Research and Application of High-Density Resistivity Method in Seawater Intrusion Investigation in Laizhou Bay

The disaster of seawater intrusion seriously affects people's lives and restricts economic development,so the detection and treatment of seawater intrusion is a long-term task.On the basis of field investigation and water quality analysis,according to the change characteristics of apparent resistivity of groundwater after Cl-reaches 250 mg/L,the theoretical basis for the application of high-density resistivity method was determined,and the characteristic values of apparent resistivity for seawater intrusion interfaces in different geological characteristic regions in Laizhou Bay area were determined by typical profile tests.Combined with water quality investigation and other means,profiles for the high-density resistivity method were arranged,and the interfaces between saline and fresh water were accurately divided.

Contrast between 2D inversion and 3D inversion based on 2D high-density resistivity data

The 2D data processing adopted by the high-density resistivity method regards the geological structures as two degrees, which makes the results of the 2D data inversion only an approximate interpretation;the accuracy and effect can not meet the precise requirement of the inversion. Two typical models of the geological bodies were designed, and forward calculation was carried out using finite element method. The forward-modeled profiles were obtained. 1% Gaussian random error was added in the forward models and then 2D and 3D inversions using a high-density resistivity method were undertaken to realistically simulate field data and analyze the sensitivity of the 2D and 3D inversion algorithms to noise. Contrast between the 2D and 3D inversion results of least squares inversion shows that two inversion results of high-density resistivity method all can basically reflect the spatial position of an anomalous body. However, the 3D inversion can more effectively eliminate the influence of interference from Gaussian random error and better reflect the distribution of resistivity in the anomalous bodies. Overall, the 3D inversion was better than 2D inversion in terms of embodying anomalous body positions, morphology and resistivity properties.

Application of high-density resistivity method to evaluate safety around Minyan Tunnel,Helong City

By determining the distribution and extent of geological structures surrounding the Mingyan Tunnel,Xicheng Town,Helong City,Jilin Province,we can evaluate the stability of the rock mass and assess potential hazards during tunnel construction.We use the high-density resistivity method to analyze the subsurface structure of the study area.Conductive anomalies are likely to represent joint and fissure systems within strongly weathered host rocks,and the bedrock surrounding the tunnel is relatively stable and does not contain well-developed faults.High-density resistivity analysis can provide valuable information in the context of tunnel engineering and safety.

Viability of high-density resistivity method for evaluating mountain slope stability in Erdaojiang District,Tonghua City,China

The authors employ the high-density resistivity method to image the subsurface structure of a mountain in Erdaojiang District,Tonghua City,Jilin Province,China,to evaluate the potential risk of slope failure on surrounding residential areas and infrastructure,and identify a shallow fault that extends across the center of the mountain and is perpendicular to the mountain slope and accurately locate the spatial position and depth of another fault on the southern side of the mountain.The results provide an important basis for evaluating mountain slope stability.This study also demonstrates that the high-density resistivity method is effective for detecting mountain faults.

Application of high-density resistivity method in archaeological investigation of Sumicheng ancient city site

The authors employ the high-density resistivity method during an archaeological investigation of Sumicheng site,an ancient city of the Tang Dynasty,to find evidence of human activities and locate a favorable target for archaeological excavation in the southern part of the outer city.There are two obvious high-resistivity structures,the south wall of the inner city and an ancient building near the south gate along the outer city wall,of which the resistivities are indicative of rammed soil foundations.The south wall of the inner city is continuous but is cut off abruptly to the east,which we suggest it is due to either wall damage or destruction.The resistivity signature of the target area is verified by archaeological excavation,proving the feasibility and effectiveness of implementing the high-density resistivity method for archaeological exploration.

Application of high-density resistivity method for assessing construction safety of Shimodong tunnel in Helong City of Jilin Province

Some unfavorable geological conditions can affect the construction of tunnels.In order to evaluate the damage degree of tunnel construction and determine the surrounding rock grade and stability of the tunnel,the authors used high-density resistivity method to detect the surrounding rocks of Shimodong tunnel in Xicheng Town of Helong City.The underground resistivity structures of the entrance,exit and middle parts of the tunnel are obtained.Through analysis,it is found that there are no bedrock faults near the tunnel,although some joints and fissures are developed in some locations,which are characterized by low-resistivity anomalies.The tunnel structures are stable overall,favorable for safe and efficient construction.The study also proves the good application effect of the high-density resistivity method in tunnel safety detection.

Frost Resistance of Pervious Concrete Mixed with Waste Glass Powder

The contents of waste glass powder(WGP)(0%,10%,15%,20%,25%)and water-binder ratio(W/C)(0.24,0.26,0.28)were used as influencing factors,and the quality loss rate(Δm)and compressive strength loss rate(Δfc)were used as characterization parameters.The Ca/Si ratio and main element contents of C-S-H gels with different WGP content were investigated by energy dispersive spectrometry(EDS).The pore structure evolution characteristics of WGP composite cementing materials were investigated by low field nuclear magnetic resonance(NMR).UsingΔfc as the index of frost resistance degradation and Weibull function,the frost resistance degradation of glass doped pervious concrete(WGP-PC)was modeled.The results show that,with WGP,for the same number of cycles,Δm andΔfc decrease and increase with the increase of WGP.Under the same WGP content,Δm andΔfc decrease first and then increase with the increase of W/C.After 100 freeze-thaw cycles,the samples with WGP content of 20%and W/C of 0.26 have the best freeze-resistance.Microscopic tests show that with the increase of WGP content,the Ca/Si ratio of C-S-H gel decreases at first and then increases with the increase of WGP content.The extreme value of Ca/Si is 2.36 when WGP is added by 20%.The pore volume of hardened paste with 20%WGP content decreased by 18.6%compared with that of cement system without WGP.The overall compactness of the specimen was improved.On the basis of the test data,a life prediction model was established according to Weibull function.The experiment showed thatΔfc could be used as a durability degradation index,and the slope of the reliability curve became gentle after WGP was added,which reduced the damage degradation rate of PC.W/C was 0.26.It's about 5000 hours.

Attenuation-compensated reverse time migration of GPR data constrained by resistivity

The high-frequency electromagnetic waves of ground-penetrating radar(GPR)attenuate severely when propagated in an underground attenuating medium owing to the influence of resistivity,which remarkably decreases the resolution of reverse time migration(RTM).As an effective high-resolution imaging method,attenuation-compensated RTM(ACRTM)can eff ectively compensate for the energy loss caused by the attenuation related to media absorption under the influence of resistivity.Therefore,constructing an accurate resistivity-media model to compensate for the attenuation of electromagnetic wave energy is crucial for realizing the ACRTM imaging of GPR data.This study proposes a resistivity-constrained ACRTM imaging method for the imaging of GPR data by adding high-density resistivity detection along the GPR survey line and combining it with its resistivity inversion profile.The proposed method uses the inversion result of apparent resistivity data as the GPR RTM-resistivity model for imposing resistivity constraints.Moreover,the hybrid method involving image minimum entropy and RTM is used to estimate the medium velocity at the diff raction position,and combined with the distribution characteristics of the reflection in the GPR profile,a highly accurate velocity model is built to improve the imaging resolution of the ACRTM.The accuracy and eff ectiveness of the proposed method are verified using the ACRTM test of the GPR simulated data of a typical attenuating media model.On this basis,the GPR and apparent resistivity data were observed on a field survey line,and use the GPR resistivity-constrained ACRTM method to image the observed data.A comparison of the proposed method with the conventional ACRTM method shows that the proposed method has better imaging depth,stronger energy,and higher resolution,and the obtained results are more conducive for subsequent data analysis and interpretation.

Application effect of high-density electrical method on detecting artificial filling layer: A case study of Chengjiangshan area of Huaibei City

High-density electrical method has been proved to be an effective method for probing shallow sedimentary layers.It is principally used to identify the boundary between the Quaternary soil layer and bedrock according to the vertical change of apparent resistivity.However,the artificial filling layer has the characteristics of heterogeneity and high porosity,which makes it challenging to detect the artificial filling layer by high-density electrical method.The key to solve this problem is to detect the difference of conductivity between the filling layer and the underlying bedrock.This paper takes the land in Chengjiangshan area of Huaibei City,Anhui Province as the detection target.On the basis of fully analyzing the physical properties of the artificial filling layer,two-dimensional high-density electrical survey and inversion are used to define the thickness of the artificial filling layer.The research shows that the highdensity resistivity method has obvious advantages in delineating the distribution of bedrock and the thickness of the filling layer,and the reliability of the high-density electrical method in the detection of the artificial filling layer,and delineates the scope of the filling layer is verified by the borehole data.

竖向对称式织物热板仪的研制与试验

为进一步探索织物热阻的精确测量方法,以热惯量最小的思路,设计了竖向对称式热板仪,并在理论上解决了这种设计的非均匀温度场分布解析和平均温度的测量问题。在恒温恒湿室中,通过LabVIEW虚拟仪器控制一块悬挂于空中的铜制试验板,织物被包覆在热板表面,由此热量可直接由板的对称两个方向全部穿透织物并向外传递。使用该热板仪和传统的YG606E热板仪在相同条件下对12块织物的热阻进行对比测量试验,配对t检验显示,两种仪器的测量结果无显著性差异,相对标准偏差显示,新热板仪的数据重复精度更高,证明了竖向对称式设计的可行性和优越性。

应用锁相红外探伤法分析机用镍钛锉的疲劳抗性

目的 :使用锁相红外探伤法检测机用镍钛锉的疲劳抗性,及时发现器械磨损情况,为临床安全使用并及时弃用镍钛锉提供参考。方法:选取Reciproc-Blue(RB)、MTWO和S3等3种机用镍钛锉各20套,分别预备60°和90°弯曲的树脂模拟根管,分为6个亚组。记录每组锉中25#锉使用后的疲劳值、折断前的使用次数及折断长度。采用SPSS26.0软件包对数据进行统计学分析。结果:随着使用次数的增加,3种锉的疲劳值逐渐增大。在2种弯曲根管中,RB组折断前使用次数较MTWO组和S3组显著增加(P<0.05)。3种锉在90°弯曲根管中使用次数均显著少于60°弯曲根管中相应各组使用次数(P<0.05),3种锉发生折断的长度相比无显著差异(P>0.05)。结论:锁相红外探伤法可对镍钛锉的疲劳程度进行无损检测并做定量分析。

一种基于薄膜式力敏电阻的咬合力检测系统的设计与测试

咬合力是衡量咀嚼功能的重要指标,目前临床尚无广泛使用的咬合力检测产品。该研究利用薄膜式力敏电阻(FSR)作为传感器,采用高精度数据采集卡和LabWindows/CVI程序设计了一种咬合力检测系统,并在50~500 N压力范围内进行了压力-电压响应特性测试和真人咬合测试。结果显示,该系统具有良好的线性响应,压力测量的平均相对误差为8.2%,灵敏度为344.827N/V,分辨率为1.68N,且咬合安装方便,可明显区分5名受试人员的咬合力差异,具备实际应用潜力。

接地电阻测量仪智能化改造方法的研究

为了解决传统接地电阻测量工作存在的测量数据不便、记录不准确、数据利用不深入等问题,对接地电阻测量仪进行智能化改造,设计开发数据采集模块连接接地电阻测量仪及土壤电阻率测量仪,将接地电阻测量工作与土壤电阻率测量工作结合,简化接地电阻测量工作流程,转变数据测量及录入工作模式,将接地电阻数据与土壤电阻率结合,并实现测量数据的全自动化读取录入,将工作向智能化、自动化方法引领,使得数量庞大的测量数据可以表达更多内容,更大化发挥数据的作用,使得数据联动性更强、可分析性更高。

基于接地电阻测量仪的数据管理系统设计

接地电阻测量仪的数据管理是接地电阻测量工作的重要内容之一。为使数量庞大的接地电阻测量数据可表达更多内容,发挥更大作用,设计了数据管理系统。结合土壤电阻率数据,对接地系统的情况进行分析,使得数据联动性更强,可分析程度更高。

多特征反向传播-人工神经网络微钻阻力年轮识别方法

峰谷年轮识别算法仅使用峰谷差值这一个特征进行年轮识别,因此该算法的误判率和漏判率较高。为了进一步提高微钻阻力年轮识别精度,提出了一种基于多个波峰特征的反向传播-人工神经网络(BP-ANN)年轮识别方法。首先使用峰谷年轮算法识别有效波峰,然后使用波峰阻力值、波峰与前波谷和后波谷的阻力差值、波峰与前波谷和后波谷的距离、前波谷与后波谷的距离等6个参数描述波峰特征;然后根据阻力图与圆盘图像确定有效波峰的类型,如果该波峰是一个年轮信号,则标记为“1”,否则标记为“0”;最后使用BP-ANN算法构建有效波峰分类模型。结果显示,BP-ANN模型的准确率比峰谷年轮识别算法提高了1.26个百分点,误判率和漏判率比峰谷年轮识别算法分别减少了1.06和1.38个百分点。结果表明:基于多个波峰特征的BP-ANN模型的年轮识别方法可行;与传统的峰谷年轮识别算法相比,该方法可有效提高年轮识别精度,有效降低年轮误判率和漏判率.

Effect of Tides on the Stratigraphic Resistance of the South Coast of the Laizhou Bay

Seawater intrusion is a global environmental problem that is becoming increasingly severe with the overexploitation of underground freshwater in coastal regions and sea-level rise caused by global climate change. Although a series of achievements has been made on seawater intrusion, the role of tidal effects has not been fully revealed. In this paper, a typical case of tidal effects on seawater intrusion is provided. The high-density resistivity method was applied to the high-frequency continuous measurement of the stratigraphic resistance of the south coast of the Laizhou Bay, followed by the panel data analysis method. The results indicate that the formation resistivity in coastal area was affected by the tidal level significantly, particularly in the seawater intrusion channel. The effect of tide on the intensity distribution of formation resistivity was evaluated using this method. Because of the presence of a brine layer in the section, the trends of the tidal level effect on the formation resistivity in the left and right sides of the section were opposite, and the intensity of the effect increased sideways.

DUALFREQUENCY AND MULTIPARAMETERIP INSTRUMENT AND ITS APPLICATION RESEARCH

Variable IP method mainly measures the Percent Frequency Effect (PFE), and phase IP method mainly measures phase. They both aim at finding IP anomaly. However, only using PFE anomaly or single phase anomaly can′t distinguish IP body′s property. The authors put forward a new method——dualfrequency and multiparameter IP method, which can not only find anomaly of PFE and phase, but also provide the property information of IP anomaly resource. The authors also have invented the dualfrequency and multiparameter IP instrument. A lot of experiments and field work have been done. The results show that the instrument is valuable in distinguishing IP anomalies.

电阻率法在有色金属矿产勘探中的研究进展

电阻率法以岩矿石电阻率差异为勘探基础,具有装置简便、能有效处理复杂地形等特点,在有色金属勘探中具有独特的优势,是有色金属勘探的最重要方法,其理论方法、观测仪器和反演解释技术不断更新完善。观测理论和方法技术由简单模型和特定装置向二维、三维发展,甚至出现跨维的观测方式,以求实现观测效率与效果的平衡。电阻率法仪器装备也同步发展,由单一装置设计向分布式、阵列式仪器发展,其自动化程度、观测精度和数据量都在不断提高。观测数据的反演解释同样也向符合实际勘探需要的非线性三维和智能化联合反演发展,其精度和可靠性越来越好。这些方法技术的发展不仅进一步巩固了电阻率法在有色金属勘探中的重要地位,而且还有向金属矿山环境和地质灾害监测与探查方面应用不断拓展的趋势。

Virtual Instrument Testing System for R～T Curve of the High Temperature Superconductor

College of Electrical Engineering, Yanshan University, Qinhuangdao hebei 066004)Qi, hanhong Tian,Yongjun, Wei,Yanjun Wang, Tiansheng(State Key Laboratory for Superconductor, Institute of Physics, Chinese Academy of Science, Beijing 100080)Zheng,DongningAbatract : A set of virtual instrument system based on Labview for measuring the R^T curve of the high temperature superconductor is designed in this paper. The control for the Current Source and nanovoltage meter is realized by the IEEE488 bus. The superconductivity is measured based on the zero resistance characteristics of the superconductor. The measurement is of high precision and of high speed. The man-machine interface is direct and friendly.

Vitalstim吞咽治疗仪及舌压抗阻反馈训练对脑梗死后吞咽障碍患者舌骨运动度及吞咽功能的影响

目的探讨Vitalstim吞咽治疗仪及舌压抗阻反馈训练对脑梗死后吞咽障碍患者舌骨运动度及吞咽功能的影响。方法选取2021年8月至2022年8月盐城市第三人民医院收治的脑梗死后吞咽障碍患者81例,随机分为3组:对照A组、对照B组、联合组,每组各27例。对照A组采取Vitalstim吞咽治疗仪,对照B组采取舌压抗阻反馈练习,联合组采取Vitalstim吞咽治疗仪及舌压抗阻反馈练习。统计3组干预效果、干预前后舌骨运动度、吞咽功能及生活质量、不良事件发生率。结果(1)联合组总有效率高于对照A组、对照B组(P均<0.05),对照A组、对照B组治疗总有效率差异无统计学意义(P>0.05)。(2)干预后3组舌骨上、下移动度较干预前增大,且联合组舌骨上、下移动度大于对照A组、对照B组(P均<0.05),干预后对照A组、对照B组舌骨上、下移动度间差异无统计学意义(P均>0.05)。(3)干预后3组标准吞咽功能评定表(SSA)分值较干预前下降,改良曼恩吞咽能力评估量表(MMASA)分值、吞咽障碍的结局与严重度量表(DOSS)分值较干预前增高,且联合组SSA分值较对照A组、对照B组低,MMASA及DOSS分值较对照A组、对照B组高(P均<0.05),干预后对照A组、对照B组的SSA、MMASA、DOSS分值差异无统计学意义(P均>0.05)。(4)干预后3组吞咽障碍特异性生活质量表(SWAL-QOL)分值较干预前增高,且联合组SWAL-QOL分值高于对照A组、对照B组(P均<0.05),干预后对照A组、对照B组SWAL-QOL分值差异无统计学意义(P>0.05)。(5)联合组不良事件发生率低于对照A组、对照B组(P均<0.05),对照A组、对照B组不良事件发生率差异无统计学意义(P>0.05)。结论联合Vitalstim吞咽治疗仪及舌压抗阻反馈训练对脑梗死后吞咽障碍患者实施干预效果显著,有利于减少不良事件的发生。