资源类型

期刊论文 46

年份

2024 3

2023 4

2022 3

2021 3

2020 3

2019 4

2018 3

2017 2

2016 1

2015 2

2013 1

2010 4

2009 3

2008 1

2007 2

2005 2

2004 1

2003 1

2000 2

展开 ︾

关键词

Matlab 1

RLC网络；谐振性质；振荡特性；幅频特性 1

三星一线 1

中性原子量子计算 1

人工增雨 1

人工影响天气 1

人工消雾 1

人工表面等离激元 1

人工防雹 1

人脑功能磁共振 1

传递函数 1

低导热率 1

光量子计算 1

全氟化碳 1

共振检测 1

共振能量转移 1

内外因耦合 1

分布式量子计算 1

分数量子能级 1

展开 ︾

检索范围：

排序： 展示方式：

Fault tolerant control strategy for modular PWM current source inverter

《能源前沿（英文）》 2023年 第17卷 第2期   页码 228-238 doi: 10.1007/s11708-022-0852-6

摘要： In this paper, a fault-tolerant control method for an input-series output-parallel modular grid-tied pulse-width modulation (PWM) current source inverter is proposed to address the most commonly seen single symmetrical gate-commutated thyristor (SGCT) open-circuit fault problems. This method actively offsets the neutral point of the current space vector to ensure a sinusoidal output of the grid current, and it can achieve the upper limit power of the inverter under the condition of a single SGCT open-circuit fault. In addition, an active damping control method based on grid harmonic current feedback is proposed after analyzing the influence of the transformer ferromagnetic resonance caused by the neutral point offset on the power quality of the grid current. It has been demonstrated that the proposed method effectively suppresses the resonance caused by the transformer and the modified modulation, improving the grid current’s power quality.

关键词： current source converter (CSC)     fault-tolerant control     space vector modulation     active damping     resonance suppression     power quality    

HTML PDF 收藏

Electromagnetic interference modeling and suppression techniques in variable-frequency drive systems

Le YANG, Shuo WANG, Jianghua FENG

《机械工程前沿（英文）》 2018年 第13卷 第3期   页码 329-353 doi: 10.1007/s11465-018-0466-1

摘要：

Electromagnetic interference (EMI) causes electromechanical damage to the motors and degrades the reliability of variable-frequency drive (VFD) systems. Unlike fundamental frequency components in motor drive systems, high-frequency EMI noise, coupled with the parasitic parameters of the trough system, are difficult to analyze and reduce. In this article, EMI modeling techniques for different function units in a VFD system, including induction motors, motor bearings, and rectifier-inverters, are reviewed and evaluated in terms of applied frequency range, model parameterization, and model accuracy. The EMI models for the motors are categorized based on modeling techniques and model topologies. Motor bearing and shaft models are also reviewed, and techniques that are used to eliminate bearing current are evaluated. Modeling techniques for conventional rectifier-inverter systems are also summarized. EMI noise suppression techniques, including passive filter, Wheatstone bridge balance, active filter, and optimized modulation, are reviewed and compared based on the VFD system models.

关键词： variable-frequency drive (VFD)     electromagnetic interference (EMI)     motor drive modeling     EMI noise suppression    

HTML PDF 收藏

Polyethylene hydrogenolysis over bimetallic catalyst with suppression of methane formation

《化学科学与工程前沿（英文）》 doi: 10.1007/s11705-024-2461-x

摘要： Hydrogenolysis has been explored as a promising approach for plastic chemical recycling. Noble metals, such as Ru and Pt, are considered effective catalysts for plastic hydrogenolysis, however, they result in a high yield of low-value gaseous products. In this research, an efficient bimetallic catalyst was developed by separate impregnation of Ni and Ru on SiO2 support resulting in liquid products yield of up to 83.1 C % under mild reaction conditions, compared to the 65.5 C % yield for the sole noble metal catalyst. The carbon distribution of the liquid products from low density polyethylene hydrogenolysis with Ni-modified catalyst also shifted to a heavier fraction, compared to that with Ru catalyst. Meanwhile, the NiRu catalyst exhibited excellent performance in suppressing the cleavage of the end-chain C–C bond, leading to a methane yield of only 10.4 C %, which was 69% lower than that of the Ru/SiO2 catalyst. Temperature programmed reduction and desorption of hydrogen and propane were further conducted to reveal the detailed mechanism of low density polyethylene hydrogenolysis over the bimetallic catalyst. The results suggested that the Ni-Ru alloy exhibited stronger H adsorption properties indicating improved hydrogen coverage on the catalyst surface thus enhancing the desorption of reaction intermediates. The carbon number distribution was ultimately skewed toward heavier liquid products.

关键词： hydrogenolysis     polyethylene     bimetallic catalyst     depolymerization mechanism    

HTML PDF 收藏

Identification of cadmium-induced genes in maize seedlings by suppression subtractive hybridization

Quanlin DAI, Baifei HUANG, Zhongyi YANG, Jiangang YUAN, Junzhi YANG

《环境科学与工程前沿（英文）》 2010年 第4卷 第4期   页码 449-458 doi: 10.1007/s11783-010-0250-x

摘要： A maize variety, Huatian-1, had an unusually low translocation rate of cadmium (Cd) (59.6 mg·kg in the roots and 0.093 mg·kg in the grain) compared to 24 other varieties while being grown in soils with 16.50 mg·kg Cd. This indicates that this particular species may have special mechanisms that affect the absorption and translocation pattern of Cd. In this paper, the technique of suppression subtractive hybridization (SSH) was used to isolate and identify Cd-induced genes from Huatian-1 hydroponically ?exposed? to? 0.1 mM ?CdCl ?for? 1 h,? 12 h, 24 h, and 48 h. We found a total of 15 differentially expressed genes in the four groups; 2, 3, 4, and 6 genes were from the groups of 1 h, 12 h, 24 h, and 48 h treatment, respectively. Phospholipase mRNA, adenosine triphosphate (ATP) phosphoribosyl transferase 2, and were turned on in the maize in response to Cd stress, and it might provide new clues to explain the mechanism of maize tolerance to Cd.

关键词： Zea mays L.     cadmium (Cd)     suppression subtractive hybridization    

HTML PDF 收藏

Vibration suppression of speed-controlled robots with nonlinear control

Paolo BOSCARIOL,Alessandro GASPARETTO

《机械工程前沿（英文）》 2016年 第11卷 第2期   页码 204-212 doi: 10.1007/s11465-016-0380-3

摘要：

In this paper, a simple nonlinear control strategy for the simultaneous position tracking and vibration damping of robots is presented. The control is developed for devices actuated by speed-controlled servo drives. The conditions for the asymptotic stability of the closed-loop system are derived by ensuring its passivity. The capability of achieving improved trajectory tracking and vibration suppression is shown through experimental tests conducted on a three-axis Cartesian robot. The control is aimed to be compatible with most industrial applications given the simplicity of implementation, the reduced computational requirements, and the use of joint position as the only measured signal.

关键词： industrial robot     nonlinear control     vibration damping     model-free control     motion control    

HTML PDF 收藏

Multi-harmonic forced vibration and resonance of simple beams to moving vehicles

《结构与土木工程前沿（英文）》 2023年 第17卷 第7期   页码 981-993 doi: 10.1007/s11709-023-0979-5

摘要： This study modeled the moving-vehicle-induced forcing excitation on a single-span prismatic bridge as a multiple frequency-multiplication harmonic load on the modal coordinates of a linear elastic simple Euler–Bernoulli beam, and investigated the forced modal oscillation and resonance behavior of this type of dynamic system. The forced modal responses consist of multiple frequency-multiplication steady-state harmonics and one damped mono-frequency complementary harmonic. The analysis revealed that a moving load induces high-harmonic forced resonance amplification when the moving speed is low. To verify the occurrence of high-harmonic forced resonance, numerical tests were conducted on single-span simple beams based on structural modeling using the finite element method (FEM) and a moving sprung-mass oscillator vehicle model. The forced resonance amplification characteristics of the fundamental mode for beam response estimation are presented with consideration to different end restraint conditions. The results reveal that the high-harmonic forced resonance may be significant for the investigated beams subjected to vehicle loads moving at specific low speeds. For the investigated single-span simple beams, the moving vehicle carriage heaving oscillation modulates the beam modal frequency, but does not induce notable variation of the modal oscillation harmonic structure for the cases that vehicle of small mass moves in low speed.

关键词： forced vibration     linear Euler beam     moving load     harmonic structure     frequency modulation     end restraints    

HTML PDF 收藏

Sectional model test study on vortex-excited resonance of vehicle-bridge system of Shanghai Bridge over

Li ZHOU, Yaojun GE

《结构与土木工程前沿（英文）》 2009年 第3卷 第1期   页码 67-72 doi: 10.1007/s11709-009-0007-4

摘要： It is necessary to study how vehicles influence the vortex-excited resonance of vehicle-bridge systems, because lock-in wind speed is low and vortex-excited resonance is sensitive to any change in the main girder sections. Based on the Shanghai Bridge over the Yangtse River, the vortex-excited resonance of a 1∶60 scale sectional model was tested in a TJ-1wind tunnel, with or without vehicles at the attack angle of 0°, +3 and -3°, respectively. The conversion relationships between the resonant amplitudes of the sectional model and that of the prototype bridge were also established by mode shape correction. The result indicates that: 1) for the bridge with vehicles, the vertical vortex-excited resonance is accompanied by torsion vibration with the same frequency, and vice versa, 2) the amplitude of vortex-excited resonance of the bridge with vehicles is much larger than that of the bridge without vehicles, and 3) the lock-in wind speed of the vortex-excited resonance becomes smaller due to the disturbance of vehicles. It is obvious that vehicles bring about changes in the aerodynamic shape of the main girder. Therefore, the influence of vehicles on vortex-excited resonance performance of vehicle-bridge systems, in terms of both amplitude and mode, should not be ignored.

关键词： vehicle-bridge system     sectional mode     vortex-excited resonance     wind tunnel test     mode shape correction    

HTML PDF 收藏

Extended stochastic resonance (SR) and its applications in weak mechanical signal processing

Niaoqing HU, Min CHEN, Guojun QIN, Lurui XIA, Zhongyin PAN, Zhanhui FENG,

《机械工程前沿（英文）》 2009年 第4卷 第4期   页码 450-461 doi: 10.1007/s11465-009-0072-3

摘要： To catch symptoms of machine failure as early as possible, one of the most important strategies is to apply more progressive techniques during signal processing. This paper presents a method based on stochastic resonance (SR) to detect weak fault signal. First, a discrete model of a bistable system that can demonstrate SR is researched, and the stability condition for controlling the selection of model parameters of the discrete model and guarantee the solving convergence are established. Then, the frequency range of the weak signals that the SR model can detect is extended through a type of normalized scale transformation. Finally, the method is applied to extract the weak characteristic component from heavy noise to indicate the little crack fault in a bearing outer circle.

关键词： extended stochastic resonance (SR)     stability analysis of SR     scale transform     weak signal detection     incipient fault detection     envelope analysis    

HTML PDF 收藏

新型细水雾添加剂的制备及其灭火性能评价

刘江虹,金翔,廖光煊

《中国工程科学》 2010年 第12卷 第9期   页码 58-62

摘要：

在研究传统细水雾添加剂的基础上，取长补短，采用物理工艺制备出新型复合添加剂，针对典型火源（酒精池火、煤油池火与木垛火），改变添加剂浓度开展了一系列灭火实验。结果表明：新型复合添加剂显著增强了细水雾的灭火性能，可提高灭火时间5～8倍。随着细水雾中添加剂含量的不断增加，油池火的灭火时间呈现出先快速下降，而后略微增长的趋势；而木垛火的灭火时间表现为平缓下降，并趋于稳定。含新型复合添加剂的细水雾灭火是物理化学复合作用机制，但主导灭火机理是燃料表面的冷却与隔离作用。

关键词： 细水雾     添加剂     制备     灭火性能    

HTML PDF 收藏

Discovery of the mechanisms of acupuncture in the treatment of migraine based on functional magnetic resonance

《医学前沿（英文）》 2023年 第17卷 第5期   页码 993-1005 doi: 10.1007/s11684-023-0989-7

摘要： Migraine is one of the most prevalent and disabling neurological disease, but the current pharmacotherapies show limited efficacy and often accompanied by adverse effects. Acupuncture is a promising complementary therapy, but further clinical evidence is needed. The influence of acupuncture on migraine is not an immediate effect, and its mechanism remains unclear. This study aims to provide further clinical evidence for the anti-migraine effects of acupuncture and explore the mechanism involved. A randomized controlled trial was performed among 10 normal controls and 38 migraineurs. The migraineurs were divided into blank control, sham acupuncture, and acupuncture groups. Patients were subjected to two courses of treatment, and each treatment lasted for 5 days, with an interval of 1 day between the two courses. The effectiveness of treatment was evaluated using pain questionnaire. The functional magnetic resonance imaging (fMRI) data were analyzed for investigating brain changes induced by treatments. Blood plasma was collected for metabolomics and proteomics studies. Correlation and mediation analyses were performed to investigate the interaction between clinical, fMRI and omics changes. Results showed that acupuncture effectively relieved migraine symptoms in a way different from sham acupuncture in terms of curative effect, affected brain regions, and signaling pathways. The anti-migraine mechanism involves a complex network related to the regulation of the response to hypoxic stress, reversal of brain energy imbalance, and regulation of inflammation. The brain regions of migraineurs affected by acupuncture include the lingual gyrus, default mode network, and cerebellum. The effect of acupuncture on patients’ metabolites/proteins may precede that of the brain.

关键词： acupuncture     migraine     fMRI     metabolome     proteome    

HTML PDF 收藏

A convolutional neural network based approach to sea clutter suppression for small boat detection

Guan-qing Li, Zhi-yong Song, Qiang Fu,liguanqing09@nudt.edu.cn,songzhiyong08@nudt.edu.cn

《信息与电子工程前沿（英文）》 2020年 第21卷 第10期   页码 1413-1534 doi: 10.1631/FITEE.1900523

摘要： Current methods for radar target detection usually work on the basis of high signal-to-clutter ratios. In this paper we propose a novel convolutional neural network based dual-activated clutter suppression algorithm, to solve the problem caused by low signal-to-clutter ratios in actual situations on the sea surface. Dual activation has two steps. First, we multiply the activated weights of the last dense layer with the activated feature maps from the upsample layer. Through this, we can obtain the s (CAMs), which correspond to the positive region of the sea clutter. Second, we obtain the suppression coefficients by mapping the CAM inversely to the sea clutter spectrum. Then, we obtain the activated range-Doppler maps by multiplying the coefficients with the raw range-Doppler maps. In addition, we propose a sampling-based data augmentation method and an effective multiclass coding method to improve the prediction accuracy. Measurement on real datasets verified the effectiveness of the proposed method.
HTML PDF 收藏

Improvement of engine performance with high compression ratio based on knock suppression using Miller

Haiqiao WEI, Jie YU, Lei ZHOU

《能源前沿（英文）》 2019年 第13卷 第4期   页码 691-706 doi: 10.1007/s11708-019-0621-3

摘要： In theory, high compression ratio has the potential to improve the thermal efficiency and promote the power output of the SI engine. However, the application of high compression ratio is substantially limited by the knock in practical working process. The objective of this work is to comprehensively investigate the application of high compression ratio on a gasoline engine based on the Miller cycle with boost pressure and split injection. In this work, the specific optimum strategies for CR10 and CR12 were experimentally investigated respectively on a single cylinder DISI engine. It was found that a high level of Miller cycle with a higher boost pressure could be used in CR12 to achieve an effective compression ratio similar to CR10, which could eliminate the knock limits at a high compression ratio and high load. To verify the advantages of the high compression ratio, the fuel economy and power performance of CR10 and CR12 were compared at full and partial loads. The result revealed that, compared with CR10, a similar power performance and a reduced fuel consumption of CR12 at full load could be achieved by using the strong Miller cycle and split injection. At partial load, the conditions of CR12 had very superior fuel economy and power performance compared to those of CR10.

关键词： high compression ratio     knock     Miller cycle     split injection     engine performance    

HTML PDF 收藏

Growth suppression of colorectal cancer expressing S492R EGFR by monoclonal antibody CH12

Qiongna Dong, Bizhi Shi, Min Zhou, Huiping Gao, Xiaoying Luo, Zonghai Li, Hua Jiang

《医学前沿（英文）》 2019年 第13卷 第1期   页码 83-93 doi: 10.1007/s11684-019-0682-z

摘要：

Colorectal cancer (CRC) is a common malignant tumor in the digestive tract, and 30%–85% of CRCs express epidermal growth factor receptors (EGFRs). Recently, treatments using cetuximab, also named C225, an anti-EGFR monoclonal antibody, for CRC have been demonstrated to cause an S492R mutation in EGFR. However, little is known about the biological function of S492R EGFR. Therefore, we attempted to elucidate its biological function in CRC cells and explore new treatment strategies for this mutant form. Our study indicated that EGFR and S492R EGFR accelerate the growth of CRC cells in vitro and in vivo and monoclonal antibody CH12, which specifically recognizes an EGFR tumor-specific epitope, can bind efficiently to S492R EGFR. Furthermore, mAb CH12 showed significantly stronger growth suppression activities and induced a more potent antibody-dependent cellular cytotoxicity effect on CRC cells bearing S492R EGFR than mAb C225. mAb CH12 obviously suppressed the growth of CRC xenografts with S492R EGFR mutations in vivo. Thus, mAb CH12 may be a promising therapeutic agent in treating patients with CRC bearing an S492R EGFR mutation.

关键词： S492R EGFR ectodomain mutation     colorectal cancer     mAb CH12     immunnotherapy    

HTML PDF 收藏

脉冲水射流水力共振设计

蒲家宁,陈明

《中国工程科学》 2009年 第11卷 第2期   页码 36-42

摘要：

在导管首端设置正弦脉冲流发生器，下游某处设置空气室，精心构建系统条件造成水力共振，使喷 嘴处脉冲射流的压力振幅大大提高。系统的数学物理模型用水力瞬变特征线有限差分方程建立，变时步方法解算。最优水力共振条件用Matlab直接搜索算法搜寻。正弦脉冲流发生器由恒流泵和正弦容积变化活塞 缸构成，电动活塞泵用凸轮传动给出恒定流量，活塞缸活塞用凸轮或曲轴连杆传动使缸容正弦变化。

关键词： 脉冲水射流     水力共振     特征线解法     变时步法     Matlab     直接搜寻算法     正弦脉冲流发生器    

HTML PDF 收藏

基于改进无传感器反馈控制方法的电磁振动器振动谐波抑制技术 Research Article

李伟1,2,崔俊宁1,2,边星元1,2,邹丽敏1,2

《信息与电子工程前沿（英文）》 2024年 第25卷 第3期   页码 472-483 doi: 10.1631/FITEE.2300031

摘要： 为实现电磁振动器低谐波失真振动波形输出，提出一种基于改进无传感器反馈控制方法的电磁振动器振动谐波抑制技术。在不改变原驱动电路的情况下，利用驱动线圈的交流等效电阻获得高精度的振动速度信息，建立简单可靠的无传感器速度反馈控制系统。通过研究不同关键参数值对系统的影响，有效扩展了低频振动速度特性频带，增强了速度反馈控制的谐波抑制能力。进行了大量实验来证明所提出的方法的有效性，并与传统的控制方法进行比较。在0.01 Hz至1.00 Hz的频率范围内开展对比实验，实验结果表明，所提出的方法与开环控制相比可以将振动波形的谐波失真降低约40%，与传统的无传感器反馈控制方法相比可以将谐波失真降低20%。

关键词： 振动校准；电磁振动器；谐波抑制；无传感器控制方法；速度反馈控制    

HTML PDF 收藏

标题 作者 时间 类型 操作

Fault tolerant control strategy for modular PWM current source inverter

期刊论文

Electromagnetic interference modeling and suppression techniques in variable-frequency drive systems

Le YANG, Shuo WANG, Jianghua FENG

期刊论文

Polyethylene hydrogenolysis over bimetallic catalyst with suppression of methane formation

期刊论文

Identification of cadmium-induced genes in maize seedlings by suppression subtractive hybridization

Quanlin DAI, Baifei HUANG, Zhongyi YANG, Jiangang YUAN, Junzhi YANG

期刊论文

Vibration suppression of speed-controlled robots with nonlinear control

Paolo BOSCARIOL,Alessandro GASPARETTO

期刊论文

Multi-harmonic forced vibration and resonance of simple beams to moving vehicles

期刊论文

Sectional model test study on vortex-excited resonance of vehicle-bridge system of Shanghai Bridge over

Li ZHOU, Yaojun GE

期刊论文

Extended stochastic resonance (SR) and its applications in weak mechanical signal processing

Niaoqing HU, Min CHEN, Guojun QIN, Lurui XIA, Zhongyin PAN, Zhanhui FENG,

期刊论文

新型细水雾添加剂的制备及其灭火性能评价

刘江虹,金翔,廖光煊

期刊论文

Discovery of the mechanisms of acupuncture in the treatment of migraine based on functional magnetic resonance

期刊论文

A convolutional neural network based approach to sea clutter suppression for small boat detection

Guan-qing Li, Zhi-yong Song, Qiang Fu,liguanqing09@nudt.edu.cn,songzhiyong08@nudt.edu.cn

期刊论文

Improvement of engine performance with high compression ratio based on knock suppression using Miller

Haiqiao WEI, Jie YU, Lei ZHOU

期刊论文

Growth suppression of colorectal cancer expressing S492R EGFR by monoclonal antibody CH12

Qiongna Dong, Bizhi Shi, Min Zhou, Huiping Gao, Xiaoying Luo, Zonghai Li, Hua Jiang

期刊论文

脉冲水射流水力共振设计

蒲家宁,陈明

期刊论文

基于改进无传感器反馈控制方法的电磁振动器振动谐波抑制技术

李伟1,2,崔俊宁1,2,边星元1,2,邹丽敏1,2

期刊论文