A new grey forecasting model based on BP neural network and Markov chain was proposed. In order to combine the grey forecasting model with neural network, an important theorem that the grey differential equation is eq...A new grey forecasting model based on BP neural network and Markov chain was proposed. In order to combine the grey forecasting model with neural network, an important theorem that the grey differential equation is equivalent to the time response model, was proved by analyzing the features of grey forecasting model(GM(1,1)). Based on this, the differential equation parameters were included in the network when the BP neural network was constructed, and the neural network was trained by extracting samples from grey system's known data. When BP network was converged, the whitened grey differential equation parameters were extracted and then the grey neural network forecasting model (GNNM(1,1)) was built. In order to reduce stochastic phenomenon in GNNM(1,1), the state transition probability between two states was defined and the Markov transition matrix was established by building the residual sequences between grey forecasting and actual value. Thus, the new grey forecasting model(MNNGM(1,1)) was proposed by combining Markov chain with GNNM(1,1). Based on the above discussion, three different approaches were put forward for forecasting China electricity demands. By comparing GM(1, 1) and GNNM(1,1) with the proposed model, the results indicate that the absolute mean error of MNNGM(1,1) is about 0.4 times of GNNM(1,1) and 0.2 times of GM(I, 1), and the mean square error of MNNGM(1,1) is about 0.25 times of GNNM(1,1) and 0.1 times of GM(1,1).展开更多
Natural gas output remained stable growth and reached 130.9 billion cubic meters in 2015, 3% higher than the same period last year. Shale gas saw huge progress. China titus became the third country in the world fu!fil...Natural gas output remained stable growth and reached 130.9 billion cubic meters in 2015, 3% higher than the same period last year. Shale gas saw huge progress. China titus became the third country in the world fu!filling commercial development after U.S. attd Canada. Natural gas import growth and growth rate declined obviously, and the imported pipeline gas and LNG totaled 61.2 billion cubic meters in 2015. Apparent natural gas consumption was 186.5 billion cubic meters in 2015, rising by 4.4% as compared with the same period last year, but it hit a historic low. There is higher dozonward pressure on domestic macro economy in 2016. However, natural gas demand will see more rapid growth, propelled by such favorable factors as gas price regulation and environmental protection policies. It is prospected that natural gas market will take a turn for the better than in 2015, and natural gas supply will still be rich in general in 2016.展开更多
Chinese economy has turned from rapid development into new normal. With economic transition, demand for oil and gas decreases as well. Consumed diesel-gasoline ratio keeps declining, and diesel export increases consid...Chinese economy has turned from rapid development into new normal. With economic transition, demand for oil and gas decreases as well. Consumed diesel-gasoline ratio keeps declining, and diesel export increases considerably. Gas demand grows at medium speed, and supply meets demand in general. Alternative energy dominated by gas and electricity will develop faster. As crude oil import right is gradually liberalized, domestic oil market structure will be changed. Oil price drop brings the best opportunity for oil and gas market reform, and environmental protection becomes main force boosting natural gas development.展开更多
Wetlands play a very important role in ecosystems. Qixinghe Wetland is a nature reserve area in northeastern China. In this paper, diatom communities and environmental qualities were investigated at eight sites in Qix...Wetlands play a very important role in ecosystems. Qixinghe Wetland is a nature reserve area in northeastern China. In this paper, diatom communities and environmental qualities were investigated at eight sites in Qixinghe Wetland. This study was to examine diatom species patterns in relation to environmental variables in wetlands, and to use diatoms as indicators to water quality in wetlands and wetland classification. Diatoms were sampled in summers and autumns in 2002 and 2004, during which 180 taxa were identified. Environmental variations in pH, temperature, biochemical oxygen demand (BOD), and chemical oxygen demand (COD) were measured. The seasonal composition and abundance of diatoms changed greatly during the study period. The relationship between diatoms and chemical water quality was estimated statistically. Canonical correspondence analysis (CCA) with forward selection and Monte Carlo permutation tests revealed that all water environmental variables changed during the study period (P<0.05). Among all the parameters, variation in BOD among the sites was a very important determinant of species composition according to the CCA, and BOD decreased from 2002 to 2004. Our results suggest that the water quality had improved during the three-year period because of enhanced environmental protection with less human disturbance. We conclude that diatoms can be used to indicate water quality and habitat conditions in this wetland.展开更多
The trial of oil displacement driven by natural gas injection in China has been successfully accomplished recently for the first time in Zhongyuan Oilfield, Henan Province. This technology is ready for oilfield applic...The trial of oil displacement driven by natural gas injection in China has been successfully accomplished recently for the first time in Zhongyuan Oilfield, Henan Province. This technology is ready for oilfield application in July.展开更多
Modern craflwork art, based on traditional craflwork art, with the constant development of the social production level, gradually forms; and they have a very close relationship. But, today' s modern craftwork art is ...Modern craflwork art, based on traditional craflwork art, with the constant development of the social production level, gradually forms; and they have a very close relationship. But, today' s modern craftwork art is not completed by hands and simple tools and doesn' t depend on the limited natural materials to cope with today' s human life needs, but it must be equipped with the beauty wisdom, industrial science and technology, economic ideas and production and manufacturing technology, so that it can produce the modern craftworks full of the era significance. This paper first analyzes the charm of modern craftwork art design, and then explains how to use the modern craftwork art design, which has a certain practical value and reference significance.展开更多
The first domestic ERWФ610 high-frequency straight-seam steel pipe production line was built in Shanghai Zhongyou TIPO Steel Pipe Co Ltd recently. This steel pipe production line initiated inside China has drawn the ...The first domestic ERWФ610 high-frequency straight-seam steel pipe production line was built in Shanghai Zhongyou TIPO Steel Pipe Co Ltd recently. This steel pipe production line initiated inside China has drawn the attention from many enterprises including PetroChina and CNOOC. It is known that the first batch of products have been transported to the construction site of the West-East Gas Transmission Project.展开更多
Alpine-cold regions are characterized as hypoxia,strong wind,heavy rain,cold climate,huge temperature difference between day and night,and vertical climate. All these make it difficult for an emergency rescue when a n...Alpine-cold regions are characterized as hypoxia,strong wind,heavy rain,cold climate,huge temperature difference between day and night,and vertical climate. All these make it difficult for an emergency rescue when a natural disaster such as earthquake happens. Based on the characteristics of emergency rescue in alpinecold region,several multifunctional protective equipments have been developed by the Quartermaster Equipment Institute of General Logistics Departmen(tGLD)of the Chinese People's Liberation Army(CPLA). These equipments are lightweight,durable and environment adaptable.展开更多
Nowadays human society enters the 21st century, with the rapid economic and technological development, people's material and spiritual requirements has got great satisfaction. However, natural environmental damage br...Nowadays human society enters the 21st century, with the rapid economic and technological development, people's material and spiritual requirements has got great satisfaction. However, natural environmental damage brought by us is also accelerating. Natural disasters happen frequently, including ecological degradation and deterioration, energy resources crisis, greenhouse effect, earthquakes, tsunamis, volcanoes etc. The global crisis has once again waken-up call to mankind. How to properly solve these crises had become a common and urgent responsibility of mankind. This paper will mainly discuss and seek some new potential methods in solving energy crisis and environmental problems from the perspective of automotive and architecture design. As an architect, how to avoid light pollution and reduce heat absorption of roof, increasing heat reflectance of roof are becoming their main and urgent responsibilities. On the other hand, reducing greenhouse effect, researching and developing new low-carbon, low-emission fuel sources are also becoming automotive designers' obligations. Living in harmony with nature & earth is becoming the common human themes of the 21 st century.展开更多
Mechanisms of animal learning and memory were traditionally studied without reference to niche-specific functional considerations. More recently, ecological demands have informed such investigations, most notably with...Mechanisms of animal learning and memory were traditionally studied without reference to niche-specific functional considerations. More recently, ecological demands have informed such investigations, most notably with respect to foraging in birds. In parallel, behavioural ecologists, primarily concerned with functional optimization, have begun to consider the role of mechanistic factors, including cognition, to explain apparent deviations from optimal predictions. In the present paper we discuss the application of laboratory-based constructs and paradigms of cognition to the real-world challenges faced by avian foragers. We argue that such applications have been handicapped by what we term the 'paradigmatic assumption' - the assumption that a given laboratory paradigm maps well enough onto a congruent cognitive mechanism (or cognitive ability) to justify confiation of the two. We present evidence against the paradigmatic assumption and suggest that to achieve a profitable integration between function and mechanism, with respect to animal cognition, a new conceptualization of cognitive mechanisms - functional cogni- tion - is required. This new conceptualization should define cognitive mechanisms based on the informational properties of the animal's environment and the adaptive challenges faced. Cognitive mechanisms must be examined in settings that mimic the im- portant aspects of the natural environment, using customized tasks designed to probe defined aspects of the mechanisms' opera- tion. We suggest that this approach will facilitate investigations of the functional and evolutionary relevance of cognitive mecha- nisms, as well as the patterns of divergence, convergence and specialization of cognitive mechanisms within and between species .展开更多
基金Project(70572090) supported by the National Natural Science Foundation of China
文摘A new grey forecasting model based on BP neural network and Markov chain was proposed. In order to combine the grey forecasting model with neural network, an important theorem that the grey differential equation is equivalent to the time response model, was proved by analyzing the features of grey forecasting model(GM(1,1)). Based on this, the differential equation parameters were included in the network when the BP neural network was constructed, and the neural network was trained by extracting samples from grey system's known data. When BP network was converged, the whitened grey differential equation parameters were extracted and then the grey neural network forecasting model (GNNM(1,1)) was built. In order to reduce stochastic phenomenon in GNNM(1,1), the state transition probability between two states was defined and the Markov transition matrix was established by building the residual sequences between grey forecasting and actual value. Thus, the new grey forecasting model(MNNGM(1,1)) was proposed by combining Markov chain with GNNM(1,1). Based on the above discussion, three different approaches were put forward for forecasting China electricity demands. By comparing GM(1, 1) and GNNM(1,1) with the proposed model, the results indicate that the absolute mean error of MNNGM(1,1) is about 0.4 times of GNNM(1,1) and 0.2 times of GM(I, 1), and the mean square error of MNNGM(1,1) is about 0.25 times of GNNM(1,1) and 0.1 times of GM(1,1).
文摘Natural gas output remained stable growth and reached 130.9 billion cubic meters in 2015, 3% higher than the same period last year. Shale gas saw huge progress. China titus became the third country in the world fu!filling commercial development after U.S. attd Canada. Natural gas import growth and growth rate declined obviously, and the imported pipeline gas and LNG totaled 61.2 billion cubic meters in 2015. Apparent natural gas consumption was 186.5 billion cubic meters in 2015, rising by 4.4% as compared with the same period last year, but it hit a historic low. There is higher dozonward pressure on domestic macro economy in 2016. However, natural gas demand will see more rapid growth, propelled by such favorable factors as gas price regulation and environmental protection policies. It is prospected that natural gas market will take a turn for the better than in 2015, and natural gas supply will still be rich in general in 2016.
文摘Chinese economy has turned from rapid development into new normal. With economic transition, demand for oil and gas decreases as well. Consumed diesel-gasoline ratio keeps declining, and diesel export increases considerably. Gas demand grows at medium speed, and supply meets demand in general. Alternative energy dominated by gas and electricity will develop faster. As crude oil import right is gradually liberalized, domestic oil market structure will be changed. Oil price drop brings the best opportunity for oil and gas market reform, and environmental protection becomes main force boosting natural gas development.
基金Supported by the National Natural Science Foundation of China (Nos.30870157, 31070183)the Natural Science Foundation of Heilongjiang Province, China (No. C200828)+1 种基金the Aid Program for Science and Technology Innovative Research Team (No. KJTD2011-2)the Projects in advance of Harbin Normal University
文摘Wetlands play a very important role in ecosystems. Qixinghe Wetland is a nature reserve area in northeastern China. In this paper, diatom communities and environmental qualities were investigated at eight sites in Qixinghe Wetland. This study was to examine diatom species patterns in relation to environmental variables in wetlands, and to use diatoms as indicators to water quality in wetlands and wetland classification. Diatoms were sampled in summers and autumns in 2002 and 2004, during which 180 taxa were identified. Environmental variations in pH, temperature, biochemical oxygen demand (BOD), and chemical oxygen demand (COD) were measured. The seasonal composition and abundance of diatoms changed greatly during the study period. The relationship between diatoms and chemical water quality was estimated statistically. Canonical correspondence analysis (CCA) with forward selection and Monte Carlo permutation tests revealed that all water environmental variables changed during the study period (P<0.05). Among all the parameters, variation in BOD among the sites was a very important determinant of species composition according to the CCA, and BOD decreased from 2002 to 2004. Our results suggest that the water quality had improved during the three-year period because of enhanced environmental protection with less human disturbance. We conclude that diatoms can be used to indicate water quality and habitat conditions in this wetland.
文摘The trial of oil displacement driven by natural gas injection in China has been successfully accomplished recently for the first time in Zhongyuan Oilfield, Henan Province. This technology is ready for oilfield application in July.
文摘Modern craflwork art, based on traditional craflwork art, with the constant development of the social production level, gradually forms; and they have a very close relationship. But, today' s modern craftwork art is not completed by hands and simple tools and doesn' t depend on the limited natural materials to cope with today' s human life needs, but it must be equipped with the beauty wisdom, industrial science and technology, economic ideas and production and manufacturing technology, so that it can produce the modern craftworks full of the era significance. This paper first analyzes the charm of modern craftwork art design, and then explains how to use the modern craftwork art design, which has a certain practical value and reference significance.
文摘The first domestic ERWФ610 high-frequency straight-seam steel pipe production line was built in Shanghai Zhongyou TIPO Steel Pipe Co Ltd recently. This steel pipe production line initiated inside China has drawn the attention from many enterprises including PetroChina and CNOOC. It is known that the first batch of products have been transported to the construction site of the West-East Gas Transmission Project.
文摘Alpine-cold regions are characterized as hypoxia,strong wind,heavy rain,cold climate,huge temperature difference between day and night,and vertical climate. All these make it difficult for an emergency rescue when a natural disaster such as earthquake happens. Based on the characteristics of emergency rescue in alpinecold region,several multifunctional protective equipments have been developed by the Quartermaster Equipment Institute of General Logistics Departmen(tGLD)of the Chinese People's Liberation Army(CPLA). These equipments are lightweight,durable and environment adaptable.
文摘Nowadays human society enters the 21st century, with the rapid economic and technological development, people's material and spiritual requirements has got great satisfaction. However, natural environmental damage brought by us is also accelerating. Natural disasters happen frequently, including ecological degradation and deterioration, energy resources crisis, greenhouse effect, earthquakes, tsunamis, volcanoes etc. The global crisis has once again waken-up call to mankind. How to properly solve these crises had become a common and urgent responsibility of mankind. This paper will mainly discuss and seek some new potential methods in solving energy crisis and environmental problems from the perspective of automotive and architecture design. As an architect, how to avoid light pollution and reduce heat absorption of roof, increasing heat reflectance of roof are becoming their main and urgent responsibilities. On the other hand, reducing greenhouse effect, researching and developing new low-carbon, low-emission fuel sources are also becoming automotive designers' obligations. Living in harmony with nature & earth is becoming the common human themes of the 21 st century.
文摘Mechanisms of animal learning and memory were traditionally studied without reference to niche-specific functional considerations. More recently, ecological demands have informed such investigations, most notably with respect to foraging in birds. In parallel, behavioural ecologists, primarily concerned with functional optimization, have begun to consider the role of mechanistic factors, including cognition, to explain apparent deviations from optimal predictions. In the present paper we discuss the application of laboratory-based constructs and paradigms of cognition to the real-world challenges faced by avian foragers. We argue that such applications have been handicapped by what we term the 'paradigmatic assumption' - the assumption that a given laboratory paradigm maps well enough onto a congruent cognitive mechanism (or cognitive ability) to justify confiation of the two. We present evidence against the paradigmatic assumption and suggest that to achieve a profitable integration between function and mechanism, with respect to animal cognition, a new conceptualization of cognitive mechanisms - functional cogni- tion - is required. This new conceptualization should define cognitive mechanisms based on the informational properties of the animal's environment and the adaptive challenges faced. Cognitive mechanisms must be examined in settings that mimic the im- portant aspects of the natural environment, using customized tasks designed to probe defined aspects of the mechanisms' opera- tion. We suggest that this approach will facilitate investigations of the functional and evolutionary relevance of cognitive mecha- nisms, as well as the patterns of divergence, convergence and specialization of cognitive mechanisms within and between species .