Introduction: Foreign bodies (FB) in the lower airways (LAs) constitute a potentially life-threatening emergency requiring immediate management. The objective of our study was to describe the patient pathway and manag...Introduction: Foreign bodies (FB) in the lower airways (LAs) constitute a potentially life-threatening emergency requiring immediate management. The objective of our study was to describe the patient pathway and management of foreign bodies in the lower airways. Methodology: This was a descriptive study with retrospective data collection conducted over a 6-year period (January 1, 2014, to December 31, 2019) in the ENT and Head and Neck Surgery Department of Donka National Hospital. Results: We observed a prevalence of 1.79%. The average age was 5.71 years, with a sex ratio of 1.2. However, 82.61% of the cases originated from rural areas. We noted that 78.83% of patients were referred after visiting 1 to 2 healthcare facilities (75.36%). The consultation delay was 3 days. Penetration syndrome was present in 98.56% of cases. The foreign body incidents occurred during play in 54.84% and during meals in 29.09% of cases. Radiographs were performed in 93.9% of cases. Endoscopy was used for both diagnostic and therapeutic purposes in all patients. The foreign bodies were located in the trachea (37.68%), larynx (26.08%), and bronchi (21.73%). Non-organic foreign bodies were predominant (52.17%). Postoperative outcomes were uncomplicated in 95.98% of cases, and the lethality rate was 2.85%. Conclusion: The pathway of patients with foreign bodies in the airways remains unpredictable in our context due to parental hesitations. Early management reduces morbidity and mortality rates.展开更多
The growing demand for ocean space has generated significant interest in multi-body floating systems,where gap resonance in confined regions plays a critical role in ensuring the safety of offshore operations.This stu...The growing demand for ocean space has generated significant interest in multi-body floating systems,where gap resonance in confined regions plays a critical role in ensuring the safety of offshore operations.This study develops a numerical tank model using the Smoothed Particle Hydrodynamics(SPH)method,implemented through the open-source code DualSPHysics,to investigate hydrodynamic resonance in a twin-floater system and to examine the influence of internal tank sloshing on its hydrodynamic characteristics.The hydrodynamic behavior of the gap flow between a fixed twin-floater system in the numerical tank is validated through systematic comparison with experimental data.Subsequently,the wave-induced motions and forces on a twin-floater system are compared with those on a single floater.Furthermore,the effects of internal tank sloshing on the hydrodynamic response of the twin-floater system are explored.A parametric study is conducted to analyze the influence of incident wave frequency on floater motion and tank sloshing dynamics.The results show that the presence of an internal tank can significantly reduce pitch motion and vertical forces on the floating body,while exerting minimal influence on heave motion and horizontal forces.The findings provide new insights into the hydrodynamic performance of twin-floater systems and their interaction with internal sloshing phenomena.展开更多
Planetary surfaces,shaped by billions of years of geologic evolution,display numerous impact craters whose distribution of size,density,and spatial arrangement reveals the celestial body's history.Identifying thes...Planetary surfaces,shaped by billions of years of geologic evolution,display numerous impact craters whose distribution of size,density,and spatial arrangement reveals the celestial body's history.Identifying these craters is essential for planetary science and is currently mainly achieved with deep learning-driven detection algorithms.However,because impact crater characteristics are substantially affected by the geologic environment,surface materials,and atmospheric conditions,the performance of deep learning models can be inconsistent between celestial bodies.In this paper,we first examine how the surface characteristics of the Moon,Mars,and Earth,along with the differences in their impact crater features,affect model performance.Then,we compare crater detection across celestial bodies by analyzing enhanced convolutional neural networks and U-shaped Convolutional Neural Network-based models to highlight how geology,data,and model design affect accuracy and generalization.Finally,we address current deep learning challenges,suggest directions for model improvement,such as multimodal data fusion and cross-planet learning and list available impact crater databases.This review can provide necessary technical support for deep space exploration and planetary science,as well as new ideas and directions for future research on automatic detection of impact craters on celestial body surfaces and on planetary geology.展开更多
The long-term stability of CO_(2) storage represents a pivotal challenge in geological CO_(2) storage(CGS),particularly within deep saline aquifers characterized by complex fault-block systems.While the injection site...The long-term stability of CO_(2) storage represents a pivotal challenge in geological CO_(2) storage(CGS),particularly within deep saline aquifers characterized by complex fault-block systems.While the injection sites and rate under different fault structures will directly affect the CO_(2) storage effect and the risk of leakage.This study investigates the Gaoyou Sag in the Subei Basin,a representative fault-block reservoir,through an integrated numerical-experimental approach.A three-dimensional simulation model incorporating multiphase flow dynamics was developed to characterize subsurface CO_(2) transport and dissolution processes.A novel fault seal capacity evaluation framework was proposed,integrating three critical geological indices(fault throw/reservoir thickness/caprock thicknesses)with the coupling of formation physical properties,temperature,and pressure for the rational selection of injection sites and rates.The results show that Optimal storage performance is observed when the fault throw is lower than the reservoir and caprock thicknesses.Furthermore,higher temperature and pressure promote the dissolution and diffusion of CO_(2),while compared to the structural form of faults,the physical properties of faults have a more significant effect on CO_(2) leakage.The larger reservoir space and the presence of an interlayer reduce the risk of CO_(2) leakage,and augmenting storage potential.Decreasing the injection rate increases the proportion of dissolved CO_(2),thereby enhancing the safety of CO_(2) storage.展开更多
In 2005, the classical intersection bodies and L_p intersection bodies were extended. Afterwards, the concept of gen-eral L_p intersection bodies and the generalized intersection bodies was introduced. In this paper, ...In 2005, the classical intersection bodies and L_p intersection bodies were extended. Afterwards, the concept of gen-eral L_p intersection bodies and the generalized intersection bodies was introduced. In this paper, we define the generalized bodies with parameter. Besides, we establish the extremal values for volume, Brunn-Minkowski type inequality for radial combination and L_p harmonic Blaschke combination of this notion.展开更多
The boundary identification and quantitative thickness prediction of channel sand bodies are always difficult in seismic exploration.We present a new method for boundary identification and quantitative thickness predi...The boundary identification and quantitative thickness prediction of channel sand bodies are always difficult in seismic exploration.We present a new method for boundary identification and quantitative thickness prediction of channel sand bodies based on seismic peak attributes in the frequency domain.Using seismic forward modeling of a typical thin channel sand body,a new seismic attribute-the ratio of peak frequency to amplitude was constructed.Theoretical study demonstrated that seismic peak frequency is sensitive to the thickness of the channel sand bodies,while the amplitude attribute is sensitive to the strata lithology.The ratio of the two attributes can highlight the boundaries of the channel sand body.Moreover,the thickness of the thin channel sand bodies can be determined using the relationship between seismic peak frequency and thin layer thickness.Practical applications have demonstrated that the seismic peak frequency attribute can depict the horizontal distribution characteristics of channels very well.The ratio of peak frequency to amplitude attribute can improve the identification ability of channel sand body boundaries.Quantitative prediction and boundary identification of channel sand bodies with seismic peak attributes in the frequency domain are feasible.展开更多
BACKGROUND Gastrointestinal foreign bodies represent a significant clinical challenge in em-ergency and surgical settings.While accidental ingestion predominates in healthy adults,intentional ingestion is frequently o...BACKGROUND Gastrointestinal foreign bodies represent a significant clinical challenge in em-ergency and surgical settings.While accidental ingestion predominates in healthy adults,intentional ingestion is frequently observed in pediatric,psychiatric,and incarcerated populations.Metallic sewing needles,characterized by their sharp morphology and high mobility,pose particular risks of visceral injury and com-plications due to their penetrative potential.Although preoperative imaging facilitates initial localization,subsequent migration of multiple needles com-plicates therapeutic interventions,increasing procedural complexity and patient risk.CASE SUMMARY We present a novel application of magnetic-assisted localization in managing a complex case of intentional ingestion of 30 metallic sewing needles in a psy-chiatric patient.The widespread distribution of needles throughout the gas-trointestinal tract necessitated an innovative surgical approach.Intraoperative implementation of cylindrical magnetic localization technology enabled precise identification and successful extraction of all foreign bodies while minimizing tissue trauma.CONCLUSION Magnetic-assisted localization represents an effective and safe technique to manage multiple magnetic gastrointestinal foreign bodies.This approach offers significant advantages in complex cases,particularly for needle-like metallic objects,and warrants consideration as a valuable tool in gastrointestinal surgery.展开更多
We show that the volume of the projection bodyΠ(Z)of an n-dimensional zonotope Z with n+1 generators and of volume 1 is always exactly 2^(n).Moroever,we point out that an upper bound on the volume ofΠ(K)of a central...We show that the volume of the projection bodyΠ(Z)of an n-dimensional zonotope Z with n+1 generators and of volume 1 is always exactly 2^(n).Moroever,we point out that an upper bound on the volume ofΠ(K)of a centrally symmetric n-dimensional convex body of volume 1 is at least 2^(n)(9/8)^([n/3]).展开更多
BACKGROUND Acute abdominal pain is often easy to be diagnosed because of acute abdomen,and can be treated reasonably and effectively.It is more difficult to establish the cause of chronic abdominal pain,and some patie...BACKGROUND Acute abdominal pain is often easy to be diagnosed because of acute abdomen,and can be treated reasonably and effectively.It is more difficult to establish the cause of chronic abdominal pain,and some patients repeatedly visit several hos-pitals and still cannot be diagnosed.Chronic abdominal pain caused by chronic appendicitis is such a case.If the degree of abdominal pain is mild and there is no sign of peritonitis,chronic appendicitis is not performed unless the patient re-quests it.CASE SUMMARY We report an extremely rare case of chronic appendicitis caused by a foreign body in the appendix in a 35-year-old woman.The patient had a long-term abdominal pain of unclear cause,and she was repeatedly treated in several hospitals.After antibiotic treatment,the abdominal pain was gradually relieved,but abdominal pain often recurs.We conducted abdominal computed tomography examination,and upon the advice of radiologists,we considered the possibility of foreign bodies in the appendix,and excluded other causes of abdominal pain.The patient requested and consented to laparoscopic appendectomy,and a chicken bone was found in the appendiceal cavity by postoperative incision of the appendiceal spe-cimen.Histopathological examination confirmed chronic appendicitis with fo-reign body giant cell reaction.The patient recovered and was discharged from the hospital.After 2 months of follow-up,abdominal pain did not recur,and the patient had a complete recovery.Core Tip:We report an extremely rare case of chronic appendicitis caused by a chicken bone in the appendix.The patient was 35-year-old woman,and had a long-term abdominal pain of unknown cause.Abdominal computed tomography examination suggested foreign bodies in the appendix,and laparoscopic appendectomy was performed.The postoperative specimen revealed chicken bones in the appendix cavity,and histopathological examination confirmed chronic appendicitis with giant cell reaction of foreign bodies.The patient recovered and was followed up for two months without abdominal pain.Citation:Huang T,Li SK,Wang W,Zhang R.Chronic abdominal pain caused by foreign bodies in the appendix:A case report.World INTRODUCTION Appendicitis is one of the common diseases that cause abdominal pain[1].Appendicitis can be diagnosed and treated effectively when patients with acute abdominal pain are admitted to hospital because of factors such as blockage and infection of appendicitis[2,3].However,the diagnosis of chronic appendicitis is difficult.Acute appendicitis caused by foreign bodies in the appendix is easy to diagnose because of the final surgical treatment[4-6],while chronic appendicitis caused by foreign bodies in the appendix is more difficult to diagnose because of the mild degree of abdominal pain.We here report an extremely rare case of chronic appendicitis caused by foreign bodies in the appendix.The patient had a long-term abdominal pain of unclear cause,and she was repeatedly treated in several hospitals.Abdominal color ultrasound examination indicated a coprolith in the appendiceal cavity and the appendix was normal,so the patient could not be treated with surgery.We conducted abdominal computed tomography(CT)examination,and upon the advice of radiologists,we considered the possibility of foreign bodies in the appendix,and excluded other causes of abdominal pain.The patient requested and consented to laparoscopic appendectomy,and a chicken bone was found in the appendiceal cavity by postoperative incision of the appendiceal specimen.The patient recovered and was discharged from hospital.After 2 months of follow-up,abdominal pain did not recur and the patient had a full recovery.展开更多
The presentation of a foreign body in the lower urinary tract is a challenging urological emergency with highly variable management approaches.A retrospective cohort study was undertaken to identify the patients who p...The presentation of a foreign body in the lower urinary tract is a challenging urological emergency with highly variable management approaches.A retrospective cohort study was undertaken to identify the patients who presented with selfinserted genitourethral foreign body to adult tertiary centers within our local health network(Southern Adelaide Local Health Network,Adelaide,Australia)from October 2002 to October 2022.Patient demographics,type of foreign body,psychiatric comorbidities,retrieval techniques,complications,and readmission data were extracted.Twenty-seven cases were identified with a median age of 44 years.Twenty-three(85.2%)were male and 4(14.8%)were female.Ten patients(37.0%)had a concurrent psychiatric illness.The most commonly inserted foreign bodies were plastic tubes/wires(29.6%).Twenty cases(74.1%)were retrieved endoscopically.Three patients(11.1%)required open cystotomy and one underwent a transperineal urethrotomy.Four patients(14.8%)represented after discharge.Two patients had repeat presentations for genitourinary foreign body insertion.A significant monotonic positive trend of foreign body presentations was identified(Mann–Kendall tau=0.95,P=0.043).Presentations of genitourethral foreign body insertions have trended upward over the past two decades.However,most cases were successfully managed endoscopically.展开更多
The study on sand body connectivity and distribution patterns is of great significance for well emplacement and injection-production pattern analysis in the A oilfield of the Weixi?nan Sag currently at a pre-developme...The study on sand body connectivity and distribution patterns is of great significance for well emplacement and injection-production pattern analysis in the A oilfield of the Weixi?nan Sag currently at a pre-development stage.Based on the current drilling data,seismic data,and fault development characteristics,this study investigates the connectivity,geometric morphology,planar distribution,and vertical evolution of composite sand bodies(multi-stage superimposed channel sand bodies)within the fault block using seismic forward and inversion modeling.The El3I oil layer group in the third member of the Liushagang Formation is developed in the fan delta-front sub-facies,which mainly consists of subaqueous distributary channels.The thickness of single-stage subaqueous distributary channel sand bodies ranges from 2 to 6 m,and the width of composite channel sand bodies varies from 50 to 100 m.Under the long-term transgression background,the subaqueous distributary channels in the El3I oil layer group are relatively narrow,forming superimposed and continuous composite channel sand bodies through lateral migration and vertical stacking.The long-term base-level cycles control the width of subaqueous distributary channels,while the mid-term base-level cycles control the thickness of these channels.The subaqueous distributary channels developed during the late stage of mid-term base-level fall are thicker than those formed during the early stage.Accordingly,quantitative relationships between channel thickness and width are established for the early and late stages of mid-term base-level fall,to finely depict the evolution patterns of channel sand body geometry and stacking styles across different stages.These findings provide important guidance for accurately predicting the planar distribution and channel width of composite subaqueous distributary channels at different stages of the mid-term baselevel cycles.展开更多
In this article,we explain how the famous Archimedes’principle of flotation can be used to construct various floating bodies.We survey some of the most important results regarding the floating bodies,including their ...In this article,we explain how the famous Archimedes’principle of flotation can be used to construct various floating bodies.We survey some of the most important results regarding the floating bodies,including their relations with affine surface area and projection body,their extensions in different settings such as space forms and log-concave functions,and mention some associated open problems.展开更多
In 1694,Gregory and Newton proposed the problem to determine the kissing number of a rigid material ball.This problem and its higher dimensional generalization have been studied by many mathematicians,including Minkow...In 1694,Gregory and Newton proposed the problem to determine the kissing number of a rigid material ball.This problem and its higher dimensional generalization have been studied by many mathematicians,including Minkowski,van der Waerden,Hadwiger,Swinnerton-Dyer,Watson,Levenshtein,Odlyzko,Sloane and Musin.In this paper,we introduce and study a further generalization of the kissing numbers for convex bodies and obtain some exact results,in particular for balls in dimensions three,four and eight.展开更多
In this paper,the definition of the general L p-mixed projection bodies is introduced,and the general L p-projection bodies given by Ludwig is a special case for the general L p-mixed projection bodies.Then the Petty ...In this paper,the definition of the general L p-mixed projection bodies is introduced,and the general L p-projection bodies given by Ludwig is a special case for the general L p-mixed projection bodies.Then the Petty projection inequality for the general L p-mixed projection bodies is shown.Moreover,the monotonicity for the general L p-mixed projection bodies is obtained.展开更多
Zhu,Lü and Leng extended the concept of L_p-polar curvature image. We continuously study the L_p-polar curvature image and mainly expound the relations between the volumes of star bodies and their L_p-polar curva...Zhu,Lü and Leng extended the concept of L_p-polar curvature image. We continuously study the L_p-polar curvature image and mainly expound the relations between the volumes of star bodies and their L_p-polar curvature images in this article. We first establish the L_p-affine isoperimetric inequality associated with L_p-polar curvature image. Secondly,we give a monotonic property for L_p-polar curvature image. Finally, we obtain an interesting equation related to L_p-projection body of L_p-polar curvature image and L_p-centroid body.展开更多
The effect of resonance on the motion of two cylindrical rigid bodies has been studied in the light of Bhatnagar [1] [2] [3] and under some defined axiomatic restrictions. Here we have calculated variation in Eulerian...The effect of resonance on the motion of two cylindrical rigid bodies has been studied in the light of Bhatnagar [1] [2] [3] and under some defined axiomatic restrictions. Here we have calculated variation in Eulerian angles due to resonance in terms of orbital elements and unperturbed Eulerian angles.展开更多
To make a geologic body more outstanding, it is necessary to preserve edges when filtering. For this reason, a filtering method based on anisotropic diffusion is introduced. The key point of this method is that diffus...To make a geologic body more outstanding, it is necessary to preserve edges when filtering. For this reason, a filtering method based on anisotropic diffusion is introduced. The key point of this method is that diffusion filtering will be made along the edge while diffusion is forbidden in the direction perpendicular to the edge, so the filtering has directionality. When doing anisotropic diffusion filtering, parameters like diffusion coefficient and threshold have great impacts on the results, so the anisotropic diffusion model parameters are discussed, the diffusion coefficient equation is introduced, and the diffusion threshold selection criterion is derived and analyzed. In addition, this method was used with the diffusion coefficient equation＇s proper diffusion threshold to highlight the tidal channel geobodies in the XX area, sand body in the YY area, and faults in the ZZ area. The good delineation results prove that the diffusion threshold selection criterion introduced in this paper is reasonable.展开更多
Deep-water turbidite channels have attracted much attention as a focused issue in petroleum exploration and development. Extensive studies have been performed on the architecture of turbidite channels, and most resear...Deep-water turbidite channels have attracted much attention as a focused issue in petroleum exploration and development. Extensive studies have been performed on the architecture of turbidite channels, and most researches have focused on their geometric shapes, sedimentary processes and controlling factors. However, little attention has been paid to the distribution patterns, distribution laws and quantitative studies of composite sand bodies of turbidite channels. Taken one slope area of the Niger Delta Basin as an example, this study conducted a semi-quantitative to quantitative analysis on architecture of composite sand bodies of turbidite channels based on cores, well logging and seismic surveys. It is shown that turbidite channel systems can be classified as confined and unconfined channel systems. For confined channel systems, the vertical evolution process involves four stages. The sinuosity of a channel system is controlled by slope, with a negative power function relationship between them. When slope gradient reaches four degrees, the channel system is nearly straight. Based on the migration direction and migration amount of single channels within channel complexes, channel composite patterns can be divided into four classes（the lateral composite, en-echelon composite, swing composite and vertical composite） and several subclasses. Various channel composite patterns show specific distribution laws spatially. For meandering channel complexes at the middle-late evolution stage of confined channel systems, the lateral migration amongst single channels shows the features of integrity and succession. The sinuosity of single channels in the late period is greater than that in the early period, and cut-offs may occur locally when the sinuosity is larger than five degrees. This study provides a better understanding for the geological theory of deep-water sedimentary, and also improves exploitation benefits of this type of reservoirs.展开更多
The structural characteristics of protein body accumulation in different endosperm regions of hard wheat cultivar （XM33） and soft wheat cultivar （NM13） under drought stress were investigated. Drought stress treatm...The structural characteristics of protein body accumulation in different endosperm regions of hard wheat cultivar （XM33） and soft wheat cultivar （NM13） under drought stress were investigated. Drought stress treatment was implemented from plant regreening to the caryopsis mature stage. Microscope images of endosperm cells were obtained using resin semi- thin slice technology to observe the distribution and relative area of protein body （PB）. Compared with NM13, relative PB area of XM33 was significantly higher in sub-aleurone endosperm region. The amount of accumulation, including the size and relative area of PB, in two wheat cultivars was higher in sub-aleurone region than that in central region at 18 days post anthesis （DPA）. Drought stress significantly enhanced the sizes and relative areas of PBs in the dorsal and abdominal endosperms in two wheat cultivars. Particularly for dorsal endosperm, drought stress enhanced the relative PB area at 18 DPA and NM13 （5.0% vs. 6.73%） showed less enhancement than XM33 （5.49% vs. 8.96%）. However, NM13 （9.58% vs. 12.02%） showed greater enhancement than XM33 （10.25% vs. 11.7%） at 28 DPA. The protein content in the dorsal and abdominal endosperms of the two wheat cultivars decreased at 12 DPA and then increased until 38 DPA. Drought stress significantly increased the protein contents in the two main regions. From 12 to 38 DPA, the amount of PB accumulation and the protein content were higher in XM33 than those in NM13. The results revealed that PB distribution varied in different endosperm tissues and that the amount of PB accumulation was remarkably augmented by drought stress.展开更多
Based on the data of field measurement and drilling in the Tongling area, a series of numerical simulations are carried out by using the 'Surplus Space Method' (SSM), which is first put forward in this paper a...Based on the data of field measurement and drilling in the Tongling area, a series of numerical simulations are carried out by using the 'Surplus Space Method' (SSM), which is first put forward in this paper and applied to predict the shallow-seated magmatic bodies. The results of the numerical simulations show the existence and the 3-D shape of a conical magmatic structure at a depth of-1000 m beneath the center of the area: its top offsets southwards and bifurcates to several branches, while its lower part stretches northeastwards and contracts rapidly to a point at about -1000 m depth. This point is reckoned to be a 'sink' of magma system, transferring ore materials and heat energy from the deep magma chamber to the sub-surface apophyses. The preliminary application of the SSM proves that it may be developed as a new detection means for determining the existence of shallow-seated magmatic bodies and analyzing their three-dimensional features.展开更多
文摘Introduction: Foreign bodies (FB) in the lower airways (LAs) constitute a potentially life-threatening emergency requiring immediate management. The objective of our study was to describe the patient pathway and management of foreign bodies in the lower airways. Methodology: This was a descriptive study with retrospective data collection conducted over a 6-year period (January 1, 2014, to December 31, 2019) in the ENT and Head and Neck Surgery Department of Donka National Hospital. Results: We observed a prevalence of 1.79%. The average age was 5.71 years, with a sex ratio of 1.2. However, 82.61% of the cases originated from rural areas. We noted that 78.83% of patients were referred after visiting 1 to 2 healthcare facilities (75.36%). The consultation delay was 3 days. Penetration syndrome was present in 98.56% of cases. The foreign body incidents occurred during play in 54.84% and during meals in 29.09% of cases. Radiographs were performed in 93.9% of cases. Endoscopy was used for both diagnostic and therapeutic purposes in all patients. The foreign bodies were located in the trachea (37.68%), larynx (26.08%), and bronchi (21.73%). Non-organic foreign bodies were predominant (52.17%). Postoperative outcomes were uncomplicated in 95.98% of cases, and the lethality rate was 2.85%. Conclusion: The pathway of patients with foreign bodies in the airways remains unpredictable in our context due to parental hesitations. Early management reduces morbidity and mortality rates.
基金supported by the National Natural Science Foundation of China(Nos.52271316 and 12302314)the Science and Technology Project in Guangzhou(No.2024A04J9886).
文摘The growing demand for ocean space has generated significant interest in multi-body floating systems,where gap resonance in confined regions plays a critical role in ensuring the safety of offshore operations.This study develops a numerical tank model using the Smoothed Particle Hydrodynamics(SPH)method,implemented through the open-source code DualSPHysics,to investigate hydrodynamic resonance in a twin-floater system and to examine the influence of internal tank sloshing on its hydrodynamic characteristics.The hydrodynamic behavior of the gap flow between a fixed twin-floater system in the numerical tank is validated through systematic comparison with experimental data.Subsequently,the wave-induced motions and forces on a twin-floater system are compared with those on a single floater.Furthermore,the effects of internal tank sloshing on the hydrodynamic response of the twin-floater system are explored.A parametric study is conducted to analyze the influence of incident wave frequency on floater motion and tank sloshing dynamics.The results show that the presence of an internal tank can significantly reduce pitch motion and vertical forces on the floating body,while exerting minimal influence on heave motion and horizontal forces.The findings provide new insights into the hydrodynamic performance of twin-floater systems and their interaction with internal sloshing phenomena.
基金funded by the National Natural Science Foundation of China(12363009 and 12103020)Natural Science Foundation of Jiangxi Province(20224BAB211011)+1 种基金Youth Talent Project of Science and Technology Plan of Ganzhou(2022CXRC9191 and 2023CYZ26970)Jiangxi Province Graduate Innovation Special Funds Project(YC2024-S529 and YC2023-S672).
文摘Planetary surfaces,shaped by billions of years of geologic evolution,display numerous impact craters whose distribution of size,density,and spatial arrangement reveals the celestial body's history.Identifying these craters is essential for planetary science and is currently mainly achieved with deep learning-driven detection algorithms.However,because impact crater characteristics are substantially affected by the geologic environment,surface materials,and atmospheric conditions,the performance of deep learning models can be inconsistent between celestial bodies.In this paper,we first examine how the surface characteristics of the Moon,Mars,and Earth,along with the differences in their impact crater features,affect model performance.Then,we compare crater detection across celestial bodies by analyzing enhanced convolutional neural networks and U-shaped Convolutional Neural Network-based models to highlight how geology,data,and model design affect accuracy and generalization.Finally,we address current deep learning challenges,suggest directions for model improvement,such as multimodal data fusion and cross-planet learning and list available impact crater databases.This review can provide necessary technical support for deep space exploration and planetary science,as well as new ideas and directions for future research on automatic detection of impact craters on celestial body surfaces and on planetary geology.
基金the Beijing Natural Science Foundation(No.8232044)the Science Foundation of China University of Petroleum,Beijing(No.2462023BJRC030).
文摘The long-term stability of CO_(2) storage represents a pivotal challenge in geological CO_(2) storage(CGS),particularly within deep saline aquifers characterized by complex fault-block systems.While the injection sites and rate under different fault structures will directly affect the CO_(2) storage effect and the risk of leakage.This study investigates the Gaoyou Sag in the Subei Basin,a representative fault-block reservoir,through an integrated numerical-experimental approach.A three-dimensional simulation model incorporating multiphase flow dynamics was developed to characterize subsurface CO_(2) transport and dissolution processes.A novel fault seal capacity evaluation framework was proposed,integrating three critical geological indices(fault throw/reservoir thickness/caprock thicknesses)with the coupling of formation physical properties,temperature,and pressure for the rational selection of injection sites and rates.The results show that Optimal storage performance is observed when the fault throw is lower than the reservoir and caprock thicknesses.Furthermore,higher temperature and pressure promote the dissolution and diffusion of CO_(2),while compared to the structural form of faults,the physical properties of faults have a more significant effect on CO_(2) leakage.The larger reservoir space and the presence of an interlayer reduce the risk of CO_(2) leakage,and augmenting storage potential.Decreasing the injection rate increases the proportion of dissolved CO_(2),thereby enhancing the safety of CO_(2) storage.
基金Supported by the National Natural Science Foundation of China(11561020,11161019)
文摘In 2005, the classical intersection bodies and L_p intersection bodies were extended. Afterwards, the concept of gen-eral L_p intersection bodies and the generalized intersection bodies was introduced. In this paper, we define the generalized bodies with parameter. Besides, we establish the extremal values for volume, Brunn-Minkowski type inequality for radial combination and L_p harmonic Blaschke combination of this notion.
基金supported by National Key Science and Technology Special Projects (Grant No.2008ZX05000-004)CNPC Key S and T Special Projects (Grant No.2008E-0610-10)
文摘The boundary identification and quantitative thickness prediction of channel sand bodies are always difficult in seismic exploration.We present a new method for boundary identification and quantitative thickness prediction of channel sand bodies based on seismic peak attributes in the frequency domain.Using seismic forward modeling of a typical thin channel sand body,a new seismic attribute-the ratio of peak frequency to amplitude was constructed.Theoretical study demonstrated that seismic peak frequency is sensitive to the thickness of the channel sand bodies,while the amplitude attribute is sensitive to the strata lithology.The ratio of the two attributes can highlight the boundaries of the channel sand body.Moreover,the thickness of the thin channel sand bodies can be determined using the relationship between seismic peak frequency and thin layer thickness.Practical applications have demonstrated that the seismic peak frequency attribute can depict the horizontal distribution characteristics of channels very well.The ratio of peak frequency to amplitude attribute can improve the identification ability of channel sand body boundaries.Quantitative prediction and boundary identification of channel sand bodies with seismic peak attributes in the frequency domain are feasible.
基金Supported by National Natural Science Foundation of China,No.82170676the Natural Science Foundation of Shaanxi Provincial Key Industries Innovation Chain(Cluster)-Social Development Project,No.2020ZDLSF02-03+1 种基金the Key Project of Shaanxi Province's 14th Five-Year Education Science Planning:Research on the Training Model for Top-notch Innovative Talents in Higher Education Institutions of Shaanxi Province,No.SGH24Z16the Xi'an Talents Plan Project,No.XAYC210064.
文摘BACKGROUND Gastrointestinal foreign bodies represent a significant clinical challenge in em-ergency and surgical settings.While accidental ingestion predominates in healthy adults,intentional ingestion is frequently observed in pediatric,psychiatric,and incarcerated populations.Metallic sewing needles,characterized by their sharp morphology and high mobility,pose particular risks of visceral injury and com-plications due to their penetrative potential.Although preoperative imaging facilitates initial localization,subsequent migration of multiple needles com-plicates therapeutic interventions,increasing procedural complexity and patient risk.CASE SUMMARY We present a novel application of magnetic-assisted localization in managing a complex case of intentional ingestion of 30 metallic sewing needles in a psy-chiatric patient.The widespread distribution of needles throughout the gas-trointestinal tract necessitated an innovative surgical approach.Intraoperative implementation of cylindrical magnetic localization technology enabled precise identification and successful extraction of all foreign bodies while minimizing tissue trauma.CONCLUSION Magnetic-assisted localization represents an effective and safe technique to manage multiple magnetic gastrointestinal foreign bodies.This approach offers significant advantages in complex cases,particularly for needle-like metallic objects,and warrants consideration as a valuable tool in gastrointestinal surgery.
文摘We show that the volume of the projection bodyΠ(Z)of an n-dimensional zonotope Z with n+1 generators and of volume 1 is always exactly 2^(n).Moroever,we point out that an upper bound on the volume ofΠ(K)of a centrally symmetric n-dimensional convex body of volume 1 is at least 2^(n)(9/8)^([n/3]).
文摘BACKGROUND Acute abdominal pain is often easy to be diagnosed because of acute abdomen,and can be treated reasonably and effectively.It is more difficult to establish the cause of chronic abdominal pain,and some patients repeatedly visit several hos-pitals and still cannot be diagnosed.Chronic abdominal pain caused by chronic appendicitis is such a case.If the degree of abdominal pain is mild and there is no sign of peritonitis,chronic appendicitis is not performed unless the patient re-quests it.CASE SUMMARY We report an extremely rare case of chronic appendicitis caused by a foreign body in the appendix in a 35-year-old woman.The patient had a long-term abdominal pain of unclear cause,and she was repeatedly treated in several hospitals.After antibiotic treatment,the abdominal pain was gradually relieved,but abdominal pain often recurs.We conducted abdominal computed tomography examination,and upon the advice of radiologists,we considered the possibility of foreign bodies in the appendix,and excluded other causes of abdominal pain.The patient requested and consented to laparoscopic appendectomy,and a chicken bone was found in the appendiceal cavity by postoperative incision of the appendiceal spe-cimen.Histopathological examination confirmed chronic appendicitis with fo-reign body giant cell reaction.The patient recovered and was discharged from the hospital.After 2 months of follow-up,abdominal pain did not recur,and the patient had a complete recovery.Core Tip:We report an extremely rare case of chronic appendicitis caused by a chicken bone in the appendix.The patient was 35-year-old woman,and had a long-term abdominal pain of unknown cause.Abdominal computed tomography examination suggested foreign bodies in the appendix,and laparoscopic appendectomy was performed.The postoperative specimen revealed chicken bones in the appendix cavity,and histopathological examination confirmed chronic appendicitis with giant cell reaction of foreign bodies.The patient recovered and was followed up for two months without abdominal pain.Citation:Huang T,Li SK,Wang W,Zhang R.Chronic abdominal pain caused by foreign bodies in the appendix:A case report.World INTRODUCTION Appendicitis is one of the common diseases that cause abdominal pain[1].Appendicitis can be diagnosed and treated effectively when patients with acute abdominal pain are admitted to hospital because of factors such as blockage and infection of appendicitis[2,3].However,the diagnosis of chronic appendicitis is difficult.Acute appendicitis caused by foreign bodies in the appendix is easy to diagnose because of the final surgical treatment[4-6],while chronic appendicitis caused by foreign bodies in the appendix is more difficult to diagnose because of the mild degree of abdominal pain.We here report an extremely rare case of chronic appendicitis caused by foreign bodies in the appendix.The patient had a long-term abdominal pain of unclear cause,and she was repeatedly treated in several hospitals.Abdominal color ultrasound examination indicated a coprolith in the appendiceal cavity and the appendix was normal,so the patient could not be treated with surgery.We conducted abdominal computed tomography(CT)examination,and upon the advice of radiologists,we considered the possibility of foreign bodies in the appendix,and excluded other causes of abdominal pain.The patient requested and consented to laparoscopic appendectomy,and a chicken bone was found in the appendiceal cavity by postoperative incision of the appendiceal specimen.The patient recovered and was discharged from hospital.After 2 months of follow-up,abdominal pain did not recur and the patient had a full recovery.
文摘The presentation of a foreign body in the lower urinary tract is a challenging urological emergency with highly variable management approaches.A retrospective cohort study was undertaken to identify the patients who presented with selfinserted genitourethral foreign body to adult tertiary centers within our local health network(Southern Adelaide Local Health Network,Adelaide,Australia)from October 2002 to October 2022.Patient demographics,type of foreign body,psychiatric comorbidities,retrieval techniques,complications,and readmission data were extracted.Twenty-seven cases were identified with a median age of 44 years.Twenty-three(85.2%)were male and 4(14.8%)were female.Ten patients(37.0%)had a concurrent psychiatric illness.The most commonly inserted foreign bodies were plastic tubes/wires(29.6%).Twenty cases(74.1%)were retrieved endoscopically.Three patients(11.1%)required open cystotomy and one underwent a transperineal urethrotomy.Four patients(14.8%)represented after discharge.Two patients had repeat presentations for genitourinary foreign body insertion.A significant monotonic positive trend of foreign body presentations was identified(Mann–Kendall tau=0.95,P=0.043).Presentations of genitourethral foreign body insertions have trended upward over the past two decades.However,most cases were successfully managed endoscopically.
文摘The study on sand body connectivity and distribution patterns is of great significance for well emplacement and injection-production pattern analysis in the A oilfield of the Weixi?nan Sag currently at a pre-development stage.Based on the current drilling data,seismic data,and fault development characteristics,this study investigates the connectivity,geometric morphology,planar distribution,and vertical evolution of composite sand bodies(multi-stage superimposed channel sand bodies)within the fault block using seismic forward and inversion modeling.The El3I oil layer group in the third member of the Liushagang Formation is developed in the fan delta-front sub-facies,which mainly consists of subaqueous distributary channels.The thickness of single-stage subaqueous distributary channel sand bodies ranges from 2 to 6 m,and the width of composite channel sand bodies varies from 50 to 100 m.Under the long-term transgression background,the subaqueous distributary channels in the El3I oil layer group are relatively narrow,forming superimposed and continuous composite channel sand bodies through lateral migration and vertical stacking.The long-term base-level cycles control the width of subaqueous distributary channels,while the mid-term base-level cycles control the thickness of these channels.The subaqueous distributary channels developed during the late stage of mid-term base-level fall are thicker than those formed during the early stage.Accordingly,quantitative relationships between channel thickness and width are established for the early and late stages of mid-term base-level fall,to finely depict the evolution patterns of channel sand body geometry and stacking styles across different stages.These findings provide important guidance for accurately predicting the planar distribution and channel width of composite subaqueous distributary channels at different stages of the mid-term baselevel cycles.
基金supported by the Research Funding of Wuhan Polytechnic University(2024RZ083)Elisabeth M.Werner’s work was supported by the NSF grant DMS-2103482.Deping Ye’s work was supported by an NSERC grant,Canada.Ning Zhang’s work was supported by the NSF of China(11901217,11971005).
文摘In this article,we explain how the famous Archimedes’principle of flotation can be used to construct various floating bodies.We survey some of the most important results regarding the floating bodies,including their relations with affine surface area and projection body,their extensions in different settings such as space forms and log-concave functions,and mention some associated open problems.
基金supported by the National Natural Science Foundation of China(12226006,11921001)the Natural Key Research and Development Program of China(2018YFA0704701).
文摘In 1694,Gregory and Newton proposed the problem to determine the kissing number of a rigid material ball.This problem and its higher dimensional generalization have been studied by many mathematicians,including Minkowski,van der Waerden,Hadwiger,Swinnerton-Dyer,Watson,Levenshtein,Odlyzko,Sloane and Musin.In this paper,we introduce and study a further generalization of the kissing numbers for convex bodies and obtain some exact results,in particular for balls in dimensions three,four and eight.
文摘In this paper,the definition of the general L p-mixed projection bodies is introduced,and the general L p-projection bodies given by Ludwig is a special case for the general L p-mixed projection bodies.Then the Petty projection inequality for the general L p-mixed projection bodies is shown.Moreover,the monotonicity for the general L p-mixed projection bodies is obtained.
基金Supported by the National Natural Science Foundation of China(11161019)
文摘Zhu,Lü and Leng extended the concept of L_p-polar curvature image. We continuously study the L_p-polar curvature image and mainly expound the relations between the volumes of star bodies and their L_p-polar curvature images in this article. We first establish the L_p-affine isoperimetric inequality associated with L_p-polar curvature image. Secondly,we give a monotonic property for L_p-polar curvature image. Finally, we obtain an interesting equation related to L_p-projection body of L_p-polar curvature image and L_p-centroid body.
文摘The effect of resonance on the motion of two cylindrical rigid bodies has been studied in the light of Bhatnagar [1] [2] [3] and under some defined axiomatic restrictions. Here we have calculated variation in Eulerian angles due to resonance in terms of orbital elements and unperturbed Eulerian angles.
基金sponsored by National Natural Science Foundation of china (Grant Nos. 40904034 and 41174115)
文摘To make a geologic body more outstanding, it is necessary to preserve edges when filtering. For this reason, a filtering method based on anisotropic diffusion is introduced. The key point of this method is that diffusion filtering will be made along the edge while diffusion is forbidden in the direction perpendicular to the edge, so the filtering has directionality. When doing anisotropic diffusion filtering, parameters like diffusion coefficient and threshold have great impacts on the results, so the anisotropic diffusion model parameters are discussed, the diffusion coefficient equation is introduced, and the diffusion threshold selection criterion is derived and analyzed. In addition, this method was used with the diffusion coefficient equation＇s proper diffusion threshold to highlight the tidal channel geobodies in the XX area, sand body in the YY area, and faults in the ZZ area. The good delineation results prove that the diffusion threshold selection criterion introduced in this paper is reasonable.
基金granted by the National Science and Technology Major Project of the Ministry of Science and Technology of China (Grant No.2011ZX05030-005 and No.2011ZX05009-003)the National Natural Science Foundation of China (Grant No. 40902035)
文摘Deep-water turbidite channels have attracted much attention as a focused issue in petroleum exploration and development. Extensive studies have been performed on the architecture of turbidite channels, and most researches have focused on their geometric shapes, sedimentary processes and controlling factors. However, little attention has been paid to the distribution patterns, distribution laws and quantitative studies of composite sand bodies of turbidite channels. Taken one slope area of the Niger Delta Basin as an example, this study conducted a semi-quantitative to quantitative analysis on architecture of composite sand bodies of turbidite channels based on cores, well logging and seismic surveys. It is shown that turbidite channel systems can be classified as confined and unconfined channel systems. For confined channel systems, the vertical evolution process involves four stages. The sinuosity of a channel system is controlled by slope, with a negative power function relationship between them. When slope gradient reaches four degrees, the channel system is nearly straight. Based on the migration direction and migration amount of single channels within channel complexes, channel composite patterns can be divided into four classes（the lateral composite, en-echelon composite, swing composite and vertical composite） and several subclasses. Various channel composite patterns show specific distribution laws spatially. For meandering channel complexes at the middle-late evolution stage of confined channel systems, the lateral migration amongst single channels shows the features of integrity and succession. The sinuosity of single channels in the late period is greater than that in the early period, and cut-offs may occur locally when the sinuosity is larger than five degrees. This study provides a better understanding for the geological theory of deep-water sedimentary, and also improves exploitation benefits of this type of reservoirs.
基金supported by the National Natural Science Foundation of China (31171482,31571573)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions,China (PAPD)+1 种基金the Foundation of Excellent Doctoral Dissertation of Yangzhou UniversityChina and the Jiangsu Province College Students Innovation Training Program in 2015,China (201511117063Y)
文摘The structural characteristics of protein body accumulation in different endosperm regions of hard wheat cultivar （XM33） and soft wheat cultivar （NM13） under drought stress were investigated. Drought stress treatment was implemented from plant regreening to the caryopsis mature stage. Microscope images of endosperm cells were obtained using resin semi- thin slice technology to observe the distribution and relative area of protein body （PB）. Compared with NM13, relative PB area of XM33 was significantly higher in sub-aleurone endosperm region. The amount of accumulation, including the size and relative area of PB, in two wheat cultivars was higher in sub-aleurone region than that in central region at 18 days post anthesis （DPA）. Drought stress significantly enhanced the sizes and relative areas of PBs in the dorsal and abdominal endosperms in two wheat cultivars. Particularly for dorsal endosperm, drought stress enhanced the relative PB area at 18 DPA and NM13 （5.0% vs. 6.73%） showed less enhancement than XM33 （5.49% vs. 8.96%）. However, NM13 （9.58% vs. 12.02%） showed greater enhancement than XM33 （10.25% vs. 11.7%） at 28 DPA. The protein content in the dorsal and abdominal endosperms of the two wheat cultivars decreased at 12 DPA and then increased until 38 DPA. Drought stress significantly increased the protein contents in the two main regions. From 12 to 38 DPA, the amount of PB accumulation and the protein content were higher in XM33 than those in NM13. The results revealed that PB distribution varied in different endosperm tissues and that the amount of PB accumulation was remarkably augmented by drought stress.
基金This study was financially supported by the National Important Basic Research and Development Planning Program(No.1999043206)the National Natural Science Foundation of China(No.40234051)+1 种基金the Special Plan of Science and Technology of the Ministry of Land and Resources(20010103)the"Trans-century Training Program for Outstanding Talents”Fund sponsored by the.Ministry of Education.
文摘Based on the data of field measurement and drilling in the Tongling area, a series of numerical simulations are carried out by using the 'Surplus Space Method' (SSM), which is first put forward in this paper and applied to predict the shallow-seated magmatic bodies. The results of the numerical simulations show the existence and the 3-D shape of a conical magmatic structure at a depth of-1000 m beneath the center of the area: its top offsets southwards and bifurcates to several branches, while its lower part stretches northeastwards and contracts rapidly to a point at about -1000 m depth. This point is reckoned to be a 'sink' of magma system, transferring ore materials and heat energy from the deep magma chamber to the sub-surface apophyses. The preliminary application of the SSM proves that it may be developed as a new detection means for determining the existence of shallow-seated magmatic bodies and analyzing their three-dimensional features.
