Interior path following primal-dual algorithms. part I: Linear programming

We describe a primal-dual interior point algorithm for linear programming problems which requires a total of number of iterations, whereL is the input size. Each iteration updates a penalty parameter and finds the Newton direction associated with the Karush-Kuhn-Tucker system of equations which characterizes a solution of the logarithmic barrier function problem. The algorithm is based on the path following idea.     

Ab-initio calculations on small hydrides including electron correlation

The ground state energies of CH ₃ ⁺ , CH₃, and CH ₃ ^– are calculated both in the SCF (near Hartree-Fock) approximation and in the IEPA-PNO scheme including correlation energy. Due to a more appropriate choice of the basis, our SCF-values for CH ₃ ^– are substantially better than previously published ones. Both CH ₃ ⁺ and CH₃ are planar whereas the equilibrium bond angles in CH ₃ ^– are nearly tetrahedral. The inversion barrier of CH ₃ ^– is 2kcal/mol. The force constants of the out-of-plane bending modes are changed by correlation in the case of CH₃ from 0.03–1.8 mdyn/Å. The localized MO's that correspond to the CH-bonds are bent in the non-equilibrium geometries. The dependence of the different pair correlation contributions on the angle that describes out-of-plane deformation is analyzed. The electron affinity of CH₃ is 0.3 eV. Finally the Pariser-Parr disproportionation reaction is analyzed in the light of the present results. Changes in correlation energy for this reaction amount to less than 1 eV.     

The o-chlorotoluene photodissociation at 266 nm

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Ab initio quantum chemical and NMR study of the symmetric monooximes of 1,2,3-phenalenetrione and 1,2,3-indantrione

The possibility for nitroso-oxime tautomerism in symmetric monooximes of 1,2,3-phenalenetrione and 1,2,3-indantrione is studied by means of ab initio quantum chemical methods and NMR spectroscopy. For both compounds, ab initio calculations with different basis sets predict the oxime tautomer as most stable in agreement with the ¹H- and ¹³C-NMR results in CDCl₃ and DMSO-d₆ solutions. A coalescence of the signals for the carbon atoms from carbonyl groups of 1,2,3-phenalenetrione monooxime in DMSO-d₆ solution at temperature 360 K is observed. This coalescence may be attributed to rotation of the hydrogen atom from the hydroxyl group around the N---O bond. The rotational transition structures for both compounds at different computational levels were located in the gas phase and in solution.     

Deposition of SiOx Films from Hexamethyldisiloxane/Oxygen Radiofrequency Glow Discharges: Process Optimization by Plasma Diagnostics

Optical emission and Fourier transform infrared absorption diagnostics have been carried out in hexamethyldisiloxane/oxygen RF discharges for studying the effects of the feed composition and the power on the deposition of SiO₂—like thin films. Ex situ FTIR absorption has been utilized to monitor organic moieties and silanol groups in the film. It is shown that carbon-free films can be obtained by highly diluting the monomer in oxygen, while medium-to-high power is necessary to abate silanol groups. These two conditions represent the optimization criterion to obtain excellent barrier films for food packaging applications.     

电缆用无纺布堵水带高吸水树脂的研究

电缆用无纺布堵水带高吸水树脂的研究钟安永，陈德本，周宗华，姚文（四川联合大学（东区）化学系成都６１００６４）关键词高吸水树脂，无纺布堵水带，丙烯酸甲酯－醋酸乙烯共聚物塑料绝缘电力电缆、通讯电缆、光纤电缆等在使用中常常因为护套破损而导致水的纵向渗透，使...     

Embedded Nanoparticles in Schottky and Ohmic Contacts: A Review

Schottky and Ohmic contacts are essential parts of electronic and optoelectronic devices based on semiconductor materials. Controlling the contact/semiconductor interface properties is the key to obtaining a contact with an optimum performance. Contacts incorporated by nanomaterials, i.e., nano-sized particles that are embedded at the interface of contact/semiconductor, can transform the conventional approaches of contact fabrication, resulting in more reproducible, tunable and efficient electronic, and optoelectronic devices. This article is a review of theoretical and fabrication progress on the last two decades to produce contacts with embedded nanoparticles (NPs). The review covers common routes of NPs deposition on different substrates (e.g., Si, Ge, SiC, GaN, GaAs₆₇P₃₃, and InP) for nanostructured contact fabrication and the theoretical models to investigate the NPs effects on the conduction mechanism and electrical properties of devices.     

Kinetic and thermodynamic characterization of C–N bond rotation by N‐methylacetohydroxamic acid in aqueous media

Hydroxamic acids (HAs) perform tasks in medicine and industry that require bidentate metal binding. The two favored conformations of HAs are related by rotation around the C(=O)–N bond. The conformations are unequal in stability. Recently, we reported that the most stable conformation of a small secondary HA in water places the oxygen atoms anti to one another. The barrier to C–N bond rotation may therefore modulate metal binding by secondary HAs in aqueous media. We have now determined the activation barrier to C–N rotation from major to minor conformation of a small secondary HA in D₂O to be 67.3 kJ/mol. The HA rotational barrier scales with solvent polarity, as is observed in amides, although the HA barrier is less than that of a comparable tertiary amide in aqueous solution. Successful design of new secondary HAs to perform specific tasks requires solid understanding of rules governing HA structural behavior. Results from this work provide a more complete foundation for HA design efforts. Copyright © 2015 John Wiley & Sons, Ltd.     

Tunneling of slow quantum packets through the high Coulomb barrier

We study the tunneling of slow quantum packets through a high Coulomb barrier. We show that the transmission coefficient can be quite different from the standard expression obtained in the plane wave (WKB) approximation (and larger by many orders of magnitude), even if the momentum dispersion is much smaller than the mean value of the momentum.     

复合漏电模型建立及阶梯场板GaN肖特基势垒二极管设计

准垂直GaN肖特基势垒二极管(SBD)因其低成本和高电流传输能力而备受关注.但其主要问题在于无法很好地估计器件的反向特性,从而影响二极管的设计.本文考虑了GaN材料的缺陷以及多种漏电机制,建立了复合漏电模型,对准垂直Ga N SBD的特性进行了模拟,仿真结果与实验结果吻合.基于此所提模型设计出具有高击穿电压的阶梯型场板结构准垂直GaN SBD.根据漏电流、温度和电场在反向电压下的相关性,分析了漏电机制和器件耐压特性,设计的阶梯型场板结构准垂直GaN SBD的Baliga优值BFOM达到73.81 MW/cm~2.