Electromagnetic interference(EMI)shielding materials with superior shielding efficiency and low-reflection properties hold promising potential for utilization across electronic components,precision instruments,and fif...Electromagnetic interference(EMI)shielding materials with superior shielding efficiency and low-reflection properties hold promising potential for utilization across electronic components,precision instruments,and fifth-generation communication equipment.In this study,multistage microcellular waterborne polyurethane(WPU)composites were constructed via gradient induction,layer-by-layer casting,and supercritical carbon dioxide foaming.The gradient-structured WPU/ironcobalt loaded reduced graphene oxide(FeCo@rGO)foam serves as an impedance-matched absorption layer,while the highly conductive WPU/silver loaded glass microspheres(Ag@GM)layer is employed as a reflection layer.Thanks to the incorporation of an asymmetric structure,as well as the introduction of gradient and porous configurations,the composite foam demonstrates excellent conductivity,outstanding EMI SE(74.9 dB),and minimal reflection characteristics(35.28%)in 8.2-12.4 GHz,implying that more than 99.99999%of electromagnetic(EM)waves were blocked and only 35.28%were reflected to the external environment.Interestingly,the reflectivity of the composite foam is reduced to 0.41%at 10.88 GHz due to the resonance for incident and reflected EM waves.Beyond that,the composite foam is characterized by low density(0.47 g/cm^(3))and great stability of EMI shielding properties.This work offers a viable approach for craft-ing lightweight,highly shielding,and minimally reflective EMI shielding composites.展开更多
Perfect anomalous reflections have been demonstrated in optical phase gradient metasurfaces(PGMs),but they suffer from single-frequency(narrow-band)response due to the intrinsic limitation of natural geometric periodi...Perfect anomalous reflections have been demonstrated in optical phase gradient metasurfaces(PGMs),but they suffer from single-frequency(narrow-band)response due to the intrinsic limitation of natural geometric periodicity.Here,we provide both numerical and analytical evidence that a depth gradient metasurface can achieve discrete ultra-broadband perfect anomalous reflection in the microwave range in the absence of geometric periodicity.Remarkably,by adjusting the operating frequency of the incident wave,the same effect can be steadily obtained via a physically equivalent phase periodicity in the PGM.Based on this mechanism,a perfect retroreflector with a broadband response ranging from 1 GHz to 40 GHz is realized.Our work has promising applications in communication,source tracking,and military satellites.展开更多
We report an interesting and abnormal electromagnetic phenomenon with regard to a terajet(TJ)that is generated in a reflection mode,which is realized by placing a dielectric scatterer onto a metal reflection plate.We ...We report an interesting and abnormal electromagnetic phenomenon with regard to a terajet(TJ)that is generated in a reflection mode,which is realized by placing a dielectric scatterer onto a metal reflection plate.We show that the introduction of an air hollow into metal reflection plate beneath the scatterer does not induce an expected decrease but an abnormal increase of focal length of the TJ by as much as more than three times.This abnormal phenomenon takes place in case that the air hollow is shallow and there exists a critical hollow depth for a given lateral size of air hollow.Larger than the critical depth,the phenomenon no longer occurs.It is explained from viewpoints of both ray optics in terms of role of relative portion of central waves in TJ formation and electromagnetic field theory with regard to hollow-induced phase singularities.展开更多
Curriculum ideological and political education is an important direction of higher education reform in the new era,aiming to realize the organic integration of professional knowledge imparting and ideological and poli...Curriculum ideological and political education is an important direction of higher education reform in the new era,aiming to realize the organic integration of professional knowledge imparting and ideological and political education.Taking preliminary landscape design course as an example,this paper expounded in detail the implementation of teaching reform from three aspects:the formulation of teaching objectives,the integration of teaching contents and the innovation of teaching methods.This paper systematically summarized the implementation effect of ideological and political education reform,and reflected on the excavation of ideological and political elements,integration degree,innovation of teaching methods,teachers’ideological and political ability and practical teaching.The exploration on curriculum ideological and political teaching provides useful reference and thinking for similar courses,and promotes the sustainable development of curriculum ideological and political education.展开更多
The power generation performance of a heaving body wave energy converter(HBWEC)can be enhanced through strategic deployment in proximity to natural or artificial coastal structures.In this study,coastal structures are...The power generation performance of a heaving body wave energy converter(HBWEC)can be enhanced through strategic deployment in proximity to natural or artificial coastal structures.In this study,coastal structures are represented by a partial reflection wall,enabling the device to harness additional reflected wave energy.However,the mechanisms by which the reflection coefficient and the clearance between the wall and the device affect energy conversion performance remain inadequately understood.This study experimentally investigates these effects.The findings demonstrate that the clearance impact on HBWEC power performance near partial reflection walls aligns with standing wave variation characteristics,with optimal positioning near the second antinode of the HBWEC's heaving natural period.Enhanced reflection coefficients improve energy conversion efficiency within the wave spectrum around the device's heaving natural period.Additionally,significant water sloshing observed within the clearance may diminish power performance,as verified through computational fluid dynamics(CFD)analysis.This phenomenon results from the multiplicative relationship of leeside clearance with 0.5λ(λis the wavelength).These insights suggest that practical engineering implementation requires balanced consideration of reflection coefficient,clearance,sloshing phenomenon,and heaving restriction system,rather than individual parameter optimization.展开更多
Global challenges like epidemics,wars,and climate change expose humans to life-and-death threats daily,triggering death anxiety and subsequent death reflection,which involves deliberate cognitive processing of mortali...Global challenges like epidemics,wars,and climate change expose humans to life-and-death threats daily,triggering death anxiety and subsequent death reflection,which involves deliberate cognitive processing of mortality.While some studies have shown the positive impacts of death reflection,such as on well-being,the relationship between death reflection and existential well-being,closely related to life and death,remains unexplored.This study aimed to investigate the effects of death reflection on existential well-being and the mediating role of relational self-esteem.675 university students from Sichuan and Hubei,China,completed the death reflection scale,relational self-esteem scale,and the existential well-being subscale of the spiritual well-being scale.Results indicated that death reflection was positively correlated with both relational self-esteem and existential well-being,and relational self-esteem was positively related to existential well-being.Mediation analysis confirmed that relational self-esteem mediated the relationship between death reflection and existential well-being.This study not only enriches the research content on the positive effects of death reflection theoretically,but also holds significant practical value in guiding individuals who have experienced death or been exposed to death-related information in their psychological reconstruction and recovery.展开更多
U_(S)-admitting spaces,which were introduced by Heckmann,enjoy many nice properties similar to those of the extensively studied well-filtered spaces.In this paper,we present a direct construction of the U_(S)-admittin...U_(S)-admitting spaces,which were introduced by Heckmann,enjoy many nice properties similar to those of the extensively studied well-filtered spaces.In this paper,we present a direct construction of the U_(S)-admitting reflections by using U_(S)-admitting determined sets.展开更多
Fracture identification is important for the evaluation of carbonate reservoirs. However, conventional logging equipment has small depth of investigation and cannot detect rock fractures more than three meters away fr...Fracture identification is important for the evaluation of carbonate reservoirs. However, conventional logging equipment has small depth of investigation and cannot detect rock fractures more than three meters away from the borehole. Remote acoustic logging uses phase-controlled array-transmitting and long sound probes that increase the depth of investigation. The interpretation of logging data with respect to fractures is typically guided by practical experience rather than theory and is often ambiguous. We use remote acoustic reflection logging data and high-order finite-difference approximations in the forward modeling and prestack reverse-time migration to image fractures. First, we perform forward modeling of the fracture responses as a function of the fracture-borehole wall distance, aperture, and dip angle. Second, we extract the energy intensity within the imaging area to determine whether the fracture can be identified as the formation velocity is varied. Finally, we evaluate the effect of the fracture-borehole distance, fracture aperture, and dip angle on fracture identification.展开更多
Borehole acoustic reflection logging can provide high resolution images of nearborehole geological structure. However, the conventional seismic migration and imaging methods are not effective because the reflected wav...Borehole acoustic reflection logging can provide high resolution images of nearborehole geological structure. However, the conventional seismic migration and imaging methods are not effective because the reflected waves are interfered with the dominant borehole-guided modes and there are only eight receiving channels per shot available for stacking. In this paper, we apply an equivalent offset migration method based on wave scattering theory to process the acoustic reflection imaging log data from both numerical modeling and recorded field data. The result shows that, compared with the routine post-stack depth migration method, the equivalent offset migration method results in higher stack fold and is more effective for near-borehole structural imaging with low SNR acoustic reflection log data.展开更多
We introduce the Thomsen anisotropic parameters into the approximate linear reflection coefficient equation for P-SV wave in weakly anisotropic HTI media. From this we get a new, more effective, and practical reflecti...We introduce the Thomsen anisotropic parameters into the approximate linear reflection coefficient equation for P-SV wave in weakly anisotropic HTI media. From this we get a new, more effective, and practical reflection coefficient equation. We performed forward modeling to AVO attributes, obtaining excellent results. The combined AVO attribute analysis of PP and PS reflection data can greatly reduce ambiguity, obtain better petrophysical parameters, and improve parameter accuracy.展开更多
Antimony tin oxide （ATO） nano-particles doped with different Sb contents were prepared by co-precipitation method, using SnCl4·5H2O and SbCl3 as main raw materials. Microstructure, morphology and reflectivity c...Antimony tin oxide （ATO） nano-particles doped with different Sb contents were prepared by co-precipitation method, using SnCl4·5H2O and SbCl3 as main raw materials. Microstructure, morphology and reflectivity curves were characterized by XRD, FESEM, UV-visible spectroscopy and laser, and the effects of Sb content on crystalline microstructure, crystal size and reflectivity curves of the ATO nano-particles were investigated systematically. The results show that the ATO nano-particles prepared by co-precipitation method have tetragonal rutile structure, with particle size distribution range of several decade nanometer. With the increase of Sb content, the grain size of ATO decreases, and the unit cell volume increases. Compared with the SnO2 particles without Sb, the 1.06 μm laser reflection of ATO nano-particles doped with Sb is obviously lower. With the increase of Sb content, the reflection increases first, then decreases;when the Sb content is 20%, 1.06μm laser reflection of ATO nano-particles is below 0.02%, and the laser reflection performance is the best.展开更多
Aiming at a series of existing problems of ecological landscape in farmland and in residential district at northern villages,and problems like low recovery rate of wastes,uncertain evaluation index of ecological lands...Aiming at a series of existing problems of ecological landscape in farmland and in residential district at northern villages,and problems like low recovery rate of wastes,uncertain evaluation index of ecological landscape,managers' low consciousnesses and insufficient organization and management at northern villages;the corresponding planning suggestions were proposed.Scientific farming,developing ecological agriculture and perfecting ecological corridor system were of great significance to ecological landscape of farmland.Reasonable ecological construction,fully utilizing renewable energy sources,overall planning,improving land utilization rate and highlighting regional characteristic of ecological landscape were of great significance to ecological landscape of residential district.Tourism agriculture development should be emphasized,ecological landscape theory study enhanced,administrative organization perfected and reasonable ecological evaluation carried out,respecting the principle of ecology,fully exploring regional characteristics,strengthening government's guidance and considering villagers' will,so as to construct a society in which man and nature were in harmony.展开更多
[Objective] The aim was to analyze risks of transgenic technology. [Method] Discussions on risks of transgenic technologies were conducted from perspective of philosophy. [Result] Mechanistic philosophy and reductioni...[Objective] The aim was to analyze risks of transgenic technology. [Method] Discussions on risks of transgenic technologies were conducted from perspective of philosophy. [Result] Mechanistic philosophy and reductionism are causes of reflection on risks of transgenic technology. Considering transgene is an artificial choice taking place of natural choice, it is inevitable for risks of transgenic technology to be found. In addition, social system constitutes the root for out-of-control of transgenic technology, hence, mechanism risk is the primary cause of transgenic risks. [Conclusion] It is inescapable for science view to be changed from arbitrary and lopsided to reflective and comprehensive and for technology view to be changed from exterminative and genesic to protective and symbiotic.展开更多
This paper presents some reflections on non-English major postgraduate English teaching reform. The author points out some understandings on the English proficiency of non-English major postgraduate students and curri...This paper presents some reflections on non-English major postgraduate English teaching reform. The author points out some understandings on the English proficiency of non-English major postgraduate students and curriculum changes in the reform. The author thinks that postgraduate English teaching reform is a systematic project, with a goal to meet the practical needs of postgraduate students and improve their ability to use English in their study and work. Hence, every effort of the reform should be made to satisfy the practical needs of the students and to make their English study contribute to their achievements in their own subject area.展开更多
A new method of nanocontact fabrication for Adreev reflection measurement based on the nanopore method using a SiN membrane with focused ion beam technique is presented. With this method, controllable, clean,tensionle...A new method of nanocontact fabrication for Adreev reflection measurement based on the nanopore method using a SiN membrane with focused ion beam technique is presented. With this method, controllable, clean,tensionless nano-contacts for spin polarization probing can be obtained. Measurements of the fabricated samples show complicated spectral structures with a zero bias anomaly and dip structures from quasipartical interactions. A control sample of Co40Fe40B20 is measured with Nb tip method. None of the measured spectra can be explained satisfactorily by present theory. Further analysis of the contact interface and a more complete theory are needed to extract a reliable spin polarization message with the point contact Andreev reflection method.展开更多
In this study,polyacrylic acid(PAA)films were employed as a model system,and a series of PAA films with tunable water wettability was systematically prepared by varying molecular weight and curing temperature.Using at...In this study,polyacrylic acid(PAA)films were employed as a model system,and a series of PAA films with tunable water wettability was systematically prepared by varying molecular weight and curing temperature.Using attenuated total reflectance Fourier-transform infrared spectroscopy(ATR-FTIR),the molecular configurations of surface carboxyl groups(COOH),free carboxyl(COOH_(f))and hydrogen-bonded carboxyl(COOH_(HB),were directly correlated with the polar component of surface energy(γ^(s,p)).By decomposing theγ^(s,p)values of the PAA thin films as a sum of the contributions of COOH_(f)and COOH_(H B),the intrinsic polar component of surface energy of COOH_(H B)(γ_(H B)^(s,p*))was quantified for the first time as 8.34 mN/m,significantly lower than that of COOH_(f)(γ_(f)^(s,p*)=34 mN/m).This result highlights that hydrogen bonding markedly reduces theγ^(s,p),providing a rational explanation for the relatively large water contact angle observed on PAA thin films.Furthermore,it establishes a thermodynamic basis for estimating the fraction of surface COOH_(H B)groups(f H B)from wettability measurements.Further extension of the model to carboxyl-terminated self-assembled monolayers(COOH-SAMs)revealed that surface COOH density(ΣCOOH)critically regulates wetting behavior:whenΣCOOH ranges from 4.30 to 5.25 nm^(-2),COOH groups predominantly exist in a free state and facilitate effective hydration layers,thereby promoting superhydrophilicity.Overall,this study not only establishes a unified thermodynamic framework linking surface COOH configurations to macroscopic wettability,but also validates its universality by extending it to COOH-SAMs systems,thereby providing a unified theoretical framework for the controllable design of hydrophilicity in various COOH-functionalized surfaces.展开更多
In an academic environment increasingly shaped by metrics and the imperatives of“publish or perish”,it is rare to encounter a leading scientist willing to interweave personal narrative with conceptual reflection.The...In an academic environment increasingly shaped by metrics and the imperatives of“publish or perish”,it is rare to encounter a leading scientist willing to interweave personal narrative with conceptual reflection.The Soul of Geography by Fu(2025)achieves precisely this.The book resists simple categorisation:it is neither a conventional monograph nor a memoir,but rather a hybrid text that integrates autobiography,disciplinary reflection,and scientific arguments.In doing so,Fu articulates not only the trajectory of his own career but also a vision of geography as a discipline of theoretical depth and practical relevance.展开更多
Objective:To explore the application of the Registered Nurses'Association of Ontario(RNAO)Best Practice Guideline(BPG)for Developing and Sustaining Nursing Leadership through the lens of nursing students transitio...Objective:To explore the application of the Registered Nurses'Association of Ontario(RNAO)Best Practice Guideline(BPG)for Developing and Sustaining Nursing Leadership through the lens of nursing students transitioning from classroom learning to clinical practice.Through this reflection,the authors hope to inspire and empower future nursing leaders to champion innovation,resilience,and excellence in healthcare.Methods:By integrating evidence-based leadership principles,the authors reflect on their personal experiences,challenges,and successes in implementing these guidelines in real-world settings.Results:The paper highlights the significance of leadership in fostering healthy work environments and improving patient outcomes,emphasizing the role of nursing students as emerging leaders.Practical strategies for applying BPG,the RNAO BPG suggests leadership skills on professional development,and recommendations for embedding leadership principles into nursing education and practice are discussed.Conclusions:Implementing nursing leadership from the beginning of a nursing student's journey is vital for shaping the next generation of healthcare leaders.By integrating leadership principles early in nursing education,students can develop the skills needed to navigate clinical challenges,collaborate effectively with healthcare teams,and advocate for positive change.Starting with leadership guidelines in nursing school ensures that future nurses are equipped to foster supportive work environments,improve patient outcomes,and drive innovation from the very start of their careers,making leadership an inherent part of their professional identity.展开更多
基金supported by the Natural Science Foundation of Anhui Province(No.2308085QE146 and 2208085ME116)the National Natural Science Foundation of China(No.52173039)+1 种基金the Natural Science Foundation of Jiangsu Province(No.BK20210894)the Anhui Provincial Universities Outstanding Youth Research Project(No.2023AH020018).
文摘Electromagnetic interference(EMI)shielding materials with superior shielding efficiency and low-reflection properties hold promising potential for utilization across electronic components,precision instruments,and fifth-generation communication equipment.In this study,multistage microcellular waterborne polyurethane(WPU)composites were constructed via gradient induction,layer-by-layer casting,and supercritical carbon dioxide foaming.The gradient-structured WPU/ironcobalt loaded reduced graphene oxide(FeCo@rGO)foam serves as an impedance-matched absorption layer,while the highly conductive WPU/silver loaded glass microspheres(Ag@GM)layer is employed as a reflection layer.Thanks to the incorporation of an asymmetric structure,as well as the introduction of gradient and porous configurations,the composite foam demonstrates excellent conductivity,outstanding EMI SE(74.9 dB),and minimal reflection characteristics(35.28%)in 8.2-12.4 GHz,implying that more than 99.99999%of electromagnetic(EM)waves were blocked and only 35.28%were reflected to the external environment.Interestingly,the reflectivity of the composite foam is reduced to 0.41%at 10.88 GHz due to the resonance for incident and reflected EM waves.Beyond that,the composite foam is characterized by low density(0.47 g/cm^(3))and great stability of EMI shielding properties.This work offers a viable approach for craft-ing lightweight,highly shielding,and minimally reflective EMI shielding composites.
基金supported by the National Natural Science Foundation of China(Grant Nos.12274313,62275184,and 62411540033)Collaborative Innovation Center of Suzhou Nano Science and Technology,Suzhou Basic Research Project(Grant No.SJC2023003)+1 种基金the Gusu Leading Talent Plan for Scientific and Technological Innovation and Entrepreneurship(Grant No.ZXL2024400)the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Perfect anomalous reflections have been demonstrated in optical phase gradient metasurfaces(PGMs),but they suffer from single-frequency(narrow-band)response due to the intrinsic limitation of natural geometric periodicity.Here,we provide both numerical and analytical evidence that a depth gradient metasurface can achieve discrete ultra-broadband perfect anomalous reflection in the microwave range in the absence of geometric periodicity.Remarkably,by adjusting the operating frequency of the incident wave,the same effect can be steadily obtained via a physically equivalent phase periodicity in the PGM.Based on this mechanism,a perfect retroreflector with a broadband response ranging from 1 GHz to 40 GHz is realized.Our work has promising applications in communication,source tracking,and military satellites.
基金Project supported by the National Natural Science Foundation of China(Grant No.61875148)the Key Awards Program of Cultivating Outstanding Innovative Postgraduates in Arts and Sciences of Tianjin University(Grant No.C1-2022002)+3 种基金the Talent Project of Anhui Science and Technology University(Grant No.DQYJ202304)the University-Level Research Project of Tianjin Sino-German University of Applied Sciences(Grant No.zdkt2018-007)China Association for Science and Technology Young Talent Support Project Doctoral Special Programthe National High-level University Scholarship Program for Graduate Students of China Scholarship Council(Grant No.202406250166)。
文摘We report an interesting and abnormal electromagnetic phenomenon with regard to a terajet(TJ)that is generated in a reflection mode,which is realized by placing a dielectric scatterer onto a metal reflection plate.We show that the introduction of an air hollow into metal reflection plate beneath the scatterer does not induce an expected decrease but an abnormal increase of focal length of the TJ by as much as more than three times.This abnormal phenomenon takes place in case that the air hollow is shallow and there exists a critical hollow depth for a given lateral size of air hollow.Larger than the critical depth,the phenomenon no longer occurs.It is explained from viewpoints of both ray optics in terms of role of relative portion of central waves in TJ formation and electromagnetic field theory with regard to hollow-induced phase singularities.
基金Sponsored by Teaching Research Project of Yangtze University(JY2023028).
文摘Curriculum ideological and political education is an important direction of higher education reform in the new era,aiming to realize the organic integration of professional knowledge imparting and ideological and political education.Taking preliminary landscape design course as an example,this paper expounded in detail the implementation of teaching reform from three aspects:the formulation of teaching objectives,the integration of teaching contents and the innovation of teaching methods.This paper systematically summarized the implementation effect of ideological and political education reform,and reflected on the excavation of ideological and political elements,integration degree,innovation of teaching methods,teachers’ideological and political ability and practical teaching.The exploration on curriculum ideological and political teaching provides useful reference and thinking for similar courses,and promotes the sustainable development of curriculum ideological and political education.
基金supported by the National Natural Science Foundation of China(Grant Nos.52201322,52401323,and52222109)the Fundamental Research Funds for the Central Universities(Grant No.2024ZYGXZR042)+1 种基金Guangdong Basic and Applied Basic Research Foundation(Grant Nos.2022B1515020036 and 2023A1515012144)the Project of State Key Laboratory of Subtropical Building and Urban Science(Grant No.2023ZB14)。
文摘The power generation performance of a heaving body wave energy converter(HBWEC)can be enhanced through strategic deployment in proximity to natural or artificial coastal structures.In this study,coastal structures are represented by a partial reflection wall,enabling the device to harness additional reflected wave energy.However,the mechanisms by which the reflection coefficient and the clearance between the wall and the device affect energy conversion performance remain inadequately understood.This study experimentally investigates these effects.The findings demonstrate that the clearance impact on HBWEC power performance near partial reflection walls aligns with standing wave variation characteristics,with optimal positioning near the second antinode of the HBWEC's heaving natural period.Enhanced reflection coefficients improve energy conversion efficiency within the wave spectrum around the device's heaving natural period.Additionally,significant water sloshing observed within the clearance may diminish power performance,as verified through computational fluid dynamics(CFD)analysis.This phenomenon results from the multiplicative relationship of leeside clearance with 0.5λ(λis the wavelength).These insights suggest that practical engineering implementation requires balanced consideration of reflection coefficient,clearance,sloshing phenomenon,and heaving restriction system,rather than individual parameter optimization.
文摘Global challenges like epidemics,wars,and climate change expose humans to life-and-death threats daily,triggering death anxiety and subsequent death reflection,which involves deliberate cognitive processing of mortality.While some studies have shown the positive impacts of death reflection,such as on well-being,the relationship between death reflection and existential well-being,closely related to life and death,remains unexplored.This study aimed to investigate the effects of death reflection on existential well-being and the mediating role of relational self-esteem.675 university students from Sichuan and Hubei,China,completed the death reflection scale,relational self-esteem scale,and the existential well-being subscale of the spiritual well-being scale.Results indicated that death reflection was positively correlated with both relational self-esteem and existential well-being,and relational self-esteem was positively related to existential well-being.Mediation analysis confirmed that relational self-esteem mediated the relationship between death reflection and existential well-being.This study not only enriches the research content on the positive effects of death reflection theoretically,but also holds significant practical value in guiding individuals who have experienced death or been exposed to death-related information in their psychological reconstruction and recovery.
基金Supported by the National Natural Science Foundation of China(Grant No.12571507)。
文摘U_(S)-admitting spaces,which were introduced by Heckmann,enjoy many nice properties similar to those of the extensively studied well-filtered spaces.In this paper,we present a direct construction of the U_(S)-admitting reflections by using U_(S)-admitting determined sets.
基金supported by National Petroleum Major Project(Grant No.2011ZX05020-008)
文摘Fracture identification is important for the evaluation of carbonate reservoirs. However, conventional logging equipment has small depth of investigation and cannot detect rock fractures more than three meters away from the borehole. Remote acoustic logging uses phase-controlled array-transmitting and long sound probes that increase the depth of investigation. The interpretation of logging data with respect to fractures is typically guided by practical experience rather than theory and is often ambiguous. We use remote acoustic reflection logging data and high-order finite-difference approximations in the forward modeling and prestack reverse-time migration to image fractures. First, we perform forward modeling of the fracture responses as a function of the fracture-borehole wall distance, aperture, and dip angle. Second, we extract the energy intensity within the imaging area to determine whether the fracture can be identified as the formation velocity is varied. Finally, we evaluate the effect of the fracture-borehole distance, fracture aperture, and dip angle on fracture identification.
基金supported by the National Natural Science Foundation of China (Grant No.50674098)the 863 Program (Grant No.2006AA06Z207 & 2006AA06Z213)the 973 Program (Grant No.2007CB209601)
文摘Borehole acoustic reflection logging can provide high resolution images of nearborehole geological structure. However, the conventional seismic migration and imaging methods are not effective because the reflected waves are interfered with the dominant borehole-guided modes and there are only eight receiving channels per shot available for stacking. In this paper, we apply an equivalent offset migration method based on wave scattering theory to process the acoustic reflection imaging log data from both numerical modeling and recorded field data. The result shows that, compared with the routine post-stack depth migration method, the equivalent offset migration method results in higher stack fold and is more effective for near-borehole structural imaging with low SNR acoustic reflection log data.
基金the National "973" Project (No.2007CB209603) the "863" Project (No.2006AA06Z108)
文摘We introduce the Thomsen anisotropic parameters into the approximate linear reflection coefficient equation for P-SV wave in weakly anisotropic HTI media. From this we get a new, more effective, and practical reflection coefficient equation. We performed forward modeling to AVO attributes, obtaining excellent results. The combined AVO attribute analysis of PP and PS reflection data can greatly reduce ambiguity, obtain better petrophysical parameters, and improve parameter accuracy.
基金Project(10KJB430008)supported by the Natural Science Foundation of Colleges in Jiangsu Province,ChinaProjects(2013(CXZZ13_0421),2012(CXLX12_0425))supported by Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),ChinaResearch and Innovation Program for College Graduates of Jiangsu Province,China
文摘Antimony tin oxide （ATO） nano-particles doped with different Sb contents were prepared by co-precipitation method, using SnCl4·5H2O and SbCl3 as main raw materials. Microstructure, morphology and reflectivity curves were characterized by XRD, FESEM, UV-visible spectroscopy and laser, and the effects of Sb content on crystalline microstructure, crystal size and reflectivity curves of the ATO nano-particles were investigated systematically. The results show that the ATO nano-particles prepared by co-precipitation method have tetragonal rutile structure, with particle size distribution range of several decade nanometer. With the increase of Sb content, the grain size of ATO decreases, and the unit cell volume increases. Compared with the SnO2 particles without Sb, the 1.06 μm laser reflection of ATO nano-particles doped with Sb is obviously lower. With the increase of Sb content, the reflection increases first, then decreases;when the Sb content is 20%, 1.06μm laser reflection of ATO nano-particles is below 0.02%, and the laser reflection performance is the best.
文摘Aiming at a series of existing problems of ecological landscape in farmland and in residential district at northern villages,and problems like low recovery rate of wastes,uncertain evaluation index of ecological landscape,managers' low consciousnesses and insufficient organization and management at northern villages;the corresponding planning suggestions were proposed.Scientific farming,developing ecological agriculture and perfecting ecological corridor system were of great significance to ecological landscape of farmland.Reasonable ecological construction,fully utilizing renewable energy sources,overall planning,improving land utilization rate and highlighting regional characteristic of ecological landscape were of great significance to ecological landscape of residential district.Tourism agriculture development should be emphasized,ecological landscape theory study enhanced,administrative organization perfected and reasonable ecological evaluation carried out,respecting the principle of ecology,fully exploring regional characteristics,strengthening government's guidance and considering villagers' will,so as to construct a society in which man and nature were in harmony.
文摘[Objective] The aim was to analyze risks of transgenic technology. [Method] Discussions on risks of transgenic technologies were conducted from perspective of philosophy. [Result] Mechanistic philosophy and reductionism are causes of reflection on risks of transgenic technology. Considering transgene is an artificial choice taking place of natural choice, it is inevitable for risks of transgenic technology to be found. In addition, social system constitutes the root for out-of-control of transgenic technology, hence, mechanism risk is the primary cause of transgenic risks. [Conclusion] It is inescapable for science view to be changed from arbitrary and lopsided to reflective and comprehensive and for technology view to be changed from exterminative and genesic to protective and symbiotic.
文摘This paper presents some reflections on non-English major postgraduate English teaching reform. The author points out some understandings on the English proficiency of non-English major postgraduate students and curriculum changes in the reform. The author thinks that postgraduate English teaching reform is a systematic project, with a goal to meet the practical needs of postgraduate students and improve their ability to use English in their study and work. Hence, every effort of the reform should be made to satisfy the practical needs of the students and to make their English study contribute to their achievements in their own subject area.
文摘A new method of nanocontact fabrication for Adreev reflection measurement based on the nanopore method using a SiN membrane with focused ion beam technique is presented. With this method, controllable, clean,tensionless nano-contacts for spin polarization probing can be obtained. Measurements of the fabricated samples show complicated spectral structures with a zero bias anomaly and dip structures from quasipartical interactions. A control sample of Co40Fe40B20 is measured with Nb tip method. None of the measured spectra can be explained satisfactorily by present theory. Further analysis of the contact interface and a more complete theory are needed to extract a reliable spin polarization message with the point contact Andreev reflection method.
文摘In this study,polyacrylic acid(PAA)films were employed as a model system,and a series of PAA films with tunable water wettability was systematically prepared by varying molecular weight and curing temperature.Using attenuated total reflectance Fourier-transform infrared spectroscopy(ATR-FTIR),the molecular configurations of surface carboxyl groups(COOH),free carboxyl(COOH_(f))and hydrogen-bonded carboxyl(COOH_(HB),were directly correlated with the polar component of surface energy(γ^(s,p)).By decomposing theγ^(s,p)values of the PAA thin films as a sum of the contributions of COOH_(f)and COOH_(H B),the intrinsic polar component of surface energy of COOH_(H B)(γ_(H B)^(s,p*))was quantified for the first time as 8.34 mN/m,significantly lower than that of COOH_(f)(γ_(f)^(s,p*)=34 mN/m).This result highlights that hydrogen bonding markedly reduces theγ^(s,p),providing a rational explanation for the relatively large water contact angle observed on PAA thin films.Furthermore,it establishes a thermodynamic basis for estimating the fraction of surface COOH_(H B)groups(f H B)from wettability measurements.Further extension of the model to carboxyl-terminated self-assembled monolayers(COOH-SAMs)revealed that surface COOH density(ΣCOOH)critically regulates wetting behavior:whenΣCOOH ranges from 4.30 to 5.25 nm^(-2),COOH groups predominantly exist in a free state and facilitate effective hydration layers,thereby promoting superhydrophilicity.Overall,this study not only establishes a unified thermodynamic framework linking surface COOH configurations to macroscopic wettability,but also validates its universality by extending it to COOH-SAMs systems,thereby providing a unified theoretical framework for the controllable design of hydrophilicity in various COOH-functionalized surfaces.
文摘In an academic environment increasingly shaped by metrics and the imperatives of“publish or perish”,it is rare to encounter a leading scientist willing to interweave personal narrative with conceptual reflection.The Soul of Geography by Fu(2025)achieves precisely this.The book resists simple categorisation:it is neither a conventional monograph nor a memoir,but rather a hybrid text that integrates autobiography,disciplinary reflection,and scientific arguments.In doing so,Fu articulates not only the trajectory of his own career but also a vision of geography as a discipline of theoretical depth and practical relevance.
文摘Objective:To explore the application of the Registered Nurses'Association of Ontario(RNAO)Best Practice Guideline(BPG)for Developing and Sustaining Nursing Leadership through the lens of nursing students transitioning from classroom learning to clinical practice.Through this reflection,the authors hope to inspire and empower future nursing leaders to champion innovation,resilience,and excellence in healthcare.Methods:By integrating evidence-based leadership principles,the authors reflect on their personal experiences,challenges,and successes in implementing these guidelines in real-world settings.Results:The paper highlights the significance of leadership in fostering healthy work environments and improving patient outcomes,emphasizing the role of nursing students as emerging leaders.Practical strategies for applying BPG,the RNAO BPG suggests leadership skills on professional development,and recommendations for embedding leadership principles into nursing education and practice are discussed.Conclusions:Implementing nursing leadership from the beginning of a nursing student's journey is vital for shaping the next generation of healthcare leaders.By integrating leadership principles early in nursing education,students can develop the skills needed to navigate clinical challenges,collaborate effectively with healthcare teams,and advocate for positive change.Starting with leadership guidelines in nursing school ensures that future nurses are equipped to foster supportive work environments,improve patient outcomes,and drive innovation from the very start of their careers,making leadership an inherent part of their professional identity.
