In many machine learning applications,data are not free,and there is a test cost for each data item. For the economical reason,some existing works try to minimize the test cost and at the same time,preserve a particul...In many machine learning applications,data are not free,and there is a test cost for each data item. For the economical reason,some existing works try to minimize the test cost and at the same time,preserve a particular property of a given decision system. In this paper,we point out that the test cost one can afford is limited in some applications. Hence,one has to sacrifice respective properties to keep the test cost under a budget. To formalize this issue,we define the test cost constraint attribute reduction problem,where the optimization objective is to minimize the conditional information entropy. This problem is an essential generalization of both the test-cost-sensitive attribute reduction problem and the 0-1 knapsack problem,therefore it is more challenging. We propose a heuristic algorithm based on the information gain and test costs to deal with the new problem. The algorithm is tested on four UCI(University of California-Irvine) datasets with various test cost settings. Experimental results indicate the appropriate setting of the only user-specified parameter λ.展开更多
Covering-based rough sets process data organized by a covering of the universe. A soft set is a parameterized family of subsets of the universe. Both theories can deal with the uncertainties of data. Soft sets have no...Covering-based rough sets process data organized by a covering of the universe. A soft set is a parameterized family of subsets of the universe. Both theories can deal with the uncertainties of data. Soft sets have not any restrictions on the approximate description of the object,and they might form a covering of the universe. From this viewpoint,we establish a connection between these two theories. Specifically,we propose a complementary parameter for this purpose. With this parameter,the soft covering approximation space is established and the two theories are bridged. Furthermore,we study some relations between the covering and the soft covering approximation space and obtain some significant results. Finally,we define a notion of combine parameter which can help us to simplify the set of parameters and reduce the storage requirement of a soft covering approximation space.展开更多
An effective numerical algorithm for computing the determinant of a pentadiagonal Toeplitz matrix has been proposed by Xiao-Guang Lv and others [1]. The complexity of the algorithm is (9n + 3). In this paper, a new al...An effective numerical algorithm for computing the determinant of a pentadiagonal Toeplitz matrix has been proposed by Xiao-Guang Lv and others [1]. The complexity of the algorithm is (9n + 3). In this paper, a new algorithm with the cost of (4n + 6) is presented to compute the determinant of a pentadiagonal Toeplitz matrix. The inverse of a pentadiagonal Toeplitz matrix is also considered.展开更多
A novel organic-inorganic hybrid compound constructed from mixed ligands, Co3(SIP)2(bipy)4(H2O)6·6.5H2O (H3SIP = 5-sulfoisophthalic acid, bipy = 4,4′-bipyridyl), has been hydrothermally synthesized and c...A novel organic-inorganic hybrid compound constructed from mixed ligands, Co3(SIP)2(bipy)4(H2O)6·6.5H2O (H3SIP = 5-sulfoisophthalic acid, bipy = 4,4′-bipyridyl), has been hydrothermally synthesized and characterized by IR, TGA and single-crystal X-ray diffraction. The crystal belongs to orthorhombic, space group P212121 with a = 11.395(2), b = 19.395(4), c = 30.675(6) A^°, Mr = 1513.05, V= 6779(2) A^°^3, Dc= 1.482 g/cm^3, F(000) = 3120, μ = 0.873 mm^-1, Z= 4, the final R = 0.0439 and wR = 0.119 for 13421 observed reflections with I〉 2σ(I). The structure of the compound presents a 3-D framework containing Co-bipy 1-D chain and 2-D bilayer motifs and carboxylate spacers, and the connection of 1-D chain and 2-D bilayer motifs by carboxylate ligand results in the final open framework with twofold interpenetration net. A probe reaction of the oxidation of benzaldehyde with H2O2 using the title compound as catalyst was carded out in a liquid-solid system, showing that the compound has high oxidative catalytic activity to the reaction.展开更多
An organically templated 2-D uranyl sulfate, {(C2H8N)[(UO2)Cl(SO4)(H2O)] }n 1, has been hydrothermally synthesized. The crystal and molecular structures have been determined by X-ray crystallography method and...An organically templated 2-D uranyl sulfate, {(C2H8N)[(UO2)Cl(SO4)(H2O)] }n 1, has been hydrothermally synthesized. The crystal and molecular structures have been determined by X-ray crystallography method and spectral techniques. 1 belongs to monoclinic, space group P21/c with a = 8.3545(17), b = 10.550(2), c = 12.370(3)A, β = 102.64(3)°, V = 1063.9(4)A3, Mr = 464.64, De= 2.901 g/cm^3, F(000) = 836,μ = 15.710 mm^-1, Z= 4, the final R = 0.0286 and wR = 0.0685 for 10164 observed reflections with Ⅰ 〉 2σ(Ⅰ). 1 presents a two-dimensional layer-like structure constructed from infinite anionic [(UO2)Cl(H2O)(SO4)]^- layers with [C2H8N]^+ cations balancing the charge and a number of intermoleeular hydrogen bonds (C-H…O and O-H…Cl) existing in the solid state. The fluorescence properties of 1 have also been discussed.展开更多
A novel 1-D iodoplumbate hybrid, 2(Pb3I9)^3*·3(C14H18N2)^2+ 1, has been hydrothermally synthesized and characterized by IR spectra, TGA and single-crystal X-ray diffraction. Complex 1 crystallizes in monocl...A novel 1-D iodoplumbate hybrid, 2(Pb3I9)^3*·3(C14H18N2)^2+ 1, has been hydrothermally synthesized and characterized by IR spectra, TGA and single-crystal X-ray diffraction. Complex 1 crystallizes in monoclinic, space group P21/c, with a = 12.057(2), b = 14.024(3), c = 24.742(5) A, β = 90.48(3)°, V = 4183.6(14) A^3, Z = 4, R= 0.0477 and wR = 0.0800. The title compound consists of 1-D chains (Pb3I9)n^3n* parallel to the [100] direction and stacks of alkylated 4,4'-bipyridium cations running along the [011] direction. Each anionic chain is surrounded by six arrays of alkylated 4,4'-bipyridium cations through extensive C-H…I atypical hydrogen-bonding interactions to afford an interesting 3-D supramolecular network. Significant fluorescent property of the compound was observed at room temperature.展开更多
A novel organic-inorganic hybrid compound, [Pb2I4(bipy)], (bipy = 4,4′-bipyridine), was synthesized by self-assembly and its structure was determined by X-ray crystallography method The crystal belongs to the mon...A novel organic-inorganic hybrid compound, [Pb2I4(bipy)], (bipy = 4,4′-bipyridine), was synthesized by self-assembly and its structure was determined by X-ray crystallography method The crystal belongs to the monoclinic system, space group P2 1/c with α = 4.4691(9), b = 15.385(3), c = 14.136(3) A, β = 93.75(3)°, V= 969.9(3) A^3, Mr = 1078.16, Dc= 3.692 g/cm^3, F(000) = 916, μ = 23.688 mm^-1, Z = 2, the final R = 0.0395 and wR = 0.0887 for 1557 observed reflections with I 〉 2σ(I). The title compound presents a two-dimensional layer-like structure constructed from [PbI5N] octahedron and bis-bridging ligand 4,4′-bipyridine. The fluorescence of the title compound is also discussed in this communication.展开更多
A novel one-dimensional chain-like coordination polymer constructed from 3-nitrobenzene- 1,2-dicarboxylic acid, [Cd2(C8H3NO6)2(H2O)4]n·2nH2O, has been synthesized and its structure was determined by X-ray cry...A novel one-dimensional chain-like coordination polymer constructed from 3-nitrobenzene- 1,2-dicarboxylic acid, [Cd2(C8H3NO6)2(H2O)4]n·2nH2O, has been synthesized and its structure was determined by X-ray crystallography method. The crystal belongs to monoclinic, space group P21/c with a = 6.1252(8), b = 20.706(3), c = 8.8067(11)A, β = 95.608(2)^o, V = 1111.6(2)A^3, Mr = 751.12, De= 2.244 g/cm^3, F(000) = 736,μ = 2.011 mm^-1, Z= 2, the final R = 0.0262 and wR = 0.0692 for 2338 observed reflections with I 〉 2a(I). The structure of the title compound presents a 1-D chain-like structure constructed by dimer units, [Cd2(C8H3NO6)2(H2O)4]n, through two carboxylate oxygen atoms. The fluorescence of the title compound has been also discussed in this paper.展开更多
In vapour deposition, single atoms (adatoms) on the substrate surface are the main source of growth. The change in its density plays a decisive role in the growth of thin films and quantum size islands. In the nucle...In vapour deposition, single atoms (adatoms) on the substrate surface are the main source of growth. The change in its density plays a decisive role in the growth of thin films and quantum size islands. In the nucleation and cluster coalescence stages of vapour deposition, the growth of stable clusters occurs on the substrate surface covered by stable clusters. Nucleation occurs in the non-covered part, while the total area covered by stable clusters on the substrate surface will gradually increase. Carefully taking into account the coverage effect, a revised single atom density rate equation is given for the famous and widely used thin-film rate equation theory, but the work of solving the revised equation has not been done. In this paper, we solve the equation and obtain the single-atom density and capture number by using a uniform depletion approximation. We determine that the single atom density is much lower than that evaluated from the single atom density rate equation in the traditional rate equation theory when the stable cluster coverage fraction is large, and it goes down very fast with an increase in the coverage fraction. The revised equation gives a higher value for the 'average' capture number than the present equation. It also increases with increasing coverage. That makes the preparation of single crystalline thin film materials difficult and the size control of quantum size islands complicated. We also discuss the effect of the revision on coalescence and the number of stable clusters in vapour deposition.展开更多
In this paper, we are concerned with the existence and non-existence of global solutions of a semi-linear heat equation with fractional Laplacian. We obtain some extem sion of results of Weissler who considered the ca...In this paper, we are concerned with the existence and non-existence of global solutions of a semi-linear heat equation with fractional Laplacian. We obtain some extem sion of results of Weissler who considered the case α = 1, and h ≡ 1.展开更多
Some topological properties of cone metric spaces are discussed and proved that every cone metric space (X, d) is complete if and only if every family of closed subsets of X which has the finite intersection propert...Some topological properties of cone metric spaces are discussed and proved that every cone metric space (X, d) is complete if and only if every family of closed subsets of X which has the finite intersection property and which for every c ε E, 0 〈〈 c contains a set of diameter less that c has non-empty intersection.展开更多
The influence of additive Konjac Glucomannan (KGM) in a variety of con- centrations on the crystallization morphology and structure of calcium oxalate (CaOxa) has been investigated by infrared spectroscopy, scanni...The influence of additive Konjac Glucomannan (KGM) in a variety of con- centrations on the crystallization morphology and structure of calcium oxalate (CaOxa) has been investigated by infrared spectroscopy, scanning electron microscope, X-ray diffraction and so on. The results showed KGM can complex with the Ca^2+ ions; low concentration KGM prevents CaOxa from aggregating, raises the concentration of ions in the solution, reduces the quantity of crystals and inhibits their growth, and the crystals are round and blunt; while high concentration KGM promotes the growth of crystal, which appears in sheet-like or irregular shape. Only CaOxa monohydrate was observed in a certain system with or without the presence of KGM.展开更多
A solvothermal process was developed for the preparation of cauliflower-like Bi2S3 from N,N-dimethylformamide (DMF) solution of bismuth nitrate [Bi(NO3)3.5H2O] and thioacetamide (TAA) with 2-undecyl-1-dithiourei...A solvothermal process was developed for the preparation of cauliflower-like Bi2S3 from N,N-dimethylformamide (DMF) solution of bismuth nitrate [Bi(NO3)3.5H2O] and thioacetamide (TAA) with 2-undecyl-1-dithioureido-ethyl-imidazoline (SUDEI) as the morphology-controlling agent. The obtained Bi2S3 products were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray diffraction (XRD), etc. The sensing properties of Bi2S3 with different morphologies were evaluated by the electrochemical analysis of dopamine (DA) and ascorbic acid (AA) coexisting solution. The results showed that cauliflower-like Bi2S3 showed a better resolving ability than rod-like Bi2S3 for the simultaneous determination of DA and AA,展开更多
In this paper,spaces with a locally countable sn-network are discussed.It is shown that a space with a locally countable sn-network iff it is an snf-countable space with a locally countable k-network.As its applicatio...In this paper,spaces with a locally countable sn-network are discussed.It is shown that a space with a locally countable sn-network iff it is an snf-countable space with a locally countable k-network.As its application,almost-open and closed mappings(or finite-to-one and closed mapping) preserve locally countable sn-networks,and a perfect preimage theorem on spaces with a locally countable sn-network is established.展开更多
The Ti-axiom,the Ti-ordered axiom and Ti-pairwise axiom(i = 0,1,2,3,4) of topological ordered space are discussed and proved that they are equivalence under the certain conditions.
In this paper, we proved that a sequential space has a cs*-regular cs*-network (or a cs*-regular weak base) is metrizable, which generalized related results in [6], [12] and [14].
A new liquid-liquid microextraction method based on the solidification of floating organic drops coupled with gas chromatography was developed for the determination of trace benzene, toluene and xylene(BTX) in water...A new liquid-liquid microextraction method based on the solidification of floating organic drops coupled with gas chromatography was developed for the determination of trace benzene, toluene and xylene(BTX) in water samples. In the microextraction procedure, a microdrop of n-decanol was delivered to the surface of the analytes’ solution, and stirred for a desired time. Following the absolute extraction, the sample vial was cooled in an ice bath for 10 min. The solidified n-decanol was then transferred into a plastic tube and melted naturally; and 1 μL of it was injected into gas chromatography for analysis. Factors relevant to the extraction efficiency were studied and optimized. The optimal experimental conditions were: 15 μL of n-decanol as extractive solvent, 30 mL of solution containing analytes, no salt, the stirring rate 400 r/min, the extraction temperature 30 °C, and the extraction time 30 min. Under those optimized conditions, the detection limit(LOD) of analytes was in a range of 0.05―0.10 ng/mL by the developed method. A good linearity(r0.99) in a calibration range of 0.01―100 μg/mL was obtained. The recoveries of the real samples at different spiked levels of BTX were in the range from 92.2% to 103.4%.展开更多
This paper combines interval-valued intuitionistic fuzzy sets and rough sets.It studies rougheness in interval-valued intuitionistic fuzzy sets and proposes one kind of interval-valued intuitionistic fuzzy-rough sets ...This paper combines interval-valued intuitionistic fuzzy sets and rough sets.It studies rougheness in interval-valued intuitionistic fuzzy sets and proposes one kind of interval-valued intuitionistic fuzzy-rough sets models under the equivalence relation in crisp sets.That extends the classical rough set defined by Pawlak.展开更多
The relations between the multifractal packing dimension of Borel probability measures and the asymptotic behavior of the function Ф*(x)=limsup logv(B(x,r))-qlogu(B(x,r))/logr are discussed and some appli...The relations between the multifractal packing dimension of Borel probability measures and the asymptotic behavior of the function Ф*(x)=limsup logv(B(x,r))-qlogu(B(x,r))/logr are discussed and some applications are given.展开更多
基金supported by the National Natural Science Foundation of China under Grant No. 60873077/F020107
文摘In many machine learning applications,data are not free,and there is a test cost for each data item. For the economical reason,some existing works try to minimize the test cost and at the same time,preserve a particular property of a given decision system. In this paper,we point out that the test cost one can afford is limited in some applications. Hence,one has to sacrifice respective properties to keep the test cost under a budget. To formalize this issue,we define the test cost constraint attribute reduction problem,where the optimization objective is to minimize the conditional information entropy. This problem is an essential generalization of both the test-cost-sensitive attribute reduction problem and the 0-1 knapsack problem,therefore it is more challenging. We propose a heuristic algorithm based on the information gain and test costs to deal with the new problem. The algorithm is tested on four UCI(University of California-Irvine) datasets with various test cost settings. Experimental results indicate the appropriate setting of the only user-specified parameter λ.
基金supported by National Natural Science Foundation of China under Grant No. 60873077/F020107the Science Research Project of Zhangzhou Normal University under Grant No. SK09002
文摘Covering-based rough sets process data organized by a covering of the universe. A soft set is a parameterized family of subsets of the universe. Both theories can deal with the uncertainties of data. Soft sets have not any restrictions on the approximate description of the object,and they might form a covering of the universe. From this viewpoint,we establish a connection between these two theories. Specifically,we propose a complementary parameter for this purpose. With this parameter,the soft covering approximation space is established and the two theories are bridged. Furthermore,we study some relations between the covering and the soft covering approximation space and obtain some significant results. Finally,we define a notion of combine parameter which can help us to simplify the set of parameters and reduce the storage requirement of a soft covering approximation space.
文摘An effective numerical algorithm for computing the determinant of a pentadiagonal Toeplitz matrix has been proposed by Xiao-Guang Lv and others [1]. The complexity of the algorithm is (9n + 3). In this paper, a new algorithm with the cost of (4n + 6) is presented to compute the determinant of a pentadiagonal Toeplitz matrix. The inverse of a pentadiagonal Toeplitz matrix is also considered.
基金Supported by the Natural Science Foundation of Fujian Province (2008 J0172)Innovate Project of Fujian Province (2007F3107)National Natural Science Foundation of China (20705031)
文摘A novel organic-inorganic hybrid compound constructed from mixed ligands, Co3(SIP)2(bipy)4(H2O)6·6.5H2O (H3SIP = 5-sulfoisophthalic acid, bipy = 4,4′-bipyridyl), has been hydrothermally synthesized and characterized by IR, TGA and single-crystal X-ray diffraction. The crystal belongs to orthorhombic, space group P212121 with a = 11.395(2), b = 19.395(4), c = 30.675(6) A^°, Mr = 1513.05, V= 6779(2) A^°^3, Dc= 1.482 g/cm^3, F(000) = 3120, μ = 0.873 mm^-1, Z= 4, the final R = 0.0439 and wR = 0.119 for 13421 observed reflections with I〉 2σ(I). The structure of the compound presents a 3-D framework containing Co-bipy 1-D chain and 2-D bilayer motifs and carboxylate spacers, and the connection of 1-D chain and 2-D bilayer motifs by carboxylate ligand results in the final open framework with twofold interpenetration net. A probe reaction of the oxidation of benzaldehyde with H2O2 using the title compound as catalyst was carded out in a liquid-solid system, showing that the compound has high oxidative catalytic activity to the reaction.
基金Supported by the Project of Natural Science Foundations of Fujian (No. 2008J0172)National Natural Science Foundation of China (20705031)
文摘An organically templated 2-D uranyl sulfate, {(C2H8N)[(UO2)Cl(SO4)(H2O)] }n 1, has been hydrothermally synthesized. The crystal and molecular structures have been determined by X-ray crystallography method and spectral techniques. 1 belongs to monoclinic, space group P21/c with a = 8.3545(17), b = 10.550(2), c = 12.370(3)A, β = 102.64(3)°, V = 1063.9(4)A3, Mr = 464.64, De= 2.901 g/cm^3, F(000) = 836,μ = 15.710 mm^-1, Z= 4, the final R = 0.0286 and wR = 0.0685 for 10164 observed reflections with Ⅰ 〉 2σ(Ⅰ). 1 presents a two-dimensional layer-like structure constructed from infinite anionic [(UO2)Cl(H2O)(SO4)]^- layers with [C2H8N]^+ cations balancing the charge and a number of intermoleeular hydrogen bonds (C-H…O and O-H…Cl) existing in the solid state. The fluorescence properties of 1 have also been discussed.
基金supported by the Natural Science Foundation of Fujian Province (008 J0172)Innovation Project of Fujian Province (2007F3107)National Natural Science Foundation of China (20705031)
文摘A novel 1-D iodoplumbate hybrid, 2(Pb3I9)^3*·3(C14H18N2)^2+ 1, has been hydrothermally synthesized and characterized by IR spectra, TGA and single-crystal X-ray diffraction. Complex 1 crystallizes in monoclinic, space group P21/c, with a = 12.057(2), b = 14.024(3), c = 24.742(5) A, β = 90.48(3)°, V = 4183.6(14) A^3, Z = 4, R= 0.0477 and wR = 0.0800. The title compound consists of 1-D chains (Pb3I9)n^3n* parallel to the [100] direction and stacks of alkylated 4,4'-bipyridium cations running along the [011] direction. Each anionic chain is surrounded by six arrays of alkylated 4,4'-bipyridium cations through extensive C-H…I atypical hydrogen-bonding interactions to afford an interesting 3-D supramolecular network. Significant fluorescent property of the compound was observed at room temperature.
基金Supported by the National Natural Science Foundation of China (20705031)the Natural Science Foundation of Fujian Province ((2008 J0172)+1 种基金the Yong Innovation Foundation of Fujian Science & Technology Committee (2007F3107)the Student Innovate Project of Zhangzhou Normal University (08xscxxsyxm25)
文摘A novel organic-inorganic hybrid compound, [Pb2I4(bipy)], (bipy = 4,4′-bipyridine), was synthesized by self-assembly and its structure was determined by X-ray crystallography method The crystal belongs to the monoclinic system, space group P2 1/c with α = 4.4691(9), b = 15.385(3), c = 14.136(3) A, β = 93.75(3)°, V= 969.9(3) A^3, Mr = 1078.16, Dc= 3.692 g/cm^3, F(000) = 916, μ = 23.688 mm^-1, Z = 2, the final R = 0.0395 and wR = 0.0887 for 1557 observed reflections with I 〉 2σ(I). The title compound presents a two-dimensional layer-like structure constructed from [PbI5N] octahedron and bis-bridging ligand 4,4′-bipyridine. The fluorescence of the title compound is also discussed in this communication.
基金Supported by the Project of Fujian Science & Technology Committee (2006F5067)National Natural Science Foundations of China(20705031)
文摘A novel one-dimensional chain-like coordination polymer constructed from 3-nitrobenzene- 1,2-dicarboxylic acid, [Cd2(C8H3NO6)2(H2O)4]n·2nH2O, has been synthesized and its structure was determined by X-ray crystallography method. The crystal belongs to monoclinic, space group P21/c with a = 6.1252(8), b = 20.706(3), c = 8.8067(11)A, β = 95.608(2)^o, V = 1111.6(2)A^3, Mr = 751.12, De= 2.244 g/cm^3, F(000) = 736,μ = 2.011 mm^-1, Z= 2, the final R = 0.0262 and wR = 0.0692 for 2338 observed reflections with I 〉 2a(I). The structure of the title compound presents a 1-D chain-like structure constructed by dimer units, [Cd2(C8H3NO6)2(H2O)4]n, through two carboxylate oxygen atoms. The fluorescence of the title compound has been also discussed in this paper.
基金Project supported by the Natural Science Foundation of Fujian Province of China (Grant No.A0220001)
文摘In vapour deposition, single atoms (adatoms) on the substrate surface are the main source of growth. The change in its density plays a decisive role in the growth of thin films and quantum size islands. In the nucleation and cluster coalescence stages of vapour deposition, the growth of stable clusters occurs on the substrate surface covered by stable clusters. Nucleation occurs in the non-covered part, while the total area covered by stable clusters on the substrate surface will gradually increase. Carefully taking into account the coverage effect, a revised single atom density rate equation is given for the famous and widely used thin-film rate equation theory, but the work of solving the revised equation has not been done. In this paper, we solve the equation and obtain the single-atom density and capture number by using a uniform depletion approximation. We determine that the single atom density is much lower than that evaluated from the single atom density rate equation in the traditional rate equation theory when the stable cluster coverage fraction is large, and it goes down very fast with an increase in the coverage fraction. The revised equation gives a higher value for the 'average' capture number than the present equation. It also increases with increasing coverage. That makes the preparation of single crystalline thin film materials difficult and the size control of quantum size islands complicated. We also discuss the effect of the revision on coalescence and the number of stable clusters in vapour deposition.
基金supported by National Natural Science Foundation of China(10976026)
文摘In this paper, we are concerned with the existence and non-existence of global solutions of a semi-linear heat equation with fractional Laplacian. We obtain some extem sion of results of Weissler who considered the case α = 1, and h ≡ 1.
基金Foundation item: Supported by tile National Natural Science Foundation of China(10971185, 10971186) Supported by the Research Fund for Higher Education of Fujian Province(JK2011031)
文摘Some topological properties of cone metric spaces are discussed and proved that every cone metric space (X, d) is complete if and only if every family of closed subsets of X which has the finite intersection property and which for every c ε E, 0 〈〈 c contains a set of diameter less that c has non-empty intersection.
基金Supported by the National Natural Science Foundation of China (31071518 and 31271837)the doctoral program of higher education of the specialized research fund for the project funded by the United (20113515110010)+2 种基金Science and Technology Planning Project of technological department (2012GA7200022)the Natural Science Foundation of Fujian Province (2011J01285)the funding (type A, No. JA11167) from the Fujian Education Department
文摘The influence of additive Konjac Glucomannan (KGM) in a variety of con- centrations on the crystallization morphology and structure of calcium oxalate (CaOxa) has been investigated by infrared spectroscopy, scanning electron microscope, X-ray diffraction and so on. The results showed KGM can complex with the Ca^2+ ions; low concentration KGM prevents CaOxa from aggregating, raises the concentration of ions in the solution, reduces the quantity of crystals and inhibits their growth, and the crystals are round and blunt; while high concentration KGM promotes the growth of crystal, which appears in sheet-like or irregular shape. Only CaOxa monohydrate was observed in a certain system with or without the presence of KGM.
基金National Nature Science Foundation of China(No.20705031)Youth Innovation Foundation of Fujian(No.2007F3106).
文摘A solvothermal process was developed for the preparation of cauliflower-like Bi2S3 from N,N-dimethylformamide (DMF) solution of bismuth nitrate [Bi(NO3)3.5H2O] and thioacetamide (TAA) with 2-undecyl-1-dithioureido-ethyl-imidazoline (SUDEI) as the morphology-controlling agent. The obtained Bi2S3 products were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray diffraction (XRD), etc. The sensing properties of Bi2S3 with different morphologies were evaluated by the electrochemical analysis of dopamine (DA) and ascorbic acid (AA) coexisting solution. The results showed that cauliflower-like Bi2S3 showed a better resolving ability than rod-like Bi2S3 for the simultaneous determination of DA and AA,
基金Supported by the NNSF of China(1097118510971186)Supported by NSF of Fujian Province(2008F5066)
文摘In this paper,spaces with a locally countable sn-network are discussed.It is shown that a space with a locally countable sn-network iff it is an snf-countable space with a locally countable k-network.As its application,almost-open and closed mappings(or finite-to-one and closed mapping) preserve locally countable sn-networks,and a perfect preimage theorem on spaces with a locally countable sn-network is established.
基金The project is supported by the NNSF of China(No.10971185,10971186)Fujian Province support college research plan project(No.JK2011031)
文摘The Ti-axiom,the Ti-ordered axiom and Ti-pairwise axiom(i = 0,1,2,3,4) of topological ordered space are discussed and proved that they are equivalence under the certain conditions.
基金Supported by the NNSF of China(10571151,10671173)Supported by the NSF of Fujian Province(2006J0228,2008F5066)
文摘In this paper, we proved that a sequential space has a cs*-regular cs*-network (or a cs*-regular weak base) is metrizable, which generalized related results in [6], [12] and [14].
基金Supported by the National Natural Science Foundation of China(No.21105088)the Program for Science and Technology Projects of the Education Department of Fujian Province,China(No.JA10211)
文摘A new liquid-liquid microextraction method based on the solidification of floating organic drops coupled with gas chromatography was developed for the determination of trace benzene, toluene and xylene(BTX) in water samples. In the microextraction procedure, a microdrop of n-decanol was delivered to the surface of the analytes’ solution, and stirred for a desired time. Following the absolute extraction, the sample vial was cooled in an ice bath for 10 min. The solidified n-decanol was then transferred into a plastic tube and melted naturally; and 1 μL of it was injected into gas chromatography for analysis. Factors relevant to the extraction efficiency were studied and optimized. The optimal experimental conditions were: 15 μL of n-decanol as extractive solvent, 30 mL of solution containing analytes, no salt, the stirring rate 400 r/min, the extraction temperature 30 °C, and the extraction time 30 min. Under those optimized conditions, the detection limit(LOD) of analytes was in a range of 0.05―0.10 ng/mL by the developed method. A good linearity(r0.99) in a calibration range of 0.01―100 μg/mL was obtained. The recoveries of the real samples at different spiked levels of BTX were in the range from 92.2% to 103.4%.
基金Foundation item: Supported by the NSF of Fujian(Z0511033)Supported by the Eduction Committee of Fujian(JB04298)Supported by the Eduction Committee of Henan (2004606018, 200510483002)
文摘In this paper, we prove that a space with a compact Countable weak base if and only if it is a weak open cs-image of a metric space.
基金supported by grants from the National Natural Science Foundation of China(Nos.10971185 and 10971186)the Natural Science Foundation of Fujiang Province in China(No.2008F5066).
文摘This paper combines interval-valued intuitionistic fuzzy sets and rough sets.It studies rougheness in interval-valued intuitionistic fuzzy sets and proposes one kind of interval-valued intuitionistic fuzzy-rough sets models under the equivalence relation in crisp sets.That extends the classical rough set defined by Pawlak.
基金Supported by the Education Committee of Fujian Province(JA08155)
文摘The relations between the multifractal packing dimension of Borel probability measures and the asymptotic behavior of the function Ф*(x)=limsup logv(B(x,r))-qlogu(B(x,r))/logr are discussed and some applications are given.