Background:The optimal strategy for adjuvant therapy after curative resection for hepatocellular carcinoma(HCC)patients with solitary tumor and microvascular invasion(MVI)is controversial.This trial evaluated the effi...Background:The optimal strategy for adjuvant therapy after curative resection for hepatocellular carcinoma(HCC)patients with solitary tumor and microvascular invasion(MVI)is controversial.This trial evaluated the efficacy and safety of adjuvant transcatheter arterial chemoembolization(TACE)after hepatectomy versus hepatectomy alone in HCC patients with a solitary tumor≥5 cm and MVI.Methods:In this randomized,open-labeled,phase III trial,HCC patients with a solitary tumor≥5 cm and MVI were randomly assigned(1:1)to receive either 1-2 cycles of adjuvant TACE after hepatectomy(Hepatectomy-TACE)or hepatectomy alone(Hepatectomy Alone).The primary endpoint was disease-free survival(DFS);the secondary end-points included overall survival(OS)and adverse events.Results:Between June 1,2009,and December 31,2012,250 patients were enrolled and randomly assigned to the Hepatectomy-TACE group(n=125)or the Hepatectomy Alone group(n=125).Clinicopathological characteristics were balanced between the two groups.The median follow-up time from randomization was 37.5 months[interquartile range 18.3-48.2 months].The median DFS was significantly longer in the Hepatectomy-TACE group than in the Hepatectomy Alone group[17.45 months(95%confidence interval[CI]11.99-29.14)vs.9.27 months(95%CI 6.05-13.70),hazard ratio[HR]=0.70(95%CI 0.52-0.95),P=0.020],respectively.The median OS was also significantly longer in the Hepatectomy-TACE group than in the Hepatectomy Alone group[44.29 months(95%CI 25.99-62.58)vs.22.37 months(95%CI 10.84-33.91),HR=0.68(95%CI 0.48-0.97),P=0.029].Treatment-related adverse events were more frequently observed in the Hepatectomy-TACE group,although these were generally mild and manageable.The most common grade 3 or 4 adverse events in both groups were neutropenia and liver dysfunction.Conclusion:Hepatectomy followed by adjuvant TACE is an appropriate option after radical resection in HCC patients with solitary tumor≥5 cm and MVI,with acceptable toxicity.展开更多
The method of the phase plane is emploied to investigate the solitary and periodic traveling waves for a class of nonlinear dispersive partial differential equations.By using the bifurcation theory of dynamical system...The method of the phase plane is emploied to investigate the solitary and periodic traveling waves for a class of nonlinear dispersive partial differential equations.By using the bifurcation theory of dynamical systems to do qualitative analysis,all possible phase portraits in the parametric space for the traveling wave systems are obtained.It can be shown that the existence of a singular straight line in the traveling wave system is the reason why smooth solitary wave solutions converge to solitary cusp wave solution when parameters are varied.The different parameter conditions for the existence of solitary and periodic wave solutions of different kinds are rigorously determined.展开更多
Simulation of solitary wave run-up on a vertical circular cylinder is carried out in a viscous numerical wave tank developed based on the open source codes Open FOAM. An incompressible two-phase flow solver naoe-FOAM-...Simulation of solitary wave run-up on a vertical circular cylinder is carried out in a viscous numerical wave tank developed based on the open source codes Open FOAM. An incompressible two-phase flow solver naoe-FOAM-SJTU is used to solve the Reynolds-Averaged Navier–Stokes（RANS） equations with the SST k ？？ turbulence model. The PISO algorithm is utilized for the pressure-velocity coupling. The air-water interface is captured via Volume of Fluid（VOF） technique. The present numerical model is validated by simulating the solitary wave run-up and reflected against a vertical wall, and solitary wave run-up on a vertical circular cylinder. Comparisons between numerical results and available experimental data show satisfactory agreement. Furthermore, simulations are carried out to study the solitary wave run-up on the cylinder with different incident wave height H and different cylinder radius a. The relationships of the wave run-up height with the incident wave height H, cylinder radius a are analyzed. The evolutions of the scattering free surface and vortex shedding are also presented to give a better understanding of the process of nonlinear wave-cylinder interaction.展开更多
A principle of generating the nonlinear large-amplitude internal wave in a stratified fluid tank with large cross-section is pro- posed according to the ＇jalousie＇ control mode. A new wave-maker based on the princip...A principle of generating the nonlinear large-amplitude internal wave in a stratified fluid tank with large cross-section is pro- posed according to the ＇jalousie＇ control mode. A new wave-maker based on the principle was manufactured and the experi- ments on the generation and evolution of internal solitary wave were conducted. Both the validity of the new device and ap- plicability range of the KdV-type internal soliton theory were tested. Furthermore, a measurement technique of hydrodynamic load of internal waves was developed. By means of accurately measuring slight variations of internal wave forces exerted on a slender body in the tank, their interaction characteristics were determined. It is shown that through establishing the similarity between the model scale in the stratified fluid tank and the full scale in the numerical simulation the obtained measurement re- suits of internal wave forces are confirmed to be correct.展开更多
Based on in-situ time series data from the acoustic Doppler current profiler （ADCP） and thermistor chain in Wenchang area, a sequence of internal solitary wave （ISW） packets was observed in September 2005, propaga...Based on in-situ time series data from the acoustic Doppler current profiler （ADCP） and thermistor chain in Wenchang area, a sequence of internal solitary wave （ISW） packets was observed in September 2005, propagating northwest on the continental shelf of the northwestern South China Sea （SCS）. Corresponding to different stratification of the water column and tidal condition, both elevation and depression ISWs were observed at the same mooring location with amplitude of 35 m and 25 m respectively in different days. Regular arrival of the remarkable ISW packets at approximately the diurnal tidal period and the dominance of diurnal internal waves in the study area, strongly suggest that the main energy source of the waves is the diurnal tide. Notice that the wave packets were all riding on the troughs and shoulders of the internal tides, they were probably generated locally from the shelf break by the evolution of the internal tides due to nonlinear and dispersive effects.展开更多
BACKGROUND:Predictors of poor prognosis of solitary hepatocellular carcinoma(SHCC),a subgroup encompassing most patients with the malignancy,are still controversial.Hence,risk factors for portal vein tumor thrombosis(...BACKGROUND:Predictors of poor prognosis of solitary hepatocellular carcinoma(SHCC),a subgroup encompassing most patients with the malignancy,are still controversial.Hence,risk factors for portal vein tumor thrombosis(PVTT) in SHCC are obscure.The present study was designed to address this issue.METHOD:Clinicopathological and follow-up data for 156 consecutive patients with SHCC following curative hepatic resection were analyzed using uni-and multi-variate analyses.RESULTS:Univariate analysis showed that PVTT,tumornode-metastasis(TNM) stage,Edmondson-Steiner grade and preoperative serum alpha-fetoprotein(AFP) level were associated with the overall and disease-free survival,whereas tumor size only influenced the overall survival.In multivariate Cox regression tests,Edmondson-Steiner grade and TNM stage were independent prognostic markers for both overall and diseasefree survival.In addition,the Chi-square test showed that AFP level and Edmondson-Steiner grade were correlated with PVTT.Among them,only Edmondson-Steiner grade was shown to be of independent significance for PVTT in multi-variate logistic regression analysis.Additionally,AFP,the sole preoperative factor for PVTT,was not adequately sensitive and specific.CONCLUSIONS:Factors relating to post-surgical prognosis and PVTT in SHCC are all tumor-related.Of these,EdmondsonSteiner grade and TNM stage might be of particular importance in survival analysis.In addition,accurate prediction of PVTT by clinicopathological parameters before surgery remains difficult.展开更多
Background Computer-aided diagnosis （CAD） of lung cancer is the subject of many current researches. Statistical methods and artificial neural networks have been applied to more quantitatively characterize solitary p...Background Computer-aided diagnosis （CAD） of lung cancer is the subject of many current researches. Statistical methods and artificial neural networks have been applied to more quantitatively characterize solitary pulmonary nodules （SPNs）. In this study, we developed a CAD scheme based on an artificial neural network to distinguish malignant from benign SPNs on thin-section computed tomography （CT） images, and investigated how the CAD scheme can help radiologists with different levels of experience make diagnostic decisions. Methods Two hundred thin-section CT images of SPNs with proven diagnoses （135 small peripheral lung cancers and 65 benign nodules） were analyzed. Three clinical features and nine CT signs of each case were studied by radiologists, and the indices of qualitative diagnosis were quantified. One hundred and forty nodules were selected randomly to form training samples, on which the neural network model was built. The remaining 60 nodules, forming test samples, were presented to 9 radiologists with 3-20 years of clinical experience, accompanied by standard reference images. The radiologists were asked to determine whether a nodule was malignant or benign first without and then with CAD output. Diagnostic performance was evaluated by receiver operating characteristic （ROC） analysis. Results CAD outputs on test samples had higher agreement with pathological diagnoses （Kappa=0.841, P〈0.001）. Compared with diagnostic results without CAD output, the average area under the ROC curve with CAD output was 0.96 （P〈0.001） for junior radiologists, 0.94 （P=0.014） for secondary radiologists and 0.96 （P=0.221） for senior radiologists, respectively. The differences in diagnostic performance with CAD output among the three levels of radiologists were not statistically significant （P=0.584, 0.920 and 0.707, respectively）. Conclusions This CAD scheme based on an artificial neural network could improve diagnostic performance and assist radiologists in distinguishing maligna展开更多
For settlement of the well-known problem of contemporary radar imaging models, i. e. , the problem of a general underestimation of radar signatures of hydrodynamic features over oceanic internal waves and underwater b...For settlement of the well-known problem of contemporary radar imaging models, i. e. , the problem of a general underestimation of radar signatures of hydrodynamic features over oceanic internal waves and underwater bottom topography in tidal waters at high radar frequency bands （ X-band and C-band）, the impact of the ocean surface mixed layer turbulence and the significance of strat- ified oceanic model on SAR remote sensing of internal solitary waves are proposed. In the north of the South China Sea by utilizing some observed data of background field the nonlinearity coefficient, the dispersion coefficient, the horizontal variability coefficient and the phase speed in the generalized K-dV equation are determined approximately. Through simulations of internal tide transfor- mation the temporal evolution and spatial distribution of the vertical displacement and horizontal velocity of internal wave field are obtained. The simulation results indicate that the maximum amplitudes of internal solitary waves occur at depth 35 m, but the maximum current speeds take place at depth 20 m in this area of the sea （about 20°30＇N, 114°E） in August. It was noticed that considering the effects of flood current and ebb current respectively is appropriate to investigate influence of the background shear flow on coefficients of the K-dV equation. The obtained results provide the possibility for the simulation of SAR signatures of internal solitary waves under considering the impact of ocean surface mixed layer turbulence in the companion paper.展开更多
A total of 137 internal solitary waves （ISWs） are captured during a field experiment conducted in the deep basin west of the Luzon Strait （LS） from March to August, 2010. Mooring observations reveal that a fully d...A total of 137 internal solitary waves （ISWs） are captured during a field experiment conducted in the deep basin west of the Luzon Strait （LS） from March to August, 2010. Mooring observations reveal that a fully developed ISW owns a maximum westward velocity of more than 1.8 m/s and an amplitude of about 200 m. The ISWs in the South China Sea （SCS） are most active in July, which may be due to the strong stratification in summer. Most of the ISW episodes are detected around and after the 1st or 15th lunar day, indicating that the ISW in the SCS is triggered by astronomic tides. Half part of the observed ISWs were detected around 19：00 local time, which can be explained by the fact that type-a ISWs emerged in the evening at roughly the same time each day. The propagation direction of the ISWs and the astronomic tides in the LS show that the area south of the Batan Island is probably the main source region of the type-a ISWs, while the area south of Itbayat Island and south of the Batan Island is likely the main source region of the type-b ISWs observed at the mooring. Moreover, for the resonance of semidiurnal internal tides emitting from the double ridges in the LS, the underwater ridge south of the Itbayat Island and south of the Batan Island is believed to favor the generation of the energetic ISWs.展开更多
In this paper, based on hyperbolic tanh-function method and homogeneous balance method, and auxiliary equation method, some new exact solitary solutions to the generalized mKdV equation and generalized Zakharov-Kuzent...In this paper, based on hyperbolic tanh-function method and homogeneous balance method, and auxiliary equation method, some new exact solitary solutions to the generalized mKdV equation and generalized Zakharov-Kuzentsov equation are constructed by the method of auxiliary equation with function transformation with aid of symbolic computation system Mathematica. The method is of important significance in seeking new exact solutions to the evolution equation with arbitrary nonlinear term.展开更多
In this article, a novel （G＇/G）-expansion method is proposed to search for the traveling wave solutions of nonlinear evolution equations. We construct abundant traveling wave solutions involving parameters to the B...In this article, a novel （G＇/G）-expansion method is proposed to search for the traveling wave solutions of nonlinear evolution equations. We construct abundant traveling wave solutions involving parameters to the Boussinesq equation by means of the suggested method. The performance of the method is reliable and useful, and gives more general exact solutions than the existing methods. The new （G＇/G）-expansion method provides not only more general forms of solutions but also cuspon, peakon, soliton, and periodic waves.展开更多
From the nonlinear sine-Gordon equation, new transformations are obtained in this paper, which are applied to propose a new approach to construct exact periodic solutions to nonlinear wave equations. It is shown that ...From the nonlinear sine-Gordon equation, new transformations are obtained in this paper, which are applied to propose a new approach to construct exact periodic solutions to nonlinear wave equations. It is shown that more new periodic solutions can be obtained by this new approach, and more shock wave solutions or solitary wave solutions can be got under their limit conditions.展开更多
BACKGROUND: Solitary necrotic nodule of the liver is a rare nonmalignant lesion. The present study aimed to clarify the clinical features of the disease. METHOD: The medical records of 51 patients with histologically ...BACKGROUND: Solitary necrotic nodule of the liver is a rare nonmalignant lesion. The present study aimed to clarify the clinical features of the disease. METHOD: The medical records of 51 patients with histologically confirmed solitary necrotic nodule of the liver who received surgical resection at our institution were retrospectively reviewed. RESULTS: Solitary necrotic nodule of the liver was found mainly in males (68.6%, 35/51), and patients ranged in age from 5 to 69 years with a mean of 45.3. Most of the patients (72.5%) had no significant symptoms, with negative results for the serum tumor markers alpha-fetoprotein, carbohydrate antigen 19-9 and carcinoembryonic antigen. The mean diameter of the nodule was 23 mm (range 10-55 mm). Compared with ultrasonographic and computed tomography findings, the specific features of magnetic resonance imaging were more helpful for differential diagnosis of the disease. CONCLUSIONS: Solitary necrotic nodule of the liver is a rare nonmalignant lesion, showing no notable symptoms and potential complications. The pathological change of the disease is not significant over a lifetime. Conservative treatment and clinical follow-up are recommended.展开更多
The （G＇/G, 1/G）-expansion method for finding exact travelling wave solutions of nonlinear evolution equations, which can be thought of as an extension of the （G＇/G）-expansion method proposed recently, is present...The （G＇/G, 1/G）-expansion method for finding exact travelling wave solutions of nonlinear evolution equations, which can be thought of as an extension of the （G＇/G）-expansion method proposed recently, is presented. By using this method abundant travelling wave so- lutions with arbitrary parameters of the Zakharov equations are successfully obtained. When the parameters are replaced by special values, the well-known solitary wave solutions of the equations are rediscovered from the travelling waves.展开更多
基金supported by the National Natural Science Foundation of China(No.81172037)Science and Technology Program of Guangdong Province,China(No.2013B021800159)Clinical Trials Project(308 Project)of Sun Yat-sen University Cancer Center(No.308-2015-014).
文摘Background:The optimal strategy for adjuvant therapy after curative resection for hepatocellular carcinoma(HCC)patients with solitary tumor and microvascular invasion(MVI)is controversial.This trial evaluated the efficacy and safety of adjuvant transcatheter arterial chemoembolization(TACE)after hepatectomy versus hepatectomy alone in HCC patients with a solitary tumor≥5 cm and MVI.Methods:In this randomized,open-labeled,phase III trial,HCC patients with a solitary tumor≥5 cm and MVI were randomly assigned(1:1)to receive either 1-2 cycles of adjuvant TACE after hepatectomy(Hepatectomy-TACE)or hepatectomy alone(Hepatectomy Alone).The primary endpoint was disease-free survival(DFS);the secondary end-points included overall survival(OS)and adverse events.Results:Between June 1,2009,and December 31,2012,250 patients were enrolled and randomly assigned to the Hepatectomy-TACE group(n=125)or the Hepatectomy Alone group(n=125).Clinicopathological characteristics were balanced between the two groups.The median follow-up time from randomization was 37.5 months[interquartile range 18.3-48.2 months].The median DFS was significantly longer in the Hepatectomy-TACE group than in the Hepatectomy Alone group[17.45 months(95%confidence interval[CI]11.99-29.14)vs.9.27 months(95%CI 6.05-13.70),hazard ratio[HR]=0.70(95%CI 0.52-0.95),P=0.020],respectively.The median OS was also significantly longer in the Hepatectomy-TACE group than in the Hepatectomy Alone group[44.29 months(95%CI 25.99-62.58)vs.22.37 months(95%CI 10.84-33.91),HR=0.68(95%CI 0.48-0.97),P=0.029].Treatment-related adverse events were more frequently observed in the Hepatectomy-TACE group,although these were generally mild and manageable.The most common grade 3 or 4 adverse events in both groups were neutropenia and liver dysfunction.Conclusion:Hepatectomy followed by adjuvant TACE is an appropriate option after radical resection in HCC patients with solitary tumor≥5 cm and MVI,with acceptable toxicity.
基金National Natural Science Foundation of China(No.19731003,No.19961003)Yunnan Provincial Natural Science Foundation of China(No.1999A0018M,No.2000A0002M)
文摘The method of the phase plane is emploied to investigate the solitary and periodic traveling waves for a class of nonlinear dispersive partial differential equations.By using the bifurcation theory of dynamical systems to do qualitative analysis,all possible phase portraits in the parametric space for the traveling wave systems are obtained.It can be shown that the existence of a singular straight line in the traveling wave system is the reason why smooth solitary wave solutions converge to solitary cusp wave solution when parameters are varied.The different parameter conditions for the existence of solitary and periodic wave solutions of different kinds are rigorously determined.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51379125,51411130131,and 11432009)Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning(Grant No.2013022)the National Basic Research Program of China(973 Program,Grant No.2013CB036103)
文摘Simulation of solitary wave run-up on a vertical circular cylinder is carried out in a viscous numerical wave tank developed based on the open source codes Open FOAM. An incompressible two-phase flow solver naoe-FOAM-SJTU is used to solve the Reynolds-Averaged Navier–Stokes（RANS） equations with the SST k ？？ turbulence model. The PISO algorithm is utilized for the pressure-velocity coupling. The air-water interface is captured via Volume of Fluid（VOF） technique. The present numerical model is validated by simulating the solitary wave run-up and reflected against a vertical wall, and solitary wave run-up on a vertical circular cylinder. Comparisons between numerical results and available experimental data show satisfactory agreement. Furthermore, simulations are carried out to study the solitary wave run-up on the cylinder with different incident wave height H and different cylinder radius a. The relationships of the wave run-up height with the incident wave height H, cylinder radius a are analyzed. The evolutions of the scattering free surface and vortex shedding are also presented to give a better understanding of the process of nonlinear wave-cylinder interaction.
基金supported by the National Natural Science Foundation of China(Grant No.11072267)the National High Technology Research and Development Program of China(Grant No.2008AA09Z316)the Pre-Research Foundation of PLA University of Science&Technology(Grant No.KYLYZLXY1202)
文摘A principle of generating the nonlinear large-amplitude internal wave in a stratified fluid tank with large cross-section is pro- posed according to the ＇jalousie＇ control mode. A new wave-maker based on the principle was manufactured and the experi- ments on the generation and evolution of internal solitary wave were conducted. Both the validity of the new device and ap- plicability range of the KdV-type internal soliton theory were tested. Furthermore, a measurement technique of hydrodynamic load of internal waves was developed. By means of accurately measuring slight variations of internal wave forces exerted on a slender body in the tank, their interaction characteristics were determined. It is shown that through establishing the similarity between the model scale in the stratified fluid tank and the full scale in the numerical simulation the obtained measurement re- suits of internal wave forces are confirmed to be correct.
基金The Key Program of Knowledge Innovation Project of Chinese Academy of Sciences under contract No.KZCX1-YW-12the National 863 Program under contract Nos 2008AA09A401 and 2006AA09A109
文摘Based on in-situ time series data from the acoustic Doppler current profiler （ADCP） and thermistor chain in Wenchang area, a sequence of internal solitary wave （ISW） packets was observed in September 2005, propagating northwest on the continental shelf of the northwestern South China Sea （SCS）. Corresponding to different stratification of the water column and tidal condition, both elevation and depression ISWs were observed at the same mooring location with amplitude of 35 m and 25 m respectively in different days. Regular arrival of the remarkable ISW packets at approximately the diurnal tidal period and the dominance of diurnal internal waves in the study area, strongly suggest that the main energy source of the waves is the diurnal tide. Notice that the wave packets were all riding on the troughs and shoulders of the internal tides, they were probably generated locally from the shelf break by the evolution of the internal tides due to nonlinear and dispersive effects.
基金supported by a grant from the Beijing Municipal Fund for Key Disciplines,China (100230446)
文摘BACKGROUND:Predictors of poor prognosis of solitary hepatocellular carcinoma(SHCC),a subgroup encompassing most patients with the malignancy,are still controversial.Hence,risk factors for portal vein tumor thrombosis(PVTT) in SHCC are obscure.The present study was designed to address this issue.METHOD:Clinicopathological and follow-up data for 156 consecutive patients with SHCC following curative hepatic resection were analyzed using uni-and multi-variate analyses.RESULTS:Univariate analysis showed that PVTT,tumornode-metastasis(TNM) stage,Edmondson-Steiner grade and preoperative serum alpha-fetoprotein(AFP) level were associated with the overall and disease-free survival,whereas tumor size only influenced the overall survival.In multivariate Cox regression tests,Edmondson-Steiner grade and TNM stage were independent prognostic markers for both overall and diseasefree survival.In addition,the Chi-square test showed that AFP level and Edmondson-Steiner grade were correlated with PVTT.Among them,only Edmondson-Steiner grade was shown to be of independent significance for PVTT in multi-variate logistic regression analysis.Additionally,AFP,the sole preoperative factor for PVTT,was not adequately sensitive and specific.CONCLUSIONS:Factors relating to post-surgical prognosis and PVTT in SHCC are all tumor-related.Of these,EdmondsonSteiner grade and TNM stage might be of particular importance in survival analysis.In addition,accurate prediction of PVTT by clinicopathological parameters before surgery remains difficult.
基金This work was supported by a grant from Beijing Natural Science Foundation(No.7062020).
文摘Background Computer-aided diagnosis （CAD） of lung cancer is the subject of many current researches. Statistical methods and artificial neural networks have been applied to more quantitatively characterize solitary pulmonary nodules （SPNs）. In this study, we developed a CAD scheme based on an artificial neural network to distinguish malignant from benign SPNs on thin-section computed tomography （CT） images, and investigated how the CAD scheme can help radiologists with different levels of experience make diagnostic decisions. Methods Two hundred thin-section CT images of SPNs with proven diagnoses （135 small peripheral lung cancers and 65 benign nodules） were analyzed. Three clinical features and nine CT signs of each case were studied by radiologists, and the indices of qualitative diagnosis were quantified. One hundred and forty nodules were selected randomly to form training samples, on which the neural network model was built. The remaining 60 nodules, forming test samples, were presented to 9 radiologists with 3-20 years of clinical experience, accompanied by standard reference images. The radiologists were asked to determine whether a nodule was malignant or benign first without and then with CAD output. Diagnostic performance was evaluated by receiver operating characteristic （ROC） analysis. Results CAD outputs on test samples had higher agreement with pathological diagnoses （Kappa=0.841, P〈0.001）. Compared with diagnostic results without CAD output, the average area under the ROC curve with CAD output was 0.96 （P〈0.001） for junior radiologists, 0.94 （P=0.014） for secondary radiologists and 0.96 （P=0.221） for senior radiologists, respectively. The differences in diagnostic performance with CAD output among the three levels of radiologists were not statistically significant （P=0.584, 0.920 and 0.707, respectively）. Conclusions This CAD scheme based on an artificial neural network could improve diagnostic performance and assist radiologists in distinguishing maligna
基金the National High Technology Research and Development Project ("863"Program) of China under contract No.2002AA633120the National Natural Science Foundation of China under contract No.40706055
文摘For settlement of the well-known problem of contemporary radar imaging models, i. e. , the problem of a general underestimation of radar signatures of hydrodynamic features over oceanic internal waves and underwater bottom topography in tidal waters at high radar frequency bands （ X-band and C-band）, the impact of the ocean surface mixed layer turbulence and the significance of strat- ified oceanic model on SAR remote sensing of internal solitary waves are proposed. In the north of the South China Sea by utilizing some observed data of background field the nonlinearity coefficient, the dispersion coefficient, the horizontal variability coefficient and the phase speed in the generalized K-dV equation are determined approximately. Through simulations of internal tide transfor- mation the temporal evolution and spatial distribution of the vertical displacement and horizontal velocity of internal wave field are obtained. The simulation results indicate that the maximum amplitudes of internal solitary waves occur at depth 35 m, but the maximum current speeds take place at depth 20 m in this area of the sea （about 20°30＇N, 114°E） in August. It was noticed that considering the effects of flood current and ebb current respectively is appropriate to investigate influence of the background shear flow on coefficients of the K-dV equation. The obtained results provide the possibility for the simulation of SAR signatures of internal solitary waves under considering the impact of ocean surface mixed layer turbulence in the companion paper.
基金The Program for New Century Excellent Talents in Universities of China under contract No.NCET-10-0764the National High Tech-nology Research and Development(863)Program of China under contract No.2013AA09A502the National Natural Science Foundation of China under contract Nos 41176010,91028008,40890153,41176008 and 40776005
文摘A total of 137 internal solitary waves （ISWs） are captured during a field experiment conducted in the deep basin west of the Luzon Strait （LS） from March to August, 2010. Mooring observations reveal that a fully developed ISW owns a maximum westward velocity of more than 1.8 m/s and an amplitude of about 200 m. The ISWs in the South China Sea （SCS） are most active in July, which may be due to the strong stratification in summer. Most of the ISW episodes are detected around and after the 1st or 15th lunar day, indicating that the ISW in the SCS is triggered by astronomic tides. Half part of the observed ISWs were detected around 19：00 local time, which can be explained by the fact that type-a ISWs emerged in the evening at roughly the same time each day. The propagation direction of the ISWs and the astronomic tides in the LS show that the area south of the Batan Island is probably the main source region of the type-a ISWs, while the area south of Itbayat Island and south of the Batan Island is likely the main source region of the type-b ISWs observed at the mooring. Moreover, for the resonance of semidiurnal internal tides emitting from the double ridges in the LS, the underwater ridge south of the Itbayat Island and south of the Batan Island is believed to favor the generation of the energetic ISWs.
基金Project supported by the National Natural Science Foundation of China （Grant No 10461006）, the High Education Science Research Program （Grant No NJ02035） of Inner Mongolia Autonomous Region, Natural Science Foundation of Inner Mongolia Autonomous Region （Grant No 2004080201103） and the Youth Research Program of Inner Mongolia Normal University （Grant No QN005023）.
文摘In this paper, based on hyperbolic tanh-function method and homogeneous balance method, and auxiliary equation method, some new exact solitary solutions to the generalized mKdV equation and generalized Zakharov-Kuzentsov equation are constructed by the method of auxiliary equation with function transformation with aid of symbolic computation system Mathematica. The method is of important significance in seeking new exact solutions to the evolution equation with arbitrary nonlinear term.
文摘In this article, a novel （G＇/G）-expansion method is proposed to search for the traveling wave solutions of nonlinear evolution equations. We construct abundant traveling wave solutions involving parameters to the Boussinesq equation by means of the suggested method. The performance of the method is reliable and useful, and gives more general exact solutions than the existing methods. The new （G＇/G）-expansion method provides not only more general forms of solutions but also cuspon, peakon, soliton, and periodic waves.
文摘From the nonlinear sine-Gordon equation, new transformations are obtained in this paper, which are applied to propose a new approach to construct exact periodic solutions to nonlinear wave equations. It is shown that more new periodic solutions can be obtained by this new approach, and more shock wave solutions or solitary wave solutions can be got under their limit conditions.
文摘BACKGROUND: Solitary necrotic nodule of the liver is a rare nonmalignant lesion. The present study aimed to clarify the clinical features of the disease. METHOD: The medical records of 51 patients with histologically confirmed solitary necrotic nodule of the liver who received surgical resection at our institution were retrospectively reviewed. RESULTS: Solitary necrotic nodule of the liver was found mainly in males (68.6%, 35/51), and patients ranged in age from 5 to 69 years with a mean of 45.3. Most of the patients (72.5%) had no significant symptoms, with negative results for the serum tumor markers alpha-fetoprotein, carbohydrate antigen 19-9 and carcinoembryonic antigen. The mean diameter of the nodule was 23 mm (range 10-55 mm). Compared with ultrasonographic and computed tomography findings, the specific features of magnetic resonance imaging were more helpful for differential diagnosis of the disease. CONCLUSIONS: Solitary necrotic nodule of the liver is a rare nonmalignant lesion, showing no notable symptoms and potential complications. The pathological change of the disease is not significant over a lifetime. Conservative treatment and clinical follow-up are recommended.
基金Supported by the International Cooperation and Exchanges Foundation of Henan Province (084300510060)the Youth Science Foundation of Henan University of Science and Technology of China (2008QN026)
文摘The （G＇/G, 1/G）-expansion method for finding exact travelling wave solutions of nonlinear evolution equations, which can be thought of as an extension of the （G＇/G）-expansion method proposed recently, is presented. By using this method abundant travelling wave so- lutions with arbitrary parameters of the Zakharov equations are successfully obtained. When the parameters are replaced by special values, the well-known solitary wave solutions of the equations are rediscovered from the travelling waves.
