Element Patterns Research Articles

A Socio- Stylistic Study of the Role of Social Identity in Selected Feminist Texts

The current study explores the relationship between social identity and stylistic features in the context of contemporary feminism with reference to gender, race, and class variables. Although many studies have been conducted concerning the concept of feminist language, the relationship between social identity and linguistic features has not received enough attention, which is why the present study aims to identify the specific strategies that are used to address the goals of feminism. This research seeks to fill this gap through an analysis of twenty four contemporary Feminist texts in articles, speeches and social media posts. Employing socio-stylistic eclectic approach, the research analyses the patterns of stylistic elements in various media contexts and analyses how such elements work with the audience as well as embody different social roles. The results of the study advance the theoretical macro-socio-linguistic paradigm of socio-stylistics by identifying the link between language and social status. In addition, the study is helpful for the leaders of feminism to know how language can be utilized in a constructive manner to advance the cause of feminism.

Early Paleogene alkaline magmatism in the Subandean Ranges of Jujuy Province

The Zapla Range (Jujuy province) represents the southern edge of the central Andean Subandean Ranges in Argentina. In the northernmost area of the Zapla Range, basaltic rocks are interbedded in the Mealla Formation. These volcanic units form part of the post-rift magmatism of the Salta rift basin, which mainly focused on the Lomas de Olmedo sub-basin to the east. In this paper, six of these basaltic occurrences are characterized on the basis of new geological, petrographic and geochemical data, in order to explore their emplacement, petrogenesis and possible tectonic setting during rift evolution. Peperites in the upper contact of sills evidence the interaction between basalts and unconsolidated or poorly consolidated wet sediments. This implies that there was concomitance between sedimentation and subsurface magma emplacement, suggesting a Paleocene age for the magmatic event according to zircon U-Pb data available for Mealla Formation rocks. Other basaltic units show hipocrystalline textures and lack peperites at the top, which points to their extrusive nature. Additionally, some of these lava flows are spatially associated with pyroclastic deposits that reveal the occurrence of explosive hydrovolcanic eruptions. The study rocks are classified as alkaline basalts and basanites with high Mg# and Ni- and Cr-rich compositions, close to primitive magmas. They show affinity with continental intraplate settings. The analyses of Ba/Nb, Nb/La, (La/Yb)N, (La/Sm)N, (Gd/Yb)N and (Dy/Yb)N ratios, as well as normalized trace and rare earth element patterns, suggests a genesis by low degrees of partial melting of a residual garnet-bearing mantle source. Therefore, basalts from this part of the Subandean Ranges evidence a magmatic episode probably linked to an extensional reactivation stage of the Salta Group rift system in the Lomas de Olmedo depocenter during the Paleocene (∼60 Ma).

Hydrogeochemical dynamics under saltwater-freshwater mixing in a mangrove wetland over tidal cycles

Seawater and groundwater interactions shape the hydrogeochemical profile of mangrove aquifers, revealing how biogeochemical processes adapt to saline-freshwater mixing via the fluctuating patterns of key hydrochemical indicators and primary biogenic elements. This study, utilizing a multi-level monitoring profile spanning the entire submerged aquifer within a mangrove wetland, analyzed the spatiotemporal dynamics of DO, ORP, pH, alkalinity and biogenic elements (C, N, S). The results revealed that among the basic hydrochemical parameters, total alkalinity showed the most stable spatiotemporal distribution and was positively correlated with salinity. pH demonstrated a significant negative correlation with salinity, whereas the correlations of ORP and DO with salinity were not substantial. The discharge of terrestrial freshwater into the mangrove wetland is marked by hydrogeochemical reactions favoring the input of Mg2+ and DIC, with potential iron mineral precipitation within the aquifer. Spatial distribution of biogenic elements in the groundwater showed no apparent pattern across sampling periods. DOC concentrations ranged from 0.3 to 1.3 mmol/L. Three components of dissolved organic matter were identified using three-dimensional fluorescence spectroscopy, with high molecular weight components (C1 + C2) accounting for an average of 47 to 73 %. Both elevated DOC concentrations and high molecular weight component ratios were primarily found in shallow layers of dense mangrove areas, decreasing with depth. Concentrations of ammonia, nitrite, and nitrate varied dynamically, reflecting active biochemical processes in the shallow to mid-layers of the aquifer. Furthermore, sulfate and sulfide concentrations, ranging from 0 to 26 mmol/L and 0.4 to 576.8 μmol/L, respectively, underscore the interplay of biogeochemical reactions, especially sulfate reduction. These findings highlight valuable insights into the complex biogeochemical processes within mangrove aquifers and provide theoretical guidance for protecting the ecological health of mangrove wetlands.

Beyond linear narratives: Complex copper ore exploitation strategies in Early Bronze Age China revealed by geochemical characterization of smelting remains

Despite decades of efforts to reconstruct the bronze production and metal distribution systems of the Shang period in Bronze Age China, there remains limited understanding of the ore choices and smelting practices of the Shang people. This study addresses this research gap by conducting a detailed investigation of Shang period copper ores and smelting remains uncovered at the Tongling site in the Middle Yangtze River valley. The results of lead isotope, copper isotope, trace element, and rare earth element (REE) pattern help to classify the slags from this site into two groups, associated with smelting sulphidic (Group A) and oxidic (Group B) copper ores, respectively. This finding not only serves as the first physical evidence of the use of sulphidic copper ores in Early Bronze Age China but also provides pivotal details of the copper resource exploitation strategies of the Shang people. It challenges the traditional narrative that the Shang people moved to this area solely for the high-grade supergene deposits. The parallel use of both supergene and hypogene ores at the same site complicates the notion of a linear, technological evolution from simpler to more advanced copper sources. Despite the presence of hypogene ores, the study reveals that the Shang people maintained labour-intensive smelting practices, including crushing slag to recover trapped metallic prills, to meet the demands of large-scale bronze casting. This nuanced approach to copper resource exploitation reflects a complex, context-dependent strategy rather than a technological revolution. By highlighting these intricate metallurgical choices, this research contributes to a broader rethinking of early technological development, underscoring the diversity and adaptability of ancient craft industries and their role in shaping Shang society.

Analysis of spatial structure and singularity of microbial biogeochemical anomalies in the Taiwan Strait Basin

The abundance of specific hydrocarbon-oxidizing bacteria (MV value) in surface soil is closely linked to the concentration of thermogenic light hydrocarbons found in the underlying layers. The identification of these bacteria using specific detection techniques offers unique insights into microbiological anomalies associated with oil and gas, underscoring the significance of delineating microbiological geochemical anomalies in the exploration process. Accurate determination of the anomaly range is crucial for forecasting potential oil and gas reservoirs. In this study, a variety of fractal and geological statistical methods were employed to analyze microbiological geochemical data from the Taiwan Strait Basin. The multifractal approach allows for the simultaneous assessment of spatial autocorrelation and singularity in geochemical fields, with the fractal distribution reflecting the localized enrichment and depletion patterns of microbiological geochemical elements in rocks and other substrates. Geological statistical methods, such as the variation function, enable the assessment of spatial autocorrelation in geochemical and geophysical fields. The results indicate that microbiological anomalies in the Jiulongjiang Depression are mainly concentrated in the southwestern part of the study area, with some anomalies also observed in the central region. Conversely, microbiological anomalies in the Jinjiang Depression are predominantly located in the southern portion of the study area. Microbiological anomalies in the study area (Jinjiang Depression and Jiulongjiang Depression) exhibit a northeast-southwest strip distribution, aligning with the trend of the depressions and faults, suggesting that faults could influence the distribution of oil and gas resources in the region. Based on microbiological statistical analyses, the Jiulongjiang Depression shows better potential for oil and gas prospects compared to the Jinjiang Depression, guiding future research efforts in the Jiulongjiang Depression.

Geochemistry of Mafic Rocks From the Nagrota–Kathindi Section, Himachal Pradesh, Northwestern Himalaya: A Probable Example of Plume–Lithosphere Interaction

ABSTRACTThe Northwest Himalayan region has a record of several phases of mafic magmatic activity spanning from Precambrian to Cenozoic in a dynamic tectonic setting. Here, we studied detailed petrography and new whole‐rock geochemistry of mafic volcanic and dykes from the Nagrota–Kathindi Section (NKS), Himachal region of the NW Himalaya, to understand the petrogenesis and possible tectonic setting. Both rock types have comparable mineralogical compositions (clinopyroxene + plagioclase + actinolite‐tremolite + chlorite + iron oxides ± hornblende ± epidote ± quartz ± carbonates) overprinted by greenschist to lower amphibolite facies metamorphism. The mafic volcanic and dykes of NKS exhibit subalkaline basalts to basaltic andesites and a typical tholeiite compositional character. The chondrite‐normalized rare earth element pattern exhibits similar LREE‐enrichment and strong HREE‐fractionation, whereas primitive mantle‐normalized multi‐element patterns show pronounced LILE‐enrichment of Rb, Ba, Th, LREE, and HFSE depletion of Nb, K, P, and Ti. The Zr–Y–Nb–Th relationships indicate that both rock types were derived from the plume source, whereas low Nb/La (< 1), similar high large‐ion lithophile element concentrations, and pronounced negative Nb, Zr, P, and Ti anomalies suggest that components other than mantle plume must have been involved in the generation and evolution of both rock types, that is, most likely plume and subcontinental lithosphere mantle (SCLM) interaction. The genesis of parent magma for the NKS volcanic and dykes was derived by 4%–6% and 10%–20% partial melting from the spinel + garnet lherzolite stability field. The majority of the studied samples correspond to spinel + garnet peridotite melting on (Gd/Yb)N versus CaO/Al2O3 diagram, thereby corroborating residual garnet in the mantle restite. All the basalts and dykes from the NK section did erupt/intrude in an intracontinental rift setting based on geochemical discrimination. The key petro‐tectonic processes attributed to the formation of these rocks are as follows: (i) the melting of the ascending plume by adiabatic decompression; (ii) the partial melting of this plume–SCLM source in the melting regime, which produces basaltic magma with a tholeiitic composition; and (iii) the release of heat that provides the thermal condition for melting of SCLM and interaction between upwelling mantle plume and subduction metasomatized SCLM.

Metagratings for underwater acoustic wavefront manipulation

Metagratings are flat periodic assemblies of small scatterers, engineered to achieve effects such as steering, beamforming, or absorption. They have recently received attention in both electromagnetism and acoustic fields. In this work, we report the design, modeling, and experimental characterization of metagratings to steer underwater acoustic wavefronts towards anomalous directions (i.e. not classically allowed by Snell-Decartes relationships) with high efficiency (close to 100%). They are build from simple assemblies of small brass cylinders, hold by 3D-printed plastic supports, and can redirect ultrasonic wavefronts either in reflection mode (when placed in front of a reflective surface like e.g. the water / air interface) or in transmission mode. Furthermore, we demonstrate how metagratings build from an asymmetrical pattern of multiple basic elements can achieve near perfect asymmetrical transmission: a wavefront incident from side of the structure is fully transmitted, while a similar wavefront incoming from the other side is fully reflected, achieving an acoustic one-way mirror effect. This work combine theoretical analysis, finite element modeling, and experimentation in water tanks to explore and demonstrate the potential of such metagratings for various applications in underwater acoustics, like communication, noise mitigation, and stealth.

Two phases of granulite-facies metamorphism superimposied on retrograde eclogite: Constraints on the early Paleozoic tectonic evolution of the Qinling Orogenic Belt, central China

Existing studies provide adequate petrological evidences on ca. 500 Ma ultra-high pressure (UHP) metamorphism in the North Qinling Orogenic Belt (NQOB) in central China, but the genesis of 470–420 Ma multi-phase granulite-facies metamorphism in the NQOB and their relationship with the ca. 500 Ma UHP metamorphism remain controversial, resulting in the early Paleozoic evolution of the Qinling Orogenic Belt (QOB) highly debatable. In this study, we present mafic granulites and host felsic gneisses with a “red-eye socket” texture from the Shuanglong area, eastern NQOB, which recorded two phases of granulite-facies metamorphism superimposing on former eclogite-facies metamorphism. The former eclogite-facies metamorphism is indicated by eclogite-facies zircon trace element patterns and 496–495 Ma zircon ages, which are the same with those of the HP–UHP eclogite-facies metamorphic rocks in NQOB. The first granulite-facies metamorphism occurred at 460–448 Ma is characterized by coarse-grained minerals in matrix. Compositions and zonings of these minerals define an anticlockwise P–T path involving a prograde stage (751–763 °C), a high-temperature peak stage (9.2 kbar and 864 °C), and a near-isobaric cooling retrograde stage (8.3 kbar and 818 °C). The second granulite-facies metamorphism occurred at 422–421 Ma is represented by coronal garnet and coexisting fine-grained mineral aggregates. Coronal garnet compositional zonings suggest a clockwise P–T path consisting of a high-pressure peak stage (9.5–11.2 kbar and 748–783 °C) and a decompressing and heating retrograde stage (9.2–9.5 kbar and 789–800 °C). Combining dating results of leucosomes in these rocks and existing data, we proposed a new model for early Paleozoic tectonic evolution of the NQOB. The North Qinling Terrane (NQT), probably separated from the South China Block (SCB) during the breakup of Rodinia, drifted northwards and underwent UHP metamorphism at 500 Ma and then rapidly exhumed to crust level. Later, the Shangdan Ocean subducted northwards beneath the exhumed NQT at 470–440 Ma, resulting in the first granulite-facies metamorphism and contemporaneous migmatization and magmatism. Finally, the closure of the Shangdan Ocean led to collision between the NQT and South Qinling Terrane/SCB and the second granulite-facies metamorphism and anatexis at 422–418 Ma.

U-Pb Ages of Zircon Grains in the Playa Azul Beach Sediments, Guerrero State, Mexican Pacific

ABSTRACT The mineralogy of bulk sediments, U-Pb ages and chemistry of 195 detrital zircon grains recovered in the Playa Azul beach, Mexican Pacific coast were performed to infer their provenance. The bulk sediments were composed of minerals like quartz, feldspar, titanite, plagioclase, zircon, and magnetite. The average Th/U ratio in zircon grains was ~ > 0.2, indicated an igneous origin. The chondrite normalized rare earth element (REE) patterns of zircons were depleted in low REE (LREE) and enriched in heavy REE (HREE), with positive cerium and negative europium anomalies, indicating a granitoid source. U-Pb ages of zircon grains revealed the predominance of Cenozoic and Mesozoic ages in samples PAC2 (~ 33.8 - 61.8 Ma, n = 90 and ~ 67 - 132 Ma, n = 10, respectively) and PAC19 (~ 0.1 -39.6 Ma, n = 55 and ~ 67 - 251 Ma, n = 20, respectively). Minor peaks were represented by Palaeozoic (n = 9) and Precambrian (n = 11) ages in PAC19. Zircon ages and their morphology indicated that they were mostly derived from the nearby terranes. The source terranes, which supplied Cenozoic zircons to the beach area were the coastal Cenozoic plutons and Cuicateco terrane. The Mesozoic zircons in the Playa Azul coastal sediments were derived from the Mixteca (Acatlan Complex), Guerrero, and Xolapa terranes, located along the Mexican Pacific coastal zone. The Proterozoic zircons were represented by the coastal Oaxacan Complex. In addition, the Arteaga Complex in the Guerrero State, adjacent to the playa Azul beach was the potential source for the Eocene zircons.

The dialogue of the past and the present in the innovative trends of the works of pottery of Qinzhou Nixing

The object of this study is the ceramic art of Qingzhou Nisin, which has a history of over 1300 years. The aesthetic characteristics of Qingzhou Nisin ceramics are highlighted, and the current situation of insufficient innovation in modern ceramics is summarized and analyzed. The importance of design innovations is emphasized. A new method of innovative design for Qingzhou Nisin ceramics is proposed, which involves combining the regional culture of Guangxi Beibu Gulf with traditional artistic elements of Qingzhou Nisin ceramics to give them new vitality. The article highlights four aspects that facilitate the realization of innovations in Qingzhou Nisin ceramic design: the fusion of pattern elements, the integration of morphological elements, the integration of texture components, and the use of complex materials. The research methodology includes a literature review of Qingzhou Nisin ceramic art and its contribution to the development of innovative trends in this direction, an analysis of Qingzhou Nisin's works was made in order to understand its style and approach to creating ceramic art. The main conclusions of the study are that Qingzhou Nisin ceramic art is an important part of Chinese civilization, and its development should be based on preserving the continuity of traditions and culture. To restore the connection between the regional culture of Guangxi Beibu Gulf and innovations in Qingzhou Nisin ceramic design, research and innovation practices are necessary. To develop Qingzhou Nisin ceramic art, innovations in design should be based on preserving the continuity of traditions and culture, as well as restoring the connection between regional culture and innovations. Overall, the article shows that Qingzhou Nisin ceramic art is an important part of Chinese civilization, and its development should be based on preserving the continuity of traditions and culture.

Research on Innovative Development of Miao Embroidery Intangible Cultural Heritage in Guizhou, China Based on Digital Design

Objective – Miao embroidery is vital to Miao culture, representing their national identity through its patterns and colours. However, in the face of globalization and the digital age, there is an urgent need to combine tradition with modern technology to innovate and preserve Miao embroidery. Methodology – In this study, we explored the artistic characteristics of Miao embroidery by digital means and used computer design tools to refine the pattern elements and colour genes. Research methods combine qualitative and quantitative analysis, including phenomenology, ethnographic research, content analysis, questionnaires, image and colour analysis, etc. Findings – Through computer graphics software, pattern colour extraction, and innovation are realized, the integration of traditional culture and modern design is promoted, and a new way is provided for the digital protection and dissemination of intangible cultural heritage. Novelty – The research enhances the vitality and influence of Miao embroidery in global cultural diversity and includes case studies and practices of digitized intangible cultural heritage. Type of Paper: Empirical JEL Classification: O10, O19, O33. Keywords: Guizhou Miao embroidery; cultural innovation; qualitative and quantitative analysis; digitized intangible cultural heritage Reference to this paper should be made as follows: Na Z; Sharudin, S.A. (2024). Research on Innovative Development of Miao Embroidery Intangible Cultural Heritage in Guizhou, China Based on Digital Design, J. Bus. Econ. Review, 9(2), 85–94. https://doi.org/10.35609/jber.2024.9.2(1)

Social entrepreneurial ecosystems in Euroregions

Purpose The purpose of this paper is to extend the knowledge of social entrepreneurial ecosystems and test their effect on social entrepreneurial activity in a cross-border context. Design/methodology/approach The current research used the fuzzy set Qualitative Comparative Analysis method on a sample of 4,357 cross-border cooperation (CBC) projects implemented between 2014 and 2020, spread over 40 Euroregions. Findings Single ecosystem elements can be sufficient conditions but with a limited effect on cross-border social entrepreneurship. Configurations of ecosystem elements can be necessary conditions with synergetic effects. A geographical pattern was identified in the spread of configurations across Europe. Research limitations/implications Geographical, quantitative and project data constraints exist. The authors call for research into synergies between ecosystem elements in cross-border contexts and ecosystem patterns across Europe. Practical implications Policymakers, their cross-border counterparts and Euroregions could coordinate their efforts to improve ecosystems’ impact and involve social entrepreneurs to scale impact in neighboring countries. Social implications Involving social entrepreneurs in CBC projects will show how social impact in one country can be valuable for solving issues in the neighboring country. This will increase the valuation of innovative solutions, create opportunities for scaling social impact and contribute to the European (EU) Cohesion Policy. Originality/value The study uses a novel approach by investigating the effect of social entrepreneurial ecosystems in Euroregions on social entrepreneurial activity in a cross-border context. The study shows that the impact of social entrepreneurial ecosystems does not stop at the country’s borders.

Unraveling the Protolith Origin of Serpentinite Rocks from the Tengnoupal Area, Manipur Ophiolite Complex, Indo-Myanmar Range

Objective: This article mainly focuses on investigating the protolith origin of serpentinite rocks in and around Tengnoupal, within the Manipur Ophiolite Complex (MOC), using a combined petrographic and geochemical approach. Methods: During fieldwork, samples were collected and cut into thin sections to reveal their mineralogical and textural relationships. Major oxides and trace elements were determined by XRF, and rare earth elements analysis was carried out by ICP-MS to determine the nature and origin of the rocks. Findings: The studied rock samples exhibit varying degrees of serpentinization, ranging from partial to complete, and exhibit a pseudomorphic texture including mesh and hour structures replacing the original olivine and bastite texture replacing pyroxene. Geochemically, the analyzed rock types exhibit komatiitic affinity and are characterized by high magnesium numbers (Mg# average 84.4). The studied serpentinite rocks have lower Al/Si ratios (Average=0.05) and higher Mg/Si ratios (average= 0.95) in bulk rock compositions indicating a refractory abyssal mantle peridotite protolith when compared to the primitive mantle. The high Ti (range 300-480 ppm) and Cr (628-3186 ppm) contents indicate a subduction environment. In addition, the rock samples exhibit slight depletion chondrite-normalized Rare Earth Elements (REE) patterns ((La/Yb) N = average 0.87). The rocks exhibit spoon-shaped normalized Rare Earth Element patterns and primitive mantle are similar to mid-oceanic ridge abyssal mantle rocks. Novelty: The origins of the rocks studied suggest a transitional phase between abyssal and subduction zone-related serpentinites, forming after harzburgite-peridotite. As subduction began, dehydrated orogenic peridotite from the abyssal serpentinites was thrust or obducted, forming the MOC serpentinites. This indicates that the serpentinite rocks in MOC share similarities with those found in mid-oceanic ridge environments, which is characteristic of a supra-subduction zone setting. Keywords: Ultramafic rocks, Serpentinization, Supra­subduction zone, Abyssal, REE

Application and Innovative Design Strategies of Cultural Elements in the Costume Patterns of Qing Dynasty Emperors

This article deeply explores the application and innovative design of cultural elements in the clothing patterns of Qing Dynasty emperors. Firstly, it analyzes the richness and symbolism of Qing Dynasty emperor clothing patterns, the uniqueness and aesthetic value of colors, as well as the exquisite and innovative craftsmanship. The second point is to point out the limitations of traditional element application, cultural connotation misinterpretation and shallowness, as well as the disconnect between market adaptability and consumer demand in current design. Propose optimization measures to address these issues, aiming to promote the widespread application and inheritance of cultural elements of Qing Dynasty emperor costume patterns in modern design.

Chemical speciation of essential trace elements in edible bamboo shoots from different varieties and sampling locations by HPLC – ICP-MS and HPLC - electrospray MS/MS

Samples of five different commonly consumed bamboo species collected at five different locations in the State of Manipur, northeast India, were investigated for the concentrations and, for the first time, for the chemical forms of essential trace elements. Several elements were determined in the bamboo shoots of which Fe, Zn, Cu, Mn, and Ni were present above the 1 ppm level in bamboo juice. An analysis of data for the variability using the ANOVA method, indicated no statistically significant effect of the geographical location on the trace element pattern and speciation. However, nickel and, to lesser extent, zinc concentrations and speciation were affected by the bamboo variety. Speciation revealed the presence of metal complexes with nicotianamine (NA), deoxymugineic acid (DMA) and histidine.

Synthesis of maximally sparse conformal circular arc array with a required beam pattern by unitary matrix pencil method

This paper extends the unitary matrix pencil (UMP) method to synthesize maximally sparse conformal circular-arc array with a required beam pattern. Due to the nonlinearity between the circular-arc array pattern and its element pattern, Fourier transform preprocessing for the required beam pattern is introduced to achieve a mathematical expression, i.e., sum of a series of undamped complex exponentials, which is related to array element positions and their excitations. Then, the UMP method is used to determine the reduced number of elements and their position distributions. Moreover, the complex excitations of array elements are reconstructed by obtaining the least-square solution of an over-determined equation. A set of examples for synthesizing sparse conformal circular-arc arrays with different desired patterns and E-type patch element including the mutual coupling are conducted. Results show that the proposed UMP method can achieve a considerably lower pattern reconstruction error with a reduced number of elements than results in the literature, which demonstrates its effectiveness and robustness.

Benzvalene-like Carboranes: Genuine Rule Breakers and Good Kinetic Stability.

Substituents are widespread in chemistry, but it has remained quite difficult to reliably determine the thermodynamic and kinetic stabilities of substituted compounds, though they are key to helping establish a structural rule and synthetic viability, respectively. As an important class of valence isomers in the benzene family, benzvalene-like structures have been extensively studied in systems associated with electron-neutral (i.e., C, Si, Ge, Pb, and Sn) and electron-rich (e.g., P) skeletons. However, stable benzvalene-like examples associated with electron-deficient skeletons have been very limited, possibly due to the very complicated bonding patterns of electron-deficient elements. Here, we performed an extensive structural search at the density functional theory (DFT) and CBS-QB3 level for the well-known six-vertex dicarboranes (C2B4R6), one of the central families of boranes and carboranes chemistry. We unexpectedly found that all of the previously reported benzvalene-like structures III (C2B4R6) as the long-chased "rule breaker" examples of the Wade-Mingos rule (W-M rule) are not the lowest-lying structures. Promisingly, for the first time, we succeeded in identifying several substituted III as the genuine lowest-lying structures and thus true "rule breakers." Thus, "benzvalenes" present hitherto the fourth member of the lowest-lying structural patterns for the family of six-vertex dicarboranes. Moreover, the presently revealed good kinetic stability of III' (C2B4R2R'4) over a wide range of substituents promoted us to recommend a novel kind of synthesizable carboranes beyond the Wade-Mingos rule, i.e., "benzvalene-like carboranes" with all of the classical skeletal atoms.

Ultrahigh-pressure to high-pressure eclogite in Cuban ophiolitic mélange reveals proto-Caribbean spreading ridge subduction

Proto-Caribbean oceanic crust produced during ocean-floor spreading between diverging North and South American plates was subsequently subducted beneath the Caribbean plate. However, the timing and spatial configuration of proto-Caribbean spreading ridge subduction remain subjects of debate. High-pressure (HP) basaltic metamorphic rocks, representing relics of the subducted proto-Caribbean oceanic crust, commonly occur in Cuban ophiolitic mélanges. In this study, an integrated set of petrological, geochemical, and geochronological data is presented for eclogite from the Las Villas mélange, central Cuba. The typical geochemical signature of mid-ocean-ridge basalt (MORB) indicates that the protolith of eclogite formed at the proto-Caribbean spreading ridge. Based on pressure-temperature (P-T) estimates obtained by pseudosection analysis as well as Zr-in-rutile and Ti-in-zircon thermometry, the following P-T paths for representative samples can be derived: a prograde path from 24−25 kbar and 510−520 °C to peak conditions of 29−31 kbar and 525−575 °C, and a complex retrograde path initially following almost isothermal exhumation to 25−27 kbar, followed by near-isobaric heating to 610−640 °C before final exhumation. This is the first documentation of prograde oceanic ultrahigh-pressure (UHP) metamorphism in the northern Caribbean area. U-Pb dating of magmatic zircon with steep heavy rare earth element (HREE) patterns and negative Eu anomalies yielded a protolith age of 126.3 ± 0.7 Ma. In contrast, metamorphic zircon with flat HREE patterns and without an Eu anomaly yielded a weighted mean age of 118.6 ± 1.6 Ma. The short time interval of >8 m.y. between MORB magmatism and UHP metamorphism suggests that the oceanic crust was subducted to great depth (∼100 km) shortly after generation in an oceanic ridge, which provides robust evidence for subduction of the proto-Caribbean spreading ridge. Furthermore, this work demonstrates high potential to trace ancient spreading ridge subduction by joint petrological, geochemical, and geochronological study of oceanic eclogite.

Exploring bonding temperature variations in diffusion brazing of B4C ceramics with Ni-Cr-Si-Fe-B interlayer: Mechanical and microstructural analysis

This study examines the impact of the bonding temperature parameter on the quality of diffusion brazing joints of B4C ceramics using a Ni-Cr-Si-Fe-B interlayer. Various factors including shear strength, hardness, microstructure, interfacial phenomena, elemental diffusion patterns, formed compounds and phases, and fracture surfaces of the samples were analyzed and compared. The brazed sample at 1110 °C for 1/2 h exhibited the highest shear strength of 62 MPa. Increase of the bonding temperature to the optimum level (1090–1110 °C) enhances the fluidity of the molten interlayer, facilitating its diffusion into the porosities of the ceramic components. This increase also promotes higher interactions within the system, creating favorable conditions for element diffusion. However, surpassing the optimum temperature (1110–1130 °C) may lead to increased destructive reactions and intensify the impact of the coefficient of thermal expansion (CTE) mismatch, resulting in residual stresses and a subsequent decrease in bond strength. The excessive increase in the bonding temperature (1130–1150 °C) can lead to the excessive fluidity of the molten interlayer, potentially causing effusion onto the joint's fixture and damaging the samples. The results indicate the formation of various compounds between the elements of the interlayer and carbon and boron elements, including SiC, Ni4B3, CrB2, Fe2B, Ni6Si2B, and B2Fe3Ni3, at the fracture surface of the sample bonded at 1110 °C. The more substantial peaks of these compounds, compared to other samples, could be a reason for the higher strength of this particular sample.

Geochemistry and geochronology of 1.7-1.8 Ga peraluminous A-type granites and granite-gneiss from the Mahakoshal Basin, Central Indian Tectonic Zone (CITZ): implications for an accretionary orogen for the evolution of CITZ

ABSTRACT Here, we report petrography, whole-rock geochemistry, and zircon U-Pb geochronology to understand the origin, source, geodynamic setting, and evolution of A-type granite and granite gneiss as well as establish their emplacement age from Mahakoshal Basin. Mineralogically, Sidhi granite gneiss and Madanmahal granite of the Mahakoshal Basin dominantly consist of quartz, K-feldspar, and plagioclase. Geochemically, Sidhi granite gneiss and Madanmahal granite are ferroan in nature. The studied rocks are akin to peraluminous A-type granites and have average zircon saturation temperatures of 955°C and 977°C, respectively. The studied rock types are derived from partial melting of pre-existing crust indicated by (Y/Nb)N >0.18, (Th/Nb)N >2, (Ce/Pb)N <1, and (La/Nb)N >2 accompanied by the Eu, Ba, Sr, Ti, and Nb negative anomalies. The zircon U-Pb geochronology yielded emplacement ages of 1723 ± 16 Ma for the Sidhi granite gneiss and 1801 ± 64 Ma for the Madanmahal granite. Based on similar geochemical characteristics such as rare earth element patterns, Eu anomalies, and Ce/Pb, La/Nb, and Th/Nb ratios, we propose that the Sidhi granite gneiss and Madanmahal granite are derived from the same source i.e. Bundelkhand gneisses and granites, and formed in a post-orogenic rift environment of the accretionary orogen setting.