德国迈向能源转型

德国在今年5月关闭了位于巴符州的已有36年历史的奥布里希海姆核电站，并计划在今后20年内关闭所有核电站。     

试论能源转型中的电能替代

随着经济的发展,同时加速了工业的进程,自然环境在这个发展迅速的时代承载着巨大的压力,传统能源在使用中带来了很多资源和环境问题。电能替代成为能源转型中的必然趋势,本文主要阐述了电能替代的的主要内容,实施中的问题和未来的发展路径。     

摆脱“能源困境”更需“三管齐下”

一、当前我国面临的能源困境中国地质科学院的“未来20年中国矿产资源的需求与安全供应问题”报告预测:未来20年中国石油需求缺口超过60亿吨,天然气超过2万亿立方米,钢铁缺口总量为30亿吨,铜超过5000万吨,精炼铝1亿吨,即重要矿产资源的供应将是不可持续的。目前,中国能源消费结     

我国清洁能源形势发展分析

能源问题已经上升到世界发展的战略问题，当然也是中国发展的一个重要问题。中国要想实现能源转型，应大力发展清洁、可再生能源，同时还要高效用能。这样，才能使我国能源发展支撑实现新的经济发展目标和建成小康社会。     

试论我国低碳经济面临的困境及对策

随着国际低碳经济的呼声不断高涨,我国工业化进程发展过程中的能耗问题已经成为了制约经济发展的重要因素。低碳经济不仅要以低消耗的工业发展为前提,同时还需要结合本国的低碳技术水平,从而使经济发展走上可持续道路。因此,重视中国经济向低碳型的转变,需要政府和企业共同努力,一方面大力推行节约型发展战略,另一方面重视低碳技术的创新和推广,进一步为经济转型提供可靠的保障。     

东亚安全困境与中国的策略选择

冷战结束后，东亚的安全环境发生了重大而深刻的变革。冷战时期形成的赖以维系东亚地区和平与稳定的诸多条件已经产生巨大变迁，安全困境的存在成为东亚安全环境的最重要特征。新形势下，全面审视并理顺各种地缘关系，捍卫国家主权和国家利益，维护和促进东亚地区的安全与繁荣，均须中国回以对应策略。     

煤炭企业能源转换与节能

近年来，能源转换与节能工作越来越成为人们关注的问题，有效合理地使用能源，是实现能源综合利用、促进企业经济发展，提高企业经济增长的质量和效益、促进经济增长方式转变的有效途径。煤炭企业，虽然是能源生产大户，但又是电、煤、油、水等能源消耗浪费大户，煤炭企业的能源利用率仅为22％，比国外先进水平低28个百分点，比全国平均水平低8个百分点，探究其主要原因是能源使用与转换中损失严重，利用率低，节能效果不明显。同时，煤炭企业能源转换与节能的潜力也是十分巨大的，特别在市场经济条件下，搞好能源转换与节能，对企业立足市…     

可再生能源正逐步向替代能源转型

在2008年10月30日举行的中国电力发展和技术创新院士论坛上,中国工程院副院长杜祥琬院士如是说：“随着社会经济的快速发展,能源和环境对可持续发展的约束将越来越严重,大力节能、控制需求总量、发展清洁能源技术、加快开发利用可再生能源,是优化我国能源结构、填补我国常规能源缺口和保护环境的重要途径,是实现可持续发展的必由之路。”     

中国低碳能源战略雏议

1．2009：世界和中国能源的第三次大转型人类从19世纪开始工业化进程以来已经经历了两次能源构成的转型。图l给出了世界能源构成变化的历史轨迹（黑线，为文献[1]给出。图中自2001至2100各点及红色箭头是本文所加）。第一次大转型开始于19世纪，由蒸汽机的发明和推广应用所促成的由薪柴为主的可再生能源向煤的转化。第二次是在20世纪初的20年间，从煤转向石油。推动力是汽车和飞机的普遍使用。而从现在开始，人类将开始第三次能源大转型。     

中国能源发展战略的探讨

据经济专家分析,我国又将进入一个经济快速发展期,能源短缺现象已在一些省市频频出现,并有不断发展的趋势。能源供求问题将在今后一段时期内成为我国经济发展的重要问题,解决能源问题的关键首先是要建立起我国能源发展战略,并在能源战略的指导下建立起一套适合我国国情的能源政策体系,使我国能源管理走向法制化和制度化。下面就建立我国能源发展战略的依据、重点、特征和指导思想进行探讨性的论述。1.能源发展战略的概述能源是国民经济发展的命脉,能源需求量与国内生产总值具有较高的相关性。许多发达国家为了保障本国经济的可持续发展,防止…     

我国建筑节能战略研究

给出了我国建筑运行能耗现状,并按照北方城镇建筑采暖、长江流域住宅采暖、住宅用能、非住宅建筑用能以及农村民用建筑用能的分类方法,分别分析了各类建筑能耗的特点、问题和节能的主要途径,同时对比了发达国家同类建筑用能与我国的差别。在基于数据和实际现象的分析的基础上,提出我国建筑能耗显著低于发达国家的主要原因是由于不同的生活方式和建筑使用模式所致,而维持目前这种相对节约的建筑使用方式与生活模式是实现我国建筑节能目标的基础。不同的生活方式和建筑使用方式需要不同的技术措施去实现节能,因此我国一定要采用与发达国家不同的技术途径来实现建筑节能目标。     

Kittle型反铁电相变的序参量和自由能

根据Kittle型反铁电相变对称性的变化，选择轴矢量R作为序参量是合适的。由Landau连续相变理论，相变温度附近的自由能就可以写成R幂级数展开的形式。自由能取极小，可得到关于序参量的方程，从而荻得相变温度与自由能的关系。     

我国能源形势及发展对策

总结了近年来我国能源发展取得的成绩,研究分析了我国能源发展面临的形势和挑战,提出了当前和今后一个时期能源工作的主要任务。特别强调保证能源安全供应是能源战线的一项首要任务、基本任务和长期任务,同时要大力节约能源,调整优化能源结构,加快能源科技自主创新,扩大能源国际合作,推动能源科学发展,为经济社会健康、持续、协调发展提供保障。     

Energy transition toward carbon-neutrality in China: Pathways,implications and uncertainties

Achieving carbon neutrality in China before 2060 requires a radical energy transition. To identify the possible transition pathways of China’s energy system, this study presents a scenario-based assessment using the Low Emissions Analysis Platform (LEAP) model. China could peak the carbon dioxide (CO₂) emissions before 2030 with current policies, while carbon neutrality entails a reduction of 7.8 Gt CO₂ in emissions in 2060 and requires an energy system overhaul. The assessment of the relationship between the energy transition and energy return on investment (EROI) reveals that energy transition may decrease the EROI, which would trigger increased energy investment, energy demand, and emissions. Uncertainty analysis further shows that the slow renewable energy integration policies and carbon capture and storage (CCS) penetration pace could hinder the emission mitigation, and the possible fossil fuel shortage calls for a much rapid proliferation of wind and solar power. Results suggest a continuation of the current preferential policies for renewables and further research and development on deployment of CCS. The results also indicate the need for backup capacities to enhance the energy security during the transition.     

Development of renewable energy in China: significance & strategic objectives

Based on CAE’s research report, this paper illustrates the background and purposes of the development strategy research of renewable energy in China, emphasizes the significance of developing renewable energy in China, gives the strategic positions and development objectives of renewable energy in China in the first half of 21st century and contributes to green house gas emissions reduction and environmental protection in China.     

Laser-based directed energy deposition of novel Sc/Zr-modified Al-Mg alloys: columnar-to-equiaxed transition and aging hardening behavior

The control of grain morphology is important in laser additive manufacturing(LAM), as grain morphology further affects the hot cracking resistance, anisotropy, and strength–ductility synergy of materials. To develop a solidification-control solution and achieve columnar-to-equiaxed transition(CET) in Al-based alloys during LAM, Sc-and-Zr-modified Al-Mg alloys were processed via directed energy deposition(DED).CET was achieved by introducing high potent primary Al_3(Sc,Zr) nucleation sites ahead of the solidification interface. Furthermore, the relationship between the solidification control parameters and precipitation behavior of primary Al_3(Sc,Zr) nucleation sites was established using the time-dependent nucleation theory. Then, the CET was studied according to the Hunt criterion. The results indicated that coarse columnar grain structure was still obtained at the inner region of the molten pool at low Sc/Zr contents owing to the effective suppression of the precipitation of the primary Al_3(Sc,Zr) nucleation sites via rapid solidification during DED. In addition, the relatively low melt temperature at the fusion boundary unavoidably promoted the precipitation of primary Al_3(Sc,Zr) nucleation sites, which resulted in a fine equiaxed grains band at the edge of the molten pool. As the Sc/Zr content increased, the solidification cooling rate was not sufficient to suppress the precipitation of the primary Al_3(Sc,Zr) nucleation sites, and a fully equiaxed grain structure was obtained. Furthermore, the effect of the layer-by-layer manufacturing process on the subsequent precipitation strengthening of secondary Al_3(Sc,Zr) precipitates was discussed.Both the remelting and subsequent aging during thermal cycling should be considered to achieve greater precipitation strengthening.     

我国可再生能源战略地位和发展路线图研究

我国经济正处于快速发展时期,对能源的需求将持续增长,能源和环境对可持续发展的约束将越来越严重.发展清洁能源技术、加速本地化清洁资源的开发是必然的选择.可再生能源是环境代价小、发展前景明确、争议较少的技术.我国已经颁布了<可再生能源法>,通过立法的方式,建立起强有力的促进发展可再生能源的政策框架,并发布了指导产业发展的<可再生能源中长期发展规划>以及一系列的管理政策,确定大力开发和利用可再生能源为我国能源发展必然的战略选择.     

Monte Carlo calculations on the beta-delta phase transition in nitrogen with a generalized free energy method

Monte Carlo simulations that utilize an (N, P, T) ensemble with periodic deformable boundary conditions cannot describe phase transitions properly when a large potential barrier is involved. An alternative method is to calculate the Gibbs free energy difference between phases; the transition occurs when the difference is equal to zero. The Gibbs free-energy difference can be calculated using a generalized free-energy method. This method is used to determine the- phase transition of solid nitrogen at room temperature. The Gibbs freeenergy difference between the and the phase was obtained at 4.0 GPa. The difference at other pressures could be determined with the equation of state. The transition pressure was found at about 6.2 GPa, 1.3 GPa above the experimental pressure.     

Kinetics of the glass transition in As22S78 chalcogenide glass: Activation energy and fragility index

Differential scanning calorimetry (DSC) has been used to probe the dynamics of the glass transition in As₂₂S₇₈ chalcogenide glass. Non-isothermal measurements were performed at different heating rates (5–35 K min⁻¹). The experimental result of this kinetic glass transition phenomenon was analyzed on the basis of the relaxation process occurring in the transition temperature range. The activation energy of the glass transition was determined from the heating rate dependence of the glass transition temperature. The fragility index m of the glass was estimated from the measurements of the activation energy of the relaxation process, which characterizes the glass transition. Different kinetic methods as well as isoconversional methods were used. Isoconversional analysis of the experimental data shows that the activation energy of glass transition process is varying with the degree of transformation (and hence with temperature) from the glassy to the supercooled phase.