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The Contribution Margin due to a Limiting Factor in the Presence of Several Sales Options: Actuality Is Not Always As It Appears at the Beginning of the Analysis
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作者 Maria Silvia Avi 《Journal of Modern Accounting and Auditing》 2023年第1期1-22,共22页
The analysis of company data useful for economic decisions,if not interpreted in an overall view of the company situation,can lead to wrong conclusions.This is the case when a company has to choose between several sal... The analysis of company data useful for economic decisions,if not interpreted in an overall view of the company situation,can lead to wrong conclusions.This is the case when a company has to choose between several sales options for one or more products in the presence of a limiting factor.The continuation of the investigation often denies the initial analysis.Not everything is as it appears,therefore,at the beginning of the deepening of the data useful for economic decisions.As it is well known,the choices of profitability concerning the planning of the sale of company products take place,at least in the majority of cases,through the determination of the contribution margin,i.e.the profitability margin connected to the individual goods/services sold by the companies(selling price net of variable costs).The contribution margin can be determined with four objectives:(1)Determination of the yield of the single product,net of variable costs only.In this case,the margin defines unitary,from net product yield to unitary contribution margin.(2)Determination of the return on total sales of an individual product,net of variable costs.In this hypothesis,reference is made to the first level(or gross)contribution margin.(3)Determination of the ability of the individual product to contribute to the coverage of fixed costs common to the company.This margin is determined net of special product variable and fixed costs.This aggregate is defined as a Level II(or semi-gross)margin.(4)Determination of the useful value in the planning choices in case of presence of scarce productive factors.In this case,it must identify the so-called unitary margin for low factor.Here we will only deal with the problem of the use of the contribution margin in the presence of rare factors.To complete the analysis,below are some very brief considerations regarding,respectively,the unitary,level I,and level II contribution margin in order to better understand where the problem of the most convenient choice of income is located in the event of the presence of rare production factors,especially in an environment characterized by a plurality of sales options. 展开更多
关键词 contribution margin unit contribution margin first level contribution margin second level contribution margin Unit Scarce factor contribution margin Unit Scarce factor contribution margin in the presence of a plurality of sales options profit
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Beyond authorship: Analyzing contributions in PLOS ONE and the challenges of appropriate attribution 被引量:1
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作者 Abdelghani Maddi Jaime A.Teixeira da Silva 《Journal of Data and Information Science》 CSCD 2024年第3期88-115,共28页
Purpose:This study aims to evaluate the accuracy of authorship attributions in scientific publications,focusing on the fairness and precision of individual contributions within academic works.Design/methodology/approa... Purpose:This study aims to evaluate the accuracy of authorship attributions in scientific publications,focusing on the fairness and precision of individual contributions within academic works.Design/methodology/approach:The study analyzes 81,823 publications from the journal PLOS ONE,covering the period from January 2018 to June 2023.It examines the authorship attributions within these publications to try and determine the prevalence of inappropriate authorship.It also investigates the demographic and professional profiles of affected authors,exploring trends and potential factors contributing to inaccuracies in authorship.Findings:Surprisingly,9.14%of articles feature at least one author with inappropriate authorship,affecting over 14,000 individuals(2.56%of the sample).Inappropriate authorship is more concentrated in Asia,Africa,and specific European countries like Italy.Established researchers with significant publication records and those affiliated with companies or nonprofits show higher instances of potential monetary authorship.Research limitations:Our findings are based on contributions as declared by the authors,which implies a degree of trust in their transparency.However,this reliance on self-reporting may introduce biases or inaccuracies into the dataset.Further research could employ additional verification methods to enhance the reliability of the findings.Practical implications:These findings have significant implications for journal publishers,Beyond authorship:Analyzing contributions in PLOS ONE and Maddi,A.,&the challenges of appropriate attribution highlighting the necessity for robust control mechanisms to ensure the integrity of authorship attributions.Moreover,researchers must exercise discernment in determining when to acknowledge a contributor and when to include them in the author list.Addressing these issues is crucial for maintaining the credibility and fairness of academic publications.Originality/value:This study contributes to an understanding of critical issues within academic authorship,shedding light on the prevalence and impact of inappropriate authorship attributions.By calling for a nuanced approach to ensure accurate credit is given where it is due,the study underscores the importance of upholding ethical standards in scholarly publishing. 展开更多
关键词 Authorship Funding acquisition Research integrity Author contributions CREDIT Inappropriate authorship APC ring
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Opinions of Students on the Contribution of the DIVA 3D Virtual Dissection Table to the Teaching of Anatomy at the Faculty of Medicine and Odontostomatology of Bamako
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作者 Abdoulaye Kanté Tata Touré +8 位作者 Ousmane Toumany Chérif Haidara Uhl Jean François Mariam Daou Mamadou A. Keita Bakary Keïta Bréhima Bengaly Drissa Traoré Adégné Togo Nouhoum Ongoïba 《Forensic Medicine and Anatomy Research》 2024年第2期13-25,共13页
Objective: Study the contribution of the DIVA 3D dissection table in the teaching of anatomy at the Faculty of Medicine and Odontology of Bamako. Material and Methods: This was a qualitative study carried out from Nov... Objective: Study the contribution of the DIVA 3D dissection table in the teaching of anatomy at the Faculty of Medicine and Odontology of Bamako. Material and Methods: This was a qualitative study carried out from November 1 to December 30, 2023 at the clinical and morphological anatomy laboratory of the Faculty of Medicine and Odontostomatology of Bamako. Included in this study were students who participated in practical and tutorial sessions. The variables studied during this study were: the previous performance of dissection on a cadaver by the students, the opinion of the students on dissection on a cadaver, the replacement of dissection on a cadaver by virtual dissection in the absence of a body, the level student satisfaction. Results: We surveyed 130 participants. The average age was 22 ± 0.2 years with extremes of 17 and 29 years. 95.3% of participants were students. According to 66.7% of participants, virtual dissection is a good palliative in the absence of a corpse. 95.3% of participants found using the virtual dissection table easy with an average of 7.88 ± 1.4. The overall assessment was well rated by 99.3% of participants. Conclusion: According to the results of this study, the virtual dissection table should be improved by integrating commented videos. The use of the DIVA 3D virtual dissection table during practical and tutorial sessions is well appreciated by the students. We believe that the teaching of anatomy using 3D digital technology should be included in the study programs of the Faculty of Medicine and Odontostomatology. 展开更多
关键词 Student Opinion contribution DIVA 3D Virtual Dissection Table Anatomy Teaching FMOS
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National Social Investment Programmes in Nigeria:A Descriptive Analysis of the Socio-Economic Contributions of N-Power Programme in Benue State
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作者 Robert Idoko Ogwola Dennis Anyebe Olofu Charles Amobi Aneke 《Management Studies》 2024年第1期9-20,共12页
This study analysed the socio-economic contributions of N-Power programme amongst the beneficiaries of the scheme in Benue State.Prior to the introduction of N-Power programme,successive administrations in Nigeria hav... This study analysed the socio-economic contributions of N-Power programme amongst the beneficiaries of the scheme in Benue State.Prior to the introduction of N-Power programme,successive administrations in Nigeria have made concerted efforts towards improving the standard of living of the citizenry through the execution of various welfare or social intervention programmes,but not much successes were recorded.Learning from the mistakes of the past regimes,and by way of deliberate state policy,the Buhari’s government initiated a multi-pronged social investment policy,one of which is the N-power programme that came onboard in 2016,which also doubles as the subject of this study.To achieve the goal of this study,a combination of desktop research and survey design was employed.Questionnaires were administered to 390 respondents through a combination of stratified and random sampling techniques.The results of the survey were matched with that of the secondary data obtained through online websites and other related sources.The result indicated that N-Power made positive contributions to the socio-economic life of the beneficiaries in Benue State:specifically,the scheme contributed in poverty eradication,employment generation,skills acquisitions and capacity building.However,some aspect of our findings revealed that the programme has a number of challenges such as:inadequate cash support,delay in monthly cash transfer to beneficiaries,distance participants had to move to their work stations,absence of posting in N-Teach scheme,and lack of adequate working tools amongst others.To salvage this problem the paper recommended the following solutions:expansion of the scheme to cover N-Teach and other aspects,increment in the monthly cash transfer to cushion the high rate of inflation,support for the participants/beneficiaries in transportation and logistics,enrolment of more youth into the various schemes,proper monitoring and evaluation of the implementation of the schemes amongst others. 展开更多
关键词 NATIONAL social investment programme N-Power contributionS socio-economic development
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An Analysis of Innovative Contributions to the Important Discourse on the Development of New Quality Productivity
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作者 Yao Hao Jie Wu 《Journal of Contemporary Educational Research》 2024年第6期135-141,共7页
The discourse on developing high-quality productivity marks a significant theoretical innovation,which is conducive to the modernization and sinicization of Marxism.It refines our understanding of“new quality product... The discourse on developing high-quality productivity marks a significant theoretical innovation,which is conducive to the modernization and sinicization of Marxism.It refines our understanding of“new quality productivity,”defining it as an advanced form driven by innovation,embodying“high technology,efficiency,and quality,”with the aim of comprehensively enhancing productivity.It elucidates the necessity of cultivating such forces,asserting that they are crucial for achieving high-quality development,securing a leading position in global technology,and fulfilling the aspirations for a better life.Moreover,it outlines a new implementation route,emphasizing strategies such as fostering technological autonomy,nurturing emerging industries,integrating education and talent in technology,adopting a“build through challenges”approach,adjusting solutions locally,and providing categorized guidance,all of which are based on the ongoing comprehensive reforms. 展开更多
关键词 New quality productivity Basic connotation Important discourse Realistic approach Innovative contributions
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An evaluation method of contribution rate based on fuzzy Bayesian networks for equipment system-of-systems architecture
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作者 XU Renjie LIU Xin +2 位作者 CUI Donghao XIE Jian GONG Lin 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2023年第3期574-587,共14页
The contribution rate of equipment system-of-systems architecture(ESoSA)is an important index to evaluate the equipment update,development,and architecture optimization.Since the traditional ESoSA contribution rate ev... The contribution rate of equipment system-of-systems architecture(ESoSA)is an important index to evaluate the equipment update,development,and architecture optimization.Since the traditional ESoSA contribution rate evaluation method does not make full use of the fuzzy information and uncertain information in the equipment system-of-systems(ESoS),and the Bayesian network is an effective tool to solve the uncertain information,a new ESoSA contribution rate evaluation method based on the fuzzy Bayesian network(FBN)is proposed.Firstly,based on the operation loop theory,an ESoSA is constructed considering three aspects:reconnaissance equipment,decision equipment,and strike equipment.Next,the fuzzy set theory is introduced to construct the FBN of ESoSA to deal with fuzzy information and uncertain information.Furthermore,the fuzzy importance index of the root node of the FBN is used to calculate the contribution rate of the ESoSA,and the ESoSA contribution rate evaluation model based on the root node fuzzy importance is established.Finally,the feasibility and rationality of this method are validated via an empirical case study of aviation ESoSA.Compared with traditional methods,the evaluation method based on FBN takes various failure states of equipment into consideration,is free of acquiring accurate probability of traditional equipment failure,and models the uncertainty of the relationship between equipment.The proposed method not only supplements and improves the ESoSA contribution rate assessment method,but also broadens the application scope of the Bayesian network. 展开更多
关键词 equipment system-of-systems architecture(ESoSA) contribution rate evaluation fuzzy Bayesian network(FBN) fuzzy set theory
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Moisture Sources and Their Contributions to Summer Precipitation in the East of Southwest China
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作者 李永华 黄丁安 +3 位作者 卢楚翰 向波 周杰 何卷雄 《Journal of Tropical Meteorology》 SCIE 2023年第2期153-167,共15页
Complex topography,special geographical location and sea-land-air interactions lead to high interannual variability of summer precipitation in the east of Southwest China(ESWC).However,the contributions,influencing fa... Complex topography,special geographical location and sea-land-air interactions lead to high interannual variability of summer precipitation in the east of Southwest China(ESWC).However,the contributions,influencing factors and mechanisms of remote and local evaporation remain to be further investigated.Using clustering analysis and Hybrid Single-Particle Lagrangian Integrated Trajectory version 5 model,we analyze the contributions of remote moisture transport and local evaporation to summer precipitation in the ESWC and their causes.There are mainly five remote moisture channels in the ESWC,namely the Arabian Sea channel,Bay of Bengal channel,western Pacific channel,Northwest channel 1 and Northwest channel 2.Among the five channels,the western Pacific channel has the largest number of trajectories,while the Bay of Bengal channel has the largest contribution rate of specific humidity(33.33%)and moisture flux(33.14%).The amount of regional average precipitation is close to that of the precipitation caused by remote moisture transport,and both are considerably greater than the rainfall amount caused by local evaporation.However,on interannual time scales,precipitation recirculation rates are negatively correlated to regional average precipitation and precipitation caused by remote moisture transport but are consistent with that caused by local evaporation.An apparent"+-+"wave train can be found on the height anomaly field in East Asia,and the sea surface temperature anomalies are positive in the equatorial Middle-East Pacific,the South China Sea,the Bay of Bengal and the Arabian Sea.These phenomena cause southwest-northeast moisture transport with strong updrafts,thereby resulting in more precipitation in the ESWC. 展开更多
关键词 east of Southwest China summer precipitation moisture sources local evaporation contributions of moisture
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The contribution of root respiration of Pinus koraiensis seedlings to total soil respiration under elevated CO_2 concentrations 被引量:14
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作者 刘颖 韩士杰 +3 位作者 李雪峰 周玉梅 张军辉 贾夏 《Journal of Forestry Research》 SCIE CAS CSCD 2004年第3期187-191,共5页
The impacts of elevated atmospheric CO2 concentrations (500 靘olmol-1and 700 靘olmol-1) on total soil respiration and the contribution of root respiration of Pinus koraiensis seedlings were investigated from May to Oc... The impacts of elevated atmospheric CO2 concentrations (500 靘olmol-1and 700 靘olmol-1) on total soil respiration and the contribution of root respiration of Pinus koraiensis seedlings were investigated from May to October in 2003 at the Research Station of Changbai Mountain Forest Ecosystems, Chinese Academy of Sciences, Jilin Province, China. After four growing seasons in top-open chambers exposed to elevated CO2, the total soil respiration and roots respiration of Pinus koraiensis seedlings were measured by a LI-6400-09 soil CO2 flux chamber. Three PVC cylinders in each chamber were inserted about 30 cm into the soil in-stantaneously to terminate the supply of current photosynthates from the tree canopy to roots for separating the root respiration from total soil respiration. Soil respirations both inside and outside of the cylinders were measured on June 16, August 20 and October 8, respectively. The results indicated that: there was a marked diurnal change in air temperature and soil temperature at depth of 5 cm on June 16, the maximum of soil temperature at depth of 5 cm lagged behind that of air temperature, no differences in temperature between treatments were found (P>0.05). The total soil respiration and soil respiration with roots severed showed strong diurnal and seasonal patterns. There was marked difference in total soil respiration and soil respiration with roots severed between treatments (P<0.01); Mean total soil respiration and contribution of root under different treatments were 3.26, 4.78 and 1.47 靘olm 2s-1, 11.5%, 43.1% and 27.9% on June 16, August 20 and October 8, respectively. 展开更多
关键词 contribution of root respiration Elevated CO2 Pinus koraiensis Root-severed technique Soil respiration
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Study on Contribution of Potassium,Nitrogen and Organic Fertilizer to Farmers' Super Rice Production Economy——Based on Empirical Study of 690 Rice Farmers in Eight Counties in Liaoning,Zhejiang and Hunan Province 被引量:5
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作者 陈庆根 王磊 《Agricultural Science & Technology》 CAS 2011年第9期1381-1384,共4页
[Objective] The aim was to investigate the contribution of potassium,nitrogen and organic fertilizer to super rice production.[Method] The data about the labor force input,fertilizer input,organic fertilizer input,con... [Objective] The aim was to investigate the contribution of potassium,nitrogen and organic fertilizer to super rice production.[Method] The data about the labor force input,fertilizer input,organic fertilizer input,contents of effective nitrogen and effective potassium in production,obtained through empirical study of 690 rice farmers in eight counties (cities) in Liaoning,Zhejiang and Hunan in 2009,were analyzed by using Cobb-Douglas production function model to study influence of material input (especially the fertilizer input) and labor force input to the yield of super rice,and the correlation between the input and the yield of rice production.[Result] The increase in amount of organic fertilizer has significantly increased the yield of super rice.The amount of chemical fertilizer applied is becoming more reasonable,but increase of yield does not result in increase of value.Different types of fertilizers have significantly different capabilities in increasing yields of super rice.The potassium fertilizer is superior to phosphorous fertilizer,while phosphorous is superior to nitrogenous fertilizer in improving production capacity.[Conclusion] The paper suggests that it should continue to increase the amount of organic fertilizers and potassium fertilizer and meanwhile control the amount of nitrogenous fertilizer in super rice production at present. 展开更多
关键词 Super rice Fertilizers contribution to growth
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Research on Economic Impact of Super Rice on Rice Growers and Contribution to Food Security 被引量:2
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作者 陈庆根 《Agricultural Science & Technology》 CAS 2015年第11期2581-2588,共8页
Super rice is an essendal part of China's rice production. Through survey on actual situation of 1568 households of rice growers in Heilongjiang, Hunan and Zhejiang provinces, this paper focused on influence of super... Super rice is an essendal part of China's rice production. Through survey on actual situation of 1568 households of rice growers in Heilongjiang, Hunan and Zhejiang provinces, this paper focused on influence of super rice development on increase of China's grain yield, influence on increase of rice growers' economic in- come, difference in production cost and profit between the North and the South, as well as profit percentage of super rice in production, processing, and sales. It obtained following results: rice price determines rice growers' income; expansion of super rice extension area plays a great role in increase of China's grain yield; by 2015 and 2020, keeping the yield of other crops not changed, merely the extension of super rice can increase grain for 5 million tons and 11 million tons separately; super rice significantly increases rice growers' economic income; for production cost of super rice, the South is higher than the North, and the profit ratio of cost is up to 35.54% on average; with respect of profit in production, processing, and sales, the ratio is 1:2:1.5; with the yield of other crops unchanged, every increase of 1% in area percentage of super rice to rice will additionally produce 1 million tons of grain for China, which is equivalent to saving the yield of 133 300 hm2 farmland and can additional feed 3.5 million people. In view of importance of super rice production, at the same time of strengthening research on super rice variety, it is required to accelerate expanding production area of super rice in suitable areas. Since the development of super rice can support China's ration demand of increasing population, China should make effort to realize "one yuan for one mu" financial subsidy for super rice of main grain production provinces and counties. Besides, China should establish special financial plan for extension of super rice. 展开更多
关键词 Super rice Economic impact contribution to food security Conclusions and recommendations
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Climate Warming Mitigation from Nationally Determined Contributions 被引量:2
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作者 Bo FU Jingyi LI +7 位作者 Thomas GASSER Philippe CIAIS Shilong PIAO Shu TAO Guofeng SHEN Yuqin LAI Luchao HAN Bengang LI 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2022年第8期1217-1228,共12页
Individual countries are requested to submit nationally determined contributions(NDCs)to alleviate global warming in the Paris Agreement.However,the global climate effects and regional contributions are not explicitly... Individual countries are requested to submit nationally determined contributions(NDCs)to alleviate global warming in the Paris Agreement.However,the global climate effects and regional contributions are not explicitly considered in the countries’decision-making process.In this study,we evaluate the global temperature slowdown of the NDC scenario(ΔT=0.6°C)and attribute the global temperature slowdown to certain regions of the world with a compact earth system model.Considering reductions in CO_(2),CH_(4),N_(2)O,BC,and SO_(2),the R5OECD(the Organization for Economic Co-operation and Development in 1990)and R5ASIA(Asian countries)are the top two contributors to global warming mitigation,accounting for 39.3%and 36.8%,respectively.R5LAM(Latin America and the Caribbean)and R5MAF(the Middle East and Africa)followed behind,with contributions of 11.5%and 8.9%,respectively.The remaining 3.5%is attributed to R5REF(the Reforming Economies).Carbon Dioxide emission reduction is the decisive factor of regional contributions,but not the only one.Other greenhouse gases are also important,especially for R5MAF.The contribution of short-lived aerosols is small but significant,notably SO_(2)reduction in R5ASIA.We argue that additional species beyond CO_(2)need to be considered,including short-lived pollutants,when planning a route to mitigate climate change.It needs to be emphasized that there is still a gap to achieve the Paris Agreement 2-degree target with current NDC efforts,let alone the ambitious 1.5-degree target.All countries need to pursue stricter reduction policies for a more sustainable world. 展开更多
关键词 climate mitigation nationally determined contributions ATTRIBUTION regional contribution integrated assessment models
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Agricultural Development of Nanjing Suburban Counties based on Contribution Models of Production Factors
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作者 李响 张琤琤 +1 位作者 李睿婷 许才明 《Agricultural Science & Technology》 CAS 2012年第12期2663-2666,共4页
According to data in Nanjing Statistical Yearbook, contribution made by agricultural production factors was analyzed with contribution models of agricultural factors and the results showed that with restriction of lab... According to data in Nanjing Statistical Yearbook, contribution made by agricultural production factors was analyzed with contribution models of agricultural factors and the results showed that with restriction of labor force and land, Nanjing suburban counties have entered into a stage of "high input-high output", considering no matter from agricultural total value of output or from agricultural added value. In future, structure configuration of agricultural input factors should be optimized in Nanjing suburban counties by technology input to improve agricultural technology and technical efficiency in order to further achieve sustainable development of agriculture. 展开更多
关键词 Nanjing suburban counties Agricultural output Input factors contribution analysis
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Evaluation of Red Blood Cell Contribution to Platelet Activation in the Bulk Applying Red Blood Cell—Platelet Thrombus as a Point Source Model 被引量:1
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作者 Taha M. Alkhamis Bahieh M. Alma’atah 《Advances in Bioscience and Biotechnology》 2022年第2期92-111,共20页
In this study, a point source mathematical model is proposed to describe the diffusion of adenosine di-phosphate (ADP) from either damaged red blood cell (RBC) or activated platelet. The convective diffusion equation ... In this study, a point source mathematical model is proposed to describe the diffusion of adenosine di-phosphate (ADP) from either damaged red blood cell (RBC) or activated platelet. The convective diffusion equation is reduced to describe the suggested problem. The final differential equation is solved using Laplace transforms and ADP concentration profiles around the source are obtained. Thrombi of 5 to 20 μm<sup>3</sup> containing platelets and a range of red blood cells (RBCs) (0%, 25%, 50%, 75%, 100%) concentrations are used to apply the model. Reported ADP concentrations in the literature are used and its dynamic release from the point source is calculated. Results suggest that RBC chemical contribution to platelet aggregation in the bulk is much less than that of platelet (almost) negligible. However, the physical effect of RBCs is dominant in the bulk through augmentation of released ADP and platelets diffusivities. Moreover, the chemical contribution reported in previous studies is suggested to be as a result of interaction of RBC with the surface under the influence of shear stresses in the boundary region. 展开更多
关键词 PLATELET Red Blood Cell AGGREGATION Adhesion Diffusion ADP Point Source Chemical contribution Physical contribution Shear Stresses HEMOLYSIS
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The Shareholders' Responsibility for Contribution of Balance of the Equity Assignee
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作者 Zhu Lina East China University of Politics and Law, Shanghai, 200042 《China's Foreign Trade》 2011年第23期52-54,共3页
2005年修订的《公司法》第31条规定:"有限责任公司成立后,作为发现设立公司出资的非货币财产的实际价额显著低于公司章程所定价额的应当由交付该出资的股东补足其差额;公司设立时的其他股东承担连带责任。"从该条规定可知,差... 2005年修订的《公司法》第31条规定:"有限责任公司成立后,作为发现设立公司出资的非货币财产的实际价额显著低于公司章程所定价额的应当由交付该出资的股东补足其差额;公司设立时的其他股东承担连带责任。"从该条规定可知,差额补缴责任的主体为公司成立后发现的特定的瑕疵出资人。 展开更多
关键词 stock rights Shareholder’ defective capital contribution Shareholder’ responsibility for contribution of balance
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Soil Organic Nitrogen and Its Contribution to Crop Production 被引量:17
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作者 LI Sheng-xiu WANG Zhao-hui +1 位作者 MIAO Yan-fang LI Shi-qing 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2014年第10期2061-2080,共20页
Plant growth and crop production depend to a large extent on soil N supplying capacity (SNSC): The higher the SNSC, the higher the dependence of crops on soil and the lower the N fertilizer recovery. Of the SNSC, s... Plant growth and crop production depend to a large extent on soil N supplying capacity (SNSC): The higher the SNSC, the higher the dependence of crops on soil and the lower the N fertilizer recovery. Of the SNSC, soil organic N (ON) played a key role in supplying N nutrient to crop production and still does in many subsistence and low-input farming systems. In this paper, soil ON contents, types, chemical components and its contribution to plant production are reviewed up to date in details, the characteristics of ON in dryland soils discussed together with its chemical components, and the mineralization and availability to plants of some important chemical components are emphasized at the last part for practical considerations. 展开更多
关键词 organic nitrogen in soil chemical components soil N supplying capacity MINERALIZATION contribution
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Weapons system portfolio selection based on the contribution rate evaluation of system of systems 被引量:11
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作者 DOU Yajie ZHOU Zhexuan +1 位作者 ZHAO Danling WEI Yong 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2019年第5期905-919,共15页
The weapons system portfolio selection problem arises at the equipment demonstration stage and deals with the military application requirements.Further,the contribution rate of the system is one of the important indic... The weapons system portfolio selection problem arises at the equipment demonstration stage and deals with the military application requirements.Further,the contribution rate of the system is one of the important indicators to evaluate the role of a system,which can facilitate the weapons system portfolio selection.Therefore,combining the system contribution rate with system portfolio selection is the focus of this study.It also focuses on calculating the contribution rates of multiple equipment systems with various types of capabilities.The contribution rate is measured by establishing a hierarchical multi-criteria value model from three dimensions.Based on the value model,the feasible portfolios are developed under certain cost constraints and the optimal weapons system portfolios are obtained by using the classification optimization selection strategy.Finally,an illustrative example is presented to verify the feasibility of the proposed model. 展开更多
关键词 WEAPON SYSTEM SYSTEM of systems (SoS) portfolioselection contribution rate EVALUATION DECISION analysis
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Contribution of Mass Elevation Effect to the Altitudinal Distribution of Global Treelines 被引量:10
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作者 ZHAO Fang ZHANG Bai-ping +4 位作者 ZHANG Shuo QI Wen-wen HE Wen-hui WANG Jing YAO Yong-hui 《Journal of Mountain Science》 SCIE CSCD 2015年第2期289-297,共9页
Alpine treeline, as a prominent ecological boundary between forested mountain slopes and alpine meadow/shrub, is highly complex in altitudinal distribution and sensitive to warming climate. Great efforts have been mad... Alpine treeline, as a prominent ecological boundary between forested mountain slopes and alpine meadow/shrub, is highly complex in altitudinal distribution and sensitive to warming climate. Great efforts have been made to explore their distribution patterns and ecological mechanisms that determine these patterns for more than 100 years, and quite a number of geographical and ecophysiological models have been developed to correlate treeline altitude with latitude or a latitude related temperature. However,on a global scale, all of these models have great difficulties to accurately predict treeline elevation due to the extreme diversity of treeline site conditions.One of the major reasons is that "mass elevation effect"(MEE) has not been quantified globally and related with global treeline elevations although it has been observed and its effect on treeline elevations in the Eurasian continent and Northern Hemisphere recognized. In this study, we collected and compiled a total of 594 treeline sites all over the world from literatures, and explored how MEE affects globaltreeline elevation by developing a ternary linear regression model with intra-mountain base elevation(IMBE, as a proxy of MEE), latitude and continentality as independent variables. The results indicated that IMBE, latitude and continentality together could explain 92% of global treeline elevation variability, and that IMBE contributes the most(52.2%), latitude the second(40%) and continentality the least(7.8%) to the altitudinal distribution of global treelines. In the Northern Hemisphere, the three factors' contributions amount to 50.4%, 45.9% and 3.7% respectively; in the south hemisphere, their contributions are 38.3%, 53%, and 8.7%, respectively. This indicates that MEE, virtually the heating effect of macro-landforms, is actually the most significant factor for the altitudinal distribution of treelines across the globe, and that latitude is relatively more significant for treeline elevation in the Southern Hemisphere probably due to fewer macro-landforms there. 展开更多
关键词 Alpine treeline Intra-mountain base elevation Multiple regression analysis Geographicalfactor Continentality contribution rate
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Solvent Selection for Extractive Distillation by the Universal Quasichemical Functional Group Activity Coefficient(UNIFAC) Group Contribution Method 被引量:7
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作者 崔现宝 翟亚锐 +2 位作者 杨志才 冯天扬 张缨 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2004年第6期862-868,共7页
A method to select solvent for extractive distillation is proposed by UNIFAC group contribution. Solventselectivity can be divided into two parts: the partial combinatorial solvent selectivity and the partial residual... A method to select solvent for extractive distillation is proposed by UNIFAC group contribution. Solventselectivity can be divided into two parts: the partial combinatorial solvent selectivity and the partial residual solventselectivity. The properties of partial combinatorial and residual solvent selectivity are demonstrated. In most cases,the partial residual solvent selectivity is predominant. The candidate groups of solvent can be selected by groupinteraction parameter using UNIFAC group interaction parameter table as a guide. 展开更多
关键词 solvent selection solvent selectivity UNIFAC group contribution extractive distillation
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Prediction of Flash Point Temperature of Organic Compounds Using a Hybrid Method of Group Contribution + Neural Network + Particle Swarm Optimization 被引量:7
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作者 Juan A. Lazzus 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2010年第5期817-823,共7页
The flash points of organic compounds were estimated using a hybrid method that includes a simple group contribution method (GCM) implemented in an artificial neural network (ANN) with particle swarm optimization (PSO... The flash points of organic compounds were estimated using a hybrid method that includes a simple group contribution method (GCM) implemented in an artificial neural network (ANN) with particle swarm optimization (PSO). Different topologies of a multilayer neural network were studied and the optimum architecture was determined. Property data of 350 compounds were used for training the network. To discriminate different substances the molecular structures defined by the concept of the classical group contribution method were given as input variables. The capabilities of the network were tested with 155 substances not considered in the training step. The study shows that the proposed GCM+ANN+PSO method represent an excellent alternative for the estimation of flash points of organic compounds with acceptable accuracy (AARD = 1.8%; AAE = 6.2 K). 展开更多
关键词 flash point group contribution method artificial neural networks particle swarm optimization property estimation
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Molecular reconstruction model based on structure oriented lumping and group contribution methods 被引量:7
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作者 Jincai Chen Zhou Fang Tong Qiu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2018年第8期1677-1683,共7页
Molecular management is a promising technology to face challenges in the refining industry, such as more stringent requirements for product oil and heavier crude oil, and to maximize the value of every molecule in pet... Molecular management is a promising technology to face challenges in the refining industry, such as more stringent requirements for product oil and heavier crude oil, and to maximize the value of every molecule in petroleum fractions. To achieve molecular management in refining processes, a novel model that is based on structure oriented lumping(SOL) and group contribution(GC) methods was proposed in this study. SOL method was applied to describe a petroleum fraction with structural increments, and GC method aimed to estimate molecular properties. The latter was achieved by associating rules between SOL structural increments and GC structures. A three-step reconstruction algorithm was developed to build a representative set of molecules from partial analytical data. First, structural distribution parameters were optimized with several properties. Then, a molecular library was created by using the optimized parameters. In the final step, maximum information entropy(MIE) method was applied to obtain a molecular fraction. Two industrial samples were used to validate the method, and the simulation results of the feedstock properties agreed well with the experimental data. 展开更多
关键词 Molecular reconstruction Structure oriented lumping Group contribution Monte Carlo Maximum information entropy
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