全文获取类型
收费全文 | 262篇 |
免费 | 15篇 |
国内免费 | 1篇 |
专业分类
林业 | 19篇 |
农学 | 14篇 |
基础科学 | 4篇 |
49篇 | |
综合类 | 15篇 |
农作物 | 35篇 |
水产渔业 | 34篇 |
畜牧兽医 | 71篇 |
园艺 | 6篇 |
植物保护 | 31篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 12篇 |
2021年 | 10篇 |
2020年 | 8篇 |
2019年 | 17篇 |
2018年 | 11篇 |
2017年 | 13篇 |
2016年 | 17篇 |
2015年 | 7篇 |
2014年 | 6篇 |
2013年 | 27篇 |
2012年 | 20篇 |
2011年 | 12篇 |
2010年 | 10篇 |
2009年 | 10篇 |
2008年 | 10篇 |
2007年 | 8篇 |
2006年 | 9篇 |
2005年 | 2篇 |
2004年 | 7篇 |
2003年 | 9篇 |
2002年 | 4篇 |
2001年 | 4篇 |
2000年 | 1篇 |
1999年 | 5篇 |
1998年 | 2篇 |
1997年 | 5篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1991年 | 3篇 |
1990年 | 4篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1976年 | 3篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有278条查询结果,搜索用时 15 毫秒
31.
Golpour Amin Broquard Coralie Milla Sylvain Dadras Hadiseh Baloch Abdul Rasheed Saito Taiju Pšenička Martin 《Fish physiology and biochemistry》2021,47(3):703-711
Fish Physiology and Biochemistry - The aim of this study was to evaluate seasonal testicular development in the cultured sterlet, Acipenser ruthenus. During annual sexual cycle of male sterlet,... 相似文献
32.
Ahmed Amin Sayed ;Sobhy Ahmed Temerak ;Salah Mahmood Mohmed Gameel ;Amr Moussa 《农业科学与技术》2014,(6):529-534
Alternate two different modes of actions of green chemicals: spinosad & methoxyfenozide to combat the lesser date moth, Batrachedra amydraula and the Almond moth, Cadra cautella Walk on dates in Dakhla Oasis, New Valley, Egypt were done in 2010 and 201 I. Based on infestation of the early insect pest B. amydraula, the three-rotation program with basic 1st spray of spinosad 24 SC at 20 mL/100 L showed insignificant difference. Based on minimum effective rotation doses, alternating spinosad 24 SC at 20 mL/100 L, then methoxyfenozide 24 SC at 15 mL/100 L with two-week interval showed zero infestation and 1.8% at the last sample of 2010 and 2011, respectively. Based on infestation of the late insect pest, Cadra spp., tlhe same previous trend of the three-rotation results. Based on minimum effective rotation doses, alternating spinosad 24 SC at 20 mL/100 L, then methoxyfenozid 24 SC at 15 mL/100 L with three-week interval indicated less than 1% and 1% infestation during harvest for 2010 and 201 l, respectively. The last reflected important value when storing the fruit. Both products proved to be working under dry hot high temperatures. 相似文献
33.
Ahmad Asoodeh Leyla Haghighi Jamashidkhan Chamani Mohamad Amin Ansari-Ogholbeyk Zahra Mojallal-Tabatabaei Milad Lagzian 《Journal of Cereal Science》2014
The present study was carried out to characterize ACE inhibitory peptides which are released from the trypsin hydrolysate of wheat gluten protein. In silico proteolitic digestion of a high molecular weight glutenin subunit was performed. Among the resultant fragments, four peptides were selected for chemical synthesis based on the chemoinformatics studies and docking properties. The ACE inhibitory activity and kinetic parameters of the most important peptides were determined. Molecular docking simulation was also performed to predict the sites on ACE in which these peptides bind and displayed inhibition mechanisms. Two peptide sequences of IPALLKR (P4) and AQQLAAQLPAMCR (P6) showed higher ACE inhibitory activity among peptide collection. The IC50 values of P6 and P4 were 43 ± 1.3 μM and 68 ± 2.8 μM, respectively. P6 peptide was proved to be a more potent ACE inhibitor than P4 peptide. Lineweaver-Burk plots revealed that P6 and P4 behaved as non-competitive and competitive ACE inhibitors, respectively. The simulations showed that P4 bound to the active site region. Conversely, P6 bound to the N-terminus entrance of substrate tunnel and obstructed the substrate access into the catalytic site. Overall, the results showed that these peptides would be considered as a model for discovering new bio-compatible ACE inhibitors. 相似文献
34.
W. Aimrun M. S. M. Amin Desa Ahmad M. M. Hanafi C. S. Chan 《Paddy and Water Environment》2007,5(2):113-121
On-the-go EC sensor is a useful tool in mapping the apparent soil electrical conductivity (ECa) to identify areas of contrasting soil properties. In non-saline soils, ECa is a substitute measurement for soil texture. It is directly related to both water holding capacity and cation exchange capacity
(CEC), which are key ingredients of productivity. This sensor measures the ECa across a field quickly and gives detailed soil features (1-s interval) with few operators. Hence, a dense sampling is possible
and therefore a high resolution ECa map can be produced. This paper presents experiences in acquiring detailed ECa information that is correlated to other soil properties for precision farming of rice. The study was conducted on a 9 ha
rice plot in MARDI Seberang Prai Station, Penang. The VerisEC3100 was pulled across the field in a series of parallel transects
spaced about 15 m apart. The study showed that shallow and deep ECa had high correlation and shallow ECa had significant correlation to P. Deep ECa had significant correlation to P, K and yield. Regression equations showed that N and P could be estimated by shallow ECa but, pH, K and yield were better estimated by deep ECa. This study was able to draw some basic ideas of nutrient zone management according to precision farming technique. 相似文献
35.
Shirazi MH Ranjbar R Eshraghi S Amin G Nouri MS Bazzaz N 《Pakistan journal of biological sciences: PJBS》2008,11(3):487-489
Antibacterial activity of Sage extract at concentrations of 0.1, 0.05, 0.025, 0.0125, 0.00625, 0.003125, 0.00156, 0.0005 and 0.00025 g dL(-1) against Salmonella typhi, Shigella sonnei, S. flexneri, Proteus vulgaris, Staphylococcus aureus, ETEC Escherichia coli and Pseudomonas aeruginosa was evaluated. Susceptibility testing of bacterial strains against 18 antibiotics was also performed for comparison. The results showed that P. aeruginosa and ETEC E. coli were completely resistant to Sage extract even at concentration of 0.1 g dL(-1). Its antibacterial activity (0.1 g dL(-1)) against P. vulgaris, S. flexneri and S. sonnei was the same as nitrofurantoin and ampicilline respectively. Sage extract (0.1 and 0.05 g dL(-1)) exhibited the same effects as ampicilline and streptomycin against S. typhi. Its antibacterial activity (0.1, 0.05 and 0.25 g dL(-1)) against S. aureus was the same as ceftazidim, chloramphenicol, gentamycin, neomycin and nitrofurantoin and was more significant compared to streptomycin and vancomycin. The results suggest Sage can be considered as an alternative herbal in the treatment of infections caused by the above-mentioned bacteria. 相似文献
36.
An unsolved problem in the digital mapping of categorical soil variables and soil types is the imbalanced number of observations, which leads to reduced accuracy and the loss of the minority class (the class with a significantly lower number of observations compared to other classes) in the final map. So far, synthetic over- and under-sampling techniques have been explored in soil science; however, more efficient approaches that do not have the drawbacks of these techniques and guarantee retention of the minority classes in the produced map are essentially required. Such approaches suggested in the present study for digital mapping of soil classes include machine learning models of ensemble gradient boosting, cost-sensitive learning and one-class classification (OCC) of the minority class combined with multi-class classification. In this regard, extreme gradient boosting (XGB) as an ensemble gradient learner, a cost-sensitive decision tree (CSDT) within the C5.0 algorithm, and a one-class support vector machine combined with multi-class classification (OCCM) were investigated to map eight soil great groups with a naturally imbalanced frequency of observations in northwest Iran. A total of 453 profile data points were used for mapping the soil great groups of the study area. A data split was done manually for each class separately, which resulted in an overall 70% of the data for calibration and 30% for validation. The bootstrapping approach of calibration (with 10 runs) was performed to produce multiple maps for each model. The 10 bootstraps were evaluated against the hold-out validation dataset. The average values of accuracy measures, including Kappa (K), overall accuracy (OA), producer's accuracy (PA) and user's accuracy (UA), were explored. In addition, the results of this study were compared with a previous study in the same area, in which resampling techniques were used to deal with imbalanced data for digital soil class mapping. The findings show that all three suggested methods can deal well with the imbalanced classification problem, with OCCM showing the highest K (= 0.76) and OA (= 82) in the validation stage. Also, this model can guarantee the retention of the minority classes in the final map. Comparing the present approaches with the previous study approach demonstrates that the three newly suggested methods can remarkably increase both overall and individual class accuracy for mapping. 相似文献
37.
Tengku Mohamad Tengku-Rozaina Wong Shu Jeng Mat Amin Amiza 《Journal Of Aquatic Food Product Technology》2018,27(6):667-679
Fish is a nutritious food for the whole family and a good source of protein and n-3 fatty acids. The fish-processing industry produces tonnes of fish-processing waste and by-products annually. Disposal of untreated by-products of the fish-processing industry may cause environmental pollution. Sardinella gibbosa or goldstripe sardinella is commonly used in surimi and fish cracker productions in Malaysia. However, data on the nutritional composition of goldstripe sardinella fillets (GSF) and by-products (GSB) remain limited. The objectives of this study are to determine the nutritional composition and thermal properties of fillets and by-products of S. gibbosa. Results showed that the protein and moisture contents of GSF were higher than GSB. Conversely, the ash and fat levels of GSF were lower than GSB. Levels of saturated fatty acids (SFA) in GSF and GSB were higher than monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids. Palmitic acid and oleic acid were the major SFA and MUFA found in GSF and GSB. Both GSF and GSB contain higher percentages of DHA and EPA. Melting and crystallization profiles of the oil from S. gibbosa fillets were similar to by-product oil, which was related to their fatty acid content. 相似文献
38.
Saleh N Aoki M Shimada T Akiyoshi H Hassanin A Ohashi F 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2005,67(5):461-465
Renal effects of the selective alpha(2)-adrenoceptor agonist, medetomidine, were investigated in anesthetized dogs. Animals were administered medetomidine 20 and 40 microg/kg intravenously (IV) and 80 mug/kg intramuscularly (IM) or 1 ml of saline IV. Urine and blood samples were collected before and at 30, 60, 90 and 120 min following medetomidine injection. Mean arterial blood pressure (MABP), renal blood flow (RBF), glomerular filtration rate (GFR), urine volume (U(v)), urine osmolality (U(osm)), free water clearance (C(H2O)), fractional clearance of sodium (F(Na)), plasma osmolality (P(osm)), plasma glucose levels and plasma antidiuretic hormone (ADH) concentrations were measured. The results showed that IV administration of medetomidine initially increased MABP 5-15 min followed by long-lasting decrease. The initial hypertension was not observed after IM administration, which was accompanied by a more profound hypotensive effects. RBF, GFR, U(v), C(H2O) increased after IV injection and decreased after IM. Medetomidine increased FNa and Posm and decreased U(osm). Plasma glucose levels initially increased and subsequently decreased. Plasma ADH concentration was decreased by IV injection but increased by IM administration. Our data imply that: 1) IV administration of medetomidine at dose rates of 20 and 40 microg/kg results in profound diuresis up to 2 hr; 2) Suppression of ADH release from the CNS is one of the mechanisms of medetomidine-induced diuresis although it may not be the principal one. 相似文献
39.
未尽利用热带水果,即在当地消费和医用的非贸易热带水果,未普及化,生长于野外,季节性强,但富含多酚类化合物、类胡萝卜素、花青素、脂肪酸、矿物质和氨基酸,因而具有一定的开发潜力。在马来西亚,热带水果丰富多样,主要有普通水果、观赏水果、特有水果、野生水果和高地水果,但大部分水果都未能充分利用,其中,典型的有罗望子、巴杖果、砂拉越芒果、钮扣山竹、榴莲、莲雾、挂尼芒果、野红毛丹和蛇皮果。这些水果可以分为3个类型:具有贸易开发潜力的主要包括无花果(Ficus sp.)、罗望子(Garcinia atroviridis)、尖必达(Artocarpus integer)、鲜花木果(Lepisan-thes alata)、野榴莲(Durio sp.)、橄榄木(Spondias cytherea)、菠萝蜜(Artocarpus heterophullus)、槟榔(Areca catechu)、野红毛丹(Nephelium ramboutan-ake)、蛇皮果(Salacca zalacca)和面包果(Artocarpus altilis);具有适于当地人们利用潜力的水果种类包括木胡瓜(Averrhoe bilimbi)、榔拜果(Baccaurea motteyana)、单贝果Baccaurea macrocarpa)、喃喃果属(Cynometra cauliflora)、西柚(Dialum indum)、黄肉榴莲(Durio kutejensis)、野生山竹(Garcinia hombroiniana)、野檬果(Garcinia parvifolia)、巴杖果(Mangifera feotida)、醋栗(Phyllanthus emblica)、蒲桃(Syzygium jambos);不具有经济利用开发潜力的水果种类包括哥露比(Salacca conferta)、青枣(Zizyphus mauritiana)、木奶果属(Baccaurea polyneura)、野檬果(Garcinia parvifolia)、番龙眼(Pometia sp.)、赤才果(Leppisanthes rubiginosa)、波漆果(Bouea microphylla)、蛋黄果(Pouteria campechiana)和仙都果(Sandoricum koetjape)。目前,有关未尽利用水果研究仍处于初期阶段,有必要使这些水果更为普及并得到有效利用,因此,政府和私人组织须采取一些措施以促进这些水果的消费。今后需对这些水果的营养成分、抗氧化作用以及疗效进行深入研究。 相似文献
40.
Do cover crops change the lability of phosphorus in a clayey subtropical soil under different phosphate fertilizers? 下载免费PDF全文
A. P. B. Teles M. Rodrigues W. F. Bejarano Herrera A. Soltangheisi L. R. Sartor P. J. A. Withers P. S. Pavinato 《Soil Use and Management》2017,33(1):34-44
Plants have developed different mechanisms to absorb and solubilize phosphorus (P) in the soil, especially in environments with low P availability. This study evaluated the effects of different winter cover crops on soil P availability in a clayey subtropical (Hapludox) soil receiving soluble P fertilizer and a rock phosphate applied to the summer crop, under no‐tillage. The experiment was carried out over 3 yrs (2009–2011) with five different cover crop species: common vetch, fodder radish, ryegrass, black oat, white clover and fallow as control. The soil was sampled after the third year of cover crop cultivation and analysed for inorganic and organic P forms according to the well‐established Hedley fractionation procedure. Phosphate fertilizers promoted accumulation of both labile and nonlabile P pools in soil in the near surface layer, especially under rock phosphate. Fertilizer applications were not able to change P fractions in deeper layers, emphasizing that the Brazilian clayey soils are a sink of P from fertilizer and its mobility is almost nil. Although the cover crops recycled a great amount of P in tissue, in a short‐term evaluation (3 yrs) they only changed the content of moderately labile P in soil, indicating that long‐term studies are needed for more conclusive results. 相似文献