几种阴阳离子对磷钨酸光催化降解甲基橙的影响

以磷钨酸为光催化剂,在紫外灯照射下,对甲基橙溶液进行光催化降解,考察了几种阴阳离子对磷钨酸光催化降解甲基橙溶液的影响。结果表明：Mg^2＋、Ca^2＋、NO3^-、SO4^2-和CO3^2-均对催化活性有促进作用,其中Mg^2＋和Ca^2＋仅有微弱的促进作用;NO3^-和SO4^2-随着浓度的增加促进作用也有所增加;CO3^2-则随着浓度的增加促进作用呈下降趋势;Mn^2＋、Al^3＋和Cl^-对光解反应存在较强的抑制作用,且Al^3＋和Cl^-随着其浓度的增加,抑制作用增强。     

废旧锂离子电池资源化技术研究

通过介绍废旧锂离子电池的组成成分及近年来废旧锂离子电池资源化处理技术的研究进展,提出目前主要回收方法有溶解分离法和直接回收正极材料的新型方法等,并对现有研究中存在的二次污染、安全性问题进行了初步探讨。     

装备环境适应性表征方法研究

通过对综合环境条件下装备故障模式的聚类分析,探索出了影响装备环境适应性的主要环境因素的途径,进一步确定了描述综合环境条件下装备环境适应性的评价参数,并利用信息熵理论找到了确定评价参数权重的手段,得到了描述装备环境适应性的定量参数与定性参数的表示方法,为评估综合环境条件下装备环境适应性奠定了基础.     

吉林市“白色污染”概况及防治措施建议

“白色污染”是中国城市特有的环境污染。在各种公共场所到处都能看见大量废弃的塑料制品,他们从自然界而来,由人类制造,但是这些废弃的塑料制品最终归于大自然时却不易被自然所消纳,从而严重影响了大自然的生态环境。首先介绍了“白色污染”的概念及其危害;然后对吉林市塑料方便袋的使用情况进行了调查,并以此反映吉林市“白色污染”的概况;最后针对中国当前“白色污染”治理过程中的不足提出了针对性的建议,以期达到能够有效缓解或根治“白色污染”的目的。     

中国自然灾害和减灾对策(之六)——提高减灾效益,用科学观念指导各领域的减灾工作

环境恶化和突发灾害是威胁人类生存的两大挑战性问题.由人类活动导致的自然环境破坏和恶化是一个长期累积的过程,类似于人体所患的慢性疾病,对其的认识和解决不仅依靠多种条件,还要很长时间的持久努力;自然灾害的发生则一般是短时间内的突然事件,类似人体的急性疾病.     

冰雪灾害中交通工程的损害类型及原因分析

通过对已建及在建的高速公路在冰灾中的损害调查,详细列出了损害的类型并进行了原因分析。并将此次灾难中暴露出的设计、施工和管理方面的问题进行了分解。     

用ScS波震相测定远震震源深度的研究

本文介绍了ScS波的传播路径及走时曲线,选用图象说明ScS波震相的运动学和动力学的主要特征.并利用ScS波震相测定沈阳地震台单台记录的八个远震震源深度,通过对ScS波、pP波和sP波在远震地震图中进行比较分析,结果表明:所得到震源深度误差都在±30Km范围内,达到所要求的精度范围,提高了单台测定震相精度,因此用ScS波震相测定远震深度是一种测定震源深度行之有效的辅助方法.     

汉江中游河谷平原植被指数时空变化及其与沙化土地动态的关联关系

针对沙化土地广泛分布的汉江中游河谷平原区,采用MODIS EVI数据分析2003~2011年区域植被状态时空变化,并据此探讨沙化土地的动态特征。利用时序植被指数统计分析,探讨研究区植被的总体变化规律;分析不同缓冲区植被指数的空间分布格局,反映了区域环境状况的空间差异以及由此而可能产生的土地利用格局的变化;并基于不同距离缓冲区的EVI时空差异对比分析,探讨沙化土地动态与植被变化的关联关系。研究表明,近9 a来汉江中游河谷平原区EVI呈明显上升趋势;随着离河流距离的逐渐增加,每千米范围内各年的年均EVI值均表现出先增大后减小的空间特征,并在距河3 km区域处EVI值达到最大;而EVI的时空差异,则体现了沙化土地的空间分布与动态特征     

The ecological implications of land use change in the Source Regions of the Yangtze and Yellow Rivers, China

The alpine ecosystems in permafrost regions are extremely sensitive to climate change. The headwater regions of Yangtze River and Yellow River of the Qinghai-Tibet Plateau are on the permafrost area. Aerial photos of the Source Regions of the Yangtze and Yellow River taken in 1968 and three phases of TM images acquired from 1986, 2000, and 2008 were used to analyze the spatial alterations of the land cover and corresponding effects on the environment guided by landscape ecology theory. Firstly, land cover types were divided into three classes and 11 subclasses. Analysis results revealed the trends and magnitude of the eco-environmental changes in the regions over the past four decades and showed a continuous degradation of grasslands and the extension of desertification and salinization. Secondly, five landscape pattern indices (i.e., NP, MPS, PR, SHEI, CONTAG) commonly used in landscape ecological studies were calculated, and results showed that this region had become more centralized and diversified. Finally, the factors causing the degradation of alpine grasslands were analyzed. The regional climate exhibited a tendency toward significant warming and desiccation with the air temperature increased by 0.03 °C per year and relative stable precipitation over the last 40 years. And the temperature of permafrost in 0–20 cm soil layer obviously raised by 0.2–0.3 °C in the last 40 years. The combined effects of climate warming and permafrost variation were the major drivers for the changes of landscape in alpine ecosystems.     

Impacts of the Rising Opportunity Cost of Farm Labor on Agricultural Land Use Structure: Theory and Empirical Evidences

Abstract

Nowadays the rising of opportunity cost of farm labor comes to the forefront of attention in China. In order to understand its impact on agricultural land-use structure, a theoretical framework of household economics is formulated drawn on Low’s model. Under the theoretical framework, the impact of the rising opportunity cost of on-farm on cropping structure is deduced in theory. And then, using statistic and survey data, taking mountain area of southern Ningxia as an example, the theoretical assumes are verified. The results show that the rise of opportunity cost of farm labor leads to less diversified cropping structure.