检索结果-南通市图书馆

Design of adiabatic two's complement multiplier-accumulator based on CTGAL

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第2期10卷 172-178页

作者： Peng-jun WANG Jian XU shi-yan ying Institute of Circuits and Systems Ningbo University Ningbo 315211 China College of Information Engineering Zhej iang University of Technology Hangzhou 310014 China

We propose a new design scheme for a Booth encoder based on clocked transmission gate adiabatic logic(CTGAL). In the new design the structural complexity of the Booth encoder is reduced while the speed of the multiplier is improved. The adiabatic two's complement multiplier-accumulator(MAC) is furthermore a design based on the CTGAL. The computer simulation results indicate that the designed circuit has the correct logic function and remarkably less energy consumption compared to that of the MAC based on complementary metal oxide semiconductor(CMOS) logic.

关键词： CTGAL circuit Adiabatic circuit Booth arithmetic Multiplier Two's complement MAC

Design of dual-edge triggered flip-flops based on quantum-dot cellular automata

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science C(Computers and Electronics) 2012年第5期13卷 385-392页

作者： Lin-rong XIAO Xie-xiong CHEN shi-yan ying Department of Information Science and Electronic Engineering Zhejiang University Hangzhou 310027 China Department of Electrical and Electronic Engineering Jiaxing University Jiaxing 314001 China College of Information Engineering Zhejiang University of Technology Hangzhou 310032 China

Quantum-dot cellular automata (QCA) technology has been widely considered as an alternative to complementary metal-oxide-semiconductor (CMOS) due to QCA's inherent *** interesting QCA-based logic circuits with smaller feature size,higher operating frequency,and lower power consumption than CMOS have been ***,QCA is limited in its sequential circuit design with high performance *** on a brief introduction of QCA and dual-edge triggered (DET) flip-flop,we propose two original QCA-based D and JK DET flip-flops,offering the same data throughput of corresponding single-edge triggered (SET) flip-flops at half the clock pulse *** logic functionality of the two proposed flip-flops is verified with the QCADesigner *** the proposed QCA-based DET flip-flops show higher performance than their SET counterparts in terms of data ***,compared with a previous DET D flip-flop,the number of cells,covered area,and time delay of the proposed DET D flip-flop are reduced by 20.5%,23.5%,and 25%,*** using a lower clock pulse frequency,the proposed DET flip-flops are promising for constructing QCA sequential circuits and systems with high performance.

关键词： Quantum-dot cellular automata (QCA) Dual-edge triggered (DET) Flip-flop Sequential circuit

Fluorescence and Thermostability of Nanometer Porphyrin Trimer

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2006年第1期22卷 14-16页

作者： shi ying-yan FA Huan-bao ZHENG Wen-qi LI Di SHAN Ning WANG Xing-qiao College of Chemistry Jilin University Changchun 130023 P. R. China Departement of Base Science Jilin Institute of Architecture and Civil Engineering Changchun 130021 R. R. China

A nanometer porphyrin trimer was firstly synthesized with 1 ,3-dibromopropane as a bridge-linked agent and the fluorescence property and thermostability were studied. The results show that the fluorescence property and thermostability of the trimer are different from those of monoporphyrin. The effects of the molecule structure on the optical property and the thermostability were also studied in detail.

关键词： Monoporphyrin Porphyrin trimer Fluorescence Thermostability

在线全文

学校读者我要写书评

暂无评论

BH_2的分子结构和势能函数

物理学报 2006年第7期55卷 3408-3412页

作者：阎世英青岛大学物理科学学院青岛266071

采用密度泛函理论(DFT)的B3P86方法和相对论有效原子实势理论模型(RECP),对BH2,BH2+和BH2—分子进行了优化,得到这些分子基态的电子状态分别是2A′,3A′,3A″.计算也得到了BH2的分子结构和势能函数,它的离解能是7.752eV,BH2分子具有C2V... 详细信息

采用密度泛函理论(DFT)的B3P86方法和相对论有效原子实势理论模型(RECP),对BH2,BH2+和BH2—分子进行了优化,得到这些分子基态的电子状态分别是2A′,3A′,3A″.计算也得到了BH2的分子结构和势能函数,它的离解能是7.752eV,BH2分子具有C2V对称性;由微观可逆性原理,判断了BH2分子的离解极解;并且导出了BH2分子的多体项展式势能函数,其势能面等值图展现了H_B_H的结构,这些结果可以用于BH2分子的微观反应动力学.

关键词： BH2 分子结构势能函数

在线全文

学校读者我要写书评

暂无评论

B_2H_6分子的几何构型

物理学报 2005年第7期54卷 3106-3110页

作者：阎世英马美仲朱正和四川大学原子分子物理所青岛大学理工学院物理系青岛266071

采用Gaussian98程序中B3P86,BP86,B3LYP,BLYP,UHF,HF及LSDA等方法,对B2H6分子可能的D3d,D3h,D2d和D2h平面型状态及立体型状态的几何构型五种情况的1重态及3重态进行了优化,得到该分子基态为1重态,它的电子状态是1Ag,B2H6的几何构型仍然... 详细信息

采用Gaussian98程序中B3P86,BP86,B3LYP,BLYP,UHF,HF及LSDA等方法,对B2H6分子可能的D3d,D3h,D2d和D2h平面型状态及立体型状态的几何构型五种情况的1重态及3重态进行了优化,得到该分子基态为1重态,它的电子状态是1Ag,B2H6的几何构型仍然是传统的对称性为乙烯式的D2h结构,其构型如图9所示,其能量最低,是-53.5865H.a.u..两个硼原子与四个H原子所在平面垂直于两个硼原子及另外二个H原子所在平面,二个硼原子之间的距离是R12=0.17542nm,B原子及H原子之间的距离是R17=0.13149nm,R13=0.11884nm,它们之间的夹角分别是,∠314=∠526=121.93°,∠817=∠827=96.3°,B2H6中硼原子采用不等性的sp3轨道和另一硼原子的不等性的sp3轨道及氢原子的1s轨道交互重叠生成桥式三中心双电子键.三中心双电子键比双中心双电子键更为稳定,计算结果也证实了这一点.

关键词：几何构型 Gaussian98 B3LYP 硼原子 H原子电子键分子基态电子状态计算结果 D2h UHF D3d 立体型平面型对称性双中心轨道氢原子距离不等夹角

在线全文

学校读者我要写书评

暂无评论

相同稀有气体原子间近程排斥势的新探索

原子与分子物理学报 1999年第3期16卷 453-456页

作者：阎世英郑广付雄鹰青岛大学理工学院物理系华中师范大学化学系成都精密光学工程研究中心

对相同稀有气体原子间电荷密度的重叠积分进行了计算。计算结果表明该重叠积分可以用来表示稀有气体原子间的排斥势。这为进一步更准确地探索原子间排斥势提供了一种开拓性的方法。

关键词：电荷密度重叠积分排斥势稀有气体原子

Spin Polarization Effect for Molecule Fe_(2)

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Physics 2006年第2期19卷 149-151页

作者：炎正馨谢安东阎世英胡栋杨向东四川大学原子分子物理研究所成都610065 四川大大学原子分子物理研究所成都610065 中物院流体物理研究所冲击波物理与爆轰物理实验室绵阳621900

Density functional method （B3p86） was used to optimize the structure of the molecule Fe2. The result showed that the ground electronic state for the molecule Fe2 is nonet state instead of septet state, which indicates that there is a spin polarization effect in the molecule Fe2, i.e., in which there are 8 parallel spin *** this case, the number of the unpaired d-orbit electrons is the largest, and these electrons occupy different spatial orbitals so that the energy of the molecule Fe2 is minimized. Meanwhile, the spin pollution was not found because the wave functions of the ground state do not mix with those of the higher energy states. In addition, the Murrell-Sorbie potential functions with the parameters for the ground electronic state and other exited electronic states of the molecule Fe2 were derived. The dissociation energy, equilibrium bond length and the vibration frequency for the ground electronic state of the molecule Fe2 are 3.5522 eV, 0.2137 nm and 292.914 cm^-1, respectively. Its force constants f2, f3 and f4 are 1.4115×1^02 a J/nm^2, -37.1751×103^aJ/nm^3 and 98.7596× 10^4 a J/nm^4, respectively. The other spectroscopic parameters ωexe, Be and αe for the ground electronic state of Fe2 are 0.3522, 0.0345 and 0.4963× 10^-4 cm^-1, respectively.

关键词： Fe2 Spin polarization Density functional theory Potential function

在线全文

学校读者我要写书评

暂无评论

单壁碳纳米管储氢研究

原子与分子物理学报 2012年第6期29卷 941-947页

作者：阎世英杨自钦青岛大学物理科学学院青岛266071 北京大学物理学院北京100871

利用Gaussian03程序计算出C-H键的键能是1.88 eV,键长是0.113 nm.已知H-H键能是4.748 eV,键长是0.074 nm.显然,H-H键能大于C-H键的键能,所以在常温常压下碳纳米管储氢时,以物理吸附H_2分子为主,化学形式的C-H键吸附为辅.另外,利用LJ势... 详细信息

利用Gaussian03程序计算出C-H键的键能是1.88 eV,键长是0.113 nm.已知H-H键能是4.748 eV,键长是0.074 nm.显然,H-H键能大于C-H键的键能,所以在常温常压下碳纳米管储氢时,以物理吸附H_2分子为主,化学形式的C-H键吸附为辅.另外,利用LJ势能函数,计算了H_2分子在碳纳米管中C原子所成的六边形中心正上方、C原子正上方以及相邻两C原子中间正上方时H_2分子与碳纳米管之间的势能.得到无论H_2分子是被吸附到管内或管外,还是被吸附到中间区域或两端区域,都是H_2分子在C原子所成的六边形中心正上方时能量最低.当H_2分子被吸附到碳纳米管中间区域时,管内和管外的H_2分子距管壁的距离分别是0.320 nm和0.309 nm;而当H_2分子被吸附到碳纳米管两端区域时,这两个距离分别是0.324 nm和0.313 nm.

关键词：碳纳米管储氢 LJ势碳氢键能

用半解析环形棱柱单元解盘形锥齿轮的振动问题

在线全文

学校读者我要写书评

暂无评论

工程力学 2005年第3期22卷 210-215页

作者：郭星辉李永强颜世英东北大学理学院力学系辽宁沈阳110004

提供了一种使用半解析环形棱柱有限元求解盘形锥齿轮行波振动的方法。单元沿齿轮截面具有8个节点,沿周向为三角函数级数,借助三角函数的正交性使单元矩阵得到简化。单元除考虑旋转作用外也可适合各种截面形状的盘类零部件,并可提高计算... 详细信息

提供了一种使用半解析环形棱柱有限元求解盘形锥齿轮行波振动的方法。单元沿齿轮截面具有8个节点,沿周向为三角函数级数,借助三角函数的正交性使单元矩阵得到简化。单元除考虑旋转作用外也可适合各种截面形状的盘类零部件,并可提高计算机的工作效率。计算结果与实测相比表明单元有很好的精度。

关键词：有限元动频振动模态阻尼比锥齿轮