The relationship between oxygen consumption rate and temperature during coal spontaneous combustion

Spontaneous combustion is a major natural disaster in coal production. In the process of exploring coal self-ignition, a series of hypotheses have been put forward, most scholars agree that the current coal-oxygen compound theory. Oxygen consumption rate reflects the status of coal spontaneous combustion, and it is also one of the parameters necessary for numerical simulation of coal spontaneous combustion. In this paper, a coal heating and oxidation experiment was designed, Experimental device consists of heating and oxidation furnace, gas chromatograph, temperature control and data acquisition systems and other equipment components. Three coal samples whose weight each is 5 g were selected for the study. By experiment, oxygen concentration at the inlet and outlet of temperature oxidation furnace was measured. Oxygen consumption rate is calculated in the heating process of coal according to air flow. In the Cartesian coordinate system, the temperature as abscissa and the oxygen consumption rate for the longitudinal coordinates, drawing the relationship between oxygen consumption rate and temperature plot. And then regression analysis was used to analyze the relationship between oxygen consumption rate and coal temperature during the heating and oxidation process of coal. The results show that the oxygen consumption rate and temperature of coal were linear relationships both before and after the critical temperature when the coal temperature is less than 180 °C. Before the critical temperature oxygen consumption rate is low, however it increases rapidly when coal temperature reaches a critical temperature. The result is important for the prevention and treatment of spontaneous combustion of coal.     

特种设备安全绩效与安全监管能力相关性研究

为强化特种设备安全监管,基于组织能力理论,通过文献计量和专家调查等方法,对特种设备安全绩效和安全监管能力的相关指标进行研究,初步确定27项监管能力指标和4项安全绩效指标。采用相关性分析法,选择安全绩效指标中万台设备事故起数作为基准指标,计算该指标与监管能力和安全绩效各指标的Spearman相关系数。在总体趋势上,基准指标与监管能力指标呈现负相关,与安全绩效指标呈现正相关。计算结果表明:可从增加监管资源投入,提高人员素质,严格监管执行过程等方面提高特种设备安全监管能力。     

梅梁湖的富营养化状况及治理对策讨论

监测结果表明，梅梁湖水体ＴＰ，ＴＮ含量分别为０．１ｍｇ／Ｌ和３．４ｍｇ／Ｌ藻类生物量达９－１３亿个细胞／Ｌ，富营养化相当严重，污染的主要原因，工农业，渔业，畜牧业和生活污水的直接排放，使水全营养盐含量较高，藻类大量繁殖，可采用“控源截汛”，“清除淤泥”，“调水搞活”及生物治理等综合性措施，对梅梁湖的富营养化进行了治理。     

地下水原位修复渗透性反应墙反应介质的改良与展望

渗透性反应墙(PRBs)是倍受关注的地下水原位修复技术之一,具有高效廉价、安装简便、维护简单等优点。详细总结了零价铁、活性炭、无机矿物材料和生物质材料等PRBs反应介质的结构、性能、适用范围、改良方法及增强吸附机制,介绍了PRBs技术在国内外地下水原位修复领域的工程应用实例,指出研发可再生型反应介质、深入研究复杂体系的污染物去除主导机制以及开展多介质混合、多种原位修复技术集成应用研究将是今后PRBs的主要研究方向。     

Study of nitrogen oxide absorption in the calcium sulfite slurry

Experiments were conducted using a bubbling reactor to investigate nitrogen oxide absorption in the calcium sulfite slurry. The effects of CaSO₃ concentration, NO₂/NO mole ratio and O₂ concentrations on NO₂ and SO₂ absorption efficiencies were investigated. Five types of additives, including MgSO₄, Na₂SO₄, FeSO₄, MgSO₄/Na₂SO₄ and FeSO₄/Na₂SO₄, had been evaluated for enhancing NO₂ absorption in CaSO₃ slurry. Results showed that CaSO₃ concentration had significant impact on NO₂ and SO₂ absorption efficiencies, and the highest absorption efficiencies of SO₂ and NO₂ could reach about 99.5 and 75.0 %, respectively. Furthermore, the NO₂ absorption was closely related to the NO₂/NO mole ratio, and the existence of NO₂ in flue gas may promote NO absorption. The presence of O₂ in simulated flue gas was disadvantage for NO _x removal because it can oxidize sulfite to sulfate. It was worth pointing out that FeSO₄/Na₂SO₄ was the best additive among those investigated additives, as the NO₂ removal efficiency was significantly increased from 74.8 to 95.0 %. IC and in situ FTIR results suggest that the main products were NO₃ ^? and NO₂ ^? in liquid phase and N₂O, N₂O₅ and HNO₃ in gas phase during the CaSO₃ absorption process.     

利用N-乙酰-β-D-氨基葡萄糖苷酶含量评价农药对花翅摇蚊种群发育的影响

为了进一步探索种群水平的生态风险评估方法,本文利用β-N-Acetyl-D-glucosaminidase(NAGase)的变化量来监测农药对摇蚊种群发育的影响。从花翅摇蚊Chironomus kiiensis体内分离纯化得到电泳纯的NAGase,并通过免疫大白兔制得NAGase的多克隆抗体。运用间接非竞争ELISA法检测抗体特异性,结果表明其与共同存在于水体的一些生物的NAGase的交叉反应率为隆线溞4.41%、老年低额溞3.12%、多刺裸腹溞3.40%、中华薄壳介4.17%、日本沼虾3.23%、白纹伊蚊7.50%、小球藻0.5%。运用抗体测得毒死蜱、氰戊菊酯和阿维菌素3种杀虫剂对于摇蚊NAGase释放量的12 d-EC50分别为1.2012、0.0043和0.6281μg·L-1,以NAGase活力作为测试终点,测得相应的12 d-EC50:1.4765、0.0051和0.6756μg·L-1,两者差异不显著,但均显著低于以死亡作为测试终点的12 d-LC50:4.8171、0.0954和2.1340μg·L-1,且毒力大小均为氰戊菊酯阿维菌素毒死蜱。上述结果表明,利用NAGase多克隆抗体可以特异性地检测农药对花翅摇蚊种群发育的影响。     

江西钨矿周边土壤重金属生态风险评价:不同评价方法的比较

对江西省大余县某钨矿区周边的农田土壤进行调查分析,并采用不同的方法对土壤进行评价,结果表明,土壤As、Pb、Zn、Cu和Ni的含量范围分别为15.33—154.65 mg·kg-1、156.29—346.98 mg·kg-1、47.73—277.72 mg·kg-1、19.06—210.24 mg·kg-1和12.00—35.11 mg·kg-1,一些土壤样点的As、Pb、Zn和Cu含量已超过国家土壤环境质量二级标准.利用地累积指数法对土壤进行评价,结果表明土壤均受到As、Pb、Zn、Cu和Ni不同程度的污染;根据CPI(综合污染指数)评价标准,65.7%的土壤处于污染状态;利用TCLP法对土壤生态风险进行评价,结果显示所有土壤并未受到重金属的污染,以内梅罗综合污染指数法对土壤进行综合评价,结果表明该农田土壤重金属生态风险处于安全范围;以潜在生态危害指数法评价,发现Pb、As和Cu达到或超过中等生态风险的样点分别占37.14%、25.72%和2.86%,其他重金属污染风险均属轻微以下.不同评价方法得出的评价结果有差异,人们在评价重金属污染土壤时要根据评价的目的慎重选择合适的评价方法.     

内蒙古典型草原土壤不同剖面深度CO_2通量格局及其驱动因子

土壤CO2的释放能够显著增加大气牛CO2的浓度,增强温室效应,从而对全球气候和环境变化产生重要影响.但是,不同的土壤层对CO2通量的贡献量有很大的差异.文章通过挖坑法结合红外气体分析法研究了内蒙古草原典犁针茅(Stipa krylovii)群落和羊草(Leymus chinensis)群落不同剖面深度土壤CO2通量格局以及影响CO2通量的驱动因素.结果表明,表层土壤移走后,土壤CO2通量的变化可分为瞬时、短期、长期三种格局.新剖面上最初的0～21 min内释放的CO2通量最均大于初始土壤表层CO2通量,而且两者比值随土壤深度增加而增大,也随土壤CO2生产能力增强而增大.2～4 d后,新剖面CO2通量持续下降至低于初始土壤表层CO2通量的水平.形成短期稳定状态.更长时间后,新剖面则逐渐表现出与初始土壤剖面表层相近的CO2通量特征.我们认为,(1)在新剖面形成时的CO2通量瞬时和短期格局主要受土壤中存留的原始CO2的浓度及其扩散过程控制,(2)长期格局则由资源水平和环境条件共同决定的土壤CO2生产能力主导.文章进一步揭示了建立包含垂直分层的SOC分解和CO2扩散过程的生态系统模型的必要性.     

能值理论研究中存在的几个问题探讨

能值理论与研究方法是当前生态经济学研究中的一个热点问题.被认为是连接生态学与经济学的桥梁,具有重大的理论和实践意义.尽管能值分析有效的将自然环境的价值纳入了产品的生产,更能真实地揭示产品的真实价值,从而克服了传统能量分析和经济分析的诸多缺陷.但其在理论和研究方法仍存在一些不足之处.综合国内外有关能值理论与研究方法的相关文献,对当前能值理论研究中能值转化率的计算问题、多产品或复合产品系统的能值流计算问题、能值价值论与市场价值论结合问题、能值与可持续发展研究问题等几个方面进行了探讨.     

云南粳稻核心种质杂种后代孕穗期耐冷性研究

以236份云南地方粳稻核心种质和云南主栽梗稻Oryza satica品种合系35配制的杂种F5、BC1F4、BC2F3和BC3F2为材料,在昆明自然低温平均17.8℃(冷害)条件下,对亲本及其后代进行孕穗期耐冷性研究.结果表明:①亲本耐冷性状间的相关性明显高于其杂种后代,不同世代间总体趋势为随着回交世代增加其性状间相关性减弱.在亲本及其杂种后代间耐冷指标性状穗颈长、穗下节长、每穗实粒数、每穗秕粒数与结实率均呈较高的(≥0.370)极显著(n=236,R0.01=0.181)相关.②株高、穗颈长、穗下节长等耐冷性状在亲本强弱耐冷系统群间的差异明显,表现为亲本耐冷性强的材料秆和穗较长、穗粒数较多,同一性状变异程度减小.但随着回交代数的增加,这些性状的平均值逐渐趋同于轮回亲本,差异减小.③穗颈长、穗下节长、每穗实粒数、每穗秕粒数与结实率在5个稻作区间的变化规律呈现一致性,亲本和F5的差异较大,而BC2F4、BC2F3和BC3F2的差异较小,且趋同于轮回亲本.通过连续回交,在BC3F1即可获得耐冷性状表现良好的材料.