Quantum mechanical photon-count formula derived by entangled state representation

By introducing the thermo entangled state representation, we derived four new photocount distribution formulas for a given density operator of light field. It is shown that these new formulas, which is convenient to calculate the photocount, can be expressed as such integrations over Laguree-Gaussian function with characteristic function, Wigner function, Q-function, and P-function, respectively.Comment: 5 pages, no figur

Mechanical cooling at the bistable regime of a dissipative optomechanical cavity with a Kerr medium

In this paper, we study static bistability and mechanical cooling of a dissipative optomechanical cavity filled with a Kerr medium. The system exhibits optical bistability for a wide input-power range with the power threshold being greatly reduced, in contrast to the case of purely dissipative coupling. At the bistable regime, the membrane can be effectively cooled down to a few millikelvin from the room temperature under the unresolved sideband condition, where the effective mechanical temperature is a nonmonotonic function of intracavity intensity and reaches its minimum near the turning point of the upper stable branch. When the system is in the cryogenics environment, the effective mechanical temperature at the bistable regime shows a similar feature as in the room temperature case, but the optimal cooling appears at the monostable regime and approaches the mechanical ground state. Our results are of interest for further understanding bistable optomechanical systems, which have many applications in nonclassical state preparations and quantum information processing.Comment: 10 pages, 5 figure

Association between TGFBR1*6A and osteosarcoma: A Chinese case-control study

<p>Abstract</p> <p>Background</p> <p>TGFBR1*6A is a common hypomorphic variant of transforming growth factor β receptor 1 (TGFBR1). TGFBR1*6A is associated with an increased cancer risk, but the association of this polymorphism with osteosarcoma remains unknown. We have measured the frequency of TGFBR1*6A variants in osteosarcoma cases and controls.</p> <p>Methods</p> <p>Our case-control study is based on 168 osteosarcoma patients and 168 age- and gender-matched controls. Blood samples were obtained and the TGFBR1*6A variant determined by PCR amplification and DNA sequencing. The odds ratio (OR) and 95% confidence interval (95% CI) for the TGFBR1*6A polymorphism were calculated by unconditional logistic regression, adjusted for both age and gender. Three models - dominant, additive and recessive - were used to analyze the contribution of the TGFBR1*6A variant to osteosarcoma susceptibility.</p> <p>Results</p> <p>Heterozygotic and homozygotic TGFBR1*6A variants represented 50.4% and 6.0% of the 168 cases, whereas the controls had 18. 5% and 1.3%, respectively. ORs for homozygosity and heterozygosity of the TGFBR1*6A allele were 4.6 [95% CI, 2.33-7.97] and 2.9 [95% CI, 1.59-5.34] in the additive model. There were significant increases in the TGFBR1*6A variants in osteosarcoma cases compared to control in all 3 models. Further analysis showed that TGFBR1*6A genotypes were not associated with gender, age, or tumor location. However, TGFBR1*6A was significantly associated with less metastasis.</p> <p>Conclusions</p> <p>TGFBR1*6A, a dominant polymorphism of TGFBR1, is associated with increased susceptibility and metastasis spread of osteosarcoma.</p

The Investigation of NOx Formation and Reduction during O2/CO2 Combustion of Raw Coal and Coal Char

AbstractThis study investigated the behavior of NOx emissions during combustion of pulverized coal char and pulverized raw coal in O2/CO2 environments under nearly isothermal condition in a drop tube furnace. A representative Chinese coal Ling Nancang (LNC) and LNC CO2-char (made in CO2 condition) were studied with four different excess oxygen ratios (α=0.6, 0.8, 1.2, and 1.4). Combustion experiments were performed with an elevated concentration (850ppm) of NO. When α increased from 0.6 to 1.4, the total amount of NOx reduction was increased in both pulverized coal and char combustion. To investigate the effects of coal and char on NOx reburn reactions, LNC coal char and the raw coal combustion experiments were also performed under three high background NO concentrations (400, 850, and 1200ppm) in O2/CO2 atmosphere. During experiments with elevated NO concentrations, there was an increase in net NO reduction; however, there was also a decrease in the calculated NO reduction ratio