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PHFH──Ⅰ型房式仓磷化氢自动环流熏蒸装置试验报告
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作者 廖吉翔 《四川粮油科技》 1996年第2期27-28,44,共3页
PHFH──Ⅰ型房式仓磷化氢自动环流熏蒸装置试验报告遂宁市粮食局(629000)廖吉翔近年来,我市修建的5m高仓较多,且大多采用“双低”表层布袋与粮堆探管相结合的施药方法,不但投药点较多、分散,熏蒸人员接触药剂时间较... PHFH──Ⅰ型房式仓磷化氢自动环流熏蒸装置试验报告遂宁市粮食局(629000)廖吉翔近年来,我市修建的5m高仓较多,且大多采用“双低”表层布袋与粮堆探管相结合的施药方法,不但投药点较多、分散,熏蒸人员接触药剂时间较长,而且pH3气体仅靠粮堆内微气流... 展开更多
关键词 粮仓 房式仓 磷化氢 自动环流 熏蒸装置
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ANALYSIS OF CAPITAL FLOW WITH GIS——Two Approaches for Regional Investment in China 被引量:1
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作者 YAO Yong-ling ( Public Administration School, Renmin University of China, Beijing 100872, P. R. China) 《Chinese Geographical Science》 SCIE CSCD 2003年第1期2-8,共7页
GIS technology has been mostly concerned with handling physical data andmodeling physical environment. However, the retirements of GIS for handling socio-economicinformation in many cases are different from those conc... GIS technology has been mostly concerned with handling physical data andmodeling physical environment. However, the retirements of GIS for handling socio-economicinformation in many cases are different from those concerning phenomena in the physical environment.Analysis of capital flow among regions requires the transitions both from economic values tophysical landscape and from physical surface to economic explanation. Rapid growth of Chineseeconomy comes mainly from investment. There are two main ways for obtaining high growth ofinvestment. One is government expenditure which usually invests in regional facility and amenityblock, which is regarded as stimulus for attracting investment. The other is the creation ofinvesting center and corresponding capital source areas, both of which need the central city withthe highest growth rate of investment among regions. This paper presents the cluster areas of bothgovernment revenue and total investment, the potential situation of capital flow between centralcity Shanghai and its neighbor provinces by using Classification' and Interpolation' functions ofArcView GIS. 展开更多
关键词 capital flow geographic information system (GIS) regional investment cluster analysis
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SDG-based Model Validation in Chemical Process Simulation 被引量:7
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作者 张贝克 许欣 +1 位作者 马昕 吴重光 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第8期876-885,共10页
Signed direct graph (SDG) theory provides algorithms and methods that can be applied directly to chemical process modeling and analysis to validate simulation models, and is a basis for the development of a software e... Signed direct graph (SDG) theory provides algorithms and methods that can be applied directly to chemical process modeling and analysis to validate simulation models, and is a basis for the development of a software environment that can automate the validation activity. This paper is concentrated on the pretreatment of the model validation. We use the validation scenarios and standard sequences generated by well-established SDG model to validate the trends fitted from the simulation model. The results are helpful to find potential problems, assess possible bugs in the simulation model and solve the problem effectively. A case study on a simulation model of boiler is presented to demonstrate the effectiveness of this method. 展开更多
关键词 model validation signed direct graph chemical process qualitative trend
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Experimental Noise Analysis of Reed Switch Sensor Signal under Environmental Vibration
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作者 Odgerel Ayurzana Hiesik Kim 《Computer Technology and Application》 2016年第2期96-102,共7页
The chattering noise problem of reed switch sensor signal for Automatic Meter Reading system was analyzed experimentally under various types of external vibrations and shocks. The external vibration level amplitude wa... The chattering noise problem of reed switch sensor signal for Automatic Meter Reading system was analyzed experimentally under various types of external vibrations and shocks. The external vibration level amplitude was measured with an accelerometer. To apply for water flow measurement devices, the reed switch sensors should keep high reliability. But the measured digital meter data are occurred difference or errors by chattering noise. The reed switch contains chattering error by itself at the force equivalent position. The vibrations such as passing vehicle near to the reed switch installed location causes chattering. In order to reduce chattering error, most system uses just software methods, for example using digital filter algorithm and also statistical calibration methods. However software approaches were implemented for reducing chattering error, there has still generated chattering error due to external mechanical vibrations and magnetic field. The chattering errors can be reduced by changing leaf spring structure using mechanical hysteresis characteristics. 展开更多
关键词 Noise analysis ACCELEROMETER MAGNET VIBRATION reed switch sensor chattering error.
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A comparison study of the simulation accuracy between WRF and MM5 in simulating local atmospheric circulations over Greater Beijing 被引量:3
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作者 LIU ZhenXin LIU ShuHua +3 位作者 HU Fei LI Ju MA YanJun LIU HePing 《Science China Earth Sciences》 SCIE EI CAS 2012年第3期418-427,共10页
Several multi-scale numerical simulation experiments were carried out using the mesoscale modeling systems MM5V3.7 and WRFV2.2 for Greater Beijing to estimate the accuracy of WRF and MM5 in simulating the characterist... Several multi-scale numerical simulation experiments were carried out using the mesoscale modeling systems MM5V3.7 and WRFV2.2 for Greater Beijing to estimate the accuracy of WRF and MM5 in simulating the characteristics and variations of mesoscale local circulation in the atmospheric boundary layer of this area. We simulated the horizontal distribution and diurnal variations of temperature and wind fields near the ground and compared them with Automatic Weather System (AWS) data collected from 19 AWS stations in Beijing. Correlation and error analyses were also made. The modeling and statistical results showed that both WRF and MM5 model the temperature field near the ground significantly better than they model the wind field. The temperature field simulated by MM5 is more coincident than that of WRF with the AWS observation records, while WRF does better than MM5 in simulating the wind field, especially under the condition of gusty wind. Neither WRF nor MM5 can capture the fine structure of urban architectural complexity, which is the main error in the wind field simulation. Both models underestimate the land surface temperature at night and overestimate the temperature during the day. All the above results are supported by statistical analysis. 展开更多
关键词 WRF MM5 Greater Beijing local atmospheric circulation simulation accuracy comparison study
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Noise reduction in cavity flow by addition of porous media 被引量:2
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作者 Ruqian Guo Xiaopeng Chen +2 位作者 Zhenhua Wan Haibao Hu Shuai Cui 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2022年第2期68-80,I0003,共14页
Self-sustained oscillation and the sound radiation of flow over an open cavity is of great importance in nature and industry.Influences of filled porous media in the cavity are investigated numerically by using a latt... Self-sustained oscillation and the sound radiation of flow over an open cavity is of great importance in nature and industry.Influences of filled porous media in the cavity are investigated numerically by using a lattice Boltzmann method in two-dimensional space.It is shown that the outcomes of the porous patch depend on the location of the patch and the original flow mode,namely shear layer(SL)and wake mode(WM).For SL flow,the porous patch either damps the vortical flow or suppresses the generation of the secondary vortex sheet on the wall.The later effect destabilizes the SL.Consequently,the radiated sound is reduced as the patch is on the trailing edge,and increased with porous patch on the floor,respectively.For flow in WM,a transition from WM to SL mode is found when the porous patch is set either on the floor or behind the leading wall.In the cases,the recirculating flow on large scale is blocked significantly due to the porous patch,therefore,the WM flow is not sustained.On the other hand,the porous patch on the trailing edge slightly weakens the sound due to dissipation.The study shows that assembling of porous media in the flow field decreases the radiated sound level only if it is done carefully. 展开更多
关键词 Cavity flow Lattice Boltzmann method Porous media AEROACOUSTIC VORTEX
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