微生物絮凝剂处理造纸中段废水的实验研究

实验从土壤中分离筛选出1株絮凝活性较高的絮凝剂产生菌,经鉴定为1株黑曲霉.采用其产生的微生物絮凝剂M-2处理造纸中段废水,对絮凝条件进行了优化,在最佳絮凝条件下,M-2对造纸中段废水的CODcr去除率可达70.6%,浊度去除率可达91.7%,其絮凝效果优于传统的絮凝剂.     

输变电项目环评存在问题分析及对策建议

列举了国家环保总局环境工程评估中心在输变电项目环境影响技术评估中遇到的一些技术和管理上亟待解决的问题,在对其分析的基础上,提出相应的对策建议.     

数据安全新思路

利用小波的时频局部化的特征,将信息的加密过程由传统的时域中进行改为在时域和频域中进行,达到信息加密和增强信息安全性的目的。采用两种方法实现信息的加密与解密的过程,一种是将明文保存为图像文件格式,对图像文件进行小波的分解与重构,实现信息的加密与解密;另一种是将明文数值化为一个系数矩阵,对数值矩阵进行小波的分解与重构,实现信息的加密与解密。通过小波分解过程进行加密,小波的重构过程进行解密,改变了传统的在空域中通过一系列的移位、迭代和置换的方式进行的加密过程,因此也不能通过传统的解密方式进行解密,增强了信息的安全性。由于小波的多样性,不同的小波变换得到的结果也会不同,增加了解密的难度,保证了数据的安全。     

响应面法优化养殖水体中炔雌醇的固相萃取条件

在单因素试验、Plackett-Burman设计试验基础上,采用Box-Behnken响应面法对养殖水体中炔雌醇(EE2)的固相萃取条件进行优化。结果表明,洗脱液体积、洗脱液组成和淋洗液体积是影响EE2固相萃取回收率的3个主要因素;EE2的最佳固相萃取条件为:水样pH值为3,进样流量为3.0 mL/min,淋洗液为体积分数为10%的甲醇水溶液,淋洗液体积7.0 mL,洗脱液为乙酸乙酯-正己烷混合溶液(体积比为9∶1),洗脱液体积12.0 mL。该条件下养殖水样中EE2固相萃取回收率为81.6%～86.7%。     

“绿水青山就是金山银山”的浙江实践与转化路径

"两山"理论,即"绿水青山就是金山银山",是习近平新时代中国特色社会主义思想的重要内容。浙江是"两山"理论的发源地,思考探寻基于浙江情境的"两山"转化路径,意义重大且十分迫切。本研究从顶层设计、高质量发展、营商环境、协同治理、技术创新等方面,总结浙江"两山"转化的实践经验及其实践特征,探讨其"两山"转化路径,以期为在全国范围内推广"两山"转化与践行提供参考。     

Plant cover synanthropization in the pechora-Ilych biosphere reserve along an altitudinal gradient

Trends in plant cover synanthropization along a plain-foothills-mountains gradient have been revealed in the reserve. Characteristics of plant communities in anthropogenically disturbed habitats, centers of concentration of anthropophytes and apophytes, and pathways of their migration are described.     

Blast wave clearing behavior for positive and negative phases

The purpose of the research was to improve prediction of response of buildings to blast waves by including the negative phase and considering clearing of both positive and negative phases. Commonly used structural design practices, which trace their origins to military design manuals, often ignore the negative phase as well as positive phase clearing. For high explosive threats, this approach is conservative in most circumstances. However, negative phase clearing had not previously been studied for blast waves, and the implications for structural response had not been evaluated. This paper presents results of modeling negative phase blast clearing behavior for a typical blast wave and discusses the differences from positive phase clearing. The implications of including positive and negative phase clearing in building blast damage analysis are also investigated through single-degree-of-freedom (SDOF) analyses.Blast waves from explosion sources like a vapor cloud explosion (VCE), pressure vessel burst or high explosive exhibit both positive and negative phases, and the relative magnitude of the positive and negative phases varies among explosion sources and the specific circumstances of each source. A fully reflected blast wave is produced if an incident blast wave were to strike an infinitely tall and wide wall in a normal orientation. Both the positive and negative phases of the blast wave are enhanced by the reflection process. However, when an incident blast wave strikes a wall of finite size in a normal orientation, rarefaction waves are created at the edges of the wall, and the rarefactions sweep down from the roof and inward from sides. The rarefaction waves result in a clearing effect for both the positive and negative phases.Clearing relieves some of the applied blast load on the reflected wall for the positive phase. However, this is not always the case for the negative phase. As shown by the results presented in this paper, clearing may either relieve or enhance the applied negative phase blast load, depending on the duration of the blast wave and the wall dimensions.The impact of negative phase clearing on structural response for generic building components was also investigated. Nonlinear SDOF methods were used to characterize response in terms of peak positive and negative displacements. It was found that the influence of the negative phase is significant and the peak structural response can occur during negative (outward) displacement.     

卷烟膨胀烟丝生产线冷端CO_2泵装置的优化改进

为解决干冰膨胀烟丝生产线冷端液体工艺泵因机械密封长期超压和气缚现象造成损坏发生CO2泄漏而导致紧急停机抢修的问题,对干冰膨胀线冷端工艺罐系统进行了优化改进。在工艺泵吸口前管路引一根气相平衡管至工艺罐顶部,当泵吸口前管路有CO2液体时,输送管路内气化的CO2气体通过气相平衡管线释放回工艺罐内,不会进入工艺泵体内。应用结果表明,工艺泵内的憋压和气缚现象消失了,机械密封受到保护。改造前机械密封平均一个季度更换一次,改造后机械密封使用5年未损毁,达到保护干冰膨胀线冷端工艺泵机械密封的目的。     

Governing Quasi-Public Network Services for adaptation to climate change

Adaptation takes place in both private and public sectors, or as an interrelation between the two, and often under the realm of public regulation. Thispaper uses the Swedish and the Norwegian electricity grid sector, as providers of a vital public good under strict public regulation, to analyse reforms' effects on adaptive capacity in this area. The paper shows that transformational changes in both sectors during the 1990s shifted both the formal organisational structure (rules and regulations), as well as the organisational culture, in the direction of economic efficiency. These two dimensions individually reduced adaptive capacity to climate change, although differently in the two countries. However, the formal structure and organisational culture also yielded substantial influence on each other. This leads to the conclusion that when designing public regulations and implementing reforms, organisational culture must be considered in the design. Also the paper contests previous findings in the literature by showing that under given conditions there exist some substitution between the two dimensions in influencing adaptive capacity, implying that both dimensions should be included when analysing adaptation since analysing them in isolation is likely to lead to wrong conclusions.     

基于前向神经网络的广义环境系统评价普适模型

为了建立由水环境、空气环境、生态环境、水资源环境、灾害环境、遥感环境、社会经济环境等不同环境系统组成的广义环境系统评价都能普适、通用的神经网络模型,针对BP神经网络因收敛速度慢、易于陷入局部极值而使实用性受限的缺陷,提出以双极性sigmoid函数作为网络隐层节点(神经元)的激活函数,而网络输出为所有隐层节点输出的线性求和的前向神经网络的广义环境系统评价模型.在设置广义环境系统指标参照值和指标值规范变换式,并对指标值进行规范变换的基础上,分别构建了适用于广义环境系统评价的任意2个指标规范值的前向神经网模型(NV-FNN(2)结构)和任意3个指标规范值的前向神经网模型(NV-FNN(3)结构).而对于指标较多的广义环境系统评价,只要将多指标分解为以上2个指标和3个指标的两种简单结构的前向神经网络的广义环境系统评价模型的组合表示即可.理论分析和实例检验结果表明:该模型对任意广义环境系统的规范指标值皆普适、通用,因而使不同环境系统的评价变得简洁、统一.规范变换和优化算法相结合的建模思想和方法对简化广义环境系统评价的多元回归、投影寻踪回归、回归支持向量机和径向基神经网络建模亦有借鉴和启迪作用.