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A new species of Begonia (B. lecongkietii N.S.Lý & M.Hughes) is described from Mount Dầu in the South Central Coast Region, Vietnam, an area with an abundance of recently described endemic plant taxa. The new species is allied to Begonia lamxayana Souvann., which occurs 600 km away in Laos, differing chiefly in having larger villose tepals with an undulate margin and larger androecium with 86–116 (versus 20–30) stamens. Begonia lecongkietii is considered Critically Endangered, owing to its small area of occupancy and decline of habitat quality.
With rapid and accelerated Arctic sea-ice loss, it is beneficial to update and baseline historical change on the regional scales from a consistent, intercalibrated, long-term time series of sea-ice data for understanding regional vulnerability and monitoring ice state for climate adaptation and risk mitigation. In this paper, monthly sea-ice extents (SIEs) derived from a passive microwave sea-ice concentration climate data record for the period of 1979–2015, are used to examine Arctic-wide and regional temporal variability of sea-ice cover and their decadal trends for 15 regions of the Arctic. Three unique types of SIE annual cycles are described. Regions of vulnerability within each of three types to further warming are identified. For the Arctic as a whole, the analysis has found significant changes in both annual SIE maximum and minimum, with −2.41 ± 0.56% per decade and −13.5 ± 2.93% per decade change relative to the 1979–2015 climate average, respectively. On the regional scale, the calculated trends for the annual SIE maximum range from +2.48 to −10.8% decade−1, while the trends for the annual SIE minimum range from 0 to up to −42% decade−1.
755 CCD observations during the years 2014-2016 have been reduced to derive the precise positions of Triton, the first satellite of Neptune. The observations were made by the 1 m telescope at Yunnan Observatory over 15 nights during the years 2014-2016. The theoretical position of Triton was retrieved from the Jet Propulsion Laboratory Horizons system. Our results show that when the newest Gaia catalogue (Gaia DR1) is referred to the mean O-Cs (observed minus computed) residuals are about 0.042 and -0.006 arcsec, the dispersions are 0.012 and 0.012 arcsec in right ascension and declination, respectively. The dispersions are improved very significantly when the Gaia DR1 is referred to. However, the agreement in right ascension is not so good as that in declination, the reason might come from the uncertainty of planet ephemeris. More observations are needed to confirm this.
The Gaia DR1 catalogue stars are taken as reference ones to reduce the Cassini ISS images of Enceladus in 2015, and a total of 494 Cassini-centered astrometric observation are obtained in right ascension(α) and declination (δ) in the international Celestial Reference Frame(ICRF). Compared with JPL ephemerides SAT367, we derive that their mean residuals are a few tens meters in α*cos(δ) and a few kilometers in δ, and their standard deviation is not over 2 kilometers. Compared with the results from UCAC4 catalogue stars, The Gaia DR1 has the equivalent precision of reduction.
The study of supernovae (SNe) and their environments in host galaxies at the highest possible angular resolution in a number of wavelength regimes is providing vital clues to the nature of their progenitor stars. We are observing SNe in the radio using the Very Large Array (VLA) and VLBI, in the X-rays with Chandra, and in the optical at the subarcsecond resolution of HST.
Recent progress in large scale computations of photoionization cross sections, radiative transitions probabilities, and collision strengths for the lowest ionization stages of Iron, i.e., Fe I-VI, are reported. These results are part of an international collaboration called the IRON Project. The present results exhibit large differences with respect to data currently in use and is expected to be of importance in the study of astrophysical objects in the UV and the EUV.
Fertilizer application can play an important role in soil organic carbon (SOC) retention and dynamics. The mechanisms underlying long-term accumulation and protection of SOC in intensive maize cropping systems, however, have not been well documented for cool high-latitude rainfed areas. Based on a 23-year fertilization experiment under a continuous maize cropping system at Gongzhuling, Jilin Province, China, the effects of fertilization regimes on SOC content and soil aggregate-associated carbon (C) composition were investigated. Results showed that, within the 0–1·0 m soil profile, SOC contents decreased significantly with soil depth in all treatments. In the topsoil layer (0–0·2 m), SOC concentrations in balanced inorganic fertilizers plus farmyard manure (MNPK), fallow system (FAL) and balanced inorganic fertilizers plus maize straw residue (SNPK) treatments were significantly greater than initial levels by 61·0, 34·1 and 20·1%, respectively. The MNPK and SNPK treatments increased SOC content by 50·7 and 12·4% compared to the unfertilized control in the topsoil layer, whereas no significant differences were found between balanced inorganic nitrogen, phosphorus and potassium fertilizers (NPK) and the unfertilized control treatment. There were no significant differences in aggregate-size distribution among the unfertilized control, NPK and MNPK treatments, whereas the SNPK treatment significantly enhanced the formation of micro-aggregates (53–250 μm) and decreased the formation of silt+clay aggregates (<53 μm) compared to the unfertilized control, NPK and MNPK treatments. Moreover, SOC concentrations in all aggregate fractions in the MNPK treatment were the highest among treatments. Furthermore, the MNPK treatment significantly increased SOC stock in micro- and silt+clay aggregates, which may slow down C decomposition in the soil. These results indicate that long-term manure amendment can benefit SOC sequestration and stability in the black soil of Northeast China.
Testing for causality is of critical importance for many econometric applications. For bivariate AR(1) processes, the limit distributions of causality tests based on least squares estimation depend on the presence of nonstationary processes. When nonstationary processes are present, the limit distributions of such tests are usually very complicated, and the full-sample bootstrap method becomes inconsistent as pointed out in Choi (2005, Statistics and Probability Letters 75, 39–48). In this paper, a profile empirical likelihood method is proposed to test for causality. The proposed test statistic is robust against the presence of nonstationary processes in the sense that one does not have to determine the existence of nonstationary processes a priori. Simulation studies confirm that the proposed test statistic works well.
Aberrant functional connectivity within the default network is generally assumed to be involved in the pathophysiology of obsessive compulsive disorder (OCD); however, the genetic risk of default network connectivity in OCD remains largely unknown.
Here, we systematically investigated default network connectivity in 15 OCD patients, 15 paired unaffected siblings and 28 healthy controls. We sought to examine the profiles of default network connectivity in OCD patients and their siblings, exploring the correlation between abnormal default network connectivity and genetic risk for this population.
Compared with healthy controls, OCD patients exhibited reduced strength of default network functional connectivity with the posterior cingulate cortex (PCC), and increased functional connectivity in the right inferior frontal lobe, insula, superior parietal cortex and superior temporal cortex, while their unaffected first-degree siblings only showed reduced local connectivity in the PCC.
These findings suggest that the disruptions of default network functional connectivity might be associated with family history of OCD. The decreased default network connectivity in both OCD patients and their unaffected siblings may serve as a potential marker of OCD.
In this paper, we review some recent results on the stochastic comparison of order statistics and related statistics from independent and heterogeneous proportional hazard rates models, gamma variables, geometric variables, and negative binomial variables. We highlight the close connections that exist between some classical stochastic orders and majorization-type orders.
First of all, we express our sincere thanks to all the discussants for their valuable comments and suggestions as well as for their own significant contributions to the area of order statistics in general, and to the topic of stochastic comparison in particular. We shall now provide our response to the comments and suggestions of all the discussants.
We conduct a comparative study mainly on two types of nc-Si based solar cell structures, a-Si/a-SiGe/nc-Si triple-junction and a-Si/nc-Si double-junction. We have attained comparable initial efficiency for the both solar cell structures, 10.8∼11.8% initial total area efficiency (85 - 95W over an area of 0.79 m2). For better compatibility to our installed manufacturing equipment, we deposit a-Si and a-SiGe component cells with the existing deposition machines. Only nc-Si bottom component cells are prepared in separate deposition machines tailored for nc-Si process. Material properties of nc-Si and TCO films are also studied by Raman spectra, SEM, and AFM.
In-situ transmission electron microscopy (TEM) method is powerful in a way that it can directly correlate the atomic-scale structure with physical and chemical properties. We will report on the construction and applications of the homemade in-situ TEM electrical and optical holders. Electrical transport of carbon nanotubes and photoconducting response on bending of individual ZnO nanowires have been studied inside TEM. Oxygen vacancy electromigration and its induced resistance switching effect have been probed in CeO2 films.
We report here on the coupling of a gas reactor with a VUV beamline at the SOLEIL
synchrotron radiation facility. The reactor may be irradiated window-less with gas
pressure up to the atmosphere. The photochemistry is monitored by a mass spectrometer gas
analyzer. This set up, termed APSIS for Atmospheric Photochemistry SImulated by
Synchrotron, has been used to simulate the atmosphere of Titan and to study the formation
of the photochemical smog and the formation of tholins.
Fullerene chemistry is booming, but how the chemical reactions affect fullerene's materials properties has seldom been studied. We have investigated optical limiting behavior of a series of fullerene derivatives, polymers, and glasses and have observed the following structure-property relationships for optical limiting in the fullerene materials: (i) The fullerene polymers with aromatic and chlorine moieties, i.e., C60-containing polycarbonate (C60-PC), polystyrene (C60- PS), and poly(vinyl chloride) (C60-PVC), limit the 8-ns pulses of 532-nm laser light more effectively than does the parent C60; (ii) the fullerene polymers with carbonyl groups, i.e., C60- containing CR-39 (C60-CR-39) and poly(methyl methacrylate), (C60-PMMA), do not enhance C60's limiting power; and (iii) the aminated fullerene derivatives, i.e., HxC60 (NHR)x [R = -(CH2CH2O)2H (1), x = 11; -(CH2)6OH (2), x = 7; -cyclo-C6H11 (3), x = 11; -(CH2)3Si(OC2H5)3 (4), x = 4], and their sol-gel glasses, i.e., 1–3/SiO2 (physical blending) and 4-SiO2 (chemical bonding), show complex limiting responses, with 4(-SiO2) performing consistently better than 1-3(/SiO2). The fullerene glasses are optically stable and their optical limiting properties remainunchanged after being subjected to continuous attack by the strong laser pulses for ca. 1 h.
Assuming that the timescale of the magnetic field decay is approximately equal to that of the stellar cooling via neutrino emission, we obtain a one-to-one relationship between the effective surface thermal temperature and the inner temperature. The ratio of the effective neutrino luminosity to the effective X-ray luminosity decreases with decaying magnetic field.
Titanium dioxide (TiO2) nanomaterials, as important photocatalysis materials, have been synthesized with many approaches. In this study, we reported the synthesis of TiO2 nanomaterials by reacting titanium isopropoxide with ethylene glycol under basic condition followed by calcination at high temperatures. The structural, optical, and photocatalytic properties of the TiO2 nanomaterials were studied with x-ray diffraction, Raman spectroscopy, transmission electron microscopy, differential scanning calorimetry, Fourier-transformed infrared spectroscopy, x-ray and ultraviolet (UV) photoemission spectroscopy, UV–vis diffusive reflectance, and photocatalytic decomposition of methylene blue. We found that the titanium ethylene glycolide decomposes at 330 °C and transforms into pure anatase TiO2 around 400 °C. The anatase phase further transforms into core/shell rutile/anatase TiO2 composite at 550 °C and displays the highest photocatalytic activity among the samples prepared. The high photocatalytic activity can be attributed to the improved charge separation at the rutile/anatase n/n junction interface and the high crystallinity of the sample after calcination.