Sources of underground CO: Crushing and ambient temperature oxidation of coal

As a harmful gas in underground coal mine, CO seriously threatened the safety of miners. Currently, the spontaneous combustion of residual coal in goaf is generally considered as the main source of underground CO. CO gas is also widely used as an indicator gas in fire prediction in mines. However, high concentrations of CO are also detected in some mines without spontaneous combustion of coal. Therefore, in the paper, with four ranks of coal, we studied other two potential CO sources: crushing and oxidation at ambient temperature. The more completely crushed coal produces more CO. The concentration of generated CO is inversely proportional to moisture content in coal. Therefore, the addition of water can inhibit the generation process of CO during the crushing process of coal. Lignite with low metamorphic grade can be oxidized to produce CO at ambient temperature (25 °C), and anthracite with high coal rank can be only oxidized to produce CO at 60 °C. Infrared spectra indicated that the coal with rich aliphatic hydrocarbons and oxygen-containing functional groups are more susceptible to oxidation at room temperature. Moreover, the smaller particle size of coal is more beneficial to the oxidation at ambient temperature to generate CO. CO generation during coal oxidation is also closely related to the ventilation rate.     

采空区注超临界CO2防灭火试验研究

为研究超临界CO₂注入采空区防灭火的规律,自主研制了产生超临界CO₂和模拟采空区遗煤自燃升温试验系统,得到了不同温压条件下超临界CO₂注入采空区前后不同监测点的温度、O₂和CO浓度变化数据信息。试验结果表明:注入采空区的超临界CO₂发生相变,有序结构急速失序,大量吸收热量,采空区内的煤体、空气温度随时间呈线性快速下降规律,其降温能力是气态N₂的10倍;超临界CO₂在自燃发火煤体中的强渗透扩散特性,使自燃煤体快速惰化,防灭火效率高;停止注入后,小范围回温符合反二次函数特征;高压力超临界CO₂相对于低压条件,防灭火性能更佳;超临界CO₂是1种降温降氧能力显著,且输送性能优良的采空区新型防灭火材料,超临界CO₂防灭火效果优于气态N₂。     

The dark side of socialization: How and when divestiture socialization undermines newcomer outcomes

This research examines the potential downsides of divestiture socialization. We theorize that supervisor behaviors and attitudes—that is, support for authenticity and creativity expectations—moderate the different stages of a model in which newcomers' authentic self‐expression mediates the negative effect of divestiture socialization on newcomer task performance, creativity, social integration, and job satisfaction. Specifically, supervisor support for authenticity allows newcomers to express their authentic self when faced with divestiture processes, and perceived supervisor creativity expectations enable them to deploy their authentic self‐expressions to enhance their creativity. A time‐lagged, multisource study of 142 newcomer—supervisor dyads provides support for these predictions, offering notable implications for theory and practice.     

Restructured frame‐of‐reference training improves rating accuracy

The use of heuristic judgments is prevalent in organizations and negatively impacts accurate employee assessments. To minimize the negative impact of heuristic judgments (i.e., anchoring and adjustment), we aim to improve rating accuracy by restructuring frame‐of‐reference (FOR) training. We conducted five studies (N = 1,143) using different samples (three including participants with hiring experience), training environments (onsite and online), and rating contexts (evaluations of sales representatives, teachers, contract negotiation specialists, and retail store managers). Across the five studies, the average improvement in rating accuracy was at least twice as large for restructured FOR (vs. control) training as it was for typical FOR (vs. control) training; the difference in rating accuracy between restructured and typical FOR training was statistically significant. Furthermore, minimizing the anchoring effect rather than increasing opportunities for rating adjustments improved rating accuracy (Study 4). Finally, restructured FOR training achieved higher criterion validity (i.e., a higher strength of the association between ratings regarding a target and the target's objective performance) than did typical FOR training (Studies 3 and 5). We discuss implications for improving the effectiveness of diverse training programs and the accuracy of judgments in organizations.     

论南方稻田耕作制度的调整与改革

本文在比较全面、系统地总结改革开放１５年来，南方稻田耕作制度调整与改革所取得的成效的基础上，指出了目前南方稻田耕作制度存在的问题，提出了在新形势下南方稻田耕作制度调整与改革的对策和思路，对指导目前南方稻田耕作制度的改革具有重要参考价值．     

农村产业结构调整问题研究

本文首先对农村产业结构调整的相关概念进行了阐述.其次,分析和归纳了判断农村产业结构合理化的标准以及农村产业结构变动的影响因素.     

型煤燃烧固硫的钠离子效应

本文用脉冲二氧化硫荧光分析仪连续测试了煤样中二氧化硫的浓度，并用Ｘ荧光、Ｘ衍射和电子扫描电镜等方法，分析了添加钠离子样品的含硫率、物相及表面形貌。实验结果表明，钠离子添加剂改变了二氧化硫释放过程，抑制了硫酸钙的分解。灰样成分中既有稳定的三元化合物３ＣａＯ．３Ａｌ２Ｏ３．ＣａＳＯ４，也有不稳定的化合物硫酸钙存在，说明钠离子添加剂对提高固硫率有促进作用。     

An Operationally Defined Method to Determine the Speciation of Mercury

This paper presents a modified method of an operationally determined speciation of mercury in soil. The analytical work was mainly concerned to suit properly with inductively coupled plasma-atomic emission spectrometry (ICP-AES). Soil samples analysed in this study were selected from open areas around a crematorium, a waste incinerator, and two power plants. Results show that both topsoil and subsoil samples were dominated by elemental mercury Hg(0) and mercuric sulphide (HgS). The significant correlation between sulphur concentration and HgS was found in topsoil samples.     

Benefits of protected areas for nonbreeding waterbirds adjusting their distributions under climate warming

Climate warming is driving changes in species distributions and community composition. Many species have a so-called climatic debt, that is, shifts in range lag behind shifts in temperature isoclines. Inside protected areas (PAs), community changes in response to climate warming can be facilitated by greater colonization rates by warm-dwelling species, but also mitigated by lowering extirpation rates of cold-dwelling species. An evaluation of the relative importance of colonization-extirpation processes is important to inform conservation strategies that aim for both climate debt reduction and species conservation. We assessed the colonization-extirpation dynamics involved in community changes in response to climate inside and outside PAs. To do so, we used 25 years of occurrence data of nonbreeding waterbirds in the western Palearctic (97 species, 7071 sites, 39 countries, 1993–2017). We used a community temperature index (CTI) framework based on species thermal affinities to investigate species turnover induced by temperature increase. We determined whether thermal community adjustment was associated with colonization by warm-dwelling species or extirpation of cold-dwelling species by modeling change in standard deviation of the CTI (CTI_SD). Using linear mixed-effects models, we investigated whether communities in PAs had lower climatic debt and different patterns of community change than communities outside PAs. For CTI and CTI_SD combined, communities inside PAs had more species, higher colonization, lower extirpation, and lower climatic debt (16%) than communities outside PAs. Thus, our results suggest that PAs facilitate 2 independent processes that shape community dynamics and maintain biodiversity. The community adjustment was, however, not sufficiently fast to keep pace with the large temperature increases in the central and northeastern western Palearctic. Our results underline the potential of combining CTI and CTI_SD metrics to improve understanding of the colonization-extirpation patterns driven by climate warming.     

Low-temperature oxidation of coal at elevated pressures

A mathematical model is presented to describe steady-state mass transfer and oxidation processes in coal at low temperatures in a fixed-bed flow reactor. The model incorporates the effects of partial pressure of oxygen, temperature and coal particle size, and accounts for the rate of coal oxidation and the composition of oxygenated products at high pressures. This is an important development since previous models did not include the effect of pressure in their formulation. It is found that, when the partial pressure of oxygen increases the rate of oxygen consumption increases accordingly. However, the influence of partial pressure of oxygen on the rate of oxidation is less pronounced when the pressure surpasses 1 MPa. In addition the model predicts that, for a constant partial pressure of oxygen, higher rates of oxygen consumption occur at lower total pressures. The same trends are also found for the concentration of oxygenated products at the reactor outlet. It is suggested that, the variation of partial pressure of oxygen leads to different concentration levels of oxygen at the surface and within the pores of coal particles, substantially affecting the rate of oxidation.