金的三正辛胺棉富集分离氢醌滴定法

论述了三正辛胺棉的制备及其动态吸附金的条件和解脱方法的研究。采用氢醌滴定法进行测定。方法的测定范围为０．５×１０＾－６－－ｘｘ×１０＾－６，方法的相对标准偏差为ＲＳＤ＝１．５％。可用于矿石中的金的野外快速测定。     

采用复合导引头提高防空导弹综合打击能力

从分析现代防空面临的主要威胁入手，指出了现有防空导弹制导方式的局限性，提出采用被动微波相位干涉仪／主动毫米波／红外凝视成像三模复合导引头提高防空导弹的综合打击能力，并对其防空应用加以阐述。     

Synthesis and electroluminescence properties of a novel poly(paraphenylene vinylene)‐based copolymer with tri(ethylene oxide) segments on the backbone

A novel light‐emitting copolymer [tri(ethylene oxide)–poly(paraphenylene vinylene) (TEO–PPV)] containing alternating rigid, conjugated distyrylbenzene [poly(paraphenylene vinylene) model oligomer] as light‐emitting units and flexible tri(ethylene oxide) as ionic conductive units was synthesized. The polymer was characterized with Fourier transform infrared, ¹H‐NMR, ultraviolet–visible spectroscopy, differential scanning calorimetry, and gel permeation chromatography. TEO–PPV has excellent solubility in conventional organic solvents such as tetrahydrofuran, chloroform, benzene, and toluene. The estimated lowest unoccupied molecular orbital, highest occupied molecular orbital, and band gap are 2.35, 5.29, and 2.94 eV, respectively. Single‐layer and double‐layer light‐emitting diodes with indium tin oxide anodes and calcium cathodes were fabricated, and the photoluminescence (PL) and electroluminescence (EL) properties were investigated. The maximum EL emissive peak (475 nm) of the devices is essentially the same as that of PL. Anomalous current–voltage characteristics were observed in both devices. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2195–2200, 2002     

短龄期再生混凝土三轴受压力学性能及其本构关系

为研究短龄期再生混凝土的三轴受压力学性能,以龄期和围压值为变量,设计了14个圆柱体再生混凝土试件进行三轴受压试验,观察其破坏形态,获取应力-应变曲线、峰值应力、峰值应变以及弹性模量等数据.基于试验数据分析了龄期和围压值对再生混凝土三轴受压力学性能的影响规律,建立了短龄期再生混凝土三轴受压的峰值应力、峰值应变和弹性模量的计算公式,并建立了再生混凝土三轴受压状态下的应力-应变本构方程.结果表明:短龄期再生混凝土的峰值应变、弹性模量受龄期影响较大,随着龄期的延长,峰值应变减小,而弹性模量却显著增大;围压值对再生混凝土的峰值应力、峰值应变和弹性模量均有显著影响.采用CEB-FIP(1990)规范中方法计算的再生混凝土三轴抗压强度值与实测值吻合较好.     

MRI/SPECT/Fluorescent Tri‐Modal Probe for Evaluating the Homing and Therapeutic Efficacy of Transplanted Mesenchymal Stem Cells in a Rat Ischemic Stroke Model

Quantitatively tracking engraftment of intracerebrally or intravenously transplanted stem cells and evaluating their concomitant therapeutic efficacy for stroke has been a challenge in the field of stem cell therapy. In this study, first, an MRI/SPECT/fluorescent tri‐modal probe (¹²⁵I‐fSiO4@SPIOs) is synthesized for quantitatively tracking mesenchymal stem cells (MSCs) transplanted intracerebrally or intravenously into stroke rats, and then the therapeutic efficacy of MSCs delivered by both routes and the possible mechanism of the therapy are evaluated. It is demonstrated that ⁽¹²⁵⁾I‐fSiO4@SPIOs have high efficiency for labeling MSCs without affecting their viability, differentiation, and proliferation capacity , and found that 35% of intracerebrally injected MSCs migrate along the corpus callosum to the lesion area, while 90% of intravenously injected MSCs remain trapped in the lung at 14 days after MSC transplantation. However, neurobehavioral outcomes are significantly improved in both transplantation groups, which are accompanied by increases of vascular endothelial growth factor, basic fibroblast growth factor, and tissue inhibitor of metalloproteinases‐3 in blood, lung, and brain tissue (p < 0.05). The study demonstrates that ¹²⁵I‐fSiO4@SPIOs are robust probe for long‐term tracking of MSCs in the treatment of ischemic brain and MSCs delivered via both routes improve neurobehavioral outcomes in ischemic rats.     

阻燃剂赛克三硅酸二溴丙酯的合成及应用研究

以三（2-羟乙基）异氰尿酸酯（赛克）、四氯化硅与2,3-二溴丙醇为原料,合成阻燃剂赛克三硅酸二溴丙酯。探讨了溶剂、反应温度与物质的量之比对产物收率的影响,优化的工艺条件：四氯化硅、2,3-二溴丙醇、赛克与2,3-二溴丙醇的量之比为3∶3∶1∶6.7。四氯化硅先与2,3-二溴丙醇在45℃反应2 h,再加入赛克于90℃反应11 h,最后滴入2,3-二溴丙醇保温90℃反应8 h;产物收率为93.3%。通过FTIR、^1H NMR、差热分析及极限氧指数等表征产物的结构及性能;应用实验表明该产物阻燃效能高,适合作聚氯乙烯（PVC）等材料的阻燃剂。在较佳用量下PVC材料的极限氧指数为25%,具有良好的阻燃性、成炭防滴落性能。     

Studies of aggregation behaviours of cereal β-glucans in dilute aqueous solutions by light scattering: Part I. Structure effects

Cereal β-glucans form aggregates even in dilute aqueous solution. Their aggregation behaviours were studied by static and dynamic light scattering. It was shown that the aggregation of cereal β-glucans in aqueous solution was a very fast dynamic process and the equilibrium of molecular association and dissociation were reached quickly. The concentration dependence of the average apparent diameters of cereal β-glucans suggested that the cluster–cluster aggregation was dominant. The structural features of cereal β-glucans played an important role on their aggregation behaviours. As molecular weight increased, the degree of aggregation decreased due to the lower diffusion rate of large molecules. For the more rigid conformation (lower diffusion rate) of β-glucans with higher tri/tetra ratio, their degrees of aggregation were lower. These results suggested that the aggregation process was diffusion limited.     

Simultaneous production of two types of synthesis gas by steam and tri‐reforming of methane using an integrated thermally coupled reactor: mathematical modeling

In this work, tri‐reforming and steam reforming processes have been coupled thermally together in a reactor for production of two types of synthesis gases. A multitubular reactor with 184 two‐concentric‐tubes has been proposed for coupling reactions of tri‐reforming and steam reforming of methane. Tri‐reforming reactions occur in outer tube side of the two‐concentric‐tube reactor and generate the needed energy for inner tube side, where steam reforming process is taking place. The cocurrent mode is investigated, and the simulation results of steam reforming side of the reactor are compared with corresponding predictions for thermally coupled steam reformer and also conventional fixed‐bed steam reformer reactor operated at the same feed conditions. This reactor produces two types of syngas with different H₂/CO ratios. Results revealed that H₂/CO ratio at the output of steam and tri‐reforming sides reached to 1.1 and 9.2, respectively. In this configuration, steam reforming reaction is proceeded by excess generated heat from tri‐reforming reaction instead of huge fired‐furnace in conventional steam reformer. Elimination of a low performance fired‐furnace and replacing it with a high performance reactor causes a reduction in full consumption with production of a new type of synthesis gas. The reactor performance is analyzed on the basis of methane conversion and hydrogen yield in both sides and is investigated numerically for various inlet temperature and molar flow rate of tri‐reforming side. A mathematical heterogeneous model is used to simulate both sides of the reactor. The optimum operating parameters for tri‐reforming side in thermally coupled tri‐reformer and steam reformer reactor are methane feed rate and temperature equal to 9264.4 kmol h^?1 and 1100 K, respectively. By increasing the feed flow rate of tri‐reforming side from 28,120 to 140,600 kmol h^?1, methane conversion and H₂ yield at the output of steam reforming side enhanced about 63.4% and 55.2%, respectively. Also by increasing the inlet temperature of tri‐reforming side from 900 to 1300 K, CH₄ conversion and H₂ yield at the output of steam reforming side enhanced about 82.5% and 71.5%, respectively. The results showed that methane conversion at the output of steam and tri‐reforming sides reached to 26.5% and 94%, respectively with the feed temperature of 1100 K of tri‐reforming side. Copyright © 2013 John Wiley & Sons, Ltd.     

Selective Removal of Uranium from High‐Level Waste Solution Employing Tri‐n‐Butyl Phosphate as the Extractant

Abstract

Conditions for the selective removal of uranium from high‐level waste solution have been optimized using tri‐n‐butyl phosphate (TBP) as the extractant. Various aqueous soluble reducing agents viz. hydroxylamine nitrate (HAN), hydrazine nitrate (HN), and diethyl hydroxylamine nitrate (DEHAN) as well as n‐dodecane soluble reductant viz. tert‐butyl hydroquinone (TBH) have been evaluated for the separation of U with respect to Pu and Np. The combination of DEHAN and TBH has been found to be most promising for the selective extraction of U from HLW. Extraction data of a few other metal ions expected to be present in high‐level waste solutions viz. Am(III), Eu(III), Zr(IV), Sr(II), and Cs(I) are also obtained.