The broad-leaved Korean pine(Pinus koraiensis) forest is one of the most biodiverse zonal communities in the North Temperate Zone and an important habitat for many endangered species.Broad-leaved Korean pine forests(B...The broad-leaved Korean pine(Pinus koraiensis) forest is one of the most biodiverse zonal communities in the North Temperate Zone and an important habitat for many endangered species.Broad-leaved Korean pine forests(BKPFs) are shrinking quickly due to deforestation and rapid urbanization. Thus, scientific protection strategies are urgently needed to change this status. Changbai Mountains contains one of the largest BKPFs and is considered a priority biodiversity conservation area in China. Guided by systematic conservation planning(SCP) methods and procedures, we chose representative species and communities in BKPFs ecosystem as priority conservation objects, and set quantitative conservation target, which is in the light of the biodiversity characteristic of BKPFs. The watershed area is used as planning unit. We used CPlan software to calculate the irreplaceability(Ir)value of each planning unit and the contribution value(Ti) of each conservation object to(1) assess the conservation efficiency;(2) identify the conservation gap of the existing conservation network. Then wecalculated a human disturbance index(HDI) for planning units in the conservation gaps and combine this with the Ir value to design three conservation scenarios to optimize the conservation network.Results show that planning units with high conservation value 14.16% of the total area, with3084.36 km2 were covered by the existing conservation network. 79.28% of planning units with high conservation value have not been protected which were concentrated mainly in the eight gap areas.Only 25.3% of protection objects achieved their conservation target with the existing conservation network. Conservation efficiency is low. Three conservation scenarios are constituted, each prioritizing a different aim:(1) ecological value;(2)species rescue; and(3) economical avoidance. The three conservation schemes potentially enable 93%,88% and 51% of conservation objects, respectively, to achieve identified conservation targets, thereby improving conservation efficiency significantly.展开更多
The aluminum–selenium(Al–Se)battery is a very promising rechargeable battery system due to its high theoretical specific capacity of 1357 mA h g^(−1)and high average discharge voltage of∼1.52 V versus Al/Al3+.Howev...The aluminum–selenium(Al–Se)battery is a very promising rechargeable battery system due to its high theoretical specific capacity of 1357 mA h g^(−1)and high average discharge voltage of∼1.52 V versus Al/Al3+.However,Al–Se batteries suffer poor reversibility,since the intermediate product Se2Cl2 dissolved in the acidic electrolyte causes significant capacity fading.To overcome this critical issue,a dual-protection design with composites of selenium nanoparticles encapsulated in mesoporous carbon(CMK-3)and separators modified by CMK-3 are developed.Because of the great physical blocking of the intermediate product dissolved in the electrolyte,the as-assembled Al–Se batteries can deliver an ultrahigh capacity of∼1295 mA h g^(−1)(approximate the theoretical specific capacity)in the first two cycles,and retain a capacity of 651 mA h g^(−1)(retention rate of 50.3%)over 400 cycles at a current density of 1000 mA g^(−1).The rational design of the Al–Se batteries with dual protection from the CMK-3 coated Se positive electrode and modified separators is effective in promoting the electrochemical performance of the batteries.展开更多
Lithium metal batteries have been regarded as typical representatives of high-energy storage systems.However,lithium dendrite growth and a fragile solid electrolyte interface(SEI)lead to safety issues and unsatisfacto...Lithium metal batteries have been regarded as typical representatives of high-energy storage systems.However,lithium dendrite growth and a fragile solid electrolyte interface(SEI)lead to safety issues and unsatisfactory performances.We tackle the above issues with a dual protection strategy by designing a silver(Ag)decorated F-doped graphene(Ag@FG)matrix.Ag@FG was synthesized by a one-step“ion atmosphere”method.When used as a current collector,Ag@FG shows a low nucleation overpotential and a long cycle life due to the enhanced lithiophilicity,high conductivity of the matrix,and the LiF-enriched SEI.The decorated Ag nanoparticles increased the lithiophilicity of the graphene matrix to induce the uniform deposition of lithium.The doped F leads to the formation of a stable SEI.Thus,Ag@FG shows a low nucleation overpotential of only 8 mV at 0.5 mA cm^(-2) and long-term stability for over 1600 h at 1.0 mA cm^(-2) and 1.0 mA h cm^(-2).The assembled full batteries with LFP also indicate its practicability with good cycling stability and rate capability.展开更多
In this paper,the Jiangxi section of the red army's long march is taken as the research object to construct a red cultural heritage corridor.Introducing the theory of heritage corridor,on the basis of its hierarch...In this paper,the Jiangxi section of the red army's long march is taken as the research object to construct a red cultural heritage corridor.Introducing the theory of heritage corridor,on the basis of its hierarchical decomposition and comparative judgment,a hierarchy model of the red cultural heritage corridor resource is established.The comprehensive scores of each factor are obtained through expert scoring,and the overall pattern of red army corridor is constructed as"ring-shape-point".New ideas for protection and utilization as well as protection implementation measures are proposed,and the spiritual and cultural connotations of long march in Jiangxi are fully explored.This could help the social and economic development of the areas along the long march of red army in Jiangxi,and promote the integrated utilization and coordinated development of resources in the red cultural heritage corridor region.展开更多
The renewable microgrid(RMG)is a critical way to organize and utilize new energy.Its control and protection strategies during the fault are the core technologies to ensure the safe operation and stability of the syste...The renewable microgrid(RMG)is a critical way to organize and utilize new energy.Its control and protection strategies during the fault are the core technologies to ensure the safe operation and stability of the system.The traditional protection principles are unsuitable for RMGs due to the flexibility of RMG operation,the complexity of RMG topology,and the variety of fault control strategies of inverter-interfaced distributed generators(IIDGs).The traditional fault component protection principle is affected by the low voltage ride-through(LVRT)control strategy and will fail in some scenarios.In order to make the fault component protection principle available in every scenario,a current-based fault control strategy is proposed.Specific fault characteristics are generated by the grid-feeding IIDGs during the fault so they can be equivalent to the open circuits,and the fault models in additional network can be simplified.By analyzing the fault characteristics,an RMG protection strategy based on the current-based fault control of IIDGs is presented.The fault directions of feeders can be distinguished and the fault feeder can be located accurately in both grid-connected and islanded RMGs.Then,the grid-feeding IIDGs can transit to LVRT mode smoothly.Thus,IIDGs are considered comprehensively in terms of coordinating with fault control and fault characteristic generation.Finally,the experimental results of the hardware platform prove the effectiveness of the proposed current-based fault control strategy,and the simulation results based on PSCAD/EMTDC verify the correctness of the protection strategy.展开更多
This thesis examines the habitat characteristics of traditional villages in Chongqing and characterisesthe spatial distribution of these villages through ArcGIS from a macro perspective.In addition,the habitats charac...This thesis examines the habitat characteristics of traditional villages in Chongqing and characterisesthe spatial distribution of these villages through ArcGIS from a macro perspective.In addition,the habitats characteristics and ecological value system of individual traditional villages are explored using typological researchmethod and corresponding comprehensive protection strategies are deeply discussed.The research results showthat these villages feature non-equilibrium aggregation,mainly concentrated in higher-altitude regions such as inthe southeast,especially in the Youyang Tujia and Miao Autonomous Region.The landscape pattern of the overallhuman settlement area of traditional villages in Chongqing has the characteristics of“woodland-terrace-pondhouse”,the spatial settlement pattern of“distribution around the terrace”,and the aquatic ecosystem model of“pond-terrace-pond”driven by the potential energy of altitude difference.By analyzing the landscape patterns ofhuman settlements,the ecological value system is summarized.Finally,comprehensive protection strategies forthese human settlements are presented,including ensuring the integrity of spatial patterns,respecting ecologicallaws,making full use of agricultural wisdom and strengthening ecological production symbiosis mechanism.展开更多
Chinese watchtower houses are part of the unique human cultural heritage of the world’s vernacular architectures.Many earthen manor watchtower houses in Chongqing,China,have absorbed the characteristics of other towe...Chinese watchtower houses are part of the unique human cultural heritage of the world’s vernacular architectures.Many earthen manor watchtower houses in Chongqing,China,have absorbed the characteristics of other tower houses across the country and have brought together various types of watchtower construction techniques.They are important connection points for the integrity of the Chinese watchtower house as a comprehensive architectural cultural heritage system.They can be a typical sample of Chinese Han classical towers.These buildings are indispensable parts of the Chinese residential watchtower system and have important cultural protection value.However,due to the general lack of excavation and attention to their historical and cultural value,these buildings are on the verge of disappearing.Although they have lost their original architectural functions,they have important value in terms of their building materials,technical composition and artistic modelling.They can stimulate special emotional resonance and become an important bridge that maintains the cultural connection between ancient and modern humans.Therefore,discussing the historical and cultural value of Chongqing rammed earth watchtower houses,the strategy for heritage protection and utilisation is of far-reaching signifcance for Chinese watchtower dwellings.展开更多
MXene,with metallic conductivity,strong hydrophilicity,and rich chemistries,has been widely used as electrode material for energy storage.However,the notorious issues of aggregation and oxidation for MXene significant...MXene,with metallic conductivity,strong hydrophilicity,and rich chemistries,has been widely used as electrode material for energy storage.However,the notorious issues of aggregation and oxidation for MXene significantly inhibit its electrochemical performance and further wide application.Herein,a physicochemical double protection strategy is proposed to stabilize MXene in the hydrothermal process effectively.Polyvinylpyrrolidone(PVP),with the structure of a long chain and abundant O/N function groups,provides physical protection against agglomeration(steric effect)and chemical protection against oxidation(electron transfer)at the same time,contributing to the synthesis of MXene-based hybrids with high conductivity and fully exposed active sites.As proof of the concept,2D MXene/Co_(9)S_(8) nanohybrids with a scaly surface are fabricated and present impressive performance,especially rate performance for hybrid supercapacitor(HSC)with MoS_(2) as the counter electrode.The HSC demonstrates a high energy density of 111 Wh kg^(-1) at 845 W kg^(-1) and an excellent rate performance of 61 Wh kg^(-1) at 16.9 kW kg^(-1).展开更多
This study,integrating both domestic and international literatures as well as field research findings,presents a comprehensive review of the geographical distribution,ecological and physiological characteristics of Ac...This study,integrating both domestic and international literatures as well as field research findings,presents a comprehensive review of the geographical distribution,ecological and physiological characteristics of Acanthus ebracteatus.It further delves into the factors leading to its endangered status and proposes corresponding protection strategies.The mian reasons for the endangered of A.ebracteatus are as follows:illegal harvesting of whole plants,habitat destruction,reproductive obstacles,and competition or interference from invasive or noxious plant species.To address these threats,a series of conservation strategies are proposed.Firstly,in-depth research on the artificial propagation techniques of A.ebracteatus should be conducted to surmount reproductive barriers.Secondly,habitat restoration initiatives need to be carried out to create a suitable ecological setting.Thirdly,in-situ protections should be enhanced while the implementing ex-situ conservation measures.Meanwhile,continuous monitoring of A.ebracteatus seedlings should be conducted to strengthen subsequent management and conservation efforts.Finally,it is recommended to rationally explore and utilize the medicinal properties of A.ebracteatus.展开更多
Economic development and transportation construction are inseparable. With the rapid economic development, China pays more and more attention to the perfection of urban rail transit supporting facilities. Nowadays, ur...Economic development and transportation construction are inseparable. With the rapid economic development, China pays more and more attention to the perfection of urban rail transit supporting facilities. Nowadays, urban rail transit has become an important way for Chinese people to travel. Compared with other travel modes, rail transit has the characteristics of safety and convenience. Ensure the smooth operation of urban rail, the signal system is the most critical and important control core. Therefore, the signal system is of great significance to the running safety of rail trains, and a good signal system can avoid signal instability and further ensure the stability and safety of train operation. Therefore, this paper studies the relevant aspects of information security protection of rail transit weak current system, and focuses on the analysis of protection schemes and measures, so as to provide more support for the development and safety of rail transit in China.展开更多
Highly efficient removal of allyloxycarbonyl （Alloc） group was achieved in the presence of CH3COONH4, Pd[P（C6H5）3]4, and NaBH4 in MeOH-THF, within 5 min in almost quantitative yields （〉90%, isolated yield） with...Highly efficient removal of allyloxycarbonyl （Alloc） group was achieved in the presence of CH3COONH4, Pd[P（C6H5）3]4, and NaBH4 in MeOH-THF, within 5 min in almost quantitative yields （〉90%, isolated yield） without affecting acetyl, benzoyl, isopropylidene, benzylidene, allyl, benzyl, benzyl carbonate, or azido groups.展开更多
Tin(Sn)is considered an effective anode material for stripping and plating due to its promising capacity,isotropic deposition,and relatively negative redox potential of-0.91 V vs.standard hydrogen electrode(SHE).Howev...Tin(Sn)is considered an effective anode material for stripping and plating due to its promising capacity,isotropic deposition,and relatively negative redox potential of-0.91 V vs.standard hydrogen electrode(SHE).However,the challenges of hydrogen evolution corrosion and“dead Sn”formation at the Snalkaline electrolyte interface restrict its reversibility,which poses challenges for flexible devices and in a broad temperature range.In this study,we successfully designed a corrosion-resistant Sn anode(CuPVDF@Sn)featuring a multilevel microchannel structure.The Sn-affinitive Cu mesh with good electronic conductivity lowers the nucleation energy barrier and enhances deposition uniformity,while PVDF improves hydrogen evolution potential.Additionally,the soft Cu mesh and PVDF provide flexibility in design.As a result,the flexible Cu-PVDF@Sn anode achieves a coulombic efficiency(CE)of 92.61% and stable cycling for over 800 h.The flexible Sn-air battery based on this anode exhibits an energy density of 504 Wh kg^(-1),a peak power density of 80 mW cm^(-2),and a cycling stability of 120 h at 5 mA cm^(-2).It also operates effectively within a wide temperature range of -15-60℃,providing strong support for excellent environmental adaptability.The proposed concept in this work might provide a promising alternative for developing stable Sn anodes in flexible Sn-air batteries.展开更多
Multiterminal hybrid HVDC systems,combining the advantages of conventional and flexible DC systems,are considered important development trends for future power networks.With the ability to suppress DC fault current,hy...Multiterminal hybrid HVDC systems,combining the advantages of conventional and flexible DC systems,are considered important development trends for future power networks.With the ability to suppress DC fault current,hybrid HVDC systems eliminate the requirement of current limiting reactors at both ends of DC lines.Thus,non-unit protection based on line boundaries is no longer applicable.In this paper,a non-unit protection scheme in cooperation with converter control is proposed to ensure protection speed,reliability,and sen-sitivity for multiterminal hybrid HVDC systems without line boundaries.In the proposed protection scheme,the protection criterion based on the transient energy of the DC voltage and the direction criterion based on the travelling wave are used to identify whether the fault occurs on the DC line.When the fault is detected as a DC-line fault,the relevant converter station is quickly blocked.After a specified hold-off duration,the converter station interfacing with multiple DC lines is prioritized for restart,while the remaining converter stations are restarted once the DC voltage is stabilized.Simulations based on PSCAD/EMTDC validate the feasibility of the proposed protection scheme and its superiority over competing approaches.展开更多
Aqueous zinc(Zn)-ion batteries(ZIBs)have garnered significant attention as promising energy storage devices,primarily due to their low cost,high power density,and excellent safety profile.However,the commercial viabil...Aqueous zinc(Zn)-ion batteries(ZIBs)have garnered significant attention as promising energy storage devices,primarily due to their low cost,high power density,and excellent safety profile.However,the commercial viability of these batteries is hindered by several issues related to the Zn metal anode,including dendritic growth,hydrogen evolution reaction(HER),surface corrosion,and passivation.This review delves into the root causes and key factors influencing these challenges from both electrochemical thermodynamics and kinetics perspectives.Subsequently,viable strategies to mitigate these issues are systematically summarized,including Zn anode reconstruction,artificial solid-electrolyte interphase(SEI)protection,electrolyte formulation optimization,and separator functionalization.Recent research advancements are examined thoroughly,with a focus on the mechanisms behind these approaches and the resulting battery performance.The review also critically assesses the strengths and limitations of these solutions.Finally,we highlight crucial research directions aimed at advancing the practical application of Zn metal anodes in future aqueous ZIBs.展开更多
The 13th Five-year Plan period （2016-2020） is a crucial period for environmental protection in China and represents the last chance for the achievement of the environmental objective under the goal of building a wel...The 13th Five-year Plan period （2016-2020） is a crucial period for environmental protection in China and represents the last chance for the achievement of the environmental objective under the goal of building a well-off society in an all-round manner. During this period of time, China＇ s environment is confronted with the following major risks： risks of environmental quality, human health, ecological security, balanced regional development and international influence. The overall conclusion is that the tendencies of changing eco-environment are complex, problems remain outstanding, and some risks have abated while others have intensified with possible improvements in the future. Future prospects mainly depend on the intensity of actions taken. It is suggested that environmental protection strategy of＂overall optimization＂ be adopted for the 13th Five-year Plan period, i.e. environmental protection requirements should be incorporated into political, economic, social and cultural spheres, so that these areas with major influence on the natural environment will improve and transform towards an environmentally friendly direction and ultimately help achieve the objective of improving eco-environment and people＇s welfare. In order to fundamentally reverse mainstream understanding on environmental protection, it is suggested to define the ＂contradiction between environmental pressures arising from growing economic development and China ＇ s limited and fragile environmental capacity＂ as a major contradiction of Chinese society.展开更多
The two-archive 2 algorithm(Two_Arch2) is a manyobjective evolutionary algorithm for balancing the convergence,diversity,and complexity using diversity archive(DA) and convergence archive(CA).However,the individuals i...The two-archive 2 algorithm(Two_Arch2) is a manyobjective evolutionary algorithm for balancing the convergence,diversity,and complexity using diversity archive(DA) and convergence archive(CA).However,the individuals in DA are selected based on the traditional Pareto dominance which decreases the selection pressure in the high-dimensional problems.The traditional algorithm even cannot converge due to the weak selection pressure.Meanwhile,Two_Arch2 adopts DA as the output of the algorithm which is hard to maintain diversity and coverage of the final solutions synchronously and increase the complexity of the algorithm.To increase the evolutionary pressure of the algorithm and improve distribution and convergence of the final solutions,an ε-domination based Two_Arch2 algorithm(ε-Two_Arch2) for many-objective problems(MaOPs) is proposed in this paper.In ε-Two_Arch2,to decrease the computational complexity and speed up the convergence,a novel evolutionary framework with a fast update strategy is proposed;to increase the selection pressure,ε-domination is assigned to update the individuals in DA;to guarantee the uniform distribution of the solution,a boundary protection strategy based on I_(ε+) indicator is designated as two steps selection strategies to update individuals in CA.To evaluate the performance of the proposed algorithm,a series of benchmark functions with different numbers of objectives is solved.The results demonstrate that the proposed method is competitive with the state-of-the-art multi-objective evolutionary algorithms and the efficiency of the algorithm is significantly improved compared with Two_Arch2.展开更多
A comprehensive risk assessment to evaluate the vulnerability of the nearshore cetaceans to increasing marine traffic is lacking.In this study,the risk to Indo-Pacific humpback dolphins(Sousa chinensis)in the main hab...A comprehensive risk assessment to evaluate the vulnerability of the nearshore cetaceans to increasing marine traffic is lacking.In this study,the risk to Indo-Pacific humpback dolphins(Sousa chinensis)in the main habitats in China was assessed based on a semiquantitative spatial vulnerability analysis.85%of the(sub)population which overlapped with the lanes of ferries and/or cargo vessels,with exposure scores of 1.23±0.31(calculated based on the proportion of sea routes that overlap the dolphin’s range).A combination of high exposure to the sea routes and sensitivity to marine traffic would render the(sub)populations to be highly vulnerable(EPRE:5.21 and XM:4.47).A low frequency of vessels and an awareness of the ecology assures a low vulnerability(SH:2.43,EZ:2.73).Uncertainty scores were commonly lower for the higher vulnerable populations,and higher for the lower vulnerable populations,suggesting additional field data and more monitoring are necessary.Six years of field data have been used to analyze the influences of various types of marine traffic on humpback dolphin behavior.Fishing and non-fishing vessels were significantly different(χ^(2)=65.19,p<0.01).The humpback dolphins were attracted by fishing vessels(83.1%)but avoided non-fishing vessels(95.2%).We recommend a management with seasonal and geographical constraints,to balance economic development and environmental conservation.展开更多
To address security and privacy issues in radio frequency identification (RFID) traceability networks, a multi-layer privacy and security framework is proposed, which includes four facets: a security model, a communic...To address security and privacy issues in radio frequency identification (RFID) traceability networks, a multi-layer privacy and security framework is proposed, which includes four facets: a security model, a communication protocol, access permission and privacy preservation. According to the security requirements that are needed in an RFID system, a security model that incorporates security requirements that include privacy of tag data, privacy of ownership, and availability of tag identity is introduced. Using this model, a secure communication protocol that can be used for anti-counterfeiting, automatic identification and privacy preservation is then developed. In order to manage the number of parties, data records of items, and complicated transitions of access permissions in an item-level traceability context, a well-designed access control protocol is proposed to parties that can prove the physical possession of an item;meanwhile, to address the privacy issues during data sharing in an RFID network, a vision of database systems that take responsibility for the privacy of the data they manage is also presented.展开更多
A novel protective roasting strategy was applied to prepare mesoporous hollow CeO_(2)microspheres(mh-CeO_(2))using silica as both a hard template and a roasting protectant.Through detailed characterization techniques ...A novel protective roasting strategy was applied to prepare mesoporous hollow CeO_(2)microspheres(mh-CeO_(2))using silica as both a hard template and a roasting protectant.Through detailed characterization techniques such as SEM,TEM,EDX,FT-IR,XRD,XPS,and N_(2)adsorption-desorption,it could be determined that hollow CeO_(2)microspheres with good dispersibility and crystallinity,uniform spherical morphology and suitable pore width as heterogeneous catalysts had been successfully prepared.mh-CeO_(2)showed much higher catalytic activity than the as-prepared SiO_(2)@CeO_(2)and reported CeO_(2)catalysts for one-pot synthesis of imines from anilines and benzyl alcohols,which is attributed to its super-high specific surface area and mesoporous hollow structure.In addition,this protective roasting strategy can also superiorly stabilize the hollow structure during the reaction,recovery and multiple calcination processes.展开更多
At present,the major problems facing the water resource environment worldwide include water pollution,water resource shortage,and water ecosystem degradation.The discharge of industrial wastewater,agricultural non-poi...At present,the major problems facing the water resource environment worldwide include water pollution,water resource shortage,and water ecosystem degradation.The discharge of industrial wastewater,agricultural non-point source pollution,and the discharge of urban sewage lead to a serious decline in water quality,which directly affects the safety of human drinking water and the living environment of aquatic organisms.Additionally,the unbalanced distribution and excessive exploitation of water resources lead to the problem of water shortage in many areas,which then leads to social and economic contradictions and ecological crises.In terms of ecosystems,the phenomena of water ecological degradation and reduction of biodiversity are increasingly obvious,and the carrying capacity of aquatic ecosystems are gradually declining.This paper aims to analyze the natural,social,and economic factors affecting the water resource environment,and propose effective strategies to protect the water ecology.To provide a theoretical basis and practical guidance for the sustainable utilization of water resources and the long-term development of the water ecosystem.展开更多
基金supported by the 12th fiveyear National Science and Technology plan of China (2012BAC01B03)
文摘The broad-leaved Korean pine(Pinus koraiensis) forest is one of the most biodiverse zonal communities in the North Temperate Zone and an important habitat for many endangered species.Broad-leaved Korean pine forests(BKPFs) are shrinking quickly due to deforestation and rapid urbanization. Thus, scientific protection strategies are urgently needed to change this status. Changbai Mountains contains one of the largest BKPFs and is considered a priority biodiversity conservation area in China. Guided by systematic conservation planning(SCP) methods and procedures, we chose representative species and communities in BKPFs ecosystem as priority conservation objects, and set quantitative conservation target, which is in the light of the biodiversity characteristic of BKPFs. The watershed area is used as planning unit. We used CPlan software to calculate the irreplaceability(Ir)value of each planning unit and the contribution value(Ti) of each conservation object to(1) assess the conservation efficiency;(2) identify the conservation gap of the existing conservation network. Then wecalculated a human disturbance index(HDI) for planning units in the conservation gaps and combine this with the Ir value to design three conservation scenarios to optimize the conservation network.Results show that planning units with high conservation value 14.16% of the total area, with3084.36 km2 were covered by the existing conservation network. 79.28% of planning units with high conservation value have not been protected which were concentrated mainly in the eight gap areas.Only 25.3% of protection objects achieved their conservation target with the existing conservation network. Conservation efficiency is low. Three conservation scenarios are constituted, each prioritizing a different aim:(1) ecological value;(2)species rescue; and(3) economical avoidance. The three conservation schemes potentially enable 93%,88% and 51% of conservation objects, respectively, to achieve identified conservation targets, thereby improving conservation efficiency significantly.
基金supported by the National Natural Science Foundation of China(51874019)the Fundamental Research Funds for the Central Universities(FRF-TP-19-079A1).
文摘The aluminum–selenium(Al–Se)battery is a very promising rechargeable battery system due to its high theoretical specific capacity of 1357 mA h g^(−1)and high average discharge voltage of∼1.52 V versus Al/Al3+.However,Al–Se batteries suffer poor reversibility,since the intermediate product Se2Cl2 dissolved in the acidic electrolyte causes significant capacity fading.To overcome this critical issue,a dual-protection design with composites of selenium nanoparticles encapsulated in mesoporous carbon(CMK-3)and separators modified by CMK-3 are developed.Because of the great physical blocking of the intermediate product dissolved in the electrolyte,the as-assembled Al–Se batteries can deliver an ultrahigh capacity of∼1295 mA h g^(−1)(approximate the theoretical specific capacity)in the first two cycles,and retain a capacity of 651 mA h g^(−1)(retention rate of 50.3%)over 400 cycles at a current density of 1000 mA g^(−1).The rational design of the Al–Se batteries with dual protection from the CMK-3 coated Se positive electrode and modified separators is effective in promoting the electrochemical performance of the batteries.
基金supported by the National Natural Science Foundation of China(22179018)the Natural Science Foundation of Liaoning Province(2021MS132)the Shandong Provincial Natural Science Foundation(ZR2020QB129).
文摘Lithium metal batteries have been regarded as typical representatives of high-energy storage systems.However,lithium dendrite growth and a fragile solid electrolyte interface(SEI)lead to safety issues and unsatisfactory performances.We tackle the above issues with a dual protection strategy by designing a silver(Ag)decorated F-doped graphene(Ag@FG)matrix.Ag@FG was synthesized by a one-step“ion atmosphere”method.When used as a current collector,Ag@FG shows a low nucleation overpotential and a long cycle life due to the enhanced lithiophilicity,high conductivity of the matrix,and the LiF-enriched SEI.The decorated Ag nanoparticles increased the lithiophilicity of the graphene matrix to induce the uniform deposition of lithium.The doped F leads to the formation of a stable SEI.Thus,Ag@FG shows a low nucleation overpotential of only 8 mV at 0.5 mA cm^(-2) and long-term stability for over 1600 h at 1.0 mA cm^(-2) and 1.0 mA h cm^(-2).The assembled full batteries with LFP also indicate its practicability with good cycling stability and rate capability.
基金Supported by the Humanities and Social Science Research Project of Jiangxi Provincial Universities(YS23104).
文摘In this paper,the Jiangxi section of the red army's long march is taken as the research object to construct a red cultural heritage corridor.Introducing the theory of heritage corridor,on the basis of its hierarchical decomposition and comparative judgment,a hierarchy model of the red cultural heritage corridor resource is established.The comprehensive scores of each factor are obtained through expert scoring,and the overall pattern of red army corridor is constructed as"ring-shape-point".New ideas for protection and utilization as well as protection implementation measures are proposed,and the spiritual and cultural connotations of long march in Jiangxi are fully explored.This could help the social and economic development of the areas along the long march of red army in Jiangxi,and promote the integrated utilization and coordinated development of resources in the red cultural heritage corridor region.
基金supported by the Fundamental Research Funds for the Central Universities(No.22120210164).
文摘The renewable microgrid(RMG)is a critical way to organize and utilize new energy.Its control and protection strategies during the fault are the core technologies to ensure the safe operation and stability of the system.The traditional protection principles are unsuitable for RMGs due to the flexibility of RMG operation,the complexity of RMG topology,and the variety of fault control strategies of inverter-interfaced distributed generators(IIDGs).The traditional fault component protection principle is affected by the low voltage ride-through(LVRT)control strategy and will fail in some scenarios.In order to make the fault component protection principle available in every scenario,a current-based fault control strategy is proposed.Specific fault characteristics are generated by the grid-feeding IIDGs during the fault so they can be equivalent to the open circuits,and the fault models in additional network can be simplified.By analyzing the fault characteristics,an RMG protection strategy based on the current-based fault control of IIDGs is presented.The fault directions of feeders can be distinguished and the fault feeder can be located accurately in both grid-connected and islanded RMGs.Then,the grid-feeding IIDGs can transit to LVRT mode smoothly.Thus,IIDGs are considered comprehensively in terms of coordinating with fault control and fault characteristic generation.Finally,the experimental results of the hardware platform prove the effectiveness of the proposed current-based fault control strategy,and the simulation results based on PSCAD/EMTDC verify the correctness of the protection strategy.
基金The Dali Prefecture Social Science Project in 2023(4301502030206)The Yunnan Provincial Department of Education Research Fund Project in 2024(2024J1125)。
文摘This thesis examines the habitat characteristics of traditional villages in Chongqing and characterisesthe spatial distribution of these villages through ArcGIS from a macro perspective.In addition,the habitats characteristics and ecological value system of individual traditional villages are explored using typological researchmethod and corresponding comprehensive protection strategies are deeply discussed.The research results showthat these villages feature non-equilibrium aggregation,mainly concentrated in higher-altitude regions such as inthe southeast,especially in the Youyang Tujia and Miao Autonomous Region.The landscape pattern of the overallhuman settlement area of traditional villages in Chongqing has the characteristics of“woodland-terrace-pondhouse”,the spatial settlement pattern of“distribution around the terrace”,and the aquatic ecosystem model of“pond-terrace-pond”driven by the potential energy of altitude difference.By analyzing the landscape patterns ofhuman settlements,the ecological value system is summarized.Finally,comprehensive protection strategies forthese human settlements are presented,including ensuring the integrity of spatial patterns,respecting ecologicallaws,making full use of agricultural wisdom and strengthening ecological production symbiosis mechanism.
基金Sichuan Fine Arts Insititute Doctoral Research Program‘Chongqing Bayu Watch Tower House Construction Art History and Culture Tracing and Application Research’(2018BSBY016)Chongqing Art Science Research Planning Project‘Study on collage protection strategy of architectural cultural heritage of endangered rammed earth blockhouses in Bayu’(21ZD04)。
文摘Chinese watchtower houses are part of the unique human cultural heritage of the world’s vernacular architectures.Many earthen manor watchtower houses in Chongqing,China,have absorbed the characteristics of other tower houses across the country and have brought together various types of watchtower construction techniques.They are important connection points for the integrity of the Chinese watchtower house as a comprehensive architectural cultural heritage system.They can be a typical sample of Chinese Han classical towers.These buildings are indispensable parts of the Chinese residential watchtower system and have important cultural protection value.However,due to the general lack of excavation and attention to their historical and cultural value,these buildings are on the verge of disappearing.Although they have lost their original architectural functions,they have important value in terms of their building materials,technical composition and artistic modelling.They can stimulate special emotional resonance and become an important bridge that maintains the cultural connection between ancient and modern humans.Therefore,discussing the historical and cultural value of Chongqing rammed earth watchtower houses,the strategy for heritage protection and utilisation is of far-reaching signifcance for Chinese watchtower dwellings.
基金financially supported by the Beijing Natural Science Founding(No.2202050)the National Natural Science Foundation of China(No.21111120074).
文摘MXene,with metallic conductivity,strong hydrophilicity,and rich chemistries,has been widely used as electrode material for energy storage.However,the notorious issues of aggregation and oxidation for MXene significantly inhibit its electrochemical performance and further wide application.Herein,a physicochemical double protection strategy is proposed to stabilize MXene in the hydrothermal process effectively.Polyvinylpyrrolidone(PVP),with the structure of a long chain and abundant O/N function groups,provides physical protection against agglomeration(steric effect)and chemical protection against oxidation(electron transfer)at the same time,contributing to the synthesis of MXene-based hybrids with high conductivity and fully exposed active sites.As proof of the concept,2D MXene/Co_(9)S_(8) nanohybrids with a scaly surface are fabricated and present impressive performance,especially rate performance for hybrid supercapacitor(HSC)with MoS_(2) as the counter electrode.The HSC demonstrates a high energy density of 111 Wh kg^(-1) at 845 W kg^(-1) and an excellent rate performance of 61 Wh kg^(-1) at 16.9 kW kg^(-1).
基金Supported by Special Innovation Projects for Regular Institutions of Higher Education in Guangdong Province(2023KTSCX071)Zhanjiang Science and Technology Bureau Project(2023A01018)Colonel-level Project(LY2207).
文摘This study,integrating both domestic and international literatures as well as field research findings,presents a comprehensive review of the geographical distribution,ecological and physiological characteristics of Acanthus ebracteatus.It further delves into the factors leading to its endangered status and proposes corresponding protection strategies.The mian reasons for the endangered of A.ebracteatus are as follows:illegal harvesting of whole plants,habitat destruction,reproductive obstacles,and competition or interference from invasive or noxious plant species.To address these threats,a series of conservation strategies are proposed.Firstly,in-depth research on the artificial propagation techniques of A.ebracteatus should be conducted to surmount reproductive barriers.Secondly,habitat restoration initiatives need to be carried out to create a suitable ecological setting.Thirdly,in-situ protections should be enhanced while the implementing ex-situ conservation measures.Meanwhile,continuous monitoring of A.ebracteatus seedlings should be conducted to strengthen subsequent management and conservation efforts.Finally,it is recommended to rationally explore and utilize the medicinal properties of A.ebracteatus.
文摘Economic development and transportation construction are inseparable. With the rapid economic development, China pays more and more attention to the perfection of urban rail transit supporting facilities. Nowadays, urban rail transit has become an important way for Chinese people to travel. Compared with other travel modes, rail transit has the characteristics of safety and convenience. Ensure the smooth operation of urban rail, the signal system is the most critical and important control core. Therefore, the signal system is of great significance to the running safety of rail trains, and a good signal system can avoid signal instability and further ensure the stability and safety of train operation. Therefore, this paper studies the relevant aspects of information security protection of rail transit weak current system, and focuses on the analysis of protection schemes and measures, so as to provide more support for the development and safety of rail transit in China.
基金supported by Ph.D.Programs Foundation of Ministry of Education of China,(No.20070019072)the Research Foundation of China Agricultural University(No.90020031).
文摘Highly efficient removal of allyloxycarbonyl （Alloc） group was achieved in the presence of CH3COONH4, Pd[P（C6H5）3]4, and NaBH4 in MeOH-THF, within 5 min in almost quantitative yields （〉90%, isolated yield） without affecting acetyl, benzoyl, isopropylidene, benzylidene, allyl, benzyl, benzyl carbonate, or azido groups.
基金funded by the National Nature Science Foundation of China(62264006)the Special Basic Cooperative Research Programs of Yunnan Provincial Undergraduate Universities’Association(202101BA070001-034)+1 种基金the“Thousand Talents Program”of Yunnan Province for Young Talents,XingDian Talent Support Program for Young TalentsFrontier Research Team of Kunming University 2023。
文摘Tin(Sn)is considered an effective anode material for stripping and plating due to its promising capacity,isotropic deposition,and relatively negative redox potential of-0.91 V vs.standard hydrogen electrode(SHE).However,the challenges of hydrogen evolution corrosion and“dead Sn”formation at the Snalkaline electrolyte interface restrict its reversibility,which poses challenges for flexible devices and in a broad temperature range.In this study,we successfully designed a corrosion-resistant Sn anode(CuPVDF@Sn)featuring a multilevel microchannel structure.The Sn-affinitive Cu mesh with good electronic conductivity lowers the nucleation energy barrier and enhances deposition uniformity,while PVDF improves hydrogen evolution potential.Additionally,the soft Cu mesh and PVDF provide flexibility in design.As a result,the flexible Cu-PVDF@Sn anode achieves a coulombic efficiency(CE)of 92.61% and stable cycling for over 800 h.The flexible Sn-air battery based on this anode exhibits an energy density of 504 Wh kg^(-1),a peak power density of 80 mW cm^(-2),and a cycling stability of 120 h at 5 mA cm^(-2).It also operates effectively within a wide temperature range of -15-60℃,providing strong support for excellent environmental adaptability.The proposed concept in this work might provide a promising alternative for developing stable Sn anodes in flexible Sn-air batteries.
基金supported by the National Natural Science Foundation of China(No.52207088)the Natural Science Foundation of Hebei Province(No.E2024202184).
文摘Multiterminal hybrid HVDC systems,combining the advantages of conventional and flexible DC systems,are considered important development trends for future power networks.With the ability to suppress DC fault current,hybrid HVDC systems eliminate the requirement of current limiting reactors at both ends of DC lines.Thus,non-unit protection based on line boundaries is no longer applicable.In this paper,a non-unit protection scheme in cooperation with converter control is proposed to ensure protection speed,reliability,and sen-sitivity for multiterminal hybrid HVDC systems without line boundaries.In the proposed protection scheme,the protection criterion based on the transient energy of the DC voltage and the direction criterion based on the travelling wave are used to identify whether the fault occurs on the DC line.When the fault is detected as a DC-line fault,the relevant converter station is quickly blocked.After a specified hold-off duration,the converter station interfacing with multiple DC lines is prioritized for restart,while the remaining converter stations are restarted once the DC voltage is stabilized.Simulations based on PSCAD/EMTDC validate the feasibility of the proposed protection scheme and its superiority over competing approaches.
基金financial support by the open foundation of State Key Laboratory of Chemical Engineering(SKL-Ch E-24B03)the Natural Science Foundation of Shandong Province,China(ZR2021QE098)financial support from the Start-Up Research Fund from the University of Macao(SRG2024-00034-IAPME).
文摘Aqueous zinc(Zn)-ion batteries(ZIBs)have garnered significant attention as promising energy storage devices,primarily due to their low cost,high power density,and excellent safety profile.However,the commercial viability of these batteries is hindered by several issues related to the Zn metal anode,including dendritic growth,hydrogen evolution reaction(HER),surface corrosion,and passivation.This review delves into the root causes and key factors influencing these challenges from both electrochemical thermodynamics and kinetics perspectives.Subsequently,viable strategies to mitigate these issues are systematically summarized,including Zn anode reconstruction,artificial solid-electrolyte interphase(SEI)protection,electrolyte formulation optimization,and separator functionalization.Recent research advancements are examined thoroughly,with a focus on the mechanisms behind these approaches and the resulting battery performance.The review also critically assesses the strengths and limitations of these solutions.Finally,we highlight crucial research directions aimed at advancing the practical application of Zn metal anodes in future aqueous ZIBs.
文摘The 13th Five-year Plan period （2016-2020） is a crucial period for environmental protection in China and represents the last chance for the achievement of the environmental objective under the goal of building a well-off society in an all-round manner. During this period of time, China＇ s environment is confronted with the following major risks： risks of environmental quality, human health, ecological security, balanced regional development and international influence. The overall conclusion is that the tendencies of changing eco-environment are complex, problems remain outstanding, and some risks have abated while others have intensified with possible improvements in the future. Future prospects mainly depend on the intensity of actions taken. It is suggested that environmental protection strategy of＂overall optimization＂ be adopted for the 13th Five-year Plan period, i.e. environmental protection requirements should be incorporated into political, economic, social and cultural spheres, so that these areas with major influence on the natural environment will improve and transform towards an environmentally friendly direction and ultimately help achieve the objective of improving eco-environment and people＇s welfare. In order to fundamentally reverse mainstream understanding on environmental protection, it is suggested to define the ＂contradiction between environmental pressures arising from growing economic development and China ＇ s limited and fragile environmental capacity＂ as a major contradiction of Chinese society.
基金supported by the National Natural Science Foundation of ChinaNatural Science Foundation of Zhejiang Province (52077203,LY19E070003)the Fundamental Research Funds for the Provincial Universities of Zhejiang (2021YW06)。
文摘The two-archive 2 algorithm(Two_Arch2) is a manyobjective evolutionary algorithm for balancing the convergence,diversity,and complexity using diversity archive(DA) and convergence archive(CA).However,the individuals in DA are selected based on the traditional Pareto dominance which decreases the selection pressure in the high-dimensional problems.The traditional algorithm even cannot converge due to the weak selection pressure.Meanwhile,Two_Arch2 adopts DA as the output of the algorithm which is hard to maintain diversity and coverage of the final solutions synchronously and increase the complexity of the algorithm.To increase the evolutionary pressure of the algorithm and improve distribution and convergence of the final solutions,an ε-domination based Two_Arch2 algorithm(ε-Two_Arch2) for many-objective problems(MaOPs) is proposed in this paper.In ε-Two_Arch2,to decrease the computational complexity and speed up the convergence,a novel evolutionary framework with a fast update strategy is proposed;to increase the selection pressure,ε-domination is assigned to update the individuals in DA;to guarantee the uniform distribution of the solution,a boundary protection strategy based on I_(ε+) indicator is designated as two steps selection strategies to update individuals in CA.To evaluate the performance of the proposed algorithm,a series of benchmark functions with different numbers of objectives is solved.The results demonstrate that the proposed method is competitive with the state-of-the-art multi-objective evolutionary algorithms and the efficiency of the algorithm is significantly improved compared with Two_Arch2.
基金supported by the National Key Research and Development Program of China (No.2022 YFF1301603)the Guangdong Basic and Applied Basic Research Foundation (No.2021A1515011467)in China+2 种基金the Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai),China (Nos.311020003 and 311021004)the National Natural Science Foundation of China (No.32201290)the 71st batch of China Postdoctoral Science Funding (No.2022M713560)。
文摘A comprehensive risk assessment to evaluate the vulnerability of the nearshore cetaceans to increasing marine traffic is lacking.In this study,the risk to Indo-Pacific humpback dolphins(Sousa chinensis)in the main habitats in China was assessed based on a semiquantitative spatial vulnerability analysis.85%of the(sub)population which overlapped with the lanes of ferries and/or cargo vessels,with exposure scores of 1.23±0.31(calculated based on the proportion of sea routes that overlap the dolphin’s range).A combination of high exposure to the sea routes and sensitivity to marine traffic would render the(sub)populations to be highly vulnerable(EPRE:5.21 and XM:4.47).A low frequency of vessels and an awareness of the ecology assures a low vulnerability(SH:2.43,EZ:2.73).Uncertainty scores were commonly lower for the higher vulnerable populations,and higher for the lower vulnerable populations,suggesting additional field data and more monitoring are necessary.Six years of field data have been used to analyze the influences of various types of marine traffic on humpback dolphin behavior.Fishing and non-fishing vessels were significantly different(χ^(2)=65.19,p<0.01).The humpback dolphins were attracted by fishing vessels(83.1%)but avoided non-fishing vessels(95.2%).We recommend a management with seasonal and geographical constraints,to balance economic development and environmental conservation.
基金Program for New Century Excellent Talents in University of Fujian Province (No.X04139)
文摘To address security and privacy issues in radio frequency identification (RFID) traceability networks, a multi-layer privacy and security framework is proposed, which includes four facets: a security model, a communication protocol, access permission and privacy preservation. According to the security requirements that are needed in an RFID system, a security model that incorporates security requirements that include privacy of tag data, privacy of ownership, and availability of tag identity is introduced. Using this model, a secure communication protocol that can be used for anti-counterfeiting, automatic identification and privacy preservation is then developed. In order to manage the number of parties, data records of items, and complicated transitions of access permissions in an item-level traceability context, a well-designed access control protocol is proposed to parties that can prove the physical possession of an item;meanwhile, to address the privacy issues during data sharing in an RFID network, a vision of database systems that take responsibility for the privacy of the data they manage is also presented.
基金National Natural Science Foundation of China(China,21802058 and 21872066)Fundamental Research Funds for the Central Universities(China,lzujbky-2017-107 and lzujbky-2017-kb11)。
文摘A novel protective roasting strategy was applied to prepare mesoporous hollow CeO_(2)microspheres(mh-CeO_(2))using silica as both a hard template and a roasting protectant.Through detailed characterization techniques such as SEM,TEM,EDX,FT-IR,XRD,XPS,and N_(2)adsorption-desorption,it could be determined that hollow CeO_(2)microspheres with good dispersibility and crystallinity,uniform spherical morphology and suitable pore width as heterogeneous catalysts had been successfully prepared.mh-CeO_(2)showed much higher catalytic activity than the as-prepared SiO_(2)@CeO_(2)and reported CeO_(2)catalysts for one-pot synthesis of imines from anilines and benzyl alcohols,which is attributed to its super-high specific surface area and mesoporous hollow structure.In addition,this protective roasting strategy can also superiorly stabilize the hollow structure during the reaction,recovery and multiple calcination processes.
基金The Knowledge Innovation Program of Wuhan-Shuguang Project(Project No.2023020201020361).
文摘At present,the major problems facing the water resource environment worldwide include water pollution,water resource shortage,and water ecosystem degradation.The discharge of industrial wastewater,agricultural non-point source pollution,and the discharge of urban sewage lead to a serious decline in water quality,which directly affects the safety of human drinking water and the living environment of aquatic organisms.Additionally,the unbalanced distribution and excessive exploitation of water resources lead to the problem of water shortage in many areas,which then leads to social and economic contradictions and ecological crises.In terms of ecosystems,the phenomena of water ecological degradation and reduction of biodiversity are increasingly obvious,and the carrying capacity of aquatic ecosystems are gradually declining.This paper aims to analyze the natural,social,and economic factors affecting the water resource environment,and propose effective strategies to protect the water ecology.To provide a theoretical basis and practical guidance for the sustainable utilization of water resources and the long-term development of the water ecosystem.
