With the continuous enhancement of human activities, the contradiction between regional development and ecological protection is prominent in the ecologically fragile arid areas. It is of great ...significance for regional sustainable development to understand the ecological supply and demand problems caused by transformation of land using and formulate ecological compensation scheme scientifically. This study takes Xinjiang in China as the research area. It explores the land use transition characteristics and the changes in carbon supply and demand of Xinjiang using methods such as GIS spatial analysis and modified comparative ecological radiation forcing. Finally, the ecological compensation scheme is studied based on the theory of ecological radiation. The research shows that (I) in the study chronology, most of the areas produced only one change in land use. Land use is gradually developing towards the direction of ecological protection. After 2000, grassland recovered well, and 14,298 km
of other ecological land was transformed into grassland. (II) The change in the carbon sink of the Xinjiang ecosystem first decreased and then increased, and the ecological deficit area started to appear after 2010. The growth of grassland and cropland areas is essential to enhance the carbon sink capacity of arid zones. (III) The amount of ecological compensation in Xinjiang is 31.47 * 10
yuan, and the proportion of the amount received by ecological compensation areas is related to the distance between the supply and demand areas, the amount of carbon sequestration, and the area of the region. This study provides a reference for achieving the healthy development of sustainable land use ecosystems in arid zones.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Summary Objective The current study used a three-dimensional (3D) computational laryngeal model to investigate the effect of false vocal folds (FVFs) on laryngeal flow resistance. Method A 3D, ...tubular shaped computational laryngeal model was designed with a high level of realism with respect to the human laryngeal anatomy. Two cases, one with the FVFs and the other without the FVFs, were created in the numerical simulation to compare the laryngeal flow behaviors. Results and Conclusion The results were discussed in a comparative manner with the previous two-dimensional (2D) computational model. On the one hand, the results demonstrated the similar mechanism as observed in the 2D model that the presence of the FVFs suppressed the deflection of the glottal jet and in doing so, reduced the mixing-related minor loss in the supraglottal region. On the other hand, the 3D flow was more stable and straighter, so the effect of FVFs on suppressing the jet deflection in the 3D model was not as prominent as in the 2D model. Furthermore, the presence of the FVFs also increased the friction-related major loss due to the increased velocity gradient in the restricted flow channel. Therefore, it was hypothesized that the final effect of the FVFs on flow resistance is the combined effect of the reduced mixing-related minor loss and increased friction-related major loss, both of which are highly related to the gap between the FVFs.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Due to the increasingly serious problem of offshore oil spills, research related to oil–water separation has attracted more and more attention. Here, we prepared a super-hydrophilic/underwater ...super-oleophobic membrane (hereinafter referred to as BTA) using poly-dopamine (PDA) to adhesive TiO2 nanoparticles on the surface of bacterial cellulose, coated with sodium alienate by vacuum-assisted filtration technique. This demonstrates its excellent underwater super-oleophobic property. Its contact angle is about 153°. Remarkably, BTA has 99% separation efficiency. More importantly, BTA still showed excellent anti-pollution property under ultraviolet light after 20 cycles. BTA has the advantages of low cost, environmentally friendliness and good anti-fouling performance. We believe it can play an important role in dealing with problems related to oily wastewater.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Existing studies for the balance control of unmanned bicycle robots only consider constant forward velocity and a single optimal objective that cannot be applied to the complex motion situation. To ...balance the bicycle robot with time‐varying forward velocity, only with the steering actuator, the multiple objective optimal balance control issue is studied here. A fuzzy state‐space model under different forward velocities is firstly offered based on the non‐linear Euler–Lagrange model. Based on this, a closed‐loop equation under a fuzzy controller is verified. To regulate the feedback gain of the fuzzy controller, a modified particle swarm optimization (MPSO) algorithm with two stages is proposed. In the MPSO's second stage, a novel objective fitness function, consisting of multiple objectives and combining the conventional Hurwitz stability analysis criterium, is designed. Procedures for the MPSO dynamic programming approach are presented. By two examples, the efficiency of the MPSO algorithm, for time‐varying and time‐constant velocity situations, and faster capacity for iteration convergence, are examined.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
In recent years, with the development of batteries, ceramics, glass and other industries, the demand for lithium has increased rapidly. Due to the rich lithium resources in seawater and salt-lake ...brine, the question of how to selectively adsorb and separate lithium ions from such brine has attracted the attention and research of many scholars. The Li-ion sieve stands out from other methods thanks to its excellent special adsorption and separation performance. In this paper, mesoporous titanium dioxide and lithium hydroxide were prepared by hydrothermal reaction using bacterial cellulose as a biological template. After calcination at 600 °C, spinel lithium titanium oxide Li
TiO
was formed. The precursor was eluted with HCl eluent to obtain H
TiO
. The lithium titanate were characterized by IR, SEM and X-ray diffraction. The adsorption properties of H
TiO
were studied by adsorption pH, adsorption kinetics, adsorption isotherm and competitive adsorption. The results show that H
TiO
has a single-layer chemical adsorption process, and has a good adsorption effect on lithium ions at pH 11.0, with a maximum adsorption capacity of 35.45 mg g
. The lithium-ion sieve can selectively adsorb Li
, and its partition coefficient is 2242.548 mL g
. It can be predicted that the lithium-ion sieve prepared by biological template will have broad application prospects.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The purpose of the paper is to achieve adsorption and secondary application of La(III) through strong coordination ability of phosphate groups and La(III). Firstly, cellulose nanocrystals (CNCs) were ...phosphorylated in two solvents (water and molten urea). p-CNC(water)/MWCNT and p-CNC(urea)/MWCNT thin films were successfully synthesized by using p-CNCs as film units based on EISA method. The addition of multi-wall carbon nanotube was to improve thermal stability and repeatability of films and carboxyl groups thereon could also involve in the coordination of La(III). Adsorption experiments show that, at pH 4.0, adsorption capacities of p-CNC(water)/MWCNT and p-CNC(urea)/MWCNT films were 21.23 and 44.71 mg g
−1
, with half equilibrium time (
t
1/2
) of 23.06 and 4.87 min. Repeatability tests show that the adsorption capacities of films remained above 82% of the maximum adsorption capacities after five adsorption–desorption cycles.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The non-smooth dynamic model of an unmanned bicycle is established to study the contact-separate and stick-slip non-smooth phenomena between wheels and the ground. According to the Carvallo-Whipple ...configuration, the unmanned bicycle is reduced to four rigid bodies, namely, rear wheel, rear frame, front fork, and front wheel, which are connected by perfect revolute joints. The interaction between each wheel and the ground is simplified as the normal contact force and the friction force at the contact point, and these forces are described by the Hunt-Crossley contact force model and the LuGre friction force model, respectively. According to the characteristics of flat and curved pavements, calculation methods for contact forces and their generalized forces are presented. The dynamics of the system is modeled by the Lagrange equations of the first kind, a numerical solution algorithm of the dynamic equations is presented, and the Baumgarte stabilization method is used to restrict the drift of the constraints. The correctness of the dynamic model and the numerical algorithm is verified in comparison with the previous studies. The feasibility of the proposed model is demonstrated by simulations under different motion states.
A new numerical approach for modeling a class of flow–structure interaction problems typically encountered in biological systems is presented. In this approach, a previously developed, ...sharp-interface, immersed-boundary method for incompressible flows is used to model the fluid flow and a new, sharp-interface Cartesian grid, immersed-boundary method is devised to solve the equations of linear viscoelasticity that governs the solid. The two solvers are coupled to model flow–structure interaction. This coupled solver has the advantage of simple grid generation and efficient computation on simple, single-block structured grids. The accuracy of the solid-mechanics solver is examined by applying it to a canonical problem. The solution methodology is then applied to the problem of laryngeal aerodynamics and vocal fold vibration during human phonation. This includes a three-dimensional eigen analysis for a multi-layered vocal fold prototype as well as two-dimensional, flow-induced vocal fold vibration in a modeled larynx. Several salient features of the aerodynamics as well as vocal fold dynamics are presented.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Short-term load forecasting is the guarantee for the safe, stable, and economical operation of power systems. Deep learning methods have been proven effective in obtaining accurate forecasting ...results. However, in recent years, the large-scale integration of distributed photovoltaic systems (DPVS) has caused changes in load curve fluctuations. Current deep learning models generally train with historical load series and load-related meteorological data series as input features, which limits the model’s ability to recognize the load fluctuations caused by DPVS. In order to further improve the accuracy of load forecasting models, this paper proposes an input feature reconstruction method based on the maximum information coefficient (MIC). Firstly, the load curves with DPVS are classified by Gaussian mixture model (GMM) clustering. Then, considering the coupling relationship between the load and input features at different times, the load data and input features are reordered. Finally, the MIC between different features and loads at different times is calculated to select the relevant features at those different times and construct new input features. The case analysis shows that the feature reconstruction strategy proposed in this paper effectively improves the prediction performance of deep neural networks.
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