Main performance of the cement grouting materials made up by Portland cement（PC） and sulphoaluminate cement（SAC） was investigated in this program, a kind of expanding agent（EA） which was mainly constituted by me...Main performance of the cement grouting materials made up by Portland cement（PC） and sulphoaluminate cement（SAC） was investigated in this program, a kind of expanding agent（EA） which was mainly constituted by metakaolin and alunite was utilized for the compensation of the shrinkage, the hydration products and micro structure of the grouting materials were researched by X-ray diffraction（XRD） and scanning electron microscopy（SEM）. The results showed that a high expansion rate of the grouting materials could be reached as the expanding agent mixed in 6% of PC mass; the addition of SAC in the S2（PC：SAC：EA=34：6：2.25） brought a further improvement of the expansion rate of the grouting materials, the analysis of XRD and SEM showed that due to the reaction of expanding agent and SAC in the grouting materials, more ettringite crystal was generated, which resulted in a higher early strength, the addition of SAC played an expansion and strength reinforcement role in the grouting materials.展开更多
The geological condition of Chinese coal mines are complex and high gassy,which account for ffty percent to seventy percent.Because of the abundant pores and cracks around the drainage drilling hole,the gas concentrat...The geological condition of Chinese coal mines are complex and high gassy,which account for ffty percent to seventy percent.Because of the abundant pores and cracks around the drainage drilling hole,the gas concentration attenuates rapidly,and the effective gas drainage period is short.The traditional sealing materials of yellow mud and cement-sand grout will readily shrink after the drilling hole is sealed,the sealing length is short and the sealing quality is not satisfactory.Currently widely used polyurethane material will shrink when it comes into contact with water,and the price is also very high.In this study,taking cement as a base material,a novel composite sealing material mixed by expansion admixture,additive,and fbrin and coupling agent was developed and the sealing performance and expansion property of the material were also studied and analyzed.The FEI Quanta TM 250 environmental scanning electron microscope was used to investigate the microstructure of material.The results revealed that the new composite sealing material had a desirable expansion performance and a defnite fluidity convenient for grouting.The solidifed material,combining closely with the drilling wall,possessed an adequate strength and was not easy to shrink.Compared to the conventional polyurethane,the gas drainage concentration by drilling sealing exceeded 40 percent,and the sealing capacity improves5 times,the sealing effect increases signifcantly.展开更多
This paper aimed to improve the water-retention performance and basic physical properties of sulfoaluminate cement（SAC）-based planting cementitious material. The effect of natural zeolite on the performance of SAC-b...This paper aimed to improve the water-retention performance and basic physical properties of sulfoaluminate cement（SAC）-based planting cementitious material. The effect of natural zeolite on the performance of SAC-based planting material was investigated. The water-retention performance, porosity, compressive strength, and alkalinity had been tested and TG-DSC analysis had been adopted in this paper. Experimental results showed that zeolite was effective to improve the water-retention capacity and 10%, 20% and 30% natural zeolite increased the pore volume of the hardened pastes by 10.6%, 26.0%, and 38.6%, especially pore size below 0.1 μm was increased by 9.7%, 26.2% and 17.5%. And 10% zeolite was beneficial to the compressive strengths of cementitious material and 1, 3, and 28 d compressive strength reached up to 35.9, 55.0, 80.3 MPa. Furthermore zeolite decreased the alkalinity of pore fluid of hardened cementitious material, while the addition of zeolite reached up to 30%, the alkalinity of pore fluid of hardened cementitious material decreased by 8.9%. Therefore zeolite was suitable for improving the performance of SAC-based planting cementitious material.展开更多
Lithium battery has recently gained more and more attention worldwide.It has wide usage that range from toys to electric cars.Choosing a suitable material that best fits the overall performance as electrode for the ba...Lithium battery has recently gained more and more attention worldwide.It has wide usage that range from toys to electric cars.Choosing a suitable material that best fits the overall performance as electrode for the battery is very essential.For cathode material,apart from the traditional and widely-used LiCoCO_(2),LiFePO_(4)and so on,there are innovations that include the use of V_(2)O_(5).Researches have been done focusing on how to further improve the performance for V_(2)O_(5)cathode in terms of different structure,forms or combination with other chemical molecules.This research paper will make a summary of the materials derived from traditional V_(2)O_(5)as well as their performances.展开更多
Objective: To improve knowledge and practice of health staff as well as the availability of material resources for diagnosis and management of schistosomiasis in two endemic provinces of DRC(Kinshasa and Bas-Congo).Me...Objective: To improve knowledge and practice of health staff as well as the availability of material resources for diagnosis and management of schistosomiasis in two endemic provinces of DRC(Kinshasa and Bas-Congo).Methods: Structured interviews were performed using questionnaires with staff from 35 healthcare facilities in 9 health zones(HZ) of Kinshasa and 2 HZ in Bas-Congo.Results: Schistosomiasis was reported to be present in all the included HZ.Health staff knew the most important symptoms of schistosomiasis, but advanced symptoms were more accurately reported in Bas-Congo.Knowledge of symptoms related to schistosomiasis such as anemia(P = 0.0 115) and pollakiuria(P = 0.0 260) was statistically different in both two provinces.Kato-Katz technique and urine filtration were unavailable in both provinces.Parasitological diagnosis was mostly performed using the direct smear method.PZQ was available in 70% of the health facilities, all situated in Bas-Congo.Diagnosis and treatment mostly relied on symptoms and cost more in urban area than in rural.Conclusions: Though knowledge on schistosomiasis among health staff appears sufficient, substantial efforts still must be made to improve the availability of diagnostic tools and treatment in the health facilities in DRC.展开更多
Experiments have been conducted on a plasma opening switch (POS) test-bed to investigate the influence of cathode materials made of aluminum, stainless steel, molybdenum and tungsten on opening performance for conduct...Experiments have been conducted on a plasma opening switch (POS) test-bed to investigate the influence of cathode materials made of aluminum, stainless steel, molybdenum and tungsten on opening performance for conduction time up to 3 microseconds, conduction current up to 100 kA. Remarkaly different opening characteristics have been shown for these materials,with tungsten being of the best opening performance.展开更多
(2) Other Magnetic Materials RE Giant Magnetostrictive Materials (GMM) Research of GMM in China started since 1980s but developed rapidly. The products can be produced in batches today. However, application of such ma...(2) Other Magnetic Materials RE Giant Magnetostrictive Materials (GMM) Research of GMM in China started since 1980s but developed rapidly. The products can be produced in batches today. However, application of such materials in apparatus is laggard than developed countries. GMM materials are mainly applied in step motors, linear actuators, ultrasonic systems, sonar systems, valves, precise controls, active vibration damping etc. It is estimated that the near 10 years will be the fast developing period of global GMM market. Global production of GMM materials during 1989 to 2005 is listed in Table 3.展开更多
Additive Manufacturing(AM)has significantly impacted the development of high-performance materials and structures,offering new possibilities for industries ranging from aerospace to biomedicine.This special issue feat...Additive Manufacturing(AM)has significantly impacted the development of high-performance materials and structures,offering new possibilities for industries ranging from aerospace to biomedicine.This special issue features pioneering research that integrates AI-driven methods with AM,enabling the design and fabrication of complex,optimized structures with enhanced properties.展开更多
An advanced ceramic cutting tool material Al2O3/TiC/TiN （LTN） is developed by incorporation and dispersion of micro-scale TiC particle and nano-scale TiN particle in alumina matrix. With the optimal dispersing and f...An advanced ceramic cutting tool material Al2O3/TiC/TiN （LTN） is developed by incorporation and dispersion of micro-scale TiC particle and nano-scale TiN particle in alumina matrix. With the optimal dispersing and fabricating technology, this multi-scale and multi-phase nanocomposite ceramic tool material can get both higher flexural strength and fracture toughness than that of A1203/TiC （LZ） ceramic tool material without nano-scale TiN particle, especially the fracture toughness can reach to 7.8 MPa . m^0.5. The nano-scale TiN can lead to the grain fining effect and promote the sintering process to get a higher density. The coexisting transgranular and intergranular fracture mode induced by micro-scale TiC and nano-scale TiN, and the homogeneous and densified microstructure can result in a remarkable strengthening and toughening effect. The cutting performance and wear mechanisms of the advanced multi-scale and multi-phase nanocomposite ceramic cutting tool are researched.展开更多
To investigate the ballistic performance and damage characteristics of quasi threedimensional（3D） needle-punched Cf/SiC composites prepared by chemical vapor infiltration（CVI）,penetration experiments were conducte...To investigate the ballistic performance and damage characteristics of quasi threedimensional（3D） needle-punched Cf/SiC composites prepared by chemical vapor infiltration（CVI）,penetration experiments were conducted by using 7.62 mm armor piercing incendiary（API）.Macro and micro fracture morphologies were then observed on recycled targets.The results show that the protection coefficient of 3D Cf/SiC composites is 2.54.High porosity and many micro thermal stress cracks may directly lead to the lower ballistic performance.Flat fracture morphology was observed on the crater surface.The low dynamic fracture strength along layer direction may be attributed to the voids and microcracks caused by residual thermal stress.The damage characteristics of Cf/Si C composites include matrix cracking,fiber bundle cracking,interfacial debonding,fiber fracture,and fiber bundle pull-out.And interfacial debonding and fiber fracture may play major roles in energy absorption.展开更多
The new adhesive material for the construction joints of tunnel lining(named as SZC) was studied based on the structural characteristics of interfaces and the characteristic of bonding construction, and the performanc...The new adhesive material for the construction joints of tunnel lining(named as SZC) was studied based on the structural characteristics of interfaces and the characteristic of bonding construction, and the performance indexes were verified by tests. The experimental results show that the adhesive capability of interface is improved effectively by using SZC material, the properties, such as anti-freezing, erosion-resistance and anti-shrinkage are improved greatly as well as durability.展开更多
Given the severe energy and environmental crises,there is a pressing need for the development of high-performance functional materials.Therefore,significant challenges facing current functional materials must be addre...Given the severe energy and environmental crises,there is a pressing need for the development of high-performance functional materials.Therefore,significant challenges facing current functional materials must be addressed,including further improving material performance,resolving complex trade-offs between properties,and achieving multifunctionality for greater energy efficiency while effectively preventing premature failures during functional processes.Traditional materials may exhibit translational periodicity at the lattice level,but their microstructures,such as grains and their characteristics,are often randomly distributed.Recent discoveries indicate that if the microstructure is constructed in an ordered manner,e.g.,grain size gradient,materials can perform distinctively compared to their conventional counterparts,potentially breaking through the trade-offs between various properties and achieving transformative performance[1-3].展开更多
To alleviate the main limitations of lithium ion diffusion rate and poor electronic conductivity for LiFePO4 cathode material, it is desirable to synthesize nano-size LiFePO4 material due to its enhanced electronic an...To alleviate the main limitations of lithium ion diffusion rate and poor electronic conductivity for LiFePO4 cathode material, it is desirable to synthesize nano-size LiFePO4 material due to its enhanced electronic and lithium ion transport rates and thus an improved high-rate performance. However, our previous synthesized LiFePO4 nanorods only exhibited low high-rate and slightly unstable cycle performance. Possible reasons are the poor crystallization and Fe2＋ oxidation of LiFePO4 nanorods prepared by hydrothermal method. In this paper, LiFePO4 nanorods were simply dealt with at 700 ℃ for 4 h under the protection of Ar and H2 mixture gas. The electrochemical properties of LiFePO4/Li cells were investigated by galvanostatic test and cyclic voltammetry（CV）. The experimental results indicated that the annealed LiFePO4 nanorods delivered an excellent cycling stability and obviously improved capacity of 150 mA·h·g-1 at 1C, and even 122 mA·h·g-1 at 5C.展开更多
To determine the fracture characteristics of asphalt mixture a novel fracture test with modified loading modes loading fixtures and the control system of the conventional overlay tester is implemented by the asphalt m...To determine the fracture characteristics of asphalt mixture a novel fracture test with modified loading modes loading fixtures and the control system of the conventional overlay tester is implemented by the asphalt material performance tester AMPT .In order to evaluate the validity of the proposed fracture test four different loading rates including 1 2 3 and 4 mm/min are examined in the AMPT. The results indicate that the fracture behavior is similar to creep at a low loading rate and does not show significant marginal tail extension at a high loading rate.It clearly shows the phase of crack initiation crack propagation and fracture at a loading rate of 3 mm/min. Besides eight fracture parameters such as fracture energy tensile strength and tensile modulus are applied to evaluate the fracture characteristics of asphalt mixture.Development of the overlay tester for the fracture test of asphalt mixture can be considered as a new fracture test of asphalt mixture.展开更多
Due to the limited thermoelectric(TE)performance of polymer materials and the inherent rigidity of inorganic materials,developing low-cost,highly flexible,and high-performance materials for flexible thermocouple senso...Due to the limited thermoelectric(TE)performance of polymer materials and the inherent rigidity of inorganic materials,developing low-cost,highly flexible,and high-performance materials for flexible thermocouple sensors(FTCSs)remains challenging.Additionally,dual-mode(contact/non-contact)temperature monitoring in FTCSs is underexplored.This study addresses these issues by using p-type(PEDOT:PSS/CNTs,2:1)and n-type(MXene/Bi_(2)Se_(3),2:1)TE materials applied via screen printing and compression onto a PPSN substrate(paper/PDMS/Si_(3)N_(4)).The resulting FTCSs exhibit excellent TE properties:electrical conductivities of 61,197.88 S/m(n-type)and 55,697.77 S/m(p-type),Seebeck coefficients of 39.88μV/K and-29.45μV/K,and power factors(PFs)of 97.66μW/mK^(2)and 55.64μW/mK^(2),respectively.In contact mode,the sensor shows high-temperature sensitivity(S_(T)=379.5μV/℃),a broad detection range(20-200℃),high resolution(~0.3℃),and fast response(~12.6 ms).In non-contact mode,it maintains good sensitivity(S_(Tmax)=52.67μV/℃),a broad detection range,high resolution(~0.8℃),and even faster response(~9.8 ms).The sensor also demonstrates strong mechanical durability,maintaining stable performance after 1000 bending cycles.When applied to dual-mode temperature monitoring in wearable devices and lithium batteries,the FTCS shows high accuracy and reliability compared to commercial K-type thermocouples,indicating significant potential for advanced medical monitoring systems and smart home technologies.展开更多
CONSPECTUS:Enhancing the performance and sustainability of materials is a major challenge facing humanity.With nearly 400 million tons of plastics manufactured per year and plastic waste accumulation of 12 billion ton...CONSPECTUS:Enhancing the performance and sustainability of materials is a major challenge facing humanity.With nearly 400 million tons of plastics manufactured per year and plastic waste accumulation of 12 billion tons expected by 2050,the production and buildup of anthropogenic petroleumbased waste is a major threat to our global ecosystem.This impending environmental catastrophe demands alternative sustainable and circular routes for material production.Additionally,there is a need for new polymeric materials that possess properties not currently found in synthetic materials for various applications in biomedical engineering,soft robotics,flexible electronics,and more.Nature offers inspiration for solving both of these environmentally,economically,and socially impactful global issues.展开更多
Dental restorative materials with antimicrobial properties can inhibit bacterial colonization, which may result in a reduction of caries at tooth-filling interaction zones. This study aimed to develop antibacterial gl...Dental restorative materials with antimicrobial properties can inhibit bacterial colonization, which may result in a reduction of caries at tooth-filling interaction zones. This study aimed to develop antibacterial glass-ionomer cements （GIC） containing a quaternary ammonium monomer （dimethylaminododecyl methacrylate, DMADDM）, and to investigate their effect on material performance and antibacterial properties. Different mass fractions （0, 1.1% and 2.2%） of DMADDM were incorporated into the GIC. The flexure strength, surface charge density, surface roughness and fluoride release were tested. A Streptococcus mutans biofilm model was used. Exopolysaccharides （EPS） staining was used to analyze the inhibitory effect of DMADDM on the biofilm matrix. In addition, biofilm metabolic activity, lactic acid metabolism and the expression of glucosyltransferase genes g/fB, gtfC and gtfD were measured. GIC containing 1.1% and 2.2% DMADDM had flexural strengths matching those of the commercial control （P〉0.1）. DMADDM was able to increase the surface charge density but reduced surface roughness （P〈0.05）. The incorporation of 1.1% and 2.2% DMADDM elevated the release of fluoride by the GIC in the first 2 days （P〈0.05）. The novel DMADDM-modified GIC significantly reduced biofilm metabolic activity （P〈 0.05） and decreased lactic acid production （P〈 0.05）. The quantitative polymerase chain reaction （qPCR） results showed that the expression of gtfB, g/fC and gtfD decreased when mass fractions of DMADDM increased （P〈0.05）. EPS staining showed that both the bacteria and EPS in biofilm decreased in the DMADDM groups. The incorporation of DMADDM could modify the properties of GIC to influence the development of S. mutans biofilms. In this study, we investigated the interface properties of antibacterial materials for the first time. GIC containing DMADDM can improve material performance and antibacterial properties and may contribute to the better management of secondary caries.展开更多
A series of nanostructured Zr-doped anatase TiO_2 tubes with the Zr/Ti molar ratio of 0.01, 0.02, 0.03, and0.09 were prepared by a sol–gel technology on a carbon fiber template. The electrochemical performance of Zr-...A series of nanostructured Zr-doped anatase TiO_2 tubes with the Zr/Ti molar ratio of 0.01, 0.02, 0.03, and0.09 were prepared by a sol–gel technology on a carbon fiber template. The electrochemical performance of Zr-doped anatase TiO_2 as anodes for rechargeable lithium batteries was investigated and compared with undoped titania. Tests represented that after 35-fold charge/discharge cycling at C/10 the reversible capacity of Zr-doped titania（Zr/Ti = 0.03） reaches 135 m A h g^（-1）, while the capacity of undoped titania（Zr/Ti = 0） yielded only 50 m A h g^（-1）. Based on the results of the physicochemical investigation, three reasons of improving electrochemical performance of Zr-doped titania were suggested. According to the scanning electron microscopy and transmission electron microscopy, Zr^（4＋） doping induces a decrease in nanoparticle size, which facilitates the Li＋diffusion. The Raman investigations show the more open structure of Zr-doped TiO_2 as compared to undoped titania due to changing of the unit cell parameters, that significantly affects on the reversibility of the insertion/extraction process. The electrochemical impedance spectroscopy results indicate that substitution of Zr^（4＋） for Ti^（4＋） into anatase TiO_2 has favorable effects on the conductivity.展开更多
基金Funded by the National Key Technology R&D Program in the12th Five Year Plan of China(No.2011BAE14B06)the National High Technology ResearchDevelopment Program of China(No.2015AA034701)
文摘Main performance of the cement grouting materials made up by Portland cement（PC） and sulphoaluminate cement（SAC） was investigated in this program, a kind of expanding agent（EA） which was mainly constituted by metakaolin and alunite was utilized for the compensation of the shrinkage, the hydration products and micro structure of the grouting materials were researched by X-ray diffraction（XRD） and scanning electron microscopy（SEM）. The results showed that a high expansion rate of the grouting materials could be reached as the expanding agent mixed in 6% of PC mass; the addition of SAC in the S2（PC：SAC：EA=34：6：2.25） brought a further improvement of the expansion rate of the grouting materials, the analysis of XRD and SEM showed that due to the reaction of expanding agent and SAC in the grouting materials, more ettringite crystal was generated, which resulted in a higher early strength, the addition of SAC played an expansion and strength reinforcement role in the grouting materials.
基金fnancially supported by the National Natural Science Foundation of China(No.51274195)the Natural Science Foundation of Jiangsu Province(No.BK2012571)+3 种基金the Program for New Century Excellent Talents in University(No.NCET-12-0959)the China Postdoctoral Science Foundation(No.20090450930)the National Basic Research Program of China(No.2011CB201205)Qing Lan Project,and the Youth Foundation of China University of Mining and Technology(No.2007A003)
文摘The geological condition of Chinese coal mines are complex and high gassy,which account for ffty percent to seventy percent.Because of the abundant pores and cracks around the drainage drilling hole,the gas concentration attenuates rapidly,and the effective gas drainage period is short.The traditional sealing materials of yellow mud and cement-sand grout will readily shrink after the drilling hole is sealed,the sealing length is short and the sealing quality is not satisfactory.Currently widely used polyurethane material will shrink when it comes into contact with water,and the price is also very high.In this study,taking cement as a base material,a novel composite sealing material mixed by expansion admixture,additive,and fbrin and coupling agent was developed and the sealing performance and expansion property of the material were also studied and analyzed.The FEI Quanta TM 250 environmental scanning electron microscope was used to investigate the microstructure of material.The results revealed that the new composite sealing material had a desirable expansion performance and a defnite fluidity convenient for grouting.The solidifed material,combining closely with the drilling wall,possessed an adequate strength and was not easy to shrink.Compared to the conventional polyurethane,the gas drainage concentration by drilling sealing exceeded 40 percent,and the sealing capacity improves5 times,the sealing effect increases signifcantly.
基金Funded by the National Natural Science Foundation of China(Nos.51302104,51472109)Science and Technology Development Plan of Shandong Province(No.2014G-ZX208001)the Program for Scientific Research Innovation Team in Colleges and Universities of Shandong Province
文摘This paper aimed to improve the water-retention performance and basic physical properties of sulfoaluminate cement（SAC）-based planting cementitious material. The effect of natural zeolite on the performance of SAC-based planting material was investigated. The water-retention performance, porosity, compressive strength, and alkalinity had been tested and TG-DSC analysis had been adopted in this paper. Experimental results showed that zeolite was effective to improve the water-retention capacity and 10%, 20% and 30% natural zeolite increased the pore volume of the hardened pastes by 10.6%, 26.0%, and 38.6%, especially pore size below 0.1 μm was increased by 9.7%, 26.2% and 17.5%. And 10% zeolite was beneficial to the compressive strengths of cementitious material and 1, 3, and 28 d compressive strength reached up to 35.9, 55.0, 80.3 MPa. Furthermore zeolite decreased the alkalinity of pore fluid of hardened cementitious material, while the addition of zeolite reached up to 30%, the alkalinity of pore fluid of hardened cementitious material decreased by 8.9%. Therefore zeolite was suitable for improving the performance of SAC-based planting cementitious material.
文摘Lithium battery has recently gained more and more attention worldwide.It has wide usage that range from toys to electric cars.Choosing a suitable material that best fits the overall performance as electrode for the battery is very essential.For cathode material,apart from the traditional and widely-used LiCoCO_(2),LiFePO_(4)and so on,there are innovations that include the use of V_(2)O_(5).Researches have been done focusing on how to further improve the performance for V_(2)O_(5)cathode in terms of different structure,forms or combination with other chemical molecules.This research paper will make a summary of the materials derived from traditional V_(2)O_(5)as well as their performances.
基金supported by the World Health Organization(WHO/TDR),project ID A61119
文摘Objective: To improve knowledge and practice of health staff as well as the availability of material resources for diagnosis and management of schistosomiasis in two endemic provinces of DRC(Kinshasa and Bas-Congo).Methods: Structured interviews were performed using questionnaires with staff from 35 healthcare facilities in 9 health zones(HZ) of Kinshasa and 2 HZ in Bas-Congo.Results: Schistosomiasis was reported to be present in all the included HZ.Health staff knew the most important symptoms of schistosomiasis, but advanced symptoms were more accurately reported in Bas-Congo.Knowledge of symptoms related to schistosomiasis such as anemia(P = 0.0 115) and pollakiuria(P = 0.0 260) was statistically different in both two provinces.Kato-Katz technique and urine filtration were unavailable in both provinces.Parasitological diagnosis was mostly performed using the direct smear method.PZQ was available in 70% of the health facilities, all situated in Bas-Congo.Diagnosis and treatment mostly relied on symptoms and cost more in urban area than in rural.Conclusions: Though knowledge on schistosomiasis among health staff appears sufficient, substantial efforts still must be made to improve the availability of diagnostic tools and treatment in the health facilities in DRC.
文摘Experiments have been conducted on a plasma opening switch (POS) test-bed to investigate the influence of cathode materials made of aluminum, stainless steel, molybdenum and tungsten on opening performance for conduction time up to 3 microseconds, conduction current up to 100 kA. Remarkaly different opening characteristics have been shown for these materials,with tungsten being of the best opening performance.
文摘(2) Other Magnetic Materials RE Giant Magnetostrictive Materials (GMM) Research of GMM in China started since 1980s but developed rapidly. The products can be produced in batches today. However, application of such materials in apparatus is laggard than developed countries. GMM materials are mainly applied in step motors, linear actuators, ultrasonic systems, sonar systems, valves, precise controls, active vibration damping etc. It is estimated that the near 10 years will be the fast developing period of global GMM market. Global production of GMM materials during 1989 to 2005 is listed in Table 3.
文摘Additive Manufacturing(AM)has significantly impacted the development of high-performance materials and structures,offering new possibilities for industries ranging from aerospace to biomedicine.This special issue features pioneering research that integrates AI-driven methods with AM,enabling the design and fabrication of complex,optimized structures with enhanced properties.
基金Selected from Proceedings of the 7th International Conference on Frontiers of DesignManufacturing(ICFDM'2006)This project is supported by National Natural Science Foundation of China(No.50275086)the University of New South Wales Visiting Professorship Scheme,Australia.
文摘An advanced ceramic cutting tool material Al2O3/TiC/TiN （LTN） is developed by incorporation and dispersion of micro-scale TiC particle and nano-scale TiN particle in alumina matrix. With the optimal dispersing and fabricating technology, this multi-scale and multi-phase nanocomposite ceramic tool material can get both higher flexural strength and fracture toughness than that of A1203/TiC （LZ） ceramic tool material without nano-scale TiN particle, especially the fracture toughness can reach to 7.8 MPa . m^0.5. The nano-scale TiN can lead to the grain fining effect and promote the sintering process to get a higher density. The coexisting transgranular and intergranular fracture mode induced by micro-scale TiC and nano-scale TiN, and the homogeneous and densified microstructure can result in a remarkable strengthening and toughening effect. The cutting performance and wear mechanisms of the advanced multi-scale and multi-phase nanocomposite ceramic cutting tool are researched.
基金Funded by the National Natural Science Foundation of China(No.51271036)
文摘To investigate the ballistic performance and damage characteristics of quasi threedimensional（3D） needle-punched Cf/SiC composites prepared by chemical vapor infiltration（CVI）,penetration experiments were conducted by using 7.62 mm armor piercing incendiary（API）.Macro and micro fracture morphologies were then observed on recycled targets.The results show that the protection coefficient of 3D Cf/SiC composites is 2.54.High porosity and many micro thermal stress cracks may directly lead to the lower ballistic performance.Flat fracture morphology was observed on the crater surface.The low dynamic fracture strength along layer direction may be attributed to the voids and microcracks caused by residual thermal stress.The damage characteristics of Cf/Si C composites include matrix cracking,fiber bundle cracking,interfacial debonding,fiber fracture,and fiber bundle pull-out.And interfacial debonding and fiber fracture may play major roles in energy absorption.
文摘The new adhesive material for the construction joints of tunnel lining(named as SZC) was studied based on the structural characteristics of interfaces and the characteristic of bonding construction, and the performance indexes were verified by tests. The experimental results show that the adhesive capability of interface is improved effectively by using SZC material, the properties, such as anti-freezing, erosion-resistance and anti-shrinkage are improved greatly as well as durability.
基金supported by the Beijing Natural Science Foundation(4242058)the National Natural Science Foundation of China(52271236,U22A20116,51931007,and 51971196)the National Key R&D Program of China(2022YFB3505600)。
文摘Given the severe energy and environmental crises,there is a pressing need for the development of high-performance functional materials.Therefore,significant challenges facing current functional materials must be addressed,including further improving material performance,resolving complex trade-offs between properties,and achieving multifunctionality for greater energy efficiency while effectively preventing premature failures during functional processes.Traditional materials may exhibit translational periodicity at the lattice level,but their microstructures,such as grains and their characteristics,are often randomly distributed.Recent discoveries indicate that if the microstructure is constructed in an ordered manner,e.g.,grain size gradient,materials can perform distinctively compared to their conventional counterparts,potentially breaking through the trade-offs between various properties and achieving transformative performance[1-3].
基金Funded by the National Natural Science Foundation of China(51208396 and 21277017)the Fundamental Research Funds for the Central Universities(2013-Ia-36 and 2013-Ia-39)the Selfdetermined and Innovative Research Funds of WUT(136814016)
文摘To alleviate the main limitations of lithium ion diffusion rate and poor electronic conductivity for LiFePO4 cathode material, it is desirable to synthesize nano-size LiFePO4 material due to its enhanced electronic and lithium ion transport rates and thus an improved high-rate performance. However, our previous synthesized LiFePO4 nanorods only exhibited low high-rate and slightly unstable cycle performance. Possible reasons are the poor crystallization and Fe2＋ oxidation of LiFePO4 nanorods prepared by hydrothermal method. In this paper, LiFePO4 nanorods were simply dealt with at 700 ℃ for 4 h under the protection of Ar and H2 mixture gas. The electrochemical properties of LiFePO4/Li cells were investigated by galvanostatic test and cyclic voltammetry（CV）. The experimental results indicated that the annealed LiFePO4 nanorods delivered an excellent cycling stability and obviously improved capacity of 150 mA·h·g-1 at 1C, and even 122 mA·h·g-1 at 5C.
基金The National Natural Science Foundation of China(No.51178114)the Chinese Western Transportation Construction Technology Project of Transportation Ministry(No.2009318000086)
文摘To determine the fracture characteristics of asphalt mixture a novel fracture test with modified loading modes loading fixtures and the control system of the conventional overlay tester is implemented by the asphalt material performance tester AMPT .In order to evaluate the validity of the proposed fracture test four different loading rates including 1 2 3 and 4 mm/min are examined in the AMPT. The results indicate that the fracture behavior is similar to creep at a low loading rate and does not show significant marginal tail extension at a high loading rate.It clearly shows the phase of crack initiation crack propagation and fracture at a loading rate of 3 mm/min. Besides eight fracture parameters such as fracture energy tensile strength and tensile modulus are applied to evaluate the fracture characteristics of asphalt mixture.Development of the overlay tester for the fracture test of asphalt mixture can be considered as a new fracture test of asphalt mixture.
基金supported by National Key Research and Development Program of China(2022YFB3205903)Anhui Province Science and Technology Innovation Key Project(202423k09020047)+1 种基金the Natural Science Foundation of China(No.2201187)Major R&D Innovation Project of Anhui Provincial Development and Reform Commission(JZ2021AFKJ0050).
文摘Due to the limited thermoelectric(TE)performance of polymer materials and the inherent rigidity of inorganic materials,developing low-cost,highly flexible,and high-performance materials for flexible thermocouple sensors(FTCSs)remains challenging.Additionally,dual-mode(contact/non-contact)temperature monitoring in FTCSs is underexplored.This study addresses these issues by using p-type(PEDOT:PSS/CNTs,2:1)and n-type(MXene/Bi_(2)Se_(3),2:1)TE materials applied via screen printing and compression onto a PPSN substrate(paper/PDMS/Si_(3)N_(4)).The resulting FTCSs exhibit excellent TE properties:electrical conductivities of 61,197.88 S/m(n-type)and 55,697.77 S/m(p-type),Seebeck coefficients of 39.88μV/K and-29.45μV/K,and power factors(PFs)of 97.66μW/mK^(2)and 55.64μW/mK^(2),respectively.In contact mode,the sensor shows high-temperature sensitivity(S_(T)=379.5μV/℃),a broad detection range(20-200℃),high resolution(~0.3℃),and fast response(~12.6 ms).In non-contact mode,it maintains good sensitivity(S_(Tmax)=52.67μV/℃),a broad detection range,high resolution(~0.8℃),and even faster response(~9.8 ms).The sensor also demonstrates strong mechanical durability,maintaining stable performance after 1000 bending cycles.When applied to dual-mode temperature monitoring in wearable devices and lithium batteries,the FTCS shows high accuracy and reliability compared to commercial K-type thermocouples,indicating significant potential for advanced medical monitoring systems and smart home technologies.
基金support from a Canada Research Chair Award(CRC Tier 2950-231953).
文摘CONSPECTUS:Enhancing the performance and sustainability of materials is a major challenge facing humanity.With nearly 400 million tons of plastics manufactured per year and plastic waste accumulation of 12 billion tons expected by 2050,the production and buildup of anthropogenic petroleumbased waste is a major threat to our global ecosystem.This impending environmental catastrophe demands alternative sustainable and circular routes for material production.Additionally,there is a need for new polymeric materials that possess properties not currently found in synthetic materials for various applications in biomedical engineering,soft robotics,flexible electronics,and more.Nature offers inspiration for solving both of these environmentally,economically,and socially impactful global issues.
基金supported by a National Natural Science Foundation of China grant 81372889 (Lei Cheng), 81430011 (Xue-dong Zhou)the Program for New Century Excellent Talents in University (Lei Cheng)+3 种基金a Youth Grant of the Science and Technology Department of Sichuan Province, China 2014JQ0033 (Lei Cheng)the International Science and Technology Cooperation Program of China 2014DFE30180 (Xue-dong Zhou)NIH R01 DE17974 (Hockin HK Xu)a Seed Grant (Hockin HK Xu) from the University of Maryland School of Dentistry
文摘Dental restorative materials with antimicrobial properties can inhibit bacterial colonization, which may result in a reduction of caries at tooth-filling interaction zones. This study aimed to develop antibacterial glass-ionomer cements （GIC） containing a quaternary ammonium monomer （dimethylaminododecyl methacrylate, DMADDM）, and to investigate their effect on material performance and antibacterial properties. Different mass fractions （0, 1.1% and 2.2%） of DMADDM were incorporated into the GIC. The flexure strength, surface charge density, surface roughness and fluoride release were tested. A Streptococcus mutans biofilm model was used. Exopolysaccharides （EPS） staining was used to analyze the inhibitory effect of DMADDM on the biofilm matrix. In addition, biofilm metabolic activity, lactic acid metabolism and the expression of glucosyltransferase genes g/fB, gtfC and gtfD were measured. GIC containing 1.1% and 2.2% DMADDM had flexural strengths matching those of the commercial control （P〉0.1）. DMADDM was able to increase the surface charge density but reduced surface roughness （P〈0.05）. The incorporation of 1.1% and 2.2% DMADDM elevated the release of fluoride by the GIC in the first 2 days （P〈0.05）. The novel DMADDM-modified GIC significantly reduced biofilm metabolic activity （P〈 0.05） and decreased lactic acid production （P〈 0.05）. The quantitative polymerase chain reaction （qPCR） results showed that the expression of gtfB, g/fC and gtfD decreased when mass fractions of DMADDM increased （P〈0.05）. EPS staining showed that both the bacteria and EPS in biofilm decreased in the DMADDM groups. The incorporation of DMADDM could modify the properties of GIC to influence the development of S. mutans biofilms. In this study, we investigated the interface properties of antibacterial materials for the first time. GIC containing DMADDM can improve material performance and antibacterial properties and may contribute to the better management of secondary caries.
基金the program of fundamental scientific researches of the Russian Academy of Sciences (project No. 0265-2014-0001)the support of the Russian Science Foundation (project No. 14-33-00009)+1 种基金the Government of the Russian Federation (the Federal Agency of Scientific Organizations)supported by the BP grant (A.A. Sokolov is superviser, competition for 2016–2017 years) for young researchers, postgraduates, and students
文摘A series of nanostructured Zr-doped anatase TiO_2 tubes with the Zr/Ti molar ratio of 0.01, 0.02, 0.03, and0.09 were prepared by a sol–gel technology on a carbon fiber template. The electrochemical performance of Zr-doped anatase TiO_2 as anodes for rechargeable lithium batteries was investigated and compared with undoped titania. Tests represented that after 35-fold charge/discharge cycling at C/10 the reversible capacity of Zr-doped titania（Zr/Ti = 0.03） reaches 135 m A h g^（-1）, while the capacity of undoped titania（Zr/Ti = 0） yielded only 50 m A h g^（-1）. Based on the results of the physicochemical investigation, three reasons of improving electrochemical performance of Zr-doped titania were suggested. According to the scanning electron microscopy and transmission electron microscopy, Zr^（4＋） doping induces a decrease in nanoparticle size, which facilitates the Li＋diffusion. The Raman investigations show the more open structure of Zr-doped TiO_2 as compared to undoped titania due to changing of the unit cell parameters, that significantly affects on the reversibility of the insertion/extraction process. The electrochemical impedance spectroscopy results indicate that substitution of Zr^（4＋） for Ti^（4＋） into anatase TiO_2 has favorable effects on the conductivity.
