丁二烯缓冲罐自聚物的生成原因及防范措施

分析了ABS树脂生产装置丁二烯缓冲罐中丁二烯自聚物的生成原因,提出了预防措施,避免丁二烯自聚物的生成,保证装置的安全平稳运行。     

寒冷地区亚麻废水处理工艺的对比分析

亚麻废水是一种较难降解的废水,采用气浮-完全推流曝气工艺和UASB法处理亚麻加工厂废水,从能耗、工艺特点、运行管理上进行对比。结果表明,采用气浮-完全推流曝气工艺在处理此类废水中可收到良好成效,且废水处理成本为0.6-0.7元/m3。     

Copulatory plugs do not assure high first male fertilisation success: sperm displacement in a lizard

Sperm competition selects for opposing male defensive and offensive reproductive traits, and its outcome may be determined by the effectiveness to which one trait has evolved to out-compete the other. We tested the effectiveness of a first male plug physical interference with a second male insemination (defence) vs the effectiveness of plug and associated sperm displacement by a second male (offence) on the outcome of sperm competition in Iberian rock lizards. We conducted a double mating experiment where we compared the proportion of eggs per clutch fertilised by the same second males (against the same first males) when they copulated with females 30 min (first male plug adhered firmly inside the female cloaca) and 4 h (first male plug loosely adhered or shed from the female cloaca) after first males. We found that second males fertilised the majority of the eggs per clutch in the 30-min treatment, whereas fertilisations were equally shared between the two males in the 4-h treatment. These results show that plugs have little defensive effectiveness, and thus, do not assure high first male fertilisation success. Instead, sperm displacement appears to be associated with plug displacement. That is, because sperm embedded in first male plugs, and displaced from competition for fertilisations by second males, is expected to increase in number with decreasing time allowed for female sperm transport, second males thus enjoy higher fertilisation success. This study shows that offensive plug displacement out-competes plug defensive role in Iberian rock lizards. Moreover, it reveals sperm displacement as a novel sperm competition mechanism in reptiles.     

注水泥塞清洁生产工艺研究与现场应用

在油田井下作业过程中,常对油井的高含水层或报废井实施封堵,这种传统的施工工艺存在一些不足之处。引入清洁生产理念,提出了用钢丝绳将水泥浆送入井筒中预定位置的施工工艺,即无管柱注水泥塞工艺。该工艺不需要水泥车等特种车辆的配合,不会发生井下开关操作失误造成的事故,比传统注灰工艺节约作业周期3/4以上。另外,该工艺从源头上实施了清洁生产措施,操作简单,经济效益较高,在油田修井作业系统有推广价值。     

某型飞机典型电连接器接插件插拔特性和接触电阻仿真研究

目的仿真分析电连接器的插拔特性和接触电阻的变化规律。方法以海军某型飞机典型电连接器接插件为研究对象,采用ANSYS Workbench静力学模块,对电连接器接插件进行插拔特性分析,采用COMSOL对接触电阻进行仿真。结果开始接触与插针圆形倒角完全进入簧片收口端倒角的中间阶段,插入力达到峰值。插针圆形倒角完全插入插孔簧片倒角,簧片变形量达到最大。最大应力位于簧片根部截面内侧开槽处。接触电阻随接触压力的增大而减小,随表面粗糙高度的增大而增大,随粗糙斜率的增大而减小。结论插拔力、接触压力和形变量在插拔过程中的变化规律由接插件的材料和结构决定,接触压力和表面粗糙度的变化对接触电阻产生了显著的规律性影响。     

低能耗污水处理技术的应用

以蚌埠市第三污水处理厂为例,详细介绍工程中所应用的一体化技术、低溶氧技术、同时硝化/反硝化技术、微孔软管曝气技术、新型推流技术等低能耗污水处理技术,并从反应机理、处理效果、节能效果等方面加以分析和比较,为相关技术人员选择污水处理工艺提供了新的思路。     

宁海发电厂脱硫除雾器运行优化及防堵措施

分析了国华宁海发电厂600MW机组WFGD系统除雾器的应用环境及结构原理，提出了运行过程中除雾器优化方式以及防堵塞措施，为其他火电厂湿法脱硫系统解决同类问题提供参考。     

Signal Recognition and Hearing Protectors With Normal and Impaired Hearing

Recognition of acoustic signals when perception is subject to interference from noise has already been extensively studied. In this study the influence of hearing protectors (HP) (plugs, muffs) and hearing loss on signal recognition is examined. Different spectrums and levels of the noise are also included. The test results are shown as the masked threshold for the signals heard and identified. In the case of normally hearing subjects a frequency-independent HP (plug) improves hearing performance, while frequency-dependent HP (muffs) tends to worsen it, especially with low-frequency noise. Hearing losses even worsen hearing performance when plugs are worn. Design suggestions are made to optimise signal recognition. Minimum signal-to-noise ratio and the use of HP are discussed.     

Optimization of esterification of fatty acid rubber seed oil for methyl ester synthesis in a plug flow reactor

To date, non-food vegetable oil has been considered as the primary source for biodiesel production. Rubber seed oil has high acid value (34 mgKOH/g) and can be used for biodiesel synthesis. The purpose of this study was to investigate esterification of fatty acid, which derived from rubber seed oil, in a plug flow reactor system at high temperature and low methanol consumption. Response surface methodology was applied for design experiment and optimization of esterification reaction. Temperature, methanol consumption, and sulfuric acid were chosen as variables to examine their influence in a conversion to methyl ester. At 140°C, at 5:1 methanol to fatty acid ratio (by mole), H₂SO₄ 1.5 (%v/w), and space time 20 min, the conversion to methyl ester attained 98.2%. Fourier transform infrared spectroscopy (FTIR) and gas chromatography-Mass spectrometry (GC-MS) were used for analysis and to confirm the formation of methyl ester. Methyl ester was characterized for biodiesel fuel properties in accordance to ASTM standard.     

A MIXING MODEL FOR A SEPARATED MECHANICAL AERATION SYSTEM1

ABSTRACT: An input-output method, using a network of ideal continuous stirred-tank and plug-flow tublar reactors, is adopted to analyze residence time distribution data for a separated mechanical aeration system. The usefulness of this modeling concept is enhanced by its simplicity, especially in the presence of a first-order reaction. This facilitates use of the model format for wastewater quality prediction. Moreover, first-order rate constants can also be estimated from the model, if conversions due to the reaction rate are available.