In a production process, the actual energy consumption is greatly affected by the production state. Certain processing operations are classified into six states, including normal production, abnormal production, plann...In a production process, the actual energy consumption is greatly affected by the production state. Certain processing operations are classified into six states, including normal production, abnormal production, planned overhaul, unplanned overhaul, transitional period from unplanned overhaul to normal production (referred for short as unplanned transition) and transitional period from planned overhaul to normal production (referred for short as planned transition). The article takes the analysis of relationship between different states of a certain processing operation and corresponding energy consumptions as a startup point to develop a process energy intensity formula with variables of operating rate, yielding rate and operating frequency, etc. This process energy intensity formula can be used to analyze effectively the pattern of impact exerted by different state variables on energy consumption.展开更多
China has witnessed rapid economic development since 1978, and during the time, energy production and consumption developed at a tremendous speed as well. Energy efficiency which can be measured by energy consumption ...China has witnessed rapid economic development since 1978, and during the time, energy production and consumption developed at a tremendous speed as well. Energy efficiency which can be measured by energy consumption per unit of GDP, however, experienced continuous decrease. Theoretically, the change of energy efficiency can be attributed to industry structural change and technological change. In order to explain the transformation of Chinese energy efficiency, we adopt logarithmic mean Divisia index techniques to decompose changes in energy intensity in the period of 1994-2005. We find that technological change is the dominant contributor in the decline of energy intensity, but the contribution has declined since 2001. The change in industry structure has decreased the energy intensity before 1998, but raised the intensity after 1998. Decomposed technological effects for all sectors indicate that technological progresses in high energy consuming industries such as raw chemical materials and chemical products, smelting and pressing of ferrous metals, manufacture of non-metallic mineral products and household contribute are the principal drivers of China's declining energy intensity.展开更多
This article explores the effects of investment upon energy intensity by applying a unique panel data of China's 27 provinces between 2004 and 2013.In addition,it also particularly stuthes other factors,such as en...This article explores the effects of investment upon energy intensity by applying a unique panel data of China's 27 provinces between 2004 and 2013.In addition,it also particularly stuthes other factors,such as energy price,economic structure,and urbanization.The results,based on four econometric regression model results,suggest that in general,the indigenous investment on research and development is a more powerful tool to decrease China's energy intensity regardless of region disparity.The foreign direct investment(FDI) has a prominent but not persistent effect on energy intensity.However,the outward direct investment has not shown its significant impact on energy intensity.At the level of an aggregate economy and China's eastern region,the results demonstrate that FDI improves energy efficiency significantly.For the central and western provinces,FDI does not support the similar conclusion.Based on these analyses,we present the corresponding regional policies for policymakers.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
In this paper,the authors have empirically analyzed the convergence in per capita GDP gap and the convergence in the variation of energy intensity with respect to the change of per capita GDP between China and eight d...In this paper,the authors have empirically analyzed the convergence in per capita GDP gap and the convergence in the variation of energy intensity with respect to the change of per capita GDP between China and eight developed countries.Then,the authors run a regression on the impact of decisive factors of economic growth on energy intensity and its change,so as to find out the economic mechanism of energy intensity gap changing with respect to the variation of economic growth.This study concludes that:First,there is a convergence in per capita GDP gap between China and the eight developed countries.With the convergence in per capita GDP gap,the energy intensity gap between China and eight different countries also converge,and the convergence rate of the latter is faster than that of the former,i.e.if the per capita GDP gap between China and the eight developed countries decreases by 1%,the energy intensity gap between them will correspondingly decrease by 1.552%.Second,the energy intensity decreases with the improvement of industrial structure,the rising of energy prices,the advances of technology,and the expansion of investment in fixed assets,and it slightly increases with the increase of FDI.Third,the energy intensity gap between China and eight developed countries narrows with the lessening of the difference in fixed assets investment,energy prices,and technological progress between China and eight developed countries,yet increases with the narrowing of the difference in FDI,and has no significant correlation with the difference in industrial structure.Fourth,the narrowing of difference in per capita GDP between China and the eight developed countries can result in the lessening of energy intensity gap,whose economic mechanism is that the decisive factors,such as difference in investment,technology,and the competition mechanism of prices,which can determine the difference in economic growth,can significantly affect the energy intensity gap.展开更多
AIM: To investigate the effect of intensive vs conventional insulin therapy on perioperative nutritional substrates metabolism in patients undergoing radical distal gastrectomy. METHODS: Within 24 h of intensive care ...AIM: To investigate the effect of intensive vs conventional insulin therapy on perioperative nutritional substrates metabolism in patients undergoing radical distal gastrectomy. METHODS: Within 24 h of intensive care unit management, patients with gastric cancer were enrolled after written informed consent and randomized to the intensive insulin therapy (IIT) group to keep glucose levels from 4.4 to 6.1 mmol/L or the conventional insulin therapy (CIT) group to keep levels less than 10 mmol/L. Resting energy expenditure (REE), respiratory quotient (RQ), resting energy expenditure per kilogram (REE/kg), and the lipid oxidation rate were monitored by the indirect calorimeter of calcium citrate malate nutrition metabolism investigation system. The changes in body composition were analyzed by multi-frequency bioimpedance analysis. Blood fasting glucose and insulin concentration were measured for assessment of Homeostasis model assessment of insulin resistance. RESULTS: Sixty patients were enrolled. Compared with preoperative baseline, postoperative REE increased by over 22.15% and 11.07%; REE/kg rose up to 27.22 ± 1.33 kcal/kg and 24.72 ± 1.43 kcal/kg; RQ decreased to 0.759 ± 0.034 and 0.791 ± 0.037; the lipid oxidation ratio was up to 78.25% ± 17.74% and 67.13% ± 12.76% supported by parenteral nutrition solutions from 37.56% ± 11.64% at the baseline; the level of Ln-HOMA-IR went up dramatically (P < 0.05, respectively) on postoperative days 1 and 3 in the IIT group. Meanwhile the concentration of total protein, albumin and triglyceride declined significantly on postoperative days 1 and 3 compared with pre-operative levels (P < 0.05, respectively). Compared with the CIT group, IIT reduced the REE/kg level (27.22 ± 1.33 kcal/kg vs 29.97 ± 1.47 kcal/kg, P = 0.008; 24.72 ± 1.43 kcal/kg vs 25.66 ± 1.63 kcal/kg, P = 0.013); and decreased the Ln-HOMA-IR score (P = 0.019, 0.028) on postoperative days 1 and 3; IIT decreased the level of CRP on postoperative days 1 and 3 (P = 0.017, 0.006); the total protein and albumin concentrations in the IIT group were greater than those in the CIT group (P = 0.023, 0.009). Postoperative values of internal cell fluid (ICF), fat mass, protein mass (PM), muscle mass, free fat mass and body weight decreased obviously on postoperative 7th day compared with the preoperative baseline in the CIT group (P < 0.05, respectively). IIT reduced markedly consumption of fat mass, PM and ICF compared with CIT (P = 0.009 to 0.026). CONCLUSION: There were some benefits of IIT in decreasing the perioperative insulin resistance state, reducing energy expenditure and consumption of proteins and lipids tissue in patients undergoing gastrectomy.展开更多
Fractal and chaotic laws of engineering structures are discussed in this paper, it means that the intrinsic essences and laws on dynamic systems which are made from seismic dissipated energy intensity E d and int...Fractal and chaotic laws of engineering structures are discussed in this paper, it means that the intrinsic essences and laws on dynamic systems which are made from seismic dissipated energy intensity E d and intensity of seismic dissipated energy moment I e are analyzed. Based on the intrinsic characters of chaotic and fractal dynamic system of E d and I e, three kinds of approximate dynamic models are rebuilt one by one: index autoregressive model, threshold autoregressive model and local-approximate autoregressive model. The innate laws, essences and systematic error of evolutional behavior I e are explained over all, the short-term behavior predictability and long-term behavior probability of which are analyzed in the end. That may be valuable for earthquake-resistant theory and analysis method in practical engineering structures.展开更多
In this paper,the authors have analyzed the relationship between energy intensity gap and GDP per worker gap of China's western and eastern provinces over the period 1997-2006.Using panel data model with lag adjus...In this paper,the authors have analyzed the relationship between energy intensity gap and GDP per worker gap of China's western and eastern provinces over the period 1997-2006.Using panel data model with lag adjustment,taking the above provinces and six industrial sectors (agriculture,forestry,animal husbandry,and fisheries,industry,construction industry,transport,storage and post & telecommunications,wholesale and retail trades & catering industry,and other sectors of tertiary industry.) as the investigated subjects,the authors have conducted empirical study on the convergence of GDP per worker gap and the convergence of energy intensity gap with respect to the variation of GDP per worker gap,and have concluded that:First,the GDP per worker gap of the six industrial sectors and provinces are convergent,and of this,the convergence rate of GDP per worker gap of Construction Industry is the fastest,while that of Industry is the slowest.Second,the overall energy intensity gap between eastern and western provinces is convergent,that is,with the narrowing of GDP per worker gap between eastern and western provinces,the energy intensity gap converges,but its convergence rate is slower than that of GDP per worker gap.Third,energy intensity gap between various industrial sectors of the east and the west is either convergent or divergent,and there are differences.The energy intensity gap of agriculture,forestry,animal husbandry,and fisheries,industry,and construction industry is convergent,while that of the other three industrial sectors is divergent.Fourth,the convergence of the overall energy intensity of the western provinces is not in conformity with the convergence of the various industrial sectors,and there are significant differences,indicating that the western provinces and autonomous regions should take measures to more effectively improve their overall energy utilization efficiency at the industrial sector level.展开更多
Empirical studies on the effects of China-African economic relations on energy intensity in Africa are scarce.To fill the gap in the literature,this study investigates the technology spillover effects of the China-Afr...Empirical studies on the effects of China-African economic relations on energy intensity in Africa are scarce.To fill the gap in the literature,this study investigates the technology spillover effects of the China-Africa trade and investment relations on energy intensity.It uses both linear and nonlinear dynamic panel estimation methods for 42 African countries from 2003 to 2015.The results show that China's technology spillover through imports significantly reduces energy intensity in Africa.The findings are consistent across specifications and sample groups.Moreover,the technology spillover coming from foreign direct investment(FDI)improves energy intensity,particularly in lower-middle-income African countries.The dynamic threshold estimation results show that countries'absorptive ability is important for technology spillover effects of FDI and imports on energy intensity.The results suggest that countries'absorptive capacity should be increased to maximize the benefits of trade and investment technology spillovers.展开更多
The present study aims to better understand the relationship between energy intensity and its determinants including energy price, technological progress, economic structure, and energy mix using the autoregressive di...The present study aims to better understand the relationship between energy intensity and its determinants including energy price, technological progress, economic structure, and energy mix using the autoregressive distributed lag(ARDL) bounds approach and vector error correction model technique. Based on China's time series over 1985-2014, the ARDL bounds approach yields empirical evidence that confirms the existence of long run relationship between energy price, technological progress, economic structure, energy mix, and energy intensity. The results show that technological progress is an important driver for the declining energy intensity in short and long run. Energy price has not been demonstrated as an important role in decreasing energy intensity in the short run. The high share of coal use in total energy use may be responsible for China's high energy intensity.However, the relative change in economic sectors plays a minor role in energy intensity reduction during the past years. In the long run, technological progress, energy mix and energy prices Granger cause energy intensity, but not vice versa except for the energy mix.展开更多
Different types of solvents were chosen, and their solubleexpansion ability to unsaturated polyster- resin was determined. Theprinciple and method of deter- mining the cohesive energy density ofunsaturated polyster re...Different types of solvents were chosen, and their solubleexpansion ability to unsaturated polyster- resin was determined. Theprinciple and method of deter- mining the cohesive energy density ofunsaturated polyster resin by using the swelling method are presentedin details.展开更多
The embodied energy/CO2 of buildings in China and Japan, which reflects the characteristic industrial efficiency ofbui|ding materials, is described in this paper. The energy consumption and CO2 intensities for the do...The embodied energy/CO2 of buildings in China and Japan, which reflects the characteristic industrial efficiency ofbui|ding materials, is described in this paper. The energy consumption and CO2 intensities for the dominant materials used in buildings are derived from the energy consumption in factories, and the energy consumption to produce equipment is derived from IO (input/output) analysis in order to compare the embodied energy/CO2 for buildings between China and Japan based on the same estimation method. Although the energy consumption of structures in China is two to three times greater than in Japan, the interior finish and air conditioning equipment, for example, are simpler and smaller. As a result, the embodied energy/CO2 of office buildings in China is only 10% to 20% greater than that of Japanese office buildings. Thus, the embodied energy/CO2 of buildings depends on both industrial efficiencies and building design trends of the country.展开更多
The objective of this research is to quantify the EEC (embodied energy/CO2) of a building. The EEC represents the energy consumption and CO2 emissions at individual phases of a building's life-cycle, such as constr...The objective of this research is to quantify the EEC (embodied energy/CO2) of a building. The EEC represents the energy consumption and CO2 emissions at individual phases of a building's life-cycle, such as construction (including manufacture of materials and equipment), renewal (including repair work) and demolition. Energy and CO2 emission intensities in terms of 401 sectors were calculated, using the 2005 I-O (input-output) table in Japan. According to our case study conducted from the construction phase to demolition, the EC (embodied CO2) of an office building used for 60 years is 12,044 t-CO2 and 1,093 kg-CO2/m^2 in total. CO2 equivalent emissions (CO2e) by Freon gases, contained in building materials, equipment and devices, were also calculated. As the results, CO2e by insulators was 2% of the building's EC and CO2e by refrigerants was 9%-12% of the building's EC. It is important to keep reducing emissions of Freon gases contained in refrigerators.展开更多
Due to increased tourist activity,many cities now have a large number of hotel buildings.It is necessary to establish measures to evaluate energy use intensity to effectively manage energy consumption in this sector.T...Due to increased tourist activity,many cities now have a large number of hotel buildings.It is necessary to establish measures to evaluate energy use intensity to effectively manage energy consumption in this sector.This study uses a combined strategy to establish an energy benchmark for hotel buildings in Vietnam.First,a survey and analysis of actual building stock data of 50 hotels in Danang,Vietnam,was conducted.The survey-based benchmark and its related data was then used to build a reference energy model to estimate an energy benchmark for other climatic regions in Vietnam by using the energy simulation method.The results reveal that the average energy use intensity for hotels in Danang was 87.4 kWh/m2.year or 8628.6 kWh/guestroom.year.However,this study proposes that because of the differing expectations of comfort standards,hotels of different grades should have separate benchmarks.This study also proposes an energy intensity-based rating scale,including 7 grades from the least energy intensive(grade A)to the most energy intensive(grade G),which can be used to manage,label,or encourage sustainable energy use in hotel buildings.The relationship between the energy use intensity and the occupancy rate of the hotels was reported,compared,and explained.It was found that occupancy rate has no significant impact on the energy use intensity.From the survey result,some predictive models were developed to estimate annual energy consumption of hotel buildings based on their grades.The simulated benchmarks for other regions were also achieved.The results demonstrate many potential applications in the management,design and construction,and renovation of this building type.展开更多
Consider the task of tracking the energy use of an entire city while also working to reduce it by 50%in 17 years.How would you go about tracking and verifying such reductions?Further,how would this be accomplished in ...Consider the task of tracking the energy use of an entire city while also working to reduce it by 50%in 17 years.How would you go about tracking and verifying such reductions?Further,how would this be accomplished in a city without a database of building-specific characteristics and no energy reporting law?To begin,let’s consider what this task would look like for one building.Where to start?Let’s try with a performance metric and point of comparison.Just as cars gauge performance by MPG,and pitchers by ERA,buildings can use Energy Use Intensity(EUI)as a performance metric.Measured in Energy/ft2/year,EUI standardizes energy use per square foot,allowing for comparison between many buildings.EUI is a snapshot of building performance over one year’s time.It is relatively easy to calculate a building’s EUI if their energy usage is known,but in order to gauge performance over a longer period,a constant comparison point must be established so that evaluation is consistent.Called the baseline,this comparison point can be established as a past year,a future goal,or the average performance of similar buildings.This paper covers the work of the Pittsburgh 2030 District team in formulating an energy performance baseline for each building in Downtown Pittsburgh for purposes of tracking energy use reduction towards the 50%reduction goals of The 2030 Challenge.Pittsburgh is a city with a large stock of aging buildings,without mandatory benchmarking laws,and no single publicly accessible real estate profile by property.Thus,the energy baseline methods included in this paper summarize efforts to create such an aggregated property characteristic database and associated energy baseline for Downtown Pittsburgh;it is the hope of the authors that these efforts will assist similar cities in mirroring 2030 District goal setting and achievement for building energy.展开更多
While being developed, Lao society and economy have gradually shifted from agricultural-based to service-industrial oriented one. As a result, final energy consumption has rapidly changed. This paper studied a trend o...While being developed, Lao society and economy have gradually shifted from agricultural-based to service-industrial oriented one. As a result, final energy consumption has rapidly changed. This paper studied a trend of changes in final energy intensity by looking at sector-wide energy demand and shares in gross domestic products. It was found that intensity of total final energy consumption in Lao PDR (People's Democratic Republic) gradually decreased during the last decades. This was resulted of high stable economic growth and comparatively slow growth in energy demand. Furthermore, Lao economy still relays mainly on less-energy intensive economic sectors, such as services and traditional agriculture. Although energy intensities of the industry, transportation and services sectors continuously decreased, but have slowed down in recent years. Moreover, energy intensity of agricultural sector continues increasing. All these facts give a ground for thinking that in the future, when socio-economic development of the country will reach higher level, there will be more energy consuming activities, then energy demand will increase while economic growth will slow down, and therefore, energy intensity is to increase. Knowledge on trend of energy consumption changes would be useful for predicting energy demand and securing energy supply in the future.展开更多
In recent years,large high efficiency and Net-Zero Energy Buildings(NZEB)are becoming a reality that are setting construction and energy benchmarks for the industry.As part of this significant effort,in 2018,Mohawk Co...In recent years,large high efficiency and Net-Zero Energy Buildings(NZEB)are becoming a reality that are setting construction and energy benchmarks for the industry.As part of this significant effort,in 2018,Mohawk College opened the 8,981 m^(2)(96,670 ft2)Joyce Centre for Partnership and Innovation(JCPI)building in Hamilton,Ontario;becoming Canada’s largest NZEB and zero-carbon institutional facility.The building integrated a high-efficiency design,construction materials,and technologies;as well as renewable energy technologies to significantly reduce its annual energy consumption and greenhouse gas emissions.Furthermore,the JCPI building was also designed as a living lab where students,faculty,researchers and industry are able to monitor and validate the performance of this state-of-the-art facility.The building was designed to have an energy use intensity of 73 kWh/m^(2)·year(0.26 GJ/m^(2)·year);hence,potentially consuming approximately 80%less energy than the average educational service building in Ontario.This paper gives an overview of the design criteria and technologies that were considered to achieve this innova-tive building.展开更多
We demonstrate that the intensity of the energy emission obtained from the Joule-Lenz law applied to the case of a single free-electron particle or a harmonic oscillator does not depend on the change of size of the co...We demonstrate that the intensity of the energy emission obtained from the Joule-Lenz law applied to the case of a single free-electron particle or a harmonic oscillator does not depend on the change of size of the corresponding energy interval () and time interval () because the ratio of??to??representing the emission rate remains constant. For a free electron, this property holds on condition the calculations of??and??refer to the states having a sufficiently large quantum index n.展开更多
Load behavior is one of the most critical factors affecting mills' energy consumption and grinding efficiency, and is greatly affected by the liner profiles. Generally, as liner profiles vary, the ball mill performan...Load behavior is one of the most critical factors affecting mills' energy consumption and grinding efficiency, and is greatly affected by the liner profiles. Generally, as liner profiles vary, the ball mill performances are extremely different. In order to study the performance of the ball mill with regular polygon angle-spiral liners(RPASLs), experimental and numerical studies on three types of RPASLs, including regular quadrilateral, pentagonal and hexagonal, are carried out. For the fine product of desired size, two critical parameters are analyzed: the energy input to the mill per unit mass of the fine product, E*, and the rate of production of the fine product, F*. Results show that the optimal structure of RPASLs is Quadrilateral ASL with an assembled angle of 50°. Under this condition, the specific energy consumption E* has the minimum value of 303 J per fine product and the production rate F* has the maximum value of 0.323. The production rate F* in the experimental result is consistent with the specific collision energy intensity to total collision energy intensity ratio Es/Et in the simulation. The relations between the production rate F* and the specific energy consumption E* with collision energy intensity Es and Et are obtained. The simulation result reveals the essential reason for the experimental phenomenon and correlates the mill performance parameter to the collision energy between balls, which could guide the practical application for Quadrilateral ASL.展开更多
By modeling metal as a special piezoelectric material with extremely small piezoelectricity and extremely large permittivity, we have obtained the analytical solutions for an interracial permeable crack in metal/piezo...By modeling metal as a special piezoelectric material with extremely small piezoelectricity and extremely large permittivity, we have obtained the analytical solutions for an interracial permeable crack in metal/piezoelectric bimaterials by means of the generalized Stroh formalism. The analysis shows that the stress fields near a permeable interracial crack tip are usually with three types of singularities: r^-1/2±iε and r^-1/2. Further numerical calculation on the oscillatory index ε are given for 28 types of metal/piezoelectric bimaterials combined by seven commercial piezoelectric materials: PZT-4, BaTiO3, PZT-5H, PZT-6B, PZT-7A, P-7 and PZT-PIC 151 and four metals: copper, silver, lead and aluminum, respectively. The explicit expressions of the crack tip energy release rate (ERR) and the crack tip generalized stress intensity factors (GSIF) are obtained. It is found that both the ERR and GSIF are independent of the electric displacement loading, although they seriously depends on the mechanical loadings.展开更多
文摘In a production process, the actual energy consumption is greatly affected by the production state. Certain processing operations are classified into six states, including normal production, abnormal production, planned overhaul, unplanned overhaul, transitional period from unplanned overhaul to normal production (referred for short as unplanned transition) and transitional period from planned overhaul to normal production (referred for short as planned transition). The article takes the analysis of relationship between different states of a certain processing operation and corresponding energy consumptions as a startup point to develop a process energy intensity formula with variables of operating rate, yielding rate and operating frequency, etc. This process energy intensity formula can be used to analyze effectively the pattern of impact exerted by different state variables on energy consumption.
基金funded by National Science Foundation (Grant No.40535027,40871065)program of Enviromental Education Base of Chinese University Students
文摘China has witnessed rapid economic development since 1978, and during the time, energy production and consumption developed at a tremendous speed as well. Energy efficiency which can be measured by energy consumption per unit of GDP, however, experienced continuous decrease. Theoretically, the change of energy efficiency can be attributed to industry structural change and technological change. In order to explain the transformation of Chinese energy efficiency, we adopt logarithmic mean Divisia index techniques to decompose changes in energy intensity in the period of 1994-2005. We find that technological change is the dominant contributor in the decline of energy intensity, but the contribution has declined since 2001. The change in industry structure has decreased the energy intensity before 1998, but raised the intensity after 1998. Decomposed technological effects for all sectors indicate that technological progresses in high energy consuming industries such as raw chemical materials and chemical products, smelting and pressing of ferrous metals, manufacture of non-metallic mineral products and household contribute are the principal drivers of China's declining energy intensity.
基金supported by the Fundamental Research Funds for the Central Universities:[Grant Number JBK1607K05]
文摘This article explores the effects of investment upon energy intensity by applying a unique panel data of China's 27 provinces between 2004 and 2013.In addition,it also particularly stuthes other factors,such as energy price,economic structure,and urbanization.The results,based on four econometric regression model results,suggest that in general,the indigenous investment on research and development is a more powerful tool to decrease China's energy intensity regardless of region disparity.The foreign direct investment(FDI) has a prominent but not persistent effect on energy intensity.However,the outward direct investment has not shown its significant impact on energy intensity.At the level of an aggregate economy and China's eastern region,the results demonstrate that FDI improves energy efficiency significantly.For the central and western provinces,FDI does not support the similar conclusion.Based on these analyses,we present the corresponding regional policies for policymakers.
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In this paper,the authors have empirically analyzed the convergence in per capita GDP gap and the convergence in the variation of energy intensity with respect to the change of per capita GDP between China and eight developed countries.Then,the authors run a regression on the impact of decisive factors of economic growth on energy intensity and its change,so as to find out the economic mechanism of energy intensity gap changing with respect to the variation of economic growth.This study concludes that:First,there is a convergence in per capita GDP gap between China and the eight developed countries.With the convergence in per capita GDP gap,the energy intensity gap between China and eight different countries also converge,and the convergence rate of the latter is faster than that of the former,i.e.if the per capita GDP gap between China and the eight developed countries decreases by 1%,the energy intensity gap between them will correspondingly decrease by 1.552%.Second,the energy intensity decreases with the improvement of industrial structure,the rising of energy prices,the advances of technology,and the expansion of investment in fixed assets,and it slightly increases with the increase of FDI.Third,the energy intensity gap between China and eight developed countries narrows with the lessening of the difference in fixed assets investment,energy prices,and technological progress between China and eight developed countries,yet increases with the narrowing of the difference in FDI,and has no significant correlation with the difference in industrial structure.Fourth,the narrowing of difference in per capita GDP between China and the eight developed countries can result in the lessening of energy intensity gap,whose economic mechanism is that the decisive factors,such as difference in investment,technology,and the competition mechanism of prices,which can determine the difference in economic growth,can significantly affect the energy intensity gap.
基金Supported by The Health Science and Technology Development Project of Shandong, No. 2005HZ024
文摘AIM: To investigate the effect of intensive vs conventional insulin therapy on perioperative nutritional substrates metabolism in patients undergoing radical distal gastrectomy. METHODS: Within 24 h of intensive care unit management, patients with gastric cancer were enrolled after written informed consent and randomized to the intensive insulin therapy (IIT) group to keep glucose levels from 4.4 to 6.1 mmol/L or the conventional insulin therapy (CIT) group to keep levels less than 10 mmol/L. Resting energy expenditure (REE), respiratory quotient (RQ), resting energy expenditure per kilogram (REE/kg), and the lipid oxidation rate were monitored by the indirect calorimeter of calcium citrate malate nutrition metabolism investigation system. The changes in body composition were analyzed by multi-frequency bioimpedance analysis. Blood fasting glucose and insulin concentration were measured for assessment of Homeostasis model assessment of insulin resistance. RESULTS: Sixty patients were enrolled. Compared with preoperative baseline, postoperative REE increased by over 22.15% and 11.07%; REE/kg rose up to 27.22 ± 1.33 kcal/kg and 24.72 ± 1.43 kcal/kg; RQ decreased to 0.759 ± 0.034 and 0.791 ± 0.037; the lipid oxidation ratio was up to 78.25% ± 17.74% and 67.13% ± 12.76% supported by parenteral nutrition solutions from 37.56% ± 11.64% at the baseline; the level of Ln-HOMA-IR went up dramatically (P < 0.05, respectively) on postoperative days 1 and 3 in the IIT group. Meanwhile the concentration of total protein, albumin and triglyceride declined significantly on postoperative days 1 and 3 compared with pre-operative levels (P < 0.05, respectively). Compared with the CIT group, IIT reduced the REE/kg level (27.22 ± 1.33 kcal/kg vs 29.97 ± 1.47 kcal/kg, P = 0.008; 24.72 ± 1.43 kcal/kg vs 25.66 ± 1.63 kcal/kg, P = 0.013); and decreased the Ln-HOMA-IR score (P = 0.019, 0.028) on postoperative days 1 and 3; IIT decreased the level of CRP on postoperative days 1 and 3 (P = 0.017, 0.006); the total protein and albumin concentrations in the IIT group were greater than those in the CIT group (P = 0.023, 0.009). Postoperative values of internal cell fluid (ICF), fat mass, protein mass (PM), muscle mass, free fat mass and body weight decreased obviously on postoperative 7th day compared with the preoperative baseline in the CIT group (P < 0.05, respectively). IIT reduced markedly consumption of fat mass, PM and ICF compared with CIT (P = 0.009 to 0.026). CONCLUSION: There were some benefits of IIT in decreasing the perioperative insulin resistance state, reducing energy expenditure and consumption of proteins and lipids tissue in patients undergoing gastrectomy.
文摘Fractal and chaotic laws of engineering structures are discussed in this paper, it means that the intrinsic essences and laws on dynamic systems which are made from seismic dissipated energy intensity E d and intensity of seismic dissipated energy moment I e are analyzed. Based on the intrinsic characters of chaotic and fractal dynamic system of E d and I e, three kinds of approximate dynamic models are rebuilt one by one: index autoregressive model, threshold autoregressive model and local-approximate autoregressive model. The innate laws, essences and systematic error of evolutional behavior I e are explained over all, the short-term behavior predictability and long-term behavior probability of which are analyzed in the end. That may be valuable for earthquake-resistant theory and analysis method in practical engineering structures.
基金sponsored by"Project Fund of Humanities and Social Sciences of Ministry of Edu-cation"(Grant No.:09YJA790157)"Proprietary Research Project of Humanities and Social Sciences of Wuhan University"(Grant No.:09ZZKY032)
文摘In this paper,the authors have analyzed the relationship between energy intensity gap and GDP per worker gap of China's western and eastern provinces over the period 1997-2006.Using panel data model with lag adjustment,taking the above provinces and six industrial sectors (agriculture,forestry,animal husbandry,and fisheries,industry,construction industry,transport,storage and post & telecommunications,wholesale and retail trades & catering industry,and other sectors of tertiary industry.) as the investigated subjects,the authors have conducted empirical study on the convergence of GDP per worker gap and the convergence of energy intensity gap with respect to the variation of GDP per worker gap,and have concluded that:First,the GDP per worker gap of the six industrial sectors and provinces are convergent,and of this,the convergence rate of GDP per worker gap of Construction Industry is the fastest,while that of Industry is the slowest.Second,the overall energy intensity gap between eastern and western provinces is convergent,that is,with the narrowing of GDP per worker gap between eastern and western provinces,the energy intensity gap converges,but its convergence rate is slower than that of GDP per worker gap.Third,energy intensity gap between various industrial sectors of the east and the west is either convergent or divergent,and there are differences.The energy intensity gap of agriculture,forestry,animal husbandry,and fisheries,industry,and construction industry is convergent,while that of the other three industrial sectors is divergent.Fourth,the convergence of the overall energy intensity of the western provinces is not in conformity with the convergence of the various industrial sectors,and there are significant differences,indicating that the western provinces and autonomous regions should take measures to more effectively improve their overall energy utilization efficiency at the industrial sector level.
文摘Empirical studies on the effects of China-African economic relations on energy intensity in Africa are scarce.To fill the gap in the literature,this study investigates the technology spillover effects of the China-Africa trade and investment relations on energy intensity.It uses both linear and nonlinear dynamic panel estimation methods for 42 African countries from 2003 to 2015.The results show that China's technology spillover through imports significantly reduces energy intensity in Africa.The findings are consistent across specifications and sample groups.Moreover,the technology spillover coming from foreign direct investment(FDI)improves energy intensity,particularly in lower-middle-income African countries.The dynamic threshold estimation results show that countries'absorptive ability is important for technology spillover effects of FDI and imports on energy intensity.The results suggest that countries'absorptive capacity should be increased to maximize the benefits of trade and investment technology spillovers.
文摘The present study aims to better understand the relationship between energy intensity and its determinants including energy price, technological progress, economic structure, and energy mix using the autoregressive distributed lag(ARDL) bounds approach and vector error correction model technique. Based on China's time series over 1985-2014, the ARDL bounds approach yields empirical evidence that confirms the existence of long run relationship between energy price, technological progress, economic structure, energy mix, and energy intensity. The results show that technological progress is an important driver for the declining energy intensity in short and long run. Energy price has not been demonstrated as an important role in decreasing energy intensity in the short run. The high share of coal use in total energy use may be responsible for China's high energy intensity.However, the relative change in economic sectors plays a minor role in energy intensity reduction during the past years. In the long run, technological progress, energy mix and energy prices Granger cause energy intensity, but not vice versa except for the energy mix.
文摘Different types of solvents were chosen, and their solubleexpansion ability to unsaturated polyster- resin was determined. Theprinciple and method of deter- mining the cohesive energy density ofunsaturated polyster resin by using the swelling method are presentedin details.
基金supported in part by the IEA/EBC/Annex57 Committee of Japan,organized through the IBEC(Institute for Building Environment and Energy Conservation).
文摘The embodied energy/CO2 of buildings in China and Japan, which reflects the characteristic industrial efficiency ofbui|ding materials, is described in this paper. The energy consumption and CO2 intensities for the dominant materials used in buildings are derived from the energy consumption in factories, and the energy consumption to produce equipment is derived from IO (input/output) analysis in order to compare the embodied energy/CO2 for buildings between China and Japan based on the same estimation method. Although the energy consumption of structures in China is two to three times greater than in Japan, the interior finish and air conditioning equipment, for example, are simpler and smaller. As a result, the embodied energy/CO2 of office buildings in China is only 10% to 20% greater than that of Japanese office buildings. Thus, the embodied energy/CO2 of buildings depends on both industrial efficiencies and building design trends of the country.
文摘The objective of this research is to quantify the EEC (embodied energy/CO2) of a building. The EEC represents the energy consumption and CO2 emissions at individual phases of a building's life-cycle, such as construction (including manufacture of materials and equipment), renewal (including repair work) and demolition. Energy and CO2 emission intensities in terms of 401 sectors were calculated, using the 2005 I-O (input-output) table in Japan. According to our case study conducted from the construction phase to demolition, the EC (embodied CO2) of an office building used for 60 years is 12,044 t-CO2 and 1,093 kg-CO2/m^2 in total. CO2 equivalent emissions (CO2e) by Freon gases, contained in building materials, equipment and devices, were also calculated. As the results, CO2e by insulators was 2% of the building's EC and CO2e by refrigerants was 9%-12% of the building's EC. It is important to keep reducing emissions of Freon gases contained in refrigerators.
基金supported by The University of Danang,University of Science and Technology,code number of the project:T2017-02-75.David Rockwood’s participation was made possible by a Core Fulbright U.S.Scholar award to Vietnam,sponsored by the U.S.Department of State’s Bureau of Educational and Cultural Affairs.
文摘Due to increased tourist activity,many cities now have a large number of hotel buildings.It is necessary to establish measures to evaluate energy use intensity to effectively manage energy consumption in this sector.This study uses a combined strategy to establish an energy benchmark for hotel buildings in Vietnam.First,a survey and analysis of actual building stock data of 50 hotels in Danang,Vietnam,was conducted.The survey-based benchmark and its related data was then used to build a reference energy model to estimate an energy benchmark for other climatic regions in Vietnam by using the energy simulation method.The results reveal that the average energy use intensity for hotels in Danang was 87.4 kWh/m2.year or 8628.6 kWh/guestroom.year.However,this study proposes that because of the differing expectations of comfort standards,hotels of different grades should have separate benchmarks.This study also proposes an energy intensity-based rating scale,including 7 grades from the least energy intensive(grade A)to the most energy intensive(grade G),which can be used to manage,label,or encourage sustainable energy use in hotel buildings.The relationship between the energy use intensity and the occupancy rate of the hotels was reported,compared,and explained.It was found that occupancy rate has no significant impact on the energy use intensity.From the survey result,some predictive models were developed to estimate annual energy consumption of hotel buildings based on their grades.The simulated benchmarks for other regions were also achieved.The results demonstrate many potential applications in the management,design and construction,and renovation of this building type.
文摘Consider the task of tracking the energy use of an entire city while also working to reduce it by 50%in 17 years.How would you go about tracking and verifying such reductions?Further,how would this be accomplished in a city without a database of building-specific characteristics and no energy reporting law?To begin,let’s consider what this task would look like for one building.Where to start?Let’s try with a performance metric and point of comparison.Just as cars gauge performance by MPG,and pitchers by ERA,buildings can use Energy Use Intensity(EUI)as a performance metric.Measured in Energy/ft2/year,EUI standardizes energy use per square foot,allowing for comparison between many buildings.EUI is a snapshot of building performance over one year’s time.It is relatively easy to calculate a building’s EUI if their energy usage is known,but in order to gauge performance over a longer period,a constant comparison point must be established so that evaluation is consistent.Called the baseline,this comparison point can be established as a past year,a future goal,or the average performance of similar buildings.This paper covers the work of the Pittsburgh 2030 District team in formulating an energy performance baseline for each building in Downtown Pittsburgh for purposes of tracking energy use reduction towards the 50%reduction goals of The 2030 Challenge.Pittsburgh is a city with a large stock of aging buildings,without mandatory benchmarking laws,and no single publicly accessible real estate profile by property.Thus,the energy baseline methods included in this paper summarize efforts to create such an aggregated property characteristic database and associated energy baseline for Downtown Pittsburgh;it is the hope of the authors that these efforts will assist similar cities in mirroring 2030 District goal setting and achievement for building energy.
文摘While being developed, Lao society and economy have gradually shifted from agricultural-based to service-industrial oriented one. As a result, final energy consumption has rapidly changed. This paper studied a trend of changes in final energy intensity by looking at sector-wide energy demand and shares in gross domestic products. It was found that intensity of total final energy consumption in Lao PDR (People's Democratic Republic) gradually decreased during the last decades. This was resulted of high stable economic growth and comparatively slow growth in energy demand. Furthermore, Lao economy still relays mainly on less-energy intensive economic sectors, such as services and traditional agriculture. Although energy intensities of the industry, transportation and services sectors continuously decreased, but have slowed down in recent years. Moreover, energy intensity of agricultural sector continues increasing. All these facts give a ground for thinking that in the future, when socio-economic development of the country will reach higher level, there will be more energy consuming activities, then energy demand will increase while economic growth will slow down, and therefore, energy intensity is to increase. Knowledge on trend of energy consumption changes would be useful for predicting energy demand and securing energy supply in the future.
文摘In recent years,large high efficiency and Net-Zero Energy Buildings(NZEB)are becoming a reality that are setting construction and energy benchmarks for the industry.As part of this significant effort,in 2018,Mohawk College opened the 8,981 m^(2)(96,670 ft2)Joyce Centre for Partnership and Innovation(JCPI)building in Hamilton,Ontario;becoming Canada’s largest NZEB and zero-carbon institutional facility.The building integrated a high-efficiency design,construction materials,and technologies;as well as renewable energy technologies to significantly reduce its annual energy consumption and greenhouse gas emissions.Furthermore,the JCPI building was also designed as a living lab where students,faculty,researchers and industry are able to monitor and validate the performance of this state-of-the-art facility.The building was designed to have an energy use intensity of 73 kWh/m^(2)·year(0.26 GJ/m^(2)·year);hence,potentially consuming approximately 80%less energy than the average educational service building in Ontario.This paper gives an overview of the design criteria and technologies that were considered to achieve this innova-tive building.
文摘We demonstrate that the intensity of the energy emission obtained from the Joule-Lenz law applied to the case of a single free-electron particle or a harmonic oscillator does not depend on the change of size of the corresponding energy interval () and time interval () because the ratio of??to??representing the emission rate remains constant. For a free electron, this property holds on condition the calculations of??and??refer to the states having a sufficiently large quantum index n.
基金Supported by National Natural Science Foundation of China(Grant Nos.51675484,51275474,51505424)Zhejiang Provincial Natural Science Foundation of China(Grant Nos.LZ12E05002,LY15E050019)
文摘Load behavior is one of the most critical factors affecting mills' energy consumption and grinding efficiency, and is greatly affected by the liner profiles. Generally, as liner profiles vary, the ball mill performances are extremely different. In order to study the performance of the ball mill with regular polygon angle-spiral liners(RPASLs), experimental and numerical studies on three types of RPASLs, including regular quadrilateral, pentagonal and hexagonal, are carried out. For the fine product of desired size, two critical parameters are analyzed: the energy input to the mill per unit mass of the fine product, E*, and the rate of production of the fine product, F*. Results show that the optimal structure of RPASLs is Quadrilateral ASL with an assembled angle of 50°. Under this condition, the specific energy consumption E* has the minimum value of 303 J per fine product and the production rate F* has the maximum value of 0.323. The production rate F* in the experimental result is consistent with the specific collision energy intensity to total collision energy intensity ratio Es/Et in the simulation. The relations between the production rate F* and the specific energy consumption E* with collision energy intensity Es and Et are obtained. The simulation result reveals the essential reason for the experimental phenomenon and correlates the mill performance parameter to the collision energy between balls, which could guide the practical application for Quadrilateral ASL.
基金Project supported by the National Natural Science Foundation of China(No.10572110)the Doctorate Foundation of the Chinese Education Ministrythe Doctorate Foundation of Xi'an Jiaotong University.
文摘By modeling metal as a special piezoelectric material with extremely small piezoelectricity and extremely large permittivity, we have obtained the analytical solutions for an interracial permeable crack in metal/piezoelectric bimaterials by means of the generalized Stroh formalism. The analysis shows that the stress fields near a permeable interracial crack tip are usually with three types of singularities: r^-1/2±iε and r^-1/2. Further numerical calculation on the oscillatory index ε are given for 28 types of metal/piezoelectric bimaterials combined by seven commercial piezoelectric materials: PZT-4, BaTiO3, PZT-5H, PZT-6B, PZT-7A, P-7 and PZT-PIC 151 and four metals: copper, silver, lead and aluminum, respectively. The explicit expressions of the crack tip energy release rate (ERR) and the crack tip generalized stress intensity factors (GSIF) are obtained. It is found that both the ERR and GSIF are independent of the electric displacement loading, although they seriously depends on the mechanical loadings.