Impact of water table on hierarchically nested groundwater flow system

Water table configuration gives rise to hierarchically nested groundwater flow systems.However,there remains a lack of comprehensive understanding regarding the controlling factors of water table and its impact on flow systems.Moreover,it remains challenging to identify characteristics of water table space variation through limited groundwater observations at the regional scale.Based on two ideal two-dimensional cross-section analytical models,this study presents a simplified approach to preliminarily assess the nonlinear interactions between water table variation and three driving factors:Topography,geol-ogy and climate.Two criteria,C1 and C2,are utilized to address issues at different scales ranging from basin to local:(i)the influence of various factors on water table configuration;and(ii)the influence of water table on groundwater flow pattern.Then,the Ordos Plateau is taken as an example to explore the role of the water table in nested groundwater systems using the provided approach and criterion.The applica-tion of this approach in the Ordos Plateau demonstrates its appropriateness as a practical method for prelim-inarily determining the characteristics of water table configuration and its impact on flow systems.The study explores the mechanism influencing spatial variation in the water table and improves understanding of the interaction between topography,geology,and climate on groundwater flow patterns.

Synthesis of （2E）－α，β－Unsaturated Amides Catalyzed by Micro Palladium Under Solid－Liquid Phase－Transfer Conditions

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Modeling of Diffusion Transport through Oral Biofilms with the Inverse Problem Method

Aim The purpose of this study was to develop a mathe-matical model to quantitatively describe the passive trans-port of macromolecules within dental biofilms. Methodology Fluorescently labeled dextrans with different molecular mass （3 kD,10 kD,40 kD,70 kD,2 000 kD） were used as a series of diffusion probes. Streptococcus mutans,Streptococcus sanguinis,Actinomyces naeslundii and Fusobacterium nucleatum were used as inocula for biofilm formation. The diffusion processes of different probes through the in vitro biofilm were recorded with a confocal laser microscope. Results Mathematical function of biofilm penetration was constructed on the basis of the inverse problem method. Based on this function,not only the relationship between average concentration of steady-state and molecule weights can be analyzed,but also that between penetrative time and molecule weights. Conclusion This can be used to predict the effective concentration and the penetrative time of anti-biofilm medicines that can diffuse through oral biofilm. Further-more,an improved model for large molecule is proposed by considering the exchange time at the upper boundary of the dental biofilm.

Study on the distribution,abundance and growth condition of Antarctic Krill(Euphausia superba)in the Prydz Bay region,Antarctica during the Austral summer of 1999/2000

Antarctic krill (Euphausia superba) were collected from the Prydz Bay region during the austral summer of 1999/2000. The sample - collection was made at 15 sites in 3 longitudinal transects. Although krill were encountered at 14 sites, the abundance was comparatively low in general. The main component of the krill population was of post -larval stages. The mean numerical and weight density of krill integrated for all sampling stations in the survey area were 16. 17 ind. 1000 m -3and 12.02 g 1000 m -3 , respectively. In the survey area, stations with larger krill density are mainly located in the slope zone, except that the largest sample was collected in the open sea zone. No krill occurred in the only station of the shelf zone during our investigation. Krill collected from the slope zone were under better growth condition than those from the open sea zone, but when the survey area is considered as a whole, the growth condition is normal. The results of the comprehensive analysis of the environmental factors show that the three large sample stations seem to be related with the cold water mass at 75 m depth and the confluence area between the high and low Chla centers at the depth of 25 m.

Existence results for unilateral contact problem with friction of thermo-electro-elasticity

This work studies a mathematical model describing the static process of contact between a piezoelectric body and a thermally-electrically conductive foundation. The behavior of the material is modeled with a thermo-electro-elastic constitutive law. The contact is described by Signorini＇s conditions and Tresca＇s friction law including the electrical and thermal conductivity conditions. A variational formulation of the model in the form of a coupled system for displacements, electric potential, and temperature is de- rived. Existence and uniqueness of the solution are proved using the results of variational inequalities and a fixed point theorem.

Effect of Device Fabrication Conditions on Photovoltaic Performance of Polymer Solar Cells Based on Poly（3-hexylthiophene） and Indene-CT0 Bisadduct

Effect of the device fabrication conditions on photovoltaic performance of the polymer solar cells based on poly（3-hexylthiophene） （P3HT） as donor and indene-C70 bisadduct （IC70BA） as acceptor was studied systematically. The device fabrication conditions we studied include pre-thermal annealing temperature, active layer thickness, and the P3HT ： IC70BA weight ratios. For devices with a 188-nm-thick active layer of P3HT ： ICToBA （1 ： 1, w ＇ w） blend film and pre-thermal annealing at 150 ℃C for 10 rain, maximum power conversion efficiency （PCE） reached 5.82% with Voc of 0.81 V, Isc of 11.37 mA/cm2, and FF of 64.0% under the illumination of AM1.5G, 100 mW/cm2.

WEAK APPROXIMATION OF OBLIQUELY REFLECTED DIFFUSIONS IN TIME-DEPENDENT DOMAINS

In an earlier paper, we proved the existence of solutions to the Skorohod problem with oblique reflection in time-dependent domains and, subsequently, applied this result to the problem of constructing solutions, in time-dependent domains, to stochastic differential equations with oblique reflection. In this paper we use these results to construct weak approximations of solutions to stochastic differential equations with oblique reflection, in time-dependent domains in Rd, by means of a projected Euler scheme. We prove that the constructed method has, as is the case for normal reflection and time-independent domains, an order of convergence equal to 1/2 and we evaluate the method empirically by means of two numerical examples. Furthermore, using a well-known extension of the Feynman-Kac formula, to stochastic differential equations with reflection, our method gives, in addition, a Monte Carlo method for solving second order parabolic partial differential equations with Robin boundary conditions in time-dependent domains.

Effects of Navier slip on unsteady flow of a reactive variable viscosity non-Newtonian fluid through a porous saturated medium with asymmetric convective boundary conditions

A study on the effects of Navier slip, in conjunction with other flow parameters, on unsteady flow of reactive variable viscosity third-grade fluid through a porous saturated medium with asymmetric convective boundary conditions is presented. The channel walls are assumed to be subjected to asymmetric convective heat exchange with the ambient, and exothermic chemical reactions take place within the flow system. The heat exchange with the ambient obeys Newton＇s law of cooling. The coupled equations, arising from the law of conservation of momentum and the first law of thermodynamics, then the derived system are non- dimensionalised and solved using a semi-implicit finite difference scheme. The lower wall slip parameter is observed to increase the fluid velocity profiles, whereas the upper wall slip parameter retards them because of backflow at the upper channel wall. Heat pro- duction in the fluid is seen to increase with the slip parameters. The wall shear stress increases with the slip parameters while the wall heat transfer rate is largely unaltered by the lower wall slip parameter but marginally increased by the upper wall slip parameter.

Synthesis of Some New 1,4-Dihydropyridine Derivatives through a Facile One-pot Hantzsch Condensation Catalyzed by Triethylamine

A facile and efficient synthesis of new 1,4-dihydropyridine derivatives was reported via Hantzsch three-com- ponent condensation reaction of aldehydes or formylphenylboronic acids, ethyl acetoacetate, and ammonium acetate in the presence of a catalytic amount of triethylamine under solvent-free conditions. The method described here of- fers several advantages including high yields, short reaction times, and simple work-up procedure.

The effect of preparation conditions of Pt/Al2O3 on its catalytic performance for the H2-SCR in the presence of oxygen

Selective catalytic reduction of NOχ by H2 in the presence of oxygen has been investigated over Pt/ A12O3 catalysts pre-treated under different conditions. Catalyst preparation conditions exert significant influence on the catalytic performance, and the catalyst pre-treated by HE or H2 then followed by O2 is much more active than that pre-treated by air. The higher surface area and the presence of metallic Pt over Pt/A12O3 pre-treated by HE or pretreated by H2 then followed by O2 can contribute to the formation of NO2, which then promotes the reaction to proceed at low temperatures.

Channel Estimation for One-Bit Massive MIMO Based on Improved CGAN

In the one-bit massive multiple-input multiple-output(MIMO)channel scenario,the accurate channel estimation becomes more difficult because the signals received by the low-resolution analog-to-digital converters(ADC)are quantized and affected by channel noise.Therefore,a one-bit massive MIMO channel estimation method is proposed in this paper.The channel matrix is regarded as a two-dimensional image.In order to enhance the significance of noise features in the image and remove them,the channel attention mechanism is introduced into the conditional generative adversarial network(CGAN)to generate channel images,and im-prove the loss function.The simulation results show that the improved network can use a smaller number of pilots to obtain better channel estimation results.Under the same number of pilots and signal-to-noise ratio(SNR),the channel estimation accuracy can be improved by about 7.5 dB,and can adapt to the scenarios with more antennas.