China actively promotes CO2 capture, utilization and storage research to achieve carbon peak and carbon neutrality

Global climate change is a common challenge facing mankind, which has evolved from a scientifific issue into a global economic and political issue of universal concern to the international community. Temperature increase, sea level rise, extreme weather and climate events caused by the climate change are becoming more and more prominent. The scientifific understanding of climate change in the international community has been deepening. The Intergovernmental Panel on Climate Change (IPCC, 2014) further strengthened the scientific conclusion that human-induced climate change is more than 95% likely to be attributed to emissions of greenhouse gases from human activities.The United Nations Climate Change Summit (held in September 2014) pointed out that climate change threatens the hard-won peace, prosperity and opportunities of all mankind, and that no one and no country is immune to its impact. Controlling global warming within 2℃ is an urgent and severe challenge faced by mankind in dealing with climate change. The awareness of all countries on the issue of climate change is gradually increasing. The 26th Conference of the Parties (held in November 2021 in Glasgow, UK) urged all countries to achieve the net zero carbon emissions by around 2050, and step up efforts to reduce carbon emission before 2030. Therefore, taking active measures to cope with climate change becomes the common aspiration and urgent need of all countries.Mitigating greenhouse gas emissions (represented by CO2) has become the consensus of the world. In September 2020, Chinese President Xi Jinping pledged at the General Debate of the 75th Session of The United Nations General Assembly that China aims to peak its CO2 emissions before 2030 and achieve carbon neutrality before 2060 (i.e., dual carbon goals), which demonstrates the responsibility of a major country.CO2 Capture, Utilization, and Storage (CCUS) is considered as an effective technology directly achieving carbon emissions mitigation, and has attracted widespread attention of the international community (Metz et al., 2005). The implementation of CCUS projects began in the 1970s, and was mainly carried out in the United States, Canada and some European countries. Those projects mainly focused on CO2 enhanced oil recovery, whereas projects with the pure purpose of CO2 sequestration are relatively rare due to their poor economy.CCUS projects in China started relatively late, and most of them were gradually implemented after 2000 (Guo et al., 2014). The initial technical routes of these projects were similar to those of projects carried out in European and American countries, which began with the geological sequestration of CO2 and enhanced oil recovery. In the past decade, CCUS projects in China began to develop in a diversified way, and there emerged a variety of carbon dioxide capture, storage and utilization technologies, including pre-combustion capture of power plants, CO2 chemical and biological utilization, etc.The realization of the dual carbon goals not only requires revolutionary changes in industrial technology, but also largely depends on the formulation of relevant policies and capital investment. The National Natural Science Foundation of China launched a special research program “Major Basic Science Issues and Countermeasures for National Carbon neutrality” in 2021 to meet the needs of basic science research for the national carbon neutrality strategy. Focusing on the two core issues of “carbon emission mitigation” and “carbon sink increase”, the special program includes a total of 28 research projects, with an average funding of about 3 million RMB per project.This special research program aims to reveal the oceans and terrestrial carbon sinks, the process mechanism, evolution trend and its mutual feedback mechanism with the climate system, delineate the geological process of carbon sequestration and the effectivity of fixing carbon. The program also has goals to increase the potential of CO2 storage, to assess the technology risk and management mode, to analyze the economic transformation, the optimal pathway, climate control, international cooperation management and policy issues. Interdisciplinary integration research is needed to condense key basic science issues and solutions for serving the national carbon-neutral strategy.It is foreseeable that China will further increase investment in realizing a carbon emission peak and its carbon-neutral strategy in the future. This is also a great opportunity for the development of CCUS-related technologies. The contribution of CCUS technology in carbon emission mitigation is generally low today. For instance, even in Norway, which has the highest proportion of carbon emissions treated by CCUS, the value is less than 5% (Cai et al., 2020). However, as the guaranteed technology of carbon peak strategy, the contribution ratio of CCUS in carbon emission mitigation is expected to significantly increase in the future.Although the CCUS technology has been implemented for many years and many projects have been carried out, there are still many challenges to be solved, such as:(i) CCUS related technology development and cost control The CCUS technology includes capture, transportation, utilization and storage, all of which need to consume a lot of energy. At present, the cost of the CCUS projects is still high. It is estimated that the cost of the whole CCUS process will be 150-540 RMB per ton of CO2 by 2025, of which CO2 capture cost accounts for more than two thirds of the total cost, about 100-480 RMB/ton. In comparison, the cost of CO2 sequestration is 50-60 RMB/ton, while the cost of CO2 transportation is very low, less than 1 RMB/ton (Cai et al., 2021). Obviously, the wider promotion of CCUS projects in the future largely depends on the further development of CO2 capture technology and the rapid reduction of cost.(ii) Effect of long-term CO2-water-rock interaction on rock structure and mechanical properties In the process of CO2 geological storage and utilization, the injected CO2 will inevitably change the pH of formation water, breaking the original water-rock balance and inducing a new water-rock reaction. Thus, the rock structure and mechanical properties of the caprock are likely to be changed over time, which affects the safety of the storage reservoirs. The current studies mostly focus on the effect of CO2-water-rock interaction on the leakage channels (porosity and permeability) of the caprock (Credoz et al., 2009; Liu et al., 2020). However, the study on the change of rock mechanical properties caused by chemical reactions requires further research attention. A few previous studies only simply correlated the evolution of rock mechanical properties with porosity, but without considering the influence of changes in mineral composition induced by CO2-water-rock interaction on the rock mechanical properties (Agarwal, 2019). Therefore, it is necessary to further deepen the relevant investigation and build a comprehensive rock mechanical parameter evolution model considering the changes of porosity, mineral composition and content, and other factors (Tian et al., 2019).(iii) CO2 leakage monitoring and risk assessment methods The leakage risk of CO2 after injection has been one of the main concerns, which directly affects the safety and feasibility of CCUS technology (Bachu, 2008). At this point, the construction of a CO2 leakage monitoring system is particularly important. However, the CO2 leakage process is usually characterized by sudden occurrence and weak surface response. Therefore, a single monitoring method is difficult to ensure the reliability of monitoring. In the future, it is necessary to combine various monitoring methods with their respective advantages.For a long-term (more than 100 years) CO2 leakage risk assessment, the most commonly used method at present is to employ the reactive transport modelling. However, due to the large time scale, parameter uncertainty and the difficulty of validation, the predicted results have high uncertainty. Some natural CO2 gas reservoirs have existed for more than thousands of years (Jonathan et al., 2018). Taking natural CO2 gas reservoirs as a natural analogue of CO2 geological sequestration can solve the problem that long-term simulated results are difficult to verify, thereby improving the reliability of long-term risk assessment (Xu et al., 2019). AcknowledgementThis work was performed in support of the National Natural Science Foundation of China (Grant Nos. 42141013 and 41772247). Conflict of interest The authors declare no competing interest.Open Access This article is distributed under the terms and conditions of the Creative Commons Attribution (CC BY-NC-ND) license, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Cited as: Xu, T., Tian, H., Zhu, H., Cai, J. China actively promotes CO2 capture, utilization and storage research to achieve carbon peak and carbon neutrality. Advances in Geo-Energy Research, 2022, 6(1): 1-3. https://doi.org/10.46690/ager.2022.01.0

Constructing “New Liberal Arts” in China’s Universities: Key Concepts and Approaches

[EN] Inspired by the concept of “New Engineering” in China’s universities and considering the features and values of the humanities and social sciences, this paper discusses issues of constructing “New Liberal Arts” in China’s universities. Firstly it states the general characteristics of the humanities and social sciences that find their realization in “New Liberal Arts”, and the qualities of “New Liberal Arts” such as being strategically important, innovative, integrated and promising. Then it proposes that a cluster of first-rate undergraduate programs with Chinese characteristics and global competitiveness be set up. The paper finally suggests new ways in which “New Liberal Arts” are to be constructed, such as to recognize new research objects, new research paradigms and new social needs of the humanities and social sciences, to break through conventional thinking stereotypes, and to do well in five aspects -- concept reconstruction, structural reorganization, model regeneration, platform building and differential development. In so doing, the paper is hoped to provide useful considerations for universities elsewhere.Wang, M.; Tian, H. (2019). Constructing “New Liberal Arts” in China’s Universities: Key Concepts and Approaches. En HEAD'19. 5th International Conference on Higher Education Advances. Editorial Universitat Politècnica de València. 1121-1128. https://doi.org/10.4995/HEAD19.2019.9111OCS1121112

Nonlinear Transport of Graphene in the Quantum Hall Regime

We have studied the breakdown of the integer quantum Hall (QH) effect with fully broken symmetry, in an ultra-high mobility graphene device sandwiched between two single crystal hexagonal boron nitride substrates. The evolution and stabilities of the QH states are studied quantitatively through the nonlinear transport with dc Hall voltage bias. The mechanism of the QH breakdown in graphene and the movement of the Fermi energy with the electrical Hall field are discussed. This is the first study in which the stabilities of fully symmetry broken QH states are probed all together. Our results raise the possibility that the v=6 states might be a better target for the quantum resistance standard.Comment: 15 pages,6 figure

Study on failure warning of tool magazine and automatic tool changer

Tool magazine and automatic tool changer (ATC) is used to store and change tools in a machining center, which plays an important role in automatic manufacturing. Therefore, the stability and reliability of tool magazine and ATC is very important to a machining center. Failures of tool magazine and ATC would increase ramp-up repair time and repair cost. So early warning system of failures for tool magazine and ATC becomes a research hotspot. The main vibration signals of tool magazine and ATC would occur obviously when the tool arm grasps a tool holder, draws a tool holder out of a tool into spindle or tool pocket and inserts a tool holder into spindle or tool pocket. To predict failures of tool magazine and ATC and improve the availability of machining center, a vibration test procedure and calculation method of vibration signal threshold of pull nails looseness which can lead to tool falling failures are proposed based on the vibration detection theory. Then, the vibration signals of tool changing are analyzed and the relationship between the maximum amplitude of vibration signals and the looseness severity of pull nails is also illustrated. The final experiment results show that the tool falling failure warning method is feasible to reduce the failures of tool magazine and ATC through the early warning system based on the threshold of vibration signals

Recombinant human thioredoxin-1 promotes neurogenesis and facilitates cognitive recovery following cerebral ischemia in mice

AbstractCerebral ischemia (CI) can induce loss of hippocampal neurons, causing cognitive dysfunction such as learning and memory deficits. In adult mammals, the hippocampal dentate gyrus contains neural stem cells (NSCs) that continuously generate newborn neurons and integrate into the pre-existing networks throughout life, which may ameliorate cognitive dysfunction following CI. Recent studies have demonstrated that recombinant human thioredoxin-1 (rhTrx-1) could promote proliferation of human adipose tissue-derived mesenchymal stem cells and angiogenesis. To investigate whether rhTrx-1 also regulates hippocampal neurogenesis following CI and its underlying mechanisms, adult mice were subjected to bilateral common carotid arteries occlusion (BCCAO) to induce CI and treated with rhTrx-1 before reperfusion. Mice treated with rhTrx-1 showed shortened escape latencies in Morris water maze by 30 days and improvements in spatial memory demonstrated by probe trial test. Enhanced NSCs proliferation was observed at day 14, indicated by BrdU and Ki67 immunostaining. Doublecortin (DCX)+ cells were also significantly increased following rhTrx-1 treatment. Despite increases in BrdU+/NeuN+ cells by day 30, the double-labeling to total BrdU+ ratio was not affected by rhTrx-1 treatment. The promotive effects of rhTrx-1 on NSCs proliferation and differentiation were further confirmed in in vitro assays. Western blot revealed increased ERK1/2 phosphorylation after rhTrx-1 treatment, and the ERK inhibitor U0126 abrogated the effects of rhTrx-1 on NSCs proliferation. These results provide initial evidence that rhTrx-1 effects neurogenesis through the ERK signaling pathway and are beneficial for improving spatial learning and memory in adult mice following global CI

Load spectrum generation of machining center based on rainflow counting method

Reliability bench tests and probability design method are two important means to improve the reliability of machine tools, while the load spectrum of machine tools is the foundation of reliability bench tests and probability design. According to the load spectrum, the actual working conditions can be simulated in laboratories. A dynamic load spectrum generation method is proposed to establish a representative load spectrum. Firstly, the cutting load measuring system is established based on the characteristics of the cutting loads, and then the actual cutting experiments designed by the orthogonal experimental method are conducted on the basis of the typical cutting conditions in laboratories. Secondly, the counting method of the cutting loads cycles is presented based on the dynamic load characteristics of a machining center. And loads cycles are counted by the proposed counting method, and then a rainflow matrix is formed. Thirdly, in order to improve the precision of the load spectrum the extrapolation of the loads is carried out using the parametric extrapolation method. Then the probability distribution functions of the mean and amplitude of the cutting loads are provided by the K-S goodness-of-fit test method. The case study indicates that the radial force, axial force, and cutting torque of the tested machining center follow gamma, normal, and Weibull distributions with different parameters, respectively. Finally, the joint distribution function of the mean and amplitude of the radial force, axial force, and cutting torque is obtained by using a combination of statistical analysis method, and the two-dimensional load spectrum of the MC is compiled

Aboveground net primary productivity of vegetation along a climate-related gradient in a Eurasian temperate grassland: spatiotemporal patterns and their relationships with climate factors

Accurate assessments of spatiotemporal patterns in net primary productivity and their links to climate are important to obtain a deeper understanding of the function, stability and sustainability of grassland ecosystems. We combined a satellite-derived NDVI time-series dataset and field-based samples to investigate spatiotemporal patterns in aboveground net primary productivity (ANPP), and we examined the effect of growing season air temperate (GST) and precipitation (GSP) on these patterns along a climaterelated gradient in an eastern Eurasian grassland. Our results indicated that the ANPP fluctuated with no significant trend during 2001-2012. The spatial distribution of ANPP was heterogeneous and decreased from northeast to southwest. The interannual changes in ANPP were mainly controlled by year-to-year GSP; a strong correlation of interannual variability between ANPP and GSP was observed. Similarly, GSP strongly influenced spatial variations in ANPP, and the slopes of fitted linear functions of the GSP-ANPP relationship increased from arid temperate desert grassland to humid meadow grassland. An exponential function could be used to fit the GSP-ANPP relationship for the entire region. An improved moisture index that combines the effects of GST and GSP better explained the variations in ANPP compared with GSP alone. In comparisons with the previous studies, we found that the relationships between spatiotemporal variations in ANPP and climate factors were probably scale dependent. We imply that the quantity and spatial range of analyzed samples contribute to these different results. Multi-scale studies are necessary to improve our knowledge of the response of grassland ANPP to climate change.ArticleENVIRONMENTAL EARTH SCIENCES.76(1):56(2017)journal articl

Static and dynamic characteristic analysis of high-speed press bed based on virtual simulation

This paper establishes a three-dimensional solid model of J76-125 Straight Side High-speed Double-crack Precision Press using CATIA, and then the model is imported into an ANSYS environment to form the static and dynamic finite element simulation model. Based on the finite element analysis method, the static stress, deformation, vibration mode and transient response of the press bed are developed under preload conditions, as well as under the combination of the preload and nominal pressure conditions. Besides, the static loading experiment, the mode experiment and the pile-driving experiment are conducted to revise the simulation model. Finally, the simulation model and analysis procedure are verified through the comparison of the experiment results and the simulation ones

Study on failure warning of tool magazine and automatic tool changer

Tool magazine and automatic tool changer (ATC) is used to store and change tools in a machining center, which plays an important role in automatic manufacturing. Therefore, the stability and reliability of tool magazine and ATC is very important to a machining center. Failures of tool magazine and ATC would increase ramp-up repair time and repair cost. So early warning system of failures for tool magazine and ATC becomes a research hotspot. The main vibration signals of tool magazine and ATC would occur obviously when the tool arm grasps a tool holder, draws a tool holder out of a tool into spindle or tool pocket and inserts a tool holder into spindle or tool pocket. To predict failures of tool magazine and ATC and improve the availability of machining center, a vibration test procedure and calculation method of vibration signal threshold of pull nails looseness which can lead to tool falling failures are proposed based on the vibration detection theory. Then, the vibration signals of tool changing are analyzed and the relationship between the maximum amplitude of vibration signals and the looseness severity of pull nails is also illustrated. The final experiment results show that the tool falling failure warning method is feasible to reduce the failures of tool magazine and ATC through the early warning system based on the threshold of vibration signals