With the increasing urgency of the carbon emission reduction task,the generation expansion planning process needs to add carbon emission risk constraints,in addition to considering the level of power adequacy.However,...With the increasing urgency of the carbon emission reduction task,the generation expansion planning process needs to add carbon emission risk constraints,in addition to considering the level of power adequacy.However,methods for quantifying and assessing carbon emissions and operational risks are lacking.It results in excessive carbon emissions and frequent load-shedding on some days,although meeting annual carbon emission reduction targets.First,in response to the above problems,carbon emission and power balance risk assessment indicators and assessment methods,were proposed to quantify electricity abundance and carbon emission risk level of power planning scenarios,considering power supply regulation and renewable energy fluctuation characteristics.Secondly,building on traditional two-tier models for low-carbon power planning,including investment decisions and operational simulations,considering carbon emissions and power balance risks in lower-tier operational simulations,a two-tier rolling model for thermal power retrofit and generation expansion planning was established.The model includes an investment tier and operation assessment tier and makes year-by-year decisions on the number of thermal power units to be retrofitted and the type and capacity of units to be commissioned.Finally,the rationality and validity of the model were verified through an example analysis,a small-scale power supply system in a certain region is taken as an example.The model can significantly reduce the number of days of carbon emissions risk and ensure that the power balance risk is within the safe limit.展开更多
Fully non-inductive plasma start-up was successfully achieved by using a well- controlled microwave source on the spherical tokamak, QUEST. Non-inductive plasmas were maintained for approximately 3-5 min, during which...Fully non-inductive plasma start-up was successfully achieved by using a well- controlled microwave source on the spherical tokamak, QUEST. Non-inductive plasmas were maintained for approximately 3-5 min, during which time power balance estimates could be achieved by monitoring wall and cooling-water temperatures. Approximately 70%-90% of the injected power could be accounted for by calorimetric measurements and approximately half of the injected power was found to be deposited on the vessel wall, which is slightly dependent on the magnetic configuration. The power distribution to water-cooled limiters, which are expected to be exposed to local heat loads, depends significantly on the magnetic configuration, however some of the deposited power is due to energetic electrons, which have large poloidal orbits and are likely to be deposited on the plasma facing components.展开更多
In this paper a simple code has been developed to analyze power balance and qualitatively evaluate current profiles for discharges with lower hybrid current drive （LHCD） and ion Bernstein wave （IBW） heating in the...In this paper a simple code has been developed to analyze power balance and qualitatively evaluate current profiles for discharges with lower hybrid current drive （LHCD） and ion Bernstein wave （IBW） heating in the HT-7 tokamak. Electron and ion thermal diffusivity, profiles of the bootstrap current density and total plasma current density can be estimated by this code using the experimental data. This code offers an easy and reasonable means to understand plasma transport in HT-7.展开更多
The article gives an overview on the dynamic political processes in the Black Sea region after some major geostrategic changes posing instability concerns in the region. The aim is to summarise the policy tendencies o...The article gives an overview on the dynamic political processes in the Black Sea region after some major geostrategic changes posing instability concerns in the region. The aim is to summarise the policy tendencies of the international organisations （NATO and EU） towards Russia and to present some analytical thoughts on current Euro-Atlantic strategies. Proposed is a different way of thinking based on the ＂congagement＂ approach.展开更多
The development of regional integrated electric-thermal energy systems(RIETES) is considered a promising direction for modern energy supply systems. These systems provide a significant potential to enhance the compreh...The development of regional integrated electric-thermal energy systems(RIETES) is considered a promising direction for modern energy supply systems. These systems provide a significant potential to enhance the comprehensive utilization and efficient management of energy resources. Therein, the real-time power balance between supply and demand has emerged as one pressing concern for system stability operation. However, current methods focus more on minute-level and hour-level power optimal scheduling methods applied in RIETES. To achieve real-time power balance, this paper proposes one virtual asynchronous machine(VAM) control using heat with large inertia and electricity with fast response speed. First, the coupling timescale model is developed that considers the dynamic response time scales of both electric and thermal energy systems. Second, a real-time power balance strategy based on VAM control can be adopted to the load power variation and enhance the dynamic frequency response. Then, an adaptive inertia control method based on temperature variation is proposed, and the unified expression is further established. In addition, the small-signal stability of the proposed control strategy is validated. Finally, the effectiveness of this control strategy is confirmed through MATLAB/Simulink and HIL(Hardware-in-the-Loop) experiments.展开更多
A 4-12GHz wideband power amplifier,using a balanced configuration with a strip line Lange coupler, is designed and fabricated. This power amplifier shows a maximum continuous wave output power of 29.5dBm at 8GHz cente...A 4-12GHz wideband power amplifier,using a balanced configuration with a strip line Lange coupler, is designed and fabricated. This power amplifier shows a maximum continuous wave output power of 29.5dBm at 8GHz center frequency with an associated gain of 8.5dB and a gain flatness of ＋ /- 0.6dB in the 4-12GHz frequency range.展开更多
A power balance static random-access memory（SRAM） for resistance to differential power analysis（DPA） is proposed. In the proposed design, the switch power consumption and short-circuit power consumption are balanc...A power balance static random-access memory（SRAM） for resistance to differential power analysis（DPA） is proposed. In the proposed design, the switch power consumption and short-circuit power consumption are balanced by discharging and pre-charging the key nodes of the output circuit and adding an additional shortcircuit current path. Thus, the power consumption is constant in every read cycle. As a result, the DPA-resistant ability of the SRAM is improved. In 65 nm CMOS technology, the power balance SRAM is fully custom designed with a layout area of 5863.6 μm^2.The post-simulation results show that the normalized energy deviation（NED） and normalized standard deviation（NSD） are 0.099% and 0.04%, respectively. Compared to existing power balance circuits, the power balance ability of the proposed SRAM has improved 53%.展开更多
The integration of solar and wind energy into the electrical grid has received global research attention due to their unpredictable characteristics.Because wind energy varies across all timescales of utility activity,...The integration of solar and wind energy into the electrical grid has received global research attention due to their unpredictable characteristics.Because wind energy varies across all timescales of utility activity,renewable energy generation should be supplemented and enhanced,from real-time,minute-to-minute variations to annual alterations influencing long-termstrategy.Wind energy generation does not only fluctuate but is also challenging to accurately forecast the timeframes of significance to electricity decision makers;day-ahead and long-term making plans of framework sufficiency such as meeting the network peak load annually.A utility that integrates wind and solar energy into its electricity mix would understand how to adapt to uncertainty and variability in operations while sustaining grid stability.Due to hydropower’s adaptability,a system using hydropower as one of its generating resources could be precisely adapted to absorb the variability of wind and solar energy.The objective of this research study is to create a hybrid system comprising hydro-wind and solar(Hybrid-HWS)integration for power balancing in an isolated electrical network in Klipkop village,Pretoria region,South Africa.The desirability of designing and building goaf storage tank in regard to capability,the fullness of line throughoutwater pumping,dispensing,storage tank spillage,and pressure difference throughout liquid flow within the storage tanks were preliminary assessed using geotechnical and weather forecasting data from a distinctive area of Klipkop town in Pretoria,South Africa.Different facility hours premised on daylight accessibility are scheduled to balance maximum load at early and late hours.However,in the scenario of electrical power,time shift requiring storage for extended periods of time,such as in terms of hours,Hybrid-HWS has been found to have a crucial role.The results of simulations showed a coordinated process design for Hybrid-HWS Energy Storage(ES)to determine everyday strategic planning in reducing the variability of the system resulting from wind-solar-pumped hydro ES output inadequacies and satisfy daily load demands.It could be recommended that by considering the adaptability characteristics,extremely rapidly,ramping,peaking support and maximum stabilizing aid of the system could be archived with pump-hydro into the energy mix which can provide specific guidelines for energy policymakers.展开更多
Mr. Luo Haocai taught at Peking University Law School for a long time. Even though he held such important positions as vice president of Peking University (PKU),chairman of the Central Committee of China Zhi Gong Part...Mr. Luo Haocai taught at Peking University Law School for a long time. Even though he held such important positions as vice president of Peking University (PKU),chairman of the Central Committee of China Zhi Gong Party, vice president of the Supreme People’s Court, and vice chairman of the Ninth and Tenth National Committee of the CPPCC, he preferred being called "Teacher Luo." My frequent interactions with Teacher Luo started in 2007 and continued to 2016 when he was the president of the CSHRS.展开更多
The research reported in this paper focuses on non-technical power loss reduction for power distribution systems. Such reduction of costs of energy not served (ENS.COST), is intelligently evaluated and optimized using...The research reported in this paper focuses on non-technical power loss reduction for power distribution systems. Such reduction of costs of energy not served (ENS.COST), is intelligently evaluated and optimized using a firefly algorithm, from where savings of 43.3% on energy not served are achieved.展开更多
Economic issue is the very focus of China's wind power development.Although all the security problems can be dealt with through technical measures,the compensation for supportive thermal power units and the subsid...Economic issue is the very focus of China's wind power development.Although all the security problems can be dealt with through technical measures,the compensation for supportive thermal power units and the subsidy from economically developed regions to resource-outputting regions would require a higher level of strategic considerations.The core purpose of developing wind energy is to reduce pollutant emissions,so planners should take into account the overall cost of all sides,without touching the bottom of social affordability.展开更多
The SG-Ⅲlaser facility(SG-Ⅲ)is the largest laser driver for inertial confinement fusion(ICF)researches in China,which has 48 beamlines and can deliver 180 kJ ultraviolet laser energy in 3 ns.In order to meet the req...The SG-Ⅲlaser facility(SG-Ⅲ)is the largest laser driver for inertial confinement fusion(ICF)researches in China,which has 48 beamlines and can deliver 180 kJ ultraviolet laser energy in 3 ns.In order to meet the requirements of precise physics experiments,some new functionalities need to be added to SG-Ⅲand some intrinsic laser performances need upgrade.So at the end of SG-Ⅲ's engineering construction,the 2-year laser performance upgrade project started.This paper will introduce the newly added functionalities and the latest laser performance of SG-Ⅲ.With these function extensions and performance upgrade,SG-Ⅲis now fully prepared for precise ICF experiments and solidly paves the way towards fusion ignition.展开更多
An X-ray radiation source with approximately constant radiation temperature is realized by irradiating golden hohlraum with a shaped laser pulse. A simple theoretical model based on power balance is used to design the...An X-ray radiation source with approximately constant radiation temperature is realized by irradiating golden hohlraum with a shaped laser pulse. A simple theoretical model based on power balance is used to design the shape of the drive laser pulse. Experiments are carried out on the Shenguang III prototype laser facility, and the experimentM results are presented for radiation sources with the flat-top lasting about 2.5 ns at two different peak temperatures of about 150 eV and 170 eV, respectively, including the the drive laser pulses and the time integrated possible improvements are discussed. time histories of the temperatures, the shapes of radiation spectra. The validity of the model and展开更多
An experiment was performed on the Shenguang III prototype laser facility to continue the study on hohlraum radiation source with approximately constant radiation temperature using a continuously shaped laser pulse.A ...An experiment was performed on the Shenguang III prototype laser facility to continue the study on hohlraum radiation source with approximately constant radiation temperature using a continuously shaped laser pulse.A radiation source with a flattop temperature of about130 e V that lasted about 5 ns was obtained.The previous analytical iteration method based on power balance and self-similar solution of ablation was modified taking into account the plasma movements and it was used to design the laser pulse shape for experiment.A comparison between experimental results and simulation is presented and better agreement was achieved using the modified method.Further improvements are discussed.展开更多
The rise of China has transformed the global power balance and made the US-China relationship increasingly strategic and complicated.While some Americans are anxious about what China’s great power aspiration means fo...The rise of China has transformed the global power balance and made the US-China relationship increasingly strategic and complicated.While some Americans are anxious about what China’s great power aspiration means for US interests,many Chinese are concerned about the US intention to keep China down.In this context,many in Beijing believe that the Obama administration’s strategic rebalance toward the Asia-Pacific is bent on hindering China’s rise as a great power.To what extent is the strategic rebalance about China?Is it part of the US strategy to contain China’s rise?Can the US and China function in relative power equality and build a balance of power to maintain peace and stability in the Asia-Pacific?Seeking answers to these important questions,this article argues that the strategic rebalance is a continuation of the long-standing struggle of the US to define its interests in the region.China remains a centerpiece in the rebalance not only because building a cooperative relationship with China is the key for its success,but also because the rebalance has to address the rapidly shifting balance of power in the region where China has emerged as an ever-more influential power.It is in US interests to work with its partners as well as China to construct a regional order based on the balance of power,and rules and institutions capable of allowing China to grow and be secured but not use its new might arbitrarily.展开更多
Many scientists and researchers in the field of international relations suggest theories which help to systematize our observations recognize stable patterns and explain those observations and paradigms. Furthermore, ...Many scientists and researchers in the field of international relations suggest theories which help to systematize our observations recognize stable patterns and explain those observations and paradigms. Furthermore, some scientists present recommendations about policies that should be selected. However, constantly in each issue of Foreign Policy, there are distinct and conflicting options for policy making. Theories of international relations are trying to find the causes and conditions that are sometimes direct countries to conflict, and sometimes to cooperate with each other. In this article, two important theoretical approaches in the field of international relations are considered which affect on the approaches of US leaders and decision making process in this country： Neo-Realism and Neo-Liberalism. The authors seek to show that what＇s the difference between these two approaches in theoretical principles？ Understanding of these differences will help to show this matter that based on suggestion of these two theories, how American policy makers must choose a rational choice from among competing alternatives？ Policymakers can select rational choices among competing alternatives, when a theory possesses empirical evidence, and values or goals.展开更多
The book Theory of International Politics without a doubt is a pillar in the field of international relations.Kenneth Waltz is considered as the founder of Neorealist theory or what is known“Structural Realism”.His ...The book Theory of International Politics without a doubt is a pillar in the field of international relations.Kenneth Waltz is considered as the founder of Neorealist theory or what is known“Structural Realism”.His book was published at a time when Neo-liberalism was dominant.Indeed,he opened a huge debate in IR and challenged the consensus that prevailed at the time.The concepts of anarchy and power are at the center of Waltz’s theory of international politics where he tried to explain how the structure of the international system is,and how this system affects the behavior of states,which they are considered as the main players in the international system.Thus,the current study’s aim is to analyze and identify the main arguments and concepts of the book and the critics directed to it.To do so,in the first section,the intellectual background of the author and introduction to the book has been mentioned.Second,the arrangement of the chapters of the book is illustrated.Following are the main arguments and concepts of the book.Then critics directed to the book are presented,and finally,the conclusion is discussed.展开更多
The security dilemma is a common problem faced with the states in the ongoing anarchic international system.It does matter in the Middle East like the other ones and also has its impact on the arms races in the region...The security dilemma is a common problem faced with the states in the ongoing anarchic international system.It does matter in the Middle East like the other ones and also has its impact on the arms races in the region too.Meanwhile there are some characters named as the order and change predicaments such as the colonial background,weak infrastructure of state construction,and the identity politics embedded in the region that do convert the current complex security dilemma into a complicated one.Not only does it have effect on the regional order,the arm race and disarmament,and also offense/defense paradox,but also does it get on the violent bandwagon in the region.Synergies of the both dilemmas did lead the region into the domestic environment change alongside of regional disorder too.Non-neutral involving the trans-regional powers into the(in)security situation in the region not only did not mitigate the situation but also volatile it too.In conclusion the paper does strive to introduce three phrased manners for transition of the complicated security dilemma.展开更多
In order to overcome the problems of power flow control and fault current limiting in multi-terminal high voltage direct current(MTDC)grids,this paper proposes a modular multi-terminal DC power flow controller(MM-DCPF...In order to overcome the problems of power flow control and fault current limiting in multi-terminal high voltage direct current(MTDC)grids,this paper proposes a modular multi-terminal DC power flow controller(MM-DCPFC)with fault current limiting function.The topology structure,operation principle,and equivalent circuit of MM-DCPFC are introduced,and such a structure has the advantages of modularity and scalability.The power balance mechanism is studied and a hierarchical power balance control strategy is proposed.The results show that MM-DCPFC can achieve internal power exchange,which avoids the use of external power supply.The fault characteristics of MM-DCPFC are analyzed,fault current limiting and self-protection methods are proposed,and the factors affecting the current limiting capability are studied.The simulation models are established in PLECS,and the simulation results verify the effectiveness of MM-DCPFC in power flow control,fault current limiting,and scalability.In addition,a prototype is developed to validate the function and control method of MM-DCPFC.展开更多
基金supported by Science and Technology Project of State Grid Anhui Electric Power Co.,Ltd. (No.B6120922000A).
文摘With the increasing urgency of the carbon emission reduction task,the generation expansion planning process needs to add carbon emission risk constraints,in addition to considering the level of power adequacy.However,methods for quantifying and assessing carbon emissions and operational risks are lacking.It results in excessive carbon emissions and frequent load-shedding on some days,although meeting annual carbon emission reduction targets.First,in response to the above problems,carbon emission and power balance risk assessment indicators and assessment methods,were proposed to quantify electricity abundance and carbon emission risk level of power planning scenarios,considering power supply regulation and renewable energy fluctuation characteristics.Secondly,building on traditional two-tier models for low-carbon power planning,including investment decisions and operational simulations,considering carbon emissions and power balance risks in lower-tier operational simulations,a two-tier rolling model for thermal power retrofit and generation expansion planning was established.The model includes an investment tier and operation assessment tier and makes year-by-year decisions on the number of thermal power units to be retrofitted and the type and capacity of units to be commissioned.Finally,the rationality and validity of the model were verified through an example analysis,a small-scale power supply system in a certain region is taken as an example.The model can significantly reduce the number of days of carbon emissions risk and ensure that the power balance risk is within the safe limit.
基金supported by Grant-in-Aid for JSPS Fellows(KAKENHI Grant Number 16H02441,24656559)performed with the support and under the auspices of the NIFS Collaboration Research Program(NIFS05KUTRO14,NIFS11KUTR061,NIFS13KUTR085,NIFS14KUTR103)+1 种基金supported in part by the Collaborative Research Program of the Research Institute for Applied Mechanics,Kyushu Universitypartly supported by the JSPS-NRF-NSFC A3 Foresight Program in the Field of Plasma Physics(No.11261140328)
文摘Fully non-inductive plasma start-up was successfully achieved by using a well- controlled microwave source on the spherical tokamak, QUEST. Non-inductive plasmas were maintained for approximately 3-5 min, during which time power balance estimates could be achieved by monitoring wall and cooling-water temperatures. Approximately 70%-90% of the injected power could be accounted for by calorimetric measurements and approximately half of the injected power was found to be deposited on the vessel wall, which is slightly dependent on the magnetic configuration. The power distribution to water-cooled limiters, which are expected to be exposed to local heat loads, depends significantly on the magnetic configuration, however some of the deposited power is due to energetic electrons, which have large poloidal orbits and are likely to be deposited on the plasma facing components.
基金National Natural Science Foundation of China(No.10505008)
文摘In this paper a simple code has been developed to analyze power balance and qualitatively evaluate current profiles for discharges with lower hybrid current drive （LHCD） and ion Bernstein wave （IBW） heating in the HT-7 tokamak. Electron and ion thermal diffusivity, profiles of the bootstrap current density and total plasma current density can be estimated by this code using the experimental data. This code offers an easy and reasonable means to understand plasma transport in HT-7.
文摘The article gives an overview on the dynamic political processes in the Black Sea region after some major geostrategic changes posing instability concerns in the region. The aim is to summarise the policy tendencies of the international organisations （NATO and EU） towards Russia and to present some analytical thoughts on current Euro-Atlantic strategies. Proposed is a different way of thinking based on the ＂congagement＂ approach.
基金supported by the National Key R&D Program of China (Grant No. 2022YFB3304001)the Major Program of the National Natural Science Foundation of China (Grant No. 52293413)。
文摘The development of regional integrated electric-thermal energy systems(RIETES) is considered a promising direction for modern energy supply systems. These systems provide a significant potential to enhance the comprehensive utilization and efficient management of energy resources. Therein, the real-time power balance between supply and demand has emerged as one pressing concern for system stability operation. However, current methods focus more on minute-level and hour-level power optimal scheduling methods applied in RIETES. To achieve real-time power balance, this paper proposes one virtual asynchronous machine(VAM) control using heat with large inertia and electricity with fast response speed. First, the coupling timescale model is developed that considers the dynamic response time scales of both electric and thermal energy systems. Second, a real-time power balance strategy based on VAM control can be adopted to the load power variation and enhance the dynamic frequency response. Then, an adaptive inertia control method based on temperature variation is proposed, and the unified expression is further established. In addition, the small-signal stability of the proposed control strategy is validated. Finally, the effectiveness of this control strategy is confirmed through MATLAB/Simulink and HIL(Hardware-in-the-Loop) experiments.
文摘A 4-12GHz wideband power amplifier,using a balanced configuration with a strip line Lange coupler, is designed and fabricated. This power amplifier shows a maximum continuous wave output power of 29.5dBm at 8GHz center frequency with an associated gain of 8.5dB and a gain flatness of ＋ /- 0.6dB in the 4-12GHz frequency range.
基金Project supported by the Zhejiang Provincial Natural Science Foundation of China(No.LQ14F040001)the National Natural Science Foundation of China(Nos.61274132,61234002)the K.C.Wong Magna Fund in Ningbo University,China
文摘A power balance static random-access memory（SRAM） for resistance to differential power analysis（DPA） is proposed. In the proposed design, the switch power consumption and short-circuit power consumption are balanced by discharging and pre-charging the key nodes of the output circuit and adding an additional shortcircuit current path. Thus, the power consumption is constant in every read cycle. As a result, the DPA-resistant ability of the SRAM is improved. In 65 nm CMOS technology, the power balance SRAM is fully custom designed with a layout area of 5863.6 μm^2.The post-simulation results show that the normalized energy deviation（NED） and normalized standard deviation（NSD） are 0.099% and 0.04%, respectively. Compared to existing power balance circuits, the power balance ability of the proposed SRAM has improved 53%.
基金This study was supported by the DUT Scholarship Scheme Masters:2022(RFA Smart Grid)Funding.
文摘The integration of solar and wind energy into the electrical grid has received global research attention due to their unpredictable characteristics.Because wind energy varies across all timescales of utility activity,renewable energy generation should be supplemented and enhanced,from real-time,minute-to-minute variations to annual alterations influencing long-termstrategy.Wind energy generation does not only fluctuate but is also challenging to accurately forecast the timeframes of significance to electricity decision makers;day-ahead and long-term making plans of framework sufficiency such as meeting the network peak load annually.A utility that integrates wind and solar energy into its electricity mix would understand how to adapt to uncertainty and variability in operations while sustaining grid stability.Due to hydropower’s adaptability,a system using hydropower as one of its generating resources could be precisely adapted to absorb the variability of wind and solar energy.The objective of this research study is to create a hybrid system comprising hydro-wind and solar(Hybrid-HWS)integration for power balancing in an isolated electrical network in Klipkop village,Pretoria region,South Africa.The desirability of designing and building goaf storage tank in regard to capability,the fullness of line throughoutwater pumping,dispensing,storage tank spillage,and pressure difference throughout liquid flow within the storage tanks were preliminary assessed using geotechnical and weather forecasting data from a distinctive area of Klipkop town in Pretoria,South Africa.Different facility hours premised on daylight accessibility are scheduled to balance maximum load at early and late hours.However,in the scenario of electrical power,time shift requiring storage for extended periods of time,such as in terms of hours,Hybrid-HWS has been found to have a crucial role.The results of simulations showed a coordinated process design for Hybrid-HWS Energy Storage(ES)to determine everyday strategic planning in reducing the variability of the system resulting from wind-solar-pumped hydro ES output inadequacies and satisfy daily load demands.It could be recommended that by considering the adaptability characteristics,extremely rapidly,ramping,peaking support and maximum stabilizing aid of the system could be archived with pump-hydro into the energy mix which can provide specific guidelines for energy policymakers.
文摘Mr. Luo Haocai taught at Peking University Law School for a long time. Even though he held such important positions as vice president of Peking University (PKU),chairman of the Central Committee of China Zhi Gong Party, vice president of the Supreme People’s Court, and vice chairman of the Ninth and Tenth National Committee of the CPPCC, he preferred being called "Teacher Luo." My frequent interactions with Teacher Luo started in 2007 and continued to 2016 when he was the president of the CSHRS.
文摘The research reported in this paper focuses on non-technical power loss reduction for power distribution systems. Such reduction of costs of energy not served (ENS.COST), is intelligently evaluated and optimized using a firefly algorithm, from where savings of 43.3% on energy not served are achieved.
文摘Economic issue is the very focus of China's wind power development.Although all the security problems can be dealt with through technical measures,the compensation for supportive thermal power units and the subsidy from economically developed regions to resource-outputting regions would require a higher level of strategic considerations.The core purpose of developing wind energy is to reduce pollutant emissions,so planners should take into account the overall cost of all sides,without touching the bottom of social affordability.
基金This work is supported by the SG-Ⅲ performance upgrade project.
文摘The SG-Ⅲlaser facility(SG-Ⅲ)is the largest laser driver for inertial confinement fusion(ICF)researches in China,which has 48 beamlines and can deliver 180 kJ ultraviolet laser energy in 3 ns.In order to meet the requirements of precise physics experiments,some new functionalities need to be added to SG-Ⅲand some intrinsic laser performances need upgrade.So at the end of SG-Ⅲ's engineering construction,the 2-year laser performance upgrade project started.This paper will introduce the newly added functionalities and the latest laser performance of SG-Ⅲ.With these function extensions and performance upgrade,SG-Ⅲis now fully prepared for precise ICF experiments and solidly paves the way towards fusion ignition.
文摘An X-ray radiation source with approximately constant radiation temperature is realized by irradiating golden hohlraum with a shaped laser pulse. A simple theoretical model based on power balance is used to design the shape of the drive laser pulse. Experiments are carried out on the Shenguang III prototype laser facility, and the experimentM results are presented for radiation sources with the flat-top lasting about 2.5 ns at two different peak temperatures of about 150 eV and 170 eV, respectively, including the the drive laser pulses and the time integrated possible improvements are discussed. time histories of the temperatures, the shapes of radiation spectra. The validity of the model and
文摘An experiment was performed on the Shenguang III prototype laser facility to continue the study on hohlraum radiation source with approximately constant radiation temperature using a continuously shaped laser pulse.A radiation source with a flattop temperature of about130 e V that lasted about 5 ns was obtained.The previous analytical iteration method based on power balance and self-similar solution of ablation was modified taking into account the plasma movements and it was used to design the laser pulse shape for experiment.A comparison between experimental results and simulation is presented and better agreement was achieved using the modified method.Further improvements are discussed.
文摘The rise of China has transformed the global power balance and made the US-China relationship increasingly strategic and complicated.While some Americans are anxious about what China’s great power aspiration means for US interests,many Chinese are concerned about the US intention to keep China down.In this context,many in Beijing believe that the Obama administration’s strategic rebalance toward the Asia-Pacific is bent on hindering China’s rise as a great power.To what extent is the strategic rebalance about China?Is it part of the US strategy to contain China’s rise?Can the US and China function in relative power equality and build a balance of power to maintain peace and stability in the Asia-Pacific?Seeking answers to these important questions,this article argues that the strategic rebalance is a continuation of the long-standing struggle of the US to define its interests in the region.China remains a centerpiece in the rebalance not only because building a cooperative relationship with China is the key for its success,but also because the rebalance has to address the rapidly shifting balance of power in the region where China has emerged as an ever-more influential power.It is in US interests to work with its partners as well as China to construct a regional order based on the balance of power,and rules and institutions capable of allowing China to grow and be secured but not use its new might arbitrarily.
文摘Many scientists and researchers in the field of international relations suggest theories which help to systematize our observations recognize stable patterns and explain those observations and paradigms. Furthermore, some scientists present recommendations about policies that should be selected. However, constantly in each issue of Foreign Policy, there are distinct and conflicting options for policy making. Theories of international relations are trying to find the causes and conditions that are sometimes direct countries to conflict, and sometimes to cooperate with each other. In this article, two important theoretical approaches in the field of international relations are considered which affect on the approaches of US leaders and decision making process in this country： Neo-Realism and Neo-Liberalism. The authors seek to show that what＇s the difference between these two approaches in theoretical principles？ Understanding of these differences will help to show this matter that based on suggestion of these two theories, how American policy makers must choose a rational choice from among competing alternatives？ Policymakers can select rational choices among competing alternatives, when a theory possesses empirical evidence, and values or goals.
文摘The book Theory of International Politics without a doubt is a pillar in the field of international relations.Kenneth Waltz is considered as the founder of Neorealist theory or what is known“Structural Realism”.His book was published at a time when Neo-liberalism was dominant.Indeed,he opened a huge debate in IR and challenged the consensus that prevailed at the time.The concepts of anarchy and power are at the center of Waltz’s theory of international politics where he tried to explain how the structure of the international system is,and how this system affects the behavior of states,which they are considered as the main players in the international system.Thus,the current study’s aim is to analyze and identify the main arguments and concepts of the book and the critics directed to it.To do so,in the first section,the intellectual background of the author and introduction to the book has been mentioned.Second,the arrangement of the chapters of the book is illustrated.Following are the main arguments and concepts of the book.Then critics directed to the book are presented,and finally,the conclusion is discussed.
文摘The security dilemma is a common problem faced with the states in the ongoing anarchic international system.It does matter in the Middle East like the other ones and also has its impact on the arms races in the region too.Meanwhile there are some characters named as the order and change predicaments such as the colonial background,weak infrastructure of state construction,and the identity politics embedded in the region that do convert the current complex security dilemma into a complicated one.Not only does it have effect on the regional order,the arm race and disarmament,and also offense/defense paradox,but also does it get on the violent bandwagon in the region.Synergies of the both dilemmas did lead the region into the domestic environment change alongside of regional disorder too.Non-neutral involving the trans-regional powers into the(in)security situation in the region not only did not mitigate the situation but also volatile it too.In conclusion the paper does strive to introduce three phrased manners for transition of the complicated security dilemma.
基金supported in part by National Key R&D Program of China(No.2018YFB0904600)National Natural Science Foundation of China(No.51807053)。
文摘In order to overcome the problems of power flow control and fault current limiting in multi-terminal high voltage direct current(MTDC)grids,this paper proposes a modular multi-terminal DC power flow controller(MM-DCPFC)with fault current limiting function.The topology structure,operation principle,and equivalent circuit of MM-DCPFC are introduced,and such a structure has the advantages of modularity and scalability.The power balance mechanism is studied and a hierarchical power balance control strategy is proposed.The results show that MM-DCPFC can achieve internal power exchange,which avoids the use of external power supply.The fault characteristics of MM-DCPFC are analyzed,fault current limiting and self-protection methods are proposed,and the factors affecting the current limiting capability are studied.The simulation models are established in PLECS,and the simulation results verify the effectiveness of MM-DCPFC in power flow control,fault current limiting,and scalability.In addition,a prototype is developed to validate the function and control method of MM-DCPFC.
