大孔树脂吸附法处理含苯肼工业废水的研究

以Hz-841大孔树脂为吸附剂,95%乙醇为脱附剂处理含苯肼4000~5000mg/L的工业废水,取得了理想的分离效果,苯肼吸附率>99.8%,树脂工作吸附量40~50g/L。     

The photodissociation of water by doped iron oxides: The unblased p/n assembly

Mott-Schottky capacitance measurements are used to locate semiconductor band edges for a short-circuited p-type/n-type α-Fe₂O₃ assembly in aqueous solution. The thermodynamic feasibility of the catalytic photodiscussion of water without external bias is verified for this assembly from an energy level diagram obtained for the electrode/electrolyte interfaces. Photocurrent stability and Auger analysis of the electrode show no evidence of electrode dissolution. Oxygen evolution is monitored from an assembly using mass spectrometry and H₂¹⁸O enriched water.     

On the solid state structure of 4-iodobenzoic acid

The solid-state structure of 4-iodobenzoic acid has been confirmed by variable temperature X-ray diffraction, variable temperature solid-state NMR and differential scanning calorimetry. 4-iodobenzoic acid crystallizes in the space group P2(1)/n, and dimerizes in the solid state about a center of inversion. Using extensive X-ray crystallographic data collections, the placement of the carboxylate H atoms from the residual electron density in difference Fourier maps was determined. The position of the electron density associated with the proton is found to vary with temperature in that the population of the disordered sites changes with varying temperature. Determination of the crystal structure between the temperatures of 248 and 198 K was not possible due to a phase transition, an endothermic event occurring at 230.77 K. The phase transition is also indicated by a change in the relaxation time of the ring carbon atoms in the solid-state NMR data. Though the dominating force in the dimeric unit in the solid state is the presence of strong hydrogen bonds, there are also van der Waals forces present between the iodine atoms. In the layered structure, the iodine-iodine distance is within the van der Waals contact radii, an interaction which causes a deformation in the electron density of the iodine atoms.     

硫代乙酰胺体系电沉积法制备CdS纳米膜

The film of surface active agents spread out on the surface of the electrolyte of Thioacetamide and cadmium chloride. CdS nanofilm was deposited at the interface of surface active agents and electrolyt by the method of electrodeposition. The optimal conditions on which the nanofilm was prepared of the least crystals and uniform particles could be attained via analytical results of L₁₆(4⁵) orthogonal experiments. The optimal conditions: castor oil/hexadecanoll 0.06 mL·cm^-2，CdCl₂/CH₃CSNH₂ 4 mmol·L^-1, cell voltage 5 V, electrodeposition temperature 15 ℃. The effects on the grain size of temperature, surface-active agent, electrodyte concentration, cell voltage and pH become smaller in the series. If the temperature was high, the movement of molecules of surface-active agent and electrodyte would be faster, thus the preparation of the film would be difficult. The grain size of thinfilm varied with the surface-active agents, however, when the amount of surface-active agents reached a certain value, the grain size would remain unchanged. The higher the electrodyte concentration, the larger the grain size of nanofilm. The surface forms were changed at the same time. If the pH of the electrodyte was higher or lower, nanofilm could not be prepared successfully, thus the pH range should be is 3～6. SEM image of the nanofilm shows the occurance of dendrite. The sucessful preparation of nanofilm is closely related to the nature of surface activre agent due to the nanofilm growth mechanism.     

Relative reactivities in vinyl copolymerization

From data in the literature on relative rates of copolymerization it has been possible to evaluate two constants, Q and e, characteristic of an individual monomer, which appear to account satisfactorily for its behavior in copolymerization. The constant Q describes the “general monomer reactivity” and is apparently related to possibilities for stabilization in a radical adduct. The constant e takes account of polar factors influencing copolymerization.     

An algorithm for semi-empirical design of nucleation rate surface

During the last half of century, Classical Nucleation Theory (CNT) has been developed and there have been advances in the molecular theory of nucleation. Most of these efforts have been directed towards small molecule system modeling using intermolecular potentials. Summarizing the nucleation theory, it can be concluded that the current theory is far from complete. Agreement is generally not obtained between experimental and theoretical results. In practical applications, parametric theories can be used for the systems of interest. However, experimental measurements are still the best source of information on nucleation. Experiments are labor intensive and costly, and thus, it is useful to extend the value of limited experimental measurements to a broader range of nucleation conditions. The available nucleation parameters represent only small regions of possible nucleation conditions over the range from the critical temperature to absolute zero. Thus, it is useful to develop better tools to use the data to estimate semi-empirical nucleation rate surfaces. Following our published approach, the nucleation rate surface for any system can be constructed over its phase diagram. This concept involves using the phase equilibrium diagram to establish lines of zero nucleation rates. Nucleation rate surfaces arise from equilibrium lines and their extensions that are representing unstable equilibria. Only limited experimental data is available for use in normalizing the slopes of the linearized nucleation rate surfaces. The nucleation rate surface is described in terms of steady-state nucleation rates. To design the surfaces of nucleation rates, several assumptions are presented. In the present study, an algorithm for the semi-empirical design of nucleation rate surfaces is introduced. The topology of the nucleation rate surface for a unary system using the example of water vapor nucleation is created semi-empirically. The nucleation of two concurrent (stable and unstable) phase states of critical embryos is considered in the context of multi-surface nucleation rates. Only one phase transition (melting) in the condensed state of water is considered for simplicity. The nucleation rate surface is constructed numerically using the available experimental results for vapor nucleation and phase diagram for water. The nucleation rate for water vapor is developed for the full temperature interval, i.e. from critical point to absolute zero. The results help to suggest a new direction for experimental nucleation research.     

结晶聚合物品相相容性的研究

通过ＤＳＣ、Ｘ－射线衍射、红外光谱及拉伸试验研究了ＨＤＰＥ与ＬＬＤＰＥ、ＨＤＰＥ与ＬＤＰＥ之间的晶相相容性．结果表明，链结构相近的ＨＤＰＥ和ＬＬＤＰＥ的晶相相容性好，能形成共晶；而链结构差异较大的ＨＤＰＥ和ＬＤＰＥ的晶相相容性较差，倾向于分别结晶，但有部分链段被对方的晶区夹持．不论是支化度大的ＬＤＰＥ链段插入以ＨＤＰＥ为主的晶区，还是支化度小的ＨＤＰＥ链段插入以ＬＤＰＥ为主的晶区，都可破坏晶区的规整性．共晶的形成使共混物的熔点、结晶度、晶粒体积等低于两组份的线性加和，而力学性能，尤其是断裂伸长率，则显著提高，呈协同效应．     

Cooperative hydrogen-bonding effects in a water square: a single-crystal neutron and partial atomic charges and hardness analysis study

Four isomorphous complexes of formula [M(L)(4)(H(2)O)(2)]SO(4).2H(2)O (M = Co, 1a; Ni, 1b; Cu, 1c; Zn, 1d) have been isolated and characterized by single-crystal X-ray diffraction and neutron diffraction using the quasi-Laue diffractometer VIVALDI at the Institut Laue-Langevin as well as by thermogravimetric analysis. The structures contain a discrete, strongly hydrogen-bonded water tetramer which causes a significant distortion of the metal coordination sphere in each case. Partial atomic charges and hardness analysis (PACHA) calculations reveal that the shortest hydrogen bonds are not the strongest in this constrained, cyclic solid-state structure and show that the distortion at the metal center is caused by the drive to maintain the integrity of the water tetramer. The system undergoes a disorder-order transition on slow cooling that provides insight into the nature of communication between water squares.     

Enantiospecific synthesis of annulated nicotine analogues from D-glutamic acid. 7-Azabicyclo[2.2.1]heptano[2.3-c]pyridines

The conformationally restricted nicotinoid (1S,4S)-7-methyl-7-azabicyclo[2.2.1]heptano[2,3-c]pyridine dihydrochloride has been prepared enantiospecifically from D-glutamic acid. The method involved a lithium cis-2,6-dimethylpiperidide-mediated intramolecular anionic cyclization of (2S,5R)-N-(tert-butyloxycarbonyl)-5-[3-(4-N-chloropyridinyl]proline methyl ester in tandem with a standard decarboxylation sequence. Reductive amination afforded the desired N-methylated [2.2.1]bicyclonicotinoid. Cyclization of the corresponding iodopyridinylproline methyl ester, obtained via ultrasound-facilitated chloro-iodo exchange, was also effected.