According to the Chapman multi-scale rock physical model, the seismic response characteristics vary for different fluid-saturated reservoirs. For class I AVO reservoirs and gas-saturation, the seismic response is a hi...According to the Chapman multi-scale rock physical model, the seismic response characteristics vary for different fluid-saturated reservoirs. For class I AVO reservoirs and gas-saturation, the seismic response is a high-frequency bright spot as the amplitude energy shifts. However, it is a low-frequency shadow for the Class III AVO reservoirs saturated with hydrocarbons. In this paper, we verified the high-frequency bright spot results of Chapman for the Class I AVO response using the frequency-dependent analysis of a physical model dataset. The physical model is designed as inter-bedded thin sand and shale based on real field geology parameters. We observed two datasets using fixed offset and 2D geometry with different fluid- saturated conditions. Spectral and time-frequency analyses methods are applied to the seismic datasets to describe the response characteristics for gas-, water-, and oil-saturation. The results of physical model dataset processing and analysis indicate that reflection wave tuning and fluid-related dispersion are the main seismic response characteristic mechanisms. Additionally, the gas saturation model can be distinguished from water and oil saturation for Class I AVO utilizing the frequency-dependent abnormal characteristic. The frequency-dependent characteristic analysis of the physical model dataset verified the different spectral response characteristics corresponding to the different fluid-saturated models. Therefore, by careful analysis of real field seismic data, we can obtain the abnormal spectral characteristics induced by the fluid variation and implement fluid detection using seismic data directly.展开更多
Rough set is a new approach to uncertainties in spatial analysis.In this paper,rough set symbols are simplified and standardized in terms of rough interpretation and specialized indication.Rough spatial entities and t...Rough set is a new approach to uncertainties in spatial analysis.In this paper,rough set symbols are simplified and standardized in terms of rough interpretation and specialized indication.Rough spatial entities and their topological relationships are also proposed in rough space,thus a universal intersected equation is developed,and rough membership function is further extended with the gray scale in our case study.We complete three works.First,a set of simplified rough symbols is advanced on the basis of existing rough symbols.Second,rough spatial entity is put forward to study the real world as it is,without forcing uncertainties into crisp set.Third,rough spatial topological relationships are studied by using rough matrix and their figures.The relationships are divided into three types,crisp entity and crisp entity (CC),rough entity and crisp entity (RC),and rough entity and rough entity (RR).A universal intersected equation is further proposed.Finally,the maximum and minimum maps of river thematic classification are generated via rough membership function and rough relationships in our case study.展开更多
The implementation method of the IEEE 802.11 Medium Access Control (MAC) protocol is mainly based on DSP (Digital Signal Processor)/ ARM (Advanced Reduced instruction set computer Machine) processor or DSP/ARM IP (Int...The implementation method of the IEEE 802.11 Medium Access Control (MAC) protocol is mainly based on DSP (Digital Signal Processor)/ ARM (Advanced Reduced instruction set computer Machine) processor or DSP/ARM IP (Intellectual Property) core. This paper presents a method based on Nios II soft-core processor embedded in Altera’s Cyclone FPGA (Field Programmable Gate Array) and MicroC/OS-II RTOS (Real-Time Operation System). The benefits and drawbacks of above methods are compared, and then the method presented in this paper is described. The hardware and software partitioning are discussed; the hardware architecture is also illustrated and the MAC software programming is described in detail. The presented method has some advantages, such as low cost, easy-implementation and very suitable for the implementation of IEEE 802.11 MAC in research stage.展开更多
In order to address the bubble formation and movement in air-water two-phase flow,single bubble rising in stagnant water is experimentally studied by digital image processing.Bubbles are released individually from the...In order to address the bubble formation and movement in air-water two-phase flow,single bubble rising in stagnant water is experimentally studied by digital image processing.Bubbles are released individually from the submerged orifices with different diameters(1.81 mm,2.07 mm,2.98 mm,3.92 mm)at different detachment frequency.Images are recorded by a high-speed video camera and processed by digital image processing technique. The factors impacting the formed volume of bubble are discussed.The experimental results showed that a threshold of gas flow rate(400 mm 3 ·s- 1)divides the bubble formation into two regimes:the constant volume regime and the growing volume regime.Especially for the growing volume regime,the surface tension is taken into account.The bubble volume is consisted of two parts:the surface tension impacting part and the gas volume flow rate impacting part.An improved correlation for bubble volume prediction is developed for the two regimes and better coincidence with the experiment data than the previous models is obtained.展开更多
In this paper, the Lie-form invariance of a nonholonomic system of relative motion in event space is studied. Firstly, the definition and the criterion of the Lie-form invariance of the nonholonomic system of relative...In this paper, the Lie-form invariance of a nonholonomic system of relative motion in event space is studied. Firstly, the definition and the criterion of the Lie-form invariance of the nonholonomic system of relative motion in event space is given. Secondly, the Hojman conserved quantity and a new type of conserved quantity deduced from the Lie-form invariance are obtained. An example is given to illustrate the application of the results.展开更多
Contrary to the conventional wisdom which suggests that a perfectly rational subject with risk-averse attitude should never gamble, this paper provides a vivid example in our real economy for people to expect a positi...Contrary to the conventional wisdom which suggests that a perfectly rational subject with risk-averse attitude should never gamble, this paper provides a vivid example in our real economy for people to expect a positive return to gamble Within the existing literature, scholars have proposed different reasons to explain why an original risk-averse person would start to gamble, with the implicit assumption that the expected payoff of a bet is always lower than its cost. In contrast, our paper discusses when and why a risk-averse person could bet strategically with a positive expected return; in particular, we used field data in Hong Kong to illustrate a vivid scenario for positive expected return in gambling.展开更多
In order to solve the problem of experimental research on the penetration process of projectile into anchored rock mass, we derived the essential similarity conditions for the physical simulation experi- ment accordin...In order to solve the problem of experimental research on the penetration process of projectile into anchored rock mass, we derived the essential similarity conditions for the physical simulation experi- ment according to the similarity theory, carried out the experiment on the penetration process of a kind of penetrating bomb into the anchored rock mass of type III, and compared the experimental results with the values computed by the professional Young's empirical formula. The test results show that the phys- ical simulation experiment can represent the actual penetration process of projectile into anchored rock mass. The research method proposed in this paper provides technical support for the experimental research on the design and reconstruction of underground protection works.展开更多
Nowadays, in order to satisfy the ISO 9001: 2015 requirements, organizations access to information from web sites, consultant guides, Internet forums, books, and courses, as a first approximation, however, the qualit...Nowadays, in order to satisfy the ISO 9001: 2015 requirements, organizations access to information from web sites, consultant guides, Internet forums, books, and courses, as a first approximation, however, the quality, reliability, validity, and accuracy of the information content in these is limited. The research topic of this study is the use of theoretical methodological tools, whose implementation supports the organizations in the fulfillment of requirement 4 of ISO 9001:2015, adapting it to their particular needs, minimizing rework in the documentation, increasing the motivation of the personnel involved and promoting well-being within the work environment. Some theoretical methodological tools were implemented in the case of Engineering laboratories of the Faculty of Higher Studies Arag6n, that support and complement the teaching-learning process in the theoretical-practical subjects of the curricula of the engineering bachelor's degrees, providing students with practical training in the use of equipment, devices, and tools, as well as extracurricular courses. In the study participated the stakeholders of laboratories. From the results, it was observed that the time for the documentation of the quality management system was reduced using the theoretical tools proposed in this study. In conclusion, this study will thus be useful as a starting point in using formal tools for the implementation of ISO 9001: 2015 standard.展开更多
Two inter-decadal shifts in East China summer rainfall during the last three decades of the 20th century have been identified.One shift occurred in the late 1970s and featured more rainfall in the Yangtze River valley...Two inter-decadal shifts in East China summer rainfall during the last three decades of the 20th century have been identified.One shift occurred in the late 1970s and featured more rainfall in the Yangtze River valley and prolonged drought in North China.The other shift occurred in the early 1990s and featured increased rainfall in South China.The role of black carbon(BC) aerosol in the first shift event is controversial,and it has not been documented for the second event.In this study,the authors used Geophysical Fluid Dynamics Laboratory's(GFDL's) atmospheric general circulation model known as Atmosphere and Land Model(AM2.1) ,which has been shown to capture East Asian climate variability well,to investigate these issues by conducting sensitive experiments with or without historical BC in East Asia. The results suggest that the model reproduces the first shift well,including intensified rainfall in the Yangtze River and weakened monsoonal circulation.However,the model captures only a fraction of the observed variations for the second shift event.Thus,the role of BC in modulating the two shift events is different,and its impact is relatively less important for the early 1990s event.展开更多
The emergence of media convergence have so huge impact on paper-based media that paper-based media no longer has a monopoly. Some people assert that paper-based media will come to an end. However, the author believes ...The emergence of media convergence have so huge impact on paper-based media that paper-based media no longer has a monopoly. Some people assert that paper-based media will come to an end. However, the author believes that the paper media will not come to an end under the media convergence trend. It will develop parallel with media integration. The reason why the author has this view is that, on one hand, paper-based media has its unique physical characteristics. In the real world, paper media brought us the aesthetic experience by "five senses" . It cannot be replaced by the media convergence. The paper media will also make survival steering dimension; on the other hand, cultural heritage of the paper media make itself a unique appreciation of the value and not transcendent. Therefore, the paper media in the media convergence trend will continue to exist and turned to be "concept book" that admiring is the main part and reading supplemented.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
N2O represents a popular oxidizer for hybrid rocket motors for a variety of reasons, including safety, ease of access and self-pressurization. It is often used as a saturated two-phase fluid in these applications to t...N2O represents a popular oxidizer for hybrid rocket motors for a variety of reasons, including safety, ease of access and self-pressurization. It is often used as a saturated two-phase fluid in these applications to take advantage of self-pressurization. Recent interest in using this oxidizer in regeneratively cooled engines requires a detailed heat transfer process analysis to the coolant, in order to quantify performance. Since the injection of N2O typically takes place in the two-phase region, our study focuses on heat transfer rates in this region, and extends the region to include superheated vapor. This analysis is critical for these cooling applications, because the exothermic decomposition nature of N2O also means that unchecked heating in the superheated region may result in a runaway reaction in the cooling passages. Furthermore, provided that sufficient heat transfer rates are available, N2O is expected to accelerate in the cooling passages due to Rayleigh flow effects much like those of a calorically perfect gas. The proximity of superheated N2O to its saturated vapor curve, at the conditions studied here, makes the suitability of a perfect gas model questionable, but that benchmarks is still useful. This paper presents the development of an experimental apparatus (a "Rayleigh tube"), specifically designed to study this problem, and test the analytical methods developed to model it. Since we focus on the development of the apparatus, the data presented were uses primarily calorically perfect gas surrogates, but the goal is to apply the apparatus and method to N2O. The design and construction of the Rayleigh tube is presented, along with preliminary results with perfect gases. Finally, we present preliminary results on heated N2O flow. Using a simple model for predicted dry-out point, we investigate where superheating may be expected to occur. We present estimates of critical heating and compare them to the heat required to achieve self-decomposition.展开更多
Suffering from fragile environment, poor accessibility and infrastructure, as well as social,political and economic marginality, the interprovincial mountain geographical entities are difficult areas for the regional ...Suffering from fragile environment, poor accessibility and infrastructure, as well as social,political and economic marginality, the interprovincial mountain geographical entities are difficult areas for the regional governance in China.By analyzing the spatial patterns and the influencing factors of the interprovincial mountain geographical names(IMGNs), the goal of this research is to clarify the geographical features of IMGNs and offer alternatives for the management of interprovincial mountain regions in China. The spatial visualization,the analysis of spatial agglomeration and the influencing factors of IMGNs were all implemented under a geographical information system. Results showed that there were 6869 IMGNs in China according to the database of "China's Second National Survey of Geographical Names(2014-2018)",including 4209 mountain geographical names, 1684 mountain peak geographical names and 976 the other mountain geographical names. Hunan Province had the largest number of names while Shanghai had the smallest number of names. In addition, the spatial variance of the mountain peak names and the mountain names were larger than that of the other mountain geographical names, and the IMGNs showed a significant clustering phenomenon in the southern part of China. The relative elevation and the population had an impact on the distribution of the IMGNs. The largest number of the names occurred where the relative elevation was between 1000-2000 m and where the population was between 40-50 million. Density of unnamed interprovincial mountain geographical entities declined from west to east in China. The analysis of generic names of different types of IMGNs implied that the naming of IMGNs is inconsistent. Based on these analyses, it is suggested that the government should take the IMGNs as management units, strengthen the naming of unnamed interprovincial mountain geographical entities, standardize the generic names of IMGNs and identify areas of poverty based on the survey of IMGNs.展开更多
The present study validated the capability of the AM2.1,a model developed at NOAA's Geophysical Fluid Dynamics Laboratory (GFDL),in reproducing the fundamental features of the East Asian Subtropical Westerly Jet S...The present study validated the capability of the AM2.1,a model developed at NOAA's Geophysical Fluid Dynamics Laboratory (GFDL),in reproducing the fundamental features of the East Asian Subtropical Westerly Jet Stream (EASWJ).The main behaviors of the EASWJ are also investigated through the reanalysis of observational NCEP/NCAR data.The mean state of the EASWJ,including its intensity,location,structure,and seasonal evolution is generally well-portrayed in the model.Compared with the observation,the model tends to reproduce a weaker jet center.And,during summer,the simulated jet center is northward-situated.Results also demonstrate the model captures the variability of EASWJ during summer well.The results of the empirical orthogonal function (EOF) applied on the zonal wind at 200 hPa (U200) over East Asia for both the observation and simulation indicate an inter-decadal shift around the late 1970s.The correlation coefficient between the corresponding principle components is as great as 0.42 with significance at the 99% confidence level.展开更多
This paper acquaints readers with the practice of effectiveness evaluation in the public sector. The purpose of this paper is to study performance measurement according to the changes in public sector reform by focusi...This paper acquaints readers with the practice of effectiveness evaluation in the public sector. The purpose of this paper is to study performance measurement according to the changes in public sector reform by focusing on performance-based budgeting in Russia. This paper suggests that the construction process of performance measurement should be aligned with outputs and outcomes of budget policy. The main research materials for this paper are based on data from a survey and follow-up interviews of budgetary managers and accountants. The survey result sets priorities and weighted some indicators to the measurement of effectiveness in the public sector. The data of this study were not large, but the study led to understanding how effectiveness is seen by budgetary managers and how measurement systems should be structured. Texts and contents from different sources such as financial annual reports and budgetary entities' websites provided insightful and interesting findings.展开更多
基金supported by the National Science and Technology Major Project (No. 2011ZX05019-008)the National Natural Science Foundation of China (No. 41074080)+1 种基金the Science Foundation of China University of Petroleum, Beijing (No. KYJJ2012-05-11)supported by the CNPC international collaboration program through the Edinburgh Anisotropy Project (EAP) of the British Geological Survey (BGS) and the CNPC Key Geophysical Laboratory at the China University of Petroleum and CNPC geophysical prospecting projects for new method and technique research
文摘According to the Chapman multi-scale rock physical model, the seismic response characteristics vary for different fluid-saturated reservoirs. For class I AVO reservoirs and gas-saturation, the seismic response is a high-frequency bright spot as the amplitude energy shifts. However, it is a low-frequency shadow for the Class III AVO reservoirs saturated with hydrocarbons. In this paper, we verified the high-frequency bright spot results of Chapman for the Class I AVO response using the frequency-dependent analysis of a physical model dataset. The physical model is designed as inter-bedded thin sand and shale based on real field geology parameters. We observed two datasets using fixed offset and 2D geometry with different fluid- saturated conditions. Spectral and time-frequency analyses methods are applied to the seismic datasets to describe the response characteristics for gas-, water-, and oil-saturation. The results of physical model dataset processing and analysis indicate that reflection wave tuning and fluid-related dispersion are the main seismic response characteristic mechanisms. Additionally, the gas saturation model can be distinguished from water and oil saturation for Class I AVO utilizing the frequency-dependent abnormal characteristic. The frequency-dependent characteristic analysis of the physical model dataset verified the different spectral response characteristics corresponding to the different fluid-saturated models. Therefore, by careful analysis of real field seismic data, we can obtain the abnormal spectral characteristics induced by the fluid variation and implement fluid detection using seismic data directly.
文摘Rough set is a new approach to uncertainties in spatial analysis.In this paper,rough set symbols are simplified and standardized in terms of rough interpretation and specialized indication.Rough spatial entities and their topological relationships are also proposed in rough space,thus a universal intersected equation is developed,and rough membership function is further extended with the gray scale in our case study.We complete three works.First,a set of simplified rough symbols is advanced on the basis of existing rough symbols.Second,rough spatial entity is put forward to study the real world as it is,without forcing uncertainties into crisp set.Third,rough spatial topological relationships are studied by using rough matrix and their figures.The relationships are divided into three types,crisp entity and crisp entity (CC),rough entity and crisp entity (RC),and rough entity and rough entity (RR).A universal intersected equation is further proposed.Finally,the maximum and minimum maps of river thematic classification are generated via rough membership function and rough relationships in our case study.
文摘The implementation method of the IEEE 802.11 Medium Access Control (MAC) protocol is mainly based on DSP (Digital Signal Processor)/ ARM (Advanced Reduced instruction set computer Machine) processor or DSP/ARM IP (Intellectual Property) core. This paper presents a method based on Nios II soft-core processor embedded in Altera’s Cyclone FPGA (Field Programmable Gate Array) and MicroC/OS-II RTOS (Real-Time Operation System). The benefits and drawbacks of above methods are compared, and then the method presented in this paper is described. The hardware and software partitioning are discussed; the hardware architecture is also illustrated and the MAC software programming is described in detail. The presented method has some advantages, such as low cost, easy-implementation and very suitable for the implementation of IEEE 802.11 MAC in research stage.
基金Supported by the National Natural Science Foundation of China(50776063)the Natural Science Foundation of Tianjin(11JCZDJC22500)
文摘In order to address the bubble formation and movement in air-water two-phase flow,single bubble rising in stagnant water is experimentally studied by digital image processing.Bubbles are released individually from the submerged orifices with different diameters(1.81 mm,2.07 mm,2.98 mm,3.92 mm)at different detachment frequency.Images are recorded by a high-speed video camera and processed by digital image processing technique. The factors impacting the formed volume of bubble are discussed.The experimental results showed that a threshold of gas flow rate(400 mm 3 ·s- 1)divides the bubble formation into two regimes:the constant volume regime and the growing volume regime.Especially for the growing volume regime,the surface tension is taken into account.The bubble volume is consisted of two parts:the surface tension impacting part and the gas volume flow rate impacting part.An improved correlation for bubble volume prediction is developed for the two regimes and better coincidence with the experiment data than the previous models is obtained.
文摘In this paper, the Lie-form invariance of a nonholonomic system of relative motion in event space is studied. Firstly, the definition and the criterion of the Lie-form invariance of the nonholonomic system of relative motion in event space is given. Secondly, the Hojman conserved quantity and a new type of conserved quantity deduced from the Lie-form invariance are obtained. An example is given to illustrate the application of the results.
文摘Contrary to the conventional wisdom which suggests that a perfectly rational subject with risk-averse attitude should never gamble, this paper provides a vivid example in our real economy for people to expect a positive return to gamble Within the existing literature, scholars have proposed different reasons to explain why an original risk-averse person would start to gamble, with the implicit assumption that the expected payoff of a bet is always lower than its cost. In contrast, our paper discusses when and why a risk-averse person could bet strategically with a positive expected return; in particular, we used field data in Hong Kong to illustrate a vivid scenario for positive expected return in gambling.
文摘In order to solve the problem of experimental research on the penetration process of projectile into anchored rock mass, we derived the essential similarity conditions for the physical simulation experi- ment according to the similarity theory, carried out the experiment on the penetration process of a kind of penetrating bomb into the anchored rock mass of type III, and compared the experimental results with the values computed by the professional Young's empirical formula. The test results show that the phys- ical simulation experiment can represent the actual penetration process of projectile into anchored rock mass. The research method proposed in this paper provides technical support for the experimental research on the design and reconstruction of underground protection works.
文摘Nowadays, in order to satisfy the ISO 9001: 2015 requirements, organizations access to information from web sites, consultant guides, Internet forums, books, and courses, as a first approximation, however, the quality, reliability, validity, and accuracy of the information content in these is limited. The research topic of this study is the use of theoretical methodological tools, whose implementation supports the organizations in the fulfillment of requirement 4 of ISO 9001:2015, adapting it to their particular needs, minimizing rework in the documentation, increasing the motivation of the personnel involved and promoting well-being within the work environment. Some theoretical methodological tools were implemented in the case of Engineering laboratories of the Faculty of Higher Studies Arag6n, that support and complement the teaching-learning process in the theoretical-practical subjects of the curricula of the engineering bachelor's degrees, providing students with practical training in the use of equipment, devices, and tools, as well as extracurricular courses. In the study participated the stakeholders of laboratories. From the results, it was observed that the time for the documentation of the quality management system was reduced using the theoretical tools proposed in this study. In conclusion, this study will thus be useful as a starting point in using formal tools for the implementation of ISO 9001: 2015 standard.
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences(Grant No.KZCX2-YW-Q11-03)
文摘Two inter-decadal shifts in East China summer rainfall during the last three decades of the 20th century have been identified.One shift occurred in the late 1970s and featured more rainfall in the Yangtze River valley and prolonged drought in North China.The other shift occurred in the early 1990s and featured increased rainfall in South China.The role of black carbon(BC) aerosol in the first shift event is controversial,and it has not been documented for the second event.In this study,the authors used Geophysical Fluid Dynamics Laboratory's(GFDL's) atmospheric general circulation model known as Atmosphere and Land Model(AM2.1) ,which has been shown to capture East Asian climate variability well,to investigate these issues by conducting sensitive experiments with or without historical BC in East Asia. The results suggest that the model reproduces the first shift well,including intensified rainfall in the Yangtze River and weakened monsoonal circulation.However,the model captures only a fraction of the observed variations for the second shift event.Thus,the role of BC in modulating the two shift events is different,and its impact is relatively less important for the early 1990s event.
文摘The emergence of media convergence have so huge impact on paper-based media that paper-based media no longer has a monopoly. Some people assert that paper-based media will come to an end. However, the author believes that the paper media will not come to an end under the media convergence trend. It will develop parallel with media integration. The reason why the author has this view is that, on one hand, paper-based media has its unique physical characteristics. In the real world, paper media brought us the aesthetic experience by "five senses" . It cannot be replaced by the media convergence. The paper media will also make survival steering dimension; on the other hand, cultural heritage of the paper media make itself a unique appreciation of the value and not transcendent. Therefore, the paper media in the media convergence trend will continue to exist and turned to be "concept book" that admiring is the main part and reading supplemented.
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.
文摘N2O represents a popular oxidizer for hybrid rocket motors for a variety of reasons, including safety, ease of access and self-pressurization. It is often used as a saturated two-phase fluid in these applications to take advantage of self-pressurization. Recent interest in using this oxidizer in regeneratively cooled engines requires a detailed heat transfer process analysis to the coolant, in order to quantify performance. Since the injection of N2O typically takes place in the two-phase region, our study focuses on heat transfer rates in this region, and extends the region to include superheated vapor. This analysis is critical for these cooling applications, because the exothermic decomposition nature of N2O also means that unchecked heating in the superheated region may result in a runaway reaction in the cooling passages. Furthermore, provided that sufficient heat transfer rates are available, N2O is expected to accelerate in the cooling passages due to Rayleigh flow effects much like those of a calorically perfect gas. The proximity of superheated N2O to its saturated vapor curve, at the conditions studied here, makes the suitability of a perfect gas model questionable, but that benchmarks is still useful. This paper presents the development of an experimental apparatus (a "Rayleigh tube"), specifically designed to study this problem, and test the analytical methods developed to model it. Since we focus on the development of the apparatus, the data presented were uses primarily calorically perfect gas surrogates, but the goal is to apply the apparatus and method to N2O. The design and construction of the Rayleigh tube is presented, along with preliminary results with perfect gases. Finally, we present preliminary results on heated N2O flow. Using a simple model for predicted dry-out point, we investigate where superheating may be expected to occur. We present estimates of critical heating and compare them to the heat required to achieve self-decomposition.
基金supported by the Project of "Atlas of the People's Republic of China (New Century Edition)”funded by Ministry of Science and Technology, China (No. 2013FY112800)
文摘Suffering from fragile environment, poor accessibility and infrastructure, as well as social,political and economic marginality, the interprovincial mountain geographical entities are difficult areas for the regional governance in China.By analyzing the spatial patterns and the influencing factors of the interprovincial mountain geographical names(IMGNs), the goal of this research is to clarify the geographical features of IMGNs and offer alternatives for the management of interprovincial mountain regions in China. The spatial visualization,the analysis of spatial agglomeration and the influencing factors of IMGNs were all implemented under a geographical information system. Results showed that there were 6869 IMGNs in China according to the database of "China's Second National Survey of Geographical Names(2014-2018)",including 4209 mountain geographical names, 1684 mountain peak geographical names and 976 the other mountain geographical names. Hunan Province had the largest number of names while Shanghai had the smallest number of names. In addition, the spatial variance of the mountain peak names and the mountain names were larger than that of the other mountain geographical names, and the IMGNs showed a significant clustering phenomenon in the southern part of China. The relative elevation and the population had an impact on the distribution of the IMGNs. The largest number of the names occurred where the relative elevation was between 1000-2000 m and where the population was between 40-50 million. Density of unnamed interprovincial mountain geographical entities declined from west to east in China. The analysis of generic names of different types of IMGNs implied that the naming of IMGNs is inconsistent. Based on these analyses, it is suggested that the government should take the IMGNs as management units, strengthen the naming of unnamed interprovincial mountain geographical entities, standardize the generic names of IMGNs and identify areas of poverty based on the survey of IMGNs.
基金supported by the National Basic Research Program of China (973 Program) under Grant 2011CB309704the National Special Scientific Research Project for Public Interest under Grant 201006021the National Natural Science Foundation of China under Grants 40890155,U0733002,and 40810059005
文摘The present study validated the capability of the AM2.1,a model developed at NOAA's Geophysical Fluid Dynamics Laboratory (GFDL),in reproducing the fundamental features of the East Asian Subtropical Westerly Jet Stream (EASWJ).The main behaviors of the EASWJ are also investigated through the reanalysis of observational NCEP/NCAR data.The mean state of the EASWJ,including its intensity,location,structure,and seasonal evolution is generally well-portrayed in the model.Compared with the observation,the model tends to reproduce a weaker jet center.And,during summer,the simulated jet center is northward-situated.Results also demonstrate the model captures the variability of EASWJ during summer well.The results of the empirical orthogonal function (EOF) applied on the zonal wind at 200 hPa (U200) over East Asia for both the observation and simulation indicate an inter-decadal shift around the late 1970s.The correlation coefficient between the corresponding principle components is as great as 0.42 with significance at the 99% confidence level.
文摘This paper acquaints readers with the practice of effectiveness evaluation in the public sector. The purpose of this paper is to study performance measurement according to the changes in public sector reform by focusing on performance-based budgeting in Russia. This paper suggests that the construction process of performance measurement should be aligned with outputs and outcomes of budget policy. The main research materials for this paper are based on data from a survey and follow-up interviews of budgetary managers and accountants. The survey result sets priorities and weighted some indicators to the measurement of effectiveness in the public sector. The data of this study were not large, but the study led to understanding how effectiveness is seen by budgetary managers and how measurement systems should be structured. Texts and contents from different sources such as financial annual reports and budgetary entities' websites provided insightful and interesting findings.