煤制乙二醇副产物杂醇油回收工艺的模拟研究

利用Aspen Plus流程模拟软件对煤制乙二醇副产物杂醇油回收工艺进行模拟研究,选用非随机双液体（NRTL）热力学方法对煤制乙二醇副产物杂醇油回收工艺进行了模拟计算,应用灵敏度分析工具分别对甲醇回收塔（T-101）、萃取精馏塔（T-102）、乙二醇回收塔（T-103）的理论板数、进料位置、回流比等参数进行了优化,优化后的参数为：甲醇回收塔塔板数50,回流比3.6,进料位置第20块塔板;萃取精馏塔的塔板数25,回流比2.3,进料位置第14块塔板;乙二醇回收塔的塔板数9,回流比0.24,进料位置第7块塔板。经济效益分析表明,年处理2.4万t杂醇油可为企业带来每年约894.87万元的收益,显著提高企业的市场竞争力。     

Preparation of superhydrophobic silver nano coatings with feather-like structures by electroless galvanic deposition

Superhydrophobic silver nanocoatings with feather-like morphology are fabricated on copper substrates by electroless galvanic deposition. The coating exhibit superhydrophobicity with a contact angle of 156.4° and glide angle of 4° without any further surface modification. Scanning electron microscope (SEM), X-ray diffraction (XRD) and contact angle measurements are used to investigate the morphology, crystal structure and superhydrophobicity, respectively, of the coatings. The coatings exhibit high thermal stability; their water contact angle did not change when the coatings were heated to 200°C for 2 h. The mechanism of superhydrophobicity of the silver coating is discussed based on the work of Amirfazli, Wenzel and Cassie.     

Enolate chelating N-heterocyclic carbene complexes of Fe(II): Synthesis, structure and their catalytic activity for ring-opening polymerization of ε-caprolactone

The reaction of anhydrous FeBr2 with two equivalents of anionic N-heterocyclic carbene (NaL1 and NaL2), which are generated in situ by the reaction of the corresponding salt [4-R-C6H4COCH2{CH- (NCHCHNiPr)}Br] (R = OCH3, H2L1Br, 1; R = F, H2L2Br, 2) with two equivalents of NaN(SiMe3)2, affords bis-ligand Fe(II) complexes of L12Fe (3) and L22Fe (4) in high yield, respectively. Attempt to synthesize mono-ligand Fe(II) bromide by the 1:1 molar ratio of NaL to FeBr2 is unsuccessful, and the same com- plexes of 3 and 4 were obtained. Both 3 and 4 have been depicted by elemental analysis and X-ray structure determination. Preliminary studies show that both 3 and 4 can be used as single-component catalyst for the ring-opening polymerization of ε-caprolactone, and the catalytic activity of 3 is higher than that of 4.     

Nonlinear optical properties of graphene-based materials

Graphene,a two-dimensional carbon atom sheet,has attracted tremendous attention and research interest because of its exceptional physical properties.Graphene has high mobility and optical transparency,in addition to flexibility,robustness and environmental stability.The main focus so far has been on fundamental physics and electronic devices.However,because the linear dispersion of the Dirac electrons enables ultrawideband tunability,we believe its true potential lies in photonics and optoelectronics.In this review,we introduce recent advances in the nonlinear optical properties of graphene-based materials.The rise of graphene in nonlinear optics is shown by several recent results,ranging from saturable absorbers and the four-wave mixing effect to giant two-photon absorption,reverse saturable absorption and optical limiting.The relevant forms of the graphene-based materials include pure graphene,graphene oxide and graphene hybrids.     

激光间接驱动聚变内爆流体不稳定性研究

激光间接驱动惯性约束聚变(ICF)内爆过程多层靶球各个界面发生的流体力学不稳定性是影响聚变点火成功的关键因素.为深入了解内爆过程这样不稳定性的发生、发展和它对聚变点火的影响,研制成了研究内爆多介质辐射流体力学过程的高精度二维(局部三维)大型LARED-S程序,并在长期研究实践中不断发展和改善.该程序模拟结果与不稳定性线性和弱非线性解析结果,以及非线性激波管实验结果都很好符合.应用这一程序,进行了大量数值模拟研究,结合理论模型分析,获得了大量流体力学不稳定性发展和演化的重要结果和物理规律认识.获得了具有不同密度、速度、磁场分布的Rayleigh-Taylor(RT)和Kelvin-Helmholtz(KH)不稳定性的线性增长率,以及它们在不可压缩条件下的弱非线性发展的解析解,表明了两者在不同Froude数、密度过渡层厚度、速度剪切层下的竞争关系;通过数值模拟,发现弱预热条件下烧蚀RT不稳定性二次谐波非线性发展导致不稳定增长尖钉(Spike)断裂的重要过程;数值模拟进一步揭露了强预热条件下,烧蚀RT不稳定性非线性发展导致不稳定增长尖钉出现射流状结构,气泡发生加速;还发现强烈的电子热传导使初始单模扰动的KH不稳定性大大削弱,然而却可能使两模扰动非线性发展增大混合尺度.在神光II激光装置上开展了一系列烧蚀RT不稳定性实验.平面靶烧蚀加速飞行轨迹实验结果与LARED-S模拟结果的比较表明腔壁辐射源能流明显小于激光注入孔的辐射能流,且辐射源的非平衡Planckian谱对靶的飞行轨迹和扰动增长有重要影响.实验分别观测到初始小扰动幅度烧蚀RT明显的增长和初始大扰动幅度尖钉变窄和气泡变宽的清晰物理图像.通过提高空间分辨率,实验获得了二次和三次谐波的增长数据.模拟结果与实验结果相符合.神光II激光装置上开展的流体不稳定性实验考核了LARED-S程序的一维和二维计算.在上述理论和实验认识基础上,进行了ICF聚变点火靶物理研究.主要研究靶丸内外表面单球谐模扰动、辐射不对称性、内爆热斑界面不稳定性、黑腔辐射M带以及氘氚(DT)主燃料低阶模面密度不均匀性等物理过程对ICF内爆流体不稳定性的影响.对于ICF间接驱动初始烧蚀层外表面和DT冰内表面的单模粗糙度扰动和辐射驱动不对称性扰动,获得了不稳定性增长规律,提高了热斑界面扰动增长对点火影响和黑腔M带X射线能谱对内爆稳定性影响的物理认识.模拟研究表明DT主燃料面密度不均匀严重影响内爆动能转换为燃料内能的效率和内爆惯性约束时间.研究结果不仅对研究ICF内爆点火有重要参考价值,而且对发生在天体和自然界中流体不稳定性的物理本质理解会有帮助.     

PdFe(110)电子结构及电催化性能的理论研究

利用密度泛函理论(DFT)的平面波赝势方法计算了不同注入电荷和掺杂Fe原子比例的PdxFey(110)表面原子结构和电子结构特性。结果表明,Fe原子比例对表面褶皱s影响较小,注入电荷数量对表面褶皱s影响很大;Fe原子掺杂使Pd的4d10轨道电子向低能级轨道移动,增加了d空穴。布居分析表明电极的表层电荷分布比金属态表面增多;Fe掺杂的表层电荷分布比不掺杂电极表面增多。电子结构分析表明,电极表面的s、p、d轨道电子和总电子均比金属态表面减少;Fe掺杂后,Pd和Fe的表面原子趋向于杂化构型,Pd表层原子向Fe表层原子发生电子转移,增加表面反应活性,有利于电催化反应。     

Flaking and degradation of polyurethane coatings after 2 years of outdoor exposure in Lhasa

The exposure of a high gloss polyurethane aircraft topcoat system with polyurethane intermediate coating and epoxy primer to strong ultraviolet radiation in Lhasa, Tibet was studied by using scanning electron microscopy (SEM), atomic force microscopy (AFM), attenuated total reflectance Fourier-transform infrared (ATR-FTIR), and X-ray photoelectron spectroscopy (XPS). Micro-flakes were found to form on the topcoat surface after exposure and the size and quantity of the flakes increased with the increase of the exposure time. The magnitude of micro-bulges and the topcoat roughness increased after a long exposure to sunlight. Flakes and micro-bulges resulted in the loss of the topcoat gloss. ATR-FTIR and XPS analysis indicated that chain scissions of the polyurea C==O group and the polyurethane C―O―C and CO―NH groups occurred, and the degradation products of NH and carbonyl groups formed due to the exposure. The breaking of the chemical structure of the polyurethane resulted in a decrease in its elasticity and in the adhesion of the flakes to its surface.     

Partial melting of the dry mafic continental crust: Implications for petrogenesis of C-type adakites

C-type adakites have been commonly considered as a result of partial melting of the mafic lower continental crust (LCC) at high pressure, as supported by high P-T experiments on hydrous basalts. However, because the mafic eclogitic LCC is generally dry, experiments on water-bearing materials cannot be used to constrain the melting processes of the dry mafic LCC. Due to the lack of systematic melting experimental studies on dry mafic rocks at crustal pressures, MELTs software was applied to simulating melting of the dry mafic LCC at 1–2 GPa. Comparison of model results with experimental data indicates that, when melting degree is greater than 20%, melts from the dry mafic LCC at 1–3 GPa cannot produce the C-type adakitic melt with high SiO₂ content (~70%). Although the limited experimental results about dry mafic rock melting at 1–2 GPa in the literature suggest that low degree melting (<10%) cannot produce silicic melt either, MELTs software simulation shows that, at pressure >1.8 GPa, low-degree melting can produce dacitic melt with high K₂O/Na₂O (~1) if SiO₂ content of the melt is controlled by residual garnet. Furthermore, the simulation also suggests that, if pressure is <1.8 GPa, abundant plagioclase (plg) in the residual phase may decrease SiO₂ content in the melt to below 62%, much lower than that of the C-type adakites observed in eastern China. Given the high P-T conditions required to produce melts with high SiO₂ and extremely low HREE contents, such melts could easily be contaminated by other crustal-derived melts, implying that the C-type adakites from eclogite melting could be less commonly observed in the outcrops than previously believed. Besides the interpretation that garnet fractionates Sr, Y, and REE, high Sr/Y and La/Yb could be also produced by multiple ways such as inheriting the source features and fractional crystallizing clinopyroxene (cpx). Therefore, it may be problematic using high Sr/Y and La/Yb as criteria to identify adakites. Instead, REE patterns with strong depletion of HREE relative to MREE (e.g. high Gd/Yb) could be a better parameter to identify the role of garnet and thus adakites. Finally, geochemical models based on MELTs simulation indicate that Eu anomaly cannot be simply used to constrain the role of plg in magmatism because Eu anomaly in the melt is a function of source characteristics, oxygen fugacity (fO₂) of magmatic systems, and plg/mafic minerals mode ratio.     

黄斑大蚊的喜湿性及其翅膀、腿表面的超疏水性

黄斑大蚊的翅膀、腿表面有很好的超疏水性, 水滴在其表面的静态接触角分别为150°,155°, 滚动角接近5°, 通过扫描电子显微镜观察发现, 在黄斑大蚊的翅膀、腿表面分布有大量呈规则排列的微纳米级复合凹槽、乳突, 复合结构及其表面的低表面能物质的协同作用使其表面具有良好的超疏水性, 这一特性使黄斑大蚊能在潮湿的环境中自由生存. 本文用 Cassie 理论对这种超疏水性进行了理论分析.     

电镀法制备Ru/Ni-foam催化剂及其催化硼氢化钠水解产氢性能研究

氢能作为一种高效、环保的可再生能源，具有广阔的应用前景，通过催化剂使硼氢化钠（NaBH₄）水解产氢是一种安全、高效和实用性强的化学产氢技术。以电化学沉积方法制备的Ru/Ni-foam（Ru/NF）作为硼氢化钠水解制氢的催化剂，研究了不同的反应温度、不同的硼氢化钠浓度、不同的反应pH以及催化剂稳定性4种因素对该催化反应的影响规律。结果表明：用电镀方法得到的Ru/NF催化剂在10%（质量分数）NaOH、15% NaBH₄、室温条件下，可以达到1894 mL/（min·g）的产氢速率，具有很好的实际应用前景。