Atomic nonlinear interferometry has wide applications in quantum metrology and quantum information science.Here we propose a nonlinear time-reversal interferometry scheme with high robustness and metrological gain bas...Atomic nonlinear interferometry has wide applications in quantum metrology and quantum information science.Here we propose a nonlinear time-reversal interferometry scheme with high robustness and metrological gain based on the spin squeezing generated by arbitrary quadratic collective-spin interaction,which could be described by the Lipkin–Meshkov–Glick(LMG)model.We optimize the squeezing process,encoding process,and anti-squeezing process,finding that the two particular cases of the LMG model,one-axis twisting and two-axis twisting outperform in robustness and precision,respectively.Moreover,we propose a Floquet driving method to realize equivalent time reverse in the atomic system,which leads to high performance in precision,robustness,and operability.Our study sets a benchmark for achieving high precision and high robustness in atomic nonlinear interferometry.展开更多
The Love Wife is considered to be a breakthrough of Gish Jen either in theme and narrative techniques. While, as the critical distinguished narrative technique from the perspective of Post-classical Narratology, the i...The Love Wife is considered to be a breakthrough of Gish Jen either in theme and narrative techniques. While, as the critical distinguished narrative technique from the perspective of Post-classical Narratology, the infinitive internal focalization will be analyzed in this paper so as to investigate the five protagonists'search for their own identity and eagerness to achieve the acknowledge both from their family and the whole society. Furthermore, the author's own view in breaking up the barrier and discrimination around the world is also well-illustrated.展开更多
Runaway is a traditional motif in women's writing. But Alice Munro uses this motif differently. In her short story, Runaway, Munro explores the psychological transition of the female protagonist, Carla, and invest...Runaway is a traditional motif in women's writing. But Alice Munro uses this motif differently. In her short story, Runaway, Munro explores the psychological transition of the female protagonist, Carla, and investigates the intricate issue of women's liberation and social reality. This essay discusses how Munro manipulates the focus of narration in order to reveal the mental struggles experienced by showing a complicated runaway experience by a rural Canadian house-wife living an ordinary life.展开更多
As an example of our new approach to complex near-field (NF) scattering of electromagnetic waves, the timereversal (TR) transmission process on an NF current-element array is mapped to the statistical process on a...As an example of our new approach to complex near-field (NF) scattering of electromagnetic waves, the timereversal (TR) transmission process on an NF current-element array is mapped to the statistical process on a kinetic Ising transmission chain. Equilibrium statistical mechanics and non-equilibrium Monte Carlo (MC) dynamics help us to find signal jamming, aging, annihilating, creating, and TR symmetry breaking on the chain with inevitable background noises; and these results are general in NF systems where complex electromagnetic scattering arises.展开更多
The performance of time-reversal focusing with a horizontal line array at different depths is investigated by normal mode modeling and computer simulation. It is observed that the focusing performance of a bottom-moun...The performance of time-reversal focusing with a horizontal line array at different depths is investigated by normal mode modeling and computer simulation. It is observed that the focusing performance of a bottom-mounted horizontal time-reversal array is much better than that of a horizontal time-reversal array at other depths in shallow water. The normal mode modeling is used to explain this result. The absolute values of the modes at different depths are compared. It is shown that the number of modes whose absolute values close to zero is smaller at the bottom than that at other depths. It means that the horizontal time-reversal array deployed at the bottom can sample more modes, obtain more information of the probe source and achieve better focusing performance. The numerical simulations of time-reversal focusing performance under various conditions, such as different sound speed profiles, and different bottom parameters, lead to similar results.展开更多
The electromagnetic time-reversal(TR)technique has the characteristics of spatiotemporal focusing in a time-reversal cavity(TRC),which can be used for pulse compression,thus forming an electromagnetic pulse with high ...The electromagnetic time-reversal(TR)technique has the characteristics of spatiotemporal focusing in a time-reversal cavity(TRC),which can be used for pulse compression,thus forming an electromagnetic pulse with high peak power.A time-reversed pulse-compression method in a single channel has high pulse compression gain.However,single channel pulse compression can only generate limited gain.This paper proposes a novel TR power-combination method in a multichannel TRC to obtain higher peak power based on TR pulse-compression theory.First,the TR power-combination model is given,and the crosstalk properties of the associated channel and the influence of the reversal performance are studied.Then,the power-combination performances for the TR pulse compression,such as combined signal to noise ratio(SNR)and combined compression gain,are analyzed by numerical simulation and experimental methods.The results show that the proposed method has obvious advantages over pulse-compression methods using a single channel cavity,and is more convenient for power combination.展开更多
As an important technique involved in the novel writing,the focalization is studied in detail in Narratology.The paper is an attempt to analyze the arrangement of focalizations and their functions in Heart of Dartness...As an important technique involved in the novel writing,the focalization is studied in detail in Narratology.The paper is an attempt to analyze the arrangement of focalizations and their functions in Heart of Dartness according to Narratology.展开更多
Winesburg, Ohio is Sherwood Anderson's masterpiece. Adopting the classical theory of narratology, this paper intends to provide a detailed analysis on the zero focalization, writer's experiment with the shift of foc...Winesburg, Ohio is Sherwood Anderson's masterpiece. Adopting the classical theory of narratology, this paper intends to provide a detailed analysis on the zero focalization, writer's experiment with the shift of focalization, the transgression of focalization and their expressive effects in the book. The author aims at presenting an illustration to the focalization experiment in Winesburg, Ohio, one of the early modern fictions.展开更多
Barn Burning is a short story written by William Faulkner, which first appeared in 1939 and has since been widely read.The story guides readers to observe the world through a 10-year-old boy, Sarty's point of view...Barn Burning is a short story written by William Faulkner, which first appeared in 1939 and has since been widely read.The story guides readers to observe the world through a 10-year-old boy, Sarty's point of view, at the same time, the continual intervening of omniscient narrator breaks through the restrictions of Sarty's subjective point of view. Faulkner's use of multiple points of view makes the novel hard to understand. In order to better appreciate Barn Burning, analysis of the use of multiple points of view with the help of Gerard Genette's focalization theory is necessary. Moreover, the application of Wayne Booth's ideas of implied author and discussion of Sarty's narrative reliability are also presented. Hopefully, it can help readers form a good habit of narrative thinking and understand the novel in a better way.展开更多
Studies about Catch-22 have been numerous,but the study of the novel’s narrative device is scarcely found.Thus,the narrative device of Catch-22 is analyzed in terms of focalization,one of Gernard Genette's narrat...Studies about Catch-22 have been numerous,but the study of the novel’s narrative device is scarcely found.Thus,the narrative device of Catch-22 is analyzed in terms of focalization,one of Gernard Genette's narrative theories.The analysis exposes the hypocrisy and meaninglessness of the bureaucratic behaviors and policies and simultaneously emphasizes bureaucracy’s devastative and corrosive effect on people.展开更多
Different from other normal modes of the Earth’s free oscillation that depend on all the six components(M_(rr),M_(tt),M_(pp),M_(rt),M_(rp),and M_(tp))of the centroid moment tensor,the amplitudes of the radial modes d...Different from other normal modes of the Earth’s free oscillation that depend on all the six components(M_(rr),M_(tt),M_(pp),M_(rt),M_(rp),and M_(tp))of the centroid moment tensor,the amplitudes of the radial modes depend on the M_(rr)component(e.g.,scalar moment(M_(0)),dip(δ),and slip(λ))and hypocenter depth of the focal mechanism,and hence can be easily used to constrain these parameters of the focal mechanism.In this study,we use the superconducting gravimeter(SG)records after the 2011 Tohoku earthquake to analyze the radial modes_(0)S_(0)and_(1)S_(0).Based on the solutions of the focal mechanism provided by the GCMT and USGS,we can obtain the theoretical amplitudes of these two radial modes.Comparing the theoretical amplitudes with the observation amplitudes,it is found that there are obvious differences between the former and the latter,which means that the GCMT and USGS focal mechanisms cannot well represent the real focal mechanism of the 2011 event.Taking the GCMT solution as a reference and changing the depth and the three parameters of the M_(rr)moment,the scalar moment(M_(0))and the dip(δ)have significant influences,but the effects of the slip(λ)and the depth are minor.After comparisons,we provide a new constraint(M_(0)=5.8±0.09×10^(22)N·m,δ=10.1±0.08°,λ=88°,and depth=20 km)for the focal mechanism of the 2011 event.In addition,we further determine the center frequency(1.631567±2.6e^(-6)mHz)and quality factor(2046.4±50.1)of the_(1)S_(0)mode.展开更多
Fluorine-18 fluorodeoxyglucose(F-18 FDG)positron emission tomography/computed tomography(PET/CT)has emerged as a cornerstone in cancer evaluation imaging,with a well-established history spanning several years.This ima...Fluorine-18 fluorodeoxyglucose(F-18 FDG)positron emission tomography/computed tomography(PET/CT)has emerged as a cornerstone in cancer evaluation imaging,with a well-established history spanning several years.This imaging modality,encompassing the examination of the body from the base of the skull to the upper thighs,comprehensively covers the chest and abdominopelvic regions in a singular scan,allowing for a holistic assessment of nearly the entire body,including areas of marginal interest.The inherent advantage of this expansive scan range lies in its potential to unveil unexpected incidental abnormal hypermetabolic areas.The identification of incidental focal FDG uptake within colorectal regions during PET/CT scans is not an uncommon occurrence,albeit fraught with challenges associated with non-specific FDG uptake.The presence of benign colorectal lesions or physiological uptake poses a particular obstacle,as these may manifest with FDG uptake levels that mimic malignancy.Consequently,physicians are confronted with a diagnostic dilemma when encountering abnormal FDG uptake in unexpected colorectal areas.Existing studies have presented divergent results concerning these uptakes.Standardized uptake value and its derivatives have served as pivotal metrics in quantifying FDG uptake in PET images.In this article,we aim to succinctly explore the distinctive characteristics of FDG,delve into imaging findings,and elucidate the clinical significance of incidental focal colorectal uptake.This discussion aims to contribute valuable insights into the nuanced interpretation of such findings,fostering a comprehensive understanding.展开更多
Since the inception of fluorine-18 fluorodeoxyglucose(F-18 FDG),positron emission tomography/computed tomography(PET/CT)utilizing F-18 FDG has become widely accepted as a valuable imaging modality in the field of onco...Since the inception of fluorine-18 fluorodeoxyglucose(F-18 FDG),positron emission tomography/computed tomography(PET/CT)utilizing F-18 FDG has become widely accepted as a valuable imaging modality in the field of oncology,with global prevalence in clinical practice.Given that a single Torso PET/CT scan encompasses the anatomical region from the skull base to the upper thigh,the detection of incidental abnormal focal hypermetabolism in areas of limited clinical interest is both feasible and not uncommon.Numerous investigations have been undertaken to delineate the distinctive features of these findings,yet the outcomes have proven inconclusive.The incongruent results of these studies present a challenge for physicians,leaving them uncertain about the appropriate course of action.This article provides a succinct overview of the characteristics of fluorodeoxyglucose,followed by a comprehensive discussion of the imaging findings and clinical significance associated with incidental focal abnormal F-18 FDG activity in several representative organs.In conclusion,while the prevalence of unrecognized malignancy varies across organs,malignancies account for a substantial proportion,ranging from approximately one-third to over half,of incidental focal uptake.In light of these rates,physicians are urged to exercise vigilance in not disregarding unexpected uptake,facilitating more assured clinical decisions,and advocating for further active evaluation.展开更多
A compound varifocal lens based on electromagnetic drive technology is designed and fabricated, where the polydimethylsiloxane(PDMS) film acts as a driving component, while the PDMS biconvex lens and the plane-concave...A compound varifocal lens based on electromagnetic drive technology is designed and fabricated, where the polydimethylsiloxane(PDMS) film acts as a driving component, while the PDMS biconvex lens and the plane-concave lens form a coaxial compound lens system. The plane-concave lens equipped with driving coils is installed directly above the PDMS lens surrounded by the annular magnet. When different currents are applied, the annular magnet moves up and down, driving the PDMS film to undergo elastic deformation, and then resulting in longitudinal movement of the PDMS lens. The position change of the PDMS lens changes the focal length of the compound lens system. To verify the feasibility and practicability of this design, a prototype of our compound lens system is fabricated in experiment. Our proposed compound lens shows that its zoom ability reaches 9.28 mm when the current ranges from -0.20 A to 0.21 A.展开更多
A medium wave(MW)640×512(25μm)Mercury Cadmium Telluride(HgCdTe)polarimetric focal plane array(FPA)was demonstrated.The micro-polarizer array(MPA)has been carefully designed in terms of line grating structure opt...A medium wave(MW)640×512(25μm)Mercury Cadmium Telluride(HgCdTe)polarimetric focal plane array(FPA)was demonstrated.The micro-polarizer array(MPA)has been carefully designed in terms of line grating structure optimization and crosstalk suppression.A monolithic fabrication process with low damage was explored,which was verified to be compatible well with HgCdTe devices.After monolithic integration of MPA,NETD<9.5 mK was still maintained.Furthermore,to figure out the underlying mechanism that dominat⁃ed the extinction ratio(ER),specialized MPA layouts were designed,and the crosstalk was experimentally vali⁃dated as the major source that impacted ER.By expanding opaque regions at pixel edges to 4μm,crosstalk rates from adjacent pixels could be effectively reduced to approximately 2%,and promising ERs ranging from 17.32 to 27.41 were implemented.展开更多
In this editorial review,we comment on the article published in the recent issue of the World Journal of Gastrointestinal Surgery.Carcinoembryonic antigen(CEA)is a fetal glycoprotein and can be secreted in very small ...In this editorial review,we comment on the article published in the recent issue of the World Journal of Gastrointestinal Surgery.Carcinoembryonic antigen(CEA)is a fetal glycoprotein and can be secreted in very small amounts from healthy adults after birth.CEA is widely used not only for diagnostic tumor markers but also importantly for the management of some gastrointestinal tumors.The most common clinical use is surveillance for the monitoring of colorectal carcinoma.However,CEA can become elevated in several malign or benign characterized pathologies.Serum CEA level may vary depending on the location of the lesion,whether it metastasizes or not,and its histopathological characteristics.It has been determined that cases with high preoperative CEA have a more aggressive course and the risk of metastasis to the lymph tissue and liver increases.In this editorial review,we focused on evaluating the role of CEA in clinical practice with a holistic approach,including the diagnostic and prognostic significance of CEA in patients with focal liver lesions,the role of CEA in follow-up after definitive surgery,and also hepatic resection for metastasis,and the management of all patients with raised CEA.展开更多
We have developed an automatic regional focal mechanism inversion system based on the Earthquake Rapid Report(ERR) system and the real-time three-component seismic waveform stream of 1 000 broadband seismic stations p...We have developed an automatic regional focal mechanism inversion system based on the Earthquake Rapid Report(ERR) system and the real-time three-component seismic waveform stream of 1 000 broadband seismic stations provided by the China Earthquake Networks Center(CENC). The system can rapidly provide a double couple solution and centroid depth within 5–15 min after receiving earthquake information from the ERR system.The data processing is triggered by earthquake information obtained from the ERR system. The system is capable of determining the focal mechanism of all shallow-depth earthquakes in the Chinese mainland with a magnitude of 5.5–6.5. It utilizes waveform data recorded by seismic stations located within 500 km from the epicenter,enabling the reporting of a focal mechanism solution within 5–15 min of an earthquake occurrence. Additionally,the system can assign a corresponding grade(A B C) to the focal mechanism solution. We processed a total of 301earthquakes that occurred from 2021 to June 2022, and after the quality control, 166 of them were selected.These selected solutions were manually checked, and 160 of them were compiled in a focal mechanism catalog.This catalog can be conveniently downloaded online via the Internet. The automatic focal mechanism solution of earthquakes in eastern China exhibits a good agreement with that provided by the Global Centroid Moment Tensor(GCMT), when available. The average Kagan angle between this catalog and GCMT is 22°, and the average difference in MWis 0.17. Furthermore, compared with GCMT, the minimum magnitude of our catalog has been reduced from approximately 5.0 to 4.0. The correlation between the centroid depth and crustal thickness in the Chinese mainland confirms the distribution of the centroid depth.展开更多
Notably,the number of incidentally detected focal liver lesions(FLLs)has increa-sed dramatically in recent years due to the increased use of radiological imaging.The diagnosis of FLLs can be made through a well-docume...Notably,the number of incidentally detected focal liver lesions(FLLs)has increa-sed dramatically in recent years due to the increased use of radiological imaging.The diagnosis of FLLs can be made through a well-documented medical history,physical examination,laboratory tests,and appropriate imaging methods.Although benign FLLs are more common than malignant ones in adults,even in patients with primary malignancy,accurate diagnosis of incidental FLLs is of utmost clinical significance.In clinical practice,FLLs are frequently evaluated non-invasively using ultrasound(US),computed tomography(CT),and magnetic resonance imaging(MRI).Although US is a cost-effective and widely used imaging method,its diagnostic specificity and sensitivity for FLL characterization are limited.FLLs are primarily characterized by obtaining enhancement patterns through dynamic contrast-enhanced CT and MRI.MRI is a problem-solving method with high specificity and sensitivity,commonly used for the evaluation of FLLs that cannot be characterized by US or CT.Recent technical advancements in MRI,along with the use of hepatobiliary-specific MRI contrast agents,have significantly improved the success of FLL characterization and reduced unnece-ssary biopsies.The American College of Radiology(ACR)appropriateness criteria are evidence-based recommendations intended to assist clinicians in selecting the optimal imaging or treatment option for their patients.ACR Appropriateness Criteria Liver Lesion-Initial Characterization guideline provides recommend-ations for the imaging methods that should be used for the characterization of incidentally detected FLLs in various clinical scenarios.The American College of Gastroenterology(ACG)Clinical Guideline offers evidence-based recommend-ations for both the diagnosis and management of FLL.American Association for the Study of Liver Diseases(AASLD)Practice Guidance provides an approach to the diagnosis and management of patients with hepatocellular carcinoma.In this article,FLLs are reviewed with a comprehensive analysis of ACR Appropri-ateness Criteria,ACG Clinical Guideline,AASLD Practice Guidance,and current medical literature from peer-reviewed journals.The article includes a discussion of imaging methods used for the assessment of FLL,current recommended imaging techniques,innovations in liver imaging,contrast agents,imaging features of common nonmetastatic benign and malignant FLL,as well as current management recommendations.展开更多
基金Project supported by the National Key R&D Program of China (Grant No.2023YFA1407600)the National Natural Science Foundation of China (Grant Nos.12275145,92050110,91736106,11674390,and 91836302)。
文摘Atomic nonlinear interferometry has wide applications in quantum metrology and quantum information science.Here we propose a nonlinear time-reversal interferometry scheme with high robustness and metrological gain based on the spin squeezing generated by arbitrary quadratic collective-spin interaction,which could be described by the Lipkin–Meshkov–Glick(LMG)model.We optimize the squeezing process,encoding process,and anti-squeezing process,finding that the two particular cases of the LMG model,one-axis twisting and two-axis twisting outperform in robustness and precision,respectively.Moreover,we propose a Floquet driving method to realize equivalent time reverse in the atomic system,which leads to high performance in precision,robustness,and operability.Our study sets a benchmark for achieving high precision and high robustness in atomic nonlinear interferometry.
文摘The Love Wife is considered to be a breakthrough of Gish Jen either in theme and narrative techniques. While, as the critical distinguished narrative technique from the perspective of Post-classical Narratology, the infinitive internal focalization will be analyzed in this paper so as to investigate the five protagonists'search for their own identity and eagerness to achieve the acknowledge both from their family and the whole society. Furthermore, the author's own view in breaking up the barrier and discrimination around the world is also well-illustrated.
文摘Runaway is a traditional motif in women's writing. But Alice Munro uses this motif differently. In her short story, Runaway, Munro explores the psychological transition of the female protagonist, Carla, and investigates the intricate issue of women's liberation and social reality. This essay discusses how Munro manipulates the focus of narration in order to reveal the mental struggles experienced by showing a complicated runaway experience by a rural Canadian house-wife living an ordinary life.
基金supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No.20100185110021)the National Natural Science Foundation of China (Grant No.61071031)
文摘As an example of our new approach to complex near-field (NF) scattering of electromagnetic waves, the timereversal (TR) transmission process on an NF current-element array is mapped to the statistical process on a kinetic Ising transmission chain. Equilibrium statistical mechanics and non-equilibrium Monte Carlo (MC) dynamics help us to find signal jamming, aging, annihilating, creating, and TR symmetry breaking on the chain with inevitable background noises; and these results are general in NF systems where complex electromagnetic scattering arises.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10774119)the Program for New Century Excellent Talents in University (Grant No. NCET-08-0455)+2 种基金the Natural Science Foundation of Shaanxi Province of China(Grant No. SJ08F07)the Foundation of National Laboratory of Acousticsthe Northwestern Polytechnical University (NPU) Foundation for Fundamental Research
文摘The performance of time-reversal focusing with a horizontal line array at different depths is investigated by normal mode modeling and computer simulation. It is observed that the focusing performance of a bottom-mounted horizontal time-reversal array is much better than that of a horizontal time-reversal array at other depths in shallow water. The normal mode modeling is used to explain this result. The absolute values of the modes at different depths are compared. It is shown that the number of modes whose absolute values close to zero is smaller at the bottom than that at other depths. It means that the horizontal time-reversal array deployed at the bottom can sample more modes, obtain more information of the probe source and achieve better focusing performance. The numerical simulations of time-reversal focusing performance under various conditions, such as different sound speed profiles, and different bottom parameters, lead to similar results.
基金Project supported by the National Key R&D Program of China(Grant No.2021YFC2203503)。
文摘The electromagnetic time-reversal(TR)technique has the characteristics of spatiotemporal focusing in a time-reversal cavity(TRC),which can be used for pulse compression,thus forming an electromagnetic pulse with high peak power.A time-reversed pulse-compression method in a single channel has high pulse compression gain.However,single channel pulse compression can only generate limited gain.This paper proposes a novel TR power-combination method in a multichannel TRC to obtain higher peak power based on TR pulse-compression theory.First,the TR power-combination model is given,and the crosstalk properties of the associated channel and the influence of the reversal performance are studied.Then,the power-combination performances for the TR pulse compression,such as combined signal to noise ratio(SNR)and combined compression gain,are analyzed by numerical simulation and experimental methods.The results show that the proposed method has obvious advantages over pulse-compression methods using a single channel cavity,and is more convenient for power combination.
文摘As an important technique involved in the novel writing,the focalization is studied in detail in Narratology.The paper is an attempt to analyze the arrangement of focalizations and their functions in Heart of Dartness according to Narratology.
文摘Winesburg, Ohio is Sherwood Anderson's masterpiece. Adopting the classical theory of narratology, this paper intends to provide a detailed analysis on the zero focalization, writer's experiment with the shift of focalization, the transgression of focalization and their expressive effects in the book. The author aims at presenting an illustration to the focalization experiment in Winesburg, Ohio, one of the early modern fictions.
文摘Barn Burning is a short story written by William Faulkner, which first appeared in 1939 and has since been widely read.The story guides readers to observe the world through a 10-year-old boy, Sarty's point of view, at the same time, the continual intervening of omniscient narrator breaks through the restrictions of Sarty's subjective point of view. Faulkner's use of multiple points of view makes the novel hard to understand. In order to better appreciate Barn Burning, analysis of the use of multiple points of view with the help of Gerard Genette's focalization theory is necessary. Moreover, the application of Wayne Booth's ideas of implied author and discussion of Sarty's narrative reliability are also presented. Hopefully, it can help readers form a good habit of narrative thinking and understand the novel in a better way.
文摘Studies about Catch-22 have been numerous,but the study of the novel’s narrative device is scarcely found.Thus,the narrative device of Catch-22 is analyzed in terms of focalization,one of Gernard Genette's narrative theories.The analysis exposes the hypocrisy and meaninglessness of the bureaucratic behaviors and policies and simultaneously emphasizes bureaucracy’s devastative and corrosive effect on people.
基金supported by the National Natural Science Foundation of China(Grants:41974022 and 42192531)the Educational Commission of Hubei Province of China(Grant:2020CFA109)+1 种基金the Special Fund of Hubei Luojia Laboratory(grant#220100002)Key Laboratory of Geospace Environment and Geodesy,Ministry of Education,Wuhan University(grant#210204)。
文摘Different from other normal modes of the Earth’s free oscillation that depend on all the six components(M_(rr),M_(tt),M_(pp),M_(rt),M_(rp),and M_(tp))of the centroid moment tensor,the amplitudes of the radial modes depend on the M_(rr)component(e.g.,scalar moment(M_(0)),dip(δ),and slip(λ))and hypocenter depth of the focal mechanism,and hence can be easily used to constrain these parameters of the focal mechanism.In this study,we use the superconducting gravimeter(SG)records after the 2011 Tohoku earthquake to analyze the radial modes_(0)S_(0)and_(1)S_(0).Based on the solutions of the focal mechanism provided by the GCMT and USGS,we can obtain the theoretical amplitudes of these two radial modes.Comparing the theoretical amplitudes with the observation amplitudes,it is found that there are obvious differences between the former and the latter,which means that the GCMT and USGS focal mechanisms cannot well represent the real focal mechanism of the 2011 event.Taking the GCMT solution as a reference and changing the depth and the three parameters of the M_(rr)moment,the scalar moment(M_(0))and the dip(δ)have significant influences,but the effects of the slip(λ)and the depth are minor.After comparisons,we provide a new constraint(M_(0)=5.8±0.09×10^(22)N·m,δ=10.1±0.08°,λ=88°,and depth=20 km)for the focal mechanism of the 2011 event.In addition,we further determine the center frequency(1.631567±2.6e^(-6)mHz)and quality factor(2046.4±50.1)of the_(1)S_(0)mode.
文摘Fluorine-18 fluorodeoxyglucose(F-18 FDG)positron emission tomography/computed tomography(PET/CT)has emerged as a cornerstone in cancer evaluation imaging,with a well-established history spanning several years.This imaging modality,encompassing the examination of the body from the base of the skull to the upper thighs,comprehensively covers the chest and abdominopelvic regions in a singular scan,allowing for a holistic assessment of nearly the entire body,including areas of marginal interest.The inherent advantage of this expansive scan range lies in its potential to unveil unexpected incidental abnormal hypermetabolic areas.The identification of incidental focal FDG uptake within colorectal regions during PET/CT scans is not an uncommon occurrence,albeit fraught with challenges associated with non-specific FDG uptake.The presence of benign colorectal lesions or physiological uptake poses a particular obstacle,as these may manifest with FDG uptake levels that mimic malignancy.Consequently,physicians are confronted with a diagnostic dilemma when encountering abnormal FDG uptake in unexpected colorectal areas.Existing studies have presented divergent results concerning these uptakes.Standardized uptake value and its derivatives have served as pivotal metrics in quantifying FDG uptake in PET images.In this article,we aim to succinctly explore the distinctive characteristics of FDG,delve into imaging findings,and elucidate the clinical significance of incidental focal colorectal uptake.This discussion aims to contribute valuable insights into the nuanced interpretation of such findings,fostering a comprehensive understanding.
文摘Since the inception of fluorine-18 fluorodeoxyglucose(F-18 FDG),positron emission tomography/computed tomography(PET/CT)utilizing F-18 FDG has become widely accepted as a valuable imaging modality in the field of oncology,with global prevalence in clinical practice.Given that a single Torso PET/CT scan encompasses the anatomical region from the skull base to the upper thigh,the detection of incidental abnormal focal hypermetabolism in areas of limited clinical interest is both feasible and not uncommon.Numerous investigations have been undertaken to delineate the distinctive features of these findings,yet the outcomes have proven inconclusive.The incongruent results of these studies present a challenge for physicians,leaving them uncertain about the appropriate course of action.This article provides a succinct overview of the characteristics of fluorodeoxyglucose,followed by a comprehensive discussion of the imaging findings and clinical significance associated with incidental focal abnormal F-18 FDG activity in several representative organs.In conclusion,while the prevalence of unrecognized malignancy varies across organs,malignancies account for a substantial proportion,ranging from approximately one-third to over half,of incidental focal uptake.In light of these rates,physicians are urged to exercise vigilance in not disregarding unexpected uptake,facilitating more assured clinical decisions,and advocating for further active evaluation.
文摘A compound varifocal lens based on electromagnetic drive technology is designed and fabricated, where the polydimethylsiloxane(PDMS) film acts as a driving component, while the PDMS biconvex lens and the plane-concave lens form a coaxial compound lens system. The plane-concave lens equipped with driving coils is installed directly above the PDMS lens surrounded by the annular magnet. When different currents are applied, the annular magnet moves up and down, driving the PDMS film to undergo elastic deformation, and then resulting in longitudinal movement of the PDMS lens. The position change of the PDMS lens changes the focal length of the compound lens system. To verify the feasibility and practicability of this design, a prototype of our compound lens system is fabricated in experiment. Our proposed compound lens shows that its zoom ability reaches 9.28 mm when the current ranges from -0.20 A to 0.21 A.
基金Supported by the self-funded project of Kunming Institute of Physics。
文摘A medium wave(MW)640×512(25μm)Mercury Cadmium Telluride(HgCdTe)polarimetric focal plane array(FPA)was demonstrated.The micro-polarizer array(MPA)has been carefully designed in terms of line grating structure optimization and crosstalk suppression.A monolithic fabrication process with low damage was explored,which was verified to be compatible well with HgCdTe devices.After monolithic integration of MPA,NETD<9.5 mK was still maintained.Furthermore,to figure out the underlying mechanism that dominat⁃ed the extinction ratio(ER),specialized MPA layouts were designed,and the crosstalk was experimentally vali⁃dated as the major source that impacted ER.By expanding opaque regions at pixel edges to 4μm,crosstalk rates from adjacent pixels could be effectively reduced to approximately 2%,and promising ERs ranging from 17.32 to 27.41 were implemented.
文摘In this editorial review,we comment on the article published in the recent issue of the World Journal of Gastrointestinal Surgery.Carcinoembryonic antigen(CEA)is a fetal glycoprotein and can be secreted in very small amounts from healthy adults after birth.CEA is widely used not only for diagnostic tumor markers but also importantly for the management of some gastrointestinal tumors.The most common clinical use is surveillance for the monitoring of colorectal carcinoma.However,CEA can become elevated in several malign or benign characterized pathologies.Serum CEA level may vary depending on the location of the lesion,whether it metastasizes or not,and its histopathological characteristics.It has been determined that cases with high preoperative CEA have a more aggressive course and the risk of metastasis to the lymph tissue and liver increases.In this editorial review,we focused on evaluating the role of CEA in clinical practice with a holistic approach,including the diagnostic and prognostic significance of CEA in patients with focal liver lesions,the role of CEA in follow-up after definitive surgery,and also hepatic resection for metastasis,and the management of all patients with raised CEA.
基金sponsored by the China Spark Program of Earthquake Science and Technology(XH23051B).
文摘We have developed an automatic regional focal mechanism inversion system based on the Earthquake Rapid Report(ERR) system and the real-time three-component seismic waveform stream of 1 000 broadband seismic stations provided by the China Earthquake Networks Center(CENC). The system can rapidly provide a double couple solution and centroid depth within 5–15 min after receiving earthquake information from the ERR system.The data processing is triggered by earthquake information obtained from the ERR system. The system is capable of determining the focal mechanism of all shallow-depth earthquakes in the Chinese mainland with a magnitude of 5.5–6.5. It utilizes waveform data recorded by seismic stations located within 500 km from the epicenter,enabling the reporting of a focal mechanism solution within 5–15 min of an earthquake occurrence. Additionally,the system can assign a corresponding grade(A B C) to the focal mechanism solution. We processed a total of 301earthquakes that occurred from 2021 to June 2022, and after the quality control, 166 of them were selected.These selected solutions were manually checked, and 160 of them were compiled in a focal mechanism catalog.This catalog can be conveniently downloaded online via the Internet. The automatic focal mechanism solution of earthquakes in eastern China exhibits a good agreement with that provided by the Global Centroid Moment Tensor(GCMT), when available. The average Kagan angle between this catalog and GCMT is 22°, and the average difference in MWis 0.17. Furthermore, compared with GCMT, the minimum magnitude of our catalog has been reduced from approximately 5.0 to 4.0. The correlation between the centroid depth and crustal thickness in the Chinese mainland confirms the distribution of the centroid depth.
文摘Notably,the number of incidentally detected focal liver lesions(FLLs)has increa-sed dramatically in recent years due to the increased use of radiological imaging.The diagnosis of FLLs can be made through a well-documented medical history,physical examination,laboratory tests,and appropriate imaging methods.Although benign FLLs are more common than malignant ones in adults,even in patients with primary malignancy,accurate diagnosis of incidental FLLs is of utmost clinical significance.In clinical practice,FLLs are frequently evaluated non-invasively using ultrasound(US),computed tomography(CT),and magnetic resonance imaging(MRI).Although US is a cost-effective and widely used imaging method,its diagnostic specificity and sensitivity for FLL characterization are limited.FLLs are primarily characterized by obtaining enhancement patterns through dynamic contrast-enhanced CT and MRI.MRI is a problem-solving method with high specificity and sensitivity,commonly used for the evaluation of FLLs that cannot be characterized by US or CT.Recent technical advancements in MRI,along with the use of hepatobiliary-specific MRI contrast agents,have significantly improved the success of FLL characterization and reduced unnece-ssary biopsies.The American College of Radiology(ACR)appropriateness criteria are evidence-based recommendations intended to assist clinicians in selecting the optimal imaging or treatment option for their patients.ACR Appropriateness Criteria Liver Lesion-Initial Characterization guideline provides recommend-ations for the imaging methods that should be used for the characterization of incidentally detected FLLs in various clinical scenarios.The American College of Gastroenterology(ACG)Clinical Guideline offers evidence-based recommend-ations for both the diagnosis and management of FLL.American Association for the Study of Liver Diseases(AASLD)Practice Guidance provides an approach to the diagnosis and management of patients with hepatocellular carcinoma.In this article,FLLs are reviewed with a comprehensive analysis of ACR Appropri-ateness Criteria,ACG Clinical Guideline,AASLD Practice Guidance,and current medical literature from peer-reviewed journals.The article includes a discussion of imaging methods used for the assessment of FLL,current recommended imaging techniques,innovations in liver imaging,contrast agents,imaging features of common nonmetastatic benign and malignant FLL,as well as current management recommendations.