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261.
A refined shear deformation theory for free vibration of functionally graded plates on elastic foundation is developed. The displacement field is chosen based on assumptions that the in-plane and transverse displacements consist of bending and shear components, and the shear components of in-plane displacements give rise to the parabolic variation of shear strain through the thickness in such a way that shear stresses vanish on the plate surfaces. Therefore, there is no need to use shear correction factor. Material properties of functionally graded plate are assumed to vary according to power law distribution of the volume fraction of the constituents. The elastic foundation is modeled as Pasternak foundation. Equations of motion are derived using Hamilton’s principle. Closed-form solution of rectangular plates is derived, and the obtained results are compared well with three-dimensional elasticity solutions and third-order shear deformation theory solutions. Finally, the influences of power law index, thickness ratio, foundation parameter, and boundary condition on the natural frequency of plates have been investigated. 相似文献
262.
Dieu Phuong Nguyen Thi Dieu Linh Tran Phuong Le Thi Ki Dong Park Thai Thanh Hoang Thi 《International journal of molecular sciences》2021,22(16)
Cordyline terminalis leaf extract (aqCT) possesses abundant polyphenols and other bioactive compounds, which are encapsulated in gelatin–polyethylene glycol–tyramine (GPT)/alpha-cyclodextrin (α-CD) gels to form the additional functional materials for biomedical applications. In this study, the gel compositions are optimized, and the GPT/α-CD ratios equal to or less than one half for solidification are found. The gelation time varies from 40.7 min to 5.0 h depending on the increase in GPT/α-CD ratios and aqCT amount. The aqCT extract disturbs the hydrogen bonding and host–guest inclusion of GPT/α-CD gel networks, postponing the gelation. Scanning electron microscope observation shows that all gels with or without aqCT possess a microarchitecture and porosity. GPT/α-CD/aqCT gels could release polyphenols from 110 to 350 nmol/mL at the first hour and sustainably from 5.5 to 20.2 nmol/mL for the following hours, which is controlled by feeding the aqCT amount and gel properties. GPT/α-CD/aqCT gels achieved significant antioxidant activity through a 100% scavenging DPPH radical. In addition, all gels are non-cytotoxic with a cell viability more than 85%. Especially, the GPT3.75α-CD10.5aqCT gels with aqCT amount of 3.1–12.5 mg/mL immensely enhanced the cell proliferation of GPT3.75α-CD10.5 gel without extract. These results suggest that the inherent bioactivities of aqCT endowed the resulting GPT/α-CD/aqCT gels with effective antioxidant and high biocompatibility, and natural polyphenols sustainably release a unique platform for a drug delivery system or other biomedical applications. 相似文献
263.
Thirty-three patients were assessed for suitability for time-limited psychotherapy (TLP). A battery of outcome measures was composed of Ss self-report measurements and objective judgments by external ("masked") raters. Ss were randomly assigned to either the experimental group, which received TLP immediately, or the control group, whose TLP was delayed for 3 months. Ss were evaluated on outcome measures at TLP termination and again at 6 and 12 months after termination. Significant improvement was observed in the experimental group after TLP, but the control Ss did not show any systematic changes after waiting. However, after TLP, the control Ss improved significantly. The gains achieved after therapy were stable in both groups after 6- and 12-month follow-ups. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
264.
YT Chia S Chua AC Thai SC Yeoh LP Kek N Selamat SS Ratnam 《Canadian Metallurgical Quarterly》1995,36(5):498-500
This retrospective study examined the obstetric and neonatal outcome in 23 pregestational diabetic pregnancies. The incidence of congenital malformations and mortality in infants of diabetic mothers was increased compared to the control population. Late booking for antenatal care and poor glycaemia control are probably the reasons for this high incidence. There was also a significantly higher preterm delivery and Caesarean section rate in the pregnancies complicated by pregestational diabetes. The neonatal morbidity was also higher than the controls in terms of jaundice, hypoglycaemia, respiratory distress syndrome and admissions to neonatal intensive care unit. Only with preconception counselling and tight glycaemia control in the periconception period and throughout pregnancy can we expect a drop in the complication rates in pregestational diabetic pregnancies. 相似文献
265.
266.
Invariant subpixel material detection in hyperspectral imagery 总被引:2,自引:0,他引:2
We present an algorithm for subpixel material detection in hyperspectral data that is invariant to the illumination and atmospheric conditions. The algorithm does not require atmospheric correction. The target material spectral reflectance is the only required prior information. A target material subspace model is constructed from the reflectance using a physical model and a background subspace model is estimated directly from the image. These two subspace models are used to compute maximum-likelihood estimates (MLEs) for the target material component and the background component at each image pixel. These estimates form the basis of a generalized likelihood ratio test for subpixel material detection. We present experimental results, using Hyperspectral Digital Imagery Collection Experiment (HYDICE) imagery, that demonstrate the utility of the algorithm for subpixel material detection under varying illumination and atmospheric conditions 相似文献
267.
Symptom production in groundnut plants infected with groundnut rosette virus (GRV) depends on the presence of satellite RNA (sat-RNA) in the GRV culture, and sat-RNA variants that induce only mild symptoms are known. One such variant drastically diminished the replication of GRV genomic RNA in infected Nicotiana benthamiana plants. This down-regulating ability did not involve either of the two open reading frames in the sat-RNA but was controlled by a region near its 5' end, which is required for sat-RNA replication. When N. benthamiana plants were inoculated with GRV and the mild satellite and challenged by inoculation with a GRV isolate (YB) containing a sat-RNA that induces yellow blotch symptoms, no symptoms appeared and little GRV genomic RNA or sat-RNA was detected in the plants, provided the two inoculations were no more than 2 days apart. A GRV isolate containing a sat-RNA that neither induces symptoms in N. benthamiana nor affects genomic RNA accumulation also provided protection against yellow blotch symptom production if inoculated before or up to 2 days after isolate YB. However, in this case protection ws incomplete and both GRV RNA and sat-RNA accumulated to normal levels. It is suggested that sequences from the mild sat-RNA may provide a novel source of resistance against rosette disease. 相似文献
268.
Lszl Baksay Jorge H. Moromisato Gaby Albrecht 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》1985,228(2-3):584-585
A new simple high aspect ratio drift chamber is discussed. By using two central sense wires the left-right position ambiguity is resolved within just one detector plane. 相似文献
269.
P. T. Bogachenko O. M. Bachillo I. M. Bachillo Thai Phung Nhe 《Power Technology and Engineering (formerly Hydrotechnical Construction)》1988,22(2):131-137
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 2, pp. 52–55, February, 1988. 相似文献
270.
Dynamic waveform matching (DWM) is a generalization of cross correlation that is useful in waveform classification and feature extraction problems. While cross correlation matches two signals by shifting the time axis of one signal relative to the other, DWM matches signals by shifting and warping the time axis until the corresponding features of the two waveforms are properly aligned. The optimum shift and warping of the time axis is determined by dynamic programming. The dynamic programming algorithm behind DWM can be used in many matching applications. Several geophysical applications of DWM are described. These include identifying local earthquake arrival times, extracting features useful for discriminating between earthquakes and underground nuclear explosions, waveform clustering, identifying quarry blasts, interpreting full wave acoustic well logs, well to well correlation, and matching P-wave reflection profiles to S-wave reflection profiles. The similarity between DWM and error correcting regular grammars can be used to add grammarlike capabilities to the matching algorithm. 相似文献