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A Survey on the Existence of Harmonic Metrics on Vector Bundles
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作者 SHEN Zhenghan ZHANG Xi 《数学进展》 北大核心 2025年第2期390-404,共15页
In this paper,we give a survey on the existence of Hermitian-Einstein metrics and harmonic metrics.
关键词 Hermitian-Einstein metric harmonic metric holomorphic vector bundle non-Hermitian Yang-Mills bundle
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A VECTOR BUNDLE VALUED MIXED HARD LEFSCHETZ THEOREM
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作者 Zeng CHEN Guanxiang WANG 《Acta Mathematica Scientia》 2025年第2期514-524,共11页
In this paper,we obtain a vector bundle valued mixed hard Lefschetz theorem.The argument is mainly based on the works of Tien-Cuong Dinh and Viet-Anh Nguyen.
关键词 hard Lefschetz theorem holomorphic vector bundle Hermitian fat vector bundle
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Stoma related complications:A registry study based on a prospective registration system
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作者 Nan Chen Jie Zhang +2 位作者 Lin Wang Qian Yang Ai-Wen Wu 《World Journal of Gastrointestinal Oncology》 2025年第3期144-154,共11页
BACKGROUND Stoma creation is a common procedure in colorectal cancer surgery,however,stoma-related complications remain a significant concern.AIM To investigate the incidence,types,and risk factors of stoma-related co... BACKGROUND Stoma creation is a common procedure in colorectal cancer surgery,however,stoma-related complications remain a significant concern.AIM To investigate the incidence,types,and risk factors of stoma-related complications in colorectal cancer patients who underwent stoma creation.METHODS Patients with stoma was prospectively recorded in the established stoma system.Data was collected from this stoma management system from November 2021 through May 2024.The rates of stoma-related complications were assessed,and potential risk factors were analyzed using univariate and multivariate logistic regression models.RESULTS A total of 734 patients were included in the analysis.The results showed that 12.3%of patients experienced stoma-related complications,with mucocutaneous separation,edema,and skin excoriation being the most common complications.The majority(90%)of complications were classified as grade 2 according to the Clavien-Dindo classification.Surgical factors,such as blood loss volume greater than 500 mL and open surgery,were significantly associated with stoma complications.Additionally,stoma features like location,shape,color,height,and edema were important factors in the association with complications.Body mass index over 30 kg/m²was also found to be a significant risk factor.CONCLUSION These findings highlight the need for a holistic approach to preventing and managing stoma complications,considering both patient-related and surgical factors. 展开更多
关键词 stoma COMPLICATION COLORECTAL REGISTRY PROSPECTIVE
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Construction of a nomogram prediction model for early postoperative stoma complications of colorectal cancer
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作者 Ming-Qin Ba Wen-Lin Zheng +4 位作者 Yu-Ling Zhang Lin-Lin Zhang Jing-Jing Chen Jie Ma Jia-Li Huang 《World Journal of Gastrointestinal Surgery》 2025年第1期165-174,共10页
BACKGROUND Postoperative enterostomy is increasing in patients with colorectal cancer,but there is a lack of a model that can predict the probability of early complications.AIM To explore the factors influencing early... BACKGROUND Postoperative enterostomy is increasing in patients with colorectal cancer,but there is a lack of a model that can predict the probability of early complications.AIM To explore the factors influencing early postoperative stoma complications in colorectal cancer patients and to construct a nomogram prediction model for predicting the probability of these complications.METHODS A retrospective study of 462 patients who underwent postoperative ostomy for colorectal cancer in the Gastrointestinal Department of the Anhui Provincial Cancer Hospital.The patients’basic information,surgical details,pathological results,and preoperative inflammatory and nutritional indicators were reviewed.We used univariate and multivariate logistic regression to analyze the risk factors for early postoperative stoma complications in colorectal cancer patients and constructed a nomogram prediction model to predict the probability of these complications.RESULTS Binary logistic regression analysis revealed that diabetes[odds ratio(OR)=3.088,95%confidence interval(CI):1.419-6.719],preoperative radiotherapy and chemotherapy(OR=6.822,95%CI:2.171-21.433),stoma type(OR=2.118,95%CI:1.151-3.898),Nutritional risk screening 2002 score(OR=2.034,95%CI:1.082-3.822)and prognostic nutritional index(OR=0.486,95%CI:0.254-0.927)were risk factors for early stoma complications after colorectal cancer surgery(P<0.05).On the basis of these results,a prediction model was constructed and the area under the re-ceiver operating characteristic curve was 0.740(95%CI:0.669-0.811).After internal validation,the area under the receiver operating characteristic curve of the validation group was 0.725(95%CI:0.631-0.820).The calibration curves for the modeling group and validation group are displayed.The predicted results have a good degree of overlap with the actual results.CONCLUSION A previous history of diabetes,preoperative radiotherapy and chemotherapy,stoma type,Nutritional risk screening 2002 score and prognostic nutritional index are risk factors for early stoma complications after colorectal cancer surgery.The nomogram prediction model constructed on the basis of the results of logistic regression analysis in this study can effectively predict the probability of early stomal complications after colorectal cancer surgery. 展开更多
关键词 COLORECTAL POSTOPERATIVE stoma COMPLICATIONS NOMOGRAM
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Stoma occlusion caused by abdominal cocoon after abdominal abscess surgery:A case report
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作者 Rui Xu Li-Xin Sun +4 位作者 Yan Chen Chuang Ding Ming Zhang Teng-Fei Chen Ling-Yong Kong 《World Journal of Clinical Cases》 2025年第15期16-21,共6页
BACKGROUND Abdominal cocoons(ACs)lack characteristic clinical manifestations and are main-ly intestinal obstructions that are difficult to distinguish from intestinal obstruc-tion caused by other causes,resulting in d... BACKGROUND Abdominal cocoons(ACs)lack characteristic clinical manifestations and are main-ly intestinal obstructions that are difficult to distinguish from intestinal obstruc-tion caused by other causes,resulting in difficult preoperative diagnosis and misdiagnosis and mistreatment.There are no reports of enterostomy occlusion caused by ACs in the literature at home and abroad.CASE SUMMARY Here,we report a 16-year-old female patient with intestinal obstruction due to AC.She was treated with abdominal surgery three times.First,she underwent a laparotomy for peritonitis after trauma from a traffic accident.During the pro-cedure,pelvic empyema,severe intestinal adhesions,and damage to the serous layer of the rectum were found,but no significant intestinal rupture and perfo-ration were found.As a precaution,she underwent a prophylactic ileostomy after a flush in her abdomen.The second and third surgeries were for treatment of recurrent stoma obstruction.The patient’s condition was complicated for a long period,but after comprehensive treatment by our department,the patient was successfully discharged from the hospital and is currently recovering well.CONCLUSION Currently,abdominal contrast-enhanced computed tomography is the best imaging modality for pre-operative evaluation of AC,but most patients are diagnosed only after intrao-perative exploration.For the treatment of typical or severe ACs,the primary me-thod of removal and healing of ACs is complete removal of the abdominal fibrous membrane.Finding a breakthrough in the anatomy is the key to the success of the surgery. 展开更多
关键词 Intraabdominal abscess Ventral cocoons ILEUS stoma occlusion Surgical complications Case report
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Patient selection and operative strategies for laparoscopic intersphincteric resection without diverting stoma
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作者 Gang Hu Ji Ma +5 位作者 Wen-Long Qiu Shi-Wen Mei Meng Zhuang Jun Xue Jun-Guang Liu Jian-Qiang Tang 《World Journal of Gastrointestinal Surgery》 2025年第3期338-348,共11页
BACKGROUND Diverting stoma(DS)is routinely proposed in intersphincteric resection for ultra-low rectal cancer,but it is associated with increased stoma-related complications and economic burden.Appropriate patient sel... BACKGROUND Diverting stoma(DS)is routinely proposed in intersphincteric resection for ultra-low rectal cancer,but it is associated with increased stoma-related complications and economic burden.Appropriate patient selection and operative strategies to avoid stoma formation need further elucidation.METHODS This study enrolled 505 consecutive patients,including 84 who underwent stoma-free(SF)intersphincteric resection.After matching,patients were divided into SF(n=78)and DS(n=78)groups.The primary endpoint was the anastomotic leakage(AL)rate within 6 months and its protective factors for both the total and SF cohorts.The secondary endpoints included overall survival and disease-free survival.RESULTS The AL rate was greater in the SF group than in the DS group(12.8%vs 2.6%,P=0.035).Male sex[(odds ratio(OR)=2.644,P=0.021],neoadjuvant chemoradiotherapy(nCRT)(OR=6.024,P<0.001),and tumor height from the anal verge≤4 cm(OR=4.160,P=0.007)were identified as independent risk factors.Preservation of the left colic artery(LCA)was protective in both the total cohort(OR=0.417,P=0.013)and the SF cohort(OR=0.312,P=0.027).The female patients who did not undergo nCRT and had preservation of the LCA experienced a significantly lower incidence of AL(2/97,2.1%).The 3-year overall survival or disease-free survival did not significantly differ be-tween the groups.CONCLUSION Female patients who do not receive nCRT may avoid the need for DS by preserving the LCA without increasing the risk of AL or compromising oncological outcomes. 展开更多
关键词 Anastomotic leakage Diverting stoma Laparoscopic intersphincteric resection Ultralow rectal cancer
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Application Value of Bundle Management in Safe Nursing Care for Patients with Autoimmune Encephalitis
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作者 Ying Cui 《Journal of Clinical and Nursing Research》 2025年第4期149-154,共6页
Objective:To explore the application effect of bundle management in the safe nursing of patients with autoimmune encephalitis.Methods:Seventy-five patients with autoimmune encephalitis who met the inclusion criteria i... Objective:To explore the application effect of bundle management in the safe nursing of patients with autoimmune encephalitis.Methods:Seventy-five patients with autoimmune encephalitis who met the inclusion criteria in our hospital from January 2024 to June 2024 were randomly divided into two groups:an observation group of 39 patients and a control group of 36 patients.The control group received routine nursing care,while the observation group implemented a bundle management strategy based on routine nursing care.Safety nursing outcomes,clinical symptom improvement time,hospital stay,and neurologic function recovery were observed in both groups.Results:The incidence of adverse events in the observation group was 12.82%,significantly lower than the 33.33%in the control group,with a statistically significant difference(P<0.05).There was no statistically significant difference in restraint usage and ICU transfer rates between the two groups(P>0.05).The clinical symptom improvement time,hospital stay,and neurologic function recovery in the observation group were significantly better than those in the control group,with a statistically significant difference(P<0.05).Conclusion:Through the bundle management model,effective connections can be ensured in various aspects of treatment and rehabilitation for patients with autoimmune encephalitis,providing patients with comprehensive and multi-level nursing services and improving their overall satisfaction and treatment effectiveness. 展开更多
关键词 bundle management Autoimmune Encephalitis Safe nursing Clinical effect
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EXISTENCE OF SOME SPECIAL CONFORMALLY-KAHLER METRICS ON CERTAIN CP1 BUNDLES
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作者 Jing CHEN Daniel GUAN 《Acta Mathematica Scientia》 2025年第2期525-539,共15页
In this paper,we prove that for certain fiber bundles there is a k-Futaki-Ono conformally Kahler metric related to a metric in any given Kahler class for any k≥2.
关键词 Hermitian metrics conformally-Kahler metrics complex manifolds scalar curvature fiber bundle almost homogeneous manifolds
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Application of Bundle Nursing Strategy in the Maintenance of Difficult Blood Vessels for Long-term Hemodialysis Patients
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作者 Yelin Wang Liangmei Fei 《Journal of Clinical and Nursing Research》 2025年第5期297-303,共7页
Objective:To study the application effect of bundle nursing strategy in the maintenance of difficult blood vessels for long-term hemodialysis patients.Methods:A prospective study was conducted on 40 long-term hemodial... Objective:To study the application effect of bundle nursing strategy in the maintenance of difficult blood vessels for long-term hemodialysis patients.Methods:A prospective study was conducted on 40 long-term hemodialysis patients admitted from January 2024 to January 2025.The patients were randomly divided into a control group(20 cases)and an observation group(20 cases)using computer random sampling.The control group received routine nursing for difficult blood vessels,while the observation group received a bundle nursing strategy for difficult blood vessels.The self-care ability,complication rate,and nursing satisfaction were compared between the two groups.Results:After nursing,the self-care ability score of the observation group was higher than that of the control group(P<0.05).The complication rate in the observation group was lower than that in the control group(P<0.05).The nursing satisfaction in the observation group was higher than that in the control group(P<0.05).Conclusion:The application of the bundle nursing strategy in the maintenance of difficult blood vessels for long-term hemodialysis patients is beneficial for improving self-care ability,reducing complications,and increasing patient satisfaction with nursing services. 展开更多
关键词 Long-term hemodialysis Difficult blood vessels Routine nursing bundle nursing strategy
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The Clinical Application Value of Bundled Nursing Care in Postoperative Recovery of Lung Cancer Patients
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作者 Cuifang Liu Yaqian Li +3 位作者 Kun Wang Pei Liu Hongyu Liang Xiaoxue Huang 《Journal of Clinical and Nursing Research》 2025年第4期183-189,共7页
Objective:To investigate the clinical application value of bundled nursing care in postoperative recovery of lung cancer patients.Methods:Eighty lung cancer patients who underwent surgical treatment from October 2022 ... Objective:To investigate the clinical application value of bundled nursing care in postoperative recovery of lung cancer patients.Methods:Eighty lung cancer patients who underwent surgical treatment from October 2022 to May 2024 were selected as the study subjects.Their clinical data were retrospectively analyzed and grouped by nursing methods.The bundled nursing care group(n=40)received bundled nursing care,while the conventional nursing care group(n=40)received routine nursing care.Lung function,immune function,complication rate,pain level,exercise tolerance,and quality of life were compared between the two groups.Results:Before nursing,there were no statistically significant differences in lung function,immune function,pain level,exercise tolerance,and quality of life between the bundled nursing care group and the conventional nursing care group(P>0.05).After nursing,both groups showed improvement in lung function,immune function,pain level,exercise tolerance,and quality of life,but the bundled nursing care group had better results and a lower complication rate,with statistical significance(P<0.05).Conclusion:The bundled nursing care has a higher clinical application value in postoperative recovery of lung cancer patients and is worthy of widespread clinical use. 展开更多
关键词 bundled nursing care Lung cancer Lung function Immune function Pain level Exercise tolerance
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Development of a capillary bundle evaporation advanced mathematical modeling for 1,2-propylene glycol-glycerin mixtures in porous media
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作者 Bingbing Li Jiantong Li +3 位作者 Side Ren Shuo Gu Zhanjian Liu Liyan Liu 《Chinese Journal of Chemical Engineering》 2025年第4期261-273,共13页
Porous liquid-conducting micro-heat exchangers have garnered considerable attention for their role in efficient heat dissipation in small electronic devices.This demand highlights the need for advanced mathematical mo... Porous liquid-conducting micro-heat exchangers have garnered considerable attention for their role in efficient heat dissipation in small electronic devices.This demand highlights the need for advanced mathematical models to optimize the selection of mixed heat exchange media and equipment design.A capillary bundle evaporation model for porous liquid-conducting media was developed based on the conjugate mass transfer evaporation rate prediction model of a single capillary tube,supplemented by mercury injection experimental data.Theoretical and experimental comparisons were conducted using 1,2-propanediol-glycerol(PG-VG)mixtures at molar ratios of 1:9,3:7,5:5,and 7:3 at 120,150,and 180℃.The Jouyban-Acree model was implemented to enhance the evaporation rate predictions.For the 7:3 PG-VG mixture at 180℃under the experimental conditions of the thermal medium,the model's error reduced from 16.75%to 10.84%post-correction.Overall,the mean relative error decreased from 11.76%to 5.98%after correction. 展开更多
关键词 Evaporation in porous media Capillary bundle model 1 2-propylene glycol-glycerin Evaporation rate
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Efficacy of single-lumen and double-lumen peripherally inserted central catheters in patients undergoing digestive surgery within bundled care contexts
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作者 Xiao-Hui Ye Rong-Hong Cui +3 位作者 Lei Xu Mei-Jun Wang Ling-Rong Ye Ming Jiang 《World Journal of Gastrointestinal Surgery》 2025年第9期215-226,共12页
BACKGROUND Peripherally inserted central catheters(PICCs)are crucial for patients requiring long-term intravenous therapy,especially within digestive surgery under bundled care protocols.AIM To evaluate and compare th... BACKGROUND Peripherally inserted central catheters(PICCs)are crucial for patients requiring long-term intravenous therapy,especially within digestive surgery under bundled care protocols.AIM To evaluate and compare the efficacy,safety,and patient-reported outcomes of single-lumen vs double-lumen PICCs among patients undergoing digestive surgery within a structured bundled care framework.METHODS This retrospective cohort study analyzed data from 249 patients who underwent digestive surgery and utilized either single-lumen(n=117)or double-lumen(n=132)PICCs between January 2021 and June 2024.Clinical outcomes,patient satisfaction,catheterization duration,and complication rates were compared using statistical analysis via SPSS(version 29.0).The bundled care protocol was consistently applied,focusing on standardized procedures,staff training,and patient support.RESULTS Single-lumen PICCs were associated with a significantly lower thrombosis rate(0.85%)than double-lumen PICCs(6.82%,P=0.039).The single-lumen group experienced shorter catheterization durations(12.5±3.14 days vs 13.6±4.50 days,P=0.025)and higher successful infusion rates(92.7%±5.32%vs 90.4%±6.60%,P=0.003).This group also reported higher comfort scores(8.40±1.20 vs 7.90±1.50,P=0.004)and lower pain levels(2.90±0.70 vs 3.20±0.80,P=0.002).Aside from thrombosis,complication rates showed no significant difference between the groups.CONCLUSION Within bundled care context,single-lumen PICCs demonstrated advantages in reducing thrombosis risk,procedural efficiency,patient comfort,and satisfaction compared with double-lumen PICCs.The findings underscore the importance of considering patient-specific needs and clinical scenarios in catheter choice. 展开更多
关键词 Single-lumen peripherally inserted central catheter Double-lumen peripherally inserted central catheter Digestive surgery bundled care Patient satisfaction THROMBOSIS
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Left bundle branch pacing cardiac resynchronization therapy vs biventricular pacing cardiac resynchronization therapy–time to write a requiem for biventricular pacing-cardiac resynchronization therapy
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作者 Akshyaya Pradhan Daljeet Saggu Monika Bhandari 《World Journal of Cardiology》 2025年第2期118-124,共7页
Cardiac resynchronization therapy(CRT)reduces heart failure(HF)hospitaliz-ations and all-cause mortality in patients with HF with reduced ejection fraction with left bundle branch(LBB)block.Biventricular pacing(BVP)is... Cardiac resynchronization therapy(CRT)reduces heart failure(HF)hospitaliz-ations and all-cause mortality in patients with HF with reduced ejection fraction with left bundle branch(LBB)block.Biventricular pacing(BVP)is considered the gold standard for achieving CRT;however,approximately 30%–40%of patients do not respond to BVP-CRT.Recent studies have demonstrated that LBB pacing(LBBP)produces remarkable results in CRT.In this meta-analysis,LBBP-CRT showed better outcomes than conventional BVP-CRT,including greater QRS duration reduction and left ventricular ejection fraction improvement,along with consistently lower pacing thresholds on follow-up.Additionally,there was a grea-ter reduction in New York Heart Association class and brain natriuretic peptide levels.This study contributes to the growing body of encouraging data on LBBP-CRT from recent years.With ongoing technological advancements and increasing operator expertise,the day may not be far when LBBP-CRT becomes the standard of care rather than the exception. 展开更多
关键词 Heart failure Left bundle branch block area pacing Narrow QRS New York Heart Association class Left ventricular ejection fraction
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Intestinal Stoma Prolapse and Surgical Treatments of This Condition in Children: A Systematic Review and a Retrospective Study 被引量:1
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作者 Prince Johnson 《Surgical Science》 2016年第9期400-426,共27页
Background: An intestinal stoma is a surgical opening of the intestine, mostly sutured to the anterior abdominal wall. Stoma prolapse is one of the common complications of stoma. A significant number of stoma prolapse... Background: An intestinal stoma is a surgical opening of the intestine, mostly sutured to the anterior abdominal wall. Stoma prolapse is one of the common complications of stoma. A significant number of stoma prolapse patients require surgical correction. Aim: The first part of this thesis is a literature review of intestinal stoma prolapse and its surgical treatments. The second part is an evaluation of the effect of surgical treatments of this condition on children at OUS-R. Methods: Literature—A literature search was performed. Fifty-seven English-language studies were selected. Methods: Patients evaluation: Design, Setting, and Participants—A retrospective review of pediatric patients (<13 years) surgically treated for intestinal stoma prolapse at OUS-R. Results: Literature—Incidence of intestinal stoma prolapse for children varies from 8.1% to 25.6%. Many proposed surgical repair procedures for stoma prolapse are available and vary from being ineffective to 100% effective. Results: Patients evaluation at OUS-R—From 2001 to 2013, 14 of the 304 children with stoma (4.6%), experienced stoma prolapse. Nine stoma prolapse were surgically corrected: Median age at stoma formation for the 9 patients was 1.7 years. Surgical procedures and success rate: Median 2, range 1 - 9 operations/person;varies from being ineffective to 50% effective. Conclusion: Limited data suggests stoma prolapse repair is a surgical challenge. Thus, preferably when possible, closure of the stoma would be most suitable. Incidence of stoma prolapse in our series of pediatric patients at Oslo University Hospital is lower than most published incidence in the pediatric medical literature. 展开更多
关键词 stoma CHILDREN NEONATES stoma Complications stoma Prolapse Surgical Management
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DTN网络中的基于Bundle协议的数据包发送算法 被引量:2
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作者 王堃 于悦 +2 位作者 张玉华 郭篁 王琳琳 《吉林大学学报(工学版)》 EI CAS CSCD 北大核心 2012年第S1期285-289,共5页
DTN传输协议引入束和分片的概念,将数据分块传输以适应经常发生链接中断的链路。研究了DTN传输层的Bundle协议和LTP(Licklider transmission protocol)协议,针对网络环境可能在短时间内剧烈变化的问题,研究了数据块的大小对传输效率的影... DTN传输协议引入束和分片的概念,将数据分块传输以适应经常发生链接中断的链路。研究了DTN传输层的Bundle协议和LTP(Licklider transmission protocol)协议,针对网络环境可能在短时间内剧烈变化的问题,研究了数据块的大小对传输效率的影响,提出了DTN网络中基于Bundle协议的数据包发送算法,动态选择最适合当前网络状况的发送策略以获得最佳的系统性能和传输效率。仿真结果表明:适当选取发送数据块的大小可以大幅度提高传输效率。 展开更多
关键词 计算机应用 容迟网络 bundle 分片 传输效率
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Crosstalk Effect in Bundled SWCNT, DWCNT and MWCNT Carbon Nanotubes
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作者 Ayoub LOUMI Hassan BELAHRACH Abdelilah GHAMMAZ 《Journal of Electrical Engineering》 2017年第6期344-348,共5页
In this paper, different models of parallel Carbon nanotube Bundles are carried out and simulated. In the first place, a model of three parallel SWCNT (singe walled carbon nanotube) Bundles and DWCNT (double walled... In this paper, different models of parallel Carbon nanotube Bundles are carried out and simulated. In the first place, a model of three parallel SWCNT (singe walled carbon nanotube) Bundles and DWCNT (double walled carbon nanotube) Bundles was established and simulated. It has been noticed that the variation on the number of Carbon nanotubes in the bundle has an impact on the crosstalk amplitude. In the second place, a model of three parallel MWCNT (multi walled carbon nanotube) Bundles was established and simulated and the crosstalk effect has been noticed and compared with SWCNT/DWCNT Bundles. Finally a model of mixed Bundles (Single-Double-Single) and (Double-Single-Double) was carried out and simulated. All simulations were established using Pspice. 展开更多
关键词 SWCNT DWCNT MWCNT SWCNT bundle DWCNT bundle MWCNT bundle crosstalk.
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基于Douglas-Peucker和Quick Bundles算法的水上交通模式识别 被引量:4
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作者 陈信强 徐祥龙 +3 位作者 彭静 孙洋 王梓创 阎莹 《上海海事大学学报》 北大核心 2022年第3期1-6,共6页
针对船舶航迹数据量大、数据冗余、航迹特征不明显等问题,提出一种融合道格拉斯-普克(Douglas-Peucker,DP)压缩算法和基于距离的快速捆绑包(Quick Bundles,QB)聚类算法的水上交通模式识别方法。该方法根据航迹数据特征、压缩率和压缩误... 针对船舶航迹数据量大、数据冗余、航迹特征不明显等问题,提出一种融合道格拉斯-普克(Douglas-Peucker,DP)压缩算法和基于距离的快速捆绑包(Quick Bundles,QB)聚类算法的水上交通模式识别方法。该方法根据航迹数据特征、压缩率和压缩误差等指标选择合理的压缩阈值实现大规模船舶自动识别系统(automatic identification system,AIS)数据的压缩。在此基础上,提出一种基于最小直接翻转距离的聚类指标,利用QB算法实现船舶航迹的有效聚类。实验结果表明,提出的方法既可以简化航迹聚类过程,也可准确高效地实现航迹聚类,为水上交通精细化管理与决策提供数据支撑。 展开更多
关键词 船舶航迹聚类 船舶自动识别系统(AIS) DOUGLAS-PEUCKER算法 Quick bundles算法
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QTL Analysis of Rice Peduncle Vascular Bundle System and Panicle Traits 被引量:17
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作者 滕胜 钱前 +3 位作者 曾大力 国广泰史 黄大年 朱立煌 《Acta Botanica Sinica》 CSCD 2002年第3期301-306,共6页
A double haploid (DH) population of rice (Oryza sativa L.) derived from anther culture of ZYQ8/JX17, a typical indica and japonica hybrid, was used for genetic analysis of rice peduncle vascular system and panicle tra... A double haploid (DH) population of rice (Oryza sativa L.) derived from anther culture of ZYQ8/JX17, a typical indica and japonica hybrid, was used for genetic analysis of rice peduncle vascular system and panicle traits. The number of large vascular bundles (LVB), the number of small vascular bundles (SVB) in the peduncle, and the panicle traits including the number of primary rachis branches (PRB), the number of spikelets per panicle (SNP), peduncle top diameter (PTD), and panicle length (PL) were investigated in the parents and DH lines. The quantitative trait loci (QTLs) for each trait were analyzed based on the constructed molecular linkage map of this population. Three QTLs for LVB (qLVB_1, qLVB_6 and qLVB_7) were detected on chromosomes 1, 6, and 7, respectively. Two putative QTLs for SVB (qSVB_4 and qSVB_6) were mapped on chromosomes 4 and 6 respectively. Four QTLs (qPRB_4a, qPRB_4b, qPRB_6 and qPRB_7) on chromosomes 4, 6, and 7, respectively, were detected for PRB. Three QTLs (qSPN_4a, qSPN_4b and qSPN_6) were identified on chromosomes 4 and 6, respectively, which could significantly affect SPN. Five QTLs for PTD (qPTD_2, qPTD_5, qPTD_6, qPTD_8 and qPTD_12) were identified on chromosomes 2, 5, 6, 8, and 12, respectively. Three QTLs for PL (qPL_4, qPL_6 and qPL_8) were detected on chromosomes 4, 6, and 8, respectively. Clustering of QTLs, such as qLVB_6, qSVB_6, qSNP_6, qPTD_6, and qPL_6 detected in the interval G122_G1314b on chromosome 6, was found. These results suggest that some QTLs for peduncle vascular bundle system are possibly responsible for the panicle traits. 展开更多
关键词 RICE peduncle vascular bundle panicle traits QTL analysis
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Bachmann’s Bundle起搏治疗心房颤动 被引量:1
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作者 喻研 王琳 《心血管病学进展》 CAS 2008年第6期871-874,共4页
心房颤动是一种最常见的心律失常,近年来许多专家学者选择不同的起搏部位来治疗心房颤动,现就Bachmann′s bun-dle起搏在治疗心房颤动中的地位进行综述。
关键词 Bachmann’s bundle 心房颤动 房间传导阻滞 起搏
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离散投资组合问题的一种基于Bundle对偶搜索的精确算法 被引量:1
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作者 张世涛 高振星 孙小玲 《应用数学与计算数学学报》 2008年第1期83-91,共9页
本文提出了离散均值一方差投资组合模型的一种新的精确算法.该算法是一个基于拉格朗日松弛和Bundle对偶搜索的分枝定界算法.我们分别用随机产生的数据和美国股票市场的真实数据进行了数值实验,并与传统次梯度对偶搜索进行了比较,数值结... 本文提出了离散均值一方差投资组合模型的一种新的精确算法.该算法是一个基于拉格朗日松弛和Bundle对偶搜索的分枝定界算法.我们分别用随机产生的数据和美国股票市场的真实数据进行了数值实验,并与传统次梯度对偶搜索进行了比较,数值结果表明本文提出的算法对解决中小规模的离散投资组合问题是有效的. 展开更多
关键词 离散均值-方差模型 拉格朗日松弛 bundle方法 次梯度方法 分枝定界法
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