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71.
Riboflavin (Rf)-mediated photosensitized degradation of vitamins A and D3 in skimmed milk under illumination with a white fluorescence lamp was studied by using the HPLC technique. The photosensitized degradation of both vitamins followed first-order kinetics, and the temperature effect on the observed photodegradation rate constant allowed the determination of the activation energy Ea as being 4 and 16 kcal/mol for vitamins A and D3, respectively. The addition of lycopene microencapsulated by spray-drying with a gum arabic-sucrose (8:2) mixture (MIC) produced a reduction of ca. 45% in the photosensitized degradation rate of both vitamins. Front-face fluorescence experiments showed the same photoprotection factor in the degradation of Rf itself, indicating that the photodegradation mechanism involved Rf-mediated reactive species, such as the excited triplet state of Rf, 3Rf*, and/or singlet molecular oxygen, 1O2. The interaction of both 3Rf* and 1O2 with MIC was evaluated in aqueous solutions by using laser-induced time-resolved absorption or emission spectroscopy, and the contribution of an inner-filter effect in the presence of MIC in skimmed milk was evaluated by diffuse reflectance spectroscopy. The main operating mechanism of photoprotection is due to the deactivation of 3Rf* by the proteic component of gum arabic; thus, gum arabic based microcapsules could be used to improve the photostability of milk during its storage and/or processing under light.  相似文献   
72.
Antinociceptive activity of the pyranocoumarin seselin in mice   总被引:1,自引:0,他引:1  
Seselin an angular pyranocoumarin at dose of 0.5, 4.5 or 40.5 mg/kg inhibited the writhing response induced by acetic acid in a significant and dose-dependent manner, by 19.5%, 26.2% and 41.4%, respectively. Using the same doses, seselin elicited a significant inhibition of formalin response during the second phase (inflammatory), by 90.3%, 97.8% and 95.3%, respectively. Besides, a significant reduction of licking time was observed during the first phase (neurogenic) at the highest doses of seselin, by 34.4% and 66.9%, respectively. On the contrary, in the hot plate test no effect was observed after seselin treatment. In conclusion, seselin was able to inhibit inflammatory hyperalgesia, suggesting that this natural product possesses both important peripheral anti-inflammatory and antinociceptive properties.  相似文献   
73.
74.
The feasibility of using recycled granular tire rubber (GTR) to remove molinate from contaminated water bodies was evaluated in this study. Adsorption equilibrium data was well described by a linear isotherm, and the adsorption was completely reversible. Breakthrough curves showed column efficiencies of approximately 40%, based on total capacity, and complete bed regeneration was achieved using clean water. The effluent from the regeneration step was successfully decontaminated using a defined bacterial mixed culture, capable of molinate mineralization. It was shown that this treated water can be used for regenerating a subsequently saturated bed. The GTR adsorbent showed two important features: complete reversibility towards molinate adsorption and stability along successive adsorption/bio-regeneration cycles. Common adsorbents, such as activated carbons and resins, loose performance very quickly under the same conditions, due to irreversible adsorption.  相似文献   
75.
The common bean (Phaseolus vulgaris L.) is the most consumed legume in the world. In Portugal, the geographic isolation of the region surrounded by the mountainous barrier of Peneda-Gerês, Barroso and Marão is thought to have the safeguard of a large number of adapted bean populations. In order to assess the value of this germplasm to breeding programs, a study of 20 Portuguese landraces collected in this Northern region were evaluated for agronomical (days to flowering, plant height, days to harvest, weight of seeds per plant and 100 seeds weight), chemical (crude protein) and genetic diversity (microsatellite DNA).  相似文献   
76.
Temperature and relative humidity (RH) are the most important environmental factors affecting the sensory quality of fresh produce, and therefore, the consumer acceptability for fruits and vegetables displayed in a produce department. Poor temperature management inevitably occurs in commercial handling and reduces the quality and maximum potential shelf life of fruits and vegetables. Since there is a lack of information on the actual temperatures registered inside local distribution trucks or in consumer retail displays, and the effects on the produce quality, the current study was designed to evaluate the segment of the distribution chain that comprises the time the produce arrives from the distribution center to the store, is displayed at the store, and then stored under household conditions. Temperature and RH were recorded in three different produce departments, at reception and during a 6-week retail display period. Truck and produce temperatures were collected immediately upon opening of the doors, and display temperatures were monitored inside 27 refrigerated and non-refrigerated retail displays. Visual quality of 37 different produce items was evaluated, and surface or pulp temperatures were measured immediately upon unloading from the delivery truck. Reasons for produce waste were recorded on a daily basis during a 6-week period. Shelf life studies were conducted under simulated household conditions using samples collected at the stores. Results from this study showed that chilling-sensitive commodities were transported under too cold conditions, whereas heat-sensitive commodities were transported under too warm conditions. Visual quality of the produce received at the store ranged from good to poor depending on the fruit or vegetable evaluated, with raspberry receiving the lowest visual quality score in 6.7% of store deliveries, and banana, fresh-cut vegetables, peach and pineapple receiving the best visual quality score in 100% of store deliveries. Temperatures measured inside retail displays showed a wide variation, depending on the store and location inside the display, ranging from ?1.2 °C to 19.2 °C in refrigerated displays and from 7.6 °C to 27.7 °C in non-refrigerated displays. RH ranged from 55.9% to 92.9% in refrigerated displays and from 29.7% to 86.6% in non-refrigerated displays. Poor temperature management was the major cause of produce waste (55%) whereas expired date and mechanical damage accounted for 45% of the produce wasted. Results from this study show that fruits and vegetables are often handled under adverse environmental conditions, resulting in produce with poor quality and shorter shelf life, and increased waste at the retail and consumer levels.  相似文献   
77.
A case of leishmaniasis in a domestic cat (Felis domesticus) is described. The animal showed a single, nodular lesion on the nose and many nodules of different size on the ears and digital regions of all the paws. Diagnosis was made by microscopic detection of amastigotes in Giemsa-stained smears from the lesions. By monoclonal antibodies the aetiological agent was identified as Leishmania (Leishmania) amazonensis, one of the seven species implicated in human leishmaniasis in Brazil. The clinical signs in feline leishmaniasis are unspecific and similar to those observed in other diseases such as cryptococcosis and in sporotrichosis, commonly found in cats. Leishmaniasis should therefore, be added to the differential diagnosis by feline veterinary practitioners and adequate investigations should carried out for dermal leishmaniasis in the area where the feline infection is detected.  相似文献   
78.
Objective: To evaluate the cardiorespiratory effects of continuous infusion of ketamine in hypovolemic dogs anesthetized with desflurane. Design: A prospective experimental study. Animals: Twelve mixed breed dogs allocated into 2 groups: saline (n=6) and ketamine (n=6). Interventions: After obtaining baseline measurements (time [T] 0) in awake dogs, hypovolemia was induced by the removal of 40 mL of blood/kg over 30 minutes. Anesthesia was induced and maintained with desflurane (1.5 minimal alveolar concentration) and 30 minutes later (T75) a continuous intravenous (IV) infusion of saline or ketamine (100 μg/kg/min) was initiated. Cardiorespiratory evaluations were obtained 15 minutes after hemorrhage (T45), 30 minutes after desflurane anesthesia, and immediately before initiating the infusion (T75), and 5 (T80), 15 (T90), 30 (T105) and 45 (T120) minutes after beginning the infusion. Measurements and main results: Hypovolemia (T45) reduced the arterial blood pressures (systolic arterial pressure, diastolic arterial pressure [DAP] and mean arterial pressure [MAP]), cardiac (CI) and systolic (SI) indexes, and mean pulmonary arterial pressure (PAP) in both groups. After 30 minutes of desflurane anesthesia (T75), an additional decrease of MAP in both groups was observed, heart rate was higher than T0 at T75, T80, T90 and T105 in saline‐treated dogs only, and the CI was higher in the ketamine group than in the saline group at T75. Five minutes after starting the infusion (T80), respiratory rate (RR) was lower and the end‐tidal CO2 (ETCO2) was higher compared with values at T45 in ketamine‐treated dogs. Mean values of ETCO2 were higher in ketamine than in saline dogs between T75 and T120. The systemic vascular resistance index (SVRI) was decreased between T80 and T120 in ketamine when compared with T45. Conclusions: Continuous IV infusion of ketamine in hypovolemic dogs anesthetized with desflurane induced an increase in ETCO2, but other cardiorespiratory alterations did not differ from those observed when the same concentration of desflurane was used as the sole anesthetic agent. However, this study did not evaluate the effectiveness of ketamine infusion in reducing desflurane dose requirements in hypovolemic dogs or the cardiorespiratory effects of ketamine–desflurane balanced anesthesia.  相似文献   
79.
1. Three experiments were conducted to evaluate the effects of the dietary addition of fungal phytase (derived from Aspergillus niger) on the performance and phosphorus utilisation in broiler chickens receiving low phosphorus diets without additional inorganic phosphates.

2. Graded amounts of supplemental phytase (125, 250, or 500 PU/kg diet) resulted in significant increases in both growth rate and food intake. However, only moderate improvements in food conversion were noted.

3. The enhancement of chick performance was related to an improved utilisation of dietary phosphorus, as confirmed by significantly elevated plasma concentrations of inorganic phosphorus and increased tibia ash percentages in birds receiving phytase‐treated diets. The apparent availability of phosphorus was markedly improved and its concentration in excreta was reduced (experiment 1, P<0.05).

4. It was concluded that an inclusion of phytase into practical broiler diet will allow the reduction or omission of additional dietary inorganic phosphorus.  相似文献   

80.
Canine babesiosis is an infectious disease caused by either Babesia gibsoni or Babesia canis protozoans. The latter is also classified under three different phylogenetic groups, referred to as subspecies B. canis canis, B. canis vogeli and B. canis rossi. The objective of the present study was to validate and standardize a PCR assay to discriminate the organisms at the subspecies level. First, the reference sequences of the 18S rRNA, 5.8S rRNA and 28S rRNA genes, including the internal transcribed spacer 1 (ITS1) and 2 (ITS2) of the most common species and subspecies of the genus Babesia were retrieved from the GenBank database. Subspecies-specific primers (BAB3, BAB4 and BAB5) and one genus-specific primer were designed from the alignment of the sequences. The PCR assays were evaluated in three different combinations of primer pairs in order to assure complete specificity for each reaction. The results of the tests had demonstrated effectiveness of the novel primer pairs BAB1/BAB3, BAB1/BAB4 and BAB1/BAB5 for the amplification of the subspecies-specific target fragments of 746 bp (B. c. canis), 546 bp (B. c. vogeli) and 342 bp (B. c. rossi) by PCR. The original enzymatic amplification assays with novel primers reported in this paper were confirmed to be a reliable tool for the specific discrimination among B. canis subspecies by single-step PCR assays.  相似文献   
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