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11.
The concentration of polycyclic aromatic hydrocarbons (PAHs) was determined in seawater, sediment, and Rock oyster Saccostrea cucullata collected from four sampling sites in the inter-tidal areas of Bushehr province. The total concentrations of 14 PAHs varied from 1.5 to 3.6 ng/L in seawater, 41.7 to 227.5 ng/g dry weight in surface sediment, and 126 to 226.1 ng/g dry weight in oyster tissue. In comparing PAH concentrations among the three matrices in Bushehr province, data showed that the pattern of individual PAHs in seawater, oyster, and sediment were different. The oysters tended to accumulate the lower molecular weight and the more water-soluble PAHs. Sediment samples were distinguished from the sea water and oyster samples by the presence of high molecular weight PAHs, especially six-ring PAHs. Three- and four-ring PAHs were the most abundant compounds among the 14 PAHs investigated in surface seawater, sediment, and oyster samples. As expected, differences in octanol/water partition coefficient among individual PAHs and the greater persistence of the higher molecular weight PAHs contributed to the accumulation patterns in oyster and sediment. The results of the study suggested that the main sources of PAHs in the seawater and sediment in the region were mixed pyrolitic and petrogenic inputs.  相似文献   
12.
Aspergillus flavus Link ex Fr., was used to evaluate the nutritive value of two experimental mental groups of turkey diets and of the soybean and rapeseed meals used in these diets. The conditions for optimum growth of the fungus were standardized. Addition of extra minerals significantly improved the development of fungal biomass. For comparing the weight gain dat between turkeys and the fungus, samples were also tested at 100 mg equal weight level. The fungus graded the diets in the same order as had been done by turkeys. There was a significant (P<0.01) positive correlation (r=0.97**) between the weight gained by turkeys and the fungal biomass developed. Resultssuggest thatAspergillus system, because of its simplicity and speed, may be a useful intermediate stage tool to evaluate protein quality of high protein meals and of compex mixed diets.
Zusammenfassung Aspergillus flavus Link ex Fr. wurde zur Bestimmung des Nährwerts von 2 Versuchsgruppen Putenfutter mit Soya- und Rapsaat-Beigabe benutzt. Die Bedingungen für ein optimales Wachstum des Pilzes waren standardisiert. Ein Zusatz von Minrealstoffen verbesserte die Entwicklung der Pilzmasse beträchtlich. Um die Gewichtszunahme zwischen Puten und der Pilzmasse zu vergleichen, testete man Proben auch auf der Basis gleichen 100 mg-Gewichts. Es wurde eine signifikante (P<0.01) positive Korrelation (r=0,97) zwischen dem Gewichtsausstieg bei Puten und dem der entwickelten Biomasse der Pilze festgestellt. Die gewonnenen Resultate lassen vermuten dass das Aspergillus-System wegen seiner Einfachkeit und der Schnelle ein wertvolles Werkzeug im intermediären Stadium sei, um die Eiweissqualität von proteinreichem Futter und von Komplexen Futtergemischen zu bestimmen.
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13.
Reproductive stage frost poses a major constraint for wheat production in countries such as Australia.However,little progress has been made in identifying key genes to overcome the constraint.In the present study,a severe frost event hit two large-scale field trials consisting of six doubled haploid(DH)wheat populations at reproductive stage(young microspore stage)in Western Australia,leading to the identification of 30 robust frost QTL on 17 chromosomes.The major 18 QTL with the phenotype variation over 9.5%were located on 13 chromosomes including 2 A,2 B,2 D,3 A,4 A,4 B,4 D,5 A,5 D,6 D,7 A,7 B and7 D.Most frost QTL were closely linked to the QTL of anthesis,maturity,Zadok stages as well as linked to anthesis related genes.Out of those,six QTL were repetitively detected on the homologous regions on 2 B,4 B,4 D,5 A,5 D,7 A in more than two populations.Results showed that the frost damage is associated with alleles of Vrn-A1 a,Vrn-D1 a,Rht-B1 b,Rht-D1 b,and the high copy number of Ppd-B1.However,anthesis QTL and anthesis related genes of Vrn-B1 a and Ta FT3-1 B on chromosomes 5 B and 1 B did not lead to frost damage,indicating that these early-flowering phenotype related genes are compatible with frost tolerance and thus can be utilised in breeding.Our results also indicate that wild-type alleles Rht-B1 a and Rht-D1 a can be used when breeding for frost-tolerant varieties without delaying flowering time.  相似文献   
14.
Carbohydrate overload models of equine acute laminitis are used to study the development of lameness. It is hypothesized that a diet-induced shift in cecal bacterial communities contributes to the development of the pro-inflammatory state that progresses to laminar failure. It is proposed that vasoactive amines, protease activators and endotoxin, all bacterial derived bioactive metabolites, play a role in disease development. Questions regarding the oral bioavailability of many of the bacterial derived bioactive metabolites remain. This study evaluates the possibility that a carbohydrate-induced overgrowth of potentially pathogenic cecal bacteria occurs and that bacterial translocation contributes toward the development of the pro-inflammatory state. Two groups of mixed-breed horses were used, those with laminitis induced by cornstarch (n=6) or oligofructan (n=6) and non-laminitic controls (n=8). Cecal fluid and tissue homogenates of extra-intestinal sites including the laminae were used to enumerate Gram-negative and -positive bacteria. Horses that developed Obel grade2 lameness, revealed a significant overgrowth of potentially pathogenic Gram-positive and Gram-negative intestinal bacteria within the cecal fluid. Although colonization of extra-intestinal sites with potentially pathogenic bacteria was not detected, results of this study indicate that cecal/colonic lymphadenopathy and eosinophilia develop in horses progressing to lameness. It is hypothesized that the pro-inflammatory state in carbohydrate overload models of equine acute laminitis is driven by an immune response to the rapid overgrowth of Gram-positive and Gram-negative cecal bacterial communities in the gut. Further equine research is indicated to study the immunological response, involving the lymphatic system that develops in the model.  相似文献   
15.
This study was carried out to investigate the growth performance, carcass yield and meat quality of large-type Korean native ducks (KND). A total of 420 day-old ducklings were divided into four treatments (seven replicates/treatment, 15 birds/replicate) by strains (A and B) and gender (male and female) in a 2 × 2 factorial arrangement under complete randomized design. The body weight (BW) of female KND was higher at week 2 and for male it was higher in week 8 (P 〈 0.05). BW gain, feed intake and feed conversion ratio of male KND were higher than those of female KND (P 〈 0.05) during week 0 to week 8. The carcass yield of both strains increased from 6 weeks to 8 weeks (P 〈 0.05). The breast meat ratio was the highest at week 8 whereas the leg meat ratio was the highest at 6 weeks of age in both strains (P 〈 0.01). Lightness (L*), yellowness (b*) and juiciness of meat were the highest at 6 weeks (P 〈 0.05). Moisture, ash and fat contents of meat were the highest at 7 weeks (P 〈 0.05) and protein content was the highest at 8 weeks (P 〈 0.01). These results may provide the basic data on growth performance and meat quality of large-type KND, which can be used for genetic improvements and rearing at commercial scale.  相似文献   
16.
To examine the sensitivity of environmental systems to climatic variability and change, integrated model systems for climate impact assessment are being developed for New Zealand (CLIMPACTS) and Bangladesh (BDCLIM). Features common to both model systems include a global climate model, regional modules for generating climate scenarios, and models for biophysical impact analyses. For CLIMPACTS, modified ecosystem models for horticultural crops, arable crops, and pasture production are being incorporated. For BDCLIM, the emphasis is on analysis ofpossible changes in agroclimatic zones and hydrology, including the risks of floods and droughts. The initial emphasis of both systems is on nationwide spatial analyses, using simplified models as much as possible. The development of integrated model systems supports the needs of the respective countries in assessing scientific uncertainties, evaluating vulnerabilities, and identifying adaptation options as a basis for international reporting requirements under the U.N. Framework Convention on Climate Change and for policy and planning at national and regional levels. The major advantage of such integrated model systems is that they can readily be updated as the science of climate change advances, thus providing an evolving tool for future reassessments of climate impacts.  相似文献   
17.
18.
The objectives of this study were to determine if phenylbutazone decreased serum thyroxine (TT4) and free thyroxine (FT4) concentrations using radioimmunoassay and equilibrium dialysis techniques in horses, and, if so, an additional objective was to determine the duration of this decreased concentration once phenylbutazone administration was discontinued. Serum TT4 and FT4 concentrations were determined before and after administration of 4.4 mg/kg of phenylbutazone IV bid for 5 days. Treatment with phenylbutazone caused a significant decrease in TT4 and FT4 concentrations ( P < .05). Serum TT4 concentration significantly decreased after day 4 of treatment and remained significantly below baseline value for 10 days after discontinuing phenylbutazone administration; it returned to a value not different from the baseline value by the 11th day. Serum FT4 concentration significantly decreased after day 4 of treatment and remained significantly below the baseline value for only 1 day after phenylbutazone administration was discontinued; it returned to a value not different from the baseline value by the 3rd day after discontinuation of phenylbutazone. These results indicate that serum TT4 and FT4 should not be used to evaluate thyroid function in horses receiving phenylbutazone. In addition, results should be interpreted cautiously when phenylbutazone has been administered within 2 days (for FT4) or within 10 days (for TT4) of sample collection.  相似文献   
19.
Current study investigated the fermentative production of cell mass and crude protein using an axenic culture of the thermotolerant strain of Chlorella vulgaris grown mixotrophically in an illuminated 10-l glass bioreactor. The process was then upscaled to 1,000-l bioreactor. The organism supported maximum specific growth rate, crude protein volumetric productivity, and specific productivity of 1.2?day?1, 2.26?g?l?1?day?1, and 0.76?g?g?1?day?1, respectively, with urea as nitrogen source. Gibbs free energy, enthalpy, and entropy values for its formation were 74.3, 56. 2?kJ?mol?1, and ?59.1?J?mol?1?K?1, respectively, in both reactors and corresponded to those of thermotolerant organisms. Algal biomass grown in 10-l bioreactor contained 0.52?±?0.03, 12.6?±?2.0, 60.0?±?4.5, 0.4?±?0.02, 4.5?±?0.2, 12?±?0.5, and 3.81?±?0.5% carotenoids, carbohydrates, crude protein, DNA, RNA, lipids, and total chlorophyll, respectively. Dry biomass supported good growth of fish larvae comparable with that on commercial diet.  相似文献   
20.
The purpose of this study was to determine whether nitric oxide (NO) is present in clinically normal horses under basal conditions and if it increases secondary to naturally acquired small intestinal strangulation obstruction. Thirty-one horses were used; 20 horses with naturally acquired small intestinal strangulation obstruction and 11 clinically normal horses with no signs of gastrointestinal tract disease. Jugular venous blood, abdominal fluid, and urine were collected for NO quantification. Plasma, abdominal fluid, and urine were stored at -70 degrees C until analyzed for NO using a chemiluminescent method. Biopsy specimens collected from the affected jejunal segment, during anesthesia or after immediately after euthanasia, or from the midjejunum of control horses, were divided into subsections for fixation in zinc formalin and cryopreservation in OCT gel. Nicotinamide adenine dinucleotide phosphate (reduced) (NADPH) diaphorase histochemical stains were performed on cryopreserved tissues and inducible nitric oxide synthase (iNOS) and nitrotyrosine immunohistochemical stains were performed on formalin-fixed, paraffin-embedded tissues. There were significantly greater plasma and abdominal fluid NO concentrations in affected horses as compared with controls, but there were no significant differences between horses for urine NO concentrations. There was a significant decrease in NADPH diaphorase stain in mucosal epithelium, vasculature, and leukocytes, and in submucosal plexi in affected horses compared with control horses. There was a significant increase in iNOS staining in mucosal and submucosal leukocytes and in mucosal leukocyte nitrotyrosine staining of the affected compared with control horses. Endothelial NOS and neuronal NOS are present under basal conditions in the jejunum of horses and probably mediate physiologic or cytoprotective effects. Plasma and abdominal fluid, but not urine, NO concentrations increase subsequent to small intestinal strangulation obstruction; this may be associated with increased mucosal and submucosal iNOS staining in leukocytes, which was likely due to increased expression subsequent to stimuli associated with ischemia. The increased nitrotyrosine staining in mucosal leukocytes of affected horses likely reflects the presence of peroxynitrite subsequent to increased NO and superoxide production and may reflect a cytotoxic role of NO in small intestinal strangulation obstruction in horses.  相似文献   
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