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.

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.

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.

Combined Influence of Insulin Resistance and Inflammatory Biomarkers on Type 2 Diabetes:A Population-based Prospective Cohort Study of Inner Mongolians in China

This prospective study was designed to examine the combined influence of insulin resistance（IR）and inflammatory biomarker levels on type 2 diabetes mellitus（T2DM）among 1,903Inner Mongolians.

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.

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.

Intraoperative systemic vascular resistance is associated with postoperative nausea and vomiting after laparoscopic hysterectomy

BACKGROUND The incidence of postoperative nausea and vomiting(PONV)in patients undergoing laparoscopic hysterectomy is very high compared with other surgeries,even when many prophylactic measures have been taken.However,the pathogenesis of PONV is multifactorial.Female sex,a history of motion sickness or PONV,nonsmokers,and perioperative opioid use are the most closely related factors.Among the multiple risk factors,suboptimal gastrointestinal(GI)perfusion may be attributed to some cases of PONV,and increased systemic vascular resistance(SVR)may lead to GI ischemia.The hypothesis of this research was that SVR is related to PONV.AIM To investigate the relationship between SVR and PONV in patients undergoing laparoscopic hysterectomy.METHODS A total of 228 patients who underwent elective laparoscopic hysterectomy were included in this prospective observational study.SVR was monitored using a noninvasive hemodynamic monitoring system.Four indices of SVR,the baseline,mean,area under the curve(AUC),and weighted AUC,were used for analysis.The incidence and severity of nausea and vomiting were evaluated while patients were awake and throughout the intervals from 0 to 2 h,2 to 6 h,and 6 to 24 h starting upon arrival at the post-anesthesia care unit.The associations between various SVR indices and PONV were investigated by logistic regression.P<0.05 was considered statistically significant.RESULTS The incidence of PONV in the study was 56.14%(128/228),and PONV tended to appear within 6 h after surgery.Five variables were significant in univariate analyses,however,only SVR mean[odds ratio(OR)=1.015,95%CI:1.005-1.109,P=0.047]and duration of surgery(OR=1.316,95%CI:1.003-2.030,P=0.012)were associated with PONV after logistic regression analysis.Furthermore,patients with high SVR mean were more likely to suffer from PONV after laparoscopic hysterectomy.On average,patients who developed PONV needed more time to tolerate diet and demonstrated poorer sleep quality on the first night after surgery.CONCLUSION In this study,PONV was a common complication after laparoscopic hysterectomy.SVR was associated with PONV,and high SVR mean was associated with a significantly increased risk of PONV.

A Review of the Methods of Identifying and Testing Plant Cold Resistance

Low-tempemture stress is a major abiotic stress influencing plant growth, economic yield and quality worldwide. Precise and reliable identification and test of plant cold resistance is a foundation for exploring low-temperature damages, cold resistance mechanism of plants, cultivating and innovating quality cold-re- sistant germplasm resources, which is rather important for woody plants because their perennial and large-sized characteristics. Generally, most researches on plant cold-resistant physiology focused on identification and utilization of cold resistance worldwide, and a few on test methods of cold resistance, but cold resistance mechanism has been less reported. Therefore, researches on methods of identifying and testing plant resistance have achieved considerable progress, accumulated much experience and formed characteristics gradually in terms of methodology. Current methods of identifying plant cold resistance include open field/outdoor culti- vation evaluation, cold and frost damage investigation, simulated cold weather, and mathematical model forecast. And the methods of testing plant cold resistance include growth condition test, frozen index investigation, electrolyte leakage, bioelectrical impedance mapping and so on. Synthesizing the methods of identifying and testing plant cold resistance should be a key matter in the present and future researches and application of plant cold resistance physiology, improvement and in- novation of the identification and test will be an important direction of the future researches. Identification and test of plant cold resistance based on genomies, meta- bonomics and proteomics should be the new trend of the researches on physiology and ecology of plant cold resistance.

Associations between aerobic and muscle-strengthening physical activity,sleep duration,and risk of all-cause mortality:A prospective cohort study of 282,473 U.S.adults

Purpose:To examine the joint associations between meeting guidelines for physical activity(PA)and sleep duration and all-cause mortality risk among adults.Methods:Participants were adults(n=282,473)aged 18-84 years who participated in the 2004-2014 U.S.National Health Interview Survey.Mortality status was ascertained using the National Death Index through December 2015.Self-reported PA(Active:meeting both aerobic(AER)and muscle-strengthening(MSA)guidelines,AER only(AER),MSA only(MSA),or not meeting either AER or MSA(Inactive))and sleep duration(Short,recommended(Rec),or Long)were classified according to guidelines,and 12 PA-sleep categories were derived.Adjusted hazard ratios and 95%confidence intervals(95%CIs)for all-cause mortality risk were estimated using Cox proportional hazards regression models.Results:A total of 282,473 participants(55%females)were included;18,793 deaths(6.7%)occurred over an average follow-up of 5.4 years.Relative to the Active-Rec group,all other PA-sleep groups were associated with increased mortality risk except for the Active-Short group(hazard ratio=1.08;95%CI:0.92-1.26).The combination of long sleep with either MSA or Inactive appeared to be synergistic.For a given sleep duration,mortality risk progressively increased among participants classified as AER,MSA,and Inactive.Within each activity level,the mortality risk was greatest among adults with long sleep.Conclusion:Relative to adults meeting guidelines for both PA and sleep duration,adults who failed to meet guidelines for both AER and muscle strengthening PA and who also failed to meet sleep duration guidelines had elevated all-cause mortality risks.These results support interventions targeting both PA and sleep duration to reduce mortality risk.

节水抗旱稻不育系沪旱7A及所配组合特征特性分析及育种展望

节水抗旱稻是同时具有水稻高产优质和旱稻节水抗旱特性的一种新的栽培稻类型。沪旱7A是上海市农业生物基因中心与上海天谷生物科技股份有限公司以武香B/内香B//沪旱1B为亲本杂交选育而成的籼型三系不育系,具有育性稳定、抗旱性强、米质优良、配合力好等特点。以沪旱7A为亲本选配的节水抗旱稻组合旱优73、旱优3015等表现出很强的杂种优势,已在生产上大面积应用。本文介绍了沪旱7A的特征特性,分析评价了其所配组合的生育期、抗性、产量等指标,提出了使用沪旱7A配组新组合时需要注意的事项和改良的方向,为沪旱7A作为节水抗旱稻核心亲本推广应用提供科学依据。

耐药菌的环境分布、传播及新型抗菌技术研究进展

抗生素的广泛使用导致细菌耐药性增加、多重耐药菌菌群数量急剧增多,严重威胁着人类生命健康.环境中耐药菌(ARB)及耐药基因(ARGs)的存在给临床治疗耐药菌感染带来了巨大挑战.有关医院中常见耐药致病菌的研究已有很多,尚缺乏环境中耐药菌的分布、传播及新型耐药菌抗菌技术等的相关研究.本文综述了耐药菌的环境分布特征及其传播机制,概述了新型抗菌技术及其应用,最后展望了有关环境耐药菌研究的未来发展方向.

深层超深层钻井液技术研究进展与展望

系统论述目前国内外深层超深层钻井液技术研究进展,分析存在的关键问题并提出未来发展方向。针对深层超深层复杂油气层钻井过程中面临的高温高压高应力、裂缝发育、井壁失稳、钻井液漏失等问题,国内外学者研发了深层超深层抗高温高盐水基钻井液技术、抗高温油基/合成基钻井液技术、储层保护钻井液技术以及钻井液防漏堵漏技术,但仍存在抗高温高压和高应力能力不足、井壁易失稳以及钻井液漏失严重等关键问题。由此提出未来深层超深层钻井液技术的发展方向:(1)抗高温高盐水基钻井液技术需致力于提升高温稳定性,改进流变性能,强化滤失量控制,提高与地层的相容性。(2)抗高温油基/合成基钻井液技术需在高温稳定剂、流型调节剂等低毒易降解的环保型添加剂和相关配套技术方面进一步攻关。(3)储层保护钻井液技术应致力于新型高性能添加剂和材料的研究,通过引入先进的传感器网络和人工智能算法,完善实时监测技术。(4)钻井液防漏堵漏技术应更加注重智能化技术的集成与应用、高性能堵漏材料的研发与应用、多元化堵漏技术与方法的探索以及环境保护与安全生产意识的提高。

Triglycerides and ratio of triglycerides to high-density lipoprotein cholesterol are better than liver enzymes to identify insulin resistance in urban middle-aged and older non-obese Chinese without diabetes

Background Insulin resistance （IR） plays an important pathophysiological role in the development of diabetes,dyslipidemia,hypertension,and cardiovascular disease.Moreover,IR can occur even in non-obese people without diabetes.However,direct detection of IR is complicated.In order to find a simple surrogate marker of IR early in nonobese people,we investigate the association of commonly-used biochemical markers （liver enzymes and lipid profiles） with IR in urban middle-aged and older non-obese Chinese without diabetes.Methods This cross-sectional study included 1 987 subjects （1 473 women）.Fasting blood samples were collected for measurement of glucose,insulin,liver enzymes,lipid profiles and creatinine.Subjects whose homeostasis model of assessment-IR （HOMA-IR） index values exceeded the 75th percentile （2.67 for women and 2.48 for men） of the population were considered to have IR.The area under the receiver operating characteristic curve （ROC） was used to compare the power of potential markers in identifying IR.Results Triglycerides （TG） and ratio of TG to high-density lipoprotein cholesterol （TG/HDL-C） discriminated IR better than other indexes for both sexes; areas under the receiver operating characteristic （ROC） curves （AUC） values were 0.770 （95％ confidence interval 0.733-0.807） and 0.772 （0.736-0.809）,respectively,for women and 0.754 （0.664-0.844）and 0.756 （0.672-0.840）,respectively,for men.To identify IR,the optimal cut-offs for TG and TG/HDL-C ratio were 1.315 mmol/L （sensitivity 74.3％,specificity 71.0％） and 0.873 （sensitivity 70.1％,specificity 73.4％）,respectively,for women,and 1.275 mmol/L （sensitivity 66.7％,specificity 74.4％） and 0.812 （sensitivity 75.8％,specificity 69.2％）,respectively,for men.Conclusion TG and TG/HDL-C ratio could be used to identify IR in urban middle-aged and older non-obese Chinese without diabetes.

马铃薯抗旱机制研究进展

马铃薯是全球第四大粮食作物,也是中国主要的粮食作物,在保障粮食安全方面有重要作用。随着全球气候变暖,干旱成为农业生产上频发的自然灾害,严重制约马铃薯生产。从干旱胁迫信号传导、转录因子、渗透调节等方面综述了马铃薯抗旱机制,从多组学发展角度论述了提高马铃薯抗旱性的途径与措施,对马铃薯耐旱研究方向及方法进行展望,为后续马铃薯抗旱机制研究及优良品种选育提供参考。

基于自然电场与电阻率法的尾矿库渗漏探测数值模拟研究

尾矿库堆存是处置矿山尾矿的常规方案,但尾矿库渗漏严重威胁生态环境。及时查明地下渗漏情况,有助于采取有效的补救方案。笔者基于有限元—无限元耦合法开展数值模拟研究,探究基于直流电阻率法及自然电场法的综合物探技术在尾矿库渗漏探测中的应用效果。研究结果表明,直流电阻率法和自然电场法能相互结合、验证、补充,能够揭露地下电阻率结构异常,同时能提供渗漏点的位置及深度信息。这些研究可为尾矿库及其它渗漏问题提供数值参考和技术方案指导。

Research progress and development of deep and ultra-deep drilling fluid technology

The research progress of deep and ultra-deep drilling fluid technology systematically reviewed,the key problems existing are analyzed,and the future development direction is proposed.In view of the high temperature,high pressure and high stress,fracture development,wellbore instability,drilling fluid lost circulation and other problems faced in the process of deep and ultra-deep complex oil and gas drilling,scholars have developed deep and ultra-deep high-temperature and high-salt resistant water-based drilling fluid technology,high-temperature resistant oil-based/synthetic drilling fluid technology,drilling fluid technology for reservoir protection and drilling fluid lost circulation control technology.However,there are still some key problems such as insufficient resistance to high temperature,high pressure and high stress,wellbore instability and serious lost circulation.Therefore,the development direction of deep and ultra-deep drilling fluid technology in the future is proposed:(1)The technology of high-temperature and high-salt resistant water-based drilling fluid should focus on improving high temperature stability,improving rheological properties,strengthening filtration control and improving compatibility with formation.(2)The technology of oil-based/synthetic drilling fluid resistant to high temperature should further study in the aspects of easily degradable environmental protection additives with low toxicity such as high temperature stabilizer,rheological regulator and related supporting technologies.(3)The drilling fluid technology for reservoir protection should be devoted to the development of new high-performance additives and materials,and further improve the real-time monitoring technology by introducing advanced sensor networks and artificial intelligence algorithms.(4)The lost circulation control of drilling fluid should pay more attention to the integration and application of intelligent technology,the research and application of high-performance plugging materials,the exploration of diversified plugging techniques and methods,and the improvement of environmental protection and production safety awareness.