剪枝后废弃物堆肥的物理化学性质及其季节变化

通过对12个不同剪枝后废弃物堆肥（PWC）样品理化性质分析,评价它们是否适合作为观赏植物的生长基。样品定期地采集于相同的堆肥处,堆肥时间大于18个月,考察季节变化对堆肥的影响。除了剪枝后废弃物堆肥外,加拿大泥炭藓和商业生长基（CQM）被用作参考材料。PWC堆肥的性质如下：PH值在8以上,显著高于泥炭和商业生长基的PH值;所有堆肥样品都显示出丰富的有机质和相当高的阳离子交换量。C／N比值在22～48之间,显著高于15～20最优范围。虽然对堆肥进行抽样时处于不同季节,但其化学性质并无显著差异．仅持水量随季节有微小变化。与加拿大泥炭和商业生长基相比,修剪下来的植物残枝可以作为盆栽观赏植物生长基的组成部分。     

Electrochemical properties and simultaneous determination of dihydroxybenzene isomers at ordered mesoporous carbon-modified electrode

The voltammetric behaviors of dihydroxybenzene isomers were studied at an ordered mesoporous carbon-modified glassy carbon (OMC/GC) electrode. Compared to the bare electrode, the electrocatalytic activity of the modified electrode toward dihydroxybenzenes is evidenced by the increase of the peak current and the decrease of the peak separation (ΔE _p) in 0.1 M pH 5.0 phosphate buffer solution (PBS). Furthermore, at the OMC/GC-modified electrode, the three isomers could be separated entirely. The oxidation peak potential difference between hydroquinone and catechol is 154 mV, whereas that difference between catechol, and resorcinol is 370 mV. In the amperometric detection, the peak currents of dihydroxybenzene increased linearly with increasing dihydroxybenzene contents. The detection limits were 7.6 × 10⁻⁸ M, 1.0 × 10⁻⁷ M, 9.0 × 10⁻⁸ M for hydroquinone, catechol and resorcinol, respectively, which are the lowest values ever reported for dihydroxybenzene isomers. These make OMC/GC electrode a promising candidate for the simultaneous determination of isomers.     

Theoretical investigation on the white-light emission from a single-polymer system with simultaneous blue and orange emission

White organic light-emitting devices (WOLEDs) have attracted considerable attention because of their good potential for various lighting applications. Among these devices, WOLEDs based on polymers (WPLEDs) are of particular interest. We report here a theoretical investigation of the white-light emission from a single-polymer system with simultaneous blue (polyfluorene as a blue host) and orange (2,1,3-benzothiadiazole-based derivative as an orange dopant) emission. A variety of theoretical methods are used and evaluated to calculate electronic and optical properties of polyfluorene and 2,1,3-benzothiadiazole-based derivatives. Simulated electronic and optical properties are found to agree well with available experimental measurements. The influence of the “CH”/N heterosubstitution on the electronic and optical properties of the 2,1,3-benzothiadiazole-based derivative is considered. Furthermore, we find that the electronic and optical properties of “CH”/N substitution derivatives can be tuned by symmetrically adding suitable electron-donating groups on N,N-disubstituted amino groups, implying good candidates as orange dopants in WPLEDs with polyfluorene as a blue-light-emitting host. Solvent (dichloromethane) effects on the electronic and optical properties of 2,1,3-benzothiadiazole-based derivatives have been investigated. In addition, low reorganization energy values of holes for designed 2,1,3-benzothiadiazole-based derivatives within the framework of the charge hopping model suggest them to be good hole transfer materials.     

Selective synthesis and novel properties of single crystalline α-CoMoO4 nanorods/nanowhiskers

The selective controlled syntheses of crystalline CoMoO₄ nanorods (rod-CoMoO₄)/nanowhiskers (whiskers-CoMoO₄) by using reverse micelles in different molar ratios (w) of [H₂O]/[CTAB] under mild hydrothermal conditions are reported for the first time. The obtained rod-CoMoO₄/whiskers-CoMoO₄ have a monoclinic structure (α-CoMoO₄), with diameter range from 10 to 80 nm and their lengths range from several tens of nanometers to 1 μm. The synthesis conditions and formation mechanism of the nanorods/nanowhiskers were discussed. The electrochemistry behaviors of Co²⁺ and CoMoO₄ in nanoscale and in macroscale are compared, from which an interesting result is obtained. Furthermore, the efficient antibacterial property of the nanorods against Escherichia coli (E. coli) was first found.     

Potassium dodecatungstocobaltate trihydrate (K5CoW12O40 · 3H2O): A mild and efficient reusable catalyst for the synthesis of amidoalkyl naphthols in solution and under solvent-free conditions

An efficient and direct procedure has been developed for the preparation of amidoalkyl naphthols by a one-pot condensation of aryl aldehydes, β-naphthol and urea or amides, in the presence of potassium dodecatungstocobaltate trihydrate [K₅CoW₁₂O₄₀ · 3H₂O, (1 mol%)] as a heterogeneous catalyst. The reactions were carried out in 1,2-dichloroethane at room temperature or under solvent-free media at elevated temperature. The present methodology offers several advantages such as excellent yields, simple procedure and the catalyst exhibited remarkable reusability.     

Synthesis of polyaniline/Ag composite nanospheres through UV rays irradiation method

In this paper, a novel morphology of polyaniline (PANI)/Ag composite nanospheres was obtained through UV rays irradiation method. The structure and morphology of the product were characterized by Fourier transform infrared (FT-IR) spectrum, X-ray diffraction (XRD) pattern, Scanning electron micrograph (SEM) and Transmission electron microscopy (TEM) images, energy-dispersive X-ray (EDAX) analysis, and electron diffraction (ED), respectively. The results showed that the diameters of the PANI nanospheres and the Ag nanofilaments were 10–60 nm and 2–5 nm, respectively. UV rays played an important role for forming PANI nanospheres underpinned by Ag nanofilaments. A potential formation mechanism of PANI nanospheres underpinned by Ag nanofilaments was investigated.     

Structure and mechanical properties of waterborne polyurethane-based composites filled with self-assembled supramolecular nanoplatelets

New composites of waterborne polyurethane (WPU) as a matrix were prepared by incorporating rigid supramolecular nanoplatelets (SNs) as filler, which were self-assembled by the selective inclusion of β-cyclodextrin (β-CD) onto poly(propylene oxide) (PPO) segment in the poly(ethylene oxide)-block-PPO-block-poly(ethylene oxide) (PEO-b-PPO-b-PEO). It is worth noting that, when the loading level of SN is lower than 3wt%, the SNs with moderate PEO length result in the simultaneous increase in strength, elongation and Young’s modulus in contrast with neat WPU. If there is no stretching free PEO chain, both strength and elongation decrease in spite of an increase in Young’s modulus. However, too long PEO chains result in the decrease of mechanical performances while the relatively higher loading-level of SNs also inhibits the enhancement of strength and elongation.     

Dy在BaTiO_3中的位占据研究

应用冷压陶瓷技术制备Dy分别掺杂在BaTiO3中的Ba位、Ti位和Ba/Ti位的陶瓷.采用X射线衍射(XRD)、拉曼光谱(RS)和电子顺磁共振(EPR)测试技术调查了Dy在BaTiO3中的位占据倾向.结果表明:Dy倾向于占据Ba位优于Ti位;无论在Ba位还是Ti位占据的名义配比下,Dy都以少量Dy3+形式不可避免地进入BaTiO3中的另一位.x=0.01时,(Ba1-xDyx)TiO3和(Ba1-xDyx)Ti1-x/4O3陶瓷出现很强的g=1.974的Ba空位缺陷信号.Ba(Ti1-xDyx)O3陶瓷在x=0.01时有第二相Ba12Dy4.67Ti8O35析出并且出现一个较弱的g=2.002的Ti空位缺陷信号.(Ba1-xDyx)(Ti1-xDyx)O3陶瓷的固溶度大于x=0.03,在825 cm-1处有较强的拉曼电荷效应.     

国产树脂与进口树脂在苯酚精制工艺中的性能对比分析

苯酚是一种重要的有机化学原料,但在生产过程中会产生多种杂质,这些杂质的存在严重的影响了苯酚的质量.本文将用于精致苯酚的国产树脂和进口树脂进行比较,分别从总离子交换容量,静态吸附,和动态吸附等各项性能进行了充分地研究,分析国产树脂与进口树脂存在的差异性,利用固相微萃取与气相色谱联用方法对苯酚中杂质含量变化进行监测,为苯酚精制工艺中树脂实现国产化提供了相关的依据.