The Paleo-Pacific Plate stagnated in the mantle transition zone beneath northeast Asia during the Late Mesozoic,resulting in the eastern Asian big mantle wedge(BMW).However,its formation mechanism remains unclear.Here...The Paleo-Pacific Plate stagnated in the mantle transition zone beneath northeast Asia during the Late Mesozoic,resulting in the eastern Asian big mantle wedge(BMW).However,its formation mechanism remains unclear.Here,we analyzed elemental and isotopic compositions of 126-60 Ma intraplate basaltic rocks to map the mantle flow pattern and investigate the implications for the formation of the BMW.These rocks exhibit eastward an increase in Ba/Nb,Ba/La,^(87)Sr/^(86)Sr,and^(208)Pb/^(204)Pb ratios,while a decrease in Nb/Yb,Zr/Yb,Ta/Yb,and Nb/Nb*ratios,indicating mixing between the fertile mantle and the depleted mantle modified by slab material,implying the occurrence of trench-perpendicular mantle flow.The coeval mantle flow and formation of the BMW,the similar directions of mantle flow and Paleo-Pacific Plate subduction,and migration of basin depocenters indicate trench-perpendicular mantle flow was a key factor in the formation of the BMW.Moreover,these basaltic rocks have elevatedδ^(66)Zn values(0.22‰to 0.52‰),indicating recycled carbonates have been added into their mantle source,which increased the mantle flow velocity.Combined with slab roll-back in the Late Mesozoic,it created the essential conditions for mantle flow to promote the formation of the eastern Asian BMW.展开更多
The frontal edge of the Makran accretionary wedge is characterized by the development of multiple imbricate thrust faults trending E-W and relatively parallel.However,the mechanisms underlying their formation and the ...The frontal edge of the Makran accretionary wedge is characterized by the development of multiple imbricate thrust faults trending E-W and relatively parallel.However,the mechanisms underlying their formation and the factors controlling their development remain subjects of debate.This paper,based on seismic profile analysis,employs physical simulation experiments to establish a'wedge'type subduction model.The study explores the influence of the initial wedge angle,horizontal sand layer thickness,and the presence or absence of a decollement layer on the structural styles of the thrust wedge.Experimental results indicate that as the initial wedge angle decreases from 11°to 8°,the lateral growth of the thrust wedge increases,whereas vertical growth diminishes.When the horizontal sand layer thickness is reduced from 4.5 cm to 3.0 cm,the spacing between the frontal thrusts decreases and the number of thrust faults increases.Both lateral and vertical growth are relatively reduced,resulting in a smaller thrust wedge.When a decollement layer is present,the structural style exhibits layered deformation.The decollement layer constrains the development of back thrusts and promotes the localized formation of frontal thrusts.In conclusion,the imbricate thrust faults at the frontal edge of the Makran accretionary wedge are primarily controlled by the characteristics of the wedge itself and the presence of the decollement layer.展开更多
Introduction: Recently, new plates with locking screws have been developed and used for medial open-wedge high tibial osteotomy (HTO). The purpose of this study was to evaluate and compare biomechanical properties of ...Introduction: Recently, new plates with locking screws have been developed and used for medial open-wedge high tibial osteotomy (HTO). The purpose of this study was to evaluate and compare biomechanical properties of different internal fixations in open-wedge HTO using the two currently available locking plates. Methods: Eight paired fresh-frozen cadaveric lower extremities were vertically embedded in steel boxes. The axial compression load was applied to the legs using the mechanical testing machine. The axial compression load test from 0 N to 550 N and the failure test were performed before and after HTO. One side of the leg of a specimen was fixed with the Puddu locking plate and the other side was fixed with the TomoFix plate to compare the two plates using the same specimen. A mode of failure and vertical displacement of the medial and lateral parts of the tibia at the osteotomy gap was recorded using a video camera in the failure test. The load–displacement data were analyzed to calculate stiffness, failure load, and displacement at failure. Results: The mean failure load was 1471.4 N and 1692.3 N and total vertical displacement at failure was 3.1 mm and 2.9 mm with the Puddu and TomoFix plates, respectively. During axial compression loading, displacements mainly occurred at the lateral osteotomy gap, while the medial gap was well preserved. No significant differences were observed in the failure load, displacement, or mode of failure between the two plates. Conclusions: The Puddu and TomoFix plates had similar biomechanical properties in open-wedge HTO. The results indicated reliable stability after open-wedge HTO without fibular osteotomy.展开更多
To overcome the inaccuracy problem of the traditional wedge evaluation of steel plates and strips caused by the ran-domness of the thicknesses of two local points and improve the reliability of the wedge index,the dou...To overcome the inaccuracy problem of the traditional wedge evaluation of steel plates and strips caused by the ran-domness of the thicknesses of two local points and improve the reliability of the wedge index,the double-centroid method for the wedge evaluation was proposed,and a model based on the centroid theory was established.Meanwhile,an integral model for the discrete thickness values of the cross-section profiles was derived.The discussion focused on the distinct characteristics of the two-point method,asymmetric method,and double-centroid method in evaluating the asymmetric distribution of cross-sections.The three methods were employed to evaluate the wedge values of both the theoretical and measured cross-sections of steel plates and strips,and the accuracies of three wedge evaluation models were analyzed and discussed.The results showed that the double-centroid method objectively reflects the degree and variation characteristics of the wedge values of the cross-sections of steel plates and strips,and this method is feasible,reliable,and outstanding.展开更多
Background: Biplanar medial opening wedge high tibial osteotomy (MOWHTO) is a treatment method that allows adequate correction of symptomatic varus knee deformity. However, MOWHTO tends to decrease patellar height and...Background: Biplanar medial opening wedge high tibial osteotomy (MOWHTO) is a treatment method that allows adequate correction of symptomatic varus knee deformity. However, MOWHTO tends to decrease patellar height and increase the posterior tibial slope, which can affect the knee joint stability. Objective: The aim of this study was to describe the technique of biplanar MOWHTO and fixation by TomoFix plate, as well as to evaluate the accuracy of the planned correction and the postoperative tibial slope. Patients and Methods: This prospective cohort study was conducted on patients who presented with varus knee deformity and underwent biplanar MOWHTO and fixation by TomoFix plate during the period from March 2016 to March 2017. Assessment of patients included pre- and postoperative Knee and function scores, mechanical femorotibial angle (mFTA), posterior tibial slope angle (pTSA), range of motion (ROM) and radiological evaluation of the healing of the osteotomy site. Results: The recruited patients were 13 (8 men and 5 women), with average age 31.7 years old. The knee and functional scores improved from the preoperative mean of 45 and 41 to the postoperative mean of 85 and 72 points, respectively. The average knee flexion was 115 degrees, which at the final follow-up remained unchanged except for one case. The mean preoperative mFTA was 13.5°varus and decreased post-operatively to a mean of 3°valgus. The average postoperative follow-up period was 12 months (10 - 18 M). Conclusion: The biplanar MOWHTO allows preservation of posterior tibial slope while correcting the varus knee adequately.展开更多
Cryogenic wedges developed due to very cold,rather arid conditions during the maximum of the last cold event when the drying up of the neighboring China Sea resulted in the failure of the East Asian Monsoon.As the cli...Cryogenic wedges developed due to very cold,rather arid conditions during the maximum of the last cold event when the drying up of the neighboring China Sea resulted in the failure of the East Asian Monsoon.As the climate ameliorated and the Monsoon rains reappeared,ice-wedges developed.Further warming permitted thawing of the ice infillings accompanied by replacement of the ice by sediments partly from the host ground as well as from the surface by wind or sheet wash.In cases of extreme surface water flow on slopes after 10 ka B.P.,small baydjarakhs typically c.50 cm high developed,only to have the resulting hollows infilled by sediments carried by wind and/or sheet wash.These shallow structures form a network on top of many of the cryogenic wedges.This complex history makes dating the ages of the wedges difficult using OSL methodology.Unfortunately,past field work ignored the problem of the angle of the cut face to the direction of the wedge infilling when sampling the contents of the narrow wedges,resulting in potential contamination of the samples with the host sediment.Sampling of the larger deposits should be alright,but the likelihood of contamination makes the interpretation of the resulting OSL dates from the narrow wedges questionable.Primary wedges consisting of primary mineral infillings should still have similar OSL dates with depth for a given wedge,but the distinction between ice-wedge infillings and soil wedges is difficult since both can exhibit older dates of the infillings with depth.The available data suggests that ice-wedges were significantly more common than sediment-filled primary wedges.A protocol to avoid having to obtain large numbers of OSL dates by more careful field sampling and the use of grain size determinations is provided in the Appendix.展开更多
BACKGROUND Wedged hepatic venous pressure(WHVP)is a crucial variable for accurately assessing the hepatic venous pressure gradient(HVPG)and is vital for the diagnosis and prognostic evaluation of patients with portal ...BACKGROUND Wedged hepatic venous pressure(WHVP)is a crucial variable for accurately assessing the hepatic venous pressure gradient(HVPG)and is vital for the diagnosis and prognostic evaluation of patients with portal hypertension(PH).AIM To investigate the anatomical characteristics of balloon-occluded hepatic venous angiography in patients with PH and analyze the relationship between the WHVP and portal venous pressure(PVP).METHODS This retrospective study included 877 patients with PH who met the inclusion criteria from January 2020 to June 2024.Routine and innovative hepatic venous angiography was performed during transjugular intrahepatic portosystemic shunt procedures to measure hepatic venous and PVPs.All patients'angiographic images were collected for analysis.The associations between WHVP and PVP in each group were analyzed via linear regression analysis,and a predictive model was established.RESULTS The 877 patients had a mean age of 52.6±13.0 years,with 582 males and 295 females.Patients were categorized into four groups on the basis of their anatomical structure.All groups showed strong correlations between WHVP and PVP.The regression coefficient between the WHVP and PVP in the hepatic right vein-portal venous angiography group was 0.884(P<0.05);in the hepatic right vein-accessory hepatic venous angiography group,it was 0.721(P<0.05);in the hepatic right vein-middle hepatic venous angiography group,it was 0.344(P<0.05);and in the hepatic right vein-nonangiography group,it was 0.293(P<0.05).CONCLUSION The presence and anatomical classification of hepatic venous collaterals are key factors influencing the relationship between WHVP with and PVP.Based on the different anatomical classifications of hepatic veins,WHVP can be used to estimate PVP,improving the accuracy of PVP prediction.展开更多
The goal of this research is to develop mine-scale discrete fracture network(DFN)models in which the influence of the spatial heterogeneity of fracture distributions may be investigated on the rock wedge stability of ...The goal of this research is to develop mine-scale discrete fracture network(DFN)models in which the influence of the spatial heterogeneity of fracture distributions may be investigated on the rock wedge stability of an open pit slope.For this purpose,spatially conditioned DFN models were developed for the pit walls at Tasiast mine using comprehensive structural data from the mine.Using Sequential Gaussian Simulation(SGS),volumetric fracture intensities(P32)were modeled across the entire mine site in the form of 3D block models.The simulated P32 block models were used as the input constraints for conditional DFN fracture generation,where the DFN grid dimension is the same as the SGS 3D blocks.The spatially constrained DFN models were further calibrated using aerial fracture intensities(P21)data from the pit walls,obtained by a survey of the pit walls using an unmanned aerial vehicle(UAV)and measured traces of joints from 3D point cloud data.The final DFN model is expected to honor the fracture intensities gathered through different means with optimal model accuracy.Finally,bench-scale and interramp scale rock wedge slope stability analyses were conducted using the calibrated conditional DFN models.This work proves the significance of conditioned DFN models in rock wedge stability analysis.Such models provide detailed information regarding rock wedge stability so that site monitoring and prevention plans can be conducted with higher efficiency.展开更多
Aim: To introduce and characterize the modified biplanar opening high tibial osteotomy with rigid fixation to treat unicompartmental knee arthritis with varus deformity in active lifestyle patients. Patients and Metho...Aim: To introduce and characterize the modified biplanar opening high tibial osteotomy with rigid fixation to treat unicompartmental knee arthritis with varus deformity in active lifestyle patients. Patients and Method: 48 patients (19 females) with monocompartmental gonarthrosis of the knee combined with varus malalignment, 41 with bilateral affection and 7 cases with unilateral gonarthritis (total 89 knees). Mean age: 53 years (range from 42 to 61 years). They were treated and followed from June 2010 to May 2014 (35 months). Biplanar opening high tibial osteotomy technique was used and fixed by low profile locked T-plate (21 cases) and low profile anatomical proximal tibial plate (27cases). Pre-operative mean varus deformity was 16.5° (9° - 19°). We utilized Lysholm score and Knee Society Score for evaluation of preoperative and follow-up data. Results: The average correction angle was 11.50 ± 2.50° (7° - 19°). Preoperative posterior tibial slope was 8.04° ± 1.30° and at last follow-up 9.15° ± 1.60°, respectively (p = 0.437). The joint space distance increased from 4.05 ± 1.30 mm to 4.83 ± 1.33 mm (p < 0.001). The average time to complete bone union was 14.69 ± 1.5 weeks. There were no cases of delayed union or non-union. No major complications like broken plate, nerve injury, or blood vessel injury occurred. No progression of degenerations developed in the three compartments of the knee at final follow-up. The mean score on the Lysholm-Gillquist knee functional scoring scale was 45.5 ± 21.7 preoperatively, and it improved to 77.0 ± 23.9 (p < 0.001). There was no obvious difference in the range of motion before and after operation. The average knee score improved from 51.19 ± 11.82 to 93.49 ± 5.10. Conclusion: Biplanar opening high tibial osteotomy fixed with locking compression plate gives good results for symptomatic unicompartmental gonarthrosis with genu varum. Also this technique can be applied for medial compartment degeneration of the knee without deformity with good functional outcomes.展开更多
The phenomenon of shock/shock interaction(SSI)is widely observed in high-speed flow,and the double wedge SSI represents one of the typical problems encountered.The control effect of single-pulse plasma synthetic jet(P...The phenomenon of shock/shock interaction(SSI)is widely observed in high-speed flow,and the double wedge SSI represents one of the typical problems encountered.The control effect of single-pulse plasma synthetic jet(PSJ)on double wedge type-Ⅵand type-ⅤSSI was investigated experimentally and numerically,and the influence of discharge energy was also explored.The findings indicate that the interaction between PSJ and the high-speed freestream results in the formation of a plasma layer and a jet shock,which collectively governs the control of SSI.The control mechanism of single-pulse PSJ on SSI lies in its capacity to attenuate both shock and SSI.For type-ⅥSSI,the original second-wedge oblique shock is eliminated under the control of PSJ,resulting in a new type-ⅥSSI formed by the jet shock and the first-wedge oblique shock.For type-ⅤSSI,the presence of PSJ effectively mitigates the intensity of Mach stem,supersonic jet,and reflected shocks,thereby facilitating its transition into type-ⅥSSI.The numerical results indicate that the peak pressure can be reduced by approximately 32.26%at maximum.Furthermore,the development of PSJ also extends in the Z direction.The pressure decreases in the area affected by both PSJ and jet shock due to the attenuation of the SSI zone.With increasing discharge energy,the control effect of PSJ on SSI is gradually enhanced.展开更多
Seismic quantitative reservoir simulations and characterizations have played a vital role in exploring stratigraphic traps,such as lateaggradational lowstands prograding wedge systems(LPWS)within lowstands systems tra...Seismic quantitative reservoir simulations and characterizations have played a vital role in exploring stratigraphic traps,such as lateaggradational lowstands prograding wedge systems(LPWS)within lowstands systems tracts(LST).However,seismic data acquisition operations are always dominated by exceptional seismic coherent noise events,e.g.,multiples,which reduce the signal strengths of the sourcegenerated incident seismic waves within vertically and laterally heterogeneous earth systems.Hence,these noise events create hurdles in predicting paleo-depositional impedance(PDI),paleo-thickness(PTS),paleo-dense fractured networks,erosional and depositional zones,faultcontrolled migrations,and types of seismic reflection configurations(SRFC),which are key elements in developing stratigraphic pinch-out traps.This research utilizes the state-of-the-art technologies of spectral wavelet-based instantaneous time-frequency analysis and seismic waveform frequency-controlled porosity-constrained static reservoir simulation(FDPVS)tools to quantify the LPWS inside the Onshore Basin,Pakistan.The use of conventional amplitude-based seismic attributes,such as the average energy,remained a better tool for deciphering the overall geological architecture of the LPWS.Conventional FDPVS realizations resolved a PDI of−1.391 gm./c.c.^(*)m/s to−0.97 gm./c.c.^(*)m/s for LPWS with PTS of 12 and 20 m,respectively.A 0.9 km lateral extent of paleo-dense fractured networks(PDFN)with a strong linear regression R^(2)=0.93 was also resolved.Average energy attribute-based instantaneous frequency FDPVS realizations enabled the imaging of parallel-toprograding SRFC with resolved magnitudes of−0.259 gm./c.c.^(*)m/s for PDI,20 m for PTS,and 0.73 km for PDFN with linear regression transforms at R^(2)=0.92,which indicates the deposition of onlap fill facies inside the LPWS during extensive sea-level fall.These realizations have also resolved frequency-controlled fault migrations on 27-Hz spectral waveform-based amplitude plots with 2.174 gm./c.c.^(*)m/s PDI for conduit fault systems and 27-Hz with 0.585 gm./c.c.^(*)m/s PDI for sealing fault systems.All these structural configurations are completely sealed up by transgressive seals of transgressive systems tracts and,hence,developed into pure stratigraphic-based oil and gas plays.This research has strong implications for side-tracking drilling locations and provides an analogue for basins with similar geology and stratigraphy worldwide.展开更多
To reduce the computational complexity and storage cost caused by wedge segmentation algorithm,a scheme of simplifying wedge matching is proposed.It takes advantage of the correlation of the wedge separation line of d...To reduce the computational complexity and storage cost caused by wedge segmentation algorithm,a scheme of simplifying wedge matching is proposed.It takes advantage of the correlation of the wedge separation line of depth map and the direction of intra-prediction for 3D high-efficiency video coding(3D-HEVC).According to the difference of wedge segmentation between adjacent edge and opposite edge,a set only including 104×4 wedgelet templates is given.By expanding of the wedge wave of a certain minimum unit,a simple separation line acquisition method for different size of depth block is put forward.Furthermore,based on the array processor(DPR-CODEC)developed by project team,an efficient parallel scheme of the improved wedge segmentation mode prediction is introduced.By the scheme,prediction unit(PU)size can be changed randomly from 4×4 to 8×8,16×16,and 32×32,which is more in line with the needs of the HEVC standard.Veri-fied with test sequence in HTM16.1 and the Xilinx virtex-6 field programmable gate array(FPGA)respectively,the experiment results show that the proposed methods save 99.2%of the storage space and 63.94%of the encoding time,the serial/parallel acceleration ratio of each template reaches 1.84 in average.The coding performance,storage and resource consumption are considered for both.展开更多
A 32-channel charge-sensitive amplifier(CSA)is designed for fast timing in the delay-line readout of a parallel plate avalanche counter(PPAC)array.It is realized on a PCB with operational amplifiers and other discrete...A 32-channel charge-sensitive amplifier(CSA)is designed for fast timing in the delay-line readout of a parallel plate avalanche counter(PPAC)array.It is realized on a PCB with operational amplifiers and other discrete components.Each channel consists of an integrator,a pole-zero cancellation net,and a linear amplification stage,which can be adapted to accommodate either positive or negative input signals.The RMS equivalent input noise charges are 3.3 fC,the conversion gains are approximately±2 mV∕fC,and the intrinsic time resolution reaches 32 ps.In the prototype PPAC application,the CSA performs as well as the commercial FTA820A amplifier,providing a position resolution as good as 0.17 mm,and exhibiting reliable stability during several hours of continuous data acquisition.展开更多
A new method was proposed for preparing AZ31/1060 composite plates with a corrugated interface,which involved cold-pressing a corrugated surface on the Al plate and then hot-pressing the assembled Mg/Al plate.The resu...A new method was proposed for preparing AZ31/1060 composite plates with a corrugated interface,which involved cold-pressing a corrugated surface on the Al plate and then hot-pressing the assembled Mg/Al plate.The results show that cold-pressing produces intense plastic deformation near the corrugated surface of the Al plate,which promotes dynamic recrystallization of the Al substrate near the interface during the subsequent hot-pressing.In addition,the initial corrugation on the surface of the Al plate also changes the local stress state near the interface during hot pressing,which has a large effect on the texture components of the substrates near the corrugated interface.The construction of the corrugated interface can greatly enhance the shear strength by 2−4 times due to the increased contact area and the strong“mechanical gearing”effect.Moreover,the mechanical properties are largely depended on the orientation relationship between corrugated direction and loading direction.展开更多
Marine thin plates are susceptible to welding deformation owing to their low structural stiffness.Therefore,the efficient and accurate prediction of welding deformation is essential for improving welding quality.The t...Marine thin plates are susceptible to welding deformation owing to their low structural stiffness.Therefore,the efficient and accurate prediction of welding deformation is essential for improving welding quality.The traditional thermal elastic-plastic finite element method(TEP-FEM)can accurately predict welding deformation.However,its efficiency is low because of the complex nonlinear transient computation,making it difficult to meet the needs of rapid engineering evaluation.To address this challenge,this study proposes an efficient prediction method for welding deformation in marine thin plate butt welds.This method is based on the coupled temperature gradient-thermal strain method(TG-TSM)that integrates inherent strain theory with a shell element finite element model.The proposed method first extracts the distribution pattern and characteristic value of welding-induced inherent strain through TEP-FEM analysis.This strain is then converted into the equivalent thermal load applied to the shell element model for rapid computation.The proposed method-particularly,the gradual temperature gradient-thermal strain method(GTG-TSM)-achieved improved computational efficiency and consistent precision.Furthermore,the proposed method required much less computation time than the traditional TEP-FEM.Thus,this study lays the foundation for future prediction of welding deformation in more complex marine thin plates.展开更多
Titanium plates with a Ti−O solid solution surface-hardened layer were cold roll-bonded with 304 stainless steel plates with high work hardening rates.The evolution and mechanisms affecting the interfacial bonding str...Titanium plates with a Ti−O solid solution surface-hardened layer were cold roll-bonded with 304 stainless steel plates with high work hardening rates.The evolution and mechanisms affecting the interfacial bonding strength in titanium/stainless steel laminated composites were investigated.Results indicate that the hardened layer reduces the interfacial bonding strength from over 261 MPa to less than 204 MPa.During the cold roll-bonding process,the hardened layer fractures,leading to the formation of multi-scale cracks that are difficult for the stainless steel to fill.This not only hinders the development of an interlocking interface but also leads to the presence of numerous microcracks and hardened blocks along the nearly straight interface,consequently weakening the interfacial bonding strength.In metals with high work hardening rates,the conventional approach of enhancing interface interlocking and improving interfacial bonding strength by using a surface-hardened layer becomes less effective.展开更多
基金financially supported by the National Key R&D Program of China(No.2022YFF0801002)the National Natural Science Foundation of China(No.42372065)the Natural Science Foundation of Jilin Province(No.20220101178JC)。
文摘The Paleo-Pacific Plate stagnated in the mantle transition zone beneath northeast Asia during the Late Mesozoic,resulting in the eastern Asian big mantle wedge(BMW).However,its formation mechanism remains unclear.Here,we analyzed elemental and isotopic compositions of 126-60 Ma intraplate basaltic rocks to map the mantle flow pattern and investigate the implications for the formation of the BMW.These rocks exhibit eastward an increase in Ba/Nb,Ba/La,^(87)Sr/^(86)Sr,and^(208)Pb/^(204)Pb ratios,while a decrease in Nb/Yb,Zr/Yb,Ta/Yb,and Nb/Nb*ratios,indicating mixing between the fertile mantle and the depleted mantle modified by slab material,implying the occurrence of trench-perpendicular mantle flow.The coeval mantle flow and formation of the BMW,the similar directions of mantle flow and Paleo-Pacific Plate subduction,and migration of basin depocenters indicate trench-perpendicular mantle flow was a key factor in the formation of the BMW.Moreover,these basaltic rocks have elevatedδ^(66)Zn values(0.22‰to 0.52‰),indicating recycled carbonates have been added into their mantle source,which increased the mantle flow velocity.Combined with slab roll-back in the Late Mesozoic,it created the essential conditions for mantle flow to promote the formation of the eastern Asian BMW.
基金the National Natural Science Foundation of China(No.42076069)。
文摘The frontal edge of the Makran accretionary wedge is characterized by the development of multiple imbricate thrust faults trending E-W and relatively parallel.However,the mechanisms underlying their formation and the factors controlling their development remain subjects of debate.This paper,based on seismic profile analysis,employs physical simulation experiments to establish a'wedge'type subduction model.The study explores the influence of the initial wedge angle,horizontal sand layer thickness,and the presence or absence of a decollement layer on the structural styles of the thrust wedge.Experimental results indicate that as the initial wedge angle decreases from 11°to 8°,the lateral growth of the thrust wedge increases,whereas vertical growth diminishes.When the horizontal sand layer thickness is reduced from 4.5 cm to 3.0 cm,the spacing between the frontal thrusts decreases and the number of thrust faults increases.Both lateral and vertical growth are relatively reduced,resulting in a smaller thrust wedge.When a decollement layer is present,the structural style exhibits layered deformation.The decollement layer constrains the development of back thrusts and promotes the localized formation of frontal thrusts.In conclusion,the imbricate thrust faults at the frontal edge of the Makran accretionary wedge are primarily controlled by the characteristics of the wedge itself and the presence of the decollement layer.
文摘Introduction: Recently, new plates with locking screws have been developed and used for medial open-wedge high tibial osteotomy (HTO). The purpose of this study was to evaluate and compare biomechanical properties of different internal fixations in open-wedge HTO using the two currently available locking plates. Methods: Eight paired fresh-frozen cadaveric lower extremities were vertically embedded in steel boxes. The axial compression load was applied to the legs using the mechanical testing machine. The axial compression load test from 0 N to 550 N and the failure test were performed before and after HTO. One side of the leg of a specimen was fixed with the Puddu locking plate and the other side was fixed with the TomoFix plate to compare the two plates using the same specimen. A mode of failure and vertical displacement of the medial and lateral parts of the tibia at the osteotomy gap was recorded using a video camera in the failure test. The load–displacement data were analyzed to calculate stiffness, failure load, and displacement at failure. Results: The mean failure load was 1471.4 N and 1692.3 N and total vertical displacement at failure was 3.1 mm and 2.9 mm with the Puddu and TomoFix plates, respectively. During axial compression loading, displacements mainly occurred at the lateral osteotomy gap, while the medial gap was well preserved. No significant differences were observed in the failure load, displacement, or mode of failure between the two plates. Conclusions: The Puddu and TomoFix plates had similar biomechanical properties in open-wedge HTO. The results indicated reliable stability after open-wedge HTO without fibular osteotomy.
基金supported by the National Natural Science Foundation of China (Grant No.52305405)the Natural Science Foundation Research Program of Shanxi Province (Grant No.202203021222121)+4 种基金the Major Project of Science and Technology of Shanxi Province (Grant No.20181102016)the Chinese Postdoctoral Science Foundation (Grant No.2021M702544)the Central Government Guides the Special Fund Projects of Local Scientific and Technological Development (YDZX20191400002149)the Open Project of Research Institute of Hai'an-Taiyuan University of Technology (Grant No.2023HA-TYUTKFYF008)the School Fund of Taiyuan University of Technology (Grant No.2022QN007).
文摘To overcome the inaccuracy problem of the traditional wedge evaluation of steel plates and strips caused by the ran-domness of the thicknesses of two local points and improve the reliability of the wedge index,the double-centroid method for the wedge evaluation was proposed,and a model based on the centroid theory was established.Meanwhile,an integral model for the discrete thickness values of the cross-section profiles was derived.The discussion focused on the distinct characteristics of the two-point method,asymmetric method,and double-centroid method in evaluating the asymmetric distribution of cross-sections.The three methods were employed to evaluate the wedge values of both the theoretical and measured cross-sections of steel plates and strips,and the accuracies of three wedge evaluation models were analyzed and discussed.The results showed that the double-centroid method objectively reflects the degree and variation characteristics of the wedge values of the cross-sections of steel plates and strips,and this method is feasible,reliable,and outstanding.
文摘Background: Biplanar medial opening wedge high tibial osteotomy (MOWHTO) is a treatment method that allows adequate correction of symptomatic varus knee deformity. However, MOWHTO tends to decrease patellar height and increase the posterior tibial slope, which can affect the knee joint stability. Objective: The aim of this study was to describe the technique of biplanar MOWHTO and fixation by TomoFix plate, as well as to evaluate the accuracy of the planned correction and the postoperative tibial slope. Patients and Methods: This prospective cohort study was conducted on patients who presented with varus knee deformity and underwent biplanar MOWHTO and fixation by TomoFix plate during the period from March 2016 to March 2017. Assessment of patients included pre- and postoperative Knee and function scores, mechanical femorotibial angle (mFTA), posterior tibial slope angle (pTSA), range of motion (ROM) and radiological evaluation of the healing of the osteotomy site. Results: The recruited patients were 13 (8 men and 5 women), with average age 31.7 years old. The knee and functional scores improved from the preoperative mean of 45 and 41 to the postoperative mean of 85 and 72 points, respectively. The average knee flexion was 115 degrees, which at the final follow-up remained unchanged except for one case. The mean preoperative mFTA was 13.5°varus and decreased post-operatively to a mean of 3°valgus. The average postoperative follow-up period was 12 months (10 - 18 M). Conclusion: The biplanar MOWHTO allows preservation of posterior tibial slope while correcting the varus knee adequately.
文摘Cryogenic wedges developed due to very cold,rather arid conditions during the maximum of the last cold event when the drying up of the neighboring China Sea resulted in the failure of the East Asian Monsoon.As the climate ameliorated and the Monsoon rains reappeared,ice-wedges developed.Further warming permitted thawing of the ice infillings accompanied by replacement of the ice by sediments partly from the host ground as well as from the surface by wind or sheet wash.In cases of extreme surface water flow on slopes after 10 ka B.P.,small baydjarakhs typically c.50 cm high developed,only to have the resulting hollows infilled by sediments carried by wind and/or sheet wash.These shallow structures form a network on top of many of the cryogenic wedges.This complex history makes dating the ages of the wedges difficult using OSL methodology.Unfortunately,past field work ignored the problem of the angle of the cut face to the direction of the wedge infilling when sampling the contents of the narrow wedges,resulting in potential contamination of the samples with the host sediment.Sampling of the larger deposits should be alright,but the likelihood of contamination makes the interpretation of the resulting OSL dates from the narrow wedges questionable.Primary wedges consisting of primary mineral infillings should still have similar OSL dates with depth for a given wedge,but the distinction between ice-wedge infillings and soil wedges is difficult since both can exhibit older dates of the infillings with depth.The available data suggests that ice-wedges were significantly more common than sediment-filled primary wedges.A protocol to avoid having to obtain large numbers of OSL dates by more careful field sampling and the use of grain size determinations is provided in the Appendix.
基金Supported by Capital Medical University Affiliated Beijing Shijitan Hospital Talent Development Program during the 14th Five-Year Plan,No.2023 LJRCLFQ.
文摘BACKGROUND Wedged hepatic venous pressure(WHVP)is a crucial variable for accurately assessing the hepatic venous pressure gradient(HVPG)and is vital for the diagnosis and prognostic evaluation of patients with portal hypertension(PH).AIM To investigate the anatomical characteristics of balloon-occluded hepatic venous angiography in patients with PH and analyze the relationship between the WHVP and portal venous pressure(PVP).METHODS This retrospective study included 877 patients with PH who met the inclusion criteria from January 2020 to June 2024.Routine and innovative hepatic venous angiography was performed during transjugular intrahepatic portosystemic shunt procedures to measure hepatic venous and PVPs.All patients'angiographic images were collected for analysis.The associations between WHVP and PVP in each group were analyzed via linear regression analysis,and a predictive model was established.RESULTS The 877 patients had a mean age of 52.6±13.0 years,with 582 males and 295 females.Patients were categorized into four groups on the basis of their anatomical structure.All groups showed strong correlations between WHVP and PVP.The regression coefficient between the WHVP and PVP in the hepatic right vein-portal venous angiography group was 0.884(P<0.05);in the hepatic right vein-accessory hepatic venous angiography group,it was 0.721(P<0.05);in the hepatic right vein-middle hepatic venous angiography group,it was 0.344(P<0.05);and in the hepatic right vein-nonangiography group,it was 0.293(P<0.05).CONCLUSION The presence and anatomical classification of hepatic venous collaterals are key factors influencing the relationship between WHVP with and PVP.Based on the different anatomical classifications of hepatic veins,WHVP can be used to estimate PVP,improving the accuracy of PVP prediction.
基金Kinross Gold and MITACS for their financial support(Grant No.FR42880).
文摘The goal of this research is to develop mine-scale discrete fracture network(DFN)models in which the influence of the spatial heterogeneity of fracture distributions may be investigated on the rock wedge stability of an open pit slope.For this purpose,spatially conditioned DFN models were developed for the pit walls at Tasiast mine using comprehensive structural data from the mine.Using Sequential Gaussian Simulation(SGS),volumetric fracture intensities(P32)were modeled across the entire mine site in the form of 3D block models.The simulated P32 block models were used as the input constraints for conditional DFN fracture generation,where the DFN grid dimension is the same as the SGS 3D blocks.The spatially constrained DFN models were further calibrated using aerial fracture intensities(P21)data from the pit walls,obtained by a survey of the pit walls using an unmanned aerial vehicle(UAV)and measured traces of joints from 3D point cloud data.The final DFN model is expected to honor the fracture intensities gathered through different means with optimal model accuracy.Finally,bench-scale and interramp scale rock wedge slope stability analyses were conducted using the calibrated conditional DFN models.This work proves the significance of conditioned DFN models in rock wedge stability analysis.Such models provide detailed information regarding rock wedge stability so that site monitoring and prevention plans can be conducted with higher efficiency.
文摘Aim: To introduce and characterize the modified biplanar opening high tibial osteotomy with rigid fixation to treat unicompartmental knee arthritis with varus deformity in active lifestyle patients. Patients and Method: 48 patients (19 females) with monocompartmental gonarthrosis of the knee combined with varus malalignment, 41 with bilateral affection and 7 cases with unilateral gonarthritis (total 89 knees). Mean age: 53 years (range from 42 to 61 years). They were treated and followed from June 2010 to May 2014 (35 months). Biplanar opening high tibial osteotomy technique was used and fixed by low profile locked T-plate (21 cases) and low profile anatomical proximal tibial plate (27cases). Pre-operative mean varus deformity was 16.5° (9° - 19°). We utilized Lysholm score and Knee Society Score for evaluation of preoperative and follow-up data. Results: The average correction angle was 11.50 ± 2.50° (7° - 19°). Preoperative posterior tibial slope was 8.04° ± 1.30° and at last follow-up 9.15° ± 1.60°, respectively (p = 0.437). The joint space distance increased from 4.05 ± 1.30 mm to 4.83 ± 1.33 mm (p < 0.001). The average time to complete bone union was 14.69 ± 1.5 weeks. There were no cases of delayed union or non-union. No major complications like broken plate, nerve injury, or blood vessel injury occurred. No progression of degenerations developed in the three compartments of the knee at final follow-up. The mean score on the Lysholm-Gillquist knee functional scoring scale was 45.5 ± 21.7 preoperatively, and it improved to 77.0 ± 23.9 (p < 0.001). There was no obvious difference in the range of motion before and after operation. The average knee score improved from 51.19 ± 11.82 to 93.49 ± 5.10. Conclusion: Biplanar opening high tibial osteotomy fixed with locking compression plate gives good results for symptomatic unicompartmental gonarthrosis with genu varum. Also this technique can be applied for medial compartment degeneration of the knee without deformity with good functional outcomes.
基金supported by the Independent Innovation Science Fund of National University of Defense Technology(No.24-ZZCX-BC-05)National Natural Science Foundation of China(Nos.92271110 and 12202488)+2 种基金the Major National Science and Technology Project(No.J2019-Ⅲ0010-0054)the National Postdoctoral Researcher Program of China(No.GZB20230985)the Natural Science Program of National University of Defense Technology(No.ZK22-30)。
文摘The phenomenon of shock/shock interaction(SSI)is widely observed in high-speed flow,and the double wedge SSI represents one of the typical problems encountered.The control effect of single-pulse plasma synthetic jet(PSJ)on double wedge type-Ⅵand type-ⅤSSI was investigated experimentally and numerically,and the influence of discharge energy was also explored.The findings indicate that the interaction between PSJ and the high-speed freestream results in the formation of a plasma layer and a jet shock,which collectively governs the control of SSI.The control mechanism of single-pulse PSJ on SSI lies in its capacity to attenuate both shock and SSI.For type-ⅥSSI,the original second-wedge oblique shock is eliminated under the control of PSJ,resulting in a new type-ⅥSSI formed by the jet shock and the first-wedge oblique shock.For type-ⅤSSI,the presence of PSJ effectively mitigates the intensity of Mach stem,supersonic jet,and reflected shocks,thereby facilitating its transition into type-ⅥSSI.The numerical results indicate that the peak pressure can be reduced by approximately 32.26%at maximum.Furthermore,the development of PSJ also extends in the Z direction.The pressure decreases in the area affected by both PSJ and jet shock due to the attenuation of the SSI zone.With increasing discharge energy,the control effect of PSJ on SSI is gradually enhanced.
文摘Seismic quantitative reservoir simulations and characterizations have played a vital role in exploring stratigraphic traps,such as lateaggradational lowstands prograding wedge systems(LPWS)within lowstands systems tracts(LST).However,seismic data acquisition operations are always dominated by exceptional seismic coherent noise events,e.g.,multiples,which reduce the signal strengths of the sourcegenerated incident seismic waves within vertically and laterally heterogeneous earth systems.Hence,these noise events create hurdles in predicting paleo-depositional impedance(PDI),paleo-thickness(PTS),paleo-dense fractured networks,erosional and depositional zones,faultcontrolled migrations,and types of seismic reflection configurations(SRFC),which are key elements in developing stratigraphic pinch-out traps.This research utilizes the state-of-the-art technologies of spectral wavelet-based instantaneous time-frequency analysis and seismic waveform frequency-controlled porosity-constrained static reservoir simulation(FDPVS)tools to quantify the LPWS inside the Onshore Basin,Pakistan.The use of conventional amplitude-based seismic attributes,such as the average energy,remained a better tool for deciphering the overall geological architecture of the LPWS.Conventional FDPVS realizations resolved a PDI of−1.391 gm./c.c.^(*)m/s to−0.97 gm./c.c.^(*)m/s for LPWS with PTS of 12 and 20 m,respectively.A 0.9 km lateral extent of paleo-dense fractured networks(PDFN)with a strong linear regression R^(2)=0.93 was also resolved.Average energy attribute-based instantaneous frequency FDPVS realizations enabled the imaging of parallel-toprograding SRFC with resolved magnitudes of−0.259 gm./c.c.^(*)m/s for PDI,20 m for PTS,and 0.73 km for PDFN with linear regression transforms at R^(2)=0.92,which indicates the deposition of onlap fill facies inside the LPWS during extensive sea-level fall.These realizations have also resolved frequency-controlled fault migrations on 27-Hz spectral waveform-based amplitude plots with 2.174 gm./c.c.^(*)m/s PDI for conduit fault systems and 27-Hz with 0.585 gm./c.c.^(*)m/s PDI for sealing fault systems.All these structural configurations are completely sealed up by transgressive seals of transgressive systems tracts and,hence,developed into pure stratigraphic-based oil and gas plays.This research has strong implications for side-tracking drilling locations and provides an analogue for basins with similar geology and stratigraphy worldwide.
基金the National Natural Science Foundation of China(No.61834005,61772417,61802304,61602377,61874087,61634004)Shaanxi International Science and Technology Cooperation Program(No.2018KW-006).
文摘To reduce the computational complexity and storage cost caused by wedge segmentation algorithm,a scheme of simplifying wedge matching is proposed.It takes advantage of the correlation of the wedge separation line of depth map and the direction of intra-prediction for 3D high-efficiency video coding(3D-HEVC).According to the difference of wedge segmentation between adjacent edge and opposite edge,a set only including 104×4 wedgelet templates is given.By expanding of the wedge wave of a certain minimum unit,a simple separation line acquisition method for different size of depth block is put forward.Furthermore,based on the array processor(DPR-CODEC)developed by project team,an efficient parallel scheme of the improved wedge segmentation mode prediction is introduced.By the scheme,prediction unit(PU)size can be changed randomly from 4×4 to 8×8,16×16,and 32×32,which is more in line with the needs of the HEVC standard.Veri-fied with test sequence in HTM16.1 and the Xilinx virtex-6 field programmable gate array(FPGA)respectively,the experiment results show that the proposed methods save 99.2%of the storage space and 63.94%of the encoding time,the serial/parallel acceleration ratio of each template reaches 1.84 in average.The coding performance,storage and resource consumption are considered for both.
基金supported by the National Natural Science Foundation of China(Nos.U2167202,12225504,12005276)the Natural Science Foundation of Shandong Province(No.ZR2024QA172)the Fundamental Research Funds of Shandong University.
文摘A 32-channel charge-sensitive amplifier(CSA)is designed for fast timing in the delay-line readout of a parallel plate avalanche counter(PPAC)array.It is realized on a PCB with operational amplifiers and other discrete components.Each channel consists of an integrator,a pole-zero cancellation net,and a linear amplification stage,which can be adapted to accommodate either positive or negative input signals.The RMS equivalent input noise charges are 3.3 fC,the conversion gains are approximately±2 mV∕fC,and the intrinsic time resolution reaches 32 ps.In the prototype PPAC application,the CSA performs as well as the commercial FTA820A amplifier,providing a position resolution as good as 0.17 mm,and exhibiting reliable stability during several hours of continuous data acquisition.
基金supported by Guangdong Major Project of Basic and Applied Basic Research, China (No. 2020B0301030006)Fundamental Research Funds for the Central Universities, China (No. SWU-XDJH202313)+1 种基金Chongqing Postdoctoral Science Foundation Funded Project, China (No. 2112012728014435)the Chongqing Postgraduate Research and Innovation Project, China (No. CYS23197)。
文摘A new method was proposed for preparing AZ31/1060 composite plates with a corrugated interface,which involved cold-pressing a corrugated surface on the Al plate and then hot-pressing the assembled Mg/Al plate.The results show that cold-pressing produces intense plastic deformation near the corrugated surface of the Al plate,which promotes dynamic recrystallization of the Al substrate near the interface during the subsequent hot-pressing.In addition,the initial corrugation on the surface of the Al plate also changes the local stress state near the interface during hot pressing,which has a large effect on the texture components of the substrates near the corrugated interface.The construction of the corrugated interface can greatly enhance the shear strength by 2−4 times due to the increased contact area and the strong“mechanical gearing”effect.Moreover,the mechanical properties are largely depended on the orientation relationship between corrugated direction and loading direction.
基金Supported by the National Natural Science Foundation of China under Grant No.51975138the High-Tech Ship Scientific Research Project from the Ministry of Industry and Information Technology under Grant No.CJ05N20the National Defense Basic Research Project under Grant No.JCKY2023604C006.
文摘Marine thin plates are susceptible to welding deformation owing to their low structural stiffness.Therefore,the efficient and accurate prediction of welding deformation is essential for improving welding quality.The traditional thermal elastic-plastic finite element method(TEP-FEM)can accurately predict welding deformation.However,its efficiency is low because of the complex nonlinear transient computation,making it difficult to meet the needs of rapid engineering evaluation.To address this challenge,this study proposes an efficient prediction method for welding deformation in marine thin plate butt welds.This method is based on the coupled temperature gradient-thermal strain method(TG-TSM)that integrates inherent strain theory with a shell element finite element model.The proposed method first extracts the distribution pattern and characteristic value of welding-induced inherent strain through TEP-FEM analysis.This strain is then converted into the equivalent thermal load applied to the shell element model for rapid computation.The proposed method-particularly,the gradual temperature gradient-thermal strain method(GTG-TSM)-achieved improved computational efficiency and consistent precision.Furthermore,the proposed method required much less computation time than the traditional TEP-FEM.Thus,this study lays the foundation for future prediction of welding deformation in more complex marine thin plates.
基金supported by the National Key R&D Program of China (No. 2018YFA0707300)the National Natural Science Foundation of China (No. 52374376)the Introduction Plan for High end Foreign Experts, China (No. G2023105001L)。
文摘Titanium plates with a Ti−O solid solution surface-hardened layer were cold roll-bonded with 304 stainless steel plates with high work hardening rates.The evolution and mechanisms affecting the interfacial bonding strength in titanium/stainless steel laminated composites were investigated.Results indicate that the hardened layer reduces the interfacial bonding strength from over 261 MPa to less than 204 MPa.During the cold roll-bonding process,the hardened layer fractures,leading to the formation of multi-scale cracks that are difficult for the stainless steel to fill.This not only hinders the development of an interlocking interface but also leads to the presence of numerous microcracks and hardened blocks along the nearly straight interface,consequently weakening the interfacial bonding strength.In metals with high work hardening rates,the conventional approach of enhancing interface interlocking and improving interfacial bonding strength by using a surface-hardened layer becomes less effective.
