Catalytic reforming of tar using corncob char and char-supported potassium catalysts

This work aims to investigate the importance of biomass char and the metal oxides in the ash in tar cracking during the volatile–char interactions. Experiments were carried out in a two-stage fixed reactor, and corncob, one typical agricultural biomass rich in potassium, was chosen as raw material. Results showed that char and char-supported potassium catalysts have good activity for tar elimination due to the good absorbability of char and catalytic property of potassium. In particular, tar conversion efficiency can reach 95.8% by using 1.5 K-char catalyst at 700 °C. The reforming reactions can be significantly enhanced during the volatile–char interactions in the presence of char and char-supported potassium catalysts. As a result, the syngas yield increased significantly with increasing temperature and supported K⁺, particularly the combustible gases including H₂, CO and CH₄. Physical and chemical structure of char changed due to reforming reactions related to the carbon, while the content of potassium was almost unchanged.     

Color ghost imaging via sparsity constraint and non-local self-similarity

We propose a color ghost imaging approach where the object is illuminated by three-color non-orthogonal random patterns. The object’s reflection/transmission information is received by only one single-pixel detector, and both the sparsity constraint and non-local self-similarity of the object are utilized in the image reconstruction process. Numerical simulation results demonstrate that the imaging quality can be obviously enhanced by ghost imaging via sparsity constraint and nonlocal self-similarity(GISCNL), compared with the reconstruction methods where only the object’s sparsity is used. Factors affecting the quality of GISCNL, such as the measurement number and the detection signal-to-noise ratio, are also studied.     

流动注射氢化物发生原子荧光法测定中药中的微量As、Hg

建立了一套流动注射－氢化物发生－原子荧光测定中药样品中微量Ａｓ、Ｈｇ的方法，研究了酸度、ＮａＢＨ４浓度、载气流速等条件对检出限的影响．在优化的工作条件下，对砷、汞的检出限分别为０．１ｎｇ／ｍＬ和０．０２ｎｇ／ｍＬ．本法具有操作简便、快速，灵敏度高等优点，可用于中药样品中微量Ａｓ、Ｈｇ的测定．     

壬基酚甜菜碱两性表面活性剂的合成和抗温耐盐性能

以壬基酚、环氧氯丙烷、二甲胺和3-氯-2-羟基丙磺酸钠为原料, 在催化剂的作用下经醚化、叔胺化、季铵化, 合成了壬基酚甜菜碱两性表面活性剂(NSZ), 并确定了最佳的反应条件。 壬基酚氯醇醚的最佳合成条件:物料比n(壬基酚):n(环氧氯丙烷)=1:4, 催化剂四丁基溴化铵用量为壬基酚用量的4%(摩尔比), 反应时间为4 h, 反应温度为95 ℃。 壬基酚叔胺的最佳合成条件:物料比为n(壬基酚氯醇醚):n(二甲胺):n(氢氧化钠)=1:2.5:1.1, 反应时间为4 h, 反应温度为60 ℃。 NSZ的最佳合成条件:以异丙醇/水为溶剂且其体积比为2:1, 反应温度为85 ℃, 反应时间24 h, n(3-氯-2羟基丙磺酸钠):n(壬基酚叔胺)=1.2:1, 反应体系的pH值为8~9。 通过测定NSZ在高温高矿化度条件下的界面性能、乳化性能和热稳定性, 证明了NSZ具有良好的耐温抗盐性能。     

茶水中多元素化学形态的同时分析

本工作建立了分离和测定茶水中Ａｌ、Ｍｎ、Ｍｇ、Ｚｎ及Ｆｅ的化学形态的方法。茶水中金属元素的各化学形态经高效液相色谱分离后，用电感耦合等离子体原子发射光谱在线检测Ｍｎ、Ｍｇ、Ｚｎ、Ｆｅ，用石墨炉原子吸收非在线测定Ａｌ。结果表明，茶水中Ａｌ等金属元素一部分以无机离子形式存在，另一部分则以有机络合物形式存在。实验发现当以Ａｌ、Ｍｎ、Ｍｇ、Ｚｎ、Ｆｅ儿茶素络合物作为标准物质时，ＨＰＬＣ的保留时间恰好与茶水     

小型化加速器用X波段多注速调管

传统的医疗及工业用直线加速器系统中一直使用磁控管作为功率源,特别是一些紧凑型加速器系统中,磁控管因为其尺寸与重量的优势成为唯一选择。通过利用多注速调管的低电压、尺寸小、重量轻的特点,研制成功功率量级远超磁控管同时尺寸重量接近的多注速调管,这将会为医疗及工业领域带来新的应用模式与产品类型。为满足医疗及工业辐照用中低能电子直线加速器的需求,近年来已研制出各类型高峰值功率速调管,在癌症治疗、无损检测、工业辐照等方面获得了广泛应用。介绍了一种小型化加速器用X波段多注速调管,其具有工作电压低、效率高、体积小、重量轻等特点,可应用于中低能放疗设备及小型化无损检测整机的加速器系统中。本管研制中重点解决了一体化线包聚焦、集成式冷却等技术,样管尺寸为ϕ200 mm×400 mm,重量为25 kg。三支样管测试已可稳定获得峰值输出功率3 MW。     

一维有序聚苯胺纳米阵列的制备及电化学储能性能

以导电玻璃FTO为基底电极, 在硫酸溶液中, 分别研究了苯胺单体浓度和恒定电流大小对聚苯胺(PANI)形貌的影响; 同时恒定苯胺单体的浓度和工作电流, 探究了不同类型的质子酸对PANI阵列形貌的影响. 结果表明, 采用恒电流方法可以制备出一维有序PANI纳米线阵列, 而且当苯胺的浓度为0.1 mol/L, 恒电流法的工作电流密度为0.03 mA/cm²时, 所制备的PANI纳米线阵列形貌最佳; 当用HCl, HNO₃和对甲苯磺酸(p-TSA)作为合成PANI的支持液时, 得到树桩状的PANI 纳米结构, 不能得到均一的纳米线阵列结构. 电化学性能测试结果表明, 制备的最佳形貌PANI纳米线阵列的比电容值可达560 F/g; 循环1000周后电容损失率为11%.     

High‐Entropy Layered Oxide Cathodes for Sodium‐Ion Batteries

Material innovation on high‐performance Na‐ion cathodes and the corresponding understanding of structural chemistry still remain a challenge. Herein, we report a new concept of high‐entropy strategy to design layered oxide cathodes for Na‐ion batteries. An example of layered O3‐type NaNi_0.12Cu_0.12Mg_0.12Fe_0.15Co_0.15Mn_0.1Ti_0.1Sn_0.1Sb_0.04O₂ has been demonstrated, which exhibits the longer cycling stability (ca. 83 % of capacity retention after 500 cycles) and the outstanding rate capability (ca. 80 % of capacity retention at the rate of 5.0 C). A highly reversible phase‐transition behavior between O3 and P3 structures occurs during the charge‐discharge process, and importantly, this behavior is delayed with more than 60 % of the total capacity being stored in O3‐type region. Possible mechanism can be attributed to the multiple transition‐metal components in this high‐entropy material which can accommodate the changes of local interactions during Na⁺ (de)intercalation. This strategy opens new insights into the development of advanced cathode materials.     

On heat transfer and flow characteristics of jets impinging onto a concave surface with varying jet arrangements

A new electrospinning process was developed for preparing TiO₂ nanofibers using a water-soluble Ti-precursor, [bis(kappa1O-hydroxo)(bis(kappa2O,O′-lactato)titanium(IV)] commonly known as titanium(IV) bis (ammonium lactato) dihydroxide (TiBALDH). The importance of the study is justified by the fact that Ti-precursors used for electrospinning, sol–gel, hydrothermal and other fiber synthesis processes are mostly non-water soluble. Accordingly, anatase TiO₂ nanofibers of diameter between 20 and 140 nm were synthesized by electrospinning and annealing. Polyvinylpyrrolidone (PVP) and different concentrations of TiBALDH were dissolved in a mixture of water, ethyl alcohol and acetic acid to optimize the electrospinning conditions. The thermal decomposition and fragmentation of PVP, TiBALDH and the fibers with 50% mass fraction of TiBALDH were studied by TGA-MS measurements. The fibers were then annealed at 1 °C min^?1 until 600 °C. The TiO₂ fibers were characterized using SEM–EDX, FTIR and XRD