The drivers of Chinese CO2 emissions from 1980 to 2030

China's energy consumption doubled within the first 25 years of economic reforms initiated at the end of the 1970s, and doubled again in the past 5 years. It has resulted of a threefold CO₂ emissions increase since early of 1980s. China's heavy reliance on coal will make it the largest emitter of CO₂ in the world. By combining structural decomposition and input–output analysis we seek to assess the driving forces of China's CO₂ emissions from 1980 to 2030. In our reference scenario, production-related CO₂ emissions will increase another three times by 2030. Household consumption, capital investment and growth in exports will largely drive the increase in CO₂ emissions. Efficiency gains will be partially offset the projected increases in consumption, but our scenarios show that this will not be sufficient if China's consumption patterns converge to current US levels. Relying on efficiency improvements alone will not stabilize China's future emissions. Our scenarios show that even extremely optimistic assumptions of widespread installation of carbon dioxide capture and storage will only slow the increase in CO₂ emissions.     

稻田CH4排放的农业气象数值模拟研究

在美国DNDC模式基础上, 综合气象学、农业气象学及生态学最新研究进展, 将作物生长、碳氮循环及CH₄排放有机耦合, 建立了一个CH₄排放数值模式, 模式通过了相关显著性检验。利用模式重点分析了气象因子对稻田CH₄排放的影响状况, 数值分析表明, 当仅考虑气象条件影响时: (1) 不同地区不同生长季节的CH₄排放量均与相应生长期的平均气温成正相关关系; (2) 功率谱分析表明稻田CH₄排放存在4~5年周期变化, 与相应生长季节的平均温度年际变化规律相一致; (3) CH₄排放量年际之间变化趋势与生长季平均气温变化趋势基本一致。利用数值计算结果, 给出了杭州及昌德地区早稻、晚稻CH₄简易统计模式, 为应用模型监测并调控农田生态系统中的CH₄排放奠定了基础。     

射电日像仪天线及工作频率的设想

The article analysizes the current situation and opportunity of the development of radioheliograph in China. It provides an idea to construct the radioheliograph by three stepsfrom small sized,to middle sized,then tobig sized. Each step is to construct a complete radioheliograph. The article also analysizes some important technical performance,such as diameter of element antenna,overall pointing error and observing frequency.     

Improvements to Griggs-type apparatus for mechanical testing at high pressures and temperatures

New and improved techniques and apparatus for testing the mechanical properties of materials at high presures and temperatures are described. These include an improved Griggs-type deformation apparatus designed to operate to 5 GPa and associated servo-controlled hydraulic drive and electronics, the design of hydrostatic (molten alkali halide mixtures) pressure assemblies to measure flow stresses as low as a few MPa, the characterization of temperature gradients and friction in such assemblies, measurement of the melting curve of an alkali halide mixture used as a confining pressure medium, and the measurement of acoustic emissions.     

Size-Resolved Characterisation of Soluble Ions in the Particles in the Tropospheric Plume of Masaya Volcano, Nicaragua: Origins and Plume Processing

We present the first application of a multi-stage impactor to study volcanic particle emissions to the troposphere from Masaya volcano, Nicaragua. Concentrations of soluble SO₄ ^2–,Cl^–, F^–, NO₃ ^–, K⁺, Na⁺,NH₄ ⁺, Ca²⁺ and Mg²⁺ were determined in 11 size bins from 0.07 m to >25.5 m. The near-source size distributions showed major modes at 0.5m (SO₄ ^2–, H⁺,NH₄ ⁺); 0.2 m and 5.0 m (Cl^–) and 2.0–5.0 m(F^–). K⁺ and Na⁺ mirrored the SO₄ ^2– size-resolvedconcentrations closely, suggesting that these were transported primarily asK₂SO₄ and Na₂SO₄ in acidic solution, while Mg²⁺ andCa²⁺ presented modes in both <1 m and >1 m particles. Changes in relative humidity were studied by comparing daytime (transparent plume) and night-time (condensed plume) results. Enhanced particle growth rates were observed in the night-time plume as well as preferential scavenging of soluble gases, such as HCl, by condensed water. Neutralisation of the acidic aerosol by background ammonia was observed at the crater rim and to a greater extent approximately 15 km downwind of the active crater. We report measurements of re-suspended near-source volcanic dust, which may form a component of the plume downwind. Elevated levels ofSO₄ ^2–, Cl^–, F^–,H⁺, Na⁺, K⁺ and Mg²⁺ were observed around the 10 m particle diameter in this dust. The volcanic SO₄ ^2– flux leaving the craterwas 0.07 kg s^–1.     

Increased accuracy of geostatistical prediction of nitrogen dioxide in the United Kingdom with secondary data

Five techniques were used to map nitrogen dioxide (NO₂) concentrations in the United Kingdom. The methods used to predict from point data, collected as part of the UK NO₂ diffusion tube network, were local linear regression (LR), inverse distance weighting (IDW), ordinary kriging (OK), simple kriging with a locally varying mean (SKlm) and kriging with an external drift (KED). These techniques may be divided into two groups: (i) those that use only a single variable in the prediction process (IDW, OK) and (ii) those that make use of additional variables as a part of prediction (LR, SKlm and KED). Nitrous oxides emission data were used as secondary data with LR, SKlm and KED. It was concluded that SKlm provided the most accurate predictions based on the summary statistics of prediction errors from cross-validation.     

Evidence for direct suspension of loessial soils on the Columbia Plateau

Wind erosion modelling efforts, both ?eld and wind tunnel studies, have traditionally focused on saltation‐based processes for estimating dust emissions from high wind events. This approach gives generally good results when saltation‐sized particles, 90 µm to 2 mm mean diameter, are prevalent on the exposed soil surface. The Columbia Plateau, located in north‐central Oregon and south‐central Washington, is a region with extensive loess deposits where up to 90 per cent of sieved particles (by mass) are less than 100 µm mean diameter. During high‐wind events, large amounts of soil and ?ne particulate matter are suspended. However, ?eld surfaces typically show little evidence of surface scouring or saltation, e.g. soil drifts or covered furrows. Velocity pro?le analysis of two high‐wind events and additional data from a third event show evidence of direct suspension process where saltation is not a major mechanism for eroding soil or generating dust emissions. Surface roughness heights are less than saltation roughness height estimates during peak wind speeds. Copyright © 2004 John Wiley & Sons, Ltd.     

Global Modelling of the Atmospheric Methyl Bromide Budget

A global three-dimensional chemical transport model has been used to identify and evaluate possible candidates for the `missing' surface source required to balance the atmospheric budget of methyl bromide. Both natural and anthropogenic emissions of methyl bromide are `coloured' in the model, thus allowing the global CH₃Br distribution to be broken-down into its source components. These coloured CH₃Br tracers are then combined in various ways to create one base-line emission scenario and five further plausible scenarios. The additional emission scenarios are specifically designed to test whether the geographical distribution and seasonal cycles of additional vegetation and/or increased biomass burning emissions are consistent with atmospheric observations of methyl bromide mixing ratios. Due to an imbalance in our current understanding of the methyl bromide budget, simulated CH₃Br mixing ratios from the base-line emission scenario are significantly lower than atmospheric measurements. Both the inclusion of a vegetation source in the tropics and a double strength biomass burning source substantially improve the agreement between model simulations and atmospheric measurements compared with the base-line emission scenario. While measurement data provides useful information on global fluxes and regional CH₃Br seasonal cycles, small differences between the simulated seasonal cycles of different emission scenarios makes it difficult to distinguish between the relative likelihoods of model scenarios containing a tropical vegetation source or an increased biomass burning source. Further measurements performed in continental mid-to-high northern latitudes, central-southern Africa and South America would be of particular benefit in future attempts to constrain the location and magnitude of the natural terrestrial sources of methyl bromide.