Spatiotemporal characteristic of Biantun toponymical landscape for the evolution of Biantun culture in Yunnan, China.

The geographical environment of Yunnan Province in China and Han migration during the Ming Dynasty contributed to the development of the Biantun culture. Biantun toponyms (BTT) record the integration process between the Central Plains and native Yunnan cultures. The GIS analysis method of toponyms was used in this study to reproduce the settlement characteristics of BTT and the spatial development of the Biantun culture in the Ming and Qing Dynasties. In addition, we have developed a toponymical landscape index to represent the degree of spatial integration between the BTT and ethnic minority toponyms in Yunnan and explore the spatial characteristics of the integration of Han immigrants and local ethnic minorities. The results show that the spatial distribution of the BTT is consistent with the sites selection of the Tuntian () in Yunnan during the Ming and Qing Dynasties, and the centroids of BTT spread to outskirts and intermontane area from central towns. In the Dali, Kunming, Qujing and other regions, the distribution characteristics of the integrated of BTT and ethnic minority toponyms reflect a higher degree of Sinicization in the central urban areas. Exploring the evolution of Biantun cultural development through the spatial characteristics of toponymical landscapes can help adjust policies for the development and protection of Biantun cultural resources.

Spatial-Temporal Characteristic Analysis of Ethnic Toponyms Based on Spatial Information Entropy at the Rural Level in Northeast China.

As a symbol language, toponyms have inherited the unique local historical culture in the long process of historical development. As the birthplace of Manchu, there are many toponyms originated from multi-ethnic groups (e.g., Manchu, Mongol, Korean, Hui, and Xibe) in Northeast China which possess unique cultural connotations. This study aimed to (1) establish a spatial-temporal database of toponyms in Northeast China using a multi-source data set, and identify their ethnic types and origin times; and (2) explore the geographical distribution characteristics of ethnic toponyms and the evolution of rural settlements by comparing the spatial analysis and spatial information entropy methods. The results found that toponyms reflect not only the spatial distribution characteristics of the density and direction of ethnic groups, but also the migration law of rural settlements. Results also confirm that toponyms contain unique cultural connotations and provide a theoretical basis for the protection and promotion of the cultural connotations of toponyms. This research provides an entropic perspective and method for exploring the spatial-temporal evolutionary characteristics of ethnic groups and toponym mapping.

Ignition hazard of non-metallic dust clouds exposed to hotspots versus electrical sparks.

Non-metallic combustible dusts contribute to more than 50% of dust explosion accidents. Almost 38% of dust explosion accidents relate to mechanical malfunction. Compared to electric sparking as an ignition source, the ignition hazard of non-metallic dust clouds exposed to simulated hotspots during mechanical malfunction has received little attention in the literature. Minimum ignition temperature of hotspots (MITH) for corn starch, wood dust, and polymethyl methacrylate (PMMA) dust fall within a narrow range from 710 to 745 °C although large differences in minimum ignition energy (MIE) were evident. A much narrower dust concentration range (around 1500 g/m3) was observed for MITH than for MIE. A longer ignition delay time when exposed to hotspots also indicated lower ignition hazard compared to ignition by electric sparking. Whether exposed to hotspots or electric sparks, average flame spread velocity (FSV) of PMMA dust was much higher than that of corn starch and wood dust. Once a dust cloud was ignited, pulsating flame propagation was similar for hotspots and electric sparking, but average FSV was higher for hotspots than for electric sparks, due to continuous radiation from the ignition source. At higher dust loadings, layer fires could occur due to sedimentation of many ignited and unburned particles exposed to hotspots.

Fire hazard of titanium powder layers mixed with inert nano TiO2 powder.

Metallic dust layers are highly sensitive to ignition from common ignition sources, even when mixed with high percentages of inert solids. In turn, dust layer fires are a potential ignition source for dust explosions or other damaging fires. Flame spread velocity (FSV), as a potential parameter for evaluating fire hazard, was investigated for titanium powder layers mixed with inert nano TiO2 powder in both natural convection and in forced airflow conditions. Increased mass percentage of nano TiO2 powder decreased FSV of Ti powder mixtures as expected. The mixing ratio of nano TiO2 to fully suppress layer fires was 80% and 90% for micro and nano Ti powder, respectively. Mechanisms governing flame spread across a layer of nano Ti powder differed from those of a layer of micro Ti powder. FSV in no airflow conditions was higher than in aided airflow for micro Ti powder because conduction was the dominant heat transfer mechanism. However, FSV in no airflow was lower than in opposed airflow for nano Ti powder because convection/radiation was the dominant heat transfer mechanism. A fly fire phenomenon contributed to greater FSVs and higher fire hazard with nano Ti powder mixtures under aided airflow conditions.

Transjugular Intrahepatic Portosystemic Shunt for Extrahepatic Portal Venous Obstruction in Children.

OBJECTIVES: To evaluate the feasibility and efficacy of transjugular intrahepatic portosystemic shunt (TIPS) for extrahepatic portal venous obstruction with recurrent variceal bleeding in children. METHODS: From November 2005 to December 2013, 28 consecutive paediatric patients with extrahepatic portal venous obstruction treated with TIPS for recurrent variceal bleeding refractory to medical/endoscopic therapy and/or surgical treatment in a tertiary-care centre were followed until last clinical evaluation or death. The median follow-up time was 36.0 months (range 4.0-106.0 months). RESULTS: Seventeen boys and 11 girls of ages 7.1 to 17.9 years (median 12.3 years) weighing 19.0 to 62.0 kg (median 33.5 kg) were treated. TIPS was successfully placed in 17 of 28 (60.7%) patients via a transjugular approach alone (n = 4), a combined transjugular/transhepatic approach (n = 9), or a combined transjugular/transsplenic approach (n = 4). Shunt dysfunction occurred in 6 of 17 (35.3%) patients. The cumulative 1- and 3-year free-from-variceal-rebleeding rates in TIPS success group were higher than those in TIPS failure group (75.0% and 67.5% vs 45.5% and 18.2%, respectively, P = 0.0075). Compared with the TIPS failure group, the improvements in the height-for-age z scores were greater in the TIPS success group (P = 0.017). Procedure-related complication occurred in 1 patient (3.6%), and no episode of post-TIPS hepatic encephalopathy occurred in any patient. Except 1 patient in the TIPS success group died at 115 postoperative days, all patients were alive. CONCLUSIONS: TIPS is feasible and effective in children with extrahepatic portal venous obstruction and recurrent variceal bleeding. TIPS could represent a less-invasive alternative to traditional surgical portosystemic shunting or a valuable treatment option if surgery and endoscopic treatment failed.