A Farewell to Arms is a classical work in the history of American literature. The author, Hemingway, creates a kind of character in his works successfully, that is, the Hemingway Hero. Due to its excellency, this nove...A Farewell to Arms is a classical work in the history of American literature. The author, Hemingway, creates a kind of character in his works successfully, that is, the Hemingway Hero. Due to its excellency, this novel is appreciated and criticized by many people. The paper aims to analyze this story in terms of structuralism. Structuralism is the belief that things cannot be understood in isolation-they have to be seen in the context of the larger structures they are part of. Parallel and contrast are two main branches in structuralism. And this novel will be analyzed in three aspects, parallel and contras in imagery, parallel and contras in characters, and parallel and contras in structure.展开更多
The dominant features of the post-war intellectual scene in France were existentialism, phenomenology, and Marxism, as well as efforts to synthesize them. In the 1960s, these theoretical currents had to cope with new ...The dominant features of the post-war intellectual scene in France were existentialism, phenomenology, and Marxism, as well as efforts to synthesize them. In the 1960s, these theoretical currents had to cope with new perspectives and ideas brought to the world of theory by the linguistically-oriented discourse of Saussure＇s structuralism and Lacanian psychoanalysis. Structuralists tried to apply structurally-linguistic model to the humanities and designed the new concept of the language, subjectivity, and society. Levi-Strauss applied the structural-linguistic analysis to the study of myths and family relationships; Lacan developed psychoanalysis based on structuralism; Althusser comes with a structuralist interpretation of Marx. Structuralists attempted to analyse the unconscious codes, rules, and binary oppositions that create the meaning, thus organizing social systems, such as sexual behaviour, fashion, culinary arts, myths, etc. Structures are unconscious, because their product and effects always overlap them. Structuralism therefore does not study individual isolated phenomena, but it moves from the analysis of phenomena that are consciously understood or known to participants in the particular discourse to their ＂unconscious infrastructures.＂ Structuralists always emphasized rigorously scientific status of their theories; at the same time, applying structurally-linguistic concepts on humanities was supposed to help to make them scientific again.展开更多
1. A General View To Structuralism What does structuralism mean? In its broadest sense structuralism is a 20th century movement in the humanities and social sciences that attach relatively little importance to ca-sual...1. A General View To Structuralism What does structuralism mean? In its broadest sense structuralism is a 20th century movement in the humanities and social sciences that attach relatively little importance to ca-sual explanation and maintains that to understand a phenomenon one must describe both its internal structure——the relations among its parts——and its relations with other phenome-展开更多
According to New Structural Economics, the ultimate direction of industrial transformation is determined by factor endowment structure and the relative price system of factors. In today＇s China, the predominant facto...According to New Structural Economics, the ultimate direction of industrial transformation is determined by factor endowment structure and the relative price system of factors. In today＇s China, the predominant factor in its labor endowment is shifting from population size to the regional movement of population and population quality, and its land endowment is changing from cheap, massive supply to expensive, limited supply, and the economy has potential of technological catch-up. Because of these three fundamental realities and the special situation that China is vast in territory and has a continuous industrial spectrum, its industrial transformation will be featured with ＂three unique regions within one country＂ and that the eastern region enters a new stage which focuses on the development of services, the six central provinces and the western triangle zone take over industries transferred from the east and the resource-rich western region becomes the ＂home front＂ as a major supplier of resources. However, this ＂three region differentiation＂ will not be automatically developed. Only in a competitive factor market, a flexible financial market and an elastic labor market can the persistent changes in endowment structure drive China＇s industrial structure towards its optimal form. To achieve this, we need to launch a series of necessary structural reforms.展开更多
Deconstruction and Structuralism are two of the twentieth century western criticism schools, and their relationship still is an issue that needs to be systematically clarified. The paper presents a review study on the...Deconstruction and Structuralism are two of the twentieth century western criticism schools, and their relationship still is an issue that needs to be systematically clarified. The paper presents a review study on the particular relationship of Deconstruction and Structuralism by comparing these two criticism schools from the respects of their origins, features, and limitations in the chronological view. It tends to prove that Deconstruction stems from the Structuralism, however Deconstruction differs itself from Structuralism in certain key features and bases itself upon a certain characteristic critique of Structuralism.展开更多
To deepen understanding of the evolution of coal char microstructural properties of coal char during the co-pyrolysis of coking coal with additives,this study incorporated two typical additives,coal tar pitch(CTP)and ...To deepen understanding of the evolution of coal char microstructural properties of coal char during the co-pyrolysis of coking coal with additives,this study incorporated two typical additives,coal tar pitch(CTP)and waste plastic(HDPE),into a blended coal sample and carried out pyrolysis experiments.The pyrolysis process and the microstructure of char were systematically characterized using various analytical techniques,including thermogravimetric analysis(TGA),X-ray diffraction(XRD)and Raman spectroscopy.Data correlation analysis was performed to reveal the mechanism of carbon structural ordering evolution within the critical temperature range(350−600℃)from colloidal layer formation to semi-coke conversion in coking coal,and to elucidate the regulatory effects of different additives on coal pyrolysis pathways.The results indicate that HDPE releases free radicals during high-temperature pyrolysis,accelerating the pyrolysis reaction and increase the yield of volatile components.Conversely,CTP facilitates pyrolysis at low temperatures through its light components,thereby delaying high-temperature reactions due to the colloidal layer’s effect.XRD results indicate that during the process of pyrolysis,there is a progressive decrease in the interlayer spacing of aromatic layers(d002),while the aromatic ring stacking height(L_(c))and lateral size(L_(a))undergo significant of carbon skeleton ordering.Further comparative reveals that CTP partially suppresses structural ordering at low temperatures,whereas HDPE promotes the condensation and alignment of aromatic clusters via a free radical mechanism.Raman spectroscopy reveals a two-stage reorganization mechanism in the microstructure of the coal char:the decrease in the I_(D)/I_(G)ratio between 350 and 550℃is primarily attributed to the cleavage of aliphatic side chains and cross-linking bonds,leading to a reduction in defective structures;whereas the increase in ID/IG between 550 and 600℃is closely associated with enhanced condensation reactions of aromatic structures.Correlation analysis further demonstrates progressive graphitization during pyrolysis,with a significant positive correlation(R^(2)>0.85)observed between d002 and the full width at half maximum of the G-band(FWHM-G).展开更多
In this study,a novel polysaccharide GPA-G 2-H was derived from ginseng.Furthermore,the coherent study of its structural characteristics,fermented characteristics in vitro,as well as antioxidant mechanism of fermented...In this study,a novel polysaccharide GPA-G 2-H was derived from ginseng.Furthermore,the coherent study of its structural characteristics,fermented characteristics in vitro,as well as antioxidant mechanism of fermented product FGPA-G 2-H on Aβ25-35-induced PC 12 cells were explored.The structure of GPA-G 2-H was determined by means of zeta potential analysis,FTIR,HPLC,XRD,GC-MS and NMR.The backbone of GPA-G 2-H was mainly composed of→4)-α-D-Glcp-(1→with branches substituted at O-3.Notably,GPA-G 2-H was degraded by intestinal microbiota in vitro with total sugar content and pH value decreasing,and short-chain fatty acids(SCFAs)increasing.Moreover,GPA-G 2-H significantly promoted the proliferation of Lactobacillus,Muribaculaceae and Weissella,thereby making positive alterations in intestinal microbiota composition.Additionally,FGPA-G 2-H activated the Nrf 2/HO-1 signaling pathway,enhanced HO-1,NQO 1,SOD and GSH-Px,while inhabited Keap 1,MDA and LDH,which alleviated Aβ-induced oxidative stress in PC 12 cells.These provide a solid theoretical basis for the further development of ginseng polysaccharides as functional food and antioxidant drugs.展开更多
Six new lanthanide complexes:[Ln(3,4-DEOBA)3(4,4'-DM-2,2'-bipy)]2·2C_(2)H_(5)OH,[Ln=Dy(1),Eu(2),Tb(3),Sm(4),Ho(5),Gd(6);3,4-DEOBA-=3,4-diethoxybenzoate,4,4'-DM-2,2'-bipy=4,4'-dimethyl-2,2'...Six new lanthanide complexes:[Ln(3,4-DEOBA)3(4,4'-DM-2,2'-bipy)]2·2C_(2)H_(5)OH,[Ln=Dy(1),Eu(2),Tb(3),Sm(4),Ho(5),Gd(6);3,4-DEOBA-=3,4-diethoxybenzoate,4,4'-DM-2,2'-bipy=4,4'-dimethyl-2,2'-bipyridine]were successfully synthesized by the volatilization of the solution at room temperature.The crystal structures of six complexes were determined by single-crystal X-ray diffraction technology.The results showed that the complexes all have a binuclear structure,and the structures contain free ethanol molecules.Moreover,the coordination number of the central metal of each structural unit is eight.Adjacent structural units interact with each other through hydrogen bonds and further expand to form 1D chain-like and 2D planar structures.After conducting a systematic study on the luminescence properties of complexes 1-4,their emission and excitation spectra were obtained.Experimental results indicated that the fluorescence lifetimes of complexes 2 and 3 were 0.807 and 0.845 ms,respectively.The emission spectral data of complexes 1-4 were imported into the CIE chromaticity coordinate system,and their corre sponding luminescent regions cover the yellow light,red light,green light,and orange-red light bands,respectively.Within the temperature range of 299.15-1300 K,the thermal decomposition processes of the six complexes were comprehensively analyzed by using TG-DSC/FTIR/MS technology.The hypothesis of the gradual loss of ligand groups during the decomposition process was verified by detecting the escaped gas,3D infrared spectroscopy,and ion fragment information detected by mass spectrometry.The specific decomposition path is as follows:firstly,free ethanol molecules and neutral ligands are removed,and finally,acidic ligands are released;the final product is the corresponding metal oxide.CCDC:2430420,1;2430422,2;2430419,3;2430424,4;2430421,5;2430423,6.展开更多
This paper reports the preparation of three di‑iron complexes containing a thiazole moiety.Esterification of complex[Fe_(2)(CO)_(6)(μ‑SCH_(2)CH(CH_(2)OH)S)](1)with 4‑methylthiazole‑5‑carboxylic acid gave the correspo...This paper reports the preparation of three di‑iron complexes containing a thiazole moiety.Esterification of complex[Fe_(2)(CO)_(6)(μ‑SCH_(2)CH(CH_(2)OH)S)](1)with 4‑methylthiazole‑5‑carboxylic acid gave the corresponding ester[Fe_(2)(CO)_(6)(μ‑tedt)](2),where tedt=SCH_(2)CH(CH_(2)OOC(5‑C_(3)HNSCH_(3)))S.Further reactions of complex 2 with tri(ptolyl)phosphine(tp)or tris(4‑fluorophenyl)phosphine(fp)gave the phosphine‑substituted derivatives[Fe_(2)(CO)_(5)(tp)(μ‑tedt)](3)and[Fe_(2)(CO)_(5)(fp)(μ‑tedt)](4).The structures of the newly prepared complexes were elucidated by elemental analysis,NMR,IR,and X‑ray photoelectron spectroscopy.Moreover,single‑crystal X‑ray diffraction analysis confirmed their molecular structures,showing that they contain a di‑iron core ligated by a bridged dithiolate bearing a thiazole moiety and terminal carbonyls.The electrochemical and electrocatalytic proton reduction were probed by cyclic voltammetry,revealing that three complexes can catalyze the reduction of protons to H_(2) under the electrochemical conditions.For comparison,complex 4 possessed the best efficiency with a turnover frequency of 23.5 s^(-1)at 10 mmol·L^(-1)HOAc concentration.In addition,the fungicidal activity of these complexes was also investigated in this study.CCDC:2477511,2;2477512,3;2477513,4.展开更多
To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content ...To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content in coal)catalysts were prepared by the incipient wetness impregnation method,followed by acid washing to remove calcium-containing minerals.Comprehensive characterization and low-temperature denitrification tests revealed that calcite-induced structural modulation of coal-derived AC significantly enhances catalytic activity.Specifically,NO conversion increased from 88.3%of Mn-Ce/De-AC to 91.7%of Mn-Ce/De-AC-1CaCO_(3)(210℃).The improved SCR denitrification activity results from the enhancement of physicochemical properties including higher Mn^(4+)content and Ce^(4+)/Ce^(3+)ratio,an abundance of chemisorbed oxygen and acidic sites,which could strengthen the SCR reaction pathways(richer NH_(3)activated species and bidentate nitrate active species).Therefore,NO removal is enhanced.展开更多
Anchovies are key forage species in coastal and pelagic food webs,playing crucial ecological and commercial roles in marine ecosystems.Encrasicholina punctifer is a commercially and ecologically important species,yet ...Anchovies are key forage species in coastal and pelagic food webs,playing crucial ecological and commercial roles in marine ecosystems.Encrasicholina punctifer is a commercially and ecologically important species,yet little is known about its osteological development characteristics.Understanding these ontogenetic patterns is essential for explaining phylogenetic relationships within Clupeiformes,informing larval identification in ichthyoplankton surveys,and enhancing aquaculture practices.This study describes the ontogenetic characteristics of the appendicular and median skeletons and fin supports in E.punctifer larvae and juveniles,providing quantitative ontogenetic timelines to address gaps in engraulid developmental biology and contribute to teleost ontogeny research.Larval and juvenile specimens of E.punctifer;size range:3.00-34.56 mm standard length(SL)and notochord length(NL)collected from the Philippine Sea were processed using the standard Alizarin red and Alcian blue clearing-and-staining technique to differentiate ossified and cartilaginous elements.Specimens were examined under a stereo microscope and imaged with an HTC1600ISP digital camera for detailed morphological analysis of skeletal structures.Caudal complex development was evident by 5.55 mm NL,with the initial appearance of cartilaginous hypurals 1–2 and parhypural,followed by Hy3–5 at 6.08 mm NL.Cartilaginous Hy6 was visible by 9.58 mm SL in postflexion larvae.Six hypural bones were present from the postflexion to juvenile stage.Principal fin rays formed via intramembranous ossification at 6.32 mm NL,and segmentation was evident by 10.24 mm SL.Neural arch 1 appeared at 7.38 mm NL,preceding full haemal arch development.Uroneurals 1–2 and ural centra ossified by 9.58 mm SL,with Hy5 detached from U1 at 10.24 mm SL.Preural centra ossified before the arches.Epurals 1 and 2 were evident by 10.24 mm SL.Dorsal fin proximal radials developed anteriorly and distal radials posteriorly.Pectoral fin development initiated with an ossified cleithrum and the coracoscapular cartilage at 5.25 mm NL.By 10.24 mm SL,cartilaginous neural and haemal arches and spines were distinct.Uroneural 1 initially develops as cartilage.The formation of a pleurostyle aligns with clupeoid fish skeletal ontogeny.Dorsal and anal fin development follows a distinctive pattern,with variability in fin support development.Our results reveal accelerated caudal complex formation in E.punctifer and contribute new knowledge on the osteological characteristics of the genus Encrasicholina,and aid in understanding larval and juvenile ontogeny of marine teleosts.展开更多
Four distinct coordination polymers(CPs)were successfully synthesized by altering solvent types and adjusting ligand concentrations,and their crystal structures were investigated.[Co(L)(FDCA)(H_(2)O)_(2)]·0.5H_(2...Four distinct coordination polymers(CPs)were successfully synthesized by altering solvent types and adjusting ligand concentrations,and their crystal structures were investigated.[Co(L)(FDCA)(H_(2)O)_(2)]·0.5H_(2)O(1)was synthesized as a 2D structure using Coas the metal source,methanol‑water(4∶6,V/V)as the solvent,and specific concentrations of 2,5‑furandicarboxylic acid(H_(2)FDCA)and 1,3,5‑triimidazole benzene(L).Adjusting to pure water and lowering the concentration of L yielded the 1D chain structure of[Co(HL)2(H_(2)O)_(2)](FDCA)_(2)·6H_(2)O(2).Using Cu(Ⅱ)as the metal source,methanol/water(9∶1,V/V)as the solvent,and specific concentrations of L and H2FDCA,the 1D chain structure of[Cu(L)(FDCA)(H_(2)O)]·2H_(2)O(3)was synthesized.Upon increasing the concentrations of L and H2FDCA,and switching the solvent to pure water,the 1D chain structure of[Cu(HL)_(2)(H_(2)O)_(2)](FDCA)_(2)·6H_(2)O(4)was obtained.This shows that changing the solvent and ligand concentrations can affect the structural changes of CPs.In addition,the solid‑state photoluminescence of CPs 1‑4 at room temperature was studied,and their morphological changes were observed via scanning electron microscopy.Density functional theory calculations revealed that the negative charge concentrates on the O and N atoms of the ligand,facilitating ligand‑metal ion coordination.CCDC:2403934,1;2403935,2;2403936,3;2403938,4.展开更多
Achieving high energy and power densities is currently a core challenge in the fabrication of energy storage materials.Although numerous high-capacity materials have been developed,conventional planar electrodes canno...Achieving high energy and power densities is currently a core challenge in the fabrication of energy storage materials.Although numerous high-capacity materials have been developed,conventional planar electrodes cannot achieve high active material loading and efficient ion/electron transport simultaneously.By contrast,three-dimensional(3D)structures have attracted increasing interest because of their capacity to enhance active material utilization,shorten ion and electron transport pathways,reduce interfacial impedance,and provide spatial accommodation for volume expansion.Additive manufacturing(AM)technology effectively fabricates energy-storage materials with 3D structures by accurately constructing complex 3D structures via layer-by-layer deposition.Recent studies have employed AM to construct ordered 3D electrodes that can optimize ion/electron transport,regulate electric field distribution,or improve the electrode-electrolyte interface,thereby contributing to enhanced kinetic performance and cycling stability.This review systematically summarizes the applications of several AM technologies in the fabrication of energy storage materials and analyzes their respective advantages and limitations.Subsequently,the advantages of AM technology in the fabrication of energy storage materials and several major optimization strategies are comprehensively discussed.Finally,the major challenges and potential applications of AM technology in energy storage material optimization are discussed.展开更多
Low-velocity impact tests are carried out to explore the energy absorption characteristics of bio-inspired lattices,mimicking the architecture of the marine sponge organism Euplectella aspergillum.These sea sponge-ins...Low-velocity impact tests are carried out to explore the energy absorption characteristics of bio-inspired lattices,mimicking the architecture of the marine sponge organism Euplectella aspergillum.These sea sponge-inspired lattice structures feature a square-grid 2D lattice with double diagonal bracings and are additively manufactured via digital light processing(DLP).The collapse strength and energy absorption capacity of sea sponge lattice structures are evaluated under various impact conditions and are compared to those of their constituent square-grid and double diagonal lattices.This study demonstrates that sea sponge lattices can achieve an 11-fold increase in energy absorption compared to the square-grid lattice,due to the stabilizing effect of the double diagonal bracings prompting the structure to collapse layer-bylayer under impact.By adjusting the thickness ratio in the sea sponge lattice,up to 76.7%increment in energy absorption is attained.It is also shown that sea-sponge lattices outperform well-established energy-absorbing materials of equal weight,such as hexagonal honeycombs,confirming their significant potential for impact mitigation.Additionally,this research highlights the enhancements in energy absorption achieved by adding a small amount(0.015 phr)of Multi-Walled Carbon Nanotubes(MWCNTs)to the photocurable resin,thus unlocking new possibilities for the design of innovative lightweight structures with multifunctional attributes.展开更多
Plastome variation,including single spontaneous nucleotide substitutions and single insertions/deletions,is the major source of leaf variegation in plants.Additionally,one recent study has showed that a simple plastom...Plastome variation,including single spontaneous nucleotide substitutions and single insertions/deletions,is the major source of leaf variegation in plants.Additionally,one recent study has showed that a simple plastome structural variation,which is induced by one pair of small inverted repeats,can also result in leaf variegation.Here we show a complex plastome structural variation caused by intermolecular and intramolecular recombination across three pairs of small inverted repeats accounts for leaf variegation in a widely cultivated shrub Heptapleurum ellipticum(Araliaceae).This plastome structural variation contains two deletions and two duplications,resulting in dramatic expansion of IRs,substantial contraction of LSC and loss of 11 genes that essential for photosynthesis.Plastome heteroplasmy was detected in both green and albino sectors of variegated leaves.Relative to green sectors,albino sectors in the variegated leaves exhibit significantly reduced expression for the 11 genes lost in the mutated plastome as well as 26 other genes,but significantly increased expression for one gene related to translation apparatus.Optical and transmission electron microscopy observations showed that mesophyll cells of albino sectors possess plastids lacking grana lamellae,which likely carry the mutated plastome and contribute to albinism.In both sectors,the first layer of spongy mesophyll cells beneath the lower epidermis contains normal chloroplasts,suggesting periclinal division of the lower epidermis during development.Our study demonstrates that multiple small repeats can collectively mediate intra-and inter-molecular recombination in plastome and offers a new mechanism accounting for leaf variegation in plants.展开更多
Niobium-based oxides show great potential in anode materials for fast-charging lithium-ion batteries,but their practical application remains hindered by intrinsically low conductivity.In this study,we successfully syn...Niobium-based oxides show great potential in anode materials for fast-charging lithium-ion batteries,but their practical application remains hindered by intrinsically low conductivity.In this study,we successfully synthesize nano-sized Wadsley-Roth FeNb_(11)O_(29)through Fe-driven phase transformation of Nb_(2)O_(5),which delivers a high specific capacity(280.5 mA h g^(−1)at 0.25 C)along with abundant redox-active sites.Moreover,the Wadsley-Roth shear structure of FeNb_(11)O_(29)facilitates rapid Li^(+)diffusion and guarantees exceptional structural stability.Theoretical calculations further confirm that FeNb_(11)O_(29)has a narrow band gap,which significantly enhances the conductivity.Owing to these merits,FeNb_(11)O_(29)achieves a full charge/discharge cycle within merely 25 s at 75 C rate and retains remarkable cycling stability over 2500 cycles.As a consequence,our assembled FeNb_(11)O_(29)||LiFePO_(4)full cell demonstrates ultra-long cyclability(>10000 cycles)and outstanding fast-charging capability(complete cycling within 2 min at 30 C).These findings highlight nano-sized FeNb_(11)O_(29)as a highly promising anode candidate for next-generation fast-charging LIBs.展开更多
The genus Boechera(Brassicaceae)serves as a model system for studying apomictic reproduction and ecological adaptations,with most species occurring in North America.The rare occurrence of Boechera species outside thei...The genus Boechera(Brassicaceae)serves as a model system for studying apomictic reproduction and ecological adaptations,with most species occurring in North America.The rare occurrence of Boechera species outside their typical range provides unique opportunities to investigate genome evolution in extralimital environments.One such species,B.calcarea,has been described from the Chandalaz Mountains in northeastern Asia(Russia).This study aimed to investigate the genome structure and evolutionary history of B.calcarea.However,our analyses reveal that the species does not belong to Boechera.Instead,an integrative approach combining cytogenetic,phylogenetic and repeatome analysis identified the species as a member of one of more ancestral clades in the tribe Arabideae.The diploid Parryodes calcarea(2n=16)exhibits Arabideae-specific chromosomal signatures,including multiple centromere repositionings.These findings clarify the misclassification of P.calcarea as Boechera,leaving Boechera falcata and Borodinia macrophylla as the only representatives of the Boechereae in the Old World.This study highlights the importance of an integrative approach in resolving taxonomic ambiguities and provides new insights into the diversification of the largest cruciferous tribe,the Arabideae.展开更多
Membrane distillation(MD)is an advanced membrane separation process that employs hydrophobic microporous membranes to sepa rate non-volatile solutes from the feed solution,driven by vapor pressure gradients generated ...Membrane distillation(MD)is an advanced membrane separation process that employs hydrophobic microporous membranes to sepa rate non-volatile solutes from the feed solution,driven by vapor pressure gradients generated through thermal difference.This technology offers strong desalination capabilities and efficiently harnesses low-grade thermal energy sources,including geothermal and waste heat,making it a cost-effective solution for freshwater scarcity.Nevertheless,hydrophobic membranes are prone to contamination by surfactants,inorganic salts,and other substances in feed solutions.To address this,low-surface-energy composite nano-inorganic materials composed of carbon nanotubes and silica were modified and synthesized via organosilicon chemistry.A superhydrophobic surface exhibiting a water contact angle of157.96°was successfully fabricated using above nano-materials on poly(vinylidene fluoride)(PVDF)membrane surface with micro-nano structures via a one-step spray-coating method.Compared to unmodified PVDF membra ne,the superhydrophobic membrane demonstrated superior resistance to common scaling agents such as CaCl_(2),Mg(OH)_(2),CaCO_(3),and CaSO_(4),while maintaining stable permeate flux(13.4 kg·m^(-2)·h^(-1))during MD tests.Additionally,the modified membra ne exhibited enhanced wetting resistance when treating feed solutions containing sodium dodecyl sulfate(SDS),significantly extending the operational lifespan of the membrane.Due to its outstanding performance,this superhydrophobic membrane is expected to promote the practical application of MD technology in the treatment of complex wa stewater and efficient seawater desalination.展开更多
Purpose-The utilization of alkali-free accelerators,primarily based on aluminum sulfate,in shotcrete often leads to significant shrinkage and cracking,jeopardizing long-term durability.This study aims to mitigate this...Purpose-The utilization of alkali-free accelerators,primarily based on aluminum sulfate,in shotcrete often leads to significant shrinkage and cracking,jeopardizing long-term durability.This study aims to mitigate this issue by investigating the efficacy of silica fume(SF)and fly ash(FA),individually and combined,in controlling the shrinkage deformation of shotcrete.Design/methodology/approach-Shotcrete mixtures were prepared with cement partially replaced by SF,FA,or their combination(SF-FA).Aluminum sulfate was used as an accelerator.The shrinkage behavior under sealed and dry conditions was monitored.The underlying mechanisms were elucidated through hardened airvoid analysis,mercury intrusion porosimetry(MIP),and internal humidity tracking.Findings-Contrary to some previous studies,both individual and combined incorporation of mineral admixtures reduced the 28-day shrinkage.The SF-FA composite exhibited the most substantial reduction(23.72%sealed,17.76%dry),followed by SF alone(18.11%sealed)and FA alone(11.35%sealed).Mechanism analysis revealed that the admixtures refined the pore structure,reduced the volume of harmful pores,and,crucially,optimized the air-void system by increasing the population of fine bubbles.This created an internal buffering effect that alleviates capillary stress.The synergistic effect in the SF-FA group is attributed to complementary pore-filling at dual scales.Originality/value-This work demonstrates that,within an aluminum sulfate-accelerated shotcrete system,silica fume can effectively reduce shrinkage when its pore-refining effect is counterbalanced by a welloptimized micro-bubble network.It provides the first comprehensive evidence of the synergistic shrinkagereducing mechanism of SF and FA in such systems,offering a practical strategy for mix design optimization to enhance the volume stability of shotcrete.展开更多
文摘A Farewell to Arms is a classical work in the history of American literature. The author, Hemingway, creates a kind of character in his works successfully, that is, the Hemingway Hero. Due to its excellency, this novel is appreciated and criticized by many people. The paper aims to analyze this story in terms of structuralism. Structuralism is the belief that things cannot be understood in isolation-they have to be seen in the context of the larger structures they are part of. Parallel and contrast are two main branches in structuralism. And this novel will be analyzed in three aspects, parallel and contras in imagery, parallel and contras in characters, and parallel and contras in structure.
文摘The dominant features of the post-war intellectual scene in France were existentialism, phenomenology, and Marxism, as well as efforts to synthesize them. In the 1960s, these theoretical currents had to cope with new perspectives and ideas brought to the world of theory by the linguistically-oriented discourse of Saussure＇s structuralism and Lacanian psychoanalysis. Structuralists tried to apply structurally-linguistic model to the humanities and designed the new concept of the language, subjectivity, and society. Levi-Strauss applied the structural-linguistic analysis to the study of myths and family relationships; Lacan developed psychoanalysis based on structuralism; Althusser comes with a structuralist interpretation of Marx. Structuralists attempted to analyse the unconscious codes, rules, and binary oppositions that create the meaning, thus organizing social systems, such as sexual behaviour, fashion, culinary arts, myths, etc. Structures are unconscious, because their product and effects always overlap them. Structuralism therefore does not study individual isolated phenomena, but it moves from the analysis of phenomena that are consciously understood or known to participants in the particular discourse to their ＂unconscious infrastructures.＂ Structuralists always emphasized rigorously scientific status of their theories; at the same time, applying structurally-linguistic concepts on humanities was supposed to help to make them scientific again.
文摘1. A General View To Structuralism What does structuralism mean? In its broadest sense structuralism is a 20th century movement in the humanities and social sciences that attach relatively little importance to ca-sual explanation and maintains that to understand a phenomenon one must describe both its internal structure——the relations among its parts——and its relations with other phenome-
文摘According to New Structural Economics, the ultimate direction of industrial transformation is determined by factor endowment structure and the relative price system of factors. In today＇s China, the predominant factor in its labor endowment is shifting from population size to the regional movement of population and population quality, and its land endowment is changing from cheap, massive supply to expensive, limited supply, and the economy has potential of technological catch-up. Because of these three fundamental realities and the special situation that China is vast in territory and has a continuous industrial spectrum, its industrial transformation will be featured with ＂three unique regions within one country＂ and that the eastern region enters a new stage which focuses on the development of services, the six central provinces and the western triangle zone take over industries transferred from the east and the resource-rich western region becomes the ＂home front＂ as a major supplier of resources. However, this ＂three region differentiation＂ will not be automatically developed. Only in a competitive factor market, a flexible financial market and an elastic labor market can the persistent changes in endowment structure drive China＇s industrial structure towards its optimal form. To achieve this, we need to launch a series of necessary structural reforms.
文摘Deconstruction and Structuralism are two of the twentieth century western criticism schools, and their relationship still is an issue that needs to be systematically clarified. The paper presents a review study on the particular relationship of Deconstruction and Structuralism by comparing these two criticism schools from the respects of their origins, features, and limitations in the chronological view. It tends to prove that Deconstruction stems from the Structuralism, however Deconstruction differs itself from Structuralism in certain key features and bases itself upon a certain characteristic critique of Structuralism.
基金Supported by National Natural Science Foundation of China(22378180,22078141)Education Department Foundation of Liaoning Province(JYTMS20230960)。
文摘To deepen understanding of the evolution of coal char microstructural properties of coal char during the co-pyrolysis of coking coal with additives,this study incorporated two typical additives,coal tar pitch(CTP)and waste plastic(HDPE),into a blended coal sample and carried out pyrolysis experiments.The pyrolysis process and the microstructure of char were systematically characterized using various analytical techniques,including thermogravimetric analysis(TGA),X-ray diffraction(XRD)and Raman spectroscopy.Data correlation analysis was performed to reveal the mechanism of carbon structural ordering evolution within the critical temperature range(350−600℃)from colloidal layer formation to semi-coke conversion in coking coal,and to elucidate the regulatory effects of different additives on coal pyrolysis pathways.The results indicate that HDPE releases free radicals during high-temperature pyrolysis,accelerating the pyrolysis reaction and increase the yield of volatile components.Conversely,CTP facilitates pyrolysis at low temperatures through its light components,thereby delaying high-temperature reactions due to the colloidal layer’s effect.XRD results indicate that during the process of pyrolysis,there is a progressive decrease in the interlayer spacing of aromatic layers(d002),while the aromatic ring stacking height(L_(c))and lateral size(L_(a))undergo significant of carbon skeleton ordering.Further comparative reveals that CTP partially suppresses structural ordering at low temperatures,whereas HDPE promotes the condensation and alignment of aromatic clusters via a free radical mechanism.Raman spectroscopy reveals a two-stage reorganization mechanism in the microstructure of the coal char:the decrease in the I_(D)/I_(G)ratio between 350 and 550℃is primarily attributed to the cleavage of aliphatic side chains and cross-linking bonds,leading to a reduction in defective structures;whereas the increase in ID/IG between 550 and 600℃is closely associated with enhanced condensation reactions of aromatic structures.Correlation analysis further demonstrates progressive graphitization during pyrolysis,with a significant positive correlation(R^(2)>0.85)observed between d002 and the full width at half maximum of the G-band(FWHM-G).
基金Supported by the National Key Research and Development Program of Traditional Chinese Medicine Modernization Project,China(No.2023YFC3504000)the Science and Technology Development Project of Jilin Province,China(No.20240404043ZP)the Science and Technology Innovation Cooperation Project of Changchun Science and Technology Bureau and Chinese Academy of Sciences,China(No.23SH14)。
文摘In this study,a novel polysaccharide GPA-G 2-H was derived from ginseng.Furthermore,the coherent study of its structural characteristics,fermented characteristics in vitro,as well as antioxidant mechanism of fermented product FGPA-G 2-H on Aβ25-35-induced PC 12 cells were explored.The structure of GPA-G 2-H was determined by means of zeta potential analysis,FTIR,HPLC,XRD,GC-MS and NMR.The backbone of GPA-G 2-H was mainly composed of→4)-α-D-Glcp-(1→with branches substituted at O-3.Notably,GPA-G 2-H was degraded by intestinal microbiota in vitro with total sugar content and pH value decreasing,and short-chain fatty acids(SCFAs)increasing.Moreover,GPA-G 2-H significantly promoted the proliferation of Lactobacillus,Muribaculaceae and Weissella,thereby making positive alterations in intestinal microbiota composition.Additionally,FGPA-G 2-H activated the Nrf 2/HO-1 signaling pathway,enhanced HO-1,NQO 1,SOD and GSH-Px,while inhabited Keap 1,MDA and LDH,which alleviated Aβ-induced oxidative stress in PC 12 cells.These provide a solid theoretical basis for the further development of ginseng polysaccharides as functional food and antioxidant drugs.
文摘Six new lanthanide complexes:[Ln(3,4-DEOBA)3(4,4'-DM-2,2'-bipy)]2·2C_(2)H_(5)OH,[Ln=Dy(1),Eu(2),Tb(3),Sm(4),Ho(5),Gd(6);3,4-DEOBA-=3,4-diethoxybenzoate,4,4'-DM-2,2'-bipy=4,4'-dimethyl-2,2'-bipyridine]were successfully synthesized by the volatilization of the solution at room temperature.The crystal structures of six complexes were determined by single-crystal X-ray diffraction technology.The results showed that the complexes all have a binuclear structure,and the structures contain free ethanol molecules.Moreover,the coordination number of the central metal of each structural unit is eight.Adjacent structural units interact with each other through hydrogen bonds and further expand to form 1D chain-like and 2D planar structures.After conducting a systematic study on the luminescence properties of complexes 1-4,their emission and excitation spectra were obtained.Experimental results indicated that the fluorescence lifetimes of complexes 2 and 3 were 0.807 and 0.845 ms,respectively.The emission spectral data of complexes 1-4 were imported into the CIE chromaticity coordinate system,and their corre sponding luminescent regions cover the yellow light,red light,green light,and orange-red light bands,respectively.Within the temperature range of 299.15-1300 K,the thermal decomposition processes of the six complexes were comprehensively analyzed by using TG-DSC/FTIR/MS technology.The hypothesis of the gradual loss of ligand groups during the decomposition process was verified by detecting the escaped gas,3D infrared spectroscopy,and ion fragment information detected by mass spectrometry.The specific decomposition path is as follows:firstly,free ethanol molecules and neutral ligands are removed,and finally,acidic ligands are released;the final product is the corresponding metal oxide.CCDC:2430420,1;2430422,2;2430419,3;2430424,4;2430421,5;2430423,6.
文摘This paper reports the preparation of three di‑iron complexes containing a thiazole moiety.Esterification of complex[Fe_(2)(CO)_(6)(μ‑SCH_(2)CH(CH_(2)OH)S)](1)with 4‑methylthiazole‑5‑carboxylic acid gave the corresponding ester[Fe_(2)(CO)_(6)(μ‑tedt)](2),where tedt=SCH_(2)CH(CH_(2)OOC(5‑C_(3)HNSCH_(3)))S.Further reactions of complex 2 with tri(ptolyl)phosphine(tp)or tris(4‑fluorophenyl)phosphine(fp)gave the phosphine‑substituted derivatives[Fe_(2)(CO)_(5)(tp)(μ‑tedt)](3)and[Fe_(2)(CO)_(5)(fp)(μ‑tedt)](4).The structures of the newly prepared complexes were elucidated by elemental analysis,NMR,IR,and X‑ray photoelectron spectroscopy.Moreover,single‑crystal X‑ray diffraction analysis confirmed their molecular structures,showing that they contain a di‑iron core ligated by a bridged dithiolate bearing a thiazole moiety and terminal carbonyls.The electrochemical and electrocatalytic proton reduction were probed by cyclic voltammetry,revealing that three complexes can catalyze the reduction of protons to H_(2) under the electrochemical conditions.For comparison,complex 4 possessed the best efficiency with a turnover frequency of 23.5 s^(-1)at 10 mmol·L^(-1)HOAc concentration.In addition,the fungicidal activity of these complexes was also investigated in this study.CCDC:2477511,2;2477512,3;2477513,4.
基金Supported by the Science and Technology Cooperation and Exchange special project of Cooperation of Shanxi Province(202404041101014)the Fundamental Research Program of Shanxi Province(202403021212333)+3 种基金the Joint Funds of the National Natural Science Foundation of China(U24A20555)the Lvliang Key R&D of University-Local Cooperation(2023XDHZ10)the Initiation Fund for Doctoral Research of Taiyuan University of Science and Technology(20242026)the Outstanding Doctor Funding Award of Shanxi Province(20242080).
文摘To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content in coal)catalysts were prepared by the incipient wetness impregnation method,followed by acid washing to remove calcium-containing minerals.Comprehensive characterization and low-temperature denitrification tests revealed that calcite-induced structural modulation of coal-derived AC significantly enhances catalytic activity.Specifically,NO conversion increased from 88.3%of Mn-Ce/De-AC to 91.7%of Mn-Ce/De-AC-1CaCO_(3)(210℃).The improved SCR denitrification activity results from the enhancement of physicochemical properties including higher Mn^(4+)content and Ce^(4+)/Ce^(3+)ratio,an abundance of chemisorbed oxygen and acidic sites,which could strengthen the SCR reaction pathways(richer NH_(3)activated species and bidentate nitrate active species).Therefore,NO removal is enhanced.
文摘Anchovies are key forage species in coastal and pelagic food webs,playing crucial ecological and commercial roles in marine ecosystems.Encrasicholina punctifer is a commercially and ecologically important species,yet little is known about its osteological development characteristics.Understanding these ontogenetic patterns is essential for explaining phylogenetic relationships within Clupeiformes,informing larval identification in ichthyoplankton surveys,and enhancing aquaculture practices.This study describes the ontogenetic characteristics of the appendicular and median skeletons and fin supports in E.punctifer larvae and juveniles,providing quantitative ontogenetic timelines to address gaps in engraulid developmental biology and contribute to teleost ontogeny research.Larval and juvenile specimens of E.punctifer;size range:3.00-34.56 mm standard length(SL)and notochord length(NL)collected from the Philippine Sea were processed using the standard Alizarin red and Alcian blue clearing-and-staining technique to differentiate ossified and cartilaginous elements.Specimens were examined under a stereo microscope and imaged with an HTC1600ISP digital camera for detailed morphological analysis of skeletal structures.Caudal complex development was evident by 5.55 mm NL,with the initial appearance of cartilaginous hypurals 1–2 and parhypural,followed by Hy3–5 at 6.08 mm NL.Cartilaginous Hy6 was visible by 9.58 mm SL in postflexion larvae.Six hypural bones were present from the postflexion to juvenile stage.Principal fin rays formed via intramembranous ossification at 6.32 mm NL,and segmentation was evident by 10.24 mm SL.Neural arch 1 appeared at 7.38 mm NL,preceding full haemal arch development.Uroneurals 1–2 and ural centra ossified by 9.58 mm SL,with Hy5 detached from U1 at 10.24 mm SL.Preural centra ossified before the arches.Epurals 1 and 2 were evident by 10.24 mm SL.Dorsal fin proximal radials developed anteriorly and distal radials posteriorly.Pectoral fin development initiated with an ossified cleithrum and the coracoscapular cartilage at 5.25 mm NL.By 10.24 mm SL,cartilaginous neural and haemal arches and spines were distinct.Uroneural 1 initially develops as cartilage.The formation of a pleurostyle aligns with clupeoid fish skeletal ontogeny.Dorsal and anal fin development follows a distinctive pattern,with variability in fin support development.Our results reveal accelerated caudal complex formation in E.punctifer and contribute new knowledge on the osteological characteristics of the genus Encrasicholina,and aid in understanding larval and juvenile ontogeny of marine teleosts.
文摘Four distinct coordination polymers(CPs)were successfully synthesized by altering solvent types and adjusting ligand concentrations,and their crystal structures were investigated.[Co(L)(FDCA)(H_(2)O)_(2)]·0.5H_(2)O(1)was synthesized as a 2D structure using Coas the metal source,methanol‑water(4∶6,V/V)as the solvent,and specific concentrations of 2,5‑furandicarboxylic acid(H_(2)FDCA)and 1,3,5‑triimidazole benzene(L).Adjusting to pure water and lowering the concentration of L yielded the 1D chain structure of[Co(HL)2(H_(2)O)_(2)](FDCA)_(2)·6H_(2)O(2).Using Cu(Ⅱ)as the metal source,methanol/water(9∶1,V/V)as the solvent,and specific concentrations of L and H2FDCA,the 1D chain structure of[Cu(L)(FDCA)(H_(2)O)]·2H_(2)O(3)was synthesized.Upon increasing the concentrations of L and H2FDCA,and switching the solvent to pure water,the 1D chain structure of[Cu(HL)_(2)(H_(2)O)_(2)](FDCA)_(2)·6H_(2)O(4)was obtained.This shows that changing the solvent and ligand concentrations can affect the structural changes of CPs.In addition,the solid‑state photoluminescence of CPs 1‑4 at room temperature was studied,and their morphological changes were observed via scanning electron microscopy.Density functional theory calculations revealed that the negative charge concentrates on the O and N atoms of the ligand,facilitating ligand‑metal ion coordination.CCDC:2403934,1;2403935,2;2403936,3;2403938,4.
基金support of the National Natural Science Foundation of China(No.52574411)Beijing Natural Science Foundation(No.2242043).
文摘Achieving high energy and power densities is currently a core challenge in the fabrication of energy storage materials.Although numerous high-capacity materials have been developed,conventional planar electrodes cannot achieve high active material loading and efficient ion/electron transport simultaneously.By contrast,three-dimensional(3D)structures have attracted increasing interest because of their capacity to enhance active material utilization,shorten ion and electron transport pathways,reduce interfacial impedance,and provide spatial accommodation for volume expansion.Additive manufacturing(AM)technology effectively fabricates energy-storage materials with 3D structures by accurately constructing complex 3D structures via layer-by-layer deposition.Recent studies have employed AM to construct ordered 3D electrodes that can optimize ion/electron transport,regulate electric field distribution,or improve the electrode-electrolyte interface,thereby contributing to enhanced kinetic performance and cycling stability.This review systematically summarizes the applications of several AM technologies in the fabrication of energy storage materials and analyzes their respective advantages and limitations.Subsequently,the advantages of AM technology in the fabrication of energy storage materials and several major optimization strategies are comprehensively discussed.Finally,the major challenges and potential applications of AM technology in energy storage material optimization are discussed.
基金supported by the Khalifa University of Science and Technology internal grants(Nos.2021-CIRA-109,2020-CIRA-007,and 2020-CIRA-024).
文摘Low-velocity impact tests are carried out to explore the energy absorption characteristics of bio-inspired lattices,mimicking the architecture of the marine sponge organism Euplectella aspergillum.These sea sponge-inspired lattice structures feature a square-grid 2D lattice with double diagonal bracings and are additively manufactured via digital light processing(DLP).The collapse strength and energy absorption capacity of sea sponge lattice structures are evaluated under various impact conditions and are compared to those of their constituent square-grid and double diagonal lattices.This study demonstrates that sea sponge lattices can achieve an 11-fold increase in energy absorption compared to the square-grid lattice,due to the stabilizing effect of the double diagonal bracings prompting the structure to collapse layer-bylayer under impact.By adjusting the thickness ratio in the sea sponge lattice,up to 76.7%increment in energy absorption is attained.It is also shown that sea-sponge lattices outperform well-established energy-absorbing materials of equal weight,such as hexagonal honeycombs,confirming their significant potential for impact mitigation.Additionally,this research highlights the enhancements in energy absorption achieved by adding a small amount(0.015 phr)of Multi-Walled Carbon Nanotubes(MWCNTs)to the photocurable resin,thus unlocking new possibilities for the design of innovative lightweight structures with multifunctional attributes.
基金supported financially by the National Natural Science Foundation of China(31811530297 and 32170217).
文摘Plastome variation,including single spontaneous nucleotide substitutions and single insertions/deletions,is the major source of leaf variegation in plants.Additionally,one recent study has showed that a simple plastome structural variation,which is induced by one pair of small inverted repeats,can also result in leaf variegation.Here we show a complex plastome structural variation caused by intermolecular and intramolecular recombination across three pairs of small inverted repeats accounts for leaf variegation in a widely cultivated shrub Heptapleurum ellipticum(Araliaceae).This plastome structural variation contains two deletions and two duplications,resulting in dramatic expansion of IRs,substantial contraction of LSC and loss of 11 genes that essential for photosynthesis.Plastome heteroplasmy was detected in both green and albino sectors of variegated leaves.Relative to green sectors,albino sectors in the variegated leaves exhibit significantly reduced expression for the 11 genes lost in the mutated plastome as well as 26 other genes,but significantly increased expression for one gene related to translation apparatus.Optical and transmission electron microscopy observations showed that mesophyll cells of albino sectors possess plastids lacking grana lamellae,which likely carry the mutated plastome and contribute to albinism.In both sectors,the first layer of spongy mesophyll cells beneath the lower epidermis contains normal chloroplasts,suggesting periclinal division of the lower epidermis during development.Our study demonstrates that multiple small repeats can collectively mediate intra-and inter-molecular recombination in plastome and offers a new mechanism accounting for leaf variegation in plants.
基金financially supported by the National Natural Science Foundation of China(52272209).Dedicated to his Alma Mater,Tianjin University,on the occasion of her 130th anniversary by Wei Zhang,who earned his bachelor's degree there in 1997.
文摘Niobium-based oxides show great potential in anode materials for fast-charging lithium-ion batteries,but their practical application remains hindered by intrinsically low conductivity.In this study,we successfully synthesize nano-sized Wadsley-Roth FeNb_(11)O_(29)through Fe-driven phase transformation of Nb_(2)O_(5),which delivers a high specific capacity(280.5 mA h g^(−1)at 0.25 C)along with abundant redox-active sites.Moreover,the Wadsley-Roth shear structure of FeNb_(11)O_(29)facilitates rapid Li^(+)diffusion and guarantees exceptional structural stability.Theoretical calculations further confirm that FeNb_(11)O_(29)has a narrow band gap,which significantly enhances the conductivity.Owing to these merits,FeNb_(11)O_(29)achieves a full charge/discharge cycle within merely 25 s at 75 C rate and retains remarkable cycling stability over 2500 cycles.As a consequence,our assembled FeNb_(11)O_(29)||LiFePO_(4)full cell demonstrates ultra-long cyclability(>10000 cycles)and outstanding fast-charging capability(complete cycling within 2 min at 30 C).These findings highlight nano-sized FeNb_(11)O_(29)as a highly promising anode candidate for next-generation fast-charging LIBs.
基金supported by the Czech Science Foundation(projects 24-11371S to TM and 23-06840S to MAL)Masaryk University Grant Agency(project MUNI/R/1268/2022 to TM)Additional support(PT)was provided as part of a long-term research project of the Czech Academy of Sciences,Institute of Botany(RVO 67985939).
文摘The genus Boechera(Brassicaceae)serves as a model system for studying apomictic reproduction and ecological adaptations,with most species occurring in North America.The rare occurrence of Boechera species outside their typical range provides unique opportunities to investigate genome evolution in extralimital environments.One such species,B.calcarea,has been described from the Chandalaz Mountains in northeastern Asia(Russia).This study aimed to investigate the genome structure and evolutionary history of B.calcarea.However,our analyses reveal that the species does not belong to Boechera.Instead,an integrative approach combining cytogenetic,phylogenetic and repeatome analysis identified the species as a member of one of more ancestral clades in the tribe Arabideae.The diploid Parryodes calcarea(2n=16)exhibits Arabideae-specific chromosomal signatures,including multiple centromere repositionings.These findings clarify the misclassification of P.calcarea as Boechera,leaving Boechera falcata and Borodinia macrophylla as the only representatives of the Boechereae in the Old World.This study highlights the importance of an integrative approach in resolving taxonomic ambiguities and provides new insights into the diversification of the largest cruciferous tribe,the Arabideae.
基金financially supported by the National Natural Science Foundation of China(No.22308085)Science and Technology Plan Project of Shijiazhuang(Nos.241130547A and241791337A)Natural Science Foundation of Hebei Province(No.B2020208083)。
文摘Membrane distillation(MD)is an advanced membrane separation process that employs hydrophobic microporous membranes to sepa rate non-volatile solutes from the feed solution,driven by vapor pressure gradients generated through thermal difference.This technology offers strong desalination capabilities and efficiently harnesses low-grade thermal energy sources,including geothermal and waste heat,making it a cost-effective solution for freshwater scarcity.Nevertheless,hydrophobic membranes are prone to contamination by surfactants,inorganic salts,and other substances in feed solutions.To address this,low-surface-energy composite nano-inorganic materials composed of carbon nanotubes and silica were modified and synthesized via organosilicon chemistry.A superhydrophobic surface exhibiting a water contact angle of157.96°was successfully fabricated using above nano-materials on poly(vinylidene fluoride)(PVDF)membrane surface with micro-nano structures via a one-step spray-coating method.Compared to unmodified PVDF membra ne,the superhydrophobic membrane demonstrated superior resistance to common scaling agents such as CaCl_(2),Mg(OH)_(2),CaCO_(3),and CaSO_(4),while maintaining stable permeate flux(13.4 kg·m^(-2)·h^(-1))during MD tests.Additionally,the modified membra ne exhibited enhanced wetting resistance when treating feed solutions containing sodium dodecyl sulfate(SDS),significantly extending the operational lifespan of the membrane.Due to its outstanding performance,this superhydrophobic membrane is expected to promote the practical application of MD technology in the treatment of complex wa stewater and efficient seawater desalination.
文摘Purpose-The utilization of alkali-free accelerators,primarily based on aluminum sulfate,in shotcrete often leads to significant shrinkage and cracking,jeopardizing long-term durability.This study aims to mitigate this issue by investigating the efficacy of silica fume(SF)and fly ash(FA),individually and combined,in controlling the shrinkage deformation of shotcrete.Design/methodology/approach-Shotcrete mixtures were prepared with cement partially replaced by SF,FA,or their combination(SF-FA).Aluminum sulfate was used as an accelerator.The shrinkage behavior under sealed and dry conditions was monitored.The underlying mechanisms were elucidated through hardened airvoid analysis,mercury intrusion porosimetry(MIP),and internal humidity tracking.Findings-Contrary to some previous studies,both individual and combined incorporation of mineral admixtures reduced the 28-day shrinkage.The SF-FA composite exhibited the most substantial reduction(23.72%sealed,17.76%dry),followed by SF alone(18.11%sealed)and FA alone(11.35%sealed).Mechanism analysis revealed that the admixtures refined the pore structure,reduced the volume of harmful pores,and,crucially,optimized the air-void system by increasing the population of fine bubbles.This created an internal buffering effect that alleviates capillary stress.The synergistic effect in the SF-FA group is attributed to complementary pore-filling at dual scales.Originality/value-This work demonstrates that,within an aluminum sulfate-accelerated shotcrete system,silica fume can effectively reduce shrinkage when its pore-refining effect is counterbalanced by a welloptimized micro-bubble network.It provides the first comprehensive evidence of the synergistic shrinkagereducing mechanism of SF and FA in such systems,offering a practical strategy for mix design optimization to enhance the volume stability of shotcrete.
