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Internal hernia as a rare cause of small bowel obstruction:An insight from 13 years of experience
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作者 Payal Kaw Anu Behari +2 位作者 Supriya Sharma Ashok Kumar Rajneesh K Singh 《World Journal of Clinical Cases》 SCIE 2025年第7期21-27,共7页
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
关键词 Paraduodenal hernia internal hernia Mesenteric whirling Bowel obstruction Computed tomography
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Prediction of microstructure evolution of ZK61 alloy during hot spinning by internal state variable model
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作者 Jin-qi PAN Wen-cong ZHANG +3 位作者 Jian-lei YANG Song-hui WANG Yong WU Huan LI 《中国有色金属学报》 北大核心 2025年第1期126-142,共17页
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
关键词 internal state variable model hot spinning ZK61 alloy finite element simulation texture evolution
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Seeing beneath the surface:Harnessing point-of-care ultrasound for internal jugular vein evaluation 被引量:2
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作者 Vichayut Chayapinun Abhilash Koratala Taweevat Assavapokee 《World Journal of Cardiology》 2024年第2期73-79,共7页
Point-of-care ultrasound(POCUS)of the internal jugular vein(IJV)offers a noninvasive means of estimating right atrial pressure(RAP),especially in cases where the inferior vena cava is inaccessible or unreliable due to... Point-of-care ultrasound(POCUS)of the internal jugular vein(IJV)offers a noninvasive means of estimating right atrial pressure(RAP),especially in cases where the inferior vena cava is inaccessible or unreliable due to conditions such as liver disease or abdominal surgery.While many clinicians are familiar with visually assessing jugular venous pressure through the internal jugular vein,this method lacks sensitivity.The utilization of POCUS significantly enhances the visualization of the vein,leading to a more accurate identification.It has been demonstrated that combining IJV POCUS with physical examination enhances the specificity of RAP estimation.This review aims to provide a comprehensive summary of the various sonographic techniques available for estimating RAP from the internal jugular vein,drawing upon existing data. 展开更多
关键词 Point-of-care ultrasound Bedside ultrasound internal jugular vein Right atrial pressure Central venous pressure
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Selective internal radiation therapy segmentectomy:A new minimally invasive curative option for primary liver malignancies? 被引量:2
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作者 Riccardo Inchingolo Francesco Cortese +5 位作者 Antonio Rosario Pisani Fabrizio Acquafredda Roberto Calbi Riccardo Memeo Fotis Anagnostopoulos Stavros Spiliopoulos 《World Journal of Gastroenterology》 SCIE CAS 2024年第18期2379-2386,共8页
Transarterial radioembolization or selective internal radiation therapy(SIRT)has emerged as a minimally invasive approach for the treatment of tumors.This percutaneous technique involves the local,intra-arterial deliv... Transarterial radioembolization or selective internal radiation therapy(SIRT)has emerged as a minimally invasive approach for the treatment of tumors.This percutaneous technique involves the local,intra-arterial delivery of radioactive microspheres directly into the tumor.Historically employed as a palliative measure for liver malignancies,SIRT has gained traction over the past decade as a potential curative option,mirroring the increasing role of radiation segmentectomy.The latest update of the BCLC hepatocellular carcinoma guidelines recognizes SIRT as an effective treatment modality comparable to other local ablative methods,particularly well-suited for patients where surgical resection or ablation is not feasible.Radiation segmentectomy is a more selective approach,aiming to deliver high-dose radiation to one to three specific hepatic segments,while minimizing damage to surrounding healthy tissue.Future research efforts in radiation segmentectomy should prioritize optimizing radiation dosimetry and refining the technique for super-selective administration of radiospheres within the designated hepatic segments. 展开更多
关键词 Transarterial radioembolization Selective internal radiation therapy Radiation segmentectomy Hepatocellular carcinoma Primary liver malignancies Personalised dosimetry
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Effect of external and internal cues on core muscle activation during the Sahrmann five-level core stability test
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作者 Skyla Stifter Jessie McCaffrey +2 位作者 Tyler Nichols Ayse Ozcan Edeer Justine Ward 《World Journal of Methodology》 2025年第1期95-104,共10页
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
关键词 External cue internal cue Muscle activation Core muscles Lumbopelvic stability Pressure biofeedback unit
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Relative Impacts of Sea Ice Loss and Atmospheric Internal Variability on the Winter Arctic to East Asian Surface Air Temperature Based on Large-Ensemble Simulations with NorESM2 被引量:1
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作者 Shengping HE Helge DRANGE +4 位作者 Tore FUREVIK Huijun WANG Ke FAN Lise Seland GRAFF Yvan J.ORSOLINI 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第8期1511-1526,共16页
To quantify the relative contributions of Arctic sea ice and unforced atmospheric internal variability to the “warm Arctic, cold East Asia”(WACE) teleconnection, this study analyses three sets of large-ensemble simu... To quantify the relative contributions of Arctic sea ice and unforced atmospheric internal variability to the “warm Arctic, cold East Asia”(WACE) teleconnection, this study analyses three sets of large-ensemble simulations carried out by the Norwegian Earth System Model with a coupled atmosphere–land surface model, forced by seasonal sea ice conditions from preindustrial, present-day, and future periods. Each ensemble member within the same set uses the same forcing but with small perturbations to the atmospheric initial state. Hence, the difference between the present-day(or future) ensemble mean and the preindustrial ensemble mean provides the ice-loss-induced response, while the difference of the individual members within the present-day(or future) set is the effect of atmospheric internal variability. Results indicate that both present-day and future sea ice loss can force a negative phase of the Arctic Oscillation with a WACE pattern in winter. The magnitude of ice-induced Arctic warming is over four(ten) times larger than the ice-induced East Asian cooling in the present-day(future) experiment;the latter having a magnitude that is about 30% of the observed cooling. Sea ice loss contributes about 60%(80%) to the Arctic winter warming in the present-day(future) experiment. Atmospheric internal variability can also induce a WACE pattern with comparable magnitudes between the Arctic and East Asia. Ice-lossinduced East Asian cooling can easily be masked by atmospheric internal variability effects because random atmospheric internal variability may induce a larger magnitude warming. The observed WACE pattern occurs as a result of both Arctic sea ice loss and atmospheric internal variability, with the former dominating Arctic warming and the latter dominating East Asian cooling. 展开更多
关键词 arctic sea ice loss warm arctic–cold East Asia atmospheric internal variability large-ensemble simulation NorESM2 PAMIP
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What Is the Psychosocial Environment of Adolescents with High or Low Internalizing Behavior?
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作者 Changmin Yoo 《International Journal of Mental Health Promotion》 2025年第1期77-88,共12页
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
关键词 internalizing behavior adolescents longitudinal analysis
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Correction to:Error Calculation of Large-Amplitude Internal Solitary Waves Within the Pycnocline Introduced by the Strong Stratification Approximation
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作者 Cunguo Xu Zhan Wang Masoud Hayatdavoodi 《哈尔滨工程大学学报(英文版)》 CSCD 2024年第1期247-247,共1页
In the original publication the third author name is published incorrectly as“Hayatdavoodi Masoud”.The correct author name should be read as“Masoud Hayatdavoodi”.The correct author name is available in this correc... In the original publication the third author name is published incorrectly as“Hayatdavoodi Masoud”.The correct author name should be read as“Masoud Hayatdavoodi”.The correct author name is available in this correction. 展开更多
关键词 STRONG internal CORRECTION
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Transcriptome and metabolome analysis of preharvest internal browning in Nane plum fruit caused by high temperature
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作者 Cheng Peng Linping Deng +7 位作者 Hejun Tan Wancong Meng Jianliang Luo Zengwen Zhang Huiqiong Chen Jishui Qiu Xiaoxiao Chang Yusheng Lu 《Horticultural Plant Journal》 SCIE CAS CSCD 2024年第5期1099-1111,共13页
The preharvest internal browning of Nane plum fruit,with no visible effects on the appearance of the fruit,has become a serious problem in recent years in its production area in Guangdong Province,China.This study inv... The preharvest internal browning of Nane plum fruit,with no visible effects on the appearance of the fruit,has become a serious problem in recent years in its production area in Guangdong Province,China.This study investigated the effects of environmental factors,including temperature,on Nane plum internal browning.Plum orchards at different elevations with different incidences of internal browning were selected.Using fruits with different internal browning incidence levels,the internal browning mechanism was analyzed with transcriptome and metabolome analyses.The results revealed decreased internal browning at high altitudes.Shading treatment significantly reduced internal browning,whereas bagging and insect-proof net-covering treatments significantly increased internal browning.Because bagging and net coverings increase the local ambient temperature,the findings suggest that high temperature is an important factor influencing the internal browning of Nane plum.The metabolome experiments showed that with increased internal browning,the levels of phenolic hydroxyls such as catechol increased,with simultaneous increases in hydrogen peroxide content and oxidase activity.It can be speculated that the oxidation of phenolic hydroxyl substances is the main cause of the preharvest browning of Nane plum.Transcriptome analysis revealed the increased expression of calcium signaling-related and downstream effector genes and indicated an important role of calcium in internal browning,possibly due to its increased content in the fruit.Further,with increasingly serious internal browning,genes related to photosynthesis were down-regulated,while genes related to senescence were up-regulated,thus suggesting the up-regulation of the process of cell senescence during internal browning.In conclusion,heat stress should be eliminated to reduce preharvest internal browning in Nane plum. 展开更多
关键词 Nane plum Fruit internal browning High temperature CALCIUM
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Modelling Method and Meshing Characteristics of a Novel Curve-Surface Conjugate Internal Gear Drive
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作者 Xinxin Ye Luhe Zhang +3 位作者 Dongyu Wang Jingming Jiang Wenjun Luo Bingkui Chen 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第5期216-232,共17页
Space exploration has become a major focus in the field of technology,with gear transmissions in aerospace equipment playing a crucial role.In the extreme environment of space,gear transmissions face challenges like l... Space exploration has become a major focus in the field of technology,with gear transmissions in aerospace equipment playing a crucial role.In the extreme environment of space,gear transmissions face challenges like large temperature differentials,deformation and maintenance difficulties,which will severely impact transmission accuracy and service life.To meet the growing demands for high-performance gear transmissions with high transmission efficiency and error adaptability in the aerospace field,this paper proposes a novel curve-surface conjugate internal gear drive consisting of an involute internal gear and a curve-surface gear.The fundamental theory of curve-surface conjugation is introduced,and the construction method for curve-surface gear based on a selected contact path and meshing tube is presented.The analysis models including induced curvature,sliding ratio and tooth contact analysis with errors(ETCA)are simulated to evaluate the meshing characteristics.Additionally,prototypes are manufactured and experimental setups are established to validate the transmission performance.These results indicate that as the rotational speed increases,the transmission efficiency of the curve-surface conjugate internal gear drive improves,which is contrary to the trend observed in involute gear drives.And the transmission efficiency of the curve-surface conjugate internal gear drive surpasses that of the involute gear drive at higher rotational speeds.Moreover,this novel gear drive exhibits excellent error adaptability,maintaining intact contact paths and high transmission efficiency even in the presence of assembly errors.This study provides new ideas for the design and manufacture of high-performance gear transmissions from the perspective of spatial geometric elements. 展开更多
关键词 internal gear drive Tooth surface geometry Error adaptability Transmission efficiency
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Alkali Tolerance of Concrete Internal Curing Agent Based on Sodium Carboxymethyl Starch
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作者 陈梅花 刘荣进 +3 位作者 CHEN Ping JING Daiyan WAN Dandan FU Siyuan 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第1期82-90,共9页
Internal curing agents (ICA) based on super absorbent polymer have poor alkali tolerance and reduce the early strength of concrete.An alkali tolerate internal curing agent (CAA-ICA) was designed and prepared by using ... Internal curing agents (ICA) based on super absorbent polymer have poor alkali tolerance and reduce the early strength of concrete.An alkali tolerate internal curing agent (CAA-ICA) was designed and prepared by using sodium carboxymethyl starch (CMS) with high hydrophilicity,acrylic acid (AA) containing anionic carboxylic group and acrylamide (AM) containing non-ionic amide group as the main raw materials.The results show that the ratio of CAA-ICA alkali absorption solution is higher than that existing ICA,which solves the low water absorption ratio of the ICA in alkali environment.The water absorption ratio of CAA-ICA in saturated Ca(OH)_(2) solution is 95.8 g·g^(-1),and the alkali tolerance coefficient is 3.4.The application of CAA-ICA in cement-based materials can increase the internal relative humidity and miniaturize the pore structure.The compressive strength of mortar increases up to 12.95%at 28 d,which provids a solution to overcome the reduction of the early strength. 展开更多
关键词 alkali tolerance sodium carboxymethyl starch internal curing agent compressive strength
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Intestinal Parasitosis in Children among Internally Displaced Persons in the Hauts-Bassins Region of Burkina Faso
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作者 Barro Makoura Yerbanga W Isidore +7 位作者 Yonaba Caroline Sawadogo Safiatou Hadry Roger Sibi Matotou Nakanabo-Diallo Seydou Millogo Anselme Naon Sarah Sanogo Bintou Bamba Sanata 《Open Journal of Pediatrics》 2024年第5期814-822,共9页
Introduction: The setting up of camps for internally displaced persons in Burkina Faso as a result of terrorism creates favorable conditions for the emergence of digestive parasitosis in these displaced populations. T... Introduction: The setting up of camps for internally displaced persons in Burkina Faso as a result of terrorism creates favorable conditions for the emergence of digestive parasitosis in these displaced populations. The objective of this study was to evaluate the prevalence of digestive parasitosis in children of this population in the Hauts-Bassins region. Material and methods: This was a prospective cross-sectional study from November to December 2020, in which stool samples were collected from internally displaced children from the Sinfra reception site in Banzon and from Poya in Karangasso Vigué. The stool samples were stored at room temperature, protected from dust and insects, in a cooler and then sent to the laboratory of the CHUSS in Bobo-Dioulasso where the parasitological analyses were performed. Results: The mean age was 5.8 ± 2.4 years. The most represented age group was 5 to 10 years (75.31%). The sex ratio is 1.61. The overall prevalence of intestinal parasite infection was 53.09%. The prevalence was statistically higher among those who consumed well water than those consuming tap water (p = 0.01). Monoparasitism by protozoa and helminths represented 74.42% and 6.68% respectively. The polyparasitism rate was 9.31%. The species identified in monoparasite patients were protozoa with Entamoeba coli (37.21%), Giardia lamblia (25.58%), Endolimax nanus (6.98%) and Entamoeba histolytica/dispar (4.65%). Biparasitism was identified with combinations, such as E. coli + E. histolytica/dispar (11.63%). Conclusion: There is a high prevalence of digestive parasitosis among IDPs in the Sinfra and Poya reception site. Educational sessions on hand washing before meals, use of drinking water, etc. should emphasize preventive measures in these IDP camps. 展开更多
关键词 Digestive Parasitosis internally Displaced Children Hauts-Bassins Burkina Faso
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Internal phase control of fiber laser array based on photodetector array
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作者 靳凯凯 龙金虎 +5 位作者 常洪祥 粟荣涛 张嘉怡 陈思雨 马阎星 周朴 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第7期320-326,共7页
Coherent beam combining(CBC) of fiber laser array is a promising technique to realize high output power while maintaining near diffraction-limited beam quality. To implement CBC, an appropriate phase control feedback ... Coherent beam combining(CBC) of fiber laser array is a promising technique to realize high output power while maintaining near diffraction-limited beam quality. To implement CBC, an appropriate phase control feedback structure should be established to realize phase-locking. In this paper, an innovative internal active phase control CBC fiber laser array based on photodetector array is proposed. The dynamic phase noises of the laser amplifiers are compensated before being emitted into free space. And the static phase difference compensation of emitting laser array is realized by interference measurement based on photodetector array. The principle of the technique is illustrated and corresponding simulations are carried out, and a CBC system with four laser channels is built to verify the technique. When the phase controllers are turned on, the phase deviation of the laser array is less than λ/20, and ~ 95% fringe contrast of the irradiation distribution is obtained. The technique proposed in this paper could provide a reference for the system design of a massive high-power CBC system. 展开更多
关键词 fiber laser laser array coherent beam combining internal phase control
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Multi-Stage Multidisciplinary Design Optimization Method for Enhancing Complete Artillery Internal Ballistic Firing Performance
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作者 Jipeng Xie Guolai Yang +1 位作者 Liqun Wang Lei Li 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第7期793-819,共27页
To enhance the comprehensive performance of artillery internal ballistics—encompassing power,accuracy,and service life—this study proposed a multi-stage multidisciplinary design optimization(MS-MDO)method.First,the ... To enhance the comprehensive performance of artillery internal ballistics—encompassing power,accuracy,and service life—this study proposed a multi-stage multidisciplinary design optimization(MS-MDO)method.First,the comprehensive artillery internal ballistic dynamics(AIBD)model,based on propellant combustion,rotation band engraving,projectile axial motion,and rifling wear models,was established and validated.This model was systematically decomposed into subsystems from a system engineering perspective.The study then detailed the MS-MDO methodology,which included Stage I(MDO stage)employing an improved collaborative optimization method for consistent design variables,and Stage II(Performance Optimization)focusing on the independent optimization of local design variables and performance metrics.The methodology was applied to the AIBD problem.Results demonstrated that the MS-MDO method in Stage I effectively reduced iteration and evaluation counts,thereby accelerating system-level convergence.Meanwhile,Stage II optimization markedly enhanced overall performance.These comprehensive evaluation results affirmed the effectiveness of the MS-MDO method. 展开更多
关键词 arTILLERY internal ballistics dynamics multi-stage optimization multi-disciplinary design optimization collaborative optimization
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Experimental Study on the Variation of Optical Imaging Characteristics with Zenith Angle due to Internal Solitary Waves in Sunglint
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作者 LIU Tengfei SUN Lina +4 位作者 CHANG Zhe ZHANG Meng LIANG Keda MENG Junmin WANG Jing 《Journal of Ocean University of China》 SCIE CAS CSCD 2024年第4期943-952,共10页
Internal solitary waves(ISWs)change the roughness of the sea surface,thus producing dark and bright bands in optical images.However,reasons for changes in imaging characteristics with the solar zenith angle remain unc... Internal solitary waves(ISWs)change the roughness of the sea surface,thus producing dark and bright bands in optical images.However,reasons for changes in imaging characteristics with the solar zenith angle remain unclear.In this paper,the optical imaging pattern of ISWs in sunglint under different zenith angles of the light source is investigated by collecting optical images of ISWs through physical simulation.The experiment involves setting 10 zenith angles of the light source,which are divided into area a the optical images of ISWs in the three areas show dark-bright mode,single bright band,and bright-dark mode,which are consistent with those observed by optical remote sensing.In addition,this study analyzed the percentage of the dark and bright areas of the bands and the change in the relative gray difference and found changes in both areas under different zenith angles of the light source.The MODIS and ASAR images display a similar brightness-darkness distance of the same ISWs.Therefore,the relationship between the brightness-darkness distance and the characteristic half-width of ISWs is determined in accordance with the eKdV theory and the imaging mechanism of ISWs of the SAR image.Overall,the relationship between them in the experiment is almost consistent with the theoretical result. 展开更多
关键词 internal solitary waves optical imaging characteristic laboratory simulation zenith angle sunglint
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Loads and Dynamic Response Characteristic on FPSO Under Internal Solitary Waves
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作者 ZHANG Rui-rui LI Cui +2 位作者 PU Chun-rong LIU Qian YOU Yun-xiang 《China Ocean Engineering》 SCIE EI CSCD 2024年第5期785-796,共12页
According to the established prediction model of internal solitary wave loads on FPSO in the previous work,the lumped mass model and the movement equations of finite displacement in time domain,the dynamic response mo... According to the established prediction model of internal solitary wave loads on FPSO in the previous work,the lumped mass model and the movement equations of finite displacement in time domain,the dynamic response model of interaction between internal solitary waves and FPSO with mooring lines were established.Through calculations and analysis,time histories of dynamic loads of FPSO exerted by internal solitary waves,FPSO’s motion and dynamic tension of mooring line were obtained.The effects of the horizontal pretension of mooring line,the amplitude of internal solitary wave and layer fluid depth on dynamic response behavior of FPSO were mastered.It was shown that the internal solitary waves had significant influence on FPSO,such as the large magnitude horizontal drift and a sudden tension increment.With internal solitary wave of −170 m amplitude in the ocean with upper and lower layer fluid depth ratio being 60:550,the dynamic loads reached 991.132 kN(horizontal force),18067.3 kN(vertical force)and−5042.92 kN·m(pitching moment).Maximum of FPSO’s horizontal drift was 117.56 m.Tension increment of upstream mooring line approached 401.48 kN and that of backflow mooring line was−140 kN.Moreover,the loads remained nearly constant with different pretension but increased obviously with the changing amplitude and layer fluid depth ratio.Tension increments of mooring lines also changed little with the pretension but increased rapidly when amplitude and layer fluid depth ratio increased.However,FPSO’s motion increased quickly with not only the horizontal pretension but also the amplitude of internal solitary wave and layer fluid depth ratio. 展开更多
关键词 internal solitary wave(ISW) dynamic response FPSO dynamic loads tension increment
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Research on internal gravity waves in the Martian atmosphere based on Tianwen-1 and Mars Global Surveyor occultation data
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作者 Luo Xiao CunYing Xiao +2 位作者 Xiong Hu ZeWei Wang XiaoQi Wu 《Earth and Planetary Physics》 EI CAS CSCD 2024年第6期890-898,共9页
Internal gravity waves(IGWs)are critical in driving Martian atmospheric motion and phenomena.This study investigates Martian IGWs by using high-resolution data from China’s Tianwen-1 mission and the National Aeronaut... Internal gravity waves(IGWs)are critical in driving Martian atmospheric motion and phenomena.This study investigates Martian IGWs by using high-resolution data from China’s Tianwen-1 mission and the National Aeronautics and Space Administration’s Mars Global Surveyor(MGS)by the radio occultation(RO)technique.Key IGW parameters,such as vertical and horizontal wavelengths,intrinsic frequency,and energy density,are extracted based on vertical temperature profiles from the Martian surface to~50 km altitude.Data reveal that the Martian IGWs are predominantly small-scale waves,with vertical wavelengths between 6 and 13 km and horizontal wavelengths extending to thousands of kilometers.These waves propagate almost vertically and exhibit low intrinsic frequencies close to the inertial frequency,with the characteristic of low-frequency inertial IGWs.Tianwen-1 data indicate stronger IGW activity,higher energy density,and less dissipation than MGS data in the northern hemisphere.Moreover,MGS data in the southern hemisphere show higher buoyancy frequencies and lower vertical wavelengths,suggesting more stable atmospheric conditions conducive to IGW propagation.These extracted IGW characteristics can enhance our understanding of the atmospheric dynamics on Mars and contribute valuable information for parameterization in global circulation models. 展开更多
关键词 internal gravity waves MarS Tianwen-1 Mars Global Surveyor radio occultation
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Interaction between internal solitary waves and the seafloor in the deep sea
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作者 Zhuangcai Tian Jinjian Huang +5 位作者 Jiaming Xiang Shaotong Zhang Jinran Wu Xiaolei Liu Tingting Luo Jianhua Yue 《Deep Underground Science and Engineering》 2024年第2期149-162,共14页
Internal solitary wave(ISW),as a typical marine dynamic process in the deep sea,widely exists in oceans and marginal seas worldwide.The interaction between ISW and the seafloor mainly occurs in the bottom boundary lay... Internal solitary wave(ISW),as a typical marine dynamic process in the deep sea,widely exists in oceans and marginal seas worldwide.The interaction between ISW and the seafloor mainly occurs in the bottom boundary layer.For the seabed boundary layer of the deep sea,ISW is the most important dynamic process.This study analyzed the current status,hotspots,and frontiers of research on the interaction between ISW and the seafloor by CiteSpace.Focusing on the action of ISW on the seabed,such as transformation and reaction,a large amount of research work and results were systematically analyzed and summarized.On this basis,this study analyzed the wave–wave interaction and interaction between ISW and the bedform or slope of the seabed,which provided a new perspective for an in‐depth understanding of the interaction between ISW and the seafloor.Finally,the latest research results of the bottom boundary layer and marine engineering stability by ISW were introduced,and the unresolved problems in the current research work were summarized.This study provides a valuable reference for further research on the hazards of ISW to marine engineering geology. 展开更多
关键词 bottom boundary layer INTERACTION internal solitary wave SEAFLOOR SEDIMENT
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Internal erosion characteristics and microstructure effects of undisturbed loess
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作者 ZHANG Buping ZHU Xinghua +1 位作者 CHENG Yuxiang Aamir ASGHAR 《Journal of Mountain Science》 SCIE CSCD 2024年第11期3630-3649,共20页
Loess internal erosion caused by preferential flow often leads to serious loess ground collapse,shallow loess landslides,and other geological disasters.However,there is a lack of quantitative evaluation of the interna... Loess internal erosion caused by preferential flow often leads to serious loess ground collapse,shallow loess landslides,and other geological disasters.However,there is a lack of quantitative evaluation of the internal erodibility of undisturbed loess under the action of preferential flow,and little is known about the correlation between the internal erodibility of loess and its microstructure.In this study,we carried out a series of hole erosion tests(HET)on undisturbed loess samples from 4 typical locations on China's Loess Plateau.The internal erodibility of loess was quantitatively evaluated through an improved HET method,and its association with initial water content,clay content,and initial water head difference was investigated.On the microscopic scale,the microstructure of loess with different clay content was measured by scanning electron microscopy(SEM).The correlation between pore and particle microstructure parameters and loess internal erosion parameters was established based on grey correlation theory.When the initial water content increased from 10%to 36%,the erodibility index increased from 1 to 2.5.When the clay content increased from 8%to 27.95%,the erodibility index increased 3.5 times.The increase of initial water head difference has a positive linear effect on the internal erodibility of loess.The microstructure analysis shows that with the increase of clay content,the microstructure of undisturbed loess changes from a mosaic structure to a cementation structure,which creates favourable conditions for controlling the internal erosion of loess.Through grey correlation analysis,it has been determined that the microstructure of undisturbed loess has a significant correlation with the critical shear stress,and the loess microstructure morphology strongly correlates with the erosion rate.Under normal circumstances,the higher the clay content,the better the erosion resistance,the better the mechanical stability,and the easier to form a stable cave in loess.This study can provide a reference for revealing the cave formation mechanism in the loess area in the future. 展开更多
关键词 Undisturbed loess Preferential flow internal erosion Hole erosion test Microstructure effect Loess Plateau
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Study on the Load Characteristics of Submerged Body Under Internal Solitary Waves on the Continental Shelf and Slope
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作者 LIU Qian CUI Jian +5 位作者 MEI Huan GAO Jun-liang WU Xiang-bai ZHANG Dai-yu ZHANG Rui-rui SHANG Xiao-dong 《China Ocean Engineering》 SCIE EI CSCD 2024年第5期809-820,共12页
Based on the high-quality observation data and the numerical simulation,the evolution characteristics of internal solitary waves(ISWs)and the load on the suspend submerged body are studied on the continental shelf and... Based on the high-quality observation data and the numerical simulation,the evolution characteristics of internal solitary waves(ISWs)and the load on the suspend submerged body are studied on the continental shelf and slope separately.The observed ISWs exhibit the first mode depression ISWs.The amplitudes of ISWs on the shelf and slope areas reach 50 m and 80 m,respectively.The upper layer velocity in the westward direction is about 0.8 m/s on the continental shelf and 0.9 m/s on the continental slope during the passing through of ISWs.The lower layer is dominated by the eastward compensating flow.In the vertical direction,the water in front of the wave flows downward,while the water behind the wave flows upward,and the maximum vertical velocity exceeds 0.2 m/s.Numerical simulation results show that the larger the amplitude of ISWs,the larger the load on the submerged body.The force on the submerged body by ISWs is dominated by the vertical force,and the corresponding maximum vertical forces on the continental shelf and slope are−25 kN and −27 kN.The submerged body is subjected to a large counterclockwise moment and the sudden change of the moment will also cause the submerged body to capsize.This paper not only gives a deeper understanding of the characteristics of ISWs from the deep continental slope to the shallow continental shelf,but also has a certain guiding value for the prediction of ISWs and for marine military activities. 展开更多
关键词 internal solitary waves submerged body CFD horizontal force vertical force MOMENT South China Sea
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