Ternary strategy with a suitable third component is a successful strategy to improve the photovoltaic performance of organic solar cells(OSCs).Very recently,Y-series based giant molecule acceptors or oligomerized acce...Ternary strategy with a suitable third component is a successful strategy to improve the photovoltaic performance of organic solar cells(OSCs).Very recently,Y-series based giant molecule acceptors or oligomerized acceptors have emerged as promising materials for achieving highly efficient and stable binary OSCs,while application as third component for ternary OSCs is limited.Here a novelπ-extended giant dimeric acceptor,GDF,is developed based on central Y series core fusion and rigid BDT as linker,and then incorporated into the state-of-the-art PM1:PC6 system to construct ternary OSCs.The GDF has a near planar backbone,resulting in increasedπ-conjugation,excellent crystallinity,and good electron transport capacity.When GDF is introduced into the PM1:PC6 system,it ensues in a cascade like the lowest unoccupied molecular orbitals(LUMO)energy level alignment,a complementary absorption band with PM1 and PC6,higher and balanced hole and electron mobility,slightly smaller domain size,and a higher exciton dissociation probability for PM1:PC6:GDF(1:1.1:0.1)blend film.As a consequence,the PM1:PC6:GDF(1:1.1:0.1)ternary OSC achieves a champion PCE of 19.22%,with a significantly higher open-circuit voltage and short-circuit current density,compared to 18.45%for the PM1:PC6(1:1.2)binary OSC.Our findings show that employing aπ-extended giant dimeric acceptor as a third component significantly improves the photovoltaic performance of ternary OSCs.展开更多
Plasma-based NO_(x) synthesis has been considered as a sustainable alternative to the conventional HaberBosch process.Despite the advancements in research achieved in recent years,limited attention has been paid to th...Plasma-based NO_(x) synthesis has been considered as a sustainable alternative to the conventional HaberBosch process.Despite the advancements in research achieved in recent years,limited attention has been paid to the reversible dimerization reaction of NO_(2) to N_(2)O_(4).This reaction can significantly alter the parameters considered with the process’output,such as the concentration or volume fraction of products and the energy consumption.This work aims to investigate the significance of dimerization through theoretical analysis and experimentation.Experiments were conducted with a 2D-gliding arc reactor to evaluate the influence of dimerization in the case of plasma reactor operation.It was observed that the dimerization reaction reached equilibrium in microseconds,resulting in a maximum hypothetical NO_(2) equilibrium conversion of 48.8%.For plasma experiments,the dimerization could cause a maximum error of 14.1%in product detection,which needs to be carefully considered along with the influence of temperature variations on the measurement.展开更多
The catalysis technology of propylene dimerization to form 4-methyl-1-pentene(4MP1)using a Cu-K/K_(2)CO_(3) solid base catalyst is a well-known heterogeneous catalytic reaction.In this study,the intrinsic kinetics of ...The catalysis technology of propylene dimerization to form 4-methyl-1-pentene(4MP1)using a Cu-K/K_(2)CO_(3) solid base catalyst is a well-known heterogeneous catalytic reaction.In this study,the intrinsic kinetics of propylene dimerization were studied in a fixed-bed continuous reactor.Internal and external diffusion during the dimerization reaction experiments were eliminated by adjusting the flow rate of the carrier gas and the particle size of the catalyst support.Then,the concentration changes of each substance at the outlet of the catalyst bed under different residence times were investigated.Moreover,the suitable reaction kinetics equations was derived using the Langmuir Hinshelwood-Hougen-Watson kinetic model.Finally,the activation energy for each reaction involved in the dimerization reaction was calculated.The activation energies of 4MP1,branched by-products,and 1-hexene were 115.0,150.8,and 177.4 kJ/mol,respectively.The effect of process conditions on propylene dimerization with solid base catalysts was studied through kinetic model simulation.By comparing the theoretical values obtained from the simulation with the experimental results,the applicability and accuracy of the kinetic model were verified.展开更多
The one-colour resonant two-photon ionization （R2PI） spectrum of the 1-fluoronaphthalene （1FN） dimer has been studied in the wavelength range of 304 to 322 nm by using a supersonic molecular beam and time-of-fligh...The one-colour resonant two-photon ionization （R2PI） spectrum of the 1-fluoronaphthalene （1FN） dimer has been studied in the wavelength range of 304 to 322 nm by using a supersonic molecular beam and time-of-flight mass spectrometry. Compared with the original band 00^0 （at 313.8 nm） of the S1 ← So transition of the 1FN monomer, a red-shifted band was observed in the 1FN dimer spectrum at about 315 nm with a relatively large linewidth, nearly 2 nm. Based on the consideration of inductive effect and ab initio calculations, this red-shifted band is assigned to the first electronic excited transition of the 1FN dimer. A possible geometric structure of the 1FN dimer is also obtained with calculations that the two 1FN molecules are combined through two hydrogen bonds which are formed between the hydrogen atom of a molecule and the fluorine atom of a neighbouring molecule. A time-dependent calculation was also carried out and the results are consistent with the experimental data.展开更多
In the process of dimerization of acetylene to produce monovinylacetylene （MVA）,the loss of active component CuCl in the Nieuwland catalyst due to the formation of a dark red precipitate was investigated.The formula...In the process of dimerization of acetylene to produce monovinylacetylene （MVA）,the loss of active component CuCl in the Nieuwland catalyst due to the formation of a dark red precipitate was investigated.The formula of the precipitate was CuCl·2C2H2·1/5NH 3,and it was presumed to be formed by the combination of NH 3,C2H2 and [Cu]-acetylene π-complex,which was an intermediate in the dimerization reaction.The addition of hydrochloric acid into the catalyst can reduce the formation of precipitate,whereas excessive H＋ is unfavorable to the dimerization reaction of acetylene.To balance between high acetylene conversion and low loss rate of CuCl,the optimum mass percentage of HCl in the added hydrochloric acid was determined.The result showed the optimum mass percentage of HCl decreased from 5.0% to 3.2% when the space velocity of acetylene was from 140 h-1 to 360 h-1.The result in this work also indicated the pH of the Nieuwland catalyst should be kept in the range of 5.80-5.97 during the reaction process,which was good for both catalyst life and acetylene conversion.展开更多
The production of monovinylacetylene （MVA） through Cu（I）-catalyzed acetylene dimerization reaction was performed in different reaction media. Based on the analyses of crystals precipitated from the catalyst soluti...The production of monovinylacetylene （MVA） through Cu（I）-catalyzed acetylene dimerization reaction was performed in different reaction media. Based on the analyses of crystals precipitated from the catalyst solution and UV-Vis spectra of the catalysts, the reaction mechanism and solvent dependence were studied. The highest yield of MVA can be obtained when dimethylformamide is used as solvent because of its strong coordination ability to Cu（I）. The activation of C=C bond is presumed to be improved when the catalytic metal ion is coordinated by a solvent with less steric hindrance and electron-rich coordination atom. The results of the present study provide a possible way to accelerate the metal-catalyzed homogeneous reaction of alkyne substrates through careful selection of a solvent.展开更多
Background Previous studies had demonstrated hemostatic abnormalities in patients with heart failure (HF) and several studies have shown that abnormal coagulation indices, represented by elevated D-dimer, had prognost...Background Previous studies had demonstrated hemostatic abnormalities in patients with heart failure (HF) and several studies have shown that abnormal coagulation indices, represented by elevated D-dimer, had prognostic significance in patients with compatible or acute decompensated HF. However, the impact of D-dimer on the outcome in patients with end-stage HF remains unclear. Methods A total of 244 consecutive patients with end-stage HF due to idiopathic dilated cardiomyopathy (DCM) were prospectively enrolled from February 2011 to September 2014. D-dimer levels were measured and its prognostic value was assessed. Primary endpoint was all-cause mortality during the follow-up period. Secondary endpoints were stroke, bleeding, occurrence of sustained ventricular tachycardia or ventricular fibrillation, and major adverse cardiovascular events (MACE). Results D-dimer was significantly elevated in the non-survivors (median: 0.8 vs. 1.1 mg/L, P < 0.001). Traditional markers including B-type natriuretic peptide, troponin I, left ventricular ejection fraction, and left ventricular end-diastolic dimension provided limited prognostic value;but the addition of D-dimer refined the risk stratification. The optimal cut-off value of D-dimer to predict all-cause mortality was 0.84 mg/L by receiver operator characteristic analysis. Elevated D-dimer level was independently associated with increased risk of long-term all-cause mortality (HR = 2.315, 95% CI: 1.570–3.414, P < 0.001) and MACE (HR = 1.256, 95% CI: 1.058–1.490, P = 0.009), and the predictive value was independent of age, sex, atrial fibrillation and anticoagulation status. Conclusions Elevated D-dimer level was independently associated with poor long-term outcome in patients with end-stage HF secondary to idiopathic DCM, and the predictive value was superior to that of traditional prognostic markers.展开更多
The comparison between single-point energy scanning （SPES） and geometry optimization （OPT） in determining the equilibrium geometries of c^3∑g^＋ and B^1-Пu states of dimer 7Li2 is made at numerous basis sets by ...The comparison between single-point energy scanning （SPES） and geometry optimization （OPT） in determining the equilibrium geometries of c^3∑g^＋ and B^1-Пu states of dimer 7Li2 is made at numerous basis sets by using a symmetryadapted-cluster configuration-interaztion （SAC-CI） method in the Gaussian 03 program package. In this paper the difference of the equilibrium geometries obtained by SPES and by OPT is reported. The results obtained by SPES are found to be more reasonable than those obtained by OPT in full active space at the present SAC-CI level of theory. And the conclusion is attained that the cc-PVTZ is a most suitable basis set for these states. The calculated dissociation energies and equilibrium geometries are 0.8818 eV and 0.3090 nm for c^3∑g^＋ state, and 0.3668 eV and 0.2932 nm for B^1-Пu state respectively. The potential energy curves are calculated over a wide internuclear distance range from about 2.5α0 to 37α0 and have a least-squares fit into the Murrell-Sorbie function. According to the calculated analytic potential energy functions, the harmonic frequencies （We） and other spectroscopic data （ωeXe, Be and αe） are calculated. Comparison of the theoretical determinations at present work with the experiments and other theories clearly shows that the present work is the most complete effort and thus represents an improvement over previous theoretical results.展开更多
The resonance behaviors of local surface plasmon resonance in Au monomer and dimer are characterized sys- temically by electron energy loss spectroscopy in a scanning transmission electron microscope. The measured abs...The resonance behaviors of local surface plasmon resonance in Au monomer and dimer are characterized sys- temically by electron energy loss spectroscopy in a scanning transmission electron microscope. The measured absorption range is about 20nm larger than the physical size of the Au nanoparticles and the resonance peak energy shows a red shift when the electron beam passes off the nanoparticles. The Au dimer displays similar behaviors. Numerical simulation also reproduces those experimental results.展开更多
基金supported by the Yunnan Fundamental Research Project(202301BF070001-009,KC-22222357)the Sichuan Science and Technology Program(2023NSFSC0990)the School of Materials Science and Engineering,Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-Converting Materials and Applications。
文摘Ternary strategy with a suitable third component is a successful strategy to improve the photovoltaic performance of organic solar cells(OSCs).Very recently,Y-series based giant molecule acceptors or oligomerized acceptors have emerged as promising materials for achieving highly efficient and stable binary OSCs,while application as third component for ternary OSCs is limited.Here a novelπ-extended giant dimeric acceptor,GDF,is developed based on central Y series core fusion and rigid BDT as linker,and then incorporated into the state-of-the-art PM1:PC6 system to construct ternary OSCs.The GDF has a near planar backbone,resulting in increasedπ-conjugation,excellent crystallinity,and good electron transport capacity.When GDF is introduced into the PM1:PC6 system,it ensues in a cascade like the lowest unoccupied molecular orbitals(LUMO)energy level alignment,a complementary absorption band with PM1 and PC6,higher and balanced hole and electron mobility,slightly smaller domain size,and a higher exciton dissociation probability for PM1:PC6:GDF(1:1.1:0.1)blend film.As a consequence,the PM1:PC6:GDF(1:1.1:0.1)ternary OSC achieves a champion PCE of 19.22%,with a significantly higher open-circuit voltage and short-circuit current density,compared to 18.45%for the PM1:PC6(1:1.2)binary OSC.Our findings show that employing aπ-extended giant dimeric acceptor as a third component significantly improves the photovoltaic performance of ternary OSCs.
基金supported by the NOW’s Prescient project(16271)the LEAP-AGRI project AFRICA。
文摘Plasma-based NO_(x) synthesis has been considered as a sustainable alternative to the conventional HaberBosch process.Despite the advancements in research achieved in recent years,limited attention has been paid to the reversible dimerization reaction of NO_(2) to N_(2)O_(4).This reaction can significantly alter the parameters considered with the process’output,such as the concentration or volume fraction of products and the energy consumption.This work aims to investigate the significance of dimerization through theoretical analysis and experimentation.Experiments were conducted with a 2D-gliding arc reactor to evaluate the influence of dimerization in the case of plasma reactor operation.It was observed that the dimerization reaction reached equilibrium in microseconds,resulting in a maximum hypothetical NO_(2) equilibrium conversion of 48.8%.For plasma experiments,the dimerization could cause a maximum error of 14.1%in product detection,which needs to be carefully considered along with the influence of temperature variations on the measurement.
基金supported by the National Natural Science Foundation of China under agreement number 22378026the Project of Construction of Innovative Teams and Teacher Career Development for Universities and Colleges under Beijing Municipality(IDHT20180508).
文摘The catalysis technology of propylene dimerization to form 4-methyl-1-pentene(4MP1)using a Cu-K/K_(2)CO_(3) solid base catalyst is a well-known heterogeneous catalytic reaction.In this study,the intrinsic kinetics of propylene dimerization were studied in a fixed-bed continuous reactor.Internal and external diffusion during the dimerization reaction experiments were eliminated by adjusting the flow rate of the carrier gas and the particle size of the catalyst support.Then,the concentration changes of each substance at the outlet of the catalyst bed under different residence times were investigated.Moreover,the suitable reaction kinetics equations was derived using the Langmuir Hinshelwood-Hougen-Watson kinetic model.Finally,the activation energy for each reaction involved in the dimerization reaction was calculated.The activation energies of 4MP1,branched by-products,and 1-hexene were 115.0,150.8,and 177.4 kJ/mol,respectively.The effect of process conditions on propylene dimerization with solid base catalysts was studied through kinetic model simulation.By comparing the theoretical values obtained from the simulation with the experimental results,the applicability and accuracy of the kinetic model were verified.
基金supported by the Doctoral Special Fund of Qufu Normal University of China
文摘The one-colour resonant two-photon ionization （R2PI） spectrum of the 1-fluoronaphthalene （1FN） dimer has been studied in the wavelength range of 304 to 322 nm by using a supersonic molecular beam and time-of-flight mass spectrometry. Compared with the original band 00^0 （at 313.8 nm） of the S1 ← So transition of the 1FN monomer, a red-shifted band was observed in the 1FN dimer spectrum at about 315 nm with a relatively large linewidth, nearly 2 nm. Based on the consideration of inductive effect and ab initio calculations, this red-shifted band is assigned to the first electronic excited transition of the 1FN dimer. A possible geometric structure of the 1FN dimer is also obtained with calculations that the two 1FN molecules are combined through two hydrogen bonds which are formed between the hydrogen atom of a molecule and the fluorine atom of a neighbouring molecule. A time-dependent calculation was also carried out and the results are consistent with the experimental data.
基金supported by the National Basic Research Program of China (No. 2009CB219901)
文摘In the process of dimerization of acetylene to produce monovinylacetylene （MVA）,the loss of active component CuCl in the Nieuwland catalyst due to the formation of a dark red precipitate was investigated.The formula of the precipitate was CuCl·2C2H2·1/5NH 3,and it was presumed to be formed by the combination of NH 3,C2H2 and [Cu]-acetylene π-complex,which was an intermediate in the dimerization reaction.The addition of hydrochloric acid into the catalyst can reduce the formation of precipitate,whereas excessive H＋ is unfavorable to the dimerization reaction of acetylene.To balance between high acetylene conversion and low loss rate of CuCl,the optimum mass percentage of HCl in the added hydrochloric acid was determined.The result showed the optimum mass percentage of HCl decreased from 5.0% to 3.2% when the space velocity of acetylene was from 140 h-1 to 360 h-1.The result in this work also indicated the pH of the Nieuwland catalyst should be kept in the range of 5.80-5.97 during the reaction process,which was good for both catalyst life and acetylene conversion.
基金supported by the National Basic Research Program of China (No. 2009CB219901)
文摘The production of monovinylacetylene （MVA） through Cu（I）-catalyzed acetylene dimerization reaction was performed in different reaction media. Based on the analyses of crystals precipitated from the catalyst solution and UV-Vis spectra of the catalysts, the reaction mechanism and solvent dependence were studied. The highest yield of MVA can be obtained when dimethylformamide is used as solvent because of its strong coordination ability to Cu（I）. The activation of C=C bond is presumed to be improved when the catalytic metal ion is coordinated by a solvent with less steric hindrance and electron-rich coordination atom. The results of the present study provide a possible way to accelerate the metal-catalyzed homogeneous reaction of alkyne substrates through careful selection of a solvent.
文摘Background Previous studies had demonstrated hemostatic abnormalities in patients with heart failure (HF) and several studies have shown that abnormal coagulation indices, represented by elevated D-dimer, had prognostic significance in patients with compatible or acute decompensated HF. However, the impact of D-dimer on the outcome in patients with end-stage HF remains unclear. Methods A total of 244 consecutive patients with end-stage HF due to idiopathic dilated cardiomyopathy (DCM) were prospectively enrolled from February 2011 to September 2014. D-dimer levels were measured and its prognostic value was assessed. Primary endpoint was all-cause mortality during the follow-up period. Secondary endpoints were stroke, bleeding, occurrence of sustained ventricular tachycardia or ventricular fibrillation, and major adverse cardiovascular events (MACE). Results D-dimer was significantly elevated in the non-survivors (median: 0.8 vs. 1.1 mg/L, P < 0.001). Traditional markers including B-type natriuretic peptide, troponin I, left ventricular ejection fraction, and left ventricular end-diastolic dimension provided limited prognostic value;but the addition of D-dimer refined the risk stratification. The optimal cut-off value of D-dimer to predict all-cause mortality was 0.84 mg/L by receiver operator characteristic analysis. Elevated D-dimer level was independently associated with increased risk of long-term all-cause mortality (HR = 2.315, 95% CI: 1.570–3.414, P < 0.001) and MACE (HR = 1.256, 95% CI: 1.058–1.490, P = 0.009), and the predictive value was independent of age, sex, atrial fibrillation and anticoagulation status. Conclusions Elevated D-dimer level was independently associated with poor long-term outcome in patients with end-stage HF secondary to idiopathic DCM, and the predictive value was superior to that of traditional prognostic markers.
基金Project supported by the National Natural Science Foundation of China （Grant No 10574039）, the Henan Innovation for University Prominent Research Talents （Grant No 2006KYCX002） and the National Natural Science Foundation of Education Bureau of Henan Province, China （Grant No 2007140015）. We heartily thank Professor Zhu Zheng-Hem of Sichuan University for his helpful discussion about the reasonable dissociation stages of these calculations limits during the planning
文摘The comparison between single-point energy scanning （SPES） and geometry optimization （OPT） in determining the equilibrium geometries of c^3∑g^＋ and B^1-Пu states of dimer 7Li2 is made at numerous basis sets by using a symmetryadapted-cluster configuration-interaztion （SAC-CI） method in the Gaussian 03 program package. In this paper the difference of the equilibrium geometries obtained by SPES and by OPT is reported. The results obtained by SPES are found to be more reasonable than those obtained by OPT in full active space at the present SAC-CI level of theory. And the conclusion is attained that the cc-PVTZ is a most suitable basis set for these states. The calculated dissociation energies and equilibrium geometries are 0.8818 eV and 0.3090 nm for c^3∑g^＋ state, and 0.3668 eV and 0.2932 nm for B^1-Пu state respectively. The potential energy curves are calculated over a wide internuclear distance range from about 2.5α0 to 37α0 and have a least-squares fit into the Murrell-Sorbie function. According to the calculated analytic potential energy functions, the harmonic frequencies （We） and other spectroscopic data （ωeXe, Be and αe） are calculated. Comparison of the theoretical determinations at present work with the experiments and other theories clearly shows that the present work is the most complete effort and thus represents an improvement over previous theoretical results.
基金Supported by the National Basic Research Program of China under Grant Nos 2013CB932904 and 2012CB932302the National Natural Science Foundation of China under Grant No 11274365
文摘The resonance behaviors of local surface plasmon resonance in Au monomer and dimer are characterized sys- temically by electron energy loss spectroscopy in a scanning transmission electron microscope. The measured absorption range is about 20nm larger than the physical size of the Au nanoparticles and the resonance peak energy shows a red shift when the electron beam passes off the nanoparticles. The Au dimer displays similar behaviors. Numerical simulation also reproduces those experimental results.
