Design of ground-airborne TEM three-component air-core coil sensor

Transient electromagnetic method (TEM),as a non-seismic geophysical exploration mainstream electromagnetic method,is widely used in oil,gas,mineral and other underground resources exploration areas. The coil sensor is generally used to collect data. In view of the problems of incomplete information of the abnormal body and the data loss in the existing TEM single-component coil sensor,a three-component TEM coil sensor is designed. By analyzing the relationship between sensor sensitivity and coil structure parameters,the coil structure and turns are designed. By analyzing the frequency response characteristics of the TEM magnetic field sensor,the signal distortion is reduced by using the under-damped matching mode. By analyzing the distribution of various noise sources of the magnetic sensor,the appropriate amplifier is selected to reduce the background noise. Finally,a three-component TEM induction magnetic field sensor is designed. The weight of the sensor is controlled at 3.2 kg and the working frequency is 10 mHz-10 kHz. The background noises of X and Y components probably keep in 1.5×10^-8 V/ Hz and sensitivities are 8.4 and 9.8 nT/s,respectively,the background noise of vertical component is 2.1× 10^-7 V/ Hz and sensitivity is 18.5 nT/s. Compared with the existing single-component TEM receiving magnetic field sensor,the designed sensor realizes the signal acquisition of three components. Without too much increase in volume and total weight,it improves the sensitivity of the sensor and reduces the background noise,thus the signal-to-noise ratio (SNR) of the signal is improved.

Three-Component Model for Bidirectional Reflection Distribution Function of Thermal Coating Surfaces

We present a bidirectional reflection distribution function （BRDF） model for thermal coating surfaces based on a three-component reflection assumption, in which the specular reflection is given according to the microfacet theory and Snell＇s law, the multiple reflection is considered Nth cosine distributed, and the volume scattering is uniformly distributed in reflection angles according to the experimental results. This model describes the reflection characteristics of thermal coating surfaces more completely and reasonably. Simulation and measurement results of two thermal coating samples SR107 and S781 are given to validate that this three-component model significantly improves the modeling accuracy for thermal coating surfaces compared with the existing BRDF models.

Statistical Average of Spin Operators for Calculation of Three-Component Magnetization （II）： Solution of Equation

In this paper, the solution of Chebyshev equation with its argument being greater than 1 is obtained. The initial value of the derivative of the solution is the expression of magnetization, which is valid for any spin quantum number S. The Chebyshev equation is transformed from an ordinary differential equation obtained when we dealt with Heisenberg model, in order to calculate all three components of magnetization, by many-body Green＇s function under random phase approximation. The Chebyshev functions with argument being greater than 1 are discussed. This paper shows that the Chebyshev polynomials with their argument being greater than 1 have their physical application.

Low-Frequency Waves in Cold Three-Component Plasmas

The dispersion relation and electromagnetic polarization of the plasma waves are comprehensively studied in cold electron, proton, and heavy charged particle plasmas. Three modes are classified as the fast, intermediate, and slow mode waves according to different phase velocities. When plasmas contain positively-charged particles, the fast and intermediate modes can interact at the small propagating angles, whereas the two modes are separate at the large propagating angles. The near-parallel intermediate and slow waves experience the linear polarization, circular polarization, and linear polarization again, with the increasing wave number. The wave number regime corresponding to the above circular polarization shrinks as the propagating angle increases. Moreover, the fast and intermediate modes cause the reverse change of the electromagnetic polarization at the special wave number. While the heavy particles carry the negative charges, the dispersion relations of the fast and intermediate modes are always separate, being independent of the propagating angles. Furthermore, this study gives new expressions of the three resonance frequencies corresponding to the highly-oblique propagation waves in the general three-component plasmas, and shows the dependence of the resonance frequencies on the propagating angle, the concentration of the heavy particle, and the mass ratio among different kinds of particles.

Dark and multi-dark solitons in the three-component nonlinear Schrodinger equations on the general nonzero background

We exhibit some new dark soliton phenomena on the general nonzero background for a defocusing three-component nonlinear Schrodinger equation. As the plane wave background undergoes unitary transformation SU(3), we obtain the general nonzero background and study its modulational instability by the linear stability analysis. On the basis of this background, we study the dynamics of one-dark soliton and two-dark-soliton phenomena, which are different from the dark solitons studied before. Furthermore, we use the numerical method for checking the stability of the one-dark-soliton solution. These results further enrich the content in nonlinear Schrodinger systems, and require more in-depth studies in the future.

Three-Component Coupling Catalyzed by Phosphine: Preparation of α-Amino γ-Oxo Acid Derivatives

The three-component coupling reaction of ethyl propiolate (1), phthalimide (2), and aldehyde (3) catalyzed by tripheny- lphosphine, was developed. A solution of an equivalent amount of 1 and 2 in benzaldehyde (3a) in the presence of 30 mol% of PPh3 was heated at 100?C for 48 h to give N-(1-ethoxycarbonyl-3-oxo-3-phenylpropyl)phthalimide (4a) in 83% yield. This reaction was thought to proceed via vinylphosphonium salt formed from the reaction of ethyl propiolate (1) with triphenylphosphine in situ.

Localized waves in three-component coupled nonlinear Schrdinger equation

We study the generalized Darboux transformation to the three-component coupled nonlinear Schr ¨odinger equation.First-and second-order localized waves are obtained by this technique.In first-order localized wave,we get the interactional solutions between first-order rogue wave and one-dark,one-bright soliton respectively.Meanwhile,the interactional solutions between one-breather and first-order rogue wave are also given.In second-order localized wave,one-dark-one-bright soliton together with second-order rogue wave is presented in the first component,and two-bright soliton together with second-order rogue wave are gained respectively in the other two components.Besides,we observe second-order rogue wave together with one-breather in three components.Moreover,by increasing the absolute values of two free parameters,the nonlinear waves merge with each other distinctly.These results further reveal the interesting dynamic structures of localized waves in the three-component coupled system.

Statistical Average of Spin Operators for Calculation of Three-Component Magnetization

When one wants to calculate all the three components of magnetization of Heisenberg model under random phase approximation, at least one of the components should be the solution of an ordinary differential equation. In this paper such an equation is established. It is argued that the general expressions of magnetization for any spin quantum number S suggested before are the solution of the ordinary differential equation.

Cooperative NHC/Photoredox Catalysis:Three-Component Reaction of Aroyl Fluorides,Styrenes and Oxalates

Cooperative NHC/photoredox catalysis has emerged as an important research field in recent years.Herein,this article describes the use of cesium salt derivatives of tert-alcohols as alkyl radical precursors in a three-component reaction with styrene and aromatic acyl fluorides to synthesizeα-arylalkyl aryl ketones.The aroyl fluoride reacts with the NHC catalyst,leading to the formation of an acyl azolium ion.This acyl azolium ion can then be reduced by the photoredox catalyst,generating the corresponding ketyl radical anion.The C-radical generated from oxalate oxidation undergoes an addition reaction with the styrene derivative,followed by cross-coupling of the addition radical with the ketone radical,which is fragmented by NHC to give the target ketone.

Metallaphotoredox-Catalyzed Three-Component Couplings for Practical Synthesis of Ureas and Carbamates

Ureas are widely used in drugs,materials and catalysts because of their diamide structure,which can form strong hydrogen bonds.Therefore,it is of great scientific significance to develop efficient and green methods for the synthesis of urea compounds,especially unsymmetrical ureas.Here,we have disclosed novel and highly efficient three-component coupling reactions of organic halides,sodium cyanate and amines enabled by nickel/photoredox dual catalysis for the preparation of unsymmetrical ureas.The reaction features simple and safe operations,broad substrate scopes,and product diversities.It allows the facile synthesis of N-aryl/vinyl ureas from readily available,user-friendly feedstocks under mild conditions(27 examples,36%—98%yields).In addition,this method is further derived to alcohols as nucleophiles to synthesize a series of carbamates(15 examples,40%—95%yields).The mechanism experiment shows that the isocyanate produced by the coupling of halide and sodium cyanate may be the key intermediate in this reaction.

Light-responsive Self-Immolative L-glutamic Acid-based Polyester Nanoparticles for Controlled Drug Release via Passerini Three-Component Polymerization

L-glutamic acid(LA)is a bio-based,non-toxic,environmentally friendly material derived from biomass.The present study reports the application of Passerini three-component polymerization(P-3CP)for the straightforward preparation of LA-based light-responsive polyesters(PLTDs)under mild conditions.PLTDs with molar masses up to 8500 g/mol and high yields exceeding 90%are obtained.The chemical structures and light-responsive self-immolative behavior of PLTDs are comprehensively characterized by employing ultraviolet-visible(UV-Vis)spectroscopy,size exclusion chromatography(SEC),nuclear magnetic resonance(NMR)spectroscopy,and liquid chromatography mass spectrometry(LC-MS).Meanwhile,monodisperse PLTD-based doxorubicin-loaded nanoparticles(PLTD-DOX-NP)(size=193 nm,PDI=0.018)are formulated by nanoprecipitation method.Upon light-induced depolymerization,the PLTD-DOX-NP undergoes rapid decomposition,resulting in a burst release of 80%cargo within 13 s.Furthermore,according to biological toxicity tests,the PLTD-NP possesses adequate biosafety,both before and after irradiation.Overall,the incorporation of P-3CP with biorenewable LA-based monomer adheres to the principles of green chemistry,significantly simplifying the synthetic pathway of light-responsive polymers.

A H_(4)SiW_(12)O_(40)-catalyzed three-component tandem reaction for the synthesis of 3,3-disubstituted isoindolinones

A H_(4)SiW_(12)O_(40)-catalyzed three-component tandem reaction of 2-acylbenzoic acids,primary amines and phosphine oxides to form 3,3-disubstituted isoindolinones was developed.By employing A H_(4)SiW_(12)O_(40)as the catalyst and dimethyl carbonate(DMC)as the solvent,a diverse range of 2-acylbenzoic acid derivatives and primary amines worked well to give the C3-phosphinoyl-functionalized 3,3-disubstituted isoindolinones with the yield range of 61%-87%.Advantages of this transformation include green catalyst and solvent,available starting materials,broad substrate scope,high efficiency and operational simplicity with water as the sole by-product.The strategy achieved an efficient and green molecular fragment assembly to access isoindolinones,which would provide opportunities for the synthesis of potential biologically active molecules in a green manner.

Three-Component Transformation of CO_(2),Propargyl Alcohols and Secondary Amines intoβ-Oxopropylcarbamates Promoted by a Noble Metal-Free Metal–Organic Framework Catalyst

The three-component reaction of CO_(2),propargyl alcohols,and secondary amines frequently applies noble metal or homogeneous catalysts,therefore it is necessary and important to seek a recyclable catalyst without noble metals for this reaction,despite the multitude of challenges.Herein,a unique framework{[Ce3(Cu4I4)2(CNA)8(DMF)8](NO3)}n(CuCe-CNA)with two kinds of metal cluster nodes[Ce3]and[Cu4I4]was synthesized,displaying high thermal and chemical stabilities.CuCe-CNA-300 was obtained by removing the coordinated DMF molecules with[Ce3]cluster at 300°C,in which more metal sites are exposed and the pores are enlarged,but the three-dimensional framework still remains intact.CuCe-CNA-300 can effectively catalyze the three-component reaction of 2-methyl-3-butyn-2-alcohol,CO_(2),and pyrrolidine toβ-oxopropylcarbamates with a yield of 98%under mild conditions,and the catalytic activity is higher than those of noble metal catalysts.Additionally,CuCe-CNA-300 exhibits high catalytic efficiency for various kinds of propargyl alcohols and secondary amines,and also shows good recyclability.Mechanistic studies suggest that theα-alkylidene cyclic carbonates derived from the cycloaddition of propargyl alcohols and CO_(2) are the intermediates,which further react with secondary amines through ammonolysis reaction to generateβ-oxopropylcarbamates.Importantly,this work may open a new avenue for the one-pot transformation of CO_(2) with two or more components into value-added chemicals activated by noble metal-free metal–organic frameworks catalysts.

Photocatalyst-free visible-light-mediated three-component reaction ofα-diazoesters, cyclic ethers and NaSCN to access organic thiocyanates

A facile and environmentally friendly visible-light-induced three-component reaction of α-diazoesters,cyclic ethers and Na SCN to construct organic thiocyanates has been developed at room temperature. This reaction could occur under photocatalyst-and additive-free conditions to afford a number of organic thiocyanates with moderate to good yield and favorable functional group tolerance.

NUMERICAL INVESTIGATION OF THE VENTILATED CAVITATING FLOW AROUND AN UNDER-WATER VEHICLE BASED ON A THREE-COMPONENT CAVITATION MODEL

Based on the Reynolds-Averaged Navier-Stokes equations and mass transfer model, an approach, where a three-component cavitation model is proposed, is presented to simulate ventilated cavitating flow as well as natural cavitation. In the proposed cavitation model, the initial content of nucleus in the local flow field is updated instantaneously, and is coupled with the Rayleigh-Plesset equation to capture the cavity development. The proposed model is applied to simulate the cavitating flow around an under-water vehicle in different cavitation conditions. The results indicate that for the natural and ventilated cavitation simulation, the predicted cavitation characteristics including the cavity length, cavity diameter and cavity shape agree satisfactorily with the analytic and experimental results, for the ventilated cavitation, the proposed methods reproduce the special behavior that the axial line of the cavity bends and rises at the tail part. The study concludes that the ventilated flow rate of the non-condensate gas influences the development of natural cavitation as well as ventilated cavitation, and the vapor cavity is suppressed remarkably by the gas cavity with the increase of the gas ventilation.

Synthesis, Structure and H＋/K＋-ATPase Inhibitory Activity of Novel Triazolyl Substituted Tetrahydrobenzofuran Derivatives via One-pot Three-component Click Reaction

Eleven triazolyl substituted tetrahydrobenzofuran derivatives were synthesized in high yields as novel H＋/K＋- ATPase inhibitor via one-pot Cul-catalyzed three-component click reaction of azide, secondary amine and 3-bromopropyne under mild conditions in water. Their structures were characterized by NMR, IR, ESI-MS, ele- mental analysis and single-crystal X-ray diffraction analysis. Most of the target compounds exhibited better H＋/K＋- ATPase inhibitory activity than commercial omeprazole with IC50 values less than 15 gmol＇L-~. The initial struc- ture-activity analysis suggested that the triazole substituted by cycloalkyl, aromatic ring or O-containing side-chain seemed to be beneficial for enhancing the activity.

Facile three-component synthesis and insecticidal evaluation of hexahydroimidazo[1,2-a]pyridine derivatives

A series of new hexahydroimidazo[1,2-a]pyridine derivatives were synthesized via convenient and practical three-component reactions. Preliminary bioassays showed that majority of the target compounds exhibited moderate to excellent insecticidal activity against cowpea aphids （Aphis craccivora）. Among them, compound 91 demonstrated significant activity with LCso value of 0.00918 mmol/L which was about 3.8-fold higher than that of imidacloprid （IMI）. Furthermore, the study of stereostructure-activity relationship of four isomers of 9k indicated that configuration played a key role in insecticidal activity of these compounds.

Efficient Synthesis of Pyrrolo[2,1-a]isoquinoline and Pyrrolo[1,2-a]quinoline Derivatives via One-pot Two- step Metal-catalyzed Three-component Reactions

A sequential one-pot two-step reaction for efficient synthesis of pyrrolo[2,1-a]isoquinoline and pyrrolo[1,2-a]- quinoline derivatives in good yields has been successfully developed. The reaction included firstly Cu-catalyzed three-component reaction of isoquinoline （quinoline）, acetylenedicarboxylate and alkynylbenzene and then Pd-catalyzed intramolecular C（sp）-C（sp^2） coupling reaction of initially formed 1-alkenyl-2-alkynyl- 1,2-dihydroiso- quinoline （1,2-dihydroquinoline）.

Visible-light-induced three-component reaction of quinoxalin-2(1H)-ones,alkenes and CF_(3)SO_(2)Na leading to 3-trifluoroalkylated quinoxalin-2(1H)-ones

A facile and metal-free visible-light-enabled three-component reaction of quinoxalin-2(1 H)-ones,alkenes and CF_(3)SO_(2)Na has been developed under air at room temperature.This photocatalytic tandem reaction using 4 CzIPN as the photocatalyst and air as the green oxidant,provides a mild and environmentally friendly approach to access a series of 3-trifluoroalkylated quinoxalin-2(1 H)-ones.

Three-component reaction for synthesis of functionalized spiro[indoline-3,4'-pyrano[3,2-h]quinolines]

The functionalized spiro[indoline-3,40-pyrano[3,2-h]quinolines] were efficiently prepared in high yields from three-component reaction of 8-hydroxyquinoline, isatins and malononitrile or ethyl cyanoacetate in ethanol at room temperature for about 12 h in the presence of piperidine.