The quantitative description of the sequence structure of emulsion-processed SBR and solution-processed SBR (by lithium catalyst)was carried out based on their spectral data Of ^(13)C-NMR.The calculating formulae whic...The quantitative description of the sequence structure of emulsion-processed SBR and solution-processed SBR (by lithium catalyst)was carried out based on their spectral data Of ^(13)C-NMR.The calculating formulae which could be used to obtain diad concentration from the peak intensifies of carbon spectra, average block length, average number of block, and the microstructure composition of the molecular chain were derived. The quantitative result showed that on the molecular chain styrene unit had the tendency to attach to trans-1,4 butadiene unit. The calculated result of the microstructure was in good agreement with that obtained through IR measurement.展开更多
6 Atomic fragment types of organic compound have been defined, and the multilevel atom-pair frequency matrix has been constructed according to the occurrence number in pairs of atomic fragments with different bond len...6 Atomic fragment types of organic compound have been defined, and the multilevel atom-pair frequency matrix has been constructed according to the occurrence number in pairs of atomic fragments with different bond lengths in the molecule. On the basis of them, a novel molecular coding technique： characteristic atom-pair holographic code （CAHC）, is obtained. To some extent, this method exhibits a large number of benefits at the same time. For example, it can calculate 2D molecular topological descriptor easily, operate without difficulty and possess definite physicochemical meaning of 3D molecular structural characterization methods, and may fetch the complicated information of molecule, etc. Therefore, it is appropriate for the study on quantitative structure-property/activity relationship （QSPR/QSAR） of medicines and biological molecules. We attempt in this paper to utilize the method of CAHC to the quantitative prediction of reversed-phase liquid chromatogram （RPLC） retention data of 33 purine derivatives and 24 steroids. The fitting multiple correlation coefficient R2, cross-validated multiple correlation coefficient Q2 and predicted ability Q^2 pred over test set＇s samples of obtained partial least-square （PLS） regression model are respectively 0.990, 0.893 and 0.977, 0.897, 0.941.展开更多
The molecular electronegativity interaction vector （MEIV） was used to describe the molecular structure of 30 selected esters. Two excellent QSTR models were built up by using multiple linear regression （MLR） and p...The molecular electronegativity interaction vector （MEIV） was used to describe the molecular structure of 30 selected esters. Two excellent QSTR models were built up by using multiple linear regression （MLR） and partial least-squares regression （PLS）. The correlation coefficients （R） of the two models were 0.945 and 0.941, respectively. The models were evaluated by performing the cross validation with the leave-one-out （LOO） procedure. The cross-verification correlation coefficients （RCV） of the two models were 0.921 and 0.919, respectively. The results showed that the models constructed in this work could provide estimation stability and favorable predictive ability.展开更多
Morphology of hydraulic fracture surface has significant effects on oil and gas flow,proppant migration and fracture closure,which plays an important role in oil and gas fracturing stimulation.In this paper,we analyze...Morphology of hydraulic fracture surface has significant effects on oil and gas flow,proppant migration and fracture closure,which plays an important role in oil and gas fracturing stimulation.In this paper,we analyzed the fracture surface characteristics induced by supercritical carbon dioxide(SC-CO_(2))and water in open-hole and perforation completion conditions under triaxial stresses.A simple calculation method was proposed to quantitatively analyze the fracture surface area and roughness in macro-level based on three-dimensional(3D)scanning data.In micro-level,scanning electron micrograph(SEM)was used to analyze the features of fracture surface.The results showed that the surface area of the induced fracture increases with perforation angle for both SC-CO_(2)and water fracturing,and the surface area of SC-CO_(2)-induced fracture is 6.49%e58.57%larger than that of water-induced fracture.The fractal dimension and surface roughness of water-induced fractures increase with the increase in perforation angle,while those of SC-CO_(2)-induced fractures decrease with the increasing perforation angle.A considerable number of microcracks and particle peeling pits can be observed on SC-CO_(2)-induced fracture surface while there are more flat particle surfaces in water-induced fracture surface through SEM images,indicating that fractures tend to propagate along the boundary of the particle for SC-CO_(2)fracturing while water-induced fractures prefer to cut through particles.These findings are of great significance for analyzing fracture mechanism and evaluating fracturing stimulation performance.展开更多
Lithium-sulfur(Li-S)chemistry reaction opens a new battery era with high energy density;meanwhile,multiple electrons migration leads to the complex phase transition of sulfur species.To manipulate the binding strength...Lithium-sulfur(Li-S)chemistry reaction opens a new battery era with high energy density;meanwhile,multiple electrons migration leads to the complex phase transition of sulfur species.To manipulate the binding strength of multiple key intermediates more efficiently,the bimetallic TiVC MXene is utilized to realize multi-dimensional catalysis.Based on the macroscopic three-dimensional(3D)structure using two-dimensional(2D)MXene architecture,electron conductivity and sulfur utilization are improved.Microscopically,Ti-V catalytic systems regulate multiple reaction intermediates through intermetallic synergies customized surface properties and atomic scale coordination,thereby improving electronic and ionic conductivity.In-situ Raman spectroscopy and electrochemical analysis show that the conversion rate of polysulfides was accelerated during the charge-discharge process.The Ti-V interaction exhibits unique catalytic activity and regulates multiple continuous processes of sulfur species phase transformation,which are essential for the excellent energy performance of Li-S batteries.This study not only clarifies the catalytic mechanism of Ti-V at different dimensions but also proposes a promising strategy for the design of advanced catalytic systems in energy storage technology.展开更多
The results of quantitative characters for anatomy in stems of three varieties tomatoes seedlings showed that the cell population between vascular bundle and epidermis, the cellular layers among vascular bundles and t...The results of quantitative characters for anatomy in stems of three varieties tomatoes seedlings showed that the cell population between vascular bundle and epidermis, the cellular layers among vascular bundles and the cell population in an unit area （mm^2） of no vascular bundle areas were similar and there had small difference among three varieties. On the foundation of these studies, the developmental mechanism of tomato seedling stem was discussed.展开更多
A pure Cu （99.995 wt%） has been subjected to dynamic plastic deformation at cryogenic temperature to a strain of 2.1. Three types of microstructures that are related to dislocation slip, twinning and shear banding h...A pure Cu （99.995 wt%） has been subjected to dynamic plastic deformation at cryogenic temperature to a strain of 2.1. Three types of microstructures that are related to dislocation slip, twinning and shear banding have been quantitatively characterized by transmission electron microscopy （TEM） assisted by convergent beam electron diffraction （CBED） analysis. Microstructures originated from dislocation slip inside or outside the shear bands are characterized by low angle boundaries （〈15°） that are spaced in the nanometer scale, whereas most deformation twins are deviated from the perfect ∑3 coincidence （60°/〈111〉） up to the maximum angle of 9°. The quantitative structural characteristics are compared with those in conventionally deformed Cu at low strain rates, and allowed a quantitative analysis of the flow stress-structural parameter relationship.展开更多
The microscopic pore structure of sand-conglomerate rocks plays a decisive role in its exploration and development of such reservoirs.Due to complex gravels-cements configurations and resultant high heterogeneity in s...The microscopic pore structure of sand-conglomerate rocks plays a decisive role in its exploration and development of such reservoirs.Due to complex gravels-cements configurations and resultant high heterogeneity in sand-conglomerate rocks,the conventional fractal dimensions are inadequate to fully characterize the pore space.Based on the Pia Intermingled Fractal Units(IFU)model,this paper presents a new variable-ratio factor IFU model,which takes tortuosity and boundary layer thickness into consideration,to characterize the Triassic Karamay Formation conglomerate reservoirs in the Mahu region of the Junggar Basin,Northwest China.The modified model has a more powerful and flexible ability to simulate pore structures of porous media,and the simulation results are closer to the real conditions of pore space in low-porosity and low-permeability reservoirs than the conventional Pia IFU model.The geometric construction of the model is simplified to allow for an easing of computation.Porosity and spectral distribution of pore diameter,constructed using the modified model,are generally consistent with actual core data.Also,the model-computed permeability correlates well with experimental results,with a relative error of less than 15%.The modified IFU model performs well in quantitatively characterizing the heterogeneity of sand-conglomerate pore structures,and provides a methodology for the study of other similar types of heterogeneous reservoirs.展开更多
Although serving as the workhorse,MS/MS cannot fully satisfy the analytical requirements of quantitative sub-metabolome characterization.Because more information intrinsically correlates to more structural and concent...Although serving as the workhorse,MS/MS cannot fully satisfy the analytical requirements of quantitative sub-metabolome characterization.Because more information intrinsically correlates to more structural and concentration clues,here,efforts were devoted to comprehensively tracing and deciphering MS/MS behaviors through constructing triple three-dimensional(3×3D)-MS/MS spectrum.Ginsenosides-targeted metabolomics of notoginseng,one of the most famous edible medicinal plants,was employed as a proof-of-concept.Serial authentic ginsenosides were deployed to build the correlations between 3×3D-MS/MS spectra and structure/concentration features.Through assaying ginsenosides with progressive concentrations using QTOF-MS to configure 1st 3D spectrum,the generations of MS1 spectral signals,particularly multi-charged multimer anions,e.g.,[2Me2H]^(2-) and[2M+2HCOO]^(2-) ions,relied on both concentration and the amount of sugar chains.By programming progressive collision energies to the front collision cell of Qtrap-MS device to gain 2^(nd) 3D spectrum,optimal collision energy(OCE)corresponding to the glycosidic bond fission was primarily correlated with the masses of precursor and fragment ions and partially governed by the glycosidation site.The quantitative relationships between OCEs and masses of precursor and fragment ions were utilized to build large-scale quantitative program for ginsenosides.After applying progressive exciting energies to the back collision chamber to build 3^(rd) 3D spectrum,the fragment ion and the decomposition product anion exhibited identical dissociation trajectories when they shared the same molecular geometry.After ginsenosides-focused quantitative metabolomics,significant differences occurred for sub-metabolome amongst different parts of notoginseng.The differential ginsenosides were confirmatively identified by applying the correlations between 3×3D-MS/MS spectra and structures.Together,3×3D-MS/MS spectrum covers all MS/MS behaviors and dramatically facilitates sub-metabolome characterization from both quantitative program development and structural identification.展开更多
文摘The quantitative description of the sequence structure of emulsion-processed SBR and solution-processed SBR (by lithium catalyst)was carried out based on their spectral data Of ^(13)C-NMR.The calculating formulae which could be used to obtain diad concentration from the peak intensifies of carbon spectra, average block length, average number of block, and the microstructure composition of the molecular chain were derived. The quantitative result showed that on the molecular chain styrene unit had the tendency to attach to trans-1,4 butadiene unit. The calculated result of the microstructure was in good agreement with that obtained through IR measurement.
基金This work was supported by the State Key Laboratory of Chemo/Biosensing and Chemometrics Foundation (No. 05-12-1), Fok-Yingtung Educational Foundation (No. 98-7-6) and Chongqing University Innovation Foundation of Science and Technology ( No. 06-1-1)
文摘6 Atomic fragment types of organic compound have been defined, and the multilevel atom-pair frequency matrix has been constructed according to the occurrence number in pairs of atomic fragments with different bond lengths in the molecule. On the basis of them, a novel molecular coding technique： characteristic atom-pair holographic code （CAHC）, is obtained. To some extent, this method exhibits a large number of benefits at the same time. For example, it can calculate 2D molecular topological descriptor easily, operate without difficulty and possess definite physicochemical meaning of 3D molecular structural characterization methods, and may fetch the complicated information of molecule, etc. Therefore, it is appropriate for the study on quantitative structure-property/activity relationship （QSPR/QSAR） of medicines and biological molecules. We attempt in this paper to utilize the method of CAHC to the quantitative prediction of reversed-phase liquid chromatogram （RPLC） retention data of 33 purine derivatives and 24 steroids. The fitting multiple correlation coefficient R2, cross-validated multiple correlation coefficient Q2 and predicted ability Q^2 pred over test set＇s samples of obtained partial least-square （PLS） regression model are respectively 0.990, 0.893 and 0.977, 0.897, 0.941.
基金supported by the Youth Foundation of Education Bureau, Sichuan Province (09ZB036)Technology Bureau, Sichuan Province (2006j13-141)
文摘The molecular electronegativity interaction vector （MEIV） was used to describe the molecular structure of 30 selected esters. Two excellent QSTR models were built up by using multiple linear regression （MLR） and partial least-squares regression （PLS）. The correlation coefficients （R） of the two models were 0.945 and 0.941, respectively. The models were evaluated by performing the cross validation with the leave-one-out （LOO） procedure. The cross-verification correlation coefficients （RCV） of the two models were 0.921 and 0.919, respectively. The results showed that the models constructed in this work could provide estimation stability and favorable predictive ability.
基金National Natural Science Foundation of China(Grant No.51804318)the China Postdoctoral Science Foundation Founded Project(Grant No.2019M650963)National Key Basic Research and Development Program of China(Grant No.2014CB239203).
文摘Morphology of hydraulic fracture surface has significant effects on oil and gas flow,proppant migration and fracture closure,which plays an important role in oil and gas fracturing stimulation.In this paper,we analyzed the fracture surface characteristics induced by supercritical carbon dioxide(SC-CO_(2))and water in open-hole and perforation completion conditions under triaxial stresses.A simple calculation method was proposed to quantitatively analyze the fracture surface area and roughness in macro-level based on three-dimensional(3D)scanning data.In micro-level,scanning electron micrograph(SEM)was used to analyze the features of fracture surface.The results showed that the surface area of the induced fracture increases with perforation angle for both SC-CO_(2)and water fracturing,and the surface area of SC-CO_(2)-induced fracture is 6.49%e58.57%larger than that of water-induced fracture.The fractal dimension and surface roughness of water-induced fractures increase with the increase in perforation angle,while those of SC-CO_(2)-induced fractures decrease with the increasing perforation angle.A considerable number of microcracks and particle peeling pits can be observed on SC-CO_(2)-induced fracture surface while there are more flat particle surfaces in water-induced fracture surface through SEM images,indicating that fractures tend to propagate along the boundary of the particle for SC-CO_(2)fracturing while water-induced fractures prefer to cut through particles.These findings are of great significance for analyzing fracture mechanism and evaluating fracturing stimulation performance.
基金the financial support provided by the National Natural Science Foundation of China(No.51932005)the Liaoning Revitalization Talents Program(No.XLYC1807175)+1 种基金the Development Plan of Science and Technology of Jilin Province,China(YDZJ202301ZYTS280)the Natural Science Foundation of Jilin Province(YDZJ202401316ZYTS)。
文摘Lithium-sulfur(Li-S)chemistry reaction opens a new battery era with high energy density;meanwhile,multiple electrons migration leads to the complex phase transition of sulfur species.To manipulate the binding strength of multiple key intermediates more efficiently,the bimetallic TiVC MXene is utilized to realize multi-dimensional catalysis.Based on the macroscopic three-dimensional(3D)structure using two-dimensional(2D)MXene architecture,electron conductivity and sulfur utilization are improved.Microscopically,Ti-V catalytic systems regulate multiple reaction intermediates through intermetallic synergies customized surface properties and atomic scale coordination,thereby improving electronic and ionic conductivity.In-situ Raman spectroscopy and electrochemical analysis show that the conversion rate of polysulfides was accelerated during the charge-discharge process.The Ti-V interaction exhibits unique catalytic activity and regulates multiple continuous processes of sulfur species phase transformation,which are essential for the excellent energy performance of Li-S batteries.This study not only clarifies the catalytic mechanism of Ti-V at different dimensions but also proposes a promising strategy for the design of advanced catalytic systems in energy storage technology.
基金Supported by Committee of Nature Science Foundation of Heilongjiang Province (C2005-32)Post-doctoral Science Committee of China (LRB04-217)Scientific Research Start Committee of Northeast Agricultural University
文摘The results of quantitative characters for anatomy in stems of three varieties tomatoes seedlings showed that the cell population between vascular bundle and epidermis, the cellular layers among vascular bundles and the cell population in an unit area （mm^2） of no vascular bundle areas were similar and there had small difference among three varieties. On the foundation of these studies, the developmental mechanism of tomato seedling stem was discussed.
基金the Danish National Research Foundation and the National Natural Science Foundation of China (Grant No. 50911130230)for the Danish-Chinese center for Nanometals, within which this study was performedsponsored by MOST international S&T project(2010DFB54010), SRF for ROCS, SEM, and the Young Merit Scholar of Institute of Metal Research, Chinese Academy of Science, China
文摘A pure Cu （99.995 wt%） has been subjected to dynamic plastic deformation at cryogenic temperature to a strain of 2.1. Three types of microstructures that are related to dislocation slip, twinning and shear banding have been quantitatively characterized by transmission electron microscopy （TEM） assisted by convergent beam electron diffraction （CBED） analysis. Microstructures originated from dislocation slip inside or outside the shear bands are characterized by low angle boundaries （〈15°） that are spaced in the nanometer scale, whereas most deformation twins are deviated from the perfect ∑3 coincidence （60°/〈111〉） up to the maximum angle of 9°. The quantitative structural characteristics are compared with those in conventionally deformed Cu at low strain rates, and allowed a quantitative analysis of the flow stress-structural parameter relationship.
基金supported by the National Key Basic Research and Development Program(973 Program)of China(No.2014CB239000)the China National Science and Technology Major Projects(No.2017ZX05001)the Petrochina Science and Technology Major Projects(No.2016B-0304).
文摘The microscopic pore structure of sand-conglomerate rocks plays a decisive role in its exploration and development of such reservoirs.Due to complex gravels-cements configurations and resultant high heterogeneity in sand-conglomerate rocks,the conventional fractal dimensions are inadequate to fully characterize the pore space.Based on the Pia Intermingled Fractal Units(IFU)model,this paper presents a new variable-ratio factor IFU model,which takes tortuosity and boundary layer thickness into consideration,to characterize the Triassic Karamay Formation conglomerate reservoirs in the Mahu region of the Junggar Basin,Northwest China.The modified model has a more powerful and flexible ability to simulate pore structures of porous media,and the simulation results are closer to the real conditions of pore space in low-porosity and low-permeability reservoirs than the conventional Pia IFU model.The geometric construction of the model is simplified to allow for an easing of computation.Porosity and spectral distribution of pore diameter,constructed using the modified model,are generally consistent with actual core data.Also,the model-computed permeability correlates well with experimental results,with a relative error of less than 15%.The modified IFU model performs well in quantitatively characterizing the heterogeneity of sand-conglomerate pore structures,and provides a methodology for the study of other similar types of heterogeneous reservoirs.
基金the National Natural Science Foundation of China(No.81973444)National Administration of Traditional Chinese Medicine High level Key Discipline Construction Project of Traditional Chinese MedicinedChemistry of Chinese Materia Medica.
文摘Although serving as the workhorse,MS/MS cannot fully satisfy the analytical requirements of quantitative sub-metabolome characterization.Because more information intrinsically correlates to more structural and concentration clues,here,efforts were devoted to comprehensively tracing and deciphering MS/MS behaviors through constructing triple three-dimensional(3×3D)-MS/MS spectrum.Ginsenosides-targeted metabolomics of notoginseng,one of the most famous edible medicinal plants,was employed as a proof-of-concept.Serial authentic ginsenosides were deployed to build the correlations between 3×3D-MS/MS spectra and structure/concentration features.Through assaying ginsenosides with progressive concentrations using QTOF-MS to configure 1st 3D spectrum,the generations of MS1 spectral signals,particularly multi-charged multimer anions,e.g.,[2Me2H]^(2-) and[2M+2HCOO]^(2-) ions,relied on both concentration and the amount of sugar chains.By programming progressive collision energies to the front collision cell of Qtrap-MS device to gain 2^(nd) 3D spectrum,optimal collision energy(OCE)corresponding to the glycosidic bond fission was primarily correlated with the masses of precursor and fragment ions and partially governed by the glycosidation site.The quantitative relationships between OCEs and masses of precursor and fragment ions were utilized to build large-scale quantitative program for ginsenosides.After applying progressive exciting energies to the back collision chamber to build 3^(rd) 3D spectrum,the fragment ion and the decomposition product anion exhibited identical dissociation trajectories when they shared the same molecular geometry.After ginsenosides-focused quantitative metabolomics,significant differences occurred for sub-metabolome amongst different parts of notoginseng.The differential ginsenosides were confirmatively identified by applying the correlations between 3×3D-MS/MS spectra and structures.Together,3×3D-MS/MS spectrum covers all MS/MS behaviors and dramatically facilitates sub-metabolome characterization from both quantitative program development and structural identification.
