Au-Au碰撞中大横动量双轻子对的产生(英文)

运用微扰QCD讨论了重离子碰撞中大横动量轻子对的分布, 计算了Au-Au碰撞中两个部分子产生的轻子对的贡献。引入了轻子对产生的直接单光子过程和分解单光子过程。大横动量情况下的所有过程都包括在内, 而且考虑了核遮蔽效应和同位旋效应, 作为QGP背景的双轻子信号有了一个好的修正。The large transverse momentum distribution of lepton pairs produced in heavy-ion collisions has been studied, making use of the perturbative QCD. The contribution of the two parton production process into lepton pairs in Au Au collisions is calculated. Lepton pair production with the direct single photon process and the resolved single photon process are introduced. We believe that the photon processes are significant. The complete processes at large transverse momentum are included, and moreover, the effect of shadowing and isospin of nucleus are also considered in heavy ion collisions. Dilepton signals to regard the background of QGP have a good correction.     

Optical oxygen sensing materials based on a novel dirhenium(I) complex assembled in mesoporous silica

A new dirhenium(I) complex fac-[{Re(CO)₃(4,7-dinonadecyl-1,10-phenanthro -line)}₂ (4,4′-bipyridyl)] (trifluoromethanesulfonate)₂ (denoted as D-Re(I) ) is assembled in MCM-41 and SBA-15 type mesoporous silica support. The emission peaks of D-Re(I) in D-Re(I)/MCM-41 and D-Re(I)/SBA-15 are observed at 522 and 517 nm, respectively. Their long excited lifetimes, which are of the order of microseconds, indicate the presence of phosphorescence emission arising from the metal to ligand charge-transfer (MLCT) transition. The luminescence intensities of D-Re(I)/MCM-41 and D-Re(I)/SBA-15 decrease remarkably with increase in the oxygen concentration, meaning that they can be used as optical oxygen sensing materials based on luminescence quenching. The ratios I₀/I₁₀₀ of D-Re(I)/MCM-41 and D-Re(I)/SBA-15 are estimated to be 5.6 and 20.1, respectively. The obtained Stern-Volmer oxygen quenching plots of the mesoporous sensing materials could be fitted well to the two-site Demas model and Lehrer model.     

三能级Upper-ladder型系统中的

三能级Upper-ladder型系统中,在旋波、慢变振幅近似下,求解了考虑驱动场相位扩散后的系统密度矩阵运动方程,并给出了这个三能级梯型系统稳态线性解析解.利用对密度矩阵运动方程的稳态线性解析解的数值模拟结果,研究相位扩散对无反转激光增益、色散和粒子数差的影响;利用对密度矩阵运动方程的数值模拟结果,分析相位的扩散对无反...     

808 nm大功率半导体激光器阵列的优化设计

 采用激射波长为808 nm的GaAs/AlGaAs梯度折射率波导分别限制单量子阱结构外延片,制备了沟道深度不同的半导体激光器阵列,并对载流子分布进行理论分析和模拟。理论和实验结果表明：引入脊形台面和隔离沟道后,激光器阵列的输出功率、电光转换效率、斜率效率和光谱特性均有显著提高。随着沟道的加深,对电流侧向扩散的限制作用增强,从而提高了阵列性能。     

高效液相色谱-质谱联用法测定饮料中的苯甲酸含量

建立了高效液相色谱-质谱联用法检测饮料中的苯甲酸.选用ZORBAX XDB-C18柱(50mm×2.1mm,3.5μm)为分析柱,流动相为乙腈-水,梯度洗脱,流速为200μL·min-1;质谱条件选用气动辅助电喷雾离子源(ESI),检测方式为负离子多离子反应检测(MRM);苯甲酸校准曲线线性范围为1-500μg/L;方...     

基于台阵资料测量高铁信号视速度的方法

针对运行于高架桥上高铁引发的震源, 基于对移动组合源形成的波场传播的理论分析, 提出一种利用多台互相关测量高铁波场视速度的方法。然后, 生成分层介质条件下的高铁波场合成数据, 计算信号视速度, 并通过与理论结果的对比, 验证方法的正确性。     

掺杂预合成添加剂对氧化锌压敏电阻性能影响

为了提高氧化锌(ZnO)压敏电阻的电学性能,采用常规烧结并在ZnO压敏电阻中掺杂预先合成的BiSbO₄和Zn₂SiO₄,研究不同掺杂比例对ZnO压敏电阻的微观结构、电学性能、通流能力的影响.结果表明:ZnO压敏电阻在掺杂BiSbO₄和Zn₂SiO₄后,能够有效抑制ZnO晶粒变大,晶体结构变得致密均匀,致密性有所提高,有效提高压敏特性和通流能力.BiSbO₄和Zn₂SiO₄掺杂比例为3∶1的样品综合性能比较优异,样品的致密度为5.58 g·cm^-3,压敏电位梯度达到425 V·mm^-1,非线性系数为70,漏电流为1.2×10^-7 A·cm^-2,能量耐受能力达到334.21 J·cm^-3,残压比为2.5.     

面向多目标柔性作业车间调度的强化学习NSGA-II算法

针对非支配排序遗传算法 (NSGA-II, non-dominated sorting genetic algorithm II)在求解柔性作业车间多目标优化调度问题中多样性不足、易于早熟与局部收敛的缺点,提出一种基于强化学习的改进NSGA-II算法(RLNSGA-II, reinforcement learning non-dominated sorting genetic algorithm II)。为避免NSGA-II陷入局部收敛问题引入双种群进化策略,利用性别判定法将种群拆分为两个种群,并在进化过程中采用不同的交叉变异算子,增加算法的局部和全局搜索能力;为解决NSGA-II精英策略造成多样性不足的问题,融合多个多样性度量指标,利用强化学习动态优化种群迭代过程中的拆分比例参数以保持多样性,改善算法收敛性能。最后通过Kacem标准算例进行了仿真实验与性能分析,验证了RLNSGA-II的有效性与优越性。     

维药多伞阿魏的化学成分研究

为明确维药多伞阿魏(Ferula ferulaeoides)的主要化学成分及其抗肿瘤活性,采用硅胶柱色谱、Sephadex LH-20 凝胶柱色谱及半制备高效液相色谱法等技术进行分离纯化,运用NMR和HRMS等波谱学方法鉴定各化合物的结构,采用计算电子圆二色谱法（ECD）判定新化合物的绝对构型. 同时运用MTT法对分离得到的单体化合物在人源乳腺癌（MCF-7）细胞系上进行细胞毒活性测试. 结果从多伞阿魏的乙酸乙酯萃取物中分离得到15个化合物,分别鉴定为1- (2- hydroxyl- 4- methoxybenzoyl)- 2S*- hydroxy- 5,9,13- trimethyl- 4(E),8(E),12- tetradecatrien- 1- one ( 1 ),愈创木醇 ( 2 ),1- (2,4- dihydroxyphenyl)- 3,7,11- trimethyl- 3- vinyl- 6(E),10- dodecadiene- 1- one ( 3 ),dshamirone ( 4 ),2,3- dihydro-7- hydroxy- 2S*,3R*- dimethyl- 2- [4,8-dimethyl- 3(E),7- nonadienyl]- furo[3,2-c]coumarin ( 5 ),3- (2-hydroxyl-4-methoxybenzoyl)- 4S*,5R*- dimethyl- 5- [4,8- dimethyl- 3(E),7(E)- nonadien- 1- yl]tetrahydro- 2- furanone ( 6 ),fukanedone A ( 7 ),2,3- dihydro- 7- methoxy- 2S*,3R*- dimethyl- 2- [4- methyl- 5- (4-methyl-2-furyl)- 3(E)- pentenyl]- furo[3,2-c]coumarin ( 8 ),伞形花素 ( 9 ),2,3- dihydro- 7- methoxy- 2S*,3S*- dimethyl- 3- [4,8- dimethyl- 3(E),7- nonadienyl]- furo[3,2-c]coumarin ( 10 ),2,3- dihydro- 7- methoxy- 2S*,3R*- dimethyl- 3- [4,8-dimethyl-3(E),7-nonadienyl]- furo[3,2-c]coumarin ( 11 ),2,3- dihydro- 7- hydroxy- 2S*,3R*- dimethyl- 3- [4,8- dimethyl- 3(E),7- nonadienyl]- furo[3,2-c]coumarin ( 12 ),2,3- dihydro- 7- methoxy- 2S*,3R*- dimethyl- 2- [4,8- dimethyl- 3(E),7- nonadienyl]- furo[3,2-c]coumarin ( 13 ),2,3- dihydro- 7- methoxy- 2R*,3R*- dimethyl- 2- [4,8- dimethyl- 3(E),7- nonadienyl]- furo[3,2-c]coumarin ( 14 ),ferulaeone C ( 15 ). 其中,化合物 1 为新杂萜类化合物,化合物 9 是从该植物中首次分离得到. 化合物 3 、 4 、 5 和 15 表现出潜在的抗肿瘤活性,半数抑制浓度（IC₅₀）分别为15.11,12.98,18.01和12.87 μmol/L.      

Multiparty-controlled teleportation of an arbitrary GHZ-class state by using a d-dimensional (N+2)-particle nonmaximally entangled state as the quantum channel

We present a scheme for multiparty-controlled teleportation of an arbitrary high-dimensional GHZ-class state with a d-dimensional (N+2)-particle GHZ state following some ideas from the teleportation (Chinese Physics B, 2007, 16: 2867). This scheme has the advantage of transmitting much fewer particles for controlled teleportation of an arbitrary multiparticle GHZ-class state. Moreover,we discuss the application of this scheme by using a nonmaximally entangled state as its quantum channel.