Some Semiconductor Properties of Carboxymethyl Cellulose-Copper Complexes

Metal chelates of three grades of carboxymethyl cellulose (CMC) (LI-L3) with Cu(II) ions, either originating from CuCl₂ or CuSO₄, were prepared and characterized by elemental analysis, infrared spectra, and electrical conductivity studies. The results showed that the degree of substitution of CMCs and the origin of the Cu(II) ion have a profound effect on the amount of metal included in the polymer complexes and the structure and the electrical conductivity of the prepared complexes. CMC acts as a uninegatively charged bidentate ligand when it is chelated with Cu(II) of CuCl₂ via the carboxymethyl group and exhibits the formula Cu(L)₂, whereas it acts as a binegatively charged bitentate ligand when it is chelated with CuSO₄ via the carboxymethyl and secondary hydroxyl groups and exhibits the formula CuL.2H₂O. The investigation revealed that the electrical conductivity depends on the temperature and has two maximum peaks. The values of the activation energy for the conductivity of CMC and their complexes indicated that the samples changed from a low-semiconductor to a high-semiconductor property with heating. It is found that CMC-Cu(II) complexes formed from CuSO₄ exhibit a high-semiconductor property compared to complexes derived from CuCl₂.     

Effect of Silver Loading on the Lean NOx Reduction with Methanol Over Ag–Al2O3

The influence of silver loading on the lean NO_x reduction activity using methanol as reductant has been studied for alumina supported silver catalysts. In general, increasing the silver loading (0–3 wt%), in Ag–Al₂O₃, shifts or extends the activity window, for lean NO_x reduction towards lower temperatures. In particular Ag–Al₂O₃ with 3 wt% silver is active for NO_x reduction under methanol-SCR conditions in a broad temperature interval (200–500 °C), with high activity in the low temperature range (maximum around 300 °C) typical for exhaust gases from diesel and other lean burn engines. Furthermore, increasing the C/N molar ratio enhances the reduction of NO_x. However, too high C/N ratios results in poor selectivity to N₂.     

Processing of highly porous TiO2 bone scaffolds with improved compressive strength

In the present study, the effect of sintering time and recoating procedures on the pore architectural parameters and compressive strength of highly porous ceramic TiO₂ foams were investigated. Long sintering times (>5 h) at 1500 °C led to an inward collapse of one wall of the triangular voids typically found in the strut interior of foams prepared using the replication method. This strut folding led to increased compressive strength, while the pore architectural features were not significantly affected. Furthermore, majority of the internal porosity of the foam struts was partially eliminated and became accessible for infiltration with TiO₂ slurry. Recoating procedures were found to markedly reduce the flaw size and number in the TiO₂ foam struts, which led to significant strengthening of the ceramic structure (0.7 → 3.4 MPa) by improved structural uniformity and slightly increased strut diameter.     

云计算：风险以及规避措施

云安全忧思 虽然云计算能够给企业带来诸多好处，不过其存在的问题也是非常显著的，安全性就是其面临的最大挑战之一（或者这根本就是最大的挑战）。在云端存储数据基本可以等同于将大量的钱放在云上，这无疑会给技术高超的黑客们提供了一个施展才华的好机会。     

Coordinate intracellular expression of Salmonella genes induced during infection

Salmonella typhimurium in vivo-induced (ivi) genes were grouped by their coordinate behavior in response to a wide variety of environmental and genetic signals, including pH, Mg2+, Fe2+, and PhoPQ. All of the seven ivi fusions that are induced by both low pH and low Mg2+ (e.g., iviVI-A) are activated by the PhoPQ regulatory system. Iron-responsive ivi fusions include those induced under iron limitation (e.g., entF) as well as one induced by iron excess but only in the absence of PhoP (pdu). Intracellular expression studies showed that each of the pH- and Mg2+-responsive fusions is induced upon entry into and growth within three distinct mammalian cell lines: RAW 264.7 murine macrophages and two cultured human epithelial cell lines: HEp-2 and Henle-407. Each ivi fusion has a characteristic level of induction consistent within all three cell types, suggesting that this class of coordinately expressed ivi genes responds to general intracellular signals that are present both in initial and in progressive stages of infection and may reflect their responses to similar vacuolar microenvironments in these cell types. Investigation of ivi expression patterns reveals not only the inherent versatility of pathogens to express a given gene(s) at various host sites but also the ability to modify their expression within the context of different animal hosts, tissues, cell types, or subcellular compartments.     

Experimental investigation of soliton optical phase jitter

The soliton optical phase stability versus amplified spontaneous noise is investigated in a recirculation loop experiment in the presence of in-line filters. The behavior of phase fluctuations is shown to be in good agreement with numerical simulations. The phase standard deviation is kept below 0.15×π for distances up to 8000 km. We, therefore, demonstrate the feasibility of phase-shift keying on solitons for long-haul transmission systems     

AN INTERPRETATIVE BIOGRAPHY OF WINSOME HALL ANDREW (1905-1997)

This biographical account of Winsome Hall Andrew is a largely chronological account of an early twentieth century NSW architect whose work deserves further serious evaluation. It is also a demonstration of biographical narrative as an strategy for bringing women into a particular kind of historical presence, stressing the complexity of social expectations of women as fundamental to an understanding of their public productivity. It is also a somewhat poignant story which depends upon the honesty and courage of Hall Andrew's friends and relatives in acknowledging the difficulties in her life as well as the niceties. Finally, it is presented as an example of the complex interpretative strategy of my PhD thesis, an attempt to be accessible, relevant, critical, honest and fair.