Superhydrophobic surface(SHS) has been well developed, as SHS renders the property of minimizing the water/solid contact interface. Water droplets deposited onto SHS with contact angles exceeding 150°, allow them...Superhydrophobic surface(SHS) has been well developed, as SHS renders the property of minimizing the water/solid contact interface. Water droplets deposited onto SHS with contact angles exceeding 150°, allow them to retain spherical shapes, and the low adhesion of SHS facilitates easy droplet collection when tilting the substrate. These characteristics make SHS suitable for a wide range of applications. One particularly promising application is the fabrication of microsphere and supraparticle materials. SHS offers a distinct advantage as a universal platform capable of providing customized services for a variety of microspheres and supraparticles. In this review, an overview of the strategies for fabricating microspheres and supraparticles with the aid of SHS, including cross-linking process, polymer melting,and droplet template evaporation methods, is first presented. Then, the applications of microspheres and supraparticles formed onto SHS are discussed in detail, for example, fabricating photonic devices with controllable structures and tunable structural colors, acting as catalysts with emerging or synergetic properties, being integrated into the biomedical field to construct the devices with different medicinal purposes, being utilized for inducing protein crystallization and detecting trace amounts of analytes. Finally,the perspective on future developments involved with this research field is given, along with some obstacles and opportunities.展开更多
Cavitation is a common issue in pumps,causing a decrease in pump head,a fall in volumetric efficiency,and an intensification of outlet flow pulsation.It is one of the main hazards that affect the regular operation of ...Cavitation is a common issue in pumps,causing a decrease in pump head,a fall in volumetric efficiency,and an intensification of outlet flow pulsation.It is one of the main hazards that affect the regular operation of the pump.Research on pump cavitation mainly focuses on mixed flow pumps,jet pumps,external spur gear pumps,etc.However,there are few cavitation studies on external herringbone gear pumps.In addition,pumps with different working principles significantly differ in the flow and complexity of the internal flow field.Therefore,it is urgent to study the cavitation characteristics of external herringbone gear pumps.Compared with experimentalmethods,visual research and cavitation area identification are achieved through computation fluid dynamic(CFD),and changing the boundary conditions and shape of the gear rotor is easier.The simulation yields a head error of only 0.003%under different grid numbers,and the deviation between experimental and simulation results is less than 5%.The study revealed that cavitation causes flow pulsation at the outlet,and the cavitation serious area is mainly distributed in the meshing gap and meshing area.Cavitation can be inhibited by reducing the speed,increasing the inlet pressure,and changing the helix angle can be achieved.For example,when the inlet pressure is 5 bar,the maximumgas volume fraction in themeshing area is less than 50%.These results provide a reference for optimizing the design and finding the optimal design parameters to reduce or eliminate cavitation.展开更多
In this paper, we mainly study the orbital graphs of primitive groups with the socle A<sub>7</sub> x A<sub>7 </sub>which acts by diagonal action. Firstly, we calculate the element conjugat...In this paper, we mainly study the orbital graphs of primitive groups with the socle A<sub>7</sub> x A<sub>7 </sub>which acts by diagonal action. Firstly, we calculate the element conjugate classes of A7</sub>, then we discuss the stabilizer of two points in A7</sub>. Finally, according to the relation between suborbit and orbital, we obtain the orbitals, and determine the orbital graphs.展开更多
In this paper, we consider the problem of irregular shapes tracking for multiple extended targets by introducing the Gaussian surface matrix(GSM) into the framework of the random finite set(RFS) theory. The Gaussian s...In this paper, we consider the problem of irregular shapes tracking for multiple extended targets by introducing the Gaussian surface matrix(GSM) into the framework of the random finite set(RFS) theory. The Gaussian surface function is constructed first by the measurements, and it is used to define the GSM via a mapping function. We then integrate the GSM with the probability hypothesis density(PHD) filter, the Bayesian recursion formulas of GSM-PHD are derived and the Gaussian mixture implementation is employed to obtain the closed-form solutions. Moreover, the estimated shapes are designed to guide the measurement set sub-partition, which can cope with the problem of the spatially close target tracking. Simulation results show that the proposed algorithm can effectively estimate irregular target shapes and exhibit good robustness in cross extended target tracking.展开更多
Averrhoa carambola is commonly known as star fruit because of its peculiar shape,and its fruit is a rich source of minerals and vitamins.It is also used in traditional medicines in countries such as India,China,the Ph...Averrhoa carambola is commonly known as star fruit because of its peculiar shape,and its fruit is a rich source of minerals and vitamins.It is also used in traditional medicines in countries such as India,China,the Philippines,and Brazil for treating various ailments,including fever,diarrhea,vomiting,and skin disease.Here,we present the first draft genome of the Oxalidaceae family,with an assembled genome size of 470.51 Mb.In total,24,726 protein-coding genes were identified,and 16,490 genes were annotated using various well-known databases.The phylogenomic analysis confirmed the evolutionary position of the Oxalidaceae family.Based on the gene functional annotations,we also identified enzymes that may be involved in important nutritional pathways in the star fruit genome.Overall,the data from this first sequenced genome in the Oxalidaceae family provide an essential resource for nutritional,medicinal,and cultivational studies of the economically important star-fruit plant.展开更多
In this work, the magnesium aluminum spinel (MgAl2O4) was prepared by Mg and Al as precursors through a method of sol-gel subsequent with high temperature calcination. The wide range of synthetic conditions, including...In this work, the magnesium aluminum spinel (MgAl2O4) was prepared by Mg and Al as precursors through a method of sol-gel subsequent with high temperature calcination. The wide range of synthetic conditions, including organic alcohols, ammonia content, dispersant, alkoxide concentration, hydrolysis time, hydrolysis temperature and calcination temperature were screened over as-prepared samples. This work provides a necessary experimental basis for the synthesis of MgAl2O4 with uniform particle size of spherical structure, which has a potential to be used in many industrial and military applications.展开更多
Cluster-assembled materials have attracted particular attention for their complex hierarchical structures and unique properties.However,the majority of cluster-based assemblies developed so far are either non-magnetic...Cluster-assembled materials have attracted particular attention for their complex hierarchical structures and unique properties.However,the majority of cluster-based assemblies developed so far are either non-magnetic or only exhibit magnetic ordering with a relatively low Curie temperature,limiting their applications in spintronics.Thus,two-dimensional(2D)cluster-assembled materials with room-temperature magnetism remain highly desirable.For this purpose,based on first principles calculations,we design a series of thermodynamically stable 2D cluster-based metal-organic frameworks(MOFs)Fe_(n)-(pyz)(n=1-6)by utilizing Fenmetal clusters as nodes and nitrogen-containing pyrazine ligands as organic linkers.These 2D cluster-based MOFs exhibit robust ferrimagnetic ordering due to the strong d-p direct exchange interaction between d-electron spin of Fe_(n)(n=1-6)clusters and charge transfer-induced p-electron spin of pyrazine ligands.In particular,the ferrimagnetic Curie temperatures are well above room temperature(up to 836 K).Additionally,altering the size of Fe_(n)clusters in Fe_(n)-(pyz)(n=1-6)MOFs results in diverse functional spintronic properties,including bipolar magnetic semiconductors,half semiconductors and Dirac half metals.Moreover,these 2D assembled MOFs possess sizable magnetic anisotropy energies,up to 9.16 me V per formula.展开更多
Passive daytime radiative cooling(PDRC)technology is emerging as one of the most promising solutions to the global problem of spacing cooling,but its practical application is limited due to reduced cooling effectivene...Passive daytime radiative cooling(PDRC)technology is emerging as one of the most promising solutions to the global problem of spacing cooling,but its practical application is limited due to reduced cooling effectiveness caused by daily wear and tear,as well as dirt contamination.To tackle this problem,we report a novel strategy by introducing a renewable armor structure for prolonging the anti-fouling and cooling effectiveness properties of the PDRC coatings.The armor structure is designed by decorating fluorinated hollow glass microspheres(HGM)inside rigid resin composite matrices.The HGM serve triple purposes,including providing isolated cavities for enhanced solar reflectance,reinforcing the matrices to form robust armored structures,and increasing thermal emittance.When the coatings are worn,the HGM on the surface expose their concave cavities with numerous hydrophobic fragments,generating a highly rough surface that guarantee the superhydrophobic function.The coatings show a high sunlight reflectance(0.93)and thermal emittance(0.94)in the long-wave infrared window,leading to a cooling of 5℃ below ambient temperature under high solar flux(∼900 W/m^(2)).When anti-fouling functions are reduced,they can be regenerated more than 100 cycles without compromising the PDRC function by simple wearing treatment.Furthermore,these coatings can be easily prepared using a one-pot spray method with low-cost materials,exhibit strong adhesion to a variety of substrates,and demonstrate exceptional environmental stability.Therefore,we anticipate their immediate application opportunities for spacing cooling.展开更多
Lithium(Li)dendrite issue,which is usually caused by inhomogeneous Li nucleation and fragile solid electrolyte interphase(SEI),impedes the further development of high-energy Li metal batteries.However,the integrated c...Lithium(Li)dendrite issue,which is usually caused by inhomogeneous Li nucleation and fragile solid electrolyte interphase(SEI),impedes the further development of high-energy Li metal batteries.However,the integrated construction of a high-stable SEI layer that can regulate uniform nucleation and facilitate fast Li-ion diffusion kinetics for Li metal anode still falls short.Herein,we designed an artificial SEI with hybrid ionic/electronic interphase to regulate Li deposition by in-situ constructing metal Co clusters embedded in LiF matrix.The generated Co and LiF both enable fast Li-ion diffusion kinetics,meanwhile,the lithiophilic properties of Co clusters can serve as Li-ion nucleation sites,thereby contributing to uniform Li nucleation and non-dendritic growth.As a result,a dendrite-free Li deposition with a low overpotential(16.1 mV)is achieved,which enables an extended lifespan over 750 h under strict conditions.The full cells with high-mass-loading LiFePO_(4)(11.5 mg/cm^(2))as cathodes exhibit a remarkable rate capacity of 84.1 mAh/g at 5 C and an improved cycling performance with a capacity retention of 96.4%after undergoing 180 cycles.展开更多
The chemoselective hydrogenation of structurally diverse nitroaromatics is a challenging process.Generally,catalyst activity tends to decrease when excellent selectivity is guaranteed.We here present a novel photocata...The chemoselective hydrogenation of structurally diverse nitroaromatics is a challenging process.Generally,catalyst activity tends to decrease when excellent selectivity is guaranteed.We here present a novel photocatalyst combining amino-functionalized carbon dots(N-CDs)with copper selenite nanoparticles(N-CDs@CuSeO_(3))for simultaneously improving selectivity and activity.Under visible light irradiation,the prepared N-CDs@CuSeO_(3)exhibits 100%catalytic selectivity for the formation of 4-aminostyrene at full conversion of 4-nitrostyrene in aqueous solvent within a few minutes.Such excellent photocatalytic performance is mainly attributed to the precise control of the hydrogen species released from the ammonia borane by means of light-converted electrons upon N-CDs@CuSeO_(3).Besides,the defect states at the interface of N-CDs and CuSeO_(3)enable holes to be trapped for promoting separation and transfer of photogenerated charges,allowing more hydrogen species to participate in catalytic reaction.展开更多
Presently,interfacial solar water evaporation(ISWE)is now injecting new vitality into the field of water remediation.However,during the ISWE process,the nonvolatile pollutants might be concentrated in residual water,a...Presently,interfacial solar water evaporation(ISWE)is now injecting new vitality into the field of water remediation.However,during the ISWE process,the nonvolatile pollutants might be concentrated in residual water,and further contaminate the environment.Preparing advanced photothermal materials is in need to get comprehensive purification of various pollutants in residual water.Herein,we report a facile laser thermal method to prepare Cu_(2−x)S/sulfur/reduced graphene oxide(Cu_(2−x)S/S/rGO)nanocomposites for realizing all-round residual water remediation during the ISWE process.The as-prepared Cu2−xS/S/rGO nanocomposites demonstrated excellent photothermal and photocatalytic properties.Through blending with GO nanosheets having excellent adsorption capacity,the synergetic effect of photothermal,photocatalytic,and adsorption properties resulted in highly efficient purification of rhodamine B,bacterial,and heavy metal ions in residual water during the ISWE process.The experimental results also showed that,increasing solar light intensity can promote the residual water remediation,but ultrafast water evaporation under high light intensity may deteriorate the purifying effect.This report may pave a new way to prepare multifunctional materials for water remediation through the ISWE technology.展开更多
Transition metal dichalcogenides(TMDs)have been regarded as promising cathodes for aqueous zinc-ion batteries(AZIBs)but suffer from sluggish reaction kinetics due to their poor conductivity and the strong electrostati...Transition metal dichalcogenides(TMDs)have been regarded as promising cathodes for aqueous zinc-ion batteries(AZIBs)but suffer from sluggish reaction kinetics due to their poor conductivity and the strong electrostatic interaction between Zn-ion and cathode materials.Herein,a well-defined structure with MoSSe nanosheets vertically anchored on graphene is used as the cathode for AZIBs.The dissolution of Se into MoS2 lattice together with heterointerface design via developing C-O-Mo bonds improves the inherent conductivity,enlarges interlayer spacing,and generates abundant anionic vacancies.As a result,the Zn2+intercalation/deintercalation process is greatly improved,which is confirmed by theoretical modeling and ex-situ experimental results.Remarkably,the assembled AZIBs exhibit high-rate capability(124.2 mAh·g^(−1)at 5 A·g^(−1))and long cycling life(83%capacity retention after 1,200 cycles at 2 A·g^(−1)).Moreover,the assembled quasi-solid-state Zn-ion batteries demonstrate a stable cycling performance over 100 cycles and high capacity retention over 94%after 2,500 bending cycles.This study provides a new strategy to unlock the electrochemical activity of TMDs via interface design and atomic engineering,which can also be applied to other TMDs for multivalent batteries.展开更多
Herein,Cu–Al bimetallic oxide was synthesized and mixed with mesoporous silica spheres via a simple hydrothermal method.The prepared sample was then analyzed and employed to activate potassium peroxydisulfate for bis...Herein,Cu–Al bimetallic oxide was synthesized and mixed with mesoporous silica spheres via a simple hydrothermal method.The prepared sample was then analyzed and employed to activate potassium peroxydisulfate for bisphenol A removal.Based on the results of X-ray diffraction,scanning electron microscopy,and energy dispersion spectroscopy,Cu–Al bimetallic oxide was determined as CuO-Al2O3,and mesoporous silica spheres were found around the these particles.At 30 min,a bisphenol A degradation level of 90%was achieved,and it remained at over 60%after five consecutive cycles,indicating the catalyst’s superior capacity and stability.In terms of removal performance,the radical pathway(including■OH•,and■)and singlet oxygen(■)bisphenol A,potassium peroxydisulfate,and the catalyst played a dominant role.The introduction of Al2O3 promoted the formation of surface oxygen vacancies,which improved ligand complex formation between potassium peroxydisulfate and the catalyst,thereby facilitating electron migration.Furthermore,mesoporous silica spheres augment not only enhanced bisphenol A adsorption but also alleviated Cu leaching.Overall,this work is expected to provide significant support for the rational development of catalysts with high catalytic activity for persulfate activation via surface electron migration.展开更多
Context:As the increasing number of pet canines,the identification of canine has attracted much attentions in the forensic field,however,the genetic diversities of pet canines still remained unknown.Aims:To explore ge...Context:As the increasing number of pet canines,the identification of canine has attracted much attentions in the forensic field,however,the genetic diversities of pet canines still remained unknown.Aims:To explore genetic polymorphisms of 19 short tandem repeat(STR)loci and genetic relationships between the two studied canine groups and reference group.Subjects and Methods:In the present study,genetic polymorphisms of 19 STR loci and a sex-linked zinc finger locus were analyzed in a total of 594 canines in Standard Poodle and Bichon Frise groups from China.Results:A total of 166,159 alleles were observed in the Standard Poodle,Bichon Frise groups with the corresponding allelic frequencies ranging from 0.0030-0.6108 to 0.0012-0.6148,respectively.The combined discrimination power and probability of exclusion of 19 STR loci in Standard Poodle and Bichon Frise groups were 0.9999999999999497,0.999962884;and 0.99999999999999995,0.999965955,respectively.Furthermore,the genetic distances between the two canine groups and Labrador retriever group were calculated,and the results indicated that Standard Poodle and Bichon Frise groups showed a closer genetic relationship,while the two canine groups had distant genetic relationships with Labrador retriever group.The result of population genetic structure revealed that genetic component distributions in the three canine groups were different.The predicted accuracies of the constructed random forest prediction model for three validation sets(25%individuals randomly selected from three populations with 808 individuals)were higher than 0.9,especially for the individuals in validation set from the Bichon Frise group is 1.Conclusions:The 19 STR loci could be used for individual identification,canine breed identification and paternity testing in the two canine groups.展开更多
Chemistry,as a central science,plays an indispensable role in creating new substances,making new materials,and improving people’s lives.Chemistry has always been changing throughout time toward precision,particularly...Chemistry,as a central science,plays an indispensable role in creating new substances,making new materials,and improving people’s lives.Chemistry has always been changing throughout time toward precision,particularly in recent years.Precision chemistry means greater efficiency,superior performance,and increased environmental friendliness.This is the dream of all chemists and is driven by both internal and external forces.Internally,chemical research has evolved beyond the molecular level to explore the constructions,properties,and intermolecular interactions of macromolecules,supramolecules,molecular aggregates,and even living systems;it now focuses more on complex systems and multiscale processes.Externally,it comes from the requirements for the creation of new substances beyond the“trial-and-error”research paradigm to achieve sustainable development of human society and to fundamentally solve energy,environmental,and health problems.Precision chemistry will have a significant impact on many areas of scientific research.展开更多
The influence of Mg content on the microstructures and mechanical properties at room temperatures of Al-3.5Cu-(0.71-1.81)Mg alloys was studied.Precipitation phases in the alloys were identified by TEM and HRTEM.The re...The influence of Mg content on the microstructures and mechanical properties at room temperatures of Al-3.5Cu-(0.71-1.81)Mg alloys was studied.Precipitation phases in the alloys were identified by TEM and HRTEM.The results show that when Mg contents increase from 0.71 to 1.81 wt%,the precipitates are transformed from S,S″,Ω,and θ' phases to Sand S′phases,and Ω phase is first observed in Al-3.48Cu-0.71 Mg alloy with Cu/Mg mass ratio of 5 during the conventional aging heat treatment(190 ℃/12 h).Regard to aging hardness effect of the tested alloys,the hardness of the alloys improves with the increase of Mg content,but the increases become slow when Mg content is greater than 1.35 wt%.展开更多
Low-cost porous ceramic microspheres from waste gangue were prepared by simple spray drying and subsequent calcination. Effects of calcination temperature on phase and microstructure evolution, specific surface area, ...Low-cost porous ceramic microspheres from waste gangue were prepared by simple spray drying and subsequent calcination. Effects of calcination temperature on phase and microstructure evolution, specific surface area, pore structure, and dye adsorption mechanism of the microspheres were investigated systematically. Results showed that the microspheres were spherical, with some mesopores both on the surface and inside the spheres. The phase kept kaolinite after calcined at 800 and 900 ℃ and transformed into mullite at 1000 ℃. The microspheres calcined at 800 ℃ showed larger adsorption capacity and removal efficiency than those calcined at higher temperatures. Methylene blue(MB) and basic fuchsin(BF) removal efficiency reached 100% and 99.9% with the microsphere dosage of 20 g/L, respectively, which was comparable to that of other low-cost waste adsorbents used to remove dyes in the literature. Adsorption kinetics data followed the pseudosecond-order kinetic model, and the isotherm data fit the Langmuir isotherm model. The adsorption process was attributed to multiple adsorption mechanisms including physical adsorption, hydrogen bonding, and electrostatic interactions between dyes and gangue microspheres. The low-cost porous microspheres with excellent cyclic regeneration properties are promising absorbent for dyes in wastewater filtration and adsorption treatment.展开更多
Fractal theory and regression analysis were employed for the first time to investigate the effect of pore size and pore distribution on high-temperature mechanical properties of porous alumina ceramics(PAC). In the pr...Fractal theory and regression analysis were employed for the first time to investigate the effect of pore size and pore distribution on high-temperature mechanical properties of porous alumina ceramics(PAC). In the present work, PAC with the comparable porosity, different pore sizes and pore distributions were prepared using carbon black as the pore-forming agent. Particular emphasis in this study was placed on the establishment of correlation between the thermal shock resistance and pore properties. The relationship between fractal dimension(D_f) and thermal shock resistance parameter(R_(st)) in specimens presented the negative power function, indicating that low D_f could benefit the improvement of thermal shock resistance in specimens. The results showed that the increase of pore size and pore sphericity leads to a reduced D_f, the enhanced hot modulus of rupture(HMOR) and R_(st). The decrease of proportion of micro-pores below 2 μm, the increase of mean pore size and pore sphericity could result in the decrease of D_f, and then improve R_(st) and HMOR of specimens. Based on the correlation between R_(st) and pore characteristics, PAC with improved thermal shock resistance could be achieved when their pore structure meets the above features.展开更多
Electrolytic MnO_(2)/Zn batteries have attracted extensive attention for use in large-scale energy storage applications due to their low cost,high output voltage,safety,and environmental friendliness.However,the poor ...Electrolytic MnO_(2)/Zn batteries have attracted extensive attention for use in large-scale energy storage applications due to their low cost,high output voltage,safety,and environmental friendliness.However,the poor electrical conductivity of MnO_(2)limits its deposition and dissolution at large capacities,which leads to sluggish reaction kinetics and drastic capacity decay.Here,we report a theory-guided design principle for an electrolytic MnO_(2)/Zn battery co-regulated with transition metal ions that has improved electrochemical performance in terms of deposition and stripping chemistries.We start with first-principles calculations to predict the electrolytic effects of regulating transition metal ions in the deposition/stripping chemistry of the MnO_(2)cathode.The results indicate that with the simultaneous incorporation of strongly electronegative Co and Ni,the MnO_(2)cathode tends to possess more active electron states,faster charge-transfer kinetics,and better electrical conductivity than either MnO_(2)regulated with Co or Ni on their own,or pristine MnO_(2);hence,this co-regulation is beneficial for the cathode solid/liquid MnO_(2)/Mn2t reactions.We then fabricate and demonstrate a novel Co2t and Ni2t coregulated MnO_(2)/Zn(Co-Ni-MnO_(2)/Zn)battery that yields significantly better electrochemical performance,finding that the synergistic regulation of Co and Ni on MnO_(2)can significantly increase its intrinsic conductivity and achieve high rates and Coulombic efficiencies at large capacities.The aqueous Co-Ni-MnO_(2)/Zn battery exhibits a high rate(10C,100 mA cm^(-2)),high Coulombic efficiency(91.89%),and excellent cycling stability(600 cycles without decay)at a large areal capacity of 10 mAh cm^(-2).Our proposed strategy of co-regulation with transition metal ions offers a versatile approach for improving the electrochemical performance of aqueous electrolytic MnO_(2)/Zn batteries in large-scale energy storage applications.展开更多
基金the financial support from Shenzhen Science and Technology Program (JCYJ20210324142210027, X.D.)the National Natural Science Foundation of China (52103136, 22275028, U22A20153, 22102017, 22302033, and 52106194)+5 种基金the Sichuan Outstanding Young Scholars Foundation (2021JDJQ0013)Natural Science Foundation of Sichuan Province (2022NSFSC1271)Sichuan Science and Technology Program (2023JDRC0082)“Oncology Medical Engineering Innovation Foundation” project of University of Electronic Science and Technology of China and Sichuan Cancer Hospital (ZYGX2021YGCX009)“Medical and Industrial Cross Foundation” of University of Electronic Science and Technology of China and Sichuan Provincial People’s Hospital (ZYGX2021YGLH207)Shandong Key R&D grant (2022CXGC010509)。
文摘Superhydrophobic surface(SHS) has been well developed, as SHS renders the property of minimizing the water/solid contact interface. Water droplets deposited onto SHS with contact angles exceeding 150°, allow them to retain spherical shapes, and the low adhesion of SHS facilitates easy droplet collection when tilting the substrate. These characteristics make SHS suitable for a wide range of applications. One particularly promising application is the fabrication of microsphere and supraparticle materials. SHS offers a distinct advantage as a universal platform capable of providing customized services for a variety of microspheres and supraparticles. In this review, an overview of the strategies for fabricating microspheres and supraparticles with the aid of SHS, including cross-linking process, polymer melting,and droplet template evaporation methods, is first presented. Then, the applications of microspheres and supraparticles formed onto SHS are discussed in detail, for example, fabricating photonic devices with controllable structures and tunable structural colors, acting as catalysts with emerging or synergetic properties, being integrated into the biomedical field to construct the devices with different medicinal purposes, being utilized for inducing protein crystallization and detecting trace amounts of analytes. Finally,the perspective on future developments involved with this research field is given, along with some obstacles and opportunities.
基金supported by a Grant(2024-MOIS35-005)of Policy-linked Technology Development Program on Natural Disaster Prevention and Mitigation funded by Ministry of Interior and Safety(MOIS,Korea).
文摘Cavitation is a common issue in pumps,causing a decrease in pump head,a fall in volumetric efficiency,and an intensification of outlet flow pulsation.It is one of the main hazards that affect the regular operation of the pump.Research on pump cavitation mainly focuses on mixed flow pumps,jet pumps,external spur gear pumps,etc.However,there are few cavitation studies on external herringbone gear pumps.In addition,pumps with different working principles significantly differ in the flow and complexity of the internal flow field.Therefore,it is urgent to study the cavitation characteristics of external herringbone gear pumps.Compared with experimentalmethods,visual research and cavitation area identification are achieved through computation fluid dynamic(CFD),and changing the boundary conditions and shape of the gear rotor is easier.The simulation yields a head error of only 0.003%under different grid numbers,and the deviation between experimental and simulation results is less than 5%.The study revealed that cavitation causes flow pulsation at the outlet,and the cavitation serious area is mainly distributed in the meshing gap and meshing area.Cavitation can be inhibited by reducing the speed,increasing the inlet pressure,and changing the helix angle can be achieved.For example,when the inlet pressure is 5 bar,the maximumgas volume fraction in themeshing area is less than 50%.These results provide a reference for optimizing the design and finding the optimal design parameters to reduce or eliminate cavitation.
文摘In this paper, we mainly study the orbital graphs of primitive groups with the socle A<sub>7</sub> x A<sub>7 </sub>which acts by diagonal action. Firstly, we calculate the element conjugate classes of A7</sub>, then we discuss the stabilizer of two points in A7</sub>. Finally, according to the relation between suborbit and orbital, we obtain the orbitals, and determine the orbital graphs.
基金supported by the National Natural Science Foundation of China(6130501761304264+1 种基金61402203)the Natural Science Foundation of Jiangsu Province(BK20130154)
文摘In this paper, we consider the problem of irregular shapes tracking for multiple extended targets by introducing the Gaussian surface matrix(GSM) into the framework of the random finite set(RFS) theory. The Gaussian surface function is constructed first by the measurements, and it is used to define the GSM via a mapping function. We then integrate the GSM with the probability hypothesis density(PHD) filter, the Bayesian recursion formulas of GSM-PHD are derived and the Gaussian mixture implementation is employed to obtain the closed-form solutions. Moreover, the estimated shapes are designed to guide the measurement set sub-partition, which can cope with the problem of the spatially close target tracking. Simulation results show that the proposed algorithm can effectively estimate irregular target shapes and exhibit good robustness in cross extended target tracking.
基金supported by funding from the National Key R&D Program of China(No.2019YFC1711000)the Shenzhen Municipal Government of China(grants JCYJ20170817145512476 and JCYJ20160510141910129)+1 种基金the Guangdong Provincial Key Laboratory of Genome Read and Write(grant 2017B030301011)the NMPA Key Laboratory for the Rapid Testing Technology of Drugs.
文摘Averrhoa carambola is commonly known as star fruit because of its peculiar shape,and its fruit is a rich source of minerals and vitamins.It is also used in traditional medicines in countries such as India,China,the Philippines,and Brazil for treating various ailments,including fever,diarrhea,vomiting,and skin disease.Here,we present the first draft genome of the Oxalidaceae family,with an assembled genome size of 470.51 Mb.In total,24,726 protein-coding genes were identified,and 16,490 genes were annotated using various well-known databases.The phylogenomic analysis confirmed the evolutionary position of the Oxalidaceae family.Based on the gene functional annotations,we also identified enzymes that may be involved in important nutritional pathways in the star fruit genome.Overall,the data from this first sequenced genome in the Oxalidaceae family provide an essential resource for nutritional,medicinal,and cultivational studies of the economically important star-fruit plant.
文摘In this work, the magnesium aluminum spinel (MgAl2O4) was prepared by Mg and Al as precursors through a method of sol-gel subsequent with high temperature calcination. The wide range of synthetic conditions, including organic alcohols, ammonia content, dispersant, alkoxide concentration, hydrolysis time, hydrolysis temperature and calcination temperature were screened over as-prepared samples. This work provides a necessary experimental basis for the synthesis of MgAl2O4 with uniform particle size of spherical structure, which has a potential to be used in many industrial and military applications.
基金supported by the National Natural Science Foundation of China(22288201,22273092,22322304)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0450101)+2 种基金the Youth Innovation Promotion Association CAS(2019441)the Innovation Program for Quantum Science and Technology(2021ZD0303306)USTC Tang Scholar。
文摘Cluster-assembled materials have attracted particular attention for their complex hierarchical structures and unique properties.However,the majority of cluster-based assemblies developed so far are either non-magnetic or only exhibit magnetic ordering with a relatively low Curie temperature,limiting their applications in spintronics.Thus,two-dimensional(2D)cluster-assembled materials with room-temperature magnetism remain highly desirable.For this purpose,based on first principles calculations,we design a series of thermodynamically stable 2D cluster-based metal-organic frameworks(MOFs)Fe_(n)-(pyz)(n=1-6)by utilizing Fenmetal clusters as nodes and nitrogen-containing pyrazine ligands as organic linkers.These 2D cluster-based MOFs exhibit robust ferrimagnetic ordering due to the strong d-p direct exchange interaction between d-electron spin of Fe_(n)(n=1-6)clusters and charge transfer-induced p-electron spin of pyrazine ligands.In particular,the ferrimagnetic Curie temperatures are well above room temperature(up to 836 K).Additionally,altering the size of Fe_(n)clusters in Fe_(n)-(pyz)(n=1-6)MOFs results in diverse functional spintronic properties,including bipolar magnetic semiconductors,half semiconductors and Dirac half metals.Moreover,these 2D assembled MOFs possess sizable magnetic anisotropy energies,up to 9.16 me V per formula.
基金supported by the National Natural Science Foundation of China(Nos.52003035,52203135 and 51973023)the CHN Energy Group Project(No.GJNY-21-183).
文摘Passive daytime radiative cooling(PDRC)technology is emerging as one of the most promising solutions to the global problem of spacing cooling,but its practical application is limited due to reduced cooling effectiveness caused by daily wear and tear,as well as dirt contamination.To tackle this problem,we report a novel strategy by introducing a renewable armor structure for prolonging the anti-fouling and cooling effectiveness properties of the PDRC coatings.The armor structure is designed by decorating fluorinated hollow glass microspheres(HGM)inside rigid resin composite matrices.The HGM serve triple purposes,including providing isolated cavities for enhanced solar reflectance,reinforcing the matrices to form robust armored structures,and increasing thermal emittance.When the coatings are worn,the HGM on the surface expose their concave cavities with numerous hydrophobic fragments,generating a highly rough surface that guarantee the superhydrophobic function.The coatings show a high sunlight reflectance(0.93)and thermal emittance(0.94)in the long-wave infrared window,leading to a cooling of 5℃ below ambient temperature under high solar flux(∼900 W/m^(2)).When anti-fouling functions are reduced,they can be regenerated more than 100 cycles without compromising the PDRC function by simple wearing treatment.Furthermore,these coatings can be easily prepared using a one-pot spray method with low-cost materials,exhibit strong adhesion to a variety of substrates,and demonstrate exceptional environmental stability.Therefore,we anticipate their immediate application opportunities for spacing cooling.
基金financially supported by the National Natural Science Foundation of China(Nos.22279097,52172217)Natural Science Foundation of Guangdong Province(No.2021A1515010144)Shenzhen Science and Technology Program(No.JCYJ20210324120400002).
文摘Lithium(Li)dendrite issue,which is usually caused by inhomogeneous Li nucleation and fragile solid electrolyte interphase(SEI),impedes the further development of high-energy Li metal batteries.However,the integrated construction of a high-stable SEI layer that can regulate uniform nucleation and facilitate fast Li-ion diffusion kinetics for Li metal anode still falls short.Herein,we designed an artificial SEI with hybrid ionic/electronic interphase to regulate Li deposition by in-situ constructing metal Co clusters embedded in LiF matrix.The generated Co and LiF both enable fast Li-ion diffusion kinetics,meanwhile,the lithiophilic properties of Co clusters can serve as Li-ion nucleation sites,thereby contributing to uniform Li nucleation and non-dendritic growth.As a result,a dendrite-free Li deposition with a low overpotential(16.1 mV)is achieved,which enables an extended lifespan over 750 h under strict conditions.The full cells with high-mass-loading LiFePO_(4)(11.5 mg/cm^(2))as cathodes exhibit a remarkable rate capacity of 84.1 mAh/g at 5 C and an improved cycling performance with a capacity retention of 96.4%after undergoing 180 cycles.
基金Fundamental Research Program of Shanxi Province of China(No.20210302123037)Research Project Supported by Shanxi Scholarship Council of China(No.2022-136)Specialized Research Fund for Sanjin Scholars Program of Shanxi Province of China.
文摘The chemoselective hydrogenation of structurally diverse nitroaromatics is a challenging process.Generally,catalyst activity tends to decrease when excellent selectivity is guaranteed.We here present a novel photocatalyst combining amino-functionalized carbon dots(N-CDs)with copper selenite nanoparticles(N-CDs@CuSeO_(3))for simultaneously improving selectivity and activity.Under visible light irradiation,the prepared N-CDs@CuSeO_(3)exhibits 100%catalytic selectivity for the formation of 4-aminostyrene at full conversion of 4-nitrostyrene in aqueous solvent within a few minutes.Such excellent photocatalytic performance is mainly attributed to the precise control of the hydrogen species released from the ammonia borane by means of light-converted electrons upon N-CDs@CuSeO_(3).Besides,the defect states at the interface of N-CDs and CuSeO_(3)enable holes to be trapped for promoting separation and transfer of photogenerated charges,allowing more hydrogen species to participate in catalytic reaction.
基金supported by the key research and development program of Shanxi Province(International Cooperation)(No.201903D421082)Natural Science Foundation of Shanxi Province(No.20210302123029)+1 种基金the National Natural Science Foundation of China(Nos.51602292 and 22105181)Scientific and Technological Innovation Programs of Higher Education in Shanxi(Nos.2019L0589 and 2020L0279).
文摘Presently,interfacial solar water evaporation(ISWE)is now injecting new vitality into the field of water remediation.However,during the ISWE process,the nonvolatile pollutants might be concentrated in residual water,and further contaminate the environment.Preparing advanced photothermal materials is in need to get comprehensive purification of various pollutants in residual water.Herein,we report a facile laser thermal method to prepare Cu_(2−x)S/sulfur/reduced graphene oxide(Cu_(2−x)S/S/rGO)nanocomposites for realizing all-round residual water remediation during the ISWE process.The as-prepared Cu2−xS/S/rGO nanocomposites demonstrated excellent photothermal and photocatalytic properties.Through blending with GO nanosheets having excellent adsorption capacity,the synergetic effect of photothermal,photocatalytic,and adsorption properties resulted in highly efficient purification of rhodamine B,bacterial,and heavy metal ions in residual water during the ISWE process.The experimental results also showed that,increasing solar light intensity can promote the residual water remediation,but ultrafast water evaporation under high light intensity may deteriorate the purifying effect.This report may pave a new way to prepare multifunctional materials for water remediation through the ISWE technology.
基金supported by the National Natural Science Foundation of China(No.52172217)Natural Science Foundation of Guangdong Province(No.2021A1515010144)+4 种基金Natural Science Foundation of Shanghai(No.17ZR1414100)the Shenzhen Science and Technology Program(No.JCYJ20210324120400002)G.M.Z.appreciates the support from the National Key Research and Development Program of China(No.2019YFA0705700)Joint Funds of the National Natural Science Foundation of China(No.U21A20174)the Overseas Research Cooperation Fund of Tsinghua Shenzhen International Graduate School.
文摘Transition metal dichalcogenides(TMDs)have been regarded as promising cathodes for aqueous zinc-ion batteries(AZIBs)but suffer from sluggish reaction kinetics due to their poor conductivity and the strong electrostatic interaction between Zn-ion and cathode materials.Herein,a well-defined structure with MoSSe nanosheets vertically anchored on graphene is used as the cathode for AZIBs.The dissolution of Se into MoS2 lattice together with heterointerface design via developing C-O-Mo bonds improves the inherent conductivity,enlarges interlayer spacing,and generates abundant anionic vacancies.As a result,the Zn2+intercalation/deintercalation process is greatly improved,which is confirmed by theoretical modeling and ex-situ experimental results.Remarkably,the assembled AZIBs exhibit high-rate capability(124.2 mAh·g^(−1)at 5 A·g^(−1))and long cycling life(83%capacity retention after 1,200 cycles at 2 A·g^(−1)).Moreover,the assembled quasi-solid-state Zn-ion batteries demonstrate a stable cycling performance over 100 cycles and high capacity retention over 94%after 2,500 bending cycles.This study provides a new strategy to unlock the electrochemical activity of TMDs via interface design and atomic engineering,which can also be applied to other TMDs for multivalent batteries.
基金This study was financially supported by the National Natural Science Foundation of China(Grant Nos.51408295 and 41907364)National Key R&D Program of China(Grant Nos.2022YFB3805104 and 2021YFB3801400)+1 种基金Key Research and Development Project of Shandong Province(Grant Nos.2017GSF217013 and 2018GSF117007)Major Scientific and Technological Innovation Project of Shandong Province(Grant No.2021CXGC011206).
文摘Herein,Cu–Al bimetallic oxide was synthesized and mixed with mesoporous silica spheres via a simple hydrothermal method.The prepared sample was then analyzed and employed to activate potassium peroxydisulfate for bisphenol A removal.Based on the results of X-ray diffraction,scanning electron microscopy,and energy dispersion spectroscopy,Cu–Al bimetallic oxide was determined as CuO-Al2O3,and mesoporous silica spheres were found around the these particles.At 30 min,a bisphenol A degradation level of 90%was achieved,and it remained at over 60%after five consecutive cycles,indicating the catalyst’s superior capacity and stability.In terms of removal performance,the radical pathway(including■OH•,and■)and singlet oxygen(■)bisphenol A,potassium peroxydisulfate,and the catalyst played a dominant role.The introduction of Al2O3 promoted the formation of surface oxygen vacancies,which improved ligand complex formation between potassium peroxydisulfate and the catalyst,thereby facilitating electron migration.Furthermore,mesoporous silica spheres augment not only enhanced bisphenol A adsorption but also alleviated Cu leaching.Overall,this work is expected to provide significant support for the rational development of catalysts with high catalytic activity for persulfate activation via surface electron migration.
基金supported by Shaanxi Science and Technology Co‑ordination and Innovation Project under Grant(number 2015KTCL03‑03)。
文摘Context:As the increasing number of pet canines,the identification of canine has attracted much attentions in the forensic field,however,the genetic diversities of pet canines still remained unknown.Aims:To explore genetic polymorphisms of 19 short tandem repeat(STR)loci and genetic relationships between the two studied canine groups and reference group.Subjects and Methods:In the present study,genetic polymorphisms of 19 STR loci and a sex-linked zinc finger locus were analyzed in a total of 594 canines in Standard Poodle and Bichon Frise groups from China.Results:A total of 166,159 alleles were observed in the Standard Poodle,Bichon Frise groups with the corresponding allelic frequencies ranging from 0.0030-0.6108 to 0.0012-0.6148,respectively.The combined discrimination power and probability of exclusion of 19 STR loci in Standard Poodle and Bichon Frise groups were 0.9999999999999497,0.999962884;and 0.99999999999999995,0.999965955,respectively.Furthermore,the genetic distances between the two canine groups and Labrador retriever group were calculated,and the results indicated that Standard Poodle and Bichon Frise groups showed a closer genetic relationship,while the two canine groups had distant genetic relationships with Labrador retriever group.The result of population genetic structure revealed that genetic component distributions in the three canine groups were different.The predicted accuracies of the constructed random forest prediction model for three validation sets(25%individuals randomly selected from three populations with 808 individuals)were higher than 0.9,especially for the individuals in validation set from the Bichon Frise group is 1.Conclusions:The 19 STR loci could be used for individual identification,canine breed identification and paternity testing in the two canine groups.
文摘Chemistry,as a central science,plays an indispensable role in creating new substances,making new materials,and improving people’s lives.Chemistry has always been changing throughout time toward precision,particularly in recent years.Precision chemistry means greater efficiency,superior performance,and increased environmental friendliness.This is the dream of all chemists and is driven by both internal and external forces.Internally,chemical research has evolved beyond the molecular level to explore the constructions,properties,and intermolecular interactions of macromolecules,supramolecules,molecular aggregates,and even living systems;it now focuses more on complex systems and multiscale processes.Externally,it comes from the requirements for the creation of new substances beyond the“trial-and-error”research paradigm to achieve sustainable development of human society and to fundamentally solve energy,environmental,and health problems.Precision chemistry will have a significant impact on many areas of scientific research.
基金financially supported by the National Basic Research Program of China(Nos.2012CB619500 and 2010CB731700)the National Natural Science Foundation of China(No.51375503)
文摘The influence of Mg content on the microstructures and mechanical properties at room temperatures of Al-3.5Cu-(0.71-1.81)Mg alloys was studied.Precipitation phases in the alloys were identified by TEM and HRTEM.The results show that when Mg contents increase from 0.71 to 1.81 wt%,the precipitates are transformed from S,S″,Ω,and θ' phases to Sand S′phases,and Ω phase is first observed in Al-3.48Cu-0.71 Mg alloy with Cu/Mg mass ratio of 5 during the conventional aging heat treatment(190 ℃/12 h).Regard to aging hardness effect of the tested alloys,the hardness of the alloys improves with the increase of Mg content,but the increases become slow when Mg content is greater than 1.35 wt%.
基金funded by China Postdoctoral Science Foundation(Grant No.2017M610085)National Natural Science Foundation of China(NSFC,Nos.51702184 and 51572140)
文摘Low-cost porous ceramic microspheres from waste gangue were prepared by simple spray drying and subsequent calcination. Effects of calcination temperature on phase and microstructure evolution, specific surface area, pore structure, and dye adsorption mechanism of the microspheres were investigated systematically. Results showed that the microspheres were spherical, with some mesopores both on the surface and inside the spheres. The phase kept kaolinite after calcined at 800 and 900 ℃ and transformed into mullite at 1000 ℃. The microspheres calcined at 800 ℃ showed larger adsorption capacity and removal efficiency than those calcined at higher temperatures. Methylene blue(MB) and basic fuchsin(BF) removal efficiency reached 100% and 99.9% with the microsphere dosage of 20 g/L, respectively, which was comparable to that of other low-cost waste adsorbents used to remove dyes in the literature. Adsorption kinetics data followed the pseudosecond-order kinetic model, and the isotherm data fit the Langmuir isotherm model. The adsorption process was attributed to multiple adsorption mechanisms including physical adsorption, hydrogen bonding, and electrostatic interactions between dyes and gangue microspheres. The low-cost porous microspheres with excellent cyclic regeneration properties are promising absorbent for dyes in wastewater filtration and adsorption treatment.
基金financially support from the National Basic Research Program of China(973 Program,Grant No.2012CB722702)the National Natural Science Foundation of China(Grant No.51572140)the China Postdoctoral Science Foundation(Grant No.2017M610085),and the China Postdoctoral Science Foundation(Grant No.2016T90092)
文摘Fractal theory and regression analysis were employed for the first time to investigate the effect of pore size and pore distribution on high-temperature mechanical properties of porous alumina ceramics(PAC). In the present work, PAC with the comparable porosity, different pore sizes and pore distributions were prepared using carbon black as the pore-forming agent. Particular emphasis in this study was placed on the establishment of correlation between the thermal shock resistance and pore properties. The relationship between fractal dimension(D_f) and thermal shock resistance parameter(R_(st)) in specimens presented the negative power function, indicating that low D_f could benefit the improvement of thermal shock resistance in specimens. The results showed that the increase of pore size and pore sphericity leads to a reduced D_f, the enhanced hot modulus of rupture(HMOR) and R_(st). The decrease of proportion of micro-pores below 2 μm, the increase of mean pore size and pore sphericity could result in the decrease of D_f, and then improve R_(st) and HMOR of specimens. Based on the correlation between R_(st) and pore characteristics, PAC with improved thermal shock resistance could be achieved when their pore structure meets the above features.
基金This work was financially supported by the USTC(No.KY2060000150)Natural Science Foundation of Guangdong Province(No.2021A1515010144)National Natural Science Foundation of China(No.51602009).
文摘Electrolytic MnO_(2)/Zn batteries have attracted extensive attention for use in large-scale energy storage applications due to their low cost,high output voltage,safety,and environmental friendliness.However,the poor electrical conductivity of MnO_(2)limits its deposition and dissolution at large capacities,which leads to sluggish reaction kinetics and drastic capacity decay.Here,we report a theory-guided design principle for an electrolytic MnO_(2)/Zn battery co-regulated with transition metal ions that has improved electrochemical performance in terms of deposition and stripping chemistries.We start with first-principles calculations to predict the electrolytic effects of regulating transition metal ions in the deposition/stripping chemistry of the MnO_(2)cathode.The results indicate that with the simultaneous incorporation of strongly electronegative Co and Ni,the MnO_(2)cathode tends to possess more active electron states,faster charge-transfer kinetics,and better electrical conductivity than either MnO_(2)regulated with Co or Ni on their own,or pristine MnO_(2);hence,this co-regulation is beneficial for the cathode solid/liquid MnO_(2)/Mn2t reactions.We then fabricate and demonstrate a novel Co2t and Ni2t coregulated MnO_(2)/Zn(Co-Ni-MnO_(2)/Zn)battery that yields significantly better electrochemical performance,finding that the synergistic regulation of Co and Ni on MnO_(2)can significantly increase its intrinsic conductivity and achieve high rates and Coulombic efficiencies at large capacities.The aqueous Co-Ni-MnO_(2)/Zn battery exhibits a high rate(10C,100 mA cm^(-2)),high Coulombic efficiency(91.89%),and excellent cycling stability(600 cycles without decay)at a large areal capacity of 10 mAh cm^(-2).Our proposed strategy of co-regulation with transition metal ions offers a versatile approach for improving the electrochemical performance of aqueous electrolytic MnO_(2)/Zn batteries in large-scale energy storage applications.