Ni^(2+)and Cd^(2+)in wastewater accumulated through the ecological chain and could jeopardize human health.Adsorption of Ni^(2+)and Cd^(2+)from wastewater using recovered perlite was an important way to solve the prob...Ni^(2+)and Cd^(2+)in wastewater accumulated through the ecological chain and could jeopardize human health.Adsorption of Ni^(2+)and Cd^(2+)from wastewater using recovered perlite was an important way to solve the problem of resource utilization of solid waste from agar production.Our previous study confirmed that recovered perlite from agar extraction residue had better pore size and specific surface area than commercial perlite.However,the adsorption efficiency and adsorption mechanism of recovered perlite were the main factors limiting its adsorption application.The adsorption process of Ni^(2+)and Cd^(2+)by recovered perlite in aqueous solution was described by the pseudo-second-order kinetic equation,and the relevant adsorption mechanism was mainly chemisorption.Compared with commercial perlite,the adsorption removal rate of Ni^(2+)and Cd^(2+)by enzymatic recovered perlite could reach 92.9%and 89.2%,respectively,and were improved by 12.63%and 13.03%.Langmuir isothermal adsorption model could better describe the isothermal adsorption process of recovered perlite on heavy metal Ni^(2+)and Cd^(2+),and the relevant adsorption mechanism was mainly monolayer adsorption.The X-ray photoelectron spectroscopy(XPS)results indicated that the decrease of Si—O Si^(2+)hydroxyl coordination bond and the increase of C—Si bond might make the binding effect of recovered perlite with heavy metals stronger.The competitive adsorption of Ni^(2+)and Cd^(2+)by recovered perlite was still dominated by chemisorption and monolayer adsorption.This study was expected to provide a theoretical basis and technical support for the removal of Ni^(2+)and Cd^(2+)from wastewater using recovered perlite from seaweed residue.展开更多
High qualityβ-Ga_(2)O_(3)single crystal nanobelts with length of 2−3 mm and width from tens of microns to 132μm were synthesized by carbothermal reduction method.Based on the grown nanobelt with the length of 600μm...High qualityβ-Ga_(2)O_(3)single crystal nanobelts with length of 2−3 mm and width from tens of microns to 132μm were synthesized by carbothermal reduction method.Based on the grown nanobelt with the length of 600μm,the dual-Schottky-junctions coupling device(DSCD)was fabricated.Due to the electrically floating Ga_(2)O_(3)nanobelt region coupling with the double Schottky-junctions,the current I_(S2)increases firstly and rapidly reaches into saturation as increase the voltage V_(S2).The saturation current is about 10 pA,which is two orders of magnitude lower than that of a single Schottky-junction.In the case of solar-blind ultraviolet(UV)light irradiation,the photogenerated electrons further aggravate the coupling physical mechanism in device.I_(S2)increases as the intensity of UV light increases.Under the UV light of 1820μW/cm^(2),I_(S2)quickly enters the saturation state.At V_(S2)=10 V,photo-to-dark current ratio(PDCR)of the device reaches more than 104,the external quantum efficiency(EQE)is 1.6×10^(3)%,and the detectivity(D*)is 7.5×10^(12)Jones.In addition,the device has a very short rise and decay times of 25−54 ms under different positive and negative bias.DSCD shows unique electrical and optical control characteristics,which will open a new way for the application of nanobelt-based devices.展开更多
Sn doping is an effective way to improve the response rate of Ga_(2)O_(3) film based solar-blind detectors. In this paper,Sn-doped Ga_(2)O_(3) films were prepared on a sapphire substrate by radio frequency magnetron s...Sn doping is an effective way to improve the response rate of Ga_(2)O_(3) film based solar-blind detectors. In this paper,Sn-doped Ga_(2)O_(3) films were prepared on a sapphire substrate by radio frequency magnetron sputtering. The films were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and ultraviolet visible spectroscopy, and the effect of annealing atmosphere on the properties of films was studied. The Ga_(2)O_(3) films changed from amorphous to β-Ga_(2)O_(3) after annealing at 900 °C. The films were composed of micro crystalline particles with a diameter of about 5–20 nm.The β-Ga_(2)O_(3) had high transmittance for wavelengths above 300 nm, and obvious absorption for solar-blind signals at 200–280 nm.The metal semiconductor metal type solar-blind detectors were prepared. The detector based on Sn-doped β-Ga_(2)O_(3) thin film annealed in N_2 has the best response performance to 254 nm light. The photo-current is 10 μA at 20 V, the dark-current is 5.76 pA,the photo dark current ratio is 1.7 × 10~6, the response rate is 12.47 A/W, the external quantum efficiency is 6.09 × 10~3%, the specific detection rate is 2.61 × 10~(12) Jones, the response time and recovery time are 378 and 90 ms, respectively.展开更多
Peroxidase plays an important role in living systems;however,its storage difficulty and easy inactivation have limited its applications in complex environments.To address these problems,herein,we proposed a method to ...Peroxidase plays an important role in living systems;however,its storage difficulty and easy inactivation have limited its applications in complex environments.To address these problems,herein,we proposed a method to synthesize peroxidase mimics by amination,carbonization,and Fe^(3+)-doping of industrial alkali lignin.The Fe^(3+)-doped lignin-based peroxidase mimic(Fe-LPM),with active centers of coordination between Fe^(3+)and N atoms,showed higher tolerance to pH value and temperature than natural peroxidase.Using Fe-LPM,10-100 mmol/L of H_(2)O_(2) and glucose could be colorimetrically detected with the lowest detection limits of 80μmol/L and 1.5 mmol/L and visual detection limits of 1.0 mmol/L and 10 mmol/L,respectively.The Fe-LPM maintained peroxidase-like activity after 10 cycles and could even be used for H_(2)O_(2) detection in practical samples.This work not only provides a new approach to synthesize peroxidase mimics using biomass materials but also promotes the high-value utilization of lignin.展开更多
This study aimed to improve the thermostability of arylsulfatase from Pseudoalteromonas carrageenovora. A library of P. carrageenovora arylsulfatase mutants was constructed by introducing random mutagenesis using erro...This study aimed to improve the thermostability of arylsulfatase from Pseudoalteromonas carrageenovora. A library of P. carrageenovora arylsulfatase mutants was constructed by introducing random mutagenesis using error-prone PCR. After screening, two mutants of H260L and D84A/H260L showed enhanced thermal stability than the wild-type predecessor (WT). Site-directed mutagenesis demonstrated that only amino acid residue at Position 260 plays an important role in the thermostability of P. carrageenovora arylsulfatase. Thermal inactivation analysis showed that the half-life (t1/2) values at 55°C for H260L, H260I, H260Q, H260F and H260R were 40.6, 48.4, 30.9, 29.1 and 34.5 min, respectively, while that of WT was 9.1 min. Structure modeling demonstrated that the additional hydrogen bonds and/or optimization of surface charge-charge interactions could be responsible for the increased thermostability imparted by H260L, H260I, H260Q, H260F and H260R.展开更多
Event cameras,characterized by their low latency,large dynamic range,and extremely high temporal resolution,have recently received increasing attention.These features make them particularly well-suited for virtual/aug...Event cameras,characterized by their low latency,large dynamic range,and extremely high temporal resolution,have recently received increasing attention.These features make them particularly well-suited for virtual/augmented reality(VR/AR)applications.To facilitate the development of three-dimensional(3D)perception and navigation algorithms in VR/AR applications using event cameras,we introduce the Stereo Event camera dataset for Virtual and Augmented Reality(SEVAR),which comprises a wide variety of head-mounted indoor sequences,including scenarios with rapid motion and a large dynamic range.展开更多
An agarase gene containing 1 302 bp was cloned from Microbulbifer sp. AG1. It encoded a mature protein of 413 amino acids plus a 20-residue signal peptide. The recombinant enzyme without the signal peptide was express...An agarase gene containing 1 302 bp was cloned from Microbulbifer sp. AG1. It encoded a mature protein of 413 amino acids plus a 20-residue signal peptide. The recombinant enzyme without the signal peptide was expressed and purified from Escherichia coli BL21(DE3). When agarose was used as a substrate, the optimal temperature and pH for the enzyme were 60℃ and 7.5, respectively. The recombinant agarase showed excellent thermostability with 67% and 19% of residual activities after incubation at 50℃ and 60℃ for 1 h, respectively.Except SDS, the recombinant agarase had a relatively good resistance against the detected inhibitors, detergents and urea denaturant. Thin layer chromatography analysis and enzyme assay using p-nitrophenyl-α/β-Dgalactopyranoside revealed that the recombinant agarase was a β-agarase that degraded agarose into neoagarotetraose as the main end product. The enzymatic hydrolysis products with different degree of polymerization exhibited the antioxidant activities.展开更多
It has become a research hotspot to explore raw material substitutes of concrete.It is important to research the mechanical properties of self-compacting concrete(SCC)with slag powder(SP)and rubber particle(RP)replaci...It has become a research hotspot to explore raw material substitutes of concrete.It is important to research the mechanical properties of self-compacting concrete(SCC)with slag powder(SP)and rubber particle(RP)replacing cement and coarse aggregate,respectively.12 kinds of composite modified self-compacting concrete(CMSCC)specimens were prepared by using 10%,20%and 30%SP and 30%,40%,50%and 60%RP.The rheological properties,mechanical properties and microstructure of the CMSCC were investigated.Results indicate that the workability,compressive strength,splitting tensile strength and flexural strength of CMSCC prepared by 20%SP and less than 40%RP are improved.In order to maximize the utilization of waste materials,20%SP and 40%RP can be used as the optimal ratio of the combined modifier.The microstructure shows that the addition of proper amount of SP is conducive to the formation of increasingly more uniform C-S-H gel.C-SH gel can fill the internal pores of the sample and enhance the adhesion between the aggregate,thus improving the mechanical properties of CMSCC.RP has a rougher surface and lower density and stiffness,which inhibits the workability and mechanical properties of CMSCC.The above research results have important theoretical and practical significance for the selection of raw materials of self-compacting concrete and the rational use of industrial wastes.展开更多
Graphene’s optical absorption coefficient increases linearly with the number of layers making it more effective in the construction of optical tuning graphene-based devices. Refractive index(RI) is one of the importa...Graphene’s optical absorption coefficient increases linearly with the number of layers making it more effective in the construction of optical tuning graphene-based devices. Refractive index(RI) is one of the important optical parameters of the graphene for accurately describing its optical characteristics and further applications. In view of the RI research of the multilayer graphene is lacking and existing measurement methods are complicated. Optical power tuning RI of multilayer graphene is investigated using a simple measurement and no temperature cross sensitivity all optical fiber sensing structure.Optical power tuning RI characteristics of multilayer graphene are studied by tuning the introducing broad band light power from 0.57 mW to 22.7 m W. Different thickness graphene coating shows different tuning efficiency. At 4.86-μm thickness,a 3.433-nm Bragg wavelength shift is obtained with 156.2-pm/mW wavelength versus optical power tuning sensitivity corresponding to 3.25×10~3 RI change and 0.154 URI/W(URI, unit of RI) RI optical power tuning efficiency.展开更多
By using angle-resolvea photoemission spectroscopy(ARPES) combined with the first-principies electronic structure calculations,we report the quantized states at the surface of a single crystal 2 H-TaSe_(2).We have obs...By using angle-resolvea photoemission spectroscopy(ARPES) combined with the first-principies electronic structure calculations,we report the quantized states at the surface of a single crystal 2 H-TaSe_(2).We have observed sub-bands of quantized states at the three-dimensional Brillouin zone center due to a highly dispersive band with light effective mass along k_(z) direction.The quantized sub-bands shift upward towards E_(F) while the bulk band at Γ shifts downward with the decrease of temperature across charge density wave(CDW) formation.The band shifts could be intimately related to the CDW.While neither the two-dimensional Fermi-surface nesting nor purely strong electron-phonon coupling can explain the mechanism of CDW in 2 H-TaSe_(2),our experiment may ignite the interest in understanding the CDW mechanism in this family.展开更多
With the increasing requirements of the multicast services in the whole data traffic service, the optical multicast technology becomes a key technology supporting wide bandwidth and high speed multicasting communicati...With the increasing requirements of the multicast services in the whole data traffic service, the optical multicast technology becomes a key technology supporting wide bandwidth and high speed multicasting communication. The transmission efficiency, capacity and robustness of optical multicast network can be further improved by introducing network coding technology into optical multicast networks. Meanwhile, facing to demand of emerging rate-variable multi-granularity multicast service, a multi-path transmission scheme based on network coding for routing and spectrum allocation (RSA) is proposed. It can not only allocate spectrum resources effectively and flexibly for various-rate multicast traffic, but also balance the network load, improve network throughput and reduce transmission blocking rate. In this paper, RSA problem is decomposed into two subproblems, namely routing allocation based on network coding and spectrum allocation based on maximum spectrum first (MSF) strategy, which are solved sequentially. Simulation experiments are carried out to analyze transmission performance with proposed RSA scheme. The simulation results show that the proposed RSA mechanism can allocate spectrum resources efficiently and flexibly for multi-granularity multicast traffic. Compared with RSA schemes based on shortest path tree (SPT) and minimal spanning tree (MST), the proposed RSA scheme is more efficient for spectrum resource utilization and load balancing, and spectrum resource is saved more than 20%.展开更多
The emissions trading is a kind of sustainable development measures that is based on market mechanism, and its growing is closely connected with the market development level. The level of American emissions permits ma...The emissions trading is a kind of sustainable development measures that is based on market mechanism, and its growing is closely connected with the market development level. The level of American emissions permits market is relatively high, and also predicts the prospect of professional bourse pattern. Most of emissions permits transactions in China are organized by government environment authority, which make it lack of market function. Emissions permits is a kind of property rights. It is important and profitable, while the emissions trading market obviously possesses the two-class of original allocation and second-time transfer. But there are some decisive differences between emissions permits and ordinary transaction object, so the specialized bourse for emissions trading should be built.展开更多
Comprehensive Summary,In nature,fishes have evolved functional skins with effective hydrodynamic performance and anti-fouling,facilitating predation and escaping from predators.Although a large number of fish scale-in...Comprehensive Summary,In nature,fishes have evolved functional skins with effective hydrodynamic performance and anti-fouling,facilitating predation and escaping from predators.Although a large number of fish scale-inspired structured surfaces have been explored,the incorporation of mucus on the structured surfaces has been largely ignored.Inspired by the skin of Osteichthyes fishes,a Janus hydrogel coating(JHC)is successfully prepared by a two-step UV light irradiation at room temperature.The bottom side of JHC(STH)achieves a shear adhesive strength of 103.3±17.5 kPa and can strongly adhere to a large variety of surfaces,including metals,ceramic and polymers.The top surface of JHC(SLH)replicates the structure of cycloid scales,while the nature of hydrogel mimics the mucus on fish skin.SLH possesses prominent mechanical,anti-swelling,anti-fouling and drag reduction properties.The design strategy for JHC has potential applications in numerous fields,like,pipeline transportation,bioengineering,and shipping industry.展开更多
In view of the problem that the sensing characteristics of the multi-mode interferometric fiber sensors cannot be accurately analyzed,an analysis method based on the fast Fourier transform(FFT)and inverse fast Fourier...In view of the problem that the sensing characteristics of the multi-mode interferometric fiber sensors cannot be accurately analyzed,an analysis method based on the fast Fourier transform(FFT)and inverse fast Fourier transform(IFFT)is proposed and demonstrated theoretically and experimentally.The suitabilities of the rectangular window function with the narrow main lobe(high spectrum resolution)and low side lobe(high main mode energy leakage)and the Hanning window function with the wide main lobe(low spectrum resolution)and high side lobe(high energy concentration)in this kind of sensor analysis are discussed,respectively.This method can not only realize the sensing performance analysis of the various modes,but also overcome the inconsistency of the different interference wavelength(dip)sensing characteristics in the conventional analysis methods.At the same time,this method is also beneficial to solve the repetitive problem of such sensors.展开更多
Ultralong ZnO nanocombs have been synthesized on silicon substrates with a high growth rate of~7μm/s using a simple“thermal evaporation and condensation”method promoted by Cu catalysts.The lengths of the ZnO nanoco...Ultralong ZnO nanocombs have been synthesized on silicon substrates with a high growth rate of~7μm/s using a simple“thermal evaporation and condensation”method promoted by Cu catalysts.The lengths of the ZnO nanocombs range from several millimeters to more than one centimeter and the diameters of the branches are about 300 nm.The growth mechanism of the ultralong nanocombs and the catalytic behavior of the copper are discussed.The nanocombs were readily separated and their applications as optical polarizer and grating were investigated.The results show that the ultralong ZnO nanocombs can act as effective optical components in miniaturized integrated optics systems.展开更多
基金financially supported by National Natural Science Foundation of China(22038012,32172339,and 22178142)National Key Research and Development Program(2023YF D2100603)。
文摘Ni^(2+)and Cd^(2+)in wastewater accumulated through the ecological chain and could jeopardize human health.Adsorption of Ni^(2+)and Cd^(2+)from wastewater using recovered perlite was an important way to solve the problem of resource utilization of solid waste from agar production.Our previous study confirmed that recovered perlite from agar extraction residue had better pore size and specific surface area than commercial perlite.However,the adsorption efficiency and adsorption mechanism of recovered perlite were the main factors limiting its adsorption application.The adsorption process of Ni^(2+)and Cd^(2+)by recovered perlite in aqueous solution was described by the pseudo-second-order kinetic equation,and the relevant adsorption mechanism was mainly chemisorption.Compared with commercial perlite,the adsorption removal rate of Ni^(2+)and Cd^(2+)by enzymatic recovered perlite could reach 92.9%and 89.2%,respectively,and were improved by 12.63%and 13.03%.Langmuir isothermal adsorption model could better describe the isothermal adsorption process of recovered perlite on heavy metal Ni^(2+)and Cd^(2+),and the relevant adsorption mechanism was mainly monolayer adsorption.The X-ray photoelectron spectroscopy(XPS)results indicated that the decrease of Si—O Si^(2+)hydroxyl coordination bond and the increase of C—Si bond might make the binding effect of recovered perlite with heavy metals stronger.The competitive adsorption of Ni^(2+)and Cd^(2+)by recovered perlite was still dominated by chemisorption and monolayer adsorption.This study was expected to provide a theoretical basis and technical support for the removal of Ni^(2+)and Cd^(2+)from wastewater using recovered perlite from seaweed residue.
基金supported by Natural Science Basic Research Program in Shaanxi Province of China(No.2023-JCYB-574)National Natural Science Foundation of China(No.62204203).
文摘High qualityβ-Ga_(2)O_(3)single crystal nanobelts with length of 2−3 mm and width from tens of microns to 132μm were synthesized by carbothermal reduction method.Based on the grown nanobelt with the length of 600μm,the dual-Schottky-junctions coupling device(DSCD)was fabricated.Due to the electrically floating Ga_(2)O_(3)nanobelt region coupling with the double Schottky-junctions,the current I_(S2)increases firstly and rapidly reaches into saturation as increase the voltage V_(S2).The saturation current is about 10 pA,which is two orders of magnitude lower than that of a single Schottky-junction.In the case of solar-blind ultraviolet(UV)light irradiation,the photogenerated electrons further aggravate the coupling physical mechanism in device.I_(S2)increases as the intensity of UV light increases.Under the UV light of 1820μW/cm^(2),I_(S2)quickly enters the saturation state.At V_(S2)=10 V,photo-to-dark current ratio(PDCR)of the device reaches more than 104,the external quantum efficiency(EQE)is 1.6×10^(3)%,and the detectivity(D*)is 7.5×10^(12)Jones.In addition,the device has a very short rise and decay times of 25−54 ms under different positive and negative bias.DSCD shows unique electrical and optical control characteristics,which will open a new way for the application of nanobelt-based devices.
基金supported by the National Natural Science Foundation of China (Grant No. 62204203)the Shaanxi Natural Science Basic Research Program (Grant No. 2022JQ-701)。
文摘Sn doping is an effective way to improve the response rate of Ga_(2)O_(3) film based solar-blind detectors. In this paper,Sn-doped Ga_(2)O_(3) films were prepared on a sapphire substrate by radio frequency magnetron sputtering. The films were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and ultraviolet visible spectroscopy, and the effect of annealing atmosphere on the properties of films was studied. The Ga_(2)O_(3) films changed from amorphous to β-Ga_(2)O_(3) after annealing at 900 °C. The films were composed of micro crystalline particles with a diameter of about 5–20 nm.The β-Ga_(2)O_(3) had high transmittance for wavelengths above 300 nm, and obvious absorption for solar-blind signals at 200–280 nm.The metal semiconductor metal type solar-blind detectors were prepared. The detector based on Sn-doped β-Ga_(2)O_(3) thin film annealed in N_2 has the best response performance to 254 nm light. The photo-current is 10 μA at 20 V, the dark-current is 5.76 pA,the photo dark current ratio is 1.7 × 10~6, the response rate is 12.47 A/W, the external quantum efficiency is 6.09 × 10~3%, the specific detection rate is 2.61 × 10~(12) Jones, the response time and recovery time are 378 and 90 ms, respectively.
基金The authors are grateful for the financial support by the
文摘Peroxidase plays an important role in living systems;however,its storage difficulty and easy inactivation have limited its applications in complex environments.To address these problems,herein,we proposed a method to synthesize peroxidase mimics by amination,carbonization,and Fe^(3+)-doping of industrial alkali lignin.The Fe^(3+)-doped lignin-based peroxidase mimic(Fe-LPM),with active centers of coordination between Fe^(3+)and N atoms,showed higher tolerance to pH value and temperature than natural peroxidase.Using Fe-LPM,10-100 mmol/L of H_(2)O_(2) and glucose could be colorimetrically detected with the lowest detection limits of 80μmol/L and 1.5 mmol/L and visual detection limits of 1.0 mmol/L and 10 mmol/L,respectively.The Fe-LPM maintained peroxidase-like activity after 10 cycles and could even be used for H_(2)O_(2) detection in practical samples.This work not only provides a new approach to synthesize peroxidase mimics using biomass materials but also promotes the high-value utilization of lignin.
基金The National Natural Science Foundation of China under contract No.31401632the Program for New Century Excellent Talents in Fujian Province University,China under contract No.B15139
文摘This study aimed to improve the thermostability of arylsulfatase from Pseudoalteromonas carrageenovora. A library of P. carrageenovora arylsulfatase mutants was constructed by introducing random mutagenesis using error-prone PCR. After screening, two mutants of H260L and D84A/H260L showed enhanced thermal stability than the wild-type predecessor (WT). Site-directed mutagenesis demonstrated that only amino acid residue at Position 260 plays an important role in the thermostability of P. carrageenovora arylsulfatase. Thermal inactivation analysis showed that the half-life (t1/2) values at 55°C for H260L, H260I, H260Q, H260F and H260R were 40.6, 48.4, 30.9, 29.1 and 34.5 min, respectively, while that of WT was 9.1 min. Structure modeling demonstrated that the additional hydrogen bonds and/or optimization of surface charge-charge interactions could be responsible for the increased thermostability imparted by H260L, H260I, H260Q, H260F and H260R.
基金supported by the Zhejiang Provincial Natural Science Foundation of China(No.2023C03012)the Postdoctoral Preferential Funding Project of Zhejiang Province,China(No.ZJ2022116)the Independent Project of Hangzhou Institute for Advanced Study,China(No.B02006C019014)。
文摘Event cameras,characterized by their low latency,large dynamic range,and extremely high temporal resolution,have recently received increasing attention.These features make them particularly well-suited for virtual/augmented reality(VR/AR)applications.To facilitate the development of three-dimensional(3D)perception and navigation algorithms in VR/AR applications using event cameras,we introduce the Stereo Event camera dataset for Virtual and Augmented Reality(SEVAR),which comprises a wide variety of head-mounted indoor sequences,including scenarios with rapid motion and a large dynamic range.
基金The Natural Science Foundation of Fujian Province of China under contract No.2016J01162the Program for New Century Excellent Talents in Fujian Province University,China under contract No.B15139
文摘An agarase gene containing 1 302 bp was cloned from Microbulbifer sp. AG1. It encoded a mature protein of 413 amino acids plus a 20-residue signal peptide. The recombinant enzyme without the signal peptide was expressed and purified from Escherichia coli BL21(DE3). When agarose was used as a substrate, the optimal temperature and pH for the enzyme were 60℃ and 7.5, respectively. The recombinant agarase showed excellent thermostability with 67% and 19% of residual activities after incubation at 50℃ and 60℃ for 1 h, respectively.Except SDS, the recombinant agarase had a relatively good resistance against the detected inhibitors, detergents and urea denaturant. Thin layer chromatography analysis and enzyme assay using p-nitrophenyl-α/β-Dgalactopyranoside revealed that the recombinant agarase was a β-agarase that degraded agarose into neoagarotetraose as the main end product. The enzymatic hydrolysis products with different degree of polymerization exhibited the antioxidant activities.
基金This research was supported by the Key Science and Technology Projects in Transportation Industry(2018-MS2-051).
文摘It has become a research hotspot to explore raw material substitutes of concrete.It is important to research the mechanical properties of self-compacting concrete(SCC)with slag powder(SP)and rubber particle(RP)replacing cement and coarse aggregate,respectively.12 kinds of composite modified self-compacting concrete(CMSCC)specimens were prepared by using 10%,20%and 30%SP and 30%,40%,50%and 60%RP.The rheological properties,mechanical properties and microstructure of the CMSCC were investigated.Results indicate that the workability,compressive strength,splitting tensile strength and flexural strength of CMSCC prepared by 20%SP and less than 40%RP are improved.In order to maximize the utilization of waste materials,20%SP and 40%RP can be used as the optimal ratio of the combined modifier.The microstructure shows that the addition of proper amount of SP is conducive to the formation of increasingly more uniform C-S-H gel.C-SH gel can fill the internal pores of the sample and enhance the adhesion between the aggregate,thus improving the mechanical properties of CMSCC.RP has a rougher surface and lower density and stiffness,which inhibits the workability and mechanical properties of CMSCC.The above research results have important theoretical and practical significance for the selection of raw materials of self-compacting concrete and the rational use of industrial wastes.
基金Project supported by the Natural Science Foundation of Shandong Province,China(Grant Nos.ZR2009AM017 and ZR2013FM019)the National Postdoctoral Project of China(Grant Nos.200902574 and 20080441150)+1 种基金the Fund from the Educational Department of Shandong Province,China(Grant No.J06P14)the Opening Foundation of State Key Laboratory of Minning Disaster Prevention and Control Co-founded by Shandong Province and the Ministry of Science and Technology of China(Grant No.MDPC201602)
文摘Graphene’s optical absorption coefficient increases linearly with the number of layers making it more effective in the construction of optical tuning graphene-based devices. Refractive index(RI) is one of the important optical parameters of the graphene for accurately describing its optical characteristics and further applications. In view of the RI research of the multilayer graphene is lacking and existing measurement methods are complicated. Optical power tuning RI of multilayer graphene is investigated using a simple measurement and no temperature cross sensitivity all optical fiber sensing structure.Optical power tuning RI characteristics of multilayer graphene are studied by tuning the introducing broad band light power from 0.57 mW to 22.7 m W. Different thickness graphene coating shows different tuning efficiency. At 4.86-μm thickness,a 3.433-nm Bragg wavelength shift is obtained with 156.2-pm/mW wavelength versus optical power tuning sensitivity corresponding to 3.25×10~3 RI change and 0.154 URI/W(URI, unit of RI) RI optical power tuning efficiency.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11774421,11774424,11574394,11774423,11822412,and 11874047)the National Key R&D Program of China(Grant Nos.2016YFA0401002,2018YFA0307000,2016YFA0300504,and 2018FYA0305800)the Fundamental Research Funds for the Central Universities,China(Grant No.2042018kf-0030)。
文摘By using angle-resolvea photoemission spectroscopy(ARPES) combined with the first-principies electronic structure calculations,we report the quantized states at the surface of a single crystal 2 H-TaSe_(2).We have observed sub-bands of quantized states at the three-dimensional Brillouin zone center due to a highly dispersive band with light effective mass along k_(z) direction.The quantized sub-bands shift upward towards E_(F) while the bulk band at Γ shifts downward with the decrease of temperature across charge density wave(CDW) formation.The band shifts could be intimately related to the CDW.While neither the two-dimensional Fermi-surface nesting nor purely strong electron-phonon coupling can explain the mechanism of CDW in 2 H-TaSe_(2),our experiment may ignite the interest in understanding the CDW mechanism in this family.
文摘With the increasing requirements of the multicast services in the whole data traffic service, the optical multicast technology becomes a key technology supporting wide bandwidth and high speed multicasting communication. The transmission efficiency, capacity and robustness of optical multicast network can be further improved by introducing network coding technology into optical multicast networks. Meanwhile, facing to demand of emerging rate-variable multi-granularity multicast service, a multi-path transmission scheme based on network coding for routing and spectrum allocation (RSA) is proposed. It can not only allocate spectrum resources effectively and flexibly for various-rate multicast traffic, but also balance the network load, improve network throughput and reduce transmission blocking rate. In this paper, RSA problem is decomposed into two subproblems, namely routing allocation based on network coding and spectrum allocation based on maximum spectrum first (MSF) strategy, which are solved sequentially. Simulation experiments are carried out to analyze transmission performance with proposed RSA scheme. The simulation results show that the proposed RSA mechanism can allocate spectrum resources efficiently and flexibly for multi-granularity multicast traffic. Compared with RSA schemes based on shortest path tree (SPT) and minimal spanning tree (MST), the proposed RSA scheme is more efficient for spectrum resource utilization and load balancing, and spectrum resource is saved more than 20%.
文摘The emissions trading is a kind of sustainable development measures that is based on market mechanism, and its growing is closely connected with the market development level. The level of American emissions permits market is relatively high, and also predicts the prospect of professional bourse pattern. Most of emissions permits transactions in China are organized by government environment authority, which make it lack of market function. Emissions permits is a kind of property rights. It is important and profitable, while the emissions trading market obviously possesses the two-class of original allocation and second-time transfer. But there are some decisive differences between emissions permits and ordinary transaction object, so the specialized bourse for emissions trading should be built.
基金supported by Joint Fund of Ministry of Education for Equipment Pre-research(8091B022230)the Fundamental Research Funds for the Central Universities(2042022kf1220)+1 种基金National Natural Science Foundation of China(62161160311,51973165)Open Fund of Hubei Key Laboratory of Electronic Manufacturing and Packaging Integration(Wuhan University)(EMPI2023020).
文摘Comprehensive Summary,In nature,fishes have evolved functional skins with effective hydrodynamic performance and anti-fouling,facilitating predation and escaping from predators.Although a large number of fish scale-inspired structured surfaces have been explored,the incorporation of mucus on the structured surfaces has been largely ignored.Inspired by the skin of Osteichthyes fishes,a Janus hydrogel coating(JHC)is successfully prepared by a two-step UV light irradiation at room temperature.The bottom side of JHC(STH)achieves a shear adhesive strength of 103.3±17.5 kPa and can strongly adhere to a large variety of surfaces,including metals,ceramic and polymers.The top surface of JHC(SLH)replicates the structure of cycloid scales,while the nature of hydrogel mimics the mucus on fish skin.SLH possesses prominent mechanical,anti-swelling,anti-fouling and drag reduction properties.The design strategy for JHC has potential applications in numerous fields,like,pipeline transportation,bioengineering,and shipping industry.
基金This work was supported by the State Key Laboratory of Mining Disaster Prevention and Control,Shandong University of Science and Technology(Grant Nos.MDPC201602 and MDPC2022ZR04)Department of Education1of Shandong Province(Grant No.J06P14)+1 种基金The Qingdao Feibo Technology Co.,Ltd.(Grant No.02040102401)Postdoctoral Research Foundation of China(Grant Nos.200902574 and 20080441150).
文摘In view of the problem that the sensing characteristics of the multi-mode interferometric fiber sensors cannot be accurately analyzed,an analysis method based on the fast Fourier transform(FFT)and inverse fast Fourier transform(IFFT)is proposed and demonstrated theoretically and experimentally.The suitabilities of the rectangular window function with the narrow main lobe(high spectrum resolution)and low side lobe(high main mode energy leakage)and the Hanning window function with the wide main lobe(low spectrum resolution)and high side lobe(high energy concentration)in this kind of sensor analysis are discussed,respectively.This method can not only realize the sensing performance analysis of the various modes,but also overcome the inconsistency of the different interference wavelength(dip)sensing characteristics in the conventional analysis methods.At the same time,this method is also beneficial to solve the repetitive problem of such sensors.
基金from the Chinese National Key Basic Research Special Fund(Grant Nos.2006CB921704 and 2007CB924902)the Specialized Research Fund for the Doctoral Program of Higher Education(Grant No.20070269016)+1 种基金Chenguang Project of Shanghai Education Development Foundation(Grant No.2008CGB23)the Excellent Young Teachers Program of Shanghai Higher Learning Institutions(Grant No.AAYQ0723).
文摘Ultralong ZnO nanocombs have been synthesized on silicon substrates with a high growth rate of~7μm/s using a simple“thermal evaporation and condensation”method promoted by Cu catalysts.The lengths of the ZnO nanocombs range from several millimeters to more than one centimeter and the diameters of the branches are about 300 nm.The growth mechanism of the ultralong nanocombs and the catalytic behavior of the copper are discussed.The nanocombs were readily separated and their applications as optical polarizer and grating were investigated.The results show that the ultralong ZnO nanocombs can act as effective optical components in miniaturized integrated optics systems.
