Attachment--and loss.

Cause, conseguenze e strategie di mitigazione Proponiamo il primo di una serie di articoli in cui affronteremo l’attuale problema dei mutamenti climatici. Presentiamo il documento redatto, votato e pubblicato dall’Ipcc - Comitato intergovernativo sui cambiamenti climatici - che illustra la sintesi delle ricerche svolte su questo tema rilevante.

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Climate Change 2007: The Physical Science Basis.

The detection of psychiatric illness by questionnaire

Abstract A two-dimensional version of the Pennsylvania State University mesoscale model has been applied to Winter Monsoon Experiment data in order to simulate the diurnally occurring convection observed over the South China Sea. The domain includes a representation of part of Borneo as well as the sea so that the model can simulate the initiation of convection. Also included in the model are parameterizations of mesoscale ice phase and moisture processes and longwave and shortwave radiation with a diurnal cycle. This allows use of the model to test the relative importance of various heating mechanisms to the stratiform cloud deck, which typically occupies several hundred kilometers of the domain. Frank and Cohen's cumulus parameterization scheme is employed to represent vital unresolved vertical transports in the convective area. The major conclusions are: Ice phase processes are important in determining the level of maximum large-scale heating and vertical motion because there is a strong anvil componen...

Numerical study of convection observed during the Winter Monsoon Experiment using a mesoscale two-dimensional model [presentation]

Fluorescent carbon nanoparticles or carbon quantum dots (CQDs) are a new class of carbon nanomaterials that have emerged recently and have garnered much interest as potential competitors to conventional semiconductor quantum dots. In addition to their comparable optical properties, CQDs have the desired advantages of low toxicity, environmental friendliness low cost and simple synthetic routes. Moreover, surface passivation and functionalization of CQDs allow for the control of their physicochemical properties. Since their discovery, CQDs have found many applications in the fields of chemical sensing, biosensing, bioimaging, nanomedicine, photocatalysis and electrocatalysis. This article reviews the progress in the research and development of CQDs with an emphasis on their synthesis, functionalization and technical applications along with some discussion on challenges and perspectives in this exciting and promising field.

Carbon quantum dots and their applications

The effects of vacuum pre-oxidation treatment on the isothermal and cyclic oxidation behaviour of a cold-sprayed NiCoCrAlY coating are investigated. It is found that the cold-sprayed NiCoCrAlY coating has a dense structure with low oxygen content and consists of a single γ-matrix phase. A uniform and continuous α-Al2O3 layer with a thickness of 0.47 ± 0.02 μm can be obtained by pre-oxidation treatment in a vacuum environment. The pre-oxidation treatment decreases the growth rate of thermally grown oxide by the formation of Al2O3 with larger grain sizes and thus improves the thermal cyclic life of coating. Surface-geometry imperfections are the source of initial spallation of thermally grown oxide.

Effect of pre-oxidation on the isothermal and cyclic oxidation behaviour of cold-sprayed NiCoCrAlY coating

With deep-level-transient spectroscopy (DLTS), we detected three palladium-related levels, ${E}_{c}\ensuremath{-}0.18$ eV, ${E}_{c}\ensuremath{-}0.22$ eV, and ${E}_{v}+0.33$ eV [referred to as $E(0.18)$, $E(0.22)$, and $H(0.33)$, respectively] in $n$- and $p$-type silicon. It was revealed by quenching and annealing experiments that the three levels belong to different palladium centers. The mutual transformation between the $E(0.18)$ and $E(0.22)$ centers was studied. Applying uniaxial stress to samples in the DLTS measurements, we studied the symmetries of the three palladium centers, and concluded that the $H(0.33)$ and $E(0.22)$ centers most probably have ${T}_{d}$ symmetry while the $E(0.18)$ center has ${C}_{2v}$ symmetry. The latter is most likely the negative palladium center with ${C}_{2v}$ symmetry observed by Woodbury and Ludwig Phys. Rev. 126 466 1962 with electron paramagnetic resonance in $n$-type silicon. The microstructures of the $E(0.18)$ and $E(0.22)$ centers were considered to be a palladium atom with closed $4d$ shell occupying an off-center position and an on-center one, respectively, in a vacancy.

Energy levels and symmetries of palladium centers in silicon

The cyclic freeze–thaw process has been recognized as one of the most primary factors leading to structural and function failure of concrete Strain, which may have certain inherent advantages when compared to traditional test parameters such as real-time non-destructive monitoring, which is more accurate and continuous with little error caused by manual intervention, was used to characterize the deformation and deterioration of a concrete matrix under a cyclic freeze–thaw process in this study With the cyclic freeze–thaw process, the strain hysteretic loop is raised upwards indicating that residual strain is generated in the concrete matrix The residual strain generated proves that damage in the concrete matrix is continuously accumulated and an irreversible deterioration process The variation of freeze characteristic temperature ΔTf and the apparent frost heaving coefficient Δαf defined in this study can be used to characterize the degree of freeze–thaw damage and the frost resistance of concrete, respectively Through theoretical analysis, a numerical model, which can show the relationship between concrete freeze–thaw damage and residual strain has been deducted and verified, which indicates that residual strain can be used to characterize the frost resistance of concrete subjected to a cyclic freeze–thaw process such as traditional parameters Moreover, the residual strain generated in 35 wt% NaCl solution is larger than in water, showing that chloride attack accelerates the freeze–thaw damage of concrete

Deformation of a concrete matrix subject to a cyclic freeze–thaw process

Dendritic coarsening of gamma ' phase in a directionally solidified superalloy during 24,000h of exposure at 1173 K

Ten nitrated polycyclic aromatic hydrocarbons (nPAHs) and 4 oxygenated polycyclic aromatic hydrocarbons (oPAHs) in fine particulate matter (PM2.5) samples from Mount Tai were analyzed during summer (June to August), 2015. During the observation campaign, the mean concentration of total nPAHs and oPAHs was 31.62 pg/m3 and 0.15 ng/m3, respectively. Two of the monitored compounds, namely 9-nitro-anthracene (9N-ANT) (6.86 pg/m3) and 9-fluorenone (9FO) (0.05 ng/m3) were the predominant compounds of nPAHs and oPAHs, respectively. The potential source and long-range transportation of nPAHs and oPAHs were investigated by the positive matrix factorization (PMF) method and the potential source contribution function (PSCF) methods. The results revealed that biomass/coal burning, gasoline vehicle emission, diesel vehicle emission and secondary formation were the dominant sources of nPAHs and oPAHs, which were mainly from Henan province and Beijing-Tianjin-Hebei region and Bohai sea. The incremental life cancer risk (ILCR) values were calculated to evaluate the exposure risk of nPAHs and oPAHs for three group people (infant, children and adult), and the values of ILCR were 7.02 × 10−10, 3.49 × 10−9 and 1.41 × 10−8 for infant, children and adults, respectively. All these values were lower than the standard of EPA (Environmental Protection Agency) (

Fine particle-bound PAHs derivatives at mountain background site (Mount Tai) of the North China: Concentration, source diagnosis and health risk assessment.

Lei Wang

Papers

Effect of pre-oxidation on the isothermal and cyclic oxidation behaviour of cold-sprayed NiCoCrAlY coating

Energy levels and symmetries of palladium centers in silicon

Deformation of a concrete matrix subject to a cyclic freeze–thaw process

Dendritic coarsening of gamma ' phase in a directionally solidified superalloy during 24,000h of exposure at 1173 K

Fine particle-bound PAHs derivatives at mountain background site (Mount Tai) of the North China: Concentration, source diagnosis and health risk assessment.