Considering the influence of quadratic gradient term and medium deformation on the seepage equation, a well testing interpretation model for low permeability and deformation dual medium reservoirs was derived and esta...Considering the influence of quadratic gradient term and medium deformation on the seepage equation, a well testing interpretation model for low permeability and deformation dual medium reservoirs was derived and established. The difference method was used to solve the problem, and pressure and pressure derivative double logarithmic curves were drawn to analyze the seepage law. The research results indicate that the influence of starting pressure gradient and medium deformation on the pressure characteristic curve is mainly manifested in the middle and late stages. The larger the value, the more obvious the upward warping of the pressure and pressure derivative curve;the parameter characterizing the dual medium is the crossflow coefficient. The channeling coefficient determines the time and location of the appearance of the “concave”. The smaller the value, the later the appearance of the “concave”, and the more to the right of the “concave”.展开更多
In order to control the ferrite and austenite percentage in duplex stainless steel welding, many researchers try to change the laser welding parameters and cooling medium, but ignore to study the influence of heat sin...In order to control the ferrite and austenite percentage in duplex stainless steel welding, many researchers try to change the laser welding parameters and cooling medium, but ignore to study the influence of heat sink effect on weld strength. In this work, the effect of aluminium heat sink and varying cooling medium on the laser welding of duplex stainless steel (DSS) 2205 is studied. The 2 mm thick DSS sheets welded with pulsed Nd: YAG laser welding machine by varying the cooling medium (air and oil) and an aluminium plate used as a heat sink. The welded specimens tested for tensile strength, micro-hardness, distortion, microstructure and radiography analysis. The faster cooling rate in the oil quenching process enhances the ferrite percentage compared with air-cooled samples. But the faster cooling rate in oil quenching leads to more distortion and using aluminium as a heat sink influenced positively the distortion to a small extent. The lower cooling rate in air quenching leads to a higher tensile strength of the welded specimen. The objective of this work is to analyse experimentally the effect of cooling medium and heat sink in the mechanical and metallurgical properties of laser welded duplex stainless steel.展开更多
An excellent Lonicera edulis strain, L1-8 that was bred by Northeast Institute of Geography and Agro-ecology, Chinese Academy of Sciences, was used as material in this research. The axillary buds of its dormant branch...An excellent Lonicera edulis strain, L1-8 that was bred by Northeast Institute of Geography and Agro-ecology, Chinese Academy of Sciences, was used as material in this research. The axillary buds of its dormant branches were used as explants. A fourfactor and four-level orthogonal test was designed in order to choose the best differentiation medium for providing the technical support of Lonicera edulis micropropagation. The results showed that the culture medium and concentration of 6-BA were the main factors, and the best differentiation condition was MS culture medium containing 2.0 mg · L-1 6-BA, 0.3 mg · L-1 IBA and 1.5 mg · L-1 GA3.展开更多
<b><span style="font-family:Verdana;">Aim: </span></b><span style="font-family:""><span style="font-family:Verdana;">The objective of this study w...<b><span style="font-family:Verdana;">Aim: </span></b><span style="font-family:""><span style="font-family:Verdana;">The objective of this study was to isolate, identify, and explore the </span><i><span style="font-family:Verdana;">in</span></i><span style="font-family:Verdana;">-</span><i><span style="font-family:Verdana;">vitro</span></i><span style="font-family:Verdana;"> antifungal susceptibility pattern of dermatophytes isolated from clinica</span><span style="font-family:Verdana;">lly suspected cases of dermatophytosis (tinea infections) attending th</span><span style="font-family:Verdana;">e Dermatology Department at J.S.S Hospital. </span><b><span style="font-family:Verdana;">Methods: </span></b><span style="font-family:Verdana;">This study was conducted at JSS Medical College and Hospital from December 2016 to December 2017. Clinical samples (e.g., skin scrapings and hair stumps) were collected under asep</span><span style="font-family:Verdana;">tic precautions. The identification of dermatophytes was perfor</span><span style="font-family:Verdana;">med</span><span style="font-family:Verdana;"> through microscopic examination using 10%, 20% & 40% potassium hydroxide (KOH) and culture on Sabouraud dextrose agar (SDA), SDAac, PDA and Dermatophyte test medium (DTM). All dermatophytes isolates were subjected to antifungal susceptibility testing using the agar-base</span><span style="font-family:Verdana;">d disk diffusion (ABDD) and E-test method against Terbinafine, Itraconazole, Fluconazole, and Griseofulvin. Data were analyzed by using Chi square test. </span><b><span style="font-family:Verdana;">Results: </span></b><span style="font-family:Verdana;">A 100 samples were studied, 46% tinea corporis, 2%tinea cruris, 9% tinea pedis, 5% tin</span><span><span style="font-family:Verdana;">ea faciei. The dermatophytes isolated were </span><i><span style="font-family:Verdana;">Trichophyton rubrum</span></i><span style="font-family:Verdana;"> 1</span></span><span style="font-family:Verdana;">1 (35%), </span><i><span style="font-family:Verdana;">Trichophyton mentagrophyte</span></i><span style="font-family:Verdana;"> 8 (25%), </span><i><span style="font-family:Verdana;">Trichophyton tonsurans</span></i><span style="font-family:Verdana;"> 5 (16%), Microsporum gypseum 3</span></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">(10%), </span><i><span style="font-family:Verdana;">Trichophyton verrucosum</span></i><span style="font-family:Verdana;"> 2 (6%), </span><i><span style="font-family:Verdana;">Trichophyton violaceum</span></i><span style="font-family:Verdana;"> 1</span></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">(3%) and </span><i><span style="font-family:Verdana;">Microsporum audouinii</span></i><span style="font-family:Verdana;"> 1 (3%). Out of 31 dermatophytes 17 were sensitive to all four antifungal agents within the range of FLC (2</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">-</span><span style="font-family:""> </span><span style="font-family:Verdana;">6</span><span style="font-family:""> </span><span style="font-family:Verdana;">mcg/ml), ITR (0.125</span><span style="font-family:""> </span><span style="font-family:Verdana;">-</span><span style="font-family:""> </span><span style="font-family:Verdana;">2), TER (0.125</span><span style="font-family:""> </span><span style="font-family:Verdana;">-</span><span style="font-family:""> </span><span style="font-family:Verdana;">2), and GRI (0.125</span><span style="font-family:""> </span><span style="font-family:Verdana;">-</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">2), 5 isolates were resistant in which 2 were resistant to FLC (64.256 mcg/ml), 2 isolates were resistant to TER 2 (32.38 mcg/ml), 1 isolate was resistant to both GRI and TER (16.32 mcg/ml) and 9 isolates were within the intermediate range. </span><b><span style="font-family:Verdana;">Conclusion: </span></b><span style="font-family:Verdana;">Every patient with a tinea infection should be properly studied for a mycological examination and should be treated accordingly. Dermatophyte test medium is more useful as an identification medium in the isolation of dermatophytes. The ABDD method appears to be a simple, cost-effective, and promising method for the evaluation of antifungal susceptibility of dermatophytes. E-test method is the most sensitive method due to the fact that quantitative MICs can be obtained directly from the E-strip. However, the E-test method is expensive and difficult in defining the precise borders of the inhibition zones in dermatophytes</span></span><span style="font-family:Verdana;">.展开更多
Heavy rain is a kind of severe weather, often causing floods and serious soil erosion, leading to engineering losses, embankment rupture and crop flooding and other significant economic losses. Especially for some low...Heavy rain is a kind of severe weather, often causing floods and serious soil erosion, leading to engineering losses, embankment rupture and crop flooding and other significant economic losses. Especially for some low-lying terrain areas, rainwater cannot quickly vent caused by farm water and soil moisture being too saturated, so it will cause more geological disasters. This article combines live and forecast data, aiming at the results of the mid-rainstorm forecast in North China during the period of 7.19-2016, and compares with the actual situation of rainstorm. We carry out the mid-term forecast of the rainstorm. The atmosphere is a kind of medium with various fluctuation phenomena, and its physical properties and changes are studied by the analysis of volatility which is an important research method. It is important to improve the accuracy of such severe weather forecasting rainstorms and to take precautionary measures in a timely manner to minimize the losses caused by rainstorms.展开更多
Mud inrush in mountain tunnel is an independent geological hazard type different from water inrush,landslide and debris flow.The intrinsic factor of mud inrush is the instability failure of disaster medium.Its essence...Mud inrush in mountain tunnel is an independent geological hazard type different from water inrush,landslide and debris flow.The intrinsic factor of mud inrush is the instability failure of disaster medium.Its essence is that when the cohesion decreases gradually with the increase of void ratio to the point where the movement of soil particles cannot be restricted,soil particles and groundwater form slurry and gush out.Thus,accurate calculation of cohesion with variable void ratios is crucial for analyzing the reliability of disaster medium.In this study,the disaster medium was regarded as graded soil and a structural model was established wherein soil particles were simplified as cubes and the inter-particle pores were represented by the clearance between cubes.On the basis of the structure model of disaster medium,a function between the soil particle distance and void ratio was derived.Cohesion is equivalent to the resultant force between soil particles per unit area;thus,a cohesion function was derived in which the void ratio is the main variable.This function considers the influence of gradation characteristics on cohesion variation and is generally applicable to various types of disaster medium.A series of direct shear tests were carried out to determine the cohesion variation for different types of disaster medium with variable void ratios.By comparing the variation of cohesion obtained through direct shear tests with those deduced by the proposed cohesion function,we verified the validity and general applicability of the cohesion function.It is of great significance because the cohesion function can accurately predict the variation of cohesion by using the void ratio,and effectively evaluate the possibility of mud inrush according to the initial mechanical properties of disaster medium.展开更多
Based on the flow mechanism of hydraulic fractured wells, through integrating linear-flow model and effective well-radius model, a new model of well test analysis for wells with vertical fracture was established. In t...Based on the flow mechanism of hydraulic fractured wells, through integrating linear-flow model and effective well-radius model, a new model of well test analysis for wells with vertical fracture was established. In the model, wellbore storage, the damage in the wall of fracture and all kinds of boundary conditions are considered. The model is concise in form, has intact curves and computes fast, which may meet the demand of real-time computation and fast responded well test interpretation. A new method to determine effective well radius was presented, and the correlation between effective well radius and the fracture length, fracture conductivity, skin factor of fracture was given. Matching flow rate or pressure tested, the optimization model that identified formation and fracture parameters was set up. The automatic matching method was presented by synthetically using step by step linear least square method and sequential quadratic programming. At last, the application was also discussed. Application shows that all of these results can analyze and evaluate the fracturing treatment quality scientifically and rationally, instruct and modify the design of fracturing and improve fracturing design level.展开更多
文摘Considering the influence of quadratic gradient term and medium deformation on the seepage equation, a well testing interpretation model for low permeability and deformation dual medium reservoirs was derived and established. The difference method was used to solve the problem, and pressure and pressure derivative double logarithmic curves were drawn to analyze the seepage law. The research results indicate that the influence of starting pressure gradient and medium deformation on the pressure characteristic curve is mainly manifested in the middle and late stages. The larger the value, the more obvious the upward warping of the pressure and pressure derivative curve;the parameter characterizing the dual medium is the crossflow coefficient. The channeling coefficient determines the time and location of the appearance of the “concave”. The smaller the value, the later the appearance of the “concave”, and the more to the right of the “concave”.
文摘In order to control the ferrite and austenite percentage in duplex stainless steel welding, many researchers try to change the laser welding parameters and cooling medium, but ignore to study the influence of heat sink effect on weld strength. In this work, the effect of aluminium heat sink and varying cooling medium on the laser welding of duplex stainless steel (DSS) 2205 is studied. The 2 mm thick DSS sheets welded with pulsed Nd: YAG laser welding machine by varying the cooling medium (air and oil) and an aluminium plate used as a heat sink. The welded specimens tested for tensile strength, micro-hardness, distortion, microstructure and radiography analysis. The faster cooling rate in the oil quenching process enhances the ferrite percentage compared with air-cooled samples. But the faster cooling rate in oil quenching leads to more distortion and using aluminium as a heat sink influenced positively the distortion to a small extent. The lower cooling rate in air quenching leads to a higher tensile strength of the welded specimen. The objective of this work is to analyse experimentally the effect of cooling medium and heat sink in the mechanical and metallurgical properties of laser welded duplex stainless steel.
基金Supported by the State Bureau of Foreign Experts 2013 Annual Talent Introduction of Foreign Technology,Project Management(20132300046)
文摘An excellent Lonicera edulis strain, L1-8 that was bred by Northeast Institute of Geography and Agro-ecology, Chinese Academy of Sciences, was used as material in this research. The axillary buds of its dormant branches were used as explants. A fourfactor and four-level orthogonal test was designed in order to choose the best differentiation medium for providing the technical support of Lonicera edulis micropropagation. The results showed that the culture medium and concentration of 6-BA were the main factors, and the best differentiation condition was MS culture medium containing 2.0 mg · L-1 6-BA, 0.3 mg · L-1 IBA and 1.5 mg · L-1 GA3.
文摘<b><span style="font-family:Verdana;">Aim: </span></b><span style="font-family:""><span style="font-family:Verdana;">The objective of this study was to isolate, identify, and explore the </span><i><span style="font-family:Verdana;">in</span></i><span style="font-family:Verdana;">-</span><i><span style="font-family:Verdana;">vitro</span></i><span style="font-family:Verdana;"> antifungal susceptibility pattern of dermatophytes isolated from clinica</span><span style="font-family:Verdana;">lly suspected cases of dermatophytosis (tinea infections) attending th</span><span style="font-family:Verdana;">e Dermatology Department at J.S.S Hospital. </span><b><span style="font-family:Verdana;">Methods: </span></b><span style="font-family:Verdana;">This study was conducted at JSS Medical College and Hospital from December 2016 to December 2017. Clinical samples (e.g., skin scrapings and hair stumps) were collected under asep</span><span style="font-family:Verdana;">tic precautions. The identification of dermatophytes was perfor</span><span style="font-family:Verdana;">med</span><span style="font-family:Verdana;"> through microscopic examination using 10%, 20% & 40% potassium hydroxide (KOH) and culture on Sabouraud dextrose agar (SDA), SDAac, PDA and Dermatophyte test medium (DTM). All dermatophytes isolates were subjected to antifungal susceptibility testing using the agar-base</span><span style="font-family:Verdana;">d disk diffusion (ABDD) and E-test method against Terbinafine, Itraconazole, Fluconazole, and Griseofulvin. Data were analyzed by using Chi square test. </span><b><span style="font-family:Verdana;">Results: </span></b><span style="font-family:Verdana;">A 100 samples were studied, 46% tinea corporis, 2%tinea cruris, 9% tinea pedis, 5% tin</span><span><span style="font-family:Verdana;">ea faciei. The dermatophytes isolated were </span><i><span style="font-family:Verdana;">Trichophyton rubrum</span></i><span style="font-family:Verdana;"> 1</span></span><span style="font-family:Verdana;">1 (35%), </span><i><span style="font-family:Verdana;">Trichophyton mentagrophyte</span></i><span style="font-family:Verdana;"> 8 (25%), </span><i><span style="font-family:Verdana;">Trichophyton tonsurans</span></i><span style="font-family:Verdana;"> 5 (16%), Microsporum gypseum 3</span></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">(10%), </span><i><span style="font-family:Verdana;">Trichophyton verrucosum</span></i><span style="font-family:Verdana;"> 2 (6%), </span><i><span style="font-family:Verdana;">Trichophyton violaceum</span></i><span style="font-family:Verdana;"> 1</span></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">(3%) and </span><i><span style="font-family:Verdana;">Microsporum audouinii</span></i><span style="font-family:Verdana;"> 1 (3%). Out of 31 dermatophytes 17 were sensitive to all four antifungal agents within the range of FLC (2</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">-</span><span style="font-family:""> </span><span style="font-family:Verdana;">6</span><span style="font-family:""> </span><span style="font-family:Verdana;">mcg/ml), ITR (0.125</span><span style="font-family:""> </span><span style="font-family:Verdana;">-</span><span style="font-family:""> </span><span style="font-family:Verdana;">2), TER (0.125</span><span style="font-family:""> </span><span style="font-family:Verdana;">-</span><span style="font-family:""> </span><span style="font-family:Verdana;">2), and GRI (0.125</span><span style="font-family:""> </span><span style="font-family:Verdana;">-</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">2), 5 isolates were resistant in which 2 were resistant to FLC (64.256 mcg/ml), 2 isolates were resistant to TER 2 (32.38 mcg/ml), 1 isolate was resistant to both GRI and TER (16.32 mcg/ml) and 9 isolates were within the intermediate range. </span><b><span style="font-family:Verdana;">Conclusion: </span></b><span style="font-family:Verdana;">Every patient with a tinea infection should be properly studied for a mycological examination and should be treated accordingly. Dermatophyte test medium is more useful as an identification medium in the isolation of dermatophytes. The ABDD method appears to be a simple, cost-effective, and promising method for the evaluation of antifungal susceptibility of dermatophytes. E-test method is the most sensitive method due to the fact that quantitative MICs can be obtained directly from the E-strip. However, the E-test method is expensive and difficult in defining the precise borders of the inhibition zones in dermatophytes</span></span><span style="font-family:Verdana;">.
文摘Heavy rain is a kind of severe weather, often causing floods and serious soil erosion, leading to engineering losses, embankment rupture and crop flooding and other significant economic losses. Especially for some low-lying terrain areas, rainwater cannot quickly vent caused by farm water and soil moisture being too saturated, so it will cause more geological disasters. This article combines live and forecast data, aiming at the results of the mid-rainstorm forecast in North China during the period of 7.19-2016, and compares with the actual situation of rainstorm. We carry out the mid-term forecast of the rainstorm. The atmosphere is a kind of medium with various fluctuation phenomena, and its physical properties and changes are studied by the analysis of volatility which is an important research method. It is important to improve the accuracy of such severe weather forecasting rainstorms and to take precautionary measures in a timely manner to minimize the losses caused by rainstorms.
基金funded by the National Natural Science Foundation of China(Grant No.U1706223)the Natural Science Foundation of Shandong Province(Grant No.ZR2017MEE070)
文摘Mud inrush in mountain tunnel is an independent geological hazard type different from water inrush,landslide and debris flow.The intrinsic factor of mud inrush is the instability failure of disaster medium.Its essence is that when the cohesion decreases gradually with the increase of void ratio to the point where the movement of soil particles cannot be restricted,soil particles and groundwater form slurry and gush out.Thus,accurate calculation of cohesion with variable void ratios is crucial for analyzing the reliability of disaster medium.In this study,the disaster medium was regarded as graded soil and a structural model was established wherein soil particles were simplified as cubes and the inter-particle pores were represented by the clearance between cubes.On the basis of the structure model of disaster medium,a function between the soil particle distance and void ratio was derived.Cohesion is equivalent to the resultant force between soil particles per unit area;thus,a cohesion function was derived in which the void ratio is the main variable.This function considers the influence of gradation characteristics on cohesion variation and is generally applicable to various types of disaster medium.A series of direct shear tests were carried out to determine the cohesion variation for different types of disaster medium with variable void ratios.By comparing the variation of cohesion obtained through direct shear tests with those deduced by the proposed cohesion function,we verified the validity and general applicability of the cohesion function.It is of great significance because the cohesion function can accurately predict the variation of cohesion by using the void ratio,and effectively evaluate the possibility of mud inrush according to the initial mechanical properties of disaster medium.
基金theNaturalGasExploitationKeyLabofSichuanProvince (No .0 1 6)
文摘Based on the flow mechanism of hydraulic fractured wells, through integrating linear-flow model and effective well-radius model, a new model of well test analysis for wells with vertical fracture was established. In the model, wellbore storage, the damage in the wall of fracture and all kinds of boundary conditions are considered. The model is concise in form, has intact curves and computes fast, which may meet the demand of real-time computation and fast responded well test interpretation. A new method to determine effective well radius was presented, and the correlation between effective well radius and the fracture length, fracture conductivity, skin factor of fracture was given. Matching flow rate or pressure tested, the optimization model that identified formation and fracture parameters was set up. The automatic matching method was presented by synthetically using step by step linear least square method and sequential quadratic programming. At last, the application was also discussed. Application shows that all of these results can analyze and evaluate the fracturing treatment quality scientifically and rationally, instruct and modify the design of fracturing and improve fracturing design level.
