Numerical simulation and dimension reduction analysis of electromagnetic logging while drilling of horizontal wells in complex structures

Electromagnetic logging while drilling(LWD)is one of the key technologies of the geosteering and formation evaluation for high-angle and horizontal wells.In this paper,we solve the dipole source-generated magnetic/electric fields in 2D formations efficiently by the 2.5D finite diff erence method.Particularly,by leveraging the field’s rapid attenuation in spectral domain,we propose truncated Gauss–Hermite quadrature,which is several tens of times faster than traditional inverse fast Fourier transform.By applying the algorithm to the LWD modeling under complex formations,e.g.,folds,fault and sandstone pinch-outs,we analyze the feasibility of the dimension reduction from 2D to 1D.For the formations with smooth lateral changes,like folds,the simplified 1D model’s results agree well with the true responses,which indicate that the 1D simplification with sliding window is feasible.However,for the formation structures with drastic rock properties changes and sharp boundaries,for instance,faults and sandstone pinch-outs,the simplified 1D model will lead to large errors and,therefore,2.5D algorithms should be applied to ensure the accuracy.

ISOPARAMETRIC HYPERSURFACES AND COMPLEX STRUCTURES

The main purpose of this note is to construct almost complex or complex structures on certain isoparametric hypersurfaces in unit spheres.As a consequence,complex structures on S^(1)×S^(7)×S^(6),and on S^(10)×S^(3)×S(2)with vanishing first Chern class,are built.

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.

Experimental Investigation on Complex Structures Machining by Electrochemical Micromachining Technology

Electrochemical micromachining （EMM） technology for fabricating micro structures is presented in this article. By applying ultra short pulses, dissolution of a workpiece can be restricted to the region very close to the electrode. First, an EMM system for meeting the requirements of the EMM process is established. Second, sets of experiments is carried out to investigate the influence of some of the predominant electrochemical process parameters such as electrical parameters, feed rate, electrode geometry features and electrolyte composition on machining quality, especially the influences of pulse on time on shape precision and working end shape of electrode on machined surface quality. Finally, after the preliminary experiments, a complex microstructure with good shape precision and surface quality is successfully obtained.

Simulation of stochastic wind field for large complex structures based on modified Fourier spectrum

Simulation for stochastic wind field is very important in analyzing dynamic responses of large complex structures due to strong wind.The typical simulation method is the spectrum representation method (SRM),but the SRM has drawbacks of inferior precision in lower frequency and slow calculating speed.In view of this,the modified Fourier spectrum method (MFSM) is introduced into the simulation of stochastic wind field in this paper.In this method,phase information of wind velocity time history is determined by cross power spectral density (CPSD) between adjacent points,and the wind velocity time history with time and space correlation is generated by iterative modification for CPSD considering auto power spectral density (APSD).Simulation of the wind field for a long-span bridge is undertaken to verify the effectiveness of the MFSM.Simulation results of the SRM and the MFSM are compared.It can be concluded that the MFSM is more accurate and has higher calculation speed than the SRM.

Product and Complex Structures on 3-Bihom-Lie Algebras

In this paper,we introduce the notion of a product structure on a 3-Bihom-Lie algebra,which is a Nijenhuis operator with some conditions.We prove that a 3-Bihom-Lie algebra has a product structure if and only if it is the direct sum of two vector spaces which are also Bihom-subalgebras.Then we give four special conditions under each of which a 3-Bihom-Lie algebra has a special decomposition.Similarly,we introduce a complex structure on a 3-Bihom-Lie algebra and there are also four types of special complex structures.Finally,we establish the relation between a complex structure and a product structure.

The Bott-Chern and Aeppli Cohomologies of Complex Structures on S^(3)×S^(3)

We calculate the dimensions of Bott–Chern and Aeppli cohomologies associated to a complex structure on S^(3)×S^(3).We express them in terms mainly of Hogde numbers.

A review of the design methods of complex topology structures for 3D printing

As a matter of fact,most natural structures are complex topology structures with intricate holes or irregular surface morphology.These structures can be used as lightweight infill,porous scaffold,energy absorber or micro-reactor.With the rapid advancement of 3D printing,the complex topology structures can now be efficiently and accurately fabricated by stacking layered materials.The novel manufacturing technology and application background put forward new demands and challenges to the current design methodologies of complex topology structures.In this paper,a brief review on the development of recent complex topology structure design methods was provided;meanwhile,the limitations of existing methods and future work are also discussed in the end.

Syntheses and Crystal Structures of Hg(Ⅱ)and Ag(Ⅰ)Complexes Containing 2-Acetylpyridine-paminobenzoylhydrazone Ligand

The two complexes [HgI_2L]（DMF）（1） and [AgL_2]（ClO_4）（CH_3CN）（2） were synthesized from the reaction of Schiff base ligand（2-acetylpyridine-p-aminobenzoylhydrazone）（L） with HgI_2 or AgClO_4 respectively. The compounds are characterized by ^1H NMR,FTIR and elemental analysis. The structures of the ligand and two complexes are measured via single-crystal X-ray diffraction. In these two complexes,the structures are both distorted triangular bipyramids with five-coordinated centers.

Syntheses,Crystal Structures and Antibacterial Activities of Schiff Base of Nickel(Ⅱ)and Copper(Ⅱ)Complexes

A new kind of Schiff base HL（HL= 1-phenyl-3-methyl-4-（p-methylbenzoyl）-5-pyrazolone with L-Leucine methyl ester） and complexes Ni L′_2·0.75C_2H_5OH·0.25H_2O,Cu L′′2（L′ = 1-phenyl-3-methyl-4-（p-methylbenzoyl）-5-pyrazolone with L-leucine ethyl,L′′ = 1-phenyl-3-methyl-4-（p-methylbenzoyl）-5-pyrazolone with L-leucine） have been synthesized and structurally determined by X-ray diffraction. For HL： crystal structure determination indicates that there are two independent HLs with different conformations in one asymmetric unit. For complex 1： the Ni（Ⅱ） ion is six-coordinated by two carbonyl oxygen atoms from pyrazolone ring,two nitrogen atoms from different HL′ and two oxygen atoms from L-Leucine ethyl ester to form a distorted octahedral geometry. For complex 2： the Cu（Ⅱ） ion is four-coordinated by one carbonyl oxygen atom from the pyrazolone ring,one nitrogen atom from HL′′,and two different carboxylic oxygen atoms from L-leucine with the same conformation to form a distorted quadrilateral geometry.

Synthesis,Crystal Structures and Intermolecular Magnetic Coupling Mechanism of the Mononuclear Radical Complex[1-N-methyl-1,10-phenanthrolium][Ni(dmit)_2]

The mononuclear radical anionic complex [1-N-methyl-1,10-phenanthrolium][Ni（dmit）2]（dmit = 1,3-dithiole-2-thione-4,5-dithiolate） with a new countercation has been prepared and its crystal structure was determined by X-ray crystallography at 298 and 80 K. In the mononuclear radical anionic complex, the nickel ion assumes a slightly distorted square-planar geometry. There are two and three kinds of intermolecular interactions between adjacent mononuclear radical anionic complexes in the crystal at 298 and 80 K, respectively（i.e., Models A and B at 298 K; and Models C, D and E at 80 K）. The variable-temperature magnetic moments indicate a strong antiferromagnetic interaction between the adjacent mononuclear radical anionic complexes, and the theoretical calculations reveal that the stronger antiferromagnetic coupling strength at lower temperature should be contributed to the larger overlap integrals between the short contact atoms. This study is the first to reveal the mechanism of stronger magnetic coupling strength at lower temperature for a mononuclear radical anionic nickel complex with dmit as the ligand.

Hydrothermal Syntheses and Crystal Structures of Two Complexes with 3,5-Dinitrosalicylate and 2,2′-Bipyridine Ligands

The two title complexes, [Cd{3,5-（NO2）2sal}（2,2′-bipy）]n 1 and [Mn{3,5- （NO2）2sal}（2,2′-bipy）]n 2 （3,5-（NO2）2sal = 3,5-dinitrosalicylate, 2,2＇-bipy = 2,2′-bipyridine）, were synthesized by the hydrothermal reaction and structurally characterized. Complex 1 crystallizes in triclinic, space group P1, a = 5.581（4）, b = 12.071（8）, c = 12.88（1）A, α= 92.10（3）,β= 96.73（3）, γ = 102.02（2）°, C17H10N407Cd, Mr = 494.69, V= 841（1）A3, Z = 2, Dc = 1.954 g/cm3, F（000） = 488, μ= 1.353 mm^-1, R = 0.0248 and wR = 0.0761. Complex 2 crystallizes in monoclinic with space group P21/c, a = 8.604（3）, b = 23.88（1）, c = 8.894（3） A, β = 102.45（1）°, C17H10N407Mn, Mr = 437.23, V= 1785（1） A3, Z=.4, Dc = 1.627 g/cm3, F（000） = 884, μ = 0.791 mm^-1, R = 0.0471 and wR = 0.1250. Complex 1 possesses an infinite 1D polymeric chain structure consisting of the repeated basic four-membered ring units （Cd2O2） and eight-membered ring units （CdOCO）2. Compound 2displays a linear 1D chain through Mn（Ⅱ） atoms and bridging carboxylate groups of 3,5-dinitrosalicylic acid ligands with the Mn…Mn separation of 4.472（2）A. The fluorescence properties and cyclic voltammetric behaviors of the complexes are also reported.

Syntheses,Structures,and Luminescent Properties of New Zn~Ⅱ-Y~Ⅲ and Zn~Ⅱ-Ln~Ⅲ Schiff Base Complexes

Eight new ZnⅡ-yⅢ and ZnⅡ-LnⅢ heterometallic Schiff base complexes： MZnL2（NO3）3 （M = Y （1）, La （2）, Pr （3）, Nd （4）, Eu （5）, Gd （6）, Dy （7）, Er （8）; L = 2-（（（2- （imidazo[1,5-a]pyridin-3-yl）phenyl）imino）methyl）-6-methoxyphenol）, have been rationally synthesized under solvothermal conditions and characterized by IR, elemental analyses （EA）, single-crystal X-ray diffraction, and powder XRD. Furthermore, luminescence in the visible region for solids 1-8 suggested zine/ligand-centered emission at room temperature.

ClO_4^--directed Assembly of Two Co^ⅡComplexes Based on Flexible N-donor Ligands:Syntheses,Crystal Structures and Magnetic Properties

The reaction of Co^II ions with 1,4-bis（imidazol）butane（bimb） or 1,4-bis（triazol）butane（bitb） in the presence of ClO4^-, respectively affords two CoII coordination complexes, namely {[Co（bimb）3]·2ClO4}n（I） and {[Co（bitb）3]·2ClO4}n（II）. Single-crystal X-ray analysis indicates that both complexes I and II show the same α-Po topological structures. However, complex I exhibits a 2-fold interpenetrating network, while complex II features a 3-fold interpenetrating network. In addition, solid-state properties such as thermal stabilities and magnetic properties of two complexes were also investigated.

Investigation on Molecular and Crystal Structures of Metal Complexes with Aminopolycarboxylic Acids(Ⅰ)─Synthesis and Structure of Na_2[Fe~Ⅲ(ida)2]2·3H_2O

The crystal structure of the title complex salt has been determined by single-crystal X-ray structure analysis. The crystal data are as follows; Monoclinic, P21/c, a=15.6480(10)A,b=16.7870(10)A, c=10.347(2)A, β=90.790(10), V=2717.7(6)A3, Z=3, and R=0.0333 for 4789 unique reflections. The complex anion has a pseudo-octahedral structure distorted more than the CrⅢand CoⅢ analogs, in which cach iminodiacetato ligand (ida2-) is coordinated in a facial fashion with the two N atoms in a cis configuration, resulting in an unsyin-fac structure.

Reactivity of Fe3(CO)(12) with Alkynes R-C≡C-R＇： Syntheses and Crystal Structures of Substituted Cyclic Ketones and Carbonyl Iron Complexes

The reactivity of carbonyl iron cluster with alkynes has been studied by the thermal reaction of Fe_3（CO）_（12） with R-C≡C-R＇（R = Fc（Ferrocenyl）; R′ = Ph（Phenyl）, Fc, H）. The hexacarbonyldiiron cluster with ferracyclopentadiene ring（μ_2, η~4-C_4Ph_4）Fe_2（CO）_6（1） and one tetraphenyl substituted cyclopentadienone（Ph_4C_4CO）（2） were simultaneously obtained by the reaction of Fe_3（CO）_（12） with alkyne（Ph-C≡C-Ph）. Only one ferrole cluster（μ_2, η~4-C_4Fc_2H_2）Fe_2（CO）_6（3） was separated by using Fc-C≡C-H as alkyne. One tri-carbonyl iron complex（η~4-C_4Fc_4CO）Fe（CO）_3（4） and an unexpected new cyclic ketone compound 2,2,4,5-tetraferrocenylcyclopenta-4-en-1,3-di-one [Fc_4C_3（CO）_2]（5） were obtained by using Fc-C≡C-Fc as alkyne. A new complex（η4-2,4-diphenyl-3,5-diferrocenylcyclopenta-2,4-dien-1-one）-tricarbonyl iron（η~4-C_4Ph_2Fc_2CO）Fe（CO）_3（6） was synthesized by the reaction of Fe_3（CO）_（12） with Fc-C≡C-Ph. The structures of compounds 1~6 were determined by X-ray single-crystal diffraction and spectroscopic characterization. The crystal structures of two new compounds 5 and 6 were analyzed. Our experimental results reveal the structural models of the reaction products are affected by the kinds of substituents from alkynes R-C≡C-R′.

Hydrothermal Syntheses and Crystal Structures of Two Complexes with Cyclic Dimer and 2D Network Structures of 3-Nitrophthalate and N-Donor Ligand

Two complexes, [Cd（nphth）（2,2＇-bipy）（H20）]2.2H20 （1） and [Cd（nphth）（4,4＇- bipy）（H20）], （2） （nphth = 3-nitrophthalate, 2,2＇-bipy = 2,2＇-bipyridine, 4,4＇-bipy = 4,4＇-bipyridine）, were synthesized by hydrothermal reactions and structurally characterized. Complex 1 crystallizes in triclinic with space group Pi, a = 0.7599（4）, b = 1.0551（6）, c = 1.2448（6） nm, α = 88.96（2）, β = 75.40（2）, γ= 76.76（2）°, V= 0.9393（9） nm3, Z = 1, Dc = 1.816 Mg/m3, F（000） = 512, μ = 1.217 mm-1, S = 0.946, the final R = 0.0238 and wR = 0.0631, Complex 2 crystallizes in monoclinic, space group P21/c, a = 0.737（5）, b = 2.338（1）, c = 1.0030（6） nm, β = 96：359（9）°, V= 1.803（2） nm3, Z = 4, Dc = 1.826 Mg/m3, F （000） = 984,μ = 1.260 mm-1, S = 1.016, the final R = 0.0455 and wR = 0.1007. Complex 1 exhibits a discrete cyclic binuclear structure and complex 2 possesses a 2D layer structure with cyclic binuclear unit. The fluorescent spectrum study shows that complex 1 exhibits fluorescent emission in the solid state at room temperature.

Syntheses, Crystal Structures and Antibacterial Activities of Cobalt(Ⅱ) and Manganese(Ⅱ) Complexes with Schiff Base Ligand Derived from Tryptamine

Two new mononuclear complexes, namely [Co（L）2]（1） and [Mn（L）2]（2）（HL = N-（3-methylsalicylidene）tryptamine）, have been synthesized by the reactions of the ligand with cobalt acetate or manganese acetate in anhydrous ethanol. The crystal structures of the complexes were characterized by IR spectrum, elemental analysis, PXRD and single-crystal X-ray diffraction analysis. Complex 1 crystallizes in monoclinic, space group C2/c, with a = 23.146（2）, b = 9.4864（10）, c = 13.9261（15）A, β = 102.898（2）°, V = 2980.6（5） ？3, Z = 4, Dc = 1.367 g/cm3, F（000） = 1284 and μ = 0.616 mm^-1. Complex 2 crystallizes in monoclinic, space group P21/n, with a = 14.807（11）, b = 13.118（10）, c = 16.663（13） A, β = 111.237（14）°, V = 3017（4） A^3, Z = 4, Dc = 1.342 g/cm^3, F（000） = 1276 and μ = 0.477 mm-1. The units of complex 1 are linked by intermolecular N–H…π hydrogen bonds into infinite 1D chains, which are further extended into a 3D supramolecular structure by a series of π···π stacking interactions. The units of complex 2 are linked by intermolecular N–H…π hydrogen bonds and C–H…π hydrogen bonds into an infinite 3D supramolecular structure. Meanwhile, the antibacterial activities of the ligand and its complexes have been tested against four kinds of bacteria. The results show that the three compounds all have excellent antibacterial activities and that 1 and 2 possess stronger inhibiting effects against the bacteria than the Schiff base.

Discussion on the Complex Structure of Nilpotent Lie Groups Gk

Consider the real, simply-connected, connected, s-step nilpotent Lie group G endowed with a left-invariant, integrable almost complex structure J, which is nilpotent. Consider the simply-connected, connected nilpotent Lie group Gk, defined by the nilpotent Lie algebra g/ak, where g is the Lie algebra of G, and ak is an ideal of g. Then, J gives rise to an almost complex structure Jk on Gk. The main conclusion obtained is as follows: if the almost complex structure J of a nilpotent Lie group G is nilpotent, then J can give rise to a left-invariant integrable almost complex structure Jk on the nilpotent Lie group Gk, and Jk is also nilpotent.

Large-scale complex physical modeling and precisionanalysis

Large-scale 3D physical models of complex structures can be used to simulate hydrocarbon exploration areas. The high-fidelity simulation of actual structures poses challenges to model building and quality control. Such models can be used to collect wideazimuth, multi-azimuth, and full-azimuth seismic data that can be used to verify various 3D processing and interpretation methods. Faced with nonideal imaging problems owing to the extensive complex surface conditions and subsurface structures in the oil-rich foreland basins of western China, we designed and built the KS physical model based on the complex subsurface structure. This is the largest and most complex 3D physical model built to date. The physical modeling technology advancements mainly involve 1） the model design method, 2） the model casting flow, and 3） data acquisition. A 3D velocity model of the physical model was obtained for the first time, and the model building precision was quantitatively analyzed. The absolute error was less than 3 mm, which satisfies the experimental requirements. The 3D velocity model obtained from 3D measurements of the model layers is the basis for testing various imaging methods. Furthermore, the model is considered a standard in seismic physical modeling technology.