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Full-scale site evaluation of ventilation expressway embankments underlain by warm permafrost along the Gonghe−Yushu Expressway

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Frontiers of Structural and Civil Engineering 2023年第7期17卷 1047-1059页

作者： Shuangjie WANG Qi ZHANG Yuanhong DONG Kun YUAN Binhua HU Huilong zhao nanlu zhao CCCC First Highway Consultants Co. Ltd.Xi’an 710065China State Key Laboratory of Road Engineering Safety and Health in Cold and High-Altitude Regions Xi’an 710065China Qinghai Huashixia Permafrost Highway Engineering Safety National Observation and Research Station Xi’an 710065China

Ventilation embankments,including those with forced ventilation,natural ventilation,and combination of these,were adopted for the construction of the Gonghe−Yushu Expressway in warm permafrost *** evaluate the actual thermal performance of ventilation embankment in the Qinghai−Tibet Plateau,four types of ventilation embankments were selected as objects,and their long-term thermal characteristics were analyzed based on monitoring *** was found that:1)under the strong scale effect of a wide embankment,the crushed-rock embankment(CRE)was warming up and the permafrost table was declining year by ***,the combined ventilated slab and CRE and ventilated ducts embankment can effectively decrease the ground temperature and raise permafrost table in the year with a colder winter;2)transverse temperature difference caused by the shady–sunny slope effect existed in all the four ***,it was weakened by the combined ventilated slab and CRE and the ventilated ducts embankment due to their stronger cooling effect;and 3)the pre-existing embankment had a remarkable thermal disturbance to the adjacent newly-built embankment,so a reasonable embankment spacing should be considered in practical *** findings would provide a reference for construction of expressway embankments in permafrost regions.

关键词： warm permafrost expressway ventilation embankments temperature field

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STUDY ON THICKNESS DETECTION OF IDUSTRIAL PIPE NETWORK BY HIGH-FREQUENCY ULTRASOUND

STUDY ON THICKNESS DETECTION OF IDUSTRIAL PIPE NETWORK BY HI...

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2010全国压电和声波理论及器件技术研讨会

作者： Ji-min zhao,Shi-feng YANG,Yang LI,Xiu-qing WANG College of Electronic Information and Automation,Tianjin University of Science & Technology, 1038 Dagu nanlu,Hexi District,Tianjin 300222,China

The inside and outside surfaces of the industrial pipe network could engender the oxidation layer by corrosion because of long-term *** could even put industrial production and human safety into a potential *** the non-destructive inspection of the metal thickness of pipe networks and the deduction of the erosive distribution of the inference wall is of great ***,because the oxidation layer/metal matrix interface reflection signal is low and the resolution is low because of the pulse peak width that is used,the current pipeline thickness measurement instrument is unable to accurately measure the thickness of the pure metal wall and the oxide *** is to say,the current instrument measurement of the thickness of the pipe wall is the sum of the metal layer and the oxide,rather than the pure metal layer which contributes to the *** errors will occur during the check of the pipeline strength and the calculation of the *** order to overcome problems that exist in the current ultrasonic measurement of the thickness of the industrial pipe wall,a high-frequency ultrasonic thickness measurement system is proposed in this paper.A high-frequency,narrow-pulse,small chip perforated wedge of longitudinal and transverse sensor is adopted,combined with a broad-spectral-bandwidth oscilloscope,thus composing the metal layer and wall pipe oxide thickness measurement *** system could greatly improve the testing precision and *** with the cross-correlation function method,the distinguished precision of the delay between reflected signals is improved(experiments showed that the thinnest oxide thickness that could be accurately detected is 0.07mm),so the erosive distribution of the steel tube wall could be accurately deduced.A formula for calculating the smallest theoretical resolution of the system is presented,which lays a foundation of the accurate detection of industrial pipe wall stress and other phys

关键词： Industrial pipe non-destructive inspection high frequency ultrasonic testing precision

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CROP WATER STRESS MEASUREMENT SYSTEM BASED ON ACOUSTICAL EMISSION TECHNOLOGY

CROP WATER STRESS MEASUREMENT SYSTEM BASED ON ACOUSTICAL EMI...

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第三届全国压电和声波理论及器件技术研讨会

作者： Shi-feng YANG,Xiu-qing WANG,Ji-min zhao and Jian-ying GUO College of Electronic Information and Automation,Tianjin University of Science & Technology 1038 Dagu nanlu,Hexi District,Tianjin 300222,China

A microcomputer-based system of continuously measures water stress in crop in a non-destructive testing method was *** by cohesion between water molecules or adhesion to the conduit wall,the crop xylem cavitation was accompanied by the vessel walls vibration which is the indicator of the water *** physics of ultrasonic acoustic emissions(AEs) were used to measure the crop xylem cavitation events which were the transmission of *** acoustic emissions could be measured both in the audio frequencies and in ultrasonic frequencies between 0.1 and 1 *** optimize the cavitation measurement precision,the PCI-2 data acquisition equipment(DAQ) and R15 sensors,the Physical Acoustics Corp.(PAC),were *** data recorded by the DAQ transferred the microcomputer to be processed and *** conclusions can be draw:cavitation induce AEs tend to shift to higher frequency when crop wood dehydration phenomena produces;the strongest frequencies of AEs in the range of 100-300KHz;to some extend,the frequencies and counts changed gradually with the environment of the temperature. illumination,humidity,concentration of carbon dioxide,transpiration:an interruption of water supply or over-irrigation can easily result in changing of the AEs Frequency and *** system could be useful for agronomists testing irrigation regulation and in search of non-destructive of recording the water stress under the greenhouse conditions,

关键词： Non-destructive testing ultrasonic acoustic emissions xylem cavitation data acquisition

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THE RESEARCH OF ACOUSTIC WAVE NON-DESTRUCTIVE EXAMINATION TECHNOLOGY FOR ANCHORING QUALITY OF ANCHORED BOLT

THE RESEARCH OF ACOUSTIC WAVE NON-DESTRUCTIVE EXAMINATION TE...

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2010全国压电和声波理论及器件技术研讨会

作者： Ji-min zhao,Shi-feng YANG,Pei-cheng TANG,Xiu-qing WANG College of Electronic Information and Automation,Tianjin University of Science & Technology,1038 Dagu nanlu, Hexi District,Tianjin 300222,China

The key factor to the evaluation of bolt performance is its length embedded in cement mortar and the saturation between the bolt and ***,the main task of testing the quality of anchored bolt is to evaluate these two technical *** earlier means of anchoring test is to test the anchor pullout *** there are many flaws in this approach,such as destructive,not fully reflecting the quality of the anchor bolt,the situation for cement mortar to package the reinforced bar can not be detected,and the actual length of anchor can not be detected,*** view of this,in this paper,the technology of wave nondestructive examination of anchoring quality is *** technology determines quickly and accurately the anchor construction conditions,and also reduces the damage to the existing *** theoretical basis is the acoustic wave propagation in the *** saturation detection is based on the theory of wave propagation in the *** consists of exciting at the exposed end of the bolt,which results in elastic stress wave propagating along the bar and a reflected signal when the medium at the bottom or around the bar *** can determine the density of anchor position in cement mortar by the reflected signals from the sensor attached to the end of the *** waveform analysis,we can calculate the position of non-dense based on the two adjacent points of reflected ***,in the premise of fixed excitation energy,calculation of the mean square root of the amplitude of waveform behind reflex points can determine the density of cement mortar *** is proved by theoretical analysis and practical application that this technology is a very effective method for nondestructive testing of bolt.

关键词： Anchoring quality of anchored bolt nondestructive testing acoustic stress wave excitation

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AtTMEM18 plays important roles in pollen tube and vegetative growth in Arabidopsis

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Journal of Integrative Plant Biology 2016年第7期58卷 679-692页

作者： Xiao-Ying Dou Ke-Zhen Yang zhao-Xia Ma Li-Qun Chen Xue-Qin Zhang Jin-Rong Bai De Ye Beijing Radiation Center 12 Haidian NanluBeijing 100875China State Key Laboratory of Plant Physiology and Biochemistry College of Biological SciencesChina Agricultural University2 Yuanmingyuan XiluBeijing 100193China.

In flowering plants, pollen tube growth is essential for delivery of male gametes into the female gametophyte or embryo sac for double fertilization. Although many genes have been identified as being involved in the process, the molecular mechanisms of pollen tube growth remains poorly understood. in this study, we identified that the Arabidopsis Transmembrane Protein 18 （AtTMEM18） gene played important roles in pollen tube growth. The AtTMEM18 shares a high similarity with the Transmembrane 18 proteins （TMEM18s） that are conserved in most eukaryotes and may play important roles in obesity in humans. Mutation in the AtTMEM18 by a Ds insertion caused abnormal callose deposition in the pollen grains and had a significant impact on pollen germination and pollen tube growth. AtTMEM18 is expressed in pollen grains, pollen tubes, root tips and other vegetative tissues. The pollen-rescued assays showed that the mutation in AtTMEM18 also caused defects in roots, stems, leaves and transmitting tracts. AtTMEM18-GFP was located around the nuclei. Genetic assays demonstrated that the localization of AtTMEM18 around the nuclei in the generative cells of pollen grains was essential for the male ***, expression of the rice TM EM18-homologous protein （OsTMEM18） driven by LAT52 promoter could recover the fertility of the Arabidopsis attmem18 mutant. These results suggested that the TMEM18 is important for plant growth in Arabidopsis.

关键词： Arabidopsis male gametophyte plant pollen TMEM18 transmembrane protein

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