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91.
Bond distances, vibrational frequencies, dissociation energies, electron affinities, ionization potentials and dipole moments
of the title molecules in neutral and charged ions were studied by use of density functional method. Ground states for each
molecule were assigned. The calculated bond distance decreases with the increasing of atomic number of 4d metals, reaches
minimum at RhS, then increases. For cationic molecules, the calculated bond distance decreases to the minimum at MoS+, then increases. The calculated vibrational frequency decreases from YS(YS+) to PdS(PdS+) for both neutral and cationic molecules. The bond ionic character decreases from YS(YS+) to PdS(PdS+) for neutral and cationic molecules. The bonding patterns are discussed and compared with the available studies.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
92.
Nobuaki Seiji Tomoyuki Shuji Yasukazu 《Journal of Photochemistry and Photobiology, C: Photochemistry Reviews》2000,1(2)
New research fields have opened up that are related to the interactions between molecules and high-intensity optical fields where the laser intensity ranges from 1012–1017 W cm−2. A broad outline of this area will be described from the perspective of products and new techniques for beam generation. Studies of large molecules have begun and some examples are introduced herein. Parent ions with little fragmentation are found to form in the intensity region below 1016 W cm−2. The formation of intact ions can be used in femtosecond laser mass spectrometry. In the intensity region above 1016 W cm−2, electrons are stripped from the molecules by optical field ionization and the highly charged ions can undergo a Coulomb explosion. Coulomb explosions of benzene and C60 have been demonstrated, and the mechanism can be analyzed by means of molecular dynamics simulations. A high intensity femtosecond laser beam can be converted to radiation sources of coherent VUV light, X-rays etc. and some possibilities for new chemical applications will be discussed. 相似文献
93.
The new experimental results on the effective quantum numbers and term energies of the highly excited odd-parity 4s4d 3D1,2,3 →4snf 3F2,3,4 Rydberg transitions of zinc have been presented. The experiment was performed using the three dye lasers simultaneously pumped by the second harmonic (532?nm) of the Q-switched Nd:YAG laser. The new observation includes the 4snf 3F3 (12?≤n?≤?50) series excited from the 4s4d 3D2 intermediate level. In addition, the 4snf 3F2 (12?≤n?≤?28) and 4snf3F4 (12?≤n?≤?33) series are observed from the thermally populated 4s4d 3D1,3 fine structure components. The ionization potential of zinc has been determined from the unperturbed 4snf 3F3 series as 75769.31?±?0.15?cm?1, which is in excellent agreement with the previously reported value. 相似文献
94.
《Journal of Electrostatics》2014,72(2):99-106
Numerical modeling of corona discharges has followed the same set of procedures for many years. Corona discharges on large scales are modeled only for ion drift, neglecting ionization. Studies of the ionization zone are often conducted in uniform axisymmetric configurations. However, in configurations that induce non-uniform electric fields, a combination of the two procedures is necessary to accurately capture the discharge physics and ion distribution. The present study conducts numerical simulations of a wire-cylinder corona using both the models and demonstrates the necessity of including the ionization physics to obtain improved accuracy, particularly in the presence of non-uniform electric fields. 相似文献
95.
与双模场依赖强度耦合下多光子通道中原子比 特周期量子回声产生和调控 总被引:3,自引:3,他引:0
旋波近似条件下,运用全量子理论研究了与双模相干光场依赖强度耦合多光子通道中原子比特周期量子回声的产生和控制. 采用数值计算的方法,讨论了双模相干光场平均光子数分布形式、分布范围及原子跃迁时吸收(或发射)的光子数k对原子比特态保真度演化的影响,获得了产生和控制原子比特周期量子回声的系统参量;根据纠缠理论,分析了原子比特态保真度演化与原子约化熵演化的关联. 结果表明:在k=1的双光子过程中,调控光场平均光子数呈对称或不对称分布,当它的取值在一定范围内,原子比特保持良好的相干性和保真度,产生周期量子回声; 对于k≥2的多光子过程,原子比特与双模相干光场始终处于最大纠缠,因此导致了原子比特始终处于部分失真状态,不产生周期量子回声. 本研究揭示了周期量子回声产生的物理实质是原子比特与光场周期性退纠缠. 相似文献
96.
97.
电化学电喷雾电离源控制系统的研制 总被引:1,自引:0,他引:1
控制系统是电化学电喷雾电离源的核心部件及研制难点.本研究通过单片机控制数模、模数转换及蓝牙无线通讯模块构建了一套电化学电喷雾电离源(EC/ESI source)的控制系统.利用此系统及一种同轴式探针组成了完整的电化学电喷雾电离源,对9,10-二苯基蒽进行了循环伏安及在线电化学/电喷雾电离质谱(Online EC/ESI-MS)测试.结果表明:此系统具有高达±1 mV的电势控制精度,电流测量精度优于±0.1 μA(增益为0.01 V/μA)或±0.01 μA(增益为0.1 V/μA).本系统具有成本低廉,可在电喷雾高压上安全悬浮,易于操控的特点. 相似文献
98.
99.
用飞秒Ti:sapphire激光测定了3个对称噁二唑衍生物4-{N,N-双[4-(4-[5-(4-叔丁基苯基)-1,3,4-噁二唑-2]苯乙烯基)苯基]氨基}苯甲醛(Bis-oxa)、2,5-双{4-[2-N,N-双(4-{4-[5-(4-叔丁基苯基)-1,3,4-噁二唑-2]苯乙烯基}苯基)氨基苯乙烯基]苯基}-1,3,4-噁二唑(Quadri-oxa)和2,5-双(4-{2-N,N-双[({3,5-二[5-(4-叔丁基苯基)-1,3,4-噁二唑-2]苯基}乙烯基)苯基]氨基苯乙烯基}苯基)-1,3,4-噁二唑(Octu-oxa)的三光子吸收谱和三光子荧光光谱. 在1260 nm飞秒激光激发下, 2,4和8-支噁二唑衍生物的三光子吸收系数分别为5.0×10-5, 10.0×10-5和10.0×10-5 cm3/GW2, 三光子频率上转换荧光发射波长分别为533, 544和551 nm. 研究了多支化合物线性吸收和透过、单光子荧光及量子产率、荧光寿命、多光子荧光光谱和三光子吸收系数谱. 对称多支噁二唑衍生物具有很强的三光子吸收和上转换荧光性质. 相似文献
100.
U. Galster P. Kaminski M. Beckert H. Helm U. Müller 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,17(3):307-318
We have performed kinematically complete investigations of molecular photodissociation of triatomic hydrogen in a fast beam
translational spectrometer recently built in Freiburg. The apparatus allows us to investigate laser-induced dissociation of
neutral molecules into two, three, or more neutral products. The fragments are detected in coincidence and their vectorial
momenta in the center-of-mass frame are determined. We demonstrate the potential of the method at the fragmentation of the
3 s
2
A
1
′
(
N
= 1,
K
= 0) state of triatomic hydrogen. In this state, three-body decay into ground state hydrogen atoms H+H+H, two-body predissociation
into H+H
2
(v
,
J), and photoemission to the H
3
ground state surface with subsequent two-body decay are competing channels. In the case of two-body predissociation, we determine
the rovibrational population in the H
2
(v
,
J) fragment. The vibrational distribution of H
2
is compared with approximate theoretical predictions. For three-body decay, we measure the six-fold differential photodissociation
cross-section. To determine accurate final state distributions, the geometric collection efficiency of the apparatus is calculated
by a Monte Carlo simulation, and the raw data are corrected for apparatus efficiency. The final state momentum distribution
shows pronounced correlation patterns which are characteristic for the dissociation mechanism. For a three-body decay process
with a discrete kinetic energy release we have developed a novel data reduction procedure based on the detection of two fragments.
The final state distribution determined by this independent method agrees extremely well with that observed in the triple-coincidence
data. In addition, this method allows us to fully explore the phase space of the final state and to determine the branching
ratios between the two- and three-body decay processes.
Received 29 March 2001 相似文献