Modeling of multiphase flow in low permeability porous media:Effect of wettability and pore structure properties

Multiphase flow in low permeability porous media is involved in numerous energy and environmental applications.However,a complete description of this process is challenging due to the limited modeling scale and the effects of complex pore structures and wettability.To address this issue,based on the digital rock of low permeability sandstone,a direct numerical simulation is performed considering the interphase drag and boundary slip to clarify the microscopic water-oil displacement process.In addition,a dual-porosity pore network model(PNM)is constructed to obtain the water-oil relative permeability of the sample.The displacement efficiency as a recovery process is assessed under different wetting and pore structure properties.Results show that microscopic displacement mechanisms explain the corresponding macroscopic relative permeability.The injected water breaks through the outlet earlier with a large mass flow,while thick oil films exist in rough hydrophobic surfaces and poorly connected pores.The variation of water-oil relative permeability is significant,and residual oil saturation is high in the oil-wet system.The flooding is extensive,and the residual oil is trapped in complex pore networks for hydrophilic pore surfaces;thus,water relative permeability is lower in the water-wet system.While the displacement efficiency is the worst in mixed-wetting systems for poor water connectivity.Microporosity negatively correlates with invading oil volume fraction due to strong capillary resistance,and a large microporosity corresponds to low residual oil saturation.This work provides insights into the water-oil flow from different modeling perspectives and helps to optimize the development plan for enhanced recovery.

Dual Instinct and Structural Theories: DSM-5-TR

The genetic based Dual Instinct Theory is determined by evolutionary history. Aggression is required for survival and sex for propagation of species. Aggressive and sexual drive derivatives with their corresponding defence mechanisms are combined with biologically based stages of infant/child development and the functional entity of Structural Theory. This model of human nature is the applied to the diagnostic categories of DSM-5-TR. Objectives: To follow the innate Dual Instinct Theory from life to death and through Artificial Intelligence;connect it with biological stages of development of the Structural Theory and illustrate its manifestations in DSM-5-TR classifications. Method: Review of selected published literature. Applying the principle of focus and cognition of informed clinical observation of innate drive derivatives in conjunction with The Structural Theory. Both theories are functional entities with no structures involved. Sigmund Freud’s biologically based stages of development;oral, anal, genital pubic, adult, and geriatric along with a variety of unconscious, automatic, and persistent defense mechanisms are selectively folded into diagnosis listed in the manual.

High performance carrier stored trench bipolar transistor with dual shielding structure

We propose a novel high performance carrier stored trench bipolar transistor(CSTBT)with dual shielding structure(DSS-CSTBT).The proposed DSS-CSTBT features a double trench structure with different trench profiles in the surface,in which a shallow gate trench is shielded by a deep emitter trench and a thick oxide layer under it.Compared with the conventional CSTBT(con-CSTBT),the proposed DSS-CSTBT not only alleviates the negative impact of the shallow gate trench and highly doped CS layer on the breakdown voltage(BV),but also well reduces the gate-collector capacitance CGC,gate charge Q_(G),and turn-off loss E_(OFF)of the device.Furthermore,lower turn-on loss E_(ON)and gate drive loss E_(DR)are also obtained.Simulation results show that with the same CS layer doping concentration N_(CS)=1.5×10^(16)cm^(-3),the BV increases from 1312 V of the con-CSTBT to 1423 V of the proposed DSS-CSTBT with oxide layer thickness under gate(T_(og2))of 1μm.Moreover,compared with the con-CSTBT,the C_(GC)at V_(CE)of 25 V and miller plateau charge(Q_(GC))for the proposed DSS-CSTBT with T_(og2)of 1μm are reduced by 79.4%and 74.3%,respectively.With the VGEincreases from 0 V to 15 V,the total QGfor the proposed DSS-CSTBT with T_(og2)of 1μm is reduced by 49.5%.As a result,at the same on-state voltage drop(V_(CEON))of 1.55 V,the E_(ON)and E_(OFF)are reduced from 20.3 mJ/cm^(2)and 19.3 mJ/cm^(2)for the con-CSTBT to8.2 mJ/cm^(2)and 9.7 mJ/cm^(2)for the proposed DSS-CSTBT with T_(og2)of 1μm,respectively.The proposed DSS-CSTBT not only significantly improves the trade-off relationship between the V_(CEON)and E_(OFF)but also greatly reduces the E_(ON).

Analysis of Responses of Floating Dual Pontoon Structure

A numerical model is developed by use of the boundary integral equation method to investigate the responses of a two-dimensional floating structure. The structure under consideration consisting of two pontoons, is connected by a rigid framework, and linked to the sea floor by a mooring system. The theoretical conception is based on potential theory with hnear external forces, and applied to an arbitrarily shaped body and water depth. The discussion includes the influence of draft and space between pontoons on the responses of the floating structure. Finally, the validity of the method is adequately verified by experimental results.

The Chinese Urban-rural Dual Economic Structure Model and Analysis

Based on the characteristics of urban-rural dual economic structure in China,we build a dynamic endogenous urban-rural dual economic model closely linked to China's reality,and carry out mathematical economics analysis of optimized conditions for urban and rural sectors. The main results show that:(i) The labor growth rate of urban-rural sectors must be greater than the time discount rate,or else there would be a vicious cycle of diminishing returns in the sectors;(ii) The accumulation rate of physical capital and human capital of urban-rural sectors,and the rate of technological progress,need to be greater than the corresponding depreciation rate plus the time discount rate,otherwise there would be a vicious cycle of diminishing returns in the sectors;(iii) The low accumulation rate in the rural sector,and the occurrence of labor outflow,human capital loss and lack of investment,will expand income gap between urban and rural areas,which is a reason for solidification of urban-rural dual economic structure.

Superamphiphobic, light-trapping FeSe2 particles with a micro-nano hierarchical structure obtained by an improved solvothermal method

Wettability and the light-trapping effect of FeSe2 particles with a micro-nano hierarchical structure have been inves- tigated. Particles are synthesized by an improved solvothermal method, wherein hexadecyl trimetbyl ammonium bromide （CTAB） is employed as a surfactant. After modifying the particles with heptadecafluorodecyltrimethoxy-silane （HTMS）, we find that the water contact angle （WCA） of the FeSe2 particles increases by 6.1~ and the water sliding angle （WSA） decreases by 2.5~ respectively, and the diffuse reflectivity decreases 29.4% compared with similar FeSe2 particles synthe- sized by the conventional method. The growth process of the particles is analyzed and a growth scenario is given. Upon altering the PH values of the water, we observe that the superhydrophobic property is maintained quite consistently across a wide PH range of 1-14. Moreover, the modified particles were also found to be superoleophobic. To the best of our knowledge, there is no systematic research on the wettability of FeSe2 particles, so our research provides a reference for other researchers.

Investigation on Surface Plasmon Polaritons and Localized Surface Plasmon Production Mechanism in Micro-Nano Structures

The simulation mechanism of surface plasmon polaritons(SPPs)and localized surface plasmon(LSP)in different structures was studied,including the Au reflection grating(Au grating),Au substrate with dielectric ribbons grating(Au substrate grating),and pure electric conductor(PEC)substrate with Au ribbons grating(Au ribbons grating).And the characteristics of the Smith-Purcell radiation in these structures were presented.Simulation results show that SPPs are excited on the bottom surface of Au substrate grating grooves and LSP is stimulated on the upper surface both of Au ribbons grating grooves and Au grating grooves.Owing to the irreconcilable contradiction between optimizing the grating diffraction radiation efficiency and optimizing the SPPs excitation efficiency in the Au substrate grating,only 40-times enhancement of the radiation intensity was obtained by excited SPPs.However,the LSP enhanced structure overcomes the above problem and gains much better radiation enhancement ability,with about 200-times enhancement obtained in the Au ribbons grating and more than 500-times enhancement obtained in the Au grating.The results presented here provide a way of developing miniature,integratable,tunable,high-power-density radiation sources from visible light to ultraviolet rays at room temperature.

Kinematic Structure of a Heavy Rain Event from Dual-Doppler Radar Observations

The detailed kinematic structure of a heavy rain event that occurred in the middle reaches of the Yangtze River was investigated using dual-Doppler radar observation. A variational analysis method was developed to obtain the three-dimensional wind fields. Before the analysis, a data preprocessing procedure was carried out, in which the temporal variation with the scanning time interval and the effect of the earth curvature on the data position were taken into account. The analysis shows that a shear line in the lower and middle levels played an important role in the rainfall event. The precipitation fell mainly on the south end of the shear line where southerly flow prevailed and convergence and updraft were obvious. With the movement and decay of the shear line, the precipitation moved and decayed correspondingly.

Science Letters:Dual structure of composite right/left-handed transmission line

A dual structure of composite right/left handed (CRLH) transmission line (TL) is analyzed in which an inductance LR is in parallel with a capacitance CL and a shunt capacitance CR is in series with an inductance LL. Both the distributed and lumped cases are considered. The dispersion diagram and transmission properties of the dual CRLH TL are given and compared with those of a standard CRLH TL. Contrary to the frequency response of a standard CRLH TL, a dual CRLH TL has a left-handed (negative phase shift) band at higher frequencies and a right-handed (positive phase shift) band at lower frequencies. A novel dual-band balun is presented as an application.

TEMPERING RESPONSE OF A DEFORMED LOW CARBON DUAL PHASE STRUCTURE

The low carbon dual phase structure was cold de formed first,then was tempered at 200 to 600℃.The variation in strength and ductility during tempering of the steel was investigated.It was found that a fter the de formed dual phase structure was tempered at 200 to 600℃, with the increase in the tempering temperature the tensile strength decreases rapidly;the lotal elongation remains constant at 200 to 500℃ but began to rise dramatically at a critical temperature between 500 and 600℃.However,when the non-deformed dual phase structure was tempered at the same temperature range,the tensile strength decreases and the total elongation increases continuously with the increase of temperature.It was demonstrated from TEM analysis that precipitating carbides density along the boundaries ofmartensite lath and the recrystallized grains are responsible for the tempering response ofthe de formed dual phase structure.

Dual Characteristic Pairs in Generalized Complex Structures

This paper presents the relations between spinors and dual characteristic pairs, and gives a way to get the dual characteristic pairs of Dirac structure associated to a generalized complex structure.

Study on Factors Influencing Urban-rural Dual Economic Structure of Chongqing Based on the State Space Variable Parameter Method

Firstly,this paper reviews and analyzes historic background of urban-rural integration of Chongqing,and the evolution and trend of urban and rural dual economic structure.On the basis of previous researches,it selects factors and variables influencing urban and rural dual economic structure,and establishes an econometric model.By state space Kalman filtering method,it analyzes dynamic influence of factors upon urban-rural dual economic intensity.According to empirical conclusion,it puts forward corresponding policy recommendations for promoting integrated urban and rural economic development of Chongqing.

Phase composition, transition and structure stability of functionally graded cemented carbide with dual phase structure

The phase composition, phase transition and phase structure transformation of the wire-cut section of functionally graded WC-Co cemented carbide with dual phase structure were investigated by XRD phase analysis. It is shown that the composition of η phase in the core zone is Co_3W_3C (M_6 C type). The structure of cobalt based solid solution binder phase is fcc type. At the cooling stage of the sintering process, the phase transition of η phase, i.e. M_6C→M_12C and the martensitic phase transition of the cobalt based solid solution binder phase, i.e. fcc→hcp are suppressed, which facilitates the strengthening of the alloy. Because the instantaneous temperature of the discharge channel is as high as 10 000 ℃ during the wire cutting process, the processed surface is oxidized. Nevertheless, the oxide layer thickness is in micro grade. In the oxide film, η phase is decomposed into W_2C and CoO, and cobalt based solid solution binder is selectively oxidized, while WC remains stable due to the existence of carbon containing liquid organic cutting medium.

Bis(1-(4-(dimethylamino)benzylidene)-4-phenylthiose micarbaznato)palladium(Ⅱ):Synthesis,Crystal Structure and Its Dual Fluorescence Property

The title compound bis（1-（4-（dimethylamino）benzylidene）-4-phenylthiosemicar-bazato）-palladium（Ⅱ）（PdL2） was obtained by reacting 1-（4-（dimethylamino）benzylidene）-4-phenyl-thiosemicarbazide with dichlorobis（benzonitrile）palladium（Ⅱ） in methanol,and its structure was characterized by single-crystal X-ray diffraction.The crystal of PdL2 was obtained in dimethyl-formamide（DMF） solvent with solvent molecules involved in the cell and crystallizes in the monoclinic system,space group C2 with a = 18.485（15）,b = 7.090（5）,c = 17.595（11） ,β = 121.21（3）o,V = 1972（2） 3,Z = 2,Mr = 847.40,Dc = 1.427 g/cm3,μ = 0.624 mm-1,F（000） = 880,R = 0.0607 and wR = 0.1358.The Pd atom adopts a distorted square planar coordination geometry with two Pd-N and two Pd-S bonds.The ligand loses a proton from its tautomeric thiol form and coordinates to the Pd atom via mercapto sulfur and the imine nitrogen atom,which binds to palladium as bidentate N,S-donors forming five-membered chelate rings.The complex formed hydrogen bonding interaction with solvent DMF molecules from the hydrogen of phenylamine to the oxygen of DMF and several intramolecular hydrogen bonds.Pd（Ⅱ） perturbed ligand π-π＊ transition and metal-to-ligand charge transfer（MLCT） transition are observed in its electronic absorption spectra.The complex exhibits intraligand 1π-π＊（IL） state and MLCT state dual fluorescent emissions in organic solvent at room temperature.

Space Topologies and Their Dual Space Topologies for Conventional Functional Space Topologies

In this paper, we have studied the topology of some classical functional spaces. Among these spaces, there are standard spaces, spaces that can be metrizable and others that cannot be metrizable. But they are all topological vector spaces and it is in this context that we have chosen to present this work. We are interested in the topology of its spaces and in the topologies of their dual spaces. The first part, we presented the fundamental topological properties of topological vector spaces. The second part, we studied Frechet spaces and particularly the space S(Rn) of functions of class C∞ on Rn which are as well as all their rapidly decreasing partial derivatives. We have also studied its dual S'(Rn) the space of tempered distributions. The last part aims to define a topological structure on an increasing union of Frechet spaces called inductive limit of Frechet spaces. We study in particular the space D(Ω) of functions of class C∞ with compact supports on Ω as well as its dual D' (Ω) the space distributions over the open set Ω.

Potential application of functional micro-nano structures in petroleum

This paper takes micro-nano motors and metamaterials as examples to introduce the basic concept and development of functional micro nano structures, and analyzes the application potential of the micro-nano structure design and manufacturing technology in the petroleum industry. The functional micro-nano structure is the structure and device with special functions prepared to achieve a specific goal. New functional micro-nano structures are classified into mobile type(e.g. micro-nano motors) and fixed type(e.g. metamaterials), and 3 D printing technology is a developed method of manufacturing. Combining the demand for exploration and development in oil and gas fields and the research status of intelligent micro-nano structures, we believe that there are 3 potential application directions:(1) The intelligent micro-nano structures represented by metamaterials and smart coatings can be applied to the oil recovery engineering technology and equipment to improve the stability and reliability of petroleum equipment.(2) The smart micro-nano robots represented by micro-motors and smart microspheres can be applied to the development of new materials for enhanced oil recovery, effectively improving the development efficiency of heavy oil, shale oil and other resources.(3) The intelligent structure manufacturing technology represented by 3 D printing technology can be applied to the field of microfluidics in reservoir fluids to guide the selection of mine flooding agents and improve the efficiency of mining.

Structure and Magnetic Properties of Fe-N Films Prepared by Dual Ion Beam Sputtering

Fe-N films were prepared on Si substrate by dual ion beam sputtering (DIBS). It is found that the crystal structure of the films varies from α-Fe, to ε-Fe2-3N, ε-Fe2-3N +γ-Fe4N, and finally γ'-Fe4N with the increase in substrate temperature (TS). The magnetic properties of the films were investigated by a vibrating sample magnetometer (VSM). The structure of the films is insensitive to the ratios of N2/Ar in main ion source(MIS), and is mainly influenced by the substrate temperature (Ts).

Synthesis and electrochemical performance of micro-nano structured Li Fe1-xMnxPO4/C(0≤x≤0.05)cathode for lithium-ion batteries

Micro-nano structured Li Fe（1-x）MnxPO4/C（0≤x≤0.05）cathodes were prepared by spray drying,followed by calcination at 700°C.The spherical Li Fe（1-x）MnxPO4/C（0≤x≤0.05）particles with the size of 0.5 to5.0μm are composed of lots of nanoparticles of 20 to 30 nm,and have the well-developed interconnected pore structure.In contrast,when Mn doping content is 3 mol%（x=0.03）,the Li Fe（0.97）Mn（0.03）PO4/C demonstrates maximum specific surface area of 31.30 m^2/g,more uniform pore size and relatively better electrochemical performance.The initial discharge capacities are 161.59,157.04 and 153.13 m Ah/g at a discharge rate of 0.2,0.5 and 1 C,respectively.Meanwhile,the discharge capacity retentions are～100%after 120 cycles.The improved electrochemical performance should be attributed to higher specific surface,smaller polarization voltage,and a high Li~＋diffusion rate due to the micro-nano porous structure and lattice expansion produced by Mn doping.