期刊文献+
共找到65,697篇文章
< 1 2 250 >
每页显示 20 50 100
基于“TUBE”理论的交叉航路设计研究 被引量:1
1
作者 陶媚 郭兰申 +1 位作者 卢炯 张新瑜 《河北工业大学学报》 CAS 北大核心 2011年第5期39-43,共5页
针对当前航路网络日趋复杂,航路交叉点越来越多,出现飞行冲突的几率大大增加的问题,提出基于"TUBE"理论的交叉航路设计方法,该设计方法将航路中的航空器抽象为一种流体,当航空器进入航路时采用汇流的方法,离开航路时采用分流... 针对当前航路网络日趋复杂,航路交叉点越来越多,出现飞行冲突的几率大大增加的问题,提出基于"TUBE"理论的交叉航路设计方法,该设计方法将航路中的航空器抽象为一种流体,当航空器进入航路时采用汇流的方法,离开航路时采用分流的方法,使航空器在飞越航路交叉点时不存在互相穿越的飞行情况,并基于该理论进行了建模计算,计算结果表明该方法的采用可以降低管制员的工作负荷,同时更好地提高民航的运行效率和飞行的安全性. 展开更多
关键词 空域规划 tube”理论 交叉航路 穿越飞行 航路网络
下载PDF
基于“T-tube”模型的中心动脉脉搏波双通道盲辨识 被引量:1
2
作者 王璐 冯澍婷 +1 位作者 姚阳 徐礼胜 《东北大学学报(自然科学版)》 EI CAS CSCD 北大核心 2015年第2期199-203,212,共6页
提出了由两路人体外周动脉脉搏波(peripheral artery pulse wave,PAP)来估计中心动脉脉搏波(central aortic pulse wave,CAP)的多通道盲辨识(multi-channel blind system identification,MBSI)方法,旨在实现心血管系统中心动脉脉搏波的... 提出了由两路人体外周动脉脉搏波(peripheral artery pulse wave,PAP)来估计中心动脉脉搏波(central aortic pulse wave,CAP)的多通道盲辨识(multi-channel blind system identification,MBSI)方法,旨在实现心血管系统中心动脉脉搏波的实时无创连续监测.首先简单介绍了多通路盲辨识算法,并证明了心血管系统IIR模型特性可由FIR模型逼近,从而简化了MBSI算法.然后介绍了心血管"T-tube"模型,并结合两路外周动脉实测(肱动脉、股动脉)脉搏波来重建中心动脉脉搏波和辨识模型.结果表明,MBSI算法稳定性较好,估计出的CAP波形畸变率百分比小于6%、形态整体能量误差百分比小于3%. 展开更多
关键词 中心动脉脉搏波 外周动脉脉搏波 “T-tube”模型 多通道盲辨识 无创测量
下载PDF
基于可拓相平面稳定域划分的Tube-MPC车辆稳定性控制
3
作者 苏东旭 赵治国 +2 位作者 赵坤 李刚 于勤 《汽车工程》 EI CSCD 北大核心 2024年第9期1654-1667,共14页
针对分布式四轮驱动电动车辆在极限工况下稳定性控制难题,考虑了横摆角速度、横纵向加速度等传感器噪声以及质心侧偏角估计误差的影响,提出了基于可拓理论的相平面稳定域划分方法以及自适应管道模型预测控制(ATMPC)算法,以快速量化车辆... 针对分布式四轮驱动电动车辆在极限工况下稳定性控制难题,考虑了横摆角速度、横纵向加速度等传感器噪声以及质心侧偏角估计误差的影响,提出了基于可拓理论的相平面稳定域划分方法以及自适应管道模型预测控制(ATMPC)算法,以快速量化车辆稳定性程度,并在满足跟踪精度的前提下保证车辆行驶的稳定性。所设计的车辆横摆稳定性控制系统采用分层设计架构,其中上层基于可拓理论,将车辆质心侧偏角-橫摆角速度相平面与可拓控制域相关联,并根据车辆实际状态判断可拓控制域并计算关联函数,实现了下层的管道模型预测控制(TubeMPC)控制目标权重与控制模式的决策;下层基于Tube-MPC对期望横摆角速度和质心侧偏角进行跟踪,实现附加横摆力矩的精准决策,之后采用轮胎负荷率优化方法进行横摆力矩的分配。通过CarSim与Simulink软件联合仿真,对所设计的控制策略进行仿真验证。结果表明,相较于常规MPC算法,所提出的控制架构与ATMPC控制策略能够有效提升车辆在极限工况下的行驶稳定性以及噪声干扰环境下的鲁棒性。 展开更多
关键词 分布式驱动车辆 稳定性控制 可拓相平面 管道模型预测控制
下载PDF
Sandwich structures with tapered tubes as core:A quasi-static investigation
4
作者 Xinmei Xiang Dehua Shao +5 位作者 Xin Zhang Umer Sharif Ngoc San Ha Li Xiang Jing Zhang Jiang Yi 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第3期447-462,共16页
In this article,the experimental and finite element analysis is utilized to investigate the quasi-static compression features of sandwich constructions built with tapered tubes.3D printing technology was utilized to c... In this article,the experimental and finite element analysis is utilized to investigate the quasi-static compression features of sandwich constructions built with tapered tubes.3D printing technology was utilized to create the hollow centers of the tapering tubes,with and without corrugations.The results demonstrate that the energy absorption(EA)and specific energy absorption(SEA)of the single corrugated tapered tube sandwich are 51.6% and 19.8% higher,respectively,than those of the conical tube sandwich.Furthermore,the results demonstrate that energy absorbers can benefit from corrugation in order to increase their efficiency.Additionally,the tapered corrugated tubes'resistance to oblique impacts was studied.Compared to a straight tube,the tapered tube is more resistant to oblique loads and has a lower initial peak crushing force(PCF),according to numerical simulations.After conducting a parametric study,it was discovered that the energy absorption performance of the sandwich construction is significantly affected by the amplitude,number of corrugations,and wall thickness.EA and SEA of DTS with corrugation number of 8 increased by 17.4%and 29.6%,respectively,while PCF decreased by 9.2% compared to DTS with corrugation number of 10. 展开更多
关键词 Sandwich structure Corrugated tube Tapered tube QUASI-STATIC Energy absorption
下载PDF
High Density 3D Carbon Tube Nanoarray Electrode Boosting the Capacitance of Filter Capacitor
5
作者 Gan Chen Fangming Han +6 位作者 Huachun Ma Pei Li Ziyan Zhou Pengxiang Wang Xiaoyan Li Guowen Meng Bingqing Wei 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第11期242-254,共13页
Electric double-layer capacitors(EDLCs)with fast frequency response are regarded as small-scale alternatives to the commercial bulky aluminum electrolytic capacitors.Creating carbon-based nanoarray electrodes with pre... Electric double-layer capacitors(EDLCs)with fast frequency response are regarded as small-scale alternatives to the commercial bulky aluminum electrolytic capacitors.Creating carbon-based nanoarray electrodes with precise alignment and smooth ion channels is crucial for enhancing EDLCs’performance.However,controlling the density of macropore-dominated nanoarray electrodes poses challenges in boosting the capacitance of line-filtering EDLCs.Herein,a simple technique to finely adjust the vertical-pore diameter and inter-spacing in three-dimensional nanoporous anodic aluminum oxide(3D-AAO)template is achieved,and 3D compactly arranged carbon tube(3D-CACT)nanoarrays are created as electrodes for symmetrical EDLCs using nanoporous 3D-AAO template-assisted chemical vapor deposition of carbon.The 3D-CACT electrodes demonstrate a high surface area of 253.0 m^(2) g^(−1),a D/G band intensity ratio of 0.94,and a C/O atomic ratio of 8.As a result,the high-density 3D-CT nanoarray-based sandwich-type EDLCs demonstrate a record high specific areal capacitance of 3.23 mF cm^(-2) at 120 Hz and exceptional fast frequency response due to the vertically aligned and highly ordered nanoarray of closely packed CT units.The 3D-CT nanoarray electrode-based EDLCs could serve as line filters in integrated circuits,aiding power system miniaturization. 展开更多
关键词 Compactly arranged Three-dimensional carbon tube nanoarray Dimensional carbon tube nanoarray Fast frequency response Electric double-layer capacitors Layer capacitors AC line-filtering FILTERING
下载PDF
Analysis of impact pressure,rock-breaking effect,and ground vibration induced by the disposable CO_(2)fracturing tube
6
作者 Chong Yu Yongan Ma +3 位作者 Haibo Li Shouchun Deng Yafei Hao Kuan Zhu 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第8期3099-3121,共23页
The technology of expansion fracturing with liquid CO_(2)(EFLCO_(2))has attracted increasing attention due to reduced vibration and damage.The disposable fracturing tube has been developed and is gradually replacing t... The technology of expansion fracturing with liquid CO_(2)(EFLCO_(2))has attracted increasing attention due to reduced vibration and damage.The disposable fracturing tube has been developed and is gradually replacing the Cardox tube.However,there is a lack of impact pressure testing of disposable tubes under real working conditions,selection of gas explosion design parameters,and systematic analysis of blasting vibration.This limitation has constrained the widespread application of disposable fracturing tubes in engineering.A joint monitoring of the pressure-time curves in the disposable tubes and boreholes was conducted.The rock-breaking effect of varying hole spacing parameters in the EFLCO_(2)design was analyzed,and a systematic study was carried out on the vibration peak value,frequency,and energy characteristics.The results show that(1)the pressure distribution characteristics,stress peak value,and duration in the disposable tubes are different from those of Cardox tubes,which show multi-peak distribution,low-pressure peak value,and short duration.The correlation between the pressure in the disposable tube,filling pressure,and liquid CO_(2)weight is established,and a theoretical calculation method for the borehole wall pressure is proposed;(2)The hole spacing in rocks of different hardness is suggested;and(3)At the same scale distance,the peak particle velocity(PPV)caused by EFLCO_(2)(PPVCO_(2))is significantly smaller than that caused by blasting(PPVexplosive).The ratio of PPVexplosive to PPVCO_(2)is a power function related to scale distance,and a distance-related zonality exist in this relationship.The frequency composition of the vibration signal caused by EFLCO_(2)is relatively simple with a narrow frequency band.Its PPV and energy are mainly concentrated in the low-frequency band.This research contributes to the optimization of disposable fracturing tubes,gas explosion design,and vibration hazard control. 展开更多
关键词 Disposable tube Liquid CO_(2) Impact pressure Hole spacing Vibration effect Cardox tube
下载PDF
Nasogastric tube syndrome:A Meta-summary of case reports
7
作者 Deven Juneja Prashant Nasa +1 位作者 Gunjan Chanchalani Ravi Jain 《World Journal of Clinical Cases》 SCIE 2024年第1期119-129,共11页
BACKGROUND Since its description in 1790 by Hunter,the nasogastric tube(NGT)is commonly used in any healthcare setting for alleviating gastrointestinal symptoms or enteral feeding.However,the risks associated with its... BACKGROUND Since its description in 1790 by Hunter,the nasogastric tube(NGT)is commonly used in any healthcare setting for alleviating gastrointestinal symptoms or enteral feeding.However,the risks associated with its placement are often underes-timated.Upper airway obstruction with a NGT is an uncommon but potentially life-threatening complication.NGT syndrome is characterized by the presence of an NGT,throat pain and vocal cord(VC)paralysis,usually bilateral.It is poten-tially life–threatening,and early diagnosis is the key to the prevention of fatal upper airway obstruction.However,fewer cases may have been reported than might have occurred,primarily due to the clinicians'unawareness.The lack of specific signs and symptoms and the inability to prove temporal relation with NGT insertion has made diagnosing the syndrome quite challenging.AIM To review and collate the data from the published case reports and case series to understand the possible risk factors,early warning signs and symptoms for timely detection to prevent the manifestation of the complete syndrome with life-threatening airway obstruction.METHODS We conducted a systematic search for this meta-summary from the database of PubMed,EMBASE,Reference Citation Analysis(https://www.referencecitation-analysis.com/)and Google scholar,from all the past studies till August 2023.The search terms included major MESH terms"Nasogastric tube","Intubation,Gastrointestinal","Vocal Cord Paralysis",and“Syndrome”.All the case reports and case series were evaluated,and the data were extracted for patient demographics,clinical symptomatology,diagnostic and therapeutic interventions,clinical course and outcomes.A datasheet for evaluation was further prepared.RESULTS Twenty-seven cases,from five case series and 13 case reports,of NGT syndrome were retrieved from our search.There was male predominance(17,62.96%),and age at presentation ranged from 28 to 86 years.Ten patients had diabetes mellitus(37.04%),and nine were hypertensive(33.33%).Only three(11.11%)patients were reported to be immunocompromised.The median time for developing symptoms after NGT insertion was 14.5 d(interquartile range 6.25-33.75 d).The most commonly reported reason for NGT insertion was acute stroke(10,37.01%)and the most commonly reported symptoms were stridor or wheezing 17(62.96%).In 77.78%of cases,bilateral VC were affected.The only treatment instituted in most patients(77.78%)was removing the NG tube.Most patients(62.96%)required tracheostomy for airway protection.But 8 of the 23 survivors recovered within five weeks and could be decannulated.Three patients were reported to have died.CONCLUSION NGT syndrome is an uncommon clinical complication of a very common clinical procedure.However,an under-reporting is possible because of misdiagnosis or lack of awareness among clinicians.Patients in early stages and with mild symptoms may be missed.Further,high variability in the presentation timing after NGT insertion makes diagnosis challenging.Early diagnosis and prompt removal of NGT may suffice in most patients,but a significant proportion of patients presenting with respiratory compromise may require tracheostomy for airway protection. 展开更多
关键词 Nasogastric tube Nasogastric tube syndrome Ryle’s tube Sofferman syndrome Vocal cord paralysis
下载PDF
Crashworthiness Design and Multi-Objective Optimization of Bionic Thin-Walled Hybrid Tube Structures
8
作者 Pingfan Li Jiumei Xiao 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第4期999-1016,共18页
Thin-walled structures are widely used in cars due to their lightweight construction and energy-absorbing properties.However,issues such as high initial stress and lowenergy-absorbing efficiency arise.This study propo... Thin-walled structures are widely used in cars due to their lightweight construction and energy-absorbing properties.However,issues such as high initial stress and lowenergy-absorbing efficiency arise.This study proposes a novel energy-absorbing structure inwhich a straight tube is combinedwith a conical tube and a bamboo-inspired bulkhead structure is introduced.This configuration allows the conical tube to flip outward first and then fold together with the straight tube.This deformation mode absorbs more energy and less peak force than the conical tube sinking and flipping inward.Through finite element numerical simulation,the specific energy absorption capacity of the structure is increased by 26%compared to that of a regular circular cross-section tube.Finally,the impact resistance of the bionic straight tapered tube structure is further improved through multi-objective optimization,promoting the engineering application and lightweight design of hybrid cross-section tubes. 展开更多
关键词 CRASHWORTHINESS tube inversion multi-objective optimization energy absorption
下载PDF
Hollow tubes constructed by carbon nanotubes self-assembly for CO_(2) capture
9
作者 CHEN Xu-rui WU Jun +1 位作者 GU Li CAO Xue-bo 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第7期2256-2267,共12页
Carbon nanotubes(CNTs)have garnered significant attention in the fields of science,engineering,and medicine due to their numerous advantages.The initial step towards harnessing the potential of CNTs involves their mac... Carbon nanotubes(CNTs)have garnered significant attention in the fields of science,engineering,and medicine due to their numerous advantages.The initial step towards harnessing the potential of CNTs involves their macroscopic assembly.The present study employed a gentle and direct self-assembly technique,wherein controlled growth of CNT sheaths occurred on the metal wire’s surface,followed by etching of the remaining metal to obtain the hollow tubes composed of CNTs.By controlling the growth time and temperature,it is possible to alter the thickness of the CNTs sheath.After immersing in a solution containing 1 g/L of CNTs at 60℃for 24 h,the resulting CNTs layer achieved a thickness of up to 60μm.These hollow CNTs tubes with varying inner diameters were prepared through surface reinforcement using polymers and sacrificing metal wires,thereby exhibiting exceptional attributes such as robustness,flexibility,air tightness,and high adsorption capacity that effectively capture CO_(2) from the gas mixture. 展开更多
关键词 carbon nanotubes SELF-ASSEMBLY hollow tubes CO_(2)capture
下载PDF
Heat Transfer Enhancement of the Absorber Tube in a Parabolic Trough Solar Collector through the Insertion of Novel Cylindrical Turbulators
10
作者 Yasser Jebbar Fadhil Fluiful Wisam Khudhayer 《Fluid Dynamics & Materials Processing》 EI 2024年第6期1279-1297,共19页
This study includes an experimental and numerical analysis of the performances of a parabolic trough collector(PTC)with and without cylindrical turbulators.The PTC is designed with dimensions of 2.00 m in length and 1... This study includes an experimental and numerical analysis of the performances of a parabolic trough collector(PTC)with and without cylindrical turbulators.The PTC is designed with dimensions of 2.00 m in length and 1.00 m in width.The related reflector is made of lined sheets of aluminum,and the tubes are made of stainless steel used for the absorption of heat.They have an outer diameter of 0.051 m and a wall thickness of 0.002 m.Water,used as a heat transfer fluid(HTF),flows through the absorber tube at a mass flow rate of 0.7 kg/s.The dimensions of cylindrical turbulators are 0.04 m in length and 0.047 m in diameter.Simulations are performed using the ANSYS Fluent 2020 R2 software.The PTC performance is evaluated by comparing the experimental and numerical outcomes,namely,the outlet temperature,useful heat,and thermal efficiency for a modified tube(MT)(tube with novel cylindrical turbulators)and a plain tube(PT)(tube without novel cylindrical turbulators).According to the results,the experimental outlet temperatures recorded 63.2°C and 50.5°C for the MT and PT,respectively.The heat gain reaches 1137.5 Win the MT and 685.8 Win the PT.Compared to the PT collector,the PTC exhibited a(1.64 times)higher efficiency. 展开更多
关键词 Parabolic trough collector turbulators absorber tube ANSYS thermal efficiency
下载PDF
A novel efficient energy absorber with free inversion of a metal foam-filled circular tube
11
作者 Jianxun ZHANG Jinwen BAI 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第1期1-14,共14页
In this paper, a novel efficient energy absorber with free inversion of a metal foam-filled circular tube(MFFCT) is designed, and the axial compressive behavior of the MFFCT under free inversion is studied analyticall... In this paper, a novel efficient energy absorber with free inversion of a metal foam-filled circular tube(MFFCT) is designed, and the axial compressive behavior of the MFFCT under free inversion is studied analytically and numerically. The theoretical analysis reveals that the energy is mainly dissipated through the radial bending of the metal circular tube, the circumferential expansion of the metal circular tube, and the metal filled-foam compression. The principle of energy conservation is used to derive the theoretical formula for the minimum compressive force of the MFFCT over free inversion under axial loading. Furthermore, the free inversion deformation characteristics of the MFFCT are analyzed numerically. The theoretical steady values are found to be in good agreement with the results of the finite element(FE) analysis. The effects of the average diameter of the metal tube, the wall thickness of the metal tube, and the filled-foam strength on the free inversion deformation of the MFFCT are considered. It is observed that in the steady deformation stage, the load-carrying and energy-absorbing capacities of the MFFCT increase with the increase in the average diameter of the metal tube, the wall thickness of the metal tube, or the filled-foam strength. The specific energy absorption(SEA) of free inversion of the MFFCT is significantly higher than that of the metal tube alone. 展开更多
关键词 metal foam-filled circular tube(MFFCT) free inversion load-carrying capacity energy absorption
下载PDF
Study on the low mechanical anisotropy of extruded Mg-Zn-Mn-Ce-Ca alloy tube in the compression process
12
作者 Dandan Li Qichi Le +6 位作者 Xiong Zhou Xiaoqiang Li Chenglu Hu Ruizhen Guo Tong Wang Ping Wang Wenxin Hu 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第3期1054-1067,共14页
In this study,the extruded Mg-Zn-Mn-Ce-Ca alloy tube with a low compression anisotropy along the ED,45ED and TD was prepared.The effect of the second phases,initial texture and deformation behavior on this low mechani... In this study,the extruded Mg-Zn-Mn-Ce-Ca alloy tube with a low compression anisotropy along the ED,45ED and TD was prepared.The effect of the second phases,initial texture and deformation behavior on this low mechanical anisotropy was investigated.The results revealed that the alloy tube contains the high content(Mg1-xZnx)11Ce phase and the low content of Mg12Ce phase.These second phases are respectively incoherent and coherent with the Mg matrix,and their influence can be ignored.Additionally,the alloy tube exhibited a weak basal fiber texture,where the c-axis was aligned along the 0°∼30°tilt from TD to ED.Such a texture made the initial deformation(at 1.0%∼1.6%strain)of the three samples controlled by comparable basalslip.As deformation progressed(1.6∼9.0%strain),larger amounts of ETWs nucleated and gradually approached saturation in the three samples,re-orienting the c-axis to a 0°∼±30°deviation with respect to the loading directions.Meanwhile,the prismatic and pyramidal<c+a>slips replaced the dominant deformation progressively until fracture.Eventually,the similar deformation mechanisms determined by the weak initial texture in the three samples contribute to the comparable strain hardening rates,resulting in the low compressive anisotropy of the alloy tube. 展开更多
关键词 Mg alloy tube Low mechanical anisotropy Weak texture Deformation mechanism.
下载PDF
Modified intratympanic steroid therapy for sudden sensorineural hearing loss via tympanic tube and gelfoam as a salvage treatment
13
作者 Sichao Liang Yunshuo Li +6 位作者 Zhenping Guo Manlin Lu Xin Li Jia Xu Wenjing Chen Juanjuan Gao Haijin Yi 《Journal of Otology》 CAS CSCD 2024年第1期19-23,共5页
Background: Sudden sensorineural hearing loss(SSNHL) is a prevalent emergency in ear, nose, and throat practice. Previous studies have demonstrated that intratympanic steroid therapy(IST) can serve as a salvage treatm... Background: Sudden sensorineural hearing loss(SSNHL) is a prevalent emergency in ear, nose, and throat practice. Previous studies have demonstrated that intratympanic steroid therapy(IST) can serve as a salvage treatment for SSNHL after the failure of systemic steroid therapy(SST).Objective: This study aimed to analyze the efficacy of modified IST involving the insertion of a tympanic tube and gelfoam as a salvage treatment for patients with SSNHL, and to explore its associated factors.Methods: Totally, 74 patients who were aged 22–81 years with SSNHL were enrolled and allocated to either the control group(n = 25) or the treatment group(n = 49) based on their treatment modalities. All patients received SST lasting for at least 7 days. Subsequently, patients in the treatment group, after SST failure, underwent IST twice a week for 2–6 weeks, while the control group did not. Efficacy was assessed by the improvement in pure tone average at the affected frequency at the beginning and end of IST.Results: Hearing improvement in all patients after IST in the treatment group was 9.71 ± 14.84 dB, with significant improvement at affected frequencies(250-8000 Hz) compared with the control group(P < 0.05). The findings indicated the duration from the onset of SSNHL to the beginning of IST as an independent factor for pure tone average improvement after treatment(P = 0.002), whereas age, duration of SST, and time of IST were not(P > 0.05).Conclusion: The modified IST was demonstrated to be a safe and effective method as a salvage treatment for SSNHL. This study explored the efficacy of a modified IST approach, incorporating the utilization of tympanic tubes and gelfoam as key components. The findings underscore the advantages of gelfoam as a strategic drug carrier placed in the round window niche. By minimizing drug loss, extending action time, and increasing perilymph concentration, gelfoam enhances the therapeutic impact of IST, contributing to improved hearing outcomes in patients with SSNHL. 展开更多
关键词 Modified intratympanic steroid therapy Sudden sensorineural hearing loss GELFOAM Tympanic tube
下载PDF
Analysis and Optimization of the Electrohydraulic Forming Process of Sinusoidal Corrugation Tubes
14
作者 Da Cai Yinlong Song +2 位作者 Hao Jiang Guangyao Li Junjia Cui 《Fluid Dynamics & Materials Processing》 EI 2024年第4期873-887,共15页
Aluminum alloy thin-walled structures are widely used in the automotive industry due to their advantages related to light weight and crashworthiness.They can be produced at room temperature by the electrohydraulic for... Aluminum alloy thin-walled structures are widely used in the automotive industry due to their advantages related to light weight and crashworthiness.They can be produced at room temperature by the electrohydraulic forming process.In the present study,the influence of the related parameters on the forming quality of a 6063 aluminum alloy sinusoidal corrugation tube has been assessed.In particular,the orthogonal experimental design(OED)and central composite design(CCD)methods have been used.Through the range analysis and variance analysis of the experimental data,the influence degree of wire diameter(WD)and discharge energy(DE)on the forming quality was determined.Multiple regression analysis was performed using the response surface methodology.A prediction model for the attaching-die state coefficient was established accordingly.The following optimal arrangement of parameters was obtained(WD=0.759 mm,DE=2.926 kJ).The attaching-die state coefficient reached the peak value of 0.001.Better optimized wire diameter and discharge energy for a better attaching-die state could be screened by CCD compared with OED.The response surface method in CCD was more suitable for the design and optimization of the considered process parameters. 展开更多
关键词 Electrohydraulic forming aluminum alloy tube process parameters attaching-die state 1 Introduction
下载PDF
A new abdominal drainage tube fixation method for 3-port laparoscopic cholecystectomy improves patients’postoperative quality of life
15
作者 Fenghua Zhang Lin Lin +2 位作者 Huan Zhang Jinghua Liu Rui Wang 《Laparoscopic, Endoscopic and Robotic Surgery》 2024年第3期107-112,共6页
Objective Laparoscopic surgery has become a routine general surgery with many advantages,such as alleviating abdominal pain.However,postoperative pain caused by abdominal drainage tubes has attracted little attention ... Objective Laparoscopic surgery has become a routine general surgery with many advantages,such as alleviating abdominal pain.However,postoperative pain caused by abdominal drainage tubes has attracted little attention from medical staff.The aim of this study was to explore the influence of a new abdominal drainage tube fixation method for 3-port laparoscopic cholecystectomy(LC)on patients’postoperative quality of life.Methods Patients who underwent 3-port LC with abdominal drainage tubes in the Department of Hepatobiliary Surgery of Linyi People’s Hospital from March 1,2023 to October 31,2023 due to gallstones with chronic cholecystitis were selected for this study.The patients were randomly divided into an experimental group and a control group.In the experimental group,the new abdominal drainage tube fixation method was used,while in the control group,the traditional method was used.Afterward,the quality of life of patient in terms of pain,activity,recovery time,and mental health status was evaluated.The exudate around the patient’s drainage tube was collected for bacterial culture and analysis.Results A total of 139 patients were randomly divided into an experimental group(70 patients)and a control group(69 patients).The patients’baseline characteristics were not significantly different.The patients in the experimental group had better outcomes in quality of life,with higher pain scores(24.03±2.37 vs.15.48±2.29,p<0.001)and activity scores(20.57±1.78 vs.14.13±1.43,p<0.001),and a shorter postoperative recovery time(2.36±0.68 d vs.2.96±1.34 d,p<0.001).The same results were shown in linear regression analysis scores of the 2 groups.The positive rate of bacterial culture in the exudate around the patient’s drainage tube in the experimental group was significantly lower than that in the control group(12.9%vs.43.5%,p<0.001);and furthermore,the positive rate of conditional pathogenic bacteria was even lower(7.1%vs.33.3%,p<0.001)in the experimental group than in the control group.Conclusion This new abdominal drainage tube fixation method can effectively promote patient rehabilitation and improve the quality of life for patient following 3-port LC with abdominal drainage tubes. 展开更多
关键词 Abdominal drainage tube Surgical site infection Quality of life Fixation method Laparoscopic cholecystectomy
下载PDF
High-grade serous carcinoma of the fallopian tube in a young woman with chromosomal 4q abnormality:A case report
16
作者 Kai-Cheng Zhang Shao-Yin Chu Dah-Ching Ding 《World Journal of Clinical Cases》 SCIE 2024年第18期3539-3547,共9页
BACKGROUND Few studies have reported an association between an increased risk of acquiring cancers and survival in patients with 4q deletion syndrome.This study presents a rare association between chromosome 4q abnorm... BACKGROUND Few studies have reported an association between an increased risk of acquiring cancers and survival in patients with 4q deletion syndrome.This study presents a rare association between chromosome 4q abnormalities and fallopian tube highgrade serous carcinoma(HGSC)in a young woman.CASE SUMMARY A 35-year-old woman presented with acute dull abdominal pain and a known chromosomal abnormality involving 4q13.3 duplication and 4q23q24 deletion.Upon arrival at the emergency room,her abdomen appeared ovoid and distended with palpable shifting dullness.Ascites were identified through abdominal ultrasound,and computed tomography revealed an omentum cake and an enlarged bilateral adnexa.Blood tests showed elevated CA-125 levels.Paracentesis was conducted,and immunohistochemistry indicated that the cancer cells favored an ovarian origin,making us suspect ovarian cancer.The patient underwent debulking surgery,which led to a diagnosis of stage IIIC HGSC of the fallopian tube.Subsequently,the patient received adjuvant chemotherapy with carboplatin and paclitaxel,resulting in stable current condition.CONCLUSION This study demonstrates a rare correlation between a chromosome 4q abnormality and HGSC.UBE2D3 may affect crucial cancer-related pathways,including P53,BRCA,cyclin D,and tyrosine kinase receptors,thereby possibly contributing to cancer development.In addition,ADH1 and DDIT4 may be potential influencers of both carcinogenic and therapeutic responses. 展开更多
关键词 High-grade serous carcinoma Fallopian tube Young age Chromosomal abnormality Mental retardation AGING Case report
下载PDF
Numerical simulation of the influence factors of NO_(x) emission on a W-type radiant tube
17
作者 LIU Yanyan 《Baosteel Technical Research》 CAS 2024年第1期1-7,共7页
The radiant tube burner was modeled and analyzed by the numerical simulation method to investigate the influence factors and rules of NO_(x) emissions in a W-type radiant tube.These factors,which include air preheatin... The radiant tube burner was modeled and analyzed by the numerical simulation method to investigate the influence factors and rules of NO_(x) emissions in a W-type radiant tube.These factors,which include air preheating temperature,excess air coefficient,and fuel gas composition,were modified to study their effects on NO_(x) emissions under varying working conditions.Simulation results were compared with the theoretical calculation value based on chemical reaction equilibrium theory and the onsite experimental value to verify the simulation accuracy.The results show that NO_(x) emissions rise with increasing air preheating temperatures.NO_(x) production increases to an extreme value and then decreases during the oxygen-poor to oxygen-enriched process with the rise of the excess air coefficient.Enhancing the proportion of coke oven gas in the fuel gas raises the combustion temperature as well as the NO_(x) discharge.Both the thermal efficiency and NO_(x) emissions should be balanced.Therefore,the recommended values based on the simulation results are as follows:the air preheating temperature should not exceed 400℃,the excess air coefficient should be between 1.1 and 1.2,and the volume fraction of the coke oven gas should not exceed 30%. 展开更多
关键词 W-type radiant tube NO_(x) combustion numerical simulation
下载PDF
Primary ovarian cancer combined with primary fallopian tube cancer:A case report
18
作者 Su-Ning Bai Qi Wu Li-Yun Song 《World Journal of Clinical Cases》 SCIE 2024年第17期3188-3193,共6页
BACKGROUND Low grade serous carcinoma of the ovary(LGSOC)is a rare type of epithelial ovarian cancer with a low incidence rate.The origin of ovarian cancer has always been a hot topic in gynecological oncology researc... BACKGROUND Low grade serous carcinoma of the ovary(LGSOC)is a rare type of epithelial ovarian cancer with a low incidence rate.The origin of ovarian cancer has always been a hot topic in gynecological oncology research,and some scholars believe that the origin of ovarian malignant tumors is the fallopian tubes.Primary fallopian tube cancer is the lowest incidence of malignant tumors in the female reproductive system.There are only a few reports in the literature,but the mortality rate is very high.But in clinical practice,fallopian tube cancer is very common,but in most cases,it is classified as ovarian cancer.CASE SUMMARY We report a 54 years old postmenopausal woman who was hospitalized with a lower abdominal mass and underwent surgical treatment.The final pathological confirmation was low-grade serous carcinoma of the right ovary and low-grade serous carcinoma of the left fallopian tube.No special treatment was performed after the surgery,and the patient was instructed to undergo regular follow-up without any signs of disease progression.CONCLUSION The prognosis of LGSOC is relatively good,over 80%of patients still experience disease recurrence. 展开更多
关键词 Low grade serous carcinoma of the ovary Primary fallopian tube cancer Ovarian cancer Epithelial ovarian cancer Case report
下载PDF
Creep rupture properties and microstructure stability of the GH984G alloy tube
19
作者 WANG Tingting XU Songqian 《Baosteel Technical Research》 CAS 2024年第1期43-48,共6页
GH984G alloy is a significant candidate material for 650-700℃ ultra-supercritical coal-fired generating units.In this paper,creep rupture properties and microstructure stability of the GH984G alloy tube were studied,... GH984G alloy is a significant candidate material for 650-700℃ ultra-supercritical coal-fired generating units.In this paper,creep rupture properties and microstructure stability of the GH984G alloy tube were studied,and the findings indicated excellent creep rupture properties at 700℃.Furthermore,the extrapolated strength for 100000 h was found to be 153.8 MPa,which satisfies the requirements for the long-term performance of high-temperature materials in power stations.Aging at 700℃ with the extension of time,the grain boundary carbides and the particle size of the γ′phase on the matrix gradually coarsen,but its spherical morphology remains uniformly distributed.However,no harmful phase precipitates were found even after aging at 700℃ for up to 19144 h.Excellent microstructure stability guarantees the 700℃ creep rupture properties of the GH984G alloy tube. 展开更多
关键词 GH984G alloy tube nickel-iron-based superalloy stress-rupture properties microstructure stability
下载PDF
Clinical application of reserved gastric tube in neuroendoscopic endonasal surgery for pituitary tumor
20
作者 Xi Chen Long-Yao Zhang +3 位作者 Zhi-Feng Wang Yi Zhang Yu-Hua Yin Xue-Jian Wang 《World Journal of Clinical Oncology》 2024年第3期411-418,共8页
BACKGROUND The neuroendoscopic approach has the advantages of a clear operative field,convenient tumor removal,and less damage,and is the development direction of modern neurosurgery.At present,transnasal surgery for ... BACKGROUND The neuroendoscopic approach has the advantages of a clear operative field,convenient tumor removal,and less damage,and is the development direction of modern neurosurgery.At present,transnasal surgery for sphenoidal pituitary tumor is widely used.But it has been found in clinical practice that some patients with this type of surgery may experience post-operative nausea and vomiting and other discomforts.AIM To explore the effect of reserved gastric tube application in the neuroendoscopic endonasal resection of pituitary tumors.METHODS A total of 60 patients who underwent pituitary adenoma resection via the endoscopic endonasal approach were selected and randomly divided into the experimental and control groups,with 30 in each group.Experimental group:After anesthesia,a gastric tube was placed through the mouth under direct vision using a visual laryngoscope,and the fluid accumulated in the oropharynx was suctioned intermittently with low negative pressure throughout the whole process after nasal disinfection,during the operation,and when the patient recovered from anesthesia.Control group:Given the routine intraoperative care,no gastric tube was left.The number of cases of nausea/vomiting/aspiration within 24 h post-operation was counted and compared between the two groups;the scores of pharyngalgia after waking up,6 h post-operation,and 24 h postoperation.The frequency of postoperative cerebrospinal fluid leakage and intracranial infection were compared.The hospitalization days of the two groups were statistically compared.RESULTS The times of postoperative nausea and vomiting in the experimental group were lower than that in the control group,and the difference in the incidence of nausea was statistically significant(P<0.05).After the patient woke up,the scores of sore throat 6 h after the operation and 24 h after operation were lower than those in the control group,and the difference was statistically significant(P<0.05).The number of cases of postoperative cerebrospinal fluid leakage and intracranial infection was higher than that of the control group,but there was no statistically significant difference from the control group(P>0.05).The hospitalization days of the experimental group was lower than that of the control group,and the difference was statistically significant(P<0.05).CONCLUSION Reserving a gastric tube in the endoscopic endonasal resection of pituitary tumors,combined with intraoperative and postoperative gastrointestinal decompression,can effectively reduce the incidence of nausea,reduce the number of vomiting and aspiration in patients,and reduce the complications of sore throat The incidence rate shortened the hospitalization days of the patients. 展开更多
关键词 NEUROENDOSCOPY Endonasal approach Pituitary tumor Reserved gastric tube NAUSEA VOMITING ASPIRATION COMPLICATIONS
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部