站控、通信及网络系统的防雷措施

论述了输油泵站控制系统及微波通信系统遭受雷击的危害及原因,有针对性地采取了各种防雷的有效措施,完善微波通讯和站控及网络防雷保护系统,为确保输油安全生产提供了有利保证.     

Mn对超富集植物短毛蓼和水蓼生长、Mn吸收及氮素代谢的影响

采用水培的方法,研究了不同浓度Mn(0.0003、0.5、1、2、4、8 mmol · L^-1)对Mn超富集植物短毛蓼(Polygonum pubescens Blume)和水蓼(Polygonum hydropiper L.)叶片铵态氮、硝态氮、游离脯氨酸、可溶性蛋白质含量及氮素代谢关键酶:硝酸还原酶(NR)、谷氨酰胺合成酶(GS)、谷氨酸合酶(GOGAT)和谷氨酸脱氢酶(GDH)活性的影响.结果表明,随着Mn处理浓度的增加,短毛蓼和水蓼的根、茎、叶中Mn含量显著增加(p<0.05),在相同Mn处理浓度下短毛蓼中Mn含量均大于同部位水蓼中Mn含量.在Mn处理浓度小于1 mmol · L^-1时,Mn对短毛蓼的株高、株重影响不显著,但对水蓼的影响显著(p<0.05),表明短毛蓼比水蓼更耐Mn污染.Mn处理显著降低了短毛蓼硝态氮含量(p<0.05),提高了可溶性蛋白质含量,浓度为8 mmol · L^-1的Mn处理显著提高了水蓼硝态氮、铵态氮、可溶性蛋白质含量及短毛蓼、水蓼游离脯氨酸含量(p<0.05).Mn引起了短毛蓼和水蓼氮素代谢关键酶活性的变化,显著降低了水蓼叶片NR、短毛蓼叶片GS活性(p<0.05);在Mn处理浓度为1 mmol · L^-1时,短毛蓼叶片NR活性最高,为对照的1.91倍,而2、4、8 mmol · L^-1 Mn处理显著降低了短毛蓼和水蓼GOGAT活性(p<0.05).另外,Mn处理显著提高了短毛蓼和水蓼叶片GDH活性(p<0.05),在Mn处理浓度为8 mmol · L^-1时,短毛蓼、水蓼叶片GDH活性分别为对照的16.29倍和1.29倍.     

A study on the factor market distortion and the carbon emission scale effect of two-way FDI

Based on the data of 30 Chinese provinces for the period from 2004 to 2015, this paper expounds the carbon emissions effect of two-way foreign direct investment (FDI) from the perspective of scale effect and factor market distortions. This study uses Kaya identity to decompose carbon emission and construct simultaneous equations model to empirically examine the factor market distortion and the carbon emission scale effect of two-way FDI. The results show that the inward foreign direct investment (IFDI) increase regional carbon emission through scale effect and also exacerbates factor market distortion in China, whereas the outward FDI trends reduce carbon emission and reduces factor market distortions in China. The study also shows that human capital, research and development (R&D), trade openness, and capital accumulation are important determinants of two-way FDI. Therefore, the study proposes that IFDI policies should focus on acquiring green technologies. In addition, the domestic enterprises should be encouraged to participate in global business.     

A real-time simulating non-isothermal mathematical model for the passive feed direct methanol fuel cell

In order to understand the complex transport phenomena in a passive direct methanol fuel cell (DMFC), a theoretical model is essential. The analytical model provides a computationally efficient framework with a clear physical meaning. For this, a non-isothermal, analytical model for the passive DMFC has been developed in this study. The model considers the coupled heat and mass transport along with electrochemical reactions. The model is successfully validated with the experimental data. The model accurately describes the various species transport phenomena including methanol crossover and water crossover, heat transport phenomena, and efficiencies related to the passive DMFC. It suggests that the maximum real efficiency can be achieved by running the cell at low methanol feed concentration and moderate current density. The model also accurately predicts the effect of various operating and geometrical parameters on the cell performance such as methanol feed concentration, surrounding temperature, and polymer electrolyte membrane thickness. The model predictions are in accordance with the findings of the other researchers. The model is rapidly implementable and can be used in real-time simulation and control of the passive DMFC. This comprehensive model can be used for diagnostic purpose as well.     

阳离子型聚合物对低温低浊水的絮凝效果与形态学特性

采用微絮凝-深床直接过滤工艺,以西安市曲江水厂低温低浊水质为原水(水温低于10 ℃,初始浊度低于10NTU),投加阳离子型聚合物(简称CP)作主混凝剂或助凝剂,借助分形数学理论与图像分析技术,对滤料粒径、原水浊度、原水温度、药剂种类、聚合物分子量及投加量、混合强度等因素对处理效果的影响进行了研究,分析探讨了不同药剂处理低温低浊水的作用机理、絮凝形态学特征以及絮体结构的分形特性.结果表明,①当温度低于4 ℃、初始浊度小于4NTU时,不宜单独采用Al2(SO4)3或PAC作为絮凝剂;当温度为4～10 ℃、初始浊度小于10NTU时,如果只投加Al2(SO4)3或PAC作为絮凝剂,宜用细砂滤料过滤;低温低浊条件下,无机混凝剂形成的絮体粒径小、结构松散脆弱、有效质量密度低、沉速慢,但表征絮体分形特性的分维值较高.②CP作絮凝剂能显著改善低温低浊水的絮凝效果与过滤性能,但混合强度需增大,宜用粗砂滤料过滤;③单独用CP作絮凝剂时,宜投加分子量较低的弱阳性聚合物或投加低剂量较高分子量的强阳性聚合物;CP用作助凝剂时,能显著减少主混凝剂用量,但宜投加强阳性聚合物或增加弱阳性聚合物的剂量.④CP兼备电性中和与吸附架桥絮凝作用,能形成粒径较大、吸附性能与过滤性能良好的网状絮体构型,其有效质量密度高,产生的污泥量少,污泥沉降速度快,脱水效果好,但分维值低.⑤各种水处理药剂的处理效果为:Al2(SO4)3(或PAC) CP＞CP＞PAC＞Al2(SO4)3,这种差别由絮体的形态学特性与构型特征各异引起.     

滇池流域磷循环系统的物质流分析

研究营养元素在社会经济系统中的物质代谢结构及特征,是有效预防和控制地表水体富营养化的关键性分析技术之一.以滇池流域磷循环为研究案例,运用物质流分析方法建立了2000年流域静态物质流模型(PHOSFAD),并在此基础上识别出流域磷循环系统的总体结构特征,以及资源开采、化工生产、农业种植、畜禽养殖、居民生活等生产和消费部门的物质利用效率特征,为科学防治滇池水体富营养化提供了重要决策依据和参考.     

原子吸收法直接测量土壤中的汞含量

实验采用DMA-80自动测汞仪直接测定土壤中的汞含量,详细介绍了土壤样品中汞分析条件的选择,方法在0．4—400ng范围内,线性良好,其检出限为0．2ug／kg。     

基于微电荷法的烟气颗粒物浓度检测技术及其应用

目前针对烟气颗粒物浓度的检测方法较多,但均存在不足。详细分析了基于微电荷法的烟气颗粒物浓度检测技术的基本原理和关键的技术难点,介绍了由于微处理器、数字电子技术和材料科学等的飞速发展带来的技术革新,技术的进步为其应用开拓了更为广泛的应用领域并逐步在工业场合得到推广。     

微絮凝-直接过滤工艺用于东江流域典型印染废水回用的实验研究

以东莞地区某典型印染企业尾水为研究对象,针对东江流域饮用水源河流水质污染现状及纳污河流水质改善目标要求与企业对尾水回用的实际需求,进行了印染废水深度处理回用工艺的适用性研究.通过混凝烧杯实验,选用工业PACl、FeSO4、HPAC 3种药剂,对微絮凝-直接过滤集成工艺用于印染废水尾水深度处理后水质回用的可行性,进行了实...     

The herbicide paraquat induces alterations in the elemental and biochemical composition of non-target microalgal species

Huge quantities of pesticides are dispersed in the environment, affecting non-target organisms. Since paraquat affects the photosynthetic process, the biochemical composition of affected species should be altered. The effect of paraquat on Chlamydomonas moewusii, a freshwater non-target species, was studied. After 48 h of herbicide exposure, growth rate, dry weight, and chlorophyll a and protein content were affected by paraquat concentrations above 0.05 μM. C/N ratio was also affected due to a decrease in nitrogen content in the dry biomass, while the carbon content remained constant for all paraquat concentrations assayed. Enzymes involved in nitrogen assimilation were affected by paraquat, being nitrate reductase activity more sensitive to paraquat than nitrite reductase. Based on the results obtained in the present study, paraquat exerts adverse effects upon a common freshwater green microalga, thus the application of this herbicide for weed control must be carried out very carefully, so that any disturbance affecting algae will have severe repercussions on higher trophic levels and on the elemental biogeochemical cycles.