Structural Evolvement of Heating Treatment of Mg/AI-LDH and Preparation of Mineral Mesoporous Materials

Although hydrotalcite, or layered double hydroxides (LDHs), is not a common mineral, it is an important material that can be easily synthesized in laboratory. In this study, structural evolvement and BET surface area changes of heat treated Mg/Al-LDH is evaluated by XRD, TEM and N2-BET analyses. The results indicate that the magnesium-aluminum LDH with carbonate as interlayer anion, periclase-like oxides was formed at temperatures of 400-800℃. Meanwhile, 2-3 nanometer mesoporous were formed during decomposition of LDH. However, the heat treated samples still preserve the morphology of the original LDH plates. Periclase-like formed from LDH heat treatment may re-hydrolyze and recover the structure of LDH. However, crystallinity of the recovered LDH is lower than that of the original LDH. This heat treatment will result in formation of (Mg, Al)-oxide nano-crystals and nanopores among the nano-crystals. When heating temperature exceeds 1000, the periclase-like (Mg, Al)-oxide is transformed into a composite with periclase (MgO) and spinel phases. The periclase can be re-hydrolyzed and dissolved in HCl solution. After acid treatment, the sample with a high surface area is composed of spinel nano-crystals and nanopores among them. Our results will provide a new and economic way to synthesize mesoporous materials through pathways of phase transformation of precursor materials with different composition.

Assessing spatial and temporal variability in waterconsumption and the maintainability oasis maximumarea in an oasis region of Northwestern China

Water consumption is a key role in improving the efficiency and sustainability of water management in arid environments.In this study, we explored an approach based on meta-analysis, MODIS NDVI products, land-use spatial distribution, andsoil water physical parameters to gain insight into long-term and large scale distribution of land use and water consumption,maintain maximum Zhangye Oasis area according to Heihe River runoff, and suitable water resource management inZhangye Oasis. This approach was initiated in order to improve the efficiency of irrigation and water resource managementin arid regions. Results showed that Heihe River runoff can maintain a maximum Zhangye Oasis area of 22.49×104 hm2.During the 2000−2016 growing seasons, actual oasis water consumption ranged from 11.35×108 m3 to 13.73×108 m3, witha mean of (12.89 ± 0.60)×108 m3;if maintaining agricultural production and oasis stability was chosen, oasis water consumptionranged from 10.24×108 m3 to 12.37×108 m3, with a mean of (11.62 ± 0.53)×108 m3. From the perspective of waterresources management and ecosystem stability, it is necessary to reduce the area of Zhangye Oasis or choose the minimumwater consumption method to manage the oasis, to ease the pressure of water shortage and maintain stable and sustainabledevelopment of the Zhangye Oasis. These results can provide future practical guidance for water resource management ofcoordinated development of the economy and the environment in an arid area.

Experimental study of flame microstructure and propagation behavior of mine-gas explosion

The high speed cameral and schlieren images methods were used to record the photograph of flame propagation process.Meanwhile,the ionization current probes were set up to detect the reaction intensity of the reaction zone.The characteristics of methane/air flame propagation and microstructure were analyzed in detail by the experi- mental results coupled with chemical reaction thermodynamics.The high speed schlieren image showed the transition from laminar flame to turbulence combustion.The ion current curves disclosed the reaction intensity and combustion characteristic of flame front.In the test,the particular tulip flame was formed clearly,which was induced to some extent by turbulent combustion.Based on the schlieren images and iron current result,it can be drawn that the small scale turbulence combustion also appears in laminar flame,which thickens the flame front,but makes little influence on the flame front shape.During the laminar-turbulent transition,the explosion pressure plays an important role on the flame structure change.

Assessment of Climate Change Impacts on the Water Resources of Megech River Catchment, Abbay Basin, Ethiopia

This study was aimed to assess the impact of climate change on the water resource of Megech river catchment. In this study, large scale regional climate model (REMO) output was downscaled statistically to metrological variables at a daily resolution using SDSM model version 5.11. We noticed that statistical downscaling smooth out the bias between REMO output and observed data. According to the projected climate data, the maximum temperature is likely to have an increasing trend +0.57°C while the minimum temperature shows a decreasing trends ﹣0.61°C. There is no clear trend for precipitation, both increasing and decreasing trend observed in the catchment. The HBV-Light hydrological model was successfully calibrated (1991-1995) and validated (1998-2000) using current climatic inputs and observed river flows. The overall performances of the model was good at monthly time scale both on calibration (NSE = 0.91) and validation (NSE = 0.86). Future discharge (2015-2050) was simulated using statistically downscaled 20 ensembles climate scenario data for both A1B and B1 scenarios. HBV-Light model simulation results showed a reduction of the peak discharge in August and September.

Study on Decoloration of Acidic Scarlet GR by Pyrolusite Oxidation under an Acid Condition

由软锰矿的酸的猩鸿的 GR 的去色在这篇论文被学习。软锰矿，反应温度，和颤动速度去色效率的氢指数答案，剂量和颗粒度的 Theeffects 被讨论。根据实验结果，去色效率可以由软锰矿为 40 mg/L GR 答案超过 95% 。氢指数在影响酸的猩鸿的 GR 的去色的所有因素之中是很重要的。软锰矿，反应温度，和颤动速度的剂量和颗粒度在去色上有小 benitfit。Thehigh 去色效率和在软锰矿和酸的猩鸿的 GR 之间的产品的货到付款以及英尺红外系列的低移动效率显示酸的猩鸿的 GR 在矿物质的接口上经历氧化还原反应，它的色基是 oxidated 和 decolored，但是它没被氧化彻底地移开。

Ecological residence:theory and application in China

This paper makes an overall introduction of ecological residence (ER), a new type of eco-building and studiesits origin, definition, status quo and characteristics. Firstly, it shapes like a forest seen from afar and like a garden seeninside; secondly, its environment should be up to the natural level; thirdly, designing, management, green energyutilization and sanitation should be up to environmental standard; fourthly, the green ecology concept is not only appliedto building but also rooted in the residents. In this paper, the features of ecological residence are summarized - coziness,health, high-efficiency and beauty, and principles of ecological residence are proposed - ecology-based, human-oriented,local-conditions-based and systematic. Also, techniques, problems and various understandings are discussed for theenhancement of ecological residence.

Experimental investigation on microstructure behavior of premixed methane-air flame-flow interaction in a semi-vented chamber

To explore the premixed methane-air flame microstructure behavior and the flame-flow interaction,the premixed methane/air flame was studied in a semi-vented chamber.A high speed camera and schlieren images methods were used to record the processes of interaction between rarefaction wave and flame.Meanwhile,a pressure sensor was utilized to catch the pressure variation in the process of flame propagation.The experiment results showed that the interference of rarefaction wave on flame caused the flame front structure change,which led to the flame transition from laminar to turbulent quickly.The rarefaction wave intervened in the flame by turning the flame front surface into dentiform structure.The violent turbulent combustion began to appear in part of the flame front and spreaded to the whole flame front surface.The rarefaction also decreased the flame propagation speed.

An Approximate Analytical Solution for Grout Transport Modeling: A Case Study in Luling Mining, China

This case study describes the effects of a grouting process developed to decrease groundwater flow exiting from a ruptured mine ventilation shaft lining in Luling coal mine at Huaibei, China. The primary purpose of grouting at this site is to prevent groundwater flow into the mine from adjacent aquifers. The study supports a transport perspective to describe the miscible grout movement, and provides an approximate analytical method to determine grout concentration based on Wilson and Miller's (1978) model. This study shows that the breakthrough curves (BTCs) established from the Wilson and Miller's model match the experimental BTCs obtained from test grouting performed at the site, and Rd a retardation factor of 1.1 is determined. The retardation factor and the BTC are subsequently used to guide the actual production grouting. The monitored result shows that the groundwater inflow at the disrupted ventilation well has been reduced by 47% after drilling and grouting just one borehole. The discharge rate was measured at no more than 4 m3/h after completion of four injection boreholes, which is about 13% of the 30 m3/h before grouting.