全文获取类型
收费全文 | 141篇 |
免费 | 8篇 |
专业分类
林业 | 4篇 |
农学 | 17篇 |
基础科学 | 2篇 |
39篇 | |
农作物 | 37篇 |
水产渔业 | 17篇 |
畜牧兽医 | 21篇 |
园艺 | 4篇 |
植物保护 | 8篇 |
出版年
2023年 | 2篇 |
2022年 | 5篇 |
2021年 | 7篇 |
2020年 | 10篇 |
2019年 | 14篇 |
2018年 | 11篇 |
2017年 | 14篇 |
2016年 | 15篇 |
2015年 | 6篇 |
2014年 | 8篇 |
2013年 | 23篇 |
2012年 | 6篇 |
2011年 | 7篇 |
2010年 | 2篇 |
2009年 | 6篇 |
2008年 | 2篇 |
2007年 | 3篇 |
2005年 | 3篇 |
2003年 | 2篇 |
2002年 | 1篇 |
2001年 | 1篇 |
1992年 | 1篇 |
排序方式: 共有149条查询结果,搜索用时 15 毫秒
41.
Mahdi Jaberi Behzad Gharehyazi Mahmood Khosrowchahli Ali Sharafi Nafiseh Aboofazeli 《The Journal of Horticultural Science and Biotechnology》2018,93(2):204-208
Plant regeneration ability was studied in the medicinal-ornamental plant, Cosmos bipinnatus ‘Sonata white’, which is a dicotyledonous recalcitrant plant to shoot induction. Cotyledons were used as sources of explants to investigate plant regeneration. High frequency of direct shoot induction was obtained when BA (5 mg/l) and AgNO3 (5 mg/l) were used in combination with 20 mg/l adenine sulphate (73.8%) in Murashige and Skoog (MS) medium. The highest shoot number per explant (5.7) was induced on MS medium supplemented with 5 mg/l BA, 5 mg/l AgNO3, and 40 mg/l adenine. Eight week-old shoots were transferred to root induction media containing MS and half-strength MS medium with different concentration of IBA. The highest rate of root induction (70.8%) was obtained on half-strength MS medium with 1.5 mg/l IBA within four weeks. The plantlets were transferred to pot and kept in the greenhouse condition. Seventy percent of the plantlets successfully acclimatised.
Abbreviations: BA, 6-benzylaminopurine; IBA, Indole-3-butyric acid; MS, Murashige and Skoog; PGRs, plant growth regulators. 相似文献
42.
Hossein Ali Ghasemi Mehdi Kazemi-Bonchenari Amir Hossein Khaltabadi-Farahani Mahdi Khodaei Motlagh 《Tropical animal health and production》2013,45(7):1635-1640
A two-month trial was conducted to investigate the effects of pelleting rations with 70:30, 65:35, and 60:40 concentrate to high-quality roughage (alfalfa hay) ratios on hematological and biochemical parameters of ostriches. A total of 18 seven-month-old male ostrich chicks, initially weighing an average of 60–70 kg, were distributed into three different outdoor paddocks at a stocking density of six birds per paddock. In the morning, blood collection was made from the wing vein after about 12 h of fasting. All rations resulted in no significant change in hematological parameters. However, with increasing alfalfa inclusion rate, the heterophil/lymphocyte ratio tended to be lower (P?=?0.089); whereas the values of hemoglobin, packed cell volume (PCV), and mean corpuscular hemoglobin (MCH) tended to be higher (P values 0.069, 0.072 and 0.094, respectively). In terms of plasma biochemical parameters, increasing the ratio of concentrate to alfalfa hay in ostrich diets resulted in significant (P?<?0.05) depression in the values of glucose (up to 20.2 %), total cholesterol (up to 19.2 %), creatine kinase (up to 27.9 %), and aspartate aminotransferase (up to 29.9 %). Additionally, the 65:35 or 60:40 rations caused a decrease in low-density lipoprotein cholesterol level (27.9 and 42 %, respectively; P?=?0.008) compared to the 70:40 ration. Without exception, no rations affected the values of leukocyte subsets, total protein, albumin, globulin, uric acid, alanine aminotransferase, gamma glutamyl transferase, triglycerides, high-density lipoprotein cholesterol, and very low density lipoprotein. Based on our results, the concentrate to alfalfa ratio of 60:40 could be suggested as optimum ratio for good health conditions of juvenile ostriches. 相似文献
43.
Sayedeh Saba Bilgrami Saadollah Houshmand Mahdi Kadivar Baratali Fakheri Vahid Shariati 《Archives of Agronomy and Soil Science》2018,64(3):331-346
Micronutrient deficiency is one of the most common and widespread nutritional issues. Among the factors mitigating the bioavailability of Zn (zinc) and Fe (iron), phytic acid plays a key role; therefore, in order to scrutinize genetic alterations ?related to micronutrient and phytate contents, we examined the concentrations of zinc, iron, and phytic acid, as well as its mole ratio to ?zinc in various wheat species grown in two planting seasons. The concentrations of phytic acid and its mole ratio to zinc were 0.61?1.55 g kg?1 dry weight and 1.88?4.17 for autumn, and 0.97?2.02 g kg?1 dry weight and 2.10?4.05 for spring planting. There was a significant discrepancy among wheat species; tritipyrum had the highest concentration of iron, phytic acid and its mole ratio to zinc, and T. monococcum and T. aestivum recorded reasonable zinc bioavailability. Correlation studies between grain phytic acid concentrations and other measured traits revealed various relationships, denoting an irrefutable impact of planting season and wheat ploidy levels on modification of wheat genotypes. The characters contributing more positively with principal component (PC) 1 were Zn and Fe under spring planting and Fe under autumn planting. Spike number per square meter, biological yield and grain yield in spring cultivation, and grain zinc concentration in autumn cultivation were positively correlated to principal component (PC) 2. Given that the concentration of Fe and Zn in all the studied genotypes is relatively high and due to the existence of other desirable agronomic traits, this study believes that it could possibly enhance the applicability of some of these genotypes for breeding purposes. 相似文献
44.
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
45.
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
46.
Mohammad Reza Shahparvari Mahdi Safi Siyamak Safapour Kamaledin Gharanjig 《Fibers and Polymers》2018,19(8):1663-1669
In the present research, a method of assessing relative compatibility rating of single and binary mixtures of walnut green shell, cochineal, and weld natural dyes on aluminum pre-mordanted woolen yarns was proposed, where a proportion of the calculated diffusion coefficients of dyes was postulated. To calculate the diffusion coefficient values, the uptake behavior of dyes was derived as the K/S and the exhaustion curves by dyeing the woolen yarn samples with the individual dye as well as with the mixtures of dyes obtained from practical conditions of dyeing. A typical method was employed to dye the samples at two temperatures of 80 and 95 oC. The method proposed for determination of the compatibility of dyes was more verified at higher temperature, that is, 95 oC, against a conventional method of solution analysis. The results of compatibility showed that the selected binary mixtures of cochineal-weld have an excellent compatibility. The other mixtures, that is, walnut green shell-cochineal and walnut green shell-weld showed weak-moderate and very weak compatibility, respectively. 相似文献
47.
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
48.
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
49.
Mohammad Reza Neyshaburi Hossein Bayat Kourosh Mohammadi Nader Nariman-Zadeh Mahdi Irannejad 《Archives of Agronomy and Soil Science》2013,59(2):257-273
Soil water retention characteristic is required for modeling of water and substance movement in unsaturated soils and need to be estimated using indirect methods. Point pedotransfer functions (PTFs) for prediction of soil water content at matric suctions of 1, 5, 25, 50, and 1500 kPa were developed and validated using a data-set of 148 soil samples from Hamedan and Guilan provinces, Iran, by multiobjective group method of data handling (mGMDH). In addition to textural and structural properties, fractal parameters of the power-law fractal models for both particles and aggregates distributions were also included as predictors. Their inclusion significantly improved the PTFs’ accuracy and reliability. The aggregate size distribution fractal parameters ranked next to the particle size distribution (PSD) in terms of prediction accuracy. The mGMDH-derived PTFs were significantly more reliable than those by artificial neural networks but their accuracies were practically the same. Similarity between the fractal behavior of particle and void size distributions may contribute to the improvement of the derived PTFs using PSD fractal parameters. It means that both distributions of the pore and particle size represent the fractal behavior and can be described by fractal models. 相似文献
50.
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