Due to the high price and formation damage of the guargum fracturing fluid, many oilfields are more and more interested in surfactant based fracturing fluids. The rheological properties of erucicamide dimethyl amidopr...Due to the high price and formation damage of the guargum fracturing fluid, many oilfields are more and more interested in surfactant based fracturing fluids. The rheological properties of erucicamide dimethyl amidopropyl betaine (EDAB)-HC1 acid blended system and its suitability as fracturing fluid were investigated in this work. The effects of pH, concentration of EDAB, and temperature on the rheological properties of the blended system were studied. The results show that addition of EDAB improved the viscosity of the system from less than 10 mPa. s to about 400 mPa. s, which could retard the acid-rock reaction to about one half at 60℃ and one quarter at 90℃ comparing to straight HC1 acid, suggesting that there is sufficient time for the blended fluid to react with formation rock when it is used as fracturing fluid in an oil field. Core flow tests demonstrated that the EDAB-acid blended fluid could divert itself from high permeability formation core to low permeability one, thus ensuring proper acid placement in the target reservoirs.展开更多
The World Health Organization (WHO) standard assay for determining antibody level is the rapid fluorescent focus inhibition test (RFFIT) and is used to determine the degree of immunity after vaccination against ra...The World Health Organization (WHO) standard assay for determining antibody level is the rapid fluorescent focus inhibition test (RFFIT) and is used to determine the degree of immunity after vaccination against rabies. To compare the difference in RFFIT results between the laboratories of The National Institute of Infectious Disease in Japan (NIID) and the Chinese Centre for Disease Control (CCDC) as well the influence of the choice of standard serum (STD) for the detection, the two laboratories detection methods were simultaneously manipulated by RFFIT. The reference serums used in NIID and the WHO standard serum used in CCDC were compared in the same RFFIT detection to determine the titer of four sera samples C1, Sl, S2 and S4 in parallel, and the titers of the detected sera samples were calculated using the standard formula for neutralizing antibody titer. No significant difference was found in RFFIT methods from the two laboratories and the RFFIT testing procedures of the two laboratories have good consistency. However, different titers were obtained with the tentative internal standard serum (TI-STD) produced by adjusting to 2.0 IU of WHO standard serum in NIID and the WHO STD. The titer determined with the TI-STD was higher than that determined with WHO STD, This difference appears to be significant and requires further investigation展开更多
Social media has become an inevitable part of our lives in the age of network society. People establish multiple identities for themselves, with or without references to the real world, and behave according to those i...Social media has become an inevitable part of our lives in the age of network society. People establish multiple identities for themselves, with or without references to the real world, and behave according to those identities. Self-made components of virtual presence are not limited to identities only; many users also create hyper-personalities for themselves with the help of new technologies. Then, the fundamental question becomes: Why do people create self-made identities and hyper-personalities to portray or hide themselves in social media environments? The answer to this question has certain connections and implications for behaviors of social media users. Therefore, researchers have investigated why some people find social media attractive and attend whenever possible, while others are afraid of social media and hesitate to attend. Positive and negative behaviors of social media users can be classified as braggadocian and preventative. Braggadocian behaviors are related to courageously taking advantage of social media, whereas preventative behaviors are concerned with avoidance of social media. The dominant behavioral pattern of a user depends on what one can achieve through attending or preventing social media. This paper first discusses basic elements of human behavior that drive social media such as altruism, hedonism, connectionism, homophily, multiple identities, memetics, narcissism, and tribalism. Then, it focuses on precautionary elements of human behavior such as avoidance, escape, blocking, fear, hiding, removal, and protectionism. Whether they are attentive or not, one thing is clear: People refrain or enrich their own lives in social media rather than being abused or watching others in industrial media.展开更多
To study the pressure distribution of the volute casing, front casing and back casing in a prototype centrifugal pump, the pressure experiments and numerical simulations are carried out at six working conditions in th...To study the pressure distribution of the volute casing, front casing and back casing in a prototype centrifugal pump, the pressure experiments and numerical simulations are carried out at six working conditions in this paper. The experimental results shows that the asymmetry of static pressure distribution on volute casing and front cavity is caused by the tongue of the volute and it may result in high radial and axial resultant force which can cause vibration and noise in the centrifugal pump. With the increasing of flow rote, the asymmetry of static pressure distribution and the magnitude of static pressure values reduce. The numerical results indicate that the pressure fluctuation near the tongue is strongest and it becomes slighter at point away from the tongue. With the increasing of flow rote, the local high=pressure region in impeller passage reduces and the flow becomes smoother accordingly, whereas the fluid speed becomes much higher which may cause further flow losses. The results predicted by numcrical simulation are in coincident with the experimental ones. It shows that the turbulence model for simulating the flow field in centrifugal pumps is feasible.展开更多
基金Supported by the Fundamental Research Funds for the Central Universities(2652013107)the Laboratory Open Funds of China University of Geosciences(Beijing)
文摘Due to the high price and formation damage of the guargum fracturing fluid, many oilfields are more and more interested in surfactant based fracturing fluids. The rheological properties of erucicamide dimethyl amidopropyl betaine (EDAB)-HC1 acid blended system and its suitability as fracturing fluid were investigated in this work. The effects of pH, concentration of EDAB, and temperature on the rheological properties of the blended system were studied. The results show that addition of EDAB improved the viscosity of the system from less than 10 mPa. s to about 400 mPa. s, which could retard the acid-rock reaction to about one half at 60℃ and one quarter at 90℃ comparing to straight HC1 acid, suggesting that there is sufficient time for the blended fluid to react with formation rock when it is used as fracturing fluid in an oil field. Core flow tests demonstrated that the EDAB-acid blended fluid could divert itself from high permeability formation core to low permeability one, thus ensuring proper acid placement in the target reservoirs.
基金Grant from National Institute of Infectious Diseases(NIID)National Department Public Benefit Research Foundation (201103032)
文摘The World Health Organization (WHO) standard assay for determining antibody level is the rapid fluorescent focus inhibition test (RFFIT) and is used to determine the degree of immunity after vaccination against rabies. To compare the difference in RFFIT results between the laboratories of The National Institute of Infectious Disease in Japan (NIID) and the Chinese Centre for Disease Control (CCDC) as well the influence of the choice of standard serum (STD) for the detection, the two laboratories detection methods were simultaneously manipulated by RFFIT. The reference serums used in NIID and the WHO standard serum used in CCDC were compared in the same RFFIT detection to determine the titer of four sera samples C1, Sl, S2 and S4 in parallel, and the titers of the detected sera samples were calculated using the standard formula for neutralizing antibody titer. No significant difference was found in RFFIT methods from the two laboratories and the RFFIT testing procedures of the two laboratories have good consistency. However, different titers were obtained with the tentative internal standard serum (TI-STD) produced by adjusting to 2.0 IU of WHO standard serum in NIID and the WHO STD. The titer determined with the TI-STD was higher than that determined with WHO STD, This difference appears to be significant and requires further investigation
文摘Social media has become an inevitable part of our lives in the age of network society. People establish multiple identities for themselves, with or without references to the real world, and behave according to those identities. Self-made components of virtual presence are not limited to identities only; many users also create hyper-personalities for themselves with the help of new technologies. Then, the fundamental question becomes: Why do people create self-made identities and hyper-personalities to portray or hide themselves in social media environments? The answer to this question has certain connections and implications for behaviors of social media users. Therefore, researchers have investigated why some people find social media attractive and attend whenever possible, while others are afraid of social media and hesitate to attend. Positive and negative behaviors of social media users can be classified as braggadocian and preventative. Braggadocian behaviors are related to courageously taking advantage of social media, whereas preventative behaviors are concerned with avoidance of social media. The dominant behavioral pattern of a user depends on what one can achieve through attending or preventing social media. This paper first discusses basic elements of human behavior that drive social media such as altruism, hedonism, connectionism, homophily, multiple identities, memetics, narcissism, and tribalism. Then, it focuses on precautionary elements of human behavior such as avoidance, escape, blocking, fear, hiding, removal, and protectionism. Whether they are attentive or not, one thing is clear: People refrain or enrich their own lives in social media rather than being abused or watching others in industrial media.
基金supported by the Joint Project from National Natural Science Foundation of China and Liaoning Province(U1608258)
文摘To study the pressure distribution of the volute casing, front casing and back casing in a prototype centrifugal pump, the pressure experiments and numerical simulations are carried out at six working conditions in this paper. The experimental results shows that the asymmetry of static pressure distribution on volute casing and front cavity is caused by the tongue of the volute and it may result in high radial and axial resultant force which can cause vibration and noise in the centrifugal pump. With the increasing of flow rote, the asymmetry of static pressure distribution and the magnitude of static pressure values reduce. The numerical results indicate that the pressure fluctuation near the tongue is strongest and it becomes slighter at point away from the tongue. With the increasing of flow rote, the local high=pressure region in impeller passage reduces and the flow becomes smoother accordingly, whereas the fluid speed becomes much higher which may cause further flow losses. The results predicted by numcrical simulation are in coincident with the experimental ones. It shows that the turbulence model for simulating the flow field in centrifugal pumps is feasible.