基于PAGM模型的浇注系统对螺旋桨铸件夹渣率的影响

基于分散相粒子运动模型,考虑夹渣在随流运动过程中动态聚合长大现象,构建了夹渣聚合长大模型(PAGM,Particles Aggregation Growth Model)。采用PAGM对铝合金螺旋桨铸件浇注过程中夹渣的运动轨迹、聚合长大行为及最终位置进行了模拟计算和试验验证。在此基础上研究了浇注系统对铸件夹渣分布及夹渣率的影响。结果表明,浇注系统设计对夹渣运动行为及分布有较大影响,PAGM可有效提升对铸件夹渣分布预测的准确性,为铸件优化设计及失效分析提供参考。     

Synthesis of bio‐based polyurethanes from epoxidized soybean oil and isopropanolamine

Epoxidized soybean oil (ESO) and isopropanolamine were used to synthesize a new polyol mixture for preparation of bio‐based polyurethanes. The chemical synthetic route for reaction of ESO with isopropanolamine was analyzed by ¹H‐NMR. The results suggested that both ester groups and epoxy groups in ESO had reacted with amino group of isopropanolamine through simultaneous ring‐opening and amidation reactions. Epoxy groups in various situations exhibited different reactivity, and the unreacted epoxy groups were further opened by hydrochloric acid. The synthesized polyol mixture had high hydroxyl number of 317.0 mg KOH/g. A series of polyurethanes were prepared by curing the synthesized polyol mixture with 1,6‐diisocyanatohexance along with different amount of 1,3‐propanediol (PDO) as chain extender. Tensile tests showed that yield strengths of the polyurethanes ranged from 2.74 to 27.76 MPa depending on the content of PDO. Differential scanning calorimetry analysis displayed one glass transition temperature in the range of 24.4–28.7°C for all of the polyurethane samples, and one melt peak at high content of PDO. Thermogravimetric analysis showed that thermal degradations of the polyurethanes started at 240–255°C. In consideration of simple preparation process and renewable property of ESO, the bio‐based polyurethane would have wide range of applications. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

某渔业车间火灾后检测鉴定及加固修复对策研究

对威海市某渔业车间火灾后的结构性能进行检测,运用贯入法检测砌筑砂浆的强度损伤情况,采用取芯方式检测混凝土的强度,通过静载试验检验预应力混凝土双T板残余承载力。根据检测结果及分析,综合评定了结构受损情况,并对圈梁、屋面板、墙体等受损部位给出了相应的修复加固措施,为工程事故的加固处理提供依据。     

油田企业经济可承受合理投资规模初探

针对如何考察油田企业投资规模是否合理的问题,探讨了油田企业经济可承受合理投资规模的前提条件、实现保证以及检验途径。     

Preparation and electrochemical properties of poly‐2,5‐dihydroxyaniline/activated carbon composite electrode in organic electrolyte

Poly‐2,5‐dimethoxyaniline coating has been fabricated on active carbon (AC) substrates by cyclic voltammetry (CV) in organic system. The resulted coating is hydrolyzed to produce poly‐2,5‐dihydroxyaniline (PDHA) to enhance the capacitance of the composite electrode. Scanning electron microscope, Fourier transform infrared spectroscopy, X‐ray diffraction, Raman spectra, CV, electrochemical impedance spectroscopy, and galvanostatic charge/discharge test are used to investigate the properties of these electrodes. In organic electrolyte, due to the introduced hydroquinone units, high value of capacitance up to 975 F g^?1 of the PDHA/AC has been obtained at a current density of 0.37 A g^?1 at a potential window of 0–1.5 V. An asymmetric capacitor has been assembled with the PDHA/AC positive and pure AC negative electrodes, which is able to obtain a specific energy as high as 178 Whkg^?1 in the potential range of 0–2.0 V at a current density of 0.93 A g^?1. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

原子吸收法测定代森锌和福美锌

文章建立了代森锌和福美锌含量的原子吸收测定方法。代森锌和福美锌在酸性热溶液中分解,通过非吸收线法确定不存在非特征衰减,在锌元素共振吸收波长213.9 nm下测定样品溶液中锌元素含量,用锌元素换算得到代森锌和福美锌含量。实验结果表明,该方法的测定代森锌标准偏差为0.0017,变异系数为1.49%,平均回收率为99.3%,...     

Facile non-aqueous synthesis of high color rendering C@ZrSiO4 encapsulation pigment with carbon-containing precursors as in-situ carbon sources

A zircon encapsulated carbon black (C@ZrSiO₄) pigment with high color rendering was synthesized via facile non-aqueous acetic acid (NAA) assisted sol-gel method using carbon-containing precursors (zirconium n-propoxide and tetraethoxysilane) as in-situ carbon sources. The effects of the NAA amount and heat treatment temperature on the structure and properties of the synthesized encapsulation pigments were characterized by XRD, FT-IR, FE-SEM, HR-TEM, EDS, XPS and CIELAB colorimeter, respectively. The results showed that the C@ZrSiO₄ encapsulated pigments heating at 1000?°C for 2?h in N₂ atmosphere presented a dense and stable encapsulation structure as well as deep dark hue when the mole ratio of NAA and Zr (NAA/Zr) was 3:1, and the chromaticity values were L*?= 21.20, a*?= 0.56, b*?= ?0.09 and C_ab =?0.57, respectively, which were contributed to the high homogeneity at atomic level in ZrSiO₄ sol and the tight bonding between carbon black carbonized by carbon containing group and zircon matrix. In addition, the pigment exhibited excellent chemical stability, thermal stability and tinctorial strength when it was used in water, acid, alkali, organic solvents and ceramic glaze. Especially, these pigments improved the utilization of raw materials and avoided the use of heavy metals or transition metals as coloring agent, which was an environment-friendly black ceramic pigment.     

蒙元文化博物馆

简要介绍了蒙元文化博物馆的规划、建筑设计思路和理念。蒙元文化博物馆的的总体设计着重于建造一个符合草原景观特点和能够反映蒙元文化建筑特点的建筑。