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181.
为研究破碎带对断层活化的影响,选取破碎带宽度、岩石内摩擦角、粘结系数及抗拉强度作为破碎带的特征参数,采用FLAC3D模拟工作面推进对断层的影响,借助正交表确定模拟方案,通过对正交试验结果进行方差分析,以此研究影响断层活化的破碎带特征参数敏感性。结果表明:破碎带特征参数对断层活化的敏感性主次顺序为破碎带宽度﹥岩石内摩擦角﹥岩石粘结系数﹥岩石抗拉强度,且断层破碎带宽度越大,岩石内摩擦角越小,断层活化可能性也就越高,而岩石粘结系数与抗拉强度对断层活化影响较小。  相似文献   
182.
通过建立微型生态系统,研究了不同养殖密度和处理时间条件下,背角无齿蚌(Anodonta woodiana)对大宗淡水鱼养殖水体理化指标和营养盐的影响及净化特征。研究结果表明,背角无齿蚌对水体pH、CODMn和NH4+-N的影响不明显;电导率、总固溶物、NO2--N、DTP、PO43--P和DOC呈升高的趋势;DO随蚌养殖密度和时间的增加而降低;能够显著降低水体的浊度、Chl-a、TN、NO3--N和TP含量(P3和15.35 d、25 ind./m3和10 d时,对NO3--N、TP的去除率可进一步提升至42.6%和35.0%。本研究表明,背角无齿蚌可以用于养鱼水体的水质净化。  相似文献   
183.
ABSTRACT: This paper presents the results of a statistical analysis performed for the watershed and stream corridor in the South Fork of the Clearwater River (SFCR) basin, in north central Idaho. The analysis was performed for 61 six‐field hydrological unit codes (HUCs) of the SFCR basin using an extensive record (up to 100 years) for 50 watershed and in‐stream parameters, including hydrologic, flow, fish, anthropogenic, and natural activity data. The objective of this research was twofold: first, the development of quantitative relations that describe the Index of Fish Density (IFD) of particular fish species as a function of watershed and instream parameters; and second, to provide a robust confirmation for the effects of some of these parameters, previously recorded by the fisheries profession, by using well established statistical techniques. The uniqueness of this work is the compilation and statistical analysis of large data sets to quantitatively describe the impacts of watershed and instream parameters on the IFD of all salmonids and specific fish species. Factor analysis was employed to regroup parameters that are highly correlated to each other into a set of single factors and to relate the IFD to these factors. Using factor extraction, 12 factors were developed from the 50 watershed and instream parameters. Multiple regression diagnostic tests indicated that only 7 of the 12 factors are strong predictors offish indicators. The strongest predictors are longitude, latitude, elevation, watershed gradient, and water temperature. The analysis indicated that the present model has reasonable predictive power, considering the uncertainty involved in estimating the interdependence of IFD with watershed parameters.  相似文献   
184.
木薯皮堆肥过程中酶活性的变化   总被引:4,自引:0,他引:4  
以木薯皮为原料进行高温堆肥发酵,研究了堆肥化过程中理化性质和酶活性的变化情况.结果表明:在堆肥发酵过程中.温度变化呈先上升后下降趋势,到后期已趋近于初始温度;而含水率在堆肥处理过程中变化不大.各处理的pH值在发酵结束时为7.3~7.5.过氧化氢酶活性初期较高,随后迅速降低,并维持在较低水平.纤维素酶和脲酶活性在堆肥初期增加,之后逐渐降低.由于堆肥原料不同,不同处理的酶活性变化趋势表现出一定的差异.考虑到堆肥腐熟度受多方面因素的影响,判断堆肥腐熟度时应根据多种指标(包括生物学、化学、物理学指标)综合判断.  相似文献   
185.
本文对化学品登记时所要求的理化和生物降解数据做了解释。涉及到的测试参数包括:紫外—可见光谱、熔点、沸点,蒸汽压曲线、水溶解度、吸附—解吸、分配系数(正丁醇—水)、液体和固体密度、颗粒物粒度分布、与 pH 有关的水解作用、在水中的离解常数和快速生物降解。  相似文献   
186.
小波分析在语音识别系统中的研究与应用   总被引:2,自引:0,他引:2  
在语音识别系统的不同处理阶段,大部分可以使用小波分析技术进行实现,并且这种实现方法比传统的方法具有更好的效果.本文重点探讨了在端点检测、噪声去除以及参数提取过程中使用小波分析技术的原理及方法,并提出现阶段所存在的问题及解决方案.  相似文献   
187.
Global warming and climate change have been identified as the most important challenges of the 21st century. Greenhouse Gases Observation Satellite (GOSAT) measures the concentrations of carbon dioxide (CO 2) and methane (CH 4) in the atmosphere column from the earth's surface to the upper atmosphere. In this research, GOSAT Thermal And Near Infrared Sensor for Carbon Observation – Fourier Transform Spectrometer (TANSO‐FTS) level 2 data and meteorological parameters were used in the assessment of changes in CO 2 concentration (XCO 2) from 2009 to 2015. We investigated the relationship between XCO 2 and meteorological parameters (temperature and precipitation) obtained from weather stations and the Normalized Difference Vegetation Index (NDVI) in the year 2013 in Iran. The results reveal a steady increase in the mean atmospheric CO 2 concentration, from 384.89 to 400.39 ppm. It was observed that the XCO 2 varied significantly depending on the month, with the highest concentration of CO 2 in April/May and the lowest concentration in August/September. The correlation between XCO 2 and average monthly air temperature is negative, which means that a reduction in XCO 2 with an increase in temperature is dependent on photosynthetic activities in the growing seasons. The highest and lowest correlation coefficient between the NDVI and XCO 2 was obtained in the spring and in the fall, respectively. These findings are useful for recognizing factors that affect CO 2 concentration in different seasons in arid and semi‐arid regions, and as an initial step toward sustainable management.  相似文献   
188.
Increasing micro plastic concentration in the marine environment is a severe threat to the marine ecosystem and indirectly to human society depending on the marine environment. Also, the surface and subsurface water quality parameters are the indicators of the usability of the water sources for human activities. The primary source of micro plastic is the water river systems from land to sea. This study establishes a correlation between water quality parameters and micro plastic concentration to find the most suitable quality parameter for finding the micro plastic concentration in urban coastal estuaries of Chennai coast, Tamil Nadu, India. Twenty samples from Adyar and Cooum estuaries were collected, with ten each on August 2019 and August 2020. They are tested for temperature pH, EC, Turbidity, TDS, DO, BOD, COD, Salinity and micro plastic concentrations. Correlation tests such as Pearson's and Spearman's are performed based on the initial Normality and Homogeneity test. The results show that all the parameters are significantly not correlated with the Micro plastic Concentration, and Micro plastic Concentration is considered an independent factor.  相似文献   
189.
In the present study, air pollutant concentrations have been analyzed statistically with meteorological factors in the city of Elazig, which is located in the east Anatolia region of Turkey, for the months of September, October, November, December, January, February, March, and April during the years 2003 and 2004. SPSS code was used for statistical analyses. The relationship between monitored air pollutant concentrations, such as SO2 and the total suspended particles (TSP) data, and meteorological factors such as wind speed, temperature, relative humidity and pressure was investigated. According to the results of linear and non-linear regression analysis, it was found that there is a moderate and weak level of relation between the air pollutant concentrations and the meteorological factors in Elazig. The correlation between the previous day's SO2, TSP concentrations and actual concentrations of these pollutants on that day was investigated and the coefficient of determination R was found to be 0.80 and 0.76, respectively. The statistical models of SO2 and TSP, including all of the meteorological parameters, gave an R of 0.50 and 0.40, respectively. Further, in order to develop this model, the previous day's SO2 and TSP concentrations were added to the equations. The new model for SO2 and TSP was improved considerably with R = 0.85 and 0.80, respectively.  相似文献   
190.
金刚石钻进规程的实验室模拟及参数校核   总被引:3,自引:0,他引:3  
金刚石钻进的钻进规程决定了钻进效率和钻头的使用寿命,也决定了钻进的安全性、可靠性和经济效益。因此,选择最佳的钻进规程尤其重要。本文通过智能微钻实验台对金刚石钻进的模拟钻进参数及其变化曲线、参数值,以及对应的钻进速度、进尺变化曲线、参数值进行分析,得到相应岩石条件下的最优钻进规程。  相似文献   
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