Hydrocarbon production from shale has attracted much attention in the recent years. When applied to this prolific and hydrocarbon rich resource plays, our understanding of the complexities of the flow mechanism（sorpt...Hydrocarbon production from shale has attracted much attention in the recent years. When applied to this prolific and hydrocarbon rich resource plays, our understanding of the complexities of the flow mechanism（sorption process and flow behavior in complex fracture systems- induced or natural） leaves much to be desired. In this paper, we present and discuss a novel approach to modeling, history matching of hydrocarbon production from a Marcellus shale asset in southwestern Pennsylvania using advanced data mining, pattern recognition and machine learning technologies. In this new approach instead of imposing our understanding of the flow mechanism, the impact of multi-stage hydraulic fractures, and the production process on the reservoir model, we allow the production history, well log, completion and hydraulic fracturing data to guide our model and determine its behavior. The uniqueness of this technology is that it incorporates the so-called ＂hard data＂ directly into the reservoir model, so that the model can be used to optimize the hydraulic fracture process. The ＂hard data＂ refers to field measurements during the hydraulic fracturing process such as fluid and proppant type and amount, injection pressure and rate as well as proppant concentration. This novel approach contrasts with the current industry focus on the use of ＂soft data＂（non-measured, interpretive data such as frac length, width,height and conductivity） in the reservoir models. The study focuses on a Marcellus shale asset that includes 135 wells with multiple pads, different landing targets, well length and reservoir properties. The full field history matching process was successfully completed using this data driven approach thus capturing the production behavior with acceptable accuracy for individual wells and for the entire asset.展开更多
AIM, To determine the prevalence of hepatitis B in Nahavand and evaluate the HBsAg positive prevalence in families with a member who was confirmed to have HBV infection. METHODS： This study was performed in two phase...AIM, To determine the prevalence of hepatitis B in Nahavand and evaluate the HBsAg positive prevalence in families with a member who was confirmed to have HBV infection. METHODS： This study was performed in two phases. In the first phase, 1 824 subjects in Nahavand city were selected. The interviewers visited the houses of chosen families to flU the questionnaire and take the blood samples. All subjects signed an informed consent before interviews and blood sampling. The samples were evaluated for HBV virologic markers. In the second phase, 115 HBsAg-positive cases were enrolled and evaluated for HBV virologic markers. RESULTS： The prevalence of positive HBsAg in Nahavand was 2.3%. The most frequent relatives of index cases were sons and daughters （32.2% and 23.5% respectively）. Twelve （11%） of all family members were HBsAg positive. Fifty （56.2%） were isolated HBsAb positive and only one person （2.5%） was isolated HBcAb positive. The higher rates of HBsAg marker were detected in the brothers （1-25%） and fathers （1-12.5%）. The infection rate in husbands and wives of index cases was 10%. Only two （16.7%） of all HBsAg-positive participants reported previous HBV vaccination. CONCLUSION： The prevalence of intr-familial HBV infection is lower in Nahavand of Iran compared to other studies. More attention should be paid to HBV vaccination and risk-lowering activities.展开更多
AIM： TO determine the expression of DNA （MMR） proteins, including hMLH1 and hMSH2, in gastric epithelial cells in the patients with or without Helicobacter pylori （H pylori）-infected gastritis. METHODS： Fifty Hp...AIM： TO determine the expression of DNA （MMR） proteins, including hMLH1 and hMSH2, in gastric epithelial cells in the patients with or without Helicobacter pylori （H pylori）-infected gastritis. METHODS： Fifty Hpylori-positive patients and 50 H pylori-negative patients were enrolled in the study. During endoscopy of patients with non-ulcer dyspepsia, two antral and two corpus biopsies were taken for histological examination （Giemsa stain） and for immunohistochemical staining of hMLH1 and hMSH2. RESULTS： The percentage of epithelial cell nuclei that demonstrated positivity for hMLH1 staining was 84.14 ± 7.32% in Hpylori-negative patients, while it was 73.34 ±10.10% in Hpylori-positive patients （P 〈 0.0001）. No significant difference was seen between the two groups regarding the percentage of epithelial cell nuclei that demonstrated positivity for hMSH2 staining （81.16±8.32% in H pylori-negative versus 78.24 ± 8.71% in Hpylori-positive patients; P = 0.09）. CONCLUSION： This study indicates that Hpylori might promote development of gastric carcinoma at least in part through its ability to affect the DNA MMR system展开更多
A novel coronavirus of zoonotic origin(SARSCoV-2)has recently been recognized in patients with acute respiratory disease.COVID-19 causative agent is structurally and genetically similar to SARS and bat SARS-like coron...A novel coronavirus of zoonotic origin(SARSCoV-2)has recently been recognized in patients with acute respiratory disease.COVID-19 causative agent is structurally and genetically similar to SARS and bat SARS-like coronaviruses.The drastic increase in the number of coronavirus and its genome sequence have given us an unprecedented opportunity to perform bioinformatics and genomics analysis on this class of viruses.Clinical tests like PCR and ELISA for rapid detection of this virus are urgently needed for early identification of infected patients.However,these techniques are expensive and not readily available for point-of-care(POC)applications.Currently,lack of any rapid,available,and reliable POC detection method gives rise to the progression of COVID-19 as a horrible global problem.To solve the negative features of clinical investigation,we provide a brief introduction of the general features of coronaviruses and describe various amplification assays,sensing,biosensing,immunosensing,and aptasensing for the determination of various groups of coronaviruses applied as a template for the detection of SARS-CoV-2.All sensing and biosensing techniques developed for the determination of various classes of coronaviruses are useful to recognize the newly immerged coronavirus,i.e.,SARS-CoV-2.Also,the introduction of sensing and biosensing methods sheds light on the way of designing a proper screening system to detect the virus at the early stage of infection to tranquilize the speed and vastity of spreading.Among other approaches investigated among molecular approaches and PCR or recognition of viral diseases,LAMP-based methods and LFAs are of great importance for their numerous benefits,which can be helpful to design a universal platform for detection of future emerging pathogenic viruses.展开更多
Aerators on discharge tunnel outlets may be regarded as an effective protection against cavitation erosion. The air entrainment of aerators is governed by a number of independent parameters, including the bottom slope...Aerators on discharge tunnel outlets may be regarded as an effective protection against cavitation erosion. The air entrainment of aerators is governed by a number of independent parameters, including the bottom slope of releasing free-surface flow tunnel downstream of service gate, the end top slope of pressure tunnel, the height of step, and the Froude number at take-off. During eight phases of experiments, the effects of above-mentioned parameters were observed on the cavity length downstream of the fully open operating service gate of a discharge tunnel. The results show that, the bottom slope of releasing free-surface flow tunnel has obvious effect on the cavity length as well as the Froude number at gate take-off. The effect of the step height variations on the cavity length could be considered for higher discharges and steeper tunnel top slope, particularly in higher discharges, resulting in shorter cavity length downstream of service gate.展开更多
Due to different latitudes and variation of altitude in geographical areas in Iran,the climatic conditions of Iran are such that the variations of the heating degree-days(HDD)are in a broad range of 60 to 3000 for res...Due to different latitudes and variation of altitude in geographical areas in Iran,the climatic conditions of Iran are such that the variations of the heating degree-days(HDD)are in a broad range of 60 to 3000 for residential buildings in different climatic regions.In addition,in many cases,the building design and construction processes follow patterns which do not necessarily meet national energy requirements and standards.Based on these two reasons,it is essential to identify the current status of energy consumption indicators in residential buildings.That way,it gets more convenient to adopt new strategies to improve the current state of energy consumption of buildings.In this study,heating energy consumption indices of residential buildings is investigated.Using the combination of the results of statistical data analysis,questionnaires,filled in for 500 buildings,and a reference building simulation in different climates of Iran,the heating atlas of residential buildings was prepared.According to the results,the average heating energy index(HE1)of buildings in Iran can be less than 1 to more than 41.3(m^(3)(N.G)/(m^(2)-yr))depending on climatic conditions and building design and construction quality.However,in the coldest center of province,the average of this index is 26.3(m^(3)(N.G)/(m^(2)-yr))in the hottest one that is equal 2.2.The variations of the thermal base load(supply of hot water)varied from less than 13.12 to more than 378.84(m^(3)(N.G)/(person-yr)).In provincial capitals,the lowest thermal base load index(TBLI)of buildings is 24.78 and the highest is 226.49(m^(3)(N.G)/(person-yr)).In this paper,beside charts and tables,results of heating energy consumption indices are also presented in the form of graphical atlases,i.e.color contour plots,to deliver a better picture of the whole country.展开更多
Experimental results were compared with the computed results obtained from the nine most well-known methods for computation of discharge in a compound channel. The results demonstrate a high accuracy of the divided ch...Experimental results were compared with the computed results obtained from the nine most well-known methods for computation of discharge in a compound channel. The results demonstrate a high accuracy of the divided channel method with the horizontal division lines, while the length of division line is included within the calculation of the wetted perimeter. In addition, as relative depth increases, the results of the all methods converge to each other and also in case of steeper slopes in lower relative depths, more agreements between different calculated methods and experimental results were observed. Furthermore, the results show the effects of the maximum momentum transfer on the horizontal interface between the main channel and flood plains, while further angular distance from the horizontal interface toward the vertical interface between main channel and flood plains causes gradual decrease of momentum transfer effects.展开更多
Traditional Numerical Reservoir Simulation has been contributing to the oil and gas industry for decades.The current state of this technology is the result of decades of research and development by a large number of e...Traditional Numerical Reservoir Simulation has been contributing to the oil and gas industry for decades.The current state of this technology is the result of decades of research and development by a large number of engineers and scientists.Starting in the late 1960s and early 1970s,advances in computer hardware along with development and adaptation of clever algorithms resulted in a paradigm shift in reservoir studies moving them from simplified analogs and analytical solution methods to more mathematically robust computational and numerical solution models.展开更多
Understanding predator-prey interactions has a pivotal role in biological control programs. This study evaluated the functional response of three larval instars of the green lacewing, Chrysoperla carnea （Stephens）, ...Understanding predator-prey interactions has a pivotal role in biological control programs. This study evaluated the functional response of three larval instars of the green lacewing, Chrysoperla carnea （Stephens）, preying upon eggs and first instar larvae of the cotton bollworm, Helicoverpa armigera Hubner. The first and second instar larvae of C. carnea exhibited typeⅡ functional responses against both prey stages. However, the third instar larvae of C. carnea showed a type II functional response to the first instar larvae of H. armigera, but a typeⅢ functional response to the eggs. For the first instar larvae of C. carnea, the attack rate on H. armigera eggs was significantly higher than that on the larvae, whereas the attack rate of the second instar C. carnea on H. armigera larvae was significantly higher than that on the eggs. For the third instar larvae of C. carnea, the attack rate on the larvae was 1.015±0.278/h, and the attack coefficient on the eggs was 0.036 ±0.005. The handling times of the third instar larvae on larvae and eggs were 0.087 ± 0.009 and 0.071 ± 0.001 h, respectively. The highest predation rate was found for the third instar larvae of C. carnea on H. armigera eggs. Results of this study revealed that the larvae of C. carnea, especially the third instar, had a good predation potential in controlling H. armigera eggs and larvae. However, for a comprehensive estimation of the bio- control abilities of C. carnea toward H, armigera, further field-based studies are needed.展开更多
Using artificial intelligence(AI) and machine learning(ML) techniques, we developed and validated the smart proxy models for history matching of reservoir simulation, sensitivity analysis, and uncertainty assessment b...Using artificial intelligence(AI) and machine learning(ML) techniques, we developed and validated the smart proxy models for history matching of reservoir simulation, sensitivity analysis, and uncertainty assessment by artificial neural network(ANN). The smart proxy models were applied on two cases, the first case study investigated the application of a proxy model for calibrating a reservoir simulation model based on historical data and predicting well production while the second case study investigated the application of an ANN-based proxy model for fast-track modeling of CO2 enhanced oil recovery, aiming at the prediction of the reservoir pressure and phase saturation distribution at injection stage and post-injection stage. The prediction effects for both cases are promising. While a single run of basic numerical simulation model takes hours to days, the smart proxy model runs in a matter of seconds, saving 98.9% of calculating time. The results of these case studies demonstrate the advantage of the proposed workflow for addressing the high run-time, computational time and computational cost of numerical simulation models. In addition, these proxy models predict the outputs of reservoir simulation models with high accuracy.展开更多
Sol-gel coatings containing various amounts of hydroxylated nanodiamond(HND)particles were applied on the magnesium alloy for corrosion protection.The micrometric defects in the sol-gel coating completely disappeared ...Sol-gel coatings containing various amounts of hydroxylated nanodiamond(HND)particles were applied on the magnesium alloy for corrosion protection.The micrometric defects in the sol-gel coating completely disappeared after adding 0.01,0.02 and 0.05 wt.%of the HND nanoparticles.The AFM analyses showed that average roughness of the sol-gel film is about 6.7 nm which increases to 16.1 and 20.2 nm after incorporating 0.005 and 0.02 wt.%of the HNDs,respectively.The corrosion resistance of the coatings was tested in Harrison’s solution by means of EIS technique after 15,30,60 and 120 min immersion.The corrosion resistance of the sol-gel coating was remarkably enhanced by incorporating different contents of the HNDs and the best result was obtained for 0.01 wt.%.The results of the EIS experiments were confirmed by the potentiodynamic polarization tests.The corrosion resistance enhancement was attributed to the film compactness(due to the chemical interaction with the HNDs),formation of tortuous pathways for diffusion of the corrosive solution,and filling of the defects by the nanoparticles.However,the beneficial effect of the HNDs on the corrosion resistance gradually diminished as the content of nanoparticle was increased.Finally,the micromorphology of the sol-gel nanocomposites was studied after the corrosion tests.展开更多
近年来极端暴雨天气与自然灾害频发,导致农田损毁,影响耕作。该研究利用高精度农田数字地形模型(Farmland Digital Terrain Model,FDTM),基于地形因子综合属性提出一种识别农田微地形特征(凸起特征及洼地特征)的方法。首先,基于SfM(Stru...近年来极端暴雨天气与自然灾害频发,导致农田损毁,影响耕作。该研究利用高精度农田数字地形模型(Farmland Digital Terrain Model,FDTM),基于地形因子综合属性提出一种识别农田微地形特征(凸起特征及洼地特征)的方法。首先,基于SfM(Structure from Motion)技术处理试验田的航拍图像,获取高精度农田FDTM,分析FDTM的高程方差随局部窗口尺度的变化趋势,确定分析窗口的尺度区间为31像素×31像素至51像素×51像素。其次,选择高程、地形起伏度和坡度综合评价在51像素×51像素窗口下提取的315个高程极值点,获取多窗口地形因子综合隶属度。最后,根据斯特吉斯公式确定阈值为0.627,提取16个农田凸起特征顶点,并结合等高线图识别凸起特征的外形轮廓;同理,建立反转数字地形模型(Reverse-FDTM,RFDTM),将FDTM中的洼地特征转变为RFDTM中的凸起特征,识别9个农田洼地特征。研究结果可为农田复垦及精准土地平整作业提供理论依据与方法支持。展开更多
This study provides a checklist of species distributed at the altitude gradient of MoghanSabalan rangelands in Ardabili province, Northwest Iran. We evaluated the changes in species composition, growth types of specie...This study provides a checklist of species distributed at the altitude gradient of MoghanSabalan rangelands in Ardabili province, Northwest Iran. We evaluated the changes in species composition, growth types of species, Raunkiaer's life forms, geographical distribution, threat and endemicity status, and palatability of species along two altitudinal gradients in the sampling plots, which were conducted in eleven sites/habitats with 300 meters above sea level(masl) altitude intervals(from 100 to 3300 masl). We assessed the plant species composition with special reference to the gradient analysis, and identified overall 396 species, which was comprising 44 families and 194 genera. Results showed that Asteraceae family is by far the most species-rich family, followed by Poaceae, Fabaceae, Caryophyllaceae and Brassicaceae. Among the genera, Astragalus is the most diverse genus, followed by Allium, Veronica and Bromus, Galium, Silene and Ranunculus. Results indicated that the number of species increased as the altitude increased to 1200-1500 masl, but then starts to decline to 3300 masl. Family-to-genera ratio was 1:4.4, the family-tospecies ratio was 1:9, and the genera-to-species ratio was 1:2.04. Growth type of species analysis shows that the frequency of perennial plants was higher in the study area followed by annual species while the lower group was biennial species. The number of annuals showed a decreasing trend towards higher altitude. Hemicryptophytes and therophytes were the most frequent life forms constituted each with(41.9%). Hemicryptophytes showed an increasing trend with altitude, while therophytes showed a decreasing trend with altitude increase, followed by geophytes, chamaephytes, and phanerophytes. Results showed more than half of the species of the study area belonged to Iran-Turanian region and these species showed an increasing trend with altitude. In contrast, Sahara-Sindian species comprise a minor component of the spectrum, with decreasing trend with altitude. The rare and endangered species 展开更多
基金RPSEA and U.S.Department of Energy for partially funding this study
文摘Hydrocarbon production from shale has attracted much attention in the recent years. When applied to this prolific and hydrocarbon rich resource plays, our understanding of the complexities of the flow mechanism（sorption process and flow behavior in complex fracture systems- induced or natural） leaves much to be desired. In this paper, we present and discuss a novel approach to modeling, history matching of hydrocarbon production from a Marcellus shale asset in southwestern Pennsylvania using advanced data mining, pattern recognition and machine learning technologies. In this new approach instead of imposing our understanding of the flow mechanism, the impact of multi-stage hydraulic fractures, and the production process on the reservoir model, we allow the production history, well log, completion and hydraulic fracturing data to guide our model and determine its behavior. The uniqueness of this technology is that it incorporates the so-called ＂hard data＂ directly into the reservoir model, so that the model can be used to optimize the hydraulic fracture process. The ＂hard data＂ refers to field measurements during the hydraulic fracturing process such as fluid and proppant type and amount, injection pressure and rate as well as proppant concentration. This novel approach contrasts with the current industry focus on the use of ＂soft data＂（non-measured, interpretive data such as frac length, width,height and conductivity） in the reservoir models. The study focuses on a Marcellus shale asset that includes 135 wells with multiple pads, different landing targets, well length and reservoir properties. The full field history matching process was successfully completed using this data driven approach thus capturing the production behavior with acceptable accuracy for individual wells and for the entire asset.
文摘AIM, To determine the prevalence of hepatitis B in Nahavand and evaluate the HBsAg positive prevalence in families with a member who was confirmed to have HBV infection. METHODS： This study was performed in two phases. In the first phase, 1 824 subjects in Nahavand city were selected. The interviewers visited the houses of chosen families to flU the questionnaire and take the blood samples. All subjects signed an informed consent before interviews and blood sampling. The samples were evaluated for HBV virologic markers. In the second phase, 115 HBsAg-positive cases were enrolled and evaluated for HBV virologic markers. RESULTS： The prevalence of positive HBsAg in Nahavand was 2.3%. The most frequent relatives of index cases were sons and daughters （32.2% and 23.5% respectively）. Twelve （11%） of all family members were HBsAg positive. Fifty （56.2%） were isolated HBsAb positive and only one person （2.5%） was isolated HBcAb positive. The higher rates of HBsAg marker were detected in the brothers （1-25%） and fathers （1-12.5%）. The infection rate in husbands and wives of index cases was 10%. Only two （16.7%） of all HBsAg-positive participants reported previous HBV vaccination. CONCLUSION： The prevalence of intr-familial HBV infection is lower in Nahavand of Iran compared to other studies. More attention should be paid to HBV vaccination and risk-lowering activities.
文摘AIM： TO determine the expression of DNA （MMR） proteins, including hMLH1 and hMSH2, in gastric epithelial cells in the patients with or without Helicobacter pylori （H pylori）-infected gastritis. METHODS： Fifty Hpylori-positive patients and 50 H pylori-negative patients were enrolled in the study. During endoscopy of patients with non-ulcer dyspepsia, two antral and two corpus biopsies were taken for histological examination （Giemsa stain） and for immunohistochemical staining of hMLH1 and hMSH2. RESULTS： The percentage of epithelial cell nuclei that demonstrated positivity for hMLH1 staining was 84.14 ± 7.32% in Hpylori-negative patients, while it was 73.34 ±10.10% in Hpylori-positive patients （P 〈 0.0001）. No significant difference was seen between the two groups regarding the percentage of epithelial cell nuclei that demonstrated positivity for hMSH2 staining （81.16±8.32% in H pylori-negative versus 78.24 ± 8.71% in Hpylori-positive patients; P = 0.09）. CONCLUSION： This study indicates that Hpylori might promote development of gastric carcinoma at least in part through its ability to affect the DNA MMR system
基金Nanjing Forestry University[Grant Nos.163020139,164020818,163020217 and 16302023]National Natural Science Foundation of China(5201101466).
文摘A novel coronavirus of zoonotic origin(SARSCoV-2)has recently been recognized in patients with acute respiratory disease.COVID-19 causative agent is structurally and genetically similar to SARS and bat SARS-like coronaviruses.The drastic increase in the number of coronavirus and its genome sequence have given us an unprecedented opportunity to perform bioinformatics and genomics analysis on this class of viruses.Clinical tests like PCR and ELISA for rapid detection of this virus are urgently needed for early identification of infected patients.However,these techniques are expensive and not readily available for point-of-care(POC)applications.Currently,lack of any rapid,available,and reliable POC detection method gives rise to the progression of COVID-19 as a horrible global problem.To solve the negative features of clinical investigation,we provide a brief introduction of the general features of coronaviruses and describe various amplification assays,sensing,biosensing,immunosensing,and aptasensing for the determination of various groups of coronaviruses applied as a template for the detection of SARS-CoV-2.All sensing and biosensing techniques developed for the determination of various classes of coronaviruses are useful to recognize the newly immerged coronavirus,i.e.,SARS-CoV-2.Also,the introduction of sensing and biosensing methods sheds light on the way of designing a proper screening system to detect the virus at the early stage of infection to tranquilize the speed and vastity of spreading.Among other approaches investigated among molecular approaches and PCR or recognition of viral diseases,LAMP-based methods and LFAs are of great importance for their numerous benefits,which can be helpful to design a universal platform for detection of future emerging pathogenic viruses.
基金supported by the National Natural Science Foundation of China (Grand No.50879021)the Ministry of Science and Technology of China (Grant No2008BAB19B04)
文摘Aerators on discharge tunnel outlets may be regarded as an effective protection against cavitation erosion. The air entrainment of aerators is governed by a number of independent parameters, including the bottom slope of releasing free-surface flow tunnel downstream of service gate, the end top slope of pressure tunnel, the height of step, and the Froude number at take-off. During eight phases of experiments, the effects of above-mentioned parameters were observed on the cavity length downstream of the fully open operating service gate of a discharge tunnel. The results show that, the bottom slope of releasing free-surface flow tunnel has obvious effect on the cavity length as well as the Froude number at gate take-off. The effect of the step height variations on the cavity length could be considered for higher discharges and steeper tunnel top slope, particularly in higher discharges, resulting in shorter cavity length downstream of service gate.
文摘Due to different latitudes and variation of altitude in geographical areas in Iran,the climatic conditions of Iran are such that the variations of the heating degree-days(HDD)are in a broad range of 60 to 3000 for residential buildings in different climatic regions.In addition,in many cases,the building design and construction processes follow patterns which do not necessarily meet national energy requirements and standards.Based on these two reasons,it is essential to identify the current status of energy consumption indicators in residential buildings.That way,it gets more convenient to adopt new strategies to improve the current state of energy consumption of buildings.In this study,heating energy consumption indices of residential buildings is investigated.Using the combination of the results of statistical data analysis,questionnaires,filled in for 500 buildings,and a reference building simulation in different climates of Iran,the heating atlas of residential buildings was prepared.According to the results,the average heating energy index(HE1)of buildings in Iran can be less than 1 to more than 41.3(m^(3)(N.G)/(m^(2)-yr))depending on climatic conditions and building design and construction quality.However,in the coldest center of province,the average of this index is 26.3(m^(3)(N.G)/(m^(2)-yr))in the hottest one that is equal 2.2.The variations of the thermal base load(supply of hot water)varied from less than 13.12 to more than 378.84(m^(3)(N.G)/(person-yr)).In provincial capitals,the lowest thermal base load index(TBLI)of buildings is 24.78 and the highest is 226.49(m^(3)(N.G)/(person-yr)).In this paper,beside charts and tables,results of heating energy consumption indices are also presented in the form of graphical atlases,i.e.color contour plots,to deliver a better picture of the whole country.
文摘Experimental results were compared with the computed results obtained from the nine most well-known methods for computation of discharge in a compound channel. The results demonstrate a high accuracy of the divided channel method with the horizontal division lines, while the length of division line is included within the calculation of the wetted perimeter. In addition, as relative depth increases, the results of the all methods converge to each other and also in case of steeper slopes in lower relative depths, more agreements between different calculated methods and experimental results were observed. Furthermore, the results show the effects of the maximum momentum transfer on the horizontal interface between the main channel and flood plains, while further angular distance from the horizontal interface toward the vertical interface between main channel and flood plains causes gradual decrease of momentum transfer effects.
文摘Traditional Numerical Reservoir Simulation has been contributing to the oil and gas industry for decades.The current state of this technology is the result of decades of research and development by a large number of engineers and scientists.Starting in the late 1960s and early 1970s,advances in computer hardware along with development and adaptation of clever algorithms resulted in a paradigm shift in reservoir studies moving them from simplified analogs and analytical solution methods to more mathematically robust computational and numerical solution models.
文摘Understanding predator-prey interactions has a pivotal role in biological control programs. This study evaluated the functional response of three larval instars of the green lacewing, Chrysoperla carnea （Stephens）, preying upon eggs and first instar larvae of the cotton bollworm, Helicoverpa armigera Hubner. The first and second instar larvae of C. carnea exhibited typeⅡ functional responses against both prey stages. However, the third instar larvae of C. carnea showed a type II functional response to the first instar larvae of H. armigera, but a typeⅢ functional response to the eggs. For the first instar larvae of C. carnea, the attack rate on H. armigera eggs was significantly higher than that on the larvae, whereas the attack rate of the second instar C. carnea on H. armigera larvae was significantly higher than that on the eggs. For the third instar larvae of C. carnea, the attack rate on the larvae was 1.015±0.278/h, and the attack coefficient on the eggs was 0.036 ±0.005. The handling times of the third instar larvae on larvae and eggs were 0.087 ± 0.009 and 0.071 ± 0.001 h, respectively. The highest predation rate was found for the third instar larvae of C. carnea on H. armigera eggs. Results of this study revealed that the larvae of C. carnea, especially the third instar, had a good predation potential in controlling H. armigera eggs and larvae. However, for a comprehensive estimation of the bio- control abilities of C. carnea toward H, armigera, further field-based studies are needed.
文摘Using artificial intelligence(AI) and machine learning(ML) techniques, we developed and validated the smart proxy models for history matching of reservoir simulation, sensitivity analysis, and uncertainty assessment by artificial neural network(ANN). The smart proxy models were applied on two cases, the first case study investigated the application of a proxy model for calibrating a reservoir simulation model based on historical data and predicting well production while the second case study investigated the application of an ANN-based proxy model for fast-track modeling of CO2 enhanced oil recovery, aiming at the prediction of the reservoir pressure and phase saturation distribution at injection stage and post-injection stage. The prediction effects for both cases are promising. While a single run of basic numerical simulation model takes hours to days, the smart proxy model runs in a matter of seconds, saving 98.9% of calculating time. The results of these case studies demonstrate the advantage of the proposed workflow for addressing the high run-time, computational time and computational cost of numerical simulation models. In addition, these proxy models predict the outputs of reservoir simulation models with high accuracy.
文摘Sol-gel coatings containing various amounts of hydroxylated nanodiamond(HND)particles were applied on the magnesium alloy for corrosion protection.The micrometric defects in the sol-gel coating completely disappeared after adding 0.01,0.02 and 0.05 wt.%of the HND nanoparticles.The AFM analyses showed that average roughness of the sol-gel film is about 6.7 nm which increases to 16.1 and 20.2 nm after incorporating 0.005 and 0.02 wt.%of the HNDs,respectively.The corrosion resistance of the coatings was tested in Harrison’s solution by means of EIS technique after 15,30,60 and 120 min immersion.The corrosion resistance of the sol-gel coating was remarkably enhanced by incorporating different contents of the HNDs and the best result was obtained for 0.01 wt.%.The results of the EIS experiments were confirmed by the potentiodynamic polarization tests.The corrosion resistance enhancement was attributed to the film compactness(due to the chemical interaction with the HNDs),formation of tortuous pathways for diffusion of the corrosive solution,and filling of the defects by the nanoparticles.However,the beneficial effect of the HNDs on the corrosion resistance gradually diminished as the content of nanoparticle was increased.Finally,the micromorphology of the sol-gel nanocomposites was studied after the corrosion tests.
文摘近年来极端暴雨天气与自然灾害频发,导致农田损毁,影响耕作。该研究利用高精度农田数字地形模型(Farmland Digital Terrain Model,FDTM),基于地形因子综合属性提出一种识别农田微地形特征(凸起特征及洼地特征)的方法。首先,基于SfM(Structure from Motion)技术处理试验田的航拍图像,获取高精度农田FDTM,分析FDTM的高程方差随局部窗口尺度的变化趋势,确定分析窗口的尺度区间为31像素×31像素至51像素×51像素。其次,选择高程、地形起伏度和坡度综合评价在51像素×51像素窗口下提取的315个高程极值点,获取多窗口地形因子综合隶属度。最后,根据斯特吉斯公式确定阈值为0.627,提取16个农田凸起特征顶点,并结合等高线图识别凸起特征的外形轮廓;同理,建立反转数字地形模型(Reverse-FDTM,RFDTM),将FDTM中的洼地特征转变为RFDTM中的凸起特征,识别9个农田洼地特征。研究结果可为农田复垦及精准土地平整作业提供理论依据与方法支持。
基金supported by the Grant and Research Program of the University of Mohaghegh Ardabili
文摘This study provides a checklist of species distributed at the altitude gradient of MoghanSabalan rangelands in Ardabili province, Northwest Iran. We evaluated the changes in species composition, growth types of species, Raunkiaer's life forms, geographical distribution, threat and endemicity status, and palatability of species along two altitudinal gradients in the sampling plots, which were conducted in eleven sites/habitats with 300 meters above sea level(masl) altitude intervals(from 100 to 3300 masl). We assessed the plant species composition with special reference to the gradient analysis, and identified overall 396 species, which was comprising 44 families and 194 genera. Results showed that Asteraceae family is by far the most species-rich family, followed by Poaceae, Fabaceae, Caryophyllaceae and Brassicaceae. Among the genera, Astragalus is the most diverse genus, followed by Allium, Veronica and Bromus, Galium, Silene and Ranunculus. Results indicated that the number of species increased as the altitude increased to 1200-1500 masl, but then starts to decline to 3300 masl. Family-to-genera ratio was 1:4.4, the family-tospecies ratio was 1:9, and the genera-to-species ratio was 1:2.04. Growth type of species analysis shows that the frequency of perennial plants was higher in the study area followed by annual species while the lower group was biennial species. The number of annuals showed a decreasing trend towards higher altitude. Hemicryptophytes and therophytes were the most frequent life forms constituted each with(41.9%). Hemicryptophytes showed an increasing trend with altitude, while therophytes showed a decreasing trend with altitude increase, followed by geophytes, chamaephytes, and phanerophytes. Results showed more than half of the species of the study area belonged to Iran-Turanian region and these species showed an increasing trend with altitude. In contrast, Sahara-Sindian species comprise a minor component of the spectrum, with decreasing trend with altitude. The rare and endangered species
