Synthesis of Diarylthiobarbituric acid Chromophores with Enhanced Second-order Optical Nonlinearities and Thermal Stability

In summary, the compounds reported here demonstrate that it is possible to design chromophores that simultaneously exhibit large nonlinearity and good thermal stability. Furthermore, with the synthesis of bis(4-hydroxyphenyl)thiobarbituric acid, we believe that it should be possible to covalently incorporate these and other rather nonlinear chromophores into poled polymers at high concentrations. Experiments to test this hypothesis are in progress

Statistical Correlation between the Distribution of Lyα Emitters and Intergalactic Medium Hi at z∼2.2 Mapped by the Subaru/Hyper Suprime-Cam

The correlation between neutral Hydrogen (HI) in the intergalactic medium (IGM) and galaxies now attracts great interests. We select four fields which include several coherently strong Ly$\alpha$ absorption systems at $z\sim2.2$ detected by using background quasars from the whole SDSS/(e)BOSS database. Deep narrow-band and $g$-band imaging are performed using the Hyper Suprime-Cam on the Subaru Telescope. We select out 2,642 Ly$\alpha$ emitter (LAE) candidates at $z=2.177\pm0.023$ down to the Ly$\alpha$ luminosity of $L_{\text{Ly}\alpha}\approx 2 \times 10^{42} {\rm erg~s}^{-1}$ to construct the galaxy overdensity maps, covering an effective area of 5.39 deg$^2$. Combining the sample with the Ly$\alpha$ absorption estimated from 64 (e)BOSS quasar spectra, we find a moderate to strong correlation between the LAE overdensity $\delta_{\rm LAE}$ and the effective optical depth $\tau_{\rm LoS}$ in line-of-sights, with $P$-value$=0.09\%$ ($<0.01\%$) when the field that contains a significant quasar overdensity is in(ex)cluded. The cross-correlation analysis also clearly suggests that up to $4\pm1$ pMpc, LAEs tend to cluster in the regions rich in HI gas, indicated by the high $\tau_{\rm LoS}$, and avoid the low $\tau_{\rm LoS}$ region where the HI gas is deficient. By averaging the $\tau_{\rm LoS}$ as a function of the projected distance ($d$) to LAEs, we find a $30\%$ excess signal at $2\sigma$ level at $d<200$ pkpc, indicating the dense HI in circumgalactic medium, and a tentative excess at $400<d<600$ pkpc in IGM regime, corroborating the cross-correlation signal detected at about $0.5$ pMpc. These statistical analyses indicate that galaxy$-$IGM HI correlations exist on scales ranging from several hundred pkpc to several pMpc at $z\sim2.2$.Comment: 27 pages, 15 figures; Resubmitted to ApJ after the first referee's report. Comments are welcom

Synthesis of Diarylthiobarbituric acid Chromophores with Enhanced Second-order Optical Nonlinearities and Thermal Stability

In summary, the compounds reported here demonstrate that it is possible to design chromophores that simultaneously exhibit large nonlinearity and good thermal stability. Furthermore, with the synthesis of bis(4-hydroxyphenyl)thiobarbituric acid, we believe that it should be possible to covalently incorporate these and other rather nonlinear chromophores into poled polymers at high concentrations. Experiments to test this hypothesis are in progress

Direct Electrochemistry and Electrocatalysis of Hemoglobin at Mesoporous Carbon Modified Electrode

The novel highly ordered mesoporous carbon (known as FDU-15), prepared by the organic-organic self-assembly method was been used for first time for the immobilization of hemoglobin (Hb) and its bioelectrochemical properties were studied. The resulting Hb/FDU-15 film provided a favorable microenvironment for Hb to perform direct electron transfers at the electrode. The immobilized Hb also displayed its good electrocatalytic activity for the reduction of hydrogen peroxide. The results demonstrate that mesoporous carbon FDU-15 can improve the Hb loading with retention of its bioactivity and greatly promote the direct electron transfer, which can be attributed to its high specific surface area, uniform ordered porous structure, suitable pore size and biocompatibility. Our present study may provide an alternative way for the construction of nanostructure biofunctional surfaces and pave the way for its application to biosensors

Clinical and Epidemiologic Research Prevalence of and Risk Factors for Pterygium in Rural Adult Chinese Populations of the Bai Nationality in Dali: The Yunnan Minority Eye Study

PURPOSE. The purpose of the study was to describe the prevalence, severity, and associated risk factors for pterygium in a population-based sample of rural residents of the Bai minority population in rural Dali, China. METHODS. A population-based survey of Chinese Bai Nationality aged ‡50 years from randomly selected block groups in southwestern China was conducted. A clinical examination by experienced ophthalmologists was carried out, and the presence of pterygium was diagnosed at the examination. Pterygium was graded clinically by slit lamp examination. Questionnaires were conducted on risk factors. RESULTS. From a total of 2742 eligible subjects, 2133 (77.8%) were examined. CONCLUSIONS. The prevalence of pterygium in Dali is 39.0% among Chinese Bai aged 50 years and older. Independent associations with increasing age (&gt;59 years), female sex, lack of education, and occupations linked to outdoor work suggest a multifactorial cause of this condition. (Invest Ophthalmol Vis Sci. 2012;53:6617-6621

Wide Band Series Switch Fabricated Using Metal As Sacrificial layer

Series switches with metal-to-metal contact have been fabricated to operate from dc to 40 GHz. The insertion loss has been measured to be less than 0.4 dB at 5 GHz and 0.8 dB at 40 GHz when switch is on and the isolation ranges from 38 dB at 2 GHz to 15 dB at 40 GHz when the switch is off. The results agree well with simulation by Zeland IE3D. Cantilever beam is used as the mechanical structure and CPW line works as the transmission line. The cantilever is made of SiO2 and Al is used as the sacrificial layer