In this paper, we derive an approximation of the SS-wave reflection coefficient and the expression of S-wave ray elastic impedance (SREI) in terms of the ray parameter. The SREI can be expressed by the S-wave incide...In this paper, we derive an approximation of the SS-wave reflection coefficient and the expression of S-wave ray elastic impedance (SREI) in terms of the ray parameter. The SREI can be expressed by the S-wave incidence angle or P-wave reflection angle, referred to as SREIS and SREIP, respectively. Our study using elastic models derived from real log measurements shows that SREIP has better capability for lithology and fluid discrimination than SREIS and conventional S-wave elastic impedance (SEI). We evaluate the SREIP feasibility using 25 groups of samples from Castagna and Smith (1994). Each sample group is constructed by using shale, brine-sand, and gas-sand. Theoretical evaluation also indicates that SRE1P at large incident angles is more sensitive to fluid than conventional fluid indicators. Real seismic data application also shows that SRE1P at large angles calculated using P-wave and S-wave impedance can efficiently characterize tight gas-sand.展开更多
As the stiffness of the elastic support varies with the physical-chemical erosion and mechanical friction, model catastrophe of a single degree-of-freedom(DOF) isolation system may occur. A 3-DOF four-point-elastic-su...As the stiffness of the elastic support varies with the physical-chemical erosion and mechanical friction, model catastrophe of a single degree-of-freedom(DOF) isolation system may occur. A 3-DOF four-point-elastic-support rigid plate(FERP) structure is presented to describe the catastrophic isolation system. Based on the newly-established structure, theoretical derivation for stiffness matrix calculation by free response(SMCby FR) and the method of stiffness identification by stiffness matrix disassembly(SIby SMD)are proposed. By integrating the SMCby FR and the SIby SMD and defining the stiffness assurance criterion(SAC), the procedures for stiffness identification of a FERP structure(SIFERP) are summarized. Then, a numerical example is adopted for the SIFERP validation, in which the simulated tested free response data are generated by the numerical methods, and operation for filtering noise is conducted to imitate the practical application. Results in the numerical example demonstrate the feasibility and accuracy of the developed SIFERP for stiffness identification.展开更多
The Moroccan Spring in 2011 has been a golden opportunity for Moroccan women to put their country on the democratization track. Their decision to take an integral part in all aspects of the uprisings stems from their ...The Moroccan Spring in 2011 has been a golden opportunity for Moroccan women to put their country on the democratization track. Their decision to take an integral part in all aspects of the uprisings stems from their belief that their participation and contribution are necessary for any potential democratic changes that would undoubtedly secure and bring them more rights. However, the appointment of only one female minister in the first Islamist-led government and the reluctance to implement the provisions of the new constitution, namely the issue of gender parity, are but two of the new alarming examples that have disappointed Moroccan women. Based on interviews with women's movement organizations' leaders and 20 February Movement (20-FMVT) female activists and through following the development of the Arab Spring in Morocco in particular and in the Middle Eastern & Northern Africa region in general, this paper considers the different roles, specificity, and gains of Moroccan women during and after the so-called Moroccan Spring. The paper argues that despite their limited gains in the aftermath of this momentum, Moroccan women managed once again to prove their agency and ability to change laws and instigate reforms.展开更多
基金sponsored by National Natural Science Fund Projects (No.41204072 and No.U1262208)Research Funds Provided to New Recruitments of China University of Petroleum-Beijing (YJRC-2011-03)Science Foundation of China University of Petroleum-Beijing (YJRC-2013-36)
文摘In this paper, we derive an approximation of the SS-wave reflection coefficient and the expression of S-wave ray elastic impedance (SREI) in terms of the ray parameter. The SREI can be expressed by the S-wave incidence angle or P-wave reflection angle, referred to as SREIS and SREIP, respectively. Our study using elastic models derived from real log measurements shows that SREIP has better capability for lithology and fluid discrimination than SREIS and conventional S-wave elastic impedance (SEI). We evaluate the SREIP feasibility using 25 groups of samples from Castagna and Smith (1994). Each sample group is constructed by using shale, brine-sand, and gas-sand. Theoretical evaluation also indicates that SRE1P at large incident angles is more sensitive to fluid than conventional fluid indicators. Real seismic data application also shows that SRE1P at large angles calculated using P-wave and S-wave impedance can efficiently characterize tight gas-sand.
基金Project(51221462)supported by the National Natural Science Foundation of ChinaProject(20120095110001)supported by the PhD Programs Foundation of Ministry of Education of ChinaProject(CXZZ13_0927)supported by Research and Innovation Project for College Graduates of Jiangsu Province,China
文摘As the stiffness of the elastic support varies with the physical-chemical erosion and mechanical friction, model catastrophe of a single degree-of-freedom(DOF) isolation system may occur. A 3-DOF four-point-elastic-support rigid plate(FERP) structure is presented to describe the catastrophic isolation system. Based on the newly-established structure, theoretical derivation for stiffness matrix calculation by free response(SMCby FR) and the method of stiffness identification by stiffness matrix disassembly(SIby SMD)are proposed. By integrating the SMCby FR and the SIby SMD and defining the stiffness assurance criterion(SAC), the procedures for stiffness identification of a FERP structure(SIFERP) are summarized. Then, a numerical example is adopted for the SIFERP validation, in which the simulated tested free response data are generated by the numerical methods, and operation for filtering noise is conducted to imitate the practical application. Results in the numerical example demonstrate the feasibility and accuracy of the developed SIFERP for stiffness identification.
文摘The Moroccan Spring in 2011 has been a golden opportunity for Moroccan women to put their country on the democratization track. Their decision to take an integral part in all aspects of the uprisings stems from their belief that their participation and contribution are necessary for any potential democratic changes that would undoubtedly secure and bring them more rights. However, the appointment of only one female minister in the first Islamist-led government and the reluctance to implement the provisions of the new constitution, namely the issue of gender parity, are but two of the new alarming examples that have disappointed Moroccan women. Based on interviews with women's movement organizations' leaders and 20 February Movement (20-FMVT) female activists and through following the development of the Arab Spring in Morocco in particular and in the Middle Eastern & Northern Africa region in general, this paper considers the different roles, specificity, and gains of Moroccan women during and after the so-called Moroccan Spring. The paper argues that despite their limited gains in the aftermath of this momentum, Moroccan women managed once again to prove their agency and ability to change laws and instigate reforms.