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To identify the response of groundwater level variation to global climate change in Northwest China’s inland basins, the Golmud River Catchment was chosen as a case in this paper. Approaches of time series analysis and correlation analysis were adopted to investigate the variation of groundwater level influenced by global climate change from 1977 to 2017. Results show that the temperature in the Golmud River Catchment rose 0.57°C every 10 years. It is highly positive correlated with global climate temperature, with a correlation coefficient, 0.87. The frequency and intensity of extreme precipitation were both increased. Generally, groundwater levels increased from 1977 to 2017 in all phreatic and confined aquifers and the fluctuation became more violent. Most importantly, extreme precipitation led to the fact that groundwater level rises sharply, which induced city waterlogging. However, no direct evidence shows that normal precipitation triggered groundwater level rise, and the correlation coefficients between precipitation data from Golmud meteorological station located in the Gobi Desert and groundwater level data of five observation wells are 0.13, 0.02, –0.11, 0.04, and –0.03, respectively. This phenomenon could be explained as that the main recharge source of groundwater is river leakage in the alluvial-pluvial Gobi plain because of the high total head of river water and goodness hydraulic conductivity of the vadose zone. Data analysis shows that glacier melting aggravated because of local temperature increased. As a result, runoff caused groundwater levels to ascend from 1977 to 2017. Correlation coefficients of two groundwater wells observation data and runoff of Golmud River are 0.80 and 0.68. The research results will contribute to handling the negative effects of climate change on groundwater for Northwestern China. © 2021 China Geology Editorial Office.

Five complexes of Nd(iii) with bis(2,4,4-trimethylpentyl)dithiophosphinic acid were identified spectroscopically.

Crash hot spot identification and prediction using spatial statistics and random forest methods on the interstate of Michigan are evaluated. The Getis-Ord statistics are adopted to identify hot spots using location, frequency, and equivalent property damage only weights computed from the cost and severity of crashes. In the random forest approach, data patterns between 2010 and 2017 are determined to predict hot spots of crashes in 2018. Accordingly, the results indicate that: (i) interstate routes have witnessed 13,089 crashes on significant hot spots, 7,413 on cold spots, and the rest in other locations; (ii) random forest shows 76.7% and 74% accuracy for validation and prediction, respectively. The performance of the model is further affirmed with precision, recall, and F-scores of 75%, 74%, and 70%, respectively; and (iii) clustering of the crashes exhibits spatial dependence of high and low equivalent property damage only crashes. The practical significance of the approach is highlighted in the identification and prediction of hot spots.

Traffic accidents occur frequently every year. Skid-resistance performance is an important indicator in evaluating road safety. In this paper, the road surface texture information is obtained by a line laser scanner. The original two-dimensional (2D) signal is decomposed into eight intrinsic mode functions by complementary ensemble empirical mode decomposition (CEEMD). Eight intrinsic mode functions compose an 800 × 8 data matrix. The matrix is decomposed by singular value decomposition (SVD), and singular value vectors are obtained. The singular values are summed and linearly fitted to the friction value measured by the British pendulum friction meter. The study finds that the singular value sum of one to five has a good linear correlation with the friction value with the goodness of fit greater than 0.8. At the same time, contour arithmetic mean deviation Ra is applied for verification. The results show that the singular value sum has a strong correlation with Ra. When the number of Intrinsic Mode Function (IMF) decomposition is greater than eight, there is a good correlation between the number of IMF and the friction value from IMF2 to IMF6. When the number of IMF decomposition is less than eight, the singular value sum numbers with R2 more than 0.8 gradually decrease. It is suggested that the road surface friction performance can be estimated by solving the singular value of the 2D signal. It provides new technical support for the detection and evaluation of anti-skid performance.

The fabrication of underwater devices is necessary for the exploration of water environments and interactions in the Human–Computer Interaction (HCI) field. However, there are fewer approaches to support prototyping used in water environments. The existing prototype methods lack systematic waterproof treatments and provide insufficient software for balance and buoyancy analysis. To address these limitations, we present ElectroPaper, a new approach for the design and fabrication of prototypes used in water environments (surface or beneath) with paper-based electronic interfaces with a crease layer, hardware distribution layer, and hollow-out layer to support physical properties, such as waterproofing, foldability, and conformability. The approach includes a computational design tool for assisting in balance analysis, three-dimensional (3D) model unfolding, and circuit drawing. We describe the design and fabrication process and provide several example applications to illustrate the feasibility and utility of our approach. ElectroPaper provides an inexpensive and effective medium for the fabrication of customized digital prototypes for water environment use.

The performance of a commercial NH3-SCR catalyst used for 20,000 h in a 660 MW coal fired power plant was evaluated after treated in situ with water vapor at 300–350 °C for 336 h. The conversion of NOx reached 91.4% after this water treatment. The recovery of catalytic activity is mainly due to the removal of potassium, arsenic and sulfate-containing deposits from the catalyst surface, as well as the increase of surface active oxygen species and specific surface area. These results indicate that commercial NH3-SCR catalysts are deactivated by the deposition of water-soluble substances and which can be in situ regenerated cost-effectively with high-temperature water vapor treatment.

Commercial selective catalytic reduction (SCR) catalysts used in a 1000 MW coal-fired power plant were in situ treated by high-temperature water vapor. The de-NOx efficiency of the deactivated catalyst increased about 25–30%, comparable to fresh commercial SCR catalysts, after being treated with simulated flue gas with 15–20 vol% high-temperature water vapor. It indicates that treatment by in situ 15–20 vol% high-temperature water vapor could significantly extend the lifetime of commercial SCR catalyst. High-temperature water vapor could remove Fe, Na, Ca, sulphate species and SiO2 depositing on SCR catalyst. Compared with the deactivated catalyst, the specific surface area, the ratio of V4+/V5+ and Lewis acid content of health-care catalyst increased from 41.679 to 44.596 m2·g−1, 1.35 to 1.80 and 45.5 to 73.8%, respectively. Density functional theory (DFT) calculation demonstrated that the electrons transferred from H2O molecule to V5+ cations in the process of H2O adsorption and the subsequent hydroxylation of V5+cations during H2O dissociation contribute to the reduction of V5+ to V4+ on the SCR catalyst.

Near surface temperature of the Moon and thermal behaviors of the lunar regolith can provide important information for constraining thermal and magmatic evolution models of the Moon and engineering constrains for in situ lunar exploration system. In this study, China’s Chang’E-2 (CE-2) microwave radiometer (MRM) data at high frequency channels are used to investigate near surface temperature of the Moon given the penetration ability of microwave into the desiccated and porous lunar regolith. Factors that affect high frequency brightness temperature (TB), such as surface slope, solar albedo and dielectric constant, are analyzed first using a revised Racca’s temperature model. Radiative transfer theory is then used to model thermal emission from a semi-infinite regolith medium, with considering dielectric constant and temperature profiles within the regolith layer. To decouple the effect of diurnal temperature variation in the uppermost lunar surface, diurnal averaged brightness temperatures at high frequency channels are used to invert mean diurnal surface and subsurface temperatures based on their bilinear profiles within the regolith layer. Our results show that, at the scale of the spatial resolution of CE-2 MRM, surface slope of crater wall varies typically from about 20 ° to 30 ° , and this causes a variation in TB about 10–15 K. Solar albedo can give rise to a TB difference of about 5–10 K between maria and highlands, whereas a ∼2–8 K difference can be compensated by the dielectric constant on the other hand. Inversion results indicate that latitude ( ϕ ) variations of the mean diurnal surface and subsurface temperatures follow simple rules as cos 0.30 ϕ and cos 0.36 ϕ , respectively. The inverted mean diurnal temperature profiles at the Apollo 15 and 17 landing sites are also compared with the Apollo heat flow experiment data, showing an inversion uncertainty