硫酸盐草浆黑液制粉状活性炭的研究

本文探讨硫酸盐草浆纸厂黑液的治理和利用,提出用酸化法从黑液中沉析木素制取粉状活性炭。大约生产10t草浆可制取1t优质粉状活性炭。同时还含有占总碱量24%的Na_2S可回收。排出的废液即使不再经过处理,其污染程度也已大大降低。     

铅笔板高温热压改性技术研究

为克服高温烤板处理的缺点 ,进行了椴木铅笔板热压干燥基本规律及温度、时间与含水率的关系研究和热压干燥的铅笔板与烤板的吸湿性、脆性对比试验。研究结果表明 :高温热压可使木材进行热分解 ,热压干燥后的铅笔板的吸湿性和脆性能达到烤板的要求 ,并在质量稳定性方面优于烤板 ,更重要的是它解决了烤板对环境的污染问题     

论中国的环境税--税收手段治理环境

环境税是政府通过税收手段矫正制度失灵(市场失灵和政府失灵),实现环境保护和资源保护的一个有效工具。环境税的征收从经济角度为解决我国日益严重的环境问题提供了思路,但目前我国的环境保护税费制度不适应市场经济体制。我国环境税制建设本身需要分为近期和远期规划进行实施,同时需要从宏观方面进行配套建设。     

饮用水的水质污染对人的危害

饮用水的质量,是人们普遍关心的问题。饮用水受到各种污染后,对人的危害是不容忽视的。本文就国内外饮用水的水质污染对人体造成的危害进行了综述。     

杨红腹叶蜂无公害防治方法

杨红腹叶蜂是尚志市新发现的危害杨树叶部的一种重要害虫,严重发生时杨树叶子全部被其吃光,结合形态特征,生物学特征,提出切实可行的防治办法。     

大气氮沉降对森林土壤酸化的影响

因大气污染而不断增加的大气氮沉降量，在许多地区超过了森林生态系统的氮需求。氮在土壤中的化学和生物化学反应对H^ 离子的产生与消耗有重要影响。NH4^ 和NO3^-输入与输出的平衡状态影响着土壤－土壤溶液系统的酸化速率。过剩的氮沉降将加增NH4^ 的硝化和NO^-的淋失，加速土壤的酸化。土壤酸化对森林有危害作用。     

The variation of tree-ring widths of Scots pine (Pinus sylvestris L.) affected by air pollution

Using eight populations of Scots pine growing in foothills of the Sudetes (southern Poland) as an example, the character and causes of annual ring variation in 1900–1999 were studied. The climate had a short-term effect on radial growth during the whole period investigated. A long-term decrease of radial growth occurred after 1960, but only in some localities. It was probably caused by non-climatic factors, most likely by industrial pollution. The decline of trees during that period is mainly evidenced by a high variation of width of annual rings, a small similarity of chronologies of annual ring widths, and a lack of signal years. After 1990, the tree recovery process was evident. It was most intensive in localities where the earlier stress was the most severe. Then, trees started to produce wide annual rings, homogeneity of the growth reaction increased, and the signal years began to occur.     

蛭石与人造沸石氨氮等温吸附理论式与判别式

为比较在高起始氨氮浓度C0点和介质用量W0点上,吸附理论通式Qe=W0qmC0/[qmKw W0(qm-qe) C0]与其简化方程Qe=W0qmC0/[qm(Kw W0) C0]的适用性,测定了给定pH值和温度条件下反应平衡时NH4Cl溶液中蛭石和人造沸石的氨氮吸附量(Qe).在该试验条件下确定的蛭石单位介质吸附容量qm和介质系数Kw值分别为22 mg/g和15.5 g/L,人造沸石的qm和Kw的值分别为45 mg/g和8 g/L.在整个试验氨氮浓度C0和介质用量W0范围内,用该通式描述两介质刘氨氮的等温吸附过程具有很高的精确度.而简化方程仅在有限范围内即C0相对小或W0相对大时才适用.若给定预测相对误差(RD),则C0/qm(Kw W0)≤RD可作为简化方程应用的判别式.     

杉木采伐对集水区土壤热状况的影响

土壤作为森林生态系统的子体系 ,是林木扎根并赖以生存的基础 ,也是土壤微生物一切生命活动的场所。因此 ,有关土壤养分、水分及其土壤物理结构特征等方面的研究报告颇多 (王政权等 ,2 0 0 0 ;张合平等 ,1 997)。但是有关森林土壤的热状况 ,以及林木采伐后对土壤热状况影响的研究报导很少 (康文星等 ,1 989;刘煊景等 ,1 993)。本文在获得采伐前连续 3年和采伐后连续 3年的观测数据的基础上 ,就杉木人工林生态系统土壤的热状况各因子之间 ,土壤各组成成分对热状况的单一或组合效应 ,以及皆伐这种人为强烈干扰对土壤热状况的影响进行了剖析。…     

Thermal diffusion in Masson pine wood

In order to analyze the effects of the temperature gradient on moisture movement during the highly intensive microwave-vacuum drying, thermal diffusion of Masson pine wood was studied. Internal distribution of temperature and moisture in Masson pine samples sealed by epoxy resin and aluminum foil was measured, the magnitude of thermal diffusion was calculated and the influencing factors of thermal diffusion were discussed. Results showed that with the transfer of moisture toward the low temperature in wood, opposite temperature and moisture gradient occurred. The initial moisture content （MC）, temperature and time are important factors affecting this process; the thermal diffusion is in proportion to wood temperature, its initial moisture and time. The temperature and distance from hot surface is strongly linearly correlated, and the relationship between MCs at different locations and distance from the hot end surface changes from logarithmically form to exponentially form with the increase in experimental time.