羟基中环二胺接枝壳聚糖的合成与表征

以具有环氧活性基的壳聚糖与3-羟基-1，5-二氮杂环庚烷或3-羟基1，5-二氮杂环辛烷反应，合成了两种含羟基的氮杂冠醚壳聚糖衍生物，其组成及结构经元素分析，IR，X-射线粉末衍射及^13C NMR等方法确证。     

木材溶液中羟基与异氰酸酯反应的研究

以涂料工业广泛应用的新型助剂二元酸酯 (DBE)为液化试剂 ,盐酸为催化剂 ,将苯甲基化木材溶液化后 ,与不同结构的异氰酸酯反应 .利用FT IR及1 3C NMR分析液化苯甲基木质纤维素与不同结构异氰酸酯得到了聚氨酯树脂 ,证明了木材中羟基可以用来作为聚醚多元醇与异氰酸酯制备聚氨酯材料 .通过准确测量体系中游离的NCO含量 ,从而得出不同结构异氰酸酯与木材溶液中羟基的反应规律 .实验结果表明 ,异氰酸酯的存在大大促进了木材结构中羟基的释放 ,由于不同异氰酸酯的活性不同 ,使得羟基值变化亦不相同 ,其顺序为IPDI>HDI>TDI .为了保证最终的材料性能 ,选择TDI和IPDI作为木材溶液制备聚氨酯树脂的异氰酸酯组份较好     

Mild and efficient Cs2CO3-promoted synthesis of phosphonates

A mild and convenient synthesis for phosphonates using cesium carbonate (Cs₂CO₃), tetrabutylammonium iodide (TBAI) and DMF was developed at room temperature. Numerous dialkyl phosphites were screened using a diverse array of alkyl halides and these reaction conditions were found to be highly efficient producing various phosphonates exclusively in moderate to high yields.     

Reaction mechanism studies on isoquinoline with hydroxyl radical in aqueous solutions

The reaction mechanism between isoquinoline and ·OH radical in aqueous dilute solutions under different conditions was studied by pulse radiolysis. The main characteristic peaks in these transient absorption spectra were attributed and the growth-decay trends of several transient species were investigated. Under neutral or alkaline conditions, the reaction of ·OH radical and isoquinoline produces OH-adducts with respective rate constants of 3.4 × 10⁹ and 6.6 × 10⁹ mol⁻¹ · dm³ · s⁻¹ while under acidic conditions, the isoquinoline was firstly protonated and then ·OH added to the benzene ring and produced protonated isoquinoline OH-adducts with a rate constant of 3.9 × 10⁹ mol⁻¹ · dm³ · s⁻¹. With a better understanding on radiolysis of isoquinoline, this study is of help for its degradation and for environmental protection. __________ Translated from Journal of Fudan University (Natural Science), 2006, 45(6): 774–778 [8BD1;81EA: 590D;65E6;5B66;62A5;(自然科学版)]     

Study on the Intramolecular Hydrogen Bonds of Dibenzofurans, Xanthones and Anthraquinones with One or Two Positions Substituted by Hydroxyls

<正>The thermodynamic properties of dibenzofurans (DFs), xanthones (XTs) and an- thraquinones (AQs) with one and two positions substituted with hydroxyls in the ideal gas state at 298.15 K and 1.013×10~5 pa were calculated at the B3LYP/6-311G~* level using Gaussian 03 program. The isodesmic reactions were designed to calculate the standard free energy of formation (Δ_fG~e). Three types of hydrogen bonds exist in the three kinds of chemicals and their bond energies were ascertained as 7-15, 15-23 and 49-58 kJ·mol~(-1) respectively by comparing the Δ_fG~e values. Electronic density topology analysis was applied to validate the strength of bond.     

Internal radiocesium contamination of adults and children in Fukushima 7 to 20 months after the Fukushima NPP accident as measured by extensive whole-body-counter surveys

The Fukushima Dai-ichi NPP accident contaminated the soil of densely-populated regions in Fukushima Prefecture with radioactive cesium, which poses significant risks of internal and external exposure to the residents. If we apply the knowledge of post-Chernobyl accident studies, internal exposures in excess of a few mSv/y would be expected to be frequent in Fukushima.Extensive whole-body-counter surveys (n = 32,811) carried out at the Hirata Central Hospital between October, 2011 and November, 2012, however show that the internal exposure levels of residents are much lower than estimated. In particular, the first sampling-bias-free assessment of the internal exposure of children in the town of Miharu, Fukushima, shows that the ¹³⁷Cs body burdens of all children (n = 1,383, ages 6–15, covering 95% of children enrolled in town-operated schools) were below the detection limit of 300 Bq/body in the fall of 2012. These results are not conclusive for the prefecture as a whole, but are consistent with results obtained from other municipalities in the prefecture, and with prefectural data.     

Birefringence control by hydrogen bonding on compatible polymer pair composed of hydrogenated ring‐opening polymer and modified polystyrene

A new polymer blend composed of a hydrogenated ring‐opening polymer (HROP) with an ester group and hydroxyl functionalized polystyrene (HFP) produced the excellent transparent materials which enabled a precise birefringence control in keeping with the other physical properties for optical film use. The blend with a composition from 0.28 to 0.35 for the HFP weight fraction showed an extraordinary wavelength dispersion, transmitting through a zero birefringence point at the critical fraction of 0.45, while each polymer showed an ordinary wavelength dispersion. The observed excellent transparency even above those of the glass transition temperature was attributed to a depressed phase separation that resulted from strong hydrogen bond between the ester and hydroxyl groups. An IR analysis of the film demonstrated a remarkable red‐shift in the carbonyl peak with an increase of the hydroxylated polystyrene content, indicating a strong hydrogen bond between those groups. This new polymer blend provides a useful design to achieve practical demands for film use, both optical and mechanical under the fabrication conditions using the melt extrusion technique. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3132–3143     

Die Füllstandsmeßeinrichtung 24016

Seit nahezu 10 Jahren warden vom VEB Robotron Meβelektronik “Otto Schön” Dresden kontinuierliche Füllstandsmeβeinrichtungen hergestellt. Sie arbeiten nach dem Prinzip der Strahlenstreuung im Füllgut. Quelle und Strahlungsdetektor befinden sich — durch einen Absorber getrennt — in einer gemeinsamen Sonde. Die Sonde wird durch einen Motorantrieb dem jeweiligen Füllstand nachgeführt. Diese Messung wird bei Behälterhöhen bis maximal 40 m eingesetzt. In den Behälter ist der Einbau eines Schutzrohres für die Sonde erforderlich. Da strahlungsquelle und Detektor in einer gemeinsamen Sonde untergebracht sind, wird keine groβe Quellenaktivität benötigt. Die beschriebene neue Entwicklung ersetzt ab 2. Halbjahr 1982 den mit einigen Nachteilen behafteten Vorläufer dieser Füllstandsmeβanlage. Durch die vorgenommenen Verbesserungen warden der Inbetriebnahme- und der Wartungsaufwand verringert und die Zuverlässigkeit erhöbt.     

Synthesis and Characterization of Poly(ether ether ketone)s with (2,5‐dihydroxy)phenyl Side Group

A new monomer, (2,5‐dimethoxy)phenylhydroquinone (DMPH), was prepared in a two‐step synthetic procedure. One aromatic poly(ether ether ketone)s with 2,5‐dimethoxy phenyl side group (DMP‐PEEK) was synthesized via an aromatic nucleophilic substitution reaction with 4,4′‐difluorobenzophenone (DFB). Poly(ether ether ketone)s with 2,5‐dihydroxy phenyl side group (DHP‐PEEK) was obtained via hydrolysis of methoxy group on the DMP‐PEEK. Both of the high molecular weight polymers could be obtained despite the steric effect of the bulky pendant groups. The two polymers have good solubility at room temperature.     

Multilayered 2D Cesium-Based Hybrid Perovskite with Strong Polarization Sensitivity: Dimensional Reduction of CsPbBr3

3D perovskite CsPbBr₃ has recently taken a blooming position for optoelectronic applications. However, due to the lack of natural anisotropy of optical attributes, it is a great challenge to fulfil polarization-sensitive photodetection. Here, for the first time, we exploited dimensionality reduction of CsPbBr₃ to tailor a 2D-multilayered hybrid perovskite, (TRA)₂CsPb₂Br₇ ( 1 , in which TRA is (carboxy)cyclohexylmethylammonium), serving as a potential polarized-light detecting candidate. Its unique quantum-confined 2D structure results in intrinsic anisotropy of electrical conductivity, optical absorbance, and polarization-dependent responses. Particularly, it exhibits remarkable dichroism with the photocurrent ratio (I_pc/I_pa) of ≈2.1, being much higher than that of the isotropic CsPbBr₃ crystal and reported CH₃NH₃PbI₃ nanowire (≈1.3), which reveals its great potentials for polarization-sensitive photodetection. Further, crystal-based detectors of 1 show fascinating responses to the polarized light, including high detectivity (>10¹⁰ Jones), fast responding time (≈300 μs), and sizeable on/off current ratios (>10⁴). To our best knowledge, this is the first study on 2D Cs-based hybrid perovskite exhibiting strong polarization-sensitivity. The work highlights an effective pathway to explore new polarization sensitive candidates for hybrid perovskites and promotes their future electronic applications.