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Variations of Atmospheric ELF/VLF Radio Noise Due to Seismogenic Modifications in Tropospheric Conductivity
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作者 Masashi Hayakawa Alexander P. Nickolaenko 《Open Journal of Earthquake Research》 2024年第2期113-132,共20页
We suggest a possible explanation of the influence of pre-seismic activity on the registration rate of natural ELF(extremely low frequency)/VLF(very low frequency) pulses and the changes of their characteristics. The ... We suggest a possible explanation of the influence of pre-seismic activity on the registration rate of natural ELF(extremely low frequency)/VLF(very low frequency) pulses and the changes of their characteristics. The main idea is as follows. The distribution of the electric field around a thundercloud depends on the conductivity profile of the atmosphere. Quasi-static electric fields of a thundercloud decrease in those tropospheric regions where an increase of air conductivity is generated by pre-seismic activities due to emanation of radioactive gas and water into the lower atmosphere. The electric field becomes reduced in the lower troposphere, and the probability decreases of the cloud-to-ground (CG) strokes in such “contaminated” areas. Simultaneously, the electric field grows inside and above the thunderclouds, and hence, we anticipate a growth in the number of horizontal and tilted inter-cloud (or intra-cloud) (both termed as IC discharges) strokes. Spatial orientation of lightning strokes reduces vertical projection of their individual amplitudes, while the rate (median number strokes per a unit time) of discharges grows. We demonstrate that channel tilt of strokes modifies the spectral content of ELF/VLF radio noise and changes the rate of detected pulses during the earthquake preparation phase. 展开更多
关键词 ELF/VLF Radio noise Earthquake Precursor Pre-Seismic Modification Conductivity Anomaly in the Lower Atmosphere Radioactive Radon Gases CG Lightning Discharges ic Discharges Cloud-to-Ionosphere Discharge
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Precoder Design and Impulsive Noise Mitigation Scheme for Industrial Wireless Communications 被引量:2
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作者 Yanjing Sun Xinyan Li +3 位作者 Jiasi Zhou Ruirui Chen BowenWang Yanfen Wang 《China Communications》 SCIE CSCD 2021年第4期182-197,共16页
In industrial wireless scenarios,the impulsive noise(IN)incurred by machine running or operation causes a serious influence on the powerlimited industrial wireless communications.It is challenging to ensure efficient ... In industrial wireless scenarios,the impulsive noise(IN)incurred by machine running or operation causes a serious influence on the powerlimited industrial wireless communications.It is challenging to ensure efficient and reliable transmission with quality of service(QoS)guarantee for machinetype communication devices(MTCDs).Considering the IN in the industrial process,this paper establishes the multiuser multiple-input single-output(MU-MISO)orthogonal frequency division multiplexing(OFDM)system model,which combines transmitter and receiver design.Two precoding schemes are designed to improve communication effectiveness at the transmitter.More specifically,the precoder design scheme which combines semi-definite relaxation(SDR)with difference-of-two-convex-function(D.C.)iterative algorithm,is developed by utilizing the Dinkelbach method to improve the system effectiveness.To decrease the computational complexity,we devise the quadratic-based fractional programming(QFP)algorithm,which decouples the variables by using a quadratic transform method.On this basis,the IN mitigation scheme is studied to reduce the system error rate(SER)at the receiver.With the goal of improving the reliability of industrial wireless communications,we propose a hybrid nonlinear IN mitigation(HNINM)scheme and then derive its closed-form expression of SER.The simulation results show that the proposed QFP algorithm achieves superior performance while the HNINM scheme decreases the SER of industrial wireless communications. 展开更多
关键词 Industrial wireless communications precoder design impulsive noise mitigation
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Mechanical and Acoustic Performance Test of New Designed Metal Noise Barrier Unit Plate with No Riveted Connection 被引量:1
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作者 LUAN Haoxiang WU Jin +3 位作者 PAN Jiayu ZHU Wanxu ZHOU Hongmei PENG Hanze 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2020年第2期343-352,共10页
The modern transportation system is increasingly developed during recent years.It is an effective solution to set the noise barriers to reduce the traffic noise pollution caused by different kinds of transportation sy... The modern transportation system is increasingly developed during recent years.It is an effective solution to set the noise barriers to reduce the traffic noise pollution caused by different kinds of transportation systems.Many deficiencies on concrete noise barriers and metal noise barriers with rivet structure can be eliminated by a new kind of noise barrier with no-riveted structure.The mechanical performance examination and acoustic performance test are conducted on the new-designed noise barrier with no-riveted structure.The results indicate that the maximum stress is 1.74 MPa and the maximum deformation is 1.04 mm with load acting on the unit plate.The noise reduction coefficient of this kind of no-riveted noise barrier unit plate is 0.75 and its noise insulation is 40 dB,which were conform to or superior to the standard requirements.Therefore,this new designed noise barrier meets the field application requirements of mechanical and acoustic performance,which demonstrates the noise barriers can be widely promoted. 展开更多
关键词 noise barrier unit plate no-riveted connection structure design mechanical performance acoustic performance
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A Novel Multi-Functional Leakage Current Protector IC Design
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作者 韩雁 王泽 +1 位作者 俞宏 谢俊杰 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2005年第8期1537-1542,共6页
A novel type of leakage current protector chip,implemented in the mixed-signal 0.6μm CMOS process,is presented. This chip has the advantages of low power dissipation (10mW), accurate protection control based on dig... A novel type of leakage current protector chip,implemented in the mixed-signal 0.6μm CMOS process,is presented. This chip has the advantages of low power dissipation (10mW), accurate protection control based on digital response delay time and integration of multi-functions such as leakage current/over-voltage/over-load detection and protection,auto switch-on and so forth. Additionally, the chip is programmable to suit different three-level protection applications with a high anti-interference ability. 展开更多
关键词 leakage current protector ic design programmable ic
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Research of Background Noise Characteristics of the Zhangzhou Seismic Array
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作者 Zheng Zhong Hao Chunyue +1 位作者 Huang Zhao Zhang Shuang 《Earthquake Research in China》 CSCD 2017年第4期548-559,共12页
The data recorded during the site survey in the Zhangzhou area in Fujian Province between October 23, 2007 and December 3, 2007 was analyzed. The main methods adopted for the noise level of this area are the noise roo... The data recorded during the site survey in the Zhangzhou area in Fujian Province between October 23, 2007 and December 3, 2007 was analyzed. The main methods adopted for the noise level of this area are the noise root mean square( RMS),noise power spectrum density and noise coherency function. The results indicate that the noise levels of the survey sites are higher in the 1 s-10 s periods,which is the main frequency band of preliminary microseism,and also,two main noise sources were found in 1. 5 Hz and around 5 Hz. According to arithmetic,the direction and frequency band of the noise source were analyzed and academic proofs were presented. At last,we found that the noise source in 1. 5 Hz was made by the water wave aroused by the wind in the reservoir region and the noise source around 5 Hz was made by the power station in the northeast direction. 展开更多
关键词 SMALL APERTURE SEISMic ARRAY Space noise FIELD ARRAY design noise SOURCE
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Automotive Interior Noise Reduction in High Frequency Using Statistical Energy Analysis
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作者 陈鑫 王登峰 +1 位作者 朱磊 马正东 《Defence Technology(防务技术)》 SCIE EI CAS 2009年第3期161-167,共7页
Statistical energy analysis (SEA) is an effective method for predicting high frequency vibro-acoustic performance of automobiles. A full vehicle SEA model is presented for interior noise reduction. It is composed of a... Statistical energy analysis (SEA) is an effective method for predicting high frequency vibro-acoustic performance of automobiles. A full vehicle SEA model is presented for interior noise reduction. It is composed of a number of subsystems based on a 3D model with all parameters for each subsystem. The excitation inputs are measured through road tests in different conditions,including inputs from the engine vibration and the sound pressure of the engine bay. The accuracy in high frequency of SEA model is validated,by comparing the analysis results with the testing pressure level data at driver's right ear. Noise contribution and sensitivity of key subsystems are analyzed. Finally,the effectiveness of noise reduction is verified. Based on the SEA model,an approach combining test and simulation is proposed for the noise vibration and harshness (NVH) design in vehicle development. It contains building the SEA model,testing for subsystem parameter identification,validating the simulation model,identifying subsystem power inputs,analyzing the design sensitivity. An example is given to demonstrate the interior noise reduction in high frequency. 展开更多
关键词 统计能量分析 汽车内饰 高频振动 降噪 车辆模型 噪声降低 模型验证 试验压力
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High-efficiency prediction method for helicopter global/ground noise based on near-field acoustic holography
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作者 Mengxue SHAO Yang LU +1 位作者 Xice XU Jiaxin LU 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2024年第7期271-284,共14页
Noise reduction program design is an effective approach that relies on efficient noise prediction for reducing ground noise during flight.The existing noise prediction methods have the limitations of being computation... Noise reduction program design is an effective approach that relies on efficient noise prediction for reducing ground noise during flight.The existing noise prediction methods have the limitations of being computationally expensive or only applicable to far-fields.In this paper,a High-Efficiency Prediction Method(HEPM)for helicopter global/ground noise based on near-field acoustic holography is proposed.The HEPM can predict the global noise based on acoustic modal analysis and has the advantages of high prediction accuracy and low time cost.The process is given as follows:firstly,the rotor noise on the holographic surface in the specified flight is obtained by simulations or experiments.Secondly,the global noise model,which maps time-domain noise to acoustic modes,is established based on near-field acoustic holography and Fourier acoustic analysis methods.Finally,combined with acoustic modal amplitude,the model established enables efficiently predicting the global/ground noise in the corresponding flight state.To verify the accuracy of the prediction method,a simulation study is conducted in hovering and forward flight states using a model helicopter with a 2-meter rotor and Rotor Body Interaction(ROBIN)fuselage.The comparison of HEPM with numerical results shows that the average prediction errors of the global and ground noise are less than 0.3 dB and 0.2 dB,respectively.For a region containing 100000 observers,the computation time of the HEPM is only one-fifth of that of the acoustic hemisphere method,demonstrating the rapidity of the proposed method. 展开更多
关键词 HELicOPTER Rotor noise prediction noise abatement procedure design Acoustic modal analysis Near-field acoustic holography
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Experimental Demonstration of <i>g<sub>m</sub></i>/I<i><sub>D</sub></i>Based Noise Analysis
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作者 Jack Ou Pietro M. Ferreira Jui-Chu Lee 《Circuits and Systems》 2014年第4期69-75,共7页
Recent studies using BSIM3 models have suggested that noise depends on the transconductance-to-drain ratio gm/ID of a transistor. However, to the best of our knowledge, no experimental result demonstrating gm/ID depen... Recent studies using BSIM3 models have suggested that noise depends on the transconductance-to-drain ratio gm/ID of a transistor. However, to the best of our knowledge, no experimental result demonstrating gm/ID dependent noise previously observed in simulation is available in the literature. This paper examines the underlying principles that make it possible to analyze noise using gm/ID based noise analysis. Qualitative discussion of normalized noise is presented along with experimental results from a 130 nm CMOS process. A close examination of the experimental results reveals that the device noise is width independent from 1 Hz to 10 kHz. Moreover, noise increases as gm/ID is reduced. The experiment observation that noise is width independent makes it possible for circuit designers to generate normalized parameters that are used to study noise intuitively and accurately. 展开更多
关键词 gm/ID design METHODOLOGY noise Analysis FLicKER noise
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Flap side-edge noise mechanism and shape modification noise reduction design 被引量:1
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作者 HAN Xiao ZHOU Wangyi +3 位作者 BAI Junqiang YU Peixun LI Yi SONG Xiang 《Chinese Journal of Acoustics》 CSCD 2018年第3期257-274,共18页
Flap side-edge noise is a significant noise source for airplane at takeoff and landing stages. The generation mechanism of flap side-edge noise is analyzed by numerical simulation on unsteady flow field using Very Lar... Flap side-edge noise is a significant noise source for airplane at takeoff and landing stages. The generation mechanism of flap side-edge noise is analyzed by numerical simulation on unsteady flow field using Very Large Eddy Simulation (VLES). Two kinds of flap side-edge shape modifications are proposed, and their frequency spectrum and directivity of far-field noise are compared with the baseline configuration using permeable integral surface Ffowcs Williams and Hawkings (FW-H) acoustic analogy method to investigate their effects on noise reduction. Via the numerical simulation of flow field and acoustic field, it proves that the flap side-edge noise is broadband noise in nature. The different shapes of flap side-edge change the pattern of flow field, vortex structures and the development of vortex, thus having influences on noise source distributions and characteristics of far-field noise. The result shows that at the given 5° angle of attack, the proposed flap side-edge shape modifications can reduce the overall sound pressure level (OASPL) by 1 to 2 dB without decreasing the lift and drag aerodynamic performances. 展开更多
关键词 Flap side-edge noise mechanism and shape modification noise reduction design FIGURE
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HYDRODYNAMIC CHARACTERISTICS AND OPTIMIZATION DESIGN OF EFFICIENT AXIAL-FLOW BLAST WITH LOW NOISE AND ENERGY SAVING
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作者 Tan Soon Keat 《Journal of Hydrodynamics》 SCIE EI CSCD 2002年第4期40-46,共7页
Based on the demand on efficient axial-flow blast with low noise and energy saving, a blade was designed through the application of the unequal work distribution principle and the exponential twisted camber was used t... Based on the demand on efficient axial-flow blast with low noise and energy saving, a blade was designed through the application of the unequal work distribution principle and the exponential twisted camber was used to shape blades. Then, the hydrodynamic characteristics of blades were studied and the strengths and vibrations of blades and hydro-dynamic noise of blast were analyzed. Furthermore, the software of optimization design of axial-flow blast was developed. Finally, the HMF-T40No.20 axial-flow blast used in large textile conditioner system of cotton spinning industry was designed, which could meet the required total safety and environmental requirements as the corresponding test demonstrates. The study is beneficial to designing axial-flow blast. 展开更多
关键词 Acoustic noise design noise abatement Optimization Software engineering Turbomachine blades
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Design of low noise airfoil with high aerodynamic performance for use on small wind turbines 被引量:7
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作者 Taehyung KIM Seungmin LEE +1 位作者 Hogeon KIM Soogab LEE 《Science China(Technological Sciences)》 SCIE EI CAS 2010年第1期75-79,共5页
Wind power is one of the most reliable renewable energy sources and internationally installed capacity is increasing radically every year.Although wind power has been favored by the public in general,the problem with ... Wind power is one of the most reliable renewable energy sources and internationally installed capacity is increasing radically every year.Although wind power has been favored by the public in general,the problem with the impact of wind turbine noise on people living in the vicinity of the turbines has been increased.Low noise wind turbine design is becoming more and more important as noise is spreading more adverse effect of wind turbine to public.This paper demonstrates the design of 10 kW class wind turbines,each of three blades,a rotor diameter 6.4 m,a rated rotating speed 200 r/min and a rated wind speed 10 m/s.The optimized airfoil is dedicated for the 75% spanwise position because the dominant source of a wind turbine blade is trailing edge noise from the outer 25% of the blade.Numerical computations are performed for incompressible flow and for Mach number at 0.145 and for Reynolds numbers at 1.02×106 with a lift performance,which is resistant to surface contamination and turbulence intensity.The objectives in the design process are to reduce noise emission,while sustaining high aerodynamic efficiency.Dominant broadband noise sources are predicted by semi-empirical formulas composed of the groundwork by Brooks et al.and Lowson associated with typical wind turbine operation conditions.During the airfoil redesign process,the aerodynamic performance is analyzed to reduce the wind turbine power loss.The results obtained from the design process show that the design method is capable of designing airfoils with reduced noise using a commercial 10 kW class wind turbine blade airfoil as a basis.Therefore,the new optimized airfoil showing 2.9 dB reductions of total sound pressure level(SPL) and higher aerodynamic performance are achieved. 展开更多
关键词 WIND TURBINE aerodynamic noise AIRFOIL SELF noise low noise AIRFOIL design
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基于归一化模板匹配算法的动作电位检测IC
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作者 庞勋 姚镭 《现代电子技术》 北大核心 2024年第2期1-6,共6页
针对多通道神经元动作电位(AP)信号采集硬件系统中,前端采集IC因电极阻抗、应用环境、系统功耗以及系统面积等因素而导致原始信号信噪比较低的问题,设计一种基于归一化模板匹配算法的AP信号检测IC。该检测IC基于模板匹配算法,并引入信... 针对多通道神经元动作电位(AP)信号采集硬件系统中,前端采集IC因电极阻抗、应用环境、系统功耗以及系统面积等因素而导致原始信号信噪比较低的问题,设计一种基于归一化模板匹配算法的AP信号检测IC。该检测IC基于模板匹配算法,并引入信号归一化以去除冗余信息。为确保芯片的实时性并降低功耗,芯片整体采用三级流水线结构,各个模块间插入门控时钟,同时可通过SPI总线配置更新其工作状态。在SMIC 180 nm数字工艺下,裸片面积为0.98 mm^(2),配置模板信息时功耗为701μW,完全工作时功耗为8.07 mW,且采用QFN48封装形式。测试结果表明,所设计的AP信号检测IC具有较好的抗噪性能,可用于信噪比较低的环境来降低信号传输带宽,即使在-10 dB信噪比环境下,评价模型综合性能的F1-Score仍可达到94.65%。 展开更多
关键词 动作电位检测 ic设计 模板匹配算法 信号归一化 抗噪性能 检测芯片测试
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Effects of Bionic Volute Tongue on Aerodynamic Performance and Noise Characteristics of Centrifugal Fan Used in the Air-conditioner 被引量:10
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作者 Liming Wu Xiaomin Liu Menghao Wang 《Journal of Bionic Engineering》 SCIE EI CSCD 2020年第4期780-792,共13页
The aerodynamic noise generated by the centrifugal fan used in the air conditioner is related to the comfort of human living and working,which can be controlled by using the bionic design and optimization of key compo... The aerodynamic noise generated by the centrifugal fan used in the air conditioner is related to the comfort of human living and working,which can be controlled by using the bionic design and optimization of key components of centrifugal fan.Inspired by the non-smooth leading edge of long-eared owl wing,eight kinds of volute tongues are proposed to reduce the aerodynamic noise of a centrifugal fan.The flow and sound characteristics are numerically investigated by incorporating computational fluid dynamics and computational aero-acoustics.The optimal result exhibits a noise reduction of up to 1.5 dB with a slight increase in mass flow rate.The acoustic characteristics,with respect to the sound pressure level,power spectral density,and sound directivity are discussed.The time-domain,frequency-domain,and root mean square values of pressure fluctuation are monitored and analyzed to assess the unsteady flow interaction between the volute tongue and impeller.The intensity and scale of vortices in the centrifugal fan are suppressed in the upstream and downstream of the bionic volute tongue,and the turbulence effect on the surface of the volute tongue becomes even and weak. 展开更多
关键词 bionic design volute tongue centrifugal fan noise reduction numerical simulation
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A low noise multi-channel readout IC for X-ray cargo inspection 被引量:1
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作者 王旭 杨洪艳 +1 位作者 袁颖 吴武臣 《Journal of Semiconductors》 EI CAS CSCD 2013年第4期121-126,共6页
A low noise multi-channel readout integrated circuit (IC) which converts a detector current to analog voltage for X-ray cargo inspection is described. The readout IC provides 32 channels of a circuit having a maxi- ... A low noise multi-channel readout integrated circuit (IC) which converts a detector current to analog voltage for X-ray cargo inspection is described. The readout IC provides 32 channels of a circuit having a maxi- mum dynamic range of 15 bit and is comprised of integrator gain selection, timing generator, shift register chain, integrator array, sample/hold (S/H) stage amplifier etc. and occupies a die area of 2.7 × 13.9 mm2. It operates at It was fabricated using 0.6 μm standard CMOS process, 1 MHz, consumes 100 mW from a 5 V supply and 4.096 V as reference, and has a measured output noise of 85 μVms on 63 pF of integrator gain capacitance and 440 pF of photodiode terminal capacitance so that steel plate penetration thickness can reach more than 400 mm. 展开更多
关键词 low noise multi-channel readout ic dynamic range X-ray cargo inspection
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Optimization Design of Vibration Characteristics of Ship Composite Brace with Rigid Vibration Isolation Mass 被引量:1
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作者 王强勇 姚熊亮 +1 位作者 于丹竹 庞福振 《Journal of Marine Science and Application》 2011年第2期215-219,共5页
In considering the theory of structural dynamic optimization design, a design method of the structural style of ship composite brace with rigid vibration isolation mass was studied. Two kinds of structural dynamic opt... In considering the theory of structural dynamic optimization design, a design method of the structural style of ship composite brace with rigid vibration isolation mass was studied. Two kinds of structural dynamic optimization formulations minimizing the vibration acceleration of the non-pressure hull on the restraining condition of the gross weight of the ship cabin were established: 1) dynamic optimization of the sectional dimensions of the rigid vibration isolation mass in the composite brace; 2) dynamic optimization of the arranging position of the rigid vibration isolation mass. Through the optimization results, sectional dimensions and the arranging position of the rigid vibration isolation mass with better performance in reducing vibration were gained, and some reference was provided for practical engineering designs as well as enrichment of the design method of a novel ship vibration-isolation brace. 展开更多
关键词 rigid vibration isolation mass composite brace impedance mismatch optimization design vibration and noise reduction
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Study on Design and Application of Plant Acoustic Barrier along Highway
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作者 姚阳 屠书荣 薛芳 《Journal of Landscape Research》 2011年第3期25-28,共4页
Through analysis on characteristic of highway traffic noise and pollution-treating and noise-reducing mechanism,the paper had illustrated feasibility and advantage to reduce traffic noise along highway by making use o... Through analysis on characteristic of highway traffic noise and pollution-treating and noise-reducing mechanism,the paper had illustrated feasibility and advantage to reduce traffic noise along highway by making use of plant acoustic barrier,introduced design model and methods of plant acoustic barrier,and principles and scope for plants' selection.On this basis,by taking K37+100-K37+250 section of Yunnan Chuda Highway for example,application of plant acoustic barrier had been studied,general situation and design schemes of pilot project analyzed,and some matters needing attention proposed.Based on the analysis of a large amount of statistical data and researches on pilot project of noise-reducing by plants along Yunnan Chuda Highway,it hoped to provide reference for similar engineering projects. 展开更多
关键词 HIGHWAY TRAFFic noise PLANT Acoustic BARRIER design
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Top-Down Design of 260k Color TFT-LCD One-Chip Driver ICs
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作者 魏廷存 高武 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2008年第4期706-712,共7页
A top-down design methodology is proposed for the design of TFT-LCD one-chip driver ICs,and a 260k color, 176RGB× 220-dot TFT-LCD one-chip driver IC is successfully developed with silicon verification. This IC is... A top-down design methodology is proposed for the design of TFT-LCD one-chip driver ICs,and a 260k color, 176RGB× 220-dot TFT-LCD one-chip driver IC is successfully developed with silicon verification. This IC is a typical mixed-signal VLSI and is implemented by a 0.18μm HV CMOS process. The static power dissipation is about 5mW for 260k color display mode,and the settling time of the output grayscale voltages within 0.2% error is less than 26μs. 展开更多
关键词 TFT-LCD driver ic top-down design driving circuit mixed-signal VLSI
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Aerodynamic Characteristics and Noise Collaborative Optimization of an Airfoil
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作者 ZHAN Zhihuan GU Chaojie +1 位作者 XIAO Qing CHEN Dongyang 《Wuhan University Journal of Natural Sciences》 CAS CSCD 2020年第3期238-246,共9页
Aerodynamic noise is the main problem restricting its development nowadays in green energy,ocean engineering and aerospace engineering.In order to limit the aerodynamic noise of an airfoil structure,a method is propos... Aerodynamic noise is the main problem restricting its development nowadays in green energy,ocean engineering and aerospace engineering.In order to limit the aerodynamic noise of an airfoil structure,a method is proposed in this paper by designing low noise airfoils.This method optimized the aerodynamic noise of two-dimensional airfoil,and considered the aerodynamic performance of the airfoil at the same time.Based on Joukowski conformal transformation,airfoil geometry is parameterized firstly.Then,the optimization model taking the lift-to-drag ratio and airfoil self-noise as the design objective,is established to modify the airfoil by active set algorithm until the airfoil can satisfy the design condition.Finally,the noise of the optimized airfoil is verified according to the prediction theory of airfoil noise.Moreover,the relationship between airfoil geometry and noise is analyzed.The results show that the lift-to-drag ratio of the optimized airfoil increased,and the noise also decreased.Thus,the optimization method can be used to address special design of low-noise airfoil.Besides,the optimization method in this paper can provide reference for improving lift-to-drag ratio and reducing noise of the airfoil in aircraft and submarine rudder system. 展开更多
关键词 wind turbine blade lift-to-drag ratio aerodynamic noise optimization design of airfoil active set algorithm
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IC封装设备远距离芯片传输装置设计
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作者 邱彪 莫小勇 +1 位作者 梁建智 潘峰 《机械工程与自动化》 2023年第2期89-91,共3页
芯片传输装置是IC封装设备的一个关键部件,其工艺操作性能直接影响IC封装的生产效率和成品率。为了匹配当前芯片远距离传输工艺的新要求,对远距离芯片传输工艺进行了分析,提出了一种双旋转盘交替式直线轨道芯片传输方案。构建了传输装... 芯片传输装置是IC封装设备的一个关键部件,其工艺操作性能直接影响IC封装的生产效率和成品率。为了匹配当前芯片远距离传输工艺的新要求,对远距离芯片传输工艺进行了分析,提出了一种双旋转盘交替式直线轨道芯片传输方案。构建了传输装置结构模型,并进行了芯片传输实施方式描述。 展开更多
关键词 ic封装设备 远距离芯片传输装置 设计
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DYNAMIC DESIGN OF INTERNAL COMBUSTION ENGINE BLOCK STRUCTURE
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作者 Yu, Ming Huang, Rongqing Lou, Yutao 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 1998年第1期39-43,共5页
Several main steps of internal combustion engine block structure dynamic design,such as model set up,structure dynamic response analysis,optimizing design and vibration and noise control,are discussed for the type of... Several main steps of internal combustion engine block structure dynamic design,such as model set up,structure dynamic response analysis,optimizing design and vibration and noise control,are discussed for the type of EQ6100 gasoline engine block 展开更多
关键词 Engine block Dynamic design icE
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