臭氧对水中甲基对硫磷的降解

通过研究臭氧对水中甲基对硫磷的降解.探索臭氧对甲基对硫磷的降解机制和影响因素.将臭氧气体充入反应器中与甲基对硫磷进行反应,采用GC-MS和标准样品对中间产物进行定性分析,并用HIPLC同时监测甲基对硫磷的残留量和中间产物的生成量.结果表明,臭氧对甲基对硫磷的降解由臭氧直接氧化和羟基自由基间接氧化共同完成,降解历程遵循假一级反应动力学.50 mmol/L离子清除剂叔丁醇使甲基对硫磷的降解速率降低60%,而溶液pH值对降解速率则无明显影响.通过GC/MS分析,确定了甲基对氧磷为甲基对硫磷的臭氧降解中间产物.甲基对氧磷的生成量受到溶液pH和甲基对硫磷起始浓度的影响,较低溶液pH和较高甲基对硫磷起始浓度均有利于甲基对氧磷的积累,而离子清除剂则对甲基对氧磷的生成量没有显著影响.     

Visualizing heavy fermions emerging in a quantum critical Kondo lattice

In solids containing elements with f orbitals, the interaction between f-electron spins and those of itinerant electrons leads to the development of low-energy fermionic excitations with a heavy effective mass. These excitations are fundamental to the appearance of unconventional superconductivity and non-Fermi-liquid behaviour observed in actinide- and lanthanide-based compounds. Here we use spectroscopic mapping with the scanning tunnelling microscope to detect the emergence of heavy excitations with lowering of temperature in a prototypical family of cerium-based heavy-fermion compounds. We demonstrate the sensitivity of the tunnelling process to the composite nature of these heavy quasiparticles, which arises from quantum entanglement of itinerant conduction and f electrons. Scattering and interference of the composite quasiparticles is used to resolve their energy-momentum structure and to extract their mass enhancement, which develops with decreasing temperature. The lifetime of the emergent heavy quasiparticles reveals signatures of enhanced scattering and their spectral lineshape shows evidence of energy-temperature scaling. These findings demonstrate that proximity to a quantum critical point results in critical damping of the emergent heavy excitation of our Kondo lattice system.     

An eco- and inno-product design system applying integrated and intelligent qfde and triz methodology

The green environmental laws and regulations are legislated, implemented, and enforced in many countries and economic regions. The provision of green products and services are the fast growing trend in global consumer markets. Therefore, introducing new products with environmental considerations becomes critical for global brand manufacturers. This research depicts an integrated and intelligent eco- and inno-product design methodology to support environmental friendly green product development. The methodology adopts approaches, such as life cycle assessment (LCA), quality function deploymnet for environement (QFDE), theory of inventive problem solving (TRIZ) and back-propagation network (BPN) to achieve eco- and inno-design objectives. LCA evaluates and compares the environmental impacts of production. QFDE transforms high-level concerns of environment into design requirements. When there are many historical QFDE data, the BPN prediction model is trained and deployed to automate the specifications of green design improvement. TRIZ is to support the creation of innovative product design ideas effectively and efficiently during the concept design stage. Finally, this paper presents two eco-design cases of power adaptor to demonstrate the proposed methodology.     

The dynamical mass of a classical Cepheid variable star in an eclipsing binary system

Stellar pulsation theory provides a means of determining the masses of pulsating classical Cepheid supergiants-it is the pulsation that causes their luminosity to vary. Such pulsational masses are found to be smaller than the masses derived from stellar evolution theory: this is the Cepheid mass discrepancy problem, for which a solution is missing. An independent, accurate dynamical mass determination for a classical Cepheid variable star (as opposed to type-II Cepheids, low-mass stars with a very different evolutionary history) in a binary system is needed in order to determine which is correct. The accuracy of previous efforts to establish a dynamical Cepheid mass from Galactic single-lined non-eclipsing binaries was typically about 15-30% (refs 6, 7), which is not good enough to resolve the mass discrepancy problem. In spite of many observational efforts, no firm detection of a classical Cepheid in an eclipsing double-lined binary has hitherto been reported. Here we report the discovery of a classical Cepheid in a well detached, double-lined eclipsing binary in the Large Magellanic Cloud. We determine the mass to a precision of 1% and show that it agrees with its pulsation mass, providing strong evidence that pulsation theory correctly and precisely predicts the masses of classical Cepheids.