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Sperm concentration of wild yak bull is 2. 13 billion per milliliter. Survival time at 0-4 ℃ is 57hrs. After thawing survival time at 37 ℃ is 12 hrs. Resistance coefficient is 144,000. Abnormal sperm rate and acrosomal integrated rate of post-thawing is 9.17% and 87.53% respectively. Moving viscosity is 1. 169 cp. Total nitrogen is 1 437.7 mg/100 ml. Head of sperm is significantly shorter and end piece is significantly longer than that of domestic yak and yellow cattle. Activity of hyaluronidase is highly stronger than the domestic yak,and the activity of LDH is higher than the domestic yak by 48 %. Hence,the fertility of the wild yak bull is powerful and the artificial inseminated rate with domestic yak and yellow cattle is 88.9% and 71.58% respectively.  相似文献   
2.
In accordance with the EPPO guideline for the efficacy evaluation of plant protection products, resistance risk analysis PP 1/213(1), a method was established to determine the baseline sensitivity of key weed species to florasulam, a new triazolopyrimidine sulfonanilide herbicide for post-emergence control of dicotyledonous weeds in cereals. The aim of the baseline monitoring project was to understand the natural variation in response to florasulam of diverse populations of Papaver rhoeas at the time of product launch. The method entailed seed collection from representative agricultural areas throughout Europe. The seed was subjected to glasshouse tests where dose-response studies were conducted and ED80 values generated. This enabled a sensitivity index to be calculated for each country, giving an indication of the variation in P rhoeas response to florasulam in the populations tested.  相似文献   
3.
Ionomic profiles are primarily influenced by genetic and environmental factors. Identifying ionomic responses to varietal effects is necessary to understand the ionomic variations among species or subspecies and to potentially understand genetic effects on ionomic profiles. We cultivated 120 rice (Oryza sativa) varieties to seedling stage in identical hydroponic conditions and determined the concentrations of 26 elements (including 3 anions) in the shoots and roots of rice. Although the subspecies effects were limited by the genus Oryza pre-framework and its elemental chemical properties, we found significant differences in ionomic variations in most elements among the aus, indica and japonica subspecies. Principal component analysis of the correlations indicated that variations in the root-to-shoot ionomic transport mechanisms were the main causes of ionomic differences among the subspecies. Furthermore, the correlations were primarily associated with the screening of varieties for elemental covariation effects that can facilitate breeding biofortified rice varieties with safe concentrations of otherwise toxic elements. The japonica subspecies exhibited the strongest elemental correlations and elemental covariation effects, therefore, they showed greater advantages for biofortification than the indica and aus subspecies, whereas indica and aus subspecies were likely safer in metal(loid) polluted soils. We also found that geographical and historical distribution significantly defined the ionomic profiles. Overall, the results of this study provided a reference for further association studies to improve the nutritional status and minimize toxicity risks in rice production.  相似文献   
4.
Shape-Controlled Synthesis of Colloidal Platinum Nanoparticles   总被引:1,自引:0,他引:1  
The shapes and sizes of platinum nanoparticles were controlled by changes in the ratio of the concentration of the capping polymer material to the concentration of the platinum cations used in the reductive synthesis of colloidal particles in solution at room temperature. Tetrahedral, cubic, irregular-prismatic, icosahedral, and cubo-octahedral particle shapes were observed, whose distribution was dependent on the concentration ratio of the capping polymer material to the platinum cation. Controlling the shape of platinum nanoparticles is potentially important in the field of catalysis.  相似文献   
5.
Clymene dolphins, Stenella clymene, are endemic to the tropical and subtropical Atlantic Ocean, where their occurrence is documented from fewer than 200 records. The species is particularly poorly known in the eastern Atlantic off the coast of Africa where only 12 verified records exist, predominantly comprising dead animals. Marine mammal survey work was carried out off central West Africa during 2004 and 2005, producing two new observations of freeranging Clymene dolphins. Both sightings occurred in deep-water (466 and 684 m) over the shelf edge, off northern Angola and Congo respectively. A pod of 250 Clymene dolphins was observed off Congo, while the Angola sighting was of a mixed-species group of 12 Clymene dolphins with common dolphins, Delphinus sp. These records represent the first confirmed presence of Clymene dolphins off Angola and Congo, and extend the known southern limit of the confirmed distribution range of this species in the South-East Atlantic to 06°26‘S.  相似文献   
6.
Horses are stabled overnight for a number of practical reasons; however, there is little research quantifying nocturnal equine behavioral patterns or the extent to which different environments influence nocturnal behavior. The aim of this study was to establish whether differences in duration of sleep and ingestive behaviors were apparent for horses bedded on straw (group 1) or shavings (group 2). Ten geldings of mixed breed (mean age: 7.3 ± 3.53 years) bedded on either shavings (n = 5) or straw (n = 5) were observed between 7 pm and 7 am. Duration of behaviors according to a predefined ethogram was recorded in minutes using a video recorder and continuous focal sampling. Mann–Whitney U tests were used to identify whether any significant differences in duration of ingestion and sleep behaviors occurred for horses bedded on straw compared with shavings. Of the total observation period, group 1 spent, on average, 29.3% of their time budget engaged in recumbent behaviors, compared with 12.2% for group 2. However, no significant differences in duration were established between horses bedded on straw or shavings for standing sleep, sternal recumbency, and lateral recumbency behaviors (P > 0.05). Ingestive behaviors occupied approximately one-third of the time budget, with no significant difference (P > 0.05) observed between groups. On average, group 1 spent a longer proportion of the observation period ingesting bedding (8.1%) compared with group 2 (1%). Duration of bedding ingestion appeared to peak between 1 am and 7 am for both groups. Although not quantified, general observations revealed horses were motivated to alternate between eating hay and bedding in both groups, owing to the prevalence of bedding ingestion. The results indicate that straw bedding facilitates the display of ingestive and sleep behaviors, whereas horses bedded on shavings spent a greater proportion of their nocturnal time budget engaged in “other” behaviors. Further research is required to investigate the extent to which different types of bedding material enrich the environment of horses that are stabled overnight.  相似文献   
7.
Continuous chromatographic separator techniques have allowed the extraction of more simple sugars from molasses (MOL). The resultant byproduct, concentrated separator byproduct (CSB), has reduced readily fermentable carbohydrates but elevated CP and mineral content. The feed value of CSB was compared to that of MOL in two separate trials. In Trial 1, a chopped forage mixture containing 84% meadow grass hay and 8% alfalfa hay was mixed with either CSB or MOL at 7.3% of DM. Diets were administered to four ruminally cannulated cows in a single reversal design. digestibility of DM, ADF, NDF, and CP were measured. Ruminal pH, ammonia nitrogen (NH3), VFA, total viable bacteria (TVB), cellulose-xylan fermenting bacteria (CXFB), and ciliated protozoa (PTZ) were evaluated. Blood profiles of electrolytes were also measured. Digestibility of DM, ADF, NDF, and CP were 69.03, 68.58; 57.48, 57.77; 65.62, 64.75; and 67.63, 65.07% for the MOL and CSB diets, respectively. Only CP digestibility differed (P less than .02). Ruminal pH, NH3, VFA, TVB, CXFB, and PTZ were 6.97, 6.93; 14.21, 16.71 mg/dL; 74.30, 74.78 mumol/mL; 26.79, 27.36 x 10(9)/mL; 21.72, 21.36%; and 13.90, 7.80 x 10(3)/mL for the MOL and CSB diets, respectively. Ruminal measurements did not differ. Blood electrolyte profiles were not altered. Trial 2 was similar to Trial 1 except the basal diet used was 47% barley grain, 35% alfalfa hay, and 10% barley straw. Either MOL or CSB was added at 7.3% of the DM. Digestibilities of DM, ADF, NDF, and CP were 69.52, 71.33; 35.96, 37.11; 27.93, 33.47; and 71.10, 73.66% for the MOL and CSB diets, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
8.
A rapid immunologic test for scrapie in sheep   总被引:1,自引:0,他引:1  
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9.
Carbon nanotube quantum resistors   总被引:1,自引:0,他引:1  
The conductance of multiwalled carbon nanotubes (MWNTs) was found to be quantized. The experimental method involved measuring the conductance of nanotubes by replacing the tip of a scanning probe microscope with a nanotube fiber, which could be lowered into a liquid metal to establish a gentle electrical contact with a nanotube at the tip of the fiber. The conductance of arc-produced MWNTs is one unit of the conductance quantum G0 = 2e2/h = (12.9 kilohms)-1. The nanotubes conduct current ballistically and do not dissipate heat. The nanotubes, which are typically 15 nanometers wide and 4 micrometers long, are several orders of magnitude greater in size and stability than other typical room-temperature quantum conductors. Extremely high stable current densities, J > 10(7) amperes per square centimeter, have been attained.  相似文献   
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