The design of the true random number generator based on the nuclear decay

随着计算机技术的发展和普及,数据安全越来越受到人们的重视,几乎所有的密码系统都需要不可预测的密钥进行加密,因此,如何快速得到真正的随机数成为当前人们迫切解决的问题。 核衰变信号是自然界的真随机源，由核衰变得到的序列虽然是真随机序列但却不能满足均匀性和独立性要求。因此必须利用软件的方式加以优化。本文采用与伪随机序列异或方式对其进行优化。为了最大限度利用所得真随机数，笔者用VB开发了远程访问真随机源且能嵌入Web使用的控件。 本设计的关键技术在于核衰变信号的引入和获取及对输出的随机序列进行均匀性和独立性的处理，以及可以远程访问真随机源且能嵌入Web使用的控件设计。本文解决该课题主要做以下几个方...With the development of the computer technolegy, data safety is more and more important to us. Almost all code system require unpredictable key to encrypt data ,Therefore how to acquire true random number become a urgent problem to people. Nuclear disintegration signal is the natural source of the true random number, the true random sequence acquired form nuclear disintegration is the true rand...学位：工学硕士院系专业：物理与机电工程学院物理学系_微电子学与固体电子学学号：2005130168

The Design Of The True Random Number Generator Based On The γSpectrometry Measuring

本文介绍了一种基于γ能谱测量的真随机数发生器的设计,详细阐述了设计思路。以核脉冲信号作为真随机源,引进伪随机序列进行优化并对结果进行了检测分析。This paper introduces a design of true random number generator based on the γspectrometry measuring, particularly describe the design methods.The acquisition of the true random number is based on the nuclear signal pulse.We introduces the pseudo random number sequence to raise the quality of the random numbers and give the analysis of the result

氢气在碳纳米管基材料上的吸附-脱附特性

利用高压容积法测定多壁碳纳米管(MWCNTs)及钾盐修饰的相应体系(K+-MWCNTs)的储氢容量,并用程序升温脱附(TPD)方法表征研究氢气在MWCNTs基材料上的吸附-脱附特性.结果表明,在经纯化MWC-NTs上,室温、9.0MPa实验条件下氢的储量可达1.51%(质量分数);K+盐对MWCNTs的修饰对增加其储氢容量并无促进效应,但相应化学吸附氢物种的脱附温度有所升高;K+的修饰也改变了MWCNTs表面原有的疏水性质.在低于723K的温度下,H2/MWCNTs体系的脱附产物几乎全为氢气;773K以上高温脱附产物不仅含H2,也含有CH4、C2H4、C2H2等C1/C2烃混合物;H2/K+-MWCNTs储氢试样的脱附产物除占主体量的H2及少量C1/C2烃混合物外,还含水汽,其量与吸附质H2源水汽含量密切相关.H2在碳纳米管基材料上吸附兼具非解离(即分子态)和解离(即原子态)两种形式

甲烷在流态化催化剂床裂解生长多壁碳纳米管

在常压、823～873K、流化床反应条件下,用自行研制的Ni0.5Mg0.5O催化剂,催化甲烷分解生长碳纳 米管(CNTs),考察催化剂床层由固定床过渡到流化床状态的条件及其对制管过程的影响。结果表明,在 Φ32mm管式反应器及相应供热工况条件下,其流化床操作条件以管壁温度控制在约853K、原料气CH4线速 v为18～22cm/s、空速GHSV为3×104～6×104mL(STP) CH4/(h·g)为宜;反应1.0h,最高产率达 10g CNTs/g,这相当于固定床将制管反应时间延长至4～5h的产率水平。所得CNTs产物经TEM、SEM、 TPH、XRD和LRS等测试技术表征。结果表明,其为多壁碳纳米管(MWCNTs),外管径在10～50nm范围;纯 化后的CNTs产物含碳量≥99.5%,石墨状碳含量≥90%

H_2在K~0-MWCNTs上储存和吸附/脱附特性研究

利用高压容积法辅以卸压升温脱附排水法,测定金属K修饰多壁碳纳米管对H2的吸附储存容量.结果表明,在室温(25℃),7.25MPa实验条件下,x%K0-MWCNTs(x%=30%～35%,质量百分数)对H2的吸附储存容量可达3.80wt%(质量百分数),是相同条件下单纯MWCNTs氢吸附储量的2.5倍;室温下卸至常压的脱附氢量为3.36wt%(占总吸附氢量的～88%),后续升温至673K的脱附氢量为0.41wt%(占总吸附氢量的～11%).利用LRS和H2-TPD-GC/MS等谱学方法对H2/K0-MWCNTs吸附体系的表征研究表明,H2在K0-MWCNTs上吸附存在非解离(即分子态)和解离(即原子态)两种吸附态;在≤723K温度下,H2/K0-MWCNTs体系的脱附产物几乎全为H2气;723K以上高温脱附产物不仅含H2,也含有CH4,C2H4和C2H2等C1/C2-烃

Study of storage and adsorption/desorption characteristics of H-2 on MWCNTs modified by metal potassium

Storage capacity of H-2 in a kind of potassium-modified multiwalled carbon nanotubes, K-0-MWCNTs, was measured by using high-pressure volumetric method combined with desorption water-displacement method. It was experimentally shown that appropriate incorporation of a certain amount of metallic potassium into the MWCNTs could significantly increase the storage capacity of hydrogen. Under conditions of 7.25 MPa and ambient temperature, H-2 uptake of 3.8 wt% could be achieved by the x%K-0-MWCNTs (x%=30%-35%, mass percentage), which was 2.5 times as high as that by the KO-free MWCNTs under the same conditions. It was also indicated that adsorption of 99% of the H2 was reversible, and that 88% of the stored hydrogen (equalling storage capacities of 3.36 wt%) could be desorbed while the pressure was relieved to atmospheric pressure and similar to 11% of the stored hydrogen (equalling storage capacities of 0.41 wt%) was desorbed in the following process of elevating temperature from room temperature to 673 K. The Raman-spectroscopic and TPD-MS/GC investigations of the H-2/K-0-MWCNTs adsorption systems showed that adsorption of H-2 on the MWCNTs could occur in associative and dissociative forms, with the observed v(s)(C-H) for CH2, v(C-H) for CH and v(H-H) for H-2 (a) at 2856, 3228 and 3946 cm(-1), respectively, and that H-2 Was the predominant products desorbed at temperatures lower than 723 K, whereas in addition to H-2, light hydrocarbons such as CH4, C2H4, C2H2, etc. were also involved in the products desorbed at temperatures higher than 723 K

H_2在金属钾修饰碳纳米管上的吸附与储存

利用高压容积法、辅以卸压升温脱附排水法,测定金属钾修饰多壁碳纳米管(K~0-MWCNTs)对H_2的吸附储存容量。结果表明,在室温(～25℃)、～7.25MPa实验条件下其对氢的吸附储存容量可达3.80％(质量百分数);室温下卸至常压的脱附氢量为3.36％(占总吸附氢量的～89％),后续升温(升至673K)的脱附氢量为0.41％(占总吸附氢量的～11％)

Intrinsic Kinetics of Pyrolysis of CH_4 to Grow CNTs over a Ni-Mg-O Catalyst

［中文文摘］考察甲烷在Ni0.5Mg0.5O催化剂上裂解生长碳纳米管(CNT)的本征动力学.在常压,540～640℃,GHSV=(2.0～9.0)×104mLh-1g catal-1.反应条件下,测得甲烷裂解转化率随反应温度、接触时间的变化,运用最小二乘法拟合求算出反应速率,进而建立反应动力学方程的幂函数模型,求得甲烷和氢气的反应级数分别为1.32和-1.41,反应活化能Ea为172kJmol-1,并根据实验数据验证了甲烷在Ni基催化剂上吸附、解离、脱氢的机理模型.［英文文摘］Reaction kinetics of catalytic pyrolysis of methane over nickel2based catalyst s has been extensively studied. Over a quarter of the century , many effort s were being directed at preventing f rom deactivation of catalyst due to carbon deposit accumulation in many processes involving methane conversion reactions , while the ki2 netic study aimed at the catalytic pyrolysis of methane to grow carbon nanotubes has been few and far between in literature. In the present work , the int rinsic kinetics of methane pyrolysis to grow carbon nanotubes on a Ni-Mg-O catalyst was investigated. Under the reaction condition of 0. 1 MPa , 540～640 ℃, GHSV = (2. 0～9.0) ×104 mL (STP) h -1 g-catal. - 1,changes of methane conversion with reaction temperature and contact time were measured. By using least square method , the reaction rate was calculated , and a model of powder function for the reaction2kinetic equation was established , and through calculations based upon this equation , it was ac2 quired that the reaction order of CH4 and H2 was 1. 32 and - 1. 41 respectively , and the activation energy Ea was 172 kJ mol - 1 . The result s of the present investigation provide experimental evidence in supporting the mechanism and kinetic model of dissociative chemisorption followed by successive dehydrogenation of methane ,with the first step of dehydrogenation as the rate2determining step, on the Ni2Mg2O catalyst .福建省自然科学基金(2001H017); 国家自然科学基金(50072021)