Adjacent Rings Research Articles

Detection of interstellar 1-cyanopyrene: A four-ring polycyclic aromatic hydrocarbon

Polycyclic aromatic hydrocarbons (PAHs) are organic molecules containing adjacent aromatic rings. Infrared emission bands show that PAHs are abundant in space, but only a few specific PAHs have been detected in the interstellar medium. We detect 1-cyanopyrene, a cyano-substituted derivative of the related four-ring PAH pyrene, in radio observations of the dense cloud TMC-1 using the Green Bank Telescope. The measured column density of 1-cyanopyrene is ∼ 1 .52×10 12 cm − 2 , from which we estimate that pyrene contains up to 0.1% of the carbon in TMC-1. This abundance indicates that interstellar PAH chemistry favors the production of pyrene. We suggest that some of the carbon supplied to young planetary systems is carried by PAHs that originate in cold molecular clouds.

On the chemistry of sunlight-induced DNA lesions: A perspective on the alkaline chemical-induced reactivities of photo-damaged pyrimidine intra-strand dimers.

Photoexcitation of cellular as well as isolated DNAs upon exposure to the UV portion of sunlight or other UV sources can lead to the covalent dimerization of adjacent intra-strand stacked pyrimidine nucleobase rings (i.e., at 5'-Py-p-Py-3' sites). These modifications generate, in mammalian DNA as well as the DNA of all other forms of life, lesions such as cyclobutane pyrimidine dimers (CPDs) and pyrimidine (6-4) pyrimidone photoproducts (6-4PPs); and, in bacterial endospores, spore photoproducts (SPs). Importantly, the lesions formed in higher organisms can lead to disease states including cancer. While the formation, structure, and biological outcomes of pyrimidine dimer lesions have been the focus of much research, less has been known about their fundamental chemical properties until recently. Such an understanding of these lesions may lead to novel means to chemically identify and quantitate their presence in the genome. This review is intended to provide an overview of intra-strand pyrimidine dimer lesions derived from 5'-T-p-T sites with a focus on presenting what is currently known about their individual invitro alkaline chemical reactivities. Included here are descriptions of investigations of the DNA lesions CPD, 6-4PP, and SP, and, for comparison, the monomeric pyrimidine lesion 5,6-dihydo-2'-deoxyuridine (dHdU). Of interest, the alkaline hydrolyses of these various lesions are all found to be centered on the loss of aromaticity of a lesion Py ring (T) leading to a carbonyl "hot spot," the focal point of initial hydrolytic attack.

Nano-organic polymers with rich redox sites as anode materials for dual-ion batteries

Organic electrode materials (OEMs) are considered one of the potential electroactive materials used in rechargeable batteries due to their high availability, low price, and sustainability. Nevertheless, the high solubility of their organic small molecules and their low electrical conductivity limit their practical applications. In this study, porous nanorods organic conjugated polymer were successfully prepared by a solvothermal method using 1,4,5,8-naphthalenetetracarboxylic anhydride and azodicarbonamide as precursors for dual-ion battery anodes. The successful synthesis of polymer extends the π-conjugated structure, effectively reducing its solubility in organic electrolytes. Moreover, the azo group (NN) in the polymer was easily conjugated with the adjacent aromatic ring, increasing the utilization of the active site, thereby improving the conductivity of the material so that the polymer has a high discharge capacity (90.5 mAh g−1 at 2 C, up to 96 % capacity retention). Even with a high rate of 10 C, the polymer still exhibits excellent electrochemical performance (50.0 mAh g−1 at 270 cycles). Moreover, reaction kinetics tests show that the electrode material was based on a pseudocapacitive storage mechanism influenced by diffusion and double-layer control. Therefore, the design strategy of such a material paves the way for the application of dual-ion batteries.

Supramolecular assembly governed by tetrel, CN⋅⋅⋅π and other weak noncovalent interactions in two acrylonitrile derivatives with D-π-A topology: Crystallography, optical properties and theoretical studies

Two D-π-A acrylonitriles, (Z)-3-(4-methoxyphenyl)-2-(pyridin-4-yl)acrylonitrile (1) and (Z)-3-(4-piperidin-1-yl)-2-(pyridin-4-yl)acrylonitrile (2), were synthesized to investigate how the varying donor moieties affect their structural and optical properties. Compound 1 crystallized with two crystallographically independent molecules, each showing different orientations of the methoxy group, and exhibited herringbone molecular arrangement in the solid-state. This structure is stabilized by CH···N/π interactions, π-stacking, cyano···π stacking (CN···π) and a σ-hole tetrel bond involving the C and O atoms of the methoxy group. Compound 2 crystallized with a single molecule in the asymmetric unit and displayed columnar packing mode. This structure is stabilized intermolecular CH···N interactions, where all nitrogen atoms serve as acceptors, as well as by intermolecular CH···π interactions and π-stacking between adjacent pyridyl rings. Hirshfeld surfaces and 2D-fingerprint plots revealed the effect of donor moieties on the intermolecular interactions. The energetics of the molecular dimers observed in these structures were characterized by both CLP-PIXEL energy and DFT calculations. The nature of the tetrel bond was characterized using molecular electrostatic surface potential and deformation electron density maps. Theoretical charge density analysis was performed to characterize the noncovalent interactions in various molecular dimers of 1 and 2. The absorption spectra of compounds 1 and 2 exhibit a 40 nm red-shift in solution, attributed to the presence of the piperidyl moiety in compound 2.

Research on Residual Gas Adsorption on Surface of Hexagonal Boron Nitride-Based Memristor.

As a promising nonvolatile memory device with two ends, the memristor has received extensive attention for its industrial manufacture. Density functional theory was used to analyze the adsorption properties of residual gas on hexagonal boron nitride (h-BN)-based memristor model surfaces with Stone-Wales-5577 grain boundary defects [h-BN(SW)]. First, by calculating the adsorption energy, geometric parameters, and charge transfer, we identified the most stable adsorption sites for hydrogen atoms (H-TB1) and H2 molecules (H2-TN2). We observed a tendency toward chemisorption for hydrogen atoms and physical adsorption for H2 molecules at these sites. Furthermore, two coadsorption configurations were formed by introducing H2 molecules and hydrogen atoms into single adsorption configurations: namely H-TB1_H2-TN1TN2 and H2-TN2_H-TB1TN1TN3. In the case of hydrogen-based configuration, there is weak dissociation of the H2 molecule, which does not facilitate hydrogen atom adsorption. However, adjacent hydrogen atoms tend to form stable dimers, while excess hydrogen atoms have a tendency to weakly chemisorb in the case of H2-based configuration. The pristine h-BN surface is more favorable for hydrogen atom migration compared to the h-BN(SW) surface due to its higher adsorption energy. On the h-BN(SW) surface, hydrogen atoms tend to migrate inward from the center of adjacent heptagonal boron nitride rings while coadsorption has a minimal impact on their vertical migration as well as that of H2 molecules. This work provides theoretical insights into the H/H2 trace gas interaction during h-BN wafer-level fabrication for memristor devices.

Case studies of the load-bearing performance of shield tunnel segment with misaligned defects

The segment misalignment is a common defect in the segment installation of a shield tunnel construction, due to the complexity and uncertainty of its construction conditions. This raises a concerning about the safety of the segment lining for the shield tunnel. In this paper, the integrated numerical models with surrounding rock, peastone grouting and segment lining were built using three-dimensional finite element method, by introducing two kinds of misaligned defects of segments. One was the misalignment that elongated the horizontal axis of the transversal ring section of segment lining, another was the misalignment between adjacent rings of segments. To eliminate the impact of boundary on numerical results, seven rings of segments are built for the three-dimensional finite element models, and the middle ring is dealt with for the results analysis under V-class surrounding rock, including the circumferential stress of outer and inner layers of the segment, the contact stress on joint surface between segments, and the stress of locating pins between adjacent rings. Results indicate that the two kinds of misaligned defects create pronounced impact on tensile stress of segment at the bottom and the crown segments, respectively, which produces a greater tensile stress to increase cracking risk even abrupt fracture of segment. However, the misaligned defects have a slight impact on the contact stress and the locating pins stress. Therefore, attention should be paid to the cracking of bottom or crown segments in the segment lining of shield tunnel.

Effect of the Inter-Ring Delay Time on Rock Fragmentation: Field Tests at the Underground Mine

The effect of inter-ring delay time (IRDT) on rock fragmentation in the tunnel excavation blasting was studied at the Xinjiang Beizhan Iron Mine, China, to improve the rock fragmentation and optimize the blast design. Blasting tests were conducted with an IRDT of 50, 100, 150, 200, and 500 ms; each adjacent ring had an equal IRDT, and two replicate tests were conducted. The blasting plan with IRDT of 100 ms was the original blasting plan used in the mine. Two optimized blasting plans were proposed and implemented based on the experimental results, along with a control experiment using the original blasting plan. The fragment size of each blast test was measured and analyzed by the block-analyzed software. Both collision theoretical and field tests indicated that the IRDT plays an important role in rock fragmentation and that as the IRDT increases, the degree of rock fragmentation increases first and then decreases. For example, the fragment sizes X20, X50, and X80 showed an increase followed by a decrease; the percentage of large fragments (1-P750) showed a decline followed by a rise; the percentage of small fragments P25 showed an increase followed by a decline. The blasting plan with an IRDT of 150 ms had the most optimal rock fragmentation effect, with the lowest percentage of large fragments, the highest percentage of small fragments, and the smallest average fragment size of X50. Furthermore, the two optimized blasting plans demonstrated better control over blasting costs and rock fragmentation compared to the original blasting plan.

Tricyclic 1,4-Diphosphinines: Local vs. Global Aromaticity.

1D and 2D (Sigma only model) calculations were performed on recently established tricyclic 1,4-diphosphinines as well as related benzene and pyrazine derivatives. The study was extended to evaluate the effect of the fused rings on the overall aromatic properties with a special focus on functional groups such as carbenes. The effect of non-aromatic heterocycles on the local ring current of the central ring is small, while aromatic heterocycles (e. g. NHC, imidazolium) lead to a global aromaticity. A higher sulfur content of the adjacent five-membered rings reduces the central ring current. The comparison to related tricyclic benzene and pyrazine derivatives showed that the 1,4-diphosphinine systems resemble more closely the situation in the benzene derivatives than the pyrazines. The effect of charged systems was studied using bis(TTF)-fused 1,4-diphosphinines and, according to values, the neutral form doesn't possess significant aromaticity but the tetracation resembles the global aromatic situation observed for other heterocycles in this study.

Propagation properties of a partially coherent Laguerre–Gaussian beam with multiple off-axis vortex phases

In this paper, a new theoretical model of a partially coherent Laguerre–Gaussian (LG) beam carrying multiple off-axis vortex phases was established. The evolution properties of the focused intensity of the beam after passing through a thin lens were theoretically studied, and then the modulation effect of multiple off-axis vortex phases on the beam with multiring structured intensity was explored. The results indicate that the multiple off-axis vortex phases can reconstruct the multiring structured intensity within the LG beam, thus generating a structured intensity with multilobe and multiring patterns. What is more, the intensity distribution of the lobes between two adjacent rings is complementary, and its number is related to the number and topological charge of off-axis vortex phases. However, with a decrease in the coherence, such a multilobe and multiring structured intensity distribution disappears, gradually evolves into a polygonal flat-topped distribution, and finally degenerates into a quasi-Gaussian distribution. This work demonstrates the effective regulation of multiple off-axis vortex phases on a beam with a multiring structured intensity and indicates that regulating the multiple off-axis vortices provides an additional degree of freedom for optical field modulation, which will have potential applications in the fields of optical micromanipulation and optical information storage.

Quantum Chemical Investigation into the Structural Analysis and Calculated Raman Spectra of Amylose Modeled with Linked Glucose Molecules.

This study presents a quantum chemical investigation into the structural analysis and calculated Raman spectra of modeled amylose with varying units of linked glucose molecules. We systematically examined the rotation of hydroxymethyl groups and intramolecular hydrogen bonds within these amylose models. Our study found that as the number of linked glucose units increases, the linear structure becomes more complex, resulting in curled, cyclic, or helical structures facilitated by establishing various intramolecular interactions. The hydroxymethyl groups were confirmed to form interactions with oxygen atoms and with hydroxymethyl and hydroxyl groups from adjacent rings in the molecular structures. We identified distinct peaks and selected specific bands applicable in various analytical contexts by comparing their calculated Raman spectra. Representative vibrational modes within selected regions were identified across the different lengths of amylose models, serving as characteristic signatures for linear and more coiled structural conformations. Our findings contribute to a deeper understanding of amylose structures and spectroscopic signatures, with implications for theoretical studies and potential applications. This work provides valuable reference points for the detailed assignment of Raman peaks of amylose structure, facilitating their application in broader research on carbohydrate structures and their associated spectroscopic properties.

Characterize and Mediate Assembly of Triptycenes on Au(111) Surface.

Herein, we report the assembly behavior of triptycenes with aldehyde (Trip-1) and amino (Trip-2) groups on pristine and iodine-passivated Au(111) surfaces by a combination of scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and density functional theory (DFT) calculation. On Au(111) surface, Trip-1 forms long trimer chains and two-dimensional islands via aldehyde-aldehyde hydrogen bonding in one dimension and π-π stacking of adjacent benzene rings in the other dimension. In contrast, Trip-2 lies as individuals or in disorderly stacked islands. Trip-2 and Trip-1 can be mixed in an arbitrary ratio. And Trip-2 molecules disrupt the ordered self-assembly structure of Trip-1 due to the formation of stronger aldehyde-amino hydrogen bonding. DFT, XPS, and Raman spectra confirm the conformational difference of Trip-1 and -2, as well as the aldehyde-amino hydrogen bonding formation in Trip-1 and Trip-2 mixture. On the iodine-passivated Au(111) surface, Trip-1 forms single-molecule chains and a hexagonal closely packed structure due to iodine interlayer mediation. Trip-2 molecules disrupt the hexagonal closely packed structure of Trip-1.

2-(10-Bromoanthracen-9-yl)-N-phenylaniline

In the title compound, C26H18BrN, the central benzene ring makes dihedral angles with its adjacent anthracene ring system and pendant benzene ring of 87.49 (13) and 62.01 (17)°, respectively. The N—H moiety is sterically blocked from forming a hydrogen bond, but weak C—H...π interactions occur in the extended structure.

Monitoring and assessment of mechanical response of large-scale prefabricated structures in underground subway stations during construction process

Mechanical performance of prefabricated structural components during construction is critical for ensuring long-term safety and durability of prefabricated underground stations (PUS). This study aims to address the issues of structure mechanical performance of large-scale prefabricated components during assembling process. First, a strain transfer model for five-layered armored fiber optic is proposed and validated experimentally through test. Second a PUS-based distributed fiber optic sensors (DFOS) monitoring system was established. Third, a PUS based hierarchical performance assessment framework was constructed. Finally, a PUS based theoretical Construction Intelligent Monitoring Assessment Model (CIMAM) was established to quantitively assess structure safety level. A case study of Shenzhen Metro PUS was performed, and the results showed that: (a) PUS-based DFOS monitoring system presents high accuracy and high resolution, (b) The monitoring system reflects the PUS reactions during the whole construction process with good adaptability and intelligence, (c) PUS-CIMAM results show that the assembly process of components is a significant control link, particularly the performance of large-span roof during assembling process is a key controlling component, and (d) PUS-CIMAM reveals the adjacent ring construction has a disturbing effect.

Study on the Fracture of a Shield Segment in a Fully Excavated Hard Rock Section under the Influence of Construction Loads

In this paper, the initiation of the fracture of a segment caused by the pressure of the jack and other factors during shield construction is discussed. Based on the Rots model in the finite element software Diana 10.4, the fracture width is solved. Combined with in situ measurements, the mechanisms of concrete fracturing of a segment under external loads, such as the jack thrust deflection angle and uneven jack thrust caused by the changes in the segment due to the upward buoyancy and shield attitude, are studied; additionally, the occurrence conditions and engineering control measures for segment fracture are summarized. The results show that when the attitudes of the shield and segment are identical, the total thrust of the shield is recommended not to exceed 21,000 kN, and is strictly limited to 24,000 kN. When the attitude inclination angle between the shield machine and the segment is less than 1°, the impact on the segment quality is small. When the inclination angle reaches 2°, the total thrust of the shield is recommended not to exceed 16,000 kN, and is strictly limited to 18,000 kN. When the inclination reaches 3°, a fracture is easily produced. When the total thrust is 19,000 kN, it is recommended that the loading increase or decrease in the left and right four grippers should not exceed 20%, and they are prohibited to exceed 30%. The fracture width increases exponentially with the increase in misalignment between adjacent segment rings. These research results provide a theoretical basis for jack pressure control during shield construction.

Mechanistic Insights into the Excited-State Intramolecular Proton Transfer (ESIPT) Process of 2-(2-Aminophenyl)naphthalene.

The 2-(2-aminophenyl)naphthalene molecule attracted much attention due to excited-state intramolecular proton transfer (ESIPT) from an amino NH2 group to a carbon atom of an adjacent aromatic ring. The ESIPT mechanisms of 2-(2-aminophenyl)naphthalene are still unclear. Herein, the decay pathways of this molecule in vacuum were investigated by combining static electronic structure calculations and nonadiabatic dynamics simulations. The calculations indicated the existence of two stable structures (S0-1 and S0-2) in the S0 and S1 states. For the S0-1 isomer, upon excitation to the Franck-Condon point, the system relaxed to the S1 minimum quickly, and then there exist four decay pathways (two ESIPT ones and two decay channels with C atom pyramidalization). In the ESIPT decay pathways, the system encounters the S1S0-PT-1 or S1S0-PT-2 conical intersection, which funnels the system rapidly to the S0 state. In the other two pathways, the system de-excited from the S1 to the S0 state via the S1S0-1 or S1S0-2 conical intersection. For the S0-2 structure, the decay pathways were similar to those of S0-1. The dynamics simulations showed that 75 and 69% of trajectories experienced the two ESIPT conical intersections for the S0-1 and S0-2 structures, respectively. Our simulations showed that the lifetime of the S1 state of S0-1 (S0-2) is estimated to be 358 (400) fs. Notably, we not only found the detailed reaction mechanism of the system but also found that the different ground-state configurations of this system have little effect on the reaction mechanism in vacuum.

Numerical study on the influence of excavation slope on the structural behavior of ground penetrating shield tunnels

The ground penetrating shield technology (GPST) is a fast shield tunnelling method, wherein the shield is launched and received at the ground surface without constructing deep and large working shafts. With regard to the notable sloping excavation characteristics of the GPST, this study established a three-dimensional numerical model to analyze the impact of the excavation slope on the structural response of the tunnel lining based on the South Longshui Road Cross-river Tunnel project in Shanghai. The results indicate that the circumferential earth pressure acting on the lining is determined by both the buried depth and decomposition angle induced by the change in the excavation slope. The distribution of the earth pressure along the longitudinal direction may be affected by the excavation slope, and this subsequently affects convergence deformation of the tunnel. An increase in the excavation slope equalized the distributed force acting on the lining. In addition, the existence of circumferential joints exaggerates the impact of the excavation slope on the differential convergence between adjacent rings. A larger excavation slope resulted in a decrease in the proportion of convergence deformation caused by the longitudinal joints. These findings can provide important guidance for controlling the ovalization and dislocation behaviors of GPST.

Hydroxyl-assisted globally spontaneous dynamic oxygen migration on biphenylene

Dynamic covalent interfaces (DCIs) can autonomously adjust their internal structures and dynamically respond to changes in the external environment, thus holding broad application prospects in drug delivery, molecular detection, and interface catalysis. However, the dynamic properties of such DCIs greatly rely on the localized exchanges or formations of chemical bonds, seriously constraining the adaptive response efficiency. To transcend the limitations of the dynamic two-dimensional (2D) scales, employing the experimentally synthesized biphenylene monolayer as a prototype, we systematically study the hydroxyl-assisted globally spontaneous dynamic oxygen migration on biphenylene interface based on the first-principles calculations and machine-learning-based molecular dynamics (MLMD) simulations. The calculated results indicate that the stable dangling oxygen atoms on the biphenylene monolayer can attract the proton in the interfacial water, which in turn undergoes a water dissociation process and produces hydroxyl groups on the biphenylene interface. Assisted by the hydroxyl groups, the dangling oxygen atoms can achieve long-range migration, exhibiting notably low energy barriers (0.09 eV, 0.04 eV) due to the reversible proton transfer reactions. Therefore, the local dynamic covalent behaviors of oxygen atoms on the biphenylene interface are broken with the oxygen atoms migrating between the adjacent C4 rings. More importantly, the charge density difference and Bader charge analysis demonstrate that the presence of hydroxyl groups significantly enhance the stability of the dangling oxygen, effectively reducing energy barriers of oxygen migration compared to epoxy on the biphenylene interface. Furthermore, the MLMD trajectories visually show the process of realizing large-area DCIs on the biphenylene monolayer. Our work not only clarifies the oxygen-related dynamic behavior of the biphenylene interface, but also provides new ideas for the realization of large-area dynamic covalent materials (DCMs) on other carbon-based or 2D materials.

The Role of Intramolecular Reactions and Chemical Degradation in the Apparent Biotransformation Pathways of a Series of SYK Inhibitors.

In vitro metabolism studies of the spleen tyrosine kinase inhibitors AZ-A and AZ-B identified four unusual metabolites. M1 (mass-to-charge ratio 411) was formed by both molecules and was common to several analogs (AZ-C to AZ-H) sharing the same core structure, appearing to derive from the complete loss of a pendent 3,4-diaminotetrahydropyran ring and pyrazole ring cleavage resulting in a nonobvious metabolite. M2-M4 were formed by AZ-A and a subset of the other compounds only and apparently resulted from a sequential loss of H2 from parent. Initial attempts to isolate M3 for identification were unsuccessful due to sample degradation, and it was subsequently found that M2 and M3 underwent sequential chemical degradation steps to M4. M4 was successfully isolated and shown by mass spectrometry and NMR spectroscopy to be a tricyclic species incorporating the pyrazole and the 3,4-diaminotetrahydropyran groups. We propose that this arises from an intramolecular reaction between the primary amine on the tetrahydropyran and a putative epoxide intermediate on the adjacent pyrazole ring, evidence for which was generated in a β-mercaptoethanol-trapping experiment. The loss of the tetrahydropyran moiety observed in M1 was found to be enhanced in an analog that was unable to undergo the intramolecular reaction step, leading us to propose two possible reaction pathways originating from the reactive intermediate. Ultimately, we conclude that the apparently complex and unusual metabolism of this series of compounds likely resulted from a single metabolic activation step forming an epoxide intermediate, which subsequently underwent intramolecular rearrangement and/or chemical degradation to form the final observed products. SIGNIFICANCE STATEMENT: The current work provides an unusual biotransformation example showing the potential for intramolecular reactions and chemical degradation to give the appearance of complex metabolism arising from a single primary route of metabolism.

Indenoannulated Tridecacyclene: An All-Carbon Seven-Stage Redox-Amphoter.

We disclose an indenoannulated tridecacyclene comprising a central cyclooctatetraene moiety with multiple adjacent pentagonal rings which is accessible in a concise synthetic sequence. The saddle-shaped geometry of the non-benzenoid polycyclic scaffold and its unique packing behavior in the solid state were characterized by X-ray crystallography. In electrochemical studies, the compound undergoes seven reversible redox events comprising five reductions and two oxidations. The dicationic and dianionic species obtained by chemical oxidation and reduction, respectively, were characterized spectroscopically in solution. Density functional theory calculations were applied to provide insights into aromaticity evolution in the respective charged species, highlighting the beneficial effect of the non-benzenoid moieties on charge stabilization.

Effect of the tip speed ratio on the wake characteristics of wind turbines using LBM‐LES

AbstractIn this paper, the wake characteristics of Zell 2000 wind turbine under different tip velocity ratios are studied by using the lattice Boltzmann method and large eddy simulation. The adaptive mesh refinement method is performed to capture the fine flow structure and wake characteristics development. In this paper, we mainly focus on the effect of the tip speed ratio on the flow structure and unsteady characteristics of wind turbine wake. The three‐dimensional flow vorticity structures, the section vorticity diagram, the pressure fluctuation of wake and the lift coefficient of wind turbine wake are utilized to explore the effect of the tip speed ratio on the unsteady physics mechanism of wind turbine wake. With the increase of the tip speed ratio, the distance between two adjacent vortex rings along the axial direction gradually decreases, as the position of the broken vortex circles gradually approaches the center of the blade, separated vortexes are rapidly generated, and the coherent structure appears closer to the wind turbine. A relationship is established between the tip speed ratios and the positions of the broken vortex circles. It is further found that the dominant frequency amplitude gradually increases with the increase of tip speed ratio and the pressure amplitude spectra of vortex increases with the decrease of the distance between the wake and the center of the blade axis. The above series of studies can provide significant physical insight into deep understanding the influence of the tip speed ratio on the wake characteristics of wind turbines.