An algorithm for multi-exponential inversion of T2 spectrum in nuclear magnetic resonance     

ItAN Chunjiang  ;REN Li  ;WANG Zhuwen 《东北亚地学研究》2014,(2):105-109

NMR logging can provide the permeability parameter and abundant stratigraphical information such as total porosity,oil,gas and water saturation,oil viscosity,etc. And these physical parameters can be obtained by T2 spectrum inversion. NMR inversion is an important part in logging interpretation. The authors describe a multi-exponential inversion algorithm,solid iteration redress technique（ SIRT）,and apply the algorithm in real data and compare the results with those based on singular value decomposition（ SVD）. It shows that SIRT algorithm is easier to be understood and implemented,and the time spent in SIRT is much shorter than that of SVD algorithm. And the non-negative property of T2 spectrum is much easier to be implemented. It can match the results based on SVD very well. SIRT algorithm can be used in T2 spectrum inversion for NMR analysis.  相似文献   

An algorithm for multi-exponential inversion of T2spectrum in nuclear magnetic resonance     

HAN Chunjiang  ＲEN Li  WANG Zhuwen 《世界地质(英文版)》2014,17(2):105-109

NMＲ logging can provide the permeability parameter and abundant stratigraphical information such as total porosity,oil,gas and water saturation,oil viscosity,etc． And these physical parameters can be ob- tained by T2spectrum inversion． NMＲ inversion is an important part in logging interpretation． The authors de- scribe a multi-exponential inversion algorithm,solid iteration redress technique (SIＲT),and apply the algo- rithm in real data and compare the results with those based on singular value decomposition (SVD)． It shows that SIＲT algorithm is easier to be understood and implemented,and the time spent in SIＲT is much shorter than that of SVD algorithm． And the non-negative property of T2spectrum is much easier to be implemented． It can match the results based on SVD very well． SIＲT algorithm can be used in T2spectrum inversion for NMＲ analysis．  相似文献   

黄海大海洋生态系区域监测体系建设的对策建议          下载免费PDF全文

王孝程  贾川  张怡  靳青青  王紫竹  刘永健  王燕  邵魁双  王守强  关春江  郭皓 《海洋开发与管理》2022,39(2):88-94

为促进黄海生态环境保护和生态灾害治理工作,文章基于历史资料的收集和整理,分析黄海大海洋生态系的生态环境背景及其存在的问题,并提出区域监测体系建设的对策建议。研究结果表明:黄海大海洋生态系的气候变化和营养盐变化是浮游生物群落的重要影响因素,赤潮、绿潮和水母暴发是黄海大海洋生态系的主要生态灾害;应通过加强各种形式的监测和合作,不断构建黄海大海洋生态系区域监测体系。  相似文献   

The significance of 24-norcholestanes,triaromatic steroids and dinosteroids in oils and Cambrian–Ordovician source rocks from the cratonic region of the Tarim Basin,NW China     

Meijun Li  T.-G. Wang  Paul G. Lillis  Chunjiang Wang  Shengbao Shi 《Applied Geochemistry》2012

Two oil families in Ordovician reservoirs from the cratonic region of the Tarim Basin are distinguished by the distribution of regular steranes, triaromatic steroids, norcholestanes and dinosteroids. Oils with relatively lower contents of C₂₈ regular steranes, C₂₆ 20S, C₂₆ 20R + C₂₇ 20S and C₂₇ 20R regular triaromatic steroids, dinosteranes, 24-norcholestanes and triaromatic dinosteroids originated from Middle–Upper Ordovician source rocks. In contrast, oils with abnormally high abundances of the above compounds are derived from Cambrian and Lower Ordovician source rocks. Only a few oils have previously been reported to be of Cambrian and Lower Ordovician origin, especially in the east region of the Tarim Basin. This study further reports the discovery of oil accumulations of Cambrian and Lower Ordovician origin in the Tabei and Tazhong Uplifts, which indicates a potential for further discoveries involving Cambrian and Lower Ordovician sourced oils in the Tarim Basin. Dinosteroids in petroleum and ancient sediments are generally thought to be biomarkers for dinoflagellates and 24-norcholestanes for dinoflagellates and diatoms. Therefore, the abnormally high abundance of these compounds in extracts from the organic-rich sediments in the Cambrian and Lower Ordovician and related oils in the cratonic region of the Tarim Basin suggests that phytoplankton algae related to dinoflagellates have appeared and might have flourished in the Tarim Basin during the Cambrian Period. Steroids with less common structural configurations are underutilized and can expand understanding of the early development history of organisms, as well as define petroleum systems.  相似文献   

利用Hudson裂隙模型分析井径变化对声波测井响应的影响     

张雪昂  王祝文  韩春江  向旻  杨闯 《吉林大学学报(地球科学版)》2013,43(6):2050

裂隙性介质因其复杂的结构和可观的藏储量一直是资源勘查领域的重点研究对象。基于Hudson裂隙理论对裂隙介质中不同裂隙参数（数密度、角度、纵横比）下变化井径的井场响应进行数值模拟,得到如下结果：在裂隙数密度较小的情况下,纵波、横波以及斯通利波幅度对井径变化响应较敏感;在裂隙角度较大的情况下,斯通利波幅度对井径变化响应较敏感;在裂隙角度较小的情况下,横波幅度对井径变化响应较敏感;在裂隙纵横比较小的情况下,纵波、横波以及斯通利波幅度对井径变化响应较敏感;在频率-波数二维谱中,随着井径的增大,波动激发强度峰值所在的频率带以及波动的首次激发频率都向低频区域移动。由此认为：弹性波在裂隙性介质中传播时在受井径变化的影响下产生规律性响应,应用Hudson裂隙理论模拟裂隙介质的井场响应可以系统地分析裂隙参数和井径变化对声波传播规律的影响,进而指导实地裂隙储层声波测井勘探工作。  相似文献   

Effects of different organic residues on rice yield and soil quality     

Li Peng  Wei Liu  Chunjiang Su  Ping Li  Yan Fang  Xiaolan Wang  Lian Sun 《山地科学学报》2012,9(5):715-722

Calcaric regosols are a valuable land resource, distributed widely across western China. Soil quality has deteriorated considerably in recent years owing to the blind pursuit of economic benefits. A 2-year field experiment was carried out to evaluate the effects of using spent mushroom compost, leguminous plant (Vicia sepium L.) compost, and a combination of the two (at a 1:1 and 2:1 ratio), on rice yield and soil quality in a suburb of China. Vicia sepium L. composted with spent mushroom compost at a 1:1 ratio produced the highest grain and stover yield, grain and stover phosphorus concentration, and phosphorus uptake of rice; they were 56.5%, 93.2%, 89.3%, 198.6% and 22.2% greater than control soil, respectively. The 2:1 ratio (Vicia sepium L.: spent mushroom compost) produced the highest grain N concentration, stover N concentration, and N uptake; they were 31.6%, 31.4%, and 40.7% higher than control, respectively. Soil physical, chemical, and environmental properties were improved with the application of Vicia sepium L. composted with spent mushroom compost at a 2:1 ratio. In particular, soil water-stable aggregates, organic carbon, particulate organic carbon, total nitrogen, available potassium, and cation exchange capacity increased, whereas bulk density, pH, and phytoavailable heavy metals decreased. This organic treatment is beneficial to improve soil quality indicators, and contribute to soil restoration.  相似文献   

发展中地区银行业空间系统变化--以河南省为例   总被引：21，自引：0，他引：21  

李小建  周雄飞  卫春江  孔云峰 《地理学报》2006,61(4):414-424

基于对中国发展中地区的河南省的第一手调查数据,对经济水平较低、受外部影响较小但增长迅速的内陆省份银行业空间系统变化进行了量化分析和解释。结果表明,与国际上发达国家相同,中国发展中地区的国有银行业逐步向中心城市集中。其中,作为区域中心的地级城市的地位上升最为突出。其形成原因主要与制度变化有关;而区域经济的发展差异,又是促进该趋势的直接诱因。这一观点通过混合OLS模型模拟得到证明。城市内部的银行业区位变化,具有一些与发达国家的不同之处。区域经济快速发展带来了中心城市的迅速拓展。同时经济结构调整,又带来了城市内不同地区经济发展水平的变化。由此形成了银行业区位的不断扩散,新兴快速增长的地区,迅速吸引了一批银行的建立。对郑州市58家银行网点的调查表明,在1978年之前,银行网点设立十分遵循计划体制的安排;而在1979年以后,邻近地段“人均收入水平高：决定着相当一部分银行网点的布局。这从微观角度佐证了河南省的分析结论。金融系统的集中格局,为非中心地区经济发展带来的不利影响,应该给予关注。  相似文献   

吐哈盆地侏罗系煤成液态烃生成演化的热模拟实验研究   总被引：7，自引：2，他引：5  

王春东  张中宁 《地质学报》1998,72(3):276-284

利用绝对密闭式干热解方法对吐哈盆地侏罗系腐殖煤的液态烃生成演化规律进行了研究。研究结果表明,煤在低成熟阶段(R_0=0.40％～0.65％)的液态烃产率变化幅度较小、地球化学特征也保持未熟—低熟特征;热解物产率曲线在R_0=0.58％～0.59％阶段呈现一个低谷;液态烃大量生成于R_0=0.65％阶段,产率峰值出现于R_0=1.09％阶段。进一步通过热模拟产物Pr/Ph、Pr/nC_(17)、Ph/nCl_(18)及饱/芳值等参数的变化规律、热解物正构烷烃分布特征、热模拟残渣的热解色谱特征,及与典型煤成油进行对比研究.证实了侏罗系煤成液态烃主要生成并排驱于成熟阶段(R_0=0.65％～1.09％)。  相似文献   

居住区环境与噪音污染对居民心理健康的影响——以北京为例   总被引：1，自引：3，他引：1  

李春江  马静  柴彦威  关美宝 《地理科学进展》2019,38(7):1103-1110

心理健康作为当代城市居民面临的主要问题之一,已有研究证实居住区建成环境和社会环境对心理健康的影响。然而,此类研究主要聚焦于西方发达国家,而且对于噪音污染因素考虑不足,未能同时研究居住区环境和噪音污染对居民心理健康的影响。论文基于2017年北京市26个居住区居民的健康问卷调查数据,采用多层Logistic模型,探讨居住区环境(包括建成环境及社会环境)与居民感知的多种来源的噪音污染(包括道路交通噪音、轨道交通噪音、商店餐饮噪音和住房装修噪音)等多种因素与居民心理健康的相关关系。研究发现,居住区环境和噪音污染水平均与居民心理健康显著相关。与西方发达国家居住区环境与心理健康关系的研究类似,论文发现居住区医疗设施和休闲娱乐设施可达性、居民邻里关系、居住区满意度等因素与心理健康显著相关;不同的是,论文发现公园可达性、居住区交通噪音等因素与心理健康相关性不显著。此外,本文发现住房装修噪音是影响北京居民心理健康的主要噪音来源。  相似文献   

Fracturing and Failure Behavior of Carrara Marble in Quasistatic and Dynamic Brazilian Disc Tests   总被引：1，自引：0，他引：1  

Louis Ngai Yuen Wong  Chunjiang Zou  Yi Cheng 《Rock Mechanics and Rock Engineering》2014,47(4):1117-1133

The tensile strength and fracturing behavior of Carrara marble subjected to the dynamic Brazilian disc test using the split Hopkinson pressure bar technique are determined and compared with those obtained by the conventional quasistatic Brazilian disc test. Detailed observation of the cracking processes is aided by high-speed video footage captured at a frame rate of 100,000 frames per second. The dynamic increase factor is computed, revealing a strong strain rate dependence of the Carrara marble when subjected to strain rates above 1 s^?1. Similar to the quasistatic loading tests, conspicuous white zones/patches commonly appear prior to the initiation of visible cracks in the dynamic loading tests. Identification of the white patch initiation and evolution is aided by image comparison software. Comparing the cracking and failure processes under quasistatic and dynamic loading, some distinct differences in the white patch geometry and initiation load are observed. In addition, the extent of the compressive failure zones around the contact points between the loading platens and specimens is found to increase with the strain rate.  相似文献