This paper summarizes partial findings on education about standardization by CNIS in 2008. As of December 31, 2008, 21 universities and colleges in China had established a standardization curriculum. This paper deals ...This paper summarizes partial findings on education about standardization by CNIS in 2008. As of December 31, 2008, 21 universities and colleges in China had established a standardization curriculum. This paper deals with standardization education related to economic management, engineering, agriculture and science of law and summarizes respondents' opinions on teaching performances and design of teaching materials and curriculums.展开更多
Electron beam selective melting (EBSM) is an additive manufacturing technique that directly fabricates three-dimensional parts in a layerwise fashion by using an electron beam to scan and melt metal powder. In recen...Electron beam selective melting (EBSM) is an additive manufacturing technique that directly fabricates three-dimensional parts in a layerwise fashion by using an electron beam to scan and melt metal powder. In recent years, EBSM has been successfully used in the additive manufacturing of a variety of materials. Previous research focused on the EBSM process of a single material. In this study, a novel EBSM process capable of building a gradient structure with dual metal materials was developed, and a powder-supplying method based on vibration was put forward. Two different powders can be supplied individually and then mixed. Two materials were used in this study: Ti6AI4V powder and Ti47AI2Cr2Nb powder. Ti6AI4V has excellent strength and plasticity at room temperature, while Ti47AI2Cr2Nb has excellent performance at high temperature, but is very brittle. A Ti6AI4V/Ti47AI2Cr2Nb gradient material was successfully fabricated by the developed system. The microstructures and chemical compositions were characterized by optical microscopy, scanning microscopy, and electron microprobe analysis. Results showed that the interface thickness was about 300 μm. The interface was free of cracks, and the chemical compositions exhibited a staircase-like change within the interface.展开更多
As China's energy intensity fluctuated in recent years, it is necessary to examine whether this fluctuation happened at a regional level. This paper establishes a decomposition model by using the structural decomp...As China's energy intensity fluctuated in recent years, it is necessary to examine whether this fluctuation happened at a regional level. This paper establishes a decomposition model by using the structural decomposition analysis (SDA) method at a regional level. Then this model is employed to empirically analyze the changes of Beijing's energy intensity. The conclusions are as follows: during 2002-2010, except petroleum, the energy intensity decreased and the changes were mostly attributed to the technology changes, while the final use variation actually increased the energy intensity; comparing different periods of 2002-2010, the decline rates of energy intensity for coal and hydropower were decreasing, resulting from the production technology being more energy-intensive than before; the energy intensity changes of petroleum firstly increased substantially and then decreased moderately.展开更多
The study deals with a multi-faceted theoretical approach, symbolic, analytical and numerical, based on the chemical equilibrium assumption, addressed at predicting the performance trends of downdrafi wood-gasificatio...The study deals with a multi-faceted theoretical approach, symbolic, analytical and numerical, based on the chemical equilibrium assumption, addressed at predicting the performance trends of downdrafi wood-gasification processes so to assess the optimal ranges of input parameters, in particular the equivalence ratios, suitable to achieving the highest cold gas efficiencies whilst keeping the more the possible tar-free the produced bio-syngas. The time-steady, zero-dimensional model has been developed within MATLAB (the computing language and interactive environment from Matrix Laboratory) and solved by enforcing the constraints posed by the equilibrium constants in relation to two reactions, gas-water shift and methanation. Particular care is devoted toward verifying the real attainment of the equilibrium condition, as attested by an actual presence of products from the equilibrium reactions together with a zero difference AE between the energy flows entering and exiting the system, an issue often overlooked. With respect to other similar theoretical approaches, the numerical model, assisted by the symbolic counterpart for better interpretation and intrinsic validation of results, shows a distinct advantage in predicting rather accurately the syngas composition for varying gasification temperatures, as attested by cross comparisons with experimental data directly taken on an instrumented, dedicated, small-scale downdraft gasifier operational at DIME/SCL (the Savona Combustion Laboratory of DIME, the Dept. of Mechanical, Energy, Management and Transportation Engineering of Genova University). The behavior of cold gas efficiency clearly points out that, from an energy conversion point of view, the optimal gasification temperatures turn out comprised between 900 ℃ and 1,000 ℃: this range is indeed characterized by the highest concentrations in the energy-rich syngas components CO and H2. For higher temperatures, as induced by higher air-to-fuel ratios, the progressive oxidation of above components, together with increasing nitrogen levels, would decrease the bio-syngas heat values.展开更多
The paper presents an investigation of energy and exergy analysis of an existing ORC (organic rankine cycle) unit powered by hot geothermal water. The validated model of this unit was used to examine 25 refrigerants...The paper presents an investigation of energy and exergy analysis of an existing ORC (organic rankine cycle) unit powered by hot geothermal water. The validated model of this unit was used to examine 25 refrigerants belonging to different chemical compositions. The study revealed that R141b and R123 produced the best net power, energy efficiency, and exergy efficiency, whereas R125 was the lowest. Hydrofluorocarbons (except R143a), hydrocarbons, and inorganic reflected attractive energy and exergy efficiencies. All investigated mixtures gained low performance compared with other studied candidates. The R245ca was the best among the hydrofluorocarbons studied refrigerants, and R501 was the best among the mixture refrigerants. Furthermore, within the ORC system, the evaporator was found to have the highest exergy destruction and the refrigerant pump was the lowest.展开更多
The aim of this paper is firstly to determine if the Korean television drama Winter Sonata and its spinoffs are contributing to contemporary cross-cultural diffusion in Japan. Secondly, if cross-cultural diffusion is ...The aim of this paper is firstly to determine if the Korean television drama Winter Sonata and its spinoffs are contributing to contemporary cross-cultural diffusion in Japan. Secondly, if cross-cultural diffusion is occurring, is it contributing to a loss of local identity? Winter Sonata is a small but significant part of the Korean Wave and in the vanguard of Korean television drama content viewed in Japan. There have been macro political changes in East Asia, largely driven by Korea, resulting in an easing of restrictions on cross-border media trade. These in turn have progressively created a new dynamic in content and volume. The methodology used for the study is triangulation including document analysis, audience analysis, and commercial outcomes. The convergent validation derived from the three parameters advances the proposition that Winter Sonata has contributed to cultural diffusion from a Japanese perspective but not to a loss of local identity. Arguably, the process is an enriching one in East Asia reinforced by multi-lateral media trade.展开更多
China's textile and garment markets grown up with the development of reform and opening-up, they're well adapted to the national policy and economic environment in each period, and formed a large-scale development, ...China's textile and garment markets grown up with the development of reform and opening-up, they're well adapted to the national policy and economic environment in each period, and formed a large-scale development, played a positive role in promoting China's economy development. This paper has a research on the textile and garment market, industry cluster and regional economy, recognize textile professional market and regional economy as the main research object, industrial cluster as the intermediary variable. Establish textile and garment market, industrial cluster, regional economy as the main trunk of structural equation model and carry on the empirical analysis. From the empirical analysis, this paper find that the coefficient of textile and garment market effecting on industrial cluster is 0.91, and industrial cluster on regional economy is 0.93, that means results verify hypothesis relationships between the three of them Finally, according to each path coefficients, providing relevant suggestions for the Shanghai area development of textile and garment market, related industries cluster and regional economy development.展开更多
This paper theoretically analyzes the lock-in mechanism of labor division for developing countries when they stick to static comparative advantages and the internal mechanism of cultivating dynamic comparative advanta...This paper theoretically analyzes the lock-in mechanism of labor division for developing countries when they stick to static comparative advantages and the internal mechanism of cultivating dynamic comparative advantages. Through empirical analysis, this paper finds that China, while sharing the benefits of globalization, showcases the lock-in effect regarding its status in the international labor division chain. The analysis finds that in its participation in globalization, the net barter terms of trade ~BTT) and factorial terms of trade for China are deteriorating, and the income terms of trade are seriously overvalued, resulting in a series of contradictions, such as scanty returns for enterprises, slow income growth, increasing trade frictions, and intensified environmental and resource pressures. The paper analyzes rapidly changing factors in China's comparative advantages and characteristics of the changes in industries where China possesses comparative advantages. According to changes in different types of industries at different stages, this paper puts forward suggestions on direction and policies for cultivating dynamic comparative advantages.展开更多
This paper examines city growth patterns and the corresponding city size distribution evolution over long periods of time using a simple New Economic Geography(NEG) model and urban population data from Canada. The mai...This paper examines city growth patterns and the corresponding city size distribution evolution over long periods of time using a simple New Economic Geography(NEG) model and urban population data from Canada. The main findings are twofold. First, there is a transition from sequential to parallel growth of cities over long periods of time: city growth shows a sequential mode in the stage of rapid urbanization, i.e., the cities with the best development conditions will take the lead in growth, after which the cities with higher ranks will become the fastest-growing cities; in the late stage of urbanization, city growth converges according to Gibrat′s law, and exhibits a parallel growth pattern. Second, city size distribution is found to have persistent structural characteristics: the city system is self-organized into multiple discrete size groups; city growth shows club convergence characteristics, and the cities with similar development conditions eventually converge to a similar size. The results will not only enhance our understanding of urbanization process, but will also provide a timely and clear policy reference for promoting the healthy urbanization of developing countries.展开更多
This paper investigates the marginal abatement cost (MAC) of CO: emissions across 104 Chinese cities between 2001 and 2008. Based on parametric directional distance function, this paper discovers that the mean marg...This paper investigates the marginal abatement cost (MAC) of CO: emissions across 104 Chinese cities between 2001 and 2008. Based on parametric directional distance function, this paper discovers that the mean marginal abatement cost of CO2 emissions for sample cities was 967 yuan/ton. In terms of region, CO: marginal abatement cost is significantly higher in China's eastern region than in central and western regions; in terms of provincial-level region, it is the highest in Shanghai and the lowest in Shaanxi in terms of city, it is the highest in Shanghai and the lowest in Zhangjiajie with the ratio between their medians being at 48:1; in terms of time, marginal abatement cost has been always on the rise with significant intercity disparities. There is a U-shaped curve relationship between marginal abatement cost of cities and CO2 emissions per unit of GDP, which is negatively correlated with the share of secondary industry and positively correlated with the level of urbanization.展开更多
Network measures are useful for predicting fault-prone modules. However, existing work has not distinguished faults according to their severity. In practice, high severity faults cause serious problems and require fur...Network measures are useful for predicting fault-prone modules. However, existing work has not distinguished faults according to their severity. In practice, high severity faults cause serious problems and require further attention. In this study, we explored the utility of network measures in high severity faultproneness prediction. We constructed software source code networks for four open-source projects by extracting the dependencies between modules. We then used univariate logistic regression to investigate the associations between each network measure and fault-proneness at a high severity level. We built multivariate prediction models to examine their explanatory ability for fault-proneness, as well as evaluated their predictive effectiveness compared to code metrics under forward-release and cross-project predictions. The results revealed the following:(1) most network measures are significantly related to high severity fault-proneness;(2) network measures generally have comparable explanatory abilities and predictive powers to those of code metrics; and(3) network measures are very unstable for cross-project predictions. These results indicate that network measures are of practical value in high severity fault-proneness prediction.展开更多
Ubiquitin(Ub) chain isopeptide bond mimics are useful molecules for biochemical and biophysical studies. Herein, we report the semi-synthesis of the disulfide-linked K11/K48-branched tri-Ub(Ub_3^(11/48)(S-S)), the fir...Ubiquitin(Ub) chain isopeptide bond mimics are useful molecules for biochemical and biophysical studies. Herein, we report the semi-synthesis of the disulfide-linked K11/K48-branched tri-Ub(Ub_3^(11/48)(S-S)), the first example of an isopeptide mimic for the branched Ub chains,which have recently emerged as an interesting category of Ub modifications. Our strategy comprised the El-dependent synthesis of the Ub conjugate of aminoethanethiol, followed by disulfide formation with Ub(K11 C, K48 C). The structure of the synthetic isopeptide bond mimics was verified by the crystal structure of Ub_3^(11/48)(S-S). Deubiquitination and pulldown assays indicated that the synthetic Ub_3^(11/48)(S-S) could be hydrolyzed by linkage-specific deubiquitinases(K11-specific Cezanne and K48-specific OTUB1), and recognized by proteasomal ubiquitin receptor S5 a.展开更多
Authentication is the basis of the security of IEEE 802.11i standard. The authentication process in 802.11i involves two important protocols: a 4-way handshake and a group key handshake. A formal analysis of authenti...Authentication is the basis of the security of IEEE 802.11i standard. The authentication process in 802.11i involves two important protocols: a 4-way handshake and a group key handshake. A formal analysis of authentication in 802.11i is given via a belief multisets formalism. The analysis shows that the 4-way handshake and the group key handshake may provide satisfactory mutual authentication, key management, and issue of a new group temporal key from an access point to a user device, under the guarantee of mutual possession of a confidential palrwise master key. The analysis also shows that there exists a denial of service attack in the 4-way handshake and some seeming redundancies are useful in the protocol implementation.展开更多
OBJECTIVE:To establish a quantification model of Traditional Chinese Medicine(TCM)syndromes by sampling patients undergoing idiopathic precocious puberty(IPP)and early puberty.METHODS:A questionnaire for classifying a...OBJECTIVE:To establish a quantification model of Traditional Chinese Medicine(TCM)syndromes by sampling patients undergoing idiopathic precocious puberty(IPP)and early puberty.METHODS:A questionnaire for classifying and quantifying TCM syndromes was designed and administered.All the results were analyzed;the relationship between 3 types of syndrome and 47symptoms were summated.Meanwhile,the frequency distribution of each symptom or sign was aggregated.Fuzzy mathematics was used to develop a quantification model ofTCM syndromes.RESULTS:We found that precocious puberty had 3types of syndrome,including hyperactivity of fire due to Yin deficiency(Syndrome I),depressed liver Qi transforming into fire(Syndrome II),and end retention of damp heat(Syndrome III).In the IPP group,Syndrome I was the most common principal syndrome(100%).Forty-six patients(43.81%)werediagnosed with Syndrome I accompanied by Syndrome II and 11(10.48%)were diagnosed with Syndrome I accompanied by Syndrome III.In the early puberty group,Syndrome I was also the main syndrome(98.39%).The degrees of most symptoms were mild to moderate.Reddened tongue was the most common tongue manifestation(62.86%prevalence)in the IPP group.The most common pulse manifestations were slippery pulse,thread pulse,and taut pulse.The Asymptotic Normalization Coefficient(ANC)method was used to quantify the TCM syndromes in 167 cases.Diagnostic accuracy rate reached 91%,comparable to expert diagnosis.CONCLUSION:We find that there are 3 types of syndrome in the IPP group and in the early puberty group.Syndrome I(hyperactivity of fire due to Yin deficiency)is the main syndrome in the two groups.ANC may be an appropriate for quantification model ofTCM syndromes.展开更多
Seasonal and interannual changes in the Earth's gravity field are mainly due to mass exchange among the atmosphere,ocean,and continental water sources.The terrestrial water storage changes,detected as gravity chan...Seasonal and interannual changes in the Earth's gravity field are mainly due to mass exchange among the atmosphere,ocean,and continental water sources.The terrestrial water storage changes,detected as gravity changes by the Gravity Recovery and Climate Experiment(GRACE) satellites,are mainly caused by precipitation,evapotranspiration,river transportation and downward infiltration processes.In this study,a land data assimilation system LDAS-G was developed to assimilate the GRACE terrestrial water storage(TWS) data into the Community Land Model(CLM3.5) using the POD-based ensemble four-dimensional variational assimilation method PODEn4 DVar,disaggregating the GRACE large-scale terrestrial water storage changes vertically and in time,and placing constraints on the simulation of vertical hydrological variables to improve land surface hydrological simulations.The ideal experiments conducted at a single point and assimilation experiments carried out over China by the LDAS-G data assimilation system showed that the system developed in this study improved the simulation of land surface hydrological variables,indicating the potential of GRACE data assimilation in large-scale land surface hydrological research and applications.展开更多
基金supported by the Foundation for Scientific Research Program of AQSlQ's(Grant No. 2007QK30)the CNIS's Program on Basic Research Fund (Grant No. 51076S-1467) Study on Feasibility of Establishing the Discipline of StandardizationNo. 10-36 programs funded for scientific research of AQSIQ, Study on Boosting Education about Standardization and the Discipline of Standardization Development.
文摘This paper summarizes partial findings on education about standardization by CNIS in 2008. As of December 31, 2008, 21 universities and colleges in China had established a standardization curriculum. This paper deals with standardization education related to economic management, engineering, agriculture and science of law and summarizes respondents' opinions on teaching performances and design of teaching materials and curriculums.
基金funding of 2013 Beijing Science and Technology Development Project (D13110400300000 and D131100003013002)
文摘Electron beam selective melting (EBSM) is an additive manufacturing technique that directly fabricates three-dimensional parts in a layerwise fashion by using an electron beam to scan and melt metal powder. In recent years, EBSM has been successfully used in the additive manufacturing of a variety of materials. Previous research focused on the EBSM process of a single material. In this study, a novel EBSM process capable of building a gradient structure with dual metal materials was developed, and a powder-supplying method based on vibration was put forward. Two different powders can be supplied individually and then mixed. Two materials were used in this study: Ti6AI4V powder and Ti47AI2Cr2Nb powder. Ti6AI4V has excellent strength and plasticity at room temperature, while Ti47AI2Cr2Nb has excellent performance at high temperature, but is very brittle. A Ti6AI4V/Ti47AI2Cr2Nb gradient material was successfully fabricated by the developed system. The microstructures and chemical compositions were characterized by optical microscopy, scanning microscopy, and electron microprobe analysis. Results showed that the interface thickness was about 300 μm. The interface was free of cracks, and the chemical compositions exhibited a staircase-like change within the interface.
基金Supported by Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDA05150600)National Natural Science Foundation of China (No. 71273027 and No. 70903066)Beijing Planning Office of Philosophy and Social Science (No. 11JGC105)
文摘As China's energy intensity fluctuated in recent years, it is necessary to examine whether this fluctuation happened at a regional level. This paper establishes a decomposition model by using the structural decomposition analysis (SDA) method at a regional level. Then this model is employed to empirically analyze the changes of Beijing's energy intensity. The conclusions are as follows: during 2002-2010, except petroleum, the energy intensity decreased and the changes were mostly attributed to the technology changes, while the final use variation actually increased the energy intensity; comparing different periods of 2002-2010, the decline rates of energy intensity for coal and hydropower were decreasing, resulting from the production technology being more energy-intensive than before; the energy intensity changes of petroleum firstly increased substantially and then decreased moderately.
文摘The study deals with a multi-faceted theoretical approach, symbolic, analytical and numerical, based on the chemical equilibrium assumption, addressed at predicting the performance trends of downdrafi wood-gasification processes so to assess the optimal ranges of input parameters, in particular the equivalence ratios, suitable to achieving the highest cold gas efficiencies whilst keeping the more the possible tar-free the produced bio-syngas. The time-steady, zero-dimensional model has been developed within MATLAB (the computing language and interactive environment from Matrix Laboratory) and solved by enforcing the constraints posed by the equilibrium constants in relation to two reactions, gas-water shift and methanation. Particular care is devoted toward verifying the real attainment of the equilibrium condition, as attested by an actual presence of products from the equilibrium reactions together with a zero difference AE between the energy flows entering and exiting the system, an issue often overlooked. With respect to other similar theoretical approaches, the numerical model, assisted by the symbolic counterpart for better interpretation and intrinsic validation of results, shows a distinct advantage in predicting rather accurately the syngas composition for varying gasification temperatures, as attested by cross comparisons with experimental data directly taken on an instrumented, dedicated, small-scale downdraft gasifier operational at DIME/SCL (the Savona Combustion Laboratory of DIME, the Dept. of Mechanical, Energy, Management and Transportation Engineering of Genova University). The behavior of cold gas efficiency clearly points out that, from an energy conversion point of view, the optimal gasification temperatures turn out comprised between 900 ℃ and 1,000 ℃: this range is indeed characterized by the highest concentrations in the energy-rich syngas components CO and H2. For higher temperatures, as induced by higher air-to-fuel ratios, the progressive oxidation of above components, together with increasing nitrogen levels, would decrease the bio-syngas heat values.
文摘The paper presents an investigation of energy and exergy analysis of an existing ORC (organic rankine cycle) unit powered by hot geothermal water. The validated model of this unit was used to examine 25 refrigerants belonging to different chemical compositions. The study revealed that R141b and R123 produced the best net power, energy efficiency, and exergy efficiency, whereas R125 was the lowest. Hydrofluorocarbons (except R143a), hydrocarbons, and inorganic reflected attractive energy and exergy efficiencies. All investigated mixtures gained low performance compared with other studied candidates. The R245ca was the best among the hydrofluorocarbons studied refrigerants, and R501 was the best among the mixture refrigerants. Furthermore, within the ORC system, the evaporator was found to have the highest exergy destruction and the refrigerant pump was the lowest.
文摘The aim of this paper is firstly to determine if the Korean television drama Winter Sonata and its spinoffs are contributing to contemporary cross-cultural diffusion in Japan. Secondly, if cross-cultural diffusion is occurring, is it contributing to a loss of local identity? Winter Sonata is a small but significant part of the Korean Wave and in the vanguard of Korean television drama content viewed in Japan. There have been macro political changes in East Asia, largely driven by Korea, resulting in an easing of restrictions on cross-border media trade. These in turn have progressively created a new dynamic in content and volume. The methodology used for the study is triangulation including document analysis, audience analysis, and commercial outcomes. The convergent validation derived from the three parameters advances the proposition that Winter Sonata has contributed to cultural diffusion from a Japanese perspective but not to a loss of local identity. Arguably, the process is an enriching one in East Asia reinforced by multi-lateral media trade.
文摘China's textile and garment markets grown up with the development of reform and opening-up, they're well adapted to the national policy and economic environment in each period, and formed a large-scale development, played a positive role in promoting China's economy development. This paper has a research on the textile and garment market, industry cluster and regional economy, recognize textile professional market and regional economy as the main research object, industrial cluster as the intermediary variable. Establish textile and garment market, industrial cluster, regional economy as the main trunk of structural equation model and carry on the empirical analysis. From the empirical analysis, this paper find that the coefficient of textile and garment market effecting on industrial cluster is 0.91, and industrial cluster on regional economy is 0.93, that means results verify hypothesis relationships between the three of them Finally, according to each path coefficients, providing relevant suggestions for the Shanghai area development of textile and garment market, related industries cluster and regional economy development.
文摘This paper theoretically analyzes the lock-in mechanism of labor division for developing countries when they stick to static comparative advantages and the internal mechanism of cultivating dynamic comparative advantages. Through empirical analysis, this paper finds that China, while sharing the benefits of globalization, showcases the lock-in effect regarding its status in the international labor division chain. The analysis finds that in its participation in globalization, the net barter terms of trade ~BTT) and factorial terms of trade for China are deteriorating, and the income terms of trade are seriously overvalued, resulting in a series of contradictions, such as scanty returns for enterprises, slow income growth, increasing trade frictions, and intensified environmental and resource pressures. The paper analyzes rapidly changing factors in China's comparative advantages and characteristics of the changes in industries where China possesses comparative advantages. According to changes in different types of industries at different stages, this paper puts forward suggestions on direction and policies for cultivating dynamic comparative advantages.
基金Under the auspices of Key Program of Chinese Academy of Sciences(No.KZZD-EW-06-01)
文摘This paper examines city growth patterns and the corresponding city size distribution evolution over long periods of time using a simple New Economic Geography(NEG) model and urban population data from Canada. The main findings are twofold. First, there is a transition from sequential to parallel growth of cities over long periods of time: city growth shows a sequential mode in the stage of rapid urbanization, i.e., the cities with the best development conditions will take the lead in growth, after which the cities with higher ranks will become the fastest-growing cities; in the late stage of urbanization, city growth converges according to Gibrat′s law, and exhibits a parallel growth pattern. Second, city size distribution is found to have persistent structural characteristics: the city system is self-organized into multiple discrete size groups; city growth shows club convergence characteristics, and the cities with similar development conditions eventually converge to a similar size. The results will not only enhance our understanding of urbanization process, but will also provide a timely and clear policy reference for promoting the healthy urbanization of developing countries.
基金supported by the National Natural Sciences Foundation(Approval No.41201582)Beijing Natural Sciences Foundation(9152011)+1 种基金Mingde Scholars Program of Renmin University of China(Approval No.13XNJ016)Peking University-Lincoln Institute Center for Urban Development and Land Policy
文摘This paper investigates the marginal abatement cost (MAC) of CO: emissions across 104 Chinese cities between 2001 and 2008. Based on parametric directional distance function, this paper discovers that the mean marginal abatement cost of CO2 emissions for sample cities was 967 yuan/ton. In terms of region, CO: marginal abatement cost is significantly higher in China's eastern region than in central and western regions; in terms of provincial-level region, it is the highest in Shanghai and the lowest in Shaanxi in terms of city, it is the highest in Shanghai and the lowest in Zhangjiajie with the ratio between their medians being at 48:1; in terms of time, marginal abatement cost has been always on the rise with significant intercity disparities. There is a U-shaped curve relationship between marginal abatement cost of cities and CO2 emissions per unit of GDP, which is negatively correlated with the share of secondary industry and positively correlated with the level of urbanization.
基金supported by National Natural Science Foundation of China (Grant Nos. 61472175, 61472178, 61272082, 61272080, 91418202)Natural Science Foundation of Jiangsu Province (Grant No. BK20130014)Natural Science Foundation of Colleges in Jiangsu Province (Grant No. 13KJB520018)
文摘Network measures are useful for predicting fault-prone modules. However, existing work has not distinguished faults according to their severity. In practice, high severity faults cause serious problems and require further attention. In this study, we explored the utility of network measures in high severity faultproneness prediction. We constructed software source code networks for four open-source projects by extracting the dependencies between modules. We then used univariate logistic regression to investigate the associations between each network measure and fault-proneness at a high severity level. We built multivariate prediction models to examine their explanatory ability for fault-proneness, as well as evaluated their predictive effectiveness compared to code metrics under forward-release and cross-project predictions. The results revealed the following:(1) most network measures are significantly related to high severity fault-proneness;(2) network measures generally have comparable explanatory abilities and predictive powers to those of code metrics; and(3) network measures are very unstable for cross-project predictions. These results indicate that network measures are of practical value in high severity fault-proneness prediction.
基金supported by the National Key R&D Program of China(2017YFA0505200)the National Natural Science Foundation of China(91753205,21532004,21761142008)the Program of Introducing Talents of Discipline to Universities of China(B16028)
文摘Ubiquitin(Ub) chain isopeptide bond mimics are useful molecules for biochemical and biophysical studies. Herein, we report the semi-synthesis of the disulfide-linked K11/K48-branched tri-Ub(Ub_3^(11/48)(S-S)), the first example of an isopeptide mimic for the branched Ub chains,which have recently emerged as an interesting category of Ub modifications. Our strategy comprised the El-dependent synthesis of the Ub conjugate of aminoethanethiol, followed by disulfide formation with Ub(K11 C, K48 C). The structure of the synthetic isopeptide bond mimics was verified by the crystal structure of Ub_3^(11/48)(S-S). Deubiquitination and pulldown assays indicated that the synthetic Ub_3^(11/48)(S-S) could be hydrolyzed by linkage-specific deubiquitinases(K11-specific Cezanne and K48-specific OTUB1), and recognized by proteasomal ubiquitin receptor S5 a.
基金the National High Technology Research and Development Program(863)of China(No.2006AA01Z422)the National Natural Science Foundation of China(Nos.60573030,90704004)
文摘Authentication is the basis of the security of IEEE 802.11i standard. The authentication process in 802.11i involves two important protocols: a 4-way handshake and a group key handshake. A formal analysis of authentication in 802.11i is given via a belief multisets formalism. The analysis shows that the 4-way handshake and the group key handshake may provide satisfactory mutual authentication, key management, and issue of a new group temporal key from an access point to a user device, under the guarantee of mutual possession of a confidential palrwise master key. The analysis also shows that there exists a denial of service attack in the 4-way handshake and some seeming redundancies are useful in the protocol implementation.
基金Supported by the National Natural Science Foundation of China(No.81072841)the Shanghai Science and Technology Research Grant Program(No.09dZ1971600)State Key Clinical Department of TCM pediatrics
文摘OBJECTIVE:To establish a quantification model of Traditional Chinese Medicine(TCM)syndromes by sampling patients undergoing idiopathic precocious puberty(IPP)and early puberty.METHODS:A questionnaire for classifying and quantifying TCM syndromes was designed and administered.All the results were analyzed;the relationship between 3 types of syndrome and 47symptoms were summated.Meanwhile,the frequency distribution of each symptom or sign was aggregated.Fuzzy mathematics was used to develop a quantification model ofTCM syndromes.RESULTS:We found that precocious puberty had 3types of syndrome,including hyperactivity of fire due to Yin deficiency(Syndrome I),depressed liver Qi transforming into fire(Syndrome II),and end retention of damp heat(Syndrome III).In the IPP group,Syndrome I was the most common principal syndrome(100%).Forty-six patients(43.81%)werediagnosed with Syndrome I accompanied by Syndrome II and 11(10.48%)were diagnosed with Syndrome I accompanied by Syndrome III.In the early puberty group,Syndrome I was also the main syndrome(98.39%).The degrees of most symptoms were mild to moderate.Reddened tongue was the most common tongue manifestation(62.86%prevalence)in the IPP group.The most common pulse manifestations were slippery pulse,thread pulse,and taut pulse.The Asymptotic Normalization Coefficient(ANC)method was used to quantify the TCM syndromes in 167 cases.Diagnostic accuracy rate reached 91%,comparable to expert diagnosis.CONCLUSION:We find that there are 3 types of syndrome in the IPP group and in the early puberty group.Syndrome I(hyperactivity of fire due to Yin deficiency)is the main syndrome in the two groups.ANC may be an appropriate for quantification model ofTCM syndromes.
基金supported by the National Natural Science Foundation of China(Grant Nos.41075062,91125016)the National Basic Research Program of China(Grants Nos.2010CB951001,2010CB428403)
文摘Seasonal and interannual changes in the Earth's gravity field are mainly due to mass exchange among the atmosphere,ocean,and continental water sources.The terrestrial water storage changes,detected as gravity changes by the Gravity Recovery and Climate Experiment(GRACE) satellites,are mainly caused by precipitation,evapotranspiration,river transportation and downward infiltration processes.In this study,a land data assimilation system LDAS-G was developed to assimilate the GRACE terrestrial water storage(TWS) data into the Community Land Model(CLM3.5) using the POD-based ensemble four-dimensional variational assimilation method PODEn4 DVar,disaggregating the GRACE large-scale terrestrial water storage changes vertically and in time,and placing constraints on the simulation of vertical hydrological variables to improve land surface hydrological simulations.The ideal experiments conducted at a single point and assimilation experiments carried out over China by the LDAS-G data assimilation system showed that the system developed in this study improved the simulation of land surface hydrological variables,indicating the potential of GRACE data assimilation in large-scale land surface hydrological research and applications.