多频率段物理不可克隆函数

物理不可克隆函数(Physical Unclonable Functions, PUF)是一种用于保护集成电路芯片安全的新方法。传统的基于振荡器的PUF在产生响应过程中振荡器的振荡频率固定不变,因此存在着被攻击的隐患。该文提出一种新的利用多频率段的PUF(Multiple Frequency Slots based PUF, MFS-PUF)来解决这个问题,通过可配置的振荡器,每产生一位响应,振荡器的振荡频率便发生转移。在每一种振荡频率下,由于不可避免地制造差异,振荡器之间的频率会有微小差别,这些略有差异的频率组成了一个频率段(frequency slot),整个系统中则存在着多个频率段。各个频率段之间随机转变,相比于传统的基于振荡器的PUF,系统输入输出响应对(Challenge-Response Pairs, CRPs)的值更大,也更加不可预测,这使得攻击者使用建模攻击的复杂度大大增加,在保证了自身性能的同时增强了本身的安全性。     

多功能结构的支撑技术

多功能结构是航天产品前沿技术。本文首先介绍多功能结构的概念 ,然后讨论多功能结构的支撑技术 ,包括理想材料的分析、设计方法、理想材料零件的设计和制造方法、微电子元件的构型优化以及多功能结构设计方法。针对多功能结构设计 ,提出功能驱动的设计框架 ,及基于博弈论的设计方程 ,并给出一个建立设计方程的实例     

Biochemistry of bacterial multidrug efflux pumps

Bacterial pathogens that are multi-drug resistant compromise the effectiveness of treatment when they are the causative agents of infectious disease. These multi-drug resistance mechanisms allow bacteria to survive in the presence of clinically useful antimicrobial agents, thus reducing the efficacy of chemotherapy towards infectious disease. Importantly, active multi-drug efflux is a major mechanism for bacterial pathogen drug resistance. Therefore, because of their overwhelming presence in bacterial pathogens, these active multi-drug efflux mechanisms remain a major area of intense study, so that ultimately measures may be discovered to inhibit these active multi-drug efflux pumps.     

PZT Based MFS Structure for FeFET

Fabrication and properties of lead zirconate titanate (PZT) thin films have been studied for Metal-Ferroelectric-Semiconductor FET (MFSFET) devices. PZT based MFS capacitors using lead titanate (PT) as seeding layers have been respectively prepared on p-type ?111? and n-type ?100? silicon wafers directly by a sol-gel method. PZT/PT films are final annealed at 650°C for 1 min in oxygen ambient using rapid thermal annealing (RTA). The measured memory windows of the MFS capacitors are about 1.8 V and 5 V under the polarization voltages of ±5 V and ±10 V correspondingly. The MFS structure can be valuable for MFSFET applications.     

Modeling membrane proteins based on low-resolution electron microscopy maps: a template for the TM domains of the oxalate transporter OxlT

The availability of both EM and high-resolution crystallographic data for several membrane proteins (MPs) permits a detailed evaluation of the ability of molecular modeling techniques to complement EM data in the development of models of MPs. A protocol for this purpose is presented, consisting of (1) identifying transmembrane (TM) domains from sequence; (2) assigning buried and lipid-exposed faces of the TM domains; and (3) assembling the TM domains into a bundle, based on geometric restraints obtained from the EM data. The protocol is validated by predicting the structures of several 7- and 12-TM MPs to within 3-5 A r.m.s.d. from their crystal structures. The protocol is applied to generate a model of the oxalate transporter OxlT, for which a high-resolution structure is not yet available.     

仿真软件在“微机原理与接口技术”教学中的应用

针对＂微机原理与接口技术＂课程内容和特点,介绍了计算机仿真软件：EMU8086、MFS和Proteus ISIS,分别适用于汇编语言程序设计、DOS功能调用和硬件接口技术等不同知识点,并且具有操作简单、界面直观等优点。仿真软件的应用能够改善课堂教学模式,激发学生的学习兴趣,帮助学生更好地掌握理论知识,为实验和实践操作打下良好的基础。     

PROPERTIES OF FERROELECTRIC P(VDF-TrFE) 70/30 COPOLYMER FILMS AS A GATE DIELECTRIC

ABSTRACT

We directly formed the organic ferroelectric P(VDF-TrFE) 70/30 copolymer film by the spin coating for making the MFS structure in the silicon wafer. To understand the crystallization behavior of P(VDF-TrFE) 70/30 copolymer, the morphologies of copolymer thin films were studied by AFM and XRD. AFM studies revealed that as grown and annealed films showed surface roughness greater than amorphous films due to crystallization. The XRD spectrum of the films subjected to various annealing temperatures showed β -phase and this phase content was maximum at 140°C annealing. The capacitance shows hysteresis behavior like a buttery shape due to the polarization reversal in the film and this result indicates clearly that the film has a ferroelectric property. The dielectric constants of the P(VF₂-TrFE) copolymer films calculated from the capacitance at the two peak points of the C-V characteristics were about 8.7.     

The MFS–MPS for two-dimensional steady-state thermoelasticity problems

We consider the numerical approximation of the boundary and internal thermoelastic fields in the case of two-dimensional isotropic linear thermoelastic solids by combining the method of fundamental solutions (MFS) with the method of particular solutions (MPS). A particular solution of the non-homogeneous equations of equilibrium associated with a planar isotropic linear thermoelastic material is derived from the MFS approximation of the boundary value problem for the heat conduction equation. Moreover, such a particular solution enables one to easily develop analytical solutions corresponding to any two-dimensional domain occupied by an isotropic linear thermoelastic solid. The accuracy and convergence of the proposed MFS–MPS procedure are validated by considering three numerical examples.     

Method of particular solutions for solving PDEs of the second and fourth orders with variable coefficients

The paper presents a new meshless numerical method for solving partial differential equations of the second and fourth orders with variable coefficients. The key idea of the method is the use of modified particular solutions which satisfy the homogeneous boundary conditions of the problem. This allows us to seek an approximate solution in the form which satisfies the boundary conditions of the initial problem. As a result we separate the approximation of the boundary conditions and the PDE inside the solution domain. Numerical experiments are carried out for accuracy and convergence investigations. A comparison of the numerical results obtained in the paper with the exact solutions or other numerical methods indicates that the proposed method is accurate in dealing with PDEs with variable coefficients.     

The mei3 region of the Schizosaccharomyces pombe genome

Expression of the mei3 gene is sufficient to induce meiosis in the fission yeast Schizosaccharomyces pombe. The mei3 gene is located 0.64 Mb from the telomere of the left arm of Sz. pombe chromosome II. We have sequenced and analysed 107 kb of DNA from the mei3 genomic region. The sequence includes 14 known genes (bag1-B, csh3, dps1, gpt1, mei3, mfm3, pac1, prp31, rpl38-1, rpn3, rti1, spa1, spm1 and ubc4) and 26 other open reading frames (ORFs) longer than 100 codons: a density of one protein-coding gene per 2.7 kb. Twenty-one of the 40 ORFs (53%) have introns. In addition there is one lone Tf1 transposon long terminal repeat (LTR), tRNA(Trp) and tRNA(Ser) genes and a 5S rRNA gene. 14 of the novel ORFs show sequence similarities which suggest functions of their products, including a coatomer alpha-subunit, a catechol O-methyltransferase, protein kinase, asparagine synthetase, zinc metalloprotease, acetyltransferase, phosphatidylinositol 4-kinase, inositol polyphosphate phosphatase, GTPase-activating protein, permease, pre-mRNA splicing factor, 20S proteasome component and a thioredoxin-like protein. One predicted protein has similarity to the human Cockayne syndrome protein CSA and one with human GTPase XPA binding protein XAB1. Three ORFs are likely to code for proteins because they have sequence similarity with hypothetical proteins, three encode predicted coiled-coil proteins and four are sequence orphans.