DNA分子计算模型

The field of practical DNA computing opened in 1994 with Adleman's paper,in which a laboratory experi-ment involving DNA molecules was used to solve a small instance of the Hamiltonian Path problem. The characteris-tic of this computation is its powerful ability in parallelism,its huge storage and high energy efficiency. This paper mainly introduces the principles of DNA computing and the sticker computing model.     

Sticker systems with complex structures

 In this paper, we propose a variant of sticker systems which uses molecules with complex structures. Since the original sticker systems (Paun et al. (1998) [2, 8]) working on double strands of DNA have been studied as a formal model for self-assembly in DNA computing, we extend the sticker systems to working on more complex (higher-order) structures of DNA molecules. The advantage of sticker systems with complex structures is that augmented with weak codings we can obtain the characterization of recursively enumerable languages by using only sticking (hybridization) operations for complex molecules, while the usual sticker systems require more complicated operations such as the simultaneous use of couples of dominoes or coherent computations besides morphisms.     

Parallel bioinspired algorithms for NP complete graph problems

It is no longer believed that DNA computing will outperform digital computers when it comes to the computation of intractable problems. In this paper, we emphasise the in silico implementation of DNA-inspired algorithms as the only way to compete with other algorithms for solving NP-complete problems. For this, we provide sticker algorithms for some of the most representative NP-complete graph problems. The simple data structures and bit-vertical operations make them suitable for some parallel architectures. The parallel algorithms might solve either moderate-size problems in an exact manner or, when combined with a heuristic, large problems in polynomial time.     

Using sticker model of DNA computing to solve domatic partition, kernel and induced path problems

DNA computing as a powerful interdisciplinary field has been found to be very useful and applicable for solving NP-complete and intractable problems because of its huge power in parallel processing. In recent years many efforts have been done to solve NP-complete and time consuming problems with the help of DNA computing. In this paper, we use sticker model (one of the most well-known models of DNA computing) to present three DNA algorithms for solving three different NP-complete graph-based problems for the first time: domatic partition, kernel and induced path. Also we have simulated these algorithms to show their correctness.     

最大匹配问题的粘贴DNA算法

最大匹配问题(MMP)是图论中经典的组合优化问题。针对此问题提出了基于DNA粘贴计算模型的求解算法,阐述了该算法如何利用DNA链构建最大匹配问题的初始编码,说明了应用粘贴计算模型寻求最终解的生物操作过程,同时分析了此DNA并行算法的计算复杂度,最后给出了该算法的计算机模拟仿真结果和应用实例,得到了所给问题的最大匹配解,并对算法的可行性进行了验证和总结。     

Bidirectional Sticker Systems with Complex Structures and Generative Capacity

The languages generated by Bidirectional sticker systems with complex structure （BSS） are defined; The classifications of BSS are proposed and the generative capacity is discussed. The characterization of recursively enumerable language is represented by means of the above languages.     

Polymer-Solid Interface Connectivity and Adhesion: Design of a Bio-Based Pressure Sensitive Adhesive

Adhesion at polymer-solid interfaces was explored for a new bio-based pressure sensitive adhesive (PSA) in terms of sticker groups, φ_X, on the polymer phase, receptor groups, φ_Y, on the solid surface, and the bond strength of the sticker-receptor X-Y acid-base interaction, χ. The polymer-solid interface restructuring models of Gong and Lee et al. were extended with new percolation models of entanglements and interface strength to determine the optimal sticker group concentration, φ?_X. For the general case where φ_Y and χ are constant, it is predicted that when φ_X < φ?_X, that the critical peel energy behaves as G_1c ～ φ_X/φ?_X and the locus of failure is adhesive between the polymer and the solid. However, when φ_X > φ?_X, failure occurs cohesively in a polymer-polymer interface adjacent to the solid and the strength decreases as G_1c ～ φ?_X/φ_X. The switch from adhesive to cohesive failure can be understood in terms of the changes in the chain conformations of the adhered chains and their decreasing interpenetration, X_i, with the bulk chains, via X_i ～ 1/r, where r = χφ_Xφ_Y. The optimal value of φ_X which maximizes the adhesion and determines the mode of failure is given by φ?_X ≈ 0.129/C_∝, and for typical values of the characteristic ratio C_∝ in the range 7–20, φ?_X ≈ 1% mole fraction, corresponding to about 2 sticker groups per entanglement molecular weight, M_e. This result was verified for a bio-based PSA synthesized from an acrylated high oleic fatty acid, which was copolymerized with maleic anhydride as the sticker group. The observed behavior is counterintuitive to the current wisdom for the effect of acid-based interactions on adhesion, where the strength is expected to increase with the number of X-Y contacts. The surprisingly low value of φ?_X ≈ 1% sticker groups which maximizes the adhesion strength can now be readily calculated using the percolation model of entanglements and fracture.     

陶瓷烧结墨粉的研究与应用

本研究是使用可烧结的耐高温颜料代替普通墨粉中的色调剂制造一种特殊用途的墨粉,通过彩色激光打印机将所需要的图像直接打印到专用陶瓷烧结贴膜纸上,并将其直接粘到陶瓷承印物上,经高温烧结后,制造出各种陶瓷艺术品。     

钢包粘渣的原因分析

介绍了武钢300t钢包在使用中粘渣的情况，分析了钢包粘渣的原因，提出了相应的措施和对策。