BACKGROUND Intraoperative determination of resection margin and adequate residual liver parenchyma are the key points of hepatectomy for the treatment of liver tumors.Intraoperative ultrasound and indocyanine green fl...BACKGROUND Intraoperative determination of resection margin and adequate residual liver parenchyma are the key points of hepatectomy for the treatment of liver tumors.Intraoperative ultrasound and indocyanine green fluorescence navigation are the most commonly used methods at present,but the technical barriers limit their promotion.AIM To evaluate the value of the three-dimensional location approach with silk thread(3D-LAST)in precise resection of liver tumors.METHODS From September 2020 to January 2022,8 patients with liver tumors including hepatocellular carcinoma,intrahepatic cholangiocarcinoma,hilar cholangiocar-cinoma,and gastric cancer liver metastasis were included in this study.All patients underwent 3D-LAST in precise resection of liver tumors.RESULTS All patients(8/8,100%)underwent the operation successfully without any complications.During the mean follow-up of 8.7 months,all patients survived without tumor recurrence.CONCLUSION In conclusion,the 3D-LAST is a safe and effective new method for liver intraop-erative navigation,which is practical and easy to promote.Core Tip:The aim of this study is to evaluate the value of the three-dimensional location approach with silk thread(3D-LAST)in precise resection of liver tumors.Eight patients with liver tumors including hepatocellular carcinoma,intrahepatic cholangiocarcinoma,hilar cholangiocarcinoma,and gastric cancer liver metastasis underwent the operation successfully without any complications.During the mean follow-up of 8.7 months,all patients survived without tumor recurrence.In conclusion,the 3D-LAST is a safe and effective new method for liver intraoperative navigation,which is practical and easy to promote.INTRODUCTION Hepatectomy is widely used for the treatment of liver tumors.In recent decades,the concept and practice of hepatectomy have developed from irregular,regular and anatomical to the current precise resection.Necessary assistive technologies have enabled these advances.Intraoperative ultrasound(IOUS)localization and indocyanine green(ICG)fluorescence imaging guidance are two frequently-used approaches for laparoscopic hepatectomy[1,2].IOUS is an invaluable auxiliary means widely accepted in surgery for real-time diagnostic information to determine resection range and navigate the surgical path[3].However,the major limitation of IOUS is the time cost during the procedure for paging the sono-graphers and the difficulty of deciphering two dimensional images[4].ICG is a non-toxic water-soluble fluorophore that reveals fluorescence under the near-infrared spectrum[5].Since liver tissue penetration is limited to 5 to 10 mm,that restricted the visualization of deeper tumors by ICG excitation,thereby interfering with its application in laparoscopic hepatectomy[6].IOUS and ICG navigation require specific technical equipment,making implementation difficult in many centers.And these techniques will significantly increase the operation time.Three-dimensional(3D)visualization involves extracting features and producing volumetric images based on computed tomography(CT)through a computer postprocessing technique.This tool offers a reasonable approach to the clinical decision for the potential to display the complex internal anatomy in an intuitive and stereoscopic manner[7].In the past few decades,applying 3D simulation software for liver volume calculation,virtual simulation surgery,portal hypertension monitor,and surgical navigation has proven to be safe and effective[8].Therefore,we propose a new method to find obvious anatomical markers and calculate the resection range according to 3D positioning before operation.During the operation,the scope of resection was delineated with silk thread,and resection was performed.This is a new practical approach,which we named as 3D location approach with silk thread(3D-LAST).RESULTS During the study period from September 2020 to January 2022,5 patients with hepatocellular carcinoma,1 patient with intrahepatic cholangiocarcinoma,1 patient with hilar cholangiocarcinoma,and 1 patient with gastric cancer liver metastasis were assessed for liver resection.There were 5 males and 3 females.The mean age of these patients was 54.3±10.2 years(34-66 years).Preoperative 3D positioning was conducted and the scope of resection was delineated with a surgical suture successfully performed in all 8 patients without complications.The treatment results of these 8 patients are shown in Table 1.The 90-day operative mortality was zero.Complications worse than Dindo-Clavien IIIa was not observed at a mean follow-up time of 8.7 months(4-16 months),there was no evidence of tumor recurrence or extrahepatic metastasis.At the time of reporting,the patients are all alive and lead normal lives.We take one patient as an example,58-year-old male,who found a liver lesion 10 months after gastric cancer surgery.Enhanced CT showed that the lesion was located in the liver S5,about 1.5 cm in diameter,and considered metastatic lesions.We performed 3D-LAST guided hepatectomy on this patient(Figure 1).Other representative 3D-LAST surgical procedures are shown in Figure 2.展开更多
Fracture surface contour study is one of the important requirements for characterization and evaluation of the microstructure of rocks.Based on the improved cube covering method and the 3D contour digital reconstructi...Fracture surface contour study is one of the important requirements for characterization and evaluation of the microstructure of rocks.Based on the improved cube covering method and the 3D contour digital reconstruction model,this study proposes a quantitative microstructure characterization method combining the roughness evaluation index and the 3D fractal dimension to study the change rule of the fracture surface morphology after blasting.This method was applied and validated in the study of the fracture microstructure of the rock after blasting.The results show that the fracture morphology characteristics of the 3D contour digital reconstruction model have good correlation with the changes of the blasting action.The undulation rate of the three-dimensional surface profile of the rock is more prone to dramatic rise and dramatic fall morphology.In terms of tilting trend,the tilting direction also shows gradual disorder,with the tilting angle increasing correspondingly.All the roughness evaluation indexes of the rock fissure surface after blasting show a linear and gradually increasing trend as the distance to the bursting center increases;the difference between the two-dimensional roughness evaluation indexes and the three-dimensional ones of the same micro-area rock samples also becomes increasingly larger,among which the three-dimensional fissure roughness coefficient JRC and the surface roughness ratio Rs display better correlation.Compared with the linear fitting formula of the power function relationship,the three-dimensional fractal dimension of the postblast fissure surface is fitted with the values of JRC and Rs,which renders higher correlation coefficients,and the degree of linear fitting of JRC to the three-dimensional fractal dimension is higher.The fractal characteristics of the blast-affected region form a unity with the three-dimensional roughness evaluation of the fissure surface.展开更多
The anatomy of the human liver is complex,and the vascular system is highly variable.Moreover,the use of traditional com-puted tomography(CT)two-dimensional(2D)images to recon-struct the tissue and organs requires exp...The anatomy of the human liver is complex,and the vascular system is highly variable.Moreover,the use of traditional com-puted tomography(CT)two-dimensional(2D)images to recon-struct the tissue and organs requires experienced doctors and lim-its the sharing and discussion of therapeutic plans[1].展开更多
The kagome metals AV_(3)Sb_(5)(A=K,Rb,Cs)feature intertwined Dirac fermions,topological flat bands,and van Hove singularities(vHS)near the Fermi level,which give rise to a range of exotic,strongly correlated phenomena...The kagome metals AV_(3)Sb_(5)(A=K,Rb,Cs)feature intertwined Dirac fermions,topological flat bands,and van Hove singularities(vHS)near the Fermi level,which give rise to a range of exotic,strongly correlated phenomena such as charge density waves(CDW)and superconductivity.Although the vHS from V 3d states have been implicated in CDW formation,their three-dimensional nature and temperature evolution remain poorly understood.In this study,we used high-resolution angle-resolved photoemission spectroscopy and density functional theory to reveal pronounced out-of-plane dispersion of vHS and their temperature dependence in KV_(3)Sb_(5).The identified c-axis band folding and scattering channels were directly linked to the CDW order.These results demonstrate that the CDW transition in this family involves cooperative coupling between electron correlations and structural modulation along the c axis.This offers new insights into the interplay of topology,correlations,and lattice instabilities in kagome metals.展开更多
Gaseous detonation propagating in a toroidal chamber was numerically studied for hydrogen/oxygen/nitrogen mixtures. The numerical method used is based on the three-dimensional Euler equations with detailed finiterate ...Gaseous detonation propagating in a toroidal chamber was numerically studied for hydrogen/oxygen/nitrogen mixtures. The numerical method used is based on the three-dimensional Euler equations with detailed finiterate chemistry. The results show that the calculated streak picture is in qualitative agreement with the picture recorded by a high speed streak camera from published literature. The three-dimensional flow field induced by a continuously rotating detonation was visualized and distinctive features of the rotating detonations were clearly depicted. Owing to the unconfined character of detonation wavelet, a deficit of detonation parameters was observed. Due to the effects of wall geometries, the strength of the outside detonation front is stronger than that of the inside portion. The detonation thus propagates with a constant circular velocity. Numerical simulation also shows three-dimensional rotating detonation structures, which display specific feature of the detonation- shock combined wave. Discrete burning gas pockets are formed due to instability of the discontinuity. It is believed that the present study could give an insight into the interest- ing properties of the continuously rotating detonation, and is thus beneficial to the design of continuous detonation propulsion systems.展开更多
In this article, we report the preparation of a three-dimensional（3D） interconnected mesoporous anatase TiO2-SiO2 nanocomposite. The nanocomposite was obtained by using an ordered two-dimensional（2D） hexagonal mes...In this article, we report the preparation of a three-dimensional（3D） interconnected mesoporous anatase TiO2-SiO2 nanocomposite. The nanocomposite was obtained by using an ordered two-dimensional（2D） hexagonal mesoporous anatase 70 TiO2-30 SiO2-950 nanocomposite（crystallized at 950 °C for 2 h） as a precursor, NaO H as an etchant of SiO2 via a ＂creating mesopores in the pore walls＂ approach. Our strategy adopts mild conditions of creating pores such as diluted NaO H solution, appropriate temperature and solid/liquid ratio, etc. aiming at ensuring the integrities of mesopores architecture and anatase nanocrystals. XRD, TEM and N2 sorption techniques have been used to systematically investigate the physico-chemical properties of the nanocomposites. The results show that the intrawall mesopores are highly dense and uniform（average pore size 3.6 nm）, and highly link the initial mesochannels in a 3D manner while retaining mesostructural integrity. There is no significant change to either crystallinity or size of the anatase nanocrystals before and after creating the intrawall mesopores. The photocatalytic degradation rates of rhodamine B（RhB, 0.303 min^–1） and methylene blue（MB, 0.757 min^–1） dyes on the resultant nanocomposite are very high, which are 5.1 and 5.3 times that of the precursor; even up to 16.5 and 24.1 times that of Degussa P25 photocatalyst, respectively. These results clearly demonstrate that the 3D interconnected mesopores structure plays an overwhelming role to the increments of activities. The 3D mesoporous anatase TiO2-SiO2 nanocomposite exhibits unexpected-high degradation activities to RhB and MB in the mesoporous metal oxide-based materials reported so far. Additionally, the nanocomposite is considerably stable and reusable. We believe that this method would pave the way for the preparation of other 3D highly interconnected mesoporous metal oxide-based materials with ultra-high performance.展开更多
A calculation scheme, which combines a horizontal upwind finite element method with vertical implicit differences, is used to establish a three-dimensional mathematical model of tidal motion and sediment transport in...A calculation scheme, which combines a horizontal upwind finite element method with vertical implicit differences, is used to establish a three-dimensional mathematical model of tidal motion and sediment transport in tidal current. Compared with those of the relative theoretical formula, the results are satisfactory. The model mentioned above has been applied to the water area of the Lianzhou Bay, Guangxi Province. On the basis of the analysis and comparison with the field data, it shows clearly that the model calculation results are reasonable.展开更多
Objective: To study the clinical significance of multi-slice spiral CT 3-dimensional (3D) portography in portal vein tumor thrombosis of hepatocellular cacinoma.Methods: 57 cases undergoing 3D portography were collect...Objective: To study the clinical significance of multi-slice spiral CT 3-dimensional (3D) portography in portal vein tumor thrombosis of hepatocellular cacinoma.Methods: 57 cases undergoing 3D portography were collected, of which 6 cases were normal, 5 cases were subjected to cirrhosis and hypertension of portal vein, 42 cases had portal tumor thrombus of hepatic cancer, and the remaining 4 cases showed lymph node enlargment in hilar of liver. All data of the patients came from conventional multi-slice spiral CT double phase of liver. Contrast media was 1.5–2 ml/kg with the injection rate being 2.5–3 ml/s. Axis and 3D portography was analyzed and compared in 42 cases of portal tumor thrombus of hepatic cancer.Results: According to portal tumor thrombus position, 42 cases were fallen into three categories: left (13 cases), right (20 cases), main (9 cases) of potal vein. There was no difference between axis and 3D portography in displaying portal tumor thrombus of hepatic cancer (P>0.05), but 3D portography showing collateral branches was better than axis portography after main portal vein thrombus.Conclusion: Multi-slice spiral CT 3D portography can display the position and types of portal tumor thrombus of hepatic cancer. 3D combined with axis portography can better evaluate the portal tumor thrombus of hepatic cancer and guide to select the therapies. Key words portal vein - tumor thrombus - multi-slice CT - 3 dimension imaging展开更多
Through the introduction of disaster situation of Qiang Culture after Wenchuan Earthquake, the paper emphasized that carriers of Qiang Culture had been seriously damaged, the inheritance of Qiang Culture had been affe...Through the introduction of disaster situation of Qiang Culture after Wenchuan Earthquake, the paper emphasized that carriers of Qiang Culture had been seriously damaged, the inheritance of Qiang Culture had been affected, and the environment for Qiang Culture was difficult to recover. It highlighted that three-dimensional reconstruction of Qiang Culture should stress the core task and timely and effectively rescue endangered cultural heritages of Qiang Nationality from the perspectives of material and spiritual life. It had explained focuses of three-dimensional pattern construction in detail. In terms of spatial reconstruction, it should reconstruct native culture and history while material culture was constructed, and reconstruct Qiang culture highland by depending on aborigines; in terms of cluster reconstruction, it should give support to large tourism enterprises and perfect tourism chain; in terms of ecological reconstruction, it should enhance construction and demonstration of "ecological protection pilot area of Qiang culture"; in terms of development reconstruction, it should realize coordinated unity between protection and development according to classification protection, characteristic protection and key protection, so as to form the virtuous circle of post-disaster recovery protection and sustainable development.展开更多
The three-dimensional electromagnetic characteristics and non-uniform distribution of electromagnetic field in soft-contact continuous casting mold have been analyzed by numerical simulation. The results show that the...The three-dimensional electromagnetic characteristics and non-uniform distribution of electromagnetic field in soft-contact continuous casting mold have been analyzed by numerical simulation. The results show that the maximum electromagnetic flux density is found in front of slit; the electromagnetic flux density becomes large as the coil current and slit number increase. In a certain frequency range, the electromagnetic flux density increases with the increase of frequency and the frequency range is different with the change of azimuthal position along the inner wall of mold. The uniformity of electromagnetic field is influenced mainly by frequency and mold structure parameters. Increasing slit number and adjusting slit arrangement position can improve the electromagnetic flux density and the uniformity of electromagnetic field. For a soft-contact mold with 16 slits, when frequency is 20 kHz, the optimal slit arrangement parameter is a:b=1:2, c=0.展开更多
To provide appropriate uses of nonlinear ground response analysis for engineering practice, a three-dimensional soil column with a distributed mass system and a time domain numerical analysis were implemented on the O...To provide appropriate uses of nonlinear ground response analysis for engineering practice, a three-dimensional soil column with a distributed mass system and a time domain numerical analysis were implemented on the Open Sees simulation platform. The standard mesh of a three-dimensional soil column was suggested to be satisfied with the specified maximum frequency. The layered soil column was divided into multiple sub-soils with a different viscous damping matrix according to the shear velocities as the soil properties were significantly different. It was necessary to use a combination of other one-dimensional or three-dimensional nonlinear seismic ground analysis programs to confirm the applicability of nonlinear seismic ground motion response analysis procedures in soft soil or for strong earthquakes. The accuracy of the three-dimensional soil column finite element method was verified by dynamic centrifuge model testing under different peak accelerations of the earthquake. As a result, nonlinear seismic ground motion response analysis procedures were improved in this study. The accuracy and efficiency of the three-dimensional seismic ground response analysis can be adapted to the requirements of engineering practice.展开更多
Three-dimensionally ordered macro-porous （3DOM） TiO2 and ceria-modified 3DOM TiO2 supported platinum catalysts were prepared with template and impregnation methods, and the resultant samples were characterized by sc...Three-dimensionally ordered macro-porous （3DOM） TiO2 and ceria-modified 3DOM TiO2 supported platinum catalysts were prepared with template and impregnation methods, and the resultant samples were characterized by scanning electron microscopy（SEM）, X-ray diffractometer（XRD）, high-resolution transmission electron microscopy（HRTEM） and temperature programmed reducfion（TPR） techniques. The catalytic performances over the platinum-based catalysts were investigated for water-gas shift （WGS） reaction in a wide temperature range （180-360 ℃）. The results showed that 3DOM Pt/TiO2 catalyst exhibited obviously better catalytic performance than the corresponding non macro-porous catalyst, owing to the macro-porous structure favoring mass transfer. Addition of celia into 3DOM Pt/TiO2 led to improvement of catalytic activity. TPR and HRTEM results showed that the interaction existed between ceria and titanium oxide and addition of ceria promoted the reducibility of platinum oxide and TiO2 on the interface of platinum and TiO2 particles, which contributed to high activity of the celia modified catalysts. The results indicated that ceria-modified 3DOM Pt/TiO2 was a promising candidate of fuel cell oriented WGS catalyst.展开更多
To study fluctuations of the free surface of liquid steel in the mold,two different models with the same casting conditions but different thicknesses were employed to analyze the hydrodynamic behavior at the top of th...To study fluctuations of the free surface of liquid steel in the mold,two different models with the same casting conditions but different thicknesses were employed to analyze the hydrodynamic behavior at the top of the mold.The first model was a standard thickness slab,and the second had a thickness three times wider.It is found with the second model that above the plane formed by the steel jets,it is possible to observe four three-dimensional vortexes that interact with the submerged entry nozzle（SEN）and mold walls.By using a biphasic model to simulate the interface between the liquid and air inside the mold,the flow asymmetry and the fluctuations of the free surface can be clearly observed.展开更多
The present study evaluated the application of three dimensional echocardigraphy （3DE） in the diagnosis of atrial septal defect （ASD） and the measurement of its size by 3DE and compared the size with surgical find...The present study evaluated the application of three dimensional echocardigraphy （3DE） in the diagnosis of atrial septal defect （ASD） and the measurement of its size by 3DE and compared the size with surgical findings. Two-dimensional and real-time three dimensional echocardiography （RT3DE） was performed in 26 patients with atrial septal defect, and the echocardiographic data were compared with the surgical findings. Significant correlation was found between defect diameter by RT3DE and that measured during surgery （r=0.77, P〈0.001）. The defect area changed significantly during cardiac cycle. Percentage change in defect size during cardiac cycle ranged from 6%-70%. Our study showed that the size and morphology of atrial septal defect obtained with RT3DE correlate well with surgical findings. Therefore, RT3DE is a feasible and accurate non-invasive imaging tool for assessment of atrial septal size and dynamic changes.展开更多
Reticulated polyurethane was chosen as the preceramic material for preparing the porous preform using the replication process. The immersing and sintering processes were each performed twice for fabricating a high-por...Reticulated polyurethane was chosen as the preceramic material for preparing the porous preform using the replication process. The immersing and sintering processes were each performed twice for fabricating a high-porosity and super-strong skeleton. The aluminum magnesium matrix composites reinforced with three-dimensional network structure were prepared using the infiltration technique by pressure assisting and vacuum driving. Light interfacial reactions have played a profitable role in most of the ceramic-metal systems. The metal matrix composites interpenetrated with the ceramic phase have a higher wear resistance than the metal matrix phase. The volume fraction of ceramic reinforcement has a significant effect on the abrasive wear, and the wear rate can be decreased with the increase of the volume fraction of reinforcement.展开更多
Transient behavior of three-dimensional semiconductor device with heat conduc- tion is described by a coupled mathematical system of four quasi-linear partial differential equations with initial-boundary value conditi...Transient behavior of three-dimensional semiconductor device with heat conduc- tion is described by a coupled mathematical system of four quasi-linear partial differential equations with initial-boundary value conditions. The electric potential is defined by an ellip- tic equation and it appears in the following three equations via the electric field intensity. The electron concentration and the hole concentration are determined by convection-dominated diffusion equations and the temperature is interpreted by a heat conduction equation. A mixed finite volume element approximation, keeping physical conservation law, is used to get numerical values of the electric potential and the accuracy is improved one order. Two con- centrations and the heat conduction are computed by a fractional step method combined with second-order upwind differences. This method can overcome numerical oscillation, dispersion and decreases computational complexity. Then a three-dimensional problem is solved by computing three successive one-dimensional problems where the method of speedup is used and the computational work is greatly shortened. An optimal second-order error estimate in L2 norm is derived by using prior estimate theory and other special techniques of partial differential equations. This type of mass-conservative parallel method is important and is most valuable in numerical analysis and application of semiconductor device.展开更多
2D,3D chloride ion concentration at the edge and corner zones were systematically investigated for fly ash concretes made with different cement replacement percentage by fly ash （0%,10%,20%,40%,60%）,water to binder ...2D,3D chloride ion concentration at the edge and corner zones were systematically investigated for fly ash concretes made with different cement replacement percentage by fly ash （0%,10%,20%,40%,60%）,water to binder ratios （0.3,0.35,0.4）,and curing ages （28 d,90 d）.An interaction effect caused by 2D and 3D diffusion could obviously be observed through the comparison with 1D testing results.In order to quantify the interaction effect,2D and 3D diffusion interaction coefficients was proposed in this paper.Finally,the changes of 2D and 3D interaction coefficients with the change in the free chloride ion concentration were given.The above research provide an insight into chloride ion attack on the edge and corner reinforcing bars of concrete structures in the field of civil engineering.展开更多
A deformation monitoring network that covers part of North China area and takes the Beijing region as the center was measured for two times with high precision GPS in 1995 and 1996 respectively. The results from reme...A deformation monitoring network that covers part of North China area and takes the Beijing region as the center was measured for two times with high precision GPS in 1995 and 1996 respectively. The results from remeasurement indicate that present horizontal movement in the monitored area is characterized by relative motion among several main tectonic blocks. Considering the spatial distribution features obtained from geological survey and results on seismic wave and activity in the area, and stratified features of crustal medium in depth, a three dimensional finite element medium model is designed. And under the conditions of taking and not taking the action manner of the background stress field in the studied area into account, the relative motion between tectonic blocks is calculated and modeled. Based on the results from the analysis and calculations the dynamic mechanism for the present horizontal deformation in the area is discussed.展开更多
文摘BACKGROUND Intraoperative determination of resection margin and adequate residual liver parenchyma are the key points of hepatectomy for the treatment of liver tumors.Intraoperative ultrasound and indocyanine green fluorescence navigation are the most commonly used methods at present,but the technical barriers limit their promotion.AIM To evaluate the value of the three-dimensional location approach with silk thread(3D-LAST)in precise resection of liver tumors.METHODS From September 2020 to January 2022,8 patients with liver tumors including hepatocellular carcinoma,intrahepatic cholangiocarcinoma,hilar cholangiocar-cinoma,and gastric cancer liver metastasis were included in this study.All patients underwent 3D-LAST in precise resection of liver tumors.RESULTS All patients(8/8,100%)underwent the operation successfully without any complications.During the mean follow-up of 8.7 months,all patients survived without tumor recurrence.CONCLUSION In conclusion,the 3D-LAST is a safe and effective new method for liver intraop-erative navigation,which is practical and easy to promote.Core Tip:The aim of this study is to evaluate the value of the three-dimensional location approach with silk thread(3D-LAST)in precise resection of liver tumors.Eight patients with liver tumors including hepatocellular carcinoma,intrahepatic cholangiocarcinoma,hilar cholangiocarcinoma,and gastric cancer liver metastasis underwent the operation successfully without any complications.During the mean follow-up of 8.7 months,all patients survived without tumor recurrence.In conclusion,the 3D-LAST is a safe and effective new method for liver intraoperative navigation,which is practical and easy to promote.INTRODUCTION Hepatectomy is widely used for the treatment of liver tumors.In recent decades,the concept and practice of hepatectomy have developed from irregular,regular and anatomical to the current precise resection.Necessary assistive technologies have enabled these advances.Intraoperative ultrasound(IOUS)localization and indocyanine green(ICG)fluorescence imaging guidance are two frequently-used approaches for laparoscopic hepatectomy[1,2].IOUS is an invaluable auxiliary means widely accepted in surgery for real-time diagnostic information to determine resection range and navigate the surgical path[3].However,the major limitation of IOUS is the time cost during the procedure for paging the sono-graphers and the difficulty of deciphering two dimensional images[4].ICG is a non-toxic water-soluble fluorophore that reveals fluorescence under the near-infrared spectrum[5].Since liver tissue penetration is limited to 5 to 10 mm,that restricted the visualization of deeper tumors by ICG excitation,thereby interfering with its application in laparoscopic hepatectomy[6].IOUS and ICG navigation require specific technical equipment,making implementation difficult in many centers.And these techniques will significantly increase the operation time.Three-dimensional(3D)visualization involves extracting features and producing volumetric images based on computed tomography(CT)through a computer postprocessing technique.This tool offers a reasonable approach to the clinical decision for the potential to display the complex internal anatomy in an intuitive and stereoscopic manner[7].In the past few decades,applying 3D simulation software for liver volume calculation,virtual simulation surgery,portal hypertension monitor,and surgical navigation has proven to be safe and effective[8].Therefore,we propose a new method to find obvious anatomical markers and calculate the resection range according to 3D positioning before operation.During the operation,the scope of resection was delineated with silk thread,and resection was performed.This is a new practical approach,which we named as 3D location approach with silk thread(3D-LAST).RESULTS During the study period from September 2020 to January 2022,5 patients with hepatocellular carcinoma,1 patient with intrahepatic cholangiocarcinoma,1 patient with hilar cholangiocarcinoma,and 1 patient with gastric cancer liver metastasis were assessed for liver resection.There were 5 males and 3 females.The mean age of these patients was 54.3±10.2 years(34-66 years).Preoperative 3D positioning was conducted and the scope of resection was delineated with a surgical suture successfully performed in all 8 patients without complications.The treatment results of these 8 patients are shown in Table 1.The 90-day operative mortality was zero.Complications worse than Dindo-Clavien IIIa was not observed at a mean follow-up time of 8.7 months(4-16 months),there was no evidence of tumor recurrence or extrahepatic metastasis.At the time of reporting,the patients are all alive and lead normal lives.We take one patient as an example,58-year-old male,who found a liver lesion 10 months after gastric cancer surgery.Enhanced CT showed that the lesion was located in the liver S5,about 1.5 cm in diameter,and considered metastatic lesions.We performed 3D-LAST guided hepatectomy on this patient(Figure 1).Other representative 3D-LAST surgical procedures are shown in Figure 2.
基金National Key Research and Development Program of China,Grant/Award Number:2021YFC2902103National Natural Science Foundation of China,Grant/Award Number:51934001Fundamental Research Funds for the Central Universities,Grant/Award Number:2023JCCXLJ02。
文摘Fracture surface contour study is one of the important requirements for characterization and evaluation of the microstructure of rocks.Based on the improved cube covering method and the 3D contour digital reconstruction model,this study proposes a quantitative microstructure characterization method combining the roughness evaluation index and the 3D fractal dimension to study the change rule of the fracture surface morphology after blasting.This method was applied and validated in the study of the fracture microstructure of the rock after blasting.The results show that the fracture morphology characteristics of the 3D contour digital reconstruction model have good correlation with the changes of the blasting action.The undulation rate of the three-dimensional surface profile of the rock is more prone to dramatic rise and dramatic fall morphology.In terms of tilting trend,the tilting direction also shows gradual disorder,with the tilting angle increasing correspondingly.All the roughness evaluation indexes of the rock fissure surface after blasting show a linear and gradually increasing trend as the distance to the bursting center increases;the difference between the two-dimensional roughness evaluation indexes and the three-dimensional ones of the same micro-area rock samples also becomes increasingly larger,among which the three-dimensional fissure roughness coefficient JRC and the surface roughness ratio Rs display better correlation.Compared with the linear fitting formula of the power function relationship,the three-dimensional fractal dimension of the postblast fissure surface is fitted with the values of JRC and Rs,which renders higher correlation coefficients,and the degree of linear fitting of JRC to the three-dimensional fractal dimension is higher.The fractal characteristics of the blast-affected region form a unity with the three-dimensional roughness evaluation of the fissure surface.
基金supported by grants from Jilin Scientific and Technological Development Program(20200403090SF)The Health Special Foundation of Jilin Province of China(2020sczt029).
文摘The anatomy of the human liver is complex,and the vascular system is highly variable.Moreover,the use of traditional com-puted tomography(CT)two-dimensional(2D)images to recon-struct the tissue and organs requires experienced doctors and lim-its the sharing and discussion of therapeutic plans[1].
基金supported by the National Key R&D Program of China(Grant Nos.2023YFA1406304 and 2024YFA1408103)the National Science Foundation of China(Grant Nos.12494593 and 12004405)+5 种基金the Anhui Provincial Natural Science Foundation(Grant No.2408085J003)the National Key R&D Program of China(Grant No.2023YFA1406100)the open projects of the State Key Laboratory of Functional Materials for Informatics(Grant No.SKL2022)the China National Postdoctoral Program for Innovative Talents(BX20240348)support from the National Natural Science Foundation of China(Grant No.12404186)the Shanghai Sailing Program(Grant No.23YF1426900)。
文摘The kagome metals AV_(3)Sb_(5)(A=K,Rb,Cs)feature intertwined Dirac fermions,topological flat bands,and van Hove singularities(vHS)near the Fermi level,which give rise to a range of exotic,strongly correlated phenomena such as charge density waves(CDW)and superconductivity.Although the vHS from V 3d states have been implicated in CDW formation,their three-dimensional nature and temperature evolution remain poorly understood.In this study,we used high-resolution angle-resolved photoemission spectroscopy and density functional theory to reveal pronounced out-of-plane dispersion of vHS and their temperature dependence in KV_(3)Sb_(5).The identified c-axis band folding and scattering channels were directly linked to the CDW order.These results demonstrate that the CDW transition in this family involves cooperative coupling between electron correlations and structural modulation along the c axis.This offers new insights into the interplay of topology,correlations,and lattice instabilities in kagome metals.
基金supported by the National Natural Science Foundation of China (10872096)the Open Fund of State Key Laboratory of Explosion Science and Technology, Beijing University of Science and Technology (KFJJ09-13)
文摘Gaseous detonation propagating in a toroidal chamber was numerically studied for hydrogen/oxygen/nitrogen mixtures. The numerical method used is based on the three-dimensional Euler equations with detailed finiterate chemistry. The results show that the calculated streak picture is in qualitative agreement with the picture recorded by a high speed streak camera from published literature. The three-dimensional flow field induced by a continuously rotating detonation was visualized and distinctive features of the rotating detonations were clearly depicted. Owing to the unconfined character of detonation wavelet, a deficit of detonation parameters was observed. Due to the effects of wall geometries, the strength of the outside detonation front is stronger than that of the inside portion. The detonation thus propagates with a constant circular velocity. Numerical simulation also shows three-dimensional rotating detonation structures, which display specific feature of the detonation- shock combined wave. Discrete burning gas pockets are formed due to instability of the discontinuity. It is believed that the present study could give an insight into the interest- ing properties of the continuously rotating detonation, and is thus beneficial to the design of continuous detonation propulsion systems.
基金supported by the National Natural Science Foundation of China(21373056)the Science and Technology Commission of Shanghai Municipality(13DZ2275200)~~
文摘In this article, we report the preparation of a three-dimensional（3D） interconnected mesoporous anatase TiO2-SiO2 nanocomposite. The nanocomposite was obtained by using an ordered two-dimensional（2D） hexagonal mesoporous anatase 70 TiO2-30 SiO2-950 nanocomposite（crystallized at 950 °C for 2 h） as a precursor, NaO H as an etchant of SiO2 via a ＂creating mesopores in the pore walls＂ approach. Our strategy adopts mild conditions of creating pores such as diluted NaO H solution, appropriate temperature and solid/liquid ratio, etc. aiming at ensuring the integrities of mesopores architecture and anatase nanocrystals. XRD, TEM and N2 sorption techniques have been used to systematically investigate the physico-chemical properties of the nanocomposites. The results show that the intrawall mesopores are highly dense and uniform（average pore size 3.6 nm）, and highly link the initial mesochannels in a 3D manner while retaining mesostructural integrity. There is no significant change to either crystallinity or size of the anatase nanocrystals before and after creating the intrawall mesopores. The photocatalytic degradation rates of rhodamine B（RhB, 0.303 min^–1） and methylene blue（MB, 0.757 min^–1） dyes on the resultant nanocomposite are very high, which are 5.1 and 5.3 times that of the precursor; even up to 16.5 and 24.1 times that of Degussa P25 photocatalyst, respectively. These results clearly demonstrate that the 3D interconnected mesopores structure plays an overwhelming role to the increments of activities. The 3D mesoporous anatase TiO2-SiO2 nanocomposite exhibits unexpected-high degradation activities to RhB and MB in the mesoporous metal oxide-based materials reported so far. Additionally, the nanocomposite is considerably stable and reusable. We believe that this method would pave the way for the preparation of other 3D highly interconnected mesoporous metal oxide-based materials with ultra-high performance.
文摘A calculation scheme, which combines a horizontal upwind finite element method with vertical implicit differences, is used to establish a three-dimensional mathematical model of tidal motion and sediment transport in tidal current. Compared with those of the relative theoretical formula, the results are satisfactory. The model mentioned above has been applied to the water area of the Lianzhou Bay, Guangxi Province. On the basis of the analysis and comparison with the field data, it shows clearly that the model calculation results are reasonable.
文摘Objective: To study the clinical significance of multi-slice spiral CT 3-dimensional (3D) portography in portal vein tumor thrombosis of hepatocellular cacinoma.Methods: 57 cases undergoing 3D portography were collected, of which 6 cases were normal, 5 cases were subjected to cirrhosis and hypertension of portal vein, 42 cases had portal tumor thrombus of hepatic cancer, and the remaining 4 cases showed lymph node enlargment in hilar of liver. All data of the patients came from conventional multi-slice spiral CT double phase of liver. Contrast media was 1.5–2 ml/kg with the injection rate being 2.5–3 ml/s. Axis and 3D portography was analyzed and compared in 42 cases of portal tumor thrombus of hepatic cancer.Results: According to portal tumor thrombus position, 42 cases were fallen into three categories: left (13 cases), right (20 cases), main (9 cases) of potal vein. There was no difference between axis and 3D portography in displaying portal tumor thrombus of hepatic cancer (P>0.05), but 3D portography showing collateral branches was better than axis portography after main portal vein thrombus.Conclusion: Multi-slice spiral CT 3D portography can display the position and types of portal tumor thrombus of hepatic cancer. 3D combined with axis portography can better evaluate the portal tumor thrombus of hepatic cancer and guide to select the therapies. Key words portal vein - tumor thrombus - multi-slice CT - 3 dimension imaging
文摘Through the introduction of disaster situation of Qiang Culture after Wenchuan Earthquake, the paper emphasized that carriers of Qiang Culture had been seriously damaged, the inheritance of Qiang Culture had been affected, and the environment for Qiang Culture was difficult to recover. It highlighted that three-dimensional reconstruction of Qiang Culture should stress the core task and timely and effectively rescue endangered cultural heritages of Qiang Nationality from the perspectives of material and spiritual life. It had explained focuses of three-dimensional pattern construction in detail. In terms of spatial reconstruction, it should reconstruct native culture and history while material culture was constructed, and reconstruct Qiang culture highland by depending on aborigines; in terms of cluster reconstruction, it should give support to large tourism enterprises and perfect tourism chain; in terms of ecological reconstruction, it should enhance construction and demonstration of "ecological protection pilot area of Qiang culture"; in terms of development reconstruction, it should realize coordinated unity between protection and development according to classification protection, characteristic protection and key protection, so as to form the virtuous circle of post-disaster recovery protection and sustainable development.
基金Acknowledgements - This project is supported by the National Natural Science Foundation of China (Grant No.59734080) and the Pl
文摘The three-dimensional electromagnetic characteristics and non-uniform distribution of electromagnetic field in soft-contact continuous casting mold have been analyzed by numerical simulation. The results show that the maximum electromagnetic flux density is found in front of slit; the electromagnetic flux density becomes large as the coil current and slit number increase. In a certain frequency range, the electromagnetic flux density increases with the increase of frequency and the frequency range is different with the change of azimuthal position along the inner wall of mold. The uniformity of electromagnetic field is influenced mainly by frequency and mold structure parameters. Increasing slit number and adjusting slit arrangement position can improve the electromagnetic flux density and the uniformity of electromagnetic field. For a soft-contact mold with 16 slits, when frequency is 20 kHz, the optimal slit arrangement parameter is a:b=1:2, c=0.
基金National Natural Science Foundation of China under Grant No.41672266
文摘To provide appropriate uses of nonlinear ground response analysis for engineering practice, a three-dimensional soil column with a distributed mass system and a time domain numerical analysis were implemented on the Open Sees simulation platform. The standard mesh of a three-dimensional soil column was suggested to be satisfied with the specified maximum frequency. The layered soil column was divided into multiple sub-soils with a different viscous damping matrix according to the shear velocities as the soil properties were significantly different. It was necessary to use a combination of other one-dimensional or three-dimensional nonlinear seismic ground analysis programs to confirm the applicability of nonlinear seismic ground motion response analysis procedures in soft soil or for strong earthquakes. The accuracy of the three-dimensional soil column finite element method was verified by dynamic centrifuge model testing under different peak accelerations of the earthquake. As a result, nonlinear seismic ground motion response analysis procedures were improved in this study. The accuracy and efficiency of the three-dimensional seismic ground response analysis can be adapted to the requirements of engineering practice.
基金supported by the Ministry of Sciences and Technology of China (863 Programs) (2006AA05Z115, 2007AA05Z104)
文摘Three-dimensionally ordered macro-porous （3DOM） TiO2 and ceria-modified 3DOM TiO2 supported platinum catalysts were prepared with template and impregnation methods, and the resultant samples were characterized by scanning electron microscopy（SEM）, X-ray diffractometer（XRD）, high-resolution transmission electron microscopy（HRTEM） and temperature programmed reducfion（TPR） techniques. The catalytic performances over the platinum-based catalysts were investigated for water-gas shift （WGS） reaction in a wide temperature range （180-360 ℃）. The results showed that 3DOM Pt/TiO2 catalyst exhibited obviously better catalytic performance than the corresponding non macro-porous catalyst, owing to the macro-porous structure favoring mass transfer. Addition of celia into 3DOM Pt/TiO2 led to improvement of catalytic activity. TPR and HRTEM results showed that the interaction existed between ceria and titanium oxide and addition of ceria promoted the reducibility of platinum oxide and TiO2 on the interface of platinum and TiO2 particles, which contributed to high activity of the celia modified catalysts. The results indicated that ceria-modified 3DOM Pt/TiO2 was a promising candidate of fuel cell oriented WGS catalyst.
基金support by Universidad Autonoma Metropolitana (Nos.2231207 and 2270303)Sistema Nacional de Investigadores (SNI-CONACYT)
文摘To study fluctuations of the free surface of liquid steel in the mold,two different models with the same casting conditions but different thicknesses were employed to analyze the hydrodynamic behavior at the top of the mold.The first model was a standard thickness slab,and the second had a thickness three times wider.It is found with the second model that above the plane formed by the steel jets,it is possible to observe four three-dimensional vortexes that interact with the submerged entry nozzle（SEN）and mold walls.By using a biphasic model to simulate the interface between the liquid and air inside the mold,the flow asymmetry and the fluctuations of the free surface can be clearly observed.
基金supported by a grant from the Youth Science Foundation of China (No.30600213)
文摘The present study evaluated the application of three dimensional echocardigraphy （3DE） in the diagnosis of atrial septal defect （ASD） and the measurement of its size by 3DE and compared the size with surgical findings. Two-dimensional and real-time three dimensional echocardiography （RT3DE） was performed in 26 patients with atrial septal defect, and the echocardiographic data were compared with the surgical findings. Significant correlation was found between defect diameter by RT3DE and that measured during surgery （r=0.77, P〈0.001）. The defect area changed significantly during cardiac cycle. Percentage change in defect size during cardiac cycle ranged from 6%-70%. Our study showed that the size and morphology of atrial septal defect obtained with RT3DE correlate well with surgical findings. Therefore, RT3DE is a feasible and accurate non-invasive imaging tool for assessment of atrial septal size and dynamic changes.
基金This work was financially supported by the Natural Science Foundation of Shandong Province, China (Y2006F03).
文摘Reticulated polyurethane was chosen as the preceramic material for preparing the porous preform using the replication process. The immersing and sintering processes were each performed twice for fabricating a high-porosity and super-strong skeleton. The aluminum magnesium matrix composites reinforced with three-dimensional network structure were prepared using the infiltration technique by pressure assisting and vacuum driving. Light interfacial reactions have played a profitable role in most of the ceramic-metal systems. The metal matrix composites interpenetrated with the ceramic phase have a higher wear resistance than the metal matrix phase. The volume fraction of ceramic reinforcement has a significant effect on the abrasive wear, and the wear rate can be decreased with the increase of the volume fraction of reinforcement.
基金supported by National Natural Science Foundation of China(11101244,11271231)National Tackling Key Problems Program(20050200069)Doctorate Foundation of the Ministry of Education of China(20030422047)
文摘Transient behavior of three-dimensional semiconductor device with heat conduc- tion is described by a coupled mathematical system of four quasi-linear partial differential equations with initial-boundary value conditions. The electric potential is defined by an ellip- tic equation and it appears in the following three equations via the electric field intensity. The electron concentration and the hole concentration are determined by convection-dominated diffusion equations and the temperature is interpreted by a heat conduction equation. A mixed finite volume element approximation, keeping physical conservation law, is used to get numerical values of the electric potential and the accuracy is improved one order. Two con- centrations and the heat conduction are computed by a fractional step method combined with second-order upwind differences. This method can overcome numerical oscillation, dispersion and decreases computational complexity. Then a three-dimensional problem is solved by computing three successive one-dimensional problems where the method of speedup is used and the computational work is greatly shortened. An optimal second-order error estimate in L2 norm is derived by using prior estimate theory and other special techniques of partial differential equations. This type of mass-conservative parallel method is important and is most valuable in numerical analysis and application of semiconductor device.
基金Funded by National Natural Science Fundation of China (No.51178106)Open Program from Guangxi Key Laboratory of Disaster Prevention and Reduction (No.2008TMKF009)+1 种基金973 Program (No.2009CB623200)Program for New Century Excellent Talentsin University
文摘2D,3D chloride ion concentration at the edge and corner zones were systematically investigated for fly ash concretes made with different cement replacement percentage by fly ash （0%,10%,20%,40%,60%）,water to binder ratios （0.3,0.35,0.4）,and curing ages （28 d,90 d）.An interaction effect caused by 2D and 3D diffusion could obviously be observed through the comparison with 1D testing results.In order to quantify the interaction effect,2D and 3D diffusion interaction coefficients was proposed in this paper.Finally,the changes of 2D and 3D interaction coefficients with the change in the free chloride ion concentration were given.The above research provide an insight into chloride ion attack on the edge and corner reinforcing bars of concrete structures in the field of civil engineering.
文摘A deformation monitoring network that covers part of North China area and takes the Beijing region as the center was measured for two times with high precision GPS in 1995 and 1996 respectively. The results from remeasurement indicate that present horizontal movement in the monitored area is characterized by relative motion among several main tectonic blocks. Considering the spatial distribution features obtained from geological survey and results on seismic wave and activity in the area, and stratified features of crustal medium in depth, a three dimensional finite element medium model is designed. And under the conditions of taking and not taking the action manner of the background stress field in the studied area into account, the relative motion between tectonic blocks is calculated and modeled. Based on the results from the analysis and calculations the dynamic mechanism for the present horizontal deformation in the area is discussed.
