期刊文献+
共找到908篇文章
< 1 2 46 >
每页显示 20 50 100
Smart prediction of liquefaction-induced lateral spreading 被引量:1
1
作者 Muhammad Nouman Amjad Raja Tarek Abdoun Waleed El-Sekelly 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第6期2310-2325,共16页
The prediction of liquefaction-induced lateral spreading/displacement(Dh)is a challenging task for civil/geotechnical engineers.In this study,a new approach is proposed to predict Dh using gene expression programming(... The prediction of liquefaction-induced lateral spreading/displacement(Dh)is a challenging task for civil/geotechnical engineers.In this study,a new approach is proposed to predict Dh using gene expression programming(GEP).Based on statistical reasoning,individual models were developed for two topographies:free-face and gently sloping ground.Along with a comparison with conventional approaches for predicting the Dh,four additional regression-based soft computing models,i.e.Gaussian process regression(GPR),relevance vector machine(RVM),sequential minimal optimization regression(SMOR),and M5-tree,were developed and compared with the GEP model.The results indicate that the GEP models predict Dh with less bias,as evidenced by the root mean square error(RMSE)and mean absolute error(MAE)for training(i.e.1.092 and 0.815;and 0.643 and 0.526)and for testing(i.e.0.89 and 0.705;and 0.773 and 0.573)in free-face and gently sloping ground topographies,respectively.The overall performance for the free-face topology was ranked as follows:GEP>RVM>M5-tree>GPR>SMOR,with a total score of 40,32,24,15,and 10,respectively.For the gently sloping condition,the performance was ranked as follows:GEP>RVM>GPR>M5-tree>SMOR with a total score of 40,32,21,19,and 8,respectively.Finally,the results of the sensitivity analysis showed that for both free-face and gently sloping ground,the liquefiable layer thickness(T_(15))was the major parameter with percentage deterioration(%D)value of 99.15 and 90.72,respectively. 展开更多
关键词 Lateral spreading Intelligent modeling Gene expression programming(GEP) Closed-form solution Feature importance
下载PDF
Influence of network structure on spreading dynamics via tie range
2
作者 李敏 宋玉蓉 +3 位作者 宋波 李汝琦 蒋国平 张晖 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第8期606-613,共8页
There are various phenomena of malicious information spreading in the real society, which cause many negative impacts on the society. In order to better control the spreading, it is crucial to reveal the influence of ... There are various phenomena of malicious information spreading in the real society, which cause many negative impacts on the society. In order to better control the spreading, it is crucial to reveal the influence of network structure on network spreading. Motifs, as fundamental structures within a network, play a significant role in spreading. Therefore, it is of interest to investigate the influence of the structural characteristics of basic network motifs on spreading dynamics.Considering the edges of the basic network motifs in an undirected network correspond to different tie ranges, two edge removal strategies are proposed, short ties priority removal strategy and long ties priority removal strategy. The tie range represents the second shortest path length between two connected nodes. The study focuses on analyzing how the proposed strategies impact network spreading and network structure, as well as examining the influence of network structure on network spreading. Our findings indicate that the long ties priority removal strategy is most effective in controlling network spreading, especially in terms of spread range and spread velocity. In terms of network structure, the clustering coefficient and the diameter of network also have an effect on the network spreading, and the triangular structure as an important motif structure effectively inhibits the spreading. 展开更多
关键词 network spreading network motifs tie range edge removal strategy
下载PDF
Individual dynamics and local heterogeneity provide a microscopic view of the epidemic spreading
3
作者 朱友源 沈瑞哲 +1 位作者 董昊 王炜 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期656-663,共8页
The COVID-19 pandemic has caused severe global disasters,highlighting the importance of understanding the details and trends of epidemic transmission in order to introduce efficient intervention measures.While the wid... The COVID-19 pandemic has caused severe global disasters,highlighting the importance of understanding the details and trends of epidemic transmission in order to introduce efficient intervention measures.While the widely used deterministic compartmental models have qualitatively presented continuous “analytical” insight and captured some transmission features,their treatment usually lacks spatiotemporal variation.Here,we propose a stochastic individual dynamical(SID)model to mimic the random and heterogeneous nature of epidemic propagation.The SID model provides a unifying framework for representing the spatiotemporal variations of epidemic development by tracking the movements of each individual.Using this model,we reproduce the infection curves for COVID-19 cases in different areas globally and find the local dynamics and heterogeneity at the individual level that affect the disease outbreak.The macroscopic trend of virus spreading is clearly illustrated from the microscopic perspective,enabling a quantitative assessment of different interventions.Seemingly,this model is also applicable to studying stochastic processes at the “meter scale”,e.g.,human society’s collective dynamics. 展开更多
关键词 Brownian motion epidemic spreading HETEROGENEITY
下载PDF
Possible Cortical Spreading Depression Recorded Intraoperatively Following a Generalized Seizure: Illustrative Case
4
作者 Greg Schaublin Romina Shirka +4 位作者 Nabil Azar Callan Broderick Jayson Neil George R. Lee Kiara Ebinger 《Neuroscience & Medicine》 2024年第3期119-128,共10页
Background: We present a compelling case fitting the phenomenon of cortical spreading depression detected by intraoperative neurophysiological monitoring (IONM) following an intraoperative seizure during a craniotomy ... Background: We present a compelling case fitting the phenomenon of cortical spreading depression detected by intraoperative neurophysiological monitoring (IONM) following an intraoperative seizure during a craniotomy for revascularization. Cortical spreading depression (CSD, also called cortical spreading depolarization) is a pathophysiological phenomenon whereby a wave of depolarization is thought to propagate across the cerebral cortex, creating a brief period of relative neuronal inactivity. The relationship between CSD and seizures is unclear, although some literature has made a correlation between seizures and a cortical environment conducive to CSD. Methods: Intraoperative somatosensory evoked potentials (SSEPs) and electroencephalography (EEG) were monitored continuously during the craniotomy procedure utilizing standard montages. Electrophysiological data from pre-ictal, ictal, and post-ictal periods were recorded. Results: During the procedure, intraoperative EEG captured a generalized seizure followed by a stepwise decrease in somatosensory evoked potential cortical amplitudes, compelling for the phenomenon of CSD. The subsequent partial recovery of neuronal function was also captured electrophysiologically. Discussion: While CSD is considered controversial in some aspects, intraoperative neurophysiological monitoring allowed for the unique analysis of a case demonstrating a CSD-like phenomenon. To our knowledge, this is the first published example of this phenomenon in which intraoperative neurophysiological monitoring captured a seizure, along with a stepwise subsequent reduction in SSEP cortical amplitudes not explained by other variables. 展开更多
关键词 Cortical spreading Depression ELECTROENCEPHALOGRAPHY Intraoperative Neurophysiological Monitoring SEIZURE
下载PDF
Simulation Research on the Effect of Spreading Process Parameters on the Quality of Lunar Regolith Powder Bed in Additive Manufacturing
5
作者 Qi Tian Bing Luo 《Journal of Electronic Research and Application》 2023年第1期16-24,共9页
Lunar surface additive manufacturing with lunar regolith is a key step in in-situ resource utilization.The powder spreading process is the key process,which has a major impact on the quality of the powder bed and the ... Lunar surface additive manufacturing with lunar regolith is a key step in in-situ resource utilization.The powder spreading process is the key process,which has a major impact on the quality of the powder bed and the precision of molded parts.In this study,the discrete element method(DEM)was adopted to simulate the powder spreading process with a roller.The three powder bed quality indicators,including the molding layer offset,voidage fraction,and surface roughness,were established.Besides,the influence of the three process parameters,which are roller’s translational speed,rotational speed,and powder spreading layer thickness on the powder bed quality indicators was also analyzed.The results show that with the reduction of the powder spreading layer thickness and the increase of the rotational speed,the offset increased significantly;when the translational speed increased,the offset first increased and then decreased,which resulted in an extreme value;with the increase of the layer thickness and the decrease of the translational speed,the values for voidage fraction and surface roughness significantly reduced.The powder bed quality indicators were adopted as the optimization objective,and the multi-objective parameter optimization was carried out.The predicted optimal powder spreading parameters and powder bed quality indicators were then obtained.Moreover,the optimal values were then verified.This study can provide informative guidance for in-situ manufacturing at the moon in future deep space exploration missions. 展开更多
关键词 Lunar regolith additive manufacturing Numerical simulation of powder spreading process Discrete element method Powder spreading process parameters Parameters optimization
下载PDF
Functionalized alginate-based bioinks for microscale electrohydrodynamic bioprinting of living tissue constructs with improved cellular spreading and alignment 被引量:3
6
作者 Zhennan Qiu Hui Zhu +3 位作者 Yutao Wang Ayiguli Kasimu Dichen Li Jiankang He 《Bio-Design and Manufacturing》 SCIE EI CAS CSCD 2023年第2期136-149,共14页
Bioprinting has been widely investigated for tissue engineering and regenerative medicine applications.However,it is still difficult to reconstruct the complex native cell arrangement due to the limited printing resol... Bioprinting has been widely investigated for tissue engineering and regenerative medicine applications.However,it is still difficult to reconstruct the complex native cell arrangement due to the limited printing resolution of conventional bioprinting techniques such as extrusion-and inkjet-based printing.Recently,an electrohydrodynamic(EHD)bioprinting strategy was reported for the precise deposition of well-organized cell-laden constructs with microscale filament size,whereas few studies have been devoted to developing bioinks that can be applied for EHD bioprinting and simultaneously support cell spreading.This study describes functionalized alginate-based bioinks for microscale EHD bioprinting using peptide grafting and fibrin incorporation,which leads to high cell viability(>90%)and cell spreading.The printed filaments can be further refined to as small as 30μm by incorporating polyoxyethylene and remained stable over one week when exposed to an aqueous environment.By utilizing the presented alginate-based bioinks,layer-specific cell alignment along the printing struts could be observed inside the EHD-printed microscale filaments,which allows fabricating living constructs with cell-scale filament resolution for guided cellular orientation. 展开更多
关键词 Microscale electrohydrodynamic bioprinting Alginate-based bioinks Cell spreading Cell alignment
下载PDF
Topological phase transition in network spreading 被引量:1
7
作者 年福忠 张霞 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第3期629-641,共13页
This paper investigates information spreading from the perspective of topological phase transition.Firstly,a new hybrid network is constructed based on the small-world networks and scale-free networks.Secondly,the att... This paper investigates information spreading from the perspective of topological phase transition.Firstly,a new hybrid network is constructed based on the small-world networks and scale-free networks.Secondly,the attention mechanism of online users in information spreading is studied from four aspects:social distance,individual influence,content richness,and individual activity,and a dynamic evolution model of connecting with spreading is designed.Eventually,numerical simulations are conducted in three types of networks to verify the validity of the proposed dynamic evolution model.The simulation results show that topological structure and node influence in different networks have undergone phase transition,which is consistent with the phenomenon that followers and individual influence in real social networks experience phase transition within a short period.The infection density of networks with the dynamic evolution rule changes faster and reaches higher values than that of networks without the dynamic evolution rule.Furthermore,the simulation results are compared with the real data,which shows that the infection density curve of the hybrid networks is closer to that of the real data than that of the small-world networks and scale-free networks,verifying the validity of the model proposed in this paper. 展开更多
关键词 social network information spreading network structure phase transition
下载PDF
Boosting image watermarking authenticity spreading secrecy from counting-based secret-sharing 被引量:1
8
作者 Adnan Gutub 《CAAI Transactions on Intelligence Technology》 SCIE EI 2023年第2期440-452,共13页
This study presents enhancing images authentication by securing watermarking hidden data via shares generated from counting-based secret sharing.The trustfulness of shares utilised secret-sharing as an applicable priv... This study presents enhancing images authentication by securing watermarking hidden data via shares generated from counting-based secret sharing.The trustfulness of shares utilised secret-sharing as an applicable privacy creation tool for the authentication of real-life complex platforms.This research adjusts embedding the watermarking data over the images by innovative redistribution of shares to be embedded spread over all the images.The anticipated watermarking technique guaranteed to scatter the share bits implanting at different least significant bits of image pixels as boosting up the trust overall authentication practicality.The paper experimentation performance analysis shows that this improved image watermarking authentication(capacity)is averagely better by 33%–67%than other related exclusive-OR oriented and octagon approaches.Interestingly,these measurement improvements did not degrade the robustness and security of the system,inspiring our research for opening novel track of related future counting-based secret-sharing authentication progresses to come. 展开更多
关键词 counting-based secret-sharing data hiding fair data spreading image watermarking information security secret sharing
下载PDF
Simulation and Experimental Research on Liquid Spreading in a Wire-Sawn Kerf
9
作者 Lin Lin Hui Huang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2023年第6期247-260,共14页
The significance of liquids in abrasive wire sawing has been demonstrated in several studies.However,the perfor-mance of its spreading behavior is limited by the current development trend,where the wafer has a larger ... The significance of liquids in abrasive wire sawing has been demonstrated in several studies.However,the perfor-mance of its spreading behavior is limited by the current development trend,where the wafer has a larger area and the kerf is narrower.Moreover,there are very few studies on the liquid spreading behavior in wire-sawn kerfs.Therefore,a 3D CFD(computational fluid dynamics)model is presented in this paper and used to simulate the liquid spreading behavior in a kerf based on a VOF(volume of fluid)method with a CSF(continuum surface force)model,which is used to simulate multiphase flow,and an empirical correlation for characterizing the liquid dynamic contact angle using UDF(user defined functions).Subsequently,parametric simulations are performed on the kerf area,kerf width,liquid viscosity,liquid surface tension,and liquid velocity at the inlet area of the kerf,and verification experi-ments are conducted to determine the validity of the simulation model.From the simulation and experimental results,three typical liquid spreading regimes that exhibit different effects on wire sawing in the kerfs are found,and their limiting conditions are identified using non-dimensional analysis.Subsequently,a prediction model is pro-posed for the liquid spreading regime based on a set of Weber and Capillary numbers.For wire sawing,an increase in the wafer area does not change the liquid spreading regime in the kerf;however,a reduction in the kerf width sig-nificantly hinders the liquid spreading behavior.Thereby,the spreading regime can be effectively converted to facili-tate wire sawing by adjusting the physical properties and supply conditions of the liquid. 展开更多
关键词 spreading regime KERF CFD Non-dimensional analysis Prediction model
下载PDF
Effects of non-liquefiable crust layer and superstructure mass on the response of 2×2 pile groups to liquefaction-induced lateral spreading
10
作者 S.Mohsen Haeri Morteza Rajabigol +2 位作者 Saman Salaripour Hiwa Sayaf Milad Zangeneh 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第10期2701-2719,共19页
In this research,two shake table experiments were conducted to study the effects of non-liquefiable crust layer and superstructure mass on the responses of two sets of 22 pile groups to liquefactioninduced lateral spr... In this research,two shake table experiments were conducted to study the effects of non-liquefiable crust layer and superstructure mass on the responses of two sets of 22 pile groups to liquefactioninduced lateral spreading.In this regard,an inclined base layer overlain by a very loose liquefiable layer was constructed in both models;while only in one model,a non-liquefiable crust layer was built.A lumped mass,being representative of a superstructure,was attached to the cap of one pile group in both models.The models were fully instrumented with various sensors,including acceleration,displacement,and pore water pressure transducers.Also,the piles were instrumented with pair strain gauges to measure pure bending moments induced by cyclic and monotonic loadings associated with ground shaking and lateral spreading,respectively.The results showed that the existence of the non-liquefiable crust layer increases both the maximum and residual soil displacements at the free field and also the maximum bending moments in the piles.The results of the experiments indicated that the crust layer induces a high kinematic lateral soil pressure and force on the piles which are not present in the crustless case.The crust layer increases the pile cap displacement before liquefaction,albeit decreases it after liquefaction,due to the elastic rebound of the piles in the liquefiable layer.The crust layer postpones both liquefaction triggering and dissipation of excess pore water pressure.The existence of the superstructure mass on the pile caps decreases the acceleration amplitude of the pile caps,while increases their maximum displacement. 展开更多
关键词 Soil liquefaction Lateral spreading 1g shake table test Pile group Crust layer SUPERSTRUCTURE
下载PDF
BIFURCATION CONTROL FOR A FRACTIONAL-ORDER DELAYED SEIR RUMOR SPREADING MODEL WITH INCOMMENSURATE ORDERS
11
作者 叶茂林 蒋海军 《Acta Mathematica Scientia》 SCIE CSCD 2023年第6期2662-2682,共21页
A fractional-order delayed SEIR rumor spreading model with a nonlinear incidence function is established in this paper,and a novel strategy to control the bifurcation of this model is proposed.First,Hopf bifurcation i... A fractional-order delayed SEIR rumor spreading model with a nonlinear incidence function is established in this paper,and a novel strategy to control the bifurcation of this model is proposed.First,Hopf bifurcation is investigated by considering time delay as bifurcation parameter for the system without a feedback controller.Then,a state feedback controller is designed to control the occurrence of bifurcation in advance or to delay it by changing the parameters of the controller.Finally,in order to verify the theoretical results,some numerical simulations are given. 展开更多
关键词 rumor spreading FRACTIONAL-ORDER time delay bifurcation control
下载PDF
Spreading speed of a food-limited population model with delay
12
作者 TIAN Ge AN Ruo-fan 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2023年第2期264-273,共10页
This paper is concerned with the spreading speed of a food-limited population model with delay.First,the existence of the solution of Cauchy problem is proved.Then,the spreading speed of solutions with compactly suppo... This paper is concerned with the spreading speed of a food-limited population model with delay.First,the existence of the solution of Cauchy problem is proved.Then,the spreading speed of solutions with compactly supported initial data is investigated by using the general Harnack inequality.Finally,we present some numerical simulations and investigate the dynamical behavior of the solution. 展开更多
关键词 food-limited population model reaction-diffusion equations DELAY spreading speed
下载PDF
Mineralogy and geochemistry of hydrothermal sulphide from a submarine volcanic high at 18°36.4'S Central Lau Spreading Center, Southwest Pacific
13
作者 Durbar Ray Anil L.Paropkari 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第5期93-101,共9页
We report the mineralogy and geochemistry of hydrothermal sulphide from the crater of a volcanic high near 18°36.4′S of the Central Lau Spreading Center.During 1990s,that volcanic structure was reported active a... We report the mineralogy and geochemistry of hydrothermal sulphide from the crater of a volcanic high near 18°36.4′S of the Central Lau Spreading Center.During 1990s,that volcanic structure was reported active and sulphide samples were collected by MIR submersible.A section of a chimney-like structure from the crater-floor was studied here.The Fe-depleted sphalerites,and Co-depleted pyrites in that chimney were similar to those commonly found in low to moderate temperature(<300℃)sulphides from sediment-starved hydrothermal systems.Bulk analyses of three parts of that chimney section showed substantial enrichment of Zn(18%–20%)and Fe(14%–27%)but depletion of Cu(0.8%–1.3%).In chondrite-normalized rare earth element-patterns,the significant negative Ce-anomalies(Ce/Ce*=0.27–0.39)and weakly positive Eu-anomalies(Eu/Eu*=1.60–1.68)suggested sulphide mineralisation took place from reduced low-temperature fluid.The depleted concentration of lithophiles in this sulphide indicates restricted contribution of sub-ducting plate in genesis of source fluid as compared to those from other parts of Lau Spreading Centre.Uniform mineralogy and bulk composition of subsamples across the chimney section suggests barely any alteration of fluid composition and/or mode of mineralisation occurred during its growth. 展开更多
关键词 Central Lau spreading Center hydrothermal sulphide MINERALOGY GEOCHEMISTRY
下载PDF
Large colonic lipoma with a laterally spreading tumor treated by endoscopic submucosal dissection:A case report
14
作者 Jun Yong Bae Hun Kyu Kim +4 位作者 Yee Jin Kim Se Woong Kim Youngeun Lee Chang Beom Ryu Moon Sung Lee 《World Journal of Clinical Cases》 SCIE 2023年第26期6194-6199,共6页
BACKGROUND Since fat does not transmit electrical energy well,delayed perforation and postpolypectomy syndrome due to electrical thermal injury are concerns in the endoscopic removal of colonic lipoma.The endoscopic s... BACKGROUND Since fat does not transmit electrical energy well,delayed perforation and postpolypectomy syndrome due to electrical thermal injury are concerns in the endoscopic removal of colonic lipoma.The endoscopic submucosal dissection(ESD)technique concentrates electrical energy conducts to the submucosa,not the adipose tissue.This helps to minimize electrical thermal injury,especially in the case of large colonic lipomas.In rare cases,such as colonic lipomas accompanied by mucosal lesions,it is difficult for endoscopists to decide how to safely remove them.CASE SUMMARY A 78-year-old man underwent colonoscopy for colorectal cancer screening.During colonoscopy,a yellowish submucosal tumor with positive cushion sign was observed in the ascending colon measuring about 4.5 cm.A nodular mucosal lesion of about 2.5 cm was observed on the mucosal surface of the lipoma.The lipoma was so large that it occupied much of the inside of the colon,making it difficult to see the entire laterally spreading tumor(LST)at once.The LST was confined to the surface of the lipoma,which had a semipedunculated shape with a wide neck.The margin of the LST was not observed at the neck of the lipoma.ESD was performed and the colonic lipoma with the LST was successfully removed without complications.After 3 d of hospitalization,the patient was discharged without any symptoms.The final pathology report showed that the lesion consisted of submucosal lipoma and tubulovillous adenoma with lowgrade dysplasia.CONCLUSION ESD is effective and safe for treating a large colonic lipoma with an LST by minimizing electrical thermal injury. 展开更多
关键词 Colonic lipoma Endoscopic submucosal dissection Laterally spreading tumor Tubulovillous adenoma Electrical injury Case report
下载PDF
A New Model for Spreading Malware over SMS Using Network Automata
15
作者 Erick Iván Medina-Salas Ana Lilia Laureano-Cruces Ma. Elena Lárraga-Ramírez 《Communications and Network》 2023年第4期120-143,共24页
By the year 2026, it is estimated that the number of smartphone users in Mexico will be approximately 118.1 million. Each smartphone has the functionality of sending and receiving SMS (Short Message Service) messages,... By the year 2026, it is estimated that the number of smartphone users in Mexico will be approximately 118.1 million. Each smartphone has the functionality of sending and receiving SMS (Short Message Service) messages, which pose a significant threat to all users, as it makes any device vulnerable to a malware attack. In particular, worm-type malware takes advantage of this means of communication in order to spread. Studying the dynamics of malware propagation can help understand and prevent massive contagion between mobile devices. In this work, a model based on Network Automata and compartmental epidemiological models is presented, aiming to simulate, analyze and study the spread of worm-like malware through sending SMS on smartphones. 展开更多
关键词 Cellular Automaton Malware Spread Complex Systems Network Automaton
下载PDF
THE SEEPAGE CHARACTERISTICS OF HETEROGENEOUS BODY WITH DIFFERENT SPREADING SOLUTION MODES AND ITS APPLICATIONS 被引量:1
16
作者 H.J. Wang A.X. Wu +1 位作者 X.S. Chen J. Zhang 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2007年第5期363-372,共10页
As the dump was a typically heterogeneous body, the seepage was different with varied spreading solution modes. The phenomenon of lamination that occured in the site was simulated using three layers in an indoor exper... As the dump was a typically heterogeneous body, the seepage was different with varied spreading solution modes. The phenomenon of lamination that occured in the site was simulated using three layers in an indoor experiment, and the seepage effect comparison experiment of the inside spreading solution model and the top spreading solution model have been carried out. In the inside spreading solution mode, the phreatic planar flew without infiltration and the parallel layer motion model was used to calculate the seepage coefficient and equivalent seepage coefficient of each state respectively. In the top spreading solution model, the phreatic planar flew with an even infiltration on the surface, and the vertical layer motion model was adopted to calculate the above coefficient. The results showed that the seepage coefficient of the inside model was larger than the top model in the heterogeneous body, The ratio of them was between 1.42 and 3.07. On the basis of these results, the following new technologies were discussed: installing a few small diameter mechanical pore sand piles with every lamination in the using dump; drilling some holes one-off in the unused dump. These two methods could changed the top spreading solution into the inside model, thus the seepage in the dump was improved. 展开更多
关键词 heterogeneous body top spreading solution inside spreading solution sand pile drawing-injection drill
下载PDF
Numerical and Experimental Study on Droplet Spreading Motion after Impingement Considering Dynamic Contact Angle with CCUP (CIP-Combined Unified Procedure) Method
17
作者 Soyoun Son Gwonhyun Ko Hongsun Ryou 《Journal of Energy and Power Engineering》 2013年第1期10-16,共7页
The contact angle is one of important parameters to simulate droplet spreading and impingement phenomena on the surface. In the most numerical research, it is assumed constant value and it is implemented as boundary c... The contact angle is one of important parameters to simulate droplet spreading and impingement phenomena on the surface. In the most numerical research, it is assumed constant value and it is implemented as boundary condition. However, contact angle is changed according to contact line velocity and time. Hence, for accurate simulation, dynamic contact angle which has various values as time elapsed is adopted. In the present study, the numerical analysis is performed on the droplet spreading phenomena considering dynamic contact angle function which is obtained from single droplet spreading experiment on the flat and bare surface. The CIP (cubic interpolated pseudo-particle) method by Yabe is used for analysis of interface between liquid and gas phases. The numerical results considering contact angle function which newly modeled as time and contact angle are compared with numerical results considering Hoffman's function and experimental data for range of Weber number which are 4.427 and 11.334. In contrast of numerical result considering Hoffman's function, the numerical result shows good agreement with experimental data as time elapsed in contact angle evolution, deformation of droplet spreading radius and height. Indeed, overall, the results display the increasing maximum spreading radius and the decreasing height as Weber numbers increased. 展开更多
关键词 CIP method droplet spreading height droplet spreading radius dynamic contact angle Hoffman's fimction.
下载PDF
An Important Spreading Event of the Neo-Tethys Ocean during the Late Jurassic and Early Cretaceous: Evidence from Zircon U-Pb SHRIMP Dating on Diabase in Nagarze, Southern Tibet 被引量:27
18
作者 JIANG Sihong NIE Fengjun HU Peng LIU Yan 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2006年第4期522-527,共6页
Widely distributed in Gyangzê-Chigu area, southern Tibet, NW- and nearly E-W-trending diabase(gabbro)-gabbro diorite dykes are regarded as the product of the large-scale spreading of the late Neo-Tethys Ocean. ... Widely distributed in Gyangzê-Chigu area, southern Tibet, NW- and nearly E-W-trending diabase(gabbro)-gabbro diorite dykes are regarded as the product of the large-scale spreading of the late Neo-Tethys Ocean. In order to constrain the emplacement age of these dykes, zircons of two samples from diabases in Nagarzê were dated by using the U-Pb SHRIMP method. Two nearly the same weighted mean ^206pb/^23SU ages were obtained in this paper, which are 134.9±1.8 Ma (MSWD=0.65) and 135.5 ± 2.1 Ma (MSWD=1.40), respectively. They not only represent the crystallization age of the diabase, but also documented an important spreading event of the Neo-Tethys Ocean during the late Jurassic and early Cretaceous. This dating result is of great significance to reconstruct the temporal framework of the late Neo-Tethys Ocean in the Qinghai-Tibet Plateau. 展开更多
关键词 DIABASE zircon U-Pb SHRIMP dating spreading event NEO-TETHYS Nagarzê southern Tibet
下载PDF
Lymphatic spreading and lymphadenectomy for esophageal carcinoma 被引量:12
19
作者 xiang ji jie cai +1 位作者 yao chen long-qi chen 《World Journal of Gastrointestinal Surgery》 SCIE CAS 2016年第1期90-94,共5页
Esophageal carcinoma(EC) is a highly lethal malignancywith a poor prognosis. One of the most important prognostic factors in EC is lymph node status. Therefore, lymphadenectomy has been recognized as a key that influe... Esophageal carcinoma(EC) is a highly lethal malignancywith a poor prognosis. One of the most important prognostic factors in EC is lymph node status. Therefore, lymphadenectomy has been recognized as a key that influences the outcome of surgical treatment for EC. However, the lymphatic drainage system of the esophagus, including an abundant lymph-capillary network in the lamina propria and muscularis mucosa, is very complex with cervical, mediastinal and celiac node spreading. The extent of lymphadenectomy for EC has always been controversial because of the very complex pattern of lymph node spreading. In this article, published literature regarding lymphatic spreading was reviewed and the current lymphadenectomy trends for EC are discussed. 展开更多
关键词 LYMPHADENECTOMY LYMPHATIC spreading ANATOMICAL LYMPHATIC system LYMPH node metastasis Esophageal cancer
下载PDF
MUC5AC/β-catenin expression and KRAS gene alteration in laterally spreading colorectal tumors 被引量:9
20
作者 Kosaburo Nakae Hiroyuki Mitomi +6 位作者 Tsuyoshi Saito Michiko Takahashi Takashi Morimoto Yasuhiro Hidaka Naoto Sakamoto Takashi Yao Sumio Watanabe 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第39期5551-5559,共9页
AIM: To clarify differences in mucin phenotype, prolif- erative activity and oncogenetic alteration among sub- types of colorectal laterally spreading tumor (LST). METHODS: LSTs, defined as superficial elevated le... AIM: To clarify differences in mucin phenotype, prolif- erative activity and oncogenetic alteration among sub- types of colorectal laterally spreading tumor (LST). METHODS: LSTs, defined as superficial elevated lesions greater than 10 mm in diameter with a low vertical axis, were macroscopically classified into two subtypes: (1) a granular type (Gr-LST) composed of superficially spread- ing aggregates of nodules forming a fiat-based lesion with a granulonodular and uneven surface; and (2) a non-granular type (NGr-LST) with a flat smooth surface and an absence of granulonodular formation. A total of 69 LSTs, comprising 36 Gr-LSTs and 33 NGr-LSTs, were immunohistochemically stained with MUC2, MUC5AC, MUC6, CD10 (markers of gastrointestinal cell lineage), p53, 13-catenin and Ki-67 antibodies, and examined for alteration in exon 1 of v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) and exon 15 of v-raf murine sarcoma viral oncogene homologue B1 (BRAF) by poly- merase chain reaction followed by direct sequencing. RESULTS: Histologically, 15 Gr-LST samples were ad- enomas with low-grade dysplasia (LGD), 12 were high- grade dysplasia (HGD) and 9 were adenocarcinomas invading the submucosa (INV), while 12 NGr-LSTs demonstrated LGD, 14 HGD and 7 INV. In the proximal colon, MUC5AC expression was significantly higher in the Gr-type than the NGr-type. MUC6 was expressed only in NGr-LST. MUC2 or CD10 did not differ. P53 ex- pression demonstrated a significant stepwise increment in progression through LGD-HGD-INV with both types of LST. Nuclear β-catenin expression was significantly higher in the NGr-type. Ki-67 expression was signifi- cantly higher in the Gr-type in the lower one third zone of the tumor. In proximal, but not distal colon tumors, the incidence of KRAS provided mutation was signifi- cantly higher in the Gr-type harboring a specific muta- tional pattern (G12V). BRAF mutations (V600E) were detected only in two Gr-LSTs. CONCLUSION: The two subtypes of LST, especially in the proximal colon, have differing phenotypes of gastrointestinal cell lineage, proliferation and activa- tion of Wnt/β-catenin or RAS/RAF/extracellular signal- regulated kinase signaling. 展开更多
关键词 Laterally spreading tumor Mucin core pro-tein Colon Β-CATENIN Immunohistochemistry v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog Directsequencing Adenoma-carcinoma sequence
下载PDF
上一页 1 2 46 下一页 到第
使用帮助 返回顶部