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371.
Electron microprobe studies on soil samples with varying heavy metal contamination. 1. Methods and analysis of elements in pedogenic oxides EMA point analysis, line scan profiles and microprobe photos were performed on thin sections from 19 soil samples with variing heavy metal content to show the distribution of elements in soil particles on a microscopic level. The investigations showed that the detection limits generally have a range of 110-830 mg/kg in anorganic soil matrix respectively 80-320 mg/kg in organic soil matrix. The element specific heavy metal accumulation capacities on the pedogen oxides compared to the average content of the soil samples can be described for Co, Ni, Cu, Zn, Cd and Pb. The maximum trace element accumulations in concretions related to their element total content in the soil samples were by Co 3.170 times, Ni 6.635 times, Cu 323 times, Zn 112 times, Cd 2.000 times and by Pb 745 times. The accumulation and immobilization of heavy metals by iron oxides suggests that additions of Fe oxides could be used to reduce heavy metal availability and leaching to the subsoil on highly contaminated soils.  相似文献   
372.
Behaviour of heavy metals in soils. 2. Extraction of mobile heavy metals with CaCl2 and NH4NO3 156 soil samples from arable fields, grassland and forest stands were analysed for the CaCl2? and NH4NO3? extractable contents of Cd, Zn, Mn, Cu and Pb. The average amounts of Cd, Zn, Cu and Pb extracted with CaCl2 are higher compared with NH4NO3 whereas the relation for Mn is vice versa. The proportion of the NH4NO3? extractable contents in percent of the CaCl2? extractable contents of Cd, Zn and Pb decrease with increasing pH, whereas the contents of Mn and Cu increase. Inspite of a differing extraction behaviour of the two salt solutions the CaCl2? and NH4NO3? extractable amounts of Cd, Mn, Zn und Pb are highly correlated and can be converted one into another. The mobile (CaCl2, NH4NO3) proportion of the corresponding total, EDTA and DTPA heavy metal contents is in close relation to the pH of the soils. Using CaCl2 solution the threshold pH values for an increasing mobility decrease in the order Cd > Mn > Zn > Cu > Pb, using NH4NO3 as extractant the order is Mn > Cd > Zn > Cu > Pb. In the case of CaCl2 as extractant soluble chloro-Cd-complexes will be formed so that the Cd mobility in soils will be overestimated in most cases.  相似文献   
373.
Behaviour of heavy metals in soils. 1. Heavy metal mobility 158 soil samples with widely varying composition were analysed for their total, EDTA, DTPA and CaCl2 extractable contents of Cd, Zn, Mn, Cu and Pb. By means of single and multiple regressions the relations between the different heavy metal fractions and the pH, organic carbon and clay content were considered. The correlations between the total, EDTA and DTPA extractable contents are very close, whereas the CaCl2 extractable contents are not or only weakly correlated with these fractions. According to these statistical results the former fractions are considered to be the total quantity (total content) and the reactive quantity (EDTA and DTPA extractable contents) of the heavy metals, whereas the CaCl2 extractable fraction represents the mobile fraction of the heavy metals in soils. The multiple regressions show that the mobile content of heavy metals is closely correlated with each of the quantity fractions and with soil pH. In the same way the proportion of the mobile fraction (in %) of the total, EDTA and DTPA extractable heavy metal content of the soil samples is closely related to the soil pH. Hereby the proportion of the mobile content of the various elements increases in the pH range 6,5 - 3 below element-specific threshold pH values (in brackets) in the order Cd (6,5) > Mn (5,7) > Zn (5,3) > Cu (4,5) > Pb (3,5). In the pH range 6,5 - 7,5 mainly Cu and to a lesser degree also Pb show an increasing mobility due to the influence of soluble organic substances.  相似文献   
374.
375.
The black vine weevil Otiorhynchus sulcatus (Coleoptera: Curculionidae) is a well-known insect pest causing damages and economic losses on various horticultural plants. In recent times, numerous other weevils like O. rugosostriatus, O. raucus, O. ovatus or O. salicicola are becoming increasingly important in horticulture. We applied mark-release-recapture studies to estimate population size, survival rates, aggregation patterns and dispersal capabilities of adult O. raucus and O. rugosostriatus in a commercial plantation of perennial ornamental plants. Knowledge of these characteristics is important for the correct timing and design of efficient control strategies. Of 191 individually coded O. raucus and 340 O. rugosostriatus, 30 and 24%, respectively, were recaptured at least once over a period of 96 days. The majority of weevils were recaptured within 2–3 m away from their release point and thus both species can be regarded as being quite sedentary. In accordance, patchiness of weevil distribution was clearly evident in the study area. Population sizes reached maximum values after the peak of adult emergence from pupae in spring (for O. raucus) and late summer (for O. rugosostriatus), with high survival rates being evident in particular for O. raucus. This study provides for the first time data on population ecology of two weevil species, whose abundance and importance as putative insect pests in horticulture has increased over the last years.  相似文献   
376.
One year old rooted cuttings were fertilized with Osmocote exact according to 0,8 g N L? ? 1 substrate in February 2009. In August half of the plants received the same fertilizer dose while the other half was not refertilized. In autumn 2009 and in spring 2010 early resp. late frost tests were carried out under controlled conditions, furthermore sprouting was evaluated in spring 2010. Frost damage was measured with the electrolyte leakage method. In the early frost test biochemical stress responses like glucose, sucrose and proline were analyzed. In the new shoots N-, P-, and K-concentration were measured. Refertilized plants did not grow more but showed higher N-, P-, and K-concentrations. These plants had more proline in their buds and roots compared to the non-refertilized ones. Sucrose and glucose contents in the roots of refertilized plants were lower than in non-refertilized ones, in the buds there was no difference. Damage due to early frost was independent from refertilization for new shoots and buds but in roots higher for the refertilized plants. In spring 2010 refertilized plants sprouted earlier compared to non-refertilized ones. In buds damage due to late frost slightly increased in refertilized plants while in roots there was no difference between the fertilization treatments.  相似文献   
377.
Background: Cats with hypertrophic cardiomyopathy (HCM) often have no clinical signs or subtle signs. Measurement of N‐terminal pro‐brain natriuretic peptide (NT‐proBNP) has been demonstrated in people to be highly specific for heart disease and also correlates with severity of HCM. NT‐proBNP may also be valuable in detecting and grading HCM in cats, but results to date have been equivocal. Objectives: The aims of this study were to evaluate NT‐proBNP as a screening test for diagnosis of HCM in cats and determine an appropriate cut‐off value and to determine if NT‐proBNP concentrations correlated with severity of HCM in cats. Methods: Plasma NT‐proBNP concentrations were measured in 201 cats using an ELISA designed for use in cats. Cats were classified using echocardiography as clinically healthy controls (n=99) or cats with equivocal (n=9), mild (n=15), moderate (n=17), or severe (n=61) HCM. Results: NT‐proBNP concentrations (median; 25th–75th interquartile percentiles) in mildly (216.1; 87.6–392.5 pmol/L), moderately (282.7; 131.9–466.6 pmol/L), and severely (839.5; 655.3–1046.4 pmol/L) affected cats were significantly higher than those in healthy controls (18.9; 3.4–62.4 pmol/L). Concentrations in severely affected cats were significantly higher than in cats from other HCM groups. There was no significant difference between mild and moderate HCM. Cut‐off values >49 pmol/L had a sensitivity of 97.8% and specificity of 66.7%; >100 pmol/L had a sensitivity of 92.4% and specificity of 93.9%; and >150 pmol/L had a sensitivity of 88% and a specificity of 100%. Conclusions: NT‐proBNP with a cut‐off value of >100 pmol/L was useful in detecting even mild HCM. Cats with increased NT‐proBNP concentrations should be examined by echocardiography.  相似文献   
378.
Nutrition of the host animal may not only influence interactions between the host and its parasites, but also relations between different parasites species residing on the same host. We investigated effects of insoluble and soluble non-starch polysaccharides (NSP) on establishment and development of Heterakis gallinarum in chicken being treated or left untreated against Histomonas meleagridis. Six groups of one-day-old birds were allocated to three diets, two on each diet. The birds were fed ad libitum either a basal diet (CON), or CON+insoluble NSP (I-NSP) or CON+soluble NSP (S-NSP) until an age of 11wk. At an age of 19d, one of each diet groups was prophylactically treated for 9d with dimetridazole (0.05%, w/v) via drinking water against histomonas. The remaining three groups were left un-treated. Two days after starting dimetridazole treatment (at 3wk), each of the 6 groups was divided into two sub-groups. One dimetridazole treated and one dimetridazole un-treated groups of birds on each diet (6 groups) were infected with 200 embryonated eggs of H. gallinarum that were previously harvested from histomonas-carrying H. gallinarum infected chickens. The remaining 6 groups of uninfected birds, either treated or left un-treated against H. meleagridis, served as controls. Worm burdens of infected birds were determined 8wk p.i. Treatment against H. meleagridis significantly increased incidence of H. gallinarum infection and average worm length in all infected groups independent of the diet consumed (p<0.001). An interaction between effects of diet and dimetridazole treatment on worm burden (p<0.001) indicated that the S-NSP diet resulted in lowest worm burden in dimetridazole un-treated birds, whereas it caused the highest worm burden in the treated birds (p<0.05). Furthermore, the treatment resulted in higher worm burdens when compared to un-treated birds on the corresponding diets (p<0.05). Infection with H. gallinarum impaired body weight (BW) of the chicks (p<0.05) and H. meleagridis aggravated this effect (p<0.05). Dimetridazole treated and un-treated uninfected birds developed similar BW (p>0.05). Both NSP supplemented diets resulted in lower (p<0.05) BW when compared with the CON diet, S-NSP being inferior to I-NSP (p<0.05). It is concluded that H. meleagridis harms the definitive host as well as H. gallinarum. Both insoluble and soluble NSP supplemented diets favor H. gallinarum infection while S-NSP additionally intensifies histomonas infection, which then impairs establishment and development of H. gallinarum.  相似文献   
379.
It was hypothesized that the establishment and fecundity of Histomonas meleagridis free Heterakis gallinarum may be affected by dietary non-starch polysaccharides (NSPs). One-day-old female layer chicks (N=670) were fed ad libitum for 11wk one of the following diets in a three-times repeated experiment: basal diet (CON), basal diet plus pea bran rich in insoluble NSP (I-NSP), basal diet plus chicory root meal as a source of inulin rich soluble NSP (S-NSP). At the end of wk three, each feeding group was subdivided into an uninfected and an infected group of birds each being inoculated with a placebo or with 200 H. meleagridis free eggs of H. gallinarum. The birds were slaughtered 8wk post infection and their worm burdens, the nematode egg excretion, caeca sizes and weights as well as intracaecal pH and volatile fatty acid (VFA) concentrations were determined. The NSP supplemented diets and also infection led to reduced body weights (BWs) of birds and impaired the feed conversion rate (P<0.001). The NSP supplemented diets increased average length of caecum (P<0.001) with S-NSP exerting a stronger effect than I-NSP (P<0.05). Full caeca weight was increased by S-NSP (P<0.001). Feeding S-NSP lowered intracaecal pH and molar proportion of acetate and increased that of butyrate compared to CON and I-NSP (P<0.001). Caecal pool of VFA was increased with S-NSP (P<0.001). The NSP-diets elevated incidence of infection (P<0.01), average number of larvae (P<0.009) and total worm burden (P<0.001) compared to CON. The daily amount of faeces increased in NSP-fed birds (P<0.001). Number of eggs per gram of faeces (EPG), number of eggs excreted per worm population of a bird within 24h (EPD) and female worm fecundity (EPD/female worm) were elevated after feeding S-NSP (P≤0.002), whereas I-NSP led to lower EPG/female worm (P<0.05). The EPD increased in the sequence of CON相似文献   
380.
Most veterinary drugs enter the environment via manure application. However, ecotoxic effects of antibiotics are varying as a function of their physicochemical characteristics and for most antibiotics it is still unclear how these substances interact with soil biota. It was the aim of the present study to investigate effects of manure containing different concentrations of the antibiotic amoxicillin (AMX) on microbial‐community function in two different soils over an incubation time of 18 d. Therefore, soil respiration, potential nitrification, and the products of N turnover were measured. We could show that CaCl2‐extractable amounts of AMX in soil are low, even shortly after the application of high doses together with manure. Thus, not surprisingly basal respiration in soil was not influenced by the addition of the antibiotic with manure. In contrast, mainly shortly after manure addition the kinetic of substrate‐induced respiration was clearly shifted by the treatments depending on the presence of AMX in the manure. Potential nitrification rates in the two different soils were not significantly affected when data were related to the overall incubation time by the application of AMX to the manure. However, shortly after the addition of the manure containing AMX, a tendency to lower turnover rates was visible compared to the application of pure manure.  相似文献   
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