With the successful application and breakthrough of deep learning technology in image segmentation,there has been continuous development in the field of seismic facies interpretation using convolutional neural network...With the successful application and breakthrough of deep learning technology in image segmentation,there has been continuous development in the field of seismic facies interpretation using convolutional neural networks.These intelligent and automated methods significantly reduce manual labor,particularly in the laborious task of manually labeling seismic facies.However,the extensive demand for training data imposes limitations on their wider application.To overcome this challenge,we adopt the UNet architecture as the foundational network structure for seismic facies classification,which has demonstrated effective segmentation results even with small-sample training data.Additionally,we integrate spatial pyramid pooling and dilated convolution modules into the network architecture to enhance the perception of spatial information across a broader range.The seismic facies classification test on the public data from the F3 block verifies the superior performance of our proposed improved network structure in delineating seismic facies boundaries.Comparative analysis against the traditional UNet model reveals that our method achieves more accurate predictive classification results,as evidenced by various evaluation metrics for image segmentation.Obviously,the classification accuracy reaches an impressive 96%.Furthermore,the results of seismic facies classification in the seismic slice dimension provide further confirmation of the superior performance of our proposed method,which accurately defines the range of different seismic facies.This approach holds significant potential for analyzing geological patterns and extracting valuable depositional information.展开更多
Crowd counting is a promising hotspot of computer vision involving crowd intelligence analysis,achieving tremendous success recently with the development of deep learning.However,there have been stillmany challenges i...Crowd counting is a promising hotspot of computer vision involving crowd intelligence analysis,achieving tremendous success recently with the development of deep learning.However,there have been stillmany challenges including crowd multi-scale variations and high network complexity,etc.To tackle these issues,a lightweight Resconnection multi-branch network(LRMBNet)for highly accurate crowd counting and localization is proposed.Specifically,using improved ShuffleNet V2 as the backbone,a lightweight shallow extractor has been designed by employing the channel compression mechanism to reduce enormously the number of network parameters.A light multi-branch structure with different expansion rate convolutions is demonstrated to extract multi-scale features and enlarged receptive fields,where the information transmission and fusion of diverse scale features is enhanced via residual concatenation.In addition,a compound loss function is introduced for training themethod to improve global context information correlation.The proposed method is evaluated on the SHHA,SHHB,UCF-QNRF and UCF_CC_50 public datasets.The accuracy is better than those of many advanced approaches,while the number of parameters is smaller.The experimental results show that the proposed method achieves a good tradeoff between the complexity and accuracy of crowd counting,indicating a lightweight and high-precision method for crowd counting.展开更多
With the development of automation in smart grids,network reconfiguration is becoming a feasible approach for improving the operation of distribution systems.A novel reconfiguration strategy was presented to get the o...With the development of automation in smart grids,network reconfiguration is becoming a feasible approach for improving the operation of distribution systems.A novel reconfiguration strategy was presented to get the optimal configuration of improving economy of the system,and then identifying the important nodes.In this strategy,the objectives increase the node importance degree and decrease the active power loss subjected to operational constraints.A compound objective function with weight coefficients is formulated to balance the conflict of the objectives.Then a novel quantum particle swarm optimization based on loop switches hierarchical encoded was employed to address the compound objective reconfiguration problem.Its main contribution is the presentation of the hierarchical encoded scheme which is used to generate the population swarm particles of representing only radial connected solutions.Because the candidate solutions are feasible,the search efficiency would improve dramatically during the optimization process without tedious topology verification.To validate the proposed strategy,simulations are carried out on the test systems.The results are compared with other techniques in order to evaluate the performance of the proposed method.展开更多
The title compound, spiro[1-bromo(S)-4-(R)-hydroxy-5-oxa-6-oxo-bicyclo[3.1.0]- hxane-2,2?-(3?-diethyl-α-(S)-4??-Cl-benzyloxyphosphonyl-4?-(1R,2S,5R)-menthyloxybutyrolact- one)] has been synthesized via the tandem a...The title compound, spiro[1-bromo(S)-4-(R)-hydroxy-5-oxa-6-oxo-bicyclo[3.1.0]- hxane-2,2?-(3?-diethyl-α-(S)-4??-Cl-benzyloxyphosphonyl-4?-(1R,2S,5R)-menthyloxybutyrolact- one)] has been synthesized via the tandem asymmetric reaction and it crystallizes in a mono- clinic system, space group P21 with a = 11.067(3), b = 12.484(2), c = 12.356(2) ?, β = 101.95°, C29H39BrClO10P, Mr = 693.93, V = 1670.2(6) ?3, Z = 2, Dc= 1.380 g/cm3, λ(MoKα) = 0.071073 nm, μ = 1.410 mm-1, F(000) = 720, the final R = 0.0570 and wR = 0.0758 for 6190 observed reflections with I > 2σ(I). The structure is characterized by the special combination of biologic phosphonyl group and one cyclopropane as well as two butyrolactones. The intermolecular hydrogen bond between O(3)–H(3A)…O(10) in the crystal lattice has been observed.展开更多
The nitrate ester substitution derivatives of prismane were studied at the B3LYP/6-311G** level. The sublimation enthalpies and heats of formation in gas phase and solid state were calculated. The detonation perform...The nitrate ester substitution derivatives of prismane were studied at the B3LYP/6-311G** level. The sublimation enthalpies and heats of formation in gas phase and solid state were calculated. The detonation performances were also predicted by using the famous Kamlet-Jacbos equation. Our calculated results show that introducing nitrate ester group into prismane is helpful to enhance its detonation properties. Stabilities were evaluated through the bond dissociation energies, bond order, characteristic heights(H50) and band gap calculations. The trigger bonds in the pyrolysis process of prismane derivatives were confirmed as O–ON2 bond. The BDEs of all compounds were large, so these prismane derivatives have excellent stability consistent with the results of H50 and band gap.展开更多
A can0nical problem is investigated for high frequency electromagnetic radiation from amonopo1e on a conducting cylinder with c0ating-At first, the exact solution of this problem is given interms of Dyadic Green's...A can0nical problem is investigated for high frequency electromagnetic radiation from amonopo1e on a conducting cylinder with c0ating-At first, the exact solution of this problem is given interms of Dyadic Green's function method. Then, using Watson transformation and high frequency asymptotic approximate technique to the exact soluton, a UTD soultion is obtained. The radiation field excitedby a monopole is expressed in terms of the compound Fock' S functions (CFF), which reduce to the geomertrical optics result in the deep lit region and the creeping waves in the shadow region.展开更多
As gravity field, magnetic field, electric field and seismic wave field are all physical fields, their object function, reverse function and compound function are certainly infinite continuously differentiable functio...As gravity field, magnetic field, electric field and seismic wave field are all physical fields, their object function, reverse function and compound function are certainly infinite continuously differentiable functions which can be expanded into Taylor (Fourier) series within domain of definition and be further reduced into solving stochastic distribution function of series and statistic inference of optimal approximation. This is the basis of combined gravity-magnetic-electric-seismic inversion of stochastic modeling. It is an uncertainty modeling technology of combining gravity-magnetic-electric-seismic inversion built on the basis of separation of field and source gravity-magnetic difference-value (D-value) trend surface, taking distribution-independent fault system as its unit, depths of seismic and electric interfaces of interests as its corresponding bivariate compound reverse function of gravity-magnetic anomalies and using high order polynomial (high order trigonometric function) approximating to its series distribution. The difference from current dominant inversion techniques is that, first, it does not respectively create gravity-seismic, magnetic-seismic deterministic inversion model from theoretical model, but combines gravity-magnetic-electric-seismic stochastic inversion model from stochastic model; second, after the concept of equivalent geological body being introduced, using feature of independent variable of gravity-magnetic field functions, taking density and susceptibility related to gravity-magnetic function as default parameters of model, the deterministic model is established owing to better solution to the contradiction of difficulty in identifying strata and less test analytical data for density and susceptibility in newly explored area; third, under assumption of independent parent distribution, a real modeling by strata, the problem of difficult plane closure arising in profile modeling is avoided. This technology has richer and more detailed fault and strata information than sparse pattern seismic data in newly explored area, successfully inverses and plots structural map of Indosinian discontinuity in Hefei basin with combined gravity-magnetic-electric-seismic inversion. With development of high precision gravity-magnetic and overall geophysical technology, it is certain for introducing new methods of stochastic modeling and computational intelligence and promoting the development of combined gravity-magnetic-electric-seismic inversion to open a new substantial path.展开更多
The crystal and molecular structure of 4, 5-trans-2-amino-1, 3, 3-tri-cyano-4, 5-di(4-chlorophenyl) cyclopentene. ethanol - monohydrate has been deter-mined by X-ray diffraction method. The crystal (C20H12N4Cl2. C2H6O...The crystal and molecular structure of 4, 5-trans-2-amino-1, 3, 3-tri-cyano-4, 5-di(4-chlorophenyl) cyclopentene. ethanol - monohydrate has been deter-mined by X-ray diffraction method. The crystal (C20H12N4Cl2. C2H6O. H2O, Mr=443. 33) is triclinic with space group P1, a= 11. 033(4), b= 12. 199(3), c= 10. 732(3) A, a=114. 46(2), β=118. 33(3) γ=81. 56(3), V=1155- 1(7) A3, Z=2, Dc= 1. 275g/cm3, μ(MoKa) = 3. 05cm-1, F(000) = 460, R= 0. 070, Rw = 0. 089 for1965 observed reflections (I>3(I)). The phenyl groups are in equatorial positionsand form dihedral angles of 67. 89 and 63. 77° with the central 5-ring. X-ray analysisreveals that in the five membered ring the C (1) -C (2) bond is longer than normal double C=C bond while the C(2) -N (2) bond is shorter than normal C(sp)2-N bond.展开更多
The crystal and molecular structure of 3,4-trans-4, 5-trans-2-amino-3cyano-1, 3-diethyloxy carbonyl-4, 5-di (4-chlorophenyl ) cyclopentene has been determined by X-ray diffraction method. The crystal (C24H22O4N2Cl2, M...The crystal and molecular structure of 3,4-trans-4, 5-trans-2-amino-3cyano-1, 3-diethyloxy carbonyl-4, 5-di (4-chlorophenyl ) cyclopentene has been determined by X-ray diffraction method. The crystal (C24H22O4N2Cl2, Mr = 473. 35) ismonoclinic with space group P21/c, a= 6. 923(1), b= 33. 178(5), c= 10. 644 (3)β=99. 86(2)°, V=2408. 8(8) A3, Z= 4, Dc= 1. 305g/cm3,μ(MoKa) = 3. 01cm-1,F(000) =984, R=0. 052, Rw=0. 067 for 2147 observed reflections (I>3(I)). Thephenyl groups and the alkoxy carbonyl group are in equatorial positions. The phenylgroups form dihedral angles bf 70. 67 and 66. 74° with the central five-membered ring.展开更多
The zwitterionic intermediate generated from the reaction of triphenylphosphine with electron deficient acety- lenic compounds was trapped by various NH acids. The synthesis resulted in a new class of highly functiona...The zwitterionic intermediate generated from the reaction of triphenylphosphine with electron deficient acety- lenic compounds was trapped by various NH acids. The synthesis resulted in a new class of highly functionalized heterocyclic compounds. Some of the reactions produced E and Z isomers. And the stability and transformation of them were studied by dynamic 1H NMR and density functional theory (DFT) calculations.展开更多
In recent years, a methodology merging photoredox catalysis with organocatalysis termed "photoredox organo- catalysis" has emerged to allow the direct, selective and efficient functionalization of the α/β-C of car...In recent years, a methodology merging photoredox catalysis with organocatalysis termed "photoredox organo- catalysis" has emerged to allow the direct, selective and efficient functionalization of the α/β-C of carbonyl com- pounds under mild reaction condition. In this review, photophysics background of photoredox catalysis is intro- duced, followed by a report on recent advances in direct α- and β-functionalization of carbonyls with photoredox organocatalysis methodology. With this different reaction modes, valuable synthetic targets including different a/fl-functionalized carbonyls are accessible.展开更多
In this article we briefly review new quantum functional compounds primarily based on our recent works. We will highlight the effects of pressures on both materials synthesis and quantum tuning. The contents include ...In this article we briefly review new quantum functional compounds primarily based on our recent works. We will highlight the effects of pressures on both materials synthesis and quantum tuning. The contents include (I) "111"-type iron based super- conducting system, (II) pressure induced superconductivity in topological insulators and (II/) the new diluted magnetic semi- conductors with decoupled spin charge doping.展开更多
Hydrothermal liquefaction(HTL)and pyrolysis(Py)of Loktak lake biomass mixture of water hyacinth(WH)and para grass(PG)were carried out at 260-300℃ and 300-500℃ to compare the products yield and chemical characteristi...Hydrothermal liquefaction(HTL)and pyrolysis(Py)of Loktak lake biomass mixture of water hyacinth(WH)and para grass(PG)were carried out at 260-300℃ and 300-500℃ to compare the products yield and chemical characteristics of the products.In case of HTL,the maximum bio-oil yield was obtained 13.34 wt.%at 280℃ while for Py,the maximum bio-oil yield was observed 38.8 wt.%at 350℃.The obtained bio-oils and bio-chars were analyzed using GC-MS,FT-IR,NMR,TGA,TOC,and SEM.GC-MS analysis of the bio-oils were showed that the HTL bio-oil majorly contains of nitrogen containing compounds whereas the Py bio-oil contains majority of phenolic compounds.Other compounds like ketones,alcohols,acids were also observed in bio-oil.Higher intensity broad band at 3300-3500 cm^(−1) was observed in the Py bio-oil compared to HTL bio-oil.TGA and proximate analysis of bio-char revealed the higher devolatilization occured during the HTL compared to Py process.The surface morphology of the HTL bio-char was found to be rough and fragmented as compared to the pyrolysis bio-char,clearly showing the biomass macromolecules breakdown differently in HTL and Py process.展开更多
Poly(γ-glutamic acid)(γ-PGA)has been found widespread applications in biomedical field because of its excellent water solubility,biocompatibility,and bioactivity.Herein,a water-insoluble γ-PGA antibacterial compoun...Poly(γ-glutamic acid)(γ-PGA)has been found widespread applications in biomedical field because of its excellent water solubility,biocompatibility,and bioactivity.Herein,a water-insoluble γ-PGA antibacterial compound is facilely fabricated via one-pot electrostatic assembly of γ-PGA with cationic ethyl lauroyl arginate(ELA).The functionalized γ-PGA compound(γ-PGA-ELA)ethanol solution can facilely produce colorless and transparent coatings on various inorganic,metal,and polymeric substrates,especially for the lumen of slender catheters(length up to 2 m,and inner diameter down to 1 mm).The functionalized γ-PGA coating presents remarkable antibacterial efficacy in vitro and in vivo.In addition,the γ-PGA compound is used as antibacterial additives of polyolefin via melting extrusion,and the asprepared antibacterial polyolefin demonstrates advantageous antibacterial efficacy.More importantly,the functionalized γ-PGA coating exhibit good hemocompatibility,low cytotoxicity,and satisfactory histocompatibility.The as-proposed γ-PGA compound has a great potential to serve as a safe and multifunctional antibacterial candidate to combat biomedical devices-related infections.展开更多
In this paper,using aδ-doping dual-channel structure and GaAs substrate,a real space transfer transistor(RSTT)is designed and fabricated successfully.It has the standardΛ-shaped negative resistance I-V characteristi...In this paper,using aδ-doping dual-channel structure and GaAs substrate,a real space transfer transistor(RSTT)is designed and fabricated successfully.It has the standardΛ-shaped negative resistance I-V characteristics as well as a level and smooth valley region that the conventional RSTT has.The negative resistance parameters can be varied by changing gate voltage(VGS).For example,the PVCR varies from 2.1 to 10.6 while VGS changes from 0.6 V to 1.0 V.The transconductance for IP(ΔIP=ΔVGS)is 0.3 mS.The parameters of VP,VV and threshold gate voltage(VT)for negative resistance characteristics arising are all smaller than the value reported in the literature.Therefore,this device is suitable for low dissipation power application.展开更多
基金funded by the Fundamental Research Project of CNPC Geophysical Key Lab(2022DQ0604-4)the Strategic Cooperation Technology Projects of China National Petroleum Corporation and China University of Petroleum-Beijing(ZLZX 202003)。
文摘With the successful application and breakthrough of deep learning technology in image segmentation,there has been continuous development in the field of seismic facies interpretation using convolutional neural networks.These intelligent and automated methods significantly reduce manual labor,particularly in the laborious task of manually labeling seismic facies.However,the extensive demand for training data imposes limitations on their wider application.To overcome this challenge,we adopt the UNet architecture as the foundational network structure for seismic facies classification,which has demonstrated effective segmentation results even with small-sample training data.Additionally,we integrate spatial pyramid pooling and dilated convolution modules into the network architecture to enhance the perception of spatial information across a broader range.The seismic facies classification test on the public data from the F3 block verifies the superior performance of our proposed improved network structure in delineating seismic facies boundaries.Comparative analysis against the traditional UNet model reveals that our method achieves more accurate predictive classification results,as evidenced by various evaluation metrics for image segmentation.Obviously,the classification accuracy reaches an impressive 96%.Furthermore,the results of seismic facies classification in the seismic slice dimension provide further confirmation of the superior performance of our proposed method,which accurately defines the range of different seismic facies.This approach holds significant potential for analyzing geological patterns and extracting valuable depositional information.
基金Double First-Class Innovation Research Project for People’s Public Security University of China(2023SYL08).
文摘Crowd counting is a promising hotspot of computer vision involving crowd intelligence analysis,achieving tremendous success recently with the development of deep learning.However,there have been stillmany challenges including crowd multi-scale variations and high network complexity,etc.To tackle these issues,a lightweight Resconnection multi-branch network(LRMBNet)for highly accurate crowd counting and localization is proposed.Specifically,using improved ShuffleNet V2 as the backbone,a lightweight shallow extractor has been designed by employing the channel compression mechanism to reduce enormously the number of network parameters.A light multi-branch structure with different expansion rate convolutions is demonstrated to extract multi-scale features and enlarged receptive fields,where the information transmission and fusion of diverse scale features is enhanced via residual concatenation.In addition,a compound loss function is introduced for training themethod to improve global context information correlation.The proposed method is evaluated on the SHHA,SHHB,UCF-QNRF and UCF_CC_50 public datasets.The accuracy is better than those of many advanced approaches,while the number of parameters is smaller.The experimental results show that the proposed method achieves a good tradeoff between the complexity and accuracy of crowd counting,indicating a lightweight and high-precision method for crowd counting.
基金Project(61102039)supported by the National Natural Science Foundation of ChinaProject(2014AA052600)supported by National Hi-tech Research and Development Plan,China
文摘With the development of automation in smart grids,network reconfiguration is becoming a feasible approach for improving the operation of distribution systems.A novel reconfiguration strategy was presented to get the optimal configuration of improving economy of the system,and then identifying the important nodes.In this strategy,the objectives increase the node importance degree and decrease the active power loss subjected to operational constraints.A compound objective function with weight coefficients is formulated to balance the conflict of the objectives.Then a novel quantum particle swarm optimization based on loop switches hierarchical encoded was employed to address the compound objective reconfiguration problem.Its main contribution is the presentation of the hierarchical encoded scheme which is used to generate the population swarm particles of representing only radial connected solutions.Because the candidate solutions are feasible,the search efficiency would improve dramatically during the optimization process without tedious topology verification.To validate the proposed strategy,simulations are carried out on the test systems.The results are compared with other techniques in order to evaluate the performance of the proposed method.
基金Supported by the National Natural Science Foundation of China (No. 29672004)
文摘The title compound, spiro[1-bromo(S)-4-(R)-hydroxy-5-oxa-6-oxo-bicyclo[3.1.0]- hxane-2,2?-(3?-diethyl-α-(S)-4??-Cl-benzyloxyphosphonyl-4?-(1R,2S,5R)-menthyloxybutyrolact- one)] has been synthesized via the tandem asymmetric reaction and it crystallizes in a mono- clinic system, space group P21 with a = 11.067(3), b = 12.484(2), c = 12.356(2) ?, β = 101.95°, C29H39BrClO10P, Mr = 693.93, V = 1670.2(6) ?3, Z = 2, Dc= 1.380 g/cm3, λ(MoKα) = 0.071073 nm, μ = 1.410 mm-1, F(000) = 720, the final R = 0.0570 and wR = 0.0758 for 6190 observed reflections with I > 2σ(I). The structure is characterized by the special combination of biologic phosphonyl group and one cyclopropane as well as two butyrolactones. The intermolecular hydrogen bond between O(3)–H(3A)…O(10) in the crystal lattice has been observed.
基金supported by the Natural Science Foundation of Guizhou Province(QKJ[2014]2140 and QJTD[2012]052)
文摘The nitrate ester substitution derivatives of prismane were studied at the B3LYP/6-311G** level. The sublimation enthalpies and heats of formation in gas phase and solid state were calculated. The detonation performances were also predicted by using the famous Kamlet-Jacbos equation. Our calculated results show that introducing nitrate ester group into prismane is helpful to enhance its detonation properties. Stabilities were evaluated through the bond dissociation energies, bond order, characteristic heights(H50) and band gap calculations. The trigger bonds in the pyrolysis process of prismane derivatives were confirmed as O–ON2 bond. The BDEs of all compounds were large, so these prismane derivatives have excellent stability consistent with the results of H50 and band gap.
文摘A can0nical problem is investigated for high frequency electromagnetic radiation from amonopo1e on a conducting cylinder with c0ating-At first, the exact solution of this problem is given interms of Dyadic Green's function method. Then, using Watson transformation and high frequency asymptotic approximate technique to the exact soluton, a UTD soultion is obtained. The radiation field excitedby a monopole is expressed in terms of the compound Fock' S functions (CFF), which reduce to the geomertrical optics result in the deep lit region and the creeping waves in the shadow region.
文摘As gravity field, magnetic field, electric field and seismic wave field are all physical fields, their object function, reverse function and compound function are certainly infinite continuously differentiable functions which can be expanded into Taylor (Fourier) series within domain of definition and be further reduced into solving stochastic distribution function of series and statistic inference of optimal approximation. This is the basis of combined gravity-magnetic-electric-seismic inversion of stochastic modeling. It is an uncertainty modeling technology of combining gravity-magnetic-electric-seismic inversion built on the basis of separation of field and source gravity-magnetic difference-value (D-value) trend surface, taking distribution-independent fault system as its unit, depths of seismic and electric interfaces of interests as its corresponding bivariate compound reverse function of gravity-magnetic anomalies and using high order polynomial (high order trigonometric function) approximating to its series distribution. The difference from current dominant inversion techniques is that, first, it does not respectively create gravity-seismic, magnetic-seismic deterministic inversion model from theoretical model, but combines gravity-magnetic-electric-seismic stochastic inversion model from stochastic model; second, after the concept of equivalent geological body being introduced, using feature of independent variable of gravity-magnetic field functions, taking density and susceptibility related to gravity-magnetic function as default parameters of model, the deterministic model is established owing to better solution to the contradiction of difficulty in identifying strata and less test analytical data for density and susceptibility in newly explored area; third, under assumption of independent parent distribution, a real modeling by strata, the problem of difficult plane closure arising in profile modeling is avoided. This technology has richer and more detailed fault and strata information than sparse pattern seismic data in newly explored area, successfully inverses and plots structural map of Indosinian discontinuity in Hefei basin with combined gravity-magnetic-electric-seismic inversion. With development of high precision gravity-magnetic and overall geophysical technology, it is certain for introducing new methods of stochastic modeling and computational intelligence and promoting the development of combined gravity-magnetic-electric-seismic inversion to open a new substantial path.
文摘The crystal and molecular structure of 4, 5-trans-2-amino-1, 3, 3-tri-cyano-4, 5-di(4-chlorophenyl) cyclopentene. ethanol - monohydrate has been deter-mined by X-ray diffraction method. The crystal (C20H12N4Cl2. C2H6O. H2O, Mr=443. 33) is triclinic with space group P1, a= 11. 033(4), b= 12. 199(3), c= 10. 732(3) A, a=114. 46(2), β=118. 33(3) γ=81. 56(3), V=1155- 1(7) A3, Z=2, Dc= 1. 275g/cm3, μ(MoKa) = 3. 05cm-1, F(000) = 460, R= 0. 070, Rw = 0. 089 for1965 observed reflections (I>3(I)). The phenyl groups are in equatorial positionsand form dihedral angles of 67. 89 and 63. 77° with the central 5-ring. X-ray analysisreveals that in the five membered ring the C (1) -C (2) bond is longer than normal double C=C bond while the C(2) -N (2) bond is shorter than normal C(sp)2-N bond.
文摘The crystal and molecular structure of 3,4-trans-4, 5-trans-2-amino-3cyano-1, 3-diethyloxy carbonyl-4, 5-di (4-chlorophenyl ) cyclopentene has been determined by X-ray diffraction method. The crystal (C24H22O4N2Cl2, Mr = 473. 35) ismonoclinic with space group P21/c, a= 6. 923(1), b= 33. 178(5), c= 10. 644 (3)β=99. 86(2)°, V=2408. 8(8) A3, Z= 4, Dc= 1. 305g/cm3,μ(MoKa) = 3. 01cm-1,F(000) =984, R=0. 052, Rw=0. 067 for 2147 observed reflections (I>3(I)). Thephenyl groups and the alkoxy carbonyl group are in equatorial positions. The phenylgroups form dihedral angles bf 70. 67 and 66. 74° with the central five-membered ring.
文摘The zwitterionic intermediate generated from the reaction of triphenylphosphine with electron deficient acety- lenic compounds was trapped by various NH acids. The synthesis resulted in a new class of highly functionalized heterocyclic compounds. Some of the reactions produced E and Z isomers. And the stability and transformation of them were studied by dynamic 1H NMR and density functional theory (DFT) calculations.
文摘In recent years, a methodology merging photoredox catalysis with organocatalysis termed "photoredox organo- catalysis" has emerged to allow the direct, selective and efficient functionalization of the α/β-C of carbonyl com- pounds under mild reaction condition. In this review, photophysics background of photoredox catalysis is intro- duced, followed by a report on recent advances in direct α- and β-functionalization of carbonyls with photoredox organocatalysis methodology. With this different reaction modes, valuable synthetic targets including different a/fl-functionalized carbonyls are accessible.
基金supported by the National Natural Science Foundation of China and Ministry of Science and Technology(MOST)
文摘In this article we briefly review new quantum functional compounds primarily based on our recent works. We will highlight the effects of pressures on both materials synthesis and quantum tuning. The contents include (I) "111"-type iron based super- conducting system, (II) pressure induced superconductivity in topological insulators and (II/) the new diluted magnetic semi- conductors with decoupled spin charge doping.
文摘Hydrothermal liquefaction(HTL)and pyrolysis(Py)of Loktak lake biomass mixture of water hyacinth(WH)and para grass(PG)were carried out at 260-300℃ and 300-500℃ to compare the products yield and chemical characteristics of the products.In case of HTL,the maximum bio-oil yield was obtained 13.34 wt.%at 280℃ while for Py,the maximum bio-oil yield was observed 38.8 wt.%at 350℃.The obtained bio-oils and bio-chars were analyzed using GC-MS,FT-IR,NMR,TGA,TOC,and SEM.GC-MS analysis of the bio-oils were showed that the HTL bio-oil majorly contains of nitrogen containing compounds whereas the Py bio-oil contains majority of phenolic compounds.Other compounds like ketones,alcohols,acids were also observed in bio-oil.Higher intensity broad band at 3300-3500 cm^(−1) was observed in the Py bio-oil compared to HTL bio-oil.TGA and proximate analysis of bio-char revealed the higher devolatilization occured during the HTL compared to Py process.The surface morphology of the HTL bio-char was found to be rough and fragmented as compared to the pyrolysis bio-char,clearly showing the biomass macromolecules breakdown differently in HTL and Py process.
基金financially supported by the National Natural Science Foundation of China(Nos.51973221 and 51873213)the Youth Innovation Promotion Association of CAS(No.2017269)+1 种基金the Major Science and Technology Innovation Project of Shandong Province(No.2019JZZY011105)the High-Tech Research&Development Program of CAS-WEGO Group。
文摘Poly(γ-glutamic acid)(γ-PGA)has been found widespread applications in biomedical field because of its excellent water solubility,biocompatibility,and bioactivity.Herein,a water-insoluble γ-PGA antibacterial compound is facilely fabricated via one-pot electrostatic assembly of γ-PGA with cationic ethyl lauroyl arginate(ELA).The functionalized γ-PGA compound(γ-PGA-ELA)ethanol solution can facilely produce colorless and transparent coatings on various inorganic,metal,and polymeric substrates,especially for the lumen of slender catheters(length up to 2 m,and inner diameter down to 1 mm).The functionalized γ-PGA coating presents remarkable antibacterial efficacy in vitro and in vivo.In addition,the γ-PGA compound is used as antibacterial additives of polyolefin via melting extrusion,and the asprepared antibacterial polyolefin demonstrates advantageous antibacterial efficacy.More importantly,the functionalized γ-PGA coating exhibit good hemocompatibility,low cytotoxicity,and satisfactory histocompatibility.The as-proposed γ-PGA compound has a great potential to serve as a safe and multifunctional antibacterial candidate to combat biomedical devices-related infections.
文摘In this paper,using aδ-doping dual-channel structure and GaAs substrate,a real space transfer transistor(RSTT)is designed and fabricated successfully.It has the standardΛ-shaped negative resistance I-V characteristics as well as a level and smooth valley region that the conventional RSTT has.The negative resistance parameters can be varied by changing gate voltage(VGS).For example,the PVCR varies from 2.1 to 10.6 while VGS changes from 0.6 V to 1.0 V.The transconductance for IP(ΔIP=ΔVGS)is 0.3 mS.The parameters of VP,VV and threshold gate voltage(VT)for negative resistance characteristics arising are all smaller than the value reported in the literature.Therefore,this device is suitable for low dissipation power application.