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深基坑深层水平位移量测段的选择探讨
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作者 丁鸿志 厉风 +2 位作者 陈钊锋 周峰 庞学研 《现代交通技术》 2024年第5期89-92,共4页
深层水平位移是深基坑变形最重要的监测项目之一,可用于评判基坑的安全性与稳定性。受基坑开挖深度及数据精度要求的影响,当前测斜仪的数据采集存在耗时长、效率低、成本投入大等问题。在监测实施中将量测段由0.5 m改为1.0 m,可以提高... 深层水平位移是深基坑变形最重要的监测项目之一,可用于评判基坑的安全性与稳定性。受基坑开挖深度及数据精度要求的影响,当前测斜仪的数据采集存在耗时长、效率低、成本投入大等问题。在监测实施中将量测段由0.5 m改为1.0 m,可以提高数据采集效率,但也存在一些不足。通过理论联系实际的方法,结合工程实测数据,深入研究了测斜仪采用0.5 m和1.0 m量测段施测时数据间的差异,并给出了采用1.0 m量测段进行测量的前提条件。 展开更多
关键词 深基坑 深层水平位移 量测段 精度 斜仪
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A Method for Detecting Adhesive Related-Factors of Streptococcus suis Serotype 2 by Real-time PCR 被引量:1
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作者 汪伟 何孔旺 +9 位作者 倪艳秀 周俊明 张雪寒 俞正玉 吕立新 茅爱华 温立斌 王小敏 李彬 郭容莉 《Agricultural Science & Technology》 CAS 2013年第10期1378-1382,共5页
[Objective] This study aimed to establish a method for quantitative detection of mRNA transcriptional level of SS2 adhesive related-factors of Streptococcus suis serotype 2 (SS2) by fluorescent quantitative PCR. []V... [Objective] This study aimed to establish a method for quantitative detection of mRNA transcriptional level of SS2 adhesive related-factors of Streptococcus suis serotype 2 (SS2) by fluorescent quantitative PCR. []Vlethod] The gene fragments en- coding SS2 adhesive related-factors MRP, FBPS and CPS2J and a housekeeping gene aroA were amplified by reverse transcription PCR from the total RNA of SS2, cloned, and sequenced. The recombinant plasmids containing the target genes were constructed, and used as templates in Real-time PCR. [Result] Dynamic curves, stan- dard curves and melting curves of the adhesive related-factors and aroA were ob- tained by the optimized Real-time PCR system. The standard curves showed a good linear relationship between template copy number and circulation number, and the correlation coefficients (FF) of the standard curves were over 0.995. Also, these as- says were highly specific a^d there was single specific melting peak for every gene. Moreover, the assays were highly sensitive and had a detection limit of 1.0×102 copies in 1 μl of initial templates. Finally, it was highly repeatable and had a coeffi- cient of variation less than 2% for intra-assay. [Conclusion] This study will provide a way to reveal the adhesion mechanism of SS2 to different host cells at molecular level. 展开更多
关键词 Streptococcus suis serotype 2 Adhesive related-factors (adhesins) Real- time PCR
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Distributed Sampling Measurement Model in a Large-Scale High-Speed IP Networks 被引量:1
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作者 龚俭 程光 《Journal of Southeast University(English Edition)》 EI CAS 2002年第1期40-45,共6页
The distributed passive measurement is an important technology for networkbehavior research. To achieve a consistent measurement, the same packets should be sampled atdistributed measurement points. And in order to es... The distributed passive measurement is an important technology for networkbehavior research. To achieve a consistent measurement, the same packets should be sampled atdistributed measurement points. And in order to estimate the character of traffic statistics, thetraffic sample should be random in statistics. A distributed samplingmask measurement model isintroduced to tackle the difficulty of measuring the full trace of high-speed networks. The keypoint of the model is to choose some bits that are suitable to be sampling mask. In the paper, thebit entropy and bit flow entropy of IP packet headers in CERNET backbone are analyzed, and we findthat the 16 bits of identification field in IP packet header are fit to the matching field ofsampling mask. Measurement traffic also can be used to analyze the statistical character ofmeasurement sample and the randomicity of the model. At the same time the experiment resultsindicate that the model has a good sampling performance. 展开更多
关键词 sampling measurement bit entropy matching field identification field
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THE CONFIDENCE EVALUATION FOR AIRBORNE GPS DATA 被引量:1
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作者 LIU Jiyu CHEN Xiaoming 《Geo-Spatial Information Science》 2000年第1期50-56,共7页
GPS kinematic carrier phase measurements can be used to determine seven di- mension state and three attitude parameters of a motional carrier,such as an aircraft or a low- earth-orbit spacecraft,on which an antenna is... GPS kinematic carrier phase measurements can be used to determine seven di- mension state and three attitude parameters of a motional carrier,such as an aircraft or a low- earth-orbit spacecraft,on which an antenna is installed to receive GPS signals. It is known from airborne GPS test results for photogrammetry in China since 1994 that GPS carrier phase measurements in a motional environment have acquired external accuracies of ± 7. 9cm for two dimensional positions and ± 18. 1cm for point heights. This paper describes airborne GPS carrier phase -measurements with multireference stations and discusses how to evaluate the confidence of GPS kinematic data. 展开更多
关键词 airborne GPS receiver GPS kinematic carrier phase measurement multireferene ground station
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A Novel 360°3D Profilometry
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作者 SONG Yuanhe,ZHAO Hong,FAN Hua,CHEN Wenyi,TAN Yushan (Research Institute for Laser & Infrared Applications, Xi’an Jiaotong University,Xi’an 710049,CHN) 《Semiconductor Photonics and Technology》 CAS 1998年第1期45-49,共5页
A new method of 360° turning 3D shape measurement in which light sectioning and phase shifting techniques are both used is presented in this paper.A sine light field is applied in the projected light stripe,meanw... A new method of 360° turning 3D shape measurement in which light sectioning and phase shifting techniques are both used is presented in this paper.A sine light field is applied in the projected light stripe,meanwhile phase shifting technique is used to calculate phase of the light slit.Thereafter wrapped phase distribution of the slit is formed and the unwrapping process will be made by means of the height information based on the light sectioning method.Therefore phase measuring results with better precision can be obtained.At last the target 3D shape data can be produced according to geometric relationships between phases and the object heights.The principles of this method are discussed in detail and experimental results are shown in this paper. 展开更多
关键词 Light Sectioning Phase Shifting Phase Unwrapping Algorithm 3D Shape Measurement
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Quantitative research of diagenesis:its effect on pore evolution of the Fuyu oil reservoir in the north Qijia region 被引量:4
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作者 HAO Guoli SHAN Xuanlong +1 位作者 LIU Wanzhu WANG Qingbin 《Mining Science and Technology》 EI CAS 2010年第5期770-777,共8页
From observing cores of 18 wells,identifying 175 ordinary thin sections and 61 thin casting sections,energy spectrum analyses of 37 samples,homogenization temperature measurement of fluid inclusions of 11 samples,we d... From observing cores of 18 wells,identifying 175 ordinary thin sections and 61 thin casting sections,energy spectrum analyses of 37 samples,homogenization temperature measurement of fluid inclusions of 11 samples,we determine the types of diagenesis and pores of the Fuyu oil reservoir in the north Qijia region.We classified the pores and measured their plane porosity using CIA 2000,the software of rock image analysis,calculated the effect of different kinds of diagenesis on porosity,studied the controlling actions of diagenesis to pore evolution quantitatively,combined with burial history,thermal history and their diagenetic environments.Our results show that mechanical compaction and carbonate cementation are the major destructive diagenesed,developed during early diagenesis stages.The reduction in porosity by mechanical compaction and carbonate cementation are about 25% and 8%,while the destructive intensity of siliceous cementation and clay mineral cementation is relatively much smaller,i.e.,the reduction of porosity is about 2% and 0.2% Dissolution is constructive diagenesis,the increment of porosity is about 6%.There are four diagenesis evolution stages,during which the porosity reduced from 30%~38% to 2%~20%.Mechanical compaction and early cementation are the main diageneses in the early diagenesis stages,when porosity was reduced to 2%~10%.Dissolution is the main diagenesis of an A I substage of the middle diagenesis stage,when porosity increased 1%~8%.The dissolution of the A Ⅱ substage of the middle diagenesis stage affected by late cementation,raised porosity 1%~5%.The porosity varied slightly during the middle stage B. 展开更多
关键词 north Qijia region Fuyu oil reservoir DIAGENESIS pore evolution quantitative research
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Selection of a Minimal Complexity of a Transformation Functions of Pressure Sensors with a Maintained Given Measurement Accuracy
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作者 Ekaterina Lapina Andrey Lapin 《Journal of Mechanics Engineering and Automation》 2015年第10期585-590,共6页
For series manufacture of pressure sensors, stage of technological tests is performed, related to a definition of the manufacturing accuracy of the sensors. Technological test plan of pressure sensors involves testing... For series manufacture of pressure sensors, stage of technological tests is performed, related to a definition of the manufacturing accuracy of the sensors. Technological test plan of pressure sensors involves testing the sensors on certain fixed temperature and pressure points available in the table. According to a test results, we determine transformation function mathematical model coefficients of sensors and accordance by the claimed accuracy class, of the manufactured sensors. The cost of pressure sensors mostly depends on the cost of this step and determined by the complexity of the used transformation function model. The analysis of a contemporary works associated with the choice of transformation functions for smart pressure sensors. A new proposed indicator of model complexity of a sensor transformation function. In details shown features of the complexity indicator use and given an example. In the article was set and resolved the task to reduce the cost of the tests for commercially available sensors, by reducing the number of temperature points, without compromising the accuracy of the sensor measurement ability. 展开更多
关键词 Pressure transducers (sensors) transformation function smart pressure sensors function of a minimal complexity PRESSURE measurement accuracy.
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Measurment of gas-liquid two-phase slug flow with a Venturi meter based on blind source separation
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作者 王微微 梁霄 张明柱 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第9期1447-1452,共6页
We propose a novel flow measurement method for gas–liquid two-phase slug flow by using the blind source separation technique. The flow measurement model is established based on the fluctuation characteristics of diff... We propose a novel flow measurement method for gas–liquid two-phase slug flow by using the blind source separation technique. The flow measurement model is established based on the fluctuation characteristics of differential pressure(DP) signals measured from a Venturi meter. It is demonstrated that DP signals of two-phase flow are a linear mixture of DP signals of single phase fluids. The measurement model is a combination of throttle relationship and blind source separation model. In addition, we estimate the mixture matrix using the independent component analysis(ICA) technique. The mixture matrix could be described using the variances of two DP signals acquired from two Venturi meters. The validity of the proposed model was tested in the gas–liquid twophase flow loop facility. Experimental results showed that for most slug flow the relative error is within 10%.We also find that the mixture matrix is beneficial to investigate the flow mechanism of gas–liquid two-phase flow. 展开更多
关键词 Two-phase slug flow Flow measurement Differential pressure Blind source separation Independent component analysis
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Surveying on two-zone height of sublevel strip mining 被引量:3
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作者 WU Chao-fan WU Wen-jin +1 位作者 YANG Wei-min WANG Han-jun 《Journal of Coal Science & Engineering(China)》 2010年第2期129-134,共6页
The site drilling packer permeability test and TEM to the 2100 workface in Gucheng coalmine determined the two-zone height under sublevel strip mining.The conclusion considers that the lying strata deterioration law o... The site drilling packer permeability test and TEM to the 2100 workface in Gucheng coalmine determined the two-zone height under sublevel strip mining.The conclusion considers that the lying strata deterioration law of the strip mining is similar to that of the sublevel mining.Thus, against that the actually measured data lacked, it is feasible to refer to the reservation of the waterproof coal pillar in the neighbor coalmine under sublevel situation.However, it is necessary to further launch the research on lying strata deterioration law under sublevel striping mining for the purpose of providing the right foundation for the layout of the workface not mined so far and the reservation of the waterproof coal pillar in the mining area. 展开更多
关键词 sublevel strip mining water conducted zone collapsed zone pressure water test
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Performance of Smallholder Dairy Farming in Nakuru County, Kenya
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作者 Dennis Kinambuga Benjamin K. Mutai +2 位作者 George Owuor Aquilars M. Kalio Emmanuel K. Kinuthia 《Journal of Agricultural Science and Technology(A)》 2012年第4期481-488,共8页
The Kenya dairy sub-sector has been undergoing developments since the 1980s in the areas of adoption of intensive dairy farming, especially zero grazing. There have been concerted efforts by the government and other d... The Kenya dairy sub-sector has been undergoing developments since the 1980s in the areas of adoption of intensive dairy farming, especially zero grazing. There have been concerted efforts by the government and other development partners to commercialize the sub-sector so as to make it more profitable to farmers, especially smallholder farmers, but the profitability in the sector continues to be variable with some smallholder farmers making losses. The causes of the varying profits have not been empirically established, with the influence of institutional arrangements and financial factors contributing to this inconsistency not fully established. This study dwelt on establishing the critical institutional arrangements and financial factors that constrain the profitability of smallholder dairy farmers in Nakuru County. A multi-stage sampling procedure was used to select respondents. Data were collected by structured interviews at the farm level. Data Envelopment Analysis (DEA) was used to come up with profit efficiency rankings among the farmers, and the Frontier Model was used to establish the factors that constrain profit efficiency. The mean efficiency according to the results was 86%. The farm and farmer characteristics that were significant in explaining profitability efficiency according to the frontier results were: feeding system, breed type, and gender. The financial characteristics included debt amount and debt asset ratio. Additionally, issues of trust were also found to have an effect on profitability, and they included trust in local buyer price, trust in unit of measurement of institutional buyer, and trust in unit of measurement of middlemen. 展开更多
关键词 PROFITABILITY data envelopment analysis dairy farming SMALLHOLDER
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Parameters Influencing the Noise Emission of Planing Machines
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作者 Lucia Gross Uwe Heisel 《Journal of Environmental Science and Engineering(A)》 2016年第2期102-108,共7页
Regarding woodworking machines, machine acoustics are of particular significance due to the high noise emission of these machines. Among other things, this can be attributed to the adoption of the European Commission ... Regarding woodworking machines, machine acoustics are of particular significance due to the high noise emission of these machines. Among other things, this can be attributed to the adoption of the European Commission Machinery Directive as a national law, which demands protection against noise emission in the design phase of new machines. In order to accomplish this, it is necessary to examine and locate the causes of emissions on existing machines. In this paper, the sound source is located through sound intensity measurements, using planing machines as an example, which are particularly noise-intensive woodworking machines. In addition, different influencing parameters on noise emission are analyzed, such as manual and automatic feed, rotational speed and the influence of the type of wood of the workpiece. 展开更多
关键词 Production process noise emission woodworking machines.
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