应用热力系统流网模型分析高压加热器泄漏后热力系统流网的变化

要分析火电机组高压加热器泄漏后,热力系统的变化情况,必须首先知道热力系统流体网络内工质压力和质量流量的变化情况。为了获得以上数据,应用流体网络理论建立了某机组热力系统流网模型,经验证建模方法可行。应用该建模方法,建立了3号高压加热器泄漏后的热力系统流网模型。通过模型求解,得到了3号高压加热器泄漏后工质压力和质量流量分布情况,分析了高压加热器泄漏后,热力系统流体网络的变化。     

Micro-bore titanium housed polymer monoliths for reversed-phase liquid chromatography of small molecules

A new method for the fixation of polymethacrylate monoliths within titanium tubing of up to 0.8 mm I.D. for use as a chromatographic column under elevated temperatures and pressures is described. The preparation of butyl methacrylate–ethylene dimethacrylate-based monolithic stationary phases with desired porous structures was achieved within titanium tubing with pre-oxidised internal walls. The oxidised titanium surface was subsequently silanised with 3-trimethoxysilylpropyl methacrylate resulting in tight bonding of butyl methacrylate porous monolith to the internal walls, providing stationary phase stability at column temperatures up to 110 °C and at operating column pressure drops of >28 MPa. The titanium housed monoliths exhibited a uniform and dense porous structure, which provided peak efficiencies of up to 59,000 theoretical plates per meter when evaluated for the separation of small molecules in reversed-phase mode, under optimal conditions (achieved at 15 μL/min and temperature of 110 °C for naphthalene with a retention factor, k = 0.58). The developed column was applied to the reversed-phase isocratic separation of a text mixture of pesticides.     

坦克测压取样管路系统动态特性分析及信号的修正

针对坦克动力舱排风口气压测量问题,研究了测压取样管道内的空气柱谐振效应对测量的影响,及在脉动气压测量中的校准技术。利用声学换能器为标准气压激励源,构建了测压管道动态特性测试系统。通过扫频方式研究了四种倒L结构取样管道在多种气压幅度激励条件下的传输特性;并且设计了频域滤波器对风压畸变信号进行修。实验结果表明:取样管道系统属于线性系统。实测风压的强脉动特征主要受管道频响特性的影响。经过频域滤波之后风压畸变信号的脉动特性明显减弱。     

阳离子表面活性剂提高低渗透油藏注水效率机理

针对长庆油田低渗透油藏注水困难的问题,采用可见光分光光度计和微电泳仪研究了一种水溶性双阳离子表面活性剂在岩石颗粒表面的吸附特性和对岩石颗粒表面电性的影响规律,选用长庆油田长6地层的岩心,评价了该处理剂的抑制黏土膨胀效果及降压增注能力。结果表明,表面活性剂在岩心颗粒表面的吸附等温线遵循Langmuir吸附规律,与岩心颗粒之间的静电引力较大。吸附后,使岩石表面电势减弱,减弱了黏土的膨胀,对黏土颗粒的运移具有一定的抑制作用,因而能够降低注入水对岩心渗透性的伤害程度,明显提高低渗透油藏注水效率。     

低气压对水体表面张力影响研究

表面张力是液体接触气体时的基本特性。本文设计了低气压下表面张力系数测量装置,研究了气压降低对水体表面张力系数的影响,提出了低气压下表面张力系数计算公式。研究表明,相同水体温度下,气压与水体表面张力系数间呈良好的线性关系,气压越低,表面张力系数越大;气压降低时,气压和温度对水体表面张力的影响是基本独立的。     

New perspective on the determination of flame retardants in sewage sludge by using ultrahigh pressure liquid chromatography–tandem mass spectrometry with different ion sources

Analysis of 11 polybrominated diphenyl ethers (PBDEs), tetrabromobisphenol A bis 2,3-dibromopropylether (TBBPA-bis), tetrachlorobisphenol A (TCBPA), tetrabromobisphenol A (TBBPA) and hexabromocyclododecanes (HBCDs) was optimized by ultrahigh pressure liquid chromatography/tandem mass spectrometry (UPLC–MS/MS) operating in negative ion (NI) mode. Electrospray ionization (ESI), atmospheric pressure photoionization (APPI) and atmospheric pressure chemical ionization (APCI) sources were tested and for PBDEs APCI gave higher sensitivity than APPI while for TBBPA-bis APCI and APPI showed similar performance. ESI was the best option for TCBPA, TBBPA and HBCDs. Detection limits were between 20 and 59 fg for the compounds analyzed by ESI, 0.10 and 0.72 pg for PBDEs and 6 pg for TBBPA-bis. The matrix effect of sewage sludge extract was also tested showing negligible ion suppression for APCI and an increase of the background level of all investigated pollutants leading to a worsening of the limits of quantification by a factor between 1.2 and 3.3. The UPLC-APCI/MS/MS method for PBDEs, after pressurized liquid extraction (PLE), was validated by comparison with the concentration values from the NIST 1944 standard reference material. The advantages of the methods include low detection limits, PBDE congeners specificity using selected multiple reaction monitoring (MRM) transitions, and the absence of thermal degradation of higher PBDE congeners, especially BDE-209. The methods were applied for the determination of the above reported flame retardants in sewage sludge in order to get more information about the degradation on PBDEs (in particular BDE-209) during municipal wastewater treatments.     

页岩气双二维水平井极限延伸能力研究

页岩气藏的开发多采用水平井,水平段的延伸能力直接影响到页岩气藏的综合开发效益。双二维水平井具有施工难度小、邻井碰撞风险低、作业费用低等优点。根据长宁页岩气的钻井实际情况,分析了钻机承载能力、钻柱安全系数、地层承压能力及额定泵压等因素对水平井延伸能力的影响,推导了相应计算模型。以长宁已钻页岩气井为基础,计算了不同影响因素随水平段长度的变化。研究表明,双二维水平井的延伸能力主要受地层承压能力和额定泵压影响,钻井施工中应选择合理的钻井液密度和排量,降低水平段岩屑床高度,采取适当的堵漏措施,选择高额定泵压的钻井泵。     

(Fe0.03Ni0.97)8(Si0.79P0.21)3的等温状态方程研究

 采用固态高温烧结反应方法,成功合成出了陨硅镍铁石样品(Fe_0.03Ni_0.97)₈(Si_0.79P_0.21)₃。X射线衍射结果表明,合成样品的结构为R3'c,对应的晶胞参数为a=b=0.663 8(1) nm,c=3.789 2(2) nm,V=1.446 15(6) nm³。在室温下,对样品进行原位高压X射线衍射研究,实验最高压力达到21.3 GPa,随着压力的升高,晶胞体积逐渐减小,但并没有观察到结构相变。利用Birch-Murnaghan状态方程对体积与压力的关系进行拟合,获得常温常压下的体积V₀=1.441 4(24) nm³,体积模量K₀=220(7) GPa。晶轴与压力的关系利用Murnaghan状态方程拟合,获得a轴和c轴的模量分别为K_a=257(9)和K_c=165(4),c轴较a轴容易压缩。     

冲击载荷下土的动态力学性能研究

 利用分离式霍普金森压杆（Split Hopkinson Pressure Bar,SHPB）技术,研究了土体在不同应变率条件下的冲击动态力学性能,发现土体有明显的应变率效应,与静载相比,冲击载荷下土的动强度和动模量均有很大的提高。根据实验曲线的特征,以一根线性弹簧和两个不同松弛时间的Maxwell体并联的粘弹性模型来表达土体的损伤型粘弹性本构模型,两个Maxwell体分别表示土体的低应变率响应和高应变率响应,模型的数值拟合曲线与实测动态本构曲线具有较好的一致性。拟合参数表明,土体对低应变率的响应与混凝土相同,对高应变率的敏感性远远高于混凝土。     

激光辐照环境对金属材料反射特性的影响

 利用积分球绝对测量法,对在20 Pa真空缺氧、1 000 Pa空气,10⁵ Pa空气及1 000 Pa氧气环境下,1 064 nm波长连续激光辐照30CrMnSiA碳钢材料过程中的反射光信号进行了测量,得到了30CrMnSiA碳钢在4种辐照环境下的反射率和温度变化曲线。结果表明：在空气组分辐照环境的低压到10⁵ Pa范围内,材料初始反射率随压力增大而增大;在缺氧和富氧环境的激光辐照过程中,缺氧环境下材料反射率变化缓慢,且变化拐点温度高于富氧环境,富氧环境下材料被加热后的快速氧化反应有利于材料对激光能量的吸收;不同辐照环境（缺氧和富氧）相同材料温度条件下,材料反射率并不相同。