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91.
Mixed-metal carbonyl clusters of W2Ir2(CO)10(η^5-C5H4Me)2 1 and W2Ir2(μ-L)(CO)8(η^5-C5H4Me)2 (L = dppe 2, dppf 3) have been studied by TDDFT method focusing on their electronic and nonlinear optical properties. These three clusters exhibit the first static hyperpolarizabilities of medium magnitude (βtot-10×10^-30 esu). The origin of β is discussed by the new proposed orbital-pair decomposition scheme by Barandes et al. The result suggests that the β values of the two clusters are mainly originated from d-d electron transition within the metal skeleton, and d-p (π*) electron transition from metals to carbonyls and phenyl. The additional coordination by the electron donor group, ferrocene, makes cluster 3 own much larger β values, and the relatively longer range charge transfer from d orbitals of ferrocene to d orbirals of Ir and W is responsible for the enhanced β values. 相似文献
92.
研究了具有欠完整立方烷构型的过渡金属原子簇分子的二阶非线性光学性质。利用TDDFT方法计算了选取的簇分子及相应模拟构造分子的静态和动态的一阶非线性光学超级化率(ijk);并计算了不同金属、桥原子和配体以及簇芯对该类化合物一阶超级化率的影响。选取其中的一个簇分子为基本模型,分析了该分子的电子结构和分子轨道,在微观水平上阐述了其非线性光学性质的可能起源。认为由过渡金属和硫原子组成的簇芯和与桥原子相连的配体对该类簇合物的二阶非线性光学性质的起决定性的作用。 相似文献
93.
高压密封微波消解-等离子体发射光谱法测定5种蒙药中8种金属元素.实验结果表明:其中铁、锶、锰的含量较高.测定方法简便、快速、省时、稳定性好、回收率均在97.5%-105.5%.测试方法具有较好的精密度和准确度. 相似文献
94.
用描写相对论性核 核碰撞的LUCIAE模型及相应的MonteCarlo事例产生器分析了WA97最近发表的 1 5 8AGeVp Pb和Pb Pb碰撞中单奇异粒子 (Λ ,Λ)和多奇异粒子 (Ξ-,Ξ-,Ω-,Ω-)的多重数和横质量分布 .由于LUCIAE模型包含了弦碎裂微观过程中奇异夸克压低因子随碰撞体系的能量、中心度和质量的增大而增大 ,以及由它导致的相对论性核 核碰撞宏观过程中奇异粒子产额随上述三因素之增而增的物理机制 ;LUCIAE模型计算结果能较好描写WA97实验所揭示的相对论性核 核碰撞中奇异粒子产额随中心度之增而增和奇异粒子增强随奇异夸克数之增而增的实验事实 ,以及单奇异和多奇异粒子的横质量分布 . 相似文献
95.
Ben-Hao SA 《理论物理通讯》1997,27(4):507-510
We use the event generator LUClAE to analyze the WA85 data of ratio of Ω- to Ω- in reaction (200A GeV/c)S + W. The result indicates that the reproduction of WA85 data might be achieved in hadronic rescattering regime of LUCIAE and might need not to rely on the formation of QGP. 相似文献
96.
The dependence of phase transition,associated with the disassembly of hot nuclei,on the mass number of hot nuclei is investigated.By studying six hot nuclei ranging from 56Ni* to 238U*,we find that in the curves of excitation energy of hot nuclei vs.Thermodynamic temperature T(E*) of 63Cu* and heavier ones there are always two temperature plateaus,but in T(E*) of 56Ni the first temperature plateau (at lower excitation energy) shrinks into a kink. 相似文献
97.
IMPROVEMENT OF THERMODYNAMICAL MONTE CARLO SIMULATION IN SU(2) PURE GAUGE FIELD THEORY ——AN APPROACH TO CONTINUUM PHYSICS LIMIT 下载免费PDF全文
The thermodynamical quantities of SU(2) pure lattice gauge field have been simulated first time on the asymmetric lattice (ξ>1).The finite size effect and continuum physics limits have also been studied.The results show that the use of asymmetric lattice is of benefit to calculate the thermodynamical quantities and study the behavior of continuum physics limits.In addition,it is explained that the efficiency of the whole Monte Carlo simulation and the calculation of heat capacity will be improved quite a lot by using bias sampling technique. 相似文献
98.
99.
A series of tetrahedral iridium carbonyl clusters coordinated by systematically varied series of ligands have been studied by TDDFT method focusing on their electronic and non- linear optical properties. The clusters of Ir4(CO)12 (1), Ir4(μ-CO)3(CO)9 (2), Ir4(μ-L)(CO)10 (L = dppm 3, dppe 4, (Ph2P)2CHMe 5, Ph2P(CH2)3PPh2 6) and Ir4(CO)10(phen) (phen = 1,10-phen- anthroline) (7) exhibit the first static hyperpolarizabilities of medium magnitude (βtot-10×10^-30 esu). The second order nonlinear optical response of the seven clusters increase from 0 to 23 ×10^-30 esu; the high symmetric cluster Ir4(CO)12 debases its symmetry and presents the second order nonlinear optical behavior as the coordination style of some carbonyls changes to bridge style, and then the response increases regularly with the systematical variation of the ligands. The origination of the first hyperpolarizability is discussed by the expanded orbital decomposition scheme. The results suggest the d-d electron transition from the apical iridium atom to the other three Ir atoms inside the metal skeleton, and d-πelectron transitions from metals to carbonyls are responsible for the first hyperpolarizabilities. Particularly, for cluster 7, the charge transfer from d orbitals of iridium to π* orbirals of phenanthroline originates the first hyperpolarizabilities. 相似文献
100.
V. A. Doroshchuk V. Ya. Demchenko A. N. Gorbachevskii A. V. Chernyi S. A. Kulichenko 《Journal of Analytical Chemistry》2009,64(10):1012-1016
The micellar extraction of barium with phases of nonionic surfactant Triton X-100 was studied in the presence of aliphatic
monocarboxylic acids, crown ethers, and Carboxyarsenazo and its mixtures with cetylpyridinium chloride and octylamine. It
was shown that the complete extraction of barium into the micellar phase was attained using Carboxyarsenazo and cationic surfactants
in the presence of octylamine through the formation of a ternary hydrophobic complex. The conditions for the determination
of the atomic absorption of barium in water with preconcentration into the nonionic surfactant phase at the cloud point temperature
were developed. 相似文献