Based on sine and cosine functions, the compactly supported orthogonal wavelet filter coefficients with arbitrary length are constructed for the first time. When N = 2(k-1) and N = 2k, the unified analytic constructio...Based on sine and cosine functions, the compactly supported orthogonal wavelet filter coefficients with arbitrary length are constructed for the first time. When N = 2(k-1) and N = 2k, the unified analytic constructions of orthogonal wavelet filters are put forward, respectively. The famous Daubechies filter and some other well-known wavelet filters are tested by the proposed novel method which is very useful for wavelet theory research and many application areas such as pattern recognition.展开更多
The properties and structures of thermotropical liquid crystalline copolyesters based on p-hydroxybenzoic acid (PHBA), terephthalic acid (TPR) and bisphenol A (BPA) were studied by DSC, WAXD, hot stage polarized micro...The properties and structures of thermotropical liquid crystalline copolyesters based on p-hydroxybenzoic acid (PHBA), terephthalic acid (TPR) and bisphenol A (BPA) were studied by DSC, WAXD, hot stage polarized microscopy and NMR. It was found that most of the copolyesters were soluble in many common organic solvents. The copolyesters had low T-m/T-f values and a broad range of liquid crystal phase, making the polymers readily melt-processable. The effects of annealing at different temperatures on the copolyester containing 33% PHBA were also discussed. It was noted that annealing at ca. 200 degrees C (below Tc - n) could lead to the increasing of the crystallinity of the copolyester while the microstructure and sequence structure had not changed. Annealing at ca. 280 degrees C (near Tc - n) could bring a change of crystal and sequence structure and simultaneously made the microdomains be ordered more perfectly.展开更多
The kinetics of ultrasonic degradation of aqueous solution of polyacrylamide(PAM)and poly(ethyleneoxide)(PEO)as well as ultrasonic block copolymerization of aqueous solution of the mixture of PAM/PEOwere studied...The kinetics of ultrasonic degradation of aqueous solution of polyacrylamide(PAM)and poly(ethyleneoxide)(PEO)as well as ultrasonic block copolymerization of aqueous solution of the mixture of PAM/PEOwere studied respectively.The degradation reaction of PEO follows a linear relationship between(P1-P∞)-1and irradiation time,while that of PAM follows a linear relationship between(P1-P∞)-1/2and irradiation time.The structure of the copolymer was identified by IR,NMR and DTA,and the copolymer prepared is a blockone.The copolymer formed by irradiating 1% aqueous solution of PEO/PAM mixture(1:1)for a period of40min.at 18.2 kHz with a sonic intensity corresponding to 2.OA input current on the reversed main circuitamounts to 61.8%.展开更多
The effect of isobutylene-isoprene rubber (IIR) on the crystallizing behavior of isotactic polypropylene (IPP) as well as the morphology of the blends in relation with its properties have been studied by DSC, WAXD, po...The effect of isobutylene-isoprene rubber (IIR) on the crystallizing behavior of isotactic polypropylene (IPP) as well as the morphology of the blends in relation with its properties have been studied by DSC, WAXD, polarized light microscope, SEM and mechanical properties test. The experimental results show that IIR has slight influence on melting point, crystallinity, crystallization rate of IPP. It seems certain that IIR has not entered into IPP phase in melt state. IIR has retarding action on the growth of IPP crystal and is an effective nucleating agent of IPP spherulites. The impact strength of the blend increases rapidly with IIR content more than 30 parts; the tensile strength of the blend, however, decreases as IIR content increases. The temperature and time of alter heat-treatment also have great influence on the impact strength of the blend. The impact strength of IPP/IIR (100/20) heat-treated at about 130℃ for 2h is 5 times as high as that of the untreated blend.展开更多
According to the lower-bound theorem of limit analysis the Rigid Finite Element Meth-od(RFEM)is applied to structural limit analysis and the linear programmings for limit analysis are deducedin this paper.Moreover,the...According to the lower-bound theorem of limit analysis the Rigid Finite Element Meth-od(RFEM)is applied to structural limit analysis and the linear programmings for limit analysis are deducedin this paper.Moreover,the Thermo-Parameter Method(TPM)and Parametric Variational principles(PVP)are used to reduce the computational effort while maintaining the accuracy of solutions.A better solution isalso obtained in this paper.展开更多
The lateral mixing of solids in a gas-solids fluidized bed is very complicated.It can be caused by:(a)bubble movement through the bed,(b)bubble burst at the bed surface,and(c)gross particle circulation in thebed.Howev...The lateral mixing of solids in a gas-solids fluidized bed is very complicated.It can be caused by:(a)bubble movement through the bed,(b)bubble burst at the bed surface,and(c)gross particle circulation in thebed.However,experiments show that the major factors effected the lateral mixing of solids are the bubblemovement through the bed and the bubble burst at the bed surface.Thus a model with two mixing re-gions,i.e.mixing in bubble rising region and mixing in bubble breaking region,was proposed.Based on thismodel,an equation for predicting the lateral dispersion coefficient of solids in gas-solids fluidized beds wasderived without any adjustable parameter.The calculated values by this equation are well comparable withthe observed data including the present work and the other investigations.展开更多
The correlation between Young's modulus of mica-filled high density polyethylene (HDPE), low density polyethylene(LDPE) and the state of dispersion of plasma-treated mica in the polymer matrices was studied. The m...The correlation between Young's modulus of mica-filled high density polyethylene (HDPE), low density polyethylene(LDPE) and the state of dispersion of plasma-treated mica in the polymer matrices was studied. The modulus and the number average diameter of mica aggregates in matrix were determined with tensile testing and image analysis respectively. The interface structure of the filler/matrix and the bulk structure of matrix were examined through the dielectric spectrometry, differential scanning calorimetry (DSC) and dynamic viscoelastic spectrometry. The results show that the Young's modulus of the filial polyethylene depends to a great extent upon the state of dispersion of filler in matrix, but it is independent of the interface structure and bulk structure. The better the dispersion, the higher the Young's modulus.展开更多
Various aspects of the rheological behaviour of liquid crystalline copolyesters, i.e.,samples of copoly (p-hydroxybenzoate / bisphenol A terephthalate), were explored by usingInstron capillary rheometer. The experimen...Various aspects of the rheological behaviour of liquid crystalline copolyesters, i.e.,samples of copoly (p-hydroxybenzoate / bisphenol A terephthalate), were explored by usingInstron capillary rheometer. The experimental results indicated that the apparent viscositywas affected significantly by shear rate, melt temperature and p-hydroxybenzoate unit con-tent. The flow activation energies △E_η are in the range of 205.1 to 74.5 kJ/mol, dependingon the shear rate of 10-1000 s^(-1), at temperature 568-603K. These copolyesters exhibit ayield phenomenon in the shear flow, and the values of yield stress decrease with increasingtemperature. It is quite unusual that the extrudate of the copolyester shows the smallerswelling ratio even than unity at the lower temperature and lower shear rates.展开更多
The hadronic vacuum polarization correction to the photon propagator is found by using the Dubnicka-Meshcheryakov parametrization of the pion form factor and new experimental data on the e^(+)e^(-)→hadrons anniKilati...The hadronic vacuum polarization correction to the photon propagator is found by using the Dubnicka-Meshcheryakov parametrization of the pion form factor and new experimental data on the e^(+)e^(-)→hadrons anniKilation cross section.展开更多
The effect of γ-ray irradiation on the mechanical properties of high densitypolyethylene(HDPE) filled with sericite-tridymite-cristobalite(STC) was studied. The ex-perimental results show that γ-ray irradiation can ...The effect of γ-ray irradiation on the mechanical properties of high densitypolyethylene(HDPE) filled with sericite-tridymite-cristobalite(STC) was studied. The ex-perimental results show that γ-ray irradiation can improve the affinity between HDPE andSTC, and the dispersion of STC in HDPE matrix. Compared with HDPE/STC (80/20)blend, the yield stress and impact strength of irradiated HDPE (10kGy)/STC (80/20) blendare increased from 22.8 MPa and 70J/m to 28.5 MPa and 144J/m. The yield stress andimpact strength of HDPE/irradiated HDPE/STC (48/32/20) are 27.8MPa and 210J/m,respectively.展开更多
It is well known that the potential curve of ground state for almost all neutral diatomic molecules has only one minimum.However,the doubly charged diatomic ions may have both potential minimum and maximum or singly r...It is well known that the potential curve of ground state for almost all neutral diatomic molecules has only one minimum.However,the doubly charged diatomic ions may have both potential minimum and maximum or singly repulsive branch.In order to describe the potential of this kind of diatomic ions,two of the authors Zhu and Wang have proposed a new analytical potential function with four parameters ai(i=l,...,4),andρ=R-R_(min) for those with both minimum and maximum,andρ=R for those with singly repulsive branch.The present work has derived this new potential function for HBe^(2+)with R_(min)=0.182 nm,R_(max)=0.335 nm andΔE=E_(max)-E_(min)=0.84 eV,and for HBe2+with R_(min)=0.147 nm,R_(max)=0.185 nm andΔE=E_(max)-E_(min)=0.062 eV.It is found that the potential for HF^(2+)is one with singly repulsive branch.The dissociation limits,parameters ai(i=1,...,4),force constants and spectroscopic data of these ions all are given out.展开更多
A general method for an analytical calculation of SU(N)lattice gauge theories with finite N≥3 developed.As an example,the order parameter(E)of lattice SU(4)gauge systetn is calculated.The result is in good agree^nent...A general method for an analytical calculation of SU(N)lattice gauge theories with finite N≥3 developed.As an example,the order parameter(E)of lattice SU(4)gauge systetn is calculated.The result is in good agree^nent with Monte Carlo simulations.展开更多
Classical trajectories have been calculated for the reaction C+CH→C2+H using many-body expansion(MBE) potential energy function of C2H.The present work gives the reactive cross sections at relative kinetic energy of ...Classical trajectories have been calculated for the reaction C+CH→C2+H using many-body expansion(MBE) potential energy function of C2H.The present work gives the reactive cross sections at relative kinetic energy of 1.0,7.5,13.0,20.0and 30.0 kcal,From which it is found that this is a reaction without energy thres-hold.展开更多
In this paper, Tang-Toennies potential is applied to the He-H<sub>2</sub> system and the variationof A, b and C<sub>2</sub>n with r is formulated. The dispersion coefficients obtained are in fa...In this paper, Tang-Toennies potential is applied to the He-H<sub>2</sub> system and the variationof A, b and C<sub>2</sub>n with r is formulated. The dispersion coefficients obtained are in fairly goodagreement with those acquired by the universally accepted method of Meyer et al. and theyalso conform with the outcome that K. T. Tang and J. Peter Toennies achieved. As a result,the He-H<sub>2</sub> potential function done by the author matches, when r and R are varied, the resu-1ts calculated by Meyer within large region. Using such a potential function, the author hascomputed the forty-four different kinds of vibrational and rotational excitation cross sectionsfor He-H<sub>2</sub> collision, and conducted research on the changing patterns of the partial wavecross sections for elastic atom-molecule collision and the partial wave excitation cross sectionsfor inelastic collision with the increase of quantum number.展开更多
The superstructure and properties of polymers might be improved and enhanced througl intermolecular complexation. In this paper, the preparation, structure and properties of P(MMA-MAA)/PEO intermolecular complex throu...The superstructure and properties of polymers might be improved and enhanced througl intermolecular complexation. In this paper, the preparation, structure and properties of P(MMA-MAA)/PEO intermolecular complex through hydrogen bonding are studied. By acid hydrolysis of PMMA, a series of P(MMA-MAA) copolymers have been prepared, the MAA content of which depends on the temperature and time of hydrolyzation. In case the MAA content in P(MMA-MAA) is beyond 0.4 mole fraction, the hydrogen bonding between P(MMA-MAA) and PEO is strong enough to form intermolecular complex. The supermolecular structure of the complex is quite different from that of its constituent, which was observed by an X-ray diffraction and transmission electron microscope. The crystallization of PEO is confined owing to complexation. The complex exhibits quite a lot of good properties in thermal stability, gas permeability as well as mechanical strength, and could be used in many fields.展开更多
Z. Artstein has derived a strong law of large numbers for random compact sets with respect to Hausdorff distance. In this note, we give an equivalent theorem for almost everywhere convergence of the sequence of random...Z. Artstein has derived a strong law of large numbers for random compact sets with respect to Hausdorff distance. In this note, we give an equivalent theorem for almost everywhere convergence of the sequence of random sets with respect to the topology, and the relationships among all convergences of the sequence of random sets.展开更多
The problem of how to give a unified interpretation for the electron paramagntic res-onance(EPR) parameters (the zero-field splitting parameter a and the g-tensor) and the op-tical spectrum of a cubic d^5 complex had ...The problem of how to give a unified interpretation for the electron paramagntic res-onance(EPR) parameters (the zero-field splitting parameter a and the g-tensor) and the op-tical spectrum of a cubic d^5 complex had long been open since it was put forward by VanVleck and Penny in 1934. In the 1990s, two different methods for the unified calculationof the parameter a and spectrum of a cubic d^5 complex were proposed respectively byKang and Zhou et al, respectively. However, they did not deal with how to展开更多
With an experimental method developed for measuring the electrical resistance of met-als in diamond anvil cell (DAC), we measured the pressure dependence of resistance ofmanganin up to 18.5 GPa. The relationship bet...With an experimental method developed for measuring the electrical resistance of met-als in diamond anvil cell (DAC), we measured the pressure dependence of resistance ofmanganin up to 18.5 GPa. The relationship between the resistance of manganin and thepressure is linear below 13 GPa. Another linear relationship is obtained in the range of 13-18.5 GPa. A "turning point" of linear relation is formed at 13 GPa. The piezoresistancecoefficient of manganin measured is 0.024 GPa<sub>1</sub> below 13 GPa, which is in good agreementwith those given in literature. A new resistance-pressure relation is obtained in the rangeof 13~18.5 GPa. with the piezoresistance coefficient of 0.020 GPa<sup>-1</sup>.展开更多
We measured the pressure dependences of electrical resistances for iron,nickel and copper up to 42 GPa.The results at lower pressure range are in agreement withthose reported in literature.In addition,we observed the ...We measured the pressure dependences of electrical resistances for iron,nickel and copper up to 42 GPa.The results at lower pressure range are in agreement withthose reported in literature.In addition,we observed the discontinuities of iron(32-34GPa)and nickel(28.8 GPa).展开更多
文摘Based on sine and cosine functions, the compactly supported orthogonal wavelet filter coefficients with arbitrary length are constructed for the first time. When N = 2(k-1) and N = 2k, the unified analytic constructions of orthogonal wavelet filters are put forward, respectively. The famous Daubechies filter and some other well-known wavelet filters are tested by the proposed novel method which is very useful for wavelet theory research and many application areas such as pattern recognition.
文摘The properties and structures of thermotropical liquid crystalline copolyesters based on p-hydroxybenzoic acid (PHBA), terephthalic acid (TPR) and bisphenol A (BPA) were studied by DSC, WAXD, hot stage polarized microscopy and NMR. It was found that most of the copolyesters were soluble in many common organic solvents. The copolyesters had low T-m/T-f values and a broad range of liquid crystal phase, making the polymers readily melt-processable. The effects of annealing at different temperatures on the copolyester containing 33% PHBA were also discussed. It was noted that annealing at ca. 200 degrees C (below Tc - n) could lead to the increasing of the crystallinity of the copolyester while the microstructure and sequence structure had not changed. Annealing at ca. 280 degrees C (near Tc - n) could bring a change of crystal and sequence structure and simultaneously made the microdomains be ordered more perfectly.
文摘The kinetics of ultrasonic degradation of aqueous solution of polyacrylamide(PAM)and poly(ethyleneoxide)(PEO)as well as ultrasonic block copolymerization of aqueous solution of the mixture of PAM/PEOwere studied respectively.The degradation reaction of PEO follows a linear relationship between(P1-P∞)-1and irradiation time,while that of PAM follows a linear relationship between(P1-P∞)-1/2and irradiation time.The structure of the copolymer was identified by IR,NMR and DTA,and the copolymer prepared is a blockone.The copolymer formed by irradiating 1% aqueous solution of PEO/PAM mixture(1:1)for a period of40min.at 18.2 kHz with a sonic intensity corresponding to 2.OA input current on the reversed main circuitamounts to 61.8%.
文摘The effect of isobutylene-isoprene rubber (IIR) on the crystallizing behavior of isotactic polypropylene (IPP) as well as the morphology of the blends in relation with its properties have been studied by DSC, WAXD, polarized light microscope, SEM and mechanical properties test. The experimental results show that IIR has slight influence on melting point, crystallinity, crystallization rate of IPP. It seems certain that IIR has not entered into IPP phase in melt state. IIR has retarding action on the growth of IPP crystal and is an effective nucleating agent of IPP spherulites. The impact strength of the blend increases rapidly with IIR content more than 30 parts; the tensile strength of the blend, however, decreases as IIR content increases. The temperature and time of alter heat-treatment also have great influence on the impact strength of the blend. The impact strength of IPP/IIR (100/20) heat-treated at about 130℃ for 2h is 5 times as high as that of the untreated blend.
基金The project supported by National Natural Science Foundation of China
文摘According to the lower-bound theorem of limit analysis the Rigid Finite Element Meth-od(RFEM)is applied to structural limit analysis and the linear programmings for limit analysis are deducedin this paper.Moreover,the Thermo-Parameter Method(TPM)and Parametric Variational principles(PVP)are used to reduce the computational effort while maintaining the accuracy of solutions.A better solution isalso obtained in this paper.
基金Project Supported by National Natural Science Foundation of China.
文摘The lateral mixing of solids in a gas-solids fluidized bed is very complicated.It can be caused by:(a)bubble movement through the bed,(b)bubble burst at the bed surface,and(c)gross particle circulation in thebed.However,experiments show that the major factors effected the lateral mixing of solids are the bubblemovement through the bed and the bubble burst at the bed surface.Thus a model with two mixing re-gions,i.e.mixing in bubble rising region and mixing in bubble breaking region,was proposed.Based on thismodel,an equation for predicting the lateral dispersion coefficient of solids in gas-solids fluidized beds wasderived without any adjustable parameter.The calculated values by this equation are well comparable withthe observed data including the present work and the other investigations.
基金Project supported by National Natural Science Foundation of China
文摘The correlation between Young's modulus of mica-filled high density polyethylene (HDPE), low density polyethylene(LDPE) and the state of dispersion of plasma-treated mica in the polymer matrices was studied. The modulus and the number average diameter of mica aggregates in matrix were determined with tensile testing and image analysis respectively. The interface structure of the filler/matrix and the bulk structure of matrix were examined through the dielectric spectrometry, differential scanning calorimetry (DSC) and dynamic viscoelastic spectrometry. The results show that the Young's modulus of the filial polyethylene depends to a great extent upon the state of dispersion of filler in matrix, but it is independent of the interface structure and bulk structure. The better the dispersion, the higher the Young's modulus.
文摘Various aspects of the rheological behaviour of liquid crystalline copolyesters, i.e.,samples of copoly (p-hydroxybenzoate / bisphenol A terephthalate), were explored by usingInstron capillary rheometer. The experimental results indicated that the apparent viscositywas affected significantly by shear rate, melt temperature and p-hydroxybenzoate unit con-tent. The flow activation energies △E_η are in the range of 205.1 to 74.5 kJ/mol, dependingon the shear rate of 10-1000 s^(-1), at temperature 568-603K. These copolyesters exhibit ayield phenomenon in the shear flow, and the values of yield stress decrease with increasingtemperature. It is quite unusual that the extrudate of the copolyester shows the smallerswelling ratio even than unity at the lower temperature and lower shear rates.
文摘The hadronic vacuum polarization correction to the photon propagator is found by using the Dubnicka-Meshcheryakov parametrization of the pion form factor and new experimental data on the e^(+)e^(-)→hadrons anniKilation cross section.
基金Project supported by the National Natural Science Foundation of China and Ford-China R & D Fund.
文摘The effect of γ-ray irradiation on the mechanical properties of high densitypolyethylene(HDPE) filled with sericite-tridymite-cristobalite(STC) was studied. The ex-perimental results show that γ-ray irradiation can improve the affinity between HDPE andSTC, and the dispersion of STC in HDPE matrix. Compared with HDPE/STC (80/20)blend, the yield stress and impact strength of irradiated HDPE (10kGy)/STC (80/20) blendare increased from 22.8 MPa and 70J/m to 28.5 MPa and 144J/m. The yield stress andimpact strength of HDPE/irradiated HDPE/STC (48/32/20) are 27.8MPa and 210J/m,respectively.
文摘It is well known that the potential curve of ground state for almost all neutral diatomic molecules has only one minimum.However,the doubly charged diatomic ions may have both potential minimum and maximum or singly repulsive branch.In order to describe the potential of this kind of diatomic ions,two of the authors Zhu and Wang have proposed a new analytical potential function with four parameters ai(i=l,...,4),andρ=R-R_(min) for those with both minimum and maximum,andρ=R for those with singly repulsive branch.The present work has derived this new potential function for HBe^(2+)with R_(min)=0.182 nm,R_(max)=0.335 nm andΔE=E_(max)-E_(min)=0.84 eV,and for HBe2+with R_(min)=0.147 nm,R_(max)=0.185 nm andΔE=E_(max)-E_(min)=0.062 eV.It is found that the potential for HF^(2+)is one with singly repulsive branch.The dissociation limits,parameters ai(i=1,...,4),force constants and spectroscopic data of these ions all are given out.
基金Partially Supported by the National Natural Science Foundation of China。
文摘A general method for an analytical calculation of SU(N)lattice gauge theories with finite N≥3 developed.As an example,the order parameter(E)of lattice SU(4)gauge systetn is calculated.The result is in good agree^nent with Monte Carlo simulations.
文摘Classical trajectories have been calculated for the reaction C+CH→C2+H using many-body expansion(MBE) potential energy function of C2H.The present work gives the reactive cross sections at relative kinetic energy of 1.0,7.5,13.0,20.0and 30.0 kcal,From which it is found that this is a reaction without energy thres-hold.
文摘In this paper, Tang-Toennies potential is applied to the He-H<sub>2</sub> system and the variationof A, b and C<sub>2</sub>n with r is formulated. The dispersion coefficients obtained are in fairly goodagreement with those acquired by the universally accepted method of Meyer et al. and theyalso conform with the outcome that K. T. Tang and J. Peter Toennies achieved. As a result,the He-H<sub>2</sub> potential function done by the author matches, when r and R are varied, the resu-1ts calculated by Meyer within large region. Using such a potential function, the author hascomputed the forty-four different kinds of vibrational and rotational excitation cross sectionsfor He-H<sub>2</sub> collision, and conducted research on the changing patterns of the partial wavecross sections for elastic atom-molecule collision and the partial wave excitation cross sectionsfor inelastic collision with the increase of quantum number.
基金Project supported by the Science Fund of State Education Committee of China.
文摘The superstructure and properties of polymers might be improved and enhanced througl intermolecular complexation. In this paper, the preparation, structure and properties of P(MMA-MAA)/PEO intermolecular complex through hydrogen bonding are studied. By acid hydrolysis of PMMA, a series of P(MMA-MAA) copolymers have been prepared, the MAA content of which depends on the temperature and time of hydrolyzation. In case the MAA content in P(MMA-MAA) is beyond 0.4 mole fraction, the hydrogen bonding between P(MMA-MAA) and PEO is strong enough to form intermolecular complex. The supermolecular structure of the complex is quite different from that of its constituent, which was observed by an X-ray diffraction and transmission electron microscope. The crystallization of PEO is confined owing to complexation. The complex exhibits quite a lot of good properties in thermal stability, gas permeability as well as mechanical strength, and could be used in many fields.
文摘Z. Artstein has derived a strong law of large numbers for random compact sets with respect to Hausdorff distance. In this note, we give an equivalent theorem for almost everywhere convergence of the sequence of random sets with respect to the topology, and the relationships among all convergences of the sequence of random sets.
文摘In researches on topology of lattices, many papers discuss fuzzy lattices, i.e. completely distributive lattices with order reversing involution ','.
文摘The problem of how to give a unified interpretation for the electron paramagntic res-onance(EPR) parameters (the zero-field splitting parameter a and the g-tensor) and the op-tical spectrum of a cubic d^5 complex had long been open since it was put forward by VanVleck and Penny in 1934. In the 1990s, two different methods for the unified calculationof the parameter a and spectrum of a cubic d^5 complex were proposed respectively byKang and Zhou et al, respectively. However, they did not deal with how to
文摘With an experimental method developed for measuring the electrical resistance of met-als in diamond anvil cell (DAC), we measured the pressure dependence of resistance ofmanganin up to 18.5 GPa. The relationship between the resistance of manganin and thepressure is linear below 13 GPa. Another linear relationship is obtained in the range of 13-18.5 GPa. A "turning point" of linear relation is formed at 13 GPa. The piezoresistancecoefficient of manganin measured is 0.024 GPa<sub>1</sub> below 13 GPa, which is in good agreementwith those given in literature. A new resistance-pressure relation is obtained in the rangeof 13~18.5 GPa. with the piezoresistance coefficient of 0.020 GPa<sup>-1</sup>.
文摘We measured the pressure dependences of electrical resistances for iron,nickel and copper up to 42 GPa.The results at lower pressure range are in agreement withthose reported in literature.In addition,we observed the discontinuities of iron(32-34GPa)and nickel(28.8 GPa).