湖南省绥宁县黄桑坪自然保护区珍稀濒危植物长苞铁杉自然种群年龄结构及生态对策

通过对湖南省绥宁县黄桑坪自然保护区长苞铁杉的种群结构、特定时间生命表、生殖价分析、分布数量与环境因子的关系进行分析.结果表明:(1)种群结构数量具有"中间大,两头小"的特点,为衰退型种群,虽然种群有一定的幼龄个体,但死亡率高,35 a内长苞铁杉的年龄结构模型为:Age(a)=0.002 765(DBH)3-0.128 756(DBH)2+4.120 978(DBH)+13.439 846(R=0.991 2,F=2 654.48);(2)长苞铁杉种群既有r对策特征,又有K对策特征,该种群处于r对策→K对策的过渡阶段;(3)长苞铁杉的累积剩余生殖价(SRRV)和整个生活史的总生殖价(TRV)呈现出逐渐递减的趋势,而生殖投资策略(OREx)在整个生长过程中具有"n"型变化特征,说明长苞铁杉种群有实现生殖与恢复的可能,但能力有限.     

深孔预裂爆破强制放顶技术的研究与应用

针对顾桥矿坚厚硬顶板会出现大面积悬顶的情况,且大面积悬露的顶板突然断裂后有压倒支架、产生强冲击瓦斯风暴的可能性,故在顾桥矿1123(1)工作面实施深孔预裂爆破弱化坚硬顶板技术的研究。通过试验表明:顾桥矿1123(1)工作面在实施深孔预裂爆破弱化坚硬顶板后,顶板的初次垮落步距从预测的45-50m减小到27.3m左右,支柱承受压力在可以接受范围内,未出现顶板强烈来压压倒支架的情况;回风巷中瓦斯浓度控制在0.6%以下,抽采瓦斯量稳定在70m3/min,未出现瓦斯超限和煤与瓦斯突出的情况。     

电梯部件错误安装的危害

通过检验案例发现的隐患,阐述了安全部件在电梯运行中的重要性。对安全部件安装过程中存在的问题,分析了失效原因以及存在的问题,提出了解决方法。     

非正规填埋场矿化垃圾理化性质与资源化利用研究

为探索非正规垃圾填埋场矿化垃圾资源化利用问题,以广东省东莞市常平镇桥沥垃圾填埋场矿化垃圾为例,多点采集样品经人工分拣和不同粒径段筛分后,对其物理组成和化学性质进行了分析.结果表明:矿化垃圾中腐殖土主要在40mm粒径段以下,占47.3%,塑料、织物及木竹等可燃轻质垃圾主要在大于80mm粒径段,占40.1%;工程筛分粒径可选40mm,筛上物主要为可燃物,筛下物主要为腐殖土;按照有机肥堆肥腐熟标准,筛下物腐殖土基本可达到腐熟,营养物质含量达到《城市生活垃圾农用标准》(GB8172-1987)要求,但部分重金属含量超标;矿化垃圾经筛分后的轻质垃圾,热值约为6000kJ/kg,可直接进行焚烧处理,将其制备成垃圾衍生燃料(RDF)后,热值可达10000~24000kJ/kg.     

换流站联锁防误与微机防误系统实现方式比较

为确保安全生产过程中不发生人为误操作责任事故,分析了银川东换流站联锁防误闭锁软、硬件实现方式,并与综自站微机防误系统实现方式进行了比较,阐述了换流站联锁实现方式的优点及换流站引入微机防误系统的弊端。分析结果表明:换流站联锁防误系统软、硬件实现方式与综自站“五防”闭锁实现方式相比存在实时性好、可靠性高、人为干扰因素少、利于实现顺序控制和集中监控且使用便捷等优点。可考虑在部分综自站推广使用。     

非离子表面活性剂对土壤中甲基对硫磷的增溶、洗脱及其在土壤中的吸附

探讨了3种非离子表面活性剂Brij30、Brij35和Tween80溶液对水溶液中甲基对硫磷的增溶作用,对土壤中甲基对硫磷的洗脱作用以及土壤对3种非离子表面活性剂的吸附作用.增溶实验结果表明,3种非离子表面活性剂在水溶液中均对甲基对硫磷有较好的增溶作用,而且无论在临界胶束浓度前或后,表面活性剂对甲基对硫磷的增溶顺序均为:Tween80,Brij30和Brij35.淋洗实验结果表明,3种非离子表面活性剂对土壤中甲基对硫磷的去除效果不如蒸馏水好,而且实验土壤对3种非离子表面活性剂均有较强的吸附作用.这种吸附作用对土壤中甲基对硫磷的去除有严重不利影响.     

Characteristics of chemical components in PM<Subscript>2.5</Subscript> at a plateau city,South-west China

A sampling campaign including summer, autumn and winter of 2014 and spring of 2015 was accomplished to obtain the characteristic of chemical components in PM_2.5 at three sites of Kunming, a plateau city in South-west China. Nine kinds of water-soluble inorganic ions (WSI), organic and element carbon (OC and EC) in PM_2.5 were analyzed by ion chromatography and thermal optical reflectance method, respectively. Results showed that the average concentrations of total WSI, OC and EC were 22.85±10.95 µg·m^-3, 17.83±9.57 µg·m^-3 and 5.11±4.29 µg·m^-3, respectively. They totally accounted for 53.0% of PM_2.5. Secondary organic and inorganic aerosols (SOA and SIA) were also assessed by the minimum ratio of OC/EC, nitrogen and sulfur oxidation ratios. The annual average concentrations of SOA and SIA totally accounted for 28.3% of the PM_2.5 concentration. The low proportion suggested the primary emission was the main source of PM_2.5 in Kunming. However, secondary pollution in the plateau city should also not be ignorable, due to the appropriate temperature and strong solar radiation, which can promote the atmospheric photochemical reactions.

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Removing carbonyl sulfide with metal-modified activated carbon

A Cu-Co-K/activated carbon (AC) adsorbent has been developed for the removal of carbonyl sulfide (COS). The effects of COS concentration, reaction temperature and relative humidity were closely examined. A breakthrough of 33.23 mg COS·g⁻¹ adsorbent at 60°C, under 30% relative humidity and in presence of 1.0% oxygen was exhibited in the Cu-Co-K/AC adsorbent prepared. Competitive adsorption studies for COS in the presence of CS₂, and H₂S were also conducted. TPD analysis was used to identify sulfur-containing products on the carbon surface, and the results indicated that H₂S, COS and SO₂ were all evident in the effluent gas generated from the exhausted Cu-Co-K/AC. Structure of the activated carbon samples has been characterized using nitrogen adsorption, and their surface chemical structures were also determined with X-ray photoelectron spectroscopy (XPS). It turns out that the modification with Cu(OH)₂CO₃-CoPcS-KOH can significantly improve the COS removal capacity, forming SO42− species simultaneously. Regeneration of the spent activated carbon sorbents by thermal desorption has also been explored.     

渤海湾表层沉积物各形态重金属的分布特征与生态风险评价

根据2008年春对渤海湾的调查,通过分级萃取的实验方法以及总量和分形态风险评价的手段,重点研究了渤海湾表层沉积物各形态重金属的分布特征、影响因素和潜在生态风险.结果表明,重金属在渤海湾中央的泥质区富集,自然来源是控制V、Ni、Cu、Pb、Co和Cd分布的主要因素,而Zn和Cr较易受环境变化或人为输入等影响,其中Pb作为大气沉降和陆源输入都存在的重金属,其受控因素与其他重金属有一定差异.形态分析表明,V、Zn和Cr以残渣态为主,Co、Ni和Cu则是可浸取态占优势.其中Co的可浸取态质量分数在A断面先增加后降低,Ni的可浸取态质量分数在海河口附近A3站达最大值(98.86%),Cu和Pb的可浸取态高值区出现在A断面的中央区域,优势形态是铁锰氧化物结合态,Cu在湾口的A10站降到最小值(43.83%),在黄河口的D1站达最大值(73.89%).风险评价表明,重金属总量富集因子由大到小:Pb>Cd>Zn>Cr>V>Co>Cu>Ni,其中Pb、Cd和Zn的富集因子均大于1,但渤海湾沉积物总体质量良好,潜在生态风险较低.从形态角度评价,V和Cr基本无污染,Zn局部轻微污染,Co大部分轻度污染,Cu由无污染到中度污染,Ni由轻度污染到重度污染,Pb则属重度污染,其中Pb在渤海湾口A11站的P%(次生相与原生相分布比值)达1 329%.综合评价得出,Pb是渤海湾沉积物污染最严重的重金属,Cu和Zn有潜在污染,V、Cr和Co基本清洁.     

Higher CO2 absorption using a new class of calcium hydroxide (Ca(OH)2) nanoparticles

Environmental Chemistry Letters - With rising atmospheric carbon dioxide (CO2) concentrations globally, there is an urgent need for highly efficient CO2 capture technologies. This report introduces...