论文

Sphere;; affine geometry;; similarity geometry;; motion of surface;; integrable equation

论文导师屈长征，论文学位硕士，论文专业应用数学

Boolean function; algebraic degree; correlation immunity; resilient; nonlinearity; balancedness

论文导师戚文峰，论文学位硕士，论文专业密码学

Ancientness; knowledge of science and technology; prevalence and inheritance

论文导师王兵，论文学位硕士，论文专业科学技术哲学

In this thesis,based on the DFT+NEGF first-principles method,we construct a lead-molecule-lead sandwich system with single benzene-based molecule to investigate the relationship between the structure and properties of the molecular devices and the factors that influence properties of the molecular devices.Our computational investigations on these molecular devices are primarily concentrated on the effect of contact geometry between molecules and electrodes,the effect of side groups,the effect of different torsion angle between two phenyl rings and the effect of external electric field.This thesis consists of five chapters:In Chapter one,we mainly introduce the research background and development of the molecular electronics,including the experimental fabrication of molecular electronic components and theoretical simulation methods.Afterwards we discuss the questions that need to be solved in this area.Finally,the main contents of this thesis are listed.In Chapter two,we introduce the theoretical methods used in this thesis, including the main first-principles calculation methods,i.e.,the Density-Functionmethod and nonequilibrium Green\'s function.

本论文拟采用密度泛函理论和非平衡格林函数相结合的第一性原理计算方法，选取苯基小分子作为研究对象，构建了金属电极/有机小分子/金属电极三明治结构体系，系统地研究了苯基分子器件结构的改变与分子电输运性质之间的关系以及影响分子器件电输运性质的相关因素，其中重点研究了分子与电极间可能的接触结构改变、官能团、分子间的扭转角以及外电场对苯基分子电输运性质的影响，本论文主要包括以下五个章节的内容：第一章为综述部分，主要介绍了分子电子学产生的背景、分子器件的研究意义、当前研究分子器件的实验和主要理论方法，以及目前在研究分子器件中存在的一些问题，最后给出了本论文的主要研究内容和技术路线。

Congratulations your paper is very BRIGHT and even encompasses all the precedings ones by its clarity about the functional equation, the definition of the unctions, etc.

祝贺，你的论文（陈一文注：指蒋春暄最新的论文《Riemann paper (1859) is false》，即《黎曼的论文（1859）是错误的》）非常聪明，在函数方程式、函数定义方面的清晰性方面涵盖了所有以前的论文。

The paper investigates both block-type pilot linear minimum mean square error algorithm and IEEE802.16 OFDM channel estimation analysis. Simulation results confirm the block-type pilot structure is more suitable for IEEE802.16 system. An optimal pilot setting algorithm, based on space frequency domain, is explored and the pilot chart is presented. The proposed algorithm finds its application in MIMO-OFDM. Simulation results show the algorithm presents a good approximation to the perfect channel state information curve, with about 2dB difference in SNR. The simulation results also demonstrate the algorithm achieves fairly high stability in the environment of fast fading, performance of the proposed algorithm is better that of pilot training channel estimation.3. Taking into account the characteristics of IEEE802.16 OFDM system, OFDM system simulation platform is constructed in Matlab, exploiting simulink as a tool. OFDM modulation and demodulation simulation system are configured on LabVIEW platform. All the system signal processing is simulated, including defining system parameters, designing modulation model, and verifying all the proposed algorithms under different environments, such as white Gaussian noise, multi-path fading, with or without guard interval etc. Bit error performance is evaluated. The research provides valid theoretical basis for practical OFDM system performance evaluation.4. Taking advantage of software radio, the paper designs a hardware platform with both 256-IFFT/FFT and 512-IFFT/FFT OFDM schemes co-existing in one platform. You can predetermine one from the two schemes to carry out almost the same model function with different system performance and parameter setting.5. Referring to IEEE802.16 standard, the paper proposes a design method for generating signals and frames suitable for laboratory investigations implemented in laboratory environment.6. Based on 6701evm digital evaluation card, combined with analogy front-end, the paper designs a DSP software model to deal with baseband signal processing. An overall OFDM scheme, with modulation and demodulation function, is accomplished.

讨论分析了MIMO-OFDM中一种基于空频域的最优导频设置算法，给出了导频图案，通过仿真实验表明，该算法与理想的信道状态信息曲线非常接近，信噪比差距约在2dB左右，并且在快衰落条件下具有较好的稳定性，其性能要优于基于前导训练的信道估计方法。3、根据IEEE802.16OFDM系统特点，论文分别在Matlab中应用Simulink工具构建OFDM系统仿真平台、在LabVIEW平台上实现了OFDM调制解调仿真系统，模拟了整个系统的信号流程，进行了OFDM仿真系统参数的选择和调制模块的仿真设计、论证各算法性能，并根据各种不同的条件：例如高斯噪声、多径衰落、有无保护间隔等，对系统的误码特性进行了评估，为正确评价实际OFDM系统的性能提供了有效的理论依据。4、论文以软件无线电思想作为指导，提出了以256点IFFT／FFT为核心和以512点IFFT／FFT为核心的两种OFDM算法模式并存于同一个硬件平台、且可预选的方案，它们在参数选取和性能指标上有所差异，均实现了相似的模块和功能。5、论文参考IEEE 802.16无线网络标准的参数设置，针对本设计系统的应用环境和系统硬件的性能速率，提出了一种应用于实验室环境的信号结构、帧格式等参数设计。6、论文基于TI公司的6701evm数字评估板卡，结合模拟前端搭建数字中频平台，设计了基带处理的DSP软件模块并进行系统调试，基本实现了一套完整的OFDM调制解调方案。

In the second part of the paper, the sport techniques of the flight elements was analysised in-depth theoretically by the movement technical structure:①the giant swing was first analysised in mechanics by applying the Kane's method, the dynamic equation of 5-link multi-body model was established, and the computer simulation software of the giant swing on the high bar was developed.

其次，作为单杠上飞行动作系统性研究的另一主要方面，本论文对飞行动作一般技术结构中的各技术环节进行了深入的理论分析：①着重对飞行动作准备阶段的回环运动技术进行了动力学分析，主要采用了多体力学理论中的Kane方法，建立了5环节人体回环运动的动力学方程，并应用计算机数值仿真技术研制开发了用于回环运动动力学分析的数值仿真软件，进而以动作实例对回环运动进行了数值仿真与误差分析，其所得到的数值仿真结果能够满足对人体回环运动的动力学分析和仿真要求；②对于飞行动作的撒手技术环节，本论文从人体环节相对运动角度，来分析撒手时人体质心的运动以及撒手时角动量参数，并列举了几种飞行动作撒手技术的基本力学指标；③关于飞行动作的空中技术，论文在总结了空翻转体动力学机理的研究成果基础上，对人体空中运动定量化问题进行了一般性描述，并进一步应用刚体动力学理论，着重建立起了描述空翻与转体技术之间定量化的关系，讨论了空翻转体运动的稳定性及其运动模式的转换问题，它对于定量地评定空翻转体技术以及今后对空翻转体动作进行数值仿真都具有理论上和实践上的重要意义；④关于飞行动作再握技术环节，本论文避免了以再握瞬时性的力学参数指标来描述再握技术特征的简单化途径，提出以再握下摆与回环下摆相对比的方法来研究再握技术，并以飞行动作再握技术的具体实例进行了对比分析，表明再握下摆技术相比回环下摆技术有着相当的困难性和复杂性，运动员对再握下摆过程中各环节的相对运动实施有效的控制，是连接高难动作以及顺利流畅地完成成套动作的关键。

Keywords: regulated power supply of direct current; single2ch ip m icrocomputer, digital control Abstract:This system to dc voltage source as the core, mainly AT89S52 SCM, through the keyboard controller to install dc power supply output voltage, setting stepping class can reach.01v output voltage, the range of 0-9.9 V, the maximum current 330mA for, and can show the actual pipe by digital output voltage values.

数控直流稳压电源论文关键词：论文关键词：直流稳压电源单片机数字控制论文摘要：论文摘要：本系统以直流电压源为核心，AT89S52 单片机为主控制器，通过键盘来设置直流电源的输出电压，设置步进等级可达 0.1V，输出电压范围为 0—9.9V，最大电流为 330mA，并可由液晶屏显示实际输出电压值。

A great many significant achievements have been acquired: Cultivation of Students Cooperative Learning and Researching Ability in Informatization Environment has achieved National Excellent "15" Key Attack Topic; Research on School Network Resource Pool Construction won the first prize in East China Area; there are a great many disquisitions of our teachers in varied core periodicals intended for high schools; our teachers has been frequently awarded prizes in the civic and provincial evaluation and competition of educational disquisition.

学校的课题研究硕果累累，《信息化环境中学生的协作学习和探究能力培养》等课题曾获全国优秀&十五&重点课题，《校园网资源库建构模式研究》获得华东地区评比一等奖；翻开中学各专业核心期刊，我校教师的论文赫然在目，在省市组织的教育教学论文评比中，我校教师频频获奖。2004年以来，我校教师在国家级刊物上发表论文200余篇，出版著作近100部，有150多人次在各级各类论文比赛中获得一、二、三等奖。

The commercial bank, one of the most important part of the b- anking, exists risks of various kind; however, accountancy's risk of the commercial bank is a main risk for the commercial bank.

中华论文联盟为您代写毕业论文，代写本科毕业论文，代写硕士毕业论文商业银行作为银行业的主要组成部分，存在着各种各样的风险，而商业银行的会计风险是商业银行的主要风险之一。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了