自1951年《关于难民地位的公约》(《日内瓦公约》)生效以来,面对全世界范围内不断加剧的难民危机,越来越多的国家倾向于区域内寻求合作,履行难民保护的国际义务,分担保护难民的责任,"安全第三国"(Safe Third Country)的概念...自1951年《关于难民地位的公约》(《日内瓦公约》)生效以来,面对全世界范围内不断加剧的难民危机,越来越多的国家倾向于区域内寻求合作,履行难民保护的国际义务,分担保护难民的责任,"安全第三国"(Safe Third Country)的概念也应运而生。该概念产生于欧洲,并在美国、加拿大和澳大利亚等国家得到不同程度的模仿和实践。然而,国家和国家以及区域组织间以双边条约的形式对"安全第三国"原则的实践本质上违反了《难民地位公约》所规定的"不推回原则",其不可避免地扩大化必须以难民权利的有效保障为前提。我国边境地区也时常有难民涌入的情况发生,而目前世界上亚太地区的难民保护区域合作机制最不完善,因此对这一问题的厘清,有利于我国未来在探索难民保护的区域合作中把握好方向。展开更多
With the research on and development of Genetically Modified Food (GMF), people's attitude toward GMF may fall into two divergent categories, typical- ly represented by the United States(US) and the European Unio...With the research on and development of Genetically Modified Food (GMF), people's attitude toward GMF may fall into two divergent categories, typical- ly represented by the United States(US) and the European Union(EU), respectively. The former follows a "sound science principle" and firmly objects to the precautionary principle, namely a permissive policy of positive support of and voluntary labelling on GMF; while the latter adopts a cautiously precautionary principle, requiring mandatory labelling and traceability. From the standpoint of regulatory principles, together with corresponding supervisory measures and relevant provisions, this paper compared the execution of directives and provisions on GMF from the initial policies enacted by the US and EU to current situation combined with the track and analysis of latest polic ies issued.展开更多
The population growth and demand for high living standard not only increase food demand but also cause more loss of the limited cultivated land resources. Cultivated land loss caused by disasters and the implementatio...The population growth and demand for high living standard not only increase food demand but also cause more loss of the limited cultivated land resources. Cultivated land loss caused by disasters and the implementation of the "Conversion of Cropland to Forest or Grassland" project make this situation even worse in China. Thus, there is a problem to be solved imminently that to what extent the cultivated land can guarantee food security of China. Based on time-series data on food production and cultivated land area from 1989 to 2003 and other research results, this paper constructs quality index of cultivated land according to different land quality. Regression models are adopted to predicate changes of main factors from 2004 to 2030, which have great effect on cultivated land area or grain productivity, and verify accuracy with coc^cient of determination (R2). Nine results were got according to three scenarios of decreasing rate of population growth rate and three cases of urban and rural built-up area per capita. There results show that China's food supply can only be maintained at a low to middle level of 370-410kg per capita, that is, China has enough land productivity to meet primary demand of food independently. However, it cannot reach the safe target of 500kg per capita if there is no breakthrough in breeding or no remarkable improvement of irrigation works, when the grain self-sufficiency maintains no less than 80%. To breed productive crops and to improve land productivity by mefiorating low quality cultivated land are appropriate measures to shrink the gap between food demand and supply. The results may offer helpful information for the formulation of policies on population growth, land use, protection of cultivated land.展开更多
AIM: To investigate the effect of a new infant formula supplemented with a low level (0.24 g/100 mL) of galacto-oligosaccharide (GOS) on intestinal micro-flora (Bif idobacteria, Lactobacilli and E. coli) and fermentat...AIM: To investigate the effect of a new infant formula supplemented with a low level (0.24 g/100 mL) of galacto-oligosaccharide (GOS) on intestinal micro-flora (Bif idobacteria, Lactobacilli and E. coli) and fermentation characteristics in term infants, compared with human milk and a standard infant formula without GOS. METHODS: Term infants (n = 371) were approached in this study in three hospitals of China. All infants started breast-feeding. Those who changed to formula-feeding within 4 wk after birth were randomly assigned to one of the two formula groups. Growth and stool characteristics, and side effects that occurred in recruited infants were recorded in a 3-mo follow-up period. Fecal samples were collected from a subpopulation of recruited infants for analysis of intestinal bacteria (culture technique), acetic acid (gas chromatography) and pH (indicator strip). RESULTS: After 3 mo, the intestinal Bifidobacteria, Lactobacilli , acetic acid and stool frequency were significantly increased, and fecal pH was decreased in infants fed with the GOS-formula or human milk, compared with those fed with the formula withoutGOS. No significant differences were observed between the GOS formula and human milk groups. Supplementation with GOS did not influence the incidence of crying, regurgitation and vomiting. CONCLUSION: A low level of GOS (0.24 g/100 mL) in infant formula can improve stool frequency, decrease fecal pH, and stimulate intestinal Bifidobacteria and Lactobacilli as in those fed with human milk.展开更多
AIM To assess the efficacy and safety of combined directly acting antivirals(DAAs) for the treatment of Chinese chronic hepatitis C(CHC) patients in a real-world setting.METHODS Hospitalized CHC patients who were trea...AIM To assess the efficacy and safety of combined directly acting antivirals(DAAs) for the treatment of Chinese chronic hepatitis C(CHC) patients in a real-world setting.METHODS Hospitalized CHC patients who were treated with DAAs at Peking University First Hospital between January 2015 and December 2016 were enrolled. Samples and clinical data were collected at 0 wk, 2 wk, 4 wk, 8 wk, 12 wk, or 24 wk during DAAs treatment and at 4 wk, 12 wk, and 24 wk after the end of treatment. RESULTS Fifty-four patients who underwent DAAs treatment were included in our study, of whom 83.3%(45/54) achieved rapid virological response at 2 wk after treatment initiation(RVR 2) and 94.4%(51/54)achieved sustained virological response at 24 wk after the end of treatment(SVR 24). Serum creatinine and uric acid levels at the end of treatment were significantly increased compared with baseline levels(83.6 ± 17.9 vs 88.8 ± 19.4, P 01 < 0.001; 320.8 ± 76.3 vs 354.5 ± 87.6, P 01 < 0.001), and no significant improvements were observed at 24 w after the end of treatment(83.6 ± 17.9 vs 86.8 ± 19.1, P 02 = 0.039; 320.8 ± 76.3 vs 345.9 ± 89.4, P 02 = 0.001). The total frequency of adverse events(AEs) during treatment was 33.3%(18/54), with major AEs being fatigue(16.7%), headache(7.4%), anorexia(7.4%), and insomnia(5.6%). CONCLUSION Though based in a small cohort of patients, the abnormal changes in renal function indices and relative high frequency of AEs during combined DAAs treatment should be taken as a note of caution.展开更多
China has to raise agricultural productivity in its limited and shrinking farmland to guarantee food security for its huge and ever-growing population. Sustainable soil nutrient management is of paramount importance t...China has to raise agricultural productivity in its limited and shrinking farmland to guarantee food security for its huge and ever-growing population. Sustainable soil nutrient management is of paramount importance to the world's most populous country. Critical challenges the country is facing in sustaining soil fertility and in alleviating the hazardous impact of intensive fertilizer use are discussed in this paper. It is emphatically pointed out that national strategies as well as area-specific action plans with respect to scientific nutrient management are urgently needed to balance productivity and sustainability in the future. Relevant proposals for addressing those challenges are also presented.展开更多
Based on an internationally recognized concept of food security, this paper has created a system of eight indicators to analyze China's food security. For the proper control and analysis of this study, the authors of...Based on an internationally recognized concept of food security, this paper has created a system of eight indicators to analyze China's food security. For the proper control and analysis of this study, the authors of this paper have chosen these indicators: supply, distribution, consumption, utilization efficiency, food security results, stability, sustainability and controllability. Results indicate that China's food security is currently at a high level and has been increasing in recent years. China's food security has multiple advantages with various indicators that include a self-sufficiency ratio, per capita calorie intake and protein supply that are above world average levels, even exceeding the average level of some developed countries. Major challenges facing China's food security include an unreasonable nutrition structure and poor environmental sustainability. In order to increase China's food security level, efforts must be made to adjust output structure, adopt an environmentally friendly pattern of production, attach importance to demand management, reduce unreasonable consumption and loss and moderately lower China's food reserve ratio.展开更多
Big data has been taken as a Chinese national strategy in order to satisfy the developments of the social and economic requirements and the development of new information technology. The prosperity of big data brings ...Big data has been taken as a Chinese national strategy in order to satisfy the developments of the social and economic requirements and the development of new information technology. The prosperity of big data brings not only convenience to people's daily life and more opportunities to enterprises, but more challenges with information security as well. This paper has a research on new types and features of information security issues in the age of big data, and puts forward the solutions for the above issues: build up the big data security management platform, set up the establishment of information security system and implement relevant laws and regulations.展开更多
In view of the fact that safety production supervision of coal mines in China features low efficacy, this paper applies principles of cybernetics to simulate the dynamic process of safety supervision, and proposes tha...In view of the fact that safety production supervision of coal mines in China features low efficacy, this paper applies principles of cybernetics to simulate the dynamic process of safety supervision, and proposes that institutional variables be controlled to support intermediate goals, which in turn contribute to the ultimate safety production objective. Rather than focusing all attention on safety issues of working faces, supervising departments of coalmines are advised to pay much more attention to institutional factors that may impact people’s attitude and behavior, which are responsible for most coalmine accidents. It is believed that such a shift of attention can effectively reduce coalmining production accidents and greatly enhance supervision efficacy.展开更多
The value of friction coefficient between the main cable and saddle, relates to not only the anti-slippage stability of three-tower suspension bridge, but also the reasonable stiffness of the middle tower and the magn...The value of friction coefficient between the main cable and saddle, relates to not only the anti-slippage stability of three-tower suspension bridge, but also the reasonable stiffness of the middle tower and the magnitude of rigidity of the whole bridge. First, the paper does some comparative studies about the relevant provisions of international norms, and then, summarizes the relevant load test results both at home and abroad. Finally, the paper draws the appropriate anti-slippage safety factor for the most unfavorable load in accordance with international load standards, and discusses the rationality and feasibility of the friction coefficient of 0.2 between main cable and saddle.展开更多
Snow avalanche is a serious threat to the safety of roads in alpine mountains. In the western Tianshan Mountains, large scale avalanches occur every year and affect road safety. There is an urgent need to identify the...Snow avalanche is a serious threat to the safety of roads in alpine mountains. In the western Tianshan Mountains, large scale avalanches occur every year and affect road safety. There is an urgent need to identify the characteristics of triggering factors for avalanche activity in this region to improve road safety and the management of natural hazards. Based on the observation of avalanche activity along the national road G218 in the western Tianshan Mountains, avalanche event data in combination with meteorological, snowpack and earthquake data were collected and analyzed. The snow climate of the mountain range was examined using a recently developed snow climate classification scheme, and triggering conditions of snow avalanche in different snow climate regions were compared. The results show that snowfall is the most common triggering factor for a natural avalanche and there is high probability of avalanche release with snowfall exceeding 20.4 mm during a snowfall period. Consecutive rise in temperature within three days and daily mean temperature reaching 0.5℃ in the following day imply a high probability of temperaturerise-triggered avalanche release. Earthquakes have a significant impact on the formation of large size avalanches in the area. For the period 2011-2017, five cases were identified as a consequence of earthquake with magnitudes of 3.3≤M_L≤5.1 and source-to-site distances of 19~139 km. The Tianshan Mountains are characterized by a continental snow climate with lower snow density, lower snow shear strength and high proportion depth hoar, which explains that both the snowfall and temperature for triggering avalanche release in the continental snow climate of the Tianshan Mountains are lower than that in maritime snow climate and transitional snow climate regions. The findings help forecast avalanche release for mitigating avalanche disaster and assessing the risk of avalanche disaster.展开更多
The mortgage loan has evolved from a local lending instrument into a major global security and its role is unparallel to other financial instruments in the process of financial globalization. This paper explains how t...The mortgage loan has evolved from a local lending instrument into a major global security and its role is unparallel to other financial instruments in the process of financial globalization. This paper explains how technology and financial innovation transformed the mortgage loan from a local security into a premier global security traded worldwide. It examines the fundamental flaws of this process and why it does not work in regards to mortgage lending and the re-securitization products that were created through financial innovation. The findings show that regulation was unable to keep pace with financial innovation, which created an environment where actors in the financial service sector were able to behave geographically irresponsibly by using information asymmetries to their advantage by par- ticipating in moral hazard activities and engaging in other immoral and unethical business practices that were centered around localized geography, which ultimately contributed to the global financial crisis. It also examines the roll of financial innovation in regard to the Lehman Brothers Mini-Bond in Hung and its role as a driving force behind China's newly emerging shadow banking sector. It concludes with a policy recommendation and its implication for China's continued economic development.展开更多
The TNC IF-T Protocol Binding to TLS(TIPBT) is specified by Trusted Computing Group(TCG) for TNC assessment exchanges.However,the TIPBT cannot be analysed by current Strand Space Model(SSM) because of the different re...The TNC IF-T Protocol Binding to TLS(TIPBT) is specified by Trusted Computing Group(TCG) for TNC assessment exchanges.However,the TIPBT cannot be analysed by current Strand Space Model(SSM) because of the different requirements from the traditional security protocols.In order to solve this problem,first,we give an extension of the SSM and point out the TIPBT cannot prevent Man-in-the-Middle(MITM) attacks in some cases based on the extended SSM.Then,we improve the TIPBT and show that the improved TIPBT can resist MITM attacks in the extended SSM.展开更多
Based on fuzzy integrated evaluation theory, the safety of coal industry was analyzed, the factors affecting the safety of coal industry was considered, and its fuzzy in- tegrated estimating theory and results were gi...Based on fuzzy integrated evaluation theory, the safety of coal industry was analyzed, the factors affecting the safety of coal industry was considered, and its fuzzy in- tegrated estimating theory and results were given. Finally this paper proposed a new method of industry safety estimation. According to this method, we can integrate the fac- tors affecting coal industry and deal with the parameters and targets of evaluating factors by quantitative analysis, thus give a scientific and reasonable safety degree analyzing evaluation.展开更多
The DPSIR assessment method, which implies the relationships among driving force (D), pressure (P), status (S), impact (I), and response (R), is widely applied by scholars. This paper aims to establish a com...The DPSIR assessment method, which implies the relationships among driving force (D), pressure (P), status (S), impact (I), and response (R), is widely applied by scholars. This paper aims to establish a comprehensive assessment system for regional energy security in eastern coastal China based on the above model using different indicators. Factor analysis and the SPSS statistical analysis software were used to carry out scientific and quantitative assessments. The results indicated that con- tradictions of energy supply and demand as well as environmental pollution are the critical factors that present great challenges to regional energy security in this area. The authors argued that a sustainable, stable, and safe supply energy supply is crucial in solving the aforesaid dilemma, and improving the energy use efficiency is one of the best choices. Some countermeasures and suggestions regarding regional energy supply stability and utilization security were pointed out.展开更多
Delay/Disruption-Tolerant Networking(DTN) originated from research on Interplanetary Internet and still today space applications are the most important application field and research stimulus. This paper investigates ...Delay/Disruption-Tolerant Networking(DTN) originated from research on Interplanetary Internet and still today space applications are the most important application field and research stimulus. This paper investigates DTN communications between the Earth and the far side of the Moon, by means of a lunar orbiter acting as relay. After an introductory part, the paper presents a comprehensive analysis of the DTN performance that can be achieved on the identified communication scenario. The focus is on the evaluation of the stateof-the-art ability of Interplanetary Overlay Network(ION), the NASA DTN implementation of Bundle Protocol(BP) and Contact Graph Routing(CGR), to meet the many challenges of the space communication scenario investigated(and more generally of a future interplaynetary Internet): intermittent links, network partitioning, scarce bandwidth, long delays, dynamic routing, handling of high priority and emergency traffic, interoperability issues. A study of security threats and Bundle Security Protocol(BSP) countermeasures complete the work.The many results provided, confirm the essential role of DTN in future space communications.展开更多
In despite of fluctuation in recent years, the grain yield in China has been increasing, which relieves the conflict between supply and demand and turns the situation of food security good. However, because of the rap...In despite of fluctuation in recent years, the grain yield in China has been increasing, which relieves the conflict between supply and demand and turns the situation of food security good. However, because of the rapid increase in food consumption, the conflicts of food quality and structure in the supply and demand equilibrium has become more and more obvious and the long-effective mechanism of food security has not been estab-lished yet. It is found that the factors affecting food security in China include the scarcity and dissipation of resources, farmers’ low enthusiasm in planting grain crops and the inappropriateness of the emphasis and measures of macro-economic regulation and control. Therefore, the authors advance to optimize resources allocation, strengthen macro-economic regulation and control and policy stimulation and establish the mechanism of allocating grain production cost, to set up the long-effective mechanism of China food security and keep it stable in the long term.展开更多
Similar to conventional automobiles,same safety problems exist in electric vehicles.In the meantime,since its structural and power features are different,electric vehicles have their particular safety problems.Both do...Similar to conventional automobiles,same safety problems exist in electric vehicles.In the meantime,since its structural and power features are different,electric vehicles have their particular safety problems.Both domestic and international organizations have released some safety standards for electric vehicles which have also been added and complemented along with the development and research of electric vehicles.展开更多
From the year of 1949 to the present, the China national coal output has been increasing quickly and became first in the world in 2009. But at the same time, major coal mining accidents still exist nowadays. In order ...From the year of 1949 to the present, the China national coal output has been increasing quickly and became first in the world in 2009. But at the same time, major coal mining accidents still exist nowadays. In order to review the overall situation and provide information on major accidents of coal mines in China, we investigated 26 major coal mining accidents in China between the years of 1949 and 2009 through statistical methods, each of which led to more than 100 fatalities. Statistical characteristics about accident-related factors such as time, death toll, accident reasons, characters and nature of enterprise were analyzed. And some special conclusions have been achieved. For example, although we have made great progress, the safety situation in China coal mining industry is still serious, and the reasons for the mining accidents are all human errors which are not inevitable. Such results may be helpful to prevent major accidents in coal mines. Moreso, based on both the knowledge of other countries which have good safety situation nowadays and the safety management situation of China, we made suggestion on safety management of China coal mining. In conclusion, countermeasures were proposed in accordance with the results of statistical studies and the analyses of problems existed in coal mines, including the perfec- tion of safety supervision organization, the establishment of cooperating agency among government, coal mines and workers, the perfection of safety rules and regulations, the improvement of safety investment, the enhancement of safety training, the development of safety technique, and the development of emer- gency rescue technique and equipment.展开更多
文摘自1951年《关于难民地位的公约》(《日内瓦公约》)生效以来,面对全世界范围内不断加剧的难民危机,越来越多的国家倾向于区域内寻求合作,履行难民保护的国际义务,分担保护难民的责任,"安全第三国"(Safe Third Country)的概念也应运而生。该概念产生于欧洲,并在美国、加拿大和澳大利亚等国家得到不同程度的模仿和实践。然而,国家和国家以及区域组织间以双边条约的形式对"安全第三国"原则的实践本质上违反了《难民地位公约》所规定的"不推回原则",其不可避免地扩大化必须以难民权利的有效保障为前提。我国边境地区也时常有难民涌入的情况发生,而目前世界上亚太地区的难民保护区域合作机制最不完善,因此对这一问题的厘清,有利于我国未来在探索难民保护的区域合作中把握好方向。
文摘With the research on and development of Genetically Modified Food (GMF), people's attitude toward GMF may fall into two divergent categories, typical- ly represented by the United States(US) and the European Union(EU), respectively. The former follows a "sound science principle" and firmly objects to the precautionary principle, namely a permissive policy of positive support of and voluntary labelling on GMF; while the latter adopts a cautiously precautionary principle, requiring mandatory labelling and traceability. From the standpoint of regulatory principles, together with corresponding supervisory measures and relevant provisions, this paper compared the execution of directives and provisions on GMF from the initial policies enacted by the US and EU to current situation combined with the track and analysis of latest polic ies issued.
基金Under the auspices of the National Natural Science Foundation of China (No. 40671007), Innovation Project of Institute of Geographical Sciences and Natural Resources Research, CAS
文摘The population growth and demand for high living standard not only increase food demand but also cause more loss of the limited cultivated land resources. Cultivated land loss caused by disasters and the implementation of the "Conversion of Cropland to Forest or Grassland" project make this situation even worse in China. Thus, there is a problem to be solved imminently that to what extent the cultivated land can guarantee food security of China. Based on time-series data on food production and cultivated land area from 1989 to 2003 and other research results, this paper constructs quality index of cultivated land according to different land quality. Regression models are adopted to predicate changes of main factors from 2004 to 2030, which have great effect on cultivated land area or grain productivity, and verify accuracy with coc^cient of determination (R2). Nine results were got according to three scenarios of decreasing rate of population growth rate and three cases of urban and rural built-up area per capita. There results show that China's food supply can only be maintained at a low to middle level of 370-410kg per capita, that is, China has enough land productivity to meet primary demand of food independently. However, it cannot reach the safe target of 500kg per capita if there is no breakthrough in breeding or no remarkable improvement of irrigation works, when the grain self-sufficiency maintains no less than 80%. To breed productive crops and to improve land productivity by mefiorating low quality cultivated land are appropriate measures to shrink the gap between food demand and supply. The results may offer helpful information for the formulation of policies on population growth, land use, protection of cultivated land.
文摘AIM: To investigate the effect of a new infant formula supplemented with a low level (0.24 g/100 mL) of galacto-oligosaccharide (GOS) on intestinal micro-flora (Bif idobacteria, Lactobacilli and E. coli) and fermentation characteristics in term infants, compared with human milk and a standard infant formula without GOS. METHODS: Term infants (n = 371) were approached in this study in three hospitals of China. All infants started breast-feeding. Those who changed to formula-feeding within 4 wk after birth were randomly assigned to one of the two formula groups. Growth and stool characteristics, and side effects that occurred in recruited infants were recorded in a 3-mo follow-up period. Fecal samples were collected from a subpopulation of recruited infants for analysis of intestinal bacteria (culture technique), acetic acid (gas chromatography) and pH (indicator strip). RESULTS: After 3 mo, the intestinal Bifidobacteria, Lactobacilli , acetic acid and stool frequency were significantly increased, and fecal pH was decreased in infants fed with the GOS-formula or human milk, compared with those fed with the formula withoutGOS. No significant differences were observed between the GOS formula and human milk groups. Supplementation with GOS did not influence the incidence of crying, regurgitation and vomiting. CONCLUSION: A low level of GOS (0.24 g/100 mL) in infant formula can improve stool frequency, decrease fecal pH, and stimulate intestinal Bifidobacteria and Lactobacilli as in those fed with human milk.
基金Supported by National Natural Science Foundation of China,No.81373056Beijing Municipal Committee of Science and Technology,No.D161100002716003National Major Project for Infectious Diseases Control,No.2012ZX10002003-004-003
文摘AIM To assess the efficacy and safety of combined directly acting antivirals(DAAs) for the treatment of Chinese chronic hepatitis C(CHC) patients in a real-world setting.METHODS Hospitalized CHC patients who were treated with DAAs at Peking University First Hospital between January 2015 and December 2016 were enrolled. Samples and clinical data were collected at 0 wk, 2 wk, 4 wk, 8 wk, 12 wk, or 24 wk during DAAs treatment and at 4 wk, 12 wk, and 24 wk after the end of treatment. RESULTS Fifty-four patients who underwent DAAs treatment were included in our study, of whom 83.3%(45/54) achieved rapid virological response at 2 wk after treatment initiation(RVR 2) and 94.4%(51/54)achieved sustained virological response at 24 wk after the end of treatment(SVR 24). Serum creatinine and uric acid levels at the end of treatment were significantly increased compared with baseline levels(83.6 ± 17.9 vs 88.8 ± 19.4, P 01 < 0.001; 320.8 ± 76.3 vs 354.5 ± 87.6, P 01 < 0.001), and no significant improvements were observed at 24 w after the end of treatment(83.6 ± 17.9 vs 86.8 ± 19.1, P 02 = 0.039; 320.8 ± 76.3 vs 345.9 ± 89.4, P 02 = 0.001). The total frequency of adverse events(AEs) during treatment was 33.3%(18/54), with major AEs being fatigue(16.7%), headache(7.4%), anorexia(7.4%), and insomnia(5.6%). CONCLUSION Though based in a small cohort of patients, the abnormal changes in renal function indices and relative high frequency of AEs during combined DAAs treatment should be taken as a note of caution.
基金Project supported by the Knowledge Innovation Program of Chinese Academy of Sciences (Nos. KZCX3-SW-417 and KZCX2-413).
文摘China has to raise agricultural productivity in its limited and shrinking farmland to guarantee food security for its huge and ever-growing population. Sustainable soil nutrient management is of paramount importance to the world's most populous country. Critical challenges the country is facing in sustaining soil fertility and in alleviating the hazardous impact of intensive fertilizer use are discussed in this paper. It is emphatically pointed out that national strategies as well as area-specific action plans with respect to scientific nutrient management are urgently needed to balance productivity and sustainability in the future. Relevant proposals for addressing those challenges are also presented.
基金sponsored by the Chinese Academy of Social Sciences(CASS)Innovation Programme
文摘Based on an internationally recognized concept of food security, this paper has created a system of eight indicators to analyze China's food security. For the proper control and analysis of this study, the authors of this paper have chosen these indicators: supply, distribution, consumption, utilization efficiency, food security results, stability, sustainability and controllability. Results indicate that China's food security is currently at a high level and has been increasing in recent years. China's food security has multiple advantages with various indicators that include a self-sufficiency ratio, per capita calorie intake and protein supply that are above world average levels, even exceeding the average level of some developed countries. Major challenges facing China's food security include an unreasonable nutrition structure and poor environmental sustainability. In order to increase China's food security level, efforts must be made to adjust output structure, adopt an environmentally friendly pattern of production, attach importance to demand management, reduce unreasonable consumption and loss and moderately lower China's food reserve ratio.
基金supported by National Key Technology Support Program(No.2013BAD17B06)Major Program of National Social Science Fund(No.15ZDB154)
文摘Big data has been taken as a Chinese national strategy in order to satisfy the developments of the social and economic requirements and the development of new information technology. The prosperity of big data brings not only convenience to people's daily life and more opportunities to enterprises, but more challenges with information security as well. This paper has a research on new types and features of information security issues in the age of big data, and puts forward the solutions for the above issues: build up the big data security management platform, set up the establishment of information security system and implement relevant laws and regulations.
文摘In view of the fact that safety production supervision of coal mines in China features low efficacy, this paper applies principles of cybernetics to simulate the dynamic process of safety supervision, and proposes that institutional variables be controlled to support intermediate goals, which in turn contribute to the ultimate safety production objective. Rather than focusing all attention on safety issues of working faces, supervising departments of coalmines are advised to pay much more attention to institutional factors that may impact people’s attitude and behavior, which are responsible for most coalmine accidents. It is believed that such a shift of attention can effectively reduce coalmining production accidents and greatly enhance supervision efficacy.
基金National Science and Technology Support Program of China(No.2009BAG15B01)
文摘The value of friction coefficient between the main cable and saddle, relates to not only the anti-slippage stability of three-tower suspension bridge, but also the reasonable stiffness of the middle tower and the magnitude of rigidity of the whole bridge. First, the paper does some comparative studies about the relevant provisions of international norms, and then, summarizes the relevant load test results both at home and abroad. Finally, the paper draws the appropriate anti-slippage safety factor for the most unfavorable load in accordance with international load standards, and discusses the rationality and feasibility of the friction coefficient of 0.2 between main cable and saddle.
基金supported by the Science and Technology Service Network Initiative of the Chinese Academy of Science (Grant No.KFJSTSZDTP-015)the National Project of Investigation of Basic Resources for Science and Technology (Grant No.2017FY100501)the supports in field and laboratory work from the Tianshan Station for Snow cover and Avalanche Research,Chinese Academy of Sciences
文摘Snow avalanche is a serious threat to the safety of roads in alpine mountains. In the western Tianshan Mountains, large scale avalanches occur every year and affect road safety. There is an urgent need to identify the characteristics of triggering factors for avalanche activity in this region to improve road safety and the management of natural hazards. Based on the observation of avalanche activity along the national road G218 in the western Tianshan Mountains, avalanche event data in combination with meteorological, snowpack and earthquake data were collected and analyzed. The snow climate of the mountain range was examined using a recently developed snow climate classification scheme, and triggering conditions of snow avalanche in different snow climate regions were compared. The results show that snowfall is the most common triggering factor for a natural avalanche and there is high probability of avalanche release with snowfall exceeding 20.4 mm during a snowfall period. Consecutive rise in temperature within three days and daily mean temperature reaching 0.5℃ in the following day imply a high probability of temperaturerise-triggered avalanche release. Earthquakes have a significant impact on the formation of large size avalanches in the area. For the period 2011-2017, five cases were identified as a consequence of earthquake with magnitudes of 3.3≤M_L≤5.1 and source-to-site distances of 19~139 km. The Tianshan Mountains are characterized by a continental snow climate with lower snow density, lower snow shear strength and high proportion depth hoar, which explains that both the snowfall and temperature for triggering avalanche release in the continental snow climate of the Tianshan Mountains are lower than that in maritime snow climate and transitional snow climate regions. The findings help forecast avalanche release for mitigating avalanche disaster and assessing the risk of avalanche disaster.
基金Under the auspices of International Centre for China Development Studies,the University of Hong Kong
文摘The mortgage loan has evolved from a local lending instrument into a major global security and its role is unparallel to other financial instruments in the process of financial globalization. This paper explains how technology and financial innovation transformed the mortgage loan from a local security into a premier global security traded worldwide. It examines the fundamental flaws of this process and why it does not work in regards to mortgage lending and the re-securitization products that were created through financial innovation. The findings show that regulation was unable to keep pace with financial innovation, which created an environment where actors in the financial service sector were able to behave geographically irresponsibly by using information asymmetries to their advantage by par- ticipating in moral hazard activities and engaging in other immoral and unethical business practices that were centered around localized geography, which ultimately contributed to the global financial crisis. It also examines the roll of financial innovation in regard to the Lehman Brothers Mini-Bond in Hung and its role as a driving force behind China's newly emerging shadow banking sector. It concludes with a policy recommendation and its implication for China's continued economic development.
基金supported in part by the National Natural Science Foundation of China under Grants No.60473072,No.60803151the Joint Fund of Natural Science Foundation of China with the Guangdong Provincial Government under Grant No.U0632004
文摘The TNC IF-T Protocol Binding to TLS(TIPBT) is specified by Trusted Computing Group(TCG) for TNC assessment exchanges.However,the TIPBT cannot be analysed by current Strand Space Model(SSM) because of the different requirements from the traditional security protocols.In order to solve this problem,first,we give an extension of the SSM and point out the TIPBT cannot prevent Man-in-the-Middle(MITM) attacks in some cases based on the extended SSM.Then,we improve the TIPBT and show that the improved TIPBT can resist MITM attacks in the extended SSM.
文摘Based on fuzzy integrated evaluation theory, the safety of coal industry was analyzed, the factors affecting the safety of coal industry was considered, and its fuzzy in- tegrated estimating theory and results were given. Finally this paper proposed a new method of industry safety estimation. According to this method, we can integrate the fac- tors affecting coal industry and deal with the parameters and targets of evaluating factors by quantitative analysis, thus give a scientific and reasonable safety degree analyzing evaluation.
基金Supported by the State Nature Science Foundation (40771085) the National Science & Technology Support Program (2006BZC 18B01-05)
文摘The DPSIR assessment method, which implies the relationships among driving force (D), pressure (P), status (S), impact (I), and response (R), is widely applied by scholars. This paper aims to establish a comprehensive assessment system for regional energy security in eastern coastal China based on the above model using different indicators. Factor analysis and the SPSS statistical analysis software were used to carry out scientific and quantitative assessments. The results indicated that con- tradictions of energy supply and demand as well as environmental pollution are the critical factors that present great challenges to regional energy security in this area. The authors argued that a sustainable, stable, and safe supply energy supply is crucial in solving the aforesaid dilemma, and improving the energy use efficiency is one of the best choices. Some countermeasures and suggestions regarding regional energy supply stability and utilization security were pointed out.
文摘Delay/Disruption-Tolerant Networking(DTN) originated from research on Interplanetary Internet and still today space applications are the most important application field and research stimulus. This paper investigates DTN communications between the Earth and the far side of the Moon, by means of a lunar orbiter acting as relay. After an introductory part, the paper presents a comprehensive analysis of the DTN performance that can be achieved on the identified communication scenario. The focus is on the evaluation of the stateof-the-art ability of Interplanetary Overlay Network(ION), the NASA DTN implementation of Bundle Protocol(BP) and Contact Graph Routing(CGR), to meet the many challenges of the space communication scenario investigated(and more generally of a future interplaynetary Internet): intermittent links, network partitioning, scarce bandwidth, long delays, dynamic routing, handling of high priority and emergency traffic, interoperability issues. A study of security threats and Bundle Security Protocol(BSP) countermeasures complete the work.The many results provided, confirm the essential role of DTN in future space communications.
文摘In despite of fluctuation in recent years, the grain yield in China has been increasing, which relieves the conflict between supply and demand and turns the situation of food security good. However, because of the rapid increase in food consumption, the conflicts of food quality and structure in the supply and demand equilibrium has become more and more obvious and the long-effective mechanism of food security has not been estab-lished yet. It is found that the factors affecting food security in China include the scarcity and dissipation of resources, farmers’ low enthusiasm in planting grain crops and the inappropriateness of the emphasis and measures of macro-economic regulation and control. Therefore, the authors advance to optimize resources allocation, strengthen macro-economic regulation and control and policy stimulation and establish the mechanism of allocating grain production cost, to set up the long-effective mechanism of China food security and keep it stable in the long term.
文摘Similar to conventional automobiles,same safety problems exist in electric vehicles.In the meantime,since its structural and power features are different,electric vehicles have their particular safety problems.Both domestic and international organizations have released some safety standards for electric vehicles which have also been added and complemented along with the development and research of electric vehicles.
基金support from the Science and Technology Programming Project of Shandong Provincein China (No. 2010GSF10808)the National Natural Science Foundation of China (No. 51074100)
文摘From the year of 1949 to the present, the China national coal output has been increasing quickly and became first in the world in 2009. But at the same time, major coal mining accidents still exist nowadays. In order to review the overall situation and provide information on major accidents of coal mines in China, we investigated 26 major coal mining accidents in China between the years of 1949 and 2009 through statistical methods, each of which led to more than 100 fatalities. Statistical characteristics about accident-related factors such as time, death toll, accident reasons, characters and nature of enterprise were analyzed. And some special conclusions have been achieved. For example, although we have made great progress, the safety situation in China coal mining industry is still serious, and the reasons for the mining accidents are all human errors which are not inevitable. Such results may be helpful to prevent major accidents in coal mines. Moreso, based on both the knowledge of other countries which have good safety situation nowadays and the safety management situation of China, we made suggestion on safety management of China coal mining. In conclusion, countermeasures were proposed in accordance with the results of statistical studies and the analyses of problems existed in coal mines, including the perfec- tion of safety supervision organization, the establishment of cooperating agency among government, coal mines and workers, the perfection of safety rules and regulations, the improvement of safety investment, the enhancement of safety training, the development of safety technique, and the development of emer- gency rescue technique and equipment.