One of the greatest challenges in the agroecosystem is to improve cropland intensification while preserving agroecosystem services.While many studies have investigated the effect of cropland intensification on agroeco...One of the greatest challenges in the agroecosystem is to improve cropland intensification while preserving agroecosystem services.While many studies have investigated the effect of cropland intensification on agroecosystem service,the interactive coupling and coordination among these factors remain largely unexplored.In view of this,this study performed a case study of the Loess Plateau in Shaanxi Province,China and constructed comprehensive evaluation models to quantify the cropland intensification and agroecosystem service in this area.Balance analysis and the coupling coordination degree model were used to evaluate the interactive relationship between cropland intensification and agroecosystem service,and statistical analysis and spatial autocorrelation were used to analyze the spatial characteristics and potential mechanism of the coupling coordination.Results show that both the cropland intensification and agroecosystem service in the study area were relatively low yet gradually increased from 2000 to 2020.Agroecosystem service lag was identified as the dominant unbalanced development type.Improving the supply capacity of agroecosystem services plays a key role in the balanced development of cropland in the Loess Plateau.The coupling coordination degree between cropland intensification and agroecosystem service ranges from basic coordination to serious incoordination.Therefore,cropland intensification practices in the area should be optimized to enhance this coordination degree.An upward trend was also observed in the coupling coordination degree from2000 to 2020.The withdrawal of marginal cropland in the Grain for Green program is one of the most important reasons for this trend,especially for the northern region.Around 83.6%of the high-high clusters are concentrated in the southern region of the Loess Plateau,whereas 70.5%of the low-low clusters are distributed in the northern region.These clustering characteristics are mainly attributed to the environmental suitability of these areas for agriculture and their degree of economic development.展开更多
We have deduced incremental harmonic balance an iteration scheme in the (IHB) method using the harmonic balance plus the Newton-Raphson method. Since the convergence of the iteration is dependent upon the initial va...We have deduced incremental harmonic balance an iteration scheme in the (IHB) method using the harmonic balance plus the Newton-Raphson method. Since the convergence of the iteration is dependent upon the initial values in the iteration, the convergent region is greatly restricted for some cases. In this contribution, in order to enlarge the convergent region of the IHB method, we constructed the zeroth-order deformation equation using the homotopy analysis method, in which the IHB method is employed to solve the deformation equation with an embedding parameter as the active increment. Taking the Duffing and the van der Pol equations as examples, we obtained the highly accurate solutions. Importantly, the presented approach renders a convenient way to control and adjust the convergence.展开更多
With the rapid social and economic development of the Taihu region, Taihu Lake now faces an increasingly severe eutrophication problem. Pollution from surrounding catchments contributes greatly to the eutrophication o...With the rapid social and economic development of the Taihu region, Taihu Lake now faces an increasingly severe eutrophication problem. Pollution from surrounding catchments contributes greatly to the eutrophication of water bodies in the region. Investigation of surface flow and associated mass transport for the Xitiaoxi catchment is of a significant degree of importance as the Xitiaoxi catchment is one of the major catchments within the Taihu region. A SWAT-based distributed hydrological model was established for the Xitiaoxi catchment. The model was calibrated and verified using hydrometeorological data from 1988 to 2001. The results indicate that the modeled daily and annual stream flow match the observed data both in the calibration period and the verification period, with a linear regression coefficient R2 and a coefficient e for modeled daily stream flow greater than 0.8 at Hengtangcun and Fanjiacun gauge stations. The results show that the runoff process in the Xitiaoxi catchment is affected both by rainfall and human activities (e.g., reservoirs and polder areas). Moreover, the human activities weaken flood peaks more noticeably during rainstorms. The Water balance analysis reveals the percentages of precipitation made up by surface flow, evapotranspiration, groundwater recharge' and the change of soil storage, all of which are considered useful to the further understanding of the hydrological processes in the Xitiaoxi catchment. This study provides a good base for further studies in mass transport modeling and comparison of modeling results from similar hydrological models.展开更多
Based on the principle of energy conservation,the applicable technique for drained cell retrofitted from conventional one was analyzed with 2D finite element model. The model employed a 1D heat transfer scheme to comp...Based on the principle of energy conservation,the applicable technique for drained cell retrofitted from conventional one was analyzed with 2D finite element model. The model employed a 1D heat transfer scheme to compute iteratively the freeze profile until the thickness variable reached the terminating requirement. The calculated 2D heat dissipation from the cell surfaces was converted into the overall 3D heat loss. The potential drop of the system, freeze profile and heat balance were analyzed to evaluate their variation with technical parameters when designing the 150 kA conventional cell based drained cell. The simulation results show that the retrofitted drained cell is able to keep thermal balance under the conditions that the current is 190 kA, the anodic current density is 0.96 A/cm2, the anode-cathode distance is 2.5 cm, the alumina cover is 16 cm thick with a thermal conductivity of 0.20 W/(m·℃ ) and the electrolysis temperature is 946 ℃ .展开更多
The stoichiometric matrix of a simplified metabolic network inBacillus Subtillis was constructed from the flux balance equations,which were used for reconciliation of the measured rates anddetermination of the inner m...The stoichiometric matrix of a simplified metabolic network inBacillus Subtillis was constructed from the flux balance equations,which were used for reconciliation of the measured rates anddetermination of the inner metabolic rates. Thus more reliableresults of the true and empirical maintenance coefficients wereobtained. The true maintenance coefficient is linearly related to thespecific growth rate and changes with the P/O ratio. The measuredbiomass yield of adenosine triphosphate (ATP) is also linearlyrelated to the P/O ratio.展开更多
A mass balance analysis was undertaken for liquid steel production using a computer program specially developed for the AC electric arc furnace at an important alloy steel producer in Turkey. The data obtained by usin...A mass balance analysis was undertaken for liquid steel production using a computer program specially developed for the AC electric arc furnace at an important alloy steel producer in Turkey. The data obtained by using the computer program were found to be very close to the actual production ones.展开更多
This thesis research on nutritious balance of specific examples in Chinese recipes applying diversity indices and cluster analysis. Initially, based on data of the nutritional ingredients of food, such as proteins, fa...This thesis research on nutritious balance of specific examples in Chinese recipes applying diversity indices and cluster analysis. Initially, based on data of the nutritional ingredients of food, such as proteins, fat and vitamins, we categorize 1200 kinds of specific food using cluster analysis;then, according to a recipe given by a local restaurant, we calculate and compare the diversity indices based on the components of 25 single dishes in the recipe and analyze the nutritious balance of each dish.展开更多
In order to identify the day and night pollution sources of PM10 in ambient air in Longyan City,the authors analyzed the elemental composition of respirable particulate matters in the day and night ambient air samples...In order to identify the day and night pollution sources of PM10 in ambient air in Longyan City,the authors analyzed the elemental composition of respirable particulate matters in the day and night ambient air samples and various pollution sources which were collected in January 2010 in Longyan with inductivity coupled plasma-mass spectrometry(ICP-MS).Then chemical mass balance(CMB) model and factor analysis(FA) method were applied to comparatively study the inorganic components in the sources and receptor samples.The results of factor analysis show that the major sources were road dust,waste incineration and mixed sources which contained automobile exhaust,soil dust/secondary dust and coal dust during the daytime in Longyan City,China.There are two major sources of pollution which are soil dust and mixture sources of automobile exhaust and secondary dust during the night in Longyan.The results of CMB show that the major sources are secondary dust,automobile exhaust and road dust during the daytime in Longyan.The major sources are secondary dust,soil dust and automobile exhaust during the night in Longyan.The results of the two methods are similar to each other and the results will guide us to plan to control the PM10 pollution sources in Longyan.展开更多
The basic structure and working principle of an unequal-arm buoyancy balance are introduced in this article. Different kinds of error produeed in the unequal-arm buoyancy balance has been researched and analyzed. Firs...The basic structure and working principle of an unequal-arm buoyancy balance are introduced in this article. Different kinds of error produeed in the unequal-arm buoyancy balance has been researched and analyzed. First the temperature influence of the crossbeam is analyzed, then the measurement error is calculated; second, the error produced by the pivot and the counterweight system is analyzed, then the corresponding error reduction method is proposed. It is shown that the error reduction method can promote the precision of the buoyancy, which is critical to balance.展开更多
Although many sensitivity analyses using the soil and water assessment tool(SWAT) in a complex watershed have been conducted, little attention has been paid to the application potential of the model in unique plots. I...Although many sensitivity analyses using the soil and water assessment tool(SWAT) in a complex watershed have been conducted, little attention has been paid to the application potential of the model in unique plots. In addition, sensitivity analysis of percolation and evapotranspiration with SWAT has seldom been undertaken. In this study, SWAT99.2 was calibrated to simulate water balance components for unique plots in Southern China from 2000 to 2001, which included surface runoff, percolation, and evapotranspiration. Twenty-one parameters classified into four categories, including meteorological conditions, topographical characteristics, soil properties, and vegetation attributes, were used for sensitivity analysis through one-at-a-time(OAT) sampling to identify the factor that contributed most to the variance in water balance components. The results were shown to be different for different plots, with parameter sensitivity indices and ranks varying for different water balance components. Water balance components in the broad-leaved forest and natural grass plots were most sensitive to meteorological conditions, less sensitive to vegetation attributes and soil properties, and least sensitive to topographical characteristics. Compared to those in the natural grass plot, water balance components in the broad-leaved forest plot demonstrated higher sensitivity to the maximum stomatal conductance(GSI) and maximum leaf area index(BLAI).展开更多
Cross-efficiency evaluation is recognized as an effective way of efficiency assessment for a set of decision making units (DMUs) in the framework of data envelopment analysis (DEA). It has been generally suggested tha...Cross-efficiency evaluation is recognized as an effective way of efficiency assessment for a set of decision making units (DMUs) in the framework of data envelopment analysis (DEA). It has been generally suggested that secondary goals be introduced for cross-efficiency evaluation owing to the non-uniqueness of optimal solutions in self-evaluation. This paper develops a variety of secondary goals in the spirit of promoting balance in the output efficiencies of the DMU under evaluation. The proposed models attempt to make each output contribute as equally as possible to the self-evaluated efficiency. In this way, the weight flexibility can for one thing be reduced by the introduced secondary goals with selections from alternate optimal solutions, in addition to counting on the dilution of flexibility in the subsequent peer-evaluation. The proposed approach might be applicable to evaluation problems in which multiple outputs are considered important and balance is encouraged to put all dimensions into sufficient use. The effectiveness of the proposed approach and its comparisons with some relevant secondary goals are illustrated empirically using numerical examples.展开更多
Based on evolution history of earth ecosystem,by studying and analyzing three development stages of natural ecological chain and man-made ecological chain before and after the birth of human beings on the earth,and co...Based on evolution history of earth ecosystem,by studying and analyzing three development stages of natural ecological chain and man-made ecological chain before and after the birth of human beings on the earth,and comparing the energy consumption of human activities and the impact of environmental factors related to natural ecological chain in these stages,following characteristics are found. First,the increasing intelligence of human activities has an increasing impact on the natural ecological chain. Second,the increasing energy consumption of human activities is directly proportional to the degree of natural ecological impact. Third,the traditional production mode of consumption type and the development speed of science and technology are inversely proportional to the change cycle of man-made ecological chain and directly proportional to the degree of ecological crisis. An ecosystem has the ability to regulate,but it has its limits. Beyond this limit,the ecological balance will be destroyed. So,the goal is to transform into a circular type of modern production mode and scientific and technological development as soon as possible,and to shift to a balance between human material requirements and the maintenance and stability of the environment,namely the era of ecological chain of coexistence where nature and human beings are highly harmonious.展开更多
Based on a questionnaire survey of Chinese public hospitals, this paper explores the consequence and realization path of balanced scorecard (BSC, hereafter) usage. The results show that BSC usage can improve hospita...Based on a questionnaire survey of Chinese public hospitals, this paper explores the consequence and realization path of balanced scorecard (BSC, hereafter) usage. The results show that BSC usage can improve hospital performance remarkably. With the structural equation model analysis, we further find that, this function is realized in an indirect way through the perception of organizational fairness and organizational commitment. The BSC has direct effect to improve the perception of organizational fairness and organizational commitment, which further influence the performance. The results not only complement empirical evidences for BSC usage, but also provide guidance to regulators and hospitals to implement BSC in compensation contract.展开更多
The balance sheet and the income statement have different functions and cooperate with each other to form an organic whole,complete and without redundancy to describe an enterprise’s economic activities.The financial...The balance sheet and the income statement have different functions and cooperate with each other to form an organic whole,complete and without redundancy to describe an enterprise’s economic activities.The financial analysis method is used to analyze how the data of the two reports reflect the capital structure,profit ability,operational capacity,and solvency of the enterprise.展开更多
This article utilizes a large amount of statistical data to analyze the global distribution of foreign trade in China since 1990,as well as the factors involved and the changes in trends.The research results indicate ...This article utilizes a large amount of statistical data to analyze the global distribution of foreign trade in China since 1990,as well as the factors involved and the changes in trends.The research results indicate that China has gained a favourable balance against developed countries and a disadvantageous balance against developing countries;China enjoys a trade surplus with North American and European countries while suffering deficits with those in the Asia.pacific region,as well as with resource-abundant Australia,Africa and South America. With regard to trends,the structure of China’s foreign trade will not undergo fundamental changes in the short term,but in the long run will be transformed in line with restructuring of the growth pattern.展开更多
It is of great significance to optimize the spatial matching of basic education facilities in rural areas and promote the equalization of urban and rural basic public services and the overall revitalization of rural a...It is of great significance to optimize the spatial matching of basic education facilities in rural areas and promote the equalization of urban and rural basic public services and the overall revitalization of rural areas.Based on the theory of spatial accessibility and spatial balance of supply and demand,this paper constructs the evaluation system of rural basic education facilities and layout rationality.In this study,we took 42 primary and secondary schools and 2089 rural areas with concentrated population in six township areas of Hancheng City as the research subjects.We used ArcGIS network analysis,population coupling model,and other methods,from the administrative scale and rural population concentration area scale for evaluation.The accessibility of basic education facilities and its coupling relationship with the spatial distribution of student population describe the spatial and geographical pattern of basic education facilities in rural areas.The results show that the accessibility of rural administrative scale and the spatial balance of supply and demand of population concentration area scale are associated with great problems,the differences between towns are obvious,and the overall level of the best performing towns is still low.On the scale of population concentration area,the overall coupling degree is too low,the"dislocation"distribution of educational facilities and student population is obvious,and the matching degree of the student population and school in different towns is significantly different,showing a more obvious"core-periphery"spatial structure characteristics centered on the eastern and southeast regions.The terrain characteristics of rural areas in Shaanxi province are prominent,and the accessibility of the road network is particularly significant.Therefore,optimizing the construction of rural roads and optimizing school layout according to local conditions will become an important solution to promote the balanced allocation of basic education resources in Shaanxi province.展开更多
The strict and high-standard requirements for the safety and stability ofmajor engineering systems make it a tough challenge for large-scale finite element modal analysis.At the same time,realizing the systematic anal...The strict and high-standard requirements for the safety and stability ofmajor engineering systems make it a tough challenge for large-scale finite element modal analysis.At the same time,realizing the systematic analysis of the entire large structure of these engineering systems is extremely meaningful in practice.This article proposes a multilevel hierarchical parallel algorithm for large-scale finite element modal analysis to reduce the parallel computational efficiency loss when using heterogeneous multicore distributed storage computers in solving large-scale finite element modal analysis.Based on two-level partitioning and four-transformation strategies,the proposed algorithm not only improves the memory access rate through the sparsely distributed storage of a large amount of data but also reduces the solution time by reducing the scale of the generalized characteristic equation(GCEs).Moreover,a multilevel hierarchical parallelization approach is introduced during the computational procedure to enable the separation of the communication of inter-nodes,intra-nodes,heterogeneous core groups(HCGs),and inside HCGs through mapping computing tasks to various hardware layers.This method can efficiently achieve load balancing at different layers and significantly improve the communication rate through hierarchical communication.Therefore,it can enhance the efficiency of parallel computing of large-scale finite element modal analysis by fully exploiting the architecture characteristics of heterogeneous multicore clusters.Finally,typical numerical experiments were used to validate the correctness and efficiency of the proposedmethod.Then a parallel modal analysis example of the cross-river tunnel with over ten million degrees of freedom(DOFs)was performed,and ten-thousand core processors were applied to verify the feasibility of the algorithm.展开更多
A new type of vibration structure (i.e. supporting system, called swing frame cus- tomarily) of vertical dynamic balancing machine has been designed, which is based on an analysis for the swing frame of a traditiona...A new type of vibration structure (i.e. supporting system, called swing frame cus- tomarily) of vertical dynamic balancing machine has been designed, which is based on an analysis for the swing frame of a traditional double-plane vertical dynamic balancing machine. The static unbalance and couple unbalance can be e?ectively separated by using the new dynamic balancing machine with the new swing frame. By building the dynamics model, the advantages of the new structure are discussed in detail. The modal and harmonic response are analyzed by using the ANSYS7.0. By comparing the ?nite element modal analysis with the experimental modal analy- sis, the natural frequencies and vibration modes are found. There are many spring boards in the new swing frame. Their sti?nesses are di?erent and assorted with each other. Furthermore, there are three sensors on the measuring points. Therefore, the new dynamic balancing machine can measure static unbalance and coupling unbalance directly, and the interaction between them is faint. The result shows that the new vertical dynamic balancing machine is suitable for inertial measurement of ?ying objects, and can overcome the shortcomings of traditional double-plane vertical dynamic balancing machines, which the e?ect of plane-separation is inferior. The vertical dynamic balancing machine with the new vibration structure can ?nd wide application in the future. The modelling and analysis of the new vibration structure will provide theoretical basis and practical experience for designing new-type vertical dynamic balancing machines.展开更多
Temperature sensitivity of soil respiration is essential to predict possible changes in terrestrial carbon budget on various scenarios about atmospheric and soil climates. Although it is often evaluated by using respi...Temperature sensitivity of soil respiration is essential to predict possible changes in terrestrial carbon budget on various scenarios about atmospheric and soil climates. Although it is often evaluated by using respiratory quotient “Q<sub>10</sub>”, Q<sub>10</sub> values of soil respiration seem to vary depending on methods or scales of evaluation. Aiming at probing how Q<sub>10</sub> values of soil respiration are evaluated differently for a field, this study used a model of soil respiration rate, and numerically evaluated soil respiration rates along depth by fitting the model to depth distributions of CO<sub>2</sub> concentration measured in a field. And temperature sensitivity of soil respiration rate was evaluated by comparing the determined soil respiration rates with atmospheric and soil temperatures measured in the field. The results showed that the relation between surface CO<sub>2</sub> emission rates and atmospheric temperatures was represented by lower Q<sub>10</sub> values than that between soil respiration rates and soil temperatures, presumably because the top soil layers had acclimatized in more extent to the existing thermal regime than the underlying deeper layers. Thus, for evaluating effects of long-term rise in atmospheric temperature on soil respiration, it is necessary to precisely predict the long-term change in depth distribution of soil temperature as well as to quantify temperature sensitivity of soil respiration along depth. The evaluated sensitivity of surface CO<sub>2</sub> emission rate to atmospheric temperature showed hysteresis, implying the needs for more knowledge about temperature sensitivity of soil respiration evaluated in both warming and cooling processes for better understandings and predictions about terrestrial carbon cycling.展开更多
Background:Human immunodeficiency virus type 1(HIV-1)remains a persistent global health challenge.Therefore,a continuous exploration of novel therapeutic strategies is essential.A comprehensive understanding of how HI...Background:Human immunodeficiency virus type 1(HIV-1)remains a persistent global health challenge.Therefore,a continuous exploration of novel therapeutic strategies is essential.A comprehensive understanding of how HIV-1 utilizes the cellular metabolism machinery for replication can provide insights into new therapeutic approaches.Methods:In this study,we performed a flux balance analysis using a genome-scale metabolic model(GEM)integrated with an HIV-1 viral biomass objective function to identify potential targets for anti–HIV-1 interventions.We generated a GEM by integrating an HIV-1 production reaction into CD4+T cells and optimized for both host and virus optimal states as objective functions to depict metabolic profiles of cells in the status for optimal host biomass maintenance or for optimal HIV-1 virion production.Differential analysis was used to predict biochemical reactions altered optimal for HIV-1 production.In addition,we conducted in silico simulations involving gene and reaction knock-outs to identify potential anti–HIV-1 targets,which were subsequently validated by human phytohemagglutinin(PHA)blasts infected with HIV-1.Results:Differential analysis identified several altered biochemical reactions,including increased lysine uptake and oxidative phosphorylation(OXPHOS)activities in the virus optima compared with the host optima.In silico gene and reaction knock-out simulations revealed de novo pyrimidine synthesis,and OXPHOS could serve as potential anti–HIV-1 metabolic targets.In vitro assay confirmed that targeting OXPHOS using metformin could suppress the replication of HIV-1 by 56.6%(385.4±67.5 pg/mL in the metformintreated group vs.888.4±32.3 pg/mL in the control group,P<0.001).Conclusion:Our integrated host-virus genome-scale metabolic study provides insights on potential targets(OXPHOS)for anti-HIV therapies.展开更多
基金Under the auspices of the National Natural Science Foundation of China(No.41901262)Natural Science Basic Research Program of Shaanxi(No.2024JC-YBQN-0300)Fundamental Research Funds for the Central Universities(No.GK202103125,GK202207005)。
文摘One of the greatest challenges in the agroecosystem is to improve cropland intensification while preserving agroecosystem services.While many studies have investigated the effect of cropland intensification on agroecosystem service,the interactive coupling and coordination among these factors remain largely unexplored.In view of this,this study performed a case study of the Loess Plateau in Shaanxi Province,China and constructed comprehensive evaluation models to quantify the cropland intensification and agroecosystem service in this area.Balance analysis and the coupling coordination degree model were used to evaluate the interactive relationship between cropland intensification and agroecosystem service,and statistical analysis and spatial autocorrelation were used to analyze the spatial characteristics and potential mechanism of the coupling coordination.Results show that both the cropland intensification and agroecosystem service in the study area were relatively low yet gradually increased from 2000 to 2020.Agroecosystem service lag was identified as the dominant unbalanced development type.Improving the supply capacity of agroecosystem services plays a key role in the balanced development of cropland in the Loess Plateau.The coupling coordination degree between cropland intensification and agroecosystem service ranges from basic coordination to serious incoordination.Therefore,cropland intensification practices in the area should be optimized to enhance this coordination degree.An upward trend was also observed in the coupling coordination degree from2000 to 2020.The withdrawal of marginal cropland in the Grain for Green program is one of the most important reasons for this trend,especially for the northern region.Around 83.6%of the high-high clusters are concentrated in the southern region of the Loess Plateau,whereas 70.5%of the low-low clusters are distributed in the northern region.These clustering characteristics are mainly attributed to the environmental suitability of these areas for agriculture and their degree of economic development.
基金supported by the National Natural Science Foundation of China (10772202)Doctoral Program Foundation of Ministry of Education of China (20050558032)Guangdong Province Natural Science Foundation (07003680, 05003295)
文摘We have deduced incremental harmonic balance an iteration scheme in the (IHB) method using the harmonic balance plus the Newton-Raphson method. Since the convergence of the iteration is dependent upon the initial values in the iteration, the convergent region is greatly restricted for some cases. In this contribution, in order to enlarge the convergent region of the IHB method, we constructed the zeroth-order deformation equation using the homotopy analysis method, in which the IHB method is employed to solve the deformation equation with an embedding parameter as the active increment. Taking the Duffing and the van der Pol equations as examples, we obtained the highly accurate solutions. Importantly, the presented approach renders a convenient way to control and adjust the convergence.
基金supported by the National Natural Science Foundation of China (Grant No. 40471018)the National Basic Research Program of China (973 Program, Grant No. 2002 CB412310)Hundred Talents Programme of the Chinese Academy of Sciences
文摘With the rapid social and economic development of the Taihu region, Taihu Lake now faces an increasingly severe eutrophication problem. Pollution from surrounding catchments contributes greatly to the eutrophication of water bodies in the region. Investigation of surface flow and associated mass transport for the Xitiaoxi catchment is of a significant degree of importance as the Xitiaoxi catchment is one of the major catchments within the Taihu region. A SWAT-based distributed hydrological model was established for the Xitiaoxi catchment. The model was calibrated and verified using hydrometeorological data from 1988 to 2001. The results indicate that the modeled daily and annual stream flow match the observed data both in the calibration period and the verification period, with a linear regression coefficient R2 and a coefficient e for modeled daily stream flow greater than 0.8 at Hengtangcun and Fanjiacun gauge stations. The results show that the runoff process in the Xitiaoxi catchment is affected both by rainfall and human activities (e.g., reservoirs and polder areas). Moreover, the human activities weaken flood peaks more noticeably during rainstorms. The Water balance analysis reveals the percentages of precipitation made up by surface flow, evapotranspiration, groundwater recharge' and the change of soil storage, all of which are considered useful to the further understanding of the hydrological processes in the Xitiaoxi catchment. This study provides a good base for further studies in mass transport modeling and comparison of modeling results from similar hydrological models.
基金Projects(50374081 60634020) supported by the National Natural Science Foundation of China
文摘Based on the principle of energy conservation,the applicable technique for drained cell retrofitted from conventional one was analyzed with 2D finite element model. The model employed a 1D heat transfer scheme to compute iteratively the freeze profile until the thickness variable reached the terminating requirement. The calculated 2D heat dissipation from the cell surfaces was converted into the overall 3D heat loss. The potential drop of the system, freeze profile and heat balance were analyzed to evaluate their variation with technical parameters when designing the 150 kA conventional cell based drained cell. The simulation results show that the retrofitted drained cell is able to keep thermal balance under the conditions that the current is 190 kA, the anodic current density is 0.96 A/cm2, the anode-cathode distance is 2.5 cm, the alumina cover is 16 cm thick with a thermal conductivity of 0.20 W/(m·℃ ) and the electrolysis temperature is 946 ℃ .
基金Supported by the Key Program of National Natural Science Foundation of China (No. 20036010) and the National Science Fund for Distinguished Young Scholars (No. 20028607).
文摘The stoichiometric matrix of a simplified metabolic network inBacillus Subtillis was constructed from the flux balance equations,which were used for reconciliation of the measured rates anddetermination of the inner metabolic rates. Thus more reliableresults of the true and empirical maintenance coefficients wereobtained. The true maintenance coefficient is linearly related to thespecific growth rate and changes with the P/O ratio. The measuredbiomass yield of adenosine triphosphate (ATP) is also linearlyrelated to the P/O ratio.
文摘A mass balance analysis was undertaken for liquid steel production using a computer program specially developed for the AC electric arc furnace at an important alloy steel producer in Turkey. The data obtained by using the computer program were found to be very close to the actual production ones.
文摘This thesis research on nutritious balance of specific examples in Chinese recipes applying diversity indices and cluster analysis. Initially, based on data of the nutritional ingredients of food, such as proteins, fat and vitamins, we categorize 1200 kinds of specific food using cluster analysis;then, according to a recipe given by a local restaurant, we calculate and compare the diversity indices based on the components of 25 single dishes in the recipe and analyze the nutritious balance of each dish.
基金Supported by the Natural Basic Research Program of China(No.2005CB422207)the Fund of Eco-enviromental Impacts and Protection in Devoloping and Utilizing of Oil-shale Resources(No.OSR-01-06)
文摘In order to identify the day and night pollution sources of PM10 in ambient air in Longyan City,the authors analyzed the elemental composition of respirable particulate matters in the day and night ambient air samples and various pollution sources which were collected in January 2010 in Longyan with inductivity coupled plasma-mass spectrometry(ICP-MS).Then chemical mass balance(CMB) model and factor analysis(FA) method were applied to comparatively study the inorganic components in the sources and receptor samples.The results of factor analysis show that the major sources were road dust,waste incineration and mixed sources which contained automobile exhaust,soil dust/secondary dust and coal dust during the daytime in Longyan City,China.There are two major sources of pollution which are soil dust and mixture sources of automobile exhaust and secondary dust during the night in Longyan.The results of CMB show that the major sources are secondary dust,automobile exhaust and road dust during the daytime in Longyan.The major sources are secondary dust,soil dust and automobile exhaust during the night in Longyan.The results of the two methods are similar to each other and the results will guide us to plan to control the PM10 pollution sources in Longyan.
基金supported by the Education Fund in Hunan Province under Grant No.07D014
文摘The basic structure and working principle of an unequal-arm buoyancy balance are introduced in this article. Different kinds of error produeed in the unequal-arm buoyancy balance has been researched and analyzed. First the temperature influence of the crossbeam is analyzed, then the measurement error is calculated; second, the error produced by the pivot and the counterweight system is analyzed, then the corresponding error reduction method is proposed. It is shown that the error reduction method can promote the precision of the buoyancy, which is critical to balance.
基金supported by the National Natural Science Foundation of China(Grants No.51569007 and 41301289)the Natural Science Foundation of Guangxi Province,China(Grant No.2015GXNSFCA139004)+1 种基金the Fund of the IRCK by UNESCO(Grant No.KDL201601)the Project of High Level Innovation Team and Outstanding Scholar in Guangxi Colleges and Universities(Grant No.002401013001)
文摘Although many sensitivity analyses using the soil and water assessment tool(SWAT) in a complex watershed have been conducted, little attention has been paid to the application potential of the model in unique plots. In addition, sensitivity analysis of percolation and evapotranspiration with SWAT has seldom been undertaken. In this study, SWAT99.2 was calibrated to simulate water balance components for unique plots in Southern China from 2000 to 2001, which included surface runoff, percolation, and evapotranspiration. Twenty-one parameters classified into four categories, including meteorological conditions, topographical characteristics, soil properties, and vegetation attributes, were used for sensitivity analysis through one-at-a-time(OAT) sampling to identify the factor that contributed most to the variance in water balance components. The results were shown to be different for different plots, with parameter sensitivity indices and ranks varying for different water balance components. Water balance components in the broad-leaved forest and natural grass plots were most sensitive to meteorological conditions, less sensitive to vegetation attributes and soil properties, and least sensitive to topographical characteristics. Compared to those in the natural grass plot, water balance components in the broad-leaved forest plot demonstrated higher sensitivity to the maximum stomatal conductance(GSI) and maximum leaf area index(BLAI).
文摘Cross-efficiency evaluation is recognized as an effective way of efficiency assessment for a set of decision making units (DMUs) in the framework of data envelopment analysis (DEA). It has been generally suggested that secondary goals be introduced for cross-efficiency evaluation owing to the non-uniqueness of optimal solutions in self-evaluation. This paper develops a variety of secondary goals in the spirit of promoting balance in the output efficiencies of the DMU under evaluation. The proposed models attempt to make each output contribute as equally as possible to the self-evaluated efficiency. In this way, the weight flexibility can for one thing be reduced by the introduced secondary goals with selections from alternate optimal solutions, in addition to counting on the dilution of flexibility in the subsequent peer-evaluation. The proposed approach might be applicable to evaluation problems in which multiple outputs are considered important and balance is encouraged to put all dimensions into sufficient use. The effectiveness of the proposed approach and its comparisons with some relevant secondary goals are illustrated empirically using numerical examples.
文摘Based on evolution history of earth ecosystem,by studying and analyzing three development stages of natural ecological chain and man-made ecological chain before and after the birth of human beings on the earth,and comparing the energy consumption of human activities and the impact of environmental factors related to natural ecological chain in these stages,following characteristics are found. First,the increasing intelligence of human activities has an increasing impact on the natural ecological chain. Second,the increasing energy consumption of human activities is directly proportional to the degree of natural ecological impact. Third,the traditional production mode of consumption type and the development speed of science and technology are inversely proportional to the change cycle of man-made ecological chain and directly proportional to the degree of ecological crisis. An ecosystem has the ability to regulate,but it has its limits. Beyond this limit,the ecological balance will be destroyed. So,the goal is to transform into a circular type of modern production mode and scientific and technological development as soon as possible,and to shift to a balance between human material requirements and the maintenance and stability of the environment,namely the era of ecological chain of coexistence where nature and human beings are highly harmonious.
文摘Based on a questionnaire survey of Chinese public hospitals, this paper explores the consequence and realization path of balanced scorecard (BSC, hereafter) usage. The results show that BSC usage can improve hospital performance remarkably. With the structural equation model analysis, we further find that, this function is realized in an indirect way through the perception of organizational fairness and organizational commitment. The BSC has direct effect to improve the perception of organizational fairness and organizational commitment, which further influence the performance. The results not only complement empirical evidences for BSC usage, but also provide guidance to regulators and hospitals to implement BSC in compensation contract.
文摘The balance sheet and the income statement have different functions and cooperate with each other to form an organic whole,complete and without redundancy to describe an enterprise’s economic activities.The financial analysis method is used to analyze how the data of the two reports reflect the capital structure,profit ability,operational capacity,and solvency of the enterprise.
文摘This article utilizes a large amount of statistical data to analyze the global distribution of foreign trade in China since 1990,as well as the factors involved and the changes in trends.The research results indicate that China has gained a favourable balance against developed countries and a disadvantageous balance against developing countries;China enjoys a trade surplus with North American and European countries while suffering deficits with those in the Asia.pacific region,as well as with resource-abundant Australia,Africa and South America. With regard to trends,the structure of China’s foreign trade will not undergo fundamental changes in the short term,but in the long run will be transformed in line with restructuring of the growth pattern.
文摘It is of great significance to optimize the spatial matching of basic education facilities in rural areas and promote the equalization of urban and rural basic public services and the overall revitalization of rural areas.Based on the theory of spatial accessibility and spatial balance of supply and demand,this paper constructs the evaluation system of rural basic education facilities and layout rationality.In this study,we took 42 primary and secondary schools and 2089 rural areas with concentrated population in six township areas of Hancheng City as the research subjects.We used ArcGIS network analysis,population coupling model,and other methods,from the administrative scale and rural population concentration area scale for evaluation.The accessibility of basic education facilities and its coupling relationship with the spatial distribution of student population describe the spatial and geographical pattern of basic education facilities in rural areas.The results show that the accessibility of rural administrative scale and the spatial balance of supply and demand of population concentration area scale are associated with great problems,the differences between towns are obvious,and the overall level of the best performing towns is still low.On the scale of population concentration area,the overall coupling degree is too low,the"dislocation"distribution of educational facilities and student population is obvious,and the matching degree of the student population and school in different towns is significantly different,showing a more obvious"core-periphery"spatial structure characteristics centered on the eastern and southeast regions.The terrain characteristics of rural areas in Shaanxi province are prominent,and the accessibility of the road network is particularly significant.Therefore,optimizing the construction of rural roads and optimizing school layout according to local conditions will become an important solution to promote the balanced allocation of basic education resources in Shaanxi province.
基金supported by the National Natural Science Foundation of China(Grant No.11772192).
文摘The strict and high-standard requirements for the safety and stability ofmajor engineering systems make it a tough challenge for large-scale finite element modal analysis.At the same time,realizing the systematic analysis of the entire large structure of these engineering systems is extremely meaningful in practice.This article proposes a multilevel hierarchical parallel algorithm for large-scale finite element modal analysis to reduce the parallel computational efficiency loss when using heterogeneous multicore distributed storage computers in solving large-scale finite element modal analysis.Based on two-level partitioning and four-transformation strategies,the proposed algorithm not only improves the memory access rate through the sparsely distributed storage of a large amount of data but also reduces the solution time by reducing the scale of the generalized characteristic equation(GCEs).Moreover,a multilevel hierarchical parallelization approach is introduced during the computational procedure to enable the separation of the communication of inter-nodes,intra-nodes,heterogeneous core groups(HCGs),and inside HCGs through mapping computing tasks to various hardware layers.This method can efficiently achieve load balancing at different layers and significantly improve the communication rate through hierarchical communication.Therefore,it can enhance the efficiency of parallel computing of large-scale finite element modal analysis by fully exploiting the architecture characteristics of heterogeneous multicore clusters.Finally,typical numerical experiments were used to validate the correctness and efficiency of the proposedmethod.Then a parallel modal analysis example of the cross-river tunnel with over ten million degrees of freedom(DOFs)was performed,and ten-thousand core processors were applied to verify the feasibility of the algorithm.
基金Project supported by the National Natural Science Foundation of China (No.10176011).
文摘A new type of vibration structure (i.e. supporting system, called swing frame cus- tomarily) of vertical dynamic balancing machine has been designed, which is based on an analysis for the swing frame of a traditional double-plane vertical dynamic balancing machine. The static unbalance and couple unbalance can be e?ectively separated by using the new dynamic balancing machine with the new swing frame. By building the dynamics model, the advantages of the new structure are discussed in detail. The modal and harmonic response are analyzed by using the ANSYS7.0. By comparing the ?nite element modal analysis with the experimental modal analy- sis, the natural frequencies and vibration modes are found. There are many spring boards in the new swing frame. Their sti?nesses are di?erent and assorted with each other. Furthermore, there are three sensors on the measuring points. Therefore, the new dynamic balancing machine can measure static unbalance and coupling unbalance directly, and the interaction between them is faint. The result shows that the new vertical dynamic balancing machine is suitable for inertial measurement of ?ying objects, and can overcome the shortcomings of traditional double-plane vertical dynamic balancing machines, which the e?ect of plane-separation is inferior. The vertical dynamic balancing machine with the new vibration structure can ?nd wide application in the future. The modelling and analysis of the new vibration structure will provide theoretical basis and practical experience for designing new-type vertical dynamic balancing machines.
文摘Temperature sensitivity of soil respiration is essential to predict possible changes in terrestrial carbon budget on various scenarios about atmospheric and soil climates. Although it is often evaluated by using respiratory quotient “Q<sub>10</sub>”, Q<sub>10</sub> values of soil respiration seem to vary depending on methods or scales of evaluation. Aiming at probing how Q<sub>10</sub> values of soil respiration are evaluated differently for a field, this study used a model of soil respiration rate, and numerically evaluated soil respiration rates along depth by fitting the model to depth distributions of CO<sub>2</sub> concentration measured in a field. And temperature sensitivity of soil respiration rate was evaluated by comparing the determined soil respiration rates with atmospheric and soil temperatures measured in the field. The results showed that the relation between surface CO<sub>2</sub> emission rates and atmospheric temperatures was represented by lower Q<sub>10</sub> values than that between soil respiration rates and soil temperatures, presumably because the top soil layers had acclimatized in more extent to the existing thermal regime than the underlying deeper layers. Thus, for evaluating effects of long-term rise in atmospheric temperature on soil respiration, it is necessary to precisely predict the long-term change in depth distribution of soil temperature as well as to quantify temperature sensitivity of soil respiration along depth. The evaluated sensitivity of surface CO<sub>2</sub> emission rate to atmospheric temperature showed hysteresis, implying the needs for more knowledge about temperature sensitivity of soil respiration evaluated in both warming and cooling processes for better understandings and predictions about terrestrial carbon cycling.
基金the National Natural Science Foundation of China(82071784)the Fundamental Research Funds for the Central Universities(2042022dx0003 and PTPP2023002)+1 种基金the Key Research and Development Project of Hubei Province(2020BCA069)the Translational Medicine and Interdisciplinary Research Joint Fund of Zhongnan Hospital of Wuhan University(ZNJC202007).
文摘Background:Human immunodeficiency virus type 1(HIV-1)remains a persistent global health challenge.Therefore,a continuous exploration of novel therapeutic strategies is essential.A comprehensive understanding of how HIV-1 utilizes the cellular metabolism machinery for replication can provide insights into new therapeutic approaches.Methods:In this study,we performed a flux balance analysis using a genome-scale metabolic model(GEM)integrated with an HIV-1 viral biomass objective function to identify potential targets for anti–HIV-1 interventions.We generated a GEM by integrating an HIV-1 production reaction into CD4+T cells and optimized for both host and virus optimal states as objective functions to depict metabolic profiles of cells in the status for optimal host biomass maintenance or for optimal HIV-1 virion production.Differential analysis was used to predict biochemical reactions altered optimal for HIV-1 production.In addition,we conducted in silico simulations involving gene and reaction knock-outs to identify potential anti–HIV-1 targets,which were subsequently validated by human phytohemagglutinin(PHA)blasts infected with HIV-1.Results:Differential analysis identified several altered biochemical reactions,including increased lysine uptake and oxidative phosphorylation(OXPHOS)activities in the virus optima compared with the host optima.In silico gene and reaction knock-out simulations revealed de novo pyrimidine synthesis,and OXPHOS could serve as potential anti–HIV-1 metabolic targets.In vitro assay confirmed that targeting OXPHOS using metformin could suppress the replication of HIV-1 by 56.6%(385.4±67.5 pg/mL in the metformintreated group vs.888.4±32.3 pg/mL in the control group,P<0.001).Conclusion:Our integrated host-virus genome-scale metabolic study provides insights on potential targets(OXPHOS)for anti-HIV therapies.