300MW锅炉临炉加热系统改造分析

针对大唐河北发电有限公司马头热电分公司2台300MW锅炉启动时间较长的问题,从锅炉运行、设计两方面分析原因,提出改造锅炉底部加热系统的方案,并说明改造效果及改造效益.     

燃煤电厂新型静电布袋复合除尘器的开发与气流分布试验研究

提出一种新的燃煤电厂静电布袋复合除尘器，分析其技术经济特点，并提出一些需解决的技术闯题。其中静电除尘单元与布袋除尘单元之间的结合形式是一个技术难点，将影响整个除尘系统的效率和布袋的使用寿命。研究开发出一套气流分布试验台，采用一定形式的气流分布板进行冷态试验研究，分析了几个关键截面的流场，掌握了气流分布规律，确定了气流分布板的开孔分布，为进一步进行中试试验和实现工程化奠定了基础。研究表明，采用具有独创性的结合形式后，该新型静电布袋复合除尘器应用于工程后将具有非常大的经济和环保优势。     

火电厂主、辅机及辅助设备顺序控制系统的发展

回顾国内、外火电厂顺序控制系统的发展,特别介绍３５ａ来我国顺序控制系统经历的起步阶段,以程序控制器（ＰＬＣ）为核心硬件的中期阶段和主、辅机顺序控制系统融入分散控制系统（ＤＣＳ阶段、现场总线控制系统（ＦＣＳ）介入阶段,并对由不同形式组成的顺序控制系统的特点进行评价,展望下一世纪该系统的发展趋势。     

300 kt/a P2 O5大型国产化湿法磷酸装置稀酸系统设计

介绍了300kt／aP2O5大型湿法磷酸装置稀酸系统的工艺特点、设备选型、生产情况及主要设备国产化情况,实现了除反应槽搅拌器减速机以外的设备全部国产化,节省了投资,从一年多的运行情况来看,主要工艺指标均达到设计要求。     

冬青树叶表面的红外光谱特征

用红外衰减全反射技术(ATR)研究了各生长期和不同环境中冬青树叶表面的红外光谱特征.当用黑色塑料袋套在冬青枝条上48 h后,树叶表面的水分有所增加,其它成分变化甚微.当用透明塑料袋套在枝条上48 h后,树叶表面酯类物质的特征峰1 730、1 682 cm-1增加,且峰强度相当.当冬青叶片与甲苯气体接触48 h后,叶片反面酯类物质的特征峰(1 730、1 168、1 039 cm-1)有所减少.同样,叶片正面的酯类物质(1 730、1 168、1 039 cm-1)也有所减少.扫描电镜能谱也证实了叶片反面酯类物质确有减少.     

Metabolic Pathways for Observed Impacts of Crop Load on Floral Induction in Apple

The triggers of biennial bearing are thought to coincide with embryonic development in apple and occurs within the first 70 days after full bloom (DAFB). Strong evidence suggests hormonal signals are perceived by vegetative apple spur buds to induce flowering. The hormonal response is typically referred to as the floral induction (FI) phase in bud meristem development. To determine the metabolic pathways activated in FI, young trees of the biennial bearing cultivar ‘Nicoter’ and the less susceptible cultivar ‘Rosy Glow’ were forced into an alternate cropping cycle over five years and an inverse relationship of crop load and return bloom was established. Buds were collected over a four-week duration within 70 DAFB from trees that had maintained a four-year biennial bearing cycle. Metabolomics profiling was undertaken to determine the differentially expressed pathways and key signalling molecules associated with biennial bearing. Marked metabolic differences were observed in trees with high and low crop load treatments. Significant effects were detected in members of the phenylpropanoid pathway comprising hydroxycinnamates, salicylates, salicylic acid biosynthetic pathway intermediates and flavanols. This study identifies plant hormones associated with FI in apples using functional metabolomics analysis.     

长岛海缆和风电场对末端电压的影响与解决方案

风电场实际发电量受来风的影响从零至最大发电量之间变化,使风电场与主网连接点的电压变动率很大。长岛风电场通过110kV海缆与大陆主电网连接,由于电缆的电容电感分布参数加剧了电压的变化。当主网往风电场送电并且输送的无功较小时需要补偿感性无功以补充电缆的充电电容,而风电场往主网送电时在风电场处需补偿容性无功。     

基于需求响应的虚拟电厂多时间尺度优化调度

随着我国不断加快新型电力系统建设,风电、光伏等越来越多的分布式资源大规模并网,但其随机性、波动性及分散性的特点给电力系统带来了多重不确定性。提出了一种考虑价格型需求响应的虚拟电厂多时间尺度优化调度方法,在日内调度模型中引入用户价格型需求响应,对用户负荷进行精准调控;采用基于蒙特卡罗与曼哈顿概率距离的场景生成与削减法处理风光出力、电价不确定性,减少日前日内出力偏差,再结合日前调度构成了多时间尺度优化调度模型,并采用滚动优化得到日内优化调度结果。以湖南某小型虚拟电厂系统进行算例仿真,结果表明,所提多时间尺度优化调度策略能够精确预测风光出力及用户负荷,在有效抑制功率波动的同时保证了系统的经济性。     

The Impact of Plant Phytochemicals on the Gut Microbiota of Humans for a Balanced Life

The gastrointestinal tract of humans is a complex microbial ecosystem known as gut microbiota. The microbiota is involved in several critical physiological processes such as digestion, absorption, and related physiological functions and plays a crucial role in determining the host’s health. The habitual consumption of specific dietary components can impact beyond their nutritional benefits, altering gut microbiota diversity and function and could manipulate health. Phytochemicals are non-nutrient biologically active plant components that can modify the composition of gut microflora through selective stimulation of proliferation or inhibition of certain microbial communities in the intestine. Plants secrete these components, and they accumulate in the cell wall and cell sap compartments (body) for their development and survival. These compounds have low bioavailability and long time-retention in the intestine due to their poor absorption, resulting in beneficial impacts on gut microbiota population. Feeding diets containing phytochemicals to humans and animals may offer a path to improve the gut microbiome resulting in improved performance and/or health and wellbeing. This review discusses the effects of phytochemicals on the modulation of the gut microbiota environment and the resultant benefits to humans; however, the effect of phytochemicals on the gut microbiota of animals is also covered, in brief.