The generalized inversion of S-wave amplitude spectra from the free-field strong motion recordings of the China National Strong Motion Observation Network System （NSMONS） are used to evaluate the site effects in the...The generalized inversion of S-wave amplitude spectra from the free-field strong motion recordings of the China National Strong Motion Observation Network System （NSMONS） are used to evaluate the site effects in the Wenchuan area. In this regard, a total of 602 recordings from 96 aftershocks of the Wenchuan earthquake with magnitudes of M3.7-M6.5 were selected as a dataset. These recordings were obtained from 28 stations at a hypocenter distance ranging from 30 km to 150 km. The inversion results have been verified as reliable by comparing the site response at station 62WUD using the Generalized Inversion Technique （GIT） and the Standard Spectral Ratio method （SSR）. For all 28 stations, the site predominant frequency F and the average site amplification in different frequency bands of 1.0-5.0 Hz, 5.0-10.0 Hz and 1.0-10.0 Hz have been calculated based on the inversion results. Compared with the results from the horizontal-to-vertical spectral ratio （HVSR） method, it shows that the HVSR method can reasonably estimate the site predominant frequency but underestimates the site amplification. The linear fitting between the average site amplification for each frequency band and the V20 （the average uppermost-20 m shear wave velocity） shows good correlation. A distance measurement called the asperity distance DAspt is proposed to reasonably characterize the source-to-site distance for large earthquakes. Finally, the inversed site response is used to identify the soil nonlinearity in the main shock and aftershocks of Wenchuan earthquake. In ten of the 28 stations analyzed in the main shock, the soil behaved nonlinearly, where the ground motion level is apparently beyond a threshold ofPGA 〉 300 cm/s^2 or PGV 〉 20 cm/s, and only one station coded 51SFB has evidence of soil nonlinear behavior in the aftershocks.展开更多
Waterborne ultrafine particles of epoxy resin were prepared by phase inversion technique. The results of SEM revealed that the particles diameter was in the range of 50 to 100 nm and the effects on amount of water req...Waterborne ultrafine particles of epoxy resin were prepared by phase inversion technique. The results of SEM revealed that the particles diameter was in the range of 50 to 100 nm and the effects on amount of water required at phase inversion point were also discussed.展开更多
BACKGROUND In laparoscopic proximal gastrectomy(LPG),the prolapse of the hepatic left lateral lobe near the lesser curvature and esophageal hiatus can obstruct the field of vision and operation.Therefore,it is necessa...BACKGROUND In laparoscopic proximal gastrectomy(LPG),the prolapse of the hepatic left lateral lobe near the lesser curvature and esophageal hiatus can obstruct the field of vision and operation.Therefore,it is necessary to retract or obstruct the hepatic left lateral lobe to ensure a clear field of vision.AIM To investigate the safety and clinical efficacy of the modified hepatic left lateral lobe inversion technique for LPG.METHODS A retrospective analysis was conducted on the clinical data of 13 consecutive patients with early-stage upper gastric adenocarcinoma or adenocarcinoma of the esophagogastric junction treated with LPG from January to December 2023 at the Department of Gastrointestinal Surgery,Second Affiliated Hospital of Fujian Medical University.The modified hepatic left lateral lobe inversion technique was used to expose the surgical field in all patients,and short-term outcomes were observed.RESULTS In all 13 patients,the modified hepatic left lateral lobe inversion technique was successful during surgery without the need for re-retraction or alteration of the liver traction method.There were no instances of esophageal hiatus occlusion,eliminating the need for forceps to assist in exposure.There was no occurrence of intraoperative hepatic hemorrhage,hepatic vein injury,or hepatic congestion.No postoperative digestive complications of Clavien-Dindo grade≥II occurred wi-thin 30 days after surgery,except for a single case of pulmonary infection.Some patients experienced increases in alanine aminotransferase and aspartate aminotransferase levels on the first day after surgery,which significantly decreased by the third day and returned to normal by the seventh day after surgery.CONCLUSION The modified hepatic left lateral lobe inversion technique has demonstrated satisfactory results,offering ad-vantages in terms of facilitating surgical procedures,reducing surgical trauma,and protecting the liver.展开更多
Mesozoic-Palaeozoic marine carbonate rocks are crucial hydrocarbon reservoirs in the Central Uplift area of the South Yellow Sea Basin(SYSB).Due to the scarcity of boreholes and the significant heterogeneity of carbon...Mesozoic-Palaeozoic marine carbonate rocks are crucial hydrocarbon reservoirs in the Central Uplift area of the South Yellow Sea Basin(SYSB).Due to the scarcity of boreholes and the significant heterogeneity of carbonate reservoirs,the distribution of porous carbonate reservoirs and their related key controlling factors remain unclear.In this study,factors affecting the distribution of porous Carboniferous-Early Permian carbonate reservoirs in the SYSB were investigated through seismic inversion and isotope analysis.The log-seismic characteristics of porous carbonate reservoirs,sensitive lithology parameters,and physical property parameters were extracted and analyzed.The pre-stack simultaneous inversion technique was applied to predict the lithology and physical properties of porous carbonate reservoirs.Moreover,the sedimentary of carbonate was analyzed using isotopes of carbon,oxygen,and strontium.The results show that porous carbonate reservoirs are mainly developed in the open platform sediments with porosities of 3%-5%and are mainly distributed in the paleo-highland(Huanglong Formation and Chuanshan Formation)and the slope of paleo-highland(Hezhou Formation).The porous carbonate reservoirs of the Qixia Formation are only locally developed.In addition,the negativeδ13C excursions indicate a warm and humid tropical climate with three sea-level fluctuations in the study area from the Carboniferous to Early Permian.The favorable conditions for developing porous carbonate rocks include the sedimentary environment and diagenetic process.The primary pore tends to form in high-energy environments of the paleo-highland,and the secondary pore is increased by dissolution during the syngenetic or quasi-syngenetic period.According to the hydrocarbon potential analysis,the Late Ordovician Wufeng Formation and Lower Silurian Gaojiabian Formation are the source rocks in the high-maturity-over-maturity stage,the Carboniferous-Lower Permian carbonate is the good reservoirs,and the Late Permian Longtan-Dalong Formation is the stable seal,ensuring a huge hydrocarbon accumulation potential in SYSB.The methods proposed in this study can be applied to other carbonate-dominated strata worldwide.展开更多
As core components of precision-guided projectiles,projectile-borne components are highly susceptible to failure or even damage in complex high-overload environments,thereby significantly compromising launch reliabili...As core components of precision-guided projectiles,projectile-borne components are highly susceptible to failure or even damage in complex high-overload environments,thereby significantly compromising launch reliability and safety.However,accurately characterizing the mechanical behavior of propellants remains challenging due to the limitations in the current internal ballistic theory and the constraints of large-scale artillery firing experiments.This complicates the high-precision numerical modeling of projectile launch,and obstructs investigations into the failure mechanisms of projectile-borne components.Therefore,this paper identifies propellant parameters using the computational inverse method under uncertainty,further establishes high-precision numerical models of projectile launch,and explores the failure mechanisms of projectile-borne components in complex high-overload environments.First,a projectile launching experiment is meticulously designed and executed to obtain the breech pressure and muzzle velocity.Then,a general simulation model is built,and the powder burn model is used to simulate the ignition and combustion.Subsequently,the propellant parameters are effectively identified with the computational inverse method by the combination of the experiments and simulations.A high-precision numerical model of projectile launch is modified with the parameters validated by another experiment,and the high-overload characteristics during projectile launch are thoroughly analyzed based on this model.Finally,the high-overload characteristics of projectile-borne components are analyzed to elucidate the stress variation laws and to reveal the failure mechanisms influenced by time and spatial locations.This research provides an effective method for perfectly identifying propellant parameters and building high-precision numerical models of projectile launch.Additionally,it provides significant guidance for the anti-high overload design and analysis of projectile-borne components.展开更多
Composites were prepared with polysulfone through ex-situ toughening technique. The dynamic parameters of cyanate/epoxy resin were studied by differential scanning calorimetric（DSC） analysis and dynamic mechanical a...Composites were prepared with polysulfone through ex-situ toughening technique. The dynamic parameters of cyanate/epoxy resin were studied by differential scanning calorimetric（DSC） analysis and dynamic mechanical analysis（DMA）. Microstructual toughening mechanism was studied through scanning electron microscopy（SEM）. The particle microstructure in interlaminar region of composites toughened through ex-situ toughening technique revealed that a reaction induced phase decomposition and phase inversion happened in the interlaminar region. The thermosetting particles were surrounded by the PS phase, which could signifi cantly improve the delamination resistance of composites. The compression after impact（CAI） can be signifi cantly improved from 180 MPa to 260 MPa by using ex-situ toughening while the mechanical properties are not affected.展开更多
An inversion method was applied to crustal earthquakes dataset to find S-wave attenuation characteristics beneath the Eastern Tohoku region of Japan. Accelerograms from 85 shallow crustal earthquakes up to 25 km depth...An inversion method was applied to crustal earthquakes dataset to find S-wave attenuation characteristics beneath the Eastern Tohoku region of Japan. Accelerograms from 85 shallow crustal earthquakes up to 25 km depth and magnitude range between 3.5 and 5.5 were analyzed to estimate the seismic quality factor Qs. A homogeneous attenuation model Qs for the wave propagation path was evaluated from spectral amplitudes, at 24 different frequencies between 0.5 and 20 Hz by using generalized inversion technique. To do this, non-parametric attenuation functions were calculated to observe spectral amplitude decay with hypocentral distance. Then, these functions were parameterized to estimate Qs. It was found that in Eastern Tohoku region, the Qs frequency dependence can be approximated with the function 33 f 1.22 within a frequency range between 0.5 and 20 Hz. However, the frequency dependence of Qs in the frequency range between 0.5 and 6 Hz is best approximated by Qs （f） = 36 f 0.94 showing relatively weaker frequency dependence as compared to the relation Qs （f） = 6 f^ 2.09 for the frequency range between 6 and 15 Hz. These results could be used to estimate source and site parameters for seismic hazard assessment in the region.展开更多
The objective of this study is to evaluate the efficacy of laparoscopic surgery combined with the rectal inversion and specimen extraction(RIES)technique for rectal cancer,focusing on both short-term and long-term out...The objective of this study is to evaluate the efficacy of laparoscopic surgery combined with the rectal inversion and specimen extraction(RIES)technique for rectal cancer,focusing on both short-term and long-term outcomes.A retrospective comparative analysis was performed on 120 patients who underwent laparoscopic radical excision for rectal cancer from June 2017 to June 2021.Patients were categorized into two groups:Group RIES(n=58),which received the novel RIES technique,and Group AIES(n=62),which underwent the conventional abdominal incision for specimen extraction.Short-term outcomes,such as postoperative pelvic sepsis,temporary ileus,anastomotic leakage,and anastomotic stricture,were meticulously recorded.Longterm efficacy was evaluated through the 3-year overall survival(OS),disease-free survival(DFS),and local recurrence rate(LRR).The RIES group demonstrated a 3-year OS,DFS,and LRR of 86.2%,77.6%,and 8.6%,respectively,with a low incidence of short-term complications.Comparatively,the AIES group showed a 3-year OS,DFS,and LRR of 83.9%,74.2%,and 19.4%,respectively,with slightly higher rates of postoperative complications.Statistical analysis using the Student's t-test,the chi-square(χ^(2))test revealed no significant differences in the primary outcomes between the two groups,and suggested the noninferiority of the RIES technique.The study suggests that the RIES technique is a safe,feasible,and potentially functional and oncological superior approach to rectal cancer treatment,without compromising clinical efficacy.Further research is warranted to validate thesefindings in a larger,multicenter,and randomized controlled trial.展开更多
As mask features scale to smaller dimensions, the so-called ＂3-D mask effects＂ which have mostly been neglected before, become important. This paper properly models the 3-D thick mask effects, and then analyses the ...As mask features scale to smaller dimensions, the so-called ＂3-D mask effects＂ which have mostly been neglected before, become important. This paper properly models the 3-D thick mask effects, and then analyses the object-based inverse lithography technique using a simulated annealing algorithm to determine the mask shapes that produce the desired on-wafer results. Evaluations against rigorous simulations show that the synthesized masks provide good image fidelity up to 0.94, and this approach gives improved accuracy and faster results than existing methods.展开更多
基金Nonprofit Industry Research Project of CEA under Grant No. 201208014National Natural Science Fund No. 51278473Environmental Protection Research Fund for Public Interest No. 201209040
文摘The generalized inversion of S-wave amplitude spectra from the free-field strong motion recordings of the China National Strong Motion Observation Network System （NSMONS） are used to evaluate the site effects in the Wenchuan area. In this regard, a total of 602 recordings from 96 aftershocks of the Wenchuan earthquake with magnitudes of M3.7-M6.5 were selected as a dataset. These recordings were obtained from 28 stations at a hypocenter distance ranging from 30 km to 150 km. The inversion results have been verified as reliable by comparing the site response at station 62WUD using the Generalized Inversion Technique （GIT） and the Standard Spectral Ratio method （SSR）. For all 28 stations, the site predominant frequency F and the average site amplification in different frequency bands of 1.0-5.0 Hz, 5.0-10.0 Hz and 1.0-10.0 Hz have been calculated based on the inversion results. Compared with the results from the horizontal-to-vertical spectral ratio （HVSR） method, it shows that the HVSR method can reasonably estimate the site predominant frequency but underestimates the site amplification. The linear fitting between the average site amplification for each frequency band and the V20 （the average uppermost-20 m shear wave velocity） shows good correlation. A distance measurement called the asperity distance DAspt is proposed to reasonably characterize the source-to-site distance for large earthquakes. Finally, the inversed site response is used to identify the soil nonlinearity in the main shock and aftershocks of Wenchuan earthquake. In ten of the 28 stations analyzed in the main shock, the soil behaved nonlinearly, where the ground motion level is apparently beyond a threshold ofPGA 〉 300 cm/s^2 or PGV 〉 20 cm/s, and only one station coded 51SFB has evidence of soil nonlinear behavior in the aftershocks.
基金This project is supported by the Scientific Fund of Polymer Physics Laboratory,Institute of Chemistry,Chinese Academy of Sciences.
文摘Waterborne ultrafine particles of epoxy resin were prepared by phase inversion technique. The results of SEM revealed that the particles diameter was in the range of 50 to 100 nm and the effects on amount of water required at phase inversion point were also discussed.
基金Key Clinical Specialty Discipline Construction Program of Fujian,Fujian Health Medicine and Politics,No.[2022]884.
文摘BACKGROUND In laparoscopic proximal gastrectomy(LPG),the prolapse of the hepatic left lateral lobe near the lesser curvature and esophageal hiatus can obstruct the field of vision and operation.Therefore,it is necessary to retract or obstruct the hepatic left lateral lobe to ensure a clear field of vision.AIM To investigate the safety and clinical efficacy of the modified hepatic left lateral lobe inversion technique for LPG.METHODS A retrospective analysis was conducted on the clinical data of 13 consecutive patients with early-stage upper gastric adenocarcinoma or adenocarcinoma of the esophagogastric junction treated with LPG from January to December 2023 at the Department of Gastrointestinal Surgery,Second Affiliated Hospital of Fujian Medical University.The modified hepatic left lateral lobe inversion technique was used to expose the surgical field in all patients,and short-term outcomes were observed.RESULTS In all 13 patients,the modified hepatic left lateral lobe inversion technique was successful during surgery without the need for re-retraction or alteration of the liver traction method.There were no instances of esophageal hiatus occlusion,eliminating the need for forceps to assist in exposure.There was no occurrence of intraoperative hepatic hemorrhage,hepatic vein injury,or hepatic congestion.No postoperative digestive complications of Clavien-Dindo grade≥II occurred wi-thin 30 days after surgery,except for a single case of pulmonary infection.Some patients experienced increases in alanine aminotransferase and aspartate aminotransferase levels on the first day after surgery,which significantly decreased by the third day and returned to normal by the seventh day after surgery.CONCLUSION The modified hepatic left lateral lobe inversion technique has demonstrated satisfactory results,offering ad-vantages in terms of facilitating surgical procedures,reducing surgical trauma,and protecting the liver.
基金This study was supported by the project ofthe Science and Technology Innovation Fund of Command Center of Natural Resources Intergrated Survey entitled“Temporal and spatial distribution of paleochannel and origin of organic carbon burial in the Western Bohai Sea since 2.28Ma”(KC20220011)the project entitled“Characterization of Carboniferous-Early Permian heterogeneous porous carbonate reservoirs and hydrocarbon potential analysis in the central uplift of the South Yellow Sea Basin”(KLSG2304)+3 种基金by the Key laboratory of Submarine Science,Ministry of Natural Resources,the project entitled“1∶50000 Marine regional Geological survey in Caofeidian Sea Area,Bohai Sea”(ZD20220602)“1∶250000 Marine regional Geological survey in Weihai Sea Area,North Yellow Sea”(DD20230412)“Geological survey on tectonic and sedimentary conditions of Laoshan uplift”(DD2016015)by the China Geological Survey,and the project entitled“Study on Hydrocarbon Accumulation Failure and Fluid Evolution Reduction of the Permian Reservoir in the Laoshan Uplift,South Yellow Sea”(42076220)organized by the National Natural Science Foundation of China.
文摘Mesozoic-Palaeozoic marine carbonate rocks are crucial hydrocarbon reservoirs in the Central Uplift area of the South Yellow Sea Basin(SYSB).Due to the scarcity of boreholes and the significant heterogeneity of carbonate reservoirs,the distribution of porous carbonate reservoirs and their related key controlling factors remain unclear.In this study,factors affecting the distribution of porous Carboniferous-Early Permian carbonate reservoirs in the SYSB were investigated through seismic inversion and isotope analysis.The log-seismic characteristics of porous carbonate reservoirs,sensitive lithology parameters,and physical property parameters were extracted and analyzed.The pre-stack simultaneous inversion technique was applied to predict the lithology and physical properties of porous carbonate reservoirs.Moreover,the sedimentary of carbonate was analyzed using isotopes of carbon,oxygen,and strontium.The results show that porous carbonate reservoirs are mainly developed in the open platform sediments with porosities of 3%-5%and are mainly distributed in the paleo-highland(Huanglong Formation and Chuanshan Formation)and the slope of paleo-highland(Hezhou Formation).The porous carbonate reservoirs of the Qixia Formation are only locally developed.In addition,the negativeδ13C excursions indicate a warm and humid tropical climate with three sea-level fluctuations in the study area from the Carboniferous to Early Permian.The favorable conditions for developing porous carbonate rocks include the sedimentary environment and diagenetic process.The primary pore tends to form in high-energy environments of the paleo-highland,and the secondary pore is increased by dissolution during the syngenetic or quasi-syngenetic period.According to the hydrocarbon potential analysis,the Late Ordovician Wufeng Formation and Lower Silurian Gaojiabian Formation are the source rocks in the high-maturity-over-maturity stage,the Carboniferous-Lower Permian carbonate is the good reservoirs,and the Late Permian Longtan-Dalong Formation is the stable seal,ensuring a huge hydrocarbon accumulation potential in SYSB.The methods proposed in this study can be applied to other carbonate-dominated strata worldwide.
基金Project supported by the National Natural Science Foundation of China (No. 12302435)。
文摘As core components of precision-guided projectiles,projectile-borne components are highly susceptible to failure or even damage in complex high-overload environments,thereby significantly compromising launch reliability and safety.However,accurately characterizing the mechanical behavior of propellants remains challenging due to the limitations in the current internal ballistic theory and the constraints of large-scale artillery firing experiments.This complicates the high-precision numerical modeling of projectile launch,and obstructs investigations into the failure mechanisms of projectile-borne components.Therefore,this paper identifies propellant parameters using the computational inverse method under uncertainty,further establishes high-precision numerical models of projectile launch,and explores the failure mechanisms of projectile-borne components in complex high-overload environments.First,a projectile launching experiment is meticulously designed and executed to obtain the breech pressure and muzzle velocity.Then,a general simulation model is built,and the powder burn model is used to simulate the ignition and combustion.Subsequently,the propellant parameters are effectively identified with the computational inverse method by the combination of the experiments and simulations.A high-precision numerical model of projectile launch is modified with the parameters validated by another experiment,and the high-overload characteristics during projectile launch are thoroughly analyzed based on this model.Finally,the high-overload characteristics of projectile-borne components are analyzed to elucidate the stress variation laws and to reveal the failure mechanisms influenced by time and spatial locations.This research provides an effective method for perfectly identifying propellant parameters and building high-precision numerical models of projectile launch.Additionally,it provides significant guidance for the anti-high overload design and analysis of projectile-borne components.
基金Funded by the National Natural Science Foundation of China(51373137)
文摘Composites were prepared with polysulfone through ex-situ toughening technique. The dynamic parameters of cyanate/epoxy resin were studied by differential scanning calorimetric（DSC） analysis and dynamic mechanical analysis（DMA）. Microstructual toughening mechanism was studied through scanning electron microscopy（SEM）. The particle microstructure in interlaminar region of composites toughened through ex-situ toughening technique revealed that a reaction induced phase decomposition and phase inversion happened in the interlaminar region. The thermosetting particles were surrounded by the PS phase, which could signifi cantly improve the delamination resistance of composites. The compression after impact（CAI） can be signifi cantly improved from 180 MPa to 260 MPa by using ex-situ toughening while the mechanical properties are not affected.
基金a part of author’s M.Sc Research under the project:‘‘Strengthening of Earthquake Engineering Center’’,funded by Higher Education Commission,Government of Pakistan
文摘An inversion method was applied to crustal earthquakes dataset to find S-wave attenuation characteristics beneath the Eastern Tohoku region of Japan. Accelerograms from 85 shallow crustal earthquakes up to 25 km depth and magnitude range between 3.5 and 5.5 were analyzed to estimate the seismic quality factor Qs. A homogeneous attenuation model Qs for the wave propagation path was evaluated from spectral amplitudes, at 24 different frequencies between 0.5 and 20 Hz by using generalized inversion technique. To do this, non-parametric attenuation functions were calculated to observe spectral amplitude decay with hypocentral distance. Then, these functions were parameterized to estimate Qs. It was found that in Eastern Tohoku region, the Qs frequency dependence can be approximated with the function 33 f 1.22 within a frequency range between 0.5 and 20 Hz. However, the frequency dependence of Qs in the frequency range between 0.5 and 6 Hz is best approximated by Qs （f） = 36 f 0.94 showing relatively weaker frequency dependence as compared to the relation Qs （f） = 6 f^ 2.09 for the frequency range between 6 and 15 Hz. These results could be used to estimate source and site parameters for seismic hazard assessment in the region.
文摘The objective of this study is to evaluate the efficacy of laparoscopic surgery combined with the rectal inversion and specimen extraction(RIES)technique for rectal cancer,focusing on both short-term and long-term outcomes.A retrospective comparative analysis was performed on 120 patients who underwent laparoscopic radical excision for rectal cancer from June 2017 to June 2021.Patients were categorized into two groups:Group RIES(n=58),which received the novel RIES technique,and Group AIES(n=62),which underwent the conventional abdominal incision for specimen extraction.Short-term outcomes,such as postoperative pelvic sepsis,temporary ileus,anastomotic leakage,and anastomotic stricture,were meticulously recorded.Longterm efficacy was evaluated through the 3-year overall survival(OS),disease-free survival(DFS),and local recurrence rate(LRR).The RIES group demonstrated a 3-year OS,DFS,and LRR of 86.2%,77.6%,and 8.6%,respectively,with a low incidence of short-term complications.Comparatively,the AIES group showed a 3-year OS,DFS,and LRR of 83.9%,74.2%,and 19.4%,respectively,with slightly higher rates of postoperative complications.Statistical analysis using the Student's t-test,the chi-square(χ^(2))test revealed no significant differences in the primary outcomes between the two groups,and suggested the noninferiority of the RIES technique.The study suggests that the RIES technique is a safe,feasible,and potentially functional and oncological superior approach to rectal cancer treatment,without compromising clinical efficacy.Further research is warranted to validate thesefindings in a larger,multicenter,and randomized controlled trial.
基金Supported by the National Key Basic Research and Development(973) Program of China (No. 2006CB302700)the Basic Research Foundation of Tsinghua National Laboratory for Information Science and Technology (TNList)
文摘As mask features scale to smaller dimensions, the so-called ＂3-D mask effects＂ which have mostly been neglected before, become important. This paper properly models the 3-D thick mask effects, and then analyses the object-based inverse lithography technique using a simulated annealing algorithm to determine the mask shapes that produce the desired on-wafer results. Evaluations against rigorous simulations show that the synthesized masks provide good image fidelity up to 0.94, and this approach gives improved accuracy and faster results than existing methods.
