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41.
The release of previously stored soil SO4 2? is tightly connected with the reversibility of soil and water acidification. Thus soil SO4 2? dynamics have to be included when predicting the reversibility of acidification. Our aim was to compare two modelling approaches: The model MAGIC (Cosby et al., 1985) describes SO4 2? dynamics with the Langmuir sorption isotherme. In the SO-MODEL (Prenzel, 1991) a precipitation/ dissolution of jurbanite is defined. Even though it was possible to calibrate both models to lysimeter data of the Solling D1 site in 1 m depth, the prognosis for SO4 2? concentrations in the soil solution differed significantly. While MAGIC predicted the observed gradual decrease of SO4 2? concentration with decreasing deposition, the SO-MODEL calculated stable concentrations up to the year 2026 followed by a sudden drop. Because the prognosis established with the SO-MODEL is incompatible with observed field data, we concluded that the predicted SO4 2? dynamic of the SO-MODEL was unrealistic.  相似文献   
42.
In order to investigate possible advantages of open water drinkers such as troughs and bells in the intensive husbandry of ducks, we evaluated in this study the effect of open water systems on the behavior and health of peking ducks. In this investigation six fattening trials each with 1152 Cherry Valley Peking ducks were analyzed. The average fattening period was 47 to 49 days. The ducks were kept on straw in six standardized compartments each 32 qm with 192 ducks. 25% of the compartment with perforated grid, with one of the tested water systems. In contrast to pens with nipple-drinkers only, the ducks in pens with open water troughs/showers had the opportunity to exhibit their natural drinking behavior and water associated activities in accordance with the animal welfare requirements. In the free-choice pens the open water systems were significantly preferred, and over a 24-hour period the ducks in watering areas with open water troughs showed higher activity. Limiting the access to the open water systems to eight, four or two hours per day led to an increased use per time unit. Ducks with access to nipple drinkers only showed a significantly higher percentage of plugged up nostrils than animals from pens with open water drinkers. Open water drinkers had also a positive impact on the plumage condition.  相似文献   
43.
44.
OBJECTIVE: To validate a radioimmunoassay for measurement of procollagen type III amino terminal propeptide (PIIINP) concentrations in canine serum and bronchoalveolar lavage fluid (BALF) and investigate the effects of physiologic and pathologic conditions on PIIINP concentrations. SAMPLE POPULATION: Sera from healthy adult (n = 70) and growing dogs (20) and dogs with chronic renal failure (CRF; 10), cardiomyopathy (CMP; 12), or degenerative valve disease (DVD; 26); and sera and BALF from dogs with chronic bronchopneumopathy (CBP; 15) and healthy control dogs (10 growing and 9 adult dogs). PROCEDURE: A radioimmunoassay was validated, and a reference range for serum PIIINP (S-PIIINP) concentration was established. Effects of growth, age, sex, weight, CRF, and heart failure on S-PIIINP concentration were analyzed. In CBP-affected dogs, S-PIIINP and BALF-PIIINP concentrations were evaluated. RESULTS: The radioimmunoassay had good sensitivity, linearity, precision, and reproducibility and reasonable accuracy for measurement of S-PIIINP and BALF-PIIINP concentrations. The S-PIIINP concentration reference range in adult dogs was 8.86 to 11.48 mug/L. Serum PIIINP concentration correlated with weight and age. Growing dogs had significantly higher S-PIIINP concentrations than adults, but concentrations in CRF-, CMP-, DVD-, or CBP-affected dogs were not significantly different from control values. Mean BALF-PIIINP concentration was significantly higher in CBP-affected dogs than in healthy adults. CONCLUSIONS AND CLINICAL RELEVANCE: In dogs, renal or cardiac disease or CBP did not significantly affect S-PIIINP concentration; dogs with CBP had high BALF-PIIINP concentrations. Data suggest that the use of PIIINP as a marker of pathologic fibrosis might be limited in growing dogs.  相似文献   
45.
The increase in atmospheric CO2 concentration [CO2] has been demonstrated to stimulate the growth of C3 crops. However, little information exists about the effect of elevated [CO2] on biomass production of sugar beet, and data from field experiments are lacking. In this study, sugar beet was grown within a crop rotation over two rotation cycles (2001, 2004) at present and elevated [CO2] (375 μl l?1 and 550 μl l?1) in a free air CO2 enrichment (FACE) system and at two levels of nitrogen supply [high (N2), and 50% of high (N1)], in Braunschweig, Germany. The objective of the present study was to determine the CO2 effect on seasonal changes of leaf growth and on final biomass and sugar yield. Shading treatment was included to test whether sugar beet growth is sink limited under elevated [CO2]. CO2 elevation did not affect leaf number but increased individual leaf size in early summer resulting in a faster row closure under both N levels. In late summer CO2 enrichment increased the fraction of senescent leaves under high but not low N supply, which contributed to a negative CO2 effect on leaf area index and canopy chlorophyll content under high N at final harvest. Petioles contained up to 40% water-soluble carbohydrates, which were hardly affected by CO2 but increased by N supply. More N increased biomass production by 21% and 12% in 2001 and 2004, respectively, while beet and sugar yield was not influenced. Concentration of α-amino N in the beet fresh weight was increased under low N and decreased under high N by CO2 enrichment. The CO2 response of total biomass, beet yield and white sugar yield was unaffected by N supply. Averaged over both N levels elevated [CO2] increased total biomass by 7% and 12% in 2001 and 2004, respectively, and white sugar yield by 12% and 13%. The shading treatment in 2004 prevented the decrease in leaf area index under elevated [CO2] and high N in September. Moreover, the CO2 effect on total biomass (24%) and white sugar yield (28%) was doubled as compared to the unshaded conditions. It is concluded that the growth of the storage root of sugar beet is not source but sink limited under elevated [CO2], which minimizes the potential CO2 effect on photosynthesis and beet yield.  相似文献   
46.
The purpose of the study was to investigate the prevalence of gastric lesions and to provide diagnostic values for serum pepsinogen in non-infected pigs and in pigs with gastric disease. In an abattoir survey, the pepsinogen concentrations were measured in the serum from 62 non-infected pigs, 33 pigs with gastric lesions and 17 pigs infected with Hyostrongylus rubidus, using a specific radioimmunoassay (RIA). The mean (±SE) pepsinogen concentrations in the serum of non-infected pigs, in pigs with gastric ulcers, and in pigs with a heavy H. rubidus infection were 630.8±39.2 ng/ml, 1084.5±166.2 ng/ml and 1095.2±102.3 ng/ml, respectively (p<0.05). Because of the higher concentrations of pepsinogen in the blood of pigs with gastric ulcers or parasitic infections, it is suggested that the measurement of serum pepsinogen by RIA may be an effective biochemical approach to the diagnosis of chronic gastric disorders in pigs.  相似文献   
47.
ABSTRACT

Veneer checking is a common enough occurrence in woodworking. It appears as cracks in the veneer and generally following the grain. Their appearance and the variation of their depth and frequencies have tremendous impact on their utilization. Finding a means of identifying and characterizing the veneer checks is an important ongoing challenge. An automated device, named SMOF, was developed in LABOMAP (Arts et Metiers – France) and achieves this task. By using the SMOF device, the lathe checks occurred in veneers of two species: zeen oak (Quercus canariensis Willd.) and afares oak (Quercus afares Pomel) were detected, automatically imaged and then, the depth and intervals of checks measured. The results were described by statistical distributions that exhibited abnormalities, such as skewness and kurtosis, which were assessed by mode analysis. It has been established that hot soaking temperature (from 60°C to 90°C) reduce slightly the cutting forces for both species, no produce significant heart checks within the loose side of veneers. However, low soaking temperature (from 50°C to 65°C) allow avoiding deeper lathe checking, producing shallower ones acceptable for veneer production.  相似文献   
48.
The global atmospheric CO2-concentration is increasing and there has been an increase in Germany of about 30 ppm from 340 ppm to 370 ppm CO2 during the last two decades. The hectare yield of many crops has also increased during this time period. The objective of the present study was to estimate whether the past and future change in the atmospheric composition significantly contributes to the increase in hectare yield. Different crop species (beans, Phaseolus vulgaris, cv Pfälzer Juni; spring barley, Hordeum vulgare L., cvs. Alexis and Arena; spring wheat, Triticum aestivum L., cvs. Star and Turbo; maize, Zea mays L., cvs. Bonny and Boss) were grown at ambient (372 ppm) and at slightly elevated CO2-concentrations (459 ppm and 539 ppm) in open-top chambers and the effect of the different CCVconcentrations on the growth and yield of the plants was measured. The past and future CO2-effect was estimated from the slope of a linear CO2-yield curve (percentage increase in yield per ppm CO2′ 100% at 370 ppm) fitted to the data and those from previous studies on wheat and maize. The percentage increase in yield per ppm CO2 is insignificant for beans, of borderline significance for silage maize (0.06 % per ppm), and 0.35 % per ppm and 0.26 % per ppm for barley and wheat, respectively. The COj-elevation primarily decreases the tiller dieback of the cereals. Considering the increase in CO2 of 30 ppm and in the hectare yield of 25 % (barley) and 28 % (wheat) from 1970 to 1990, the contribution of CO2 to the increase in the agricultural production is estimated to be one fourth up to one half of the increase in hectare yield of spring cereals. Given a recent yearly increase of 2 ppm the future CO:-related increase in hectare yield is estimated to be about 0.5–0.7% per year.  相似文献   
49.
The effects of seven compounds 1–7, isolated from a tropical ascidian Lissoclinum cf. badium, on IL-8 production in PMA-stimulated HL-60 cells were examined. Lissoclibadins 2 (2) and 3 (3) and lissoclinotoxin F (5) increased the IL-8 production in a dose-dependent manner. Compounds 2 and 5 are structural isomers possessing dimeric structures of trans and cis-orientations, respectively, and showed a very similar activity on the induction of IL-8 levels. Compound 3 and lissoclinotoxin E (4) are also structural isomers having dimeric trans and cis-structures, respectively, but 4 did not induce the IL-8 production. Lissoclibadin 1 (1, trimeric compound) and two monomeric compounds (6 and 7) did not increase the IL-8 level. Therefore, the differences in their structures remarkably affected the IL-8 production activity, the inhibition of cell proliferation, and the survival of HL-60 cells. Lissoclibadin 2 was the most interesting compound of the seven metabolites tested in this study.  相似文献   
50.
Remy W 《Science (New York, N.Y.)》1982,215(4540):1625-1627
Three gametophytic plants now known from the Lower Devonian of Scotland and Germany show common features in their fertile parts. The morphological and anatomical structures indicate affinities to bryophytic gametophytes, although there is no evidence for a parasitic sporogonium-like sporophyte as in the Bryophyta. Several of the vascular plant sporophytes from the Rhynie Chert also have a few characteristics reminiscent of bryophytes. But these ancient gametophytes, if related to the sporophytes, indicate a closer relation of Bryophyta to Tracheophyta than would the study of sporophytes alone.  相似文献   
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