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Evaluation of power regeneration in primary suspension for a railway vehicle

Ruichen WANG, Zhiwei WANG

《机械工程前沿（英文）》 2020年 第15卷 第2期   页码 265-278 doi: 10.1007/s11465-019-0571-9

摘要： To improve the fuel economy of rail vehicles, this study presents the feasibility of using power regenerating dampers (PRDs) in the primary suspension systems of railway vehicles and evaluates the potential and recoverable power that can be obtained. PRDs are configured as hydraulic electromagnetic-based railway primary vertical dampers and evaluated in parallel and series modes (with and without a viscous damper). Hydraulic configuration converts the linear behavior of the track into a unidirectional rotation of the generator, and the electromagnetic configuration provides a controllable damping force to the primary suspension system. In several case studies, generic railway vehicle primary suspension systems that are configured to include a PRD in the two configuration modes are modeled using computer simulations. The simulations are performed on measured tracks with typical irregularities for a generic UK passenger route. The performance of the modified vehicle is evaluated with respect to key performance indicators, including regenerated power, ride comfort, and running safety. Results indicate that PRDs can simultaneously replace conventional primary vertical dampers, regenerate power, and exhibit desirable dynamic performance. A peak power efficiency of 79.87% is theoretically obtained in series mode on a top-quality German Intercity Express track (Track 270) at a vehicle speed of 160 mile/h (~257 km/h).

关键词： railway vehicle     primary damper     power regeneration     ride comfort     running safety    

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Evaluation of a developed bypass viscous damper performance

Mahrad FAHIMINIA, Aydin SHISHEGARAN

《结构与土木工程前沿（英文）》 2020年 第14卷 第3期   页码 773-791 doi: 10.1007/s11709-020-0627-2

摘要： In this study, the dynamic behavior of a developed bypass viscous damper is evaluated. Bypass viscous damper has a flexible hose as an external orifice through which the inside fluid transfer from one side to the other side of the inner piston. Accordingly, the viscosity coefficient of the damper can be adjusted using geometrical dimensions of the hose. Moreover, the external orifice acts as a thermal compensator and alleviates viscous heating of the damper. According to experimental results, Computational Fluid Dynamic (CFD) model, a numerical formula and the simplified Maxwell model are found and assessed; therefore, the verification of numerical and computational models are evaluated for simulating. Also, a simplified procedure is proposed to design structures with bypass viscous dampers. The design procedure is applied to design an 8-story hospital structure with bypass viscous dampers, and it is compared with the same structure, which is designed with concentric braces and without dampers. Nonlinear time history analyses revealed that the hospital with viscous damper experiences less structural inelastic demands and fewer story accelerations which mean fewer demands on nonstructural elements. Moreover, seismic behaviors of nonstructural masonry claddings are also compared in the cases of hospital structure with and without dampers.

关键词： developed viscous damper     external orifice     energy dissipation     seismic behavior     CFD model of viscous damper     a simplified model    

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Parametric control of structural responses using an optimal passive tuned mass damper under stationary

Min-Ho CHEY, Jae-Ung KIM

《结构与土木工程前沿（英文）》 2012年 第6卷 第3期   页码 267-280 doi: 10.1007/s11709-012-0170-x

摘要： In this study, the structural control strategy utilizing a passive tuned mass damper (TMD) system as a seismic damping device is outlined, highlighting the parametric optimization approach for displacement and acceleration control. The theory of stationary random processes and complex frequency response functions are explained and adopted. For the vibration control of an undamped structure, the optimal parameters of a TMD, such as the optimal tuning frequency and optimal damping ratio, to stationary Gaussian white noise acceleration are investigated by using a parametric optimization procedure. For damped structures, a numerical searching technique is used to obtain the optimal parameters of the TMD, and then the explicit formulae for these optimal parameters are derived through a sequence of curve-fitting schemes. Using these specified optimal parameters, several different controlled responses are examined, and then the displacement and acceleration based control effectiveness indices of the TMD are examined from the view point of RMS values. From the viewpoint of the RMS values of displacement and acceleration, the optimal TMDs adopted in this study shows clear performance improvements for the simplified model examined, and this means that the effective optimization of the TMD has a good potential as a customized target response-based structural strategy.

关键词： tuned mass damper     parametric optimization     passive control     white noise     earthquake excitation    

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Hysteretic behavior of cambered surface steel tube damper: Theoretical and experimental research

《结构与土木工程前沿（英文）》 2023年 第17卷 第4期   页码 606-624 doi: 10.1007/s11709-023-0925-6

摘要： A novel cambered surface steel tube damper (CSTD) with a cambered surface steel tube and two concave connecting plates is proposed herein. The steel tube is the main energy dissipation component and comprises a weakened segment in the middle, a transition segment, and an embedded segment. It is believed that during an earthquake, the middle weakened segment of the CSTD will be damaged, whereas the reliability of the end connection is ensured. Theoretical and experimental studies are conducted to verify the effectiveness of the proposed CSTD. Formulas for the initial stiffness and yield force of the CSTD are proposed. Subsequently, two CSTD specimens with different steel tube thicknesses are fabricated and tested under cyclic quasi-static loads. The result shows that the CSTD yields a stable hysteretic response and affords excellent energy dissipation. A parametric study is conducted to investigate the effects of the steel tube height, diameter, and thickness on the seismic performance of the CSTD. Compared with equal-stiffness design steel tube dampers, the CSTD exhibits better energy dissipation performance, more stable hysteretic response, and better uniformity in plastic deformation distributions.

关键词： cambered surface steel tube damper     energy dissipation capacity     finite element model     hysteretic performance     parametric study    

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Dynein axonemal heavy chain 10 deficiency causes primary ciliary dyskinesia in humans and mice

《医学前沿（英文）》   页码 957-971 doi: 10.1007/s11684-023-0988-8

摘要： Primary ciliary dyskinesia (PCD) is a congenital, motile ciliopathy with pleiotropic symptoms. Although nearly 50 causative genes have been identified, they only account for approximately 70% of definitive PCD cases. Dynein axonemal heavy chain 10 (DNAH10) encodes a subunit of the inner arm dynein heavy chain in motile cilia and sperm flagella. Based on the common axoneme structure of motile cilia and sperm flagella, DNAH10 variants are likely to cause PCD. Using exome sequencing, we identified a novel DNAH10 homozygous variant (c.589C > T, p.R197W) in a patient with PCD from a consanguineous family. The patient manifested sinusitis, bronchiectasis, situs inversus, and asthenoteratozoospermia. Immunostaining analysis showed the absence of DNAH10 and DNALI1 in the respiratory cilia, and transmission electron microscopy revealed strikingly disordered axoneme 9+2 architecture and inner dynein arm defects in the respiratory cilia and sperm flagella. Subsequently, animal models of Dnah10-knockin mice harboring missense variants and Dnah10-knockout mice recapitulated the phenotypes of PCD, including chronic respiratory infection, male infertility, and hydrocephalus. To the best of our knowledge, this study is the first to report DNAH10 deficiency related to PCD in human and mouse models, which suggests that DNAH10 recessive mutation is causative of PCD.

关键词： DNAH10     mice     motile cilia     mutation     primary ciliary dyskinesia    

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Effect of magneto rheological damper on tool vibration during hard turning

P. Sam PAUL, A. S. VARADARAJAN

《机械工程前沿（英文）》 2012年 第7卷 第4期   页码 410-416 doi: 10.1007/s11465-012-0341-4

摘要：

Recently, the concept of hard turning has gained considerable attention in metal cutting as it can apparently replace the traditional process cycle of turning, heat treating, and finish grinding for assembly of hard wear resistant steel parts. The present investigation aims at developing a magneto rheological (MR) fluid damper for suppressing tool vibration and promoting better cutting performance during hard turning. The magneto rheological Fluid acts as a viscoelastic spring with non-linear vibration characteristics that are controlled by the composition of the magneto rheological fluid, the shape of the plunger and the electric parameters of the magnetizing field. Cutting experiments were conducted to arrive at a set of electrical, compositional and shape parameters that can suppress tool vibration and promote better cutting performance during turning of AISI 4340 steel of 46 HRC with minimal fluid application using hard metal insert with sculptured rake face. It was observed that the use of MR fluid damper reduces tool vibration and improves the cutting performance effectively. Also commercialization of this idea holds promise to the metal cutting industry.

关键词： tool vibration     magneto rheological damper     hard turning     surface finish     tool wear    

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Analytical study on damping performances of magnetorheological grease damper based on disk squeeze mode

Danxia ZHAO, Changrong LIAO, Qiong LIU, Jing LUO

《机械工程前沿（英文）》 2011年 第6卷 第3期   页码 312-317 doi: 10.1007/s11465-011-0235-x

摘要：

In this paper, a small displacement-type magnetorheological grease (MRG) damper based on disk squeeze mode is proposed. The squeeze flow differential equation is obtained. The Navier slip condition is considered on the surfaces and the boundary compatible condition is established. The radial velocity profiles and the radial pressure distributions are derived respectively, and the mathematical stress expression is calculated. To verify rationality of analytical method, the MRG damper is designed and fabricated according to the technical requirements of an engine vibration isolation system. The experimental damping force from MTS870 Electro-hydraulic Servo with sine wave excitation shows that the proposed analytical method is feasible and provides the reference value for designing MRG damper based on disk squeeze mode.

关键词： magnetorheological grease (MRG)     damper     squeeze model    

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Application of coupled multi-body dynamics–discrete element method for optimization of particle damper

Danhui DAN, Qianqing WANG, Jiongxin GONG

《结构与土木工程前沿（英文）》 2021年 第15卷 第1期   页码 244-252 doi: 10.1007/s11709-021-0696-x

摘要： With the application of the particle damping technology to cable vibration attenuation, the rootless cable damper overcomes the limit in installation height of existing dampers. Damping is achieved through energy dissipation by collisions and friction. In this paper, a coupled multi-body dynamics–discrete element method is proposed to simulate the damping of the damper–cable system under a harmonic excitation. The analyses are done by combining the discrete element method in EDEM and multi-body dynamics in ADAMS. The simulation results demonstrate the damping efficiency of rootless particle damper under different excitations and reveal the influence of the design parameters on its performance, including the filling ratio, particle size, coefficient of restitution, and coefficient of friction.

关键词： granular material     vibration control     discrete element method     particle damper     cable vibration    

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Approach for natural gas to be a primary energy source in China

Weihe HUANG, Jindian CHEN, Chuan FU, Yan HUANG

《工程管理前沿（英文）》 2019年 第6卷 第4期   页码 467-476 doi: 10.1007/s42524-019-0068-6

摘要： This work reveals the positioning of natural gas in the evolution of world energy and the general law of its development. In the long-term adjustment of energy structure, natural gas has gradually become the primary energy source because of five factors: policy, resources, technology, facilities, and market. To expedite the revolution of energy production and consumption, China must urgently expand the use of natural gas toward a more positive role in complementing coal and renewable energy and prioritize its usage in three areas, namely, urban gas, power generation, and industrial fuel. Natural gas is expected to account for approximately 15% of China’s total energy consumption in the future. For natural gas to be the primary energy, the exploitation of gas resources must be expanded, resource access must be improved, a flexible trade system must be set up, infrastructure investment must be increased, and the security system must be enhanced.

关键词： natural gas     energy revolution     primary energy     utilization areas     approaching means    

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Effect of traditional Chinese medicine combined with Western therapy on primary hepatic carcinoma: a

null

《医学前沿（英文）》 2017年 第11卷 第2期   页码 191-202 doi: 10.1007/s11684-017-0512-0

摘要：

Primary hepatic carcinoma (PHC) is a common malignant tumor in China. Cancer is comprehensively treated with various therapeutic regimes, including traditional Chinese medicine (TCM). TCM has been widely used to improve the quality of life, delay the time of cancer progression, and prolong the median survival time. This systematic review with meta-analysis aimed to assess the effect of TCM combined with Western therapy on primary hepatic carcinoma. A comprehensive literature search was conducted in six databases, including CNKI, VIP, Wan-Fang Database, CBM, PubMed, and Cochrane library. A total of 44 randomized controlled trials (RCTs) involving 3429 participants suffering from PHC were selected. Meta-analysis results indicated that the overall effect of TCM and Western integrative treatment on PHC was higher than that of Western intervention alone, which can postpone tumor recurrence and metastasis and prolong the overall survival time of patients with PHC. Although the obtained evidence remained weak because of the poor methodological quality of the included studies, this review provided relevant data supporting the efficacy and safety of TCM combined with Western therapies. In future research, individual RCT studies should incorporate accepted standards for trial design and reporting, proper outcome indicators according to international standards, blinding in allocation concealment, and valid follow-up periods.

关键词： traditional Chinese medicine     primary hepatic carcinoma     meta-analysis    

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Tuning the primary selective nanochannels of MOF thin-film nanocomposite nanofiltration membranes for

《环境科学与工程前沿（英文）》 2022年 第16卷 第4期 doi: 10.1007/s11783-021-1474-7

摘要：

• PA layer properties tune the primary nanochannels in MIL-101(Cr) TFN NF membranes.

关键词： Porous metal organic framework     Thin-film nanocomposite membrane     Primary selective nanochannels     Nanofiltration     Endocrine disrupting compounds    

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Primary hypertrophic osteoarthropathy: an update

null

《医学前沿（英文）》 2013年 第7卷 第1期   页码 60-64 doi: 10.1007/s11684-013-0246-6

摘要：

Digital clubbing, which has been recognized as a sign of systemic disease, is one of the most ancient diseases. However, the pathogenesis of clubbing and hypertrophic osteoarthropathy has hitherto been poorly understood. The study of a clinically indistinguishable idiopathic form (primary hypertrophic osteoarthropathy, PHO) provides an opportunity to understand the pathogenesis of hypertrophic osteoarthropathy. Current advances in the study of PHO are discussed. The impaired metabolism of prostaglandin E2 (PGE2) plays a central role in its pathogenesis.

关键词： digital clubbing     primary hypertrophic osteoarthropathy     prostaglandin E2 (PGE2)    

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Case report of neurofibromatosis type 1 combined with primary ciliary dyskinesia

《医学前沿（英文）》 2021年 第15卷 第6期   页码 933-937 doi: 10.1007/s11684-021-0860-7

摘要： Neurofibromatosis (NF) is a genetic disease in which the lungs are rarely involved. However, in NF cases with lung involvement, chest computed tomography may show bilateral basal reticulations, apical bullae, and cysts without bronchiectasis. Herein, we report a patient diagnosed with NF on the basis of the results of genetic testing who presented with early-onset wet cough and bronchiectasis. Considering the differential diagnosis of bronchiectasis combined with his early-onset wet cough, sinusitis, and sperm quality decline, we considered the possibility of primary ciliary dyskinesia (PCD). Further electron microscopy analysis of cilia and identification of homozygous mutations in the RSPH4A gene confirmed the diagnosis of PCD. Therefore, for patients with NF, when an image change exists in the lungs that does not correspond to NF, the possibility of other diagnoses, including PCD, must be considered.

关键词： primary ciliary dyskinesia     neurofibromatosis     bronchiectasis     transmission electron microscopy     genetic sequencing    

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Diagnostic evaluation of plasma aldosterone concentration to plasma renin activity ratio in primary aldosteronism

ZHANG Huilan, WANG Daowen

《医学前沿（英文）》 2008年 第2卷 第1期   页码 11-14 doi: 10.1007/s11684-008-0003-4

摘要： Using the plasma aldosterone concentration to plasma renin activity ratio (PAC/PRA ratio) as the screening test of choice for primary aldosteronism in hypertensive patients, we studied the clinical characteristics and the diagnostic value of PAC/PRA ratio in primary aldosteronism. The plasma aldosterone concentration (PAC) and plasma renin activity (PRA) levels were measured by radioimmunoassay in 902 hypertensive patients from out-patient clinics or hospitals. One hundred and twenty-six suspected primary aldosteronism patients whose PAC/PRA ratio was > 25 ng/dL/ng/mL/hr had a lamellar computed tomography (CT) scan in the adrenal gland and follow-up visits. The proportion of primary aldosteronism in hypertensive patients was 14% (126/902). There were 54 patients with unilateral or bilateral hyperplasia and 25 patients with adenoma according to the CT scan. 39% (49/126) of the patients with primary aldosteronism had hypokalemia. Twenty-five patients received surgical treatment. The efficacy and cure rates were 100% (25/25) and 48% (12/25), respectively. The effective rate of aldactone and the single-drug cure rate were 89% (48/54) and 24% (13/54), respectively. Primary aldosteronism affects over 10% of hypertensive patients in China. The PAC/PRA ratio can be considered as a routine screening test in hypertensives, especially resistant hypertensive patients and a high PAC/PRA ratio is an invaluable index in primary aldosteronism diagnosis.
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Lack of CFAP54 causes primary ciliary dyskinesia in a mouse model and human patients

《医学前沿（英文）》 doi: 10.1007/s11684-023-0997-7

摘要： Primary ciliary dyskinesia (PCD) is a highly heterogeneous recessive inherited disorder. FAP54, the homolog of CFAP54 in Chlamydomonas reinhardtii, was previously demonstrated as the C1d projection of the central microtubule apparatus of flagella. A Cfap54 knockout mouse model was then reported to have PCD-relevant phenotypes. Through whole-exome sequencing, compound heterozygous variants c.2649_2657delinC (p. E883Dfs*47) and c.7312_7313insCGCAGGCTGAATTCTTGG (p. T2438delinsTQAEFLA) in a new suspected PCD-relevant gene, CFAP54, were identified in an individual with PCD. Two missense variants, c.4112A>C (p. E1371A) and c.6559C>T (p. P2187S), in CFAP54 were detected in another unrelated patient. In this study, a minigene assay was conducted on the frameshift mutation showing a reduction in mRNA expression. In addition, a CFAP54 in-frame variant knock-in mouse model was established, which recapitulated the typical symptoms of PCD, including hydrocephalus, infertility, and mucus accumulation in nasal sinuses. Correspondingly, two missense variants were deleterious, with a dramatic reduction in mRNA abundance from bronchial tissue and sperm. The identification of PCD-causing variants of CFAP54 in two unrelated patients with PCD for the first time provides strong supportive evidence that CFAP54 is a new PCD-causing gene. This study further helps expand the disease-associated gene spectrum and improve genetic testing for PCD diagnosis in the future.

关键词： primary ciliary dyskinesia     CFAP54     cilia    

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标题 作者 时间 类型 操作

Evaluation of power regeneration in primary suspension for a railway vehicle

Ruichen WANG, Zhiwei WANG

期刊论文

Evaluation of a developed bypass viscous damper performance

Mahrad FAHIMINIA, Aydin SHISHEGARAN

期刊论文

Parametric control of structural responses using an optimal passive tuned mass damper under stationary

Min-Ho CHEY, Jae-Ung KIM

期刊论文

Hysteretic behavior of cambered surface steel tube damper: Theoretical and experimental research

期刊论文

Dynein axonemal heavy chain 10 deficiency causes primary ciliary dyskinesia in humans and mice

期刊论文

Effect of magneto rheological damper on tool vibration during hard turning

P. Sam PAUL, A. S. VARADARAJAN

期刊论文

Analytical study on damping performances of magnetorheological grease damper based on disk squeeze mode

Danxia ZHAO, Changrong LIAO, Qiong LIU, Jing LUO

期刊论文

Application of coupled multi-body dynamics–discrete element method for optimization of particle damper

Danhui DAN, Qianqing WANG, Jiongxin GONG

期刊论文

Approach for natural gas to be a primary energy source in China

Weihe HUANG, Jindian CHEN, Chuan FU, Yan HUANG

期刊论文

Effect of traditional Chinese medicine combined with Western therapy on primary hepatic carcinoma: a

null

期刊论文

Tuning the primary selective nanochannels of MOF thin-film nanocomposite nanofiltration membranes for

期刊论文

Primary hypertrophic osteoarthropathy: an update

null

期刊论文

Case report of neurofibromatosis type 1 combined with primary ciliary dyskinesia

期刊论文

Diagnostic evaluation of plasma aldosterone concentration to plasma renin activity ratio in primary aldosteronism

ZHANG Huilan, WANG Daowen

期刊论文

Lack of CFAP54 causes primary ciliary dyskinesia in a mouse model and human patients

期刊论文