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基于DSP的压力测深系统设计 被引量:1
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作者 冯驰 张海东 《应用科技》 CAS 2009年第11期24-26,共3页
针对压力水深测量系统介绍了其基于DSP(digital signal processing,数字信号处理)的设计,并给出了系统电路设计和软件实现方法.采用TI公司的TMS320F28335作为核心,压阻式液位变送器作为测量传感器来设计测深系统.能够在风浪近水面等环... 针对压力水深测量系统介绍了其基于DSP(digital signal processing,数字信号处理)的设计,并给出了系统电路设计和软件实现方法.采用TI公司的TMS320F28335作为核心,压阻式液位变送器作为测量传感器来设计测深系统.能够在风浪近水面等环境下快速获得准确水深数据,具有反应周期短且可靠性高等特点.系统除实现高速计算水深功能外,还具有通过上位机检测绘制水面波形并对系统工作状态进行控制等功能. 展开更多
关键词 DSP 压力测深 大风浪 近水面
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高准确度压力测深技术的研究(二) 被引量:2
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作者 廖云和 《海洋技术》 1989年第2期17-26,共10页
四、几个深度压力计算公式的讨论 (一)静压力计算公式(A、C普罗卡娅) 由于海水具有压缩性和斜压性,所以静压和深度间的关系相当复杂。
关键词 海水 水位 压力测深
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YC型压力测深仪简介
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作者 李志明 《水利水文自动化》 1989年第1期33-33,共1页
YC型压力测深仪分YC-1、YC-2两种型号。YC-1型机数字显示测量结果,人工记录;YC-2型机由微机处理数据。仪器可在各种缆道和测船上使用。主要技术指标: 1.测深精度: 水深小于3米时,误差≤±2.5%~1厘米; 水深大于3米时,误差≤±... YC型压力测深仪分YC-1、YC-2两种型号。YC-1型机数字显示测量结果,人工记录;YC-2型机由微机处理数据。仪器可在各种缆道和测船上使用。主要技术指标: 1.测深精度: 水深小于3米时,误差≤±2.5%~1厘米; 水深大于3米时,误差≤±1.1%~1厘米; 系统误差≤±0.74%~1厘米。 2.最大量程:20米 3.线性度: 展开更多
关键词 YC型 压力测深 水文仪器
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NKY─94型γ─射线测沙仪的研制和应用 被引量:2
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作者 吴永进 《水利水运科学研究》 CSCD 1996年第2期183-188,共6页
NKY—94型γ─射线测沙仪由γ探头、水深压力传感器、80C31单片机系统和电子线路组成。它实现了双参数快速同步采集处理,提高了测量泥层的分辨能力和测量浮泥、淤泥厚度的精度,拓宽了γ─射线测沙仪的使用环境。
关键词 γ─测沙 压力测深 单片机
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温度变化对压力式测深仪测量结果的影响初探 被引量:1
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作者 王君 庞永超 赵卓英 《计量技术》 2018年第7期11-14,共4页
提出了日常校准工作中两台海洋压力式测深仪在实验室校准后应用于现场测量中所得测量差异过大的现象,为了探寻其产生原因,在实验室条件下设计了一系列校准和测量实验,最终确定了测量差异是由于压力传感器受温度变化导致的。实验人员通... 提出了日常校准工作中两台海洋压力式测深仪在实验室校准后应用于现场测量中所得测量差异过大的现象,为了探寻其产生原因,在实验室条件下设计了一系列校准和测量实验,最终确定了测量差异是由于压力传感器受温度变化导致的。实验人员通过复现现场测量环境温度,对仪器进行了重新校准,利用新参数修正现场测量值,结果表明两台测深仪修正后的测量结果一致性良好。通过对数据的分析,初步发现了温度变化对海水压力测量仪器测量结果的影响规律。 展开更多
关键词 压力测深 压力传感器 校准 温度特性
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Support pressure assessment for deep buried railway tunnels using BQ-index 被引量:6
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作者 WANG Ming-nian WANG Zhi-long +3 位作者 TONG Jian-jun ZHANG Xiao DONG Yu-cang LIU Da-gang 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第1期247-263,共17页
Estimation of support pressure is extremely important to the support system design and the construction safety of tunnels.At present,there are many methods for the estimation of support pressure based on different roc... Estimation of support pressure is extremely important to the support system design and the construction safety of tunnels.At present,there are many methods for the estimation of support pressure based on different rock mass classification systems,such as Q system,GSI system and RMR system.However,various rock mass classification systems are based on different tunnel geologic conditions in various regions.Therefore,each rock mass classification system has a certain regionality.In China,the BQ-Inex(BQ system)has been widely used in the field of rock engineering ever since its development.Unfortunately,there is still no estimation method of support pressure with BQ-index as parameters.Based on the field test data from 54 tunnels in China,a new empirical method considering BQ-Inex,tunnel span and rock weight is proposed to estimate the support pressure using multiple nonlinear regression analysis methods.And then the significance and necessity of support pressure estimation method for the safety of tunnel construction in China is explained through the comparison and analysis with the existing internationally widely used support pressure estimation methods of RMR system,Q system and GSI system.Finally,the empirical method of estimating the support pressure based on BQ-index was applied to designing the support system in the China’s high-speed railway tunnel—Zhengwan high-speed railway and the rationality of this method has been verified through the data of field test. 展开更多
关键词 rock mass classification support pressure deep buried tunnel field test multiple nonlinear regression analysis BQ-Index
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Hydrophilic characteristics of soft rock in deep mines 被引量:2
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作者 Guo Hongyun Li Bing +2 位作者 Zhang Yumei Wang Xinbo Zhang Feng 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2015年第2期177-183,共7页
A series of water absorption tests on dried soft rock have been conducted by the intelligent testing system for water absorption tests in deep soft rock, including tests of water absorption with and without pres- sure... A series of water absorption tests on dried soft rock have been conducted by the intelligent testing system for water absorption tests in deep soft rock, including tests of water absorption with and without pres- sure. The results show that the water absorbing capacity of rock with a certain pressure is larger than that of rock without pressure: however, the relationship between the water absorbing percentage and the time can be expressed by w(t) = a(l - e^-bt). In hi-logarithmic coordinates, the hydrophilic relationship with time in tests with pressure could be characterized by linearity, while they present concave or convex in tests without pressure. Based on the hypothesis that each influential factor is irrelevant and they have a linear correlation with the water absorbing capacity, we calculated the weight coefficient of each factor according to experimental results under different conditions. The calculations demonstrate that the effec- tive porosity, content of smectite and kaolinite are all positively correlated with the water absorption capacity of rock; meanwhile, the fractal dimension of the effective pores presents a negative correlation with the water absorption capacity of rock. The water absorption capacity with pressure increases with increasing illite, chlorite and chlorite/smectite formation and a decrease in illite/smectite formation and the fractal dimension of the effective pores, while it is opposite in tests without pressure. The weight coefficient of smectite is smallest among positive factors, and the fractal dimension of the effective pores is the smallest amongst the negative factors. 展开更多
关键词 Deep soft rock Water absorption tests Porosity Fractal dimension Clay minerals
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Comparative study on pullout behaviour of pressure grouted soil nails from field and laboratory tests 被引量:3
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作者 HONG Cheng-yu YIN Jian-hua PEI Hua-fu 《Journal of Central South University》 SCIE EI CAS 2013年第8期2285-2292,共8页
Pullout resistance of a soil nail is a critical parameter in design and analysis for geotechnical engineers. Due to the complexity of field conditions, the pullout behaviour of cement grouted soil nail in field is not... Pullout resistance of a soil nail is a critical parameter in design and analysis for geotechnical engineers. Due to the complexity of field conditions, the pullout behaviour of cement grouted soil nail in field is not well investigated. In this work, a number of field pullout tests of pressure grouted soil nails were conducted to estimate the pullout resistance of soil nails. The effective bond lengths of field soil nails were accurately controlled by a new grouting packer system. Typical field test results and the related comparison with typical laboratory test results reveal that the apparent coefficient of friction (ACF) decreases with the increase of overburden soil pressure when grouting pressure is constant, but increases almost linearly with the increase of grouting pressure when overburden pressure (soil depth) is unchanged. Water contents of soil samples at soil nail surfaces show obvious reductions compared with the results of soil samples from drillholes. After soil nails were completely pulled out of the ground, surface conditions of the soil nails and surrounding soil were examined. It is found that the water content values of the soil at the soil/nail interfaces decrease substantially compared with those of soil samples extracted from drillholes. In addition, all soil nails expand significantly in the diametrical direction after being pulled out of ground, indicating that the pressurized cement grout compacts the soil and penetrates into soil voids, leading to a corresponding shift of failure surface into surrounding soil mass significantly. 展开更多
关键词 soil nail apparent coefficient of friction overburden soil pressure grouting pressure
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Preliminary analysis on the source properties and seismogenic structure of the 2017 M_s7.0 Jiuzhaigou earthquake 被引量:10
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作者 Zujun XIE Yong ZHENG +9 位作者 Huajian YAO Lihua FANG Yong ZHANG Chengli LIU Maomao WANG Bin SHAN Huiping ZHANG Junjie REN Lingyun JI Meiqin SONG 《Science China Earth Sciences》 SCIE EI CAS CSCD 2018年第3期339-352,共14页
At GMT time 13:19, August 8, 2017, an M1.0 earthquake struck the Jiuzhaigou region in Sichuan Province, China, causing severe damages and casualties. To investigate the source properties, seismogenic structures, and ... At GMT time 13:19, August 8, 2017, an M1.0 earthquake struck the Jiuzhaigou region in Sichuan Province, China, causing severe damages and casualties. To investigate the source properties, seismogenic structures, and seismic hazards, we systematically analyzed the tectonic environment, crustal velocity structure in the source region, source parameters and rupture process, Coulomb failure stress changes, and 3-D features of the rupture plane of the Jiuzhaigou earthquake. Our results indicate the following: (1) The Jiuzhaigou earthquake occurred on an unmarked fault belonging to the transition zone of the east Kunlun fault system and is located northwest of the Huya fault. (2) Both the mainshock and aftershock rupture zones are located in a region where crustal seismic velocity changes dramatically. Southeast to the source region, shear wave velocity at the middle to lower crust is significantly low, but it rapidly increases northeastward and lies close to the background velocity across the rupture fault. (3) The aftershock zone is narrow and distributes along the northwest-southeast trend, and most aftershocks occur within a depth range of 5-20 km. (4) The focal mechanism of the Jiuzhaigou earthquake indicates a left-lateral strike-slip fault, with strike, dip, and rake angles of 152~, 74~ and 8~, respectively. The hypocenter depth measures 20 km, whereas the centroid depth is about 6 kin. The co-seismic rupture mainly concentrates at depths of 3-13 km, with a moment magnitude (Mw) of 6.5. (5) The co-seismic rupture also strengthens the Coulomb failure stress at the two ends of the rupture fault and the east segment of the Tazang fault. Aftershocks relocation results together with geological surveys indicate that the causative fault is a near vertical fault with notable spatial variations: dip angle varies within 660-89~ from northwest to southeast and the average dip angle measures -84~. The results of this work are of fundamental importance for further studies on the source characteristics, tectonic environment, and seismic hazard evaluation of the Jiuzhaigou earthquake. 展开更多
关键词 Jiuzhaigou earthquake Velocity structure Source parameters Seismogenic structure Seismic hazard
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