Morocco wants its 12 regions to play the role as the main lever of its public policies to initiate harmonized spatial multidimensional development. In the context of this goal and Morocco’s openness over the past two...Morocco wants its 12 regions to play the role as the main lever of its public policies to initiate harmonized spatial multidimensional development. In the context of this goal and Morocco’s openness over the past two decades to bilateral and multilateral cooperation in an effort toward regional integration, this article studies the convergence of 389 regions in 36 countries(Morocco and 35 of its partner member countries in the Organization for Economic Co-operation and Development(OECD)) between 2000 and 2019 in terms of well-being. To this end, we considered the territorial dimension of β-convergence models for well-being and its four domains(economic, social, environmental, and governance). Then, we adapted the absolute β-convergence model by taking into account the existence of spatial heterogeneity according to five specifications of spatial models. Thus, apart from environmental domain, we found that β-convergence of regions is significant for well-being and three of its domains(economic, social, and governance). These convergences are made by a spatially autocorrelated error model(SEM). However, the speed and period of convergence are relatively low for social domain, partly explaining the very exacerbated tensions at the territorial level. The fastest convergence was achieved in governance domain, followed by economic domain. This suggests that emerging countries must pay particular attention to national public action in favor of social cohesion at the territorial level. The lack of convergence in environmental domain calls for common actions for all countries at the supranational level to protect the commons at the territorial level.展开更多
In this paper, the effect of the mediation effect is mainly used to test and analyze the regression model, and most scholars have studied the impact of the modernization of the industrial structure on the income gap. ...In this paper, the effect of the mediation effect is mainly used to test and analyze the regression model, and most scholars have studied the impact of the modernization of the industrial structure on the income gap. However, this paper is from another perspective, based on the social background of high-quality development, the main study is the impact mechanism of urban and rural income gap on the industrial structure, taking the Yangtze River Delta as the main research object, and specifically selecting 22 central cities in the Yangtze River Delta region, which is also one of the highlights of this study. The regression model is constructed by using the intermediary effect, and the four intermediary variables of fiscal expenditure (M<sub>1</sub>), fixed asset investment (M<sub>2</sub>), number of patent applications (M<sub>3</sub>), and total import and export (M<sub>4</sub>) are selected, which represent the role of the government, fixed asset investment, scientific and technological level and opening-up level, and study and analyze the inherent influence mechanism between each variable. Before doing specific research, I consulted the papers and literature of many other outstanding scholars, among which Cheng Yuhong and Cheng Chi’s “The Influence Mechanism of industrial structure of urban and rural income gap” [1] has great reference value for this paper. According to the research results, under the background of high-quality development in the Yangtze River Delta region, the expansion of the income gap between urban and rural areas will inhibit the upgrading of the industrial structure, so it is necessary to focus on building a new type of urbanization, accelerating the construction of an urban innovation system, optimizing the rural employment structure to narrow the income gap between urban and rural areas, and providing impetus for the continuous upgrading of the industrial structure.展开更多
In this paper, the zero voltage switching (ZVS) region of a dual active bridge (DAB) converter with wide band-gap (WBG) power semiconductor device is analyzed. The ZVS region of a DAB converter varies depending on out...In this paper, the zero voltage switching (ZVS) region of a dual active bridge (DAB) converter with wide band-gap (WBG) power semiconductor device is analyzed. The ZVS region of a DAB converter varies depending on output power and voltage ratio. The DAB converters operate with hard switching at light loads, it is difficult to achieve high efficiency. Fortunately, WBG power semiconductor devices have excellent hard switching characteristics and can increase efficiency compared to silicon (Si) devices. In particular, WBG devices can achieve ZVS at low load currents due to their low parasitic output capacitance (C<sub>o,tr</sub>) characteristics. Therefore, in this paper, the ZVS operating resion is analyzed based on the characteristics of Si, silicon carbide (SiC) and gallium nitride (GaN). Power semiconductor devices. WBG devices with low C<sub>o,tr</sub> operate at ZVS at lower load currents compared to Si devices. To verify this, experiments are conducted and the results are analyzed using a 3 kW DAB converter. For Si devices, ZVS is achieved above 1.4 kW. For WBG devices, ZVS is achieved at 700 W. Due to the ZVS conditions depending on the switching device, the DAB converter using Si devices achieves a power conversion efficiency of 91% at 1.1 kW output. On the other hand, in the case of WBG devices, power conversion efficiency of more than 98% is achieved under 11 kW conditions. In conclusion, it is confirmed that the WBG device operates in ZVS at a lower load compared to the Si device, which is advantageous in increasing light load efficiency.展开更多
Two factors determining the level of living in different areas are income level and price level. Current studies on regional gaps concentrate on the gap in income levels. The present paper studies the impact of the tw...Two factors determining the level of living in different areas are income level and price level. Current studies on regional gaps concentrate on the gap in income levels. The present paper studies the impact of the two variables on the real living standards in different regions, with the real gap in the living standards calculated with price adjustment by taking into consideration only the deviations brought about by cash income. The basic conclusion is that, despite China＇s economy having witnessed rapid growth, the statistics at the macro level cannot disguise the obvious gaps among regions; therefore, as a result of the impact of income and price, the real gap in the living standards among different regions is smaller than the gap indicated by the nominal income level. As people are sensitive to cash income level, they have a low sensitivity to changes in real purchasing power. In other words, in areas that have the same real income levels, people tend to think that people live better when the nominal income and price are both high. The differences in price indices among different regions show that the same cash income can get different goods and services in different regions. This explains the rationale of the existence of floating workers among different regions. On this basis, we predict that people working in high-income areas who enjoy higher levels of social security might prefer to live in low-price areas after retirement if the social security payment method becomes more flexible.展开更多
GAP分析是用来判别生物多样性保护的空白、遗漏区域(“gaps”)和需要采取保护行动的地区(conservation gap),它是一种评估区域生物多样性所有成分所处保护地位、被保护程度等的科学方法。强调最大限度地保护生物多样性的先决条件是通过...GAP分析是用来判别生物多样性保护的空白、遗漏区域(“gaps”)和需要采取保护行动的地区(conservation gap),它是一种评估区域生物多样性所有成分所处保护地位、被保护程度等的科学方法。强调最大限度地保护生物多样性的先决条件是通过构建保护区网络,不仅仅考虑生物多样性最高地区,应该使本地种和生态系统都得到保护。区域生态安全格局的评价不仅要考虑生物及其生境的保护,而且,更要考虑受损生态系统和破坏景观的恢复,即不仅考虑Conservation G ap,也要考虑R estoration G ap。因而,改进GAP方法可用于生态安全格局的分析与评价,且有望成为重要的研究手段。展开更多
文摘Morocco wants its 12 regions to play the role as the main lever of its public policies to initiate harmonized spatial multidimensional development. In the context of this goal and Morocco’s openness over the past two decades to bilateral and multilateral cooperation in an effort toward regional integration, this article studies the convergence of 389 regions in 36 countries(Morocco and 35 of its partner member countries in the Organization for Economic Co-operation and Development(OECD)) between 2000 and 2019 in terms of well-being. To this end, we considered the territorial dimension of β-convergence models for well-being and its four domains(economic, social, environmental, and governance). Then, we adapted the absolute β-convergence model by taking into account the existence of spatial heterogeneity according to five specifications of spatial models. Thus, apart from environmental domain, we found that β-convergence of regions is significant for well-being and three of its domains(economic, social, and governance). These convergences are made by a spatially autocorrelated error model(SEM). However, the speed and period of convergence are relatively low for social domain, partly explaining the very exacerbated tensions at the territorial level. The fastest convergence was achieved in governance domain, followed by economic domain. This suggests that emerging countries must pay particular attention to national public action in favor of social cohesion at the territorial level. The lack of convergence in environmental domain calls for common actions for all countries at the supranational level to protect the commons at the territorial level.
文摘In this paper, the effect of the mediation effect is mainly used to test and analyze the regression model, and most scholars have studied the impact of the modernization of the industrial structure on the income gap. However, this paper is from another perspective, based on the social background of high-quality development, the main study is the impact mechanism of urban and rural income gap on the industrial structure, taking the Yangtze River Delta as the main research object, and specifically selecting 22 central cities in the Yangtze River Delta region, which is also one of the highlights of this study. The regression model is constructed by using the intermediary effect, and the four intermediary variables of fiscal expenditure (M<sub>1</sub>), fixed asset investment (M<sub>2</sub>), number of patent applications (M<sub>3</sub>), and total import and export (M<sub>4</sub>) are selected, which represent the role of the government, fixed asset investment, scientific and technological level and opening-up level, and study and analyze the inherent influence mechanism between each variable. Before doing specific research, I consulted the papers and literature of many other outstanding scholars, among which Cheng Yuhong and Cheng Chi’s “The Influence Mechanism of industrial structure of urban and rural income gap” [1] has great reference value for this paper. According to the research results, under the background of high-quality development in the Yangtze River Delta region, the expansion of the income gap between urban and rural areas will inhibit the upgrading of the industrial structure, so it is necessary to focus on building a new type of urbanization, accelerating the construction of an urban innovation system, optimizing the rural employment structure to narrow the income gap between urban and rural areas, and providing impetus for the continuous upgrading of the industrial structure.
文摘In this paper, the zero voltage switching (ZVS) region of a dual active bridge (DAB) converter with wide band-gap (WBG) power semiconductor device is analyzed. The ZVS region of a DAB converter varies depending on output power and voltage ratio. The DAB converters operate with hard switching at light loads, it is difficult to achieve high efficiency. Fortunately, WBG power semiconductor devices have excellent hard switching characteristics and can increase efficiency compared to silicon (Si) devices. In particular, WBG devices can achieve ZVS at low load currents due to their low parasitic output capacitance (C<sub>o,tr</sub>) characteristics. Therefore, in this paper, the ZVS operating resion is analyzed based on the characteristics of Si, silicon carbide (SiC) and gallium nitride (GaN). Power semiconductor devices. WBG devices with low C<sub>o,tr</sub> operate at ZVS at lower load currents compared to Si devices. To verify this, experiments are conducted and the results are analyzed using a 3 kW DAB converter. For Si devices, ZVS is achieved above 1.4 kW. For WBG devices, ZVS is achieved at 700 W. Due to the ZVS conditions depending on the switching device, the DAB converter using Si devices achieves a power conversion efficiency of 91% at 1.1 kW output. On the other hand, in the case of WBG devices, power conversion efficiency of more than 98% is achieved under 11 kW conditions. In conclusion, it is confirmed that the WBG device operates in ZVS at a lower load compared to the Si device, which is advantageous in increasing light load efficiency.
文摘Two factors determining the level of living in different areas are income level and price level. Current studies on regional gaps concentrate on the gap in income levels. The present paper studies the impact of the two variables on the real living standards in different regions, with the real gap in the living standards calculated with price adjustment by taking into consideration only the deviations brought about by cash income. The basic conclusion is that, despite China＇s economy having witnessed rapid growth, the statistics at the macro level cannot disguise the obvious gaps among regions; therefore, as a result of the impact of income and price, the real gap in the living standards among different regions is smaller than the gap indicated by the nominal income level. As people are sensitive to cash income level, they have a low sensitivity to changes in real purchasing power. In other words, in areas that have the same real income levels, people tend to think that people live better when the nominal income and price are both high. The differences in price indices among different regions show that the same cash income can get different goods and services in different regions. This explains the rationale of the existence of floating workers among different regions. On this basis, we predict that people working in high-income areas who enjoy higher levels of social security might prefer to live in low-price areas after retirement if the social security payment method becomes more flexible.
文摘GAP分析是用来判别生物多样性保护的空白、遗漏区域(“gaps”)和需要采取保护行动的地区(conservation gap),它是一种评估区域生物多样性所有成分所处保护地位、被保护程度等的科学方法。强调最大限度地保护生物多样性的先决条件是通过构建保护区网络,不仅仅考虑生物多样性最高地区,应该使本地种和生态系统都得到保护。区域生态安全格局的评价不仅要考虑生物及其生境的保护,而且,更要考虑受损生态系统和破坏景观的恢复,即不仅考虑Conservation G ap,也要考虑R estoration G ap。因而,改进GAP方法可用于生态安全格局的分析与评价,且有望成为重要的研究手段。
