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Optimization and performance prediction of a new near-zero emission coal utilization system with combined gasification and combustion

GUAN Jian, WANG Qinhui, LI Xiaomin, LUO Zhongyang, CEN Kefa

《能源前沿（英文）》 2007年 第1卷 第1期   页码 113-119 doi: 10.1007/s11708-007-0013-y

摘要： In accordance with the new near-zero emission coal utilization system with combined gasification and combustion, which is based on the CO acceptor gasification process, the product gas composition of the gasifier and the combustor was calculated by means of thermodynamic equilibrium calculation software FactSage 5.2. Based on these calculations, the whole system efficiency calculation method that complies with the mass and energy conservation principle was established. To enhance the system efficiency, the system pressure and the gasifier carbon conversion ratio were optimized. The results indicate that the system efficiency increases with increasing pressure and gasifier carbon conversion ratio. After taking into consideration the influence of the pressure and carbon conversion ratio on the performance of the system, the gasifier and the combustor were synthetically studied. The optimum system pressure and carbon conversion ratio were obtained as 2.5 MPa and 0.7, respectively. The system efficiency could reach around 62.1% when operated in these two optimum parameters. If the advanced ion transport membrane (ITM) air separation technology is used, there would be an increase of another 1.3%.

关键词： influence     efficiency calculation     optimum     software FactSage     transport    

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Explicit finite element method for calculation and analysis to the elasto-plastic dynamic response of

LI Liang, DU Xiuli, LI Liyun, ZHAO Chenggang

《结构与土木工程前沿（英文）》 2007年 第1卷 第4期   页码 436-442 doi: 10.1007/s11709-007-0059-2

摘要： In order to describe the elasto-plastic dynamic response of fluid-saturated porous media, the incremental elasto-plastic wave propagation equations of fluid-saturated porous media are developed by the fundamental theory of continuum mechanics and appointing to the characteristic of fluid-saturated porous media. Then, the space discretization of these equations is performed to get their Galerkin formula. At last, the time discretization of this formula is carried out with the integral method which consists of central difference method and Newmark constant average acceleration method to get the explicit time integral formula for solving the wave propagation equations of porous media. On the basis of the integral formula mentioned above, the time-domain explicit finite element method is developed for calculation and analysis of the elasto-plastic dynamic response of fluid-saturated porous media. In this method, the decoupling technique is adopted and it does not need to solve simultaneous linear equations in each time step, so the computational effort and memory requirement can be reduced considerably by using this method.

关键词： discretization     computational     calculation     integral     requirement    

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Application of an efficient stochastic calculation method on the seismic analysis of an isolated structure

Wei GUO, Zhiwu YU

《结构与土木工程前沿（英文）》 2012年 第6卷 第4期   页码 379-384 doi: 10.1007/s11709-012-0180-8

摘要： An isolated structure often possesses distinct non-proportional damping characteristics. However, traditional seismic calculation theory and methods are derived based on the assumption that damping is proportional. Based on this drawback, a new, more efficient stochastic calculation method, an improvement on the pseudo-excitation method, is introduced. This method is then applied to the seismic analysis of an isolated structure. By comparing it with the forced decoupling, matrix inversion and iteration methods, it is shown that the presented method can produce accurate results while increasing the efficiency of the stochastic analysis. Moreover, the calculation process of the seismic response of an isolated structure is convergent. Based on the results of the example presented in this paper, the given method is applicable to the seismic analysis of an isolated structure and can be utilized in practice.

关键词： isolated structure     stochastic response     non-proportional damping     efficient     accurate     pseudo-excitation method    

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The calculation of equivalence factor for ecological footprints in China: a methodological note

Moucheng LIU,Wenhua LI,Dan ZAHNG,Ning SU

《环境科学与工程前沿（英文）》 2015年 第9卷 第6期   页码 1015-1024 doi: 10.1007/s11783-014-0670-0

摘要： The Ecological Footprint (EF), a physical indicator to measure the extent of humanity’s use of natural resources, has gained much attention since it was first used by Wackernagel and Rees in 1996. In order to appraise land area types with different levels of productivity, they introduced the concept of an equivalence factor. This relates to the average primary biomass productivities of different types of land (i.e. arable land, pasture, forest, water/fishery, built-up land and fossil energy land) to the regional average primary biomass productivity of all land types in a given year. Hence, the equivalence factor is an important parameter in the EF model and it directly affects the reliability of all results. Thus, this article calculates equivalence factors on the national and provincial levels in China based on Net Primary Production (NPP) from MODIS 1 km data in 2008. Firstly, based on the Light Utility Efficiency and CASA model, the NPP of different biologically productive lands of China and of different provinces was calculated. Secondly, China’s equivalence factor for 6 land area types was calculated based on NPP: arable land and built-up land has an equivalence factor of 1.71, forest and fossil energy land has a factor of 1.41, pasture has a factor of 0.44 and water/fishery 0.35; Finally, the equivalence factor of 6 land area types in different provinces was also calculated. The NPP of each ecosystem type varies along with the equivalence factor in different provinces. However, the ranking of the equivalence factors in different provinces remain the same, with that of arable land being the largest, and the water/fishery being the smallest.

关键词： ecological footprint     equivalence factor     net primary production     biological capacity     land types    

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Unified calculation method and its application in determining the uniaxial mechanical properties of concrete

Faxing DING, Xiaoyong YING, Linchao ZHOU, Zhiwu YU

《结构与土木工程前沿（英文）》 2011年 第5卷 第3期   页码 381-393 doi: 10.1007/s11709-011-0118-6

摘要： This paper presents a unified calculation method and its application in determining the uniaxial mechanical properties of concrete with concrete strengths ranging from 10 to 140 MPa. By analyzing a large collection of test results of the uniaxial mechanical properties of normal-strength, high-strength and super high-strength concrete in China and performing a regression analysis, unified calculation formulas for the mechanical indexes of concrete are proposed that can be applied to various grades of concrete for determining the size coefficient, uniaxial compressive strength, uniaxial tensile strength, elastic modulus, and strain at peak uniaxial compression and tension. Optimized mathematical equations for the nonlinear stress-strain relationship of concrete, including the ascending and descending branches under uniaxial stress, are also established. The elastic modulus is almost constant throughout the elastic stage for the ascending branches of the stress-strain relationship for concrete. The proposed stress-strain relationship of concrete was applied to the nonlinear finite element analysis of both a steel-concrete composite beam and a concrete-filled steel tubular stub column. The analytical results are in good agreement with the experiment results, indicating that the proposed stress-strain relationship of concrete is applicable. The achievements presented in this paper can be used as references for the design and nonlinear finite element analysis of concrete structures.

关键词： concrete     mechanical properties     stress-strain relationship     uniaxial stress     application    

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The effect of different agricultural management practices on irrigation efficiency, water use efficiency

La ZHUO, Arjen Y. HOEKSTRA

《农业科学与工程前沿（英文）》 2017年 第4卷 第2期   页码 185-194 doi: 10.15302/J-FASE-2017149

摘要： This paper explores the effect of varying agricultural management practices on different water efficiency indicators: irrigation efficiency (IE), crop water use efficiency (WUE), and green and blue water footprint (WF). We take winter wheat in an experimental field in Northern China as a case study and consider a dry, average and wet year. We conducted 24 modeling experiments with the AquaCrop model, for all possible combinations of four irrigation techniques, two irrigation strategies and three mulching methods. Results show that deficit irrigation most effectively improved blue water use, by increasing IE (by 5%) and reducing blue WF (by 38%), however with an average 9% yield reduction. Organic or synthetic mulching practices improved WUE (by 4% and 10%, respectively) and reduced blue WF (by 8% and 17%, respectively), with the same yield level. Drip and subsurface drip irrigation improved IE and WUE, but drip irrigation had a relatively large blue WF. Improvements in one water efficiency indicator may cause a decline in another. In particular, WUE can be improved by more irrigation at the cost of the blue WF. Furthermore, increasing IE, for instance by installing drip irrigation, does not necessarily reduce the blue WF.

关键词： field management     irrigation efficiency     water footprint     water productivity     water use efficiency    

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Calculation method of load distribution on pipe threaded connections under tension load

Shoujun CHEN, Lianxin GAO, Qi AN

《机械工程前沿（英文）》 2011年 第6卷 第2期   页码 241-248 doi: 10.1007/s11465-011-0219-x

摘要：

This paper presents a new calculation method that can calculate the load distribution on pipe threaded connections under tension load. On the basis of elastic mechanics, the new method was developed by analyzing each thread tooth, and a new deformation and covariant equation by making a mechanics analysis on each thread tooth was obtained. Compared with the traditional method proposed by the previous references, the new deformation and covariant equation could be used to describe the relation between the previous and the next thread tooth. By applying the new method on the sample of P-110S pipe threaded connection, the obtained results show that the load on thread tooth mainly concentrates on the four or five threads engaged and the middle teeth were not utilized well to bear the loads. The model offers a new way to calculate the loads carried on the thread teeth under tension load.

关键词： load distribution     calculation method     pipe threaded connections     tension load    

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Evaluating R&D efficiency of China’s listed lithium battery enterprises

《工程管理前沿（英文）》   页码 473-485 doi: 10.1007/s42524-022-0213-5

摘要： Promoting the growth of the lithium battery sector has been a critical aspect of China’s energy policy in terms of achieving carbon neutrality. However, despite significant support on research and development (R&D) investments that have resulted in increasing size, the sector seems to be falling behind in technological areas. To guide future policies and understand proper ways of promoting R&D efficiency, we looked into the lithium battery industry of China. Specifically, data envelopment analysis (DEA) was used as the primary approach based on evidence from 22 listed lithium battery enterprises. The performance of the five leading players was compared with that of the industry as a whole. Results revealed little indication of a meaningful improvement in R&D efficiency throughout our sample from 2010 to 2019. However, during this period, a significant increase in R&D expenditure was witnessed. This finding was supported, as the results showed that the average technical efficiency of the 22 enterprises was 0.442, whereas the average pure technical efficiency was at 0.503, thus suggesting that they were suffering from decreasing returns to scale (DRS). In contrast, the performance of the five leading players seemed superior because their average efficiency scores were higher than the industry’s average. Moreover, they were experiencing increasing scale efficiency (IRS). We draw on these findings to suggest to policymakers that supporting technologically intensive sectors should be more than simply increasing investment scale; rather, it should also encompass assisting businesses in developing efficient managerial processes for R&D.

关键词： Data Envelopment Analysis     R&D investment efficiency     China’s listed lithium battery enterprises     technical efficiency     pure technical efficiency     scale efficiency    

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Calculation on phase diagrams of polyetherimide/

Ming TAN,Gaohong HE,Yan DAI,Rujie WANG,Wenhua SHI

《化学科学与工程前沿（英文）》 2014年 第8卷 第3期   页码 312-319 doi: 10.1007/s11705-014-1434-x

摘要： The ternary phase diagrams of polyetherimide (PEI)/ , -dimethylacetamide (DMAc) with H O and BuOH as non-solvent were simulated using solubility parameter and Flory-Huggins theory. The phase diagrams show that 5.5% H O/BuOH system containing 5% BuOH and 0.5% H O, or 6.5% H O/BuOH system containing 6.2% BuOH and 0.3% H O is required to induce liquid-liquid demixing for 20 wt-% PEI/DMAc casting solution. Therefore, BuOH can enhance the phase separation of the PEI casting solution and hereby induce higher porosity of the membrane, and the diffusion of BuOH into the water coagulation bath causes larger pore size easily compared with DMAc. Our predictions that the membrane pure water flux first increases then decreases, and the rejection ratio of bovine serum albumin decreases with the increasing concentration of BuOH were validated by the experiments using the prepared membranes.

关键词： phase diagram     solubility parameter     interaction parameter     ultrafiltration     Flory-Huggins theory    

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Heuristic solution using decision tree model for enhanced XML schema matching of bridge structural calculation

Sang I. PARK, Sang-Ho LEE

《结构与土木工程前沿（英文）》 2020年 第14卷 第6期   页码 1403-1417 doi: 10.1007/s11709-020-0666-8

摘要： Research on the quality of data in a structural calculation document (SCD) is lacking, although the SCD of a bridge is used as an essential reference during the entire lifecycle of the facility. XML Schema matching enables qualitative improvement of the stored data. This study aimed to enhance the applicability of XML Schema matching, which improves the speed and quality of information stored in bridge SCDs. First, the authors proposed a method of reducing the computing time for the schema matching of bridge SCDs. The computing speed of schema matching was increased by 13 to 1800 times by reducing the checking process of the correlations. Second, the authors developed a heuristic solution for selecting the optimal weight factors used in the matching process to maintain a high accuracy by introducing a decision tree. The decision tree model was built using the content elements stored in the SCD, design companies, bridge types, and weight factors as input variables, and the matching accuracy as the target variable. The inverse-calculation method was applied to extract the weight factors from the decision tree model for high-accuracy schema matching results.

关键词： structural calculation document     bridge structure     XML Schema matching     weight factor     data mining     decision tree model    

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Improving the efficiency and effectiveness of global phosphorus use: focus on root and rhizosphere levels

null

《农业科学与工程前沿（英文）》 2019年 第6卷 第4期   页码 357-365 doi: 10.15302/J-FASE-2019275

摘要：

Phosphorus (P) is essential for life and for efficient crop production, but global P use with limited recycling is inefficient in several sectors, including agronomy. Unfortunately, plant physiologists, agronomists, farmers and end users employ different measures for P use efficiency (PUE), which often masks their values at different scales. The term P use effectiveness, which also considers energetic and sustainability measures in addition to P balances, is also a valuable concept. Major physiological and genetic factors for plant P uptake and utilization have been identified, but there has been limited success in genetically improving PUE of modern crop cultivars. In maize, studies on root architectural and morphological traits appear promising. Rhizosphere processes assist in mobilizing and capturing sparingly soluble phosphate from rock phosphate. Combinations of phosphate-solubilizing microorganisms with ammonium-based nitrogen fertilizer, as well as strategies of fertilizer placement near the roots of target crops, can moderately enhance PUE. The desired concentration of P in the products differs, depending on the final use of the crop products as feed, food or for energy conversion, which should be considered during crop production.

关键词： acquisition efficiency     plant growth promoting rhizobacteria     phosphate     use efficiency     utilization efficiency    

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Optimization of power and efficiency for an irreversible Diesel heat engine

Shiyan ZHENG, Guoxing LIN

《能源前沿（英文）》 2010年 第4卷 第4期   页码 560-565 doi: 10.1007/s11708-010-0018-9

摘要： A cyclic model of an irreversible Diesel heat engine is presented, in which the heat loss between the working fluid and the ambient during combustion, the irreversibility inside the cyclic working fluid resulting from friction, eddies flow, and other irreversible effects are taken into account. By using the thermodynamic analysis and optimal control theory methods, the analytical expressions of power output and efficiency of the Diesel heat engine are derived. Variations of the main performance parameters with the pressure ratio of the cycle are analyzed and calculated. The optimum operating region of the heat engine is determined. Moreover, the optimum criterion of some important parameters, such as the power output, efficiency, pressure ratio, and temperatures of the working fluid at the related state points are illustrated and discussed. The conclusions obtained in the present paper may provide some theoretical guidance for the optimal parameter design of a class of internal-combustion engines.

关键词： Diesel heat engine     irreversibility     power output     efficiency     parameter optimization    

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Methods and applications of DEA cross-efficiency: Review and future perspectives

Jie WU, Jiasen SUN, Liang LIANG

《工程管理前沿（英文）》 2021年 第8卷 第2期   页码 199-211 doi: 10.1007/s42524-020-0133-1

摘要： The field of engineering management usually involves evaluation issues, such as program selection, team performance evaluation, technology selection, and supplier evaluation. The traditional self-evaluation data envelopment analysis (DEA) method usually exaggerates the effects of several inputs or outputs of the evaluated decision-making unit (DMU), resulting in unrealistic results. To address this problem, scholars have proposed the cross-efficiency evaluation (CREE) method. Compared with the DEA method, CREE can rank DMUs more completely by using reasonable weights. With the extensive application of this technique, several problems, such as non-unique weights and non-Pareto optimal results, have arisen in CREE methods. Therefore, the improvement of CREE has attracted the attention of many scholars. This paper reviews the theory and applications of CREE, including the non-uniqueness problem, the aggregation of cross-efficiency data, and applications in engineering management. It also discusses the directions for future research on CREE.

关键词： cross-efficiency evaluation     efficiency     secondary goal model     aggregation     review    

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STRATEGIES FOR IMPROVING WATER USE EFFICIENCY IN DRYLAND AGROECOSYSTEMS

《农业科学与工程前沿（英文）》 2021年 第8卷 第4期   页码 599-602 doi: 10.15302/J-FASE -2021409

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Effects of dwarfing genes on water use efficiency of bread wheat

Jiakun YAN, Suiqi ZHANG

《农业科学与工程前沿（英文）》 2017年 第4卷 第2期   页码 126-134 doi: 10.15302/J-FASE-2017134

摘要： Climate change has increased the risk of drought, which significantly limits plant productivity. Various ways of increasing water availability and sustaining growth of crop plants in drought-prone environments are available. Genetic advances in grain yields under rainfed conditions have been achieved with the introduction of dwarfing genes. A thorough understanding of the effects of different dwarfing genes on root growth, coleoptile length, grain yields and water using efficiency (WUE) will provide opportunities to select appropriate genes for breeding high WUE and grain yield cultivars. This review focuses on the mechanism involved in genes that reduce plant height and affect root and coleoptile length, their consequent effects on grain yields and WUE, and suggests that for rainfed and irrigation-limited environments, combining GAR and GAI dwarfing genes in breeding may help boost WUE and yields, and more materials from different parental sources should be collected to assess opportunities for potential comprehensive application of specific genes.

关键词： coleoptile length     wheat     dwarfing genes     grain yield     root     water use efficiency    

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标题 作者 时间 类型 操作

Optimization and performance prediction of a new near-zero emission coal utilization system with combined gasification and combustion

GUAN Jian, WANG Qinhui, LI Xiaomin, LUO Zhongyang, CEN Kefa

期刊论文

Explicit finite element method for calculation and analysis to the elasto-plastic dynamic response of

LI Liang, DU Xiuli, LI Liyun, ZHAO Chenggang

期刊论文

Application of an efficient stochastic calculation method on the seismic analysis of an isolated structure

Wei GUO, Zhiwu YU

期刊论文

The calculation of equivalence factor for ecological footprints in China: a methodological note

Moucheng LIU,Wenhua LI,Dan ZAHNG,Ning SU

期刊论文

Unified calculation method and its application in determining the uniaxial mechanical properties of concrete

Faxing DING, Xiaoyong YING, Linchao ZHOU, Zhiwu YU

期刊论文

The effect of different agricultural management practices on irrigation efficiency, water use efficiency

La ZHUO, Arjen Y. HOEKSTRA

期刊论文

Calculation method of load distribution on pipe threaded connections under tension load

Shoujun CHEN, Lianxin GAO, Qi AN

期刊论文

Evaluating R&D efficiency of China’s listed lithium battery enterprises

期刊论文

Calculation on phase diagrams of polyetherimide/

Ming TAN,Gaohong HE,Yan DAI,Rujie WANG,Wenhua SHI

期刊论文

Heuristic solution using decision tree model for enhanced XML schema matching of bridge structural calculation

Sang I. PARK, Sang-Ho LEE

期刊论文

Improving the efficiency and effectiveness of global phosphorus use: focus on root and rhizosphere levels

null

期刊论文

Optimization of power and efficiency for an irreversible Diesel heat engine

Shiyan ZHENG, Guoxing LIN

期刊论文

Methods and applications of DEA cross-efficiency: Review and future perspectives

Jie WU, Jiasen SUN, Liang LIANG

期刊论文

STRATEGIES FOR IMPROVING WATER USE EFFICIENCY IN DRYLAND AGROECOSYSTEMS

期刊论文

Effects of dwarfing genes on water use efficiency of bread wheat

Jiakun YAN, Suiqi ZHANG

期刊论文