1,151 research outputs found
Analysis on the vehicle-bridge coupled vibrations of long-span cable-stayed bridge based on multiscale model
The paper introduces the principals and methods of universal multiscale modeling, and simply verifies them. It also derives the vibration equations of the bridge and the vehicles, and programs the universal program for analyzing two-axle vehicle-bridge coupled vibration via Ansys and Matlab software based on Newmark-β method. It proposes the universal method for analyzing vehicle-bridge coupled vibrations of long-span cable-stayed bridge based on multiscale model, and takes a single pylon cable-stayed bridge as an example to analyze and verify it
Merger rate of supermassive primordial black hole binaries
The probability that the primordial black hole (PBH) binaries formed in the
early Universe can be affected by the Hubble expansion of background, which is
non-negligible when the number density of PBHs is very low (it is actually this
case for supermassive PBHs). In this paper, taking into account the effect of
cosmic expansion on the comoving distance of PBH pairs, we worked out the
merger rate of PBHs with any extended mass function. The torques by all PBHs
and linear density perturbations are also considered. It is found that the
merger rate of PBH, , binaries is significantly lower for
than expected.Comment: 16 pages, 5 figure
Effect of Bushen yixue decoction on follicular development in experimental androgen-sterilized anovulatory rats and its possible mechanism of action
Purpose: To explore the activities of Bushen yixue decoction (BSY) against follicular development in anovulatory rats.Methods: Rats were divided into normal, normal control, clomifene citrate (positive control, orally, 5 mg/kg), and BSY (orally, 50, 100, 200 mg/kg) groups. Anovulatory rats were prepared by testosterone propionate injection (1.5 mg/rat). After 70 days, daily vaginal smears were performed for 10 days until no obvious sexual cycle was observed, indicating that androgen-sterilized anovulatory rats were successfully established. High performance liquid chromatography (HPLC) was used to analyse BSY chemical composition. Levels of follicular stimulating hormone (FSH), luteinizing hormone (LH), oestradiol (E2), progesterone (P), prolactin (PRL), inhibin (INH), activin (ACT) and follistatin (FS) were determined by radioimmunoassay or enzyme linked immunosorbent assay (ELISA). Western blotting was used to determine Bcl-2, cleaved-caspase-3, Bax, MMP-9 and VEGF in ovarian tissues.Results: BSY increased (p < 0.05) the levels of FSH, LH, E2 (p < 0.05) and ACT, but decreased (p < 0.05) the levels of PRL, INH and FS, relative to control rats. Expressions of VEGF (p < 0.01), MMP-9 (p < 0.05) and Bcl-2 (p < 0.01) were up-regulated by BSY, whereas Bax (p < 0.01) and C-caspase-3 (p < 0.01) were down-regulated.Conclusion: BSY promotes follicular development of anovulatory rats via regulating INH-ACT-FS hormones, VEGF, MMP-9, Caspase-3, Bax, and Bcl-2. Thus, BSY may have the potential to be developed for clinical management of infertility.Keywords: Bushen yixue decoction, Follicular development, Inhibin-Activin-Follistatin (INH-ACT-FS) system, Androgen-sterilized anovulatory rat
Auricular Reconstruction Using a Porous Polyethylene Framework
AbstractObjectiveTo report utility of Medpor frameworks in auricular reconstruction and management of frameworks protrusion.MethodsRetrorespectively analysis of clinical information in 31 patients who underwent auricular reconstruction from April 2000 to October 2002.ResultsAll 31 reconstructed auricles were in good condition at two weeks postoperatively. Framework protrusion occurred later in 11 patients. The framework was retained in 8 of these cases after secondary repair, but had to be removed in 3 patients. In 27 patients, the reconstructed auricle was rated as esthetically succesful.ConclusionMedpor framework protrusion is likely to occur when skin tension is high with minimal soft tissue coverage over the framework and can result from impact by strong external force. Despite the concern of protrusion, Medpor frameworks can be used in place of autologous cartilaginous graft in auricular reconstruction
Thermal Analysis and Characterization of Polystyrene Initiated by Benzoyl Peroxide
PresentationBased on the complexity of the polystyrene polymerization mechanism initiated by benzoyl peroxide (BPO), the thermal risk of the reaction process was estimated using thermal analysis and characterization. The polymerization process was thermally analysed using an adiabatic rate calorimeter and differential scanning calorimeter. The results demonstrated that the onset reaction temperature, adiabatic temperature rise, and maximum temperature of the synthesis reaction of BPO-initiated polymerization were lower than those of thermos initiated polymerization. Moreover, nuclear magnetic resonance imaging, gel permeation chromatography, and Fourier transform infrared spectrometry were used to characterize the polymerization products obtained under the two initiation conditions. The polystyrene obtained using the two initiation methods had the same hydrogen structure; however, their molecular weight and distribution uniformity differed considerably, and the BPO-initiated process was discovered to include the effects of the thermos initiated process. Moreover, the free radicals produced by BPO decomposition participated in the chain reaction of polystyrene polymerization, accelerated instantaneous grain growth, and promoted the formation of short- chain polystyrene. In summary, the BPO-initiated polymerization process exhibited the desired thermal safety characteristics and has potential for practical use
Radio Polarization of BL Lacertae objects
In this paper, using the database of the university of Michigan Radio
Astronomy Observatory (UMRAO) at three (4.8 GHz, 8 GHZ, and 14.5 GHz) radio
frequencies, we studied the polarization properties for 47 BL Lacertae
objects(38 radio selected BL Lacertae objects, 7 X-ray selected BL Lacertae,
and two inter-middle objects (Mkn 421 and Mkn 501), and found that (1) The
polarizations at higher radio frequency is higher than those at lower
frequency, (2) The variability of polarization at higher radio frequency is
higher than those at lower frequency, (3) The polarization is correlated with
the radio spectral index, and (4) The polarization is correlated with
core-dominance parameter for those objects with known core-dominance parameters
suggesting that the relativistic beaming could explain the polarization
characteristic of BL Lacs.Comment: 5 pages, 3 figures, 1 table. PASJ, in pres
- …