[Characteristics of Soil Selenium-cadmium Migration and Accumulation and Its Bioeffectiveness in Typical Geological High Background Area].

The prevalence of selenium-cadmium （Se-Cd） symbiosis in soils of geologically high background areas directly affects the safe utilization of Se-rich land resources. To investigate the migration and accumulation characteristics and bio-effectiveness of Se-Cd in the soil-crop system in typical geological high background areas of Southwest China and to realize the safe use of natural Se-rich land resources in geological high background areas, we collected 84 samples of agricultural crops （maize） and their supporting root systems and analyzed the Se-Cd content and physicochemical properties. Se-Cd accumulation characteristics, influencing factors, and bio-effectiveness of the soil-crop system were evaluated using geostatistics, bioenrichment factors, and geographic detectors.

[Potential Ecological Risk Assessment and Source Analysis of Heavy Metals in Soil-crop System in Xiong'an New District].

In order to evaluate the distribution characteristics of fluorine geochemistry in the surface soil and human health risk in Xiong'an New District, GIS spatial analysis and correlation analysis were used to analyze the depleted and enriched features and influencing factors of soil fluoride and to carry out the soil fluoride health risk assessment. The uncertainty of the health risk assessment results was studied based on the Monte Carlo stochastic simulation. The results showed that the average content of fluorine was 641 mg·kg, which was 1.

Temperature-Dependent Absorption of Ternary HfSSe 2D Layered Semiconductors.

In this study, we present the investigation of optical properties on a series of HfSSe crystals with different Se compositions x changing from 0 to 2. We used the chemical-vapor transport method to grow these layered ternary compound semiconductors in bulk form. Their lattice constants and crystal properties were characterized by X-ray diffraction, high-resolution transmission electron microscopy, and Raman spectroscopy.

Temperature Dependent Excitonic Transition Energy and Enhanced Electron-Phonon Coupling in Layered Ternary SnSSe Semiconductors with Fully Tunable Stoichiometry.

In this study, a series of SnSSe (0 ≤ x ≤ 2) layered semiconductors were grown by the chemical-vapor transport method. The crystal structural and material phase of SnSSe layered van der Waals crystals was characterized by X-ray diffraction measurements and Raman spectroscopy. The temperature dependence of the spectral features in the vicinity of the direct band edge excitonic transitions of the layered SnSSe compounds was measured in the temperature range of 20-300 K using the piezoreflectance (PzR) technique.

[Characteristics and Origins of Heavy Metals in Soil and Crops in Mountain Area of Southern Sichuan].

Excessive heavy metals in soils and crops will affect the human living environment and health. In order to study the enrichment characteristics and causes of heavy metals in soils and crops in a mountainous area of southern Sichuan, 1699 cultivated soil samples, 30 rice seed samples, 31 corn seed samples, 15 tea samples, and 76 crop root soil samples were collected. The enrichment characteristics and origins of heavy metals in the soil were studied using mathematical statistics, principal component analysis, and correlation analysis.

[Potential Ecological Risk Assessment and Source Analysis of Heavy Metals in Soil-crop System in Xiong'an New District].

In order to evaluate the potential ecological risk of heavy metals in the soil-crop system in the Xiong'an New District, the heavy metal contents and forms in wheat seed and root soil samples are analyzed, and the comprehensive pollution index (IPI), potential ecological risk index (RI), bio-enrichment coefficient (BFC), risk assessment code (RAC), principal component analysis, and correlation analysis are used to assess the potential ecological risk of heavy metals and analyze their sources. The results indicate that the average content of Cd, Cu, Pb, and Zn in the root soil is significantly higher than the soil background value in Hebei province. The IPI ranges from 0.

[Geochemical Survey Method of Land Quality in Land Parcel Scale City: A Case Study of the Initial Area of the Xiong'an New District].

In order to evaluate the land quality geochemical survey achievement in the service of the accurate management of urban land resources, the initial area of the Xiong'an New District as urbanization pathfinder in China is chosen as the research subject. The sample points were set by differential classification, and the spatial interpolation accuracy of the soil elements at a plot scale and a quantitative assessment of the consistency of the land plot (pattern spot) prediction evaluation were studied under the conditions of different sampling densities. The regional geochemical variation values randomly distributed on the plane can be reflected quantitatively by differential classification sampling, which can meet the basic demand of the quality attribute of a single plot (map spot) by the accurate management of urban land resources.

Dissolved and particulate phosphorus species partitioning and distribution in the Danshuei River Estuary, Northern Taiwan.

Different phosphorus fractions, including total dissolved P (TDP), dissolved inorganic P (DIP), total particulate P (TPP), and particulate inorganic P (PIP), were analyzed in the Danshuei River Estuary (DRE), northern Taiwan to study the P partitioning within the estuary. Relatively higher concentrations of TDP (4.3-12.

Quantitative microbial risk assessment of Greywater on-site reuse.

Recycle domestic greywater for on-site non-potable uses can lessen the demand on potable water and the burden on wastewater treatment plants. However, lack of studies to assess health risk associated with such practices has hindered their popularity. A Quantitative Microbial Risk Assessment was conducted to estimate the public health risks for two greywater reuse scenarios: toilet flushing and food-crop irrigation.

Ultrasonic Treatment Enhanced Ammonia-Oxidizing Bacterial (AOB) Activity for Nitritation Process.

Oxidation of ammonia to nitrite rather than nitrate is critical for nitritation process for wastewater treatment. We proposed a promising approach by using controlled ultrasonic treatment to enhance the activity of ammonia-oxidizing bacteria (AOB) and suppress that of nitrite-oxidizing bacteria (NOB). Batch activity assays indicated that when ultrasound was applied, AOB activity reached a peak level and then declined but NOB activity deteriorated continuously as the power intensity of ultrasound increased.

Influence of glucocorticoids on the osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells.

Background: Glucocorticoid has been used extensively in clinical applications, because of its several pharmacologic actions, which include immunosuppression, anti-inflammation, anti-shock, and relief of asthma. However, the long-term or high-dose application of glucocorticoid can induce adverse effects such as osteoporosis, which is known in this case as glucocorticoid-induced osteoporosis (GIOP). It is a secondary osteoporosis that results in easy fracturing, and even disability.

Use of low frequency and density ultrasound to stimulate partial nitrification and simultaneous nitrification and denitrification.

Low frequency and density ultrasound has attracted considerable attention in enhancing wastewater treatment performance, particularly in the removal of nitrogen. In the present study, two sequencing batch reactors were operated to confirm the effects of ultrasound at the frequency of 40 kHz and density of 0.027 W/mL on partial nitrification and simultaneous nitrification and denitrification (SND).

[Application of analytical pyrolysis in air pollution control for green sand casting industry].

Analytic pyrolysis was conducted to simulate the heating conditions that the raw materials of green sand would experience during metal casting process. The volatile organic compound (VOC) and hazardous air pollutant (HAP) emissions from analytical pyrolysis were analyzed by gas chromatograph-flame ionization detector/mass spectrometry (GC-FID/MS). The emissions from analytical pyrolysis exhibited some similarity in the compositions and distributions with those from actual casting processes.

Effect of a suspended carrier on membrane fouling in a submerged membrane bioreactor.

In an attempt at membrane fouling control, a kind of cylindrical plastic suspended carrier was added in a submerged membrane bioreactor (SMBR) and its effect was investigated in this study. According to the transmembrane pressure (TMP) profiles and the sludge characteristics in comparative runs with and without suspended carriers, it was found that the suspended carriers added in SMBR had two effects on membrane fouling: one was the positive effect of mechanically scouring the membrane surface and the other was the negative effect of breaking up sludge flocs. Sludge particle size distribution change was mainly responsible.