Sea Island Research Articles

Femtosecond X-ray Laser Reveals Intact Sea-Island Structures of Metastable Solid-State Electrolytes for Batteries.

Experimental characterization of the nanostructure of metastable functional materials has attracted significant attention with recent advances in computational materials discovery. However, since metastable glass-ceramics are easily damaged by irradiation, damage-free nanoimaging has not been realized thus far. Herein, we propose novel high-contrast coherent diffractive imaging that quantitatively analyzes the intact internal nanostructure of metastable glass-ceramics using femtosecond X-ray pulses. The immersion of sample particles in a solvent helps enhance the reconstructed image contrast and allows us to distinguish an ∼7% electron density difference between an amorphous form and crystals. Furthermore, morphological operations with a band-pass filter quantitatively elucidate the depth information. The evaluated volume ratio of the amorphous to crystalline phases is ∼2.5:1 for the measured metastable (Li2S)70-(P2S5)30 glass-ceramic particle. Sulfide glass-ceramics are used as electrolytes for all-solid-state batteries, which are indispensable for reducing the carbon footprint. Our results will facilitate structural studies on fragile metastable materials with important scientific and industrial implications.

Fine mapping and characterization of the Crinkled Dwarf gene in cotton

Cotton (Gossypium) is an important natural fiber crop worldwide. Plant height, which is an important commercial cotton breeding trait, is also useful for plant architecture research. Crinkled Dwarf (cr), a natural mutant of Sea Island cotton (Gossypium barbadense L.), simultaneously displays crinkled leaves and dwarfing. However, the genes controlling cr have not been characterized, and the molecular mechanism of the trait remains unknown. In this study, genetic analysis indicated that cr was likely controlled by a major recessive gene, although the cr phenotype was sensitive to environmental factors, including light intensity. Using bulked-segregant analysis and recombinant methods, the cr gene was mapped to a 35.8-kbp genomic interval on chromosome D03 that contained three annotated protein-coding genes. Comparative transcriptome analysis showed that cr enhanced stress/disease resistance and repressed plant development/growth. Endogenous phytohormone measurements showed that most auxin compounds were decreased in the cr mutant. Although the cr mutation was insensitive to exogenous auxin, gibberellin and cytokinin treatments promoted and repressed main stem elongation, respectively. However, no hormone treatment could fully rescue the crinkled leaf phenotype. These findings will contribute to the breeding of cotton lines with improved plant architecture or yield, and aid in the dissection of the genetic basis of cr.

Seasonal and Zonal Succession of Bacterial Communities in North Sea Salt Marsh Sediments.

Benthic microbial communities of intertidal zones perform important biogeochemical processes and provide accessible nutrients for higher organisms. To unravel the ecosystem services of salt marsh microbial communities, we analyzed bacterial diversity and metabolic potential along the land–sea transition zone on seasonal scales on the German North Sea Island of Spiekeroog. Analysis of bacterial community was based on amplicon sequencing of 16S rRNA genes and –transcripts. Insights into potential community function were obtained by applying the gene prediction tool tax4fun2. We found that spatial variation of community composition was greater than seasonal variations. Alphaproteobacteria (15%), Gammaproteobacteria (17%) and Planctomycetes (11%) were the most abundant phyla across all samples. Differences between the DNA-based resident and RNA-based active communities were most pronounced within the Planctomycetes (17% and 5%) and Cyanobacteriia (3% and 12%). Seasonal differences were seen in higher abundance of Gammaproteobacteria in March 2015 (25%) and a cyanobacterial summer bloom, accounting for up to 70% of the active community. Taxonomy-based prediction of function showed increasing potentials for nitrification, assimilatory nitrate and sulfate reduction from sea to land, while the denitrification and dissimilatory sulfate reduction increased towards the sea. In conclusion, seasonal differences mainly occurred by blooming of individual taxa, while the overall community composition strongly corresponded to locations. Shifts in their metabolism could drive the salt marsh’s function, e.g., as a potential nitrogen sink.

The American Elizabethan Accent: Sea Island Residents Talk

ABSTRACT This study of “American Elizabethan” compares key “Hoi Toid” sounds in the “Delmarva” accents on Smith (Maryland) and Tangier (Virginia) Islands utilizing original accent samples collected in 2019. Since these inhabited Islands are only accessible by ferry, it was hypothesized that islanders would retain more accent elements from southwest England and Ireland than mainlanders, resulting in a similarity of contemporary and historical pronunciation and prosody. Though fewer of these accent elements were present than anticipated, several phonetic realizations distinguished the Hoi Toid accents from British and Original Pronunciation accents. Previous linguistic research, including collections of local vocabulary, further inform this comparative analysis that draws attention to contemporary accent loss on Sea Coast Islands in the Chesapeake Bay. Categorization of these accents into an “American Elizabethan” accent attempts to mitigate accent loss by archiving recorded material and analysis and, furthermore, raises awareness of the impact of climate change on speakers’ environments.

A Decision Support System for Marine Regulation

The implementation of marine spatial data management and decision support based on GIS provides a powerful tool for marine regulation. This study constructed a three-dimensional spatiotemporal data model of marine resources that is hierarchical, partitioned, and classified according to the management principle of using an underground resource layer, surface matrix layer, surface overburden layer, and management layer, taking the marine resource entity as the unit. Key research topics include marine multi-source information integration, visual expression, and spatiotemporal topology analysis for typical application scenarios such as sea area use, island development and utilization, and marine environmental monitoring and protection. The study developed a marine information decision support system with comprehensive integration and visual analysis of information on maritime islands, early warning and monitoring, the marine economy, and the marine environment. The system was applied to dynamic regulation of sea area use, spatiotemporal characteristic analysis of marine resources, the regulation of human activities in marine protected areas, and the monitoring of sea level rise. Practice has proved that a three-dimensional spatiotemporal data model of marine resources can meet the application requirements of “One Map”, the basic land and spatial information platform.

A Calmodulin-Like Gene (GbCML7) for Fiber Strength and Yield Improvement Identified by Resequencing Core Accessions of a Pedigree in Gossypium barbadense.

Sea Island cotton (Gossypium barbadense) is world-renowned for its superior natural fiber. Although fiber strength is one of the most important fiber quality traits, genes contributing to fiber strength are poorly understood. Production of sea island cotton also is inextricably linked to improving its relatively low yield, thus enhancing the importance of joint improvement of both fiber quality and yield. We used genomic variation to uncover the genetic evidence of trait improvement resulting from pedigree breeding of Sea Island cotton. This pedigree was aimed at improving fiber strength and yielded an elite cultivar, XH35. Using a combination of genome-wide association study (GWAS) and selection screens, we detected 82 putative fiber-strength-related genes. Expression analysis confirmed a calmodulin-like gene, GbCML7, which enhanced fiber strength in a specific haplotype. This gene is a major-effect gene, which interacts with a minor-effect gene, GbTUA3, facilitating the enhancement of fiber strength in a synergistic fashion. Moreover, GbCML7 participates in the cooperative improvement of fiber strength, fiber length, and fiber uniformity, though a slight compromise exists between the first two of these traits and the latter. Importantly, GbCML7 is shown to boost yield in some backgrounds by increasing multiple yield components to varying degrees, especially boll number. Our work provides valuable genomic evidence and a key genetic factor for the joint improvement of fiber quality and yield in Sea Island cotton.

Identification of key proteins related to high-quality fiber in Upland cotton via proteomics analysis.

The dynamics of cotton fiber elongation and microfibirl deposition orientation were delineated; advanced ethylene synthesis and redox reaction homeostasis may be crucial for high-quality fiber formation. Fiber length, strength, and fineness determine the use and commercial value of cotton fiber, but their underlying molecular mechanisms remain obscure. We compared the dynamic change trajectories of length, diameter and microfibril orientation angle of the fibers produced by an introgression line SY6167 which generates high-quality fibers even better than Sea island cotton with those of the common-quality fibers from TM-1 across 5 to 30days post anthesis (DPA). The proteomes were profiled and compared at six representative time points using 2-DE and MS/MS. 14 proteins differentially expressed inside each of cotton line temporally and significantly different tween the two lines were identified. The dynamic change trajectories of fiber length and microfibril angle are close to "s" and reverse "s" growth curves, respectively. SY6167 and TM-1 fibers entered the logarithmic elongation phase simultaneously at 10 DPA, and SY6167 kept elongating logarithmically for 2 more days than TM-1. In parallel to logarithmic elongation, microfibril orientation angles dived sharply, and SY6167 declined faster for a shorter duration than TM-1. 53% of the identified proteins are related to redox homeostasis, and most of them are expressed at higher levels in SY6167 during logarithmic elongation. 1-Aminocyclopropane-1-Carboxylic Acid Oxidase (ACO) started to accumulate at 16 DPA in SY6167, and its encoding genes were highly expressed at this stage, with a much higher level than TM-1. These findings suggest high-quality fibers are associated with high expression of the proteins related to stress and redox homeostasis, the continuously elevated expression of ethylene synthesis ACO gene may play an essential role.

Molecular Diet Analysis of Adélie Penguins (Pygoscelis adeliae) in the Ross Sea Using Fecal DNA.

Simple SummaryThe diet of Adélie penguins, Pygoscelis adeliae, in the Ross Sea was studied applying quantitative polymerase chain reaction (qPCR) protocols to their feces. Two krill species (Euphausia superba and Euphausia crystallorophias) and notothenioid fish (mainly Pleuragramma antarctica and Pagothenia borchgrevinki) were among the most abundant components of the diet. The composition of the two krill species and notothenioid fish was found to be strongly related to the geographic characteristics of the Ross Sea.The diet of Adélie penguins, Pygoscelis adeliae, is a useful indicator in understanding the ecological conditions of their habitats. The diets of Adélie penguins were studied using metabarcoding and quantitative PCR (qPCR) analyses of fecal DNA from seven habitats along the Ross Sea region. Using metabarcoding analysis with dual universal primers (18Sv9 and miniFish), the overall diet composition and detailed information about piscine prey were clearly elucidated. It was found that two krill species (Euphausia superba and Euphausia crystallorophias) and notothenioid fish were the most abundant in the diets of Adélie penguins. Among the notothenioid prey, Pleuragramma antarctica (56.50%) and Pagothenia borchgrevinki (18.21%) were the two most abundant species. qPCR analysis showed a significant geographic difference in the composition of main prey. Penguins inhabiting outbound parts of the Ross Sea (Capes Adare (CA) and Duke of York Island (DY)) mainly preyed on E. superba, without any significant changes in prey composition. By contrast, those inhabiting the inbound parts of the Ross Sea (Edmonson Point (EP) and Inexpressible Island (II)) preyed on E. crystallorophias and notothenioid fish rather than E. superba. Compared with the outbound habitats, prey compositions for penguins inhabiting the inbound regions were significantly different year to year, which was presumably due to the food availability based on the annual environmental and meteorological conditions of the coastal region along with the inbound parts of the Ross Sea.

Shrimps of the genus Thor Kingsley, 1878 (Caridea, Thoridae): description of a new species using integrative data, remarks on Thor manningi Chace, 1972, and a world identification key

Marine shrimps of the genus Thor Kingsley, 1878 are distributed in the eastern and western Atlantic, eastern Pacific, and Indo-West Pacific. Thor manningi Chace, 1972 was originally described from Antigua and since then has been recorded from other Atlantic localities, including the Caribbean Sea, Bermuda, USA, Brazil, and Ascension Island. Specimens previously identified as T. manningi from Panama and Brazil were analyzed using a combination of morphological and molecular approaches. The analyses yielded a new species from the Atlantic coast of Panama, herein described as Thor paulae sp. nov. Moreover, we provide additional morphological observations on T. manningi, mainly regarding mouthparts and pereopods. The new species is morphologically similar to the Pacific Thor cocoensis Wicksten and Vargas, 2001 and Thor marguitae Bruce, 1978. However, it can be separated from them by the carpus of the second pereopod, rostral dorsal dentition, and chela of the first pereopod, respectively. The two species studied here can be easily distinguished by the supraorbital prominence in T. manningi (versus absent in the new species), and the pterygostomial margin rounded and unarmed in T. manningi (versus angular, with tooth in the new species). Thor manningi is morphologically closer to the western Atlantic Thor dobkini Chace, 1972 and Thor floridanus Kingsley, 1878, but can be separated from both by the merus of the first pereopod (T. dobkini) and dactylus of fourth and fifth pereopods (T. floridanus, but with the possibility of overlap). We provide a comparative table with morphological characters of all 17 valid species of Thor, as well as a worldwide identification key to the genus.

The legacy of Sea Island Creole English: Sociolinguistic features of Gullah

This paper builds on the renewed interest in preserving the multiethnic origins of the United States and recognizing a profound impact of the Black experience on the American nation. The article centers on the Gullah language, one of the primary roots of modern African American English and the only remaining English-related Creole language in North America. The pidgin language, which originally evolved as a medium of communication between slaves from various regions of Africa and their owners, is still spoken by Black communities across coastal regions of South Carolina, Georgia, and Florida. While inland African American English (AAE) has received much attention in linguistic circles over past decades, relatively little research has been done on varieties of AAE spoken in the rural American South. The purpose of this paper is to re-examine the origin and history of Gullah and to present a linguistic description of its most peculiar features. The Gullah language represents a combination of English and Central and West African languages. Geographical isolation, predominance of the Black population, and social and economic independence contributed to its development and survival. Also, in contrast with inland African Americans, the Gullah Geechee communities historically have had little contact with whites. Several folktales written in Gullah have been analyzed for discussing its persistent patterns. Characterizing Gullah is important for our increased understanding of the origins of AAE. Therefore, the article will be useful for scholars interested in Atlantic creoles and in African American and Diaspora Studies.

The Influence of Geological Hydrodynamic Conditions on the Distribution, Characteristic, and Transport of Microplastics in Groundwater Under a South China Sea Island

The Influence of Geological Hydrodynamic Conditions on the Distribution, Characteristic, and Transport of Microplastics in Groundwater Under a South China Sea Island

English

Some medicinal plants contain natural compounds such as isoflavonoids and polyphenols that produce sterility in male animals. The aim of the present study is to investigate the effects of the chloroform extract of the seeds of Sea Island cotton, Gossypium barbadense; the ethanolic extract of seeds of soybean, Glycine max; and the ethanolic extract of the leaves of rosemary, Rosmarinus officinalis, on the fertility of male albino mice as a prelude for their usage in the control of house mice. The extraction of cottonseeds was performed by soaking and shaking, and the extraction of soybeans seeds and rosemary leaves was performed using the Soxhlet apparatus. Sperm parameters, histology of testes, and biochemical parameters of treated mice were compared with the corresponding ones of untreated mice. The oral administration of all extracts caused a significant reduction in sperm count and motility, and had severe histopathological effects on the testes. The plant extracts also caused significant decreases in the concentration of free testosterone, significant increases in the activities of alanine aminotransferase and aspartate aminotransferase, and a significant decrease in the concentration of urea in serum (except the extract of soybeans). The plant extracts tested in the present study proved to have anti-fertility effects on male albino mice, but it caused significant perturbations in the kidney and liver. These extracts could be used in the control of house mice. Key words: Cotton seeds, plant extracts, Rosemary, semen analysis, soybeans, testosterone.

Genomic and GWAS analyses demonstrate phylogenomic relationships of Gossypium barbadense in China and selection for fibre length, lint percentage and Fusarium wilt resistance.

SummarySea Island cotton (Gossypium barbadense) is the source of the world’s finest fibre quality cotton, yet relatively little is understood about genetic variations among diverse germplasms, genes underlying important traits and the effects of pedigree selection. Here, we resequenced 336 G. barbadense accessions and identified 16 million SNPs. Phylogenetic and population structure analyses revealed two major gene pools and a third admixed subgroup derived from geographical dissemination and interbreeding. We conducted a genome‐wide association study (GWAS) of 15 traits including fibre quality, yield, disease resistance, maturity and plant architecture. The highest number of associated loci was for fibre quality, followed by disease resistance and yield. Using gene expression analyses and VIGS transgenic experiments, we confirmed the roles of five candidate genes regulating four key traits, that is disease resistance, fibre length, fibre strength and lint percentage. Geographical and temporal considerations demonstrated selection for the superior fibre quality (fibre length and fibre strength), and high lint percentage in improving G. barbadense in China. Pedigree selection breeding increased Fusarium wilt disease resistance and separately improved fibre quality and yield. Our work provides a foundation for understanding genomic variation and selective breeding of Sea Island cotton.

Mapping the Sea Islands Culture in Paule Marshall's Praisesong for the Widow

The Sea Islands off the coasts of Georgia and South Carolina function as a vital bridge between African Americans and their African ancestry, retaining a unique African culture that had been forgotten in the mainland communities. The Gullah/Geechee people, the inhabitants of the Sea Islands, are the most distinctive group of African Americans, who maintained a separate creole language and are unique from any other subset of African Americans. Paule Marshall’s vision of the Sea Islands in her 1983 novel Praisesong for the Widow illustrates the mythical landscape as a place for excavating and forging cultural as well as historical connections. The article focuses on the protagonist’s displaced historical memory, lost cultural connections, and self, which are awakened on the Sea Islands. Marshall links the Sea Islands and the African diaspora through the space of the Caribbean, emphasizing on discovering and recovering kinship ties. The protagonist’s understanding and awareness of a diasporic Gullah/Geechee identity comes to light when the Sea Island’s heritage wins over her oppressive American culture. The African diaspora is reunited in this novel through storytelling, dance, music, and rituals of reverence and remembrance, thereby enabling the protagonist to acknowledge and identify her Gullah roots and culture. As retrieval of real and imagined cultural inheritances is crucial to the construction and process of creolized identities, Marshall posits the Sea Islands as central and a site of cultural expression in the novel. Marshall’s depiction of the Sea Island’s role in Praisesong as a unique southern landscape serves as a healing ground for physical and cultural loss.

Source Regions of the First Immigration of Fall Armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae) Invading Australia.

Simple SummaryThe fall armyworm, Spodoptera frugiperda, is a serious invasive, crop-destroying pest, which is the subject of a global warning from the United Nations Food and Agriculture Organization (FAO). The surprisingly rapid spread of fall armyworm and its significant capacity to generate high-yield losses has attracted increased attention worldwide. In January 2020, fall armyworm was first confirmed in Torres Strait (Saibai and Erub Islands) and mainland Australia (Bamaga). However, the possible source region of the first immigration of fall armyworm was still obscure. A better understanding of the migration paths and the source regions of fall armyworm immigrants, will be useful for the monitoring and early warning of this pest in Australia. The migratory paths and wind systems for the first case of the immigration of fall armyworm invading Australia were simulated using a three-dimensional trajectory analysis program. This study has confirmed that the immigration of fall armyworm to Australia was most likely from Sulawesi and Moluccas Islands of Indonesia.Fall armyworm is recognized as one of most highly destructive global agricultural pests. In January 2020, it had first invaded Australia, posing a significant risk to its biosecurity, food security, and agricultural productivity. In this study, the migration paths and wind systems for the case of fall armyworm invading Australia were analyzed using a three-dimensional trajectory simulation approach, combined with its flight behavior and NCEP meteorological reanalysis data. The analysis showed that fall armyworm in Torres Strait most likely came from surrounding islands of central Indonesia on two occasions via wind migration. Specifically, fall armyworm moths detected on Saibai and Erub Islands might have arrived from southern Sulawesi Island, Indonesia, between January 15 and 16. The fall armyworm in Bamaga most likely arrived from the islands around Arafura Sea and Sulawesi Island of Indonesia, between January 26 and 27. The high risk period for the invasion of fall armyworm is only likely to have occurred in January–February due to monsoon winds, which were conducive to flight across the Timor Sea towards Australia. This case study is the first to confirm the immigration paths and timing of fall armyworm from Indonesia to Australia via its surrounding islands.

Rune Carvers in Military Campaigns

Runic inscriptions, such as those found in the probable Varangian contexts of Hagia Sofia and Piraeus, as well as on the Black Sea island of Berezan, where the origin of the carver is less obvious, show that some of the Scandinavians in such contexts knew how to write runes. Domestic Scandinavian runestones also display traces of martial activities, as in the inscription about the carver Ulfr, who participated in the taking of giald in England. In addition, a number of objects inscribed with runes have been found in the Garrison at Birka. Previously, runestones have figured in debates regarding conflict, tribute, and political expansion within Scandinavia. One of the questions that has been addressed deals with runestones in certain parts of Scandinavia – Bornholm, Gotland and Öland – and whether they were produced by locals, or by carvers from other parts of Scandinavia. Runestone characteristics that were earlier attributed to mainland Swedish influences on Gotland and Bornholm can in fact also be dependent on chronology, or be seen as regional eastern Scandinavian features. One of my queries has been whether it is possible to reach a more profound understanding of such phenomenon by analysing carving techniques, since my results indicate that some runestones on these islands were produced by travelling and visiting carvers, and could be indicators of the status of cross-regional relationships.

Deep sea without limitsfour new closely related species of Emertonia Wilson, 1932 (Copepoda: Harpacticoida: Paramesochridae) show characters with a world-wide distribution.

The large-scale dispersal of deep-sea harpacticoid copepods is an increasing focus for ecological studies. A fundamental prerequisite for monitoring and explaining their geographical distribution is precise descriptions of their morphology. Four new, closely related species of the family Paramesochridae (Copepoda, Harpacticoida) were found in the deep sea of the Pacific (San Diego Trough and off Chile), the Atlantic Ocean (Porcupine Abyssal Plain and Angola Basin), and the Atlantic and Indian Ocean sectors of the Southern Ocean (Weddell Sea and off Crozet Island). The discovery of Emertonia berndi sp. nov., E. hessleri sp. nov., E. ilse sp. nov., and E. serrata sp. nov. increases the number of known deep-sea species in this genus to ten. The new species are placed in Emertonia Wilson, 1932 because of their one-segmented endopods on the second and third swimming legs. The presence of a two-segmented endopod on the fourth swimming leg allocates them to the andeep-group within this genus. The four species can be distinguished from their congeners by the strongly serrated spines on the exopods of their swimming legs and an outwardly directed flexible seta on the exopod of the fifth leg. It is conveivable that these two specific characters evolved only once in the genus Emertonia. Their apparently cosmopolitan distribution covers thousands of kilometres and spans all major oceans. This biogeographical pattern may be explained by resuspension events followed by passive transport by benthic currents. Discrepancies in their dispersal ranges may be a result of changing geological and oceanographic boundaries.

Self-stratified fouling release coatings based on polydimethylsiloxane incorporated with acrylate-MQ silicone copolymer

In this study, an acrylate-MQ silicone copolymer (A-MQ) was synthesized and characterized by Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance, and differential scanning calorimetry. Next, fouling release coatings based on polydimethylsiloxane (PDMS) were prepared by incorporating A-MQ. Self-stratified coatings were prepared by controlling the additive amount of A-MQ. Surface property analysis results showed that the appropriate A-MQ additive amount ensured surface smoothness and hydrophobicity in the prepared coatings (P/A-MQ18). Incorporating A-MQ enhanced the mechanical properties of the coatings. Moreover, the shore hardness values of the surface and interface were different, indicating stratification. Observing the fracture microstructures further confirmed the formation of self-stratified structures owing to the enrichment of the surface layer by PDMS during the curing process. More importantly, a high additive amount of A-MQ led to further phase separation with the appearance of “sea–island structures” in the prepared coatings, and this deteriorated the mechanical properties of the coatings (P/A-MQ20). The pull-off test results indicated that the self-stratified coating broke from the upper layer enriched with PDMS, indicating high adhesion strength. The biofilm adhesion assay confirmed the excellent antifouling performance of the self-stratified coating, which also resulted from the enrichment of the upper layer by PDMS. These findings can be extremely useful for developing high-performance fouling release coatings.

Distribution and source determination of rare earth elements in sediment collected from the continental shelf off Hainan Island, China.

Contents of rare earth elements (REEs), major elements, and the total organic carbon (TOC) were determined for 152 surface sediment samples collected from the continental shelf off Hainan Island (CSHI). From high to low, the average contents of REEs were as follows: Ce > La > Nd > Pr > Sm > Gd > Dy > Er > Yb > Eu > Ho > Tb > Tm > Tm. The LREEs in the south are more abundant than in the north, which is shown by the higher LREE/HREE values in south than in the north. This resulted higher values for the LREE/HREE ratio in the south than in the north. The mean enrichment factor (EF) could be arranged from highest to lowest as follows: Tm > Sm > Pr > Er > La > Lu > Ce > Tb > Eu > Nd > Yb > Gd > Ho > Dy. The EF indicates that pollution as a result of human activity was more serious in the southeast of the study area than in the north. The factors affecting the REE concentrations in this area include naturally occurring minerals and industrial pollution. Based on the spatial variation of upper continental crust (UCC)-normalized REE concentrations, the CSHI was classified into three geochemical provinces. The sediment of province I was controlled by the Red and Pearl rivers. The composition of the province II is mainly controlled by the Red River and the Pearl River, although some sediments have originated from the South China Sea Island. Province III sediments mainly originated from sources on Hainan Island.

Effect of dispersion and orientation of dispersed phase on mechanical and electrical conductivity

AbstractMelt mixed polypropylene/polyamide 6 (PA6) and multiwalled carbon nanotubes (CNTs) were molded by compression, injection, and interval injection molding. PA phase exists as an isolated dispersed phase in the sea–island system with different phase orientations and dispersion degrees. CNTs prefer to be located in the minor PA phase because of their remarkable compatibility. However, when the content of CNTs is high enough, a conductive path can be formed regardless of the phase morphology. Moreover, when the CNT content is low, the dispersed PA forms an unelongated structure, which is beneficial to electrical conductivity. Although the elongated PA phase holds advantages in terms of its tensile properties, its conductivity network is defective. These results were proposed to uncover the influence of dispersed phase morphology on mechanical and electrical conductivity.