EVALUATION OF HEAVY METALS AROUND THE MINING OF DECORATIVE STONE ORE IN SUSONG COUNTY LIAOHE RIVER

In order to study the pollution of heavy metals around Liaohe Fender stone mine in Susong County, the soils at six points and the sediment at four points were selected. The effects of heavy metals Cu, Zn, Pb, Cd, Cr , Ni ,Hg and As were measured, the single factor index and the Nemero index method were used to evaluate the heavy metal elements in soil and sediment. The results showed that the values of heavy metal elements in the soil and sediment were less than 1 and the Pintegrated values were less than 0.85,the mine area was not polluted by heavy metals and belonged to the clean area within the grade Ⅰ

On the Unusual Amber Coloration of Nanoporous Sol-gel Processed Al-doped Silica Glass: An Experimental Study

Silica is the most abundant component on the earth’s surface. It plays an important role in many natural processes. Silica is also a critical material for a wide range of technical applications such as in optics and electronics. In this work, we discuss our recent experimental observation of the unusual amber coloration of aluminum doped sol-gel glass that has not been reported in the past. We characterized Al-doped sol-gel glasses, prepared at different sintering temperature, using a plethora of techniques to investigate the origin of this unusual coloration and to understand their structural and chemical properties. We used these experimental results to test a number of possible coloring mechanisms. The results suggested this coloring is likely caused by temperature-dependent aluminum-associated defect centers associated with different amorphous-to-crystalline ratios of the annealed sol-gel silica glass structures

Weikangning Therapy in Functional Dyspepsia and the Protective Role of Nrf2

Functional dyspepsia (FD) is a non-organic gastro-intestinal disorder that has a marked negative impact on quality of life. Compared with conventional pharmacological therapies, the traditional Chinese medicine weikangning (WKN) is a safe and effective treatment for FD. The present study aimed to determine the molecular mechanisms underlying the efficacy of WKN. The effect of different concentrations of WKN on the proliferation of the human gastric mucosal epithelial cell line GES-1 was assessed. The optimal WKN concentration to promote cell proliferation was determined, and this concentration was used to examine the effect of WKN compared with a domperidone-treated positive control group on the antioxidant capacity of GES-1 cells. The effect of WKN treatment on the growth and antioxidant activity of GES-1 cells was also assessed following nuclear factor erythroid 2 like 2 (Nrf2) knockdown. The optimal WKN dose for promoting cell growth was determined to be 0.025 mg/ml; at this concentra-tion the expression of the antioxidant proteins glutathione S-transferase P and superoxide dismutase 2 (SOD2) were significantly elevated (

Oxide dispersion strengthened 304L stainless steel produced by ink jetting and laser powder bed fusion

This paper discusses the fundamentals of a novel hybrid method to synthesize oxide dispersion strengthened (ODS) 304 L stainless steel (SS) alloy using a modified laser powder bed fusion (LPBF) machine. Previously, ODS metal matrix composites have been produced by LPBF via ball-milling, which is expensive to scale. Here, we selectively dope yttria nanoparticles into a SS matrix by jetting a precursor chemistry onto the SS substrate prior to laser conversion and consolidation. The new alloy shows good room temperature mechanical properties. Microstructures are studied using electron microscopy, energy dispersive spectroscopy and electron backscatter diffraction

Selective laser melting of austenitic oxide dispersion strengthened steel: Processing, microstructural evolution and strengthening mechanisms

Oxide dispersion strengthened (ODS) alloys exhibit superior mechanical properties due to the presence of nano-sized thermally stable oxide particles. However, manufacturing of ODS alloys is very complex and composed of numerous time consuming steps such as mechanical alloying, which is one of the main barriers toward the widespread application of ODS alloys. Light mixing of 304L stainless steel powder with sub-micrometer size yttria particles was coupled with selective laser melting (SLM) to produce 304L ODS nanocomposite. The added yttria was dissolved in the matrix due to the high intensity of the laser and altered the rheological properties of the melt and caused balling effect. The SLM 304L ODS alloy presented cellular substructure with a uniform dispersion of yttrium silicate (Y–Si–O) spherical nanoparticles, range 10–80 nm. As a result, the SLM 304L ODS alloy showed a high ultimate tensile strength of ~700 MPa, ductility of ~32% and microhardness of ~350 HV. The underlying mechanism for this strength and ductility improvement are identified. This study provides deep insight into an alternative method of producing ODS alloys with fewer steps and capable of manufacturing complex design geometries