期刊文献+
共找到20,575篇文章
< 1 2 250 >
每页显示 20 50 100
Red cell distribution width/platelet ratio estimates the 3-year risk of decompensation in Metabolic Dysfunction-Associated Steatotic Liver Disease-induced cirrhosis
1
作者 Marcello Dallio Mario Romeo +8 位作者 Paolo Vaia Salvatore Auletta Simone Mammone Marina Cipullo Luigi Sapio Angela Ragone Marco Niosi Silvio Naviglio Alessandro Federico 《World Journal of Gastroenterology》 SCIE CAS 2024年第7期685-704,共20页
BACKGROUND For compensated advanced chronic liver disease(cACLD)patients,the first decompensation represents a dramatically worsening prognostic event.Based on the first decompensation event(DE),the transition to deco... BACKGROUND For compensated advanced chronic liver disease(cACLD)patients,the first decompensation represents a dramatically worsening prognostic event.Based on the first decompensation event(DE),the transition to decompensated advanced chronic liver disease(dACLD)can occur through two modalities referred to as acute decompensation(AD)and non-AD(NAD),respectively.Clinically Significant Portal Hypertension(CSPH)is considered the strongest predictor of decompensation in these patients.However,due to its invasiveness and costs,CSPH is almost never evaluated in clinical practice.Therefore,recognizing noninvasively predicting tools still have more appeal across healthcare systems.The red cell distribution width to platelet ratio(RPR)has been reported to be an indicator of hepatic fibrosis in Metabolic Dysfunction-Associated Steatotic Liver Disease(MASLD).However,its predictive role for the decompensation has never been explored.AIM In this observational study,we investigated the clinical usage of RPR in predicting DEs in MASLD-related cACLD patients.METHODS Fourty controls and 150 MASLD-cACLD patients were consecutively enrolled and followed up(FUP)semiannually for 3 years.At baseline,biochemical,clinical,and Liver Stiffness Measurement(LSM),Child-Pugh(CP),Model for End-Stage Liver Disease(MELD),aspartate aminotransferase/platelet count ratio index(APRI),Fibrosis-4(FIB-4),Albumin-Bilirubin(ALBI),ALBI-FIB-4,and RPR were collected.During FUP,DEs(timing and modaities)were recorded.CSPH was assessed at the baseline and on DE occurrence according to the available Clinical Practice Guidelines.RESULTS Of 150 MASLD-related cACLD patients,43(28.6%)progressed to dACLD at a median time of 28.9 months(29 NAD and 14 AD).Baseline RPR values were significantly higher in cACLD in comparison to controls,as well as MELD,CP,APRI,FIB-4,ALBI,ALBI-FIB-4,and LSM in dACLD-progressing compared to cACLD individuals[all P<0.0001,except for FIB-4(P:0.007)and ALBI(P:0.011)].Receiving operator curve analysis revealed RPR>0.472 and>0.894 as the best cut-offs in the prediction respectively of 3-year first DE,as well as its superiority compared to the other non-invasive tools examined.RPR(P:0.02)and the presence of baseline-CSPH(P:0.04)were significantly and independently associated with the DE.Patients presenting baseline-CSPH and RPR>0.472 showed higher risk of decompensation(P:0.0023).CONCLUSION Altogether these findings suggest the RPR as a valid and potentially applicable non-invasive tool in the prediction of timing and modalities of decompensation in MASLD-related cACLD patients. 展开更多
关键词 Liver cirrhosis Red blood cell distribution width Red blood cell distribution width to platelet ratio Translational Medicine Prognostic biomarker
下载PDF
OsDA1 positively regulates grain width in rice
2
作者 Cong Li Jun Liu +4 位作者 Liya Zhang Tao Li Hongyu Li Bin Liu Tao Zhao 《The Crop Journal》 SCIE CSCD 2024年第1期92-101,共10页
The size and shape of rice grains influence their yield and commercial value.We investigated the role of OsDA1,a rice homolog of the Arabidopsis DA1 gene,in regulating grain size and shape.OsDA1 was highly expressed i... The size and shape of rice grains influence their yield and commercial value.We investigated the role of OsDA1,a rice homolog of the Arabidopsis DA1 gene,in regulating grain size and shape.OsDA1 was highly expressed in young spikelets and glumes.Its overexpression led to enlarged seeds with increased width and decreased length/width ratio(LWR)and knocking out OsDA1 reduced grain width and increased grain length and LWR.A R310K point mutation in the DA1-like domain is a potential target for breeding for increased grain width and length.OsDA1 interacted with TCP gene-family proteins to regulate grain size and shape.Our findings deepen our understanding of the molecular mechanisms underlying grain size regulation and provide useful information for improving grain yield. 展开更多
关键词 RICE Osda1 Grain size Grain shape Grain length/width ratio TCP
下载PDF
Crack Width Comparison between ACI 318, Eurocode 2 and GB 50010 for Flexural RC Members
3
作者 Guoqiang Liu Zhiyong Lu 《Open Journal of Civil Engineering》 2024年第1期116-126,共11页
Comparative research on different countries’ structural design codes holds great importance and can gain valuable insights: Awareness of Design Levels, Identifying Code Deficiencies and Optimizing Designs. The crack ... Comparative research on different countries’ structural design codes holds great importance and can gain valuable insights: Awareness of Design Levels, Identifying Code Deficiencies and Optimizing Designs. The crack width of concrete structure is an important design aspect of the civil design. The four highly recognized and widely used crack width theories are systematically summarized. Based on the mentioned theories and project practices, American code ACI system, Eurocode 2 1992-1 and Chinese code GB 50010 have different crack width control requirement and calculation methods. The crack width control method based on ACI system code has evolved from the Z-factor method to the steel bar spacing control method which is simple and easy to be adopted for engineering. Meanwhile, the ACI 224.1R also gives a direct crack width calculation method consistent with the steel bar spacing control method. The Eurocode 2 and GB 50010 based on the bond-slip & no-slip theory consider much more affecting factors than ACI for predicting crack width. Taking the crack width calculation of Tunnel 5 intake as an example, the crack widths of the structure are calculated according to ACI system code, Eurocode 2 and GB 50010 respectively, the results show that the crack width results in various codes are not much different. The EN 1992-1 and GB 50010 results are almost the same which are less than the ACI 224.1Rresults. 展开更多
关键词 Crack width Structure Serviceability Comparative Analysis
下载PDF
The Prognostic Value of Red Cell Distribution Width in Critically Ill Cerebral Infarction Patients:A Retrospective Cohort Study
4
作者 Lingyan Zhao Linna Wu Gui-Ping Li 《Journal of Clinical and Nursing Research》 2024年第2期1-12,共12页
Objective:Red blood cell distribution width(RDW)has been utilized as a prognostic indicator for mortality risk assessment in cardiovascular and cerebrovascular patients.Nevertheless,the prognostic significance of RDW ... Objective:Red blood cell distribution width(RDW)has been utilized as a prognostic indicator for mortality risk assessment in cardiovascular and cerebrovascular patients.Nevertheless,the prognostic significance of RDW in critically ill patients with cerebral infarction is yet to be investigated.The objective of this study is to examine the association between RDW and the risk of all-cause mortality in cerebral infarction patients admitted to the intensive care unit(ICU).Method:A retrospective cohort study was conducted using the Medical Information Mart for Intensive Care IV 2.2(MIMIC-IV)intensive care dataset for data analysis.The main results were the all-cause mortality rates at 3 and 12 months of follow-up.Cumulative curves were plotted using the Kaplan-Meier method,and Cox proportional hazards analysis was used to examine the relationship between RDW and mortality rates in critically ill cerebral infarction patients.Results:The findings indicate that RDW serves as a significant prognostic factor for mortality risk in critically ill stroke patients,specifically at the 3 and 12-month follow-up periods.The observed correlation between increasing RDW levels and higher mortality rates among cerebral infarction patients further supports the potential utility of RDW as a predictive indicator.Conclusion:RDW emerges as an independent predictor of mortality risk during the 3 and 12-month follow-up periods for critically ill patients with cerebral infarction. 展开更多
关键词 Red blood cell distribution width Cerebral infarction Intensive care unit All-cause mortality rate MIMIC-IV database
下载PDF
Developing nonlinear additive tree crown width models based on decomposed competition index and tree variables 被引量:1
5
作者 Siyu Qiu Peiwen Gao +4 位作者 Lei Pan Lai Zhou Ruiting Liang Yujun Sun Yifu Wang 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第5期1407-1422,共16页
Crown development is closely related to the biomass and growth rate of the tree and its width(CW)is an important covariable in growth and yield models and in forest management.To date,various CW models have been propo... Crown development is closely related to the biomass and growth rate of the tree and its width(CW)is an important covariable in growth and yield models and in forest management.To date,various CW models have been proposed.However,limited studies have explicitly focused on additive and inherent correlation of crown components and total CW as well as the influence of competition on crown radius from the corresponding direction.In this study,two model systems were used,i.e.,aggregation method system(AMS)and disaggregation method system(DMS),to develop crown width additive model systems.For calculating spatially explicit competition index(CI),four neighbor tree selection methods were evaluated.CI was decomposed into four cardinal directions and added into the model systems.Results show that the power model form was more proper for our data to fit CW growth.For each crown radius and total CW,height to the diameter at breast height(HDR)and basal area of trees larger than the subject tree(BAL)significantly contributed to the increase of prediction accuracy.The 3-m fixed radius was optimal among the four neighborhoods selection ways.After adding decomposed competition Hegyi index into model systems AMS and DMS,the prediction accuracy improved.Of the model systems evaluated,AMS based on decomposed CI provided the best performance as well as the inherent correlation and additivity properties.Our study highlighted the importance of decomposed CI in tree CW modelling for additive model systems.This study focused on methodology and could be applied to other species or stands. 展开更多
关键词 Competition decomposition ADDITIVITY Crown width Spatially explicit Competitor selection
下载PDF
Possibility of Solid Hydrometeor Growth Zone Identification Using Radar Spectrum Width
6
作者 Sung-Ho SUH Eun-Ho CHOI +1 位作者 Hong-Il KIM Woonseon JUNG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2023年第2期317-332,共16页
In this study,the correlation between simulated and measured radar velocity spectrum width(σ_(v))is investigated.The results show that the dendrites growth zones(DGZs)and needles growth zones(NGZs)mostly contain dend... In this study,the correlation between simulated and measured radar velocity spectrum width(σ_(v))is investigated.The results show that the dendrites growth zones(DGZs)and needles growth zones(NGZs)mostly contain dendrites(DN)and needles(NE),respectively.Clearσ_(v) zones(1.1<σ_(v)(m s^(-1))<1.3 and 0.3<σ_(v)(m s^(-1))<0.7 for the DGZ and NGZ,respectively)could be identified in the case studies(27 and 28 February 2016)near altitudes corresponding to temperatures of–15°C and–5°C,according to the Japan Meteorological Agency and mesoscale model reanalysis data.Oblate particles with diverse particle shapes were observed in the DGZ withσ_(v)>1.2 m s^(-1),a differential reflectivity(ZDR)higher than 0 dB,and a cross-correlation coefficient(ρhv)less than 0.96.In contrast,prolate particles with relatively uniform shapes were observed in the NGZ withσ_(v)<0.6 m s^(-1),a ZDR less than 0 dB,andρhv higher than 0.97.The simulation results show that the DN exhibited a largerσ_(v) compared to the NE,and this observedσ_(v) was strongly dependent on the wind fluctuations(v’)due to turbulence or wind shear.In contrast,the NE exhibited a significantly smallσ_(v)~0.55 m s^(-1),which converges irrespective of v’.In addition,a strong correlation between the measuredσ_(v) values at five radar elevation angles(θ=6.2°,9.1°,13.1°,19°,and 80°)and those simulated in this study confirmed the significance of the analysis results. 展开更多
关键词 spectrum width weather radar aerodynamic properties dendritic growth zone hydrometeor classifications
下载PDF
Prediction of tree crown width in natural mixed forests using deep learning algorithm
7
作者 Yangping Qin Biyun Wu +1 位作者 Xiangdong Lei Linyan Feng 《Forest Ecosystems》 SCIE CSCD 2023年第3期287-297,共11页
Crown width(CW)is one of the most important tree metrics,but obtaining CW data is laborious and timeconsuming,particularly in natural forests.The Deep Learning(DL)algorithm has been proposed as an alternative to tradi... Crown width(CW)is one of the most important tree metrics,but obtaining CW data is laborious and timeconsuming,particularly in natural forests.The Deep Learning(DL)algorithm has been proposed as an alternative to traditional regression,but its performance in predicting CW in natural mixed forests is unclear.The aims of this study were to develop DL models for predicting tree CW of natural spruce-fir-broadleaf mixed forests in northeastern China,to analyse the contribution of tree size,tree species,site quality,stand structure,and competition to tree CW prediction,and to compare DL models with nonlinear mixed effects(NLME)models for their reliability.An amount of total 10,086 individual trees in 192 subplots were employed in this study.The results indicated that all deep neural network(DNN)models were free of overfitting and statistically stable within 10-fold cross-validation,and the best DNN model could explain 69%of the CW variation with no significant heteroskedasticity.In addition to diameter at breast height,stand structure,tree species,and competition showed significant effects on CW.The NLME model(R^(2)=0.63)outperformed the DNN model(R^(2)=0.54)in predicting CW when the six input variables were consistent,but the results were the opposite when the DNN model(R^(2)=0.69)included all 22 input variables.These results demonstrated the great potential of DL in tree CW prediction. 展开更多
关键词 Mixed forests Deep neural networks Crown width Stand structure COMPETITION
下载PDF
Value of red blood cell distribution width in prediction of diastolic dysfunction in cirrhotic cardiomyopathy
8
作者 Yan-Ling Chen Zi-Wen Zhao +1 位作者 Shu-Mei Li Yong-Zhe Guo 《World Journal of Gastroenterology》 SCIE CAS 2023年第15期2322-2335,共14页
BACKGROUND Clinical diagnosis of cirrhotic cardiomyopathy(CCM) often encounters challenges of lack of timeliness and disease severity, with the commonly positive indicator usually associated with advanced heart failur... BACKGROUND Clinical diagnosis of cirrhotic cardiomyopathy(CCM) often encounters challenges of lack of timeliness and disease severity, with the commonly positive indicator usually associated with advanced heart failure.AIM To explore suitable biomarkers for early CCM prediction.METHODS A total of 505 eligible patients were enrolled in this study and divided into four groups according to Child-Pugh classification: Group Ⅰ, Class A without CCM(105 cases);Group Ⅱ, Class A with CCM(175 cases);Group Ⅲ, Class B with CCM(139 cases);and Group Ⅳ, Class C with CCM(86 cases). Logistic regression and receiver operating characteristic(ROC) curve analyses were performed to determine whether red blood cell distribution width(RDW) was an independent risk factor for CCM risk. The relationships between RDW and Child-Pugh scores, Model for End-Stage Liver Disease(MELD) scores, and N-terminal pro-brain natriuretic peptide(NT-proBNP) were analyzed by Pearson correlation analysis.RESULTS A constant RDW increase was evident from Group Ⅰ to Group Ⅳ(12.54 ± 0.85, 13.29 ± 1.19, 14.30 ± 1.96, and 16.25 ± 2.13, respectively). Pearson correlation analysis showed that RDW was positively correlated with Child-Pugh scores(r = 0.642, P < 0.001), MELD scores(r = 0.592, P < 0.001), and NT-proBNP(r = 0.715, P < 0.001). Furthermore, between Group Ⅰ and Group Ⅱ, RDW was the only significant index(odds ratio: 2.175, 95% confidence interval [CI]: 1.549-3.054, P < 0.001), and it reached statistical significance when examined by ROC curve analysis(area under the curve: 0.686, 95%CI: 0.624-0.748, P < 0.001).CONCLUSION RDW can serve as an effective and accessible clinical indicator for the prediction of diastolic dysfunction in CCM, in which a numerical value of more than 13.05% may indicate an increasing CCM risk. 展开更多
关键词 Cirrhotic cardiomyopathy CHILD-PUGH DIAGNOSIS N-terminal pro-brain natriuretic peptide Red blood cell distribution width
下载PDF
Indirect Vector Control of Linear Induction Motors Using Space Vector Pulse Width Modulation
9
作者 Arjmand Khaliq Syed Abdul Rahman Kashif +5 位作者 Fahad Ahmad Muhammad Anwar Qaisar Shaheen Rizwan Akhtar Muhammad Arif Shah Abdelzahir Abdelmaboud 《Computers, Materials & Continua》 SCIE EI 2023年第3期6263-6287,共25页
Vector control schemes have recently been used to drive linear induction motors(LIM)in high-performance applications.This trend promotes the development of precise and efficient control schemes for individual motors.T... Vector control schemes have recently been used to drive linear induction motors(LIM)in high-performance applications.This trend promotes the development of precise and efficient control schemes for individual motors.This research aims to present a novel framework for speed and thrust force control of LIM using space vector pulse width modulation(SVPWM)inverters.The framework under consideration is developed in four stages.To begin,MATLAB Simulink was used to develop a detailed mathematical and electromechanical dynamicmodel.The research presents a modified SVPWM inverter control scheme.By tuning the proportional-integral(PI)controller with a transfer function,optimized values for the PI controller are derived.All the subsystems mentioned above are integrated to create a robust simulation of the LIM’s precise speed and thrust force control scheme.The reference speed values were chosen to evaluate the performance of the respective system,and the developed system’s response was verified using various data sets.For the low-speed range,a reference value of 10m/s is used,while a reference value of 100 m/s is used for the high-speed range.The speed output response indicates that themotor reached reference speed in amatter of seconds,as the delay time is between 8 and 10 s.The maximum amplitude of thrust achieved is less than 400N,demonstrating the controller’s capability to control a high-speed LIM with minimal thrust ripple.Due to the controlled speed range,the developed system is highly recommended for low-speed and high-speed and heavy-duty traction applications. 展开更多
关键词 Space vector pulse width modulation linear induction motor proportional-integral controller indirect vector control electromechanical dynamic modeling
下载PDF
Red cell distribution width: A predictor of the severity of hypertriglyceridemia-induced acute pancreatitis
10
作者 Yong-Cai Lv Yan-Hua Yao +2 位作者 Juan Zhang Yu-Jie Wang Jing-Jing Lei 《World Journal of Experimental Medicine》 2023年第5期115-122,共8页
BACKGROUND Compared with patients with other causes of acute pancreatitis,those with hypertriglyceridemia-induced acute pancreatitis(HTG-AP)are more likely to develop persistent organ failure(POF).Therefore,recognizin... BACKGROUND Compared with patients with other causes of acute pancreatitis,those with hypertriglyceridemia-induced acute pancreatitis(HTG-AP)are more likely to develop persistent organ failure(POF).Therefore,recognizing the individuals at risk of developing POF early in the HTG-AP process is a vital for improving outcomes.Bedside index for severity in acute pancreatitis(BISAP),a simple parameter that is obtained 24 h after admission,is an ideal index to predict HTG-AP severity;however,the suboptimal sensitivity limits its clinical application.Hence,current clinical scoring systems and biochemical parameters are not sufficient for predicting HTG-AP severity.AIM To elucidate the early predictive value of red cell distribution width(RDW)for POF in HTG-AP.METHODS In total,102 patients with HTG-AP were retrospectively enrolled.Demographic and clinical data,including RDW,were collected from all patients on admission.RESULTS Based on the Revised Atlanta Classification,37(33%)of 102 patients with HTG-AP were diagnosed with POF.On admission,RDW was significantly higher in patients with HTG-AP and POF than in those without POF(14.4%vs 12.5%,P<0.001).The receiver operating characteristic curve demonstrated a good discrim-inative power of RDW for POF with a cutoff of 13.1%,where the area under the curve(AUC),sensitivity,and specificity were 0.85,82.4%,and 77.9%,respectively.When the RDW was≥13.1%and one point was added to the original BISAP to obtain a new BISAP score,we achieved a higher AUC,sensitivity,and specificity of 0.89,91.2%,and 67.6%,respectively.CONCLUSION RDW is a promising predictor of POF in patients with HTG-AP,and the addition of RDW can promote the sensitivity of BISAP. 展开更多
关键词 Red cell distribution width Bedside index for severity in acute pancreatitis Persistent organ failure Hypertriglyceridemia-induced acute pancreatitis
下载PDF
Red blood cell distribution width derivatives in alcohol-related liver cirrhosis and metabolic-associated fatty liver disease 被引量:4
11
作者 Agata Michalak Małgorzata Guz +4 位作者 Joanna Kozicka Marek Cybulski Witold Jeleniewicz Tomasz Lach Halina Cichoż-Lach 《World Journal of Gastroenterology》 SCIE CAS 2022年第38期5636-5647,共12页
BACKGROUND Looking for undiscovered blood markers of liver fibrosis and steatosis still remains an issue worth exploring.There are still plenty of unresolved issues related to the actual role of hematological indices ... BACKGROUND Looking for undiscovered blood markers of liver fibrosis and steatosis still remains an issue worth exploring.There are still plenty of unresolved issues related to the actual role of hematological indices as potential markers of liver function.AIM To study red blood cell distribution width(RDW),RDW-to-platelet ratio(RPR)and RDW-to-lymphocyte ratio(RLR) in alcohol-related liver cirrhosis(ALC) and metabolic-associated fatty liver disease(MAFLD).METHODS The study group was composed of 302 people:142 patients with ALC and 92 with MAFLD;68 persons were included as controls.RDW,RPR and RLR were measured in each person.Indirect and direct parameters of liver fibrosis were also assessed [aspartate transaminase to alkaline transaminase ratio,aspartate transaminase to platelet ratio index(APRI),fibrosis-4(FIB-4),gamma-glutamyl transpeptidase to platelet ratio(GPR),procollagen I carboxyterminal propeptide,procollagen Ⅲ aminoterminal propeptide,transforming growth factor-α,plateletderived growth factor AB,laminin].MELD score in ALC patients and nonalcoholic fatty liver disease(NAFLD) fibrosis score together with BARD score were obtained in the MAFLD group.The achieved results were compared to controls.Then a correlation between assessed markers was done.Diagnostic value of each investigated parameter and its suggested cut-off in the research group RESULTS RDW,RPR and RLR values turned out to be significantly higher in ALC and MAFLD groups compared to controls(ALC:P<0.0001;NAFLD:P<0.05,P<0.0001 and P<0.0001,respectively).RPR correlated positively with MELD score(P<0.01) and indirect indices of liver fibrosis(FIB-4 and GPR;P<0.0001) in ALC patients;negative correlations were found between PDGF-AB and both:RDW and RPR(P<0.01 and P<0.0001,respectively).RPR correlated positively with NAFLD fibrosis score and APRI(P<0.0001) in the MAFLD group;a positive relationship was observed between RDW and FIB-4,too(P<0.05).AUC values and suggested cut-offs for RDW,RPR and RLR in ALC patients were:0.912(>14.2%),0.965(>0.075) and 0.914(>8.684),respectively.AUC values and suggested cut-offs for RDW,RPR and RLR in MAFLD patients were:0.606(>12.8%),0.724(>0.047) and 0.691(>6.25),respectively.CONCLUSION RDW with its derivatives appear to be valuable diagnostic markers in patients with ALC.They can also be associated with a deterioration of liver function in this group. 展开更多
关键词 Hematological indices Alcohol-related liver cirrhosis Metabolic-associated liver disease Red blood cell distribution width Red blood cell distribution width-to-platelet ratio Red blood cell distribution width-to-lymphocyte ratio
下载PDF
Equal Width波方程的各种椭圆函数周期解和孤子解 被引量:11
12
作者 赵云梅 芮伟国 《四川师范大学学报(自然科学版)》 CAS CSCD 北大核心 2008年第2期190-193,共4页
结合齐次平衡法和F-展开法,并利用Riccati方程的结果,直接给出了Equal Width波方程的各种椭圆函数周期解.当椭圆函数的模m分别趋于1和0时,利用这些椭圆函数周期解,得到了Equal Width波方程的各种孤子解和三角函数周期解,其解的数量超过... 结合齐次平衡法和F-展开法,并利用Riccati方程的结果,直接给出了Equal Width波方程的各种椭圆函数周期解.当椭圆函数的模m分别趋于1和0时,利用这些椭圆函数周期解,得到了Equal Width波方程的各种孤子解和三角函数周期解,其解的数量超过了已有文献. 展开更多
关键词 Equal width波方程 齐次平衡法 F-展开法 孤立波解 周期波解
下载PDF
Equal Width波方程的精确行波解与波的动态模拟(英文) 被引量:4
13
作者 芮伟国 谢绍龙 冀小明 《西南民族大学学报(自然科学版)》 CAS 2006年第5期851-857,共7页
继Abdulkadir Dogan用Galar方法求解Equal Width波方程得到一些数值解之后,我们利用动力系统分支理论再次求解了这个方程。确定了存在光滑的孤立波和周期波解的参数条件。给出了一些精确的解析行波解。同时,给出了这些行波解的动态模拟图。
关键词 孤立波 周期波 波的动态模拟 Equal width方程
下载PDF
用EXP-函数法求Equal Width波方程的精确解 被引量:6
14
作者 赵云梅 芮伟国 《河南科技大学学报(自然科学版)》 CAS 2008年第2期94-98,共5页
利用EXP-函数法,再次研究了Equal Width波方程的精确解,获得了与现有文献中的解的结构不相同的新类型的精确解。本文的孤子解,比一些文献中的双曲函数解的结构更具一般性,从而大大丰富了相关文献中关于Equal Width波方程的解的类型。
关键词 Equal width波方程 EXP-函数法 精确解
下载PDF
Equal Width波方程的几种新解 被引量:2
15
作者 赵云梅 冀小明 芮伟国 《西南民族大学学报(自然科学版)》 CAS 2007年第2期244-249,共6页
应用齐次平衡法再次研究了Equal Width波方程的精确解,在不同的参数下,我求得了几种与文献[1]形式不相同的新解.在这些新解中,有一种孤波解的表达式,比文献[1]中的孤波解的那种表达式更具一般性.
关键词 Equal width波方程 齐次平衡法 孤立波解 复值型周期解
下载PDF
利用EXP-函数展开法求解Modified Equal Width波方程的精确解 被引量:3
16
作者 丁玉敏 冀小明 《西南民族大学学报(自然科学版)》 CAS 2008年第1期20-26,共7页
本文将利用EXP-函数展开法,再次研究了Modified Equal Width波方程的精确解,获得了一些与现有文献中的解的结构不相同的新类型的精确解.本文的孤子解的波形图,与一些文献中的数值解的波形图相比,基本一致,进一步验证了这些文献中的数值... 本文将利用EXP-函数展开法,再次研究了Modified Equal Width波方程的精确解,获得了一些与现有文献中的解的结构不相同的新类型的精确解.本文的孤子解的波形图,与一些文献中的数值解的波形图相比,基本一致,进一步验证了这些文献中的数值解的有效性. 展开更多
关键词 MODIFIED Equal width方程 EXP-函数展开法 精确解
下载PDF
Width Compensation and Correction for the Plan View Pattern Control Function on Plate Mill 被引量:3
17
作者 Zhi-Jie Jiao Chun-Yu He +1 位作者 Zhong Zhao Jing-Guo Ding 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2013年第5期31-35,共5页
Research works on width compensation and correction were carried out in order to eliminate the effects of the PVPC( plan view pattern control) on width accuracy of plate mill. The thickness correction calculation form... Research works on width compensation and correction were carried out in order to eliminate the effects of the PVPC( plan view pattern control) on width accuracy of plate mill. The thickness correction calculation formula was derived for compensation the width deviation caused by PVPC function,and the formula is unified under the thinning and thickening conditions. In order to improve the width calculation accuracy, width spread calculation process was modified with dividing one large reduction pass to several small reduction calculation steps. The thickness wedge was simplified to rectangle based on the volume constant principle,and the width spread model for PVPC was constructed. The width compensation and correction for the PVPC functions are used for the online control process,and the Product dimension accuracy is improved. With the decrease of crop losses,the product yield was increased with 0. 2%. 展开更多
关键词 plate mill plan view pattern control width correction and compensation width spread model
下载PDF
The 266-nm ultraviolet-beam generation of all-fiberized super-large-mode-area narrow-linewidth nanosecond amplifier with tunable pulse width and repetition rate 被引量:1
18
作者 李舜 李平雪 +4 位作者 杨敏 于可新 朱云晨 董雪岩 姚传飞 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第3期292-298,共7页
We report on a compact, stable, all-fiberized narrow-linewidth(0.045 nm) pulsed laser source emitting laser beam with a wavelength of 266 nm, and tunable pulse width and repetition rate. The system is based on all-fib... We report on a compact, stable, all-fiberized narrow-linewidth(0.045 nm) pulsed laser source emitting laser beam with a wavelength of 266 nm, and tunable pulse width and repetition rate. The system is based on all-fiberized nanosecond amplifier architecture, which consists of Yb-doped fiber preamplifiers and a super-large-mode-area Yb-doped fiber power amplifier. The fiber amplifier with a core of 50 μm is used to raise the threshold of the stimulated Brillouin scattering(SBS) effect and to obtain high output power and single pulse energy. Using lithium triborate(LBO) crystal and betabarium borate(BBO) crystal for realizing the second-harmonic generation(SHG) and fourth-harmonic generation(FHG),we achieve 17 μJ(1.73 W) and 0.66 μJ(66 mW), respectively, at wavelengths of 532 nm and 266 nm and a repetition rate of 100 kHz with pulse width of 4 ns. This source has great potential applications in fluorescence research and solar-blind ultraviolet optical communication. 展开更多
关键词 nanosecond all-fiber amplifier narrow-linewidth ultraviolet beam generation tunable pulse width and repetition rate
原文传递
Width-w NAF算法的能量攻击防范对策
19
作者 周文锦 鲁晓军 +2 位作者 朱大勇 范明钰 张涛 《电子科技大学学报》 EI CAS CSCD 北大核心 2007年第3期601-603,共3页
介绍了椭圆曲线加密的快速算法、Width-wNAF算法及能量分析攻击方法;提出了width-wNAF算法的改进算法。在不增加主循环计算量的情况下,改进算法有效地抵抗了能量分析攻击,包括简单能量分析攻击、差分能量分析攻击、改进的差分能量分析... 介绍了椭圆曲线加密的快速算法、Width-wNAF算法及能量分析攻击方法;提出了width-wNAF算法的改进算法。在不增加主循环计算量的情况下,改进算法有效地抵抗了能量分析攻击,包括简单能量分析攻击、差分能量分析攻击、改进的差分能量分析攻击以及零值点攻击。 展开更多
关键词 椭圆曲线加密 能量分析攻击 width-w NAF 零值点攻击
下载PDF
Equal Width波方程的孤立波解雨周期波解
20
作者 赵云梅 谢绍龙 陈德华 《玉溪师范学院学报》 2007年第3期1-5,共5页
结合齐次平衡法原理并利用F展开法,在F展开式中添加了F的负幂项,再次研究了Equal Width波方程的精确解,从而丰富了Equal Width波方程解的研究.
关键词 Equal width波方程 齐次平衡法 F展开法 周期波解 孤立波解
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部