The Dihedral Angle and Intersection Processes of a Conjugate Strike-Slip Fault System in the Tarim Basin, NW China

Recent studies, focused on dihedral angles and intersection processes, have increased understandings of conjugate fault mechanisms. We present new 3-D seismic data and microstructural core analysis in a case study of a large conjugate strike-slip fault system from the intracratonic Tarim Basin, NW China. Within our study area, ＂X＂ type NE and NW trending faults occur within Cambrian- Ordovician carbonates. The dihedral angles of these conjugate faults have narrow ranges, 19~ to 62~ in the Cambrian and 26~ to 51~ in the Ordovician, and their modes are 42~ and 44~ respectively. These data are significantly different from the ~60~ predicted by the Coulomb fracture criterion. It is concluded that： （1） The dihedral angles of the conjugate faults were not controlled by confining pressure, which was low and associated with shallow burial; （2） As dihedral angles were not controlled by pressure they can be used to determine the shortening direction during faulting; （3） Sequential slip may have played an important role in forming conjugate fault intersections; （4） The conjugate fault system of the Tarim basin initiated as rhombic joints; these subsequently developed into sequentially active ＂X＂ type conjugate faults; followed by preferential development of the NW-trending faults; then reactivation of the NE trending faults. This intact rhombic conjugate fault system presents new insights into mechanisms of dihedral angle development, with particular relevance to intracratonic basins.

Theoretical Studies on Dihedral Angle-Bending Isomers of M2Pt2^0/- Clusters

The structures and electronic properties of the gaseous M2Pt20/-clusters(M represents the alkaline earth metal)were investigated using the density functional theory(B3LYP and PBE0)and wave function theory(SCS-MP2,CCSD and CCSD(T)).The results indicate that the D2 hisomers with the planar structures are more stable than the C2v isomers with smaller dihedral angles and shorter Pt-Pt bond lengths.The mutual competition of M(s,p)-Pt(5d)interaction and Pt-Pt covalent bonding contributes to the different stabilizations of the two kinds of isomers.The M(s,p)-Pt(5d)interaction favors the planar isomers with D2 hsymmetry,while the Pt-Pt covalent bonding leads to the C2 visomers with bending structures.Two different crossing points are determined in the potential energy curves of Be2Pt2 with the singlet and triplet states.But there is just one crossing point in potential energy curves of Ra2Pt2 and Ca2Pt2-because of flatter potential energy curves of Ra2Pt2 with the triplet state or Ca2Pt2-with quartet state.The results reveal a unique example of dihedral angle-bending isomers with the smallest number of atoms and may help the understanding of the bonding properties of other potential angle-bending isomers.

Two Theorems on Volume and Dihedral Angles of a n-dimensional Simplex

In this gape, we obtain thorem I on volum of a n-dirmensional simplex and theorem 2 on dihedral angies of a simplex. Besides. We obtain Vasic inequality in E^n and its extension. The resultsin this paper contain and improve the results in paper [1], [2], [3], [4].

Design methodology of an osculating cone waverider with adjustable sweep and dihedral angles

When considering the practical engineering application of a waverider,the on-design and off-design aerodynamic characteristics of the design conditions,especially the lift-to-drag ratio and the stability,deserve attention.According to recently studies,the planform and rear sight shape of a waverider are closely related to the above aerodynamic performance.Thus,the planform leading-edge profile curve used to design the planform shape of a vehicle is applied to designing an osculating cone waverider.Two key parameters concerned in planform and rear sight shape,namely the plan view sweep angle of the leading edge and the dihedral angle of the underside are introduced to the waverider design process.Each parameter is inserted in the control curve equation.Especially,a parameterization scheme is put forward for the free adjustment of the sweep angle along the leading edge.Finally,three examples are generated for verification and investigation.After the verification process based on the inviscid flow field of one case,the influences of the sweep and dihedral angles on the lift-to-drag ratio and the lateral static stability are evaluated,and meaningful results are obtained.Based on these results,we can conclude that,considering the maximum lift-to-drag ratio,the sweep angle plays a role on the lift-to-drag ratio only at subsonic and trans/supersonic speed as a negligible effect is observed at hypersonic speeds,whereas the dihedral angle is seem to produce a relevant difference at hypersonic speeds.Considering the lateral static stability,the dihedral angles have more influence on the waverider than the sweep angles.

Effect of dihedral angle of bridge unit on the performance of dye-sensitized solar cell

In this work, we investigated the impact of bridge unit on their photo-physical and photovoltaic performance. Increased planarity of the dyes effectively extended the absorption, but reduces the efficiency. Interestingly we found that dyes with a thiophene conjugate unit showed inferior performance when compared with benzene. Theoretical computation indicates a large dihedral angle in the latter system. EIS analysis evidenced the severe recombination in the thiophene-based dye,showing that good planarity may lead to dye aggregation and decrease the efficiency.

The Role of Elytra in Beetle Flight: Ⅰ.Generation of Quasi-Static Aerodynamic Forces

We conducted a comprehensive study to investigate the aerodynamic characteristics and force generation of the elytra of abeetle,Allomyrina dichotoma.Our analysis included wind tunnel experiments and three-dimensional computational fluiddynamics simulations using ANSYS-CFX software.Our first approach was a quasi-static study that considered the effect ofinduced flapping flow due to the flapping motion of the fore-wings (elytra) at a frequency of around 30 Hz to 40 Hz.The dihedralangle was varied to represent flapping motion during the upstroke and downstroke.We found that an elytron producespositive lift at 0° geometric angle of attack,negative lift during the upstroke,and always produces drag during both the upstrokeand downstroke.We also found that the lift coefficient of an elytron does not drop even at a very high geometric angle of attack.For a beetle with a body weight of 5 g,based on the quasi-static method,the fore-wings (elytra) can produce lift of less than 1%of its body weight.

A fast and efficient mesh segmentation method based on improved region growing

Mesh segmentation is one of the important issues in digital geometry processing. Region growing method has been proven to be a efficient method for 3D mesh segmentation. However, in mesh segmentation, feature line extraction algorithm is computationally costly, and the over-segmentation problem still exists during region merging processing. In order to tackle these problems, a fast and efficient mesh segmentation method based on improved region growing is proposed in this paper. Firstly, the dihedral angle of each non-boundary edge is defined and computed simply, then the sharp edges are detected and feature lines are extracted. After region growing process is finished, an improved region merging method will be performed in two steps by considering some geometric criteria. The experiment results show the feature line extraction algorithm can obtain the same geometric information fast with less computational costs and the improved region merging method can solve over-segmentation well.

Some Suggestions Improving Apollo Lunar Laser Retroreflector Arrays

According to our engineering research on satellite-borne laser retroreflector array, some suggestions are proposed on how to manufacture a new Apollo LLRA that can make us measure one illuminating point and unilluminating area on the moon's surface. These suggestions are: to control the dihedral angle offset within ± 0.1″; to use the larger aperture of the transparent face of cube corner prisms; to investigate how to separate out Apollo's reflected laser from mixed beam hitting on the LLR system.

Crystal Structure of 3-(4-Methoxyphenyl)-2-(4-methylbenzoyl)-6,7-dihydro-5H-furo[3,2-g]chromene

The crystal structure of 3-（4-methoxyphenyl）-2-（4-methylbenzoyl）-6,7-dihydro-5H-furo[3,2-g]chromene was obtained by X-ray single-crystal diffraction. The molecule is in the triclinic crystal system, space group P1 with a = 11.0745（4）, b = 13.0953（7）, c = 15.8773（8） ？, α = 92.811（4）, β = 104.815（4）, γ = 111.797（4）o, Z = 4, the final R = 0.0567 and w R = 0.1540. X-ray crystal structure data revealed that one asymmetric structure unit of the title compound contained two molecules. The existence of methyl group changed the dihedral angle between furan ring and the phenyl ring at the C2 position of the furo[3,2-g]chromene scaffold as well as the conformation, and had a further influence on the bioactivity of the furo[3,2-g]chromene derivatives.

Penumbra lunar eclipse observations reveal anomalous thermal performance of Lunakhod 2 reflectors

As the signal reflected by the corner-cube reflector arrays is very weak and easily submerged during the full moon,we analyze the influence of the thermal effect of corner-cube reflector arrays on the intensity of lunar laser ranging echo.Laser ranging measurements during the penumbra lunar eclipse verify suspected thermal deformation in the Lunakhod 2 reflectors.Signal levels vary over two orders of magnitude as the penumbra eclipse progresses.This can be explained by the change in the dihedral angle of the corner-cube reflectors caused by the temperature.The results show that when the dihedral angle errors reach 1,the energy is reduced by 100 times compared with the ideal corner-cube reflector.In the experiment,our findings suggest that when the corner-cube reflector arrays enter the penumbra of the earth,the effective echo signal level which reaches 0.18 photons/s far exceeds the historical level of the full moon.However,11 minutes after the penumbra lunar eclipse,the effective echo rate of Lunakhod 2 will drop two orders of magnitude.The mechanism can explain the acute signal deficit observed at full moon.

Spacial Structure of Cationic Phosphorus Ligand-Ru （Ⅱ） Halide Complexes-by DFT Study

The full-parameter geometry optimization of cationic （ S ） - BINAP - Ru （ Ⅱ ） halide complex was performed by DFT method using B3LYP, PW91 and PBE potentials with several basis sets. PW91 with 3-21G / SDD basis sets is found to be the most suitable method with consideration of both precision and efficiency. The dihedral angles （ θ ） of the binaphthyl or biphenyl with different phosphorus ligand - Ru （ Ⅱ ） halide complexes were found changing from 59.9 to 79.3 degree, while the natural bite angle （ βn ） of those complexes only changes from 87.4 to 90.3 degree. It is different from the common view of asymmetric organic chemists＇ that θ directly influences βn.

Dihedral influence on lateral–directional dynamic stability on large aspect ratio tailless flying wing aircraft

The influence of dihedral layout on lateral–directional dynamic stability of the tailless flying wing aircraft is discussed in this paper. A tailless flying wing aircraft with a large aspect ratio is selected as the object of study, and the dihedral angle along the spanwise sections is divided into three segments. The influence of dihedral layouts is studied. Based on the stability derivatives calculated by the vortex lattice method code, the linearized small-disturbance equations of the lateral modes are used to determine the mode dynamic characteristics. By comparing 7056 configurations with different dihedral angle layouts, two groups of stability optimized dihedral layout concepts are created. Flight quality close to Level 2 requirements is achieved in these optimized concepts without any electric stability augmentation system.

一种含Tröger碱单元的AIE分子的独特力致荧光增强行为

本文报道了一种性能独特的聚集诱导发光分子DTPE-TB,它由位于中间的一个Tröger碱和两端的两个四苯基乙烯(TPE)基团构成.当DTPE-TB分子固体受到机械力作用时,Tröger碱的A-型结构通过改变二面角发生形变承载外力,使分子内运动受限加重,固体荧光增强.而TPE基团受力很小,其排列方式基本不变,所以发光波长仅有微小移动.我们将这种特殊的力致发光变色效应命名为力致荧光增强.

Micro-Raman studies on the conformational behaviors of monosodium glutamate in dehydration process

The conformational behaviors of monosodium glutamate （MSG） in a dehydration process were studied by Micro-Raman spectroscopy in combination with Hartree-Fock calculations using 6-3 1＋G^＊ method. The dehydration process of the MSG droplet was performed by decreasing the ambient relative humidity （RH）. The intensity ratio of the 935 cm^-1 band to 884 cm^-1 band （I935/ 1884） kept decreasing when RH decreased. By optimizing the geometries with different fixed dihedral angles, the downtrend of （I935/I884） is found to be due to the reduction of MSG molecular volume.

On combinatorial Gauss-Bonnet Theorem for general Euclidean simplicial complexes

For a finitely triangulated closed surface M2, let αx be the sum of angles at a vertex x. By the well-known combinatorial version of the 2- dimensional Gauss-Bonnet Theorem, it holds ∑x（2π- αx） =2αχ（M^2）, where X denotes the Euler characteristic of M^2, αx denotes the sum of angles at the vertex x, and the sum is over all vertices of the triangulation. We give here an elementary proof of a straightforward higher-dimensional generalization to Euclidean simplicial complexes K without assuming any combinatorial manifold condition. First, we recall some facts on simplicial complexes, the Euler characteristics and its local version at a vertex. Then we define δ（τ） as the normed dihedral angle defect around a simplex τ. Our main result is ∑τ（-1）^dim（τ）δ（τ） = χ（K）, where the sum is over all simplices τ of the triangulation. Then we give a definition of curvature k（x） at a vertex and we prove the vertex-version ∑x∈K0 k（x） = χ（K） of this result. It also possible to prove Morse-type inequalities. Moreover, we can apply this result to combinatorial （n ＋ 1）-manifolds W with boundary B, where we prove that the difference of Euler characteristics is given by the sum of curvatures over the interior of W plus a contribution from the normal curvature along the boundary B： χ（W）- 1/2 χ（B） = ∑τ∈W-B（-1）^dim（τ）δ（τ） ＋ ∑τB（-1）^dim（τ）ρ（τ）.