Protected areas and deforestation: new results from high‐resolution panel data

This paper investigates the effectiveness of protected areas in slowing tropical forest clearing in 64 countries in Asia/Pacific, Africa and Latin America during the period of 2001–2012 by comparing deforestation rates inside and within 10 km outside of the boundaries of protected areas. Annual time series of these deforestation rates were constructed from recently published high‐resolution data on forest clearing from Hansen et al. (2013). For 4,028 parks, panel estimation based on a variety of park characteristics was conducted to test if deforestation was lower in protected areas because of their protected status, or if other factors explained the difference. From a sample of 726 parks established since 2002, a test was also conducted to investigate the effect of park establishment on protection. Findings suggest park size, national park status and management by indigenous people all are significantly associated with effective protection across regions. For the Asia/Pacific region, the test offers compelling evidence that park establishment has a near‐immediate and powerful effect.     

Modeling Nutrient Export From Coastal California Watersheds

Nitrate and phosphate export coefficient models were developed for coastal watersheds along the Santa Barbara Channel in central California. One approach was based on measurements of nutrient fluxes in streams from specific land use classes and included a watershed response function that scaled export up or down depending on antecedent moisture conditions. The second approach for nutrient export coefficient modeling used anthropogenic nutrient loading for land use classes and atmospheric nutrient deposition to model export. In an application of the first approach to one watershed, the nitrate and phosphate models were within 20% of measured values for most storms. When applied to another year, both nitrate and phosphate models generally performed adequately with annual, storm‐flow, and base‐flow values within 20% of measured nutrient loadings. Less satisfactory results were found when applied to neighboring watersheds with difference percentages of land use and hydrologic conditions. Application of the second approach was less successful than the first approach.     

油气管线带压不停输封堵技术在长庆油田的应用

长庆油田通过对管道不停输带压封堵施工技术的探索,在改扩建工程施工中取得了良好的效果。实践证明,与常规施工方法相比可有效缩短维护抢修作业工期20%～30%。它在油气田风险管理、事故预防、环境污染治理方面是积极安全有效的。     

炼油厂稳高压消防水系统改造过程的风险分析

运用预先危险性分析法(PHA),对炼油厂稳高压消防水系统改造过程中存在的风险进行了分析,采取安全措施,取得了明显效果.     

基于泰沙基折减自重模型的隧道围岩压力的确定及验证

采用泰沙基折减自重模型,通过实例分别计算和分析了考虑内聚力和不考虑内聚力两种情况下的隧道竖向荷载大小及其与埋深的关系曲线,并与现场围岩压力测试结果进行比较,表明实测的隧道围岩最大压力值与模型计算结果相近,说明该模型适用于隧道围岩软弱破碎、风化不均的围岩压力的确定,从而为类似工程提供了借鉴。     

水环境中天然溶解有机质分子量的研究现状及意义

溶解有机质存在于所有的水环境中,它是组成不均匀、结构复杂和分子量分布很宽的有机化合物混合体。本文综述了测量溶解有机质分子量的主要方法,各种方法的原理和优缺点,其中详细介绍了高效体积排阻色谱法的原理,平均分子量和分散系数的计算,以及分子量的校正;同时介绍了可能影响分子量分布的主要地球化学因素,以及天然水中溶解有机质的分子量分布的特征。     

The effects of component dimensions on heat transfer and pressure loss in shell and tube heat exchangers

In this study, the effects of geometric properties such as baffle spacing, baffle cut, sealing strips, gaps between heat exchanger components, number of tubes and tube passes have been investigated for shell and tube heat exchangers (STHE). For this purpose, geometrical dimensions and data of a specific heat exchanger (HE) used in an industrial application have been obtained. The HTRI Xchanger Suite Educational software was utilized to analyze the reference HE, to verify the results of the software and the output temperatures of the fluids, the shell side heat transfer coefficient (HTC) and the pressure loss (PL) values were compared with the experimental data. After confirming that the results of the software were within the acceptable deviation values, the geometric dimensions of the reference design were changed and new analyzes were carried out to examine the effects of several dimension options on the performance of STHE. Results were discussed in a detailed and comprehensive manner via curves.     

圆盘式固相萃取HPLC法测定饮用水中微囊藻毒素LR和RR

采用固相微萃取与高效液相色谱联用技术（SPE／HPLC）测定饮用水的微囊藻毒索,并对SPE的萃取条件和HPLC的色谱条件进行了优化,对SPE的多项参数,诸如萃取率、检出限及测定限以及准确度和精密度均作了测试。通过实际水样进行了分析,该方法测定MC—LR（LR型微囊藻毒索）的线性范围为0．5～50ug／L,相关系数为0．9992;测定MC—RR（RR微囊藻毒索）的线性范围为0．5—50ug/L,相关系数为0．9989。SPE法之优于LLE法主要在于分析过程快速,有机溶剂使用量大大减少,方法更适合于大量水样中有机污染物的现场取样处理。     

强化接触氧化法处理高盐废水

废水中盐分含量过高,会给生物处理带来一定的难度。因为盐析作用可致使微生物的脱氢酶活性降低,同时水的渗透压也会升高,使微生物细胞脱水引起细胞原生质分离,从而导致微生物细胞破裂而死亡。传统的一些生物方法对此类废水的COD的去除率低。本试验使用两株嗜盐菌在接触氧化反应器中通过连续操作对含盐废水进行处理,研究了盐度,COD负荷,溶氧对COD去除率的影响关系。在废水盐度为35g/L,进水COD为4500mg/L,COD容积负荷为3.5kgCOD(/m·3d)时,COD去除率达到90%左右,取得较好的去除效果。     

雾霾天气下电网设备故障高精度远程视频监控系统设计研究

作为电力系统未来发展的方向,对电网设备故障监控系统进行设计具有重要意义.有利于实现电网进行安全可靠运行.提出基于ZigBee网络的电网设备故障高精度远程视频监控系统设计.利用ZigBee网络构建无线的传感网,节点是采用的CC2530,节点间采用簇状的结构与监控功能部分、视频监控信号传输以及监控的客户端相结合构成远程视频的监控系统,采用小波变换对设备故障的特征进行分析,克服了因雾霾天气产生的电网设备故障,对电网设备故障进行及时的抢修,完成对电网设备故障高精度远程视频监控系统的设计.实验结果表明,利用该系统能有效地提高电网运行的稳定性与安全性.