Socio-economic and energy-environmental impacts of technological change on China's agricultural development under the carbon neutrality strategy

Promoting agricultural modernisation through technological change is an important strategy for China.China's carbon neutrality strategy is leading to systemic socio-economic changes that could exacerbate the uncertainty of agricultural development.Therefore,applying a computable general equilibrium(CGE)model,this study characterises the agricultural sector in detail,introducing endogenous technological change proxied by research and development(R&D)to assess the impact of different technological change scenarios on agricultural development under the carbon neutrality target.The results show that allocating carbon revenue for R&D inputs can mitigate the significant negative impact of achieving carbon neutrality on knowledge capital and production in agricultural sectors.Overall,using carbon revenue only for R&D input in crop sectors has the optimal effect on increasing the agricultural sectors'knowledge capital,improving crop production and profit,reducing crop external dependence and promoting the synergistic reduction of carbon and pollutant emissions.However,this scenario has the largest negative impact on macro-economics and household welfare.In contrast,allocating carbon revenue to promote technological change in broader non-energy sectors or both crops and non-energy sectors can effectively mitigate negative socio-economic impacts,but the positive impact on agricultural development is minimal.These findings provide practical insights for the rational use of carbon revenue to expand agricultural R&D investment and ensure balanced agricultural and economic development under the carbon neutrality target.

A RCK Model with Endogenous Fertility and Exogenous Technological Change

The technological change as an exogenous variable is introduced into the RCK model with endogenous fertility in this paper. It is proved that the model has at least a nonzero steady state and the nonzero steady state is unique when the parameters satisfies some conditions. By phrase protrait analysis, the unique nonzero steady state is saddle and the economy has a unique optimal growth path. The results obtained implies that the relationship between the technological change and population growth rate determinated by the economic structure and the parental ethies. For the economy in which the parents is selfish, promoting the technological change rate decreases the fertility at the steady state. On the other hand, for the economy in which the parents is less selfish, the fertility increases as the technological change rate increases.

Skill Premium, Biased Technological Change and Income Differences

Using 1987-2006panel data for China, we explore the dynamics of the skill premium. The present paper focuses on the skill premium as an explanation for why income differences are so large in China. Our empirics show that： the rise in the relative supply of skilled labor results in an increase, instead of a decrease, in the skill premium; domestic investment is not complementary with skill formation; the skill premium is higher in more developed provinces; economic openness facilitates an increase in the skill premium; whether foreign direct investment induces skill-based technology change or not, it drives up the skill premium. An array of policy prescriptions for reducing income differences and ensuring sustained economic growth are provided.

On the Measurement of Technological Change

A decomposition into components of the overall technological change is carried out.The overall technological change is decomposed into the technological change,which consists of autonomous shift and shape-deformation in isoquants of production function over table,the scale economics or diseconomies,and the technological change,which is determined by marginal rates of substitution of factors,capital/labor ratio(capital intensity)and its changes.Under the assumption of constant returns to scale the mathematical framework reduces exactly to Solow’s framework. The mathematical formula derived can be applied to measuring the overall technological change in its components.

Research on China’s technology lists for addressing climate change

The compilation of technology lists addressing climate change has a guiding effect on promoting technological research and development,demonstration,and popularization.It is also crucial for China to strengthen ecological civilization construction,achieve the carbon emission peak and carbon neutrality target,and enhance global climate governance capabilities.This study first proposes the existing classification outline of the technology promotion lists,technology demand lists,and future technology lists.Then,different methodologies are integrated on the basis of the existing outline of four technology lists:China’s existing technological promotion list for addressing climate change,China’s demand list for climate change mitigation technology,China’s key technology list for addressing climate change,and China’s future technology list for addressing climate change.What’s more,core technologies are analyzed in the aspects of technology maturity,carbon reduction cost,carbon reduction potential,economic benefits,social influence,uncertainty,etc.The results show that:key industries and sectors in China already have relatively mature mitigation/adaptation technologies to support the achievement of climate change targets.The multi-sectoral system of promoting climate friendly technologies has been established,which has played an active role in tackling climate change.Currently,climate technology needs are concentrated in the traditional technology and equipment upgrading,renewable energy technology,and management decision-making support technology.The key technologies are concentrated in 3 major areas and 12 technological directions that urgently need a breakthrough.For carbon emmission peak and nentrality,carbon depth reduction and zero carbon emissions and geoengineering technology(CDR and SRM)have played an important role in forming the structure of global emissions and achieving carbon neutrality in the future.Thus,the uncertainty assessment for the comprehensive technology cost effectiveness,technology integration direction,technical maturity,ethics and ecological impacts is supportive to the national technology strategy.Finally,the presented study proposes several policy implications for medium-and long-term technology deployment,improving technology conversion rate,promoting the research and development of core technologies,and forming a technology list collaborative update and release mechanism.

Research and Exploration of Automatic Welding Wire Technology for Horn

With the development of science and technology,the electronic component industry has become more and more extensive,covering circuits,electrical and electrical systems from small to large.Many of these parts have very high requirements for the production process,and the production process requires a certain amount of workshop space.In the traditional production process,soldering is mainly manual welding.With the development of intelligence,impersonality and automation,the design of electronic products will gradually move towards intelligence.In this process,the application and promotion of welding technology is essential.In order to ensure the production of automatic products,this paper studies and discusses the function control problems and solutions of the soldering machine.Loudspeaker(commonly known as loudspeaker)is one of the most widely used electronic devices.With the development of the electronic industry and the change of the market environment,major manufacturers are developing new products to meet the market demand and product performance.In order to meet the needs of a large number of high reliability electronic products with different structures now and in the future,automatic welding technology is required to ensure that the welding quality and reliability have certain advantages.

Attribution of Maize Yield Increase in China to Climate Change and Technological Advancement Between 1980 and 2010

Crop yields are affected by climate change and technological advancement.Objectively and quantitatively evaluating the attribution of crop yield change to climate change and technological advancement will ensure sustainable development of agriculture under climate change.In this study,daily climate variables obtained from 553 meteorological stations in China for the period 1961-2010,detailed observations of maize from 653 agricultural meteorological stations for the period 1981-2010,and results using an Agro-Ecological Zones（AEZ） model,are used to explore the attribution of maize（Zea mays L.） yield change to climate change and technological advancement.In the AEZ model,the climatic potential productivity is examined through three step-by-step levels：photosynthetic potential productivity,photosynthetic thermal potential productivity,and climatic potential productivity.The relative impacts of different climate variables on climatic potential productivity of maize from 1961 to 2010 in China are then evaluated.Combined with the observations of maize,the contributions of climate change and technological advancement to maize yield from 1981 to 2010 in China are separated.The results show that,from 1961 to 2010,climate change had a significant adverse impact on the climatic potential productivity of maize in China.Decreased radiation and increased temperature were the main factors leading to the decrease of climatic potential productivity.However,changes in precipitation had only a small effect.The maize yields of the 14 main planting provinces in China increased obviously over the past 30 years,which was opposite to the decreasing trends of climatic potential productivity.This suggests that technological advancement has offset the negative effects of climate change on maize yield.Technological advancement contributed to maize yield increases by 99.6%-141.6%,while climate change contribution was from-41.4%to 0.4%.In particular,the actual maize yields in Shandong,Henan,Jilin,and Inner Mongolia increased by 98.4,90.4,98.7,and 121.5 kg hm^（-2） yr^（-1） over the past 30 years,respectively.Correspondingly,the maize yields affected by technological advancement increased by 113.7,97.9,111.5,and 124.8 kg hm^（-2） yr^（-1）,respectively.On the contrary,maize yields reduced markedly under climate change,with an average reduction of-9.0 kg hm^（-2） yr^（-1）.Our findings highlight that agronomic technological advancement has contributed dominantly to maize yield increases in China in the past three decades.

满足运载火箭测控需求的Ka频段CTDRSS终端技术

To meet the application requirements for a Ka-band space-based TT&C terminal for a launch vehicle,this paper proposes the implementation scheme of a space-based TT&C terminal,analyzes and solves the miniaturized design of equipment and the key technology for high-efficiency heat dissipation.The phased array antenna test shows that without external heat dissipation measures,the phased array antenna can work for a long time to meet the working requirements of launch vehicle,which has been verified in the LM-8 mission,and has wide engineering application prospects.

Editorial: Moving Forward to Respond to Rapid Changes of Computer Science and Technology

Since its inaugural issue in 1986,the Journal of Computer Science and Technology(JCST)has been the premier English journal of China Computer Federation(CCF),serving international readers and authors by disseminating scholarly and technical papers under a rigorous review process.

China-Brazil Forum on Climate Change and Energy Technology Innovation

The China-Brazil Forum on Climate Change and Energy Technology Innovation opened in Tsinghua＇s Main Building on January 14, 2009. Mr. Samuel Pinheiro Guimaraes, Brazilian Vice-Minister for Foreign Issues, Professor Luiz Pinguelli Rosa, Federal University of Rio de Janeiro, Director of COPPE, and representatives from Brazil＇s Embassy in China attended the Forum.

Modern Technology Changes Art of Protest

随着网络的发展,以及网络便捷、快速、随时随地传递信息的特点,人们请愿抗议的方式也逐渐由纸上操作转为网上投递。任何人都可以免费在网络上发泄自己的情绪或申明自己的观点,而不必付诸某种实际行动。这是现代技术对人类生活影响的一个侧面。本文就一家网络公司的情况对这一现象提供了一个颇为有趣的实例。

Time to Rethink:Educating for a Technology-Transformed World

Purpose:We hope to provoke a conversation about preparing students for an uncertain future that unforeseeable technological innovations will transform in ways we cannot predict.The unprecedented disruption caused by the COVID-19 pandemic makes this an opportune time to reconsiderall dimensions of education.Design/Approach/Methods:We present information on how technology is transforming virtually every aspect of our lives and the threats we face from social media,climate change,and growing inequality.We then analyze the adequacy of proposals for teaching new skills,such as 2Ist-Century Skills,to prepare students for a world of work that is changing at warp speed.Findings:Despite harbingers of a radically different future,most schools continue to operate much as they have for centuries,providing a one-size-fits-all education.Technology now enables an unprecedented degree of personalization.We can tailor learning opportunities to individual students'interests,talents,and potential with teachers serving as guides,resources,and critical friends.The Internet afford a cornucopia of learning opportunities-online courses,international experts,global collaborations,accessible databases,and libraries.Learning can occur virtually anywhere.Originality/Value:The future depends on decisions we are making today about education.The value of this article is that we call for rethinking every component of education rather than considering each element independently.

The Role of Engineer-in-Chief and the Introduction of Foreign Hydraulic Dredging Technology and River Conservancy into China,1890s-1930s

This paper discusses studies of the development of river conservancy in modern China,and the role of engineers-in-chief in river improvement planning on rivers such as the Hai-ho(Haihe)and the Whangpoo(Huangpu).It discusses the introduction of foreign hydraulic dredging technology and management into two major Chinese ports.It then analyses the process by which two agencies of the Chinese government absorbed and adjusted this technology to suit local circumstances in the treaty ports of Tianjin and Shanghai beginning in the 1890s.Without prior experience in river conservancy,the conservancy boards adopted a range of foreign technologies.This allowed them to develop into major institutions that facilitated increasing trade flows between China and the rest of the world.Of particular significance in this process of technological change was the role of the expatriate engineers-in-chief who were employed as chief executive officers of both agencies.They were responsible for establishing the operations of the agencies,accommodating an increasing range of responsibilities such as financial and human resource management,and training Chinese engineers and managers for senior positions until they were ready to replace the expatriate engineers-in-chief after the 1930s.

Marginal revenue of land and total factor productivity in Chinese agriculture： Evidence from spatial analysis

This paper attempts to explore the temporal and spatial nature of the marginal revenue of land, total factor productivity （TFP） change and its three components： technical change （TC）, technical efficiency change （TEC） and scale efficiency change （SEC） as seen in Chinese agricultural production from 1995 to 1999. Based on county-level data, the study utilized both stochastic frontier and mapping analyses methods. The results show that growth in the marginal revenue of land was diverse across various regions, where most gain occurred in eastern coastal zone, while loss was in Northwest and North China. China has experienced moderate decreases in annual TFP change （–0.26%） with considerable regional variations. Specifically, the administrative intervention in grain production and the deterioration of the agricultural technology diffusion system led to a moderate drop in annual TFP change. County-level mapping analyses took into account interregional variances in TFP and its components. Regarding components of TFP, TEC differences explain the majority of regional dispersions in TFP. As developed areas in China, the Huang-Huai-Hai region and the Beijing-Tianjin-Tangshan economic zone face the challenges of land conversion and grain security amidst the process of urbanization.