陕西省石煤提钒行业存在的问题及对策研究

陕西的石煤主要分布在陕南秦岭南坡的商洛地区,但大部分石煤钒矿属于难处理矿,钒大部分以V（Ⅲ）和V（Ⅳ）存在,目前企业大多采用“焙烧＋稀酸浸出＋氨法沉钒”或者“强酸浸出＋氨法沉钒”工艺进行生产。存在的问题一是钒的综合回收率为65％左右,整体偏低;二是生产废水中含有大量氨使得废水闭路循环难度大;三是矿区大部分位于汉丹江水系的中上游地区或临近出省断面,选址较为敏感。针对以上存在的问题提出了解决建议．并对陕西省石煤提钒行业的发展做出了展望。     

环境污染加剧石质文物风化:机理、过程及防护措施

石质文物的风化问题由来已久,在影响石质文物风化的各类因素中,环境恶化对石质文物的风化影响日益严重,但现有研究大多忽略了环境污染加剧的影响。在此背景下,本文从酸性气体排放、温度效应和水体污染三个方面阐述了环境污染加剧对石质文物风化的影响和作用机理,并对现有石质文物的防护措施进行综合比较分析,提出石质文物的保护建议和措施,为新形势下石质文物的保护研究提供新的思路。     

碎石桩加固饱和粉土地基的抗液化特性

除饱和砂土液化外,饱和粉土地震液化问题也是岩土地震工程中一个重要的研究课题.饱和粉土地基的地震液化及变形可以采用多种地基加固方法防治,碎石桩技术是常用方法之一.碎石桩复合地基的抗液化效应,主要是增加桩周土体的密度、利于桩体的排水以及由桩体分担地震水平剪应力(桩体减震作用).但由于粉土的土质特性,粉土-碎石桩复合地基的抗...     

Optimization and evaluation of a bottom substrate denitrification tank for nitrate removal from a recirculating aquaculture system

A bottom substrate denitrification tank for a recirculating aquaculture system was developed. The laboratory scale denitrification tank was an 8 L tank (0.04 m2 tank surface area), packed to a depth of 5 cm with a bottom substrate for natural denitrifying bacteria. An aquarium pump was used for gentle water mixing in the tank; the dissolved oxygen in the water was maintained in aerobic conditions (e.g. > 2 mg/L) while anoxic conditions predominated only at the bottom substrate layer. The results showed that, among the four substrates tested (soil, sand, pumice stone and vermiculite), pumice was the most preferable material. Comparing carbon supplementation using methanol and molasses, methanol was chosen as the carbon source because it provided a higher denitrification rate than molasses. When methanol was applied at the optimal COD:N ratio of 5:1, a nitrate removal rate of 4591 ± 133 mg-N/m2 tank bottom area/day was achieved. Finally, nitrate removal using an 80 L denitrification tank was evaluated with a 610 L recirculating tilapia culture system. Nitrate treatment was performed by batch transferring high nitrate water from the nitrification tank into the denitrification tank and mixing with methanol at a COD:N ratio of 5:1. The results from five batches of nitrate treatment revealed that nitrate was successfully removed from water without the accumulation of nitrite and ammonia. The average nitrate removal efficiency was 85.17% and the average denitrification rate of the denitrification tank was 6311 ± 945 mg-N/m2 tank bottom area/day or 126 ± 18 mg-N/L of pumice packing volume/day.     

石材加工行业尘肺病危害风险评估研究

应用国际采矿与金属委员会风险评估模型（ICMM）评估石材加工行业尘肺病风险。 以20家石材加工企业为研究对象,运用ICMM模型的定量法和矩阵法分别评估4个重点岗位的尘肺病风险,并与粉尘作业分级和文献报道进行结果验证。 结果显示打磨、雕刻、切割和破碎4个重点岗位的总粉尘和呼吸性粉尘浓度均超过职业接触限值,超限倍数范围分别为4.3~85倍和3.1~63.3倍。ICMM定量法判定该4个重点岗位的Ⅲ期矽肺风险均为最高级风险水平（不可容忍）,矩阵法判定该4个重点岗位Ⅲ期矽肺风险也均为最高级水平（高风险）。这些风险评估结果得到生产性粉尘作业分级和文献报道的支持。结论为石材加工行业尘肺病发病风险非常高,ICMM风险评估模型可应用于石材加工行业职业健康风险评估。     

500kV高压线下深孔路堑爆破安全控制技术

在京珠高速公路江夏段500kV高压线下的路堑开挖深孔爆破的工程实例中，通过选用合理的爆破方案及爆区规划，针对复杂环境采取了一系列的安全控制技术，有效地控制了飞石和爆破地震的危害，同时也保证了边坡的平整度和稳定性。     

中国古建筑防火保护探讨

分析我国古建筑的结构特点及其发生火灾的原因,给出部分古建筑火灾的实例,提出我国古建筑防火保护策略的评价方法。针对我国古建筑主要是木结构和木石结构的建筑特点,笔者提出:采用防火涂料或/和阻燃液对古建筑中的木结构进行防火保护,以延缓或阻止火势的蔓延,为施救和人员逃生赢得时间;而采用厚型无机防火涂料或隧道防火涂料来保护古建筑的石结构,可以避免火灾时因石结构强度的破坏而导致建筑物坍塌。     

酸雨对泰山古碑石刻侵蚀的模拟研究

为研究我国华东典型山地地区的酸沉降对文物古迹的影响,选取与泰山古碑石刻材质相同的花岗石,采用pH分别为3.0、3.8、4.7、5.6的人工模拟酸雨对泰山花岗石进行周期浸泡实验,测定不同pH值下的腐蚀速率;同时利用扫描电子显微镜(SEM)观测试验前后样品表面特征;并对浸泡前后的样品表面粉末进行X射线衍射分析。实验结果表明:影响石材腐蚀的主要因素是酸雨的酸度;花岗石石样受到侵蚀后,质量减少百分数随pH值降低而增大,最大质量损失达到0.073%,而当pH值大于3.8时,石样的最终腐蚀情况基本一致,基本在0.02%左右;并且无论是高酸度酸雨,还是低酸度酸雨,都对材料外观造成了损害;蚀后样品查出了CaSO4和MgSO4相分。     

Concept for cost effective improvement of river morphology in the context of the European Water Framework Directive

The EU Water Framework Directive calls for cost effective measures to achieve a “good status” in all European ground, surface and coastal waters. Besides eutrophication, the degradation of hydromorphology is the main reason for failing this objective. In this paper, we conceptualise the interactive decision support process BASINFORM-M for finding proper locations for river restoration. The concept combines the recently proposed “stepping stone approach” from aquatic ecology with elements from cost effectiveness analysis, multi-criteria analysis and participatory approaches. BASINFORM-M exemplifies a shift away from the isolated restoration of single river reaches towards a consideration of functional relationships within river networks.