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91.
92.
The adoption strategies used in animal shelters can have a large impact on the total number of adoptions and donations that take place. Reducing adoption fees during peak kitten or puppy season is one way to reduce inventories and increase the number of open spaces to save more lives, but does not necessarily increase the financial well-being of the shelter if the per-animal costs exceed the revenues generated. We developed a stochastic model to simulate the expected costs, revenues, and net income of a hypothetical animal shelter for various alternative management strategies, based on US conditions. A total of 8 scenarios were developed and compared to the base-case scenario (BC).  相似文献   
93.
The current standard scintigraphic method for estimating glomerular filtration rate (GFR) in dogs is the integral method, which normalizes renal GFR to body weight. The plasma volume method, that is normalizing GFR to plasma volume, has been reported to be more physiologically correct. The aim of this prospective study was to test the effect of hydration status on GFR measured by these two methods in a group of dogs with suspected renal disease. Eleven dogs were recruited. All dogs underwent standardized scintigraphic examinations before and after 15 ml/kg of fluid was administered intravenously at 5–7 ml/kg/min. Individual kidney GFR estimates (n = 22) were calculated using both methods and a consensus of two observers who were unaware of clinical findings. Individual kidney GFR increased significantly (P = 0.0008) after fluid administration using the integral method and individual kidney GFR using the plasma volume method remained constant. Percentage differences for individual kidney GFR before and after fluid administration were 31.4 ± 58.1% (change ± 95% CI) for the integral method and 0.1 ± 70% (change ± 95% CI) for the plasma volume method. Intravenously administered fluid increased individual kidney GFR from low to normal in 10 of 22 kidneys using the integral method and in 1 of 22 kidneys using the plasma volume method. Findings supported the use of the plasma volume method for scintigraphic calculation of GFR in dogs with suspected renal disease and indicated that errors of kidney status classification may more likely occur when the integral method is used.  相似文献   
94.
MANNER‐NPK (MANure Nutrient Evaluation Routine) is a decision support tool for quantifying manure (and other organic material) crop available nutrient supply. The user‐friendly design of an earlier version of MANNER was retained, but in response to user and stakeholder feedback, additional functionality was included to underpin new and revised nitrogen (N) transformation/loss modules (covering ammonia volatilization, nitrate leaching and nitrous oxide/di‐nitrogen emissions, and organic N mineralization) and also to estimate manure phosphorus (as P2O5), potassium (as K2O), sulphur (as SO3) and magnesium (as MgO) supply. Notably, MANNER‐NPK provides N availability estimates for following crops through the mineralization of organic N. Validation of the crop available N supply estimates was undertaken by comparing predicted values with data from more than 200 field experimental measurements. For cattle, pig and poultry manures, there was good agreement (< 0.001) between predicted and measured fertilizer N replacement values, indicating that MANNER‐NPK provides robust estimates of manure crop available N supply and N losses to the wider environment.  相似文献   
95.
Abstract. An effective fertilizer recommendation system requires information on seasonal, soil-related and cultural variations in soil mineral nitrogen (N) and nutrient requirements of the crop. This can be provided by dynamic N turnover models, such as listed by Plentinger & Penning De Vries (1996). In this paper, we describe a survey of farmer opinion designed to ascertain what farmers want from such a decision support system. Over 100 farmers were surveyed. Surveyed farmers requested that default values be available for all model inputs. Inputs should be entered both by windows-based menu (for clarity) and tabular format (for speed), have user-selected units, and be fully supported by context-sensitive help. The system should have a hierarchical structure allowing access to fixed parameters, and be compatible with commonly used farm recording packages. Recommendations should be provided both for the field (single and optional application rates), and in tabular format across the whole farm. Simulations should be easily rerun using more recent crop and weather data. Turnover processes underlying recommendations should be illustrated by flow diagrams of flux between pools, pie charts of fertilizer fate, bar charts of movement down the soil profile and graphical plots of changes in N status against time.  相似文献   
96.
When air containing CH3HgY (Y stands for a monovalent anion) is bubbled through pure water (MQ), part of the airborne CH3HgY, depending on the actual distribution constant (air/water), will be retained in the liquid phase. The resulting concentration, although usually very low, is now in many cases possible to determine, using the very sensitive analytical procedure developed by Bloom and Fitzgerald (1988). By means of an evaluation method, described in this paper, the concentration data, obtained in this way, can be used to give the average original concentration of CH3HgY in the air which had entered the bubbler and its distribution constant (air/water) as well.  相似文献   
97.
Numerous bubblings of pure H2O or very dilute H2SO4-solutions with ambient air have been undertaken. All of them have shown the formation of HgIIa and HgIIb in the liquid phase (nomenclature according to Brosset, 1987). With increasing air volume such systems clearly approach a steady state. Earlier it has been shown that Hg° in water is oxidized by O3 primarily to Hg2+, (Brosset, l.c., Iverfeldt and Lindqvist, 1986, Munthe, Thesis 1991). However, the attainment of a steady state indicates that a reaction involving a removal of Hg from the solution must exist as well. It has now been anticipated that a substance ‘X’, present in the ambient air, should be responsible, at least partly, for this removal. Starting from this assumption a model has been developed, which seems to be supported by all experimental tests hitherto performed by us. Further it has been tried to establish the chemical nature of ‘X’. So far, some experiments show that ‘X’ may be (CH3)2S. Finally it has been shown that HgIIb observed in precipitation is not identical with the corresponding compound formed by bubbling of ambient air at the ground level through it.  相似文献   
98.
Theoretical calculations and experimental work, mainly consisting of bubbling ambient air through different synthetic solutions and natural waters and also bubbling Hg- and O3-free air through precipitation samples, have given some new information. The oxidation process of Hgo by means of O3 in natural waters and in synthetic solutions has been clarified. The primary products are water soluble Hg-compounds which are reduced by SnCl2. Subsequently volatile or nonvolatile Hg-species may be formed. These are not reduced by SnCl2. Further it has been shown that in precipitation those Hg-forms, which are not reducible with SnCl2 consist of non volatile species only. The dominant one seems to be highly dispersed and easily sorbed on to solid surfaces. It is reducible with NaBH4. Besides this there is another one consisting of larger particles. Their core contains some Hg which can be released as Hgo by a high temperature thermal process. Species with the same properties have also been observed in ambient air but in very low concentrations.  相似文献   
99.
Agricultural nitrogen balance and water quality in the UK   总被引:2,自引:0,他引:2  
Abstract. Nutrient balance calculations have been advocated as indicators of the risk of nitrate loss from agricultural land. To explore this concept, a spatially distributed UK agricultural nitrogen balance was derived using annually updated statistics. The mean UK N surplus for 1995 was 115 kg N ha–1, made up of 51 kg ha–1for arable land, 140 kg ha–1 for agricultural grassland (excluding rough grazing) and an additional 14 kg N ha–1for agricultural land from pig and poultry units. Nitrogen surpluses were greater in lowland grassland (mainly in western, wetter areas) than in arable areas. However nitrate concentrations in rivers were generally greater in arable areas. The relationship between N balance and nitrate leaching was very different for grassland and arable systems, and was also sensitive to climate, level of inputs and management practices. Nitrogen surplus was therefore weakly or even negatively correlated with river nitrate concentrations or loads. A positive correlation was found only where the comparison was restricted to grassland-dominated catchments. Nitrogen surplus calculations identified areas of very high livestock densities, which would be associated with increased risk of pollution. However their use in isolation as indicators of N leaching, or of progress towards mitigation, could be misleading especially if comparing areas differing in land use, climate or soil type.  相似文献   
100.
An 11-year-old Siamese cat with an osteogenic sarcoma of the nasal cavity was treated by partial surgical excision followed by a course of high dose-per-fraction radiation therapy in conjuction with metronidazole, a hypoxic cell sensitizer. Four thousand two hundred rads were delivered to the tumor in 7 weekly fractions. Each treatment was preceded by 6 gm/m2 oral metronidazole given 3 hours before irradiation. There were no untoward side effects and the cat was in remission 2 years after treatment.  相似文献   
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