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Seismic dynamic monitoring in CO_2 flooding based on characterization of frequency-dependent velocity factor
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作者 张军华 李军 +4 位作者 肖文 谭明友 张云银 崔世凌 曲志鹏 《Applied Geophysics》 SCIE CSCD 2016年第2期307-314,418,共9页
The phase velocity of seismic waves varies with the propagation frequency, and thus frequency-dependent phenomena appear when CO2 gas is injected into a reservoir. By dynamically considering these phenomena with reser... The phase velocity of seismic waves varies with the propagation frequency, and thus frequency-dependent phenomena appear when CO2 gas is injected into a reservoir. By dynamically considering these phenomena with reservoir conditions it is thus feasible to extract the frequency-dependent velocity factor with the aim of monitoring changes in the reservoir both before and after CO2 injection. In the paper, we derive a quantitative expression for the frequency-dependent factor based on the Robinson seismic convolution model. In addition, an inversion equation with a frequency-dependent velocity factor is constructed, and a procedure is implemented using the following four processing steps: decomposition of the spectrum by generalized S transform, wavelet extraction of cross-well seismic traces, spectrum equalization processing, and an extraction method for frequency-dependent velocity factor based on the damped least-square algorithm. An attenuation layered model is then established based on changes in the Q value of the viscoelastic medium, and spectra of migration profiles from forward modeling are obtained and analyzed. Frequency-dependent factors are extracted and compared, and the effectiveness of the method is then verified using a synthetic data. The frequency-dependent velocity factor is finally applied to target processing and oil displacement monitoring based on real seismic data obtained before and after CO2 injection in the G89 well block within Shengli oilfield. Profiles and slices of the frequency-dependent factor determine its ability to indicate differences in CO2 flooding, and the predicting results are highly consistent with those of practical investigations within the well block. 展开更多
关键词 CO2 flooding Frequency-dependent velocity factor G89 well block Reservoir dynamic monitoring
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Key Environmental Factors Monitoring System of Low-power Greenhouse Based on WSN Technology
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作者 柳军 陶建平 吕晓兰 《Agricultural Science & Technology》 CAS 2016年第2期449-452,共4页
A low-power environmental monitoring system based on WSN technology is proposed to effectively monitor the environmental status and ensure the healthy growth of greenhouse crops in the greenhouse. The system performs ... A low-power environmental monitoring system based on WSN technology is proposed to effectively monitor the environmental status and ensure the healthy growth of greenhouse crops in the greenhouse. The system performs dynamic mon- itoring on the environmental data of temperature, humidity, illumination, soil tempera- ture and humidity of the greenhouse, and it reduces the energy consumption by us- ing solar energy and lithium battery as the power supply mode and dynamic power management algorithm combined with improved routing protocol. Stable and reliable, the system could effectively monitor the key environmental factors in the green- house, making it of certain promotion value. 展开更多
关键词 Environmental monitoring GREENHOUSE Wireless sensor network WSN technology Key factor
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Rock mass structural recognition from drill monitoring technology in underground mining using discontinuity index and machine learning techniques 被引量:1
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作者 Alberto Fernández JoséA.Sanchidrián +3 位作者 Pablo Segarra Santiago Gómez Enming Li Rafael Navarro 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2023年第5期555-571,共17页
A procedure to recognize individual discontinuities in rock mass from measurement while drilling(MWD)technology is developed,using the binary pattern of structural rock characteristics obtained from in-hole images for... A procedure to recognize individual discontinuities in rock mass from measurement while drilling(MWD)technology is developed,using the binary pattern of structural rock characteristics obtained from in-hole images for calibration.Data from two underground operations with different drilling technology and different rock mass characteristics are considered,which generalizes the application of the methodology to different sites and ensures the full operational integration of MWD data analysis.Two approaches are followed for site-specific structural model building:a discontinuity index(DI)built from variations in MWD parameters,and a machine learning(ML)classifier as function of the drilling parameters and their variability.The prediction ability of the models is quantitatively assessed as the rate of recognition of discontinuities observed in borehole logs.Differences between the parameters involved in the models for each site,and differences in their weights,highlight the site-dependence of the resulting models.The ML approach offers better performance than the classical DI,with recognition rates in the range 89%to 96%.However,the simpler DI still yields fairly accurate results,with recognition rates 70%to 90%.These results validate the adaptive MWD-based methodology as an engineering solution to predict rock structural condition in underground mining operations. 展开更多
关键词 Drill monitoring technology Rock mass characterization Underground mining Similarity metrics of binary vectors Structural rock factor Machine learning
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Surveillance Report of the Prevalence and Risk Factors of Chronic Non-Communicable Diseases in Tinghu District,Yancheng City,2021
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作者 Lili Yan Zhiqin Kai 《Proceedings of Anticancer Research》 2024年第4期135-141,共7页
Objective:To comprehensively understand the changes and prevalence of major chronic diseases among residents of Tinghu District,Yancheng City,in 2021,and to analyze the trends of the major risk factors for the onset o... Objective:To comprehensively understand the changes and prevalence of major chronic diseases among residents of Tinghu District,Yancheng City,in 2021,and to analyze the trends of the major risk factors for the onset of chronic diseases in the region.Methods:Chronic diseases and their risk factors in Tinghu District in 2021 were monitored among the resident population who had lived in the district for five years or more and were aged 18 years or older.The survey was conducted using random cluster sampling,with 7,130 questionnaires collected.After data processing,7,012 valid questionnaires were obtained,resulting in a qualification rate of 98.35%.Results:Among the chronic diseases reported in the survey population,hypertension had the highest prevalence at 37.61%,followed by dyslipidemia at 37.19%.Other chronic diseases were ranked in order of prevalence from highest to lowest.Regardless of gender,the top three chronic diseases were hypertension,diabetes,and hyperlipidemia.Multifactorial regression analysis identified both non-preventable risk factors(such as family history,gender,and age)and preventable risk factors(such as smoking,sedentary behavior,overweight,and obesity)as significant contributors to the major chronic diseases in Tinghu District.Conclusion:Analyzing the trends in the main risk factors for chronic disease incidence in Tinghu District,Yancheng City,provides a basis for developing a new comprehensive chronic disease prevention and control plan to address chronic disease prevention and management. 展开更多
关键词 Chronic diseases Non-communicable Social factors monitoring report
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On-line Monitoring of Insulation Dielectric Loss Factor Based on Balance Principle
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作者 Tianxiang CHEN Zhenhua SHAO +1 位作者 Shaozhen QIN Hong TIAN 《电力系统自动化》 EI CSCD 北大核心 2013年第21期180-183,共4页
关键词 介质损耗因数 平衡原则 在线监测 绝缘 相位误差 高精确度 电流传感器 位移传感器
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Numerical analysis and geophysical monitoring for stability assessment of the Northwest tailings dam at Westwood Mine 被引量:13
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作者 Coulibaly Yaya Belem Tikou Cheng LiZhen 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2017年第4期701-710,共10页
The Westwood Mine aims to reuse the tailings storage facility #1(TSF #1) for solid waste storage, but,downstream of the Northwest dike is considered critical in terms of stability. This paper uses numerical modeling a... The Westwood Mine aims to reuse the tailings storage facility #1(TSF #1) for solid waste storage, but,downstream of the Northwest dike is considered critical in terms of stability. This paper uses numerical modeling along with geophysical monitoring for assessing the Northwest dike stability during the restoration phase. The impact of waste rock deposition in the upstream TSF #1 is considered. The geophysical monitoring is based on electrical resistivity methods and was used to investigate the internal structure of the dike embankment in different deposition stages. The numerical simulations were performed with SLOPE/W code. The results show a factor of safety well above the minimum recommended value of 1.5. Geophysical monitoring revealed a vertical variation in the electrical resistivity across the dike, which indicates a multilayer structure of the embankment. Without any current in situ data, the geophysical monitoring helped estimating the nature of the materials used and the internal structure of the embankment. These interpretations were validated by geological observation of geotechnical log of the embankment. Based on this study, it is recommended that the water polishing pond be partly filled before waste rock is deposited in TSF #1. In addition, to ensure the stability of the dike, the piezometric head monitoring prior to and during waste rock deposition is recommended. 展开更多
关键词 Mine tailings impoundment DIKE Embankment Numerical analysis factor of safety Geophysical monitoring
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New Developments in Structural Health Monitoring Based on Diagnostic Lamb Wave 被引量:9
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作者 Shenfang YUAN, Yingdi XU and Ge PENGThe Smart Materials & Structures Aeronautic Key Laboratory, Nanjing University of Aeronautic and Astronautic, Nanjing 210016, China 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2004年第5期490-496,共7页
Structure health monitoring based on diagnostic Lamb waves has been found to be one of the most promising techniques recently. This paper has a brief review of the new developments on this method including the basic n... Structure health monitoring based on diagnostic Lamb waves has been found to be one of the most promising techniques recently. This paper has a brief review of the new developments on this method including the basic novel of the method, fundamentals and mathematics of Lamb wave propagation, narrowband and wideband Lamb wave excitation methods, optimization of excitation factors and diagnostic Lamb wave interpretation methods. 展开更多
关键词 Structural health monitoring Lamb wave methods factor optimization Damage localization
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Seepage safety monitoring model for an earth rock dam under influence of high-impact typhoons based on particle swarm optimization algorithm 被引量:8
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作者 Yan Xiang Shu-yan Fu +2 位作者 Kai Zhu Hui Yuan Zhi-yuan Fang 《Water Science and Engineering》 EI CAS CSCD 2017年第1期70-77,共8页
Extreme hydrological events induced by typhoons in reservoir areas have presented severe challenges to the safe operation of hydraulic structures. Based on analysis of the seepage characteristics of an earth rock dam,... Extreme hydrological events induced by typhoons in reservoir areas have presented severe challenges to the safe operation of hydraulic structures. Based on analysis of the seepage characteristics of an earth rock dam, a novel seepage safety monitoring model was constructed in this study. The nonlinear influence processes of the antecedent reservoir water level and rainfall were assumed to follow normal distributions. The particle swarm optimization (PSO) algorithm was used to optimize the model parameters so as to raise the fitting accuracy. In addition, a mutation factor was introduced to simulate the sudden increase in the piezometric level induced by short-duration heavy rainfall and the possible historical extreme reservoir water level during a typhoon. In order to verify the efficacy of this model, the earth rock dam of the Siminghu Reservoir was used as an example. The piezometric level at the SW1-2 measuring point during Typhoon Fitow in 2013 was fitted with the present model, and a corresponding theoretical expression was established. Comparison of fitting results of the piezometric level obtained from the present statistical model and traditional statistical model with monitored values during the typhoon shows that the present model has a higher fitting accuracy and can simulate the uprush feature of the seepage pressure during the typhoon perfectly. 展开更多
关键词 monitoring model Particle swarm optimization algorithm Earth rock dam Lagging effect TYPHOON Seepage pressure Mutation factor Piezometric level
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Monitoring stress and recovery states: Structural and external stages of the short version of the RESTQ sport in elite swimmers before championships 被引量:1
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作者 Michel Nicolas Philippe Vacher +1 位作者 Guillaume Martinent Laurent Mourot 《Journal of Sport and Health Science》 SCIE 2019年第1期77-88,共12页
Background: Psychological stress and recovery monitoring is a key issue for increasing athletes' health, well-being, and performance. This multistudy report examined changes and the doseàresponse relationship... Background: Psychological stress and recovery monitoring is a key issue for increasing athletes' health, well-being, and performance. This multistudy report examined changes and the doseàresponse relationships between recoveryàstress psychological states, training load(TL), heart rate(HR), heart rate recovery(HRR), and heart rate variability(HRV) while providing evidence for the factorial validity of a short French version of the RecoveryàStress Questionnaire for Athletes(RESTQ-36-R-Sport).Methods: Four hundred and seventy-three university athletes(Study 1), 72 full expert swimmers(Study 2), and 11 national to international swimmers(Study 3) participated in the study. Data were analyzed through confirmatory factor analyses(Study 1), repeated ANOVAs and correlational analyses(Study 2), t tests and correlational analyses(Study 3).Results: Multiple-group confirmatory factor analyses showed that the RESTQ-36-R-Sport scores were partially invariant across gender, type of sport, and practice level(Study 1). A doseàresponse relationship was performed between TL and RESTQ-36-R-Sport scores during an ecological training program(Study 2). Finally, relationships were found between physiological(HRR) and psychological(RESTQ-36-R-Sport) states during an ecological tapering period leading to a national championship(Study 3).Conclusion: As a whole, these findings provided evidence for the usefulness of the short version of the RESTQ-36-R-Sport for regular monitoring to prevent potential maladaptation due to intensive competitive sport practice. 展开更多
关键词 Adaptation Confirmatory factor analysis Heart rate variability monitoring RECOVERY STRESS
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Therapeutic drug monitoring in patients with inflammatory bowel disease 被引量:2
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作者 Andres J Yarur Maria T Abreu +2 位作者 Amar R Deshpande David H Kerman Daniel A Sussman 《World Journal of Gastroenterology》 SCIE CAS 2014年第13期3475-3484,共10页
Thiopurine analogs and anti-tumor necrosis factor (TNF) agents have dramatically changed the therapeutics of inflammatory bowel diseases (IBD), improving short and long-term outcomes. Unfortunately some patients do no... Thiopurine analogs and anti-tumor necrosis factor (TNF) agents have dramatically changed the therapeutics of inflammatory bowel diseases (IBD), improving short and long-term outcomes. Unfortunately some patients do not respond to therapy and others lose response over time. The pharmacokinetic properties of these drugs are complex, with high inter-patient variability. Thiopurine analogs are metabolized through a series of pathways, which vary according to the patients&#x02019; pharmacogenetic profile. This profile largely determines the ratios of metabolites, which are in turn associated with likelihoods of clinical efficacy and/or toxicity. Understanding these mechanisms allows for manipulation of drug dose, aiming to reduce the development of toxicity while improving the efficacy of treatment. The efficacy of anti-TNF drugs is influenced by many pharmacodynamic variables. Several factors may alter drug clearance, including the concomitant use of immunomodulators (thiopurine analogs and methotrexate), systemic inflammation, the presence of anti-drug antibodies, and body mass. The treatment of IBD has evolved with the understanding of the pharmacologic profiles of immunomodulating and TNF-inhibiting medications, with good evidence for improvement in patient outcomes observed when measuring metabolic pathway indices. The role of routine measurement of metabolite/drug levels and antibodies warrants further prospective studies as we enter the era of personalized IBD care. 展开更多
关键词 Inflammatory bowel disease Anti-tumor necrosis factor INFLIXIMAB ADALIMUMAB Drug level AZATHIOPRINE THIOPURINES ANTIBODIES Drug monitoring THIOGUANINE
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Statistical Analysis of Process Monitoring Data for Software Process Improvement and Its Application 被引量:2
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作者 Kazuhiro Esaki Yuki Ichinose Shigeru Yamada 《American Journal of Operations Research》 2012年第1期43-50,共8页
Software projects influenced by many human factors generate various risks. In order to develop highly quality software, it is important to respond to these risks reasonably and promptly. In addition, it is not easy fo... Software projects influenced by many human factors generate various risks. In order to develop highly quality software, it is important to respond to these risks reasonably and promptly. In addition, it is not easy for project managers to deal with these risks completely. Therefore, it is essential to manage the process quality by promoting activities of process monitoring and design quality assessment. In this paper, we discuss statistical data analysis for actual project management activities in process monitoring and design quality assessment, and analyze the effects for these software process improvement quantitatively by applying the methods of multivariate analysis. Then, we show how process factors affect the management measures of QCD (Quality, Cost, Delivery) by applying the multiple regression analyses to observed process monitoring data. Further, we quantitatively evaluate the effect by performing design quality assessment based on the principal component analysis and the factor analysis. As a result of analysis, we show that the design quality assessment activities are so effective for software process improvement. Further, based on the result of quantitative project assessment, we discuss the usefulness of process monitoring progress assessment by using a software reliability growth model. This result may enable us to give a useful quantitative measure of product release determination. 展开更多
关键词 Software PROCESS Improvement PROCESS monitoring Design Quality ASSESSMENT Multiple Regression ANALYSIS Principal COMPONENT ANALYSIS factor ANALYSIS QUANTITATIVE Project ASSESSMENT
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Hemostasis in liver transplantation:Pathophysiology,monitoring,and treatment 被引量:11
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作者 Matthias Hartmann Cynthia Szalai Fuat H Saner 《World Journal of Gastroenterology》 SCIE CAS 2016年第4期1541-1550,共10页
Recent findings in the pathophysiology and monitoring of hemostasis in patients with end stage liver disease have major impact on coagulation management during liver transplantation. There is increasing evidence, that... Recent findings in the pathophysiology and monitoring of hemostasis in patients with end stage liver disease have major impact on coagulation management during liver transplantation. There is increasing evidence, that the changes in both coagulation factors and platelet count regularly observed in patients with liver cirrhosis cannot be interpreted as a reliable indicator of diffuse bleeding risk. Instead, a differentiated view on hemostasis has led to the concept of a rebalanced coagulation system: While it is important to recognize that procoagulant factors are reduced in liver cirrhosis, it is also evident that synthesis of anticoagulant factors and fibrinolytic proteins produced in the liver is also diminished. Similarly, the decreased platelet count may be counterbalanced by increased platelet aggregability caused by highly active von Willebrand multimeres. The coagulation system is therefor stated to be rebalanced. While under normal "unstressed" conditions diffuse bleeding is rarely observed, however both diffuse bleeding or thrombus formation may occur when compensation mechanisms are exhausted. While most patients presenting for liver transplantation have severe cirrhosis, liver function and thus production of pro- and anticoagulant factors can be preserved especially in cholestatic liver disease. During liver transplantation, profound changes in the hemostasis system can occur. Surgical bleeding can lead to diffuse bleeding as coagulation factors and platelets are already reduced. Ischemia and tissue trauma can lead to alterations of hemostasis comparable to trauma induced coagulopathy. A further common disturbance often starting with the reperfusion of the transplanted organ is hyperfibrinolysis which can eventually precipitate complete consumption of fibrinogen and an endogenous heparinization by glycocalyx shedding. Moreover, thrombotic events inliver transplantations are not uncommon and contribute to increased mortality. Besides conventional laboratory methods, bed-side monitoring of hemostasis(e.g., thrombelastography, thrombelastometry) is often used during liver transplantation to rapidly diagnose decreases in fibrinogen and platelet count as well as hyperfibrinolysis and to guide treatment with blood products, factor concentrates, and antifibrinolytics. There is also evidence which suggests when algorithms based on bed-side hemostasis monitoring are used a reduction of blood loss, blood product use, and eventual mortality are possible. Notably, the bed-side monitoring of anticoagulant pathways and the thrombotic risk is not possible at time and thus a cautious and restrictive use of blood products is recommended. 展开更多
关键词 Liver transplantation HEMOSTASIS Bed-sidemonitoring THROMBELASTOGRAPHY Thrombelastometry COAGULATION factors
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Indoor Air Quality Real-Time Monitoring Results of Pathology Department
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作者 Like Shi Yue Wang +4 位作者 Liang Xu Yan Liu Dongsheng Yao Xiuwu Li Yuan Jia 《Journal of Environmental Protection》 2015年第8期851-856,共6页
In this work, the objectives were to provide a scientific basis for environmental governance and to ensure staff health by real-time monitoring of indoor air quality of the pathology department. Using eagle eye enviro... In this work, the objectives were to provide a scientific basis for environmental governance and to ensure staff health by real-time monitoring of indoor air quality of the pathology department. Using eagle eye environment monitor to make a real-time dynamic monitoring of the air quality of the pathological technical room for 30 days, the paper records the monitoring data of PM 2.5, PM 10, formaldehyde, CO2, total volatile organic compounds (TVOC) every day at Beijing time 3 a.m, 10 am, 1 pm, 4 pm, and 10 pm, and makes a summarization and analysis. The average value of CO2 concentration of the 5 time points is (0.05 ± 0.01)%, and each time point concentration are different (P 0.05);the average TVOC concentration of the 5 time points is (0.08 + 0.31) mg/m3. They are all different between the concentration at each time point (P 2 and NO are not checked out. Through the real-time online monitoring of the pathology room, we find that the formaldehyde concentration of different time periods is far more than the safety value standard, and the concentration of formaldehyde, CO2, PM 2.5, PM 10 and total volatile organic compound (TVOC) is different at different time periods, and the concentrations at working time are higher than the non-working time. We must take effective measures to control the concentration of harmful gases in order to ensure the staff’s health. 展开更多
关键词 PATHOLOGY DEPARTMENT INDOOR POLLUTION REAL-TIME monitoring Influence factorS
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Method to deploy wireless relays in industrial wireless monitoring
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作者 翁浩 Gao Jinji 《High Technology Letters》 EI CAS 2014年第2期161-165,共5页
In light of demands for wireless monitoring and the characteristics of wireless channel,a complete deployment method containing channel survey,path loss estimation,and gradient grade of wireless relay nodes is propose... In light of demands for wireless monitoring and the characteristics of wireless channel,a complete deployment method containing channel survey,path loss estimation,and gradient grade of wireless relay nodes is proposed.It can be proved by experiments that under the premise of meeting the requirements of real-time and redundant-topology,the total number of relay nodes could be minimized by using the proposed method. 展开更多
关键词 industrial wireless monitoring relay node deployment site survey path loss factor greedy randomized adaptive search procedure
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Development of a spherical tissue equivalent proportional counter for neutron monitoring
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作者 姜志刚 袁永刚 +1 位作者 王和义 陈华 《Nuclear Science and Techniques》 SCIE CAS CSCD 2015年第6期90-94,共5页
A spherical tissue equivalent proportional counter(TEPC) for neutron monitoring has been developed. It was properly designed to produce a uniform electric field intensity around the anode wire. An internal ^(241)Am al... A spherical tissue equivalent proportional counter(TEPC) for neutron monitoring has been developed. It was properly designed to produce a uniform electric field intensity around the anode wire. An internal ^(241)Am alpha source was adopted for lineal energy calibration. The TEPC was characterized in terms of dose equivalent response in a standard ^(252)Cf neutron field, and was tested with 2.45 MeV neutrons. Microdosimetric spectra, frequency mean lineal energy and dose-average mean lineal energy of 2.45 MeV neutrons were obtained and compared with FLUKA Monte Carlo simulation results. The measurement and simulation results agreed well. The mean quality factor and dose equivalent values evaluated from the 2.45 MeV neutron measurement were in good agreement with the recommended effective quality factor and ambient dose equivalent H*(10),respectively. Preliminary results have proved the availability of the developed TEPC for neutron monitoring. 展开更多
关键词 组织等效正比计数器 中子场 正比计数管 监测 种球 剂量响应 蒙特卡罗模拟 剂量当量
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河南省新乡地区金龟甲发生动态及影响因子分析 被引量:2
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作者 巩中军 段云 +7 位作者 张晶 李慧玲 蒋月丽 郭培 张自启 李彤 苗进 武予清 《环境昆虫学报》 CSCD 北大核心 2024年第1期116-126,共11页
为明确河南省新乡地区农田地下害虫优势种群组成、发生动态及影响因子,本研究于2015-2021年间利用虫情测报灯对该地区的金龟甲进行了监测。结果表明铜绿丽金龟Anomala corpulenta Motschulsky和暗黑鳃金龟Holotrichia parallela Motschu... 为明确河南省新乡地区农田地下害虫优势种群组成、发生动态及影响因子,本研究于2015-2021年间利用虫情测报灯对该地区的金龟甲进行了监测。结果表明铜绿丽金龟Anomala corpulenta Motschulsky和暗黑鳃金龟Holotrichia parallela Motschulsky为河南新乡小麦-玉米/花生1年2熟制农田地下害虫的优势种群,且暗黑鳃金龟的年度诱虫量及其在混合种群中的占比呈逐年增加趋势。金龟甲的发生在不同年份呈现单峰或双峰,暗黑鳃金龟发生盛期表现出明显的隔日出土现象即双倍节律。相较于暗黑鳃金龟发生期的6月中旬至9月上旬,铜绿丽金龟的发生期相对较短,在6月下旬至8月下旬。同时暗黑鳃金龟高峰日也晚于铜绿丽金龟,其中高峰日最多差22 d。金龟甲的发生与环境降雨、湿度、温度相关。本研究为新乡地区乃至黄淮海农田地下害虫的危害预警和综合治理提供数据支撑。 展开更多
关键词 暗黑鳃金龟 铜绿丽金龟 虫情测报灯 种群动态 气候因子
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井工煤矿甲烷排放精准监测与核算 被引量:1
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作者 解北京 李晓旭 +5 位作者 张景顺 栾铮 李军 陈伟 王兹尧 汤效平 《煤炭科学技术》 EI CAS CSCD 北大核心 2024年第4期119-130,共12页
甲烷作为全球第二大温室气体,具有增温潜势高、寿命短的特点,主要来源于煤炭、油气生产、农业、畜牧业和废弃物处理等领域。积极稳妥有序控制甲烷排放,兼具减缓全球温升的气候效益、能源资源化利用的经济效益、协同控制污染物的环境效... 甲烷作为全球第二大温室气体,具有增温潜势高、寿命短的特点,主要来源于煤炭、油气生产、农业、畜牧业和废弃物处理等领域。积极稳妥有序控制甲烷排放,兼具减缓全球温升的气候效益、能源资源化利用的经济效益、协同控制污染物的环境效益和减少生产事故的安全效益。甲烷也是煤矿生产排放中最主要的温室气体,目前对煤矿甲烷的排放监测及其在煤矿三维立体空间内的浓度分布研究将成为我国甲烷排放控制行动的重点,对煤矿企业更好顺应国家战略具有重要意义。选取山西某高瓦斯矿井、陕西某低瓦斯矿井进行甲烷排放监测核算,以固定监测、手工监测、无人机监测及矿后活动监测等方式研究我国高低瓦斯矿井甲烷分布,并对其甲烷排放量开展分析。结果表明:①美国Climate TRACE网站公布的山西某高瓦斯矿井、陕西某低瓦斯矿井2022年度甲烷排放量与实测法计算的结果差异较大,其中公布的某低瓦斯矿井年度甲烷排放量为实测法计算结果的10.92倍,自上而下的监测核算方法准确性不足,无法为碳交易提供可靠的数据支持。②矿后活动监测核算发现,采用IPCC缺省值计算的矿后活动甲烷排放量是实测法计算的3~5倍,且不同粒径和暴露时间下煤样反馈的矿后活动排放量差异较大。亟需一套统一精准的测试标准,为未来碳市场交易提供公平准确的数据。 展开更多
关键词 井工煤矿 甲烷排放 IPCC缺省值 精准监测核算 排放因子
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胎儿先天畸形超声监测结果分析
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作者 张静 江明 +2 位作者 张燕 岳家伊 滕玲玲 《中国计划生育学杂志》 2024年第3期512-516,共5页
目的:分析2020-2023年聊城市第二人民医院胎儿先天畸形(CM)监测结果并分析影响因素。方法:收集2020年1月-2023年12月在本院产前检查的孕妇5852例,根据超声筛查结果并分成畸形组和无畸形组。对孕妇相关资料行单因素分析,并通过多因素分... 目的:分析2020-2023年聊城市第二人民医院胎儿先天畸形(CM)监测结果并分析影响因素。方法:收集2020年1月-2023年12月在本院产前检查的孕妇5852例,根据超声筛查结果并分成畸形组和无畸形组。对孕妇相关资料行单因素分析,并通过多因素分析确定胎儿CM的影响因素。结果:5852例孕妇中胎儿存在CM有56例,CM发生率为0.96%;在畸形部位上,以心血管系统为主(30.4%),其次为神经系统畸形(23.2%);畸形组和无畸形组在妊娠年龄≥35岁、异常妊娠史、孕期毒物接触史、孕期用药史、孕期感染病原体、孕期补充叶酸、孕期患糖尿病或高血压、配偶吸烟间存在差异(P<0.05);logistic回归分析显示,胎儿CM的危险因素主要为妊娠年龄≥35岁(OR=2.289)、孕期有毒物接触史(OR=3.152)、孕期有用药史(OR=2.516)、孕期感染病原体(OR=2.449)、孕期患糖尿病或高血压(OR=2.792)、配偶吸烟(OR=2.584),保护因素为孕期补充叶酸(OR=0.478)。结论:本次调查妊娠年龄≥35岁、孕期有毒物接触史、孕期有用药史、孕期感染病原体、孕期患糖尿病或高血压、配偶吸烟与胎儿CM发生有关,补充叶酸可减少胎儿CM发生。提示对上述高危因素予以精准干预,并指导孕妇有效补充叶酸,以降低胎儿CM发生风险。 展开更多
关键词 胎儿先天畸形 超声监测 影响因素
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冻土区土壤甲烷排放的研究进展及发展趋势
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作者 张舜尧 施泽明 +3 位作者 杨志斌 周亚龙 张富贵 彭敏 《地学前缘》 EI CAS CSCD 北大核心 2024年第4期354-365,共12页
作为全球碳循环系统及陆地生态系统的重要组成部分,冻土区土壤甲烷排放在土壤碳库与气候变化之间的反馈联动机制中扮演着关键性角色,并因此成为全球气候变化研究中的前沿热点问题。冻土区土壤甲烷排放的气源主要为微生物产甲烷活动和冻... 作为全球碳循环系统及陆地生态系统的重要组成部分,冻土区土壤甲烷排放在土壤碳库与气候变化之间的反馈联动机制中扮演着关键性角色,并因此成为全球气候变化研究中的前沿热点问题。冻土区土壤甲烷排放的气源主要为微生物产甲烷活动和冻土层、天然气水合物中的气体释放作用,其中,微生物气源的研究较为成熟,而冻土层和天然气水合物气源甲烷的排放研究目前尚停留在定性分析阶段。在影响因子方面,文献计量学统计结果中出现频次最多的关键词依次为土壤温度、湿度和水位条件、有机质含量、地表植被条件等,这些要素可以对甲烷产生、传输和氧化吸收等多个环节产生影响。模型计算法是当前冻土区土壤甲烷排放评估预测的主要方法,包括早期的统计计算模型和近年来出现的基于土壤甲烷排放成因机理的过程模型,相关计算结果有效地支撑了全球气候变化评估研究。通过对冻土区土壤甲烷排放研究成果的梳理和总结,发现当前对冻土区土壤甲烷排放的气源和单因子影响作用认识较为明确,不同尺度的监测和评估方法也较为成熟。但是,对多气源作用下的冻土区土壤甲烷复合排放研究仍然较为薄弱,尤其是在冻土层和天然气水合物的甲烷释放方面,还缺少相关的定量计算研究。与此同时,在影响因子研究方面,也缺少多因素作用下的成因机理和驱动机制分析。因此,可以通过多方法、多因素综合监测研究,利用产甲烷微生物的元基因组分析、多气源土壤甲烷排放的同位素示踪等新技术和新方法,结合卫星遥感等大尺度观测结果,完善冻土区土壤甲烷排放的过程模型。此外,作为全球的“第三极”,青藏高原区域碳循环系统的变化将对亚洲,乃至全球气候变化产生重大影响。因此,还应进一步加强对青藏高原中纬度高原冻土区土壤甲烷排放的相关研究,为区域碳排放的定量评估和全球气候变化的研究提供理论支撑。 展开更多
关键词 冻土区 土壤甲烷排放 气源 影响因子 监测方法 发展趋势
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基于2次全国制图的土壤可蚀性因子变化趋势
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作者 赵院 田芷源 +1 位作者 梁音 赵艳 《中国水土保持科学》 CSCD 北大核心 2024年第4期146-151,共6页
2011年第1次全国水利普查水土保持专项普查基于全国各省(区、市)土壤类型图和土种志剖面数据,制作首张全国土壤可蚀性因子分布图(简称2011版K值)。为了提高土壤侵蚀评价的准确性和可信度,2022年利用全国土系调查数据和随机森林制图方法... 2011年第1次全国水利普查水土保持专项普查基于全国各省(区、市)土壤类型图和土种志剖面数据,制作首张全国土壤可蚀性因子分布图(简称2011版K值)。为了提高土壤侵蚀评价的准确性和可信度,2022年利用全国土系调查数据和随机森林制图方法对中国土壤可蚀性因子分布图进行更新(简称2022版K值)。以全国水蚀区2011版和2022版的土壤可蚀性因子(简称K值)为研究对象,分别在流域尺度和不同土壤类型下对K值大小及空间分布进行研究。结果表明:2022版全国平均K值(0.0298 t·hm^(2)·h/(MJ·mm·hm^(2)))略低于2011版K值(0.0323 t·hm^(2)·h/(MJ·mm·hm^(2))),说明全国水土流失治理发展状况有向好的趋势。其中栗钙土、暗棕壤、盐碱土等土壤类型K值的降低幅度最大,潮土、褐土、黄壤等土壤类型的K值则有所升高。K值降低主要与退耕还林、土壤改良等政策措施的出台和布设有关,升高则与集约化耕作及坡地侵蚀有关。该结果可为水土流失动态监测及治理成效评价提供科学依据。 展开更多
关键词 K因子 中国土壤流失方程 水力侵蚀 动态监测 变化趋势
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