A Foundation of Quantum Channels with Super Additiveness for Shannon Information

This paper presents a review and some results on problems of super additiveness in quantum channel for Shannon information. Especially, how to investigate concrete systems showing super additiveness is discussed. It is verified that the concept of the conventional error correction scheme does not play an important role to demonstrate, at least, the super additiveness of quantum channel, and that rather one can apply them to only selection of code word states with desirable Hamming distance. Finally, some properties of quantum reliability function are given, which are useful to discuss the general property of coding with super additiveness. Received: September 29, 1998; revised version: July 9, 1999     

Exclusion zone model of islands spatial distribution in molecular beam epitaxy

A simple model of islands spatial distribution based on the statistical nucleation model combined with a forbidden for nucleation zone is proposed. Islands nucleate at random points of uncovered substrate with a constant rate and then grow in a hemisphere at a constant velocity. Around each growing island there exists an exclusion zone of some width L within which nucleation is forbidden, while outside this zone islands continue to germinate in a usual spatially random fashion. By this model formulas for the probability that an arbitrarily chosen surface region at any given time moment t will be either empty or contain just one island, W₀(t) and W₁(t), respectively, are derived. Calculations with this formula shows that a simple introduction of the forbidden zone leads to some ordering degree in a spatial distribution of islands, similar to that observed in experiments, and provides a good quantitative coincidence with experiment at reasonable values of the model parameter L.     

Hydrothermal Chemistry Involved in Developing Practical Y Type Zeolite Catalysts

ＨｙｄｒｏｔｈｅｒｍａｌＣｈｅｍｉｓｔｒｙＩｎｖｏｌｖｅｄｉｎＤｅｖｅｌｏｐｉｎｇＰｒａｃｔｉｃａｌＹＴｙｐｅＺｅｏｌｉｔｅＣａｔａｌｙｓｔｓＨｅＭｉｎｇｙｕａｎ，ＳｈｕＸｉｎｇｔｉａｎ，ＭｉｎＥｎｚｅ（ＲｅｓｅａｒｃｈＩｎｓｔｉｔｕｔｅｏｆＰｅｔｒ...     

造纸配料组分的湿部化学

对造纸配料组分及其胶体化学特性、表面动电行为、配料组分的聚集、吸附等作了较为系统的论述。     

煤的芳烃化学研究进展

当世界上的石油资源逐渐枯竭之后，煤能否成为２１世纪化学工业的原材料？科学家们正面临极富感染力的挑战，即寻找和发展一条利用液化煤中的芳烃化合物合成有机化学品的新途径。近期研究表明，新兴的煤化学工业具有很大的发展潜力。本文主要讨论和介绍煤的非燃料利用问题，研究发展由煤制取芳烃化学品和材料的可能途径。综述有关文献２６篇。     

Interfacial chemistry of cobalt(II) during sol–gel synthesis of cobalt-containing mesoporous materials

Co-MCM-41 and Co-MCM-48 with cobalt amounts from about 3 wt.% to 9 wt.% have been synthesized under various conditions, and the samples were characterized by XRF, XRD and N₂-sorption. EXAFS least-squares curve fitting detected only oxygen and silicon backscattering shells, which verified the incorporation of cobalt into the silica framework both for as-synthesized and calcined samples. XANES profiles showed that the oxidation state of cobalt in the samples is unaltered during synthesis. It has been shown that the cobalt is precipitated as cobalt hydroxide during synthesis, and this hydroxide is in equilibrium with aqueous cobalt ions in the synthesis gel. The precipitated cobalt hydroxide precursors are incorporated into the mesoporous silica framework, while the aqueous cobalt ions remain dissolved in the aqueous phase. The cobalt amount in the final samples is therefore pH dependent. This equilibrium is also important in the formation of the mesoporous structure. Addition of increasing amounts of cobalt salt to a MCM-48 synthesis gel causes a change in the mesoporous structure from cubic Ia3d to hexagonal, which is suggested to be a consequence of the charge density matching process. The increased amounts of the divalent cobalt(II) ions in the gel screen the negatively charged silica precursors, which decreases the total surface charge density of the silica, and thus causes the surfactants to self-assemble into the hexagonal structure.     

Theory of non-linear transport in quantum waveguides

The equations for quantum ballistic transport in inhomogeneous quantum wire structures are transformed into a set of one-dimensional coupled mode equations where the coupling parameters are explicitly dependent on the shape parameters for the confinement potential. In the adiabatic approximation or in the extreme quantum limit the resulting motion is governed by an effective Hamiltonian which contains the influence of quasi-electric fields and quasi-momentum dependent forces which arise from the inhomogeneous shape parameter variation along the quantum waveguide. The subsequent transport may be described by a Boltzmann-like kinetic equation and hot-electron effects arising from variations in the waveguide profile are predicted. It is shown that transport through a wide region of an otherwise narrow wire leads to multiply-connected electron paths which will produce Aharonov-Bohm resonances. The analytical formalism is underpinned by a new numerical method suitable for 3-D studies based on representing the inhomogeneous waveguide by an equivalent network of one-dimensional wires.     

辐照绍兴酒加速陈化技术的研究

黄酒是我国独有的传统饮料酒,尤其是绍兴酒在国际上享有盛誉。但新酿成的绍兴酒味粗而辛辣,需存放三年才能达到味醇厚、香气浓郁。这样,不仅需要很大的存放场地,而且资金也不能及时周转,严重影响经济效益的提高。加速绍兴酒陈化,探索酿酒工业新工艺是当前酿酒工业迫切需解决的课题。为此,我所和绍兴酿酒总厂于1983—1984年开展~(60)Coγ线