Compounds 1 （C17H22N2,Mr =254.37） and 2 （C13H16N2,Mr=200.28） have been synthesized and their crystal structures were determined by single-crystal X-ray diffraction.Crystal 1 belongs to triclinic,space group P（1）...Compounds 1 （C17H22N2,Mr =254.37） and 2 （C13H16N2,Mr=200.28） have been synthesized and their crystal structures were determined by single-crystal X-ray diffraction.Crystal 1 belongs to triclinic,space group P（1） with a =6.524（2）,b =8.987（3）,c =12.746（5） A,α =95.220（7）,β =90.055（6）,γ =104.431（6）°,V =720.5（4） A^3,Z =2,Dc =1.173 g/cm^3,μ（MoKα） =0.069 mm1,F（000） =276,R =0.0578 and wR =0.1221 for 1487 observed reflections Ⅰ 〉 2o（Ⅰ）.Crystal 2 is of tetragonal system,space group Ⅰ41/a with a =20.763（10）,b =20.763（10）,c =11.427（6） A,V=4926（4） A3,Z =16,Dc =1.080 g/cm^3,μ（MoKα） =0.065 mm-1,F（000） =1728,R =0.0581 and wR =0.1288 for 1408 observed reflections with Ⅰ 〉 2σ（Ⅰ）.Although the two compounds are similar with the same pyrazole and benzene ring units,X-ray analysis reveals that their structures are completely different maybe caused by steric effects.展开更多
The goal of photocatalytic CO_(2)reduction is to obtain a single energy-bearing product with high efficiency and stability.Consequently,constructing highly selective photocatalysts with enhanced surface and optoelectr...The goal of photocatalytic CO_(2)reduction is to obtain a single energy-bearing product with high efficiency and stability.Consequently,constructing highly selective photocatalysts with enhanced surface and optoelectronic properties is crucial for achieving this objective.Here,we have developed a simple one-pot vulcanization method to synthesize a MIL-68(In)-derived Cd In_(2)S_(4)/In_(2)S_(3)heterojunction that exhibited stable and high selectivity.Multiple characterizations of the Cd In_(2)S_(4)/In_(2)S_(3)heterojunction revealed a hierarchical tubular structure with numerous surface reactive sites,a high visible-light utilization rate(λ<600 nm),efficient charge separation,and a prolonged charge-carrier lifetime.Moreover,an S-scheme charge transfer mechanism,based on the interleaved band between the two components,improved the reduction capability of the electrons.Benefiting from the compositional and structural synergy,the yield CO by Cd In_(2)S_(4)/In_(2)S_(3)-250(CI-250)reached 135.62μmol·g^(-1)·h^(-1),which was 49.32 times and 32.88 times higher than that of In_(2)S_(3)and Cd In_(2)S_(4),respectively.The Cd In_(2)S_(4)/In_(2)S_(3)heterojunction exhibited a quantum efficiency of 4.23%with a CO selectivity of 71%.Four cycle tests confirmed the good stability and recyclability of the CI-250.This work provides a new approach for designing and preparing high-performance hollow MOFsbased photocatalysts for scalable and sustainable CO_(2)reduction.展开更多
By investigating 17 peptide arylthioesters that were previously challenging to produce,this study reveals a clear correlation between increased ligation activity and decreased pKa values of their corresponding arylthi...By investigating 17 peptide arylthioesters that were previously challenging to produce,this study reveals a clear correlation between increased ligation activity and decreased pKa values of their corresponding arylthiols.The observed differences are attributed to variations in thioester bond strength and steric hindrance.These insights have led to the development of an improved one-pot chemical protein synthesis approach that leverages the reactivity differences between peptide arylthioesters with C-terminal Ala-SPh(4-NO_(2))and Ala-S-Ph(2,6-diCH_(3)).This approach eliminates the need for thiol-thioester exchange and additive removal steps while enabling in situ desulfurization,thereby significantly simplifying the protein synthesis process.展开更多
Rare earth metal oxides possess unique electronic properties,which are highly desirable for the fabrication of pseudocapacitor electrodes.The present study demonstrates the synthesis of boron doped graphitic carbon ni...Rare earth metal oxides possess unique electronic properties,which are highly desirable for the fabrication of pseudocapacitor electrodes.The present study demonstrates the synthesis of boron doped graphitic carbon nitride composite with varying concentrations of cerium(B-g-C_(3)N_(4)-Ce(wt%))via a facile one-pot method.A detailed investigation was carried out to elucidate the effects of doping as well as the amount of cerium on the active electrode structure.The structure and morphology of the samples were analyzed using X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),energy dispersive spectroscopy(EDS)and X-ray photoelectron spectroscopy(XPS).The structural and morphological analysis suggests the incorporation of boron into the graphitic carbon nitride phase,with spherical cerium oxide particles being embedded homogeneously in that matrix.Electrochemical characterization of the samples was carried out using cyclic voltammetry(CV),galvanostatic charge-discharge(GCD)and electrochemical impedance spectroscopy(EIS)and it is found that in-between the potential window of 0-0.45 V in a 3 mol/L potassium hydroxide(KOH)electrolyte,the Bg-C_(3)N_(4)-Ce(3%)composite displays a superior specific capacitance value of 1826.7 F/g at a current density of 1.5 A/g.The B-g-C_(3)N_(4)-Ce(3%)demonstrates excellent pseudocapacitance behavior with a high pseudocapacitance contribution.At current densities of 7.5 A/g,the heterostructure composite B-g-C_(3)N_(4)-Ce(3%)shows capacitance retention of 87%after 10000 cycles.The synergistic contribution of the individual components of the composite is explained for a better understanding of the capacitive mechanism.展开更多
A novel method for synthesis of substituted u-oxo-bis[tetraphenyl porphyrinatoiron] compotmds （[TRPPFe]20） based on the reaction among free base porphyrins （TRPPH2）, FeSO4·7H2O and H2O in one pot was proposed...A novel method for synthesis of substituted u-oxo-bis[tetraphenyl porphyrinatoiron] compotmds （[TRPPFe]20） based on the reaction among free base porphyrins （TRPPH2）, FeSO4·7H2O and H2O in one pot was proposed and investigated. Four kinds of [TRPPFe]2O were synthesized by this novel synthetic method, and their structures were characterized by elemental analysis, infrared spectra and UV-vis spectroscopy. The reaction conditions, including the effect of different iron salts on the formation of [TRPPFe]2O, the reaction time between FeSO4-7H2O and TRPPH2, the molar ratio of FeSO4-7H2O/TRPPH2 as well as the volume ratio of H2O/DMF, were investigated. The [TRPPFe]2O yield of 93% 98% could be obtained under the following optimal conditions： the reaction time of FeSOn-7H2O with TRPPH2 was about 10 h, the molar ratio of FeSOn-7H2O/TRPPH2 about 5 ： 1, and the volume ratio of H2O/DMF exceeded 2 ： 1. Further research indicated that only TRPPFeCI were formed once FeSOn-7H2O was replaced by FeCl2-4H2O, the reason of which might be that halogen ions in iron salts interfered the formation of [TRPPFe]2O, suggesting that halogen ions should be avoided in this novel synthetic method.展开更多
A mild, one-pot procedure for the synthesis of vinyl ethers in good yields from 2-hydroxyalkyl phenyl selenides with primary or secondary organic halides has been developed.
The component synthesis active vibration suppression method （CSVS） can be applied to suppress the vibration of flexible systems. By this method, several same or similar time-varying components are arranged according...The component synthesis active vibration suppression method （CSVS） can be applied to suppress the vibration of flexible systems. By this method, several same or similar time-varying components are arranged according to certain rules along the time axis. The synthesized command can suppress the arbitrary unwanted vibration harmonic while achieving the desired rigid body motion. The number of the components increases rapidly when the number of harmonic vibration is growing. In this article, the CSVS based on zero-placement technique is used to construct the synthesized command to suppress the multi-harmonics simultaneously in the discrete domain. The nature of zero-placement method is to put enough zeros to cancel system poles at necessary points. The designed synthesized command has equal time intervals between each component and which is much easier to be implemented. Using this method, the number of components increases linearly with the increasing of the number of being suppressed harmonics. For the spacecraft with flexible appendages, CSVS based on zero-placement is used to design the time optimal large angle maneuver control strategy. Simulations have verified the validity and superiority of the proposed approach.展开更多
Many methods are proposed to deal with the type synthesis of parallel kinematic mechanisms（PKMs）, but most of them are less intuitive to some extent. Thus, to propose a concise and intuitive type synthesis method fo...Many methods are proposed to deal with the type synthesis of parallel kinematic mechanisms（PKMs）, but most of them are less intuitive to some extent. Thus, to propose a concise and intuitive type synthesis method for engineering application is a very challenging issue, which should be further studied in the field. Grassmann line geometry, which can investigate the dimensions of spatial line-clusters in a concise way, is taken as the mathematic foundation. Atlas method is introduced to visually describe the degrees of freedom（DOFs） and constraints of a mechanism, and the dual rule is brought in to realize the mutual conversion of the freedom-space and constraint-space. Consequently, a systematic method based on Grassmann line geometry and Atlas method is generated and the entire type synthesis process is presented. Three type 4-DOF PKMs, i.e., 1T3R, 2T2R and 3T1R（T： translational DOF; R： rotational DOF）, are classified according to the different combinations of the translational DOFs and rotational DOFs. The type synthesis of 4-DOF PKMs is carried out and the possible configurations are thoroughly investigated. Some new PKMs with useful functions are generated during this procedure. The type synthesis method based on Grassmann line geometry and Atlas method is intuitive and concise, and can reduce the complexity of the PKMs＇ type synthesis. Moreover, this method can provide theoretical guidance for other PKMs＇ type synthesis and engineering application. A novel type synthesis method is proposed, which solves the existing methods＇ problems in terms of complicated, not intuitive and unsuitable for practical application.展开更多
The effect of synthesis methods on the activity of V/Ce/WTi catalysts was investigated for the selective catalytic reduction（SCR） of NO_x by NH_3. V/Ce/WTi-DP（deposition precipitation） catalyst showed excellent NH...The effect of synthesis methods on the activity of V/Ce/WTi catalysts was investigated for the selective catalytic reduction（SCR） of NO_x by NH_3. V/Ce/WTi-DP（deposition precipitation） catalyst showed excellent NH_3-SCR performance, especially the better medium-temperature activity and the less N_2O formation than V/Ce/WTi-IMP（impregnation）. These catalysts were characterized by X-ray diffraction（XRD）, Brumauer-Emmett-Teller（BET）, X-ray photoelectron spectroscopy（XPS）, temperature-programmed reduction（H_2-TPR）, and in situ DRIFTS techniques. The XPS and H_2-TPR results revealed that V/Ce/WTi-DP exhibited more surface Ce species, higher level of Oα and higher reducibility of Ce species. Reflected by in situ DRIFTS results, the deposition precipitation method（DP） contributed to a greater amount of weakly adsorbed NO_2, monodentate nitrate and NH_3 species with better reactive activity. Meanwhile, the cis-N_2O_2^（2-） species, an intermediate for N_2O formation, was very limited. As a result, these advantages brought about the superior SCR activity and N_2 selectivity for V/Ce/WTi-DP.展开更多
A highly branched polycarbosilane bearing allyl groups has been prepared by a one-pot synthesis with chloromethyltrichlorosilane, chloromethylmethyldichlorosilane and allyl chloride as the starting materials. The resu...A highly branched polycarbosilane bearing allyl groups has been prepared by a one-pot synthesis with chloromethyltrichlorosilane, chloromethylmethyldichlorosilane and allyl chloride as the starting materials. The resultant polymer, with the approximate formula [SiH1.2(CH3)0.71(CH2CHCH2)0.09CH2]n, has been characterized by 1H, 13C, and 29Si NMR, GPC, TG and elemental analysis. It could be cross-linked thermally at 170 °C in the absence of oxygen. Pyrolysis of the polymer gave a ceramic with a yield of about 70%.展开更多
An efficient and environmental-friendly one-pot procedure has been developed for the synthesis of 1,3,4-oxadiazole-5- thioethers by the reaction of acylhydrazine with carbon disulfide and organic halides or α, β-uns...An efficient and environmental-friendly one-pot procedure has been developed for the synthesis of 1,3,4-oxadiazole-5- thioethers by the reaction of acylhydrazine with carbon disulfide and organic halides or α, β-unsaturated carbonyl compounds. The reactions were carried out in water in the presence of potassium phosphate within 2-4 h to afford the expected products in excellent yields.展开更多
A facile one-pot synthesis of 2-aminothiazoles has been carried in PEG-400 as a greener medium at room temperature.This method avoids the use of lachrymatric a-bromoketones as well as the volatile,toxic organic solvents.
Using cetyltrimethylammonium bromide （CTAB） as the template agent, cerium nitrate as the cerium resource, yttrium nitrate as the yttrium resource, and ammonium carbonate as the precipitating agent, mesoporous CeO2 p...Using cetyltrimethylammonium bromide （CTAB） as the template agent, cerium nitrate as the cerium resource, yttrium nitrate as the yttrium resource, and ammonium carbonate as the precipitating agent, mesoporous CeO2 powders doped with different yttrium contents were successfully synthesized using a chemical precipitation method, under an alkalescent condition. Properties of the obtained samples were characterized and analyzed with X-ray diffraction （XRD）, energy dispersive analysis of X-rays （EDAX）, transmission electron microscopy （TEM）, infrared （IR） absorbance, and the BET method. For the prepared samples with 20% （molar ratio） Y-doped content, a BET specific surface area of 106. 6 m^2 · g^- 1, with an average pore size of3~27 nm were obtained. XRD patterns showed that the doped samples were with a cubic fluorite structure. TEM micrographs revealed that the doped samples showed a spherical morphology with a diameter ranging from 20 to 30 nm and a round pore shape. IR results indicated that the Ce-O-Ce vibration intensity decreased as the Y-doped content increased. N2 adsorption-desorption isotherms showed that the samples possessed typical mesopore characteristics. The average pore size of the samples decreased alter mesoporous CeO2 was doped with yttrium, and the average pore size decreased largely as the Y-doped content increased.展开更多
Hydro isomerization of linear alkanes to branched isomers is an important petrochemical process for production of gasoline with high octane number.Non-noble metal bifunctional catalysts used in this process always suf...Hydro isomerization of linear alkanes to branched isomers is an important petrochemical process for production of gasoline with high octane number.Non-noble metal bifunctional catalysts used in this process always suffer from low metal dispersion and poor metal-acid synergy.Herein,a facile one-pot synthesis method was used to simultaneously regulate metal particle sizes and acidity of the Ni-SAPO-11 hydroisomerization catalyst.The physicochemical properties are investigated using XANES,EXAFS,TEM/STEM,FT-IR,XPS,UV-vis and NH_3-TPD.Apart from the highly dispersed nickel nanoparticles with an average diameter of 8 nm,the framework Ni~(2+)ions are generated via substituting framework Al~(3+)ions of the SAPO-11.The formed NiP-OH structures have lower deprotonation energy(DPE)than the SiAl-OH ones,contributing more and stronger acid sites to the Ni-SAPO-11 catalyst.The great metal-acid synergy including high metal to acid sites ratio(n_(Ni)/n_A)and close intimacy is obtained for the Ni-SAPO-11 catalyst.The Ni-SAPO-11 catalyst outperforms the counterpart prepared by the impregnation method and exhibits comparable activity and isomers selectivity to the Pt/SAPO-11 catalyst in the n-hexane hydroisomerization.展开更多
SiO2-CaO-MgO glass and glass-ceramic powder doped with Nd3＋ were synthesized with sol-gel method. Tetraethylorthosilicate （TEOS）, Ca（NO3）2？4H2O, Mg（NO3）2？6H2O, Nd（NO3）3？6H2O, ethanol, distilled water, and ...SiO2-CaO-MgO glass and glass-ceramic powder doped with Nd3＋ were synthesized with sol-gel method. Tetraethylorthosilicate （TEOS）, Ca（NO3）2？4H2O, Mg（NO3）2？6H2O, Nd（NO3）3？6H2O, ethanol, distilled water, and HNO3 were used as starting materials. The synthesized powder’s properties were examined with simultaneous thermal analysis （STA）, X-ray diffraction （XRD）, photoluminescence （PL） and scanning electron microscopy （SEM） analysis. The STA curves showed that the softening point and crystallization temperatures were shifted to higher temperatures with increasing dopant content. Regarding XRD patterns of glass samples, Nd was found to act as an intermediate oxide in glass matrix. The XRD patterns of glass-ceramic samples indicated that bredigite and akermanite crystallized in the glass matrix after heat treating at 900 oC. The fluorescence spectra showed that glass-ceramics emitted much stronger irradiation than glasses with the same dopant content. The SEM images illustrated uniform and homogeneous distribution of applied oxides in glass and glass-ceramic compositions.展开更多
Novel Lewis acidic ionic liquids containing thionyl cations and chloroaluminate anions were obtained by one-pot synthesis for the first time. Their acidities were determined by acetonitrile probe on IR spectrography. ...Novel Lewis acidic ionic liquids containing thionyl cations and chloroaluminate anions were obtained by one-pot synthesis for the first time. Their acidities were determined by acetonitrile probe on IR spectrography. The ionic liquids were used as catalyst for Friedel-Crafts alkylation of benzene and 1-dodecene. The turnovers of l-dodecene were higher than 99%. Monoalkylbenzene selectivity was 98%, while the 2-substituent product selectivity was 45%.展开更多
In this study,a convenient method of preparing the substrate is proposed with one-pot synthesis of silver colloid under body heat,and the SERS detection uses the fresh substrate to avoid the drawback of substrates’sh...In this study,a convenient method of preparing the substrate is proposed with one-pot synthesis of silver colloid under body heat,and the SERS detection uses the fresh substrate to avoid the drawback of substrates’short life of use.The synthesis of silver colloid is carried out in a 10 mL vial by using ascorbic acid as a reductant and trisodium citrate as a stabilizer.The vial is grasped with the palm of the experimenter for several minutes without shaking.The proposed method is simple,rapid,green energy and cost-effective.By adjusting the concentration of trisodium citrate,not only the particle size can be controlled from about 110 nm to 50 nm but also the homogeneity of nanoparticles can be improved.As a SERS substrate,the silver colloid has high batch reproducibility and showed good SERS activity.The relative standard deviation between different manufacturers is 5.51%when the substrate of silver colloid is used for the detection of rhodamine 6 G.Using the substrate,the lowest detection concentrations of rhodamine 6 G,crystal violet,enrofloxacin,melamine and leucomalachite green are 1.0×10-8,6.1×10-8,1.4×10-6,7.1×10-5 and 5.1×10-8 mol/L,respectively.Results demonstrate that the developed method has the advantage of convenience and high efficiency in the field preparation of reliable SERS substrate.展开更多
The current type synthesis of the redundant actuated parallel mechanisms is adding active-actuated kinematic branches on the basis of the traditional parallel mechanisms,or using screw theory to perform multiple getti...The current type synthesis of the redundant actuated parallel mechanisms is adding active-actuated kinematic branches on the basis of the traditional parallel mechanisms,or using screw theory to perform multiple getting intersection and union to complete type synthesis.The number of redundant parallel mechanisms obtained by these two methods is limited.In this paper,based on Grassmann line geometry and Atlas method,a novel and effective method for type synthesis of redundant actuated parallel mechanisms(PMs)with closed-loop units is proposed.Firstly,the degree of freedom(DOF)and constraint line graph of the moving platform are determined successively,and redundant lines are added in constraint line graph to obtain the redundant constraint line graph and their equivalent line graph,and a branch constraint allocation scheme is formulated based on the allocation criteria.Secondly,a scheme is selected and redundant lines are added in the branch chains DOF graph to construct the redundant actuated branch chains with closed-loop units.Finally,the branch chains that meet the requirements of branch chains configuration criteria and F&C(degree of freedom&constraint)line graph are assembled.In this paper,two types of 2 rotational and 1 translational(2R1T)redundant actuated parallel mechanisms and one type of 2 translational and 1 rotational(2T1R)redundant actuated parallel mechanisms with few branches and closed-loop units were taken as examples,and 238,92 and 15 new configurations were synthesized.All the mechanisms contain closed-loop units,and the mechanisms and the actuators both have good symmetry.Therefore,all the mechanisms have excellent comprehensive performance,in which the two rotational DOFs of the moving platform of 2R1T redundant actuated parallel mechanism can be independently controlled.The instantaneous analysis shows that all mechanisms are not instantaneous,which proves the feasibility and practicability of the method.展开更多
Chloropropyl-functionalized mesoporous MCM-41（MCM-41-（CH2）3Cl） was synthesized in alkaline medium by the microwave radiation one-pot method, using cetyltrimethy-lammoniumbromide （CTAB） as novel template, tetraet...Chloropropyl-functionalized mesoporous MCM-41（MCM-41-（CH2）3Cl） was synthesized in alkaline medium by the microwave radiation one-pot method, using cetyltrimethy-lammoniumbromide （CTAB） as novel template, tetraethoxysilane （TEOS） as silica source, and chloropropyltriethoxysilane （C1PTES） as the coupling agent. The microstructure of MCM-41-（CH2）3Cl was characterized by the means of X-ray diffraction （XRD）, nitrogen absorption-desorption, Fourier transform infrared spectroscopy （FT-IR）, scanning electron microscopy （SEM）, and transmission electron microscopy （TEM）. The results show that a successful synthesis of MCM-41-（CH2）3Cl with well structure is obtained. The optimal microwave power is 120 W and the best microwave time is 50 rain. The dosage of chloropropyltriethoxysilane on the structure of chloropropyl-functionalzed MCM-41 was also investigated. It is found that the chloropropyltriethoxysilane volume between 0.8 mL and 1.6 mL is favorable for the formation of highly ordered MCM-41-（CH2）3Cl mesostructure.展开更多
基金Supported by Hubei University of Technology,Science and Technology Department of Hubei Province(No.2012FFB00706)National Natural Science Foundation of China(No.21272086)
文摘Compounds 1 （C17H22N2,Mr =254.37） and 2 （C13H16N2,Mr=200.28） have been synthesized and their crystal structures were determined by single-crystal X-ray diffraction.Crystal 1 belongs to triclinic,space group P（1） with a =6.524（2）,b =8.987（3）,c =12.746（5） A,α =95.220（7）,β =90.055（6）,γ =104.431（6）°,V =720.5（4） A^3,Z =2,Dc =1.173 g/cm^3,μ（MoKα） =0.069 mm1,F（000） =276,R =0.0578 and wR =0.1221 for 1487 observed reflections Ⅰ 〉 2o（Ⅰ）.Crystal 2 is of tetragonal system,space group Ⅰ41/a with a =20.763（10）,b =20.763（10）,c =11.427（6） A,V=4926（4） A3,Z =16,Dc =1.080 g/cm^3,μ（MoKα） =0.065 mm-1,F（000） =1728,R =0.0581 and wR =0.1288 for 1408 observed reflections with Ⅰ 〉 2σ（Ⅰ）.Although the two compounds are similar with the same pyrazole and benzene ring units,X-ray analysis reveals that their structures are completely different maybe caused by steric effects.
基金financially supported by the Program for the Development of Science and Technology of Jilin Province(Nos.20240601047RC and YDZJ202201ZYTS629)Hainan Province Science and Technology Special Fund(No.ZDYF2022SHFZ090)+1 种基金the National Natural Science Foundation(Nos.22466017 and 22061014)the specific research fund of the Innovation Platform for Academicians of Hainan Province。
文摘The goal of photocatalytic CO_(2)reduction is to obtain a single energy-bearing product with high efficiency and stability.Consequently,constructing highly selective photocatalysts with enhanced surface and optoelectronic properties is crucial for achieving this objective.Here,we have developed a simple one-pot vulcanization method to synthesize a MIL-68(In)-derived Cd In_(2)S_(4)/In_(2)S_(3)heterojunction that exhibited stable and high selectivity.Multiple characterizations of the Cd In_(2)S_(4)/In_(2)S_(3)heterojunction revealed a hierarchical tubular structure with numerous surface reactive sites,a high visible-light utilization rate(λ<600 nm),efficient charge separation,and a prolonged charge-carrier lifetime.Moreover,an S-scheme charge transfer mechanism,based on the interleaved band between the two components,improved the reduction capability of the electrons.Benefiting from the compositional and structural synergy,the yield CO by Cd In_(2)S_(4)/In_(2)S_(3)-250(CI-250)reached 135.62μmol·g^(-1)·h^(-1),which was 49.32 times and 32.88 times higher than that of In_(2)S_(3)and Cd In_(2)S_(4),respectively.The Cd In_(2)S_(4)/In_(2)S_(3)heterojunction exhibited a quantum efficiency of 4.23%with a CO selectivity of 71%.Four cycle tests confirmed the good stability and recyclability of the CI-250.This work provides a new approach for designing and preparing high-performance hollow MOFsbased photocatalysts for scalable and sustainable CO_(2)reduction.
基金CAMS Innovation Fund for Medical Sciences(CIFMS,No.2021-I2M-1-026)the National Key R&D Program of China(No.2018YFE0111400)+6 种基金the NIH Research Project Grant Program(No.R01 EB025892)the National Natural Science Foundation of China(the Training Program of the Major Research Plan,No.91853120)the National Major Scientific and Technological Special Project of China(Nos.2018ZX09711001-005 and 2018ZX09711001-013)the State Key Laboratory of Bioactive Substance and Function of Natural Medicines,Institute of Materia Medicathe Biomedical High Performance Computing Platform,Chinese Academy of Medical Sciencesthe Chinese Academy of Medical SciencesPeking Union Medical College for funding and support.
文摘By investigating 17 peptide arylthioesters that were previously challenging to produce,this study reveals a clear correlation between increased ligation activity and decreased pKa values of their corresponding arylthiols.The observed differences are attributed to variations in thioester bond strength and steric hindrance.These insights have led to the development of an improved one-pot chemical protein synthesis approach that leverages the reactivity differences between peptide arylthioesters with C-terminal Ala-SPh(4-NO_(2))and Ala-S-Ph(2,6-diCH_(3)).This approach eliminates the need for thiol-thioester exchange and additive removal steps while enabling in situ desulfurization,thereby significantly simplifying the protein synthesis process.
基金supported by Indian National Science Academy Visiting Scientist Fellowship(INSA/SP/VSP-15/2022-23)。
文摘Rare earth metal oxides possess unique electronic properties,which are highly desirable for the fabrication of pseudocapacitor electrodes.The present study demonstrates the synthesis of boron doped graphitic carbon nitride composite with varying concentrations of cerium(B-g-C_(3)N_(4)-Ce(wt%))via a facile one-pot method.A detailed investigation was carried out to elucidate the effects of doping as well as the amount of cerium on the active electrode structure.The structure and morphology of the samples were analyzed using X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),energy dispersive spectroscopy(EDS)and X-ray photoelectron spectroscopy(XPS).The structural and morphological analysis suggests the incorporation of boron into the graphitic carbon nitride phase,with spherical cerium oxide particles being embedded homogeneously in that matrix.Electrochemical characterization of the samples was carried out using cyclic voltammetry(CV),galvanostatic charge-discharge(GCD)and electrochemical impedance spectroscopy(EIS)and it is found that in-between the potential window of 0-0.45 V in a 3 mol/L potassium hydroxide(KOH)electrolyte,the Bg-C_(3)N_(4)-Ce(3%)composite displays a superior specific capacitance value of 1826.7 F/g at a current density of 1.5 A/g.The B-g-C_(3)N_(4)-Ce(3%)demonstrates excellent pseudocapacitance behavior with a high pseudocapacitance contribution.At current densities of 7.5 A/g,the heterostructure composite B-g-C_(3)N_(4)-Ce(3%)shows capacitance retention of 87%after 10000 cycles.The synergistic contribution of the individual components of the composite is explained for a better understanding of the capacitive mechanism.
基金Supported by the National Natural Science Foundation of China （20776003, 20576005） and the Key Project of Natural Science Foundation of Beijing （2061001）.
文摘A novel method for synthesis of substituted u-oxo-bis[tetraphenyl porphyrinatoiron] compotmds （[TRPPFe]20） based on the reaction among free base porphyrins （TRPPH2）, FeSO4·7H2O and H2O in one pot was proposed and investigated. Four kinds of [TRPPFe]2O were synthesized by this novel synthetic method, and their structures were characterized by elemental analysis, infrared spectra and UV-vis spectroscopy. The reaction conditions, including the effect of different iron salts on the formation of [TRPPFe]2O, the reaction time between FeSO4-7H2O and TRPPH2, the molar ratio of FeSO4-7H2O/TRPPH2 as well as the volume ratio of H2O/DMF, were investigated. The [TRPPFe]2O yield of 93% 98% could be obtained under the following optimal conditions： the reaction time of FeSOn-7H2O with TRPPH2 was about 10 h, the molar ratio of FeSOn-7H2O/TRPPH2 about 5 ： 1, and the volume ratio of H2O/DMF exceeded 2 ： 1. Further research indicated that only TRPPFeCI were formed once FeSOn-7H2O was replaced by FeCl2-4H2O, the reason of which might be that halogen ions in iron salts interfered the formation of [TRPPFe]2O, suggesting that halogen ions should be avoided in this novel synthetic method.
基金the Natural Science Foundation of Jiangxi Province(No.0420017)for financial support
文摘A mild, one-pot procedure for the synthesis of vinyl ethers in good yields from 2-hydroxyalkyl phenyl selenides with primary or secondary organic halides has been developed.
文摘The component synthesis active vibration suppression method （CSVS） can be applied to suppress the vibration of flexible systems. By this method, several same or similar time-varying components are arranged according to certain rules along the time axis. The synthesized command can suppress the arbitrary unwanted vibration harmonic while achieving the desired rigid body motion. The number of the components increases rapidly when the number of harmonic vibration is growing. In this article, the CSVS based on zero-placement technique is used to construct the synthesized command to suppress the multi-harmonics simultaneously in the discrete domain. The nature of zero-placement method is to put enough zeros to cancel system poles at necessary points. The designed synthesized command has equal time intervals between each component and which is much easier to be implemented. Using this method, the number of components increases linearly with the increasing of the number of being suppressed harmonics. For the spacecraft with flexible appendages, CSVS based on zero-placement is used to design the time optimal large angle maneuver control strategy. Simulations have verified the validity and superiority of the proposed approach.
基金supported by National Natural Science Foundation of China(Grant No.51135008)National Basic Research Program of China(973 Program,Grant No.2013CB035400)China Postdoctoral Science Foundation(Grant Nos.2012M520256,2013T60107)
文摘Many methods are proposed to deal with the type synthesis of parallel kinematic mechanisms（PKMs）, but most of them are less intuitive to some extent. Thus, to propose a concise and intuitive type synthesis method for engineering application is a very challenging issue, which should be further studied in the field. Grassmann line geometry, which can investigate the dimensions of spatial line-clusters in a concise way, is taken as the mathematic foundation. Atlas method is introduced to visually describe the degrees of freedom（DOFs） and constraints of a mechanism, and the dual rule is brought in to realize the mutual conversion of the freedom-space and constraint-space. Consequently, a systematic method based on Grassmann line geometry and Atlas method is generated and the entire type synthesis process is presented. Three type 4-DOF PKMs, i.e., 1T3R, 2T2R and 3T1R（T： translational DOF; R： rotational DOF）, are classified according to the different combinations of the translational DOFs and rotational DOFs. The type synthesis of 4-DOF PKMs is carried out and the possible configurations are thoroughly investigated. Some new PKMs with useful functions are generated during this procedure. The type synthesis method based on Grassmann line geometry and Atlas method is intuitive and concise, and can reduce the complexity of the PKMs＇ type synthesis. Moreover, this method can provide theoretical guidance for other PKMs＇ type synthesis and engineering application. A novel type synthesis method is proposed, which solves the existing methods＇ problems in terms of complicated, not intuitive and unsuitable for practical application.
基金supported by the Grant from the China Huadian Science and Technology Institute(CHDI.KJ-20)the National High-Tech Research and Development Program of China(863,2011AA03A405)
文摘The effect of synthesis methods on the activity of V/Ce/WTi catalysts was investigated for the selective catalytic reduction（SCR） of NO_x by NH_3. V/Ce/WTi-DP（deposition precipitation） catalyst showed excellent NH_3-SCR performance, especially the better medium-temperature activity and the less N_2O formation than V/Ce/WTi-IMP（impregnation）. These catalysts were characterized by X-ray diffraction（XRD）, Brumauer-Emmett-Teller（BET）, X-ray photoelectron spectroscopy（XPS）, temperature-programmed reduction（H_2-TPR）, and in situ DRIFTS techniques. The XPS and H_2-TPR results revealed that V/Ce/WTi-DP exhibited more surface Ce species, higher level of Oα and higher reducibility of Ce species. Reflected by in situ DRIFTS results, the deposition precipitation method（DP） contributed to a greater amount of weakly adsorbed NO_2, monodentate nitrate and NH_3 species with better reactive activity. Meanwhile, the cis-N_2O_2^（2-） species, an intermediate for N_2O formation, was very limited. As a result, these advantages brought about the superior SCR activity and N_2 selectivity for V/Ce/WTi-DP.
文摘A highly branched polycarbosilane bearing allyl groups has been prepared by a one-pot synthesis with chloromethyltrichlorosilane, chloromethylmethyldichlorosilane and allyl chloride as the starting materials. The resultant polymer, with the approximate formula [SiH1.2(CH3)0.71(CH2CHCH2)0.09CH2]n, has been characterized by 1H, 13C, and 29Si NMR, GPC, TG and elemental analysis. It could be cross-linked thermally at 170 °C in the absence of oxygen. Pyrolysis of the polymer gave a ceramic with a yield of about 70%.
基金Natural Science Foundation of China (Grant No.20672009)the Major State Basic Research Development Program(Grant No.2004CB719900).
文摘An efficient and environmental-friendly one-pot procedure has been developed for the synthesis of 1,3,4-oxadiazole-5- thioethers by the reaction of acylhydrazine with carbon disulfide and organic halides or α, β-unsaturated carbonyl compounds. The reactions were carried out in water in the presence of potassium phosphate within 2-4 h to afford the expected products in excellent yields.
文摘A facile one-pot synthesis of 2-aminothiazoles has been carried in PEG-400 as a greener medium at room temperature.This method avoids the use of lachrymatric a-bromoketones as well as the volatile,toxic organic solvents.
基金Project supported by the International Cooperation of Science and Technology Ministry PRC (2005DFBA028)the National Natural Science Foundation of China (59925412)
文摘Using cetyltrimethylammonium bromide （CTAB） as the template agent, cerium nitrate as the cerium resource, yttrium nitrate as the yttrium resource, and ammonium carbonate as the precipitating agent, mesoporous CeO2 powders doped with different yttrium contents were successfully synthesized using a chemical precipitation method, under an alkalescent condition. Properties of the obtained samples were characterized and analyzed with X-ray diffraction （XRD）, energy dispersive analysis of X-rays （EDAX）, transmission electron microscopy （TEM）, infrared （IR） absorbance, and the BET method. For the prepared samples with 20% （molar ratio） Y-doped content, a BET specific surface area of 106. 6 m^2 · g^- 1, with an average pore size of3~27 nm were obtained. XRD patterns showed that the doped samples were with a cubic fluorite structure. TEM micrographs revealed that the doped samples showed a spherical morphology with a diameter ranging from 20 to 30 nm and a round pore shape. IR results indicated that the Ce-O-Ce vibration intensity decreased as the Y-doped content increased. N2 adsorption-desorption isotherms showed that the samples possessed typical mesopore characteristics. The average pore size of the samples decreased alter mesoporous CeO2 was doped with yttrium, and the average pore size decreased largely as the Y-doped content increased.
基金the National Natural Science Foundation of China(21978326 and 21991091)the Fundamental Research Funds for the Central Universities(20CX06059A)+2 种基金the China Postdoctoral Science Foundation(2020M682259)the Postdoctoral Applied Research Project of Qingdao(qd20200002)the Natural Science Foundation of Shandong Province(ZR2019MB029)。
文摘Hydro isomerization of linear alkanes to branched isomers is an important petrochemical process for production of gasoline with high octane number.Non-noble metal bifunctional catalysts used in this process always suffer from low metal dispersion and poor metal-acid synergy.Herein,a facile one-pot synthesis method was used to simultaneously regulate metal particle sizes and acidity of the Ni-SAPO-11 hydroisomerization catalyst.The physicochemical properties are investigated using XANES,EXAFS,TEM/STEM,FT-IR,XPS,UV-vis and NH_3-TPD.Apart from the highly dispersed nickel nanoparticles with an average diameter of 8 nm,the framework Ni~(2+)ions are generated via substituting framework Al~(3+)ions of the SAPO-11.The formed NiP-OH structures have lower deprotonation energy(DPE)than the SiAl-OH ones,contributing more and stronger acid sites to the Ni-SAPO-11 catalyst.The great metal-acid synergy including high metal to acid sites ratio(n_(Ni)/n_A)and close intimacy is obtained for the Ni-SAPO-11 catalyst.The Ni-SAPO-11 catalyst outperforms the counterpart prepared by the impregnation method and exhibits comparable activity and isomers selectivity to the Pt/SAPO-11 catalyst in the n-hexane hydroisomerization.
基金supported by the Iran Nanotechnology Initiative Council(INIC)
文摘SiO2-CaO-MgO glass and glass-ceramic powder doped with Nd3＋ were synthesized with sol-gel method. Tetraethylorthosilicate （TEOS）, Ca（NO3）2？4H2O, Mg（NO3）2？6H2O, Nd（NO3）3？6H2O, ethanol, distilled water, and HNO3 were used as starting materials. The synthesized powder’s properties were examined with simultaneous thermal analysis （STA）, X-ray diffraction （XRD）, photoluminescence （PL） and scanning electron microscopy （SEM） analysis. The STA curves showed that the softening point and crystallization temperatures were shifted to higher temperatures with increasing dopant content. Regarding XRD patterns of glass samples, Nd was found to act as an intermediate oxide in glass matrix. The XRD patterns of glass-ceramic samples indicated that bredigite and akermanite crystallized in the glass matrix after heat treating at 900 oC. The fluorescence spectra showed that glass-ceramics emitted much stronger irradiation than glasses with the same dopant content. The SEM images illustrated uniform and homogeneous distribution of applied oxides in glass and glass-ceramic compositions.
基金the grant from the National Natural Science Foundation of China （Key Program 20533010）.
文摘Novel Lewis acidic ionic liquids containing thionyl cations and chloroaluminate anions were obtained by one-pot synthesis for the first time. Their acidities were determined by acetonitrile probe on IR spectrography. The ionic liquids were used as catalyst for Friedel-Crafts alkylation of benzene and 1-dodecene. The turnovers of l-dodecene were higher than 99%. Monoalkylbenzene selectivity was 98%, while the 2-substituent product selectivity was 45%.
文摘In this study,a convenient method of preparing the substrate is proposed with one-pot synthesis of silver colloid under body heat,and the SERS detection uses the fresh substrate to avoid the drawback of substrates’short life of use.The synthesis of silver colloid is carried out in a 10 mL vial by using ascorbic acid as a reductant and trisodium citrate as a stabilizer.The vial is grasped with the palm of the experimenter for several minutes without shaking.The proposed method is simple,rapid,green energy and cost-effective.By adjusting the concentration of trisodium citrate,not only the particle size can be controlled from about 110 nm to 50 nm but also the homogeneity of nanoparticles can be improved.As a SERS substrate,the silver colloid has high batch reproducibility and showed good SERS activity.The relative standard deviation between different manufacturers is 5.51%when the substrate of silver colloid is used for the detection of rhodamine 6 G.Using the substrate,the lowest detection concentrations of rhodamine 6 G,crystal violet,enrofloxacin,melamine and leucomalachite green are 1.0×10-8,6.1×10-8,1.4×10-6,7.1×10-5 and 5.1×10-8 mol/L,respectively.Results demonstrate that the developed method has the advantage of convenience and high efficiency in the field preparation of reliable SERS substrate.
基金Supported by National Natural Science Foundation of China(Grant No.51875499).
文摘The current type synthesis of the redundant actuated parallel mechanisms is adding active-actuated kinematic branches on the basis of the traditional parallel mechanisms,or using screw theory to perform multiple getting intersection and union to complete type synthesis.The number of redundant parallel mechanisms obtained by these two methods is limited.In this paper,based on Grassmann line geometry and Atlas method,a novel and effective method for type synthesis of redundant actuated parallel mechanisms(PMs)with closed-loop units is proposed.Firstly,the degree of freedom(DOF)and constraint line graph of the moving platform are determined successively,and redundant lines are added in constraint line graph to obtain the redundant constraint line graph and their equivalent line graph,and a branch constraint allocation scheme is formulated based on the allocation criteria.Secondly,a scheme is selected and redundant lines are added in the branch chains DOF graph to construct the redundant actuated branch chains with closed-loop units.Finally,the branch chains that meet the requirements of branch chains configuration criteria and F&C(degree of freedom&constraint)line graph are assembled.In this paper,two types of 2 rotational and 1 translational(2R1T)redundant actuated parallel mechanisms and one type of 2 translational and 1 rotational(2T1R)redundant actuated parallel mechanisms with few branches and closed-loop units were taken as examples,and 238,92 and 15 new configurations were synthesized.All the mechanisms contain closed-loop units,and the mechanisms and the actuators both have good symmetry.Therefore,all the mechanisms have excellent comprehensive performance,in which the two rotational DOFs of the moving platform of 2R1T redundant actuated parallel mechanism can be independently controlled.The instantaneous analysis shows that all mechanisms are not instantaneous,which proves the feasibility and practicability of the method.
基金Project(207759096) supported by the National Natural Science Foundation of ChinaProject(20080440696) supported by the China Postdoctoral Science Foundation
文摘Chloropropyl-functionalized mesoporous MCM-41（MCM-41-（CH2）3Cl） was synthesized in alkaline medium by the microwave radiation one-pot method, using cetyltrimethy-lammoniumbromide （CTAB） as novel template, tetraethoxysilane （TEOS） as silica source, and chloropropyltriethoxysilane （C1PTES） as the coupling agent. The microstructure of MCM-41-（CH2）3Cl was characterized by the means of X-ray diffraction （XRD）, nitrogen absorption-desorption, Fourier transform infrared spectroscopy （FT-IR）, scanning electron microscopy （SEM）, and transmission electron microscopy （TEM）. The results show that a successful synthesis of MCM-41-（CH2）3Cl with well structure is obtained. The optimal microwave power is 120 W and the best microwave time is 50 rain. The dosage of chloropropyltriethoxysilane on the structure of chloropropyl-functionalzed MCM-41 was also investigated. It is found that the chloropropyltriethoxysilane volume between 0.8 mL and 1.6 mL is favorable for the formation of highly ordered MCM-41-（CH2）3Cl mesostructure.
