资源类型

期刊论文 1016

年份

2024 3

2023 94

2022 89

2021 76

2020 71

2019 64

2018 60

2017 54

2016 41

2015 50

2014 39

2013 24

2012 22

2011 33

2010 34

2009 47

2008 36

2007 38

2006 16

2005 17

展开 ︾

关键词

高速铁路 14

高质量发展 8

创新 6

三峡工程 4

关键技术 4

发展 4

技术体系 4

京沪高速铁路 3

高压 3

中国高速铁路 2

产业发展 2

冲击波 2

勘探开发 2

增材制造 2

安全性 2

指标体系 2

混凝土面板堆石坝 2

碾压混凝土坝 2

磁悬浮列车 2

展开 ︾

检索范围:

排序: 展示方式:

Design of noise-reduction seats for high-speed trains

Xiaojun DENG, Yanju ZHAO, Haijin ZHANG, Renzhong SHUAI, Leiwei ZHU

《机械工程前沿(英文)》 2018年 第13卷 第3期   页码 385-389 doi: 10.1007/s11465-017-0438-x

摘要:

Noise-reduction seats have been successfully used in concert halls, theaters, and other places that reduce noise. In this study, a new noise-reduction seat design was proposed for high-speed trains, which have unique interior noise spectral characteristics. First, before the noise-reduction seat models were fabricated, the parameters of high-performance sound-absorbing materials and perforated plates were selected by conducting a standing-wave tube test. The sound-absorption effects of the noise-reduction seats and normal seats were investigated and compared in a reverberation chamber. Test results showed that, compared with normal seats, the noise-reduction seats obtained a significantly improved sound-absorption coefficient in the entire frequency band. Furthermore, the test results were used to establish a simulation model for calculation, and the simulation results proved that the noise-reduction seats substantially reduced the noise in an entire train car. Finally, the noise-reduction seats were fabricated and installed in a full train car of an actual high-speed train. The test results showed that, compared with the normal seats, the noise-reduction seats decreased the noise level at a standard point in the passenger car by 1.5 dB. Therefore, the noise-reduction seats are effective in noise reduction.

关键词: high-speed train     sound-absorbing materials     perforated board     noise-reduction seats    

Application of python-based Abaqus preprocess and postprocess technique in analysis of gearbox vibration and noise

Guilian YI, Yunkang SUI, Jiazheng DU

《机械工程前沿(英文)》 2011年 第6卷 第2期   页码 229-234 doi: 10.1007/s11465-011-0128-z

摘要:

To reduce vibration and noise, a damping layer and constraint layer are usually pasted on the inner surface of a gearbox thin shell, and their thicknesses are the main parameters in the vibration and noise reduction design. The normal acceleration of the point on the gearbox surface is the main index that can reflect the vibration and noise of that point, and the normal accelerations of different points can reflect the degree of the vibration and noise of the whole structure. The K-S function is adopted to process many points’ normal accelerations as the comprehensive index of the vibration characteristics of the whole structure, and the vibration acceleration level is adopted to measure the degree of the vibration and noise. Secondary development of the Abaqus preprocess and postprocess on the basis of the Python scripting programming automatically modifies the model parameters, submits the job, and restarts the analysis totally, which avoids the tedious work of returning to the Abaqus/CAE for modifying and resubmitting and improves the speed of the preprocess and postprocess and the computational efficiency.

关键词: Abaqus secondary development     Python language     vibration and noise reduction     K-S function     vibration acceleration level    

Wavelet-based iterative data enhancement for implementation in purification of modal frequency for extremely noisy ambient vibration tests in Shiraz-Iran

Hassan YOUSEFI, Alireza TAGHAVI KANI, Iradj MAHMOUDZADEH KANI, Soheil MOHAMMADI

《结构与土木工程前沿(英文)》 2020年 第14卷 第2期   页码 446-472 doi: 10.1007/s11709-019-0605-8

摘要: The main purpose of the present study is to enhance high-level noisy data by a wavelet-based iterative filtering algorithm for identification of natural frequencies during ambient wind vibrational tests on a petrochemical process tower. Most of denoising methods fail to filter such noise properly. Both the signal-to-noise ratio and the peak signal-to-noise ratio are small. Multiresolution-based one-step and variational-based filtering methods fail to denoise properly with thresholds obtained by theoretical or empirical method. Due to the fact that it is impossible to completely denoise such high-level noisy data, the enhancing approach is used to improve the data quality, which is the main novelty from the application point of view here. For this iterative method, a simple computational approach is proposed to estimate the dynamic threshold values. Hence, different thresholds can be obtained for different recorded signals in one ambient test. This is in contrast to commonly used approaches recommending one global threshold estimated mainly by an empirical method. After the enhancements, modal frequencies are directly detected by the cross wavelet transform (XWT), the spectral power density and autocorrelation of wavelet coefficients. Estimated frequencies are then compared with those of an undamaged-model, simulated by the finite element method.

关键词: ambient vibration test     high level noise     iterative signal enhancement     wavelet     cross and autocorrelation of wavelets    

The carbon dioxide removal potential of Liquid Air Energy Storage: A high-level technical and economic

Andrew LOCKLEY, Ted von HIPPEL

《工程管理前沿(英文)》 2021年 第8卷 第3期   页码 456-464 doi: 10.1007/s42524-020-0102-8

摘要: Liquid Air Energy Storage (LAES) is at pilot scale. Air cooling and liquefaction stores energy; reheating revaporises the air at pressure, powering a turbine or engine (Ameel et al., 2013). Liquefaction requires water & CO removal, preventing ice fouling. This paper proposes subsequent geological storage of this CO – offering a novel Carbon Dioxide Removal (CDR) by-product, for the energy storage industry. It additionally assesses the scale constraint and economic opportunity offered by implementing this CDR approach. Similarly, established Compressed Air Energy Storage (CAES) uses air compression and subsequent expansion. CAES could also add CO scrubbing and subsequent storage, at extra cost. CAES stores fewer joules per kilogram of air than LAES – potentially scrubbing more CO per joule stored. Operational LAES/CAES technologies cannot offer full-scale CDR this century (Stocker et al., 2014), yet they could offer around 4% of projected CO disposals for LAES and<25% for current-technology CAES. LAES CDR could reach trillion-dollar scale this century (20 billion USD/year, to first order). A larger, less certain commercial CDR opportunity exists for modified conventional CAES, due to additional equipment requirements. CDR may be commercially critical for LAES/CAES usage growth, and the necessary infrastructure may influence plant scaling and placement. A suggested design for low-pressure CAES theoretically offers global-scale CDR potential within a century (ignoring siting constraints) – but this must be costed against competing CDR and energy storage technologies.

关键词: carbon dioxide removal     Liquid Air Energy Storage     Compressed Air Energy Storage     geoengineering    

高放废物地质处置:进展与挑战

王驹

《中国工程科学》 2008年 第10卷 第3期   页码 58-65

摘要:

随着我国核能事业的飞速发展,高水平放射性废物的处理和处置,即将成为一个重大的安全和环保问题。在介绍国内外进展的基础上,重点讨论了高放废物地质处置面临的挑战:处置库场址地质演化的精确预测、深部地质环境特征、多场耦合条件下(中(高)温、应力作用、水力作用、化学作用、生物作用和辐射作用等)深部岩体、地下水和工程材料的行为、低浓度超铀放射性核素的地球化学行为与随地下水迁移行为及处置系统的安全评价。

关键词: 高放废物     地质处置     地下实验室     科学挑战    

Digital switched hydraulics

Min PAN, Andrew PLUMMER

《机械工程前沿(英文)》 2018年 第13卷 第2期   页码 225-231 doi: 10.1007/s11465-018-0509-7

摘要:

This paper reviews recent developments in digital switched hydraulics particularly the switched inertance hydraulic systems (SIHSs). The performance of SIHSs is presented in brief with a discussion of several possible configurations and control strategies. The soft switching technology and high-speed switching valve design techniques are discussed. Challenges and recommendations are given based on the current research achievements.

关键词: digital hydraulics     switched inertance hydraulic systems     energy efficiency     high-speed switching valve     fluid-borne noise    

上海大剧院观众厅使用效果评析

李道增,许瑾

《中国工程科学》 2001年 第3卷 第1期   页码 15-21

摘要:

上海率先在我国建成第一座具有国际水平的现代化大剧院。作者对该剧院及设计单位进行了多次访问调研。文章扼要地介绍该剧院观众厅的视线设计、噪声控制、音质设计、声学参数的实测结果以及所采用的可移动音罩、可调混响装置等技术措施,并引用了国内外戏剧界、音乐界著名专家观摩演出后的声学评价以及观众对观众厅使用效果所给出的评分结果。

关键词: 观众厅     视线设计     噪声控制     音质设计     可移动音罩     可调混响装置    

Theoretical analysis and actual experimental research on static characteristics of suspendome structure

CHEN Zhihua, YAN Xiangyu, SUN Ruirui, FENG Zhenchang, QIN Yali, ZHAO Jianbo

《结构与土木工程前沿(英文)》 2007年 第1卷 第3期   页码 286-292 doi: 10.1007/s11709-007-0037-8

摘要: The suspendome used as the roof of the VIP hall in Tianjin Museum was analyzed by ANASYS under the assumptions of hinged joints and rigid joints in up chord, respectively, and the results show that the member force and nodal displacement under the two assumptions have little difference. Thus, it is attained that the suspendome can be analyzed with the assumption of hinged joints. A full-scale test on the suspendome with half-cable and half-pipe was carried out. The loading system, arrangement of measuring points, and the test procedures are introduced. Also, a test on steel wire ropes for elastic module was carried out. The experimental and theoretical values of member forces and nodal displacements were compared and it showed that they accord well with each other under low-level load. While under high-level load, the experimental value was bigger than the theoretical value due to the influence of the test environment. With the increase of the load, tension of outside cables and looseness of inside cables occurred, which indicated that the prestressing value in inside cables should be properly assigned. Both the experimental and theoretical results verify that the suspendome has a wide application prospect with the advantages of perfect mechanical characteristics, low steel consumption, convenient construction and low cost.

关键词: Tianjin     influence     displacement     high-level     low-level    

用于微光摄像的高灵敏度电子轰击电荷耦器件

周立伟,刘广荣,高稚允,王仲春

《中国工程科学》 1999年 第1卷 第3期   页码 56-62

摘要:

文章综述微光成像的电子轰击电荷耦合器件(EBCCD)的进展。EBCCD是将像管的荧光屏以对电子灵敏的背照明、减薄CCD代替,将电子图像直接转变为视频信号,其在所有光照等级下,特别是在极低微光下的调制传递函数(MTF)、分辨力、信噪比、余辉等均优于像增强器耦合CCD(ICCD)。文中较为详细地叙述了倒像式EBCCD设计与减薄工艺,给出各种类型倒像式EBCCD像管的技术参数,分析和比较了近贴式与倒像式EBCCD与ICCD的性能,指出了EBCCD在军用夜视技术与民用技术未来发展中的地位与重要性。

关键词: 微光成像     电荷耦合器件     电子轰击CCD    

High-level expression of recombinant IgG1 by CHO K1 platform

Ningning Xu, Jianfa Ou, Al-Karim (Al) Gilani, Lufang Zhou, Margaret Liu

《化学科学与工程前沿(英文)》 2015年 第9卷 第3期   页码 376-380 doi: 10.1007/s11705-015-1531-5

摘要: The Chinese Hamster Ovary (CHO K1) cell was used to express a targeted anti-cancer monoclonal antibody by optimizing the platform of the construction of production cell line in this study. The adherent CHO K1 was first adapted to suspension culture in chemical defined medium. Then the glutamine synthetase (GS) vector was applied to construct a single plasmid to overexpress a monoclonal antibody IgG1. Post transfection, the production of cell pool was optimized by glutamine-free selection and amplification using various concentrations of methionine sulfoximine. The best cell pool of CHO K1/IgG1 was used to screen the top single clone using the limiting dilution cloning. Finally, a high IgG1 production of 780 mg/L was obtained from a batch culture. This study demonstrated that the construction of high producing cell line, from gene to clone, could be completed within six month and the gene amplification improved protein production greatly.

关键词: Chinese hamster ovary (CHO)     monoclonal antibody     IgG1     amplification     cell line development    

System-level Pareto frontiers for on-chip thermoelectric coolers

Sevket U. YURUKER, Michael C. FISH, Zhi YANG, Nicholas BALDASARO, Philip BARLETTA, Avram BAR-COHEN, Bao YANG

《能源前沿(英文)》 2018年 第12卷 第1期   页码 109-120 doi: 10.1007/s11708-018-0540-8

摘要: The continuous rise in heat dissipation of integrated circuits necessitates advanced thermal solutions to ensure system reliability and efficiency. Thermoelectric coolers are among the most promising techniques for dealing with localized on-chip hot spots. This study focuses on establishing a holistic optimization methodology for such thermoelectric coolers, in which a thermoelectric element’s thickness and the electrical current are optimized to minimize source temperature with respect to ambient, when the thermal and electrical parasitic effects are considered. It is found that when element thickness and electrical current are optimized for a given system architecture, a “heat flux vs. temperature difference” Pareto frontier curve is obtained, indicating that there is an optimum thickness and a corresponding optimum current that maximize the achievable temperature reduction while removing a particular heat flux. This methodology also provides the possible system level Δ ’s that can be achieved for a range of heat fluxes, defining the upper limits of thermoelectric cooling for that architecture. In this study, use was made of an extensive analytical model, which was verified using commercially available finite element analysis software. Through the optimization process, 3 pairs of master curves were generated, which were then used to compose the Pareto frontier for any given system architecture. Finally, a case study was performed to provide an in-depth demonstration of the optimization procedure for an example application.

关键词: thermoelectric cooling     thermal management     optimization     high flux electronics    

Lignin-based polymer with high phenolic hydroxyl group content prepared by the alkyl chain bridging method

《化学科学与工程前沿(英文)》 2023年 第17卷 第8期   页码 1075-1084 doi: 10.1007/s11705-022-2272-x

摘要: Inspired by the importance of the phenolic group to the electron transporting property of hole transport materials, phenolic hydroxyl groups were introduced in lignosulfonate (LS) via the alkyl chain bridging method to prepare phenolated-lignosulfonate (PLS). The results showed that the phenolic group was boosted from 0.81 mmol∙g–1 of LS to 1.19 mmol∙g–1 of PLS. The electrochemical property results showed two oxidation peaks in the cyclic voltammogram (CV) curve of PLS, and the oxidation potential of the PLS-modified electrode decreased by 0.5 eV compared with that of LS. This result indicates that PLS is more easily oxidized than LS. Based on the excellent electron transporting property of PLS, PLS was applied as a dopant in poly(3,4-ethylenedioxythiophene) (PEDOT, called PEDOT:PLSs). PLS showed excellent dispersion properties for PEDOT. Moreover, the transmittance measurement results showed that the transmittance of PEDOT:PLSs exceeded 85% in the range of 300–800 nm. The CV results showed that the energy levels of PEDOT:PLSs could be flexibly adjusted by PLS amounts. The results indicate that the phenolic hydroxyl group of lignin can be easily boosted by the alkyl chain bridging method, and phenolated lignin-based polymers may have promising potential as dopants of PEDOT to produce hole transporting materials for different organic photovoltaic devices.

关键词: lignosulfonate     phenolic group     PEDOT:PLS     hole extract layer     energy level    

Anovel approach of noise statistics estimate using H∞ filter in target tracking

Xie WANG,Mei-qin LIU,Zhen FAN,Sen-lin ZHANG

《信息与电子工程前沿(英文)》 2016年 第17卷 第5期   页码 449-457 doi: 10.1631/FITEE.1500262

摘要: Noise statistics are essential for estimation performance. In practical situations, however, a priori information of noise statistics is often imperfect. Previous work on noise statistics identification in linear systems still requires initial prior knowledge of the noise. A novel approach is presented in this paper to solve this paradox. First, we apply the H∞ filter to obtain the system state estimates without the common assumptions about the noise in conventional adaptive filters. Then by applying state estimates obtained from the H∞ filter, better estimates of the noise mean and covariance can be achieved, which can improve the performance of estimation. The proposed approach makes the best use of the system knowledge without a priori information with modest computation cost, which makes it possible to be applied online. Finally, numerical examples are presented to show the efficiency of this approach.

关键词: Noise estimate     H∞     filter     Target tracking    

珊瑚岛礁环境噪声成像 Article

夏少红, 张昌榕, 曹敬贺

《工程(英文)》 2023年 第25卷 第6期   页码 182-193 doi: 10.1016/j.eng.2021.09.022

摘要:

As valuable land in the ocean, coral islands are not only important bases for making use of marine resources and protecting marine rights and interests, but also important for breakthrough research in many fields of earth science. Hence, the economical and efficient determination of the underground structure of coral islands has become significant in coral island engineering geology, but remains challenging for traditional marine geophysical prospecting and drilling methods. While ambient noise tomography with dense arrays has been widely used in continental regions, its applicability to coral islands remains undetermined. In this study, based on the data recorded by a dense array on an isolated coral island in the South China Sea, we analyzed the ambient noise characteristics and obtained a 3D subsurface structure of the coral island using ambient noise tomography. We made the following findings: ① The ambient noise frequencies can be roughly categorized into three levels: < 1, 1–5, and > 5 Hz. The spectral characteristics of the noise below 5 Hz were consistent at different stations, but there were significant differences in the characteristics of the noise above 5 Hz. ② For ambient noise frequencies below 5 Hz, cross-correlation functions with high quality could be obtained with only 24 h of waveform data. However, it was difficult to extract meaningful cross-correlation functions for ambient noise frequencies above 5 Hz. ③ The S-wave velocity in the coral island was higher toward the sea and lower toward the lagoon, which was consistent with the high degree of cementation of the outer reef flat stratum on the seaward side. ④ There were two low-velocity horizons at 25–75 and 200–300 m, which were in good agreement with the high-porosity horizons that were revealed by drilling core samples, reflecting the weathering history of the reef. Our research demonstrates that ambient noise tomography is a potentially economical, efficient, and environmentally friendly method for the geological prospecting of coral reefs.

关键词: Coral island     Ambient noise tomography     Engineering geology     South China Sea    

Investigation of flow dynamics and decrease of vortex noise inside volute of centrifugal fans

LI Chunxi, WANG Songling

《能源前沿(英文)》 2008年 第2卷 第2期   页码 235-240 doi: 10.1007/s11708-008-0040-3

摘要: The characteristics of three-dimension flow dynamics inside the volute of a G4-73No.8D centrifugal fan was simulated numerically using a computational fluid dynamics(CFD) technique. The generation, evolution, and noise of the vortex were investigated when cylinder-shaped and cone-cylinder-shaped anti-vortex rings were added separately. Numerical results showed that large-scale vortices were broken effectively and the flow fields inside the fan were more uniform with the two anti-vortex rings installed. Experimental results indicated A-sound level and spectrum noise of the refitted fan decreased and the two anti-vortex rings were effective in decreasing vortex noise. The cone-cylinder-shaped anti-vortex ring was more effective than the cylinder-shaped one in breaking large-scale vortexes and decreasing vortex noise.

关键词: cylinder-shaped     evolution     computational     effective     large-scale    

标题 作者 时间 类型 操作

Design of noise-reduction seats for high-speed trains

Xiaojun DENG, Yanju ZHAO, Haijin ZHANG, Renzhong SHUAI, Leiwei ZHU

期刊论文

Application of python-based Abaqus preprocess and postprocess technique in analysis of gearbox vibration and noise

Guilian YI, Yunkang SUI, Jiazheng DU

期刊论文

Wavelet-based iterative data enhancement for implementation in purification of modal frequency for extremely noisy ambient vibration tests in Shiraz-Iran

Hassan YOUSEFI, Alireza TAGHAVI KANI, Iradj MAHMOUDZADEH KANI, Soheil MOHAMMADI

期刊论文

The carbon dioxide removal potential of Liquid Air Energy Storage: A high-level technical and economic

Andrew LOCKLEY, Ted von HIPPEL

期刊论文

高放废物地质处置:进展与挑战

王驹

期刊论文

Digital switched hydraulics

Min PAN, Andrew PLUMMER

期刊论文

上海大剧院观众厅使用效果评析

李道增,许瑾

期刊论文

Theoretical analysis and actual experimental research on static characteristics of suspendome structure

CHEN Zhihua, YAN Xiangyu, SUN Ruirui, FENG Zhenchang, QIN Yali, ZHAO Jianbo

期刊论文

用于微光摄像的高灵敏度电子轰击电荷耦器件

周立伟,刘广荣,高稚允,王仲春

期刊论文

High-level expression of recombinant IgG1 by CHO K1 platform

Ningning Xu, Jianfa Ou, Al-Karim (Al) Gilani, Lufang Zhou, Margaret Liu

期刊论文

System-level Pareto frontiers for on-chip thermoelectric coolers

Sevket U. YURUKER, Michael C. FISH, Zhi YANG, Nicholas BALDASARO, Philip BARLETTA, Avram BAR-COHEN, Bao YANG

期刊论文

Lignin-based polymer with high phenolic hydroxyl group content prepared by the alkyl chain bridging method

期刊论文

Anovel approach of noise statistics estimate using H∞ filter in target tracking

Xie WANG,Mei-qin LIU,Zhen FAN,Sen-lin ZHANG

期刊论文

珊瑚岛礁环境噪声成像

夏少红, 张昌榕, 曹敬贺

期刊论文

Investigation of flow dynamics and decrease of vortex noise inside volute of centrifugal fans

LI Chunxi, WANG Songling

期刊论文