Biosynthetic origin of carbon-based secondary compounds: cause of variable responses of woody plants to fertilization?

Summary. We propose that variation in the responses of carbon-based secondary compounds to fertilization in woody plants has a biosynthetic cause. The synthesis of phenylpropanoids and derived compounds (e.g., condensed tannins) competes directly with the synthesis of proteins, and therefore with plant growth, because of a common precursor, phenylalanine. In contrast, the biosynthesis of terpenoids and of hydrolyzable tannins proceeds presumably without direct competition with protein synthesis. Therefore, accelerated plant growth induced by fertilization may cause a reduction in concentrations of phenylpropanoids but may affect less or not at all the levels of other classes of secondary compounds. A meta-analysis based on fertilization experiments with 35 woody plant species supported the predicted differences fertilizing significantly decreased concentrations of phenylpropanoids but not of terpenoids or hydrolyzable tannins. Received 14 May 1998; accepted 23 June 1998.     

DX—100型离子色谱仪用于冰雪样品中阴,阳离子的测定

本文介绍了ＤＸ－１００型离子色谱仪用于冰雪样品中阴,阳离子的测定,以东北五大连池地区白龙洞和水晶宫为例,介绍了阴,阳离子测定在分析化学物质来源和成冰过程中的重要作用。     

Removal capacity and pathways of phenolic endocrine disruptors in an estuarine wetland of natural reed bed

Phenolic compounds are partly known as endocrine disruptors with various harmful effects including feminization and carcinogenesis at very low concentrations. Consequently, the pathways and removal of these compounds in natural and artificial sewage treatment systems such as wetlands have received wide concern. In this paper, a natural reed bed wetland with an area of 695 ha located in the Liaohe River estuary in Northeast China was employed as a demonstration site to study the retention and removal efficiency of phenolic compounds including 4-nonylphenol (4-NP), bisphenol A (BPA), 4-t-octylphenol (4-t-OP), and 2,4-dichlorophenol (DCP), and to evaluate their purification capacity via water and mass balance analyses during an irrigation period from May 9 to September 8, 2009. The results showed that the phenolic compounds could be retained in the wetland system and removed through various processes. On average, 27.5% of phenolic compounds could be retained by the wetland substrate during the initial three-day irrigation period with a retention capacity order of 4-t-OP > 4-NP > BPA > DCP. During the following 120 d irrigation period, the phenolic compounds could be efficiently removed with an average percentage of 91.6%. It is estimated that 1.76 kg d⁻¹ of phenolic compounds could be removed by the Liaohe River estuarine wetland (∼8 × 10⁴ ha). The reed bed wetland system therefore provides a feasible mitigation option for phenolic pollutants in sewage and wastewater.     

600MW机组湿法脱硫吸收塔溢流原因分析及对策

阐述了火电厂600MW机组石灰石—石膏湿法脱硫系统吸收塔浆液溢流的危害,分析了吸收塔浆液溢流的原因,主要是石膏浆液品质差、氧化风量不合理、浆液循环泵、浆液喷淋的影响,溢流管接口位置布置不合理等。通过适当降低运行液位、合理布置吸收塔溢流管道等措施解决了吸收塔浆液溢流问题,确保脱硫系统稳定运行。     

氨法脱硫工艺物料平衡模型的研究

建立了氨法脱硫工艺的物料衡算模型,描述了物料计算软件的计算框图和开发过程,介绍了计算模型在实际脱硫工程中的应用,表明该模型对工程设计和设备选型具有一定的指导意义。     

秦岭自然保护区群的社会效益计量研究

秦岭自然保护区群在我国生物多样性保护方面发挥了重要作用,学术界一直缺乏其社会效益计量的研究.该研究在界定秦岭自然保护区群社会效益的概念及分析其内涵的基础上,综合运用专家咨询法及文献参考方法,初步建立了秦岭自然保护区群社会效益计量指标体系,包括:社会文明进步、人类健康和社会生产生活改善3种类型11项指标.利用市场价值法、等效替代法等方法,对秦岭自然保护区群保护生物多样性的过程中所产生的社会效益进行了计量及分析.结果表明:秦岭自然保护区群在保护生物多样性的同时,每年产生了相当可观的社会效益,总货币量约11.68亿元人民币,与周边区域密切相关的社会文明进步效益为1.68亿元;人类健康效益为1.62亿元;社会生产生活改善效益为8.37亿元.该研究的社会效益计量指标及计量方法可为秦岭自然保护区群基层工作人员及类似保护区社会效益计量及评价提供参考.     

基于能流图的山东省能源消耗分析

随着工业化和城市化进程的加快,山东省能源消耗量逐渐增大,2008年山东省能源消耗占全国的11.3%.因此研究山东省能源消耗对促进节能减排有重要的意义.能流图可以直观、形象地展示能源流动情况,在国际上得到广泛的应用.能源统计数据是能源分析的基础,但我国的能源统计体系与国外有较大区别.按国际准则的能源供需体系和有关专家的意见,适当调整了山东省能源平衡表.本文的主要目的是绘制山东省2008年能流图,在此基础上分析山东省能源现状和能源利用效率.得到如下结论:①煤炭是山东的主要能源,占一次能源供应的71.84%;②山东省电力以火电为主,火电占总发电量的99.9%;③山东雀2008年能源利用效率约为35.83%;④工业部门能源消耗占终端能源消耗的74.9%.进一步说明能流图不但能够直观、定量地展示能源供应、转换和使用数量的全貌,而且可以揭示各个环节的能源利用效率水平.     

改进抽油机井“功率平衡”测试实现节能降耗

目前在抽油机井管理中普遍采用的平衡标准是"电流平衡",并认定电流平衡度在80%～120%之间时抽油机即为平衡。而真正判断抽油机平衡的标准是"功率平衡",即抽油机运行过程中,下冲程内电机平均功率与上冲程内电机平均功率相等。抽油机功率平衡既能实现节能目的,又能保证抽油机安全运行。从2008年7月开始率先在胜利油田进行抽油机功率平衡技术的试验及推广,2008年共调整抽油机功率平衡118井次,平均单日节电21.4kW.h,平均节电率9.90%,取得了良好的节能效果。