Spectromicroscopy of Nanoscale Materials in the Tender X-Ray Regime Enabled by a High Efficient Multilayer-Based Grating Monochromator.

The combination of near edge X-ray absorption spectroscopy with nanoscale X-ray imaging is a powerful analytical tool for many applications in energy technologies, catalysis, which are critical to combat climate change, as well as microelectronics and life science. Materials from these scientific areas often contain key elements, such as Si, P, S, Y, Zr, Nb, and Mo as well as lanthanides, whose X-ray absorption edges lie in the so-called tender photon energy range 1.5-5.

[Variation of O Concentration in Different Regions of Beijing from 2006-2015].

O continuous monitoring data for the Dingling, Guanyuan, Liulihe, and Qianmen sites from 2006-2015 were analyzed to investigate concentration levels, variation trends, temporal variations, and relationships with precursors and meteorological factors. The results showed that the ten year average concentrations of O at the Dingling site were the highest at 65.2 μg·m, followed by concentrations at Liulihe (53.

[Scavenging Effect of Rime and East Wind on PM Under Air Heavy Pollution in Beijing].

In order to study the scavenging effect of rime and east wind on the concentrations of PM in Beijing during the air heavy pollution, PM concentration data of some mountains and plains stations was used, together with meteorological data, wind profile data, aerosol extinction coefficient radar data collected during December 19 to 27, 2015, to analyze the clearance mechanisms of rime and east wind on PM.The results showed that ①the removal of PM by rime was a different mechanism from that by the north wind and rainy weather, in the cooling conditions, the droplets touched the branches, wire for solid condensation, leading to formation of rime, and the concentration of PM decreased;②the east wind is a special kind of wind in Beijing area, when easterly wind decreased with height, a strong upward motion could be formed, and the PM was uplifted from the surface layer to the top, while with larger westerly wind in top, it was removed into downstream and cleaned; when east wind increased with height, a weak downward movement was easy to form, and when this sinking motion could not reach the ground, the surface layer of PM capacity became small, which was beneficial to increase the concentration of PM;③the PMscavenging ability of east wind depended on two points, one was the strength and development of upward movement of the height formed by the east wind, and the second was the initial height of uplifted motion formed by east wind, the lower the origin of the ascending motion height, the more obvious the removal of PM;④after occurrence of east wind, along with the ascending motion to m·s magnitude, the mixed layer height increased to 1200-1800 meters, and PM was uplifted to top layer and cleaned.

[Exploring the Severe Haze in Beijing During December, 2015: Pollution Process and Emissions Variation].

Severe haze episodes shrouded Beijing and its surrounding regions again during December, 2015, causing major environmental and health problems. Beijing authorities had launched two red alerts for atmospheric heavy pollution in this period, adopted a series of emergency control measures to reduce the emissions from major pollution sources. To better understand the pollution process and emissions variation during these extreme pollution events, we performed a model-assisted analysis of the hourly observation data of PM₂.

[Different Air Pollution Situations of O₃ and PM₂.₅ During Summer in Beijing].

Two different pollution situations of O₃ and PM₂.₅ during summer in Beijing were analyzed from theperspective of synoptic situations, meteorological elements, precursors, atmospheric oxidation, back-trajectories of air mass and chemical compositions of PM₂.₅.

[Temporal and spatial distribution characteristics of ozone in Beijing].

Ozone concentrations obtained from 35 automatic air monitoring stations in Beijing were analyzed to investigate their temporal and spatial distribution characteristics. A process with high ozone concentration in summer was analyzed. The results showed that ozone maintained relatively high concentration from May to August while in other months, the ozone concentration was at a low level.

[Implementation results of emission standards of air pollutants for thermal power plants: a numerical simulation].

The emission inventory of air pollutants from the thermal power plants in the year of 2010 was set up. Based on the inventory, the air quality of the prediction scenarios by implementation of both 2003-version emission standard and the new emission standard were simulated using Models-3/CMAQ. The concentrations of NO2, SO2, and PM2.

Correction method for the self-absorption effects in fluorescence extended X-ray absorption fine structure on multilayer samples.

A novel correction method for self-absorption effects is proposed for extended X-ray absorption fine structure (EXAFS) detected in the fluorescence mode on multilayer samples. The effects of refraction and multiple reflection at the interfaces are fully considered in this correction method. The correction is performed in k-space before any further data analysis, and it can be applied to single-layer or multilayer samples with flat surfaces and without thickness limit when the model parameters for the samples are known.

Significance and prognostic value of Gli-1 and Snail/E-cadherin expression in progressive gastric cancer.

Abnormal activation of the hedgehog (Hh) signaling pathway has been found to be involved in the occurrence, invasion, and metastasis of cancers. Epithelial-mesenchymal transition (EMT) also plays an important role in the invasion and metastasis of cancers. However, the significance of the Hh signaling pathway and EMT in the invasion and metastasis of gastric cancer is still unclear.

Submicrometer aluminum spheres' adhesion to planar silicon substrates.

We investigate the adhesion mechanism of aluminum spheres on a silicon substrate. Aluminum particles in the size range of 60-1500 nm were deposited onto a silicon substrate. It was found that aluminum particles underwent plastic deformation rather than elastic deformation because of van der Waals interactions.

Contact between submicrometer silica spheres.

Recently, the scope of the investigation of the deformation mechanism extended to the micrometer and submicrometer regimes. The sphere-substrate contact method was usually used because it is rather difficult to make two micrometer or submicrometer spheres contact each other precisely. Here, we used the sphere-sphere contact method via a novel, simple process to investigate the deformation of spheres.

Preparation of spherical silica particles by Stöber process with high concentration of tetra-ethyl-orthosilicate.

In this paper, Stöber process with high concentration of tetra-ethyl-orthosilicate (TEOS) up to 1.24 M is used to prepare monodisperse and uniform-size silica particles. The reactions are carried out at [TEOS]=0.

Optical nonlinearity enhancement in heterostructures with thick metallic film and truncated photonic crystals.

It is hard to use bulk metals with high nonlinear susceptibilities since they are nearly opaque. Metal-dielectric photonic crystals can be transparent, but the electric field at each metal layer is still low. We theoretically studied the nonlinear response of heterostructures composed of truncated all-dielectric photonic crystals and thick metallic films.

Design of transmission multilayer polarizer for soft X-ray using a merit function.

A new method of designing soft X-ray transmission multilayer polarizer for use at a single wavelength using a merit function has been eveloped. A merit function of product of p-transmittance throughput and logarithm of transmittance polarization ratio was chosen. Characteristics of Mo/Si multilayer calculated using the merit function at 13.