BACKGROUND Internal hernia(IH)is a rare culprit of small bowel obstruction(SBO)with an incidence of<1%.It poses a considerable diagnostic challenge requiring a high index of suspicion to prevent misdiagnosis,improp...BACKGROUND Internal hernia(IH)is a rare culprit of small bowel obstruction(SBO)with an incidence of<1%.It poses a considerable diagnostic challenge requiring a high index of suspicion to prevent misdiagnosis,improper treatment,and subsequent morbidity and mortality.AIM To determine the clinico-demographic profile,radiological and operative findings,and postoperative course of patients with IH and its association with SBO.METHODS Medical records of 586 patients with features of SBO presenting at a tertiary care centre at Lucknow,India between September 2010 and August 2023 were reviewed.RESULTS Out of 586 patients,7(1.2%)were diagnosed with IH.Among these,4 had congenital IH and 3 had acquired IH.The male-to-female ratio was 4:3.The median age at presentation was 32 years.Contrast-enhanced computed tomography(CECT)was the most reliable investigation for preoperative identification,demonstrating mesenteric whirling and clumped-up bowel loops.Left paraduodenal hernia and transmesenteric hernia occurred with an equal frequency(approximately 43%each).Intraoperatively,one patient was found to have bowel ischemia and one had associated malrotation of gut.During follow-up,no recurrences were reported.CONCLUSION IH,being a rare cause,must be considered as a differential diagnosis for SBO,especially in young patients in their 30s or with unexplained abdominal pain or discomfort post-surgery.A rapid imaging evaluation,preferably with CECT,is necessary to aid in an early diagnosis and prompt intervention,thereby reducing financial burden related to unnecessary investigations and preventing the morbidity and mortality associated with closed-loop obstruction and strangulation of the bowel.展开更多
An internal state variable(ISV)model was established according to the experimental results of hot plane strain compression(PSC)to predict the microstructure evolution during hot spinning of ZK61 alloy.The effects of t...An internal state variable(ISV)model was established according to the experimental results of hot plane strain compression(PSC)to predict the microstructure evolution during hot spinning of ZK61 alloy.The effects of the internal variables were considered in this ISV model,and the parameters were optimized by genetic algorithm.After validation,the ISV model was used to simulate the evolution of grain size(GS)and dynamic recrystallization(DRX)fraction during hot spinning via Abaqus and its subroutine Vumat.By comparing the simulated results with the experimental results,the application of the ISV model was proven to be reliable.Meanwhile,the strength of the thin-walled spun ZK61 tube increased from 303 to 334 MPa due to grain refinement by DRX and texture strengthening.Besides,some ultrafine grains(0.5μm)that played an important role in mechanical properties were formed due to the proliferation,movement,and entanglement of dislocations during the spinning process.展开更多
Internal learning-based video inpainting methods have shown promising results by exploiting the intrinsic properties of the video to fill in the missing region without external dataset supervision.However,existing int...Internal learning-based video inpainting methods have shown promising results by exploiting the intrinsic properties of the video to fill in the missing region without external dataset supervision.However,existing internal learning-based video inpainting methods would produce inconsistent structures or blurry textures due to the insufficient utilisation of motion priors within the video sequence.In this paper,the authors propose a new internal learning-based video inpainting model called appearance consistency and motion coherence network(ACMC-Net),which can not only learn the recurrence of appearance prior but can also capture motion coherence prior to improve the quality of the inpainting results.In ACMC-Net,a transformer-based appearance network is developed to capture global context information within the video frame for representing appearance consistency accurately.Additionally,a novel motion coherence learning scheme is proposed to learn the motion prior in a video sequence effectively.Finally,the learnt internal appearance consistency and motion coherence are implicitly propagated to the missing regions to achieve inpainting well.Extensive experiments conducted on the DAVIS dataset show that the proposed model obtains the superior performance in terms of quantitative measurements and produces more visually plausible results compared with the state-of-the-art methods.展开更多
Using real fields instead of complex ones, it was recently claimed, that all fermions are made of pairs of coupled fields (strings) with an internal tension related to mutual attraction forces, related to Planck’s co...Using real fields instead of complex ones, it was recently claimed, that all fermions are made of pairs of coupled fields (strings) with an internal tension related to mutual attraction forces, related to Planck’s constant. The solution to Dirac equation gives four, real, 2-vectors solutions ψ1=(U1D1)ψ2=(U2D2)ψ3=(U3D3)ψ4=(U4D4)where (ψ1,ψ4) are coupled via linear combinations to yield spin-up and spin-down fermions. Likewise, (ψ2,ψ3) are coupled via linear combinations to represent spin-up and spin-down anti-fermions. Here, a deeper investigation of the free fermion internal frequency is discussed, hinting to an exchange interaction between the two components of which a fermion is made of. An upper limit estimate is given to the strength of this interaction.展开更多
BACKGROUND Pain in the back or pelvis or fear of back pain may affect the timing or cocontraction of the core muscles.In both static and dynamic movements,the Sahrmann core stability test provides an assessment of cor...BACKGROUND Pain in the back or pelvis or fear of back pain may affect the timing or cocontraction of the core muscles.In both static and dynamic movements,the Sahrmann core stability test provides an assessment of core muscle activation and a person's ability to stabilize the lumbopelvic complex.Preparatory cues and images can be used to increase the activation of these muscles.To attain optimal movement patterns,it will be necessary to determine what cueing will give the most effective results for core stability.AIM To investigate the effects of external and internal cues on core muscle activation during the Sahrmann five-level core stability test.METHODS Total 68 participants(21.83±3.47 years)were randomly allocated to an external(n=35)or internal cue group(n=33).Participants performed the Sahrmann fivelevel core stability test without a cue as baseline and the five-level stability exercises with an internal or external cue.External cue group received a pressure biofeedback unit(PBU),and the internal cue group received an audio cue.A Delsys Trigno^(TM)surface electromyography unit was used for muscle activation from the rectus abdominis,external oblique,and transverse abdominis/internal oblique muscles.RESULTS Linear mixed effects model analysis showed that cueing had a significant effect on core muscle activation(P=0.001);however,there was no significant difference between cue types(internal or external)(P=0.130).CONCLUSION Both external and internal cueing have significant effects on core muscle activation during the Sahrmann five-level core stability test and the PBU does not create higher muscle activation than internal cueing.展开更多
The authors(Cai et al.,2022)claim that their proposed machine learning(ML)models,which are based on three typical ML algorithms and are trained to predict the burst capacity of pitting corroded pipelines,perform bette...The authors(Cai et al.,2022)claim that their proposed machine learning(ML)models,which are based on three typical ML algorithms and are trained to predict the burst capacity of pitting corroded pipelines,perform better than the existing semi-empirical formulas recommended by the international engineering code developers,DNV and ASME.The authors’assessments of the semi-empiri‐cal burst capacity formulas in Figure 10(a)and Table 8(Cai et al.,2022)incorrectly indicate that DNVGL-RP F101,ASME B31G,and modified ASME B31G are dan‐gerously unsafe due to significantly overestimating burst pressures in several cases.In contrast to the results and conclusions in Cai et al.展开更多
Objective:To evaluate the effectiveness of the internal limiting membrane(ILM)flipping and covering technique in the treatment of patients with high myopic macular hole(HMMH).Methods:One hundred and two patients with ...Objective:To evaluate the effectiveness of the internal limiting membrane(ILM)flipping and covering technique in the treatment of patients with high myopic macular hole(HMMH).Methods:One hundred and two patients with HMMH who were admitted to the hospital from June 2019 to June 2024 were selected.The minimum diameter of the macular hole(MH)in all patients was≤500μm.The patients were randomly divided into two groups.The experimental group received 25G pars plana vitrectomy(PPV)combined with ILM flipping and covering technique,while the reference group received PPV combined with ILM peeling.The efficacy indicators and best corrected visual acuity levels were compared between the two groups.Results:The MH closure rate and retinal reattachment rate were higher in the experimental group than in the reference group at 3 and 6 months postoperatively(P<0.05).The best corrected visual acuity level was higher in the experimental group than in the reference group at 3 and 6 months postoperatively(P<0.05).The Chinese version of the Visual Function-Related Quality of Life Questionnaire-25(CVRQOL-25)score was higher in the experimental group than in the reference group at 3 and 6 months postoperatively(P<0.05).No serious complications were observed in both groups postoperatively,and there was no difference between the two groups(P>0.05).Conclusion:The ILM flipping and covering technique can improve the MH closure rate and retinal reattachment rate in patients with HMMH(diameter≤500μm),enhance the best corrected visual acuity level,and improve the quality of life related to visual function,with fewer postoperative complications.展开更多
Objective:This study aimed to examine the developmental trajectories of internalizing behaviors among adolescents and to identify key personal and environmental factors associated with these developmental patterns ove...Objective:This study aimed to examine the developmental trajectories of internalizing behaviors among adolescents and to identify key personal and environmental factors associated with these developmental patterns over time.Methods:Data were collected from 2242 adolescents(49.6%girls,aged 13.9–18.9 years)in South Korea.Latent class growth analysis was used to identify distinct developmental patterns of internalizing behaviors.Multinomial logistic regression analyses were conducted to examine the associations between these developmental patterns and various factors including gender,self-esteem,abuse and neglect experiences,peer relationships,and media use.Results:The analysis revealed three latent classes of internalizing behavior trajectories among adolescents.The first group,the“mid decreasing group”,comprised 54.5%of the sample(1221 students),indicating a moderate level of internalizing behavior that declined over time.The second group,the“high decreasing group”,included 19.1%of the sample(429 students),characterized by initially high levels of internalizing behavior that decreased.The third group,the“low maintained group”,represented 26.4%of the sample(592 students),indicating consistently low levels of internalizing behavior.Factors such as gender,self-esteem,experiences of abuse and neglect,peer relationships(trust and alienation),smartphone dependency,and time spent watching TV/videos were significantly associated with these latent groups.Conclusion:Three distinct developmental patterns of internalizing behaviors were identified among adolescents:mid-decreasing(54.5%),high-decreasing(19.1%),and low-maintained(26.4%).Gender,self-esteem,abuse experiences,and peer relationships were significant predictors of these developmental patterns.展开更多
Developing an efficient photocatalyst is the key to realize the practical application of photocatalysis.The S-scheme heterojunction has great potential in photocatalysis due to its unique charge-carrier migration path...Developing an efficient photocatalyst is the key to realize the practical application of photocatalysis.The S-scheme heterojunction has great potential in photocatalysis due to its unique charge-carrier migration pathway,effective light absorption and high redox capacity.However,further enhancing the built-in electric field of the S-scheme,accelerating carrier separation,and achieving higher photocatalytic performance remain unresolved challenges.Herein,based on the continuously adjustable band structure of continuous solid-solution,a novel 0D/2D all solid-solution S-scheme heterojunction with adjustable internal electric field was designed and fabricated by employing a solid-solution of ZnxCd_(1–x)S and Bi_(2)MoyW_(1–y)O_(6)respectively as reduction and oxidation semiconductors.The synergistic optimization of effective light absorption,fast photogenerated carrier separation,and high redox potential leads can be tuned to promote photocatalytic activity.Under visible light,the S-scheme system constructed by Zn_(0.4)Cd_(0.6)S quantum dot(QDs)and Bi_(2)Mo_(0.2)W_(0.8)O_(6)monolayer exhibits a high rate for photocatalytic degradation C_(2)H_(4)(150.6×10^(–3)min^(–1)),which is 16.5 times higher than that of pure Zn_(0.4)Cd_(0.6)S(9.1×10^(–3)min^(–1))and 53.8 times higher than pure Bi_(2)Mo_(0.2)W_(0.8)O_(6)(2.8×10^(–3)min^(–1)).Due to the unique charge-carrier migration pathway,photo-corrosion of Zn_(x)Cd_(1–x)S is further inhibited simultaneously.In-situ irradiation X-ray photoelectron spectroscopy,photoluminescence spectroscopy,time-resolved photoluminescence,transient absorption spectroscopy and electron paramagnetic resonance provide compelling evidence for interfacial charge transfer via S-scheme pathways,while in-situ diffuse reflectance infrared Fourier transform spectroscopy identifies the reaction pathway for C_(2)H_(4)degradation.This novel S-scheme photocatalysts demonstrates excellent performance and potential for the practical application of the fruits and vegetables preservation at room temperatures.展开更多
Double bonds of internal olefins can be efficiently migrated to the terminal carbons and regioselectively hydroesterified with formates in the presence of Pd(OAc)_(2) and 1,2-DTBPMB under mild reaction conditions,prov...Double bonds of internal olefins can be efficiently migrated to the terminal carbons and regioselectively hydroesterified with formates in the presence of Pd(OAc)_(2) and 1,2-DTBPMB under mild reaction conditions,providing a wide variety of corresponding linear carboxylic esters bearing various functional groups in good yields and>20:1 linear/branch ratios.The reaction is optionally simple and does not need to use CO gas and acid co-catalysts.展开更多
Migration is a complex demographic phenomenon.Its dynamics can be explained by several factors whose spatial and temporal evolution is not easy to control.That is why this article aims to understand the factors of mig...Migration is a complex demographic phenomenon.Its dynamics can be explained by several factors whose spatial and temporal evolution is not easy to control.That is why this article aims to understand the factors of migration from a spatiotemporal perspective to fill the gaps in the literature.The aim of this article is to analyse the spatiotemporal dynamics of internal migration factors to deduce the zones of origin and destination in Burkina Faso.To do this,several types of data were used.These included secondary,spatial,statistical and survey data.The results of this study show that the influence of internal migration factors is uneven.The spatial distribution of internal migration factors follows a north-south gradient,with favourable conditions in the south.In fact,the northern part is characterised by a large population exodus,with around 42.6%of outgoing internal migrants,and the southern part by a large population influx.This southern part of the country receives around 34.6%of internal migrants.The areas from which migrants depart have unfavourable climatic,environmental,or socio-economic conditions,whereas the areas to which migrants migrate are characterised by favourable conditions for these factors.展开更多
We use a high-resolution numerical simulation to analyze the generation and evolution of semidiurnal internal tides in the Weddell-Scotia Confluence.Our results indicate that two ridges near the Antarctic Peninsula,th...We use a high-resolution numerical simulation to analyze the generation and evolution of semidiurnal internal tides in the Weddell-Scotia Confluence.Our results indicate that two ridges near the Antarctic Peninsula,the South Scotia Ridge(SSR)and the Philip Ridge(PR),are energetic sources of semidiurnal internal tides.The strongest semidiurnal barotropic to baroclinic energy conversion occurs around the crest of the SSR,reaching 0.3 W/m^(2).The depthintegrated,tidally averaged semidiurnal internal tide energy fluxes that radiated from the SSR reach about 2 kW/m.The northward semidiurnal internal tide energy fluxes entering the Scotia Sea are stronger than the southward energy fluxes entering the Powell Basin.For the SSR region between the South Orkney Plateau and Elephant Island,the areaintegrated barotropic to baroclinic conversion rate is 0.71 GW,of which 0.56 GW(79%)dissipates locally.The dissipation of internal tides occurs mainly in water depths of less than 1000 m.The dissipation rate over the SSR is as high as 10−7 W/kg.The energy fluxes create an anticlockwise gyre between the SSR and PR.The horizontal kinetic energy and available potential energy oscillate sinusoidally with peaks occurring at quarter-wavelength intervals.This energy pattern suggests the formation of standing waves due to interference between the semidiurnal internal tides originating from the SSR and PR.The results of this study show that internal tides and related mixing need to be considered in the analysis of water mass transformation in the Southern Ocean.展开更多
Digital transformation provides enterprises with new development momenta.Understanding the relationship between digital transformation and total factor productivity(TFP)is essential.This study employs a fixedeffect mo...Digital transformation provides enterprises with new development momenta.Understanding the relationship between digital transformation and total factor productivity(TFP)is essential.This study employs a fixedeffect model and selects all Chinese A-share listed companies from 2007 to 2022 as the research sample.Internal control(IC)is introduced as a mechanistic variable.The results indicate that digital transformation significantly promotes both TFP and the effectiveness of IC.Moreover,effective IC plays a significant mediating role in the relationship between digital transformation and TFP.A heterogeneity analysis reveals that,compared to non-state-owned enterprises,state-owned enterprises can improve TFP more rapidly through digital transformation due to their resource advantages and policy support.On the one hand,these findings help enterprises better align their transformation strategies to maximize the benefits of digital transformation.On the other hand,they provide investors with insights into the transformation potential and future growth prospects of these enterprises.展开更多
The effects of internals on liquid mixing and gas-liquid mass transfer have rarely been investigated in bubble columns,and the commonly used measurement method overestimates significantly overall gas holdup.Firstly,ga...The effects of internals on liquid mixing and gas-liquid mass transfer have rarely been investigated in bubble columns,and the commonly used measurement method overestimates significantly overall gas holdup.Firstly,gas holdup measurement method is improved by conducting multi-point liquid level measurement and using net fluid volume instead of bed volume to calculate gas holdup.Then,a stable conductivity method for liquid macromixing has been established by shielding large bubbles using#16nylon mesh.Subsequently,the influences of internal coverage(=12.6%,18.9% and 25.1%) on macroscopic fluid dynamics in a bubble column with a free wall area are systematically investigated.It is found that the presence of internals has a notable effect on macroscopic fluid dynamics.The overall gas holdup and gas-liquid volumetric mass transfer coefficient decrease,and the macromixing time decreases with the increase of internal cross-sectional area coverage.These are mainly caused by the uneven distribution of airflow due to the low resistance in the free wall area.This design makes maintenance easier,but in reality,the reactor performance has decreased.Further improvements will be made to the reactor performance based on such a configuration through flow guidance using baffles.展开更多
Internal multiples are commonly present in seismic data due to variations in velocity or density of subsurface media.They can reduce the signal-to-noise ratio of seismic data and degrade the quality of the image.With ...Internal multiples are commonly present in seismic data due to variations in velocity or density of subsurface media.They can reduce the signal-to-noise ratio of seismic data and degrade the quality of the image.With the development of seismic exploration into deep and ultradeep events,especially those from complex targets in the western region of China,the internal multiple eliminations become increasingly challenging.Currently,three-dimensional(3D)seismic data are primarily used for oil and gas target recognition and drilling.Effectively eliminating internal multiples in 3D seismic data of complex structures and mitigating their adverse effects is crucial for enhancing the success rate of drilling.In this study,we propose an internal multiple prediction algorithm for 3D seismic data in complex structures using the Marchenko autofocusing theory.This method can predict the accurate internal multiples of time difference without an accurate velocity model and the implementation process mainly consists of several steps.Firstly,simulating direct waves with a 3D macroscopic velocity model.Secondly,using direct waves and 3D full seismic acquisition records to obtain the upgoing and down-going Green's functions between the virtual source point and surface.Thirdly,constructing internal multiples of the relevant layers by upgoing and downgoing Green's functions.Finally,utilizing the adaptive matching subtraction method to remove predicted internal multiples from the original data to obtain seismic records without multiples.Compared with the two-dimensional(2D)Marchenko algo-rithm,the performance of the 3D Marchenko algorithm for internal multiple prediction has been significantly enhanced,resulting in higher computational accuracy.Numerical simulation test results indicate that our proposed method can effectively eliminate internal multiples in 3D seismic data,thereby exhibiting important theoretical and industrial application value.展开更多
Ocean mixing is a consequence of essential dynamic processes such as internal tides and lee waves that occur near the seafloor topography.Internal tides and lee waves are generated by barotropic tidal currents and geo...Ocean mixing is a consequence of essential dynamic processes such as internal tides and lee waves that occur near the seafloor topography.Internal tides and lee waves are generated by barotropic tidal currents and geostrophic flows,respectively.Ocean current is composed of multiple flows;thus,internal tides and lee waves occur concurrently in the real ocean.In this paper,the Massachusetts Institute of Technology general circulation model(MITgcm)is used to conduct 2D numerical experiments.By varying background flow intensities,the energy and dissipation relationship between internal tides and lee waves are investigated.The results reveal that the internal tide beams become asymmetric due to the influence of Doppler shift.The lee wave structure gradually leads the wave field when the background flow velocity rises constantly.The presence of a background flow increases the energy portion of the high-mode wave by up to 15%-20%.Moreover,strong shear,owing to the background flow,considerably increases dissipation.When the background flow velocity is higher than the barotropic tidal current velocity,the isopycnal overturn triggered by the lee wave generates a dissipation of the same order of magnitude as the shear.展开更多
Internal solitary waves(ISWs) are a common phenomenon beneath the ocean surface and represent a significant environmental hazard that must be considered for the safe navigation of submersibles. A numerical simulation ...Internal solitary waves(ISWs) are a common phenomenon beneath the ocean surface and represent a significant environmental hazard that must be considered for the safe navigation of submersibles. A numerical simulation model for the interaction of solitary waves with submersibles at a large scale has been developed. The Miyata-ChoiCamassa(MCC) equation serves as the basis for generating ISWs. The impacts of the submergence depth, wave amplitude, and advancing velocity on the motion response and load characteristics of the submersible are examined in detail. This study elucidates the governing laws and mechanisms underlying the impact of ISWs on submersibles.The research findings indicate that shorter distances to the undisturbed surface, higher wave amplitudes, and fasteradvancing speeds result in greater effects on submersibles. For a submersible operating in the lower layer, both the alteration in density near the wave interface and the dynamic pressure induced by ISWs can reduce its lift, potentially resulting in a rapid descent. It is imperative to pay considerable attention to the impact of ISWs, as they have the potential to precipitate a loss of control of the submersible.展开更多
In the Arctic Ocean,turbulent mixing drives vertical heat flux,thereby affecting the sea ice variability.Internal wave is regarded as one of the important energy sources of mixing in this region.The high latitude and ...In the Arctic Ocean,turbulent mixing drives vertical heat flux,thereby affecting the sea ice variability.Internal wave is regarded as one of the important energy sources of mixing in this region.The high latitude and sea ice cover make internal wave in the Arctic Ocean apparently differs from that in mid-and low-latitude oceans.However,the internal wave and its underlying mechanism are less understood due to the lack of observations.This paper briefly reviews the recent studies and unresolved questions on the internal wave in the Arctic Ocean,including wind-driven near-inertial wave,internal tide,and high-frequency internal wave.The aim is to provide new insights for in-depth research in the future,with a focus on the mechanisms responsible for the evolution of internal wave under the rapidly changing Arctic climate.展开更多
Periodic isolator is well known for its wave filtering characteristic.While in middle and high frequencies,the internal resonances of the periodic isolator are evident especially when damping is small.This study propo...Periodic isolator is well known for its wave filtering characteristic.While in middle and high frequencies,the internal resonances of the periodic isolator are evident especially when damping is small.This study proposes a novel aperiodic vibration isolation for improving the internal resonances control of the periodic isolator.The mechanism of the internal resonances control by the aperiodic isolator is firstly explained.For comparing the internal resonances suppression effect of the aperiodic isolator with the periodic isolator,a dynamic model combing the rigid machine,the isolator,and the flexible plate is derived through multi subsystem modeling method and transfer matrix method,whose accuracy is verified through the finite element method.The influences of the aperiodicity and damping of the isolator on the vibration isolation performance and internal resonances suppression effect are investigated by numerical analysis.The numerical results demonstrate that vibration attenuation performances of the periodic isolator and aperiodic isolator are greatly over than that of the continuous isolator in middle and high frequencies.The aperiodic isolator opens the stop bandgaps comparing with the periodic isolator where the pass bandgaps are periodically existed.The damping of the isolator has the stop bandgap widening effect on both the periodic isolator and the aperiodic isolator.In addition,a parameter optimization algorithm of the aperiodic isolator is presented for improving the internal resonances control effect.It is shown that the vibration peaks within the target frequency band of the aperiodic isolator are effectively reduced after the optimization.Finally,the experiments of the three different vibration isolation systems are conducted for verifying the analysis work.展开更多
Since the mid-20th century,the Mongolian Plateau(MP)has experienced decadal droughts coupled with extreme heatwaves,severely affecting regional ecology and social development.However,the mechanisms behind these decada...Since the mid-20th century,the Mongolian Plateau(MP)has experienced decadal droughts coupled with extreme heatwaves,severely affecting regional ecology and social development.However,the mechanisms behind these decadalscale compound heatwavedrought events remain debated.Here,using reconstructions and simulations from the Community Earth System Model Last Millennium Ensemble,we demonstrate that,over the last millennium,decadal droughts on the MP occurred under both warm and cold conditions,differing from recent compound heatwavedrought events.We found that by examining temperature changes during these drought periods,the distinct influences of external forcings and internal variability can be simply and effectively distinguished.Specifically,colddry events were primarily driven by volcanic eruptions that weakened the East Asian summer monsoon and midlatitude westerlies,reducing moisture transport to the MP.In contrast,warmdry events were predominantly induced by internal variability,notably the negative phase of the Atlantic Multidecadal Oscillation and the expansion of the Barents Sea ice extent.The recent extreme compound event was probably influenced by the combined effects of anthropogenic forcings and internal variability.These findings deepen our understanding of how external forcings and internal variability affect decadal drought events on the MP and highlight that recent compound events are unprecedented in the context of the last millennium.展开更多
文摘BACKGROUND Internal hernia(IH)is a rare culprit of small bowel obstruction(SBO)with an incidence of<1%.It poses a considerable diagnostic challenge requiring a high index of suspicion to prevent misdiagnosis,improper treatment,and subsequent morbidity and mortality.AIM To determine the clinico-demographic profile,radiological and operative findings,and postoperative course of patients with IH and its association with SBO.METHODS Medical records of 586 patients with features of SBO presenting at a tertiary care centre at Lucknow,India between September 2010 and August 2023 were reviewed.RESULTS Out of 586 patients,7(1.2%)were diagnosed with IH.Among these,4 had congenital IH and 3 had acquired IH.The male-to-female ratio was 4:3.The median age at presentation was 32 years.Contrast-enhanced computed tomography(CECT)was the most reliable investigation for preoperative identification,demonstrating mesenteric whirling and clumped-up bowel loops.Left paraduodenal hernia and transmesenteric hernia occurred with an equal frequency(approximately 43%each).Intraoperatively,one patient was found to have bowel ischemia and one had associated malrotation of gut.During follow-up,no recurrences were reported.CONCLUSION IH,being a rare cause,must be considered as a differential diagnosis for SBO,especially in young patients in their 30s or with unexplained abdominal pain or discomfort post-surgery.A rapid imaging evaluation,preferably with CECT,is necessary to aid in an early diagnosis and prompt intervention,thereby reducing financial burden related to unnecessary investigations and preventing the morbidity and mortality associated with closed-loop obstruction and strangulation of the bowel.
基金supported by the National Natural Science Foundation of China(No.51905123)Major Scientific and Technological Innovation Program of Shandong Province,China(Nos.2020CXGC010303,2022ZLGX04)Key R&D Programme of Shandong Province,China(No.2022JMRH0308).
文摘An internal state variable(ISV)model was established according to the experimental results of hot plane strain compression(PSC)to predict the microstructure evolution during hot spinning of ZK61 alloy.The effects of the internal variables were considered in this ISV model,and the parameters were optimized by genetic algorithm.After validation,the ISV model was used to simulate the evolution of grain size(GS)and dynamic recrystallization(DRX)fraction during hot spinning via Abaqus and its subroutine Vumat.By comparing the simulated results with the experimental results,the application of the ISV model was proven to be reliable.Meanwhile,the strength of the thin-walled spun ZK61 tube increased from 303 to 334 MPa due to grain refinement by DRX and texture strengthening.Besides,some ultrafine grains(0.5μm)that played an important role in mechanical properties were formed due to the proliferation,movement,and entanglement of dislocations during the spinning process.
基金Shenzhen Science and Technology Programme,Grant/Award Number:JCYJ202308071208000012023 Shenzhen sustainable supporting funds for colleges and universities,Grant/Award Number:20231121165240001Guangdong Provincial Key Laboratory of Ultra High Definition Immersive Media Technology,Grant/Award Number:2024B1212010006。
文摘Internal learning-based video inpainting methods have shown promising results by exploiting the intrinsic properties of the video to fill in the missing region without external dataset supervision.However,existing internal learning-based video inpainting methods would produce inconsistent structures or blurry textures due to the insufficient utilisation of motion priors within the video sequence.In this paper,the authors propose a new internal learning-based video inpainting model called appearance consistency and motion coherence network(ACMC-Net),which can not only learn the recurrence of appearance prior but can also capture motion coherence prior to improve the quality of the inpainting results.In ACMC-Net,a transformer-based appearance network is developed to capture global context information within the video frame for representing appearance consistency accurately.Additionally,a novel motion coherence learning scheme is proposed to learn the motion prior in a video sequence effectively.Finally,the learnt internal appearance consistency and motion coherence are implicitly propagated to the missing regions to achieve inpainting well.Extensive experiments conducted on the DAVIS dataset show that the proposed model obtains the superior performance in terms of quantitative measurements and produces more visually plausible results compared with the state-of-the-art methods.
文摘Using real fields instead of complex ones, it was recently claimed, that all fermions are made of pairs of coupled fields (strings) with an internal tension related to mutual attraction forces, related to Planck’s constant. The solution to Dirac equation gives four, real, 2-vectors solutions ψ1=(U1D1)ψ2=(U2D2)ψ3=(U3D3)ψ4=(U4D4)where (ψ1,ψ4) are coupled via linear combinations to yield spin-up and spin-down fermions. Likewise, (ψ2,ψ3) are coupled via linear combinations to represent spin-up and spin-down anti-fermions. Here, a deeper investigation of the free fermion internal frequency is discussed, hinting to an exchange interaction between the two components of which a fermion is made of. An upper limit estimate is given to the strength of this interaction.
文摘BACKGROUND Pain in the back or pelvis or fear of back pain may affect the timing or cocontraction of the core muscles.In both static and dynamic movements,the Sahrmann core stability test provides an assessment of core muscle activation and a person's ability to stabilize the lumbopelvic complex.Preparatory cues and images can be used to increase the activation of these muscles.To attain optimal movement patterns,it will be necessary to determine what cueing will give the most effective results for core stability.AIM To investigate the effects of external and internal cues on core muscle activation during the Sahrmann five-level core stability test.METHODS Total 68 participants(21.83±3.47 years)were randomly allocated to an external(n=35)or internal cue group(n=33).Participants performed the Sahrmann fivelevel core stability test without a cue as baseline and the five-level stability exercises with an internal or external cue.External cue group received a pressure biofeedback unit(PBU),and the internal cue group received an audio cue.A Delsys Trigno^(TM)surface electromyography unit was used for muscle activation from the rectus abdominis,external oblique,and transverse abdominis/internal oblique muscles.RESULTS Linear mixed effects model analysis showed that cueing had a significant effect on core muscle activation(P=0.001);however,there was no significant difference between cue types(internal or external)(P=0.130).CONCLUSION Both external and internal cueing have significant effects on core muscle activation during the Sahrmann five-level core stability test and the PBU does not create higher muscle activation than internal cueing.
文摘The authors(Cai et al.,2022)claim that their proposed machine learning(ML)models,which are based on three typical ML algorithms and are trained to predict the burst capacity of pitting corroded pipelines,perform better than the existing semi-empirical formulas recommended by the international engineering code developers,DNV and ASME.The authors’assessments of the semi-empiri‐cal burst capacity formulas in Figure 10(a)and Table 8(Cai et al.,2022)incorrectly indicate that DNVGL-RP F101,ASME B31G,and modified ASME B31G are dan‐gerously unsafe due to significantly overestimating burst pressures in several cases.In contrast to the results and conclusions in Cai et al.
文摘Objective:To evaluate the effectiveness of the internal limiting membrane(ILM)flipping and covering technique in the treatment of patients with high myopic macular hole(HMMH).Methods:One hundred and two patients with HMMH who were admitted to the hospital from June 2019 to June 2024 were selected.The minimum diameter of the macular hole(MH)in all patients was≤500μm.The patients were randomly divided into two groups.The experimental group received 25G pars plana vitrectomy(PPV)combined with ILM flipping and covering technique,while the reference group received PPV combined with ILM peeling.The efficacy indicators and best corrected visual acuity levels were compared between the two groups.Results:The MH closure rate and retinal reattachment rate were higher in the experimental group than in the reference group at 3 and 6 months postoperatively(P<0.05).The best corrected visual acuity level was higher in the experimental group than in the reference group at 3 and 6 months postoperatively(P<0.05).The Chinese version of the Visual Function-Related Quality of Life Questionnaire-25(CVRQOL-25)score was higher in the experimental group than in the reference group at 3 and 6 months postoperatively(P<0.05).No serious complications were observed in both groups postoperatively,and there was no difference between the two groups(P>0.05).Conclusion:The ILM flipping and covering technique can improve the MH closure rate and retinal reattachment rate in patients with HMMH(diameter≤500μm),enhance the best corrected visual acuity level,and improve the quality of life related to visual function,with fewer postoperative complications.
文摘Objective:This study aimed to examine the developmental trajectories of internalizing behaviors among adolescents and to identify key personal and environmental factors associated with these developmental patterns over time.Methods:Data were collected from 2242 adolescents(49.6%girls,aged 13.9–18.9 years)in South Korea.Latent class growth analysis was used to identify distinct developmental patterns of internalizing behaviors.Multinomial logistic regression analyses were conducted to examine the associations between these developmental patterns and various factors including gender,self-esteem,abuse and neglect experiences,peer relationships,and media use.Results:The analysis revealed three latent classes of internalizing behavior trajectories among adolescents.The first group,the“mid decreasing group”,comprised 54.5%of the sample(1221 students),indicating a moderate level of internalizing behavior that declined over time.The second group,the“high decreasing group”,included 19.1%of the sample(429 students),characterized by initially high levels of internalizing behavior that decreased.The third group,the“low maintained group”,represented 26.4%of the sample(592 students),indicating consistently low levels of internalizing behavior.Factors such as gender,self-esteem,experiences of abuse and neglect,peer relationships(trust and alienation),smartphone dependency,and time spent watching TV/videos were significantly associated with these latent groups.Conclusion:Three distinct developmental patterns of internalizing behaviors were identified among adolescents:mid-decreasing(54.5%),high-decreasing(19.1%),and low-maintained(26.4%).Gender,self-esteem,abuse experiences,and peer relationships were significant predictors of these developmental patterns.
文摘Developing an efficient photocatalyst is the key to realize the practical application of photocatalysis.The S-scheme heterojunction has great potential in photocatalysis due to its unique charge-carrier migration pathway,effective light absorption and high redox capacity.However,further enhancing the built-in electric field of the S-scheme,accelerating carrier separation,and achieving higher photocatalytic performance remain unresolved challenges.Herein,based on the continuously adjustable band structure of continuous solid-solution,a novel 0D/2D all solid-solution S-scheme heterojunction with adjustable internal electric field was designed and fabricated by employing a solid-solution of ZnxCd_(1–x)S and Bi_(2)MoyW_(1–y)O_(6)respectively as reduction and oxidation semiconductors.The synergistic optimization of effective light absorption,fast photogenerated carrier separation,and high redox potential leads can be tuned to promote photocatalytic activity.Under visible light,the S-scheme system constructed by Zn_(0.4)Cd_(0.6)S quantum dot(QDs)and Bi_(2)Mo_(0.2)W_(0.8)O_(6)monolayer exhibits a high rate for photocatalytic degradation C_(2)H_(4)(150.6×10^(–3)min^(–1)),which is 16.5 times higher than that of pure Zn_(0.4)Cd_(0.6)S(9.1×10^(–3)min^(–1))and 53.8 times higher than pure Bi_(2)Mo_(0.2)W_(0.8)O_(6)(2.8×10^(–3)min^(–1)).Due to the unique charge-carrier migration pathway,photo-corrosion of Zn_(x)Cd_(1–x)S is further inhibited simultaneously.In-situ irradiation X-ray photoelectron spectroscopy,photoluminescence spectroscopy,time-resolved photoluminescence,transient absorption spectroscopy and electron paramagnetic resonance provide compelling evidence for interfacial charge transfer via S-scheme pathways,while in-situ diffuse reflectance infrared Fourier transform spectroscopy identifies the reaction pathway for C_(2)H_(4)degradation.This novel S-scheme photocatalysts demonstrates excellent performance and potential for the practical application of the fruits and vegetables preservation at room temperatures.
基金financial support from the National Natural Science Foundation of China(Nos.22271024,21632005)Changzhou University.
文摘Double bonds of internal olefins can be efficiently migrated to the terminal carbons and regioselectively hydroesterified with formates in the presence of Pd(OAc)_(2) and 1,2-DTBPMB under mild reaction conditions,providing a wide variety of corresponding linear carboxylic esters bearing various functional groups in good yields and>20:1 linear/branch ratios.The reaction is optionally simple and does not need to use CO gas and acid co-catalysts.
文摘Migration is a complex demographic phenomenon.Its dynamics can be explained by several factors whose spatial and temporal evolution is not easy to control.That is why this article aims to understand the factors of migration from a spatiotemporal perspective to fill the gaps in the literature.The aim of this article is to analyse the spatiotemporal dynamics of internal migration factors to deduce the zones of origin and destination in Burkina Faso.To do this,several types of data were used.These included secondary,spatial,statistical and survey data.The results of this study show that the influence of internal migration factors is uneven.The spatial distribution of internal migration factors follows a north-south gradient,with favourable conditions in the south.In fact,the northern part is characterised by a large population exodus,with around 42.6%of outgoing internal migrants,and the southern part by a large population influx.This southern part of the country receives around 34.6%of internal migrants.The areas from which migrants depart have unfavourable climatic,environmental,or socio-economic conditions,whereas the areas to which migrants migrate are characterised by favourable conditions for these factors.
基金The Doctor Foundation of Hebei Normal University of Science and Technology under contract No.2024YB039the Fundamental Research Funds for the Provincial Universities of Hebei under contract Nos 2023JK07 and 2022JK03+3 种基金the Major Science and Technology Support Project of Hebei Province under contract No.242S3301Zthe Fujian Provincial Natural Science Foundation of China under contract No.2021J05172the National Natural Science Foundation of China under contract No.42176244the CAS Key Deployment Project of Centre for Ocean Mega-Research of Science under contract No.COMS2020Q07.
文摘We use a high-resolution numerical simulation to analyze the generation and evolution of semidiurnal internal tides in the Weddell-Scotia Confluence.Our results indicate that two ridges near the Antarctic Peninsula,the South Scotia Ridge(SSR)and the Philip Ridge(PR),are energetic sources of semidiurnal internal tides.The strongest semidiurnal barotropic to baroclinic energy conversion occurs around the crest of the SSR,reaching 0.3 W/m^(2).The depthintegrated,tidally averaged semidiurnal internal tide energy fluxes that radiated from the SSR reach about 2 kW/m.The northward semidiurnal internal tide energy fluxes entering the Scotia Sea are stronger than the southward energy fluxes entering the Powell Basin.For the SSR region between the South Orkney Plateau and Elephant Island,the areaintegrated barotropic to baroclinic conversion rate is 0.71 GW,of which 0.56 GW(79%)dissipates locally.The dissipation of internal tides occurs mainly in water depths of less than 1000 m.The dissipation rate over the SSR is as high as 10−7 W/kg.The energy fluxes create an anticlockwise gyre between the SSR and PR.The horizontal kinetic energy and available potential energy oscillate sinusoidally with peaks occurring at quarter-wavelength intervals.This energy pattern suggests the formation of standing waves due to interference between the semidiurnal internal tides originating from the SSR and PR.The results of this study show that internal tides and related mixing need to be considered in the analysis of water mass transformation in the Southern Ocean.
基金supported by Philosophy and Social Sciences Planning Project of Guangdong Province[Grant No.GD24CTS08].
文摘Digital transformation provides enterprises with new development momenta.Understanding the relationship between digital transformation and total factor productivity(TFP)is essential.This study employs a fixedeffect model and selects all Chinese A-share listed companies from 2007 to 2022 as the research sample.Internal control(IC)is introduced as a mechanistic variable.The results indicate that digital transformation significantly promotes both TFP and the effectiveness of IC.Moreover,effective IC plays a significant mediating role in the relationship between digital transformation and TFP.A heterogeneity analysis reveals that,compared to non-state-owned enterprises,state-owned enterprises can improve TFP more rapidly through digital transformation due to their resource advantages and policy support.On the one hand,these findings help enterprises better align their transformation strategies to maximize the benefits of digital transformation.On the other hand,they provide investors with insights into the transformation potential and future growth prospects of these enterprises.
基金National Natural Science Foundation of China(22178228,22378271)are gratefully acknowledged。
文摘The effects of internals on liquid mixing and gas-liquid mass transfer have rarely been investigated in bubble columns,and the commonly used measurement method overestimates significantly overall gas holdup.Firstly,gas holdup measurement method is improved by conducting multi-point liquid level measurement and using net fluid volume instead of bed volume to calculate gas holdup.Then,a stable conductivity method for liquid macromixing has been established by shielding large bubbles using#16nylon mesh.Subsequently,the influences of internal coverage(=12.6%,18.9% and 25.1%) on macroscopic fluid dynamics in a bubble column with a free wall area are systematically investigated.It is found that the presence of internals has a notable effect on macroscopic fluid dynamics.The overall gas holdup and gas-liquid volumetric mass transfer coefficient decrease,and the macromixing time decreases with the increase of internal cross-sectional area coverage.These are mainly caused by the uneven distribution of airflow due to the low resistance in the free wall area.This design makes maintenance easier,but in reality,the reactor performance has decreased.Further improvements will be made to the reactor performance based on such a configuration through flow guidance using baffles.
文摘Internal multiples are commonly present in seismic data due to variations in velocity or density of subsurface media.They can reduce the signal-to-noise ratio of seismic data and degrade the quality of the image.With the development of seismic exploration into deep and ultradeep events,especially those from complex targets in the western region of China,the internal multiple eliminations become increasingly challenging.Currently,three-dimensional(3D)seismic data are primarily used for oil and gas target recognition and drilling.Effectively eliminating internal multiples in 3D seismic data of complex structures and mitigating their adverse effects is crucial for enhancing the success rate of drilling.In this study,we propose an internal multiple prediction algorithm for 3D seismic data in complex structures using the Marchenko autofocusing theory.This method can predict the accurate internal multiples of time difference without an accurate velocity model and the implementation process mainly consists of several steps.Firstly,simulating direct waves with a 3D macroscopic velocity model.Secondly,using direct waves and 3D full seismic acquisition records to obtain the upgoing and down-going Green's functions between the virtual source point and surface.Thirdly,constructing internal multiples of the relevant layers by upgoing and downgoing Green's functions.Finally,utilizing the adaptive matching subtraction method to remove predicted internal multiples from the original data to obtain seismic records without multiples.Compared with the two-dimensional(2D)Marchenko algo-rithm,the performance of the 3D Marchenko algorithm for internal multiple prediction has been significantly enhanced,resulting in higher computational accuracy.Numerical simulation test results indicate that our proposed method can effectively eliminate internal multiples in 3D seismic data,thereby exhibiting important theoretical and industrial application value.
基金supported by the National Natural Science Foundation of China(No.41876015)。
文摘Ocean mixing is a consequence of essential dynamic processes such as internal tides and lee waves that occur near the seafloor topography.Internal tides and lee waves are generated by barotropic tidal currents and geostrophic flows,respectively.Ocean current is composed of multiple flows;thus,internal tides and lee waves occur concurrently in the real ocean.In this paper,the Massachusetts Institute of Technology general circulation model(MITgcm)is used to conduct 2D numerical experiments.By varying background flow intensities,the energy and dissipation relationship between internal tides and lee waves are investigated.The results reveal that the internal tide beams become asymmetric due to the influence of Doppler shift.The lee wave structure gradually leads the wave field when the background flow velocity rises constantly.The presence of a background flow increases the energy portion of the high-mode wave by up to 15%-20%.Moreover,strong shear,owing to the background flow,considerably increases dissipation.When the background flow velocity is higher than the barotropic tidal current velocity,the isopycnal overturn triggered by the lee wave generates a dissipation of the same order of magnitude as the shear.
基金financially supported by the National Natural Science Foundation of China (Grant No. 52201380)Fundamental Research Funds for the Central Universities (Grant No. D5000230080)+2 种基金Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University (Grant Nos. CX 2024049 and CX2023006)the Chunhui Program of Ministry of Education of China (Grant No. HZKY20220538)the Practice and Innovation Funds for Graduate Students of Northwestern Polytechnical University (Grant No. PF2023057)。
文摘Internal solitary waves(ISWs) are a common phenomenon beneath the ocean surface and represent a significant environmental hazard that must be considered for the safe navigation of submersibles. A numerical simulation model for the interaction of solitary waves with submersibles at a large scale has been developed. The Miyata-ChoiCamassa(MCC) equation serves as the basis for generating ISWs. The impacts of the submergence depth, wave amplitude, and advancing velocity on the motion response and load characteristics of the submersible are examined in detail. This study elucidates the governing laws and mechanisms underlying the impact of ISWs on submersibles.The research findings indicate that shorter distances to the undisturbed surface, higher wave amplitudes, and fasteradvancing speeds result in greater effects on submersibles. For a submersible operating in the lower layer, both the alteration in density near the wave interface and the dynamic pressure induced by ISWs can reduce its lift, potentially resulting in a rapid descent. It is imperative to pay considerable attention to the impact of ISWs, as they have the potential to precipitate a loss of control of the submersible.
基金supported by the National Natural Science Foundation of China(Grant no.42176244)CAS Key Deployment Project of Centre for Ocean Mega-Research of Science(Grant no.COMS2020Q07)。
文摘In the Arctic Ocean,turbulent mixing drives vertical heat flux,thereby affecting the sea ice variability.Internal wave is regarded as one of the important energy sources of mixing in this region.The high latitude and sea ice cover make internal wave in the Arctic Ocean apparently differs from that in mid-and low-latitude oceans.However,the internal wave and its underlying mechanism are less understood due to the lack of observations.This paper briefly reviews the recent studies and unresolved questions on the internal wave in the Arctic Ocean,including wind-driven near-inertial wave,internal tide,and high-frequency internal wave.The aim is to provide new insights for in-depth research in the future,with a focus on the mechanisms responsible for the evolution of internal wave under the rapidly changing Arctic climate.
基金supported by the National Key Research and Development Plan of China (Grant No.2023YFB3406302)Guangdong Basic and Applied Basic Research Foundation (Grant No.2024A1515011126)the Key Research and Development Plan of Shanxi (Grant No.2024GH-ZDXM-29)。
文摘Periodic isolator is well known for its wave filtering characteristic.While in middle and high frequencies,the internal resonances of the periodic isolator are evident especially when damping is small.This study proposes a novel aperiodic vibration isolation for improving the internal resonances control of the periodic isolator.The mechanism of the internal resonances control by the aperiodic isolator is firstly explained.For comparing the internal resonances suppression effect of the aperiodic isolator with the periodic isolator,a dynamic model combing the rigid machine,the isolator,and the flexible plate is derived through multi subsystem modeling method and transfer matrix method,whose accuracy is verified through the finite element method.The influences of the aperiodicity and damping of the isolator on the vibration isolation performance and internal resonances suppression effect are investigated by numerical analysis.The numerical results demonstrate that vibration attenuation performances of the periodic isolator and aperiodic isolator are greatly over than that of the continuous isolator in middle and high frequencies.The aperiodic isolator opens the stop bandgaps comparing with the periodic isolator where the pass bandgaps are periodically existed.The damping of the isolator has the stop bandgap widening effect on both the periodic isolator and the aperiodic isolator.In addition,a parameter optimization algorithm of the aperiodic isolator is presented for improving the internal resonances control effect.It is shown that the vibration peaks within the target frequency band of the aperiodic isolator are effectively reduced after the optimization.Finally,the experiments of the three different vibration isolation systems are conducted for verifying the analysis work.
基金supported by the National Natural Science Foundation of China(Grant Nos.42130604)the National Key Research and Development Program of China(Grant No.2023YFF0804704)+2 种基金the National Natural Science Foundation of China(Grant Nos.42105044)Swedish STINT(Grant No.CH2019-8377)the Priority Academic Program Development of Jiangsu Higher Education Institutions(Grant No.164320H116)。
文摘Since the mid-20th century,the Mongolian Plateau(MP)has experienced decadal droughts coupled with extreme heatwaves,severely affecting regional ecology and social development.However,the mechanisms behind these decadalscale compound heatwavedrought events remain debated.Here,using reconstructions and simulations from the Community Earth System Model Last Millennium Ensemble,we demonstrate that,over the last millennium,decadal droughts on the MP occurred under both warm and cold conditions,differing from recent compound heatwavedrought events.We found that by examining temperature changes during these drought periods,the distinct influences of external forcings and internal variability can be simply and effectively distinguished.Specifically,colddry events were primarily driven by volcanic eruptions that weakened the East Asian summer monsoon and midlatitude westerlies,reducing moisture transport to the MP.In contrast,warmdry events were predominantly induced by internal variability,notably the negative phase of the Atlantic Multidecadal Oscillation and the expansion of the Barents Sea ice extent.The recent extreme compound event was probably influenced by the combined effects of anthropogenic forcings and internal variability.These findings deepen our understanding of how external forcings and internal variability affect decadal drought events on the MP and highlight that recent compound events are unprecedented in the context of the last millennium.
