二语写作是二语习得研究领域的重要组成部分。运用CiteSpace软件对近十年发表在Journal of Second Language Writing的231篇实证研究论文进行可视化分析,研究发现:二语写作研究整体呈波动性上升趋势,研究规模较为稳定,研究关注度逐渐提...二语写作是二语习得研究领域的重要组成部分。运用CiteSpace软件对近十年发表在Journal of Second Language Writing的231篇实证研究论文进行可视化分析,研究发现:二语写作研究整体呈波动性上升趋势,研究规模较为稳定,研究关注度逐渐提升;二语写作研究领域暂未形成明显的核心作者和机构的合作网络;研究主题主要聚焦二语写作教学方法的多元化、二语写作反馈的多焦点、二语写作评估与测试的科学化,以及学习者个体差异的多维影响等方面。基于此,提出未来该领域发展需加强学者、机构之间的相互合作;关注个体学习者写作过程的认知特征与情感因素,尤其重视青少年二语学习过程的研究;扩大二语写作纵向研究规模,推动研究的深入发展。展开更多
When microdissection testicular sperm extraction(micro-TESE)fails,a redo procedure may be the only option for patients who want a biological child.However,there are many gaps of knowledge surrounding the procedure,whi...When microdissection testicular sperm extraction(micro-TESE)fails,a redo procedure may be the only option for patients who want a biological child.However,there are many gaps of knowledge surrounding the procedure,which need to be addressed to help clinicians and patients make informed decisions.This review explores redo micro-TESE in the context of nonobstructive azoospermia(NOA).Literature was searched using Google Scholar,Medline,and PubMed.Search terms were“NOA”AND“second microdissection testicular sperm extractions”AND“redo microdissection testicles sperm extraction”AND“repeat microdissection testicular sperm extractions”AND“failed microdissection testicular sperm extractions”AND“salvage microdissection testicular sperm extractions”.Only original articles in English were included.A total of nine articles were included,consisting of four retrospective and five prospective studies.The time gap between the first and second micro-TESE varied from 6 months to 24 months.Most of the included studies reported successful surgical sperm retrieval(SSR)in the second micro-TESE in the range of 10%–21%,except in one study where it reached 42%.It has not been presented any definitive information about the use of hormonal treatment or the benefit of varicocelectomy prior to the second micro-TESE.Patients with hypospermatogenesis and Klinefelter syndrome(KS)had the highest chance of success in redo surgery.In conclusion,redo micro-TESE following a negative procedure can lead to sperm recovery in 10%–21%.Patients with hypospermatogenesis and KS have a higher chance of success.There is no enough evidence to conclude which is the best hormonal stimulation if any before a redo surgery.展开更多
Objective: To evaluate the improvement effect of combined treatment of eschar abrasion, nanosilver dressing, and mussel mucin spray on wound healing in patients with second-degree burns, and to explore their effects o...Objective: To evaluate the improvement effect of combined treatment of eschar abrasion, nanosilver dressing, and mussel mucin spray on wound healing in patients with second-degree burns, and to explore their effects on the expression level of (advanced glycation end products) AGEs in wound tissue, so as to provide a basis for the application of AGEs expression level in wound tissue in the future clinical treatment of second-degree burns. Methods: Patients with second-degree burns admitted to the Department of Burns and Plastic Surgery of the Second Affiliated Hospital of Shantou University Medical College from July 2023 to July 2024 were selected as the research subjects. This study was a non-double-blind study, and both patients and researchers were aware of the treatment methods. They were randomly divided into Group A (control group) and Group B (study group). According to the order of their visits, the patients were numbered in advance;then the seed number was taken, and 70 random numbers were generated on the computer using SAS, the first 35 corresponding to group A, and the last 35 corresponding to group B;the random numbers were arranged from small to large, and the rank of the random numbers was the patient number;finally, the patient numbers were arranged from small to large, and the corresponding groups were the grouping scheme. 1) Wound healing time: The wound healing was observed every day, and the wound healing time was calculated when the wound was completely epithelialized. 2) Wound healing: The wound healing area was measured 1, 7, and 14 days after treatment, and transparent paper was used to record combined with a computer-assisted imaging system. Wound healing rate = wound healing area (cm2)/total wound area before treatment (cm2) × 100%. The time for complete wound healing was recorded in the two groups of patients. 3) Pain: The pain was evaluated at 1, 7, and 14 days after treatment using the visual analogue scale (VAS). The higher the score, the more severe the pain. 4) Scar condition: Scar formation was evaluated 1, 3, and 6 months after wound healing using the VAS scale, with a total score of 15 points. The higher the score, the more severe the scar. 5) Detect the expression of AGEs in wound tissue. Results: The wound healed 14.03 ± 2.28 days after eschar removal, with a cure rate of 97.8%. No infection occurred in the wound after eschar removal in all patients. The wound healing time ranged from 9 to 23 days, with an average healing time of 28.41 ± 1.45 days. The healing quality was satisfactory. The Vancouver Scar Scale scored the wound healing scar as 0.81 ± 0.73 points. Western blot was used to detect the expression of AGEs, (receptor for advanced glycation end products) RAGE, and protein in the wound tissue. Results After 7, 14, and 28 days of medication, the wounds of diabetic patients healed well. The drug treatment efficacy and hydroxyproline content showed an upward trend, and the expression levels of AGEs, RAGE, and HIF-1a proteins showed a downward trend. Compared with day 0, the hydroxyproline content of the wound granulation tissue on days 7, 14, and 28 was significantly increased (P< 0.01), and the expression levels of AGEs, RAGE, and HIF-1α proteins were significantly downregulated (P< 0.05 or P< 0.01). Conclusion: Monitoring the expression levels of AGEs and RAGE can reflect the wound-healing effect of patients with second-degree burns, and the prognosis of the wound is closely related to the expression levels of AGEs, RAGE, and scab abrasion. In the treatment of second-degree burn wounds, scab abrasion can grasp the level of necrotic scab removal, can achieve “relatively accurate” removal of necrotic tissue, maximally protect the ecological tissue between wounds and retaining normal tissue, and can play a positive role in promoting the healing process of burn wounds;at the same time, nanosilver dressings have good antibacterial properties and high safety, and mussel mucin has anti-inflammatory and antioxidant activities and the characteristics of blocking nerve endings, which can effectively relieve the burning, stinging, and itching of sensitive skin and effectively promote wound healing.展开更多
Higher-order band topology not only enriches our understanding of topological phases but also unveils pioneering lower-dimensional boundary states,which harbors substantial potential for next-generation device applica...Higher-order band topology not only enriches our understanding of topological phases but also unveils pioneering lower-dimensional boundary states,which harbors substantial potential for next-generation device applications.The distinct electronic configurations and tunable attributes of two-dimensional materials position them as a quintessential platform for the realization of second-order topological insulators(SOTIs).This article provides an overview of the research progress in SOTIs within the field of two-dimensional electronic materials,focusing on the characterization of higher-order topological properties and the numerous candidate materials proposed in theoretical studies.These endeavors not only enhance our understanding of higher-order topological states but also highlight potential material systems that could be experimentally realized.展开更多
Taking the second member of the Xujiahe Formation of the Upper Triassic in the Xinchang structural belt as an example,based on data such as logging,production,seismic interpretation and test,a systematic analysis was ...Taking the second member of the Xujiahe Formation of the Upper Triassic in the Xinchang structural belt as an example,based on data such as logging,production,seismic interpretation and test,a systematic analysis was conducted on the structural characteristics and evolution,reservoir diagenesis and densification processes,and types and stages of faults/fractures,and revealing the multi-stage and multi-factor dynamic coupled enrichment mechanisms of tight gas reservoirs.(1)In the early Yanshan period,the paleo-structural traps were formed with low-medium maturity hydrocarbons accumulating in structural highs driven by buoyancy since reservoirs were not fully densified in this stage,demonstrating paleo-structure control on traps and early hydrocarbon accumulation.(2)In the middle-late Yanshan period,the source rocks became mature to generate and expel a large quantity of hydrocarbons.Grain size and type of sandstone controlled the time of reservoir densification,which restricted the scale of hydrocarbon charging,allowing for only a small-scale migration through sand bodies near the fault/fracture or less-densified matrix reservoirs.(3)During the Himalayan period,the source rocks reached overmaturity,and the residual oil cracking gas was efficiently transported along the late-stage faults/fractures.Wells with high production capacity were mainly located in Type I and II fault/fracture zones comprising the late-stage north-south trending fourth-order faults and the late-stage fractures.The productivity of the wells was controlled by the transformation of the late-stage faults/fractures.(4)The Xinchang structural belt underwent three stages of tectonic evolution,two stages of reservoir formation,and three stages of fault/fractures development.Hydrocarbons mainly accumulated in the paleo-structure highs.After reservoir densification and late fault/fracture adjustment,a complex gas-water distribution pattern was formed.Thus,it is summarized as the model of“near-source and low-abundance hydrocarbon charging in the early stage,and differential enrichment of natural gas under the joint control of fault-fold-fracture complex,high-quality reservoirs and structural highs in the late stage”.Faults/fractures with well-coupled fault-fold-fracture-pore are favorable exploration targets with high exploration effectiveness.展开更多
The generation of optical vortices from nonlinear photonic crystals(NPCs)with spatially modulated second-order nonlinearity offers a promising approach to extend the working wavelength and topological charge of vortex...The generation of optical vortices from nonlinear photonic crystals(NPCs)with spatially modulated second-order nonlinearity offers a promising approach to extend the working wavelength and topological charge of vortex beams for various applications.In this work,the second harmonic(SH)optical vortex beams generated from nonlinear fork gratings under Gaussian beam illumination are numerically investigated.The far-field intensity and phase distributions,as well as the orbital angular momentum(OAM)spectra of the SH beams,are analyzed for different structural topological charges and diffraction orders.Results reveal that higher-order diffraction and larger structural topological charges lead to angular interference patterns and non-uniform intensity distributions,deviating from the standard vortex profile.To optimize the SH vortex quality,the effects of the fundamental wave beam waist,crystal thickness,and grating duty cycle are explored.It is shown that increasing the beam waist can effectively suppress diffraction order interference and improve the beam’s quality.This study provides theoretical guidance for enhancing the performance of nonlinear optical devices based on NPCs.展开更多
We consider the space and time decays of certain problems within the second gradient thermal law.Notably,for this thermal theory,the exponential time decay is precluded.First,the time estimates of polynomial type are ...We consider the space and time decays of certain problems within the second gradient thermal law.Notably,for this thermal theory,the exponential time decay is precluded.First,the time estimates of polynomial type are obtained for both the thermal equation and the one-dimensional thermoelastic system,where the impossibility of localization with respect to time is also established.Then,the space estimates are deduced for the multidimensional thermoelastic problem,which allow to show the exponential decay of the energy.展开更多
Second harmonic generation(SHG),a fundamental and widely-studied phenomenon in nonlinear optics,has attracted significant attention for its ability to convert fundamental frequencies into their second harmonics.While ...Second harmonic generation(SHG),a fundamental and widely-studied phenomenon in nonlinear optics,has attracted significant attention for its ability to convert fundamental frequencies into their second harmonics.While the dominant SHG research has been focused on the optical and infrared regimes,its investigation in the microwave range presents challenges due to the requirements of materials with higher nonlinear coefficients and high-power microwave sources.Here,we provide an overview of methods together with underlying mechanisms for SHG in microwave frequencies,and discuss prospects and insights into the future developments of SHG-based technologies.The discussions on both numerical analyses and experimental studies will offer guidance for further SHG research and communication advancements in microwave regime.展开更多
When a pump laser beam strikes the surface of a nonlinear crystal with modulated second-order nonlinearity,various nonlinear diffraction phenomena occur,with nonlinear Raman–Nath diffraction(NRND)being a prominent ex...When a pump laser beam strikes the surface of a nonlinear crystal with modulated second-order nonlinearity,various nonlinear diffraction phenomena occur,with nonlinear Raman–Nath diffraction(NRND)being a prominent example.In this study,we use an 800-nm Ti:sapphire femtosecond laser beam to pump the surface of a periodically poled lithium niobate(PPLN)crystal thin-plate nonlinear grating.By rotating the crystal,we change the incidence angle and observe and measure the exit angle,polarization,and power of NRND spots on the other side of the crystal.The experiment shows that NRND characteristics are highly sensitive to the incidence angle of the pump laser beam,which are consistent with the theoretical prediction.We expect that this research will advance the understanding of nonlinear diffraction and provide valuable insights for nonlinear optical interaction in complicated geometric and physical configurations.展开更多
The paper aims to examine the application of multimedia technology in expanding vocabulary in second language acquisition.Incorporating innovative technology such as mobile applications,gaming applications,websites,an...The paper aims to examine the application of multimedia technology in expanding vocabulary in second language acquisition.Incorporating innovative technology such as mobile applications,gaming applications,websites,and other related online tools has increased learners’vocabulary mastery,engagement,and motivation levels.Interactional processes like media-embedded objects,teach-learning capacity algorithms,and feedback help learners receive the course in a personalized way that considers individual learning patterns or abilities.However,there are the following challenges:accessibility issues,total reliance on technology,and issues related to privacy.The following challenges affecting learning that arise from using gadgets:the digital divide,limited device access,and environmental issues that may distract a learner in a technology-enabled environment.Moreover,the security issue for data and the ethical question of users’information remain important too.Hence,the paper provides arguments that although these technologies contribute significantly to vocabulary acquisition,the challenge that emerges should be addressed by integrating technology in teaching and learning alongside conventional methods for vocabulary acquisition,which is a practical language acquisition tool that should not be monopolized.展开更多
Anxiety,motivation,and strategy have long been seen as critical in second language acquisition.This study presents a systematic review of the literature on these variables in terms of their relationship with one anoth...Anxiety,motivation,and strategy have long been seen as critical in second language acquisition.This study presents a systematic review of the literature on these variables in terms of their relationship with one another,their effects on learning outcomes,and how they are affected by technology-assisted tools in the teaching of Chinese as a second language.This study includes 24 articles for the review study based on the criteria and process of the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocol(PRISMA-P)and the clustering techniques of VOSviewer.It is found that 1)anxiety,motivation,and strategy were interrelated,that is,motivation was negatively associated with anxiety but positively related to strategy,while strategy could positively predict anxiety;2)anxiety could both positively and negatively affect learning outcomes,while motivation and strategy could both positively and insignificantly influence learning outcomes;3)the technology-assisted tools used in the classroom could both positively and negatively affect the levels of these variables and learning outcomes in the L2 Chinese context.The need to explore more complicated relationships between language-specific individual variables themselves and other possible factors that affect these variables,such as cultural ones,are also discussed for future research.展开更多
Collagen characterization is crucial for disease diagnostics,prevention,and understanding,with growing focus on quantitative analysis at tissue and fibril levels.Numerous models have been developed to quantify structu...Collagen characterization is crucial for disease diagnostics,prevention,and understanding,with growing focus on quantitative analysis at tissue and fibril levels.Numerous models have been developed to quantify structural changes in collagen linked to various pathologies.However,many approaches remain limited to conceptual descriptions or rely on custom software,often requiring programming skills,which re-stricts their clinical application and potential impact.We introduce CollagenFitJ,a plugin for the open-source software platform ImageJ/FIJI,which represents a widely used microscopy image analysis tool.CollagenFitJ makes use of the cylindrical symmetry model for collagen to enable facile quantitative assessment of polarization-resolved second harmonic generation microscopy image stacks.The plugin’s main outputs are collagen structure-related maps(e.g.,orientation and anisotropy of collagen fibrils within the focal volume),which can be accompanied by distribution and randomness maps for a series of structure-related parameters.We describe and validate the use of CollagenFitJ on images acquired on rat-tail tendons,collagen capsules surrounding human thyroid nodules,and mouse colon tumors,using both scanning and widefield second harmonic generation microscopy datasets.The plugin was designed to be user-friendly,requiring little to no experience in image processing and coding to facilitate access for life scientists,medical staff,and microscopy practitioners with limited coding skills or time availability required for coding.展开更多
Designing novel two-dimensional structures and precisely modulating their second harmonic generation(SHG)attributes are key to advancing nonlinear photonic technologies.In this work,through first-principles calculatio...Designing novel two-dimensional structures and precisely modulating their second harmonic generation(SHG)attributes are key to advancing nonlinear photonic technologies.In this work,through first-principles calculations,we propose a novel tetrahedral phase of transition metal dichalcogenides(TMDs)and validate its structural feasibility in a family of compounds,i.e.,ZX_(2)(Z=Ti,Zr,Hf;X=S,Se,Te).Cohesive energy and phonon dispersion calculations further demonstrate that eight of nine possible ZX_(2)monolayers are dynamically stable.All the ZX_(2)monolayers exhibit pronounced out-of-plane SHG with nonlinear susceptibility components reaching the order of 10^(2)pm/V.Strain engineering imposes a profound influence on the SHG response of ZX_(2)monolayers by reducing symmetry and modifying nonlinear susceptibility components.The redshift and significant enhancement of the prominent peak in SHG spectra are also revealed due to strain-induced charge redistribution and band gap reduction.Intriguingly,strain-driven nonlinear optical switching effects are realized in the ZX_(2)monolayers,with a reversible switching of SHG component ordering under tensile and compressive strain.In such a case,the anisotropic SHG pattern transforms from fourfold to twofold symmetry under the strain.Our work demonstrates the efficacy of strain engineering in precisely enhancing SHG,paving the way for the integration of novel TMD structures into tunable and flexible nonlinear optical devices.展开更多
文摘二语写作是二语习得研究领域的重要组成部分。运用CiteSpace软件对近十年发表在Journal of Second Language Writing的231篇实证研究论文进行可视化分析,研究发现:二语写作研究整体呈波动性上升趋势,研究规模较为稳定,研究关注度逐渐提升;二语写作研究领域暂未形成明显的核心作者和机构的合作网络;研究主题主要聚焦二语写作教学方法的多元化、二语写作反馈的多焦点、二语写作评估与测试的科学化,以及学习者个体差异的多维影响等方面。基于此,提出未来该领域发展需加强学者、机构之间的相互合作;关注个体学习者写作过程的认知特征与情感因素,尤其重视青少年二语学习过程的研究;扩大二语写作纵向研究规模,推动研究的深入发展。
文摘When microdissection testicular sperm extraction(micro-TESE)fails,a redo procedure may be the only option for patients who want a biological child.However,there are many gaps of knowledge surrounding the procedure,which need to be addressed to help clinicians and patients make informed decisions.This review explores redo micro-TESE in the context of nonobstructive azoospermia(NOA).Literature was searched using Google Scholar,Medline,and PubMed.Search terms were“NOA”AND“second microdissection testicular sperm extractions”AND“redo microdissection testicles sperm extraction”AND“repeat microdissection testicular sperm extractions”AND“failed microdissection testicular sperm extractions”AND“salvage microdissection testicular sperm extractions”.Only original articles in English were included.A total of nine articles were included,consisting of four retrospective and five prospective studies.The time gap between the first and second micro-TESE varied from 6 months to 24 months.Most of the included studies reported successful surgical sperm retrieval(SSR)in the second micro-TESE in the range of 10%–21%,except in one study where it reached 42%.It has not been presented any definitive information about the use of hormonal treatment or the benefit of varicocelectomy prior to the second micro-TESE.Patients with hypospermatogenesis and Klinefelter syndrome(KS)had the highest chance of success in redo surgery.In conclusion,redo micro-TESE following a negative procedure can lead to sperm recovery in 10%–21%.Patients with hypospermatogenesis and KS have a higher chance of success.There is no enough evidence to conclude which is the best hormonal stimulation if any before a redo surgery.
文摘Objective: To evaluate the improvement effect of combined treatment of eschar abrasion, nanosilver dressing, and mussel mucin spray on wound healing in patients with second-degree burns, and to explore their effects on the expression level of (advanced glycation end products) AGEs in wound tissue, so as to provide a basis for the application of AGEs expression level in wound tissue in the future clinical treatment of second-degree burns. Methods: Patients with second-degree burns admitted to the Department of Burns and Plastic Surgery of the Second Affiliated Hospital of Shantou University Medical College from July 2023 to July 2024 were selected as the research subjects. This study was a non-double-blind study, and both patients and researchers were aware of the treatment methods. They were randomly divided into Group A (control group) and Group B (study group). According to the order of their visits, the patients were numbered in advance;then the seed number was taken, and 70 random numbers were generated on the computer using SAS, the first 35 corresponding to group A, and the last 35 corresponding to group B;the random numbers were arranged from small to large, and the rank of the random numbers was the patient number;finally, the patient numbers were arranged from small to large, and the corresponding groups were the grouping scheme. 1) Wound healing time: The wound healing was observed every day, and the wound healing time was calculated when the wound was completely epithelialized. 2) Wound healing: The wound healing area was measured 1, 7, and 14 days after treatment, and transparent paper was used to record combined with a computer-assisted imaging system. Wound healing rate = wound healing area (cm2)/total wound area before treatment (cm2) × 100%. The time for complete wound healing was recorded in the two groups of patients. 3) Pain: The pain was evaluated at 1, 7, and 14 days after treatment using the visual analogue scale (VAS). The higher the score, the more severe the pain. 4) Scar condition: Scar formation was evaluated 1, 3, and 6 months after wound healing using the VAS scale, with a total score of 15 points. The higher the score, the more severe the scar. 5) Detect the expression of AGEs in wound tissue. Results: The wound healed 14.03 ± 2.28 days after eschar removal, with a cure rate of 97.8%. No infection occurred in the wound after eschar removal in all patients. The wound healing time ranged from 9 to 23 days, with an average healing time of 28.41 ± 1.45 days. The healing quality was satisfactory. The Vancouver Scar Scale scored the wound healing scar as 0.81 ± 0.73 points. Western blot was used to detect the expression of AGEs, (receptor for advanced glycation end products) RAGE, and protein in the wound tissue. Results After 7, 14, and 28 days of medication, the wounds of diabetic patients healed well. The drug treatment efficacy and hydroxyproline content showed an upward trend, and the expression levels of AGEs, RAGE, and HIF-1a proteins showed a downward trend. Compared with day 0, the hydroxyproline content of the wound granulation tissue on days 7, 14, and 28 was significantly increased (P< 0.01), and the expression levels of AGEs, RAGE, and HIF-1α proteins were significantly downregulated (P< 0.05 or P< 0.01). Conclusion: Monitoring the expression levels of AGEs and RAGE can reflect the wound-healing effect of patients with second-degree burns, and the prognosis of the wound is closely related to the expression levels of AGEs, RAGE, and scab abrasion. In the treatment of second-degree burn wounds, scab abrasion can grasp the level of necrotic scab removal, can achieve “relatively accurate” removal of necrotic tissue, maximally protect the ecological tissue between wounds and retaining normal tissue, and can play a positive role in promoting the healing process of burn wounds;at the same time, nanosilver dressings have good antibacterial properties and high safety, and mussel mucin has anti-inflammatory and antioxidant activities and the characteristics of blocking nerve endings, which can effectively relieve the burning, stinging, and itching of sensitive skin and effectively promote wound healing.
基金supported by the National Natu-ral Science Foundation of China(Grants No.12174220 and No.12074217)the Shandong Provincial Science Foundation for Excellent Young Scholars(Grant No.ZR2023YQ001)+1 种基金the Taishan Young Scholar Program of Shandong Provincethe Qilu Young Scholar Pro-gram of Shandong University.
文摘Higher-order band topology not only enriches our understanding of topological phases but also unveils pioneering lower-dimensional boundary states,which harbors substantial potential for next-generation device applications.The distinct electronic configurations and tunable attributes of two-dimensional materials position them as a quintessential platform for the realization of second-order topological insulators(SOTIs).This article provides an overview of the research progress in SOTIs within the field of two-dimensional electronic materials,focusing on the characterization of higher-order topological properties and the numerous candidate materials proposed in theoretical studies.These endeavors not only enhance our understanding of higher-order topological states but also highlight potential material systems that could be experimentally realized.
基金Supported by the National Natural Science Foundation of China(42302141).
文摘Taking the second member of the Xujiahe Formation of the Upper Triassic in the Xinchang structural belt as an example,based on data such as logging,production,seismic interpretation and test,a systematic analysis was conducted on the structural characteristics and evolution,reservoir diagenesis and densification processes,and types and stages of faults/fractures,and revealing the multi-stage and multi-factor dynamic coupled enrichment mechanisms of tight gas reservoirs.(1)In the early Yanshan period,the paleo-structural traps were formed with low-medium maturity hydrocarbons accumulating in structural highs driven by buoyancy since reservoirs were not fully densified in this stage,demonstrating paleo-structure control on traps and early hydrocarbon accumulation.(2)In the middle-late Yanshan period,the source rocks became mature to generate and expel a large quantity of hydrocarbons.Grain size and type of sandstone controlled the time of reservoir densification,which restricted the scale of hydrocarbon charging,allowing for only a small-scale migration through sand bodies near the fault/fracture or less-densified matrix reservoirs.(3)During the Himalayan period,the source rocks reached overmaturity,and the residual oil cracking gas was efficiently transported along the late-stage faults/fractures.Wells with high production capacity were mainly located in Type I and II fault/fracture zones comprising the late-stage north-south trending fourth-order faults and the late-stage fractures.The productivity of the wells was controlled by the transformation of the late-stage faults/fractures.(4)The Xinchang structural belt underwent three stages of tectonic evolution,two stages of reservoir formation,and three stages of fault/fractures development.Hydrocarbons mainly accumulated in the paleo-structure highs.After reservoir densification and late fault/fracture adjustment,a complex gas-water distribution pattern was formed.Thus,it is summarized as the model of“near-source and low-abundance hydrocarbon charging in the early stage,and differential enrichment of natural gas under the joint control of fault-fold-fracture complex,high-quality reservoirs and structural highs in the late stage”.Faults/fractures with well-coupled fault-fold-fracture-pore are favorable exploration targets with high exploration effectiveness.
基金supported by the National Nat-ural Science Foundation of China(Nos.12192251,12174185,92163216,and 62288101).
文摘The generation of optical vortices from nonlinear photonic crystals(NPCs)with spatially modulated second-order nonlinearity offers a promising approach to extend the working wavelength and topological charge of vortex beams for various applications.In this work,the second harmonic(SH)optical vortex beams generated from nonlinear fork gratings under Gaussian beam illumination are numerically investigated.The far-field intensity and phase distributions,as well as the orbital angular momentum(OAM)spectra of the SH beams,are analyzed for different structural topological charges and diffraction orders.Results reveal that higher-order diffraction and larger structural topological charges lead to angular interference patterns and non-uniform intensity distributions,deviating from the standard vortex profile.To optimize the SH vortex quality,the effects of the fundamental wave beam waist,crystal thickness,and grating duty cycle are explored.It is shown that increasing the beam waist can effectively suppress diffraction order interference and improve the beam’s quality.This study provides theoretical guidance for enhancing the performance of nonlinear optical devices based on NPCs.
基金part of the project“Qualitative and numerical analyses of some thermomechanics problems(ACUANUTER)”(Ref.PID2024-156827NB-I00)。
文摘We consider the space and time decays of certain problems within the second gradient thermal law.Notably,for this thermal theory,the exponential time decay is precluded.First,the time estimates of polynomial type are obtained for both the thermal equation and the one-dimensional thermoelastic system,where the impossibility of localization with respect to time is also established.Then,the space estimates are deduced for the multidimensional thermoelastic problem,which allow to show the exponential decay of the energy.
基金supported by the National Natural Science Foun-dation of China(No.12274339).
文摘Second harmonic generation(SHG),a fundamental and widely-studied phenomenon in nonlinear optics,has attracted significant attention for its ability to convert fundamental frequencies into their second harmonics.While the dominant SHG research has been focused on the optical and infrared regimes,its investigation in the microwave range presents challenges due to the requirements of materials with higher nonlinear coefficients and high-power microwave sources.Here,we provide an overview of methods together with underlying mechanisms for SHG in microwave frequencies,and discuss prospects and insights into the future developments of SHG-based technologies.The discussions on both numerical analyses and experimental studies will offer guidance for further SHG research and communication advancements in microwave regime.
基金supported by the Science and Technology Project of Guangdong Province,China(Grant No.2020B010190001)the National Natural Science Foundation of China(Grant No.12434016)the National Funded Postdoctoral Researcher Program(Grant No.GZB20240785).
文摘When a pump laser beam strikes the surface of a nonlinear crystal with modulated second-order nonlinearity,various nonlinear diffraction phenomena occur,with nonlinear Raman–Nath diffraction(NRND)being a prominent example.In this study,we use an 800-nm Ti:sapphire femtosecond laser beam to pump the surface of a periodically poled lithium niobate(PPLN)crystal thin-plate nonlinear grating.By rotating the crystal,we change the incidence angle and observe and measure the exit angle,polarization,and power of NRND spots on the other side of the crystal.The experiment shows that NRND characteristics are highly sensitive to the incidence angle of the pump laser beam,which are consistent with the theoretical prediction.We expect that this research will advance the understanding of nonlinear diffraction and provide valuable insights for nonlinear optical interaction in complicated geometric and physical configurations.
基金Interim Achievements of the“Yingying Technology Empowerment–Application-Oriented Talent Enhancement Project at Changchun College of Electronic Technology”under the Fourth Phase of the 2024 Ministry of Education’s Employment-Education Collaboration Project(Project Number:2024121188944Project Leader:Chunhua Ren)+3 种基金Interim Achievements of the“Directional Cultivation Project for Composite Talents at Changchun College of Electronic Technology”under the Fourth Phase of the 2024 Ministry of Education’s Supply-Demand Matching and Employment-Education Cultivation Program(Project Number:2024121107571Project Leader:Chunhua Ren)Interim Achievements of the“Research on the Cultivation Path of Craftsmanship Spirit among University Teachers in the Context of Industry-University Collaboration”under the 2025 Ministry of Education’s Industry-University Cooperative Education Project(Project Number:2505164755Project Leader:Chunhua Ren)。
文摘The paper aims to examine the application of multimedia technology in expanding vocabulary in second language acquisition.Incorporating innovative technology such as mobile applications,gaming applications,websites,and other related online tools has increased learners’vocabulary mastery,engagement,and motivation levels.Interactional processes like media-embedded objects,teach-learning capacity algorithms,and feedback help learners receive the course in a personalized way that considers individual learning patterns or abilities.However,there are the following challenges:accessibility issues,total reliance on technology,and issues related to privacy.The following challenges affecting learning that arise from using gadgets:the digital divide,limited device access,and environmental issues that may distract a learner in a technology-enabled environment.Moreover,the security issue for data and the ethical question of users’information remain important too.Hence,the paper provides arguments that although these technologies contribute significantly to vocabulary acquisition,the challenge that emerges should be addressed by integrating technology in teaching and learning alongside conventional methods for vocabulary acquisition,which is a practical language acquisition tool that should not be monopolized.
文摘Anxiety,motivation,and strategy have long been seen as critical in second language acquisition.This study presents a systematic review of the literature on these variables in terms of their relationship with one another,their effects on learning outcomes,and how they are affected by technology-assisted tools in the teaching of Chinese as a second language.This study includes 24 articles for the review study based on the criteria and process of the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocol(PRISMA-P)and the clustering techniques of VOSviewer.It is found that 1)anxiety,motivation,and strategy were interrelated,that is,motivation was negatively associated with anxiety but positively related to strategy,while strategy could positively predict anxiety;2)anxiety could both positively and negatively affect learning outcomes,while motivation and strategy could both positively and insignificantly influence learning outcomes;3)the technology-assisted tools used in the classroom could both positively and negatively affect the levels of these variables and learning outcomes in the L2 Chinese context.The need to explore more complicated relationships between language-specific individual variables themselves and other possible factors that affect these variables,such as cultural ones,are also discussed for future research.
基金supported by the Ministry of Research,Innovation and Digitalization,CNCS-UEFISCDI[Grant Nos.RO-NO-2019-0601(MEDYCONAI),PN-III-P4-PCE-2021-0444(RESONANO)]PN-IV-P1-PCE-2023-1137+2 种基金supported in part by IN2SIGHT,European Union’s Horizon 2020(GA.no.964481)by the Research Council of Lithuania(LMTLTAgreement No.P-MIP-23-237).
文摘Collagen characterization is crucial for disease diagnostics,prevention,and understanding,with growing focus on quantitative analysis at tissue and fibril levels.Numerous models have been developed to quantify structural changes in collagen linked to various pathologies.However,many approaches remain limited to conceptual descriptions or rely on custom software,often requiring programming skills,which re-stricts their clinical application and potential impact.We introduce CollagenFitJ,a plugin for the open-source software platform ImageJ/FIJI,which represents a widely used microscopy image analysis tool.CollagenFitJ makes use of the cylindrical symmetry model for collagen to enable facile quantitative assessment of polarization-resolved second harmonic generation microscopy image stacks.The plugin’s main outputs are collagen structure-related maps(e.g.,orientation and anisotropy of collagen fibrils within the focal volume),which can be accompanied by distribution and randomness maps for a series of structure-related parameters.We describe and validate the use of CollagenFitJ on images acquired on rat-tail tendons,collagen capsules surrounding human thyroid nodules,and mouse colon tumors,using both scanning and widefield second harmonic generation microscopy datasets.The plugin was designed to be user-friendly,requiring little to no experience in image processing and coding to facilitate access for life scientists,medical staff,and microscopy practitioners with limited coding skills or time availability required for coding.
基金supported by the National Natural Science Foundation of China(Grant Nos.12304220,12174157,12074150,and 12374174)the Natural Science Foundation of Jiangsu Province(Grant No.BK20230518)+2 种基金the China Postdoctoral Science Foundation(Grant No.2023M731383)the College Student Innovation Project(Grant No.202410299946X)the Scientific Research Project of Jiangsu University(Grant No.22A397).
文摘Designing novel two-dimensional structures and precisely modulating their second harmonic generation(SHG)attributes are key to advancing nonlinear photonic technologies.In this work,through first-principles calculations,we propose a novel tetrahedral phase of transition metal dichalcogenides(TMDs)and validate its structural feasibility in a family of compounds,i.e.,ZX_(2)(Z=Ti,Zr,Hf;X=S,Se,Te).Cohesive energy and phonon dispersion calculations further demonstrate that eight of nine possible ZX_(2)monolayers are dynamically stable.All the ZX_(2)monolayers exhibit pronounced out-of-plane SHG with nonlinear susceptibility components reaching the order of 10^(2)pm/V.Strain engineering imposes a profound influence on the SHG response of ZX_(2)monolayers by reducing symmetry and modifying nonlinear susceptibility components.The redshift and significant enhancement of the prominent peak in SHG spectra are also revealed due to strain-induced charge redistribution and band gap reduction.Intriguingly,strain-driven nonlinear optical switching effects are realized in the ZX_(2)monolayers,with a reversible switching of SHG component ordering under tensile and compressive strain.In such a case,the anisotropic SHG pattern transforms from fourfold to twofold symmetry under the strain.Our work demonstrates the efficacy of strain engineering in precisely enhancing SHG,paving the way for the integration of novel TMD structures into tunable and flexible nonlinear optical devices.
