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The Lead-Chelating Effects of Substituted Dithiocarbamates
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作者 SUSHIL K.TANDON NOORUS S.HASHMI DEVENDRA N.KACHRU 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 1990年第3期299-305,共7页
The effectiveness of certain substituted dithiocarbamates in mobilizing lead from preexposed rats was investigated.The animals received 10mg Pb/kg/day, intragastrically.for 8 weeks and were treated thereafter with 400... The effectiveness of certain substituted dithiocarbamates in mobilizing lead from preexposed rats was investigated.The animals received 10mg Pb/kg/day, intragastrically.for 8 weeks and were treated thereafter with 400μmol/kg, intraperitoneally.of morpholine dithiocarbamate, tetraammonium ethylenediamine diacetic acid dithiocarbamate (EDDTC), ammonium diethanolamine dithiocarbamate (ADDTC), sodium diethyldithiocarbamate.N-benzyl-D-glucamine dithiocarbamate (NBGDTC), or dimercaptosuccinic acid, daily for 5 days.All the chelating agents were effective in lowering the hepatic and renal burden of Pb.ADDTC.EDDTC, and NBGDTC were also able to lower the long bone Pb content.The lowering of Pb burden had no relationship to restoration of Pb-induced hematopoietic alterations.The relatively lower lipophilicity of substituted dithiocarbamates, owing to the presence of hydrophilic groups, seems to be advantageous in preventing passage of metal chelale into the brain.None of the substituted dithiocarbamates caused excessive excretion of urinary Cu and Zn.ADDTC and EDDTC appear to be promising in the management of Pb poisoning. 1990 Academic Press.Inc. 展开更多
关键词 The Lead-Chelating effects of substituted Dithiocarbamates DMSA
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Off-farm employment,agriculture production activities,and household dietary diversity in environmentally and economically vulnerable areas of Asia 被引量:1
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作者 Yunli Bai Xuanye Zeng +1 位作者 Chao Fu Linxiu Zhang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第2期359-373,共15页
Access to off-farm employment has been expected to be a critical approach to ending hunger and all forms of malnutrition,two important targets of achieving Zero Hunger.This study aims to investigate the role of off-fa... Access to off-farm employment has been expected to be a critical approach to ending hunger and all forms of malnutrition,two important targets of achieving Zero Hunger.This study aims to investigate the role of off-farm employment in improving dietary diversity through substitution effect and complementary effect with agricultural production activities and income effect.This study adopts Poisson/Tobit/Probit/OLS regressions and the instrument variable method based on the primary survey data collected among 1,282 households at 12 sites in environmentally and economically vulnerable areas of China,Nepal,Cambodia,Thailand,and Myanmar in 2019.The results show that off-farm employment is positively associated with household dietary diversity and the consumption of flesh meat,fish and other aquatic animals,fruits,and milk and dairy products,which are rich in protein and micronutrients.The results of mechanism analysis show that off-farm employment contributes to household dietary diversity by improving crop diversity,especially for poor households,boosting the probability of livestock raising for households with the middle one-third disposal income,and increasing household income.The positive association between off-farm employment and household dietary diversity is much higher for households with the bottom one-third disposal income,low illiteracy,and from upper-middle income countries.These findings imply that off-farm employment does play a vital role in achieving multiple benefits of poverty alleviation,malnutrition reduction,and agrobiodiversity conservation in environmentally and economically vulnerable areas.However,it may enlarge the gaps in dietary diversity between households with low human capital and from low and lower-middle income countries and those with high human capital and from middle-high countries. 展开更多
关键词 off-farm employment dietary diversity income effect substitution effect complementary effect
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Theoretical Study of the C-CI Bond Dissociation Enthalpy and Electronic Structure of Substituted Chlorobenzene Compounds 被引量:1
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作者 张瑞州 李小红 张现周 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2009年第3期235-240,339,共7页
Quantum chemical calculations were used to estimate the bond dissociation energies (BDEs) for 13 substituted chlorobenzene compounds. These compounds were studied by the hybrid density functional theory (B3LYP, B3P... Quantum chemical calculations were used to estimate the bond dissociation energies (BDEs) for 13 substituted chlorobenzene compounds. These compounds were studied by the hybrid density functional theory (B3LYP, B3PW91, B3P86) methods together with 6-31G^** and 6-311G^** basis sets. The results show that B3P86/6-311G^** method is the best method to compute the reliable BDEs for substituted chlorobenzene compounds which contain the C-C1 bond. It is found that the C-C1 BDE depends strongly on the computational method and the basis sets used. Substituent effect on the C-C1 BDE of substituted chlorobenzene compounds is further discussed. It is noted that the effects of substitution on the C-C1 BDE of substituted chlorobenzene compounds are very insignificant. The energy gaps between the HOMO and LUMO of studied compounds estimate the relative thermal stability ordering are also investigated and from this data we of substituted chlorobenzene compounds. 展开更多
关键词 Density functional theory Bond dissociation enthalpy Substituent effect substituted chlorobenzene compound
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Enhancing wood efficiency through comprehensive wood flow analysis:Methodology and strategic insights
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作者 Ruisheng Wang Peer Haller 《Forest Ecosystems》 SCIE CSCD 2024年第2期172-183,共12页
Wood,an essential natural resource in human civilization,remains widely used despite advances in technology and material substitution.The surge in greenhouse gas emissions and environmental concerns accentuates the ne... Wood,an essential natural resource in human civilization,remains widely used despite advances in technology and material substitution.The surge in greenhouse gas emissions and environmental concerns accentuates the need for optimizing wood utilization.Material flow analysis is a powerful tool for tracking material flows and stocks,aiding resource management and environmental decision-making.However,the full extent of its methodological dimensions,particularly within the context of the wood supply chain,remains relatively unexplored.In this study,we delve into the existing literature on wood flow analysis,discussing its primary objectives,materials involved,temporal and spatial scales,data sources,units,and conversion factors.Additionally,data uncertainty,data reconciliation and crucial assumptions in material flow analysis are highlighted in this paper.Key findings reveal the significance of wood cascading and substitution effects by replacing non-wood materials,where they can reduce greenhouse gas emissions more than the natural carbon sink of forests and wood products.The immediate impact of short-term wood cascading might not be as robust as the substitution effect,with energy substitution showcasing better results than material substitution.However,it's crucial to note that these conclusions could experience significant reversal from a long-term and global perspective.Strategies for improving wood efficiency involve maximizing material use,advancing construction technologies,extending product lifespans,promoting cascade use,and optimizing energy recovery processes.The study underscores the need for standardized approaches in wood flow analysis and emphasizes the potential of wood efficiency strategies in addressing environmental challenges. 展开更多
关键词 Material flow analysis WOOD METHODOLOGY Cascade use Substitution effects
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Applications of fluid substitution effect analysis on seismic interpretation
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作者 陈伟 王尚旭 +1 位作者 啜晓宇 刘勇 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第3期729-739,共11页
The root mean square(RMS) difference of time-lapse seismic amplitudes is routinely used to identify the substituted fluid type in a reservoir during oil field production and recovery. By a time-lapse seismic method, w... The root mean square(RMS) difference of time-lapse seismic amplitudes is routinely used to identify the substituted fluid type in a reservoir during oil field production and recovery. By a time-lapse seismic method, we study the effects of fluid substitution in a physical model, which is an analogy of the three-dimensional inhomogeneous reservoir. For a weak inhomogeneous medium, gas/oil substitution results in positive anomalies in the reservoir layers, and negative anomalies below the bottom of the reservoir layers; while water/oil substitution causes only weak variations in the reservoir layers, but positive anomalies below the bottom of the reservoir layers. For the strong inhomogeneous medium, no matter what kind of fluid substitution(gas/oil or water/oil), there are significant anomalies in seismic amplitude difference attributes both in and below the reservoir layers. Therefore, for weak inhomogeneous media, such as tight sandstone or thin interbedded layers, the RMS amplitude difference attributes can be used to monitor fluid changes and predict the drilling direction; for inhomogeneous medium with karst carves or fractures, it is difficult to accurately determine the distribution of fluids with the RMS amplitude difference attributes. 展开更多
关键词 inhomogeneous medium physical modeling time-lapse seismic technique fluid substitution effect seismic attribute
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Effect of Substitution Site on Two-Photon Absorption and Excited States Properties of Lipid Droplets Detection NAPBr Dyes:a Theoretical Perspective
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作者 Hong-yang Wang Xiao-fei Wang +1 位作者 Jian-zhong Fan Yong Zhou 《Chinese Journal of Chemical Physics》 SCIE EI CAS CSCD 2022年第4期673-684,I0150,共13页
Two-photon fluorescence dyes have shown promising applications in biomedical imaging.However,the substitution site effect on geometric structures and photophysical properties of fluorescence dyes is rarely illustrated... Two-photon fluorescence dyes have shown promising applications in biomedical imaging.However,the substitution site effect on geometric structures and photophysical properties of fluorescence dyes is rarely illustrated in detail.In this work,a series of new lipid droplets detection dyes are designed and studied,molecular optical properties and non-radiative transitions are analyzed.The intramolecular weak interaction and electron-hole analysis reveal its inner mechanisms.All dyes are proven to possess excellent photophysical properties with high fluorescence quantum efficiency and large stokes shift as well as remarkable two-photon absorption cross section.Our work reasonably elucidates the experimental measurements and the effects of substitution site on two-photon absorption and excited states properties of lipid droplets detection NAPBr dyes are highlighted,which could provide a theoretical perspective for designing efficient organic dyes for lipid droplets detection in biology and medicine fields. 展开更多
关键词 Substituting effect Two-photon absorption cross section Non-radiative transition Fluorescence quantum efficiency
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Fluorine substitution position effects on spiro(fluorene-9,9’-xanthene) cored hole transporting materials for high-performance planar perovskite solar cells
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作者 Zhaoning Li Yikai Yun +4 位作者 Hongyan Huang Zhucheng Ding Xuewei Li Baomin Zhao Wei Huang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第6期341-350,I0008,共11页
Fluorine substitution in molecular design has become an effective strategy for improving the overall performance of organic photovoltaics.In this study,three low-cost small molecules of spiro-linked hole transporting ... Fluorine substitution in molecular design has become an effective strategy for improving the overall performance of organic photovoltaics.In this study,three low-cost small molecules of spiro-linked hole transporting materials(SFX-O-2 F,SFX-m-2 F,and SFX-p-2 F) endowed with two-armed t rip he ny la mine moieties were synthesized via tuning of the fluorine substitution position,and they were employed for use in highly efficient perovskite solar cells(PSCs).Despite the fluorine substitution position playing a negligible role in the optical and electrochemical properties of the resulting small molecules,the photovoltaic performance thereof was observed to vary significantly.The planar n-i-p PSCs based on SFX-m-2 F demonstrated superior performance(18.86%) when compared to that of the corresponding SFX-o-2 F(9.7%) and SFX-p-2 F(16.33%) under 100 mW cm^(-2) AM1.5 G solar illumination,which is competitive with the performance of the benchmark spiro-OMeTAD-based device(18.98%).Moreover,the SFX-m-2 Fbased PSCs were observed to be more stable than the spiro-OMeTAD-based devices under ambient conditions.The improved performance of SFX-m-2 F is primarily associated with improved morphology,more efficient hole transport,and extraction characteristics at the perovskite/HTM interface.This work demonstrated the application of fluorination engineering to the tuning of material film morphology and charge transfer properties,showing the promising potential of fluorinated SM-HTMs for the construction of low-cost,high-efficiency PSCs. 展开更多
关键词 Fluorine substitution position effects Hole-transporting material Perovskite solar cell Planar n-i-p PSCs
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Effect of the Partial Substitution of V for Nb on the Magnetic Properties of Fe-based Nanocrystalline Alloy
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作者 Guiqin ZHOU, Fazeng LIAN and Guozhen LI (Institute of Materials and Metallurgy, Northeastern University, Shenyang 110006,China) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2000年第6期643-644,共2页
The variation of the magnetic properties of the nanocrystalline alloys for the partial substitution of V for Nb with crystallizing treatment temperature and time was investigated. The variation law of the magnetic pro... The variation of the magnetic properties of the nanocrystalline alloys for the partial substitution of V for Nb with crystallizing treatment temperature and time was investigated. The variation law of the magnetic properties with the annealing temperature and time is essentially the same. The magnetic properties of the Fe-based nanocrystalline alloys for the partial substitution of V for Nb reduce, and the crystallizing treatment temperature of the alloys increases. The optimum properties of Fe74Cu1Nb3Si13B9 nanocrystalline alloys crystallized at 550℃x60 min are μ0=9.2xl0^4, μm=54.8xl0^4, Hc=1.14 A/m and Bs=1.26 T. The best properties for Fe74Cu1Nb3Si13B9 alloys annealed at 560℃x60 min are μ0=8.79x10^4, μm=50.18xl0^4, Hc=1.26 A/m and Bs=1.24 T. 展开更多
关键词 Fe effect of the Partial Substitution of V for Nb on the Magnetic Properties of Fe-based Nanocrystalline Alloy
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Effect of Zn Substitution on Magnetic Properties of CuFe_2O_4: a High-Temperature Series Expansions Study
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作者 S.Salmi R.Masrour +4 位作者 A.El Grini K.Bouslykhane A.Hourmatallah N.Benzakour M.Hamedoun 《Chinese Physics Letters》 SCIE CAS CSCD 2018年第1期95-98,共4页
The magnetic properties of spinel ferrites Cu_(1-x)Zn_xFe_2O_4 are studied using high-temperature series expansions combined with the Padé approximates. The exchange interactions, inter and intra-sublattices J_... The magnetic properties of spinel ferrites Cu_(1-x)Zn_xFe_2O_4 are studied using high-temperature series expansions combined with the Padé approximates. The exchange interactions, inter and intra-sublattices J_(AA), J_(BB) and J_(AB) are obtained using a probability distribution law. The critical exponent associated with the magnetic susceptibility is obtained. 展开更多
关键词 Cu Zn effect of Zn Substitution on Magnetic Properties of CuFe_2O_4
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Experimental and genomic evidence for the indica-type cytoplasmic effect in Oryza sativa L.ssp.japonica
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作者 LIU You-hong TANG Liang +4 位作者 XU Quan MA Dian-rong ZHAO Ming-hui SUN Jian CHEN Wen-fu 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2016年第10期2183-2191,共9页
Cytoplasmic effects are important agronomical phenomena that have generated widespread interest in both theory and application. In the present study, five high yield rice cultivars(Oryza sativa L. ssp. japonica) in ... Cytoplasmic effects are important agronomical phenomena that have generated widespread interest in both theory and application. In the present study, five high yield rice cultivars(Oryza sativa L. ssp. japonica) in large-scale cultivation in northeast China were determined to possess Oryza sativa L. ssp. indica-type cytoplasm using cytoplasmic subspecies-specific molecular markers. This was confirmed by cytoplasmic genome-wide single nucleotide polymorphisms(SNPs) and functional gene sequencing. Two of these five japonica cultivars were core breeding parents with high yield and the other three were super-high-yield varieties registered by the Ministry of Agriculture of China. We constructed nuclear substitution lines to further demonstrate whether and how this indica-type cytoplasm contributed to yield improvement by comparing yield components. The results showed that under the same japonica nuclear background, the lines with indica-type cytoplasm had a significant decrease in tillers in exchange for increased grain number per panicle compared with their recurrent parents. Our results implied that botanical basis of this cytoplasmic effect was to reduce the plant's branching differentiation to produce more floral organs under the constant nutrition. Our findings open another door for the utilization of inter-subspecific hybridization for the improvement of rice cultivar. 展开更多
关键词 cytoplasmic effects cytoplasmic genome-wide SNPs super high yield rice nuclear substitution lines
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药品集中带量采购对抗菌药物使用的影响分析:以阿莫西林为例
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作者 刘俊刚 石可凡 +3 位作者 贾佳佳 杨星怡 黄洁莹 徐伟 《中国卫生资源》 CSCD 北大核心 2023年第3期269-273,共5页
目的分析抗菌药物集中带量采购(以下简称“集采”)后使用变化,为完善我国带量采购政策和促进合理用药提供参考。方法采用描述性统计分析和间断时间序列分析方法,将第二批和第三批药品集采政策落地时间设为政策干预点,分析2019年1月—202... 目的分析抗菌药物集中带量采购(以下简称“集采”)后使用变化,为完善我国带量采购政策和促进合理用药提供参考。方法采用描述性统计分析和间断时间序列分析方法,将第二批和第三批药品集采政策落地时间设为政策干预点,分析2019年1月—2021年12月全国医药企业阿莫西林销售量和销售金额在集采前后的变化情况。结果阿莫西林胶囊剂和颗粒剂在集采后销售量大幅上升,非中选的胶囊剂和颗粒剂销售量也有所上升,但涨幅低于市场整体增长率。非集采剂型中的阿莫西林片剂和混悬剂销售量和销售金额均出现降低,口服剂型中选能有效降低同为口服剂型的其他非集采品规销售量,阿莫西林注射剂销售量和销售金额在集采后短期内明显增长,通过模型预测阿莫西林注射剂长期的销售量和销售金额呈下降趋势。结论药品带量采购能够实现药价降低且达成以量换价的目标,中选药品使用量显著增长,但需要关注同通用名下非集采剂型的使用量情况,减少不同剂型间替代使用的情况;应该进一步扩大抗菌药物集采范围,将更多临床具体替代关系的药物纳入采购范畴,加强对临床抗菌药物的使用监测,保障临床抗菌药物合理使用。 展开更多
关键词 集中带量采购volume-based procurement 抗菌药物antibacterial agent 替代效应substitution effect 间断时间序列discontinuous time series 合理用药rational drug use
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Redox chemistry of N_(4-)Fe^(2+)in iron phthalocyanines for oxygen reduction reaction 被引量:2
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作者 Anuj Kumar Ying Zhang +2 位作者 Yin Jia Wen Liu Xiaoming Sun 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第8期1404-1412,共9页
A precise understanding of the redox chemistry of Nm-Mn+(like N4-Fe^(2+))systems is essential for fundamental studies and rational design of Nm-Mn+-based electrocatalysts for the oxygen reduction reaction(ORR).Herein,... A precise understanding of the redox chemistry of Nm-Mn+(like N4-Fe^(2+))systems is essential for fundamental studies and rational design of Nm-Mn+-based electrocatalysts for the oxygen reduction reaction(ORR).Herein,three different iron phthalocyanines(FePcs)adsorbed on carbon nanotubes((NH2)4FePc@CNTs,(t-Bu)4FePc@CNTs,and FePc@CNTs)were evaluated to demonstrate the effect of the electron donating power of the substituents on the Fe^(3+)/Fe^(2+)redox potential of FePc@CNTs and the role of these composites as ORR mediators in alkaline media.The Fe^(3+)/Fe^(2+)redox potential of the FePcs was found to shift towards the cathodic region upon substitution with electron-donating groups.This up-field shift in the eg-orbital leads to a lower overlap between the onset potential of the Fe^(3+)/Fe^(2+)redox couple and that of the ORR,and thus,the ORR activity decreased in the following order based on the substitution of FePc:-H>-t-Bu>-NH2. 展开更多
关键词 Iron phthalocyanines Substitution effect Oxygen reduction reaction Carbon nanotubes Activity descriptor
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Theoretical Investigations of Nonlinear Optical Properties of Transition Metal Cluster Anions
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作者 刘彩萍 洒荣建 +3 位作者 莽朝永 李巧红 李福君 吴克琛 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2008年第8期955-966,共12页
In the framework of density functional theory (DFT), the electronic excitations and nonlinear optical (NLO) properties of six binuclear transition metal cluster anions with the formula of [Ch2M-(μ-Ch)2-M'CN]^... In the framework of density functional theory (DFT), the electronic excitations and nonlinear optical (NLO) properties of six binuclear transition metal cluster anions with the formula of [Ch2M-(μ-Ch)2-M'CN]^2- (M = Mo, W; Ch = S, Se; M' = Cu, Ag) have been systemically investigated at both cases of gas phase and DMF solution. The obtained electronic absorption spectra reveal that the element replacements of metals M and ligands Ch have significant influence on the absorptions, especially on the low-lying ones. In addition, the transitions of μ-Ch→M are dominant for the low-lying excitations, whereas the transitions of M'→M as well as Ch→M are mainly responsible for the higher excitations. The calculated molecular first and second hyperpolarizabilities present the remarkable element substitution and solvent effects. The analyses show that the transitions involving μ-Ch→M charge transfer make the critical contributions to the first hyperpolarizability t, and that the charge transfers from the moieties of MCh4 to M'CN as well as those of μ-Ch→M and M'→M are responsible for the second hyperpolarizability y. Moreover, the introduction of solvent leads to the results that the transitions within the moieties of MCh4 and M'CN make larger contributions to the hyperpolarizability, especially to γ. 展开更多
关键词 transition metal cluster anions density functional theory electronic excitation spectra HYPERPOLARIZABILITY element substituting effect solvent effect
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The Empirical Analysis of the Impacts of Income Distribution Gap on Consumption Demand:Based on the Statistic Data of Chinese Urban Residents in 2000-2010
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作者 Qian Long Zhao Yong Zhong Sheng 《Chinese Journal of Population,Resources and Environment》 2012年第4期116-120,共5页
This paper analyzes the impact of income distribution gap on consumption demand from a theoretical view,and draws the conclusion that there is an inverse relationship between income distribution gap and consumption de... This paper analyzes the impact of income distribution gap on consumption demand from a theoretical view,and draws the conclusion that there is an inverse relationship between income distribution gap and consumption demand.Then,the paper finds that the existing widening income distribution gap in China has a negative impact on consumption demand,but this is not the key factor for the insufficient consumption demand because of the low level of per capital income.At last,it suggests that governments should improve the income level of entire residents and adjust income distribution structure simultaneously. 展开更多
关键词 income distribution gap consumption demand elas- ticity coefficient substitution effects
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An assessment of Charter airline benefits for Port Elizabeth and the Eastern Cape
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作者 Radu Mihailescu 《Chinese Business Review》 2010年第2期34-45,共12页
Tourism is becoming a vital component for economic development in South Africa. The income generated by the tourism industry is about 6% of the GDP, which is significant but still falls short of the goal set by the Wh... Tourism is becoming a vital component for economic development in South Africa. The income generated by the tourism industry is about 6% of the GDP, which is significant but still falls short of the goal set by the White Paper on Tourism in 2000. In the light of South Africa hosting the 2010 Football World Cup, it is important to identify ways of sustainable tourism development that would continue to increase the benefits to the economy long after the event's over. The main objective of the research was to explore an idea for increasing the level of tourist income generated in the Port Elizabeth (Eastern Cape) area. The idea was researched by means of conducting a cost-benefit analysis of two tourist related projects. These projects would introduce Charter airline services between Europe and Port Elizabeth. A second objective was to identify constraints on the project or market failures which would prevent their implementation. The economic theory behind the operation of an airline showed that lease costs and aeroplane operating costs are the two most important factors determine Charter airline's profitability. In order to offset these costs, airlines must achieve high passenger load factors. Charter airlines have the advantage over scheduled airlines, in that they will only fly if a minimum level of people has pre-booked seats. Two aeroplanes were chosen for comparison purpose: an Airbus A 340-300 and a Boeing 767-300ER. The private benefits calculated were based on load factors between 80 and 95 percent for ticket prices of USD 667 and USD 773. In addition, to private costs and benefits, social benefits were also estimated in the form of additional secondary revenue generated. With the introduction of net social benefits, both projects become profitable. A 50 percent substitution of revenue generated by the Charter tourists reduces the profits for the both projects drastically. A project based on a Boeing 767-300ER is the most efficient project as it has the highest NPV and BCR values. A reduction in the lease cost of the Airbus 340-300 could make projects based on it more competitive. A few constraints on the establishment of a Charter airline operator based in Port Elizabeth are: the lack of adequate runway for the landing of the long-haul carriers and the need of a larger liberalisation of the aviation policy by eliminating protectionism. The cost benefit analysis undertaken in this research does not take into account social costs and benefits to the economy of establishing a Charter airline based in Port Elizabeth, such as an employment, infrastructure development and poverty alleviation. Nevertheless the analysis does suggest that there are strong private and social benefits warranting the establishment of an airline business between Europe and Port Elizabeth. The economic benefits of the tourism industry and its link to airline travel are outlined in section 3. It is shown that the growth of the airline industry is a major component and contributor to tourism growth. 展开更多
关键词 cost-benefit analysis private cost/benefits Airbus A 340-300 Boeing 767-300ER substitution effect load factor discount rate.
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How does digital transformation affect corporate accounting employees?
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作者 Yunsen Chen Chen Lu Zhe Li 《China Journal of Accounting Research》 2024年第4期143-164,共22页
The rapid pace of digitalization has given rise to concerns about its influence on job roles.Our findings reveal a substitution effect on accounting employees.This effect is more evident in private firms,firms with hi... The rapid pace of digitalization has given rise to concerns about its influence on job roles.Our findings reveal a substitution effect on accounting employees.This effect is more evident in private firms,firms with higher levels of digital transformation in their accounting departments,firms in the information technology industry,firms with overconfident managers and firms with a higher-level network infrastructure.Digitalization also has a positive effect on technically skilled and highly educated employees,leading to a decline in the proportion of entry-level employees.We also document that digitalization contributes to more efficient labor investment.Our study therefore offers insights into how digital transformation can change the labor market for accounting employees. 展开更多
关键词 Digital Transformation Accounting Employees Substitution effect
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Effect of Co substitution on the glass forming ability and magnetocaloric effect of Fe88Zr8B4 amorphous alloys 被引量:2
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作者 LiangHua Gan LiYan Ma +2 位作者 BenZhen Tang Ding Ding Lei Xia 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2017年第7期81-84,共4页
As greater attention is paid to energy consumption and global warming, magnetic refrigeration (MR) technologies based on the magneto-caloric effect (MCE) have been developed. Systems based on MR are expected to be... As greater attention is paid to energy consumption and global warming, magnetic refrigeration (MR) technologies based on the magneto-caloric effect (MCE) have been developed. Systems based on MR are expected to be more compact, energy efficient, and environmentally safe compared with traditional vapor-cycle refrigeration technologies . 展开更多
关键词 effect of Co substitution on the glass forming ability and magnetocaloric effect of Fe Co FIGURE Zr8B4 amorphous alloys
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DEGREE OF BRANCHING OF THE HYPERBRANCHED POLYMERS RESULTED FROM AB_2 POLYCONDENSATION WITH SUBSTITUTION EFFECT
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作者 周志平 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2011年第5期569-574,共6页
The analytical expressions of the various structural units and the average degree of branching for the hyperbranched polymers resulted from AB2 polycondensation with substitution effect were derived by the kinetic mec... The analytical expressions of the various structural units and the average degree of branching for the hyperbranched polymers resulted from AB2 polycondensation with substitution effect were derived by the kinetic mechanism. The reactivity difference between the 13 group in linear unit and that in terminal group has great effect on the molecular parameters of the products obtained. The concentration of terminal units has a maximum with the increase of the conversion of A groups (x). The higher the reactivity ratio (r) of linear B group to branched one is, the later the maximum appears and the larger it is. The degree of branching of the hyperbranched polymers obtained is controllable by adjusting the parameters of r and x, which increases with increasing both x and r. 展开更多
关键词 Degree of branching POLYCONDENSATION Hyperbranched polymers Substitution effect.
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Preparation, Structure and Magnetic Properties of Lithium Substituted NiO by Molten Salt Method
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作者 DU Fei BIE Xiao-fei +4 位作者 BIAN Xiao-fei HU Fang CHEN Gang WANG Chun-zhong WEI Ying-jin 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2013年第2期210-213,共4页
A typical Li+ substituted NiO compound, Li0.29Ni0.710, was synthesized by molten nitrate method. The ef- fects of Li+ substitution on the structure and magnetic properties of NiO were investigated. X-Ray diffraction... A typical Li+ substituted NiO compound, Li0.29Ni0.710, was synthesized by molten nitrate method. The ef- fects of Li+ substitution on the structure and magnetic properties of NiO were investigated. X-Ray diffraction(XRD), scanning electron microscope(SEM) and high-resolution transmission electron microscope(HRTEM) analyses con- firm the cubic structure of Li0.29Ni0,710, with a primary particle size of 150 nm. Analysis of the Ni X-ray photoelec- tron spectroscopy(XPS) shows the transformation from Ni2. to Ni3+ induced by Li+ substitution. Two magnetic tran- sitions were observed at 225 and 55 K which were assigned to the ferrimagnetic ordering and spin glass transition, respectively. The different magnetic behavior with respect to that of NiO was attributed to the break of superexchange interaction Ni2+-O-Ni2+ and the formation of different spin clusters after non-magnetic Li+ doping. 展开更多
关键词 NIO Magnetic property Substitution effect
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Elemental Substitution Effects in High-T_c Superconductor YBa_2Cu_3O_(7-δ)*
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作者 张其瑞 许祝安 +4 位作者 王劲松 谭明秋 方明虎 张酣 何振辉 《Science China Mathematics》 SCIE 1993年第11期1376-1385,共10页
This paper reports the experimental results of the investigation on elemental substitution effects in YBa_2Cu_3O_(7-δ) and the new physical ideas deduced comprehensively. It is shown that all the orthorhombic crystal... This paper reports the experimental results of the investigation on elemental substitution effects in YBa_2Cu_3O_(7-δ) and the new physical ideas deduced comprehensively. It is shown that all the orthorhombic crystalline structure, oxygen content, oxidation valence of Cu atoms, and metal-semiconductor (insulator) transition are only the extrinsic factors deter mining the T_c of the systems, and there are two mechanisms of substitution effects, namely the mechanism of the substitution effects outside the CuO_2 planes and that within the CuO_2 planes. We suggest that the mobile carrier concentration and the dynamic, short-range antiferromagnetic correlation between Cu(2) atoms on the CuO_2 planes are the two intrinsic factors determining the high T_c superconductivity. 展开更多
关键词 YBa_2Cu_3O_(7-8) substitution effect intrinsic factors determining T_c.
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