Lead-free multilayer piezoelectric transformer

Author name used in this publication: K. H. LamAuthor name used in this publication: S. WangAuthor name used in this publication: C. L. SunAuthor name used in this publication: X. Z. Zhao2006-2007 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Study on the distribution regularity of gas volume in multiphase pump

In order to reduce the phase separation, air plug and turbulence vortex in the multiphase pump. The two-fluid model and the standard k-¦ turbulence model are selected, the distribution regularity of gas phase volume within the multiphase pump is researched using the CFD software about air-liquid two-phase under the different working conditions. The results of the study showed that the gas phase gathers at the rim when the gas-liquid two-phase enter into the impeller inlet, and the gas phase is gradually increased at the rim with the increase of the flow rate, the gas is concentrated in the hub at the second half of the impeller, and the most serious aggregation is the small flow rate condition. When the flow is constant, the gas obviously increases in the guide vane hub with the increase of the gas volume fraction. With the increase of the gas volume fraction, the uniformity of the gas phase in the circumferential direction is deteriorated in the inlet and the middle of impeller, and the lower gas volume fraction region is decreased in the impeller. The results of the study reveal the distribution regularity of gas volume within the multiphase pump, provide the reference basis for the design of the multiphase pump under the higher gas volume fraction

Effect of gas volume fraction on vortex motion in hydraulic turbine

In order to analyze the vortex motion in the flow channel of the hydraulic turbine impeller during the gas volume fraction change. Now, the pump with a specific speed of 55.7 is chosen as hydraulic turbine. On the basis of considering the gas compressibility, to take numerical calculation on the model under different flow rates and different gas volume fraction, to analyze the influence of gas volume fraction on vortex motion law in the impeller flow channel. Findings: When the flow rate is small, the relative velocity distribution in the impeller flow channel is uneven, the velocity field is chaotic, and there are obvious vortices, with the increase of the gas volume fraction, the vortices in the impeller flow channel gradually move to the inlet direction of the blade; With the increase of the flow rate, the flow in the channel of the hydraulic turbine impeller is unstable. Both the pressure surface and the suction surface of the blade appear vortices, the vortex region in the impeller flow channel is enlarged, and all of them are concentrated on the back of the blade. The results provide a theoretical basis for the optimal design of hydraulic turbine structures

Effect of gas volume fraction on the vortex motion within the oil-gas multiphase pump

In order to research the regular pattern of the vortex within the oil-gas multiphase pump with the gas volume fraction changes, the standard K-epsilon turbulence model is selected, the gas-liquid two-phase flow field within the multiphase pump is calculated by the CFD software under the different gas volume fraction, the regular pattern of the vortex motion within the multiphase pump is analyzed under the different gas volume fraction. The results show that, from the impeller hub to the rim, the vortex in the guide vane is gradually become smaller, the vortex within the impeller is gradually obvious, and with the increase of the gas volume fraction, the flow separation, the backflow and the vortex phenomenon within the impeller and the guide vane are gradually increased. It is also found that the flow separation has a greater influence on the turbulent dissipation within the whole flow field, that is, the more serious the area of off flow, the greater the energy loss. The results provide an important theoretical basis for the optimal design of the structure of oil-gas multiphase pump

The Interaction between the First Transmembrane Domain and the Thumb of ASIC1a Is Critical for Its N-Glycosylation and Trafficking

Acid-sensing ion channel-1a (ASIC1a), the primary proton receptor in the brain, contributes to multiple diseases including stroke, epilepsy and multiple sclerosis. Thus, a better understanding of its biogenesis will provide important insights into the regulation of ASIC1a in diseases. Interestingly, ASIC1a contains a large, yet well organized ectodomain, which suggests the hypothesis that correct formation of domain-domain interactions at the extracellular side is a key regulatory step for ASIC1a maturation and trafficking. We tested this hypothesis here by focusing on the interaction between the first transmembrane domain (TM1) and the thumb of ASIC1a, an interaction known to be critical in channel gating. We mutated Tyr71 and Trp287, two key residues involved in the TM1-thumb interaction in mouse ASIC1a, and found that both Y71G and W287G decreased synaptic targeting and surface expression of ASIC1a. These defects were likely due to altered folding; both mutants showed increased resistance to tryptic cleavage, suggesting a change in conformation. Moreover, both mutants lacked the maturation of N-linked glycans through mid to late Golgi. These data suggest that disrupting the interaction between TM1 and thumb alters ASIC1a folding, impedes its glycosylation and reduces its trafficking. Moreover, reducing the culture temperature, an approach commonly used to facilitate protein folding, increased ASIC1a glycosylation, surface expression, current density and slowed the rate of desensitization. These results suggest that correct folding of extracellular ectodomain plays a critical role in ASIC1a biogenesis and function

Ferroportin and hepcidin: a new hope in diagnosis, prognosis, and therapy for breast cancer

Breast cancer is the most prevalent malignancy in women. The success of breast cancer treatment relies on the ability to detect the disease and correct molecular abnormalities at an early stage of disease development. A recent article describes a marked decrease in the levels of ferroportin in breast cancer. More importantly, the presented results demonstrate convincingly the incredible diagnostic and prognostic value of ferroportin and hepcidin gene expression in breast cancer and suggest that determination of these two molecular markers may be used as guidance toward individualized therapy for breast cancer patients

First Measurements of eta_c Decaying into K^+K^-2(pi^+pi^-) and 3(pi^+pi^-)

The decays of eta_c to K^+K^-2(pi^+pi^-) and 3(pi^+pi^-) are observed for the first time using a sample of 5.8X10^7 J/\psi events collected by the BESII detector. The product branching fractions are determined to be B(J/\psi-->gamma eta_c)*B(eta_c-->K^+K^-pi^+pi^-pi^+pi^-)=(1.21+-0.32+- 0.23)X10^{-4}$,B(J/\psi-->gamma eta_c)*B(eta_c-->K^{*0}\bar{K}^{*0}pi^+pi^-)= (1.29+-0.43+-0.32)X10^{-4}$, and (J/\psi-->gamma eta_c)* B(eta_c-->pi^+pi^-pi^+pi^-pi^+pi^-)= (2.59+-0.32+-0.48)X10^{-4}. The upper limit for eta_c-->phi pi^+pi^-pi^+pi^- is also obtained as B(J/\psi-->gamma eta_c)*B(eta_c--> phi pi^+pi^-pi^+pi^-)< 6.03 X10^{-5} at the 90% confidence level.Comment: 11 pages, 4 figure

Resonances in J/ψ→ϕπ+π−J/\psi \to \phi \pi ^+\pi ^- and ϕK+K−\phi K^+K^-

A partial wave analysis is presented of $J/\psi \to \phi \pi ^+\pi ^-$ and $\phi K^+K^-$ from a sample of 58M $J/\psi$ events in the BES II detector. The $f_0(980)$ is observed clearly in both sets of data, and parameters of the Flatt\' e formula are determined accurately: $M = 965 \pm 8$ (stat) $\pm 6$ (syst) MeV/c$^2$, $g_1 = 165 \pm 10 \pm 15$ MeV/c$^2$, $g_2/g_1 = 4.21 \pm 0.25 \pm 0.21$. The $\phi \pi \pi$ data also exhibit a strong $\pi \pi$ peak centred at $M = 1335$ MeV/c$^2$. It may be fitted with $f_2(1270)$ and a dominant $0^+$ signal made from $f_0(1370)$ interfering with a smaller $f_0(1500)$ component. There is evidence that the $f_0(1370)$ signal is resonant, from interference with $f_2(1270)$. There is also a state in $\pi \pi$ with $M = 1790 ^{+40}_{-30}$ MeV/c$^2$ and $\Gamma = 270 ^{+60}_{-30}$ MeV/c$^2$; spin 0 is preferred over spin 2. This state, $f_0(1790)$, is distinct from $f_0(1710)$. The $\phi K\bar K$ data contain a strong peak due to $f_2'(1525)$. A shoulder on its upper side may be fitted by interference between $f_0(1500)$ and $f_0(1710)$.Comment: 17 pages, 6 figures, 1 table. Submitted to Phys. Lett.

Measurement of the Branching Fraction of J/psi --> pi+ pi- pi0

Using 58 million J/psi and 14 million psi' decays obtained by the BESII experiment, the branching fraction of J/psi --> pi+ pi- pi0 is determined. The result is (2.10+/-0.12)X10^{-2}, which is significantly higher than previous measurements.Comment: 9 pages, 8 figures, RevTex