Background As pre-cut and pre-packaged chilled meat becomes increasingly popular,integrating the carcasscutting process into the pig industry chain has become a trend.Identifying quantitative trait loci(QTLs)of pork c...Background As pre-cut and pre-packaged chilled meat becomes increasingly popular,integrating the carcasscutting process into the pig industry chain has become a trend.Identifying quantitative trait loci(QTLs)of pork cuts would facilitate the selection of pigs with a higher overall value.However,previous studies solely focused on evaluating the phenotypic and genetic parameters of pork cuts,neglecting the investigation of QTLs influencing these traits.This study involved 17 pork cuts and 12 morphology traits from 2,012 pigs across four populations genotyped using CC1 PorcineSNP50 BeadChips.Our aim was to identify QTLs and evaluate the accuracy of genomic estimated breed values(GEBVs)for pork cuts.Results We identified 14 QTLs and 112 QTLs for 17 pork cuts by GWAS using haplotype and imputation genotypes,respectively.Specifically,we found that HMGA1,VRTN and BMP2 were associated with body length and weight.Subsequent analysis revealed that HMGA1 primarily affects the size of fore leg bones,VRTN primarily affects the number of vertebrates,and BMP2 primarily affects the length of vertebrae and the size of hind leg bones.The prediction accuracy was defined as the correlation between the adjusted phenotype and GEBVs in the validation population,divided by the square root of the trait’s heritability.The prediction accuracy of GEBVs for pork cuts varied from 0.342 to 0.693.Notably,ribs,boneless picnic shoulder,tenderloin,hind leg bones,and scapula bones exhibited prediction accuracies exceeding 0.600.Employing better models,increasing marker density through genotype imputation,and pre-selecting markers significantly improved the prediction accuracy of GEBVs.Conclusions We performed the first study to dissect the genetic mechanism of pork cuts and identified a large number of significant QTLs and potential candidate genes.These findings carry significant implications for the breeding of pork cuts through marker-assisted and genomic selection.Additionally,we have constructed the first reference populations for genomic selection of pork cuts in pigs.展开更多
Background:A comprehensive landscape of chromatin states for multiple mammalian tissues is essential for elucidating the molecular mechanism underlying regulatory variants on complex traits.However,the genome-wide chr...Background:A comprehensive landscape of chromatin states for multiple mammalian tissues is essential for elucidating the molecular mechanism underlying regulatory variants on complex traits.However,the genome-wide chromatin accessibility has been only reported in limited tissue types in pigs.Results:Here we report a genome-wide landscape of chromatin accessibility of 20 tissues in two female pigs at ages of 6 months using ATAC-seq,and identified 557,273 merged peaks,which greatly expanded the pig regulatory ele-ment repository.We revealed tissue-specific regulatory elements which were associated with tissue-relevant biologi-cal functions.We identified both positive and negative significant correlations between the regulatory elements and gene transcripts,which showed distinct distributions in terms of their strength and distances from corresponding genes.We investigated the presence of transposable elements(TEs)in open chromatin regions across all tissues,these included identifications of porcine endogenous retroviruses(PERVs)exhibiting high accessibility in liver and homology of porcine specific virus sequences to universally accessible transposable elements.Furthermore,we prior-itized a potential causal variant for polyunsaturated fatty acid in the muscle.Conclusions:Our data provides a novel multi-tissues accessible chromatin landscape that serve as an important resource for interpreting regulatory sequences in tissue-specific and conserved biological functions,as well as regula-tory variants of loci associated with complex traits in pigs.展开更多
In this paper, a novel near-net-shape forming process, continuous semisolid extrusion process (CSEP) of AZ31 alloy was proposed, and the dynamical solidification behaviors and metal flow during the process were firs...In this paper, a novel near-net-shape forming process, continuous semisolid extrusion process (CSEP) of AZ31 alloy was proposed, and the dynamical solidification behaviors and metal flow during the process were firstly investigated. During casting AZ31 alloy by this process, non-uniform microstructure distributions and non- equilibrium solidification region near the roll surface were found in the roll-shoe gap. Microstructural evolution from dendrite to rosette and spherical grains was observed during the casting by CSEP. Casting temperature, roll-shoe gap width and cooling ability have great effect on casting process and metal flow, so these factors should be carefully controlled, a proper casting temperature of 710-750℃ is suggested. The white α phases were strongly stretched during the processing, and the remnant liquids are correspondingly distributes along the solid phase boundaries and also show stripped lines.展开更多
Improving the activity of Iron Ore Tailings(IOTs)to utilize them as a mineral admixture in cement-based minerals is still challenging.In this paper,the wet grinding technology was employed to stimulate the activity of...Improving the activity of Iron Ore Tailings(IOTs)to utilize them as a mineral admixture in cement-based minerals is still challenging.In this paper,the wet grinding technology was employed to stimulate the activity of IOTs,and the traditional dry grinding method was used as a reference.The effect of wet grinding on the activation of IOTs was evaluated through ion leaching from an alkaline solution and the reactivity index.Additionally,a detailed comparison between Dry-grinding Iron Ore Tailings(DIOTs)and Wet-grinding Iron Ore Tailings(WIOTs)was made.This comparison was based on particle characteristics,crystal structures,chemical structure,and surface properties.The results showed that the particle size of IOTs reduced rapidly during wet grinding.In addition,WIOTs had a higher activity index compared to DIOTs.The storage of lattice distortions in the quartz crystal structure was also more significant during the wet grinding process than during the dry grinding process.Moreover,both prolonged dry and wet grinding could destabilize the Si-O bond and decrease the surface binding energy.展开更多
A coupled thermo-mechanical model containing metal flow and temperature field for calculating temperature variation has been developed on fourteen-pass hot continuous rolling of round rod for Inconel 718 alloy using 3...A coupled thermo-mechanical model containing metal flow and temperature field for calculating temperature variation has been developed on fourteen-pass hot continuous rolling of round rod for Inconel 718 alloy using 3D elastic-plastic finite element method (FEM). The temperature of characteristic analysis points in the intermediate cross-section of the workpiece has been simulated at initial temperature ranging from 960 to 1000 ℃ and initial velocity in range of 0.15-0.55 m·s^-1. Based on finite element analysis and microstructural observation in cylindrical hot compression experiments, the appropriate hot continuous rolling technologies have been designed for rod products with different diameters. For a real rolling practice, the simulated surface temperature was examined and is in good agreement with the measured one.展开更多
3D image reconstruction for weather radar data can not only help the weatherman to improve the forecast efficiency and accuracy, but also help people to understand the weather conditions easily and quickly. Marching C...3D image reconstruction for weather radar data can not only help the weatherman to improve the forecast efficiency and accuracy, but also help people to understand the weather conditions easily and quickly. Marching Cubes (MC) algorithm in the surface rendering has more excellent applicability in 3D reconstruction for the slice images;it may shorten the time to find and calculate the isosurface from raw volume data, reflect the shape structure more accurately. In this paper, we discuss a method to reconstruct the 3D weather cloud image by using the proposed Cube Weighting Interpolation (CWI) and MC algorithm. Firstly, we detail the steps of CWI, apply it to project the raw radar data into the cubes and obtain the equally spaced cloud slice images, then employ MC algorithm to draw the isosurface. Some experiments show that our method has a good effect and simple operation, which may provide an intuitive and effective reference for realizing the 3D surface reconstruction and meteorological image stereo visualization.展开更多
The 42.1 vol. pct TiC/AZ91D magnesium-matrix composites with interpenetrating networks were fabricated by in-situ reactive infiltration process. The compressive creep behavior of as-synthesized composites was investig...The 42.1 vol. pct TiC/AZ91D magnesium-matrix composites with interpenetrating networks were fabricated by in-situ reactive infiltration process. The compressive creep behavior of as-synthesized composites was investigated at temperature ranging from 673 to 723 K under loads of 95-108 MPa. For a comparative purpose,the creep behavior of the monolithic matrix alloy AZ91D was also conducted under loads of 15-55 MPa at 548-598 K. The creep mechanisms were theoretically analyzed based on the power-law relation. The results showed that the creep rates of both TiC/AZ91D composites and AZ91D alloy increase with increasing the temperature and load. The TiC/AZ91D composites possess superior creep resistance as compared with the AZ91D alloy. At deformation temperature below 573 K, the stress exponent n of AZ91D alloy approaches theoretical value of 5, which suggests that the creep process is controlled by dislocation climb. At 598 K, the stress exponentof AZ91D is close to 3, in which viscous non-basal slip deformation plays a key role in the process of creep deformation. However, the case differs from that of AZ91D alloy when the stress exponent n of TiC/AZ91D composites exceeds 9, which shows that there exists threshold stress in the creep process of the composites, similar to other types of composites. The average activation energies for the creep of the AZ91D alloy and TiC/AZ91D composites were calculated to be 144 and 152 k J/mol, respectively. The existence of threshold stress in the creep process of the composites leads to an increase in activation energy for creep.展开更多
Herein,micro iron ore tailings(micro-IOTs)were prepared by wet-grinding and applied to improve sulphoaluminate cement(SAC)performance.The physicochemical properties of micro-IOTs were investigated by particle size ana...Herein,micro iron ore tailings(micro-IOTs)were prepared by wet-grinding and applied to improve sulphoaluminate cement(SAC)performance.The physicochemical properties of micro-IOTs were investigated by particle size analysis,XRD,and XPS.The hydrates trait and the hydration mechanism of micro-IOTs-SAC composite were studied by XRD,TGA,MIP,and SEM.The results demonstrated that micro-IOTs with an average grain diameter of 517 nm could be obtained by wet-grinding.The setting time of SAC gradually decreased with increasing micro-IOTs content.By adding 2%micro-IOTs,the compressive strengths of SAC pastes were enhanced about 22%and 10%at 4 h and 28 d,respectively.Moreover,the addition of micro-IOTs accelerated ettringite precipitation and changed its morphology,resulting in early strength improvement of the binary system.And increased later strength by micro-IOTs was closely related to the high content of AH_(3),fine pore structure,and high hydration degree of SAC.The findings suggested one new approach to utilize iron ore tailings in cementbased materials.展开更多
This is a preview pertaining to the upcoming event of the 2022 International Paper Technical Conference.Herein we provide the condensation of twelve presentations which will be given by our honorable speakers.Conferen...This is a preview pertaining to the upcoming event of the 2022 International Paper Technical Conference.Herein we provide the condensation of twelve presentations which will be given by our honorable speakers.Conference themes comprise of status quo of supply of raw material,the newest dynamic trend of papermaking industry both in China and Brazil,eucalyptus pulp as a shining role in molded pulp,high-value utilization of biomass,the most concerned hotspot—carbon reduction,and existing problems challenging the application of paper-based materials in packaging market.From the source to the end product,we offer you the full view of paper industry in expound.展开更多
Peptide-drug conjugates(PDCs)are drug delivery systems consisting of a drug covalently coupled to a multifunctional peptide via a cleavable linker.As an emerging prodrug strategy,PDCs not only preserve the function an...Peptide-drug conjugates(PDCs)are drug delivery systems consisting of a drug covalently coupled to a multifunctional peptide via a cleavable linker.As an emerging prodrug strategy,PDCs not only preserve the function and bioactivity of the peptides but also release the drugs responsively with the cleavable property of the linkers.Given the ability to significantly improve the circulation stability and targeting of drugs in vivo and reduce the toxic side effects of drugs,PDCs have already been extensively applied in drug delivery.Herein,we review the types and mechanisms of peptides,linkers and drugs used to construct PDCs,and summarize the clinical applications and challenges of PDC drugs.展开更多
The extremely low bioavailability of oral paclitaxel(PTX)mainly due to the complicated gastrointestinal environment,the obstruction of intestinal mucus layer and epithelium barrier.Thus,it is of great significance to ...The extremely low bioavailability of oral paclitaxel(PTX)mainly due to the complicated gastrointestinal environment,the obstruction of intestinal mucus layer and epithelium barrier.Thus,it is of great significance to construct a coordinative delivery system which can overcome multiple intestinal physicochemical obstacles simultaneously.In this work,a high-density PEGylation-based glycocholic acid-decorated micelles(PTX@GNPs)was constructed by a novel polymer,9-Fluorenylmethoxy carbonyl-poly ethylene glycocholic acid(Fmoc-PEG-GCA).The Fmoc motif in this polymer could encapsulate PTX viaπ-πstacking to form the core of micelles,and the low molecular weight and non-long hydrophobic chain of Fmoc ensures the high-density of PEG.Based on this versatile and flexible carriers,PTX@GNPs possess mucus trapping escape ability due to the flexible PEG,and excellent intestine epithelium targeting attributed to the high affinity of GCA with apical sodium-dependent bile acid transporter.The in vitro and in vivo results showed that this oral micelle could enhance oral bioavailability of PTX,and exhibited similar antitumor efficacy to Taxol injection via intravenous route.In addition,oral PTX@GNPs administered with lower dosage within shorter interval could increase in vivo retention time of PTX,which supposed to remodel immune microenvironment and enhance oral chemotherapy efficacy by synergistic effect.展开更多
In the last two decades, light-weight magnesium matrix composites have been the hot issue of material field due to their excellent mechanical and physical properties, e.g., high-specific strength and modulus, good wea...In the last two decades, light-weight magnesium matrix composites have been the hot issue of material field due to their excellent mechanical and physical properties, e.g., high-specific strength and modulus, good wear resistance, and damping capacity. As compared with aluminum matrix composites, magnesium matrix composites have merit in their specific weight and have wide applications in aerospace and aeronautical fields. Generally, the processing techniques for magnesium matrix composites can be categorized as conventional and special processing routes. In recent years, as a special processing route, metal melt infiltration into porous ceramic preform featured by its low cost and availability of high-volume fraction of reinforced ceramics have been receiving much attention. Thus, in this review, one emphasis was put on the description of this processing technique in association with the means to obtain good wettability, the prerequisite for this kind of processing method. Based on the recognized fact that there exist clean interface and bonding ability between ceramics and matrix metal, in-situ reaction synthesis is usually utilized to fabricate magnesium matrix composites. Therefore, the interfacial feature was also reviewed for the in-situ reaction synthesis. Characterizations of microstructures and various mechanical-physical properties were finally summarized for magnesium matrix composites including tensile response, wear resistance, creep behavior, and damping capacity.展开更多
High manganese twinning-induced plasticity (TWIP) steel is a new kind of structural material and possesses both high strength and superior plasticity and can meet the weight-lightening requirement for manufacturing ...High manganese twinning-induced plasticity (TWIP) steel is a new kind of structural material and possesses both high strength and superior plasticity and can meet the weight-lightening requirement for manufacturing vehicle body. The excellent formability of the TWIP steel comes from the extraordinary strain hardening effect during plastic deformation. The reduction of specific weight by aluminum alloying and strain hardening effect can lead to an effective weight reduction of the steel components, and provide a better choice for materials in vehicle body design. The TWIP effect in high Mn steels is generally associated with the successive work- hardening generated by twins and influenced by some factors, such as Mn content, AI addition revealed by stacking fault energy (SFE), grain size, deformation temperature and strain rate. The present review introduces some aspects of the TWIP steels relating to their physical metallurgy, influencing factors associated with their deformation mechanisms, and a prospect for the future investigation is also described. Moreover, as a potential candidate for replacing Ni-Cr austenitic stainless steel, researches on the oxidation behavior and corrosion resistance of Fe-Mn-AI-C system steels are also reviewed.展开更多
In fabricating magnesium-matrix composites, an easy and cost-effective route is to infiltrate the ceramic preform with molten Mg without any external pressure. However, a rather well wettability of molten Mg with cera...In fabricating magnesium-matrix composites, an easy and cost-effective route is to infiltrate the ceramic preform with molten Mg without any external pressure. However, a rather well wettability of molten Mg with ceramic reinforcement is needed for this process. In order to improve the wettability of the metal melt with ceramic preform during fabricating composites by metal melt infiltration, a simple and viable method has been proposed in this paper where a small amount of metal powder with higher melting point is added to the ceramic preform such that the surface tension of the Mg melt and the liquid-solid interfacial tension could be reduced. By using this method, boron carbide particulate-reinforced magnesium-matrix composites (B4C/Mg) have been successfully fabricated where Ti powder immiscible with magnesium melt was introduced into B4C preform as infiltration inducer. The infiltration ability of molten Mg to the ceramic preform was further studied in association with the processing conditions and the mechanism involved in this process was also analyzed.展开更多
The influence of cerium addition on the isothermal oxidation behavior of 00Cr17NbTi ferritic stainless steel was studied at temperature up to 1,000 ℃ for 100 h in air. The results show that cerium additions can reduc...The influence of cerium addition on the isothermal oxidation behavior of 00Cr17NbTi ferritic stainless steel was studied at temperature up to 1,000 ℃ for 100 h in air. The results show that cerium additions can reduce the grain size of this ferritic stainless steel, improve the diffusion of chromium and decrease the critical concentration of chromium to form protective Cr2O3 layer. With the increasing of cerium addition, the oxide particles become smaller and this can increase the rupture strength and spalling resistance of oxide layers. The transport mechanism through the oxide layer is varied from metal transport outward from steel to principally oxygen transport inward with the increase of cerium content, which leads to the lower oxidation rate and the better scale adherence of 00Cr17NbTi ferritic stainless steel.展开更多
In last few years, therapeutic peptides/proteins are rapidly growing in drug market considering their higher efficiency and lower toxicity than chemical drugs. However, the administration of therapeutic peptides/prote...In last few years, therapeutic peptides/proteins are rapidly growing in drug market considering their higher efficiency and lower toxicity than chemical drugs. However, the administration of therapeutic peptides/proteins is mainly limited in parenteral approach. Oral therapy which was hampered by harsh gastrointestinal environment and poorly penetrating epithelial barriers often results in low bioavailability(less than 1%–2%). Therefore, delivery systems that are rationally designed to overcome these challenges in gastrointestinal tract and ameliorate the oral bioavailability of therapeutic peptides/proteins are seriously promising. In this review, we summarized various multifunctional delivery systems, including lipid-based particles, polysaccharide-based particles, inorganic particles, and synthetic multifunctional particles that achieved effective oral delivery of therapeutic peptides/proteins.展开更多
In view of the difficulties in weeding and plant protection in the middle and late period of maize planting,this paper proposed a self-propelled thermal fogger chassis.According to the theoretical calculation and agro...In view of the difficulties in weeding and plant protection in the middle and late period of maize planting,this paper proposed a self-propelled thermal fogger chassis.According to the theoretical calculation and agronomic requirements for maize planting,the structure and working principles of the self-propelled thermal fogger chassis were introduced.On this basis,the multi-body dynamics model of chassis structure was established,and the chassis traction,steering and obstacle surmounting performances were also analyzed.Then the rationality and the feasibility of the design were verified through the furrow running test and test equipped with thermal fogger.Test results showed that,the traction performance improves with the decrease of soil deformation index and increase of cohesion,and when track pre-tensioning force was about 1000 N,the machine had a good traction performance;with the decrease of the soil deformation index and the increase of cohesive force,the stability of the single side brake turn of the chassis becomes better;on the contrary,with the increase of the tightness of the crawler,the steering radius turns smaller and the steering stability becomes worse.Under heavy clay,with the pre-tensioning of 1000 N,the machine has better steering stability and smaller turning radius.The obstacle-surmounting simulation result shows that on sandy soil road,the maximum climbing angle for the chassis is 42°,the height of vertical obstacle crossing is 170 mm and the trench width is 440 mm.The study provides a reference for the design of plant protection machinery in the middle and late stages of maize planting.展开更多
Effect of deep cryogenic treatment (DCT) on the microstructures and mechanical behavior of ultrafine-grained WC-12Co cemented carbide was investigated by using XRD, SEM, and DSC. The phase transformations of pure Co...Effect of deep cryogenic treatment (DCT) on the microstructures and mechanical behavior of ultrafine-grained WC-12Co cemented carbide was investigated by using XRD, SEM, and DSC. The phase transformations of pure Co and binder phase Co in cemented carbide were analyzed in detail to correlate the strengthening mechanism with its x -ε, phase transition. The results show that DCT resulted in a slight increase in hardness and bending strength of ultrafine- grained WC-12Co cemented carbide. For the ultrafine-grained cemented carbide after DCT, there is no significant change in the microstructure and the elemental distribution of the cemented carbides, but the fractured morphology shows a feature of plastic deformation. In the cases of pure Co and the binder phase Co in WC-12Co cemented carbide, they exhibit different features of phase transformation. The improvement of mechanical property of cemented carbide can be attributed to the increased amount of ε-Co in WC-12Co composites after DCT.展开更多
基金National Natural Science Foundation of China[grant number 32160782].
文摘Background As pre-cut and pre-packaged chilled meat becomes increasingly popular,integrating the carcasscutting process into the pig industry chain has become a trend.Identifying quantitative trait loci(QTLs)of pork cuts would facilitate the selection of pigs with a higher overall value.However,previous studies solely focused on evaluating the phenotypic and genetic parameters of pork cuts,neglecting the investigation of QTLs influencing these traits.This study involved 17 pork cuts and 12 morphology traits from 2,012 pigs across four populations genotyped using CC1 PorcineSNP50 BeadChips.Our aim was to identify QTLs and evaluate the accuracy of genomic estimated breed values(GEBVs)for pork cuts.Results We identified 14 QTLs and 112 QTLs for 17 pork cuts by GWAS using haplotype and imputation genotypes,respectively.Specifically,we found that HMGA1,VRTN and BMP2 were associated with body length and weight.Subsequent analysis revealed that HMGA1 primarily affects the size of fore leg bones,VRTN primarily affects the number of vertebrates,and BMP2 primarily affects the length of vertebrae and the size of hind leg bones.The prediction accuracy was defined as the correlation between the adjusted phenotype and GEBVs in the validation population,divided by the square root of the trait’s heritability.The prediction accuracy of GEBVs for pork cuts varied from 0.342 to 0.693.Notably,ribs,boneless picnic shoulder,tenderloin,hind leg bones,and scapula bones exhibited prediction accuracies exceeding 0.600.Employing better models,increasing marker density through genotype imputation,and pre-selecting markers significantly improved the prediction accuracy of GEBVs.Conclusions We performed the first study to dissect the genetic mechanism of pork cuts and identified a large number of significant QTLs and potential candidate genes.These findings carry significant implications for the breeding of pork cuts through marker-assisted and genomic selection.Additionally,we have constructed the first reference populations for genomic selection of pork cuts in pigs.
基金supported by National Key Research and Development Program of China(2021YFF1000601).
文摘Background:A comprehensive landscape of chromatin states for multiple mammalian tissues is essential for elucidating the molecular mechanism underlying regulatory variants on complex traits.However,the genome-wide chromatin accessibility has been only reported in limited tissue types in pigs.Results:Here we report a genome-wide landscape of chromatin accessibility of 20 tissues in two female pigs at ages of 6 months using ATAC-seq,and identified 557,273 merged peaks,which greatly expanded the pig regulatory ele-ment repository.We revealed tissue-specific regulatory elements which were associated with tissue-relevant biologi-cal functions.We identified both positive and negative significant correlations between the regulatory elements and gene transcripts,which showed distinct distributions in terms of their strength and distances from corresponding genes.We investigated the presence of transposable elements(TEs)in open chromatin regions across all tissues,these included identifications of porcine endogenous retroviruses(PERVs)exhibiting high accessibility in liver and homology of porcine specific virus sequences to universally accessible transposable elements.Furthermore,we prior-itized a potential causal variant for polyunsaturated fatty acid in the muscle.Conclusions:Our data provides a novel multi-tissues accessible chromatin landscape that serve as an important resource for interpreting regulatory sequences in tissue-specific and conserved biological functions,as well as regula-tory variants of loci associated with complex traits in pigs.
基金supports from National High-Tech R&D Program of China (GrantNo. 2007AA03Z111)Natural Science Foundation of China (Grant No. 50604007)the Program for New Century Excellent Talents in University (Grant No.NCET-06-0285 and NCET-08-0097)
文摘In this paper, a novel near-net-shape forming process, continuous semisolid extrusion process (CSEP) of AZ31 alloy was proposed, and the dynamical solidification behaviors and metal flow during the process were firstly investigated. During casting AZ31 alloy by this process, non-uniform microstructure distributions and non- equilibrium solidification region near the roll surface were found in the roll-shoe gap. Microstructural evolution from dendrite to rosette and spherical grains was observed during the casting by CSEP. Casting temperature, roll-shoe gap width and cooling ability have great effect on casting process and metal flow, so these factors should be carefully controlled, a proper casting temperature of 710-750℃ is suggested. The white α phases were strongly stretched during the processing, and the remnant liquids are correspondingly distributes along the solid phase boundaries and also show stripped lines.
基金This work was supported by University Natural Science Research Project of Anhui Province(KJ2019A0171).
文摘Improving the activity of Iron Ore Tailings(IOTs)to utilize them as a mineral admixture in cement-based minerals is still challenging.In this paper,the wet grinding technology was employed to stimulate the activity of IOTs,and the traditional dry grinding method was used as a reference.The effect of wet grinding on the activation of IOTs was evaluated through ion leaching from an alkaline solution and the reactivity index.Additionally,a detailed comparison between Dry-grinding Iron Ore Tailings(DIOTs)and Wet-grinding Iron Ore Tailings(WIOTs)was made.This comparison was based on particle characteristics,crystal structures,chemical structure,and surface properties.The results showed that the particle size of IOTs reduced rapidly during wet grinding.In addition,WIOTs had a higher activity index compared to DIOTs.The storage of lattice distortions in the quartz crystal structure was also more significant during the wet grinding process than during the dry grinding process.Moreover,both prolonged dry and wet grinding could destabilize the Si-O bond and decrease the surface binding energy.
基金the financial supports from the National Natural Science Foundation of China (Key Program,Grant No.50634030)the Program for New Century Excellent Talents in University (Grant No.NCET-06-0285)
文摘A coupled thermo-mechanical model containing metal flow and temperature field for calculating temperature variation has been developed on fourteen-pass hot continuous rolling of round rod for Inconel 718 alloy using 3D elastic-plastic finite element method (FEM). The temperature of characteristic analysis points in the intermediate cross-section of the workpiece has been simulated at initial temperature ranging from 960 to 1000 ℃ and initial velocity in range of 0.15-0.55 m·s^-1. Based on finite element analysis and microstructural observation in cylindrical hot compression experiments, the appropriate hot continuous rolling technologies have been designed for rod products with different diameters. For a real rolling practice, the simulated surface temperature was examined and is in good agreement with the measured one.
文摘3D image reconstruction for weather radar data can not only help the weatherman to improve the forecast efficiency and accuracy, but also help people to understand the weather conditions easily and quickly. Marching Cubes (MC) algorithm in the surface rendering has more excellent applicability in 3D reconstruction for the slice images;it may shorten the time to find and calculate the isosurface from raw volume data, reflect the shape structure more accurately. In this paper, we discuss a method to reconstruct the 3D weather cloud image by using the proposed Cube Weighting Interpolation (CWI) and MC algorithm. Firstly, we detail the steps of CWI, apply it to project the raw radar data into the cubes and obtain the equally spaced cloud slice images, then employ MC algorithm to draw the isosurface. Some experiments show that our method has a good effect and simple operation, which may provide an intuitive and effective reference for realizing the 3D surface reconstruction and meteorological image stereo visualization.
基金Financial supports from Natural Science Foundation (Grant No. 20032012);Liaoning Province, China; the Scientific Research Foundation for the Returned 0verseas Chinese Scholars;State Education Ministry, China and from the Starting for New Scientific Researchers of Institute of Metal Research (IMR);Chinese Academy of Sciences (CAS), are gratefully acknowledged.
文摘The 42.1 vol. pct TiC/AZ91D magnesium-matrix composites with interpenetrating networks were fabricated by in-situ reactive infiltration process. The compressive creep behavior of as-synthesized composites was investigated at temperature ranging from 673 to 723 K under loads of 95-108 MPa. For a comparative purpose,the creep behavior of the monolithic matrix alloy AZ91D was also conducted under loads of 15-55 MPa at 548-598 K. The creep mechanisms were theoretically analyzed based on the power-law relation. The results showed that the creep rates of both TiC/AZ91D composites and AZ91D alloy increase with increasing the temperature and load. The TiC/AZ91D composites possess superior creep resistance as compared with the AZ91D alloy. At deformation temperature below 573 K, the stress exponent n of AZ91D alloy approaches theoretical value of 5, which suggests that the creep process is controlled by dislocation climb. At 598 K, the stress exponentof AZ91D is close to 3, in which viscous non-basal slip deformation plays a key role in the process of creep deformation. However, the case differs from that of AZ91D alloy when the stress exponent n of TiC/AZ91D composites exceeds 9, which shows that there exists threshold stress in the creep process of the composites, similar to other types of composites. The average activation energies for the creep of the AZ91D alloy and TiC/AZ91D composites were calculated to be 144 and 152 k J/mol, respectively. The existence of threshold stress in the creep process of the composites leads to an increase in activation energy for creep.
基金This work was supported by University Natural Science Research Project of Anhui Province(KJ2019A0171)National Natural Science Foundation of China(Grant No.52005009)+1 种基金Anhui Province Natural Science Funds for Youth Fund Project(2008085QE273)Anhui Province Key Research and Development Project(202004e11020003).
文摘Herein,micro iron ore tailings(micro-IOTs)were prepared by wet-grinding and applied to improve sulphoaluminate cement(SAC)performance.The physicochemical properties of micro-IOTs were investigated by particle size analysis,XRD,and XPS.The hydrates trait and the hydration mechanism of micro-IOTs-SAC composite were studied by XRD,TGA,MIP,and SEM.The results demonstrated that micro-IOTs with an average grain diameter of 517 nm could be obtained by wet-grinding.The setting time of SAC gradually decreased with increasing micro-IOTs content.By adding 2%micro-IOTs,the compressive strengths of SAC pastes were enhanced about 22%and 10%at 4 h and 28 d,respectively.Moreover,the addition of micro-IOTs accelerated ettringite precipitation and changed its morphology,resulting in early strength improvement of the binary system.And increased later strength by micro-IOTs was closely related to the high content of AH_(3),fine pore structure,and high hydration degree of SAC.The findings suggested one new approach to utilize iron ore tailings in cementbased materials.
文摘This is a preview pertaining to the upcoming event of the 2022 International Paper Technical Conference.Herein we provide the condensation of twelve presentations which will be given by our honorable speakers.Conference themes comprise of status quo of supply of raw material,the newest dynamic trend of papermaking industry both in China and Brazil,eucalyptus pulp as a shining role in molded pulp,high-value utilization of biomass,the most concerned hotspot—carbon reduction,and existing problems challenging the application of paper-based materials in packaging market.From the source to the end product,we offer you the full view of paper industry in expound.
基金supported by grants from CAMS Innovation Fund for Medical Sciences(CIFMS,China)(2021-I2M-1-026)。
文摘Peptide-drug conjugates(PDCs)are drug delivery systems consisting of a drug covalently coupled to a multifunctional peptide via a cleavable linker.As an emerging prodrug strategy,PDCs not only preserve the function and bioactivity of the peptides but also release the drugs responsively with the cleavable property of the linkers.Given the ability to significantly improve the circulation stability and targeting of drugs in vivo and reduce the toxic side effects of drugs,PDCs have already been extensively applied in drug delivery.Herein,we review the types and mechanisms of peptides,linkers and drugs used to construct PDCs,and summarize the clinical applications and challenges of PDC drugs.
基金supported by grants from National Natural Science Foundation of China(No.82073778,China)CAMS Innovation Fund for Medical Sciences(CIFMS)(2021-I2M-1-026,China)+1 种基金Beijing Key Laboratory of Non-Clinical Drug Metabolism and PK/PD study(Z141102004414062,China)National Natural Science Foundation of China(No.82104106)。
文摘The extremely low bioavailability of oral paclitaxel(PTX)mainly due to the complicated gastrointestinal environment,the obstruction of intestinal mucus layer and epithelium barrier.Thus,it is of great significance to construct a coordinative delivery system which can overcome multiple intestinal physicochemical obstacles simultaneously.In this work,a high-density PEGylation-based glycocholic acid-decorated micelles(PTX@GNPs)was constructed by a novel polymer,9-Fluorenylmethoxy carbonyl-poly ethylene glycocholic acid(Fmoc-PEG-GCA).The Fmoc motif in this polymer could encapsulate PTX viaπ-πstacking to form the core of micelles,and the low molecular weight and non-long hydrophobic chain of Fmoc ensures the high-density of PEG.Based on this versatile and flexible carriers,PTX@GNPs possess mucus trapping escape ability due to the flexible PEG,and excellent intestine epithelium targeting attributed to the high affinity of GCA with apical sodium-dependent bile acid transporter.The in vitro and in vivo results showed that this oral micelle could enhance oral bioavailability of PTX,and exhibited similar antitumor efficacy to Taxol injection via intravenous route.In addition,oral PTX@GNPs administered with lower dosage within shorter interval could increase in vivo retention time of PTX,which supposed to remodel immune microenvironment and enhance oral chemotherapy efficacy by synergistic effect.
基金financially supported by the National Natural Science Foundation of China (Grant No.51271051)
文摘In the last two decades, light-weight magnesium matrix composites have been the hot issue of material field due to their excellent mechanical and physical properties, e.g., high-specific strength and modulus, good wear resistance, and damping capacity. As compared with aluminum matrix composites, magnesium matrix composites have merit in their specific weight and have wide applications in aerospace and aeronautical fields. Generally, the processing techniques for magnesium matrix composites can be categorized as conventional and special processing routes. In recent years, as a special processing route, metal melt infiltration into porous ceramic preform featured by its low cost and availability of high-volume fraction of reinforced ceramics have been receiving much attention. Thus, in this review, one emphasis was put on the description of this processing technique in association with the means to obtain good wettability, the prerequisite for this kind of processing method. Based on the recognized fact that there exist clean interface and bonding ability between ceramics and matrix metal, in-situ reaction synthesis is usually utilized to fabricate magnesium matrix composites. Therefore, the interfacial feature was also reviewed for the in-situ reaction synthesis. Characterizations of microstructures and various mechanical-physical properties were finally summarized for magnesium matrix composites including tensile response, wear resistance, creep behavior, and damping capacity.
基金supported by the Fundamental Research Funds for the Central Universities (No. N100507003)
文摘High manganese twinning-induced plasticity (TWIP) steel is a new kind of structural material and possesses both high strength and superior plasticity and can meet the weight-lightening requirement for manufacturing vehicle body. The excellent formability of the TWIP steel comes from the extraordinary strain hardening effect during plastic deformation. The reduction of specific weight by aluminum alloying and strain hardening effect can lead to an effective weight reduction of the steel components, and provide a better choice for materials in vehicle body design. The TWIP effect in high Mn steels is generally associated with the successive work- hardening generated by twins and influenced by some factors, such as Mn content, AI addition revealed by stacking fault energy (SFE), grain size, deformation temperature and strain rate. The present review introduces some aspects of the TWIP steels relating to their physical metallurgy, influencing factors associated with their deformation mechanisms, and a prospect for the future investigation is also described. Moreover, as a potential candidate for replacing Ni-Cr austenitic stainless steel, researches on the oxidation behavior and corrosion resistance of Fe-Mn-AI-C system steels are also reviewed.
基金Financial support from the National Natural Science Foundation of China(Grant No.51271051)
文摘In fabricating magnesium-matrix composites, an easy and cost-effective route is to infiltrate the ceramic preform with molten Mg without any external pressure. However, a rather well wettability of molten Mg with ceramic reinforcement is needed for this process. In order to improve the wettability of the metal melt with ceramic preform during fabricating composites by metal melt infiltration, a simple and viable method has been proposed in this paper where a small amount of metal powder with higher melting point is added to the ceramic preform such that the surface tension of the Mg melt and the liquid-solid interfacial tension could be reduced. By using this method, boron carbide particulate-reinforced magnesium-matrix composites (B4C/Mg) have been successfully fabricated where Ti powder immiscible with magnesium melt was introduced into B4C preform as infiltration inducer. The infiltration ability of molten Mg to the ceramic preform was further studied in association with the processing conditions and the mechanism involved in this process was also analyzed.
基金supported by the National High Technology Research and Development Program of China (No. 2012AA03A508)the Fundamental Research Funds for the Central Universities (No. N100507003)
文摘The influence of cerium addition on the isothermal oxidation behavior of 00Cr17NbTi ferritic stainless steel was studied at temperature up to 1,000 ℃ for 100 h in air. The results show that cerium additions can reduce the grain size of this ferritic stainless steel, improve the diffusion of chromium and decrease the critical concentration of chromium to form protective Cr2O3 layer. With the increasing of cerium addition, the oxide particles become smaller and this can increase the rupture strength and spalling resistance of oxide layers. The transport mechanism through the oxide layer is varied from metal transport outward from steel to principally oxygen transport inward with the increase of cerium content, which leads to the lower oxidation rate and the better scale adherence of 00Cr17NbTi ferritic stainless steel.
基金financially supported by the CAMS Innovation Fund for Medical Sciences(CAMS-2017-12M-1–011,China)National Natural Science Foundation of China(81373342)+1 种基金the Fundamental Research Funds for the Central Universities and PUMC Youth Fund(2017350003,China)PUMC Basic Fund(2018PT35002,China)
文摘In last few years, therapeutic peptides/proteins are rapidly growing in drug market considering their higher efficiency and lower toxicity than chemical drugs. However, the administration of therapeutic peptides/proteins is mainly limited in parenteral approach. Oral therapy which was hampered by harsh gastrointestinal environment and poorly penetrating epithelial barriers often results in low bioavailability(less than 1%–2%). Therefore, delivery systems that are rationally designed to overcome these challenges in gastrointestinal tract and ameliorate the oral bioavailability of therapeutic peptides/proteins are seriously promising. In this review, we summarized various multifunctional delivery systems, including lipid-based particles, polysaccharide-based particles, inorganic particles, and synthetic multifunctional particles that achieved effective oral delivery of therapeutic peptides/proteins.
基金This research was financially supported by the Special Fund of Ministry of Agriculture of China for Public Welfare Projects(No.201503136)Natural Science Fund Project in Anhui Province(No.1708085ME135)Natural Science Major Project in Anhui Province(No.KJ2018ZD016).
文摘In view of the difficulties in weeding and plant protection in the middle and late period of maize planting,this paper proposed a self-propelled thermal fogger chassis.According to the theoretical calculation and agronomic requirements for maize planting,the structure and working principles of the self-propelled thermal fogger chassis were introduced.On this basis,the multi-body dynamics model of chassis structure was established,and the chassis traction,steering and obstacle surmounting performances were also analyzed.Then the rationality and the feasibility of the design were verified through the furrow running test and test equipped with thermal fogger.Test results showed that,the traction performance improves with the decrease of soil deformation index and increase of cohesion,and when track pre-tensioning force was about 1000 N,the machine had a good traction performance;with the decrease of the soil deformation index and the increase of cohesive force,the stability of the single side brake turn of the chassis becomes better;on the contrary,with the increase of the tightness of the crawler,the steering radius turns smaller and the steering stability becomes worse.Under heavy clay,with the pre-tensioning of 1000 N,the machine has better steering stability and smaller turning radius.The obstacle-surmounting simulation result shows that on sandy soil road,the maximum climbing angle for the chassis is 42°,the height of vertical obstacle crossing is 170 mm and the trench width is 440 mm.The study provides a reference for the design of plant protection machinery in the middle and late stages of maize planting.
基金financially supported by the Major Special Project,Ministry of Industry and Information Technology,China (No.2012ZX04003061)
文摘Effect of deep cryogenic treatment (DCT) on the microstructures and mechanical behavior of ultrafine-grained WC-12Co cemented carbide was investigated by using XRD, SEM, and DSC. The phase transformations of pure Co and binder phase Co in cemented carbide were analyzed in detail to correlate the strengthening mechanism with its x -ε, phase transition. The results show that DCT resulted in a slight increase in hardness and bending strength of ultrafine- grained WC-12Co cemented carbide. For the ultrafine-grained cemented carbide after DCT, there is no significant change in the microstructure and the elemental distribution of the cemented carbides, but the fractured morphology shows a feature of plastic deformation. In the cases of pure Co and the binder phase Co in WC-12Co cemented carbide, they exhibit different features of phase transformation. The improvement of mechanical property of cemented carbide can be attributed to the increased amount of ε-Co in WC-12Co composites after DCT.