Microstructured microspheres of hydroxyapatite bioceramic

Hydroxyapatite (HAP) particles having spherical geometry and 125–1000 m in size range were prepared using a solid-in-water-in-oil (S/W/O) emulsion, cross-linking technique. An aqueous solution of chitosan containing different loading of HAP was dispersed as droplet in liquid paraffin using a stabilizing agent. Cross-linking of chitosan was induced by adding appropriate amount of glutaraldehyde saturated toluene. Chitosan microspheres containing HAP were sintered at 1150 °C to obtain pure HAP microspheres. The spheres thus produced were examined by scanning electron microscopy. The percentage yield and size distributions of the spheres were also determined.     

点评2008 布局2009 记2008年度中国游戏产业年会之高峰对话（上）

点评2008 主持人：2008年是怎样的一年,这一年里面,最值得我们关注的是哪些事情？     

Breaking concept boundaries to enhance creative potential: Using integrated concept maps for conceptual self-awareness

The authors address the role of computer support for building conceptual self-awareness—that is, enabling students to think outside of concept boundaries in hope of enhancing creative potential. Based on meta-cognition theory, we developed an integrated concept mapping system (ICMSys) to improve users’ conceptual self-awareness in addition to applying concept mapping techniques in traditional learning scenarios. Since the ICMSys accommodates different perspectives, selected ideas made by peers are retained with the help of integrated concept map (ICMap) representations used as stimuli for reflective thinking. Results from a case study with 32 information management undergraduates indicate: (a) increased levels of conceptual self-awareness, (b) evidence of conceptual improvement in the students’ redrawn concept maps, (c) that ICMap viewing frequency exerted a positive impact on level of conceptual self-awareness, and (d) a significant correlation between level of conceptual self-awareness in redrawn personal concept maps and actual conceptual changes as determined by three experts. We describe student perceptions of the ICMSys in terms of comprehension practicality and conceptual self-awareness, and give suggestions for future research.     

Catalytic properties of cobalt(II) porphyrins supported on styrene-divinylbenzene copolymer

Polymeric pyridinium chloride was synthesized by treating pyridine with 2% divinylbenzene (DVB)-crosslinked chloromethyl polystyrene. Sodium 5,10,15,20-tetrakis(4-sulfophenyl)porphyrin was synthesized and appended on the above polymer through an ionic linkage. Cobalt(II) complex of the polymeric porphyrin was synthesized and characterized chemically and spectroscopically. This complex was employed as catalyst for the oxidation of dithiocarbamates to thiuram disulfide. Electronic and ESR spectra of the complex were analyzed before and after catalysis. pH dependence of catalytic reactions was also studied. These studies provide evidence for the catalytic ability of the polymeric cobalt(II) porphyrin system. A mechanism for the catalytic reaction is suggested on the basis of the above results. © 1996 John Wiley & Sons, Inc.     

Copper (II) and silver (II) complexes of polymer-bound porphyrins with Schiff base linkage

Two percent divinylbenzene (DVB)–crosslinked polystyrene was prepared and functionalized to obtain its aldehyde analog. Amino porphyrins were anchored on this polymer support by Schiff base condensation. The anchoring positions were adjusted so as to obtain ortho-, meta-, and para-isomeric systems. The polymer-bound free-base porphyrins were metallated to obtain the corresponding Cu(II) and Ag(II) complexes by treating them with the corresponding metal salt solutions. The products were characterized chemically and spectroscopically. Electronic and ESR spectral analysis shows the microenvironmental participation of the polymer network on the electronic levels of the porphyrin system. The extents of steric and electronic participation were evaluated and are presented. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 89–93, 1998     

Fullerene lipids: Synthesis of novel nitrogen-bridged [60]fullerene fatty ester derivatives

Reactions of methyl 6-azido-hexanoate, 8-azido-octanoate, and 12-azido-dodecanoate with [60]fullerene (1) gave the corresponding aza-[60]fullerene ester derivatives (2a-2c, 22–35% based on the amount of [60]fullerene reacted). The nitrogen atom is bonded to the [60]fullerene cage to yield a “[5,6]-open” type aza substructure. This was confirmed by the appearance of 30–31 sp ² signals at δ_C 133–147 in the carbon nuclear magnetic resonance spectra. Reaction of methyl 11-azido-7-undecynoate with [60]fullerene furnished a mixture of aza-[60]fullerene (2d, 53%) and aziridine-[60]fullerene (2e, 38%) ester derivatives. Compound 2e was identified as the “[6,6]-closed” type aziridine-[60]fullerene derivative, which displayed 10 sp ² signals in the region δ_C 140–145 and one signal at δ_C 85.05 for the sp ³ carbons of the cage. Refluxing a solution of compound 2d in toluene for 50 h gave about 50% yield of compound 2e, but not vice versa.     

Removal of carbon and nutrients from domestic wastewater using a low investment, integrated treatment concept

An integrated chemical-physical-biological treatment concept for the low-cost treatment of domestic wastewater is proposed. Domestic wastewater was subjected to a chemically enhanced primary treatment (CEPT), followed by treatment in an upflow anaerobic sludge blanket (UASB) reactor. In addition, a regenerable zeolite was used to remove NH4+, either after CEPT pretreatment or after biological treatment in the UASB reactor. The CEPT pretreatment consisted of the addition of a coagulant (FeCl3) and an anionic organic flocculant and removed on average 73% of the total chemical oxygen demand (COD(t)), 85% of the total suspended solids, and 80% of PO4(3-) present in the wastewater. The UASB system, which consequently received a low COD(t) input of approximately 140 mg/L, was operated using a volumetric loading rate of 0.4 g COD(t)/L. d (hydraulic retention time [HRT]=10 h) and 0.7 g COD(t)/L. d (HRT=5 h). For these conditions, the system removed about 55% of the COD(t) in its influent, thus producing an effluent with a low COD(t) of approximately 50 mg/L. The zeolite, when applied in batch mode before the UASB reactor, removed approximately 45% of the NH4+, whereas its application as a post-treatment cartridge resulted in almost 100% NH4+ removal. The simple design and relatively low operating costs, due to low costs of added chemicals and low energy input (estimated at Euro 0.07-0.1 per m3 wastewater treated), combined with excellent treatment performance, means that this system can be used as a novel domestic wastewater treatment system for developing countries. Therefore, the system is called a Low Investment Sewage Treatment (LIST) system.     

Analysis of Dispersion in Ferrite-superconductor Layered Structures

This paper studies electromagnetic wave propagation in hybrid structures consisting of ferrite and superconducting films. Dispersion relations for transverse electric mode of propagation are derived. Numerical results are presented for two specific structures viz. a ferrite/superconductor structure and a ferrite/superconductor/ferrite structure and dependence of propagation on various structural parameters and frequency are determined. The non-reciprocal nature of propagation is also established.     

红星托儿所(马达思班上海办公室)

马达思班的建筑师们将一个托儿所改造为自己的办公室,但他们想要创作的不光是一个公司,也不光是一个工作室,而是一个工作室和展览空间的结合体。三层的云梯提供了一个互动平台,为开展交流活动提供了场所。旧建筑响亮的名字——"红星"依然闪闪照耀在此。