检索结果-南通市图书馆

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

设计和仿真无线局域网设备天线

今日电子 2008年第7期 40-40,42,44页

作者： How Siang Yap Bart van hecke Agilent EEsof EDA部门

通过采用极化分集技术，可以用低成本PCB基片制造具有良好接收机性能的无线局域网设备（WLAN）天线。本文将描述如何使用最新的三维电磁场（EM）仿真工具来设计和仿真一对2．4GHz正交极化的印刷偶极子天线，同时预测表面电流和相关的远... 详细信息

通过采用极化分集技术，可以用低成本PCB基片制造具有良好接收机性能的无线局域网设备（WLAN）天线。本文将描述如何使用最新的三维电磁场（EM）仿真工具来设计和仿真一对2．4GHz正交极化的印刷偶极子天线，同时预测表面电流和相关的远场辐射图。

关键词：无线局域网设备偶极子天线仿真工具设计正交极化三维电磁场分集技术表面电流

Schistosoma mansoni proteins attenuate gastrointestinal motility disturbances during experimental colitis in mice

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2010年第6期16卷 703-712页

作者： Nathalie E Ruyssers Benedicte Y De Winter Joris G De Man Natacha D Ruyssers ann J van Gils Alex Loukas Mark S Pearson Joel V Weinstock Paul A Pelckmans Tom G Moreels Laboratory of Experimental Medicine and Pediatrics Division of GastroenterologyUniversity of Antwerp Division of Infectious Diseases and Immunology Queensland Institute of Medical Research 4006 Brisbane Division of Gastroenterology-Hepatology Tufts New England Medical Center

AIM:To investigate the therapeutic effect of Schistosoma mansoni(***) soluble worm proteins on gastrointestinal motility disturbances during experimental colitis in mice. METHODS:Colitis was induced by intrarectal injection of trinitrobenzene sulphate(TNBS) and 6 h later,mice were treated ip with *** *** were performed 5 d after TNBS *** quantified using validated inflammation parameters. Gastric emptying and geometric center were measured to assess in vivo gastrointestinal *** activity of distal colonic segments was studied in vitro using a modified Trendelenburg *** profiles of T-lymphocytes isolated from the colon were determined by real time reverse transcriptase-polymerase chain reaction. RESULTS:Intracolonic injection of TNBS caused severe *** with *** proteins significantly ameliorated colonic inflammation after 5 *** did not affect gastric emptying but significantly decreased the geometric center and impaired colonic peristaltic activity 5 d after the induction of *** with *** proteins ameliorated these in vivo and in vitro motility *** addition,TNBS injection caused a downregulation of effector T cell cytokines after 5 d,whereas a *** protein effect was no longer observed at this time point. CONCLUSION:Treatment with *** proteins attenuated intestinal inflammation and ameliorated motility disturbances during murine experimental colitis.

关键词： Schistosoma mansoni Helminth proteins Colitis Peristalsis Crohn’s disease Gastrointestinal motility Trinitrobenzene sulphate

Palaeomagnetic Study on the Precambrian-Cambrian Boundary Candidate Stratotype Section at Meishucun, Yunnan

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 1991年第1期65卷 97-108页

作者： Liang Qizhong Fang Wu Rob van der Voo Yunnan Institute of Geological Science, Kunming,Yunnan Department of Geological Sciences,University of Michigan,ann Arbor, MI.48109-1063, U.S.A. Liu Linqun Yunnan Institute of Geological Scienc Kunming Yunnan China

The Meishucun secton has been recommended as an international candidate stratotype secton of thePrecambrian-Cambrian boundary. The paper deals with the palaeomagnetic study on the section. A total of159 palaeomagnetic samples were successively collected from the platform-facies sequence of carbonates andphosphates at the section. Thermal demagnetization results indicate a great majority of the rocks at the sectionhave been strongly overprinted by recent magnetic field, but 57 samples have preserved remanentmagnetization with antipodal directions (mean D/I=4.2°/ 7.1°, K=9, α_(95) = 6.6°). Baaed on calculation,the location of the palaeomagnetic pole was at 68.8°N and 270.7°E, which is different from any palaeopolesobtained from younger Phanerozoic rocks in South China. The results reveal a polarity zonation which in-cludes at least 9 reversal events. A comparison of China's magnetostratigraphic records with those fromSiberia, Australia and the western U.S.A. shows that all the sections are characterized by frequent polarity re-versals.

关键词： Yunnan Palaeomagnetic Study on the Precambrian-Cambrian Boundary Candidate Stratotype Section at Meishucun

Malaria among Children in Suriname, South America

在线全文

学校读者我要写书评

暂无评论

Advances in Infectious Diseases 2016年第2期6卷 42-45页

作者： Mary-ann Wagijo Edward van Eer Remy A. Hirasing Health Sciences—Specialization International Public Health Antwerp Belgium Medical Mission Paramaribo Suriname Department of Public and Occupational Health EMGO Institute for Health and Care Research VU University Medical Centre Amsterdam The Netherlands

Malaria in children is a serious infectious disease. In Suriname, many children died due to malaria in the past. To prevent malaria in children, anti-malaria campaigns were executed. The last campaign was implemented from 2005 to 2010. To develop a strategy for the future, the current prevalence and mortality rates are needed. Since 1955, all confirmed malaria cases were registered by the Medical Mission and this database was used to determine the prevalence rate. For the mortality rates we used the cause of death which was registered on death certificates. Since 2005 no children died due to malaria. Also the prevalence rate dropped dramatically from 7255 in 2001 to 10 in 2014. However, despite these great results, 10 children were still diagnosed with malaria and there is a need for continuous attention to bring this number down to zero. The mobile goldmine workers can impose a threat for a new malaria epidemic, if they spread the malaria infection in Suriname. Therefore, effective prevention measures and treatment are still needed.

关键词： Malaria Children Suriname Prevention

Orthopaedic education in the era of surgical simulation: Still at the crawling stage

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Orthopedics 2017年第4期8卷 290-294页

作者： Kivanc Atesok Peter Mac Donald Jeff Leiter James Dubberley Richard Satava ann van Heest Shepard Hurwitz J Lawrence Marsh Department of Surgery Section of Orthopaedic SurgeryUniversity of Manitoba Department of Surgery University of Wash-ington Department of Orthopaedic Surgery University of Minnesota Department of Orthopaedic Surgery University of North Carolina Department of Orthopedics and Rehabilitation University of Iowa

Surgical skills education is in the process of a crucial transformation from a master-apprenticeship model to simulation-based training. Orthopaedic surgery is one of the surgical specialties where simulation-based skills training needs to be integrated into the curriculum efficiently and urgently. The reason for this strong and pressing need is that orthopaedic surgery covers broad human anatomy and pathologies and requires learning enormously diverse surgical procedures including basic and advanced skills. Although the need for a simulationbased curriculum in orthopaedic surgery is clear, several obstacles need to be overcome for a smooth transformation. The main issues to be addressed can be summarized as defining the skills and procedures so that simulation-based training will be most effective; choosing the right time period during the course of orthopaedic training for exposure to simulators; the right amount of such exposure; using objective, valid and reliable metrics to measure the impact of simulation-based training on the development and progress of surgical skills; and standardization of the simulation-based curriculum nationwide and internationally. In the new era of surgical education, successful integration of simulation-based surgical skills training into the orthopaedic curriculum will depend on efficacious solutions to these obstacles in moving forward.

关键词： Surgical simulation Orthopaedic surgery Education Skills training

British Journal of General Practice论文摘要汇编——抗生素暴露和后续呼吸道感染的“反应失败”：英国学龄前儿童初级保健的观察队列研究

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

中国全科医学 2019年第30期22卷 3708-3708页

作者： van hecke O FULLER A BANKHEAD C 本刊编辑部(整理) University of Oxford Oxford. Pharmatelligence Cardiff. Division of Population Medicine School of Medicine Cardiff University Cardiff. Primary Care and Population Sciences University of Southampton Southampton. Nuffield Department of Primary Health Care Sciences University of Oxford Oxford.

背景儿童抗生素暴露具有重要的临床相关意义。其中包括对微生物群的破坏、抗生素耐药性以及表现为治疗“失败”的临床工作。目的探讨患急性呼吸道感染的学龄前儿童前1 年的抗生素疗程与后1 年未对抗生素治疗有反应的患急性呼吸道感染... 详细信息

背景儿童抗生素暴露具有重要的临床相关意义。其中包括对微生物群的破坏、抗生素耐药性以及表现为治疗“失败”的临床工作。目的探讨患急性呼吸道感染的学龄前儿童前1 年的抗生素疗程与后1 年未对抗生素治疗有反应的患急性呼吸道感染之间的关系。设计与场所采用2009—2016 年英国临床实践研究数据链中的初级保健数据进行队列研究。方法对12~60 个月(1 ~ 5 岁)的儿童进行急性呼吸道感染(上、下呼吸道感染或中耳炎)的抗生素治疗。为每个儿童随机选择一个初始抗生素疗程。暴露是指在给予初始抗生素处方前12 个月内服用治疗急性呼吸道感染的抗生素数量。结果是在接受初始抗生素处方后14 d 内出现“反应失败”,定义为:继续开具抗生素处方;转诊;入院;死亡;或3 d 内在急诊科就诊。使用Logistic 回归分析来估计抗生素暴露和“反应失败”的概率。结果在114 329 例接受抗生素治疗的急性呼吸道感染患儿中,前1 年接受≥ 2 次抗生素治疗的急性呼吸道感染患儿有较高的“反应失败”率;1 次抗生素治疗(230 名儿童):调整后的比值比(OR)=1.03〔95%CI(0.88,1.21),P=0.67〕;≥ 2 个抗生素疗程(97 名儿童):调整后OR=1.32〔95%CI(1.04,1.66),P=0.02〕。结论儿童急性呼吸道感染抗生素暴露可能是后续反应失败(但不一定是抗生素治疗失败)的预测因素。需要进行进一步的研究来提高对潜在“反应失败”机制的理解。

关键词：急性呼吸道感染抗生素耐药性学龄前儿童队列研究初级保健反应论文摘要英国

Assessment of different machine learning techniques in predicting the compressive strength of self-compacting concrete

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2022年第7期16卷 928-945页

作者： van Quan TRAN Hai-van Thi MAI Thuy-Anh NGUYEN Hai-Bang LY Faculty of Civil Engineering University of Transport TechnologyHanoi 100000Vietnam

The compressive strength of self-compacting concrete(SCC)needs to be determined during the construction design *** paper shows that the compressive strength of SCC(CS of SCC)can be successfully predicted from mix design and curing age by a machine learning(ML)technique named the Extreme Gradient Boosting(XGB)algorithm,including non-hybrid and hybrid *** ML techniques,such as Linear regression(LR),K-Nearest Neighbors(KNN),Support Vector Machine(SVM),Decision Trees(DTR),Random Forest(RF),Gradient Boosting(GB),and Artificial Neural Network using two training algorithms LBFGS and SGD(denoted as ann_LBFGS and ann_SGD),are also compared with the XGB ***,the hybrid models of eight ML techniques and Particle Swarm Optimization(PSO)are constructed to highlight the reliability and accuracy of SCC compressive strength prediction by the XGB_PSO hybrid *** highest number of SCC samples available in the literature is collected for building the ML *** with previously published works’performance,the proposed XGB method,both hybrid and non-hybrid models,is the most reliable and robust of the examined techniques,and is more accurate than existing ML methods(R2=0.9644,RMSE=4.7801,and MAE=3.4832).Therefore,the XGB model can be used as a practical tool for engineers in predicting the CS of SCC.

关键词： compressive strength self-compacting concrete machine learning techniques particle swarm optimization extreme gradient boosting

Application of machine learning technique for predicting and evaluating chloride ingress in concrete

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2022年第9期16卷 1153-1169页

作者： van Quan TRAN van Loi GIAP Dinh Phien VU Riya Catherine GEORGE Lanh Si HO Department of Civil Engineering University of Transport TechnologyHanoi 100000Vietnam Civil and Environmental Engineering Program Graduate School of Advanced Science and EngineeringHiroshima UniversityHiroshima 739-8527Japan

The degradation of concrete structure in the marine environment is often related to chloride-induced corrosion of reinforcement ***,the chloride concentration in concrete is a vital parameter for estimating the corrosion level of reinforcement *** research aims at predicting the chloride content in concrete using three hybrid models of gradient boosting(GB),artificial neural network(ann),and random forest(RF)in combination with particle swarm optimization(PSO).The input variables for modeling include exposure condition,water/binder ratio(W/B),cement content,silica fume,time exposure,and depth of *** results indicate that three models performed well with high accuracy of prediction(R2⩾0.90).Among three hybrid models,the model using GB_PSO achieved the highest prediction accuracy(R2=0.9551,RMSE=0.0327,and MAE=0.0181).Based on the results of sensitivity analysis using SHapley Additive exPlanation(SHAP)and partial dependence plots 1D(PDP-1D),it was found that the exposure condition and depth of measurement were the two most vital variables affecting the prediction of chloride *** the number of different exposure conditions is larger than two,the exposure significantly impacted the chloride content of concrete because the chloride ion ingress is affected by both chemical and physical *** study provides an insight into the evaluation and prediction of the chloride content of concrete in the marine environment.

关键词： gradient boosting random forest chloride content concrete sensitivity analysis

Bilinear Forms for the Recovery-Based Discontinuous Galerkin Method for Diffusion

在线全文

学校读者我要写书评

暂无评论

Communications in Computational Physics 2009年第2期5卷 683-693页

作者： Marc van Raalte Bram van Leer Centrum voor Wiskunde en Informatica P.O.Box 940791090 GB AmsterdamThe Netherlands W.M.Keck Foundation Laboratory for Computational Fluid Dynamics Department of Aerospace EngineeringThe University of MichiganAnn ArborMI 48109-2140USA

The present paper introduces bilinear forms that are equivalent to the recovery-based discontinuous Galerkin formulation introduced by van Leer in *** recovery method approximates the solution of the diffusion equation in a discontinuous function space,while inter-element coupling is achieved by a local L_(2)projection that recovers a smooth continuous function underlying the discontinuous *** we introduce the concept of a local“recovery polynomial basis”–smooth polynomials that are in the weak sense indistinguishable from the discontinuous basis polynomials–and show it allows us to eliminate the recovery *** recovery method reproduces the symmetric discontinuous Galerkin formulation with additional penalty-like terms depending on the targeted accuracy of the *** present the unique link between the recovery method and discontinuous Galerkin bilinear forms.

关键词： Diffusion equation discontinuous Galerkin methods recovery basis L_(2)projection