gain during lactation (TWG) were higher (P < 0.01) for the floor cooling sows. The floor cooling sows showed a higher (P < 0.01) daily milk production. The respiratory rate and rectal temperature values were lower (P < 0.01) for the floor cooling sows. There were differences (P < 0.01) on the cutaneous temperatures measured on the different parts of the sow's body, with the animals submitted to the cooled floor having lower values. The sows submitted to floor cooling spent less (P < 0.01) time in lateral recumbency inactive, more time nursing (P < 0.05) and more time feeding (P < 0.01) compared with control sows. The floor cooling under the sows increased daily feed intake and lysine intake, leading to a lower body weight loss, a lower weaning-to-oestrus interval and also improved nursing behaviour of the sows, leading to a higher milk production and, consequently, higher weight gains of piglets and litter during the lactation period. 相似文献
94.
A new spectrophotometric assay for the quantification of polyphenolic content has been validated. It is based on Prussian Blue method and adapted to microplate spectrophotometry. Prussian Blue reaction is critically dependent on reaction time, but microplate spectrophotometry permits exact measures of many samples at the same time. This new method is precise, reproducible, repeatable and exact. 相似文献
95.
Catarina Campos M. Filipa Castanheira Sofia Engrola Luísa M. P. Valente Jorge M. O. Fernandes Luís E. C. Conceição 《Fish physiology and biochemistry》2013,39(6):1485-1496
The present work examined the short- and long-term effects of three rearing temperatures on protein metabolism and growth trajectories of Senegalese sole larvae using 14C-labelled Artemia protein as feed. A first feeding trial was performed on larvae reared at 15, 18 and 21 °C (at 26, 17 and 14 days post-hatching (dph), respectively) and a second trial conducted on post-larvae after transfer to the same rearing temperature (~20 °C) (49, 35 and 27 dph, in larvae initially reared at 15, 18 and 21 °C, respectively). Temperature greatly influenced larvae relative growth rate (RGR) and survival, since growth at 15 °C was severely depressed. Protein digestibility and retention was highest at 18 °C during the first trial (85.35 ± 1.16 and 86.34 ± 2.33 %, respectively). However, during the second trial, post-larvae from 15 °C had the highest feed intake and protein digestibility (3.58 ± 1.54 and 75.50 ± 1.35 %, respectively), although retention was similar between treatments. Furthermore, after transfer to 20 °C larvae from 15 °C experienced compensatory growth, which was observed until 121 dph, and confirmed by RGR values, which were significantly higher at 15 ºC than at 21 ºC or 18 ºC. Results from the present study show that Solea senegalensis larval development, survival and protein digestion and retention are highly affected by thermal history. 相似文献
96.
Pedro M. Fernandes da Costa Minling Pan 《Aquaculture Economics & Management (Blackwell Science)》2013,17(4):302-315
Ahi poke (raw tuna salad) has a significant role in Hawaiian culture and economy. A consumer survey in Hawaii was used to examine consumers’ purchasing intentions for ahi poke. A censored regression analysis was conducted to analyze these purchases and connect with various consumer characteristics. Results show that many consumers eat ahi poke frequently and different consumer profiles will lead to large differences in the quantity consumed. Information obtained in this study may help producers and retailers to better target their marketing strategies and increase sales. 相似文献
97.
Guimes Rodrigues Filho Sabrina Dias RibeiroCarla da Silva Meireles Leandro Gustavo da SilvaReinaldo Ruggiero Moacir Fernandes Ferreira JuniorDaniel Alves Cerqueira Rosana Maria Nascimento de AssunçãoMara Zeni Patricia Polleto 《Industrial Crops and Products》2011,33(3):566-571
Cellulose acetate is one of the components employed in drug controlled-release systems in the form of membranes. The aim of this study was to examine the controlled-release of doxycycline employing cellulose acetate symmetric and asymmetric membranes as matrices. The cellulose triacetate was produced from sugarcane bagasse through a homogeneous acetylation reaction, using acetic acid as the solvent, acetic anhydride as the acetylating agent and sulfuric acid as the catalyst. The viscosity average molecular weight of the cellulose acetate produced was 39,000 g mol−1. The symmetric membranes were produced using a system solvent of dichloromethane/ethanol (9:1, v/v) and the asymmetric membranes were produced from the same solvent system and 10% of water. For the formulation of both, 5% of doxycycline was used. The membranes were characterized by thermal analysis (DSC and TGA) and scanning electron microscopy SEM. The release of doxycycline through cellulose triacetate matrices was examined using spectrophotometric analysis in the ultraviolet-visible region, at 275 nm. The results revealed that asymmetric membranes release 80% of the drug in 100 min, while symmetric membranes release 14% of the drug during the same time interval. 相似文献
98.
Camila Almeida Melo Lílian Karla de Oliveira Leonardo Fernandes Fraceto André Henrique Rosa 《Communications in Soil Science and Plant Analysis》2018,49(12):1530-1539
The objective of this work was to evaluate the adsorption of macronutrients calcium, potassium, magnesium, nitrogen, and phosphorus in two Brazilian tropical peat samples, investigating the effect of pH and determining the kinetics of the adsorption process. Two different Brazilian tropical peat samples were characterized using FTIR, TG, and SEM techniques. Different pH conditions were tested, as well as different mass concentrations of the peats. Differences in the chemical structures of the peat samples directly influenced the adsorptive capacities for the macronutrients. The adsorptive capacity for nitrogen was highest at pH 3, while the best adsorption of calcium and potassium was obtained at pH 6. The best fit to the data was provided by the pseudo-second-order model, which confirmed the rapid adsorption of calcium by both peats. 相似文献
99.
Tássia Rhuna Tonial dos Santos Gustavo Affonso Pisano Mateus Marcela Fernandes Silva Carolina Sayury Miyashiro Leticia Nishi Murilo Barbosa de Andrade Márcia Regina Fagundes-Klen Raquel Guttieres Gomes Rosângela Bergamasco 《Water, air, and soil pollution》2018,229(3):92
The textile industries are characterized as one of the biggest consumers of potable water and chemical products throughout its process, being responsible for the elevated wastewater generation with intense coloration and wide polluting potential. In this context, the present study proposes the development and application of a new coagulant material for textile wastewater treatment. The proposed coagulant (α-Fe2O3-MO) was composed by hematite nanoparticles (α-Fe2O3) obtained by a simple non-pollutant methodology, associated with Moringa oleifera (MO) seeds saline extract compounds. Coagulation/flocculation (CF) efficiency was evaluated by removal of physicochemical parameters such as apparent color, turbidity, and compounds with absorption at UV254nm (UV254nm) through CF tests carried out on Jar test equipment and sedimentation carried out in the presence and absence of external magnetic field (600 k Am?1). Kinetics sedimentation was from 0 to 90 min. The use of this new coagulant allowed the removal of 92.37% for apparent color, 91.43% for turbidity, and 46.09% for UV254nm, indicating that the proposed coagulant association was efficient in the treatment of this type of wastewater under external magnetic field with only 10 min of sedimentation. In addition, the resulting sludge from CF process was tested as base material for a new coagulant synthesis, demonstrating great reuse potential. Therefore, the new proposed coagulant, composed of α-Fe2O3 and the compounds present in the seed extract of MO, has applicability for textile wastewater treatment demonstrating high removal rate for all evaluated parameters with cost reduction in the proposed treatment for this wastewater. 相似文献
100.
Walter?D.?CarciochiEmail author Nicolás?Wyngaard Guillermo?A.?Divito Miguel?L.?Cabrera Nahuel?I.?Reussi Calvo Hernán?E.?Echeverría 《Biology and Fertility of Soils》2018,54(3):349-362
The development of simple predictors of sulfur (S) mineralization and its correlation with field-derived data may help improving corn S availability diagnosis. The objectives of this study were (1) to compare methods to estimate soil S mineralization, (2) to develop a model to predict soil S mineralization from S mineralization indexes and edaphic variables, and (3) to predict field-grown corn S uptake (Suptake) and apparent S mineralization (Smin-app) from different S mineralization indexes and edaphic-climatic variables. We evaluated 26 experimental sites where we measured edaphic variables as soil organic C (SOC), organic C in the particulate fraction (C-PF), S mineralization potential (Smin-10wk), S mineralized during a short-term (7 days) aerobic incubation + initial inorganic S (Smin-7d?+?Sinorg), and N mineralized during a short-term (7 days) anaerobic incubation (Nan). Additionally, 18 field experiments were carried out to quantify Suptake and Smin-app. The C-PF, Smin-7d?+?Sinorg, Nan, and SOC were variables significantly correlated with Smin-10wk (r?=?0.89, 0.89, 0.88, and 0.85, respectively). We developed a simple model to predict Smin-10wk from selected edaphic variables (Smin-10wk?=?0.038*Nan?+?0.106*SOC?+?0.74; Ra2 =?0.87). The Smin-10wk, C-PF, and Smin-7d?+?Sinorg showed a liner-plateau association with Suptake (R2?=?0.73, 0.53, and 0.48, respectively). We modified the method to estimate Smin-app to account for S losses (Smin-app (modified)) and developed a model to predict Smin-app (modified) from C-PF (Smin-app (modified)?=?4.65*C-PF?+?9.86; R2?=?0.62) or Smin-10wk (Smin-app (modified)?=?3.0*Smin-10wk?+?7.4; R2?=?0.54). Our results demonstrate that S mineralization indexes can be used to predict corn S availability under field conditions. 相似文献