Use of Nutshells as Fillers in Polymer Composites

Nutshells are agricultural waste products that can be procured at relatively low cost. In this work we examined the possibility of using these biodegradable materials as fillers in poly(lactic acid) and low density polyethylene. The nutshells were ground into powder, blended with the polymer, and then injection molded with final weight varying from 10 to 40 weight %. The mechanical and thermal properties of the composites were then studied. In general, the addition of fillers caused reductions in mechanical properties to varying extents, but thermal properties were only slightly affected. The use of maleic anhydride and peroxide with the fillers had a negative effect on poly(lactic acid) but a slightly positive effect on the stiffness of polyethylene. The results suggested that polymer-nutshell composites may be usable in applications where cost is a concern and where some reductions in mechanical properties are acceptable.     

资源型城市脆弱性评价 ——以攀枝花市为例

资源型城市作为一类特殊类型的城市,其脆弱性涉及资源、生态环境、经济和社会等多个方面。探讨资源型城市脆弱性测度及动态演变特征对其转型发展具有重要意义。以西南地区典型资源型城市攀枝花市为研究对象,通过构建脆弱性测度指标体系,利用层次分析法确定指标权重,采用多因子综合评价法研究其脆弱性及动态。结果表明：（1）攀枝花市2006~2015年城市综合脆弱性总体呈下降趋势。其综合脆弱性指数从2006年的0.74下降到2015年的0.37,经历较高脆弱度、中脆弱度和较低脆弱度的演变;（2）该市近10 a来分系统中资源脆弱性年均值最大（0.57）,其次为经济脆弱性（0.50）,社会脆弱性（0.46）和生态环境脆弱性（0.43）相对较小。其中资源、生态环境和社会脆弱性均呈下降趋势,年均变化幅度分别为0.10、0.10、0.08,经济脆弱性呈振荡上升,年均变化幅度最大（0.13）;（3）该市近10 a来经济系统对城市综合脆弱性贡献度上升明显（由2006年的15.53%上升到2015年的70.03%）,同时社会脆弱性也较突出（2015年达20.16%）。未来攀枝花市在转型与城市脆弱性调控上应坚持以经济转型为核心,推进资源综合开发利用;进一步加强矿产资源地质勘探;推进区域统筹发展,减少社会脆弱性;提高工业固体废弃物综合利用,加强生态环境建设。 关键词：资源型城市;脆弱性;攀枝花市     

建设项目环保设施竣工验收监测中的几个问题

对建设项目环境保护设施竣工验收监测工作中遇到的问题进行了探讨.提出竣工验收监测的具体内容和时间的确定,既要着眼于项目验收,更要考虑到加强环境保护的实际需要;竣工验收监测应强化标准在污染控制中的重要作用;竣工验收监测中,效率监测应考虑结果的可比性以及在竣工验收监测中应落实污染物总量控制的意见.     

Numerical simulation of municipal solid waste combustion in a novel two-stage reciprocating incinerator

A mathematical model was presented in this paper for the combustion of municipal solid waste in a novel two-stage reciprocating grate furnace. Numerical simulations were performed to predict the temperature, the flow and the species distributions in the furnace, with practical operational conditions taken into account. The calculated results agree well with the test data, and the burning behavior of municipal solid waste in the novel two-stage reciprocating incinerator can be demonstrated well. The thickness of waste bed, the initial moisture content, the excessive air coefficient and the secondary air are the major factors that influence the combustion process. If the initial moisture content of waste is high, both the heat value of waste and the temperature inside incinerator are low, and less oxygen is necessary for combustion. The air supply rate and the primary air distribution along the grate should be adjusted according to the initial moisture content of the waste. A reasonable bed thickness and an adequate excessive air coefficient can keep a higher temperature, promote the burnout of combustibles, and consequently reduce the emission of dioxin pollutants. When the total air supply is constant, reducing primary air and introducing secondary air properly can enhance turbulence and mixing, prolong the residence time of flue gas, and promote the complete combustion of combustibles. This study provides an important reference for optimizing the design and operation of municipal solid wastes furnace.     

住宅装修室内环境污染状况调查

随着国家经济发展和人民生活水平、生活质量的不断提高,人们更加注重在住房装饰装修上的金钱投入以圆梦中家居。但是,由于现实生活环境的多方因素制约,伴随住宅装修过程形成的室内环境污染也给人们希望获得健康环保的高质量生活带来严重影响。通过对新装修住宅（客厅、主卧室、次卧室）进行室内环境污染检测,获得了非常有益的实测数据。通过统计分析该数据,发现新装修住宅室内空气中的甲醛、苯及TVOC存在普遍超标,且有的情况非常严重,应当引起人们的高度关注。为此建议：装修时要明确目的,树立环保理念,综合规划设计;注意材料质量优选控制污染源头,加强施工监督和检测验收;对污染超标住宅采取必要的治理措施,加强室内通风换气,室内空气质量检测达标后才居住使用,确保居室环境的健康环保。     

西风区黄土–古土壤的碳酸盐含量对磁化率影响研究

本文选择伊犁盆地塔勒德黄土– 古土壤序列,系统地开展了沉积物碳酸盐和磁化率等指 标研究,初步探讨了伊犁黄土碳酸盐含量对磁化率增减的影响机制。研究发现,塔勒德古土壤 中低频磁化率值中明显低于黄土层,且较黄土高原古土壤值小,频率磁化率也远小于黄土高原; 碳酸盐含量在S₁ 层中含量明显高于黄土,且较黄土高原古土壤高,与剖面磁化率负相关,在古 土壤中相关度更显著。去除碳酸盐的设计实验显示加入蒸馏水后沉积物磁化率值变化在10％以 内;加入醋酸（HAc）后样品磁化率值均增加,其最大增幅达12.89%（黄土）,古土壤的磁化 率增加9% 以上;加入稀盐酸后影响程度不一,在黄土中约在15%,而对古土壤影响较大,最大 可达35%,表明沉积物中碳酸盐含量对磁化率的影响不仅是简单的稀释作用,还与干旱气候环 境下碳酸盐化、次生碳酸盐化作用相关。     

千岛湖生态环境主要问题及保护对策

1998—2000年的研究结果表明,千岛湖的富营养化进程明显加速。千岛湖上游安徽境内输入的大量营养盐、周边地区的生态环境变化、农田地表径流及水土流失是引起湖水水体质量变化的主要原因。控制上游安徽境内的入湖水质、减少农业面源污染和水土流失对水体的影响、恢复与重建湖滨植被保护带、改善整个周边地区的生态环境等是保护千岛湖生态环境的主要对策。     

高层建筑新型灭火装置的设计

高层建筑外围火灾灭火工作开展困难,为增强灭火效果,本文按照自上而下的灭火思路,探讨在高层建筑顶部设计一种新型灭火装置。该装置可迅速转向火灾一侧,升降到准确的高度,从外向内灭火。克服了现有云梯消防车存在的举高有限、供水器材的耐压强度不够等问题。该装置的设计可在紧急情况下弥补现有灭火设施的不足,为高层建筑外围灭火解决方案的完善提供了新的参考。     

Turbulence characteristics of a round offset jet with different offset ratios in a counterflow

Environmental Fluid Mechanics - A round jet entering a counterflow with different jet-to-current velocity ratios and different offset ratios was experimentally investigated using particle image...     

造纸黑液固化物有机NPK复合肥对水稻的效应研究

研究了造纸黑液固化物有机ＮＰＫ复合肥对稻产量、品质及土壤的影响，结果与复混肥“施大壮１”和“施大壮２”相比，增加水稻产量，分别增产１．７％和５．７％，该肥使稻米品质提高，并有利于保持土壤肥力。