Fragmentation Modes Research Articles

The Influence of Short Videos on College Students Purchasing Behavior

Short video has gradually developed into one of the practical expression ways of information content communication in the mobile Internetvarious social media and e-commerce use opportunities from this trend. College students are the most active and mainstream group in Short video. The fragmented communication mode, exciting content, and business behavior of short videos have been integrated into the group of college students, influencing them all the time, including but not limited to purchasing behavior. In this paper, college students are selected to build a mechanism model of the influence of word-of-mouth characteristics of social e-commerce networks on college students purchase intention, and the model is tested through empirical research. The results showed that when brand marketing is enhanced, brand interaction, experience perception, interest, and perception are enhanced. The more frequently consumers interact with the brand, the more frequently they connect and communicate with it, and their purchasing behavior will be enhanced.

Investigation on axial evolution of particle group and conversion of a single coal particle in an impinging entrained-flow gasifier

Based on a bench-scale impinging entrained-flow gasifier and visualization system, the conversion of particle group and a single coal particle in the impinging-flow zone below the burner plane is investigated in-situ. The axial evolution of particle group including particle size, particle concentration, velocity field and spatial distribution is characterized with image processing algorithm and statistical method. The particle fragmentation, single particle conversion process and volatile oxidation behavior are discussed. The results indicate that the Sauter mean diameter (SMD) is distributed in 560–720 µm in all statistical regions, and the particle concentration is distributed in 20,000–360,000. With the axial downward movement of the particle group, the SMD, particle concentration and spatial distribution frequency show an overall decreasing trend. The proportion of particles ranging in the velocity interval of 0–4 m/s increases in the three impinging-flow zones, which are 85.76 %, 92.33 % and 97.88 %, respectively. The fragmentation mode of a single coal particle can be classified into central fragmentation and peripheral fragmentation. The occurrence probabilities of the two modes in the upper impinging-flow zone are more than one-third, indicating that the particles tend to be fragmented near the burner plane. The conversion of a single coal particle can be divided into heat up and pyrolysis, volatile oxidation, volatile/char oxidation and char oxidation. In the upper impinging-flow zone, less than 30 % of the particles are in volatile oxidation stage, while about 50 % of the particles are in char oxidation stage. With the axial downward movement of the particle group, the proportion of particles in char oxidation stage decreases, while the proportion of particles in volatile oxidation stage shows an opposite trend. A macroscopic description of ignition and propagation of particle volatile flame is proposed. The propagation of volatile flame between singles particles can be extended to the propagation of volatile flame within particle groups.

Tracking the cost of living, for whom and at what price? A political economy of price indicators in Madagascar

This article studies the production and meaning of price indicators in Madagascar, a post-colonial context characterized by a weak state, the prominence of international aid, and repeated food crises. We observe a profusion of indicators, data, and analyses related to prices. Such profusion illustrates not only different meanings of the cost of living but also fragmented economies and a fragmented mode of government in which nongovernmental organizations and international organizations play a leading role. Whatever their efforts, these initiatives struggle to capture the specific features of the cost of living in a context where the subsistence economy remains hardly convertible into numbers. Our analysis confirms the close links between statistical production and modes of government. The Malagasy Consumer Price Index coexists with many disparate initiatives aimed to cope with inequalities and emergencies, reflecting a country in the throes of repeated political, economic, and social crises.

Modelling and mechanical characteristics of PDC cutter-rock interaction by combining mixed fragmentation modes with dynamic rock strength

Polycrystalline diamond compact (PDC) bit is one of the most widely used drill bits for improving the rate of penetration in deep oil and gas well and geothermal well. However, the dynamic rock fragmentation mechanics characteristics of PDC bits are still unclearly. A coupled fragmentation mechanics model of PDC cutter-rock interaction is established by combining the mixed fragmentation modes with dynamic strength. The coupling influence laws of cutter angle, cutting depth, dynamic strength ratio, breaking modes on the horizontal force coefficient (HFC), vertical force coefficient (VFC) and specific energy are analyzed. The model of this paper can optimize cutter inclination angle, cutting depth and minimum specific energy. With the increase of the cutter inclination angle, the dynamic VFC changes into two modes. The definition of the dynamic modes depends on the dynamic strength ratio. As the cutting angle increases, the cutting force increases. The cutting force increases nonlinearly with increasing cutting depth. The specific energy of rock fragmentation increases nonlinearly with increasing cutting depth. With the increase of dynamic strength, the specific energy of rock fragmentation increases nonlinearly. When the input-energy increases, the rate of penetration response is divided into three stages. The results have important guiding significance for the PDC bit design and drilling parameters optimization to increase the rate of penetration and the efficiency of exploration and development.

Influences of size, shape and strain rate on mechanical properties of single coral particle

To understand the roles of particle size, shape, and strain rate on their mechanical properties, the crushing behavior of 800 coral particles with different shape factors and size groups (i.e., 2.36–4.75 mm, 4.75–9.5 mm and 9.5–16 mm) at various loading rates (i.e., 0.06 mm/min, 0.6 mm/min, 3 mm/min and 10 mm/min) are studied. The results show that the particle crushing strength and Young's modulus perfectly conform to the Weibull statistic law. Particle crushing strength decreases with an exponent of (−0.816) of particle size and increases with an exponent of 0.062 of strain rate, and a mathematical model incorporating particle size, shape, and strain rate is proposed to explain the change of characteristic crushing strength. Additionally, irregularity, elongation, and flatness strongly relate to the crushing strength and Young's modulus, and establish a functional relationship with the geometric similarity parameter of the Weibull model. The fragmentation behavior is classified into three typical modes, and the change of fragmentation modes is affected by particle size, strain rate, and irregularity. Young's modulus calculated by Hertz theory is 0.7–0.9 GPa. The characteristic Young's modulus is in descending order of rodlike, flaky, blocky, and dendritic particles, hardly influenced by particle size and strain rate. The results can provide a reference for the microscopic numerical analysis of coral concrete.

Kinematics and stability of high-mass protostellar disk candidates at sub-arcsecond resolution

Context. The fragmentation mode of high-mass molecular clumps and the accretion processes that form the most massive stars (M ≳ 8 M⊙) are still not well understood. A growing number of case studies have found massive young stellar objects (MYSOs) to harbour disk-like structures, painting a picture that the formation of high-mass stars may proceed through disk accretion, similar to that of lower-mass stars. However, the properties of such structures have yet to be uniformly and systematically characterised. Aims. The aim of this work is to uniformly study the kinematic properties of a large sample of MYSOs and characterise the stability of possible circumstellar disks against gravitational fragmentation. Methods. We have undertaken a large observational programme (CORE) making use of interferometric observations from the Northern Extended Millimetre Array (NOEMA) for a sample of 20 luminous (L > 104 L⊙) protostellar objects in the 1.37 mm wavelength regime in both continuum and spectral line emission, reaching 0.4″ resolution (800 au at 2 kpc). Results. We present the gas kinematics of the full sample and detect dense gas emission surrounding 15 regions within the CORE sample. Using the dense gas tracer CH3CN, we find velocity gradients across 13 cores perpendicular to the directions of bipolar molecular outflows, making them excellent disk candidates. The extent of the CH3CN emission tracing the disk candidates varies from 1800 to 8500 au. Analysing the free-fall to rotational timescales, we find that the sources are rotationally supported. The rotation profiles of some disk candidates are well described by differential rotation while for others the profiles are poorly resolved. Fitting the velocity profiles with a Keplerian model, we find protostellar masses in the range of ~ 10–25 M⊙. Modelling the level population of CH3CN (12K–11K) K = 0–6 lines, we present temperature maps and find median temperature in the range 70–210 K with a diversity in distributions. Radial profiles of the specific angular momentum (j) for the best disk candidates span a range of 1–2 orders of magnitude, on average ~10−3 km s−1 pc, and they follow j ∝ r1.7, which is consistent with a poorly resolved rotating and infalling envelope-disk model. Studying the Toomre stability of the disk candidates, we find almost all (11 out of 13) disk candidates to be prone to fragmentation due to gravitational instabilities at the scales probed by our observations, as a result of their high disk to stellar mass ratio. In particular, disks with masses greater than ~ 10–20% of the mass of their host (proto)stars are Toomre unstable, and more luminous YSOs tend to have disks that are more massive compared to their host star and hence more prone to fragmentation. Conclusions. In this work, we show that most disk structures around high-mass YSOs are prone to disk fragmentation early in their formation due to their high disk to stellar mass ratio. This impacts the accretion evolution of high-mass protostars which will have significant implications for the formation of the most massive stars.

Analysis of Rock Breaking Parameters and Simulation of Mechanical Characteristics of Multi-Nozzle Jet Impact

With the continuous development of high-pressure water jet technology, research on the optimization of structural parameters for multi-nozzle configurations, the perforation effect of jet rotational impact rock breaking, and the impact force during rock breaking has received increasing attention. Through the development of a self-designed high-pressure water jet rotational drilling test device, rock breaking experiments were conducted on sandstone of different strengths using jet streams with different inclination angles, various combinations of nozzles, different target distances, and different rotational speeds. The parameters and structure of the multi-nozzle jet drill bit were optimized, and the impact of water jet-rock breaking effects was studied. The rationality of different inclination-angle jet streams in rock breaking was verified using the ALE-FEM coupling method. The changes in the force on the target body and the fragmentation mode during rock breaking with different inclination-angle jet streams were analyzed. The results showed that under the condition of adjustable inclination angles, a smaller inclination angle resulted in greater depth and a smaller diameter of rock breaking, while a larger inclination angle resulted in greater width and a smaller depth of rock breaking. The optimal combination of multi-nozzle jet streams was determined to be 20°, 30°, and 60°, which achieved a balance between rock breaking and borehole expansion performance. The efficiency of multi-nozzle jet rotational rock breaking decreased with increasing target distance, with the optimal range being 2 to 4 mm. The rotational speed of the multi-nozzle jet stream had a significant impact on rock-breaking efficiency. Under the same target distance conditions, as the drilling speed increased, the volume of rock breaking initially increased and then decreased, and the rate of volume attenuation increased with increasing target distance. The forms of rock breaking in multi-nozzle jet streams were not identical. Jet streams with smaller inclination angles mainly caused tensile failure through axial impact, while those with larger inclination angles primarily caused shear failure through radial impact. This study provides valuable guidance for optimizing the structural parameters of multi-nozzle jet drill bits and researching rotational rock breaking.

Dynamic fragmentation and chip formation of water-soaked rock in linear cutting with a coupled moisture migration-fracture model

Water can greatly influence the mechanical properties and dynamic fracture of underground rock mass. However, the dynamic fragmentation and chip formation of water-soaked rock in linear cutting is neglected. In this work, a coupled moisture migration-fracture model is utilized to investigate this problem. First, the water weakening effect on rock mechanical parameters is introduced in the coupled model according to a fitting laboratory test. Then, the uniaxial tensile, uniaxial compression, triaxial compression, and swelling experiments are utilized to calibrate the input micro-parameters. Subsequently, a series of scratch tests are carried out on the water-soaked rock samples. The stress evolution, fragmentation mode, cutting force, crack number, extent of fracture zone, chip shape, chip area, cutting work, and mechanical specific energy (MSE) with different water content are studied. The results indicate that as water content increases, the rock sample changes from brittle failure to ductile failure in linear cutting, the peak cutting force gradually decreases, and the chip area first becomes larger and then smaller, while the MSE shows an opposite trend. Especially, a water content of 2% can bring the largest chip area and the highest cutting efficiency. Moreover, the effects of cutting velocity and cutting depth on the above indexes are discussed. Finally, a complex specimen composed of half wet and half dry rock is built to further demonstrate the influence of water on rock dynamic fragmentation and chip formation in linear cutting. The modeling results in this paper provide new insights into the influence mechanism of water on rock dynamic fragmentation, chip formation, and cutting efficiency in linear cutting.

Mechanical behavior and particle crushing of marine carbonate gravel in Xisha Islands, South China Sea

Carbonate gravelly soils are widely distributed in sub-tropical marine areas. During construction and engineering operations, carbonate gravel undergoes considerable particle crushing, which has remarkable effects on their engineering properties. A series of large-diameter oedometer tests, large-diameter drained and undrained triaxial shear tests were conducted on carbonate gravel specimens taken from the South China Sea. The carbonate gravel specimens exhibit significant particle crushing at common engineering pressure levels, and the particle crushing highly depends on the initial density, loading history and stress path. Three fragmentation modes, fracture, attrition, and abrasion, are notable in carbonate gravel specimens, which induces significant variations of PSD curves and greatly effects the mechanical properties. Particle crushing in carbonate gravel specimens increases the compressibility resulting in the compression index increases with the increase of surcharge pressure; decreases the pressure-hardening resulting in the initial Young’s and secant moduli slightly increase with the increase of initial confining pressure; and decreases the dilatancy resulting in the peak and critical state friction angles significantly deceases with the increase of initial confining pressure. Particle crushing also shows great effect on the CSL of the carbonate gravel specimens in both p ′ - q space and e - p ′ space.

Effect of realistic shape on grain crushing for rounded and angular granular materials

The deformation characteristics of granular materials in the field of geotechnical engineering largely depends on particle breakage behavior, which remains unresolved to date due to complex grain morphology. In this paper, a combination of experimental and numerical study was conducted to investigate the effect of realistic shape on grain crushing behavior for two groups involving rounded and angular rock grains. A shape library was established after acquirement of grain morphology via three-dimensional scanner, in addition, statistical analysis of grain shape indicates that four indices including sphericity, convexity, inscribed circle sphericity and volume sphericity, are useful for distinguishing shape characteristics of two rock grain groups. The experimental results exhibit a marked difference in force–displacement curve, fragmentation mode and Weibull survival probability for the two rock grain groups, moreover, these results were reproduced by discrete element method (DEM) simulation of grain crushing considering realistic shape. Finally, on the basis of DEM simulation method, deeming the grain shape as the sole variable, its influence on strength distribution was explored by modifying realistic complex shape of grains without altering microscopic mechanical parameters of DEM simulation. A conclusion can be reached that realistic irregular shape enhances grain crushing strength variability, and more angular edges (indicating higher degree of shape irregularity) leads to greater variability of grain crushing strength. Meanwhile, the role of particle microstructure in weakening or strengthening the effect of grain shape was also confirmed. These findings provide a deeper insight into the effect of morphological features on grain crushing behaviours.

Global forest fragmentation change from 2000 to 2020

A comprehensive quantification of global forest fragmentation is urgently required to guide forest protection, restoration and reforestation policies. Previous efforts focused on the static distribution patterns of forest remnants, potentially neglecting dynamic changes in forest landscapes. Here, we map global distribution of forest fragments and their temporal changes between 2000 and 2020. We find that forest landscapes in the tropics were relatively intact, yet these areas experienced the most severe fragmentation over the past two decades. In contrast, 75.1% of the world’s forests experienced a decrease in fragmentation, and forest fragmentation in most fragmented temperate and subtropical regions, mainly in northern Eurasia and South China, declined between 2000 and 2020. We also identify eight modes of fragmentation that indicate different recovery or degradation states. Our findings underscore the need to curb deforestation and increase connectivity among forest fragments, especially in tropical areas.

Insight into the degradation process of functional groups modified polystyrene microplastics with dissolvable BiOBr-OH semiconductor-organic framework

The difficult separation of products after photocatalytic degradation of microplastics (MPs) limits the in-depth analysis of the MPs fragmentation process and degradation mechanism, and there are no studies about the photocatalytic degradation of functional groups modified MPs. In this work, we synthesized a “dissolvable” BiOBr-OH semiconductor-organic framework (SOF) to degrade polystyrene (PS) MPs modified by different functional groups, including –OH, –NH2, -SO3H, –COOH and -epoxy. First, a series of characterization confirmed that small molecules were intercalated into BiOBr layers to construct BiOBr-OH SOF. The BiOB-OH SOF system has significantly enhanced the photocatalytic degradation performance of microplastics, and BiOB-OH-0.75 has the strongest catalytic performance. The photocatalytic degradation performance of different functional groups modified PS-MPs differed significantly, with the weight loss order being -epoxy > –NH2 > –OH > –COOH > -SO3H. After dissolving the catalyst, clean nano plastic particles were obtained after degradation, and it was found that six types of PS-MPs exhibited three different types of fragmentation processes. The surface potential of and fragmentation mode of different PS-MPs dominated the adsorption and photocatalytic degradation of BiOBr-OH SOF. The degradation products of PS-MPs are mainly composed of styrene and functional group-modified monomer molecules and multimolecular complexes. In addition, by analyzing the toxicity of the degradation products of microplastics, it was found that solid products were the main reason for their enhanced toxicity. Finally, based on the photoelectrochemical characterization and free radical analysis, the mechanism of photocatalytic degradation of different functional groups modified PS-MPs by BiOBr-OH SOF was proposed.

Effects of process parameters on the spreading morphology of disc surface and aluminium powder produced by centrifugal atomisation

ABSTRACT An apparatus was developed to study the effects of operating parameters on liquid spreading and particle size in centrifugal atomisation. Different areas of aluminium spreading on the surface of the rotary disc were observed, in which the diameter of the ‘Plane area’ showed a linear relationship with the rotational speed. The microscopic morphology of the aluminium powder samples was analysed by scanning electron microscopy (SEM). The variation of particle size distribution curve with rotational speed was explored, and the shape of the curve was changed from ‘Single-peak’ to ‘Double-peak’ when the rotating speed increased to a certain value. The effect of the fragmentation mode on the particle size distribution and median diameter was analysed. The variation of the median diameter of the powder with the rotating speed was obtained. The effect of different disc configurations on the particle size was obtained.

Multivariable Signal Processing for Characterization of Failure Modes in Thin-Ply Hybrid Laminates Using Acoustic Emission Sensors.

The aim of this study was to find the correlation between failure modes and acoustic emission (AE) events in a comprehensive range of thin-ply pseudo-ductile hybrid composite laminates when loaded under uniaxial tension. The investigated hybrid laminates were Unidirectional (UD), Quasi-Isotropic (QI) and open-hole QI configurations composed of S-glass and several thin carbon prepregs. The laminates exhibited stress-strain responses that follow the elastic-yielding-hardening pattern commonly observed in ductile metals. The laminates experienced different sizes of gradual failure modes of carbon ply fragmentation and dispersed delamination. To analyze the correlation between these failure modes and AE signals, a multivariable clustering method was employed using Gaussian mixture model. The clustering results and visual observations were used to determine two AE clusters, corresponding to fragmentation and delamination modes, with high amplitude, energy, and duration signals linked to fragmentation. In contrast to the common belief, there was no correlation between the high frequency signals and the carbon fibre fragmentation. The multivariable AE analysis was able to identify fibre fracture and delamination and their sequence. However, the quantitative assessment of these failure modes was influenced by the nature of failure that depends on various factors, such as stacking sequence, material properties, energy release rate, and geometry.

The Research on the Happiness Brought by Chinese Short Video Software Douyin to Chinese College Students

Douyin is now a popular short video app for Chinese college students. Most Chinese college students watch Douyin for entertainment. So how Douyin brings happiness to college students is worth studying. A questionnaire was made for college students to fill out to help with the study. Through data analysis of the questionnaire results, the conclusions are showed that first Chinese college students are attracted by entertaining videos on Douyin, and they like livestream function of Douyin most, which also brings them happiness. Douyin had become a form of entertainment among college students during the quarantine as well. Furthermore, fragmented video information transmission mode on Douyin makes some students think the joy they get is continuous, while others think it is transient. In addition, most students agree that Douyin is a vulgar way of entertainment, mainly due to the uneven quality of the videos on this platform. Overall, this study presented that Douyin does bring happiness to Chines college students. However, this kind of video content that brings students happiness is tacky to some extent and has no substantive meaning.

The role of magnetic fields in the formation of multiple massive stars

Context. Most massive stars are located in multiple stellar systems. Magnetic fields are believed to be essential in the accretion and ejection processes around single massive protostars. Aims. Our aim is to unveil the influence of magnetic fields in the formation of multiple massive stars, in particular on the fragmentation modes and properties of the multiple protostellar system. Methods. Using RAMSES, we follow the collapse of a massive pre-stellar core with (non-ideal) radiation-(magneto-)hydrodynamics. We choose a setup that promotes multiple stellar system formation in order to investigate the influence of magnetic fields on the multiple system’s properties. Results. In the purely hydrodynamical models, we always obtain (at least) binary systems following the fragmentation of an axisymmetric density bump in a Toomre-unstable disk around the primary sink. This result sets the frame for further study of stellar multiplicity. When more than two stars are present in these early phases, their gravitational interaction triggers mergers until there are only two stars left. The following gas accretion increases their orbital separation, and hierarchical fragmentation occurs so that both stars host a comparable disk as well as a stellar system that then also forms a similar disk. Disk-related fragmenting structures are qualitatively resolved when the finest resolution is approximately 1/20 of the disk radius. We identify several modes of fragmentation: Toomre-unstable disk fragmentation, arm-arm collision, and arm-filament collision. Disks grow in size until they fragment and become truncated as the newly formed companion gains mass. When including magnetic fields, the picture evolves: The primary disk is initially elongated into a bar; it produces less fragments; disk formation and arm-arm collision are captured at comparatively higher resolution; and arm-filament collision is absent. Magnetic fields reduce the initial orbital separation but do not affect its further evolution, which is mainly driven by gas accretion. With magnetic fields, the growth of individual disks is regulated even in the absence of fragmentation or truncation. Conclusions. Hierarchical fragmentation is seen in unmagnetized and magnetized models. Magnetic fields, including non-ideal effects, are important because they remove certain fragmentation modes and limit the growth of disks, which is otherwise only limited through fragmentation.

Massive pre-stellar cores in radiation-magneto-turbulent simulations of molecular clouds

ABSTRACT We simulate the formation and collapse of pre-stellar cores at few-au resolution in a set of radiation-magnetohydrodynamic simulations of giant molecular clouds (GMCs) using the grid-based code RAMSES-RT. We adopt, for the first time to our best knowledge, realistic initial/boundary conditions by zooming in on to individual massive pre-stellar cores within the GMC. We identify two distinct modes of fragmentation: ‘quasi-spherical’ and ‘filamentary’. In both modes, the fragments eventually become embedded in a quasi-steady accretion disc or toroid with radii ∼500–5000 au and opening angles H/R ∼ 0.5 − 1. The discs/toroids are Toomre stable but the accreted pre-existing fragments are found orbiting the outer disc, appearing as disc fragmentation. Each core converts nearly 100 per cent of the gas mass into a few massive stars forming near the disc centre. Large and massive discs around high-mass stars are supported by magnetic pressure in the outer disc, at radii >200–1000 au, and turbulent pressure in the inner disc. The most massive core accretes several times more mass than its initial mass, forming a cluster of 8 massive (proto)stars enshrouded by a toroid, suggesting a competitive accretion scenario for the formation of stars above ∼30 M⊙. We also find that the H ii regions produced by a single massive star remain trapped in the dense circumstellar discs for a few hundred kiloyears, while the dynamic motions of massive stars in wide binaries or multiple systems displace the stars from the densest parts of the disc, allowing UV radiation to escape producing steady or pulsating bipolar H ii regions.

Cytotoxic properties of fac-Re(CO)3 complexes with quinoline coligands: Insights on the mode of cell death and DNA fragmentation

Four tricarbonyl rhenium(I) complexes featuring quinoline ligands (1–4) were examined for their potential cytotoxicity properties against three malignant cell lines and one normal cell line of different origins. The most cytotoxic compound among the synthesized complexes was complex 2, which was formed when [ReBr(CO)3(N∧O)] (N∧O = quinoline-2-carboxaldehyde) (1) and para-amino phenol reacted. Its IC50 values are in the range of 26.05–30.33 μg/mL. Complex 4, decorated with benzimidazole moiety, has been demonstrated to be harmless to normal mice splenocytes. The cellular localization of 1–4 was investigated using fluorescence microscopy to provide insight into their biotargets, cellular localization, and modes of action. Among the evaluated malignant cell lines, complex 2 exhibited the highest levels of apoptotic and necrotic alterations in the MCF-7 cell line. Re(I) complexes appeared to gather inside intercellular connections and around cellular membranes, as seen in the fluorescence microscopy images. Along the cell membrane, the compounds accumulated as well, anticipating their entry.

Kumlbúa þáttr, an Eschatological Event: The Traumatic Ontology of Being in Time in Medieval Iceland

<i>Kumlbúa þáttr</i>, an Eschatological Event: The Traumatic Ontology of Being in Time in Medieval Iceland

Interaction of isoquinoline alkaloids with pyrimidine motif triplex DNA by mass spectrometry and spectroscopies reveals diverse mechanisms

Isoquinoline alkaloids represent an important class of molecules due to their broad range of pharmacology and clinical utility. Prospective development and use of these alkaloids as effective anticancer agents have elicited great interest. In this study, in order to reveal structure-activity relationship, we present the characterization of bioactive isoquinoline alkaloid-DNA triplex interactions, with particular emphasis on the sequence selectivity and preference of binding to the two types of DNA triplexes, by electrospray ionization mass spectrometry (ESI-MS) and various spectroscopic techniques. The six alkaloids, including coptisine, columbamine, epiberberine, berberrubine, jateorhizine, and fangchinoline, were selected to explore their interactions with the TC and TTT triplex DNA structures. Berberrubine, fangchinoline, coptisine, columbamine, and epiberberine have preference for TC rich DNA sequences compared to TTT rich DNA triplex based on affinity values in MS. The experimental results from different fragmentation modes in tandem MS, subtractive and hyperchromic effects in UV absorption spectra, fluorescence quenching and enhancement in fluorescence spectra, and strong conformational changes in circular dichroism (CD) hinted that the interaction between isoquinoline alkaloid-TC/TTT DNA had diverse mechanisms including at least two different binding modes: the electrostatic binding and the intercalation binding. Interestingly, columbamine, berberrubine, and fangchinoline can stabilize TTT triplex as inferred from optical thermal melting profiles, while it was not the case in TC triplex. These results provide new insights into binding of isoquinoline alkaloids to pyrimidine motif triplex DNA.