Academia Sinica

About: Academia Sinica is a facility organization based out in Taipei, Taiwan. It is known for research contribution in the topics: Population & Galaxy. The organization has 52086 authors who have published 65998 publications receiving 1728114 citations. The organization is also known as: Central Research Academy.

CFHTLenS: the Canada-France-Hawaii Telescope Lensing Survey

Abstract: We present the Canada–France–Hawaii Telescope Lensing Survey (CFHTLenS) that accurately determines a weak gravitational lensing signal from the full 154 deg^2 of deep multicolour data obtained by the CFHT Legacy Survey. Weak gravitational lensing by large-scale structure is widely recognized as one of the most powerful but technically challenging probes of cosmology. We outline the CFHTLenS analysis pipeline, describing how and why every step of the chain from the raw pixel data to the lensing shear and photometric redshift measurement has been revised and improved compared to previous analyses of a subset of the same data. We present a novel method to identify data which contributes a non-negligible contamination to our sample and quantify the required level of calibration for the survey. Through a series of cosmology-insensitive tests we demonstrate the robustness of the resulting cosmic shear signal, presenting a science-ready shear and photometric redshift catalogue for future exploitation.

Paleozoic accretion and Cenozoic redeformation of the Chinese Tien Shan Range, central Asia

Abstract: The Tien Shan Range in central Asia contains two late Paleozoic sutures. The older, southern suture marks the collision of a passive margin at the north of the Tarim block and an active continental margin; subduction under the latter was to the north. The younger, northern suture separates a northern Carboniferous island arc from an active continental margin developed over a south-dipping subduction zone. The subduction direction under the island arc is unknown. Mesozoic elastics were deposited over the doubly sutured orogen. Rate and energy of sedimentation waned until deposition of Oligocene conglomerates above a regional unconformity-interpreted as marking the onset of deformation induced by the India-Asia collision. Molasse deposition accelerated in Pliocene and Quaternary time, and deposition continues today as active thrusts generate relief. Paleozoic structures control the gross divergence of Cenozoic thrusts across the orogen.

Highly conductive PEDOT:PSS electrode by simple film treatment with methanol for ITO-free polymer solar cells

Abstract: We proposed a simple yet robust film treatment method with methanol having only one hydroxyl group to enhance the conductivity of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) by four orders of magnitude. Different methods of film treatment: immersing PEDOT:PSS film in the methanol solution; dropping methanol on the film; and a combination of these are employed and the results are compared. The conductivity of PEDOT:PSS films was enhanced from 0.3 S cm−1 to 1362 S cm−1 after film treatment with methanol. Other alcohols like ethanol and propanol were also used to treat the PEDOT:PSS film and showed inferior conductivity enhancement compared to methanol. The conductivity enhancement was greatly affected by the hydrophilicity and dielectric constant of the alcohols used. The mechanism of conductivity enhancement was investigated through various characterization techniques including FTIR, XPS and AFM. Removal of the insulator PSS from the film, and morphology and conformational changes are the mechanisms for the conductivity enhancement. The treated films also showed high transmittance and low sheet resistance desirable for a standalone electrode. ITO-free polymer solar cells were fabricated using PEDOT:PSS electrodes treated with methanol and showed almost equal performance to ITO electrodes.

Evidence for a narrow S = +1 baryon resonance in photoproduction from the neutron.

Abstract: The $\ensuremath{\gamma}n\ensuremath{\rightarrow}{K}^{+}{K}^{\ensuremath{-}}n$ reaction on $^{12}\mathrm{C}$ has been studied by measuring both ${K}^{+}$ and ${K}^{\ensuremath{-}}$ at forward angles. A sharp baryon resonance peak was observed at $1.54\ifmmode\pm\else\textpm\fi{}0.01\text{ }\text{ }\mathrm{G}\mathrm{e}\mathrm{V}/{c}^{2}$ with a width smaller than $25\text{ }\text{ }\mathrm{M}\mathrm{e}\mathrm{V}/{c}^{2}$ and a Gaussian significance of $4.6\ensuremath{\sigma}$. The strangeness quantum number ($S$) of the baryon resonance is $+1$. It can be interpreted as a molecular meson-baryon resonance or alternatively as an exotic five-quark state ($uudd\overline{s}$) that decays into a ${K}^{+}$ and a neutron. The resonance is consistent with the lowest member of an antidecuplet of baryons predicted by the chiral soliton model.

CFHTLenS tomographic weak lensing cosmological parameter constraints: Mitigating the impact of intrinsic galaxy alignments

Abstract: We present a finely-binned tomographic weak lensing analysis of the Canada-FranceHawaii Telescope Lensing Survey, CFHTLenS, mitigating contamination to the signal from the presence of intrinsic galaxy alignments via the simultaneous fit of a cosmological model and an intrinsic alignment model. CFHTLenS spans 154 square degrees in five optical bands, with accurate shear and photometric redshifts for a galaxy sample with a median redshift of zm = 0:70. We estimate the 21 sets of cosmic shear correlation functions associated with six redshift bins, each spanning the angular range of 1:5 < < 35 arcmin. We combine this CFHTLenS data with auxiliary cosmological probes: the cosmic microwave background with data from WMAP7, baryon acoustic oscillations with data from BOSS, and a prior on the Hubble constant from the HST distance ladder. This leads to constraints on the normalisation of the matter power spectrum 8 = 0:799 0:015 and the matter density parameter m = 0:271 0:010 for a flat CDM cosmology. For a flat wCDM cosmology we constrain the dark energy equation of state parameter w = 1:02 0:09. We also provide constraints for curved CDM and wCDM cosmologies. We find the intrinsic alignment contamination to be galaxy-type dependent with a significant intrinsic alignment signal found for early-type galaxies, in contrast to the late-type galaxy sample for which the intrinsic alignment signal is found to be consistent with zero.