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基于COMSOL的低温截止阀安全性仿真研究

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液压气动与密封 2024年第9期44卷 73-77页

作者：谷文伟谢智能张瑞琦胡显青靳通安徽华东光电技术研究所有限公司安徽芜湖241000

为深入研究DN150低温截止阀在试验过程中的安全可靠性,采用数值模拟分析和现场工程试验相结合的方法,利用COMSOL Multiphysics软件计算低温截止阀在开启和关闭状态时的热量耗散、应力集中及流体流动的情况。结果表明:低温截止阀在阀门... 详细信息

为深入研究DN150低温截止阀在试验过程中的安全可靠性,采用数值模拟分析和现场工程试验相结合的方法,利用COMSOL Multiphysics软件计算低温截止阀在开启和关闭状态时的热量耗散、应力集中及流体流动的情况。结果表明:低温截止阀在阀门内外壳体处存在温度梯度,会出现显著的温度耗散情况;受热应力和固定约束影响,波纹管组件连接处出现应力集中;在阀门开关瞬间,管道中的液氮流速会出现瞬变,阀门内部的流体流动会出现漩涡流,影响阀门阀瓣和阀座密封副的密封性。

关键词：低温截止阀 COMSOL 传热流体流动

A compact X-band backward traveling-wave accelerating structure

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Nuclear Science and Techniques 2024年第5期35卷 13-29页

作者： xian-Cai Lin Hao Zha Jia-Ru Shi Qiang Gao Fang-Jun hu qing-Zhu Li huai-Bi Chen Department of Engineering Physics Tsinghua UniversityBeijing 100084China Key Laboratory of Particle and Radiation Imaging(Tsinghua University) Ministry of EducationBeijing 100084China

Very high-energy electrons(VHEEs)are potential candidates for FLASH radiotherapy for deep-seated *** proposed a compact VHEE facility based on an X-band high-gradient high-power *** this study,we investigated and realized the first X-band backward traveling-wave(BTW)accelerating structure as the buncher for a VHEE facility.A method for calculating the parameters of single cell from the field distribution was introduced to simplify the design of the BTW ***-domain circuit equations were applied to calculate the transient beam parameters of the buncher in the unsteady state.A prototype of the BTW structure with a thermionic cathode-diode electron gun was designed,fabricated,and tested at high power at the Tsinghua X-band high-power test *** structure successfully operated with 5-MW microwave pulses from the pulse compressor and outputted electron bunches with an energy of 8 MeV and a pulsed current of 108 mA.

关键词： Backward traveling-wave accelerating structure Equivalent circuit model High-power test Very high-energy electron radiotherapy

Communication Resource-Efficient Vehicle Platooning Control With Various Spacing Policies

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 362-376页

作者： Xiaohua Ge qing-Long Han xian-Ming Zhang Derui Ding IEEE School of Science Computing and Engineering TechnologiesSwinburne University of TechnologyMelbourne VIC 3122Australia

Platooning represents one of the key features that connected automated vehicles may possess as it allows multiple automated vehicles to be maneuvered cooperatively with small headways on roads. However, a critical challenge in accomplishing automated vehicle platoons is to deal with the effects of intermittent and sporadic vehicle-to-vehicle data transmissions caused by limited wireless communication resources. This paper addresses the co-design problem of dynamic event-triggered communication scheduling and cooperative adaptive cruise control for a convoy of automated vehicles with diverse spacing policies. The central aim is to achieve automated vehicle platooning under various gap references with desired platoon stability and spacing performance requirements, while simultaneously improving communication efficiency. Toward this aim, a dynamic event-triggered scheduling mechanism is developed such that the intervehicle data transmissions are scheduled dynamically and efficiently over time. Then, a tractable co-design criterion on the existence of both the admissible event-driven cooperative adaptive cruise control law and the desired scheduling mechanism is derived. Finally, comparative simulation results are presented to substantiate the effectiveness and merits of the obtained results.

关键词： Automated vehicles constant time headway spacing constant spacing cooperative adaptive cruise control event-triggered communication vehicle platooning

Accumulated-state-error-based event-triggered sampling scheme and its application to H∞ control of sampled-data systems

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Science China(Information Sciences) 2024年第6期67卷 328-341页

作者： xian-Ming ZHANG qing-Long HAN Bao-Lin ZHANG Xiaohua GE Dawei ZHANG School of Science Computingand Engineering TechnologiesSwinburne University of Technology College of Automation and Electronic Engineering Qingdao University of Science & Technology School of Mathematics Shandong University

This paper is concerned with event-triggered H∞control of sampled-data systems. Its novelties lie in three aspects:（i） A novel accumulated-state-error-based event-triggered scheme is introduced by comparing the integral of the state error from tk to t with the system state sampled at tk. This condition works well due to the fact that the so-called Zeno behaviour does not occur.（ii） A novel Lyapunov functional is constructed to establish a criterion to ensure some certain H∞performance of the closed-loop system. This Lyapunov functional is dependent on the integral of the state error involved in the event-triggered scheme.（iii） Under the event-triggered sampling scheme, suitable state-feedback controllers can be designed rather than be given a priori. Moreover, a self-triggered implementation of the proposed event-triggered sampling scheme is presented as well. Finally, a batch reactor model and an inverted pendulum system are given to demonstrate the effectiveness of the proposed method.

关键词： event-triggered sampling self-triggered implementation $H_\infty$ control looped-functional

Synthesis of Planar-Chiral[2.2]Paracyclophane-Based Oxazole-Pyrimidine Ligands and Application in Nickel-Catalyzed 1,2-Reduction ofα,β-Unsaturated Ketones

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Chinese Journal of Chemistry 2024年第7期42卷 705-710页

作者： Juan Wang qing-xian Xie xiang Li Chang-Bin Yu Yong-Gui Zhou School of Chemistry Dalian University of Technology2 Linggong RoadDalianLiaoning 116024China State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalianLiaoning 116023China

The planar-chiral ligands have been widely applied as a class of unique and significant ligands in asymmetric *** them,chiral[2.2]paracycyclophane has emerged as a privileged type of planar-chiral framework and has been utilized as an important toolbox due to their structural ***,we design and synthesize[2.2]paracyclophane-derived oxazole-pyrimidine ligands(abberviated as PYMCOX).These N,N-ligands with stable properties,rigid structure and large steric hindrance performed successfully in nickel-catalyzed asymmetric 1,2-reduction ofα,β-unsaturated ketones,affording the chiral allylic alcohols with up to 99%yield and 99%***,this reduction reaction could be conducted on gram-scale without loss of activity and enantioselectivity,and the chiral ligand could be conveniently recovered with high yield.

关键词： Oxazole-pyrimidine ligands Planar chirality Nickel Hydroboration Asymmetric synthesis

Serotonin receptor 2B induces visceral hyperalgesia in rat model and patients with diarrhea-predominant irritable bowel syndrome

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World Journal of Gastroenterology 2024年第10期30卷 1431-1449页

作者： Zheng-Yang Li Yu-qing Mao Qian hua Yong-Hong Sun Hai-Yan Wang Xuan-Guang Ye Jing-xian hu Ya-Jie Wang Miao Jiang Department of Gastroenterology Jinshan Hospital of Fudan UniversityShanghai 201508China Department of Gastroenterology Shanghai General HospitalShanghai Jiao Tong University School of MedicineShanghai 200080China Department of Gastroenterology Dalian Friendship HospitalDalian 116001Liaoning ProvinceChina Department of Pathology Jinshan Hospital of Fudan UniversityShanghai 201508China

BACKGROUND Serotonin receptor 2B(5-HT2B receptor)plays a critical role in many chronic pain *** possible involvement of the 5-HT2B receptor in the altered gut sensation of irritable bowel syndrome with diarrhea(IBS-D)was investigated in the present *** To investigate the possible involvement of 5-HT2B receptor in the altered gut sensation in rat model and patients with *** Rectosigmoid biopsies were collected from 18 patients with IBS-D and 10 patients with irritable bowel syndrome with constipation who fulfilled the Rome IV criteria and 15 healthy *** expression level of the 5-HT2B receptor in colon tissue was measured using an enzyme-linked immunosorbent assay and correlated with abdominal pain *** IBS-D rat model was induced by intracolonic instillation of acetic acid and wrap *** in visceral sensitivity and 5-HT2B receptor and transient receptor potential vanilloid type 1(TRPV1)expression were examined following 5-HT2B receptor antagonist *** in visceral sensitivity after administration of the TRPV1 antago-INTRODUCTION Irritable bowel syndrome(IBS)is a chronic functional bowel disorder characterized by recurrent abdominal pain with altered bowel habits that affects approximately 15%of the population worldwide[1].IBS significantly impacts the quality of life of *** the pathogenesis of IBS is not completely understood,the role of abnormal visceral sensitivity in IBS has recently emerged[2,3].5-Hydroxytryptamine(5-HT)is known to play a key role in the physiological states of the gastrointestinal *** 5-HT levels in IBS with diarrhea(IBS-D)patients were greater than those in healthy controls[4],suggesting a possible role of 5-HT in the pathogenesis of *** serotonin receptor 2(5-HT2 receptor)family comprises three subtypes:5-HT2A,5-HT2B,and *** 5-HT2 receptors exhibit 46%-50%overall sequence identity,and all of these receptors preferentially bind to Gq/

关键词： Diarrhea-predominant irritable bowel syndrome Serotonin receptor 2B Transient receptor potential vanilloid type-1 Visceral hypersensitivity Abdominal pain

The prognostic value of collateral circulation in coronary chronic total occlusion underwent percutaneous coronary intervention

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Journal of Geriatric Cardiology 2024年第2期21卷 232-241页

作者： Xiao-Ying hu Wei-xian YANG Chang-Dong GUAN Li-hua XIE Ke-Fei DOU Yong-Jian WU Jin-qing YUAN Jie QIAN Yue-Jin YANG Shu-Bin QIAO Lei SONG Department of Cardiology Fuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina National Clinical Research Center for Cardiovascular Diseases BeijingChina Catheterization Laboratories Fuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina

BACKGROUND The prognostic value of coronary collateral circulation(CC)in patients undergoing chronic total occlusion(CTO)percutaneous coronary intervention(PCI)is *** purpose of the study was to assess the prognostic value of current two CC grading systems and their association with long-term outcomes in patients with CTO underwent *** We consecutively enrolled patients with single-vessel CTO underwent PCI between January 2010 and *** patients were categorized into well-developed or poor-developed collaterals group according to angiographic Werner's CC(grade 2 *** 0–1)or Rentrop(grade 3 *** 0–2)grading *** primary endpoint was 5-year cardiac *** Of 2452 enrolled patients,the overall technical success rate was 74.1%.Well-developed collaterals were present in686 patients(28.0%)defined by Werner's CC grade 2,and in 1145 patients(46.7%)by Rentrop grade *** to Werner's CC grading system,patients with well-developed collaterals had a lower rate of 5-year cardiac death compared with those with poordeveloped collaterals(1.6%vs.3.3%,P=0.02),those with suboptimal recanalization was associated with higher rate of 5-year cardiac death compared with optimal recanalization(4.7%vs.0.8%,P=0.01)and failure patients(4.7%vs.1.6%,P=0.12).However,the similar effect was not shown in Rentrop grading *** In patients with the single-vessel CTO underwent PCI,well-developed collaterals by Werner's CC definition were associated with lower rate of 5-year cardiac ***'s CC grading system had a greater prognostic value than Rentrop grading system in patients with CTO underwent PCI.

关键词： coronary collateral occlusion

Liposomalα-cyperone targeting bone resorption surfaces suppresses osteoclast differentiation and osteoporosis progression via the PI3K/Akt axis

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Nano Research 2024年第4期17卷 2949-2959页

作者： Lin Yang Xueying An Wang Gong Wenshu Wu Bin Liu Xiaoyan Shao Yansi xian Rui Peng Baosheng Guo qing Jiang Division of Sports Medicine and Adult Reconstructive Surgery Department of Orthopedic SurgeryNanjing Drum Tower Hospital Clinical College of Nanjing Medical University321 Zhongshan RoadNanjing 210008China Branch of National Clinical Research Center for Orthopedics Sports Medicine and RehabilitationNanjing 210008China State Key Laboratory of Pharmaceutical Biotechnology Medical SchoolNanjing University&Division of Sports Medicine and Adult Reconstructive SurgeryDepartment of Orthopedic SurgeryNanjing Drum Tower HospitalThe Affiliated Hospital of Nanjing University Medical SchoolNanjing 210008China

Osteoporosis is a metabolic dysregulation of bone that occurs mainly in postmenopausal women,and the hyperfunction of osteoclasts is the primary contributor to postmenopausal ***,the development of effective therapeutic drugs and precise delivery systems remains a challenge in the field of anti-absorption ***,we reported theα-cyperone(α-CYP)for anti-osteoporosis and developed a liposome-based nano-drug delivery system ofα-CYP,that specifically targets the bone resorption ***,we found that theα-CYP,one of the major sesquiterpenes of Cyperus rotundus L.,attenuated the progression of osteoporosis in ovariectomized(OVX)mice and down-regulated the expression of phosphorylated proteins of phosphoinositide 3-kinase(PI3K)and protein kinase B(Akt),causing down-regulation of osteoclast-related genes/proteins and curbing osteoclast ***,α-CYP reversed the activation of osteoclastic differentiation and enhanced osteoporosis-related proteins expression caused by PI3K/Akt agonist(YS-49).More importantly,we adopted the osteoclastic resorption surface targeting peptide Asp8 and constructed the liposome(lipαC@Asp8)to deliverα-CYP to osteoclasts and confirmed its anti-osteoporosis effect and enhanced osteoclast inhibition by blocking PI3K/Akt *** conclusion,this study demonstrated thatα-CYP inhibits osteoclast differentiation and osteoporosis development by silencing PI3K/Akt pathway,and the liposome targeting delivery systems loaded withα-CYP might provide a novel and effective strategy to treat osteoporosis.

关键词： osteoporosis α-cyperone osteoclast phosphoinositide 3-kinase/protein kinase B(PI3K/Akt) liposome

Design of weak current measurement system and research on temperature impact

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Nuclear Science and Techniques 2024年第4期35卷 46-56页

作者： Chu-xiang Zhao San-Gang Li Rong-Rong Su Li Yang Ming-Zhe Liu qing-Yue Xue Shan Liao Zhi Zhou qing-Shan Tan xian-Guo Tuo Yi Cheng College of Nuclear Technology and Automation Engineering Chengdu University of Technology1#DongsanluErxianqiaoChengdu 610059China Applied Nuclear Technology in Geosciences Key Laboratory of Sichuan Province Chengdu University of Technology1#DongsanluErxianqiaoChengdu 610059China University of Science and Technology of China Hefei 230026China School of Physics and Electronic Engineering Sichuan University of Science and EngineeringZigong 643000China

A dedicated weak current measurement system was designed to measure the weak currents generated by the neutron ionization *** system incorporates a second-order low-pass filter circuit and the Kalman filtering algorithm to effectively filter out noise and minimize interference in the measurement *** conducted under normal temperature conditions has demonstrated the system's high precision ***,it was observed that temperature variations can affect the measurement *** were collected across temperatures ranging from -20 to 70℃,and a temperature correction model was established through linear regression fitting to address this *** feasibility of the temperature correction model was confirmed at temperatures of -5 and 40℃,where relative errors remained below 0.1% after applying the temperature *** research indicates that the designed measurement system exhibits excellent temperature adaptability and high precision,making it particularly suitable for measuring weak currents.

关键词： Weak current measurement system Neutron ionization chamber Kalman filter algorithm Temperature correction model