Room-temperature quantum-dot-like luminescence from site-controlled InGaN quantum disks

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98692/1/ApplPhysLett_99_263105.pd

Steady-State Experiment and Simulation of Intake Ports in a Four-Valve Direct Injection Diesel Engine

In order to analyze intake port flow characteristics of a four-valve direct injection (DI) diesel engine, steady-state flow bench experiments and numerical simulations method were coupled to investigate the following four combined intake ports: (1) helical port (left) and tangential port (right); (2) tangential port (left) and helical port (right); (3) helical port (left) port and helical (right); and (4) tangential port (left) and tangential (right) port. Results show that the simulation of port flow coefficients matches experimental findings very well, and the port coefficients of the above four combinations do not vary much, but their swirl ratios are very different. Specifically, when the valve lift is the maximum, the swirl ratio of the combination of "helical and tangential" is the greatest among the four combinations, and the swirl ratio of "tangential and tangential" is the minimum. And the3D fluid simulation method and steady-state experiment are important means to investigate the flow characteristics of the combined intake ports

Intake Flow Interference Analysis of Combination Intake Port in Diesel Engine

In order to analyze the intake flow characteristics of a four-valve direct injection(DI) diesel engine, the experiments and numerical simulations were conducted to investigate the flow coefficient, swirl ratio and intake flow interference of the following 4 combinations of intake ports: (1) helical (left) and tangential (right), abbreviation ; (2) tangential (left) and helical (right); (3) helical (left) and helical (right); and (4) tangential (left) and tangential (right).Results show that the relative flow coefficient and swirl ratio could be directly reflect the interference of combined intake port, and when the ratio was close to 1, which showed that intake port had less interference ;and when the ratio was close to 0, which showed that the interference was serious. The relative flow coefficient of the 4 combinations of intake ports has little difference, but the relative swirl ration had significant difference in the whole valve lift range. And there had little interference between adjacent intake ports, but the swirl was strongly formed in cylinder at the maximum valve lift

Flow Field Influence Analysis of Combination Intake Port to Port and In-Cylinder for a Four-Valve Diesel Engine

Intake port structure directly affects the flow characteristics and combustion process of diesel engine, and then affects the comprehensive performance of diesel engine. To the intake ports of a four-valve direct injection diesel engine, the flow characteristics are analyzed on the four combined intake ports : (1) helical (left) and tangential (right), (2) tangential (left) and helical (right); (3) helical (left) and helical (right); and (4) tangential (left) and tangential (right).And the influence of air flow in four combined intake ports to in-cylinder gas flow is also analyzed. Results show that the helical and tangential combination intake ports flow velocity increases with the valve lift increases, and small turbulence arises at the valve guide lug, and the intake flow velocity of the minimum cross-section of the junction of the guiding section and the helical section is the maximum. The air flow in- cylinder moves from top cylinder head bottom to the cylinder bottom, the air flow is enlarged gradually by the small-scale irregular swirl, which eventually converges to a single swirl. The turbulence kinetic energy is very big when the air is just entering the cylinder, the flow space expands rapidly, and the dissipation of turbulent kinetic energy is very significant with the gas moves to the bottom of the cylinder

Correlation between an oestrogen receptor gene and reproductive traits in purebred and crossbred pig populations

The relationship between an oestrogen receptor (ESR) gene and reproductive traits in 11 Large White (LW), 19 Landrace (L), 22 Meishan (MS), 22 Meishan × Large White (MS × LW) F1, 26 Large White × Meishan (LW × MS) F1, 16 Landrace × Large White (L × LW) F1 and nine Large White × Landrace (LW × L) F1 female populations was studied. Reproductive characteristics and some performance data were analyzed for associations with ESR genotype, parity and breed. The ESR genotype was associated with length of oviduct (LO). Uterine weight (UW), LO and the weight of two ovaries (OW) of purebred Meishan and LW × MS females were higher than those of purebred Large White and MS × LW females. In Large White and Meishan crosses, crossbreds with Meishan dams had higher UW, LO, uterine horn length (LUH) and OW than pigs with Large White dams. Significant effects of paternal breed of sire were observed for LO and OW. In Large White and Landrace combinations, differences in values between purebred and crossbred animals were found for UW and LO. However, maternal breed effects were not detected for UW, LO, LUH, OW. A significant effect of paternal breed of sire was observed for LO. Females with Landrace sires had a larger LO than females with Large White sires. Keywords: Pig, ESR locus, female reproductive tract components, breed effects South African Journal of Animal Science Vol. 36 (4) 2006: pp. 243-24

Impaired Osteoblast Function in GPRC6A Null Mice

GPRC6A is a widely expressed orphan G protein–coupled receptor that senses extracellular amino acids, osteocalcin, and divalent cations in vitro. GPRC6A null (GPRC6A−/−) mice exhibit multiple metabolic abnormalities including osteopenia. To investigate whether the osseous abnormalities are a direct function of GPRC6A in osteoblasts, we examined the function of primary osteoblasts and bone marrow stromal cell cultures (BMSCs) in GPRC6A−/− mice. We confirmed that GPRC6A−/− mice exhibited a decrease in bone mineral density (BMD) associated with reduced expression of osteocalcin, ALP, osteoprotegerin, and Runx2-II transcripts in bone. Osteoblasts and BMSCs derived from GPRC6A−/− mice exhibited an attenuated response to extracellular calcium-stimulated extracellular signal-related kinase (ERK) activation, diminished alkaline phosphatase (ALP) expression, and impaired mineralization ex vivo. In addition, siRNA-mediated knockdown of GPRC6A in MC3T3 osteoblasts also resulted in a reduction in extracellular calcium-stimulated ERK activity. To explore the potential relevance of GPRC6A function in humans, we looked for an association between GPRC6A gene polymorphisms and BMD in a sample of 1000 unrelated American Caucasians. We found that GPRC6A gene polymorphisms were significantly associated with human spine BMD. These data indicate that GRPC6A directly participates in the regulation of osteoblast-mediated bone mineralization and may mediate the anabolic effects of extracellular amino acids, osteocalcin, and divalent cations in bone. © 2010 American Society for Bone and Mineral Research

Evidence for Anthropogenic Surface Loading as Trigger Mechanism of the 2008 Wenchuan Earthquake

Two and a half years prior to China's M7.9 Wenchuan earthquake of May 2008, at least 300 million metric tons of water accumulated with additional seasonal water level changes in the Minjiang River Valley at the eastern margin of the Longmen Shan. This article shows that static surface loading in the Zipingpu water reservoir induced Coulomb failure stresses on the nearby Beichuan thrust fault system at <17km depth. Triggering stresses exceeded levels of daily lunar and solar tides and perturbed a fault area measuring 416+/-96km^2. These stress perturbations, in turn, likely advanced the clock of the mainshock and directed the initial rupture propagation upward towards the reservoir on the "Coulomb-like" Beichuan fault with rate-and-state dependent frictional behavior. Static triggering perturbations produced up to 60 years (0.6%) of equivalent tectonic loading, and show strong correlations to the coseismic slip. Moreover, correlations between clock advancement and coseismic slip, observed during the mainshock beneath the reservoir, are strongest for a longer seismic cycle (10kyr) of M>7 earthquakes. Finally, the daily event rate of the micro-seismicity (M>0.5) correlates well with the static stress perturbations, indicating destabilization.Comment: 22 pages, 4 figures, 3 table

Increased co-expression of genes harboring the damaging de novo mutations in Chinese schizophrenic patients during prenatal development

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