Compared to traditional polymer hydrogels,supramolecular hydrogels exhibits superior reversibility and stimulus response due to the instantaneous and reversible nature of non-covalent bonds.In this paper,we utilized t...Compared to traditional polymer hydrogels,supramolecular hydrogels exhibits superior reversibility and stimulus response due to the instantaneous and reversible nature of non-covalent bonds.In this paper,we utilized the host-vip exclusion interaction between Decamethylcucurbit[5]uril(Me_(10)Q[5])and the 2,7-diaminofluorenedihydrochloride(DAF·HCl)to construct a Q[n]-based hydrogel system.The composition,structure,and properties of the hydrogel were compre-hensively characterized using rheometer,nuclear magnetic resonance,scanning electron microscope.This cost-effective and straightforward hydrogel synthesis method paves the way for the scalable production of practical and commercially viable Q[n]-based hydrogels.展开更多
As a solid foam stabilizer, spherical silica particles with diameters ranging from 150 to 190 nm were prepared via an improved Stober methOd and were subsequently modified using three different silane coupling agents ...As a solid foam stabilizer, spherical silica particles with diameters ranging from 150 to 190 nm were prepared via an improved Stober methOd and were subsequently modified using three different silane coupling agents to attain the optimum surface hydrophobicity of the particles. Fourier transform infrared （FTIR） spectra and the measured contact angles were used to characterize the surface properties of the prepared particles. The foam stability was investigated by the foam drainage half-life and the expansion viscoelastic modulus of the liquid film. The results demonstrate that all of the modified silica nanoparticles effectively improve the foam stability. The surface hydrophobicity of the modified particles is found to be a key factor influencing the foam stability. The optimum contact angle of the particles lies in the ap- proximate range from 50° to 55°. The modifier molecular structure used can also influence the stabilizing foam property of the solid particles The foam system stabilized by （CH3）2SiCl2-modified silica particles exhibits the highest stability; its drainage half-life at maximum increases by 27% compared to that of the blank foam system and is substantially greater than those of the foam systems stabilized by KH570- and KH550-modified particles.展开更多
method of extracting astaxanthin from Phaffia rhodozyma with various solvents after acid washing was investigated. The extraction efficiency was distinctly increased after acid washing of P. rhodozyma cells. When the ...method of extracting astaxanthin from Phaffia rhodozyma with various solvents after acid washing was investigated. The extraction efficiency was distinctly increased after acid washing of P. rhodozyma cells. When the concentration of HCl was 0.4 mol.L^-1, the highest extraction efficiency of astaxanthin was achieved which was about three times higher than the control. Acetone or benzene as single polar or non-polar solvent was the most ef- fective solvent in our research. With a combination of isopropanol and n-hexane （volume ratio of 2 ： 1）, the maxi- mal extraction efficiency was achieved, approximately 60% higher than that obtained with a single solvent. The liquid-solid ratio and the extracting time were also optimized. Under the optimum extraction conditions, the extraction yield of astaxanthin exceeded 98%.展开更多
Surface dilational rheological behavior and foam stability of starch/surfactant mixed solutions were studied at different starch concentrations and constant surfactant concentration. The results show that dilational v...Surface dilational rheological behavior and foam stability of starch/surfactant mixed solutions were studied at different starch concentrations and constant surfactant concentration. The results show that dilational viscoelasticity modulus, dilational elasticity modulus and dilational viscosity modulus increase with the concentration of starch particles. Foam stability increases with dilational viscoelasticity. Foam strength also increases with starch concentration. Starch particles play a positive effect on foam stability and dilational viscoelasticity and the effect becomes more significant as drainage proceeds. Film pictures indicate that the film with 20%(by mass) starch particles is thicker than that without starch. Starch particles gather in Plateau border and resist drainage, making the foam more stable.展开更多
Researches on detection of human papillomavirus(HPV)high-risk samples were carried out by polymerase chain reaction(PCR)coupled with microchip electrophoresis(MCE).Herein,we introduced a simple,rapid,automated method ...Researches on detection of human papillomavirus(HPV)high-risk samples were carried out by polymerase chain reaction(PCR)coupled with microchip electrophoresis(MCE).Herein,we introduced a simple,rapid,automated method for detecting high-risk samples HPV16 and HPV18.In this research,general primers were initially selected to obtain sufficient detectable yield by PCR to verify feasibility of MCM method for HPV detection,then type-specific primers were further used to evaluate the specificity of MCE method.The results indicated MCE method was capable of specifically detecting high-risk HPV16 and HPV18,and also enabled simultaneous detection of multiplex samples.This MCE method described here has been successfully applied to HPV detection and displayed excellent reliability demonstrating by sequencing results.The inherent capability of MCE facilitated HPV detection conducted in a small chip with automated,high throughput,massive parallelized analysis.We envision that MCE method will definitely pave a way for clinical diagnosis,and even on-site screening of cervical cancer.展开更多
The waste fiuorgypsum was modified and applied as a cement retarder. The main chemical composition and mineral structure of the waste fluorgypsum were analyzed. Scanning electron microscopy （SEM） and eight-channel m...The waste fiuorgypsum was modified and applied as a cement retarder. The main chemical composition and mineral structure of the waste fluorgypsum were analyzed. Scanning electron microscopy （SEM） and eight-channel micro-calorimeter （TAM Air） were employed to analyze the changes in morphology and study the application performance of the modified fluorgypsum, respectively. Experimental results indicate that the flexural strength and compressive strength of the modified fiuorgypsurn are roughly equal to those of the natural gypsum. The morphology of the crystal of the fiuorgypsum changes from block particle into trimetric short column. The fluorgypsum crystals stagger mutually and improve the strength of the hardened body. The modified fluorgypsum as cement retarder could delay the hydration, reduce the heat of the hydration and make the setting time, volume stability, and the S03 content of the cement meet the national standards. The modified fluorgypsum is a good substitute for the natural gypsum.展开更多
The effect of sodium lignosulfonate(SL)as additive on the preparation of low-rank coal-water slurry(LCWS)was studied by experiments and molecular dynamics(MD)simulation s.The experimental results show that the appropr...The effect of sodium lignosulfonate(SL)as additive on the preparation of low-rank coal-water slurry(LCWS)was studied by experiments and molecular dynamics(MD)simulation s.The experimental results show that the appropriate amount of additives is beneficial to reduce the viscosity of LCWS and increase the slurry concentration.Adsorption isotherm studies showed that SL conforms to single-layer adsorption on the coal surface,andΔG_(ads)^(0) was negative,proving that the reaction was spontaneous.Zeta potential measurements showed that SL increased the negative charge on coal.FTIR scanning and XPS wide-range scanning were performed on the coal before and after adsorption,and it was found that the content of oxygen functional groups on coal increased after adsorption.Simulation results show that when a large number of SL molecules exist in the solution,some SL molecules will bind to hydrophobic hydrocarbon groups on coal.The rest of the SL molecule s,their hydrophobic alkyl tails,come into contact with each other and aggregate in solution.The agglomeration of SL molecules and the surface of coal with static electricity will also produce electrostatic interaction,which is conducive to the even dispersion of coal particles.The results of mean square displacement(MSD)and self-diffusion coefficient(D)show that the addition of SL reduces the diffusion rate of water molecules.Simulation results correspond to experimental results,indicating that MD simulation is accurate and feasible.展开更多
Although Bi_(2)Mo O_(6)(BMO) has recently received extensive attention, its visible-light photocatalytic activity remains poor due to its limited photoresponse range and low charge separation efficiency. In this work,...Although Bi_(2)Mo O_(6)(BMO) has recently received extensive attention, its visible-light photocatalytic activity remains poor due to its limited photoresponse range and low charge separation efficiency. In this work, a series of visible-light-driven Y^(3+)-doped BMO(Y-BMO) photocatalysts were synthesized via a hydrothermal method. Degradation experiments on Rhodamine B and Congo red organic pollutants revealed that the optimal degradation rates of Y-BMO were 4.3 and 5.3 times those of pure BMO, respectively. The degradation efficiency of Y-BMO did not significantly decrease after four cycle experiments. As a result of Y^(3+)doping, the crystal structure of BMO changed from a thick layer structure to a thin flower-like structure with an increased specific surface area. X-ray photoelectron spectroscopy showed the presence of highintensity peaks for the O 1s orbital at 531.01 and 530.06 eV, confirming the formation of oxygen vacancies in Y-BMO. Photoluminescence(PL) and electrochemical impedance spectroscopy measurements revealed that the PL intensity and interface resistances of composites decreased significantly, indicating reduced electron–hole pair recombination. This work provides an effective way to prepare high-efficiency Bibased photocatalysts by doping rare earth metal ions for improved photocatalytic performance.展开更多
Commercial activated carbons were modified by a series of chemical or physical treatments using H202, NH3, and heating under N2 flow without notably changing their pore structures. The resultant carbons were character...Commercial activated carbons were modified by a series of chemical or physical treatments using H202, NH3, and heating under N2 flow without notably changing their pore structures. The resultant carbons were characterized by N2 adsorption and Bohem titration and then used to remove Ponceau 4R, methyl orange and brilliant blue from aqueous solutions. Surface chemistry was found to play a signifi- cantly different role in removing these three compounds. The removal of anionic Ponceau 4R increases with increasing carbon surface ba- sicity due to the predominant dispersive interaction mechanism. In contrast, surface chemistry has little effect on the removal of anionic methyl orange, which can be explained by two parallel mechanisms involving electrostatic and dispersive interactions due to the basic amine group in a dye molecule. The influence of surface chemistry on the removal of amphoteric brilliant blue dye can also be ignored due to a weak interaction between the carbons and dye molecules, which is resulted from strong cohesive energy from electrostatic forces inside amphoteric dye molecules.展开更多
The hydrolysis and photolysis of clomazone in aqueous solutions and natural water were assessed under natural and controlled conditions. Kinetics of hydrolysis and photolysis of clomazone were determined by HPLC-DAD. ...The hydrolysis and photolysis of clomazone in aqueous solutions and natural water were assessed under natural and controlled conditions. Kinetics of hydrolysis and photolysis of clomazone were determined by HPLC-DAD. Photoproducts were identiifed by HPLC-MS. No noticeable hydrolysis occurred in aqueous buffer solutions （（25±2）°C, pH （4.5±0.1）, pH （7.4±0.1）, pH （9.0±0.1）;（50±2）°C, pH （4.5±0.1）, pH （7.4±0.1）） or in natural water up to 90 d. At pH （9.0±0.1） and （50±2）°C the half-life of clomazone was 50.2 d. Clomazone photodecomposition rate in aqueous solutions under UV radiation and natural sunlight followed ifrst-order kinetics. Degradation rates were faster under UV light （half-life of 51-59 min） compared to sunlight （half-life of 87-136 d）. Under UV light, four major photoproducts were detected and tentatively identiifed according to HPLC-MS spectral information such as 2-chlorobenzamide, N-hydroxy-（2-benzyl）-2-methylpropan-amide, 2-[2-phenol]-4,4-dimethyl-3-isoxazolidinone and 2-[（4,6-dihydroxyl-2-chlorine phenol）]-4,4-dimethyl-3-isoxazolidinone. These results suggested that clomazone photodegradation proceeds via several reaction pathways：1） dehalogenation;2） substitution of chlorine group by hydroxyl;3） cleavage of the side chain. Photosensitizers, such as H2O2 and ribolfavin, could enhance photolysis of clomazone in natural sunlight. In summary, we found that photoreaction is an important dissipation pathway of clomazone in natural water systems.展开更多
The boom of covalent organic frameworks(COFs)has been witnessed in the photocatalysis field in recent years owing to the capability of these materials to efficiently and sustainably harness solar energy[1],[2].Prepare...The boom of covalent organic frameworks(COFs)has been witnessed in the photocatalysis field in recent years owing to the capability of these materials to efficiently and sustainably harness solar energy[1],[2].Prepared from diverse aromatic building blocks,COFs have well-defined periodic structures and uniform porosities,allowing for the adjustment of photocatalytic activity at precise atomic and molecular levels.展开更多
Lithium recovery from spent lithium-ion batteries(LIBs)have attracted extensive attention due to the skyrocketing price of lithium.The medium-temperature carbon reduction roasting was proposed to preferential selectiv...Lithium recovery from spent lithium-ion batteries(LIBs)have attracted extensive attention due to the skyrocketing price of lithium.The medium-temperature carbon reduction roasting was proposed to preferential selective extraction of lithium from spent Li-CoO_(2)(LCO)cathodes to overcome the incomplete recovery and loss of lithium during the recycling process.The LCO layered structure was destroyed and lithium was completely converted into water-soluble Li2CO_(3)under a suitable temperature to control the reduced state of the cobalt oxide.The Co metal agglomerates generated during medium-temperature carbon reduction roasting were broken by wet grinding and ultrasonic crushing to release the entrained lithium.The results showed that 99.10%of the whole lithium could be recovered as Li2CO_(3)with a purity of 99.55%.This work provided a new perspective on the preferentially selective extraction of lithium from spent lithium batteries.展开更多
Sm3＋-activated Y2028 red phosphors were prepared by the combustion method and microemulsion method at the first time. X-ray characterization and electron diffraction show that, Y202S：Sm3＋, Ti4＋, Mg2＋ samples prep...Sm3＋-activated Y2028 red phosphors were prepared by the combustion method and microemulsion method at the first time. X-ray characterization and electron diffraction show that, Y202S：Sm3＋, Ti4＋, Mg2＋ samples prepared by these two methods are pure hexagonal crystals in structure with a trivial change due to dopants. Scanning electron microscopy （SEM） results show that the product presents an almond-like sheet in uniform size. Under the excitation of 269 nm ultraviolet light, Y202S：Sm3＋ samples fabricated by these two methods exhibit three main groups of red emission lines located at 564, 604, and 656 nm, respectively, which are attributed to the transitions of 4G5/2 →6H5/2, 4G~/2 →6H7/2, 4G5/2 →6H9/2, respectively. The samples prepared by microemulsion are seven times higher in fluorescent emission intensity and half time longer in afterglow time than that prepared by combustion.展开更多
The thermal decomposition temperature is one of the most important parameters to evaluate fire hazard of organic peroxide. A quantitative structure-property relationship model was proposed for estimating the thermal d...The thermal decomposition temperature is one of the most important parameters to evaluate fire hazard of organic peroxide. A quantitative structure-property relationship model was proposed for estimating the thermal decomposition temperatures of organic peroxides. The entire set of 38 organic peroxides was at random divided into a training set for model development and a prediction set for external model validation. The novel local molecular descriptors of AT1, AT2, AT3, AT4, AT5, AT6 and global molecular descriptor of ATC have been proposed in order to character organic peroxides’ molecular structures. An accurate quantitative structure-property relationship （QSPR） equation is developed for the thermal decomposition temperatures of organic peroxides. The statistical results showed that the QSPR model was obtained using the multiple linear regression （MLR） method with correlation coefficient （R）, standard deviation （S）, leave-one-out validation correlation coefficient （RCV） values of 0.9795, 6.5676 ℃ and 0.9328, respectively. The average absolute relative deviation （AARD） is only 3.86% for the experimental values. Model test by internal leave-one-out cross validation and external validation and molecular descriptor interpretation were discussed. Comparison with literature results demonstrated that novel local and global descriptors were useful molecular descriptors for predicting the thermal decomposition temperatures of organic peroxides.展开更多
Toll-like receptors(TLRs) are the critical superfamily homologues that initiate sensing of the invasion of pathogens by the Toll pathway. As one of several intracellular nucleic acid-sensing TLRs, TLR13 is activated b...Toll-like receptors(TLRs) are the critical superfamily homologues that initiate sensing of the invasion of pathogens by the Toll pathway. As one of several intracellular nucleic acid-sensing TLRs, TLR13 is activated by an unmethylated motif present in the large ribosomal subunit of bacterial RNA. However, little attention has been paid to the function of TLR13 gene homologue from Laodelphax striatellus(designated as LsToll-13) in the immune response to rice stripe virus(RSV). Herein, LsToll-13 was cloned and characterized using RACE-PCR. Phylogenetic analysis showed that LsToll-13 was clustered with the TLR13 from six insects. Real-time PCR analysis demonstrated that the expression level of LsToll-13 was significantly reduced in L. striatellus with RSV infection compared with that in the naive strain. When the expression of LsToll-13 was significantly up-regulated at 6 h after bacterial infection, the expression of ribonucleoprotein(RNP) indicated that the RSV titer in the host insect was significantly suppressed. Upon knockdown of LsToll-13, using RNA interference(RNAi) in L. striatellus, the expression level of RNP was significantly increased with enhanced RSV accumulation, suggesting that LsToll-13 potentially protects L. striatellus from RSV infection. Taken together, our results indicated that LsToll-13 might be involved in the immune response of L. striatellus to RSV infection, and provided a new insight into further elucidating the molecular mechanisms of complex pathogen-host interactions and integrative pest management.展开更多
Flexible electronic sensors composed of flexible film and conductive materials play an increasingly important role in wearable and internet information transmission.It has received more and more attention and made som...Flexible electronic sensors composed of flexible film and conductive materials play an increasingly important role in wearable and internet information transmission.It has received more and more attention and made some progress over the decades.However,it is still a great challenge to prepare biocompatible and highly transparent conductive films.Egg white is a pure natural protein-rich material.Hydroxypropylmethyl cellulose has a good compatibility and high transparency,which is an ideal material for flexible sensors.Here,we overcome the problem of poor mechanical flexibility and electrical conductivity of protein,and develop a high transparency and good flexibility hydroxypropylmethyl cellulose/egg white protein composite membrane-based triboelectric nanogenerator('X'-TENG).The experimental results show that the flexible pressure sensor based on'X'-TENG has a high sensitivity,fast response speed,and low detection limit.It can even be used as a touch/pressure sensing artificial electronic skin.It can also be made into an intelligent waffle keyboard for recording and tracking users of the keyboard.Our strategy may provide a new way to easily build flexible electronic sensors and move toward practical applications.展开更多
The title compound N-（（6-chloropyridin-3-yl）methyl）-6-ethoxy-N-ethyl-3-nitropyri-din-2-amine（4） was synthesized by reacting the mixture of 6-chloro-2-ethoxy-3-nitropyridine（1） and 2-chloro-6-ethoxy-3-nitropyri...The title compound N-（（6-chloropyridin-3-yl）methyl）-6-ethoxy-N-ethyl-3-nitropyri-din-2-amine（4） was synthesized by reacting the mixture of 6-chloro-2-ethoxy-3-nitropyridine（1） and 2-chloro-6-ethoxy-3-nitropyridine（2） with 3,and its structure was determined by X-ray single-crystal diffraction.The crystal belongs to the monoclinic system,space group P21/n with a = 7.3441（2）,b = 9.9041（3）,c = 11.7368（3） ,α = 101.410（2）,β = 102.1340（10）,γ = 99.594（2）o,μ = 0.260 mm^-1,Mr = 336.78,V = 798.58（4）（A°）^3,Z = 2,Dc = 1.401g/cm^3,F（000） = 352,T = 296（2） K,R = 0.0210 and wR = 0.1053.展开更多
The title compound ethyl 2-（6-（1,3-dioxo-4,5,6,7-tetrahydro-lH-isoindol-2（3H）- yl）-7-fluoro-3-oxo-2H-benzo[b][1,4]oxazin-4（3H）-yl） butanoate 3 was synthesized by the reaction of ethyl 2-（6-amino-7-fluoro-3-ox...The title compound ethyl 2-（6-（1,3-dioxo-4,5,6,7-tetrahydro-lH-isoindol-2（3H）- yl）-7-fluoro-3-oxo-2H-benzo[b][1,4]oxazin-4（3H）-yl） butanoate 3 was synthesized by the reaction of ethyl 2-（6-amino-7-fluoro-3-oxo-2H-benzo[b][1,4]oxazin-4（3H）-yl） butanoate with 4,5,6,7- tetraydrophthalic anhydride, and its structure was determined by X-ray single-crystal diffraction. The crystal belongs to the monoclinic system, space group P2 1/n with a = 9.3469（2）, b = 16.7715（5）, c = 13.7153（4） A, β= 104.9680（10）°, μ = 0.107 mm^-1, Mr = 430.42, V= 2077.08（10） ,A3, Z= 4, Dc = 1.376 g/cm3, F（000） = 904, T= 296（2） K, R = 0.0508 and wR = 0.1478.展开更多
Recyclability and self-healing are two most critical factors in developing sustainable polymers to deal with environmental pollution and resource waste.In this work,a dynamic cross-linked polyimide insulation film wit...Recyclability and self-healing are two most critical factors in developing sustainable polymers to deal with environmental pollution and resource waste.In this work,a dynamic cross-linked polyimide insulation film with full closed-loop recyclability is successfully prepared,which also possesses good self-healing ability after being mechanical/electrical damaged depending on the Schiff base dynamic covalent bonds.The recycled and self-healed polyimide film still maintain its good tensile strength(r t)>60 MPa with Young’s modulus(E)>4 GPa,high thermal stability with glass transition temperature(T g)>220℃,and outstanding insulation property with breakdown strength(E 0)>358 kV mm^(-1),making it a very promising low energy consumption and high temperature resistant insulation material.The strategy of using Schiff base dynamic covalent bonds for reversible repairing the structure of high T g polyimides promotes the wider application of such sustainable and recyclable material in the field of electrical power and micro-electronics.展开更多
Spectral analysis was a method of identifying substances, determining their chemical composition and calculating their content based on their spectral characteristics. This paper mainly discussed the application of va...Spectral analysis was a method of identifying substances, determining their chemical composition and calculating their content based on their spectral characteristics. This paper mainly discussed the application of various spectroscopic techniques, mainly including atomic absorption spectrometry (AAS) inductively coupled plasma emission spectrometry (ICP-AES) X-ray fluorescence spectroscopy (XRF) atomic fluorescence spectroscopy (AFS) direct reading spectroscopy (OES) glow discharge emission spectroscopy (GD-OSE) laser-induced breakdown spectroscopy (LIBS), in the formulation of non-ferrous metal standards in China. The AAS method was the most widely used single-element microanalysis method among the non-ferrous metal standards. The ICP-AES method was good at significant advantages in the simultaneous detection of multiple elements. The XRF method was increasingly used in the determination of primary and secondary trace elements due to its simple sample preparation and high efficiency. The AFS was mostly detected by single-element trace analysis. OES GD-OES and LIBS were playing an increasingly important role in the new demand area for non-ferrous metals. This paper discussed matrix elimination, sample digestion, sample preparation, instrument categories and other aspects of some standards, and summarized the advantages of spectral analysis and traditional chemical analysis methods. The new methods of future spectroscopic technology had been illustrated in the process of developing non-ferrous metal standards.展开更多
文摘Compared to traditional polymer hydrogels,supramolecular hydrogels exhibits superior reversibility and stimulus response due to the instantaneous and reversible nature of non-covalent bonds.In this paper,we utilized the host-vip exclusion interaction between Decamethylcucurbit[5]uril(Me_(10)Q[5])and the 2,7-diaminofluorenedihydrochloride(DAF·HCl)to construct a Q[n]-based hydrogel system.The composition,structure,and properties of the hydrogel were compre-hensively characterized using rheometer,nuclear magnetic resonance,scanning electron microscope.This cost-effective and straightforward hydrogel synthesis method paves the way for the scalable production of practical and commercially viable Q[n]-based hydrogels.
基金financially supported by the National Natural Science Foundation of China(No.21276022)the China National Petroleum Corporation Innovation Foundation(No.2012D-5006-0208)
文摘As a solid foam stabilizer, spherical silica particles with diameters ranging from 150 to 190 nm were prepared via an improved Stober methOd and were subsequently modified using three different silane coupling agents to attain the optimum surface hydrophobicity of the particles. Fourier transform infrared （FTIR） spectra and the measured contact angles were used to characterize the surface properties of the prepared particles. The foam stability was investigated by the foam drainage half-life and the expansion viscoelastic modulus of the liquid film. The results demonstrate that all of the modified silica nanoparticles effectively improve the foam stability. The surface hydrophobicity of the modified particles is found to be a key factor influencing the foam stability. The optimum contact angle of the particles lies in the ap- proximate range from 50° to 55°. The modifier molecular structure used can also influence the stabilizing foam property of the solid particles The foam system stabilized by （CH3）2SiCl2-modified silica particles exhibits the highest stability; its drainage half-life at maximum increases by 27% compared to that of the blank foam system and is substantially greater than those of the foam systems stabilized by KH570- and KH550-modified particles.
基金Supported by the Fundamental Research Funds for the Central Universities （FRF-AS-10-001B） and the National Natural Science Foundation of China （11071013）.
文摘method of extracting astaxanthin from Phaffia rhodozyma with various solvents after acid washing was investigated. The extraction efficiency was distinctly increased after acid washing of P. rhodozyma cells. When the concentration of HCl was 0.4 mol.L^-1, the highest extraction efficiency of astaxanthin was achieved which was about three times higher than the control. Acetone or benzene as single polar or non-polar solvent was the most ef- fective solvent in our research. With a combination of isopropanol and n-hexane （volume ratio of 2 ： 1）, the maxi- mal extraction efficiency was achieved, approximately 60% higher than that obtained with a single solvent. The liquid-solid ratio and the extracting time were also optimized. Under the optimum extraction conditions, the extraction yield of astaxanthin exceeded 98%.
基金Supported by the Petro China Company Limited Project(2011B-1303)the National Natural Science Foundation of China(21276022)CNPC Innovation Foundation(2012D-5006-0208)
文摘Surface dilational rheological behavior and foam stability of starch/surfactant mixed solutions were studied at different starch concentrations and constant surfactant concentration. The results show that dilational viscoelasticity modulus, dilational elasticity modulus and dilational viscosity modulus increase with the concentration of starch particles. Foam stability increases with dilational viscoelasticity. Foam strength also increases with starch concentration. Starch particles play a positive effect on foam stability and dilational viscoelasticity and the effect becomes more significant as drainage proceeds. Film pictures indicate that the film with 20%(by mass) starch particles is thicker than that without starch. Starch particles gather in Plateau border and resist drainage, making the foam more stable.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.21727814,81872829,21621003,21890740).
文摘Researches on detection of human papillomavirus(HPV)high-risk samples were carried out by polymerase chain reaction(PCR)coupled with microchip electrophoresis(MCE).Herein,we introduced a simple,rapid,automated method for detecting high-risk samples HPV16 and HPV18.In this research,general primers were initially selected to obtain sufficient detectable yield by PCR to verify feasibility of MCM method for HPV detection,then type-specific primers were further used to evaluate the specificity of MCE method.The results indicated MCE method was capable of specifically detecting high-risk HPV16 and HPV18,and also enabled simultaneous detection of multiplex samples.This MCE method described here has been successfully applied to HPV detection and displayed excellent reliability demonstrating by sequencing results.The inherent capability of MCE facilitated HPV detection conducted in a small chip with automated,high throughput,massive parallelized analysis.We envision that MCE method will definitely pave a way for clinical diagnosis,and even on-site screening of cervical cancer.
基金Project(21003014) supported by the National Natural Science Foundation of ChinaProject(2010FJ3167) supported by the Hunan Provincial Science and Technology Program,ChinaProject(K1104029-11) supported by the Changsha IT Project
文摘The waste fiuorgypsum was modified and applied as a cement retarder. The main chemical composition and mineral structure of the waste fluorgypsum were analyzed. Scanning electron microscopy （SEM） and eight-channel micro-calorimeter （TAM Air） were employed to analyze the changes in morphology and study the application performance of the modified fluorgypsum, respectively. Experimental results indicate that the flexural strength and compressive strength of the modified fiuorgypsurn are roughly equal to those of the natural gypsum. The morphology of the crystal of the fiuorgypsum changes from block particle into trimetric short column. The fluorgypsum crystals stagger mutually and improve the strength of the hardened body. The modified fluorgypsum as cement retarder could delay the hydration, reduce the heat of the hydration and make the setting time, volume stability, and the S03 content of the cement meet the national standards. The modified fluorgypsum is a good substitute for the natural gypsum.
基金supported by SDUST Research Fund(Grant No.2018TDJH101)Key Research and Development Project of Shandong(Grant No.2019GGX103035)+2 种基金National Natural Science Foundation of China(Grant Nos.51904174,52074175)Young Science and Technology Innovation Program of Shandong Province(Grant No.2020KJD001)Project of Shandong Province Higher Educational Young Innovative Talent Introduction and Cultivation Team。
文摘The effect of sodium lignosulfonate(SL)as additive on the preparation of low-rank coal-water slurry(LCWS)was studied by experiments and molecular dynamics(MD)simulation s.The experimental results show that the appropriate amount of additives is beneficial to reduce the viscosity of LCWS and increase the slurry concentration.Adsorption isotherm studies showed that SL conforms to single-layer adsorption on the coal surface,andΔG_(ads)^(0) was negative,proving that the reaction was spontaneous.Zeta potential measurements showed that SL increased the negative charge on coal.FTIR scanning and XPS wide-range scanning were performed on the coal before and after adsorption,and it was found that the content of oxygen functional groups on coal increased after adsorption.Simulation results show that when a large number of SL molecules exist in the solution,some SL molecules will bind to hydrophobic hydrocarbon groups on coal.The rest of the SL molecule s,their hydrophobic alkyl tails,come into contact with each other and aggregate in solution.The agglomeration of SL molecules and the surface of coal with static electricity will also produce electrostatic interaction,which is conducive to the even dispersion of coal particles.The results of mean square displacement(MSD)and self-diffusion coefficient(D)show that the addition of SL reduces the diffusion rate of water molecules.Simulation results correspond to experimental results,indicating that MD simulation is accurate and feasible.
基金financially supported by the National Natural Science Foundation of China (No.21271022)。
文摘Although Bi_(2)Mo O_(6)(BMO) has recently received extensive attention, its visible-light photocatalytic activity remains poor due to its limited photoresponse range and low charge separation efficiency. In this work, a series of visible-light-driven Y^(3+)-doped BMO(Y-BMO) photocatalysts were synthesized via a hydrothermal method. Degradation experiments on Rhodamine B and Congo red organic pollutants revealed that the optimal degradation rates of Y-BMO were 4.3 and 5.3 times those of pure BMO, respectively. The degradation efficiency of Y-BMO did not significantly decrease after four cycle experiments. As a result of Y^(3+)doping, the crystal structure of BMO changed from a thick layer structure to a thin flower-like structure with an increased specific surface area. X-ray photoelectron spectroscopy showed the presence of highintensity peaks for the O 1s orbital at 531.01 and 530.06 eV, confirming the formation of oxygen vacancies in Y-BMO. Photoluminescence(PL) and electrochemical impedance spectroscopy measurements revealed that the PL intensity and interface resistances of composites decreased significantly, indicating reduced electron–hole pair recombination. This work provides an effective way to prepare high-efficiency Bibased photocatalysts by doping rare earth metal ions for improved photocatalytic performance.
基金financially supported by the National Natural Science Foundation of China (No. 21271022)the China National Petroleum Corporation Innovation Foundation (No. 2012D-5006-0208)+1 种基金the Fundamental Research Funds for the Central Universities (No. FRF-BR-13-008)the Engineering Research Institute Foundation of University of Science and Technology Beijing (No. YJ2012-008)
文摘Commercial activated carbons were modified by a series of chemical or physical treatments using H202, NH3, and heating under N2 flow without notably changing their pore structures. The resultant carbons were characterized by N2 adsorption and Bohem titration and then used to remove Ponceau 4R, methyl orange and brilliant blue from aqueous solutions. Surface chemistry was found to play a signifi- cantly different role in removing these three compounds. The removal of anionic Ponceau 4R increases with increasing carbon surface ba- sicity due to the predominant dispersive interaction mechanism. In contrast, surface chemistry has little effect on the removal of anionic methyl orange, which can be explained by two parallel mechanisms involving electrostatic and dispersive interactions due to the basic amine group in a dye molecule. The influence of surface chemistry on the removal of amphoteric brilliant blue dye can also be ignored due to a weak interaction between the carbons and dye molecules, which is resulted from strong cohesive energy from electrostatic forces inside amphoteric dye molecules.
基金sponsored by Shandong Cynda Chemical Co.Ltd.(Shandong+1 种基金China)the Project of Pesticide Registration Residue of Ministry of Agriculture of China(FRF-SD-12-010B)
文摘The hydrolysis and photolysis of clomazone in aqueous solutions and natural water were assessed under natural and controlled conditions. Kinetics of hydrolysis and photolysis of clomazone were determined by HPLC-DAD. Photoproducts were identiifed by HPLC-MS. No noticeable hydrolysis occurred in aqueous buffer solutions （（25±2）°C, pH （4.5±0.1）, pH （7.4±0.1）, pH （9.0±0.1）;（50±2）°C, pH （4.5±0.1）, pH （7.4±0.1）） or in natural water up to 90 d. At pH （9.0±0.1） and （50±2）°C the half-life of clomazone was 50.2 d. Clomazone photodecomposition rate in aqueous solutions under UV radiation and natural sunlight followed ifrst-order kinetics. Degradation rates were faster under UV light （half-life of 51-59 min） compared to sunlight （half-life of 87-136 d）. Under UV light, four major photoproducts were detected and tentatively identiifed according to HPLC-MS spectral information such as 2-chlorobenzamide, N-hydroxy-（2-benzyl）-2-methylpropan-amide, 2-[2-phenol]-4,4-dimethyl-3-isoxazolidinone and 2-[（4,6-dihydroxyl-2-chlorine phenol）]-4,4-dimethyl-3-isoxazolidinone. These results suggested that clomazone photodegradation proceeds via several reaction pathways：1） dehalogenation;2） substitution of chlorine group by hydroxyl;3） cleavage of the side chain. Photosensitizers, such as H2O2 and ribolfavin, could enhance photolysis of clomazone in natural sunlight. In summary, we found that photoreaction is an important dissipation pathway of clomazone in natural water systems.
基金supported by the National Natural Science Foundation of China(22235001,22175020,22131005,and 22261132512)Xiaomi Young Scholar Program,Fundamental Research Funds for the Central Universities(FRF-EYIT-23-02 and QNXM2023)the University of Science and Technology Beijing,and the Russian Science Foundation within the framework of the Joint RSF-NSFC project(23-43-00136).
文摘The boom of covalent organic frameworks(COFs)has been witnessed in the photocatalysis field in recent years owing to the capability of these materials to efficiently and sustainably harness solar energy[1],[2].Prepared from diverse aromatic building blocks,COFs have well-defined periodic structures and uniform porosities,allowing for the adjustment of photocatalytic activity at precise atomic and molecular levels.
基金the Science and Technology Key Project of Anhui Province,China(No.2022e03020004).
文摘Lithium recovery from spent lithium-ion batteries(LIBs)have attracted extensive attention due to the skyrocketing price of lithium.The medium-temperature carbon reduction roasting was proposed to preferential selective extraction of lithium from spent Li-CoO_(2)(LCO)cathodes to overcome the incomplete recovery and loss of lithium during the recycling process.The LCO layered structure was destroyed and lithium was completely converted into water-soluble Li2CO_(3)under a suitable temperature to control the reduced state of the cobalt oxide.The Co metal agglomerates generated during medium-temperature carbon reduction roasting were broken by wet grinding and ultrasonic crushing to release the entrained lithium.The results showed that 99.10%of the whole lithium could be recovered as Li2CO_(3)with a purity of 99.55%.This work provided a new perspective on the preferentially selective extraction of lithium from spent lithium batteries.
基金financially supported by the Basic Theory Research Fund of Research Institute of Metallurgy Engineering,University of Science and Technology Beijing(No.YJ2012-009)
文摘Sm3＋-activated Y2028 red phosphors were prepared by the combustion method and microemulsion method at the first time. X-ray characterization and electron diffraction show that, Y202S：Sm3＋, Ti4＋, Mg2＋ samples prepared by these two methods are pure hexagonal crystals in structure with a trivial change due to dopants. Scanning electron microscopy （SEM） results show that the product presents an almond-like sheet in uniform size. Under the excitation of 269 nm ultraviolet light, Y202S：Sm3＋ samples fabricated by these two methods exhibit three main groups of red emission lines located at 564, 604, and 656 nm, respectively, which are attributed to the transitions of 4G5/2 →6H5/2, 4G~/2 →6H7/2, 4G5/2 →6H9/2, respectively. The samples prepared by microemulsion are seven times higher in fluorescent emission intensity and half time longer in afterglow time than that prepared by combustion.
基金Project(2015SK20823) supported by Science and Technology Project of Hunan Province,ChinaProject(15A001) supported by Scientific Research Fund of Hunan Provincial Education Department,China+2 种基金Project(2017CL06) supported by Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation,ChinaProject(k1403029-11) supported by Science and Technology Project of Changsha City,ChinaProject(CX2015B372) supported by the Hunan Provincial Innovation Foundation for Postgraduate,China
文摘The thermal decomposition temperature is one of the most important parameters to evaluate fire hazard of organic peroxide. A quantitative structure-property relationship model was proposed for estimating the thermal decomposition temperatures of organic peroxides. The entire set of 38 organic peroxides was at random divided into a training set for model development and a prediction set for external model validation. The novel local molecular descriptors of AT1, AT2, AT3, AT4, AT5, AT6 and global molecular descriptor of ATC have been proposed in order to character organic peroxides’ molecular structures. An accurate quantitative structure-property relationship （QSPR） equation is developed for the thermal decomposition temperatures of organic peroxides. The statistical results showed that the QSPR model was obtained using the multiple linear regression （MLR） method with correlation coefficient （R）, standard deviation （S）, leave-one-out validation correlation coefficient （RCV） values of 0.9795, 6.5676 ℃ and 0.9328, respectively. The average absolute relative deviation （AARD） is only 3.86% for the experimental values. Model test by internal leave-one-out cross validation and external validation and molecular descriptor interpretation were discussed. Comparison with literature results demonstrated that novel local and global descriptors were useful molecular descriptors for predicting the thermal decomposition temperatures of organic peroxides.
基金supported by grants from the National Natural Science Foundation of China (31572324)the General Program of Natural Science Foundation of the Higher Education Institutions of Jiangsu Province, China (16KJB180017)+2 种基金the College Students’ Innovation and Entrepreneurship Training Program Project of Jiangsu Province, China (201813843009Y)the Jiangsu Agricultural Scientific Self-innovation Fund, China (CX[15]1053)a grant from Priority Academic Program Development of Jiangsu Higher Education Institutions, China
文摘Toll-like receptors(TLRs) are the critical superfamily homologues that initiate sensing of the invasion of pathogens by the Toll pathway. As one of several intracellular nucleic acid-sensing TLRs, TLR13 is activated by an unmethylated motif present in the large ribosomal subunit of bacterial RNA. However, little attention has been paid to the function of TLR13 gene homologue from Laodelphax striatellus(designated as LsToll-13) in the immune response to rice stripe virus(RSV). Herein, LsToll-13 was cloned and characterized using RACE-PCR. Phylogenetic analysis showed that LsToll-13 was clustered with the TLR13 from six insects. Real-time PCR analysis demonstrated that the expression level of LsToll-13 was significantly reduced in L. striatellus with RSV infection compared with that in the naive strain. When the expression of LsToll-13 was significantly up-regulated at 6 h after bacterial infection, the expression of ribonucleoprotein(RNP) indicated that the RSV titer in the host insect was significantly suppressed. Upon knockdown of LsToll-13, using RNA interference(RNAi) in L. striatellus, the expression level of RNP was significantly increased with enhanced RSV accumulation, suggesting that LsToll-13 potentially protects L. striatellus from RSV infection. Taken together, our results indicated that LsToll-13 might be involved in the immune response of L. striatellus to RSV infection, and provided a new insight into further elucidating the molecular mechanisms of complex pathogen-host interactions and integrative pest management.
基金financially supported by the National Key R&D Project from Ministry of Science and Technology,China(2016YFA0202702,2016YFA0202701)the Key Research Program of Frontier Sciences,CAS(ZDBS-LY-DQC025)
文摘Flexible electronic sensors composed of flexible film and conductive materials play an increasingly important role in wearable and internet information transmission.It has received more and more attention and made some progress over the decades.However,it is still a great challenge to prepare biocompatible and highly transparent conductive films.Egg white is a pure natural protein-rich material.Hydroxypropylmethyl cellulose has a good compatibility and high transparency,which is an ideal material for flexible sensors.Here,we overcome the problem of poor mechanical flexibility and electrical conductivity of protein,and develop a high transparency and good flexibility hydroxypropylmethyl cellulose/egg white protein composite membrane-based triboelectric nanogenerator('X'-TENG).The experimental results show that the flexible pressure sensor based on'X'-TENG has a high sensitivity,fast response speed,and low detection limit.It can even be used as a touch/pressure sensing artificial electronic skin.It can also be made into an intelligent waffle keyboard for recording and tracking users of the keyboard.Our strategy may provide a new way to easily build flexible electronic sensors and move toward practical applications.
基金Supported by the National Basic Research Program of China (973 Program,2010CB126104)the NNSFC (Nos. 20572019 and 20872033)+3 种基金National Twelfth-five Key Project of China (Nos. 2011BAE06B01 and 2011BAE06B02)the NSF of Hunan Province (11JJ2006, 11JJ3022 and 10JJ3053)Science Plan of Hunan Province (2010FJ2003)research condition innovation of Hunan Province (2010PT2058)
文摘The title compound N-（（6-chloropyridin-3-yl）methyl）-6-ethoxy-N-ethyl-3-nitropyri-din-2-amine（4） was synthesized by reacting the mixture of 6-chloro-2-ethoxy-3-nitropyridine（1） and 2-chloro-6-ethoxy-3-nitropyridine（2） with 3,and its structure was determined by X-ray single-crystal diffraction.The crystal belongs to the monoclinic system,space group P21/n with a = 7.3441（2）,b = 9.9041（3）,c = 11.7368（3） ,α = 101.410（2）,β = 102.1340（10）,γ = 99.594（2）o,μ = 0.260 mm^-1,Mr = 336.78,V = 798.58（4）（A°）^3,Z = 2,Dc = 1.401g/cm^3,F（000） = 352,T = 296（2） K,R = 0.0210 and wR = 0.1053.
基金Supported by the National Natural Science Foundation of China (20872033, 20575019)Natural Science Foundation of Hunan Province (07JJ1003)+1 种基金Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China) (KLCBTCMR2008-14)Scientific Research Fund of Science and Technology Department of Hunan Province (No. 2006GK3067)
文摘The title compound ethyl 2-（6-（1,3-dioxo-4,5,6,7-tetrahydro-lH-isoindol-2（3H）- yl）-7-fluoro-3-oxo-2H-benzo[b][1,4]oxazin-4（3H）-yl） butanoate 3 was synthesized by the reaction of ethyl 2-（6-amino-7-fluoro-3-oxo-2H-benzo[b][1,4]oxazin-4（3H）-yl） butanoate with 4,5,6,7- tetraydrophthalic anhydride, and its structure was determined by X-ray single-crystal diffraction. The crystal belongs to the monoclinic system, space group P2 1/n with a = 9.3469（2）, b = 16.7715（5）, c = 13.7153（4） A, β= 104.9680（10）°, μ = 0.107 mm^-1, Mr = 430.42, V= 2077.08（10） ,A3, Z= 4, Dc = 1.376 g/cm3, F（000） = 904, T= 296（2） K, R = 0.0508 and wR = 0.1478.
基金This work was financially supported by the National Natural Science Foundation of China (No.51977114,52177020)Fundamental Research Funds for the Central Universities (No.FRF-NP-19-008 and FRF-TP-20-02B2)Scientific and Techno-logical Innovation Foundation of Foshan (BK21BE006).
文摘Recyclability and self-healing are two most critical factors in developing sustainable polymers to deal with environmental pollution and resource waste.In this work,a dynamic cross-linked polyimide insulation film with full closed-loop recyclability is successfully prepared,which also possesses good self-healing ability after being mechanical/electrical damaged depending on the Schiff base dynamic covalent bonds.The recycled and self-healed polyimide film still maintain its good tensile strength(r t)>60 MPa with Young’s modulus(E)>4 GPa,high thermal stability with glass transition temperature(T g)>220℃,and outstanding insulation property with breakdown strength(E 0)>358 kV mm^(-1),making it a very promising low energy consumption and high temperature resistant insulation material.The strategy of using Schiff base dynamic covalent bonds for reversible repairing the structure of high T g polyimides promotes the wider application of such sustainable and recyclable material in the field of electrical power and micro-electronics.
文摘Spectral analysis was a method of identifying substances, determining their chemical composition and calculating their content based on their spectral characteristics. This paper mainly discussed the application of various spectroscopic techniques, mainly including atomic absorption spectrometry (AAS) inductively coupled plasma emission spectrometry (ICP-AES) X-ray fluorescence spectroscopy (XRF) atomic fluorescence spectroscopy (AFS) direct reading spectroscopy (OES) glow discharge emission spectroscopy (GD-OSE) laser-induced breakdown spectroscopy (LIBS), in the formulation of non-ferrous metal standards in China. The AAS method was the most widely used single-element microanalysis method among the non-ferrous metal standards. The ICP-AES method was good at significant advantages in the simultaneous detection of multiple elements. The XRF method was increasingly used in the determination of primary and secondary trace elements due to its simple sample preparation and high efficiency. The AFS was mostly detected by single-element trace analysis. OES GD-OES and LIBS were playing an increasingly important role in the new demand area for non-ferrous metals. This paper discussed matrix elimination, sample digestion, sample preparation, instrument categories and other aspects of some standards, and summarized the advantages of spectral analysis and traditional chemical analysis methods. The new methods of future spectroscopic technology had been illustrated in the process of developing non-ferrous metal standards.
