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排序方式: 共有146条查询结果,搜索用时 15 毫秒
1.
The rat's willingness to ingest glucose after an initial intraoral intake test was probed by beginning a 2nd intraoral intake test at variable durations (1–220 min). In Exp 1, after an initial meal of 12.5% glucose solution averaging 26.9?±?1.7 ml, the size of the 2nd (probe) meal of the same stimulus increased linearly from 4.0?±?0.9 ml after a 1-min delay to 15.4?±?2.7 ml after a 120-min delay. In Exp 2, intraoral intake of a more concentrated (37.5%) glucose solution rose more slowly as a function of delay from 2.4?±?2.7 ml to 4.9?±?0.6 ml. For each glucose concentration, the linear recovery function and a slope that depends on stimulus concentration are consistent with a role for gastric emptying during the delay in intake recovery. In Exp 3, rats ingested 12.5% or 37.5% glucose to satiety in an initial test and received, after a variable delay, either the same or the other concentration as the probe stimulus. The same volumes were ingested at each delay whether the glucose concentration of the probe stimulus was the same or was switched from that presented in the initial test. This result shows that the taste and caloric properties of the probe stimulus played no role in determining how much of it would be ingested… (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
2.
A focusing transducer based on a 9-µm thick PVDF foil was fabricated and tested for performance. The transducer operates in the frequency range of 20–160 MHz. For operation at 78 MHz in water, a lateral resolution of 27.5 µm and a vertical resolution of 35 µm have been observed. Acoustic images of a transistor have been obtained with the focusing PVDF transducer. 相似文献
3.
H. Wolf F. Wagner Th Wichert R. Grill E. Belas Isolde Collaboration 《Journal of Electronic Materials》2006,35(6):1350-1353
Anomalous diffusion profiles of Ag in single crystalline CdTe were observed using the radiotracer 111Ag. The diffusion anneals were performed at 800 K under Cd or Te vapor and in vacuum with low Ag concentrations. The measured
Ag profiles directly reflect the distribution of the self-interstitials and vacancies of the Cd sublattice and are the result
of chemical self-diffusion which describes the variation of the deviation from stoichiometry of the binary crystal as a function
of depth and time. It turned out that the spread of the Ag dopant essentially is determined by the drift of the charged defects
within the electric field caused by the distribution of the extrinsic and intrinsic defects. 相似文献
4.
Vico JP Rol I Garrido V San Román B Grilló MJ Mainar-Jaime RC 《Journal of food protection》2011,74(7):1070-1078
A herd-based survey of Salmonella in pigs was carried in a major pig producing region of Spain. Mesenteric lymph nodes were collected from the carcasses of 25 pigs from each of 80 herds at time of slaughter. Salmonella spp. were isolated from 31% of animals and 94% of herds. Within-herd prevalence ranged from 4 to 88%, with the prevalence in most herds being greater than 10%. A large diversity of Salmonella serotypes was found, with Typhimurium, 4,[5],12:i:-, and Rissen being the most prevalent. Two or more serotypes coexisted in 73% of the herds. Salmonella Typhimurium was present in 68% of the herds. Most (82%) of the Salmonella isolates belonged to serogroups targeted by enzyme-linked immunosorbent assay tests for pig salmonellosis. Resistance to at least one antimicrobial agent was detected in 73% of the strains, and one or more resistant strains were recovered from pigs in 93% of the herds. Antimicrobial agent resistance (AR) was more frequent among the most prevalent than it was among the rarer serotypes. Twenty-five multi-AR patterns were found. Resistance to three or more families of antimicrobial agents was found in 75% of AR strains. The finding that many of the herds yielded isolates of several multi-AR patterns indicates that Salmonella infections were acquired from multiple sources. High prevalence of Salmonella in herds was associated with lack of rodent control programs, herds from farms with only finishing pigs, herds managed by more than one full-time worker, herds for which the source of drinking water was not a city supply, and relatively long fattening times. 相似文献
5.
P. Horodyský J. Franc R. Grill P. Hlídek P. Moravec J. Bok P. Höschl 《Journal of Electronic Materials》2006,35(6):1491-1494
The paper compares different methods of optical mapping of zinc concentration x in Cd1−xZnxTe wafers for low x values and reviews the procedures for deriving band-gap energy from optical spectra (photoluminescence,
absorption and reflectance) at different temperatures (liquid helium, liquid nitrogen and room temperature). Experimental
errors of these techniques are compared and the segregation coefficient of zinc is calculated. 相似文献
6.
Recent evidence suggests that the central melanocortin (MC) system is a prominent contributor to food intake and body weight control. MC receptor (MC-R) populations in the arcuate and paraventricular nuclei are considered probable sites of action mediating the orexigenic effects of systemically or intracerebroventricularly administered ligands. Yet, the highest MC4-R density in the brain is found in the dorsal motor nucleus of the vagus nerve, situated subjacent to the commissural nucleus of the solitary tract, a site of pro-opiomelanocortin mRNA expression. We evaluated the contribution of the caudal brainstem MC system by (1) performing respective dose-response analyses for an MC-R agonist (MTII) and antagonist (SHU9119) delivered to the fourth ventricle, (2) comparing, in the same rats, the fourth intracerebroventricular dose-response profiles to those obtained with lateral intracerebroventricular delivery, and (3) delivering an effective dose of MTII or SHU9119 to rats before a 24 hr period of food deprivation. Fourth intracerebroventricular agonist treatment yielded a dose-dependent reduction of short-term (2 and 4 hr) and longer-term (24 hr) food intake and body weight. Fourth intracerebroventricular antagonist treatment produced the opposite pattern of results: dose-related increases in food intake and corresponding increases in body weight change for the 24-96 hr observation period. Comparable dose-response functions for food intake and body weight were observed when these compounds were delivered to the lateral ventricle. Results from deprived rats (no effect of MTII or SHU9119 on weight loss) support the impression derived from the dose-response analyses that the body weight change that follows MC treatments is secondary to their respective effects on food intake. Results support the relevance of the brainstem MC-R complement to the control of feeding. 相似文献
7.
8.
Boron nitride (BN) coatings were deposited onto die steel and graphite substrates with a low pressure r.f. plasma. The coatings were deposited onto substrates at temperatures of 550–620 °C from a gas mixture of argon, NH3 and BCl3. X-ray diffraction and scanning electron microscopy were employed to identify and to characterize the coatings. The coatings are mostly amorphous; however, the existence of small amounts of hexagonal BN was identified. The influence on the growth rate of the deposition time and the pressure in the reactor is described. 相似文献
9.
A. Yu Stakheev G. N. Baeva G. O. Bragina N. S. Teleguina A. L. Kustov M. Grill J. R. Thøgersen 《Topics in Catalysis》2013,56(1-8):427-433
Performance of the combined catalysts [CeO2–ZrO2 + FeBETA] and [Mn/CeO2–ZrO2 + FeBETA], prepared by mechanical mixing of the component powders, was studied in soot oxidation and NH3-SCR. [CeO2–ZrO2 + FeBETA] catalyst (with component volumetric ratio of 3/1) demonstrated efficient soot oxidation at 400–450 °C and DeNO x performance similar to that of FeBETA catalyst, despite the fact that the amount of zeolite was reduced by four times indicating a strong synergistic effect between the components. Low-temperature DeNO x performance of the [CeO2–ZrO2 + FeBETA] system can be additionally enhanced by doping the CeO2–ZrO2 with Mn. It was found that NO x conversion over [Mn/CeO2–ZrO2 + FeBETA] at 150–250 °C was steadily improved by increasing the Mn loading, and [5.4 % Mn/CeO2–ZrO2 + FeBETA] attained NO x conversion above 90 % at Treact ~190 °C. Comparative studies of soot oxidation and NH3-SCR over combined catalysts and individual components indicated that the soot oxidation activity is assigned to the soot oxidation over ceria–zirconia component, while enhanced low-temperature SCR performance is a result of a “bi-functional” SCR mechanism comprising NO oxidation to NO2 over CeO2–ZrO2 component followed by fast-SCR over FeBETA. 相似文献
10.