The low-carbon transformation of power sector is significant for achieving the goal of carbon peak and carbon neutrality in China. Based on the evaluation of power carbon budget, three power transformation scenarios of deep low-carbon, zero carbon, and negative carbon were built, the key boundary conditions such as power consumption demand were studied, and a path planning optimization model was established in the paper. Using the GESP-V software package for optimized analysis, the low-carbon transformation paths were determined for power structure, power carbon emissions, and power supply costs under different scenarios. The major issues that are critical for the low-carbon transformation of the power system were discussed, including coal power development, renewable energy development and utilization, diversified supply of clean energy, and electric power balance. Several suggestions were further proposed. Specifically, the top-level design should be strengthened to steadily plan the transformation pace, major low-carbon technologies should be developed to coordinate the overall technology and industrial layout, and the market mechanism with balanced interests should be improved while establishing a green finance policy system. The high-quality low-carbon transformation of China’s power sector in the medium and long term can be promoted through the coordination of policies, technologies, and mechanisms.

Building a new electric power system that is based on new energy sources is an important direction for power system transformation and upgrading in China, and it is critical for peaking carbon emissions and achieving carbon neutrality. In this study, we analyze the changes and challenges that are brought by power system transformation and elaborate on the connotation and building principles of a new electric power system. Moreover, we categorize the development of the new system into stages and propose development suggestions for each stage considering the technical features of the system and the new energy access scale. The new electric power system proposed in this study can satisfy the increasing demand for clean power as it primarily uses new energy sources and it has the features of high safety, openness, and adaptability. Building the new electric power system should follow the technical evolution law and characteristics of power systems; it should further exploit the potentials of mature technologies and current power systems. Meanwhile, emerging technologies should be researched and developed.

Carbon capture, utilization and storage (CCUS) is an indispensable option for achieving carbon neutrality. This study evaluates the technical development level, demonstration progress, cost effectiveness, and CO2 reduction potential of CCUS in China to review the status of CCUS and identify its future direction of development. The conclusion indicates that China’s deployment of CCUS projects has developed rapidly and is generally at the stage of industrialized demonstration; although the overall development is comparable to international counterparts, some key technologies still lag behind the international advanced level. In terms of industrial demonstration, China already has the engineering capabilities for large-scale projects; however, there remains a gap between China and the advanced countries regarding the scale of demonstration projects, technology integration, off-shore storage, and industrial application. In terms of reduction potential and demand, the theoretical storage capacity of CCUS and the demand for industrial emission reduction in China are huge. However, the onshore storage potentials in different regions are significantly varied when source–sink matching is considered. In terms of cost and benefit, although the current cost of CCUS technology is high, CCUS remains a cost-effective emission-reduction option for achieving carbon neutrality in the future. It is necessary to develop the CCUS technology system, promote full-chain integrated demonstration, accelerate the pipeline network layout and infrastructure construction, and improve the fiscal and tax incentive policies and the legal and regulatory framework.

The increasing demand for carbon emission reduction has drawn wide attention on the green hydrogen-manufacturing technology. Hydrogen production by water electrolysis based on renewable energies has the lowest carbon emission among the main hydrogen manufacturing methods. This study summarizes the hydrogen demand, hydrogen industry planning, and demonstrations of hydrogen production by water electrolysis. The water electrolysis technology is analyzed, including alkaline water electrolysis and proton exchange membrane (PEM) water electrolysis. Research reveals that improving electrocatalyst activity, catalyst utilization, bipolar plate surface treatment, and electrolytic bath structures helps optimize the performance of PEM electrolytic baths and lower equipment cost. The PEM water electrolysis has high operating current density, low energy consumption, and high output pressure; therefore, it accommodates the fluctuation of renewable energy power generation and can be easily combined with renewable energy consumption. Considering the technical characteristics of hydrogen transportation and electrolytic hydrogen production as well as hydrogen transportation demand in China, a solution for green hydrogen generation and long-distance transportation is proposed. High-

China is rich in offshore wind power resources, and these resources can be locally consumed by the economically developed provinces located in the eastern coastal region. The development of offshore wind power can accelerate the energy transition in China and help achieve carbon peak in 2030 and carbon neutrality in 2060. In this article, we analyze the current situation, trends, and challenges of energy development in China, and propose that the development of offshore wind power is an important strategic support for the energy structure transformation in China. The key technologies of offshore wind power development in China are summarized including wind turbine, offshore power transmission, offshore engineering, and operation and maintenance technologies. In view of the bottleneck problems restricting the development of China’s offshore wind power industry, we propose some countermeasures and suggestions to promote the healthy and orderly development of China’s offshore wind power industry from five aspects: exploration and evaluation of offshore wind power resources, understanding of energy transition, overall planning and integrated planning, scientific and technological innovation, and policy support mechanism.

Unreasonable discharge of manure from livestock and poultry breeding is a main source of agricultural non-point source pollution in China, but the manure is also a potential resource. How to achieve the best resource utilization of livestock manure and reduce environmental pollution has become a major problem that must be solved in the sustainable development of China’s breeding industry. In this paper, the pollutant discharge coefficient method is used to calculate the amount of manure produced by livestock and poultry breeding in China, and the current situation and problems of its resource utilization are analyzed.

Human is the most dynamic factor in a manufacturing system; no matter how advanced intelligent manufacturing would be, it should meet humans’ needs and serve for a better life. Based on the theory of human–cyber–physical systems (HCPS) in the context of intelligent manufacturing, the concept of human-centered intelligent manufacturing (HCIM) is firstly proposed in this work. HCIM is discussed from the aspects of background, connotation, human factors, technical system, and practical applications. It clarifies that HCIM not only reflects an important perspective, but also represents one of the significant research directions of intelligent manufacturing. On this basis, several suggestions are recommended from policy decision-making, enterprise development, and scientific research levels, including linking HCIM with relevant national strategies, regarding HCIM as a key concept for enterprises’development, and enhancing research on human factors/ergonomics in intelligent manufacturing systems. It’s expected that this work can provide a reference to promote HCIM development and applications in China.

Peaking carbon dioxide emissions and achieving carbon neutrality is a major strategic decision taken by China and it brings significant pressure and challenges to the transport sector. Peaking carbon emissions is an important direction for the highquality development and green transformation of the transport sector. This study analyzes the status quo of green development and carbon emission in China’s transport sector and identifies the challenges for achieving the carbon peak and carbon neutrality goals in the transport sector. The overall idea is to peak carbon emissions actively and steadily by implementing categorized policies, combining short- and long-term goals, controlling carbon emission increment, and adjusting the current emission structure. An overall path for carbon reduction in the transport sector at different stages is proposed. Furthermore, we summarize several key measures to achieve carbon peak and carbon neutrality in the transport sector: (1) optimizing the transport structure, (2) promoting the energy efficiency of transport equipment, (3) popularizing low-carbon transport equipment, (4) improving the traffic organizing efficiency, and(5) encouraging low-carbon travel modes.

Co-mining of the deep mineral and geothermal resources is crucial for the sustainable development of deep mining and provides a brand-new technical means for geothermal mining in deep high-temperature strata. In this article, we analyze the important values of the co-mining, introduce the current status of development and utilization of geothermal resources worldwide, and summarize the basic research progress of the co-mining in China. Subsequently, we analyze the technical and management challenges faced by the co-mining and establish a technical system that is urgently required for comprehensive development and utilization, which involves (1) the investigation and prospect judgment of the joint development and utilization of deep mineral and geothermal resources, (2) the excavation and construction of underground tunnels and chambers in high-temperature and hard rock strata, (3) the key theory and technical system of co-construction, coexistence, and sharing of a deep mineral resource exploitation system and a geothermal development system, and (4) the theories and technologies of geothermal energy exchange and transmission in the deep high temperature strata. Furthermore, development suggestions are proposed in terms of geological exploration, scientific and technological innovation, supporting policies, top-level planning, and scientific research demonstration bases; these aim to provide a reference for the sustainable and high-quality development of the mining and geothermal industries in China.

As China’s Beidou satellite navigation system (Beidou system) achieves a primary global coverage, the low earth orbiter navigation augmentation (LEO-NA) technique becomes a hot research topic, since it can easily cooperate with the Beidou system to improve the precision for global autonomous navigation and to extend the application market of the global navigation satellite systems (GNSS). This paper analyzed the demand for and status of the LEO-NA technique, and focused on the in-orbit validation of key techniques for the “Luojia-1A” satellite. It also studied the challenges faced by the LEO-NA system, including interoperability of signal frequencies after navigation augmentation, integrated design of the communication and navigation signals, control and management of the LEO constellations, acquisition and tracking of the high-dynamic augmented signals, and integration with existing GNSS systems. Considering the pressing demand for the LEO-NA techniques, the following suggestions are proposed, including enhancing the top-level design of the LEO-NA system while focusing on the synergy of the LEO-NA and Beidou systems; promoting the integration of the communications, navigation, and remote sensing functions, and building the space-based real-time service system in a stepwise and stratified manner; and planning and constructing the satellite project and the ground infrastructure in an integrated manner.

The concepts of the marine fisheries carbon sink and carbon sink fisheries current state of research, main problems, technological needs are introduced in this paper. Compared to forestry carbon sequestration, marine fisheries carbon sink is characterized by both high efficiency and scale-up potential. Therefore, the strategy and measures for scaling up marine fisheries carbon sink are proposed, including: investigating the potential and mechanisms for marine fisheries carbon sink; vigorously developing carbon sink fisheries of which the principal part is aquaculture; strengthening the conservation and management of natural carbon sink and environment of China's seas; implementing fisheries carbon sink amplification project construction, and promoting the development of environmentally friendly aquaculture industry.

There are abundant mineral resources at the seafloor. These resources have rich varieties, vast reserves, high grade, and great development and utilization prospects. Countries in the world are accelerating the development of deep-sea mining equipment nowadays. This study analyzes the development status of the deep-sea mining equipment in China and abroad and investigates the deficiencies in technologies and equipment in China from the perspectives of fundamental scientific research, key technology development, and sea trial verification. Moreover, it summarizes the key scientific and technological issues to be resolved, and proposes the developing trends of deep-sea heavy operation equipment, ore transport equipment, and sea surface support vessels. We propose that deep-sea mining should adhere to the concepts of heavy equipment, collaboration, intelligence, and green development, and key technology innovation and independent research and development of the mining equipment should be promoted. Demonstration projects should be constructed for deep-sea polymetallic nodule mining to accelerate the development of deep-sea mining technologies and equipment, so as to realize large-scale sea trials, conduct system design for long-term operation, and promote commercial seabed mining.

With direct electricity, the water electrolysis technology provides pure hydrogen and oxygen from water. Zero-carbon recycling can be achieved with hydrogen as the energy carrier. Unstable renewable energy can be stored in hydrogen. With the concept of power-to-gas or power-to-liquid, high efficiency and zero emission are realized during energy conversion. It is a promising energy utilization solution for the human society in the future. In this review, the water electrolysis technology for industrial hydrogen production is investigated. The progress on proton exchange membrane (PEM) water electrolysis is summarized. Further, the future research trend of water electrolysis is discussed. Additionally, suggestions for hydrogen production from water electrolysis are provided.

The smart energy strategy can provide an energy sharing platform that is interconnected, transparent, and mutually beneficial. The digital twin technology can help break technical and market barriers associated with the development of smart energy. However, the digital twin technology is still in its infancy within the smart energy industry and lacks research on its development and application; a systematic research framework has not yet been formed. This study aims to promote the application of digital twin technology to the smart energy industry by summarizing the development experience of the technology in China and abroad and discussing its future development paths. After comparing the definitions and applications of digital twin technology in different fields, the definition of digital twin for smart energy systems is established, and its general architecture, key technologies, and ecological construction are discussed respectively. Moreover, application cases are briefly analyzed. Furthermore, countermeasures are proposed from three aspects: technology development, ecological construction, and policy establishment. This study is hoped to provide a reference for engineering applications of the digital twin technology in the smart energy industry.

Extreme events occur frequently in China against the background of global warming. Understanding the spatiotemporal variation of extreme events and predicting their future trends can provide a theoretical basis for formulating regional strategies that adapt to climate change. Using the CN05.1 grid meteorological data and eleven global climate models based on Coupled Model Intercomparison Project Phase 6 (CMIP6), we analyzed the evolution characteristics of extreme precipitation and high temperature events in China from 1975 to 2014, predicted the evolution of extreme events from 2015 to 2054, and proposes policy suggestions for dealing with these events. The results indicate that, from 1975 to 2014, the heavy precipitation exhibited an increasing-decreasing-increasing pattern from the northwest to southeast region of China, and the risk and catastrophability of extreme precipitation in regions located to the east of the Hu Line were great. Under SSP1-2.6 and SSP5-8.5 climate change scenarios, extreme precipitation in China will generally increase and become stronger by 2054, with a significant increase in North and Northeast China and a further increase in Northwest China. From 1975 to 2014, the number of warm nights and warm days in China increased significantly, and the increase in warm nights was higher than that of warm days. Under the SSP1-2.6 and SSP5-8.5 climate change scenarios, extreme heat events in China will increase significantly by 2054, with the greatest increase in Northwest, Southwest, and South China. To mitigate the impact of climate change and cope with the risk of extreme events in the future, China should further improve its response and emergency management capacities for dealing with flood and extreme heat risks, strengthen international cooperation, and formulate strategies adapted to local conditions.

Natural gas hydrate (NGH) is regarded worldwide as the most promising clean energy. Research on the exploration and exploitation of NGH has come to a stage of breakthrough in China. However, the accumulation mechanism and occurrence regularity of NGH from muddy silt in the South China Sea remain unclear, and the hydrate decomposition and phase transformation mechanisms during exploitation as well as safe and efficient technologies require further study. This study reviewed the research and application status of NGH exploitation technologies including depressurization and solid fluidization. Moreover, corresponding suggestions were proposed considering the existing problems regarding current NGH exploitation technologies. Specifically, basic research and major engineering should be promoted for multi-gas exploitation of NGH and deep oil and gas; technology innovation and integration should be strengthened to promote synergy between theory and practice; a numerical simulation big science platform should be established for pilot scale tests and multi-field coupling; and relevant standards need to be established and improved. This can improve the research level and technical maturity of NGH exploitation in China, facilitate its large-scale commercial development, and ensure energy security of China.

Accelerating the development of the hydrogen energy industry is crucial for realizing the carbon peaking and carbon neutralization goals and for ensuring national energy security. Hydrogen energy storage has the advantages of cross-seasonal, crossregional, and large-scale storage, as well as quick response capabilities, which is applicable to all links of “source/grid/load” of a newtype power system. This study analyzes the advantages of hydrogen energy storage over other energy storage technologies, expounds on the demands of the new-type power system for hydrogen energy, and constructs an application value system for hydrogen energy storage in the “source/grid/load” of the new-type power system. The results show that hydrogen energy storage can satisfy the requirements of the new-type power system in terms of storage capacity and discharge time; however, gaps remain in investment cost and conversion efficiency. The hydrogen energy system lacks coordination with the power system, and the application of hydrogen energy storage to the new-type power system lacks incentive policies. Moreover, standards systems are insufficient or even absent in renewable energy hydrogen production, electric–hydrogen coupling operation control, and hydrogen fuel cell power generation. Therefore, we suggest that the electric – hydrogen storage mode with high efficiency and low cost should be primarily used at present, and the electric – hydrogen–electric mode should be auxiliary. It is imperative to give full play to the power of hydrogen, electricity, and carbon markets to promote the low-carbon and low-cost development of hydrogen energy storage; actively explore the combination of hydrogen energy transport modes at different distance scales to solve the problem of mismatched distribution of hydrogen energy resources and loads; and accelerate the development of a new standards system for the electric–hydrogen coupling industry.

Space laser communication technology is a major communication technology for space broadband information transmission in the future and has the advantages of high bandwidth, fast and convenient transmission, and low cost. It is the best means to cover the“last kilometer” of information transmission. This study aims to systematically understand the development process of the space laser communication technology. It summarizes the development of research and experimental verification of the technology in China and abroad regarding satellite-ground, inter-satellite, space-ground, and inter-space links. The key technologies of laser communication are studied in detail regarding acquisition tracking, communication transceiving, atmospheric compensation, and optomechanical design. Based on this, five future development trends of space laser communication are summarized emphatically, that is, high speed, networking, multi-purpose, integration, and multi-band. To further promote the research and industrialization of the space laser communication technology, this study proposes implementing basic research plans, focusing on the research and development of core components, actively participating in the formulation of international technical standards, and guiding the development of related industries.

Based on the typical demand for advanced copper alloys by emerging industries and major engineering projects, such as electrical engineering, electronics, 5G communications, new energy vehicles, aerospace, and rail transit, this study systematically summaries the current status of international and domestic copper alloy industries, including high-strength and high-conductivity copper alloy, wear and corrosion resistance copper alloy, elastic copper alloy with ultra-high strength, advanced copper matrix composites, and copper alloy wires and foils with high precision. The typical market demand of the advanced copper alloys is analyzed and the medium and long-term development goals and key technologies of the copper alloy materials in China are proposed. Moreover, industrial development suggestions are also proposed including promotion of the overall planning and integrated development of production, research, application, and management; enhancement of equipment development, technology development, and market expansion abilities; improvement in the research and formulation of product standards; and establishment of a training system for young scientists and technicians. This study is expected to promote the green, high-end, and intelligent development of advanced copper alloy materials in China through the improvement in independent innovation system regarding the copper alloy materials, equipment, technology, and industrialization, thus to meet the demands of national economy and national defense construction.

As China develops toward a high-quality stage and the carbon peak and carbon neutral targets are proposed, a new green and low-carbon development pattern is urgently required. Coal is the primary energy of China and it provides a solid guarantee for the stable operation of the economy; however, the coal industry in China is unbalanced and insufficient in terms of efficiency, technology, market, safety, environment, and other aspects and it can no longer satisfy the new requirements for high-quality energy development and active response to climate change. In this article, we analyze the three imbalances and six insufficiencies that coal industry development faces, and define high-quality development of the coal industry considering the new requirements of energy development.Subsequently, we establish a three-level evaluation index system from three aspects of power, quality, and efficiency reforms. The system is also comprised of five dimensions—innovation-driven, intelligence and high efficiency, diversification and economy, safety and health, green and low carbon—and 23 indexes. Moreover, we evaluate the development level of the coal industry in China using the comprehensive evaluation method of GRA-TOPSIS. The development of an innovation-driven green and intelligent development system, a collaborative and integrated green and low-carbon development system, a market system with orderly competition, a comprehensive open system with win-win cooperation, and a high-quality talent team system has become the key task for the highquality development of the coal industry. Furthermore, we propose suggestions from the aspects of top-level institutional arrangement, carbon reduction in coal industry, and coal production and demand balance.

Developing biomass economy is conducive to economic growth and rural development; it reduces fossil energy consumption and improves ecological environment. Biomass economy has great development potentials, but it still faces various challenges. In this article, the biomass resources in China are comprehensively analyzed, the industry and its current situation and trend are evaluated, and the strategic objectives, key projects, and policy suggestions for industrial development are proposed. China is rich in biomass resources, and biomass briquette fuel, large-scale biogas engineering, biomass power generation and cogeneration technologies are mature. These technologies have exhibited a good momentum of large-scale development and will be the main utilization approaches for a period of time in the future. The development idea proposed in this article for the biomass economy in China regards each county-level region as a unit and considers regional resource endowment, economic development level, and industrial development requirements. The development goals of the biomass economy in China are clarified as becoming mature, system innovation, and large-scale replacement by 2025, 2035, and 2050, respectively. Furthermore, policy suggestions are proposed in terms of technology research and development, incentive policy, market cultivation, and capital investment.

Hydrogen energy is recognized as an important fundamental element to construct an integrated energy supply system dominated by clean energies. Hydrogen development and utilization have become a significant energy development direction for China. However, the inadequate development of hydrogen infrastructures is one of the main reasons hampering the large-scale application and promotion of hydrogen energy in China. This study deeply analyzed the current situation and trend of China’s hydrogen infrastructures (focusing on hydrogen refueling stations), and discussed about the difficulties and challenges in developing the hydrogen infrastructure industry in China. Referring to the advanced experiences of several developed countries, we proposed an overall development goal and route for China's hydrogen infrastructures, and put forward some reasonable suggestions on system safeguard and related policies. The study results would provide a useful reference for the formulation of China’s guidance policies on hydrogen development.

Transportation and energy are crucial for social development and civilization evolution. The energization of transportation infrastructure assets and clean transformation of transportation energies are effective decarbonization strategies for solving severe challenges such as resource shortage, climate change, and environmental pollution. This study first reviews the integration history of road transportation and energy, and investigates the demand for and trends of the integration from the perspectives of national energy security, clean transformation of energy supply, energization potential of transportation infrastructure assets, and intelligentization of the transportation system. The pathway for promoting the integrated development of road transportation and the energy sector is proposed based on assessing the wind and solar resources and the self-consistent supply capacity of energies within the road transportation system. Moreover, a roadmap for integrating road transportation and renewable energies is proposed considering the carbon peak and carbon neutralization targets. Finally, suggestions are proposed from two aspects. In terms of technology development, we suggest that China should enhance technology research and development, improve the industry chain, and promote technology innovation and integration. Additionally, it should provide policies for improving top-level design and strategic planning, exploiting new market modes, and strengthening international cooperation.

This study comprehensively analyzes the application status of aluminum alloy materials in aerospace, transportation, and other fields, and introduces the industry scale and technical level of the aluminum alloy materials in China. Moreover, the main problems of this industry are systematically summarized in view of the shortcomings of some key aluminum alloy materials in China as well as the deficiencies in original technologies such as high-performance aluminum alloy development, processing technology, and intelligent control. And the market demand for the aluminum alloy materials is analyzed based on the development trend of automobile, ship, aerospace, and other fields. According to the current status of the aluminum alloy industry in China, the following countermeasures and suggestions are proposed: enhancing the research and development system to improve the development environment; optimizing the production structure to promote production quality and efficiency and coordinate the development; strengthening policy support; promoting talent team construction; promoting intelligent manufacturing and the Internet Plus initiative; and strengthening international cooperation, particularly along the Belt and Road. This study is expected to help solve some critical problems of the industry and provide a reference for promoting the advanced and green development of aluminum alloy materials.

Vigorously developing new energy is vital for China to achieve carbon peaking and carbon neutrality goals and to accelerate the green and low-carbon transformation of its energy structure. This study first investigates the current status and trend of China's new energy development and then prospects grid integration scenarios for a high proportion of new energies in China in the medium (2030) and long term (2060). The challenges faced by the grid integration are analyzed, including coexistence of high-efficiency consumption and energy guarantee problems, increasing difficulty in safe and stable operation, and an unsuitable power market mechanism. Moreover, a key technology system is proposed from the perspectives of source side, grid side, load side, as well as energy storage and basic support. To achieve long-term steady development of the gird integration and operation for the high-proportioned new energy, we propose to strengthen coordinated planning to promote flexibility, make breakthroughs in key technologies, establish an interim mechanism between new energy policies and the power market, and improve the design of the power market to adapt to new energy consumption scenarios. This study could provide a basic reference for the research on power system planning and electric technologies.

This study compares the advantages of new energy vehicles and internal combustion engines to achieve low carbon emissions and zero pollution. Internal combustion engines are predicted to remain the main driving force of automobiles for a long time in the future. High-efficiency, energy-saving, and clean new technologies for the automobile internal combustion engine are summarized herein, including advanced combustion, turbocharging and small enhancement, multi-system and multi-variable control, waste heat recovery, intelligent cylinder stop, and cylinder water spraying technology, among others. New internal combustion engine technologies with great potential have endlessly emerged in response to the pressure of environmental pollution, global warming, and energy crisis. The internal combustion engine industry in China cannot be slack because it is an important part of the advancement of China's automobile industry toward automobile power.

Since the 21st century, the cultivated area, irrigated area, and main grain-producing zone have been continuously concentrated to the North of China, and the North-to-South grains transportation has further aggravated the dislocation of land resources and water resources, which leads to the increase of agricultural water resources stress, and the unsustainability of underground water in the main grain-producing zone to the north of the Yellow River. To ensure national food security and provide rational basic guarantees for agricultural water resources, based on the analysis of the agricultural water resources situation, the grain production and consumption, the spatial distribution characteristics of food crop irrigation water requirements, and the precipitation adapting cropping areas in China, the paper employed the irrigation quote method to calculate the minimum thresholds of farmland irrigation water requirements in 2025 and 2030 under the condition of the irrigation method adjusted and rational irrigation scale constrained by the grain consumption demand and the total water use control red line in future. The results show that, to meet the water demand for high-standard farmlands of 66.67×10⁶ hectares in the future, a bottom line of 3.23×10¹¹ m³ water for farmland irrigation should be guaranteed while strengthening water-saving conditions, and approximately 6.44×10⁹ m³ unconventional water should be exploited to supplement fresh water shortage. Strategic measures of establishing water-saving and high-efficiency modern irrigation farming and water-collecting and efficiency-improved dry farming systems are proposed. To this end, the following measures should be stressed: precipitation adapting cropping should be promoted to improve rainwater utilization efficiency, engineering and agronomic measures should be taken to increase the utilization efficiency of irrigation water, utilization of unconventional water resources should be increased, and water resource management should be enhanced.

With the increasing shortage of water resources, the development and utilization of unconventional water resources have received more and more attention from various countries. Using unconventional water resources to irrigate is one of the important measures to deal with the shortage of water resources. Unconventional water resources mainly include the reclaimed water and brackish water. In China, the agricultural unconventional water resources have relatively high potentials. It has been predicted that the amount of unconventional water available for agriculture will reach 3.438×10¹⁰ m3 in 2030 and the irrigation amount of reclaimed water and brackish water will be 1.645×10¹⁰ m3 and 2.48×10⁹ m3, respectively. In areas where the fresh water resources are lacking and the unconventional water resources are relatively abundant, especially in the arid area in the north, developing and using unconventional water resources can be regarded as a good solution for the shortage of fresh water. In this paper, based on the situation of China, the irrigation mode of unconventional water resources was summarized. From the aspects of zoning technology, suitable crop classification, pollution identification technology, high-efficient irrigation technique, monitoring and evaluation technology, and integrated application mode, this paper proposes the safe irrigation measures of unconventional water resources in China. Finally, in order to establish a technical system of agricultural unconventional water resources utilization suitable for China, this paper puts forward the development and utilization strategy, which is to further strengthen the technical research and popularization of the agricultural unconventional water resource utilization technology, to improve the recycling standards and regulation system, to bring the unconventional water resources into the planning of water resources development and utilization, and to formulate incentive policies.

China is the world's largest energy consumer and carbon emitter. Its coal-dominated energy structure and heavy industries bring considerable challenges for achieving the carbon peaking and carbon neutrality goals and for realizing high-quality energy development; this necessitates research on energy transition pathways. Herein, the study reviews the current status of China's energy development and predicts the medium- and long-term energy demand and energy transition trends in the country. Our results indicate that the total primary energy demand of China will reach 5.56 × 10⁹ to 5.96 × 10⁹ tons of standard coal in 2035. The CO₂ emission intensity per unit of GDP in 2035 will decrease by 77.6%‒81.5% compared with that in 2005. Energy-related CO₂ emissions will peak during the 15th Five-Year Plan period. Improving energy efficiency, expanding renewable energy application, promoting the carbon capture, storage and utilization technology, and developing hydrogen energy and renewable synthetic fuels are the major technical measures for reducing energy-related CO₂ emissions. Moreover, technological innovation is the core driving force for promoting the green and low-carbon transformation of key areas in China. Furthermore, suggestions are proposed from the aspects of energy conservation,renewable energy development, technological innovation, and coordination of the legal system, technologies, and the market.

High temperature gas cooled reactor (HTGR) together with its successor, the very high temperature reactor, is one of the six nuclear energy systems identified and selected by the Generation IV International Forum for further development. The paper briefly summarizes the technical characteristics of HTGR and reviews the recent research and development status of HTGR technology at home and abroad. It also discusses the strategic positioning of HTGR in China and looks ahead to the HTGR technology development road map in China. China has gone through the stages such as tracking, stepping over, and independent innovation in the past years, and now is in the front-runner status with respect to the commercial-level HTGR nuclear power plant. On this basis, China is working on the design of 600 MW pebble bed HTGR (HTR-PM600), so as to further promote industrialization of the HTGR technology and stay ahead in this field.