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991.
Mahsa Aghhavani Shajari Reza Ghorbani Alireza Koocheki 《Journal of plant nutrition》2018,41(8):1047-1064
Corm size is the most important factor in production of replacement corms and flower yield of saffron. The aim of this study was to investigate the effect of nutrition and irrigation managements on saffron corms characteristics in the experimental field of Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, in 2013–2015. The experiment was carried out as split-split plot based on a Randomized Complete Block Design with 18 treatments and three replications. Experimental factors were: 1- superabsorbent (SA) [application and no-application of superabsorbent (non-SA)], 2- irrigation intervals [irrigation every 2, 3 and 4 weeks] and 3- nutrition management [humic acid, mycorrhiza (Glomus intraradices) and control]. The results showed that the highest total weight of replacement corms per clone in sum of two years was obtained in non-SA application, two weeks irrigation intervals and humic acid treatment. The corm/tunic weight ratio decreased by increasing the irrigation intervals and this index in two weeks irrigation intervals was 31% more than four weeks irrigation intervals. Application of nutritional treatments increased the number of saffron replacement corms per clone in all of the weight categories (0-3, 3–6, 6–9 and more than 9 g) on averaged 5, 40, 36 and 25%, respectively compared with control treatment in both years. Results showed that the replacement corms yield in large weight groups was on average 34% higher in the second year than the first year. Finally, application of SA, organic and bio fertilizers and four weeks irrigation intervals improved most of criteria and yield of saffron replacement corms. 相似文献
992.
Mohammad Ajmal Afsar M. Sulaiman Akhtar Hussain Khan 《Water, air, and soil pollution》1993,68(3-4):485-492
Heavy metal ions such as Cr, Ni, Cu, Cd and Zn have been removed from the electroplating waste using Fe(III) hydroxide as adsorbent. The maximum removal of these metal ions (>90%) occurred at pH 8 to 9. Removal of SO 4 2? (98%) occurred at pH 4. Anions were found to play a negative role in the adsorption phenomenon. Metal ion Sorption has been found to decrease with increasing anionic concentrations. The methodology proposed might provide an inexpensive and economical procedure for removal and recovery of toxic metals from electroplating wastes. 相似文献
993.
A study was conducted to select the best alternative for the development of construction panels as well as investment in its manufacturing in Iran.Three alternatives are considered,cement-bonded wood composite product,substituted products(such as concrete panel) sandwich panel and a mixture of them.We apply the analytic network process(ANP) to achieve this goal.A hierarchy is designed to prioritize benefits,opportunities,costs and risks(BOCR) by using the Analytic Hierarchy Process(AHP) ratings approach.To evaluate the "control criteria" of the system,a control hierarchy is also created and prioritized by applying the Analytic Network Process(ANP).A total of four major control criteria in the system are prioritized where each one controls a decision network evaluated using ANP.The final synthesis of the system shows cement-bonded wood composite product is the best choice among three potential alternatives for the investment and development. 相似文献
994.
Gholamhosein Moradi Mohammad Reza Marvie Mohadjer Ghavamodin Zahedi Amiri Anoushirvan Shirvany Nosratollah Zargham 《林业研究》2010,21(2):201-206
在Postband地区(27°58′4″-28°2′16″N,53°17′34″-53°22′30″E),辨别植物种、植物多样性、生活型及地中海气候、Irano-Torunian和撒哈拉-新店相关植物种。2008年6月至2006年12月间,调查和辨认了29个科,69个属,总计95个种。就物种频度而言,菊科和禾本科是重要的科。按照Raunkiaer's生活型谱系统和利用■2检测,生活型谱表明,年生植物、地面芽植物、高位芽植物、地上芽植物和陷芽植物分别占据全部植物种的47%、31%、12%、7%和3%。在地理分布上,Irano-Torunia地区,拥有最高的频度的29%的物种。结果表明,一年生植物比生活型基准群谱高;高位芽植物比生活型基准群谱低,这与在干旱地区的研究数据相一致。图1表4参50。 相似文献
995.
Kambiz Abrari Vajari Hamid Jalilvand Mohammad Reza Pourmajidian Kambiz Espahbodi Alireza Moshki 《林业研究》2011,22(4):591-596
A case study was conducted in beech forests of northern Iran to determine the effect of the created gaps on some soil properties in beech stand. Changes of soil properties in small (60 150 m 2 ), medium (151 241 m 2 ), large (242 332 m 2 ) and very large (333 550 m 2 ) gaps, as well as under closed stands were studied eight years after the gap creation. Soil samples were taken from three depths, 0 10, 10 20 and 20 30 cm. The gaps were different from their around undisturbed stands in terms of the following soil parameters: Mg +2 concentration of 0 10 cm at medium gap size, bulk density of 10 20 cm at very large gap size as well as K + and Ca +2 concentrations at 20 30 cm at small and large gap sizes, respectively. Furthermore, the size of the gaps had no effect on soil characteristics through the whole profile. Water saturation percent (Sp %) at 0 10cm as well as P and Mg +2 at 20 30 cm was different amongst undisturbed stands around different gap sizes. The center and the edges of the gap were different only in terms of organic carbon at the depth of 10 20 cm. Significant differences were observed between gaps andclosed canopy regarding P and Ca +2 at depth 0 10 cm and 10 20 cm, respectively. It can be concluded that applied silvicultural system for harvesting trees which created these gaps might be suitable for conservation and forest management in the region. 相似文献
996.
Hamid Reza Naji Mohd. Hamami Sahri Tadashi Nobuchi Edi Suhaimi Bakar 《Journal of Wood Science》2013,59(6):460-468
Wood characteristics vary from pith to bark and this can influence the final use. These variations can be related to the effects of plantation management. The radial variation in fiber cells, vessel elements, and ray cells was investigated for a commercial and fast-grown species, the rubberwood (Hevea brasiliensis), at varying stocking densities. Nine-year-old trees of two new clones (RRIM 2020 and RRIM 2025) were categorized into four stocking densities of 500, 1000, 1500, and 2000 trees ha?1. The sample blocks were anatomically analyzed to determine the changes in wood cells from pith to bark. The results generally showed a centrifugal increase in fiber features, vessel diameter, ray height, and ray area. Vessel density and ray density showed a decreasing trend. Vessel areas revealed a radial irregular variation. The ray area showed a striking relationship with ray density and ray height. Ray cell pattern indicated enough variation for visual approval to ensure within and between stocking density changes. Most radial variation was explained by the effect of cambial age. Owing to different stem width and growth rates, the mean cell features were not at the same radial distances from the pith. 相似文献
997.
The effects of anethol, the major component of anise oil, on the Ca2+-dependent excitability and afterhyperpolarization (AHP) in snail neurons were examined using intracellular recording. Anethol (0.5%) significantly broadened the spike, reduced the firing frequency and enhanced the AHP amplitude. In contrast, anethol (2%) significantly increased the firing frequency and decreased the AHP. Blockade of Ca2+ channels after anethol application depolarized the membrane potential and significantly reduced the firing rate. Furthermore, in the presence of anethol (0.5%) a significant decrease in the AHP was observed by Ca2+ channels blockage. Here, anethol-induced functional modification of Ca2+ and Ca2+-activated K+ channels is suggested. 相似文献
998.
Density and resin content are two factors that have a signifi- cant effect on the production cost of wood composite. However, particle size affects resin content and density, which suggests that the interaction of these three factors can be manipulated to reduce the board density and resin content of particleboard without adversely influencing its mechani- cal properties. Some mathematical functional forms based on resin con- tent, board density and slenderness ratio were regressed and an appropri- ate form was chosen. According to analysis of the results using SHA- ZAM 9 software, the exponential function best fit the experimental data. Finally, "indifference curves" of mechanical properties were illustrated and analyzed. The results indicated that negative effects of density or resin content reduction on mechanical properties could be compensated for by controlling particles’ slenderness ratio. Interestingly, increases in slenderness ratio compensated for the negative effects of decreases in resin content or board density on module of rupture (MOR) and module of elasticity (MOE). Moreover, this "compensation ratio" intensified as resin content or density decreased and/or as the MOR or MOE increased. On the other hand, reduction in slenderness ratio indicated a comple- mentary effect on reducing internal bond (IB) strength, a result of de- creases in resin content or density. Moreover, this "complementary ratio" was intensified as resin content or density decreased and/or as IB strength increased. 相似文献
999.
The prediction of the distribution of quantitative variables in a forest stand is of great interest to forest managers, for the evaluation of forest resources and scheduling of future silvicultural treatments. The aim of this research was to model the distribution of quantitative variables for Quercus persica in open forests in Iran. To investigate the probability distribution of trees in natural stands, 642 trees were selected for measurement using a systematic random sampling method. Selected trees were measured and data were analyzed. Gamma, beta, normal,lognormal, exponential and Weibull probability distributions were fitted to the height distribution of trees. Variables of distribution functions were estimated using the maximum likelihood estimation method. Actual probability and probability which derived from functions was compared using Kolmogorov–Smirnov and Anderson–Darling tests. Beta, Weibull and Weibull probability distributions explained the distributions of tree height, DBH and crown area. 相似文献
1000.
In vitro propagation technique of Balanites aegyptiaca, a multipurpose woody tree was studied. Nodal segments including axillary bud from mature tree were used as an explant and
their morphogenetic potential was tested on MS media with various concentrations (2.5–15.0 μM) of 6-benzyladenine (BA), Kinetin,
and Thidiazuron alone or in combination with different concentrations (0.5–2.5 μM) of α-naphthalene acetic acid (NAA). Nodal
segments showed axillary bud proliferation in almost all media tried. MS medium containing 12.5 μM BA alone was effective
for inducing multiple shoots (5.0 ± 0.22) with an average shoot length (3.7 ± 0.26 cm) in 67% of cultures. A better shoot
differentiation and elongation was achieved in a combined treatment of BA (12.5 μM) and NAA (1.0 μM). Half strength MS medium
supplemented with Indole-3-butyric acid (IBA) gave the best result for rooting. The maximum frequency of root formation (68%),
number of roots (5.3 ± 0.32) and root length (4.1 ± 0.38 cm) was obtained on half strength MS medium containing 1.0 μM IBA.
The regenerated plantlets were potted and acclimatized successfully in a growth chamber and then moved to the greenhouse. 相似文献