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排序方式: 共有150条查询结果,搜索用时 15 毫秒
31.
Mahdi Najafi Ghiri Mahrooz Rezaei Abdolmajid Sameni 《Archives of Agronomy and Soil Science》2013,59(9):945-957
Zinc sorption–desorption by sand, silt and clay fractions of six representative calcareous soils of Iran were measured. Sand, silt and clay particles were fractionated after dispersion of soils with an ultrasonic probe. Zinc sorption analysis was performed by adding eight rates of Zn from 6 to 120 μmol g?1. For the desorption experiment, samples retained after the measurement of Zn sorption were resuspended sequentially in 0.01 M NaNO3 solution and shaken for 24 h. Results indicated that Zn sorption by soil fractions increased in the order clay > silt > sand, and correlated negatively with CaCO3 content and positively with cation exchange capacity (CEC) and smectite content. Results indicated that for all fractions, the Langmuir equation described the sorption rates fairly well. In contrast to sorption, Zn desorption from soil fractions increased in the order sand > silt > clay, and correlated positively with CaCO3 content, CEC and smectite content. Results showed that parabolic diffusion and two constant equations adequately described the reaction rates of Zn desorption. In general, for all soils studied, the coarser the particle size, the less Zn sorption and more Zn desorption, and this reflects much higher risk of Zn leaching into groundwater or plant uptake in contaminated soils. 相似文献
32.
Effects of blend of canola oil and palm oil on nutrient intake and digestibility,growth performance,rumen fermentation and fatty acids in goats 下载免费PDF全文
Kazeem Dauda Adeyemi Awis Qurni Sazili Mahdi Ebrahimi Anjas Asmara Samsudin Abd Rasak Alimon Roselina Karim Saiful Anuar Karsani Azad Behnan Sabow 《Animal Science Journal》2016,87(9):1137-1147
The study examined the effects of blend of 80% canola oil and 20% palm oil (BCPO) on nutrient intake and digestibility, growth performance, rumen fermentation and fatty acids (FA) in goats. Twenty‐four Boer bucks were randomly assigned to diets containing 0, 4 and 8% BCPO on a dry matter basis, fed for 100 days and slaughtered. Diet did not affect feed efficiency, growth performance, intake and digestibility of all nutrients except ether extract. Intakes and digestibilities of ether extract, unsaturated fatty acids (FA) and total FA were higher (P < 0.05) while digestibility of C18:0 was lower (P < 0.05) in oil‐fed goats than the control goats. Total volatile FA, acetate, butyrate, acetate/propionate ratio and methane decreased (P < 0.05) with increasing BCPO but propionate, NH3‐N and rumen pH did not differ between diets. Ruminal concentration of C18:0, n‐3 FA and total FA increased (P < 0.05) while C12:0, C14:0, C15:0 and n‐6 FA decreased with increasing BCPO. Analysis of the FA composition of Triceps brachii muscle showed that concentrations of C16:0, C14:0 and C18:2n‐6 were lower (P < 0.05) while C18:1n‐9, C18:3n‐3 and C20:5n‐3 were higher in oil‐fed goats compared with control goats. Dietary BCPO altered muscle lipids without having detrimental effects on nutrient intake and digestibility and growth performance in goats. 相似文献
33.
The article shows results of an international and interdisciplinary project with the title ‘Rainfall and its Erosivity in Ethiopia’. The article contains information about the traditional soil conservation practices, the reasons for intervention with traditional soil conservation technologies, the historical background of instutionalized soil conservation activities, the institutional frame work for soil conservation activities and their achievements, and the different departments and organisations for soil and water conservation as far as soil erosion in Ethiopia is concerned. As a conclusion and recommendation, the major constraints of the past activities and the current situation including future trends were discussed. 相似文献
34.
Marjan Zargar Seyed Hadi Razavi Seyed Mahdi Ojagh 《Journal Of Aquatic Food Product Technology》2013,22(8):1311-1322
ABSTRACTIn the present study, aqueous solutions of sodium caseinate (SC) 8% (w/w) were provided in the form of four treatments—including SC without any essential oil (EO) as well as SC with 0.25, 0.5, and 1% (v/w) concentrations of Zataria moltiflora EO. Fish samples were treated with aqueous solutions and stored at 4 ± 1°C for 20 days. The control and treated fish samples were analyzed for chemical (total volatile basic nitrogen, pH, thiobarbituric acid, peroxide value), microbiological (total viable count and psychrotrophic count), and sensory analyses every 4 days. Based on results, SC edible coating had no antimicrobial effect but acted like a barrier against the fish flesh contamination. Moreover, incorporating Zataria moltiflora EO with SC edible coating reduces peroxide value and thiobarbituric acid-reactive substances values as well as the chemical and microbiological spoilage of refrigerated ?sh samples. Furthermore, sensory evaluation results showed that the presence of thyme oil improved the sensory quality of the rainbow trout. 相似文献
35.
BACKGROUND: Viral protein-1 (VP1) is a major capsid protein of Coxsakievirus B3 (CVB3) that plays an important role in directing viruses towards permissive cells and acts as a main antigenic site of the virus in eliciting of host immune response, hence it seems VP1 can be considered as a vaccine candidate against CVB3 infection. In this study, cDNA of VP1 was prepared, cloned into pET expression vector and the recombinant protein (VP1) was over expressed in E. coli. METHODS: The viruses were grown in suspension cultures of Vero cells with an input virus multiplicity of 10-50 plaque-forming units/cell. After observing complete cytopathic effect, the total RNA (cells and virus) was prepared for RT-PCR and by using specific primers, VP1 cDNA was amplified and ligated into pET vectors (32 a and 28 a). The recombinant vector was transferred into competent E. coli (BL-21) and after selection of proper colony, which carried correct cDNA within the vector; cells were cultured and induced with isopropyl B-D-thiogalactopyranoside, in order to express protein (VP1). The cultures were tested for presence of VP1 by SDS-PAGE and Western-Blotting analysis. RESULTS: Molecular techniques such as PCR which showed exact defined size of the VP1 (819 bp), restriction digestion and finally immunoblot analysis of over expressed protein; all confirmed the correct cloning and expression of VP1 in this research. CONCLUSION: In this research, full length of VP1 as major capsid protein of CVB3 was over expressed in E. coli which, can be used for further studies, including neutralizing antibody production against CVB3. 相似文献
36.
Kalanaki Mahdi Ritzema Henk Bamshad Roghayeh Jones Edward Fazilatnia Mojtaba 《Paddy and Water Environment》2020,18(2):469-479
Paddy and Water Environment - Application of common leaching and flushing methods is often impractical due to freshwater scarcity, groundwater pollution and a lack of suitable drainage systems. To... 相似文献
37.
Abdollah Beykkhormizi Parvaneh Abrishamchi Ali Ganjeali Mahdi Parsa 《Journal of plant nutrition》2016,39(6):883-893
Vermicompost can play an effective role in plant growth and development and also in reducing harmful effects of various environmental stresses on plants due to its porous structure, high water storage capacity, having hormone-like substances and plant growth regulators and also high levels of macro and micro nutrients. The aim of this study was to investigate the effects of vermicompost and salinity interactions on some morphological and physiological features and concentration of mineral elements of bean (Phaseolus vulgaris L. cv. Light Red Kidney) cultivar. A factorial experimental with five different volumetric ratios of vermicompost and sand, including to: 0:100; 10:90; 25:75; 50:50 and 75:25 and four levels of salinity [20, 40, 60 and 80 mmol l?1 sodium chloride (NaCl)], and control was conducted base on Randomized Complete Block Design with three replications. Bean seeds were sowed in plastic pots, the seedlings being sampled 42 days old (flowering stage).The results showed that vermicompost had significant effect on all studied traits under stress and non-stress (p ≤ 0.05).In this experiment, the vermicompost significantly increased the photosynthetic rate and concentrations of potassium (K+) and calcium (Ca2)+in leaf and root tissues. In salinity levels of 20, 40 and 60 mmol l?1NaCl, all subjected ratios of vermicompost and in 80 mmol l?1NaCl the ratios of 10% and 75% vermicompost, significantly ameliorated negative effects of salinity. In both stress and non-stress conditions, using 10% volume of vermicompost is recommended to improve the growth of bean plants. 相似文献
38.
Shabir A. Bangroo Nayar A. Kirmani Mohammad A. Bhat Javaid A. Wani Asif M. Iqbal Zahoor A. Dar Syed Sheraz Mahdi Ajaz A. Malik 《植物养料与土壤学杂志》2021,184(1):112-122
Background : Potassium (K) availability in soil and plant uptake is restrained by the dynamic interactions among the different pools of K. Aims : To understand these interactions, a study was undertaken to assess the quantity–intensity (Q/I) and buffering characteristics of rainfed maize (Zea mays L.) growing soils. Ten contrasting soils were evaluated for K partitioning changes in exchangeable K (ΔEK) and non‐exchangeable K (ΔNEK) pools in the soil‐solution phase and buffering characteristics using a modified version of Q/I approach. Results : The partitioned Q/I isotherms showed strong adsorption with the increase in K concentration ratio (CRK) and the changes due to ΔEK were higher than changes due to ΔNEK. Total buffering capacity (PBCK) significantly correlated (r = 0.92, p <0.01) with clay content with a major share contributed by buffering capacity owing to non‐exchangeable K ( ) rather than exchangeable K ( ). The fixation capacity (β) factor, the magnitude of added K converted into a non‐exchangeable pool, ranged from 41 to 63%, whereas release (α) factor, the magnitude of added K converted to the exchangeable pool, ranged from 19 to 36%. Both threshold solution K (CKr) and threshold exchangeable K (EKr) values were found to be high in Satran clay loam (S2) and lower in Doon silty clay loam (S3) soils. The equilibrium exchangeable K (EKo) was found close to minimum exchangeable K (Emin) in Doon silty clay loam (S3) and Babaweyl sandy clay loam (S1) soils and overall Emin constituted about 8.94 to 0.57% of the EKo. Conclusion : It may be concluded that K Q/I isotherm partitioning provides a valuable insight to assess the dynamic relations. The ratio of α/β (K recharge index) could be used to evaluate the K enrichment capacity of soil to K additions while EKr and Emin can be potentially useful in the elucidation of exchangeable K as K fertility index especially in soils with poor K fertilizer management. 相似文献
39.
Interaction of water and nitrogen on maize grown for silage 总被引:3,自引:0,他引:3
Mahdi Gheysari Seyed Majid Mirlatifi Mohammad Bannayan Mehdi Homaee 《Agricultural Water Management》2009,96(5):809-821
Water scarcity and environmental pollution due to excessive nitrogen (N) applications are important environmental concerns. The Varamin region, which is located in the central part of Iran, is one of the locations where farmers apply 250-350 kg N ha−1 for silage maize without any concerns with respect to the available water for irrigation. The objective of this study was to quantify the response of the silage maize (Zea mays L.) to variable irrigation and N fertilizer applications under arid and semi-arid conditions and to determine the optimum amount of N fertilizer as a function of irrigation. The maize Hybrid 704 single-cross was planted on 3 August 2003 and on 25 June 2004. The experimental treatments consisted of three N rates (0, 150, and 200 kg N ha−1) and four levels of irrigation, including two deficit irrigation levels 0.70 SWD (soil water depletion) and 0.85 SWD, a full-irrigation level (1.0 SWD) and an over-irrigation level (1.13 SWD). Twelve treatments were arranged in a strip-plot design in a randomized complete block with three replicates. Gravimetric soil samples were collected in 2003 and a neutron probe was used in 2004 to measure soil water content. Leaf area index, total aboveground biomass (TB), plant height, stem diameter, and leaf, stem, and ear dry weight were measured during the growing seasons and at final harvest. Total aboveground biomass was affected by irrigation (P < 0.0001) during both years and was also affected by N fertilizer in 2003 (P = 0.0001) and 2004 (P < 0.0001). However, there was no irrigation and N fertilizer interaction for both years (P > 0.5). Total aboveground biomass and biomass of the crop components increased as a function of the amount of water and N applied. For each of the irrigation levels, there was an associated optimum amount of N, which increased as the amount of irrigation water that was applied increased. Among the four irrigation levels that were studied, 0.85 SWD was the optimum level of irrigation for the conditions at the experimental site. The results also indicated that an increase in N applications is not a good strategy to compensate for a decrease of TB under drought stress conditions. We concluded that the effect of N fertilizer on TB depends on the availability of water in the soil, and that the amount of N fertilizer applied should be decreased under drought stress conditions. Further research will combine these results with a crop simulation model to help optimize nitrogen and water management for silage maize. 相似文献
40.
Mahdi Najafi-Ghiri Boostani Hamid Reza Mirsoleimani Abbas Mohaviye-Asadi Negin Beizavi Majid Shafiei Mina Mirdoraghi Maryam 《Eurasian Soil Science》2020,53(7):978-985
Eurasian Soil Science - Arid and semiarid soils of southern Iran may fix a large content of applied potassium (K), but the fixed K may be gradually supplied to plants. Sixteen representative soils... 相似文献